VU University Medical Center 8th Science Exchange Day
Friday 7 March 2014
Abstract book
Meike de Wit, PhD
Photograph: Mark van den Brink
Vaste Commissie voor de Wetenschapsbeoefening (VCW)
Abstracts
VU University Medical Center
Science Exchange Day
Friday 7 March 2014
9:00 – 15.30
VUmc Amstelzaal, Foyer & Waver
Vaste Commissie voor de Wetenschapsbeoefening (VCW)
VU University Medical Center Science Exchange Day 2014
3
4
Index
Page 6
Preface
Page 7
Programme VU University Medical Center Science Exchange Day
Page 8
Members of the Vaste Commissie voor de Wetenschapsbeoefening (VCW)
Abstracts
Page 11
Animal Models
Page 24
Biomarkers: Clinical
Page 36 Biomarkers: Experimental and Methods
Page 52
Biomedical Engineering
Page 66
Clinical and Epidemiological Surveys
Page 91
Clinical Intervention
Page 107
Clinical – Surveys on Volunteers
Page 108
Diagnostic Studies – Patients
Page 135
Literature Surveys
Page 138
Preclinical Disease Models
Page 163
Quality of Care – Safety – Auditing
Page 172
Grants Desk VU/VU University Medical Center
Index
Page 173
Presenting author, title of abstract, subjectgroup, research institute
VU University Medical Center Science Exchange Day 2014
5
Preface
Welcome to the 8th edition of the VU University Medical Center Science Exchange Day.
As before, the goal of this day is to stimulate communication between researchers
across the borders of departments and the different research institutes. Hopefully
this will result in exchange of ideas and new collaborations to further strengthen our
research! Each institute has delegated an oral presenter of one of their most exciting
recent research achievements.
This year, based on evaluation results of previous years, we have included workshops
for young researchers in the program, and shortened the plenary presentations. The
central highlight of the day remains the poster session, as here the informal contacts
between researchers blossom. This year we are proud to have received 161 abstracts
showing exciting results from the research performed at CCA, EMGO+, ICaR-VU, MOVE
and NCA, as well as our partner VU University institutes AIMMS and Laserlab. The
corresponding posters cover a wide range of topics and are on display in the Foyer
of VU University Medical Center. They have been ordered by similarity in research
approach rather than by disease or discipline, to enable maximal interaction.
The categories are:
- Animal models
- Biomarkers: Clinical
- Biomarkers: Experimental and Methods
- Biomedical Engineering
- Clinical & Epidemiological Surveys
- Clinical Intervention
- Clinical – surveys on volunteers
- Diagnostic Studies – Patients
- Literature Surveys
- Preclinical Disease Models
- Quality of Care – Safety - Auditing
The VCW has rated all abstracts based on their scientific quality but also on their
appeal to researchers from across the different institutes, as interdisciplinary
communication is one of the major goals of this day. The best rated abstract will
receive an award, and additional awards will be granted to the best short oral
presentation and to the best poster on display. We gratefully acknowledge the Dean
for making these awards available.
The VU University Medical Center can take great pride in the fact that this year it
ranked number 1 in the citation analysis of the Dutch University Medical Centers
(CWTS analysis, MNCS-score). This proof of excellence is the result of the combined
efforts of the community of researchers within the VUmc.
This abstract book, as documentation of the development in the research
programmes of the VUmc research institutes remains available on the VCW website.
On behalf of all VCW members,
Prof. A.J.G. Horrevoets, PhD
Chair Vaste Commissie voor de Wetenschapsbeoefening
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Programme VU University Medical Center Science
Exchange Day
Friday 7 March 2014; 9.00 – 15.30
Amstel Lecture theatre & Foyer of VU University Medical Center
09.00 – 09.30 Registration
09.30 – 10.00
Introduction session I:
1. Outstanding: Make your grant application stand out!
Dr. L. Klomp, Director Grants Desk
2. Shining: Pimp your Curriculum Vitae but don’t overdo!
Prof. dr. G.A.M.S. van Dongen,
department of Nuclear Medicine & PET Research
3.Swift: Speeding up your publication
Prof. dr. P.J.F. Snijders, department of Pathology
4. Compelling: Powering your presentation
Prof. dr. M. Boers, department of Epidemiology & Biostatistics
5. Impressive: Grab media attention
E. Krab & drs. C. Arps, Communications department
6.Virtuous: Moral excellence in research
Prof. dr. J.C.J.M. de Haes,
Ombudsman Scientific Integrity Academic Medical Center
10.10 – 10.40 Introduction session II; Similar as session I
10.40 – 11.00 A sweet break with coffee and tea
11.00 – 11.30
Welcome by prof. dr. A.J.G. Horrevoets, chairman VCW &
Introduction of the programme
Marjolein Glas, MSc. (AIMMS)
Sandra Zwijsen, MSc. (EMGO+)
Erik Valent, MSc. (IcarVU)
11.30 – 13.30 Poster presentation
12.00 – 13.00 Lunch available (only if registered before 28 February 2014)
13.30 – 14.00
Introduction this part of the programme by prof.dr. A.J.G. Horrevoets
Boy Braaf, MSc. (Laserlab)
Joost van Kordelaar, MSc. (MOVE)
Martijn Steenwijk, MSc. (NCA)
Esther Kleibeuker, MSc. (Vumc CCA)
14.05 – 14.35 The evolution of science
by prof. dr. J.C. Clevers, President, Royal Netherlands Academy of
Arts and Science (KNAW)
14.35 – 14.50 Prize ceremony  Best abstract, Best poster, Best presentation
14.50 – 15.00 End of the programme
15.00 – 15.30 Informal reception in the Foyer
Members of VCW VUmc:
on behalf of:
A.J.G. Horrevoets, MD, PhD (chairman)
aj.horrevoets@vumc.nl ICaR-VU
Molecular Cellbiology and Immunology
M. Boers, MSc, MD, PhD
m.boers@vumc.nl Epidemiology and Biostatistics
W.M. van der Flier, PhD
wm.vdflier@vumc.nl
NCA
Neurology / Epidemiology and Biostatistics
J. Harlaar, PhD
j.harlaar@vumc.nl MOVE
Rehabilitation Medicine
R.J.A. van Moorselaar, MD, PhD
rja.vanMoorselaar@vumc.nl VUmc CCA
Urology
P.J.F. Snijders, PhD
pjf.snijders@vumc.nl VUmc CCA
Pathology
F.J. Snoek, MD, PhD
fj.snoek@vumc.nl EMGO+
Medical Psychology
J. van der Velden, PhD
j.vandervelden@vumc.nl ICaR-VU
Physiology
D.J Veltman, PhD
dj.veltman@vumc.nl NCA Psychiatry
E. Dijkstra (secretary)
e.dijkstra@vumc.nl Strategie, Bestuur & Projecten
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Abstracts
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10
Animal models
1. Extracting gene-behavior relations in mice using Markov
modeling on longitudinal automated home cage data
Emmeke Aarts1, Conor Dolan2, Oliver Stiedl1,3, Bastijn Koopmans4, Maarten, Loos3,4,
Grégoire Maroteaux1, August B. Smit3, Matthijs Verhage1,5, Sophie van der Sluis1,5
Department of Functional Genomics, VU University Amsterdam
Department of Biological Psychology, VU University Amsterdam
3
Department of Molecular and Cellular Neurobiology, VU University Amsterdam
4
Synaptologics BV
5
Department of Clinical Genetics, VU Medical Center
1
2
Introduction
Increasingly, automated home cage systems like the PhenoTyper and DualCage are used in mice
to extract gene-behavior relations. The advantage of these instrumental home cages is that the
animal is observed in a habituated environ-ment without enhancing unspecific stress levels due
to animal handling. Also, the home cage allows for a prolonged period of systematic observation,
therefore the development of behavior over time can be studied, with possible application of
disease progression over time. These systems provide measurement of behavior over multiple
hours, days or even weeks and provide a wealth of information. As yet, this information is often
summarized (e.g., frequencies, proportions of durations of one behavioral act). However, the
design allows for the study of the temporal patterns of behavior, i.e., the dynamics of behavior,
and the role of genes herein.
Methods
We use continuous time Hidden Markov Modeling (CT-HMM) within a Bayesian framework to
analyze spontaneous behavior of young (8-12 weeks) and old (50-60 weeks) C57BL/6J mice.
Additionally, to enable statistical comparisons between the two age groups, the CT-HMM is
extended to a multigroup model.
Results
Simulation studies showed that CT-HMM provides reliable and robust parameter recovery.
The CT-HMM uncovered interesting behavioral pattern differences in the two age groups.
Conclusions
The comparison between the two age groups shows that the new information on behavioral
phenotypes that is obtained with CT-HMM uncovers behavioral differences that classical behavioral
tests, and classical statistical methods, cannot detect. CT-HMM, therefore, addresses an entirely
new set of questions about mouse behavior, which makes it possible to shed a new light on the
development and prognosis of neural disorders and diseases.
VU University Medical Center Science Exchange Day 2013
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Animal models
2. Closer look at the machinery of cilia: Focusing on the
steps of IFT kinesins
Şeyda Açar1, Anna Meijering1, Bram Prevo1, Dennis L.H.Kruijssen1, Felix Oswald1,
Erwin J. G. Peterman1
1
Physics and Astronomy, Faculty of Sciences, VU University Amsterdam
Introduction
Ciliopathies, a variety of human diseases related to malfunction or not functioning of cilia focuses
attention to cilia. We use Caenorhabditis elegans as our model organism to study the intraflagellar
transport (IFT) in sensory cilia. IFT is used to build up and maintain cilia. IFT machinery is
composed of microtubules (MTs) on which the transport is achieved by kinesin and dynein motors
in a bipolar way. IFT is driven by two different kinesin-2 family motor proteins; heterotrimeric
kinesin-II and OSM-3 in the anterograde direction. Our specific question here is “What makes the
two kinesin-2 motors different?”. First of all their structure is different in that OSM-3 is a
homodimer whereas kinesin-II is a heterodimer, having two different motor domains, KLP-11 and
KLP-20.
Methods
We developed molecular biology tools to be able to make dimers of different motor domains,
in that we can make non-native dimers (e.g. one motor Osm-3 and the other KLP-20 domain of
kinesin-II), as well as the “native” dimers to study the motility of different dimeric constructs.
We use in vitro motility assays in which the motility parameters (velocity and run length) of
fluorescently labelled, truncated motors are measured using widefield epi-fluorescence and/or
total internal reflection fluorescence (TIRF) microscopy.
Results
According to our preliminary results OSM-3 is a more processive (takes more number of steps
once it is attached to the MTs) motor compared to kinesin-II. Kinesin-II is a slower (0.3µm/sec)
whereas; OSM-3 is faster (1µm/sec). Kinesin-II is most probably made less processive by one of
its motor domains, KLP-11. KLP-11 homodimers do not take steps; rather go through a cycle of
attachment /detachment on the MTs in our motility assays.
Conclusions
Our current results suggest that using the molecular biology and microscopy tools we developed,
we can dissect the processes in the stepping of kinesins towards better understanding of their
motility.
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Animal models
3. AMPK Activation Regulates Microvascular Perfusion and
insulin-mediated vasoreactivity through control over
endothelin-1 activity
Michiel P. de Boer1, Rick I. Meijer1, Erik H. Serné1,
Geerten P. van Nieuw Amerongen2, Pieter Sipkema2, Pieter Koolwijk2, Benoit Viollet3,
Victor W.M. van Hinsbergh2, Yvo M. Smulders1, Etto C. Eringa2
Department of Internal Medicine, Institute for cardiovascular research, VU University Medical
Center, The Netherlands
2
Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center,
The Netherlands
3
Institut Cochin, Inserm, U1016, Cnrs, UMR8104, Univ Paris Descartes, Paris, France
1
Introduction
Decreased tissue perfusion is an important risk factor for the development of insulin resistance
and cardiovascular disease in the obese. Obesity-associated hypoadiponectinemia and subsequent
decreased 5’AMP activated kinase (AMPK) activity have been linked to insulin resistance. It is,
however, unknown whether and how AMPK controls microvascular perfusion. Our objective was to
test whether AMPK, and especially its α2 subunit, controls muscle perfusion and insulin-induced
vasodilation and to investigate the mechanisms involved.
Methods
Effects of AMPK activation on insulin-mediated vasoreactivity were studied ex-vivo, using pressure
myography of isolated muscle resistance arteries (RA) of Wistar rats, AMPKα2 KO mice and their
WT littermates. In vivo, effects of AMPKα2 on muscle perfusion were studied using contrast
enhanced ultrasonography (CEU) during a hyperinsulinemic euglycemic clamp.
Results
Globular adiponectin (gAdn) and 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR)
increased AMPK activity which inhibited insulin-induced ERK1/2 activity, resulting in vasodilation
ex-vivo.
In mice, genetic deletion of AMPKα2 abolished the interaction between gAdn and insulin in
isolated RAs. In AMPKα2-/- mice but not in AMPKα2+/+ mice, hyperinsulinemia decreased skeletal
muscle perfusion.
Conclusions
AMPKα2 controls muscle perfusion during hyperinsulinemia through inhibition of the ERK1/2
pathway. Our findings provide a novel mechanism linking AMPK to regulation of insulin sensitivity
and organ perfusion.
VU University Medical Center Science Exchange Day 2014
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Animal models
4. MAO-A inhibition reduces basal oxygen consumption and
restores isoprenaline sensitivity of hypertrophied rat
papillary muscle in vitro
S.J.P. Bogaards1, F.M. Vaz2, I. Schalij3, D. van Groen1, W.J. van der Laarse1
VU University Medical Center, Institute for Cardiovascular Research, 1Department of Physiology,
Department of Pulmonology, Amsterdam
3
Amsterdam Medical Center, University of Amsterdam, Department of Clinical Chemistry,
Laboratory Genetic Metabolic Diseases, Amsterdam
1
2
Introduction
Mechanical efficiency (work/oxygen consumption) of RV papillary muscle of pulmonary
hypertensive rats is reduced. We hypothesize that the efficiency reduction is due to monoamine
oxidase A (MAO-A), which oxidizes catecholamines and produces H2O2 on the outer mitochondrial
membrane.
Methods
Thin papillary muscles (volume 0.3-0.6 µl) were isolated from the RV of control and monocrotaline
(MCT, 60 mg/kg)-induced pulmonary hypertensive male Wistar rats and mounted in an oxygen
chamber equipped with a motor to determine efficiency (work loops at 5 Hz sinusoidal length
changes at 37°C). Mitochondrial characteristics were determined by quantitative enzyme
histochemistry and cardiolipin and phosphatydylglycerol by HPLC-MS.
Results
The efficiency reduction (P=0.027) and cardiomyocyte hypertrophy (P=0.001) were confirmed.
Isoprenaline (1 µM) doubled power output and isometric tension in control papillary muscles. In
MCT muscles oxygen consumption doubled (P=0.004) but power output did not increase. MAO-A
inhibition by 2 µM clorgyline reduced basal oxygen consumption only in MCT papillary muscles
(by 48 SEM 24 µM/s, P=0.045), and restored the inotropic effect of isoprenaline (P=0.017). In the
RV free wall of MCT rats the ratio of maximum mitochondrial complex I/complex II activity
(P=0.032) and cardiolipin content (CL72:8; P=0.023) decreased, maximum complex II, IV and V
activities were similar to control, and phosphatidylglycerol (PG34:1, P=0.005) and MAO-A activity
(P=0.025) were increased.
Conclusions Oxidation of catecholamines in hypertrophied cardiomyocytes can prevent positive
inotropy and produces a large amount of H2O2. MAO-A contributes to the efficiency reduction of
hypertrophied myocardium because it consumes oxygen and because the H2O2 it produces may
cause mitochondrial dysfunction.
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Animal models
5. Improvement of an experimental rat model of rheumatoid
arthritis for positron emission tomography
D.M.S.H. Chandrupatla1, K. Weijers1, Y.Y. Gent1, I. de Greeuw2, M.Verlaan2, M. Mooijer2,
J. van den Hoek2, D. Laan2, M.C.M Al1, A.A. Lammertsma2, C.J. van der Laken1, C.F.M Molthoff2
1
2
Department of Rheumatology and
Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam
Introduction
Activated macrophages (MØ) play a key role in the pathophysiology of rheumatoid arthritis
(RA). To this end, animal models of RA may be helpful for innovative disease imaging techniques
(e.g. PET) and monitoring of therapeutic interventions.
Methods
Wister rats were immunized twice with methylated bovine serum albumin (mBSA) in complete
Freund’s adjuvant and Bordetella pertussis antigen followed by an intra-articular (i.a) mBSA
injection and a variable number of boost injections of mBSA) in the right knee (the control, left
knee was injected with saline). Knee sections were verified for arthritis development by specific
immunostaining for macrophage involvement in synovial tissue with the macrophage markers ED1
and ED2. Imaging feasibility of the RA rat model was evaluated by [18F]FDG and (R)-[11C]PK11195
PET tracers and ex-vivo tissue biodistribution.
Results
Synovial inflammation in the right knee was confirmed by infiltration of ED1- and ED2-positive
macrophages. Their numbers increased upon repeated i.a. boost injections along with prolonged
sustainment of synovial inflammation. The control knee showed marginal macrophage infiltration
and no synovial inflammation. Both PET tracers [18F]-FDG and (R)-[11C]-PK11195 demonstrated
increased uptake in the arthritic knee compared to the control lateral knee in rats with only a
single i.a injection. Lastly, ex-vivo tissue biodistribution 1 h after tracer injection showed 1.2-1.4
fold increased tracer uptake in RA knees compared to the control knees.
Conclusions
A RA rat model was successfully developed for imaging and monitoring of RA by PET tracers
targeting activated MØ.
VU University Medical Center Science Exchange Day 2014
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Animal models
6. Slow BMP-2 release from a fibrin-hyaluronate hydrogel for
intervertebral disc regeneration in a large animal model
Suzanne E.L. Detiger1, Lindsay S. Karfeld-Sulzer2, Keren M. Kaplan3, Roel J.W. Hoogendoorn1,
Barend J. van Royen1, Theo H. Smit1, Avner Yayon3, Franz E. Weber2, Marco N. Helder1
Department of Orthopaedic Surgery, VU University Medical Center and research institute MOVE,
Amsterdam, The Netherlands
2
Department of Maxillofacial Surgery, University Hospital Zürich, Switzerland
3
ProCore BioMed Ltd. Ness Ziona, Israel
1
Introduction: Intervertebral disc (IVD) degeneration is an important target for regenerative
strategies and starts with proteoglycan depletion from the nucleus pulposus (NP). Cellular
proteoglycan production can be increased by several growth factors, including bone morphogenetic
protein-2 (BMP-2). As unbound growth factors only exert their effect during short periods in vivo,
covalent incorporation of BMP-2 was explored. Our objective was to assess safety and efficacy of
covalently conjugated BMP-2 in a fibrin-hyaluronate hydrogel after injection into IVDs.
Methods: In seven adult goats, lumbar IVDs were chemically degenerated in three months and
subsequently randomised to three intervention groups: hydrogel with 200 ng/ml covalently
conjugated BMP-2, hydrogel alone and no intervention (negative control). After 3 months followup, IVDs were analysed by T2-weighted MRI and colorimetric assays for glycosaminoglycan (GAG)
and hydroxyproline (Hyp) content.
Results:
MRI signal intensity was significantly higher in IVDs treated with BMP-2 compared to hydrogel alone
(p=0.02; figure 1A) and lower in hydrogel-treated than in control IVDs (p=0.003). GAG content
showed the same tendency without statistical significance (figure 1B). Hydroxyproline content
remained relatively constant between the groups, representing an unchanged collagen amount in
the NP (figure 1C).
Conclusions
Fibrin-hyaluronate hydrogel with conjugated BMP-2 appeared safe and efficacious after injection
into mildly degenerated goat IVDs. Our results suggest a regenerative effect of covalently
conjugated BMP-2 compared to hydrogel alone, as substantiated by an increased MRI index,
and the trend of increased GAG content in the NP. Possibly, increasing the dose of BMP-2 could
enhance this regenerative potential in future experiments.
Figure 1: MRI index in % of healthy level (A), GAG (B) and hydroxyproline content (C) in μg / mg dry weight plotted
per intervention group (n = 7). Data plotted as mean and SD (*p < 0.05; **p < 0.01).
16
Animal models
7. A post docking role of the Synaptotagmin1-C2B base domain
Girish H. Kedar1, Anders. S. Munch2, Jon-Ruben Van Rhijn1, Jan R.T. van Weering1, Jakob Sørensen2,
Matthijs Verhage1
Secretory vesicle trafficking group, Dept. Functional Genomics, Centre for Neurogenomics and
cognitive research, Neuroscience Campus Amsterdam, VU University Amsterdam and VU Medical
Center, Amsterdam, The Netherlands
2
Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of
Copenhagen, 2200 Copenhagen N, Denmark
1
Introduction
Synaptotagmin-1 (Syt-1) is the principle Ca2+ sensor for exocytosis in neurons and neuroendocrine
cells. Syt-1 is also essential for the initial large dense core vesicle (LDCV) docking process. It
binds the t-SNARE protein SNAP25/Syntaxin acceptor complex, thereby establishing docking of
the vesicle to the plasma membrane. Additional interactions with lipids may also contribute to
this process. However, how Syt-1 regulates LDCV docking is still unresolved. To determine the
molecular mechanism of Syt-1 function in docking, we overexpressed the Syt-1 R398,399Q mutant
in Syt-1 null mutant chromaffin cells. This mutant interacts with SNARE proteins and lipids but
was previously shown to severely reduce exocytosis in neurons probably by affecting membrane
association by its base domain.
Methods
We carried out ultra-structural evaluation using electron microscope and physiological secretion
analysis by voltage clamp method
Results
We show by ultra-structural evaluation that Syt1-KO chromaffin cells infected with the R398,399Q
mutant show normal number of docked LDCV. Exocytosis in these cells is not restored, in contrast
the sustained release component is further reduced in Syt-KO cells expressing Syt-RQ.
Conclusions
Hence, the R398,399 region appears to be dispensable for LDCV docking, but is important for
secretion since Syt1- R398,399Q mutation severely impaired exocytosis.
VU University Medical Center Science Exchange Day 2014
17
Animal models
8. Microvascular flow disturbances in a rat model of
cardiopulmonary bypass are not caused by hemodilution
Nick J. Koning1,2, Rob F.P. van den Akker1,2, Hans W. Niessen3, Charissa E. van den Brom1,2,
Christa Boer2
Department of Anesthesiology, VU University Medical Center
Department of Physiology, VU University Medical Center
3
Department of Pathology, VU University Medical Center
1
2
Introduction
Although hemodilution is suspected as the main cause of microvascular flow disturbances during
cardiopulmonary bypass (CPB), this has never been investigated. We therefore investigated the
effects of hemodilution with or without extracorporeal circulation on microvascular perfusion in a
rat model for cardiopulmonary bypass.
Methods
Male Wistar rats were prepared for cremaster muscle intravital microscopy and subjected to
hemodilution alone (n=9) or hemodilution with 75 minutes of CPB (n=9). Microcirculatory
recordings, made at baseline and five consecutive time points during the experimental protocol,
were analyzed for the number of perfused and non-perfused microvessels. Renal leukocyte counts
were performed in renal cross-sections.
Results
Hematocrit levels similarly dropped to 0.24 ± 0.03 and 0.22 ± 0.02 after onset of hemodilution
with or without CPB, respectively. Following onset of CPB, the number of perfused vessels dropped
by 43% (from 9.4 (8.8-9.8) to 5.0 (3.8-7.0); P=0.008), whereas the initial reduction in perfused
capillaries in the hemodilution group was only 8% (from 8.7 (8.5-9.2) to 8.0 (7.2-8.2); P=0.038).
The reduced number of perfused vessels persisted after weaning from extracorporeal circulation
in the CPB group. An increase in non-perfused microvessels was observed only after initiation
of extracorporeal circulation. Renal leukocyte counts were higher following CPB than after
hemodilution alone.
Conclusions
Cardiopulmonary bypass-induced hemodilution is associated with a large reduction in perfused
capillaries and augmentation of stagnant microvessels, in contrast to hemodilution alone, which
yields only minor microcirculatory
disturbances. Moreover, increased renal leukocyte infiltration is observed in the CPB group.
18
Animal models
9. Lipid membranes, oxidative stress and amyloid-beta:
Alzheimer’s disease triggering and imaging with
multimodal laser-scanning microscopy
N.V. Kuzmin1,2, J.C. Baayen2,3, H.D. Mansvelder2, M.L. Groot1,2
Institute for Lasers, Life, and Biophotonics, Amsterdam
Neuroscience Campus Amsterdam, Amsterdam
3
VU University Medical Center, Amsterdam
1
2
Introduction
Multimodal laser-scanning microscopy (MLSM) using second and third harmonic generation
(SHG, THG) combined with two- and three-photon excited fluorescence provides non-invasive,
label-free contrast of living brain tissue with sub-cellular resolution, intrinsic depth sectioning,
reduced phototoxicity and fast acquisition times. In brain tissues MLSM reveals neurons, lipid
myelin sheaths surrounding axons, erythrocytes, polarized microtubule arrays inside axons and
dendrites blood vessels etc. We aim to use the MLSM to unveil the sequence of events leading to
development of Alzheimer’s disease (AD).
Methods
MLSM imaging of living brain tissues was performed with a multiple-photon laser-scanning
microscope. During real-time imaging we expose live brain cells to oxidants, amyloid-beta
oligomers and mitochondrial toxins via local micro-injections. We calibrate the label-free harmonic
signals with fluorescent dyes tracking membrane integrity, oxidants and amyloid-beta oligomers.
Results
We image interactions between live neurons in ex-vivo mouse brain slices and locally applied
oxidants, amyloid-beta oligomers, mitochondrial toxins and excitotoxic agents – the key factors in
AD onset hypotheses. We show that MLSM is a sensitive indicator of a mouse neuron health –
ethanol-induced membrane lipid oxidation and increased permeability along with glutamateinduced cell components damage both result in increase of the THG signal intensity emitted by
cell membranes and organelles respectively, accompanied by their morphological degeneration.
Conclusions
MLSM imaging proves to be a versatile technique both for morphological label-free imaging of
mouse and human (healthy and AD) brain tissues brain tissue imaging and for sensitive
visualization of dynamic changes in membrane integrity of mouse neurons. Our next step will be
to apply MLSM to study the response of living human brain cells to Aβ oligomers and oxidation,
study internalization, degradation and Aβ clearance by glial cells, as well as visualize the mode of
action of treatment strategies.
VU University Medical Center Science Exchange Day 2014
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Animal models
10. Numbers of intrinsic cardiac adrenergic cells in rat heart:
effect of hypertrophy
V.W.W. van Eif1, S.J.P. Bogaards1, I. Schalij2, W.J. van der Laarse1
VU University Medical Center, Institute for Cardiovascular Research
1
Department of Physiology,
2
Department of Pulmonology, Amsterdam
Introduction
The efficiency of hypertrophied myocardium is reduced. Upregulation of oxygen consuming
enzymes, like monoamine oxidase A (MAO-A), reduces efficiency and contributes to ROS
production. Inhibition of MAO-A in isolated papillary muscle reduced oxygen consumption,
suggesting endogenous catecholamine release. We hypothesize that intrinsic cardiac adrenergic
(ICA) cells, which predominantly produce noradrenalin, are involved.
Methods
We counted ICA cells in sections of monocrotaline (MCT, 60mg/kg) administered male Wistar
rats by tyrosine hydroxylase immunohistochemistry. Two-way ANOVA and post-hoc tests with
Bonferroni correction were performed.
Results
The number (mean±SEM) of ICA cells in controls (n=3) was 207±29 cells/ml in the right free wall,
264±19 cells/l in the right side of the septum, 162±51 cells/ml in the left side of the septum,
and 204±16 cells/ml in the left free wall. ICA cell density in the left and right side of the septum
differed (P<0.05). MCT rats developed pulmonary hypertension and right ventricular hypertrophy.
The number of ICA cells in these hearts (n=5 to 7) was 130±11 cells/ml in the right free wall,
238±13 cells/ml in the right side of the septum, 209±20 cells/ml in the left side of the septum,
and 231±23 cells/ml in the left free wall. ICA cell density in the right free wall was smaller than in
other areas of the hearts (P<0.05). The interaction of treatment and location was not significant
(P=0.075). The decrease in ICA cell density in the right free wall can be explained by hypertrophy
of cardiomyocytes.
Conclusions
We conclude that ICA cell density is high (about 200000 per rat heart) and that the number of ICA
cells does not change in hypertrophied rat myocardium.
20
Animal models
11. 3D imaging of brain tumors
Tonny Lagerweij1, Sophie A. Dusoswa1 , Adrian Negrean2 Esther Hendrikx3, Tom Wurdinger1
Department of Neurosurgery, Neuro-oncology Research Group, VU University Medical Center
Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research,
Neuroscience Campus Amsterdam, VU University
3
Molecular Cell Biology and Immunology, VU University Medical Center
1
2
Introduction
Imaging of a brain tumor in its 3D microenvironment will gain insight in structure-to-function
relationships and benefit new treatment options for patients with brain tumors. Our aim is to
develop techniques to visualize 3-dimensional the brain tumor and its surrounding tissue at single
cell resolution.
Methods
Tumor cells, expressing mCherry, are transplanted in the brain of nude mice. A cranial window
covers the tumor to enable in vivo imaging. At different time points, mice are fixed under a
2-photon microscope and 3D stacks are imaged. Ex vivo; brains were perfused with a hydrogel
solution and clarified by electrophoresis and index-matching. Tumor vasculature was stained with
lectin-DyLight488 and visualized by 2-photon microscopy.
Results
During a 100 minutes intravital imaging session, we visualized migrating E98FM glioma cells.
Furthermore, after carification of mice, we were able to clarify the brains, stain blood vessels and
create a 3D reconstructions of the brain vasculature.
Conclusions
Intracranial injection of E98FM glioma cells results in a diffuse growing, infiltrative tumor. With
intravital imaging, it was visualized that some of the E98FM cells. Clarification of brain results
in highly transparent tissue in which the blood vessels are easily stained by lectin coupled
fluorochromes. Combination of imaging techniques will reveal insight in the migration of brain
tumor cells and might bring clues towards new therapies.
VU University Medical Center Science Exchange Day 2014
21
Animal models
12. Neuropeptide secretion in the brain: Insights into
dynamics of dense-core vesicles
Claudia M. Persoon1, Ruud F.G. Toonen1, Matthijs Verhage1
Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR),
VU University/VU University Medical Center
1
Introduction
Large dense-core vesicles (DCVs) transport and secrete a diverse range of neuropeptides important
for neuronal development, communication and synaptic plasticity in the brain. Disruption of
DCV exocytosis has been associated with many disease states ranging from cognitive disorders,
stress and addiction problems, obesity to anorexia. In the neuron, DCVs are synthesized and
filled with cargo at the Golgi network and actively transported along the cytoskeleton. Upon a
calcium trigger, DCVs fuse with the plasma membrane of the soma, neurite or synapse to release
their cargo. Although the secretory pathway of synaptic vesicles has been extensively studied in
mammalian neurons, little is known about DCV trafficking and fusion mechanisms, dynamics and
localization.
Methods
Hippocampal neurons were derived from mouse brain and cultured on glial islands to study single
neurons in vitro. DCVs are visualized by expression of lenti viral particles containing a fusion
protein of Neuropeptide Y, which localized to DCVs, and a fluorescent protein. This tool allows us
to study transport and secretion of DCVs in living neurons.
Results
Quantitative analysis of endogenous cargo (ChgB) staining in hippocampal neurons showed a
predominant localization of DCVs in axons. Total number of DCVs per neuron was highly variable
and correlated with neurite length. Measurements of single release events upon different
stimulation protocols showed a releasable pool of approximately 3‐4 % of the total DCV pool size.
Conclusions
Neuropeptide containing DCVs are mainly transported to axonal regions in hippocampal neurons,
indicating a possible preference for presynaptic release of neuropeptides. Only a small part of
the DCV pool is released in hippocampal neurons upon stimulation, suggesting the presence of a
large reservoir of DCVs available for fast and plastic release.
22
Animal models
13. Deep brain stimulation of the nucleus accumbens core
affects heroin seeking and impulsivity in rats
Schippers M.C.1 Gaastra M.1, Mesman T.1, Van Mourik Y.1, Schetters D.1, Schoffelmeer A.N.M.1,
Pattij T.1, De Vries T.J.1,2
1
2
Department of Anatomy and Neuroscience, VU University Medical Center
Department of Molecular and Cellular Neurobiology, VU University
Introduction
Deep brain stimulation (DBS) is explored as a possible intervention for treatment refractory
substance dependent patients. The nucleus accumbens (NA) is involved in reward mechanisms
and therefore a promising target for DBS. Additionally, NA modulates impulsive behaviour, a key
symptom in drug addiction. We therefore studied the effect of DBS of the NAcore in rat models of
heroin seeking and impulsivity.
Methods
Male Wistar rats were bilaterally implanted with electrodes aimed at the NAcore. DBS was applied
during heroin self-administration, progressive ratio of reinforcement schedule, extinction, cueinduced and drug-induced relapse. A separate group of rats was trained and tested with DBS in the
five-choice serial reaction time task, to assess effects of DBS on inhibitory response control.
Results
NAcore DBS specifically reduced motivation for heroin taking and cue-induced relapse to heroin
seeking. A negative correlation between baseline impulsive action and change in inhibitory
response control as a result of DBS indicated a baseline dependent effect of DBS.
Conclusions
The present data show a beneficial effect of NAcore DBS on the motivation for heroin consumption
and cue-induced relapse to heroin seeking. This confirms that the NAcore is a promising brain
target for DBS in the treatment of refractory drug addicts. Additionally, DBS modulated impulsive
action in a baseline dependent manner. This observation seems in line with accumulating evidence
showing that there are intrinsic neurobiological differences between high and low impulsive
animals. Further research should explore the mechanisms by which DBS of the NA is modulating
addictive and impulsive behaviour.
VU University Medical Center Science Exchange Day 2014
23
Biomarkers: Clinical
14. Atrial fibrillation coincides with increased intravascular
depositions of the advanced glycation end-product Nε(carboxymethyl) lysine in the atria of the heart
Mark P.V. Begieneman1,2,3, Liza Rijvers1, Bela Kubat2, Walter J. Paulus4, Wim Stooker5,
Alexander B.A. Vonk6, Casper G. Schalkwijk7, Bert C. van Rossum8, Hans W.M. Niessen1,3,6,
Paul A.J. Krijnen1,3.
Pathology, VU University Medical Center
Dutch Forensic Institute
3
Institute for cardiovascular research, VU University Medical Center
4
Physiology, VU University Medical Center
5
Onze Lieve Vrouwe Gasthuis
6
Cardiac Surgery, VU University Medical Center
7
Internal Medicine, Maastricht University Medical Center
8
Cardiology, VU University Medical Center
1
2
Introduction
In patients with atrium fibrillation (AF), inflammation of the atrium is induced. In the blood of AF
patients, increased plasma levels of the advanced glycation end product (AGE) Nε-(carboxymethyl)
lysine (CML) have been described. It is known that AGEs induce inflammation in bloodvessels in
heart failure. Albeit, the effect of AF on expression level of AGE’s within atrial tissue is unknown.
This we have now analysed in atrial tissue in patients with idiopathic AF.
Methods
35 patients with idiopathic AF (living patients) and 7 controls (autopsy material) were studied.
Tissue slides of the left atria (LA) were stained with antibodies identifying neutrophilic
granulocytes, lymphocytes, macrophages, VCAM-1 and CML. Staining was subsequently quantified
in the epicardium and myocardium of the atria separately.
Results
In AF patients, significant increased expression of CML, independent of DM, was found in blood
vessels of the LA in patients with AF compared to controls. Furthermore, significantly increased
expression of VCAM-1 in blood vessels and a significant increase in the number of neutrophilic
granulocytes, lymphocytes and macrophages was found in the LA of AF patients also compared to
controls, especially in the epicardium. Finally, CML expression as found in the LA of patients with
AF correlated positively with the increased numbers of macrophages.
Conclusions
Our findings indicate that in idiopathic AF the intramyocardial arteries of the LA have a proinflammatory status coinciding with a local increase in the number of neutrophilic granulocytes,
lymphocytes and macrophages.
24
Biomarkers: Clinical
15. Fear conditioning, persistence of disruptive behavior and
psychopathic traits: an fMRI study
MD Cohn1*, A Popma1*, W van den Brink2, LE Pape1, M Kindt3, L van Domburgh1, TAH Doreleijers1†,
and DJ Veltman4†
Department of Child and Adolescent Psychiatry, VU University Medical Center
Amsterdam Institute for Addiction Research, Academic Medical Center
3
Department of Clinical Psychology, University of Amsterdam
4
Department of Psychiatry, VU University Medical Center
1
2
Introduction
Children diagnosed with Disruptive Behavior Disorders (DBD), especially those with psychopathic
traits, are at risk of developing persistent and severe antisocial behavior. Deficient fear
conditioning may be a key mechanism underlying persistence, and has been associated with
altered regional brain function in adult antisocial populations. In this study, we investigated the
associations between the neural correlates of fear conditioning, persistence of childhood-onset
DBD during adolescence and psychopathic traits.
Methods
From a cohort of children arrested before the age of 12 years, participants who were diagnosed
with Oppositional Defiant Disorder or Conduct Disorder in previous waves (mean age of onset
6.5 years, SD 3.2) were reassessed at mean age 17.6 years (SD 1.4) and categorized as persistent
(n=25) or desistent (n=25) DBD. Using the Youth Psychopathic Traits Inventory and functional
magnetic resonance imaging during a fear conditioning task, these subgroups were compared
with 26 matched healthy controls from the same cohort.
Results
Both persistent and desistent DBD subgroups were found to show higher activation in fear
processing-related brain areas during fear conditioning compared with healthy controls. In
addition, regression analyses revealed that impulsive-irresponsible and grandiose-manipulative
psychopathic traits were associated with higher activation, whereas callous-unemotional
psychopathic traits were related to lower activation in fear-related areas. Finally, the association
between neural activation and DBD subgroup membership was mediated by impulsiveirresponsible psychopathic traits.
Conclusions
These results provide evidence for heterogeneity in the neurobiological mechanisms underlying
psychopathic traits and antisocial behaviour and, as such, underscore the need to develop
personalized interventions.
VU University Medical Center Science Exchange Day 2014
25
Biomarkers: Clinical
16. Elevated inflammatory levels in chronic widespread pain:
basal inflammation and innate immune response
Ellen Generaal, MSc1; Nicole Vogelzangs, PhD1, Gary J. Macfarlane, MD PhD2, Rinie Geenen, PhD3,
Johannes H. Smit, PhD1, Joost Dekker, PhD1,4 , Brenda W.J.H. Penninx, PhD1
Department of Psychiatry and EMGO Institute for Health and Care Research, VU University
Medical Center, Amsterdam
2
Aberdeen Pain Research Collaboration (Epidemiology Group), University of Aberdeen,
Aberdeen, UK
3
Department of Clinical and Health Psychology, Utrecht University, Utrecht
4
Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam
1
Introduction
Dysregulation of the immune system may play a role in chronic widespread pain (CWP) although
study findings so far are inconsistent. This cross-sectional study examined whether basal
inflammatory markers and the innate immune response are associated with the presence and
severity of CWP.
Methods
Data are from the Netherlands Study of Depression and Anxiety including 1632 subjects. The
Chronic Pain Grade questionnaire was used to determine the presence and severity of CWP.
Subjects were categorized in a CWP group (n=754) and a control group (n=878). Blood levels of
the basal inflammatory markers C-reactive protein (CRP), interleukin (IL)-6 and tumor necrosis
factor (TNF-) alpha were determined. In addition, 13 inflammatory markers were assessed after
lipopolysaccharide (LPS) stimulation in a random subsample (n=707) to obtain a measure of the
innate immune response.
Results
Compared to controls, subjects with CWP showed elevated levels of basal inflammatory markers.
However, this association was no longer significant after adjustment for lifestyle and disease
factors. For the LPS-stimulated inflammatory markers, we did find elevated levels in CWP subjects
both before and after adjustment. Within subjects with CWP, pain intensity and pain disability were
not associated with inflammation.
Conclusions
This study demonstrates elevated basal inflammatory levels and an exaggerated innate immune
response in CWP. Since basal inflammatory markers show higher inter-individual variability, we
suggest future studies to additionally assess stimulated inflammatory markers. Longitudinal
research should investigate whether an exaggerated innate immune response is associated with
the onset or perpetuation of CWP.
26
Biomarkers: Clinical
17. Gene-dosage Dependent Overexpression at the 13q
Amplicon Identifies DIS3 as Candidate Oncogene in
Colorectal Cancer Progression
Florence L.M. de Groen, Oscar Krijgsman, Marianne Tijssen, Lianne E.M. Vriend, Bauke Ylstra,
Erik Hooijberg, Gerrit A. Meijer, Renske D.M. Steenbergen and Beatriz Carvalho
Department of Pathology, VU University Medical Center, Amsterdam
Introduction
Colorectal cancer (CRC) development is in most cases marked by the accumulation of genomic
alterations including gain of the entire q-arm of chromosome 13. This aberration occurs in
40 - 60% of all CRC and is associated with progression from adenoma to carcinoma. To date, little
is known about the effect of the 13q amplicon on the expression of the therein located genes and
their functional relevance. We therefore aimed to identify candidate genes at the 13q amplicon that
contribute to colorectal adenoma to carcinoma progression in a gene dosage-dependent manner.
Methods
Integrative analysis of whole genome expression and DNA copy number signatures resulted in the
identification of 36 genes on 13q of which significant overexpression in carcinomas compared to
adenomas was linked to a copy number gain. Five genes showing high levels of overexpression in
carcinomas versus adenomas were further tested by qRT-PCR in two independent sample sets of
colorectal tumours (n = 40 and n = 47). One candidate gene was functionally analysed by RNAi in
CRC cell lines.
Results
DIS3 and LRCH1 revealed significant overexpression in carcinomas compared to adenomas in a
13q gain dependent manner. Silencing of DIS3 affected important tumorigenic characteristics such
as viability, migration and invasion.
Conclusions
Significant overexpression of DIS3 and LRCH1 associated with adenoma to carcinoma progression
is linked to the CRC specific gain of 13q. The functional relevance of this copy number aberration
was corroborated for DIS3, thereby identifying this gene as novel candidate oncogene contributing
to the 13q-driven adenoma to carcinoma progression.
VU University Medical Center Science Exchange Day 2014
27
Biomarkers: Clinical
18. Human papillomavirus in sperm of healthy young men
Roosmarijn Luttmer1, Maaike G. Dijkstra1, Divera Pronk1, Katja S. Jordanova2,
Danielle A.M. Heideman1, Maaike C. Bleeker1, Hans Berkhof3, Peter G.A. Hompes2, Peter J.F. Snijders1,
Chris J.L.M. Meijer1
Department of Pathology, VU University Medical Center, Amsterdam
Department of Gynaecology and Obstetrics, VU University Medical Center, Amsterdam
3 Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
1
2
Introduction
The human papillomavirus (HPV) is one of the most common sexually transmitted infections
worldwide. Persistent infection with high-risk types of the virus (hrHPV) plays a key role in
anogenital and oropharyngeal carcinogenesis. In men, penile HPV infections are associated with
the presence of flat penile lesions. Recent studies have demonstrated the presence of HPV in
sperm. Very few studies have however addressed the question of the source of HPV present in
sperm. This study tested whether the detection of HPV in sperm is associated with HPV infections
of the penile epithelium and/or the presence of flat penile lesions.
Methods
A cohort of 213 healthy male students provided 3 sperm samples (with intervals of >1 week) and
1 penile scraping per person. These samples were tested for HPV using the highly sensitive
SPF10-PCR-EIA assay and the less sensitive GP5+/6+ PCR-EIA with subsequent genotyping.
Combination of both assays enables a semi-quantitative estimation of HPV viral load. Penoscopy
was performed to identify flat penile lesions. The concordance of semi-quantitative HPV viral load
in sperm and penile scrapings was assessed. Differences in HPV prevalence and viral load in men
with and without flat penile lesions were calculated.
Results
HPV was detected in sperm of 52% and 27% of participants (using SPF10-PCR and GP5+/6+-PCR
respectively). The prevalence of HPV infections of penile epithelium was 45% (SPF10-PCR) and 34%
(GP5+/6+ PCR). Flat penile lesions were detected in 15% of the population and associated with the
presence of hrHPV in penile scrapes and sperm. Substantial to good concordances were detected
between HPV detection in penile scrapings and in sperm (kappa 0,83; 0,77; 0,62 for >1, >2 and>3
semen samples HPV positive respectively). On a genotype-specific level, concordances between
penile scrape and semen were moderate to substantial (HPV16: kappa 0.68; HPV51: 0,40; HPV42:
0.63; HPV variant jc9710: 0.59). Men with a high semi-quantitative viral HPV load in penile
epithelium were more likely to have HPV positive sperm than men with a low viral load and with
HPV negative penile scrapings (Fisher’s exact test p<0.001).
Conclusion
The presence of HPV in the sperm of healthy young men is a very common phenomenon and
associated with a high HPV viral load of the infected penile epithelium and with the presence of
flat penile lesions. These data indicate that HPV positivity in sperm might result from shedding of
HPV particles and exfoliated HPV-infected cells from penile epithelium. Further research should
clarify whether HPV positivity of sperm affects male fertility and clinical reproductive outcomes.
This could warrant routine HPV screening of sperm samples used in programs of assisted
reproduction, especially intracytoplasmatic sperm injection (ICSI).
28
Biomarkers: Clinical
19. Basal nuclei are more severely atrophic in behavioral
variant Frontotemporal Dementia compared to Alzheimer’s
Disease
Christiane Möller MSc1*, Nikki Dieleman, MSc5, Wiesje M van der Flier, PhD1,2, Adriaan Versteeg3,
Yolande Pijnenburg, MD PhD1, Philip Scheltens, MD PhD1, Frederik Barkhof, MD PhD3,
Hugo Vrenken, PhD3,4
Alzheimer center & Department of Neurology, VU University Medical Center
Department of Epidemiology & Biostatistics, VU University Medical Center
3
Department of Radiology & Nuclear Medicine, VU University Medical Center
4
Department of Physics & Medical Technology, VU University Medical Center
5
Department of Radiology, University Medical Center Utrecht
1
2
Introduction
Patterns of cortical atrophy in Alzheimer’s disease (AD) and behavioral variant frontotemporal
dementia (bvFTD) are often overlapping. The involvement of fronto-striatal circuits in bvFTD
suggests that the basal nuclei may add in the diagnosis of these patients Therefore the aim of this
study was to investigate whether volumes of the basal nuclei differ between bvFTD and AD.
Methods
We included 24 patients with probable bvFTD (63years±8, 41.7% females, MMSE 24±4.5), and
matched them based on age, gender and educational level at a ratio of 1:3 to 72 probable AD
patients (63years±8.2, 41.7% females, MMSE 21±4.9) and 72 patients with subjective memory
complaints who served as controls (63years ±8.1, 41.7% females, MMSE 28±2.2). Participants were
scanned at 3T MRI. From 3D T1-weighted fast spoiled gradient echo sequence, FIRST software
estimated volumes of hippocampus, amygdala, thalamus, caudate nucleus, putamen, globus
pallidus, and nucleus accumbens. MANOVA was used to compare volumes of all structures
between groups.
Results
Volumes of hippocampus and amygdala only discriminated dementia from controls. Volumes of
thalamus and putamen did not differ between groups. Post hoc comparisons revealed that bvFTD
had more severe atrophy than AD in caudate nucleus, globus pallidus and nucleus accumbens.
Conclusions
Whereas hippocampus and amygdala only discriminated between controls and dementia, caudate
nucleus, globus pallidus and nucleus accumbens were more severly affected in bvFTD than in AD
and controls. These volume differences between bvFTD and AD provides evidence for the idea that
volumes of basal nuclei could facilitate the discrimination between AD and bvFTD.
VU University Medical Center Science Exchange Day 2014
29
Biomarkers: Clinical
20. Altered β-Adrenergic Receptor Signaling Contributes to the
Development of Right Ventricular Diastolic Dysfunction in
Pulmonary Arterial Hypertension
Silvia Rain, MD1,2, Denielli da Silva Goncalves Bos, MSc1, M. Louis Handoko, MD PhD2,3,
Nico Westerhof, PhD1,2, Ger Stienen, PhD2, Coen Ottenheijm, PhD2, Max Goebel2,
Peter Dorfmüller, MD PhD5,6, Christophe Guignabert, PhD5,6, Marc Humbert, MD PhD5,6,7,8,
Harm-Jan Bogaard, MD PhD1, Cris dos Remedios, DSc PhD9, Chandra Saripalli, MSc10,
Carlos G. Hidalgo, PhD10, Henk L. Granzier, PhD10, Anton Vonk-Noordegraaf, MD PhD1,
Jolanda van der Velden, PhD2,11*, Frances S. de Man, PhD1,2*
Both authors contributed equally.
Departments of
1
Pulmonology,
2
Physiology,
3
Cardiology and
4
Physics and Astronomy, VU University Medical
Center/Institute for Cardiovascular Research,
Amsterdam, The Netherlands
5
Université Paris-Sud, Faculté de Médecine, Le
Kremlin-Bicêtre, France
6
Inserm U999, LabEx LERMIT
7
Service d’Anatomie Pathologique, Centre
Chirurgical Marie Lannelongue, Le Plessis
Robinson, France Assistance Publique-Hôspitaux de Paris,
Service de Pneumologie, Département
Hôspital Universitaire, Thorax innovation,
(DHU-TORINO), Hôpital Bicêtre, France
9
Muscle Research Unit, Discipline of Anatomy
& Histology, Bosch Institute, The University of
Sydney, Sydney, Australia
10
Sarver Molecular Cardiovascular Research
Program, Department of Physiology,
University of Arizona, Tucson, USA
11
CIN – The Netherlands Heart Institute
8
Introduction: Patients with pulmonary arterial hypertension (PAH) develop right ventricular (RV)
failure with impaired diastolic function. β-Adrenergic receptor (β-AR) density is decreased in the
right RV myocardium of PAH patients. Inadequate downstream β-AR signaling may alter protein
kinase A (PKA) phosphorylation and therefore change the function of important proteins regulating
cardiomyocyte diastolic function.
Methods: RV heart-lung transplantation tissue from PAH patients and non-failing donors was used.
Titin, the major determinant of cardiomyocyte stiffness is regulated by PKA phosphorylation.
Western blot (WB) analysis determined titin N2B serine 469 (PKA site) phosphorylation level.
Functional assessments were performed to quantify the effect of PKA treatment on RV cardiomyocyte
stiffness. Troponin I (cTnI) regulates cardiomyocyte Ca2+-sensitivity upon PKA-dependent serine
22/23 phosphorylation. WB analysis determined the level of cTnI serine 22/23 phosphorylation.
Ca2+-handling proteins ensure rapid diastolic Ca2+-clearance. SERCA2a expression, total
phospholamban (PLN) and PLN phosphorylation at serine 16 (PKA site) were determined by WB
analysis.
Results: Cardiomyocyte stiffness – titin serine 469 was significantly lower phosphorylated
(p<0.0001). PKA incubation strongly decreased cardiomyocyte stiffness (Pinteraction<0.0001).
Myofilament Ca2+-sensitivity – PKA mediated cTnI phosphorylation (serine 22/23) was reduced in
PAH compared to donors ( p=0.0004). Cardiomyocyte Ca2+-clearance – SERCA2a expression and
PLN serine 16 phosphorylation were reduced in PAH patients.
Conclusions: Decreased PKA-dependent phosphorylation of titin, cTnI and PLN contribute to the
development of RV cardiomyocyte diastolic dysfunction in PAH patients. Impaired β-AR signaling
pathway may represent the determining mechanism involved in RV cardiomyocyte diastolic
dysfunction in PAH patients.
30
Biomarkers: Clinical
21. Triage of high-risk HPV-positive women by combined
cytology and methylation marker analysis: complementary
clinical performance
L.M.A. De Strooper1, A.T. Hesselink1, J.Berkhof 2, C.J.L.M. Meijer1, P.J.F. Snijders1,
R.D.M. Steenbergen1, D.A.M. Heideman1
1
2
Department of pathology, VU University Medical Center
Department of epidemiology and biostatistics, VU University Medical Center
Introduction
Testing for high-risk human papillomavirus (hrHPV) DNA will replace cytology as the primary
cervical screening method due to its higher sensitivity for cervical pre-cancer (i.e., cervical
intraepithelial neoplasia grade 2-3, CIN2-3) and cancer. The main drawback of hrHPV screening,
however, is a 4-6% lower specificity for (pre-)cancer than cytology. To compensate for this limitation,
triage of hrHPV-positive women has been proposed to keep the proportion of women referred
for colposcopy and/or treatment within acceptable limits. Currently, cytology is the preferred
triage tool, yet requires repeat cytology to reach a good sensitivity. DNA methylation analysis of
promoter regions of CADM1 and MAL genes is a good, alternative triage assay1. Here, we evaluated
the value of triage of hrHPV-positive women at baseline by combined analysis of cytology and the
methylation marker panel CADM1/MAL.
Methods
A cohort of 250 consecutive hrHPV-positive cervical scrapes from women participating in populationbased screening (29-61 years) was evaluated for cytology and CADM1/MAL methylation. Clinical
endpoints were CIN3 or worse (CIN3+) and CIN2 or worse (CIN2+).
Results
At a defined methylation marker threshold, combined baseline triage reached a sensitivity for
CIN3+ of 86.8% at 64.8% specificity, and for CIN2+ of 84.5% at 69.9% specificity. The odds ratio
for CIN3+ and CIN2+ of combined triage were 12.1 (95%CI:4.6-32.5) and 12.6 (95%CI:2.8-27.6)
respectively, versus that of cytology alone (7.1 (95%CI:3.3-15.0), and 9.6 (95%CI:4.9-18.8),
respectively), and methylation analysis alone (6.7 (95%CI:3.1-14.3) and 5.9 (95%CI:3.1-11.3)),
respectively.
Conclusions
This study provides a promising baseline triage strategy for hrHPV-positive women in cervical
cancer screening.
1
Hesslink et al. CCR 2011
VU University Medical Center Science Exchange Day 2014
31
Biomarkers: Clinical
22. Triaging borderline/mild dyskaryotic Pap cytology with
p16/Ki-67 dual-stained cytology testing: cross-sectional
and longitudinal outcome study
Uijterwaal MH1, Witte B.I.1, Van Kemenade F.J.2, Rijkaart D.1, Ridder R.3, Berkhof J.4,
Balfoort-Van der Meij A.5, Bleeker M.C.G.1, Snijders P.J.F1, Meijer C.J.L.M.1
Department of pathology, VU University Medical Center
Department of pathology, Erasmus University Medical Center
3
Ventana Medical Systems, Inc.
4
Department of epidemiology and biostatistics, VU University Medical Center
5
Saltro Diagnostic Centre
1
2
Introduction
Women with borderline/mildly dyskaryotic cytology smears (BMD) are currently followed-up with
repeat-testing at 6 and 18 months.
Objective
To analyze the cross-sectional and longitudinal performance of p16/Ki-67dual-stainedcytology for
detection of cervical intraepithelial neoplasia (CIN) grade 3 or worse (CIN3+) and CIN2+in women
with BMD and to compare the results with baseline human papillomavirus (HPV) testing.
Methods
Conventional Pap cytology specimens of 256 women with BMD were dual-stained for p16/Ki-67
retrospectively and compared to baseline HPV results and long-term follow-up results.
Results
p16/Ki-67 dual-stained cytology showed a sensitivity of 100.0%, a specificity of 64.4% and a
negative predictive value (NPV) of 100.0% for CIN3+. HPV testing demonstrated similar sensitivity
(96.3%), and NPV (99.1%), but a significantly lower specificity (57.6%; p=0.024) for CIN3+.
Sensitivity, specificity and NPV for CIN2+ of dual-stained cytology were 89.7%, 73.1%, and 95.1%,
respectively, similar compared to HPV testing. Dual-stained cytology showed a significant lower
referral rate than HPV testing (43.6% versus 49.1%; p=0.043). During long-term follow-up, no
CIN3+ lesions developed in HPV positive, dual-stain negative women.
Conclusions
Comparable sensitivity and NPV of dual-stained-cytology for CIN3+, combined with a significantly
higher specificity, makes p16/Ki-67 dual-stained cytology a viable alternative to HPV testing for
triaging BMD.
32
Biomarkers: Clinical
23. Brain-derived neurotrophic factor and regional brain volume
Laura S. van Velzen1, MSc, Lianne Schmaal1, PhD, Dick J. Veltman2, PhD, Brenda W. Penninx1, PhD
1
Department of Psychiatry and EMGO Institute for Health and Care Research, VU University
Medical Center, Amsterdam,
2
Department of Psychiatry, VU University Medical Center, Amsterdam
Introduction
Brain-derived neurotrophic factor (BDNF) is a protein that is involved in neuronal survival and
plasticity. Studies have examined a relationship between BDNF levels and hippocampal volume
in region-of-interest analyses, due to involvement of BDNF in neurogenesis. BDNF also protects
against neurodegeneration and this effect may not be limited to the hippocampus. We will use
a whole-brain approach to examine the relationship between BDNF and regional brain volume
in healthy subjects and patients with major depressive disorder.
Methods
Data was collected in the Netherlands Study of Depression and Anxiety (NESDA). Patients with a
current MDD diagnosis or a current diagnosis of MDD and comorbid anxiety disorder (n = 155)
and healthy subjects (n = 65) were included. Levels of BDNF were determined from blood samples
and T1 magnetic resonance images were acquired using a 3T scanner. As BDNF levels did not
differ between patients and controls, we combined these groups. We performed voxel based
morphometry (VBM) regression analyses to examine the association between grey matter volume
and BDNF values across all subjects. Age, gender, education level and scansite were included as
covariates.
Results
We observed a positive relationship between BDNF levels and volume of the right inferior frontal
gyrus, uncus, left thalamus, bilateral precuneus and cerebellum. A negative relationship was seen
between BDNF levels and volume of the left precuneus (p = .001, uncorrected).
Conclusions
We suggest that BDNF protects against neurodegeneration in several cortical and subcortical areas
and that the effect of BDNF is not limited to the hippocampus.
VU University Medical Center Science Exchange Day 2014
33
Biomarkers: Clinical
24. Genome-wide DNA methylation profiling reveals novel
biomarkers for early detection of cervical cancer
Wina Verlaat1, Peter J.F. Snijders1, Chris J.L.M. Meijer1, Wim Van Criekinge2,
Renske D.M .Steenbergen1
Department of Pathology, VU University Medical Center, Amsterdam
Department of Mathematical Modelling, Statistics and Bioinformatics, Faculty of Bioscience
Engineering, Ghent University, Ghent, Belgium
1
2
Introduction
Cervical cancer is caused by a human papillomavirus (HPV) infection, but only a minority of HPVinfected women will develop cancer. Hence, with the introduction of primary HPV testing in cervical
screening in The Netherlands in 2016, there is an urgent need for molecular markers enabling risk
stratification of hrHPV-positive women. Markers based on DNA methylation of tumour suppressor
genes are most promising. In this study we set out to define novel candidate methylation markers
by genome-wide DNA methylation profiling.
Methods
Genome-wide DNA methylation profiles were determined by Methyl Binding Domain (MBD) based
DNA enrichment followed by next generation sequencing analysis of 24 HPV-transformed cell
lines and cervical tissue specimens. The most differentially methylated gene candidates were
subsequently subjected to verification analysis on the same samples by a different method
(i.e. multiplex targeted bisulfite next generation sequencing). Ultimately, methylation of verified
candidates was assessed in an independent set of cervical tissue specimens (n=73) by methylationspecific PCRs (MSP).
Results
Of the most differentially methylated gene candidates scored by the MBD screen, hypermethylation
of 7 genes in HPV-transformed cell lines and high grade lesions was confirmed by targeted
sequence analysis. Of these 7 candidates 5 genes also revealed hypermethylation by MSP analysis
in the independent series of precancerous lesions and cervical squamous cell carcinomas
compared to normal tissue.
Conclusions
By genome-wide methylation profiling we identified 5 novel candidate methylation markers for
cervical cancer and its precursor lesions. Further validation studies on cervical scrapes will reveal
their value in HPV-based cervical screening programs.
34
Biomarkers: Clinical
25. Diagnostic Value of Amyloid Imaging in Early Onset
Dementia
Marissa D. Zwan1,2, Femke H. Bouwman1, Wiesje M. van der Flier1,3, Adriaan A. Lammertsma2,
Bart N.M. van Berckel2, Philip Scheltens1.
Alzheimer Center & Department of Neurology
Department of Radiology & Nuclear Medicine
3
Department of Epidemiology & Biostatistics, Neuroscience Campus Amsterdam, VU University
Medical Center, Amsterdam
1
2
Introduction
In early onset dementia approximately one out of three patients has an atypical clinical
presentation, which substantially complicates correct etiological diagnosis. [18F]Flutemetamol
PET, an investigational imaging agent, is being studied for detection of amyloid deposition, a
pathological hallmark of Alzheimer’s Disease (AD).
Methods
We included 80 patients with early onset dementia and physician diagnostic confidence <90%
after a full routine diagnostic work-up for dementia. All patients underwent a [18F]Flutemetamol
PET scan which were visually assessed as amyloid positive or negative. Before and after disclosing
PET results, confidence in clinical diagnosis was determined. Also, impact on patient healthcare
management was assessed after disclosing PET results.
Results
[18F]Flutemetamol PET scans were positive in 48 out of 63 (76%) patients diagnosed (pre-PET imaging)
with AD and 4 out of 17 (24%) patients diagnosed with other dementias. Overall, after disclosing
PET results confidence in etiological diagnosis increased from 76±12% to 90±16% (p<0.001).
PET results led to a change in diagnosis in 16 (20%) patients; predominantly a negative PET result
caused a change of the initial AD diagnosis to another dementia.
In 27 (34%) patients, PET results led to a change in healthcare management. For 13 patients
additional ancillary investigations were planned after access to the PET results.
Conclusions
[18F]Flutemetamol PET resulted in changes in the diagnostic process work-up of early onset
dementia patients and the diagnostic confidence of the managing physicians. Especially in
patients diagnosed with AD pre-PET imaging, a negative PET scan resulted in more changes in
clinical diagnosis and patient management.
VU University Medical Center Science Exchange Day 2014
35
Biomarkers: Experimental and Methods
26. Structural variant breakpoint detection in advanced
colorectal cancer
E van den Broek1, O. Krijgsman1, D. Sie1, J.C. Haan1, M. Komor1, J. Traets1, D.A.M.Heideman1,
M.A. van de Wiel2, B. Carvalho1, I.D. Nagtegaal3, C.J.A. Punt4, B. Ylstra1, G.A. Meijer1, R.J.A. Fijneman1
Department of Pathology, VU University Medical Center, Amsterdam
Department of Epidemiology & Biostatistics, VU University Medical Center, Amsterdam
3
Department of Pathology, Radboud University Nijmegen Medical Center, Nijmegen
4
Department of Medical Oncology, Academic Medical Center, Amsterdam
1
2
Introduction
Colorectal cancer (CRC) development is accompanied by genomic alterations driving tumor
initiation and progression. DNA copy number alterations could affect mRNA and subsequently
protein expression levels. Interestingly, accompanying chromosome breakpoints represent
structural variants (SV) that may affect gene architecture and thereby gene function. The aim of
this study was to identify recurrent SV breakpoints in advanced CRC.
Methods
Tumor versus normal DNA from 352 advanced CRC samples from CAIRO and CAIRO2 clinical
studies [Koopman et al. Lancet 2007; Tol et al. N Engl J Med 2009] were subjected to arrayComparative Genomic Hybridization (Agilent 180K arrays) to detect copy number alterations.
Using these data, we determined the prevalence of recurrent breakpoints in genes. In addition,
multiplexed amplicon analysis involving 48 cancer-related genes (Illumina TruSeq Amplicon
Cancer Panel) was applied. Multi-Dendrix was used to identify modules of cancer driver genes.
Results
We identified 748 recurrent breakpoints in genes (FDR<0.1), occurring in less than 5% up to 40%
(MACROD2) of all tumors. Mutation frequencies in APC, TP53 and KRAS were conform
expectations. Multi-Dendrix analysis revealed modules of cancer driver genes that included
commonly mutated CRC cancer genes as well as genes with recurrent breakpoints.
Conclusions
We were able to pinpoint the prevalence of 748 recurrent SV breakpoint genes using array-CGH
from 352 CRC samples. Moreover, our studies revealed several breakpoints in genes that are
mutually exclusive with the commonly mutated genes, and therefore represent novel candidate
cancer driver genes. Further studies are required to investigate their functional and clinical
relevance.
36
Biomarkers: Experimental and Methods
27. Measurement of serum testosterone, androstenedione
and dehydroepiandrosterone (DHEA) levels using
Isotope-Dilution Liquid-Chromatography Tandem Mass
Spectrometry (ID-LC-MS/MS)
Rahel M. Büttler1, Frans Martens1, Mariette T. Ackermans2, Marinus A. Blankenstein1,
Annemieke C. Heijboer1.
Department of Clinical Chemistry, Endocrine laboratory, VU University Medical Center,
Amsterdam, the Netherlands. 2Department of Clinical Chemistry, Laboratory of Endocrinology,
Academic Medical Center, Amsterdam, the Netherlands.
1 Introduction
The adrenal and gonadal androgens testosterone, androstenedione and dehydroepiandro-sterone
(DHEA) play an important role in sexual development and fertility as well as in several other
processes. We developed a method to assess serum testosterone, androstenedione and DHEA
levels in one run using Isotope-Dilution Liquid-Chromatography Tandem Mass Spectrometry
(ID-LC-MS/MS).
Methods
Sample preparation consisted of addition of internal standards (13C3-testosterone, 13C3-androstenedione
and 2H6-DHEA) and a liquid-liquid extraction using hexane-ether. The samples were analyzed on an
Acquity 2D UPLC system (Waters), equipped with a C4-column (Waters) and a Kinetex Fluorophenyl
column (Phenomenex), and a Xevo TQ-S tandem mass spectrometer (Waters).
Results
The intra-assay CVs were <4%, <4.6% and <6.2% for testosterone, androstenedione and DHEA,
respectively. The inter-assay CVs were <7% for testosterone and androstenedione and <9.3% for
DHEA. At the lower concentrations inter-assay CVs were 9%, 7% and 9.3%, for testosterone (0.08
nM), androstenedione (0.48 nM) and DHEA (1.18 nM), respectively. Recoveries of spiked analytes
were 101-107% and 97-106% for testosterone and androstenedione, respectively. Linearity was
shown in dilution series. This method tested negative for interference from several steroid
hormones. The method is suitable for EDTA and heparin plasma as well.
The present testosterone method compared well (y = 1.000 x + 0.035 nmol/L; r = 0,9982) to
another ID-LC-MS/MS method for testosterone in our lab. The latter method being concordant with
a published reference method (Bui et al. 2013).
Conclusion
In conclusion, we developed a sensitive and accurate method to measure serum testosterone,
androstenedione and DHEA serum levels in one run.
VU University Medical Center Science Exchange Day 2014
37
Biomarkers: Experimental and Methods
28. A standard benchmark for assessing the reproducibility
of brain atrophy measures in Alzheimer’s using the ADNI1
data set
Cover KS1, van Schijndel R.A.2, Versteeg A.2, Vrenken H.1,2, van Dijk B.W.1, Barkhof F.1
1
2
Physics and Medical Technology, VU University Medical Center
Radiology and Nuclear Medicine, VU University Medical Center
Introduction
To propose a standard benchmark for assessing the reproducibility of atrophy measures in
Alzheimer’s disease and to demonstrate its use with hippocampal volume measurements. While
many publications have compared the performance of algorithms for measuring brain atrophy
in Alzheimer’s disease (AD), few have assessed their reproducibility, because of the additional
burden of repeating a MRI acquistion at each patient’s visit. Although rarely mentioned in the
literature, the widely available ADNI1 data set had two identical MRI image volumes acquired at
each patient visit, making it an excellent and very large data set for reproducibility studies (Cover
et al. 2011 Psychiatry Research: Neuroimaging 2011;193:182).
Methods
A total of 562 subjects in the ADNI1 study were found to have back-to-back (BTB) MRI acquisitions
at both baseline and 12 month visits. Both FreeSurfer 5.3.0 and FSL/First 5.0.4 were run on all
4 MRI image volumes for each subject to calculate the percentage hippocampal volume change
(PHVC) over the 12 month interval for both of the BTB acquisitions for the left hippocampus. Then
the difference of the two PHVC for each subject was calculated yielding a BTB difference. The
reproducibility of each algorithm was calculated from its BTB differences as the 50 percentile of
the absolute value of the BTB differences.
Results
The list of ADNI1 MRI included in the benchmark and the computation resources used were
provided by the neuGRID Consortium (www.neugrid4you.eu). For FSL/First (N=557), which only
has cross-sectional mode, the reproducibility was 2.5% (2.3%-2.8% [95% confidence interval]).
For FreeSurfer (N=75) in cross-sectional and longitudinal modes the reproducibilites were 3.3%
(2.5%-3.7%) and 2.4% (1.5%-2.9%).
Conclusions
The three reproducibilities were similar, especially when considering the confidence intervals, but
FreeSurfer was slightly smaller. To use the proposed standard benchmark, a researcher need only
calculate the BTB reproducibility for new algorithms using the specified MRIs from ADNI1 and
compare the reproducibilities to those presented here. Thus the proposed standard benchmark
should be a valuable gauge by which to assess and compare the performance of brain atrophy
algorithms.
38
Biomarkers: Experimental and Methods
29. Preclinical evaluation of [11C]JNJ7777120 as a PET tracer of
histamine H4 receptors in the brain
Funke U1,2, Smits R.A.3, Schuit R.C.1, Metaxas A.1, Vugts D.J.1, Janssen B.1, Spaans A.1,2, Kruijer P.S.2,
Lammertsma A.A.1, Windhorst, A.D.1
Department of Radiology & Nuclear Medicine, VU University Medical Center
BV Cyclotron VU
3
Griffin Discoveries BV
1
2
Introduction
Neuroinflammatory factors can induce microglia motility via H4R activation. Further, H4R are
functionally expressed on neuronal cells. The purpose of this study was to evaluate whether
11
C-labelled JNJ7777120, a highly potent and selective H4R antagonist, could serve as a potential
PET tracer to image H4R in vivo.
Methods
Whole body PET images of male Wistar rats (~450 g, n=4) where acquired for 60 min following
intravenous injection of 11 MBq [11C]JNJ7777120. Displacement studies were performed by
administering 35 mg/kg thioperamide s.c., 15 min after [11C]JNJ7777120 injection.
Results
[11C]JNJ7777120 entered the brain rapidly with a maximal uptake of 0.6 %ID/mL at 3 min. At 25 min,
uptake reached a SUV of 1.1, which was not displaced by thioperamide, but rather elevated to a
SUV of 1.4.
Conclusions
Brain uptake of [11C]JNJ7777120 could not be displaced by another H4R targeting substance.
Further studies are needed to investigate the reasons for this lack of displacement. These will
include metabolic studies, the use of other H4R inhibitors, and in vitro studies to determine
expression levels of H4R in healthy rat brains and such possessing neuroinflammatory foci.
Research support: FP7/2007-2013, HEALTH-F2-2011-278850 (INMiND)
VU University Medical Center Science Exchange Day 2014
39
Biomarkers: Experimental and Methods
30. The blood-derived transglutaminase Factor XIII colocalises
with Aβ deposition in cerebral amyloid angiopathy and
forms complexes with Aβ in vitro
Mieke A.M. de Jager, Max V. Boot, John G.J.M. Bol, John J. Brevé,
Benjamin Drukarch, Micha M.M. Wilhelmus
Department of Anatomy and Neurosciences, Cellular Neuropharmacology section, Neuroscience
Campus Amsterdam, VU University Medical Center
1
Introduction
Cerebral amyloid angiopathy (CAA) is an important hallmark of Alzheimer’s disease and
characterized by the formation of aggregated amyloid-β peptide (Aβ) deposits in brain vessel
walls. CAA is associated with blood brain barrier leakage. Unfortunately, the mechanisms
underlying the Ab deposition in CAA remain largely unclear. The transglutaminase enzyme Factor
XIIIa (FXIIIa) is present in the blood and is important in the coagulation cascade by inducing fibrin
clots via its crosslinking activity. Fibrin is associated with deposited Aβ in CAA, and Ab is a wellknown substrate for transglutaminase crosslinking by other transglutaminases. The aim of this
study is to investigate whether blood-derived Factor XIIIa is present and active in CAA and might
be involved in Aβ aggregation and deposition in the vessel wall.
Methods
We studied the distribution of FXIIIa, its in situ activity, and its activator thrombin in human post
mortem brain sections of both AD and control cases using immunohistochemistry. Furthermore,
we analysed the binding of FXIIIa to Aβ with surface plasmon resonance (SPR) and we tested the
ability of FXIIIa to induce the aggregation and cross-linking of Aβ using Western blot analysis.
Results
We showed that the enzyme FXIII, its in situ activity and FXIII’s activator thrombin colocalise with
the Aβ deposition in CAA. Furthermore, we showed that active FXIII (FXIIIa) has a higher binding
affinity for Aβ1-42 compared to Aβ1-40. Interestingly, FXIIIa induced the formation of stable FXIIIa-Aβ
complexes and oligomers in a calcium-dependent manner in which the glutamine at position 16 of
the Aβ protein was of importance for complex formation.
Conclusions
We showed that FXIII and FXIIIa activity colocalise with the deposited Ab in CAA. In addition, we
found that FXIIIa forms strong calcium-dependent protein-protein complexes with Ab, as well as
oligomers. Together, our data suggests that FXIII is present and active in CAA, and that FXIIIa
forms unique protein complexes with Ab that might play an important role in Aβ deposition in the
vessel wall.
40
Biomarkers: Experimental and Methods
31. Recommendations on study design and data analysis for
differential gene expression using RNA-seq
E.I. Kooi, N. Ameziane, K. Roohollahi, M.P.G. Massink, J.C.D. Dorsman
Clinical genetics, VU University Medical Center
Introduction
In the past few years, next-generation sequencing has become the preferred approach for the
characterization and quantification of entire genomes. With respect to expression profiling,
RNA-seq introduces fewer technical variance compared to conventional micro-arrays while providing
additional information such as coding variants, alternative splicing, and novel transcripts.
However, RNA-sequencing pioneers often find themselves confronted with practical considerations
withholding them to embark on RNA-seq experiments. Based on our experience, with this poster
we provide various practical considerations for differential gene expression analyses.
Methods
Total RNA from 12 head and neck squamous cell carcinoma cell lines and 6 matched fibroblasts
cell lines were extracted. Extracts were prepared with TruSeq Stranded mRNA protocol and
sequenced on a Hiseq2500 using the 100bps paired-end protocol. Subsequently, the impact
of sequencing yield, strand information, alignment and read quantification was systematically
analysed to come up with recommendations for RNA-seq study design and data analysis.
Results
Comparisons of single-end and paired-end analyses of all 18 samples shows very high similarity
with regard to read counts (Pearson correlation ranging between 0.95 and 0.99). Furthermore,
including strand-specific information only slightly increases the percentage of the transcriptome
(3% of genes) that can be used for quantification. Alignment comparisons between TopHat and
STAR show relatively good concordance in read counts (Pearson correlation ranging between 0.95
and 0.98). However, STAR has a higher mapping yield and accuracy compared to TopHat.
More importantly, STAR's mapping speed is immensely higher than TopHat's, spending less than
30 minutes for whole transcriptome alignment compared to 24 hours for TopHat.
Conclusions
Our results show that sequencing costs can be drastically reduced when using RNA-seq for
differential gene expression. Taken together with STAR's accurate and efficient mapping algorithm,
cost-comparative RNA sequencing of large cohorts of samples is feasible in a short period of time
VU University Medical Center Science Exchange Day 2014
41
Biomarkers: Experimental and Methods
32. Less is enough: scaling down protein input for
phosphoproteomics based treatment selection in patients
with advanced solid tumors
Mariette Labots1, Koen van der Mijn1, Sander Piersma2, Richard de Haas1, Inge de Reus2, Jaco Knol2,
Thang Pham2, Nicole van Grieken3, Gerrit Meijer3, Henk Verheul1, Connie Jiménez2
Department of Medical Oncology, VU University Medical Center
OncoProteomics Laboratory, Department of Medical Oncology, VU University Medical Center
3
Department of Pathology, VU University Medical Center
1
2
Introduction
Mass spectrometry-based phosphoproteomics of cancer cell- and tissue lysates provides a unique
approach to evaluate the cell signaling network, revealing information on aberrantly activated
signaling pathways and potential drug targets. To enable phosphoproteomics-based treatment
selection for improved efficacy of targeted therapies in patients with advanced solid tumors,
needle biopsies should provide reproducible profiles, representative of the individual tumor
phospho-proteome. We have assessed reproducibility and tumor heterogeneity using limited input
material.
Methods
Phosphopeptide immunoprecipitation (IP) using P-Tyr-1000 anti-phosphotyrosine-coated beads
(PTMScan®, CST) was performed using 1, 5 and 10 mg protein from lysates of the colorectal cancer
(CRC) cell line HCT116 and 3 patient-derived tumors. After measurement by LC-MS/MS, MaxQuant
database searching and analysis were applied for phosphopeptide identification (ID), ion-intensitybased quantification and phosphosite localization.
Results
Cell line triplicates of 1, 5 and 10 mg protein input yielded a total of 454, 559 and 664 unique
phosphosites, and a median number of 345 (range:266-376), 435 (236-448) and 501 (476-618)
per replicate, respectively. The ID-reproducibility was 45% for 1 mg and 58% for 10 mg protein
replicates. In tissue, a median total of 622 (427-754) unique phosphosites were identified per
tumor, with a median number of 190 (91-353), 404 (199-512) and 546 (252-638) per sample using
1, 5 and 10 mg protein, respectively.
Conclusions
This scale-down study demonstrates that hundreds of phosphopeptides can be profiled at low
‘biopsy-level’ of protein input, enabling future phosphoproteomics-based therapy selection using
patient tumor biopsies. CRC heterogeneity analyses are ongoing and will be presented at the
meeting.
42
Biomarkers: Experimental and Methods
33. Discovery of biomarkers reflecting progression
pathophysiology for relapse remitting and primary
progressive MS subtypes by applying novel multiplex
aptamer approach
Arjan Malekzadeh1, Joep Killestein2 and Charlotte Teunissen1
1
2
Department of Clinical Chemistry, VU University Medical Center, Amsterdam
Department of Neurology, VU University Medical Center, Amsterdam
Introduction
The patho-physiology of multiple sclerosis disease onset and progression remains undetermined.
Understanding this is beneficial for prognosis, treatment strategies and for the development of
new neuro-protective therapies. To unravel the patho-physiology of MS disease progression and
possible identification of progression biomarkers, we performed proteomics on plasma proteins
of patients with relapse-remitting MS (RRMS) with a benign disease course (n=10), very aggressive
from onset RRMS (n=10) and primary progressive MS patients (PPMS) (n=10).
Methods
The proteomics was performed with aptamers by Somalogic, this assay detects 1129 blood
biomarkers in a low volume of 65 µl of plasma. This method has been proven in other studies for
other diseases however it has not yet been applied for MS.
Results
We observed 50 proteins differentially expressed between benign RRMS and aggressive RRMS.
A comparison between aggressive RRMS and PPMS showed the expression of 112 proteins altered
significantly. Generally, these proteins can be divided into; immune receptors, inflammatory
response, growth factors, cell signaling, blood coagulation, cell adhesion, matrix metalloproteinases
and neuronal/hormone homeostasis
Conclusions
This exploratory phase has led to the identification different pathways and markers. Subsequent
validations with the best discriminating biomarkers with customized aptamer assays on larger
sample size is required and ongoing
VU University Medical Center Science Exchange Day 2014
43
Biomarkers: Experimental and Methods
34. De novo elucidation of metabolite clusters and their
genetically influenced protein‑protein interaction
sub‑networks based on a metabolome- and genome‑wide
association study
René Pool1,2,3,4,*, Harmen H.M. Draisma1,2,3,*, Mohammed El‑Kebir5,6,*, Jan Bert van Klinken3,7,
Ko Willems van Dijk3,7, Cornelia M. van Duijn3,4,8, Christian Gieger3,9, Peter A.C. ’t Hoen3,7,
Gunnar W. Klau5,6, Nicholas G. Martin3,10, Mark I. McCarthy3,11, Michael Kobl3,9,
Andres Metspalu3,12, P. Eline Slagboom3,4,13, Tim D. Spector3,14, Konstantin Strauch3,9,15,
Dorret I. Boomsma1,2,3,4 and Aaron Isaacs3,8
* These authors contributed equally
1
VU University Amsterdam, Faculty of Psychology and
Education, dept. Biological Psychology, Amsterdam,
The Netherlands
2
The EMGO+ Institute for Health and Care Research,
Amsterdam, The Netherlands
3
ENGAGE: European Network of Genomic And Genetic
Epidemiology
4
BBMRI-NL: Infrastructure for the Application of Metabolomics Technology in Epidemiology (RP4), The
Netherlands
5
Centrum Wiskunde & Informatica (CWI), Life Sciences Amsterdam, The Netherlands
6
VU University Amsterdam, The Centre for Integrative
Bioinformatics VU (IBIVU),
Amsterdam,
The Netherlands
7
Leiden University Medical Center, Department of
Human Genetics, Leiden, The Netherlands
Erasmus Medical Center, Department of Epidemiology, Rotterdam, The Netherlands
9
Institute of Genetic Epidemiology, Helmholtz
Zentrum München - German Research Center for
Environmental Health, Neuherberg, Germany
10
Queensland Institute of Medical Research, Genetic
Epidemiology, Brisbane, Australia
11
Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
12
University of Tartu, Estonian Genome Center, Tartu,
Estonia
13
Leiden University Medical Center, Department of
Molecular Epidemiology, Leiden,
The Netherlands
14
King’s College London, Department of Twin Research & Genetic Epidemiology, London,
United Kingdom
15
Institute of Medical Informatics, Biometry and Epidemiology, Chair of Genetic Epidemiology, LudwigMaximilians-Universität, Munich, Germany
8
Introduction: A genome‑wide association study (GWAS) is a hypothesis‑generating method to identify
the associations between single‑nucleotide polymorphisms and an outcome, e.g. the serum level of a
metabolite in humans. Serum levels of biochemically closely connected metabolites are influenced by
proteins encoded by shared genes. It is difficult to identify such groups of biochemically closely connected
metabolites from the results of single‑metabolite GWASs. We developed a method that finds connected
proteins which are shared across different metabolites.
Methods: The results of GWASs for the serum levels of 129 metabolites measured in seven cohorts (N
= 7,478 subjects) by mass spectrometry‑based metabolomics techniques were pooled in meta‑analysis.
For each metabolite, gene‑wise p‑value sets were calculated as input for the integrative network analysis
approach “Heinz” to find 129 optimal sub‑networks of connected proteins in the protein‑protein
interaction network “PINA”. The 129 metabolites were then clustered based on their sub‑network
similarity. Subsequent “Heinz” analyses of the proteins of these clusters will yield ‘consensus’ PINA
sub‑networks.
Results: We found several metabolite similarity clusters containing two metabolites or more. A number
of these were part of one single chemical class. The generated consensus PINA sub-networks designated
to the metabolite similarity clusters will be analyzed using enrichment strategies.
Conclusions: We developed a method to elucidate the genetically influenced biochemical basis of (co)
variation for different metabolites. Our method finds sets of interacting genetically influenced proteins
that are shared across distinct metabolites. Thereby it highlights connections among GWAS findings for
individual metabolites as measured using metabolomics techniques.
44
Biomarkers: Experimental and Methods
35. Protein kinase activity profiling of patients with
Alzheimer’s Disease and non-demented controls reveals
pathway changes
Andrea F.N. Rosenberger1,2, Riet Hilhorst3, Rik de Wijn3, Wiesje M. van der Flier1,
Annemieke J.M. Rozemuller2, Philip Scheltens1 , Jeroen J.M. Hoozemans2 and Saskia M. van der Vies2
Alzheimer center & Department of Neurology and
Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center,
Amsterdam
3
PamGene BV International, Wolvenhoek 10, 5211 HH ‘s-Hertogenbosch
1
2
Introduction
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder affecting a constantly
growing proportion of our ageing population. There is currently no treatment or cure available.
For the discovery of new biological markers and drugable targets it is essential to identify signaling
pathways that are involved in AD pathology. This study is aimed at identifying protein kinases in
human brain tissue at different stages of the disease. Signaling pathways that are activated in AD
are identified and investigated.
Methods
For the detection of protein kinase activity brain tissue lysates from AD cases and non-demented
controls are prepared (n=20). Kinase activity profiles of the samples are determined using a
peptide-based microarray, which contains 140 peptides derived from known kinase substrate
sequences covalently attached to a porous matrix. Fluorescently labelled anti-phosphoserine,
anti-phosphothreonine and/or anti-phosphotyrosine antibodies are used to detect phosphorylated
peptides on the chip.
Results
The phosphorylation of a subset of peptides (71) decreases with progression of the disease and
can be linked to kinases using GeneGo software. FAK1 is known to be associated with senile
plaques in AD and Lck, has previously been reported to be downregulated. Pathways which are
changed in AD, f.e. the receptor mediated axon growth repulsion pathway, are identified.
Conclusions
Protein kinase activity profiling is a new approach to reveal new signaling pathways involved in AD
pathology and can potentially lead to diagnostic biomarkers and drug targets for treatment of the
disease. Those findings need to be validated in a larger cohort (n = 100).
VU University Medical Center Science Exchange Day 2014
45
Biomarkers: Experimental and Methods
36. Substrate surface alter mechano-responses of vaginal
fibroblasts from prolapsed tissues in premenopausal
women with pelvic organ prolapse
Alejandra M. Ruiz-Zapata1, Manon H. Kerkhof 2, Behrouz Zandieh-Doulabi1,3, Hans A.M. Brölmann2,
Theo H. Smit1, Marco N. Helder1
1
Department of Orthopaedics, VU University Medical Center, Research Institute MOVE, Netherlands Institute for Regenerative Medicine
2
Department of Obstetrics & Gynaecology, VU University Medical Center
3
Department of Oral Cell Biology, ACTA-University of Amsterdam and VU University, Research Institute MOVE
Introduction
Pelvic organ prolapse (POP) is a disease characterised by the weakening of the pelvic floor and
subsequent prolapse of the vagina, bladder or rectum outside the body affecting almost 50% of
elderly women. Fibroblasts are responsible for tissue remodelling and maintenance, but little is
known about their role in POP. Therefore, this study aimed to identify the effects of cyclic
mechanical loading (CML) on two different substrate surfaces on extracellular matrix (ECM)
remodelling factors by fibroblasts from women with prolapse.
Methods
Fibroblasts were isolated from the anterior vaginal wall of premenopausal women in two places:
non-prolapsed (8 controls and 10 POP cases) and prolapsed site (10 POP cases). Cells from passage
3 were seeded on collagen-coated or uncoated bioflex®plates ± CML (Flexercell; 0,2Hz; 48h).
Morphological changes were observed and matrix metalloproteinase (MMP)-2 and its inhibitor
(TIMP-2) were evaluated at protein and gene expression levels.
Results
No differences were seen between healthy controls and the non-POP site from POP cases. Cell
attachment and alignment was facilitated by collagen-coated surfaces. Mechanoresponses of
vaginal fibroblasts to matrix components and mechanical loading were different in cells from
prolapsed and non-prolapsed tissues with regard to secretion and activation of MMP-2, and gene
expression of MMP-2 and TIMP-2.
Conclusions
Fibroblasts from the prolapsed vaginal wall have altered mechanoresponses depending on matrix
substrate and compared to non-prolapsed sites. This indicates an acquired rather than an intrinsic
defect which favours the development of autologous cell-based tissue engineering constructs to
treat POP.
46
Biomarkers: Experimental and Methods
37. Quantitating neutrophil oxidative stress by Flow
Cytometry
Bob Smit1,2, Monique C. de Waard1,2 , Yvo M. Smulders2,3, Christa Boer2,4, Alexander B.A. Vonk2,5,
Dennis Veerhoek2,5, Juan J. García Vallejo2,6, René. J.P. Musters2,7, Suzanne Kamminga2,4,
Angélique M.E Spoelstra - de Man1,2
Department of Intensive Care, VU University Medical Center,
Institute for cardiovascular research, VU University Medical Center
3
Department of Internal Medicine, VU University Medical Center
4
Department of Anaesthesiology, VU University Medical Center
5
Department of Cardiothoracic Surgery, VU University Medical Center
6
Department of Molecular Cell Biology & Immunology, VU University Medical Center
7
Department of Physiology, VU University Medical Center
1
2
Introduction
Relative to pure in-vitro research, clinical research is subject to uncontrollable timetables, which
further complicates the difficult measurement of highly reactive oxygen species (ROS). We therefore
sought to establish an easy to perform assay to detect ROS in whole blood that is less subject to
delay between sample preparation and analysis
Methods
Citrated whole blood samples were collected from healthy volunteers and from patients before
(baseline) and during (1 hour of Cardiopulmonary Bypass, CPB) Coronary Artery Bypass Graft
(CABG) surgery. 30 ml citrated whole blood was incubated for 1 hour with CellROX® Green,
immediately after sampling. Erythrocytes were lysed via hypotonic shock. The remaining cells
were washed three times with PBS and stored at room temperature, in the dark, until analysis.
Mean Fluorescence Intensity of the neutrophil population, which is directly proportional to the ROS
produced, was determined by flow cytometry as soon as possible after incubation of the second
CABG sample.
Conclusions
Our current method is easy to perform, implementable into clinical
research and is able to detect different ROS responses.
100
Mean Fluorescence Intensity (a.u.)
Results
As expected, little to no ROS production was demonstrated in
healthy volunteers and baseline samples from CABG surgery
patients, while an increase was found after one hour of CPB (figure).
Interestingly, this method also showed separate ROS producing
neutrophil populations, which warrants further investigation.
80
60
40
20
0
Healthy Baseline 1HR CPB
VU University Medical Center Science Exchange Day 2014
47
Biomarkers: Experimental and Methods
38. (Z)-2-(4-[18F]fluoro-2-oxoindolin-3-ylidene)-N(4-methoxyphenyl)hydrazine carbothioamide is an
aberrant P-gp tracer
Verbeek, J.1; Eriksson, J.1; Syvänen, S.2; Voskuyl, R.A.2,3; de Lange, E.C.2; Huisman M.C.1;
Lammertsma, A.A.1 and Windhorst, A.D.1
Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam
Division of Pharmacology LACDR Leiden University, Leiden
3
Epilepsy institute of the Netherlands foundation (SEIN), Heemstede
1
2
Introduction
Recently compound 1 has been characterized as a P-gp inhibitor that is not transported1. This
characteristic is of particular interest for diseases which are implicated with increased P-gp
expression levels, such as epilepsy and Alzheimer’s disease. The P-gp binding properties of two
fluorine-18 labelled analogues were assessed in vivo.
Methods
[18F]fluoro ([18F]2a) and 6-[18F]fluoro ([18F]2b) analogues of 1 were synthesized, purified and
formulated. Ex vivo biodistribution and metabolism of [18F]2a,b were investigated in rodents and
cerebral uptake of [18F]2a was investigated using PET, both at baseline and after tariquidar pretreatment (15 mg.kg-1, iv), as well as in P-gp and BCRP knockout mice.
Results
Both [18F]2a,b were obtained in low overall yield (2.3 ± 0.9%). At 45 minutes after injection, fractions
of intact [18F]2a in plasma and brain were 12% and 69%, respectively, and for [18F]2b 7% and 16%.
Logan analysis showed a brain VT of 12.6 for [18F]2a at baseline, which did not change significantly
to 13.2 after tariquidar treatment. Ten minutes after injection, brain SUV’s of 1.4 ± 0.1, 2.3 ± 0.3
and 1.8 ± 0.1 were observed in BCRP-, P-gp knockout and wild-type mice respectively.
Conclusions
[18F]2a,b were successfully synthesized and due to fast metabolism [18F]2b was not further studied.
Tariquidar pre-treatment did not significantly alter [18F]2a brain VT indicating lack of pronounced
P-gp substrate character.
48
Biomarkers: Experimental and Methods
39. Large lactate clearance shifts in the first 8 hours after
traumatic brain injury are associated with increased
mortality
S.E. Dekker1, H.M. de Vries1, W.D. Lubbers1, C. Boer1
1
Anesthesiology, Institute for Cardiovascular Research, VU University Medical Center
Introduction
Impaired lactate clearance is predictive for mortality in general trauma patients, however the
association of this biomarker with outcome in patients with traumatic brain injury (TBI) is
unknown. This study examined the association between lactate clearance and mortality in these
patients.
Methods
Lactate values were retrieved retrospectively from the medical records of 531 patients admitted
to the emergency department (ED) between 2011-2012 with a head abbreviated injury score (AIS)
≥3. Patients without initial lactate drawn <30 minutes after admission, or without a second lactate
measurement within 8 hours after admission were excluded. Lactate clearance was calculated as
follows: Lactate clearance (%/hour)=((Lactateinitial–Lactatedelayed)/Lactateinitial)×100/Delay, and stratified
as <-20, -19 to -10, -9 to 9, 10 to 19, and >20%/h. The dataset further included the Glasgow Coma
Scale (GCS), Injury Severity Score (ISS), hospital and ICU days.
Results
Overall, 126 patients were included. Mortality rates in the <-20%/h group, -19 to -10%/h group,
and -9 to 9%/h group were 57%, 10%, and 20% respectively. In the 10 to 19 group 4 of 23 patients
died (17%), while in the highest lactate clearance group 16 of 38 patients died (42%; Χ2 p=0.01). AIS
head, GCS, ISS, hospital and ICU days were not associated with lactate clearance. Lactate clearance
was correlated with initial pH (r=-0.21, p=0.02) and initial base excess (r=-0.24, p=0.009).
Conclusions
Large shifts in lactate levels (lactate clearance <-20 or >20%/h) in the first 8 hours after ED
admission are associated with higher mortality rates compared to moderate or stable lactate
clearance.
VU University Medical Center Science Exchange Day 2014
49
Biomarkers: Experimental and Methods
40. Synthesis of a 11C-labeled tissue transglutaminase
inhibitor using a [11C]CO carbonylation reaction
Van der Wildt, B.1, Bijkerk, J.1, Drukarch, B.2, Lammertsma, A.A.1, Windhorst, A.D.1
1
2
Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam
Department of Anatomy and Neuroscience, VU University Medical Center, Amsterdam
Introduction
Tissue transglutaminase (tTG) is a calcium dependent enzyme that is responsible for the formation
of isopeptide bonds between glutamine and lysine residues resulting in mechanically and
metabolically stable protein oligomers. In neurodegenerative diseases characterized by specific
protein aggregates such as Alzheimer’s, Parkinson’s and Huntington’s disease, tTG has been
shown to be overexpressed, to be active in and to colocalize with the amyloid plaques. The aim of
this research is to develop a PET tracer for imaging of active tTG in vivo to further explore its role
in neurodegenerative diseases.
Methods
Compound 1 is a potent irreversible tTG inhibitor
with a good selectivity towards other
transglutaminase family members that structurally
allows for labeling with carbon-11 at the carbonyl
function of the acrylamide. Shortly, cyclotron
produced [11C]CO2 is reduced to [11C]CO using
molybdenum and subsequently transferred to the
reaction vial using xenon as carrier gas.
O O
S
N
N
O
O
N *
H
1
Results
The reference compound and precursor molecules for radiolabeling were synthesized in good
yields. For radiolabeling, activation of the amine precursor by the addition of Li-HMDS to the
reaction mixture was essential to obtain high radiochemical yields. After HPLC purification and
formulation, the product was obtained on average in 40% yield, starting from [11C]CO, with a purity
> 99 % and a specific activity > 100 GBq.µmol-1.
Conclusions
Compound [11C]1 could be obtained in high yield by activation of amine precursor prior to the
reaction using Li-HMDS. Metabolism and biodistribution of [11C]1 will be evaluated in vivo.
50
Biomarkers: Experimental and Methods
41. Colorectal cancer candidate biomarkers identified by
tissue secretome proteome profiling
Meike de Wit1,2, Huub Kant2, Sander R. Piersma2, Thang Pham2, Sandra Mongera1,
Maaike P.A. van Berkel3, Epie Boven3, Fredrik Pontén4, Gerrit A. Meijer1, Connie R. Jimenez2* and
Remond J.A. Fijneman1*.
Department of Pathology (Tumor Profiling Unit)
Department of Medical Oncology (OncoProteomics Laboratory)
3
Department of Medical Oncology, VU University Medical Center, Amsterdam
4
Department of Genetics and Pathology, The Rudbeck Laboratory, Uppsala University,
Uppsala, Sweden
1
2
*Shared corresponding authorship
Introduction
Colorectal cancer (CRC) is a major health problem. Biomarkers associated with molecular changes
in cancer cells can aid early detection, diagnosis, prognosis, therapy selection, and disease
monitoring. Tumor tissue secretomes are a rich source of candidate biomarkers. The aim of this
study was to identify CRC protein biomarkers in tissue secretomes.
Methods
Secretomes of four pairs of fresh human CRC tissue and patient-matched normal colon tissue
samples, and secretomes of five CRC cell lines were analyzed by GeLC-MS/MS. Data analysis was
based on label-free spectral counting, Ingenuity Pathway Analysis, Secretome/SignalP, STRING and
Cytoscape.
Results
2703 proteins were identified in tissue secretomes, of which 409 proteins were significantly
more present in CRC samples than in controls. Biomarker selection of 76 candidates was based
on consistent and abundant over-representation in cancer- compared to control-secretomes, and
presumed neoplastic origin. Overlap analysis with previously obtained datasets revealed
21 biomarkers suited for early detection of CRC. Immunohistochemistry confirmed overexpression
in CRC of one candidate marker (MCM5).
Conclusions
We identified 76 promising biomarker proteins that have potential to be used for development of
blood- or stool-based assays to support clinical management of CRC. Further studies are required to
validate clinical applicability of these candidate biomarkers.
VU University Medical Center Science Exchange Day 2014
51
Biomedical Engineering
42. Measuring mechanical changes of brain tissue in an
Alzheimer’s mouse model in vivo
Beekmans S.V. 1, Broersen R.2, Antonovaite N.1, Hoogland T.M.2, De Zeeuw C.I.24, Hol E.M.3 and
Iannuzzi D.1
Biophotonics and Medical Imaging, VU Laserlab, VU University Amsterdam
Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences (KNAW)
3
Brain Center Rudolf Magnus, UMC Utrecht, Utrecht
4
Department of Neuroscience, ErasmusMC, Rotterdam
1
2
Introduction
Brain injuries and neurodegenerative diseases, such as Alzheimer’disease, lead to reactive gliosis
in the brain parenchyma. Together with amyloid plaque deposition this gliosis might lead to a
change in the stiffness of the brain. Currently, there is no instrument that can effectively acquire
quantitative in vivo measurements of mechanical stiffness in the brain. In this study we apply
ferrule-top technology to measure stiffness changes in the cortex of the brain of an Alzheimer
mouse model, the APPswPS1dE9 mouse.
Methods
Mechanical stiffness will be measured for both the healthy mouse brain tissue and the tissue of
the Alzheimer model by means of nano-indenation using ferrule-top technology. First, extracted
and perfused C57/BL6 mouse brains will be tested in vitro to validate nano-indentation of soft
tissue. Afterwards the experiment will be extended to fresh in vitro brain tissue and finally in vivo
indentation-measurements will be done.
Results
Initial measurements on perfused mouse brains obtained by in vitro nano-indentation show that
ferrule-top technology can be applied successfully to measure the Young’s modulus (YM) of brain
tissue. We measured a YM of 1.7 ± 0.6 MPa in the cortex, whereas the YM of cerebellar tissue was
measured at 0.6 ± 0.2 MPa.
Conclusions
A pilot study was performed to assess mechanical properties of mouse brain tissue using ferruletop technology. We were able to demonstrate that brain stiffness varies between cerebellum and
cortex. This result is promising for future optomechanical experiments on brain tissue, which will
set the basis for the field of optomechanical genetics.
52
Biomedical Engineering
43. Endoscopic polarization sensitive optical coherence
tomography and in vivo animal lung imaging
Jianan Li1, Fabio Feroldi1, Mattjis de Groot1, Jianhua Mo1, Frank Helderman1, Joop de Langen2,
Johannes M.A. Daniels2, Katrien Grunberg3, Tom G. Sutedja2 and Johannes F. de Boer1
Institute for Lasers, Life and Biophotonics Amsterdam, Department of Physics and Astronomy,
VU University Amsterdam
2
Department of Pulmonary Diseases, VU University Medical Center
3
Department of Pathology, VU University Medical Center
1
Introduction
Optical Coherence Tomography is a low coherence interferometric technique that allows for high
resolution in vivo imaging of biological tissue. Polarization Sensitive OCT is one of its extensions,
as it can determine the birefringence of tissue. This can help distinguishing different types of
tissue.
Methods
We developed a catheter that allows for minimally invasive diagnosis of the bronchi. The high
scanning speed (52 frames per second) permits video rate imaging. The overall diameter of the
endoscope is 1.65 mm. The resolution of the OCT system is about 15 µm. To consistently
determine the birefringence of the tissue, a device that generates two orthogonal polarization
states was used.
Results
1) In vivo OCT image of a live goat lung
2) Ex vivo tissue birefringence image of chicken muscle and tendon
Conclusions
High resolution in vivo OCT images of lungs of live animals were acquired. The fast scanning
speed allows for quick diagnosis of large volumes of tissue. The obtained OCT images are in
agreement with the histological images of the same measured sample. The ex vivo birefringence
image validates the polarization sensitive function of the system and demonstrates the potential
of tissue specific imaging. This device can help the physician in guiding and limiting the excision
of tissue for biopsy for cancer diagnosis.
VU University Medical Center Science Exchange Day 2014
53
Biomedical Engineering
44. Dual-channel multi-photon microendoscope for label free
optical diagnosis of diseases
G. D. Galgano1, N.V. Kuzmin1, M.L. Groot1
Biophotonics & Medical Imaging, LaserLaB Amsterdam, Neuroscience Campus Amsterdam,
VU University Amsterdam
1
Introduction
High-resolution images of label-free biological tissue can be generated with multi-modal laser
scanning microscopy (MLSM) , featuring high penetration depth and low photo-damage via recording
of second and third harmonic signals and multi-photon excited (auto-)fluorescence (S. Witte et al.,
PNAS 108, 5970, 2011). By combination of the appropriate pair of channels it is possible to have
morphological and target-specific image contrast from natural occurring structures of the human
body (Hoover and Squier, Nat. Photonics 7, 23, 2013), making MLSM useful for optical diagnosis
of a wide variety of diseases.
Medical and clinical application demands image acquisition from difficult access areas in a
minimally invasive way, what motivates the integration of MLSM technology into a microendoscopic
setup.
Methods
The microendoscopic system features a simplified video-rate multi-photon microscope, equipped
with an optical fiber flexible probe. Pump radiation of 1300 nm and 300 fs is used to produce
higher order signals in the visible range, while keeping low levels of dispersion and non-linear
effects in the silica fibers.
Results
The constructed probe features a coherent fiber bundle and a custom made micro-objective, which
are assembled and characterized on resolution, field of view, imaging depth and image quality.
Conclusions
The results show that MLSM can be brought to an endoscopic system creating a versatile clinical
diagnostic tool.
54
Biomedical Engineering
45. Towards novel antibiotics: targeting the essential bacterial
cell division protein FtsQ
M. Glas1, H.B. van den Berg van Saparoea1, G.M. Koningstein1, R. Nachane2, F. Figaroa2, E. Ab2,
J. Hollander2, G. Siegal2, I.J.P. de Esch1, S. Luirink1
1
2
Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University
Department of Protein Chemistry, Leiden University
Introduction
Bacterial resistance is an emerging problem. To counter the growing threat of drug resistance, the
development of novel classes of antibiotics is of utmost importance. In this project the essential
bacterial cell division protein FtsQ is investigated as a potential antibiotic drug target. During cell
division FtsQ interacts with FtsB and FtsL forming a heterotrimeric complex. Interference with
these critical interactions inhibits bacterial cell division and thus proliferation [1].
Methods
The protein-protein interactions of FtsQ with FtsB and FtsL were
biochemically confirmed in a pull down assay. Interactions were mapped
at the amino acid level using different site-directed protein cross-linking
techniques. Furthermore, using Target Immobilized NMR Screening (TINS)
[2], a fragment library was screened for molecules that bind to FtsQ, and
the resulting hits were validated by Surface Plasmon Resonance (SPR).
Results
The protein cross-linking experiments resulted in the identification
of two interaction sites [3]. From the TINS fragment screen 72 hits were
identified to bind to FtsQ. Validation of these hits using SPR resulted
in the confirmation of a number of small molecules (fragments) that
showed significant affinity for FtsQ.
Conclusions
We identified interaction hotspots in FtsQ that constitute potential
targets for novel synthetic antimicrobial drugs. Furthermore, using
two orthogonal screening methods several fragments were identified
that interact with FtsQ. The binding sites of these molecules will be
mapped and they will be optimized towards potent inhibitors of the
essential protein-protein interactions of FtsQ.
1
F. van den Ent et al., Mol Microbiol, 2008. 68(1): p. 110-23.
2
S. Vanwetswinkel et al., Chem Biol, 2005. 12(2): p. 207-16.
3
H.B. van den Berg van Saparoea et al., J Biol Chem, 2013. 288(34): p. 24340-50.
VU University Medical Center Science Exchange Day 2014
Cell division protein FtsQ.
The interaction sites are
indicated by dotted circles.
55
Biomedical Engineering
46. The effect of medication on fMRI resting state connectivity
in focal epilepsy
Kees Hermans1,2, Pauly Ossenblok3, Albert Colon4, Kees Visser5, Ruud Verdaasdonk2, Paul Boon1,
Jan de Munck2
Department of Research and Development, Kempenhaeghe, Heeze
Department of Physics and Medical Technology, VU University Medical Center, Amsterdam
3
Department of Clinical Physics, Kempenhaeghe, Heeze
4
Department of Neurology, Kempenhaeghe, Heeze
5
Philips Healthcare, Best
1
2
Introduction
Previous studies have shown that spatial independent component analysis (ICA) of resting state
fMRI enables the identification of resting state networks (e.g. default mode network, visual
network, etc.) and, applied to patients with epilepsy, an epilepsy related network. The goal of this
study was to investigate the effect of medication withdrawal on resting state networks in patients
with refractory focal epilepsy.
Methods
Simultaneous EEG/fMRI data have been acquired for ten patients with focal epilepsy who were
candidates for epilepsy surgery. Patients were scanned before the start of standard pre-surgical
video-EEG when still on medication (condition A), and after medication withdrawal (condition B).
EEG/fMRI data were analyzed using both the general linear model (GLM) approach and ICA. Spatial
correlation of this map with all the ICs enabled identification of the epileptic IC (ICE). A similar
procedure was used to identify the other resting state fMRI networks. The difference in functional
connectivity between conditions A and B was quantified using a GLM approach applied to the
concatenated time series of the resting state components.
Results
ICEs were identified in the resting state fMRI data of ten patients with measurements in conditions
A and B. Significant differences in functional connectivity between resting states were found in
each patient. A preliminary finding is that functional connectivity is higher after medication
withdrawal.
Conclusion
In this study it was shown that differences in resting state functional connectivity caused by drugs
withdrawal can be quantified for individual patients.
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Biomedical Engineering
47. A yeast genome-wide screen uncovers roles for chromatin
modifications and ubiquitin homeostasis in
acetaminophen toxicity
Angelina Huseinovic1, Chris Vos1, Jan Kooter2
Division of Molecular Toxicology, Amsterdam Institute of Molecules, Medicines and Systems,
VU University Amsterdam
2
Department of Genetics, Amsterdam Institute of Molecules, Medicines and Systems,
VU University Amsterdam
1
Introduction
A yeast collection containing deletion strains for each non-essential gene is available. This provides
the tools to link genotypes to drug sensitivity. We screened ~1500 single gene deletion strains
towards acetaminophen (APAP) stress. Although APAP is a widely used analgesic and antipyretic
drug, the exact causes of its side effects are still unknown. One risk factor, the bioactivation of
APAP into NAPQI, is absent in yeast due to lack of a drug-metabolizing cytochrome P450. Yeast
genomics may suggest novel pathways relevant to human APAP-sensitivity.
Methods
We used a Saccharomyces cerevisiae deletion library to perform a genome-wide loss-of-function
screen. The growth of the deletion strains was quantified at various concentrations of APAP.
The identified genes were grouped by function using the String protein interaction search tool.
Results
We identified 107 deletion strains that exhibited higher resistance to APAP compared to the wild
type. Upon clustering these genes, two important central functions emerged: ubiquitin modification
and RNA polymerase II transcription. Furthermore, 70 APAP sensitive deletion strains were
identified. Here, two other clusters appeared: genes involved in histone modifications and
chromatin remodeling and genes involved in vacuolar trafficking.
Conclusions
Our study shows that APAP has pleiotropic effects in the cell, which are unrelated to bioactivation
by cytochrome P450. The transcriptional and epigenetic profile of the cell seems to be an important
determinant in APAP-sensitivity. Furthermore, it remains to be seen which of the many roles of
ubiquitin in the cell is crucial in APAP-toxicity and what is the relevance in humans.
VU University Medical Center Science Exchange Day 2014
57
Biomedical Engineering
48. Single-molecule Acoustic Pushing (smAP!): Manipulating
single-molecules with ultrasound
Gerrit Sitters1,2, Douwe Kamsma1,2, Gijs Wuite1,2 and Erwin Peterman1,2
1
2
Department of Physics and Astronomy, VU University Amsterdam, Amsterdam
LaserLaB Amsterdam, VU University Amsterdam, Amsterdam
Introduction
The ability to study individual biomolecules in vitro has greatly expanded our knowledge of
biological systems. Existing single molecule techniques such as optical and magnetic tweezers or
atomic force microscopy (AFM) allow manipulation of individual biomolecules such as DNA. They
suffer from either being technically challenging or offering low experimental throughput.
Methods
We constructed a lab-on-chip device, by combining a microfluidic system and a piezo electric
element, creating a layered resonator. The device is easy to assemble and cheap. It allows
application of controllable forces up to hundreds of pN on tethered microspheres. Forces can be
applied homogenously over an area of 0.5 cm2, allowing simultaneous measurement of multiple
microspheres.
Results
We demonstrated the value of this approach by measuring the mechanic properties of multiple
DNA molecules at the same time. This can be seen in figure 1, where two force-extension curvesA,
a DNA protein interactionsB and two force clampingC measurement are shown.
Figure 1
Conclusions
In this study we have developed a novel technique to study single biomolecules. Since it is cheap
and low tech it can be widely used by biophysicists and furthermore have application in lab on
chip devices.
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Biomedical Engineering
49. Development of a baby friendly non-contact method for
measuring vital signs, first results of clinical measurements
in an open incubator on a Neonatal Intensive Care Unit
John H.G.M. Klaessens1, Marlies van den Born1, Albert van der Veen1, Janine Sikkens-vd Kraats1,
Frank A.M. van den Dungen2, Rudolf M. Verdaasdonk1
1
2
Department Physics and Medical Technology, VU University Medical Center
Department of Pediatrics, VU University Medical Center
Introduction
For infants and neonates in an incubator vital signs, such as heart rate, breathing, skin temperature
and blood oxygen saturation are measured by sensors and electrodes sticking to the skin. This
can damage the vulnerable skin of neonates and cause infections. In addition, the wires interfere
with the care and hinder the parents in holding and touching the baby. These problems initiated
the search for baby friendly ‘non-contact’ measurement of vital signs.
Methods
Using a sensitive color video camera and specially developed software, the heart rate was derived
from subtle repetitive color changes. Potentially also respiration and oxygen saturation could be
obtained. A thermal camera was used to monitor the temperature distribution of the whole body
and detect small temperature variations around the nose revealing the respiration rate.
Results
After testing in the laboratory with volunteers, two babies were monitored (with parental consent)
in the neonatal intensive care unit (NICU) simultaneously with the regular equipment. From the
color video recordings accurate heart rates could be derived and the thermal images provided
accurate respiration rates. To correct for the movements of the baby, tracking software could be
applied. At present, the imaging processing was performed off-line. Using narrow band light
sources also non-contact blood oxygen saturation could be measured.
Conclusions
Baby friendly non-contact monitoring of vital signs has proven to be feasible and can be developed
into a real time system.
VU University Medical Center Science Exchange Day 2014
59
Biomedical Engineering
50. LC-MS based metabolomics as a tool for studying the
Warburg effect
Petra Krumpochova1, Martin Giera2,3, Bas Teusink3, Manfred Wuhrer1, Martine Smit4,
Azra Mujic-Delic4, Filipe Branco dos Santos3 and Wilfried Niessen1
Division of BioAnalytical Chemistry, Amsterdam Institute of Molecules, Medicines and Systems,
VU University Amsterdam
2
Center for Proteomics and Metabolomics, Leiden University Medical Center
3
Center for Integrative Bioinformatics, VU University Amsterdam
4
Division of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems,
VU University Amsterdam
1
Introduction
The metabolic phenomenon where cancer cells rely on aerobic glycolysis instead of oxidative
phosphorylation, was described for the first time by Otto Warburg over 80 years ago and it was
named after him. Aerobic glycolysis is an inefficient way to generate ATP producing only
2 molecules of ATP per molecule glucose, whereas oxidative phosphorylation generates 32 ATP
molecules per molecule glucose. The question immediately arises as to why cancer cells would
switch to a less productive form of energy production. One hypothesis describes increased aerobic
glycolysis as an adaptation to hypoxic environment. Although the exact mechanisms underlying
the Warburg effect are unclear, the importance of increased glycolysis in cancer cells has been
experimentally demonstrated.
Methods
In the here presented project, we aim for the development of an integrated systems biology
approach to investigate the underlying mechanisms of the Warburg effect. At the core of our
project, we established simple, fast and reproducible liquid chromatography mass spectrometry
(LC-MS/MS) based analytical platforms for detection and quantification of glycolytic intermediates
as well as purine and pyrimidine metabolites. In addition a gas chromatography mass
spectrometry (GC-MS) platform for detection and quantification of amino acids was established.
Results
Glycolytic intermediates were separated on a C18 column by ion-pairing LC, whilst purine and
pyrimidine metabolites were separated on a Luna NH2 column operated in the HILIC mode.
Selective reaction monitoring on a triplequadrupole instrument was applied for detection. Amino
acids were separated using GC after derivatization using a Zebron ZB-AAA column and detected
by MS in selective ion monitoring mode.
Conclusions
The applicability of the new platform was demonstrated by analyzing intracellular metabolite levels
in yeast samples and extracellular metabolites of NIH 3T3 mammalian cell lines. All platforms will
be further applied to various biological matrices in the context of the Warburg effect.
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Biomedical Engineering
51. Chronic hypoxia-enforced inhibition of vascularization;
Involvement of HIF1α and HIF2α
Tessa Nauta1,4, Ester Weijers1, Cees Oudejans2, Sue Gibbs3, Rik Scheper4, Victor van Hinsbergh1,
Pieter Koolwijk1
Department of Physiology, Institute of Cardiovascular Research, VU University Medical Center,
Amsterdam
2
Department of Clinical Chemistry, VU University Medical Center, Amsterdam
3
Department of Dermatology, VU University Medical Center, Amsterdam
4
ASkin BV, Amsterdam
1
Introduction
Successful transplantation and tissue engineering requires adequate vascularization. Even though
short term hypoxia stimulates angiogenesis, in chronically hypoxic tissues, endothelial cells have
reduced angiogenic capacities. The Hypoxia Inducible Factors (HIF1α and HIF2α) regulate the
expression of many genes under hypoxic conditions. Therefore, this study aims to investigate the
role of HIF1α and HIF2α in chronic hypoxia-enforced inhibition of vascularization.
Methods
Human microvascular endothelial cells (hMVECs) were (pre)cultured at 20% or 1% oxygen for 14 days
and transfected with short interfering RNAs (si-control, si-HIF1α or si-HIF2α) and either (i) seeded on
top of 3D fibrin matrices and stimulated with VEGF and TNFα to induce sprouting or (ii) stimulated
with VEGF and TNFα to isolate total RNA after 24 hours that was analyzed by genome-wide RNAsequencing.
Results
hMVECs (pre)cultured at 20% oxygen formed sprouts in vitro, whereas - surprisingly - the cells
preconditioned at 1% oxygen did not. Cells transfected with si-HIF2α were able to overcome this
inhibition and formed sprouts at 1% oxygen, while the cells transfected with si-HIF1α or si-control
could not.
The RNA-seq data showed in three different hMVECs between 530 and 630 differentially regulated
genes under chronic hypoxia, between 695 and 705 differentially regulated genes in si-HIF1α
transfected hMVECs and between 705 and 745 differentially regulated genes in si-HIF2α transfected
hMVECs.
Conclusions
Clearly, no tube-like structures were formed under chronic hypoxia. However, transfection of chronic
hypoxic cells with si-HIF2α restored the sprouting. This indicates that counter-intuitively HIF2α
impairs endothelial tube formation in vitro. The genome-wide RNA-sequence analyses will provide
us with information about the involved genes and pathways downstream of HIF2α.
VU University Medical Center Science Exchange Day 2014
61
Biomedical Engineering
52. The Forces that Shape our Spine: Mechanics in
Somitogenesis
Ben Nelemans1, Manuel Schmitz1, Marjolein Blaauboer1, Theo Smit1
1
Department of Orthopedic Surgery, VU Medical Center
Introduction
The middle layer in vertebrate embryos rhythmically organizes its mesenchymal cells from head to
tail into epithelialized segments, called somites (Fig. 1). These cell blocks are the precursors for
our segmented skeleton. This robust clockwise epithelialization is accompanied by an oscillating
gene network, called the segmentation clock. We hypothesize that besides the genetic mechanism,
mechanics play an important role in this process and might even induce the periodic gene
expression. However, little is known about the forces that shape embryos.
Methods
Chick embryos are mechanically manipulated in vitro with micromanipulators. The embryos are
axially stretched during development to identify the role of embryo elongation during
segmentation. With immunohistology we analyze the interactions between the different embryonic
layers, the cells in them and the matrix components that surround them.
Results
Our preliminary results show that additional longitudinal tension can double the already formed
segments and potentially change the number of segments. The doubled segments have similar
morphology to normal somites.
Conclusions
The axis patterning in the vertebrate embryo seems sensitive to forces. Understanding the role of
forces in the spatiotemporal segmentation could hopefully provide us with valuable information
on processes where mesenchymal to epithelial transitions play a role, not only in body plan
development, but also wound healing and cancer metastasis.
Figure 1: Two day old chick embryo, starting segmentation, in vitro
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Biomedical Engineering
53. Quantification of air flows produced by medical equipment
disturbing the clean air in the field of surgery using large
field background subtraction imaging
Rudolf Verdaasdonk1, Niek van Asperen1, Albert vd Veen1, Keith Cover1, John Klaessens1,
Peter Vandertop2
1
2
Department of Physics and Medical Technology, VU University Medical Center
Department of Neurosurgery, VU University Medical Center
Introduction
Medical equipment is usually cooled by an internal air fans exiting the chassis on the side or the
rear. These air exhausts can induce a major disturbance of the laminar flow of clean air in the
operating room (OR) specially created above the field of surgery to prevent contaminations.
Methods
A special large field air flow visualization technique has been developed to study and quantify
the air flow around equipment used in the OR that might potentially disturb the laminar flow in
the operating field. By digital subtraction of the fine line pattern in the background of the field
of interest, optical distortions induced by small density gradients in flowing air can be visualized
with high contrast and sensitivity. Short bursts of air contrast were induced at the exhaust frame
of medical equipment and followed in time. Specially developed analysis software calculated speed
and direction of the air flow.
Results
Measurements revealed that the exhaust of cooling air of critical equipment like an operating
microscope and surgical navigation system were blowing air at high speed into the clean laminar
field. Also devices warming the patient with hot air can blow into the ‘clean’ field of surgery.
Conclusions
Large field background Schlieren digital subtraction imaging shows to be a sensitive and
quantitative technique to study air flows. The awareness of the disturbance of the clean laminar air
flow should lead to guidelines to improve the design and positioning of medical equipment in the
OR to reduce infections.
VU University Medical Center Science Exchange Day 2014
63
Biomedical Engineering
54. Parallel scanning laser ophthalmoscope (PSLO) for retinal
imaging
Kari V. Vienola1,2, Mathivanan Damodaran1,2, Boy Braaf1,2, Mattijs de Groot1,2, Koenraad Vermeer2,
Johannes F. de Boer1,2
1
2
LaserLaB, Department of Physics and Astronomy, VU University
Rotterdams Oogheelkundig Instituut
Introduction
High-speed imaging of the retina is crucial for obtaining high quality images in the presence
of eye motion. To improve the speed of traditional scanners, a high-speed ophthalmic device
is presented using a digital micro-mirror device (DMD) for confocal imaging with multiple
simultaneous spots.
Methods
An experimental ophthalmic imaging system was constructed based on an 850 nm LED and a
DMD containing 1024x768 micro-mirrors. Single mirror elements are sparsely turned ON to
create multiple spots over the whole field of view. The DMD is programmed to project series of
shifted point pattern configurations, effectively scanning the spots over the sample surface. The
backscattered light from the retina is tapped off via a beam-splitter and imaged onto a CMOS
camera. A confocal image is constructed by applying an image mask of virtual pinholes to each
recorded frame. A wide-field confocal image is then created by combining all frames in a single
image.
Results
In the figure a dollar note was imaged with
all mirrors ON (widefield) and with multiple
spots configuration (every 100th mirror ON). In
widefield mode light is detected from different
planes above and below the focal plane. When
using multiple spots and virtual pinholes,
only light from the focal plane is detected.
The image on the right shows clearly the
microstructure of the bank note.
Conclusions
It is possible to create confocal images with the PSLO system. In theory the DMD can achieve higher
frame rates than traditional scanner-based systems (> 2 kHz) by illuminating the sample with
multiple spots.
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Biomedical Engineering
55. AFM nanoindentation reveals mechanical properties of
extracellular vesicles from Red Blood Cells
Daan Vorselen1,2, Jack J.W.A. van Loon2,3, Wouter H. Roos1, Gijs J.L. Wuite1
Department of Physics and Astronomy and LaserLab Amsterdam,
VU University, Amsterdam
2
Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University
of Amsterdam and VU University, Amsterdam
3
Department of Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center,
Amsterdam
1
Introduction
Extracellular vesicles (EVs) are endogenous particles involved in cell to cell communication. EVs
transport proteins and RNA, appear to play a role in disease and are interesting as a potential
drug delivery system. From proteomic studies it is known that many extracellular vesicles (EVs)
contain cytoskeletal proteins. These proteins could give rise to unique structural and mechanical
properties of EVs, and thereby affect interaction with target cells.
Methods
RBC EVs were isolated from RBCs from donors by stimulating with Ca2+ ionophore and subsequent
differential centrifugation. We studied the mechanics of RBC EVs by performing nanoindentations
using AFM (atomic force microscopy).
Results
Liposomes with a similar lipid composition as RBC EVs show behavior which corresponds to an
elastic shell with an empty core. RBC EVs however behave more like an elastic shell with a filled
core, characterized by a Hertzian force response (~ 1 MPa). Furthermore, indentation of these
vesicles can show multiple types of breaks. They show large break events corresponding to ripping
of the membrane or a collapse of the interior and small reversible break events that correspond
to different structural states of the vesicle. We show that the interior of RBC EVs is dense (using
CryoEM) and contains spectrin, which may explain how the interior influences the mechanics.
Conclusions
These observations suggest a contribution of a structured interior of the vesicle to the mechanical
properties. Our results show that extracellular vesicles differ mechanically from liposomes and
inspire further experiments with artificial vesicles to investigate the role of the vesicle mechanics
in the interaction with the target cell.
VU University Medical Center Science Exchange Day 2014
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Clinical and Epidemiological surveys
56. A way out of depression in the visually impaired: results
from a path-analysis
RMA van Nispen1, H.P.A. van der Aa1, H.L .Vreeken1, D.L. Knol², C. Roeygens³, H.C. Comijs4,
GHMB van Rens1
Department of Ophthalmology, VU University Medical Center
² Department of Epidemiology and Biostatistics, VU University Medical Center
³ Rehabilitation centre ‘Blindenzorg Licht en Liefde’
4
Department of Psychiatry VUmc/GGZinGeest
1
Introduction
Depression is negatively associated with low vision rehabilitation (LVR) outcomes; insight into
associated factors is essential to treat depression. The objective was to investigate the prevalence,
severity and associated factors of depression in visually impaired older adults.
Method
In a cross-sectional study, LVR outpatients (50+) from Belgium and the Netherlands were invited to
participate in structured face-to-face interviews at home (N=384). Independent variables (sociodemographics, health indicators), mediating variables (coping, adaptation to vision loss (AVL),
activities of daily living (ADL), mobility, reading), and the outcome (CES-D depression screener and
CIDI diagnostic interview) were assessed. A path-analyses was performed (Mplus) to investigate
the associated factors of depression.
Results
Prevalence of depression was 28% (CES-D>=16); the half-year incidence of major depression was
6.1%. Gender, youth trauma and life-time depression were independently associated with
depressive symptoms as were the mediators coping, AVL and ADL. The association genderdepression was also mediated by coping, AVL and ADL.
Conclusions
The prevalence of depression among visually impaired elderly is high, comparable with
international studies, but remains unrecognised. Outpatient occupational therapy and social work
targeted at ADL, adaptation and coping problems may positively influence depression outcomes.
A promising outpatient stepped-care program under study may directly impact on depression.
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Clinical and Epidemiological surveys
57. Preoperative anemia alters the probability of packed red
blood cell transfusion in patients undergoing vascular
surgery
David Burtman1,2, Christine F. Vermeulen1, Jan D. Blankensteijn1, Christa Boer2
1
Vascular Surgery, Institute for Cardiovascular Research, VU University Medical Center
Anesthesiology, Institute for Cardiovascular Research, VU University Medical Center
2
Introduction
Perioperative packed red blood cell (PRBC) transfusion is independently associated with
postoperative morbidity and mortality. In this study, we investigated whether preoperative anemia
increases the probability of perioperative PRBC transfusion in patients undergoing elective
vascular surgery.
Methods
This retrospective study included 1630 patients who underwent elective vascular surgery between
2004 and 2013. Study parameters included perioperative hemoglobin levels, gender, duration of
surgery, and PRBC transfusions. Severe anemia was defined as a hemoglobin <6.2 mmol/L, and
mild anemia was defined as a hemoglobin ≥6.2 and <8 mmol/l (males) or ≥6.2 and <7.4 mmol/l
(females).
Results
The lowest preoperative hemoglobin levels for males and females were 7.9 ± 1.5 and 7.4 ± 1.4
mmol/L, respectively. The prevalence of mild and severe preoperative anemia was 29.8% and 6.3%
in the total study population. Multinomial regression to reveal predictors for PRBC transfusion
included the level of preoperative anemia, duration of surgery and gender. Multinomial regression
analysis for PRBC transfusion showed that a short duration of surgery (< 3 hours) reduced the
probability of transfusion with an odds ratio of 0.06 (95% CI 0.04-0.09; P<0.001), while severe and
mild anemia increased the probability of PRBC administration by 10.1 (6.2-16.5; P<0.001) and 2.6
(1.9-3.5; P<0.001). Gender was not of influence on PRBC transfusion.
Conclusions
Preoperative anemia is a common problem in patients undergoing vascular surgery and increases
the probability for perioperative blood transfusion. Therefore, it may be useful to normalize
hemoglobin levels preoperatively in order to reduce postoperative morbidity and mortality.
VU University Medical Center Science Exchange Day 2014
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Clinical and Epidemiological surveys
58. The role of perceived barriers in explaining socioeconomic
differences in adherence to the fruit, vegetables and fish
guidelines in older Dutch adults
S.C. Dijkstra1, J.E. Neter1, M.M. van Stralen1, I.A. Brouwer1, M. Huisman2,3,4, M. Visser1, 2
¹ Department of Health Sciences and the EMGO Institute for Health and Care Research,
Faculty of Earth and Life Sciences, VU University Amsterdam
2 Department of Epidemiology and Biostatistics and the EMGO Institute for Health and
Care Research, VU University Medical Center, Amsterdam
3
Department of Sociology, VU University Amsterdam
4
Department of Psychiatry, VU University Medical Center, Amsterdam
Introduction
People with low socioeconomic status (SES) have less healthy diets. In order to reduce differences
in diet between SES groups information is needed about why low SES groups eat less healthy.
In this study we identified barriers for meeting the fruit, vegetable and fish guidelines and
investigated SES differences in older adults. Additionally, we examined to what extent these
barriers explained why lower SES groups adhere to the dietary guidelines less often.
Methods
Analyses were performed in 1,057 older adults, aged 55-85 years, participating in the Longitudinal
Aging Study Amsterdam. Indicators of SES were level of income and education. Respondents
were asked to indicate the two most important barriers they experienced for meeting the fruit,
vegetable and the fish guideline. We used a short food frequency questionnaire to assess fruit,
vegetable and fish intake.
Results
Lower SES groups were more likely to perceive barriers to meet the guidelines, in particular that
fruit, vegetables and fish were expensive. The association between income and adherence to
the fruit guideline was mediated by “perceiving any barrier to meet the fruit guideline”. The
association between income and adherence to the fish guideline was mediated by “perceiving any
barrier to meet the fish guideline” and the barrier “fish is expensive”.
Conclusions
Perceived barriers for meeting the dietary guidelines are common in older adults, especially in
lower SES groups. These barriers and particularly cost concerns partly explained the lower
adherence to the guidelines for fruit and fish in lower income groups in older adults.
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Clinical and Epidemiological surveys
59. Longitudinal data analysis with auxiliary item information
to handle missing questionnaire data
Iris Eekhout1, Craig Enders2, Jos W.R. Twisk3, Michiel R. de Boer4, Henrica C.W. de Vet5,
Martijn W. Heymans6
Department Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
Department of Psychology, Arizona State University, United States
3
Department Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
4
Department Methodology and Applied Biostatistics, Faculty of Earth and Life Sciences, Institute
for Health and care Research, Amsterdam
5
Department Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
6
Department Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
1
2
Introduction
Previous studies show that missing values in multi-item questionnaires can best be handled at the
item score level. The aim of this study is to investigate a novel method for dealing with incomplete
item scores in longitudinal questionnaire data. This novel method incorporates item information at
the background when simultaneously the study results are estimated.
Methods
The investigated method includes the item scores or some summary of a parcel of item scores as
helping variables, while using the total score of the multi-item questionnaire as the main focus
of the analysis. That way the item scores help estimating the incomplete information of the total
scores. The performance of these methods was examined in several simulated longitudinal data
conditions and analyzed through bias in regression coefficient estimates and related standard
errors. Furthermore, the methods are demonstrated in a clinical patient dataset.
Results
Results show that including the item information results in more precise estimates of study results
in terms of regression coefficient estimates and standard errors, compared to not including the
item information in the analysis.
Conclusions
The inclusion of a parcel summary is an efficient method that does not over-complicate model
estimations and is therefore recommended in situations when questionnaire scale scores are
incomplete due to missing item scores in clinical studies.
VU University Medical Center Science Exchange Day 2014
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Clinical and Epidemiological surveys
60. Body-image in gender dysphoria; concepts of selfperception & physical appearance revisited for different
subtypes
T.C. van de Grift, MD, MSc1,2, P.T. Cohen-Kettenis, PhD1,3, T.D. Steensma, PhD1, R.E. Dikmans, MD2,
G. De Cuypere, MD, PhD3, H. Richter-Appelt, PhD3, I.R. Haraldsen, MD, PhD3 &
B.P.C. Kreukels, PhD1,3
Department of Medical Psychology, VU University Medical Center, Amsterdam
Department of Plastic, Reconstructive & Hand Surgery, VU University Medical Center, Amsterdam;
3
European Network for the Investigation of Gender Incongruence (ENIGI; Amsterdam, Ghent,
Hamburg & Oslo)
1
2
Introduction
Body-image (BI) and physical appearance (PhA) are key influencers of gender dysphoria (GD). This
study aims to use the two concepts to provide a framework in understanding GD and its specifiers
(biological sex, sexual preference and onset age (OA)).
Methods
Data collection was part of the European Initiative for the Investigation of Gender Incongruence.
Between 2007 and 2012, 660 individuals with GD (1.31:1 male-female ratio) were included in the
study. Sexual preference and OA were obtained during psychological diagnostics. Body satisfaction
was measured through the Body Image Scale, and physical compatibility with the desired gender
was measured using the clinician-reported PhA scale.
Results
The majority of male-to-females (MtFs) reported ‘non-homosexual’ sexual orientation. Most
female-to-males (FtMs) reported ‘homosexual’ sexual orientation and had early onset (EO) GD.
FtMs have an appearance which is more compatible with the experienced gender and a more
positive BI than MtFs. Besides genital dissatisfaction, problem areas for MtFs include body
movement, head & neck, and hair, whereas FtMs are mainly dissatisfied with hip and chest
regions. Within the MtFs, those with EO GD and a homosexual sexual orientation have more
compatible appearances with regard to their gender identity.
Conclusions
FtMs, and EO & homosexual MtFs have more favorable PhA and BI, although both groups have
their areas of concern. Body-image problems in GD go further than solely genital dysphoria and
therefore deserve attention in psychological support.
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Clinical and Epidemiological surveys
61. New insights into the spectrum of genotypes and
phenotypes in Hypomyelination with Atrophy of the Basal
Ganglia and Cerebellum (H-ABC)
Eline M.C. Hamilton, Emiel Polder, Carola G.M. van Berkel, Truus E.M. Abbink, Nicole I. Wolf,
Marjo S. van der Knaap
Department of Child Neurology, VU University Medical Center and Neuroscience Campus
Amsterdam, Amsterdam
Introduction
Hypomyelination with Atrophy of the Basal Ganglia and Cerebellum (H-ABC) is a rare leukodystrophy
that was identified by MRI pattern analysis. Exome sequencing in 11 H-ABC patients recently
revealed the same de novo mutation in the TUBB4A gene, which encodes β-tubulin. A mutation in
this gene is also associated with adult onset dystonia type 4, in which the brain MRI is normal. We
here describe the mutation spectrum, phenotype and MRI characteristics in a cohort of 42 H-ABC
patients.
Methods
We initiated a cross-sectional observational study in our database of H-ABC patients, which involved
DNA analysis, evaluation of sequential MRIs and clinical inventory.
Results
The TUBB4A mutation observed in the first 11 H-ABC patients was by far the most common.
Additionally, 13 other mutations were identified, located at different structural domains within
β-tubulin. The clinical features were rather homogeneous, but the severity ranged from patients
with a normal early development followed by slow neurological deterioration, to patients who
acquired no intentional movements. MRI showed lack of myelin, disappearance of the putamen,
variable cerebellar atrophy and highly variable cerebral atrophy. We also found pathogenic
TUBB4A mutations in some patients with less typical MRI abnormalities. Patients with the common
mutation had the mildest disease.
Conclusions
The work here demonstrates that the distinctive H-ABC MRI pattern defines a largely homogeneous
clinical phenotype of variable severity. The results are strongly suggestive of a genotypephenotype correlation. It is likely that there is a disease continuum associated with TUBB4A
mutations, in which extrapyramidal movement abnormalities constitute the core feature.
VU University Medical Center Science Exchange Day 2014
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Clinical and Epidemiological surveys
62. Functional Gene-Set Analysis of Attention Deficit/
Hyperactivity Disorder (ADHD)
Anke R. Hammerschlag1,2, Christiaan de Leeuw1,3, Andrea Goudriaan4, Tinca J.C. Polderman1,
Matthijs Verhage5,6, August B. Smit4, Henning W. Tiemeier7,8, Mark H.G. Verheijen4,
Danielle Posthuma1,6,7
Complex Trait Genetics, Department of Functional Genomics, Neuroscience Campus Amsterdam,
VU University Amsterdam
2
The Generation R Study Group, Erasmus MC Rotterdam
3
Institute for Computing and Information Sciences, Radboud University
4
Department of Molecular and Cellular Neurobiology, Neuroscience Campus Amsterdam,
VU University Amsterdam
5
Department of Functional Genomics, Neuroscience Campus Amsterdam, VU University Amsterdam
6
Department of Clinical Genetics, VU University Medical Center
7
Department of Child and Adolescent Psychiatry, Erasmus MC Rotterdam
8
Department of Epidemiology, Erasmus MC Rotterdam
1
Introduction
Attention Deficit/Hyperactivity Disorder (ADHD) is a neurobehavioral developmental disorder
affecting about 3-7% of children worldwide. Despite the high heritability of ADHD (~75%),
genome-wide association studies (GWAS) failed to find significant genetic associations. The aim
of our study is to detect functional gene sets that might be important to the risk of ADHD. Using
gene-set analysis, the combined effect of genetic variants is tested, resulting in more statistical
power. Moreover, testing genes with similar cellular function provides immediate functional
meaning which may lead to more biological insight into the etiology of ADHD.
Methods
2,787 ADHD cases and 2,635 controls were included in the analysis. Synaptic, glial and lipid
gene sets have been manually curated by experts of the Center for Neurogenomics and Cognitive
Research (CNCR), and were based on cellular function. Gene-set analysis was conducted with JAG
software (http://ctglab.nl/software/jag), including self-contained tests and competitive tests.
Results
Four lipid gene sets showed significant associations with ADHD. However, the four groups included
the UGT1A gene family, consisting of nine genes physically overlapping in the genome. After
correction for this gene family, the associations of the lipid groups were no longer significant.
Conclusions
No statistically significant associations between gene sets and ADHD were revealed. Future plan
is to increase statistical power by conducting functional gene-set analysis in a larger sample of
12,600 ADHD cases and 83,600 controls.
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Clinical and Epidemiological surveys
63. Mental rotation in women with Complete Androgen
Insensitivity Syndrome: an fMRI study
J. van Hemmen1,2, D.J. Veltman3, A. Dessens4, P.T. Cohen-Kettenis2, J. Bakker1,5
Neuroendocrinology Group, The Netherlands Institute for Neuroscience, Amsterdam
Department of Medical Psychology, VU University Medical Center, Amsterdam
3
Department of Psychiatry, VU University Medical Center, Amsterdam
4
ErasmusMC-Sophia, Dept. of Pediatrics, Div. of Pediatric Endocrinology, Rotterdam
5
Interdisciplinary Applied Genoproteomic Group - Neurosciences, University of Luik, Luik, Belgium
1
2
Introduction
The exact mechanisms involved in the sexual differentiation of the human brain are still being
debated. The mental rotation (MR) task is a visuospatial task, eliciting sex differences in
performance as well as in neural activation patterns. We compared individuals with Complete
Androgen Insensitivity Syndrome (CAIS), who have XY chromosomes, but a female phenotype due
to non-functional androgen receptors, to control men and women in order to investigate the role
of sex hormones and sex chromosomes on the sexually differentiated neural activation patterns
during MR.
Methods
In this study, 20 women with CAIS, 29 control men and 30 control women performed a 3D MR
task during fMRI acquisitions. Between-group comparisons were performed regarding the neural
activation patterns during MR in four MR related regions of interest.
Results
Between-group comparisons showed that men had higher levels of neural activation than women
with CAIS and control women in the left inferior parietal cortex, and than women with CAIS in the
left superior parietal cortex.
Conclusions
Women with CAIS showed a female-typical neural activation pattern during MR. These results
indicate that the sexual differentiation of visuospatial neural activation patterns is not influenced
by sex chromosomal composition, but is more likely to be prone to androgenic factors. Future
studies using this unique model are likely to provide further understanding of the influence of sex
hormones and sex chromosomes on other sexually-differentiated cognitive functions and neural
properties.
VU University Medical Center Science Exchange Day 2014
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Clinical and Epidemiological surveys
64. Latent class growth (mixture) models: How do we handle
predictors of class membership?
Trynke Hoekstra1,2, Jos Twisk1,2
1
VU University Medical Center, Department of Epidemiology and Biostatistics
VU University, Department of Health Sciences and the EMGO Institute for Health and
Care Research
2
Introduction
Common longitudinal models such as multilevel models or Generalised Estimating Equations
can only to some extent handle individual variability in development; they do not allow for the
revelation of subgroups of individuals with distinct developmental trajectories. To identify such
trajectories, a range of techniques are available, of which latent class growth (mixture) models
(LCGM) are probably the most flexible. The aim of LCGM is to (statistically) identify the number
and characteristics of distinct subgroups (classes). This poster will focus on methodological
challenges concerning particularly the incorporation of predictors of these classes.
Methods
We will explain a commonly used one-step approach, a relatively conservative two-step approach
and a novel three-step approach currently available using data of the Amsterdam Growth and
Health Study (www.aggo.nl). In the conservative two-step approach, individuals are first assigned
to their most-likely class, providing a categorical variable denoting class membership. This
variable can then be analyzed in a subsequent step using common regression techniques or
ANOVA. This approach ignores possible uncertainty in class assignment, which is overcome by
the one-step approach, where predictors are already included while forming the classes. However,
these variables then influence the class formation process, hereby clouding the interpretation of
them. This issue is overcome by the new three-step approach.
Results
Detailed results will be provided; the three approaches provided fairly similar results.
Conclusions
Slight differences between the three approaches were observed. Because of the lack of
methodological studies available on this topic, researchers are advised to carefully choose which
approach to take.
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Clinical and Epidemiological surveys
65. Psychological posttraumatic growth in head and neck
cancer survivors
C. J. M. Holtmaat1, C. F. van Uden-Kraan1,2, N. van der Spek1, C. R. Leemans2,
I. M. Verdonck-de Leeuw1,2
1
2
Department of Clinical Psychology, VU University
Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center
Introduction
While the adverse effects of head and neck cancer (HNC) on quality of life are well demonstrated,
information on psychological posttraumatic growth (PTG) of HNC survivors is scarce. The aim
of this study is to investigate PTG among HNC survivors and the association with demographic
factors, psychological distress and quality of life.
Methods
A cohort of 113 HNC survivors who received treatment with curative intent at the VU University
Medical Center were asked to complete the Posttraumatic Growth Inventory (PTGI), the Hospital
Anxiety and Depression Scale (HADS), the EORTC Quality of Life Questionnaire (EORTC QLQ-C30)
and questions on demographics. To assess gender and educational level differences in PTG an
independent samples t-test and an ANOVA were used. Pearson correlations were used to
investigate the association of age, depression, anxiety and quality of life with PTG.
Results
In total 87 HNC survivors (35.6% female, mean age 57.7) returned the questionnaires (response
rate 77.0%). Fifty-five percent (55.1%) reported no or small and 44.9% reported moderate to high
levels of PTG. The level of PTG did not differ between males and females or between people
with different educational levels. There were no significant correlations between PTG and age,
depression, anxiety and quality of life.
Conclusion
Almost half of the HNC survivors reported PTG, which was not associated with demographics,
distress or quality of life. Further research on other factors that may influence PTG in HNC
survivors, such as personality and coping style, is warranted.
VU University Medical Center Science Exchange Day 2014
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Clinical and Epidemiological surveys
66. Efficacy and safety of intrauterine insemination in patients
with moderate to severe endometrisis
Lisette van der Houwen1, Anneke Schreurs1, Roel Schats1, Cornelis Lambalk1, Peter Hompes1,
Velja Mijatovic1
1
Endometriosis Center, Division of Reproductive Medicine, Department of Obstetrics and
Gynaecology, VU University Medical Center
Introduction
This study was performed to evaluate the efficacy and safety of two different IUI treatment
strategies and the additional effect of long term pituitary down-regulation in moderate to severe
endometriosis.
Methods
A retrospective analysis was established including all patients with moderate to severe endometriosis,
who started IUI between January 2007 and July 2012. A maximum of six cycles were included. Two
treatment strategies were compared; IUI with controlled ovarian hyperstimulation (COH) (n=20,
61 cycles, IUI+COH) versus IUI without COH in the first three cycles followed by IUI with COH
(n=45, 184 cycles, IUI+natural/COH). The additional effect of preceding long term pituitary downregulation was investigated.
Results
Eight (40.0%) and 7 (15.6%) ongoing pregnancies were accomplished in patients undergoing
IUI+COH and IUI+natural/COH, respectively (p=0.05). Cox regression showed a HR of 3.2
(95%CI1.1-8.5, p=0.02), reflecting a significantly higher chance on ongoing pregnancy in patients
receiving IUI+COH. Preceding long term pituitary down-regulation tended to result in a higher
ongoing pregnancy rate (adjusted HR 1.8, 95%CI0.6-5.1, p=0.26). Eight (40.0%) versus 16 (35.6%)
recurrences of endometriosis were reported in patients undergoing IUI+COH versus IUI+natural/
COH, respectively (p=0.73). Preceding long term pituitary down-regulation tended to result in a
higher chance on endometriosis recurrence (adjusted HR 2.3, 95%CI0.98-5.3, p=0.06).
Conclusions
IUI with COH could be a valuable treatment in moderate to severe endometriosis. Preceding long
term pituitary down-regulation might positively influence the ongoing pregnancy rate and can
be considered. Whether this treatment strategy can be structurally offered prior to IVF must be
investigated in a randomized controlled trial.
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Clinical and Epidemiological surveys
67. The dopaminergic reward system and leisure time exercise
behavior: A candidate allele study
Charlotte Huppertz1,2, Meike Bartels1,2,3, Maria M. Groen-Blokhuis1, Conor V. Dolan1, Marleen H.M.
de Moor1, Abdel Abdellaoui1,3, Catharina E.M. van Beijsterveldt 1, Erik A. Ehli4, Jouke-Jan Hottenga1,
Gonneke Willemsen1,2, Xiangjun Xiao5, Paul Scheet6, Gareth E. Davies4, Dorret I. Boomsma1,2,3,
James J. Hudziak7, Eco J.C. de Geus1,2,3
Department of Biological Psychology, VU University Amsterdam, The Netherlands
EMGO+ Institute for Health and Care Research, VU University Medical Center
3
Neuroscience Campus Amsterdam, VU University Medical Center
4
Avera Institute for Human Genetics, Avera McKennan Hospital and University Health Center,
South Dakota, USA
5
Department of Community and Family Medicine, Geisel School of Medicine, Dartmouth College,
New Hampshire, USA
6
Department of Epidemiology, University of Texas M.D., Anderson Cancer Center,
Department of Epidemiology, Texas, USA
7
Department of Psychiatry, Medicine, and Pediatrics, Vermont Center for Children,
Youth and Families, College of Medicine, University of Vermont, Vermont, USA
1
2
Introduction
Twin studies provide evidence that genetic influences contribute strongly to individual differences
in exercise behavior. We hypothesize that part of this heritability is explained by genetic variation
in the dopaminergic reward system. Eight single nucleotide polymorphisms (SNPs: rs265981,
rs6275, rs1800497, rs6280, rs1800955, rs1611115, rs2519152, rs4680) and three variable number
of tandem repeats (VNTRs in DRD4, upstream of DRD5, and in DAT1) were investigated for a
potential association with regular leisure time exercise behavior.
Methods
Data on exercise activities and at least one SNP/VNTR were available for 8,768 individuals aged 7
to 50 years old that were part of the Nederlands Twin Register. Exercise behavior was quantified as
weekly metabolic equivalents of task (MET) spent on exercise activities. Mixed models were fitted
in SPSS with latent genetic factors as random effects.
Results
None of the SNPs/VNTRs were associated with exercise behavior (p> .02), despite sufficient power
to detect even small effects.
Conclusions
We did not confirm that allelic variants involved in dopaminergic function play a role in creating
individual differences in exercise behavior. Possible reasons for this will be discussed, including
the fact that exercise behavior is a complex phenotype that is difficult to define and measure,
and that it is probably influenced by many genetic variants with very small effects. A plea is made
for large genome-wide association studies to unravel the genetic pathways that affect exercise
behavior in order to help personalize the strategies to increase this health-enhancing activity.
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68. Prevalence and comorbidity of pain symptoms in the
general population
L. Ligthart1,2, C.M. Visscher3, C.M.H.H. van Houtem4, A. de Jongh4,5 & D.I. Boomsma1,2
Department of Biological Psychology, VU University Amsterdam
EMGO+ Institute for Health and Care Research
3
Department of Oral Kinesiology, Academic Centre for Dentistry Amsterdam, University of
Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam
4
Department of Social Dentistry and Behavioural Sciences, Academic Centre for Dentistry
Amsterdam, University of Amsterdam and VU University, Amsterdam, The Netherlands
5
School of Health Sciences, Salford University, Manchester, United Kingdom
1
2
Introduction
The prevalence of individual pain disorders has often been studied, but few studies investigate
many different pain types at once. We aimed to investigate how different pain types relate to each
other and to comorbid traits, especially anxiety and depression, in the general population.
Methods
We analyzed data from a large population-based cohort of Dutch twin families (11.530 subjects).
Pain was assessed in eight body sites: back, neck, head, abdomen, joints, chest, teeth and face.
The Graded Chronic Pain Scale (von Korff, 1993) was used to assess the pain intensity and
disability. Anxious depression was measured with a subscale of the Adult Self Report (Achenbach,
1997).
Results
All pain types except chest pain and toothache were more common in women than in men. Women
were also more likely to report chronic pain. The prevalence of most pain types was relatively
similar across age, except for headache and abdominal pain, which decreased, and joint pain,
which strongly increased with age (with 4% and 17% chronic joint pain in the youngest and oldest
age groups, respectively). Strong and consistent comorbidity was observed: having any type of
pain was associated with an increased risk of any other type of pain (correlations between 0.1 and
0.7), as well as anxious depression.
Conclusions
Chronic pain is very common in the adult Dutch population (21%). We observed strong comorbidity
of different pain symptoms and anxious depression. Given the severe disability caused by these
conditions, research into the causes of this comorbidity is warranted.
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69. Cortical Thickness and Inattention/Hyperactivity
Symptoms in Young Children- The Generation R Study
Sabine E. Mous1,2, Ryan L. Muetzel1,2, Hanan El Marroun1,2, Tinca J.C. Polderman3, Aad van der
Lugt4, Vincent W. Jaddoe1,5, Albert Hofman5, Frank C. Verhulst2, Henning Tiemeier2,5, Danielle
Posthuma2,6,7, Tonya White2,4
The Generation R Study Group, Erasmus MC
Dep of Child and Adolescent Psychiatry/Psychology, Erasmus MC–Sophia
3
Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam
(NCA), VU University
4
Department of Radiology, Erasmus MC
5
Department of Epidemiology, Erasmus MC
6
Center for Neurogenomics and Cognitive Research, VU University
7
Department of Clinical Genetics, section Medical Genomics, VU MC
1
2
Introduction
While many neuroimaging studies have investigated the neurobiological basis of Attention-Deficit/
Hyperactivity Disorder (ADHD), few have studied the neurobiology of attention problems in the
general population. However, the ability to pay attention falls along a continuum within the
population, with children with ADHD at one extreme of the spectrum. Therefore, a dimensional
perspective of evaluating attention problems has an added value to the existing literature.
Methods
This study is embedded within the Generation R Study and includes 444 six-to-eight year-old
children with parent-reported attention and hyperactivity measures and high-resolution structural
brain imaging data. We investigated the relationship between cortical thickness across the entire
brain and Child Behavior Checklist (CBCL) attention scores.
Results
We found that greater attention problems were associated with a thinner right and left postcentral
gyrus. When correcting for potential confounding factors and multiple testing, these associations
remained significant.
Conclusions
In a large, population-based sample we showed that young children who show more attention
problems and hyperactivity have a thinner cortex in the region of the right and left postcentral
gyrus. The postcentral gyrus, being the primary somatosensory cortex, reaches its peak growth
early in development. Therefore, the thinner cortex in this region may reflect either a deviation
in cortical maturation or a failure to reach the same peak cortical thickness compared to children
without attention or hyperactivity problems.
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70. Dietary intake of Dutch food bank recipients
Judith E. Neter1, S. Coosje Dijkstra1, Marjolein Visser1,2, Ingeborg A. Brouwer1
Department of Health Sciences and the EMGO Institute for Health and Care Research,
Faculty of Earth and Life Sciences, VU University Amsterdam
2
Department of Epidemiology and Biostatistics, VU University Medical Center
1 Introduction
Recipients of the food bank are a very specific group of people with low socioeconomic status,
who are limited in their food choices due to their dependency on food parcels. A healthy diet can
contribute to the prevention of nutrition-related chronic diseases. Therefore, this study aims to
determine the dietary intake of Dutch food bank recipients.
Methods
In this cross-sectional study (Food Bank study) we obtained information on socio-demographic
characteristics by means of a general questionnaire and food intake by means of three 24-hour
recalls per participant. Data were collected of 177 food bank recipients from 13 different food
banks throughout the Netherlands. Habitual nutrient, fruit and vegetable intake were analyzed
with SPADE.
Results
Preliminary analyses of 167 participants showed that the habitual energy intake (1947.1 kcal) is
lower compared with the dietary recommendations. The habitual intakes of carbohydrate (47.3
en%), total fat (36.1 en%) polyunsaturated fatty acids (6.7 en%) and trans fatty acids (0.6 en%) were
according the dietary recommendations, while the habitual protein (15.2 en%) and saturated fat
(13.3 en%) were higher than recommended. Furthermore, the habitual fiber (16 g), fruit (78.5 g)
and vegetable (128.9 g) intakes were lower than recommended.
Conclusions
Many food bank recipients do not meet the dietary guidelines for a healthy diet. Only 5% and 15%
of the participants met the dietary recommendation for fruit and vegetables, respectively.
Interventions are needed to decrease protein and saturated fat intake and increase the fiber, fruit
and vegetable intake of Dutch food bank recipients.
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Clinical and Epidemiological surveys
71. Palliative care case management in primary care:
A descriptive study about the flexibility, duration and
content of care
Annicka van der Plas1,2, Anneke Francke1,2,3, Wim Jansen2,4, Kris Vissers5, Luc Deliens1,2,6,
Bregje Onwuteaka-Philipsen1,2
VU University Medical Center, Department of Public and Occupational Health, EMGO+ Institute for
Health and Care Research, Amsterdam
2
Center of Expertise in Palliative Care VU University medical center
3
Nivel Netherlands Institute for Health Services Research, Utrecht
4
VU University Medical Center, Department of Anaesthesiology, Amsterdam.
5
Radboud University Nijmegen Medical Center, Department of Anaesthesiology, Pain, and Palliative
Medicine, Nijmegen, the Netherlands.
6
Ghent University and Vrije Universiteit Brussel, End-of-Life Care Research Group, Brussels, Belgium
1
Introduction
In case management an individual or small team is responsible for navigating the patient through
complex care. In palliative care case management flexibility of care, duration of care for as long
as needed, and attention to physical, psychological, social, and spiritual wellbeing are considered
central points. The objective of this study is to describe the number, duration and content of
contacts the case manager has with patients and/or informal carers, and the time span between
first and last contact.
Methods
Case managers of 12 palliative care case management initiatives completed a questionnaire for
every contact they had with a patient and/or informal carer.
Results
For 738 included patients, there were 4278 recorded contacts between the case manager and the
patient and/or informal carer. The median number of contacts was 4, with a range from 1 to 36
contacts per patient. Home visits were done between zero to 22 times per patient, and lasted
48 minutes (median). Contacts by telephone occurred zero to 19 times per patient and lasted 30
minutes (median). The time between the first and last contact ranged from zero days up to two
years. Topics most discussed during contacts were physical complaints, psychological issues, life
expectancy and incurability of illness. Information on care services and illness was mostly given.
Conclusions
Case management in primary care is delivered flexible with regard to the number and duration
of contacts. Time between the first and last contact was also variable. Content of care covered all
domains of palliative care.
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72. Determinants of Undernutrition in Older Adults receiving
Home Care
Rachel van der Pols-Vijlbrief1, Hanneke Wijnhoven1, Marjolein Visser1,2
Department of Health Sciences, EMGO+ Institute for Health and Care Research,
VU University, Amsterdam
2
Department of Epidemiology and Biostatistics, EMGO+ Institute for Health and Care Research,
VU University Medical Center, Amsterdam
1
Introduction
Undernutrition is highly prevalent among older persons receiving home care, difficult to treat, and
associated with negative health outcomes. The purpose of this study was to identify the most
important, determinants of undernutrition in this vulnerable group.
Methods
In total, 308 older men and women living at home were screened by home care nurses for
undernutrition with the SNAQ65+ screening tool and completed the developed questionnaire.
Information on demographics, physical activity, nutritional intake, appetite, functional, cognitive
and health status, depression, social network, oral health, sight and hearing difficulties and
pain was asked. Multivariate backwards logistic regression analyses were used to identify the
determinants of undernutrition.
Results
Of the participants, 39.3% was undernourished or ‘at risk’ and 60.7% was well nourished. Mean
age was 81.6 years (SD: 7.7). The results suggest that being married (OR:0.393), a good appetite
(OR:0.652), not needing help with grocery shopping (OR:0.463), and eating more snacks
(OR:0.676) significantly lowers the risk for undernutrition. Furthermore, ADL independency
(OR:1.130), not physically active (OR:1.860), higher number of falls (OR:2.874), intestinal problems
(OR:2.397), and hospitalization (OR:1.288) significantly increased this risk.
Conclusions
Under nutrition is a multi-factorial problem with various determinants in different domains.
A multidimensional prevention strategy should target the modifiable determinants; poor physical
activity and appetite, support needed with groceries, low intake snacks, ADL and intestinal
problems.
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Clinical and Epidemiological surveys
73. Measurement properties of questionnaires assessing
participation in children and adolescents with a disability:
a systematic review
JFM Rainey1, R.M.A .van Nispen1, C.H. van der Zee2, G.H.M.B. van Rens1
1
2
Department of Ophthalmology, VU University Medical Center
Department of Epidemiology and Biostatistics, VU University Medical Center
Introduction
The aim of the present study is to critically appraise the measurement properties of questionnaires
measuring participation in minors with a disability.
Method
Bibliographic databases were searched for studies evaluating the measurement properties of
self-report or parent-report questionnaires measuring participation in children and adolescents
(0-18 years) with a disability. The methodological quality of the included studies and the results
of the measurement properties were evaluated using a checklist developed on consensus-based
standards.
Results
The search strategy identified 3977 unique publications, of which 22 were selected; these articles
evaluated the development and measurement properties of 8 different questionnaires. The Child
and Adolescent Scale of Participation was evaluated most extensively, generally showing moderate
positive results on content validity, internal consistency, reliability and construct validity.
The remaining questionnaires also demonstrated positive results. However, at least 50% of the
measurement properties per questionnaire were not (or only poorly) assessed.
Conclusions
Studies of high methodological quality, using modern statistical methods are needed to accurately
assess the measurement properties of currently available questionnaires. Moreover, consensus
is required on the definition of the construct ‘participation’ to determine content validity and to
enable meaningful interpretation of outcomes.
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Clinical and Epidemiological surveys
74. Anxiety in Parkinson’s disease: mind = body?
S. Rutten1-3, I. Ghielen1, C. Vriend1,2,4, H.W. Berendse4,5, J.H. Smit1,3, Y.D. van der Werf2,4,6,
O.A. van den Heuvel1,2,4
Department of Psychiatry, VU University Medical Center (VUmc), Amsterdam
Department of Anatomy & Neurosciences, VUmc, Amsterdam
3
EMGO Institute for Health and Care Research, VUmc, Amsterdam
4
Neuroscience Campus Amsterdam, VUmc, Amsterdam
5
Department of Neurology, VUmc, Amsterdam
6
Netherlands Institute for Neuroscience, Amsterdam
1
2
Introduction
Although Parkinson’s disease (PD) is best known for its characteristic motor symptoms, the nonmotor symptoms, that occur in almost all PD patients, are believed to have an even greater impact
on daily functioning and quality of life. This is especially true for anxiety, which is prevalent
in almost half of PD patients. Anxiety is, however, often not recognised in clinical practice,
and scientific literature on this subject is limited. The goal of this study was to reach a better
understanding of anxiety in PD.
Methods
For this cross-sectional study, 294 patients with idiopathic PD were included. Symptoms of anxiety
were measured with the Beck Anxiety Inventory (BAI). We dissected the BAI with principal
component analysis. The interconnection of symptoms of anxiety with depression, autonomic and
motor dysfunction was assessed through factor analysis and multiple regression analyses.
Results
Clinically relevant anxiety was present in 45% of patients. Factor analysis of the BAI resulted in one
affective and four somatic subscales. Multiple regression analyses demonstrated that depressive
symptoms contributed significantly to the outcome of all subscales of the BAI. The somatic
subscales were partially explained by symptoms of motor dysfunction and autonomic failure. The
score on the affective subscale was not influenced by these motor and autonomic symptoms.
Conclusions
Anxiety affects a large proportion of PD patients and comprises one affective and four somatic
dimensions. There is overlap between symptoms of anxiety, autonomic failure and depression
in patients with PD. The strong interplay between motor and non-motor symptoms in PD militate
a holistic approach of PD in clinical practice. The affective subscale of the BAI is not influenced
by the severity of motor or autonomic symptoms. This subscale might therefore be a more pure
measure of anxiety in PD patients and prove useful for future research.
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Clinical and Epidemiological surveys
75. The association between psychosocial stress and
mortality is mediated by lifestyle and chronic diseases:
the Hoorn Study
Femke Rutters, PhD1,2, Stefan Pilz, PhD1,2,3, Anitra Koopman, Msc1,2, Simone P. Rauh, sc1,2,
Saskia J. Te Velde, PhD1,2, Coen D. Stehouwer, MD, PhD4, Petra Elders, MD, PhD2,5,
Giel Nijpels, MD, PhD2,5, Jacqueline M. Dekker, MD, PhD1,2
Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
EMGO+ Institute for health and care research, VU University Medical Center, Amsterdam
3
Department of Internal Medicine, Division of Endocrinology and Metabolism,
Medical University of Graz, Graz, Austria
4
Department of Internal Medicine and Cardiovascular Research Institute (CARIM),
Maastricht University Medical Centre, Maastricht
5
Department of General Practice, VU University Medical Center, Amsterdam
1
2
Introduction
Psychosocial stress is associated with chronic disease. Experiencing stressful life events may lead
to premature mortality, by inducing behavioural, endocrine and metabolic changes. We evaluated
whether in the general population the number of stressful life events is associated with mortality,
and whether this relationship is mediated by behavioural changes and morbidities.
Methods
Design, setting, patients: The Hoorn study; a population-based cohort study among older men and
women.
Main outcome measure: Stressful life events experienced during the previous 5 years were assessed
by questionnaire. We calculated Cox proportional hazard ratios (HRs) for all-cause and causespecific mortality during follow-up for those who experienced stressful life events compared to
those who did not.
Results
We included 2385 participants (46% male; 62±7 years). During 20 years of follow-up 834 (35%)
participants died, of whom 239 (28.6%) died of cardiovascular disease and 235 (28.2%) of cancer.
Compared to the group with no stressful life events, the age, sex and socioeconomic status
adjusted HRs (95% confidence intervals) for all-cause mortality compared to those who had
1 event, 2 events, 3 events and ≥ 4 events were 0.89 (0.72-1.09), 1.01 (0.81-1.24), 1.29 (1.00-1.66)
and 1.44 (1.08-1.92), respectively. Similar results were observed for cardiovascular mortality and
cancer mortality. Mediation analysis showed that smoking, physical inactivity, prevalent type 2
diabetes and cardiovascular disease were statistically significant mediators of the association
between stressful life events and mortality.
Conclusions
Having 3 or more stressful life events is associated with a significantly increased risk for mortality
in an elderly population-based cohort. This association is mediated by smoking, physical inactivity,
type 2 diabetes and cardiovascular disease.
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76. The quantity and quality of daily activities in relation with
fall history and future falls in older adults
Kimberley S. van Schooten1, Sietse M. Rispens1, Petra J.M. Elders2, Paul Lips3, Jaap H. van Dieën1 en
Mirjam Pijnappels1
MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University
Amsterdam
2
EMGO+ Institute, VU University Medical Center
3
MOVE Research Institute Amsterdam, Department of Internal Medicine and Endocrinology,
VU University Medical Center
1
Introduction
Sedentary behavior and balance and gait impairments are important risk factors for falls in older
adults. However, most studies investigated the relation with falls retrospectively, while this might
be biased by fear of falling or recall. Moreover, subjective reports of physical activity are often
used, while these are known to have limited validity and precision. In this study, we compared the
associations between falls determined retrospectively and prospectively with potential risk factors
as measured by accelerometry.
Methods
We measured 121 older adults with an average age of 75.5 (SD 7.1) years. Six-months fall incidence
was retrospectively obtained by recall and prospectively by monthly telephone contact. In addition,
all participants answered validated questionnaires assessing risk factors for falls and wore a
3D trunk accelerometer during one week. Based on the accelerometer data, five activities were
classified: locomotion, sitting, standing, lying and an unclassified category. The total duration
of these activities was calculated and for the locomotion bouts, variables describing gait quality
were estimated. The associations of the questionnaires, duration of the activities and gait quality
variables with retrospective and prospective falls were investigated using logistic regression.
Results
Participants were classified as fallers if they experienced one or more falls in 6 months; 34% of the
participants had a history of falls and 38% experienced falls during follow-up.
Depression, cognition, fear of falling, grip force, processing speed and executive function were
significantly associated with retrospective falls, as well as the accelerometry-derived index of
harmonicity (gait smoothness), strength of the signal’s dominant frequency (measure of gait
variability), movement intensity and locomotion duration.
Prospectively, none of the questionnaire results was significantly associated with falls.
Accelerometry-derived walking speed, standard deviation and range of the signal (measures of
intensity), harmonic ratio (gait symmetry), local dynamic stability, and the duration of unclassified
activities were significantly associated with prospective falls.
The best prediction model for future falls comprised local dynamic stability, the duration of the
unclassified activities and fall history. Using these variables, 84.1% of the non-fallers and 55.8% of
the fallers were correctly classified.
Conclusions
Our results show that variables associated with falls differ between retrospective or prospective
analyses. Moreover, the employed questionnaires were not able to discriminate between future
fallers and non-fallers, while the accelerometry-derived variables could.
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Clinical and Epidemiological surveys
77. A twin-sibling study of components of adolescent physical
fitness
N.M. Schutte1,2, M. Bartels1,2, I. Nederend1,2, E.J.C. de Geus1,2
1
2
Department of Biological Psychology, VU University Amsterdam
EMGO+ Institute for Health and Care Research, VU University Medical Center, Amsterdam
Introduction
Physical fitness can be defined as a set of components that determine exercise ability and
performance in sports. Because exercise ability may be a major driver of voluntary exercise
behavior it is important to understand the source of the substantial variation in the components
of physical fitness seen already among adolescents. Most studies have focused on aerobic
fitness but other components like strength, flexibility and balance also play an important role in
exercise ability. The purpose of this study was to determine the causes of individual differences in
isometric strength, explosive strength, upper body flexibility and motor balance in an adolescent
sample.
Methods
Hand grip strength, explosive leg strength (vertical jump), flexibility (sit and reach) and balance
were examined in 227 healthy monozygotic and dizygotic twin pairs and 38 of their singleton
siblings (mean age 17.2 ± 1.2).
Results
Monozygotic twin correlations were consistently greater than dizygotic twin/twin-sibling/siblingsibling correlations for all components (hand grip 0.78 and 0.37 respectively, explosive leg
strength 0.72 and 0.27, flexibility 0.83 and 0.33, balance 0.31 and 0.24), suggesting a moderate
to high genetic contribution to the variation in these physical fitness components in this
adolescent sample. Analysis of the cross-trait/cross-twin correlations indicated that there is a
common set of genes influencing hand grip strength and explosive leg strength.
Conclusions
Individual differences in physical fitness components hand grip strength, explosive leg strength,
flexibility and balance are for a substantial part due to genetic factors and there is genetic covariation between hand grip strength and explosive leg strength.
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Clinical and Epidemiological surveys
78. Two-part joint regression modeling to analyze longitudinal
left censored patient reported outcomes
Alette S. Spriensma1,2, Marieke ter Wee3, , Michiel R. de Boer4, Martijn W. Heymans1,2,4,
Jolanda J. Luime5, Pascal H. de Jong5 , Maarten Boers1,3, Jos W.R. Twisk1,2,4
Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam
3
Department of Rheumatology, VU University Medical Center, Amsterdam
4
Department of Methodology and Applied Biostatistics, Faculty of Earth and Life Sciences, Institute
of Health Sciences, VU University, Amsterdam
5
Department of Rheumatology, University Medical Center, Rotterdam
1
2
Introduction
Patient reported outcomes often result into scores that have a lower limit. The true score of a
patient, however, can lie outside of this limit, which results into left censoring/an excess of zeroes
in the outcome variable. Several so-called two-part statistical models have been developed to
deal with an excess of zeroes. These models contain two distributions: A binomial distribution
to distinguish between left censored observations and uncensored observations, and a normal
distribution (or other distribution) that deals with the uncensored part; resulting into two separate
regression coefficients. However, the scores of patient reported outcomes should be seen as
one process. Therefore, the purpose of this study is to use the two-part joint mixed modeling
approach to analyze longitudinal HAQ trial data and to compare the performance of these newer
methods with the traditional methods.
Methods
A linear mixed model and a logarithmic transformation of the linear mixed model (ln(x+1))
approach are to be compared with a two-part joint binomial/normal (Tobit) mixed model and
a binomial/gamma two-part joint mixed model. In order to compare the models, differences
between observed and predicted values will be used.
Results
The predicted values of the linear mixed model and the log-transformed linear mixed model
showed similar results and did not predict the zeroes accurately. Of the two two-part joint models,
the Tobit model showed the best prediction; the binomial/Gamma did not perform very well.
Conclusions
The Tobit model showed the best performance in estimating the distribution of the HAQ-score
(0-3).
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Clinical and Epidemiological surveys
79. Predictors of dizziness in older persons: a 10-year
prospective cohort study in the community
Otto R. Maarsingh1,2, Hanneke Stam1,2, Peter M. van de Ven1,3, Natasja M. van Schoor2,
Matthew J. Ridd4, Johannes C. van der Wouden1,3
Department of General Practice & Elderly Care Medicine, VU University Medical Center,
Amsterdam, The Netherlands
2
EMGO+ Institute, VU University Medical Center, Amsterdam, The Netherlands
3
Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam,
The Netherlands
4
NIHR School for Primary Care Research, University of Bristol, Bristol, United Kingdom
1
Introduction
The current diagnosis-oriented approach of dizziness does not suit older patients. Often, it is not
possible to identify a single underlying cause, and when a disease is revealed, therapeutic options
are limited. Identification of long-term predictors of dizziness in older people may provide new
leads for the approach of dizziness in older patients.
Methods
Population-based cohort study of 1,379 community-dwelling participants, aged 60 years or older,
from the Longitudinal Aging Study Amsterdam (LASA), during 7- and 10-year follow-up. Regular
dizziness was ascertained during face-to-face medical interviews. We investigated 26 predictors
from six domains (socio-demographic, medical, medication, psychological, sensory, and balance/
gait). We performed multiple regression analysis with presence of regular dizziness at 7-year
follow-up and 10-year follow-up as dependent variables.
Results
Predictors of regular dizziness at 7-year follow-up were living alone, history of regular dizziness,
history of osteo/rheumatoid arthritis, history of cancer (not significant [n.s.]), use of nitrates,
presence of anxiety or depression, impaired vision, and impaired function of lower extremities.
Predictors of regular dizziness at 10-year follow-up were living alone (n.s.), history of regular
dizziness, history of cancer (n.s.), use of anxiolytics (n.s.), and impaired function of lower
extremities. Both models showed good calibration (Hosmer-Lemeshow P value of respectively 0.36
and 0.31) and fair discrimination (adjusted AUC after bootstrapping of respectively 0.77 and 0.71).
Conclusions
Dizziness in older age was caused by multifactorial conditions. A multifactorial approach, targeting
identified predictors amenable for treatment (e.g. physiotherapy for impaired function of lower
extremities), may be superior to the current diagnosis-oriented approach.
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Clinical and Epidemiological surveys
80. The sex, age, and cognitive domain dependent
associations between regular voluntary exercise behavior
and cognitive functioning
Suzanne Swagerman1, Eco de Geus1,2, Dorret Boomsma1, Kees-Jan Kan1
1
2
Department of Biological psychology, VU Amsterdam
Emgo+ Institute for Health and Care Research, VU University Medical Center
Introduction
Does cognitive functioning benefit from regular exercise? The answer is unclear, because
empirical results are mixed. This is partly due to (1) differences in study design (observational
or experimental), (2) the definition and reliability of measures of exercise behavior, (3) the
composition of the sample, and (4) the cognitive domain tested.
Methods
We examined the associations between average energy expenditure per week (in weekly
METhours) and cognitive performance in various cognitive domains, while controlling for sex and
age effects.
Using the widely used Computerized Neurocognitive Battery, accuracy and speed measures were
obtained in the neurocognitive domains of Abstraction and Mental Flexibility, Attention, Working
memory, Episodic Memory, Verbal Ability, Spatial Ability, Sensorimotor speed, Motor Speed, and
Emotion. The population based sample comprised 327 males and 449 females between 13 and 86
years old (mean age 43.9).
Results
Univariate analyses showed that subjects who reported more leisure time exercise tended to
perform faster and more accurate on the majority of tasks than those who were less active.
Multivariate analyses showed that sex and age confounded these relationships. Accuracy on
attention and memory related directly to weekly METhours, and only weakly so.
Conclusions
Our results suggest that in the base population the effects of voluntary regular leisure exercise
behavior on cognitive function are limited, but do not preclude beneficial effects of exercise in
clinical samples.
90
Clinical intervention
81. Microcirculatory changes during goal-directed or mean
arterial pressure-guided fluid therapy in abdominal
surgery
N.A.M. Dekker1, J. Stens1, S. de Wolf1, R. van der Zwan1, N. Koning1, C. Boer1
Department of Anesthesiology, Institute for Cardiovascular Research,
VU University Medical Center
1 Introduction
This study compared the effect of pulse pressure variation (PPV) and cardiac index (CI) guided
fluid therapy versus mean arterial pressure (MAP) guided fluid therapy on microcirculatory
perfusion in patients undergoing elective abdominal surgery.
Methods
Patients were randomized into a PPV/CI- guided group (n=11) or a MAP-guided (n=12) group. PPV,
CI and MAP were measured using the non-invasive finger arterial blood pressure measurement
device ccNexfin. A MAP of 70 mmHg was maintained. In the PPV/CI group, an intraoperative
algorithm was used keeping the PPV under 12% and CI above 2.5 L/min/m2 using fluid therapy and
dobutamine and noradrenaline infusion, respectively. Sublingual perfused vessel density (PVD) was
measured reflecting microvascular perfusion after anesthesia induction, and every subsequent
hour using sidestream dark field imaging.
Results
The first hour during surgery, a higher fluid volume was administrated in the PPV/CI-guided group
than the MAP-guided group (1014 ± 501ml versus 629 ± 463ml; P=0.07). This was associated
with a slightly reduced microcirculatory perfusion 16.7 ± 3.1 mm/mm2) compared to MAP-guided
group (17.9 ± 3.9 mm/mm2; P=0.41). The administered fluid volume correlated inversely with PVD
(r=-0.59, P=0.011).
Two hours after the start of surgery, the PVD in the PPV/CI group restored and tended to be higher
than in the MAP-guided group (21.1 ± 1.9 vs. 18.1 ± 3.4 mm/mm2; P=0.09).
Conclusion
Microcirculatory perfusion improved as surgery progressed in the PPV/CI-guided group. Our
findings suggest that goal-directed and MAP-guided fluid management are associated with distinct
patterns in fluid resuscitation, possibly affecting microvascular perfusion.
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Clinical intervention
82. Unilateral versus bilateral upper limb training after stroke
A.E.Q. van Delden1, C.E. Peper1, P.J. Beek1, G. Kwakkel1,2
1
MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences,
VU UniversityAmsterdam, Amsterdam
2
Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam,
VU University Medical Center, Amsterdam
Introduction
Within the plethora of treatment methods for the paretic upper limb, unilateral and bilateral
training protocols represent conceptually contrasting approaches with the same ultimate goal.
In the Upper Limb TRaining After stroke (ULTRA-stroke) project, unilateral and bilateral upper limb
training were compared with each other to assess the effectiveness of these interventions and to
examine how the observed changes in sensori-motor functioning relate to changes in interlimb
interactions.
Methods and Results
A systematic review and meta-analysis revealed no clinically relevant significant differences in
effectiveness between unilateral and bilateral training in patients with acute and chronic stroke.
A randomized clinical trial comparing unilateral, bilateral, and dose-matched conventional upper
limb training with patients starting the intervention between 1-6 months after stroke showed
similar results: no significant differences in change scores regarding clinical effects and bilateral
coupling were found between groups. However, the bilateral training group showed more control
over the paretic hand (i.e., greater movement harmonicity and larger wrist amplitudes) after
training than both other groups.
Conclusions
Unilateral and bilateral training are not superior to dose-matched conventional treatment or each
other in improving upper limb sensori-motor functioning after stroke. Although more control over
the paretic hand after bilateral training may indicate a beneficial influence of bilateral coupling
during training, this improvement did not translate into better outcomes on clinical measures in
favor of bilateral training.
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Clinical intervention
83. The first Dutch experience with the use of Strattice™ for
single-stage implant based breast reconstruction
R.E.G. Dikmans, MD¹, F. El Morabit¹, D.J. Hofstede, MD², S.M.H. Tuinder, MD³,
A.A.W.M. van Turnhout, MD, PhD4, O.T. Zöphel, MD, PhD5, Y.C.M.M. Smulders, MD5,
M.G. Mullender, PhD¹
Department of Plastic, Reconstructive & Hand Surgery, VU University Medical Center, Amsterdam
² Department of Plastic, Reconstructive & Hand Surgery, BovenIJ Hospital, Amsterdam
³ Department of Plastic, Reconstructive & Hand Surgery, Maastricht University Medical Center,
Maastricht
4
Department of Plastic, Reconstructive & Hand Surgery, Tergooi Hospitals, Hilversum
5
Department of Plastic, Reconstructive & Hand Surgery, Medisch Spectrum Twente, Enschede
1
Introduction
Recently, Strattice™, a porcine acellular dermal matrix has emerged as a method to assist in singlestage implant based breast reconstruction. It forms an envelope to hold the prosthesis and gives
potentially an improvement of esthetic outcome. In the Netherlands, Strattice™ is used in several
centers. The objective of this study is to evaluate the complications after the first experience with
this technique.
Methods
A retrospective chart review was conducted of patients who underwent Strattice™ assisted singlestage implant based breast reconstruction in four different centers in the Netherlands between
2010 and 2013. Collected data are comorbidities, BMI, smoking, post-operative radiation and
complications.
Results
78 patients underwent single-stage breast reconstruction with the use of Strattice™ unilateral
(54 patients) or bilateral (24 patients). A total of 99 breasts were included and evaluated. The
following complications occurred; seroma 23,23%, necrosis 17,17%, wound dehiscence 14,14%,
hematoma 13,13%, erythema 13,13%, infection 11,11%, pain 10,10% and hemorrhage 3,03%. Due
to one of these complications 19,19% of the breasts underwent re-operation with an explantation
rate of 3,03%.
Conclusions
Strattice™ assisted single-stage implant based breast reconstruction appears to be followed by
several complications, mainly seroma production. These results are comparable with complication
rates reported in literature on implant based breast reconstruction. The use of Strattice™ seems
to be a promising technique, but more experience needs to be gained. Given the potential role of
Strattice™ in breast reconstruction and the lack of solid evidence, level I studies are necessary.
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Clinical intervention
84. Implementation of quality of life in routine peadiatric care
for adolescents with type 1 Diabetes in The Netherlands:
an evaluation study
Minke Eilander1, Maartje de Wit1, Frank Snoek1
1
Medical psychology, VU University Medical Center
Introduction
The Quality of Life (QoL) method aims to improve paediatric care for youngsters with type 1
diabetes. Adolescents complete the MIND Youth Questionnaire (MY-Q) regarding their QoL and the
outcomes are discussed. Additionally parental well-being can be examined. In the Netherlands,
11 hospitals started the usage of the method in 2010. Experiences of the users were studied.
Methods
The diabetes team members, the adolescents and the parents completed an online survey regarding
their overall experience with the QoL method and the implementation. With the teams also a semi
structured interview was conducted.
Results
36 team members, 29 adolescents and 66 parents completed the online survey and 10 diabetes
teams were interviewed. The method is often used as a screening tool (by 94.1%); teams
appreciate the possibility to concrete their feelings about adolescents (85.3%). Even though 91.2%
reported the method as a high valued addition to the routine care, interviews reveal that 2 out
of 10 interviewed teams successfully implemented the QoL method. However, all teams want the
QoL method to be a part of the routine care in the nearby future. 78.8% of parents and 41.4%
of adolescents appreciate the usage of the MY-Q. An additional 41.4% of adolescents provided a
neutral opinion. 62.1% of adolescents and 78.8% of parents consider it a good idea if the method
is more frequently used. According to 80% of the parents whose well-being was examined by the
diabetes teams, it contributed to the paediatric diabetes care.
Conclusions
Implementation of the QoL method in routine care seems difficult, although the method is highly
appreciated by the teams. Adolescents themselves are neutral to positive about the usage; parents
are overall positive. It seems worthwhile to continue the usage and further implementation of the
QoL method. More effort should be made to solve logistic problems.
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Clinical intervention
85. Beneficial effects of aortic valve replacement on
myocardial energetics in aortic valve stenosis patients
A Güçlü1,6, P. Knaapen1, H.J. Harms3, A.B.A. Vonk4, W. Stooker5, A.A. Lammertsma3,
A.C. van Rossum1, J. van der Velden2,6, T. Germans1
Department of Cardiology
Department of Physiology
3
Departments of Radiology & Nuclear Medicine
4
Department of Cardiothoracic Surgery, Institute for Cardiovascular Research (ICaR-VU),
VU University Medical Center, Amsterdam
5
Department of Cardiothoracic Surgery, Onze Lieve Vrouwe Gasthuis Amsterdam
6
ICIN-The Netherlands Heart Institute, Utrecht
1
2
Introduction
Aortic valve replacement (AVR) in symptomatic aortic valve stenosis (AVS) patients is associated
with a favorable prognosis. It is already known that reduction in left ventricular (LV) loading
conditions leads to regression of LV hypertrophy. However, data regarding the effects of AVR on
myocardial energetics are currently lacking. Therefore, this pilot study was conducted to study
the effects of AVR on myocardial energetics.
Methods
Ten AVS patients were included (normal coronary arteries, mean age 62±10 years, 7 male).
Echocardiography was performed prior to AVR and repeated after 4 months to assess peak aortic
valve gradients. Changes in LV mass (LVM) and volumes were assessed by CMR. Additionally, [11C]acetate PET was performed to obtain myocardial oxygen consumption (MVO2). Next, myocardial
external efficiency (MEE), i.e. the ratio between external work and MVO2, was calculated. Fourteen
healthy controls (mean age 48±11 years, 9 male) underwent similar scanning protocols.
Results
After AVR, peak aortic valve gradient decreased from 88±20 to 24±12 mmHg, (p<0.001), as well
as LVM index from 104±21 to 75±16 g∙m-2 (p<0.001). MVO2 significantly decreased from 0.11±0.03
to 0.09±0.02 mL∙min-1∙g-1, (p=0.02), which was comparable to the MVO2 observed in controls
(0.10±0.02 mL∙min-1∙g-1). In addition, cardiac work significantly decreased from 15439±2631
to 10774±2446 mmHg·mL, (p<0.001), reaching similar values as in controls (10117±2268
mmHg·mL). Consequently, AVR resulted in a significant improvement in MEE from 32±7 to 37±5
%, (p=0.02).
Conclusions
At 4 months follow-up, the detrimental effects of AVS are partially reversed by AVR in patients
with normal coronary arteries and preserved ejection fraction, evident from regression of LV
hypertrophy and improvement of myocardial efficiency.
VU University Medical Center Science Exchange Day 2014
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Clinical intervention
86. Beware: Body awareness training in the treatment of
wearing-off related anxiety in patients with parkinson’s
disease
I. Ghielen1, C.J.T. de Goede2, M. Houniet-de Gier3, E. Colette3, I.A.L. Burgers-Bots2, H.W. Berendse4,6,
S. Rutten1, G Kwakkel2, OA van den Heuvel1,5,6, EEH van Wegen2
Department of Psychiatry, VU University Medical Center
Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam,
VU University Medical Center
3
Department of Medical Psychology, VU University Medical Center
4
Department of Neurology, VU University Medical Center
5
Department of Anatomy & Neurosciences, VU University Medical Center
6
Neuroscience Campus Amsterdam
1
2
Introduction
Approximately 60% of patients with Parkinson’s Disease (PD) that receive dopamine replacement
therapy eventually develop the wearing-off phenomenon due to on-off fluctuations. Wearing-off
is not only accompanied by motor symptoms but also by non-motor symptoms, such as anxiety,
which have a major impact on the patient’s quality of life. We developed and pilot-tested the
effectiveness of a comprehensive Body Awareness Intervention to reduce the negative impact of
wearing-off and increase self-efficacy.
Methods
Four PD patients participated in the experimental body-awareness pilot group therapy for 6 weeks,
2 sessions per week. The Body Awareness Intervention combines elements and techniques
from physical and psychological therapies. The randomized controlled trial (36 PD patients) will
be performed with a control group that receives treatment as usual. Patients will be randomly
assessed to one of the conditions. Self-efficacy, mobility, mood, and quality of life will be assessed
prior to and after both interventions.
Results
The patients participating in the pilot group rated the intervention as very positive. Patients
reported being more able to relax and being less afraid of losing control. A 14,6% average
reduction on the Beck Anxiety Inventory (BAI) score was found. Pilot results were used to optimize
the treatment protocol for implementation in the randomized controlled trial.
Conclusions
The Body Awareness Intervention is appreciated by the patients and brings body and mind
together in the treatment of wearing-off. The added value of this new approach, compared with
treatment as usual, will now be tested in a randomized controlled study.
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Clinical intervention
87. Effectiveness of an intercultural module: drop-out and
no-show rates in non-Western migrants with affective
disorders
Annelies van Loon1, Anneke van Schaik1,3, Jack Dekker2, Aartjan Beekman1,3.
GGZ inGeest, Amsterdam, the Netherlands,
Arkin Academy, Arkin Mental Health Institute, Amsterdam, the Netherlands.
3
Department of Psychiatry, VU university Medical Center, Amsterdam, the Netherlands.
EMGO+ , Institute for Health and Care Research, VU University Medical Center, Amsterdam
Funding: Netherlands Organization for Health Research and Development (ZonMw)
1
2
Introduction
Non-Western outpatients in specialized mental health care seem to benefit less from treatment
because of early drop-out. In this study we explored the effects of a cultural competence training
for therapists on the drop-out and no-show rates among Turkish and Moroccan migrants with
depressive and anxiety disorders.
Methods
A randomized clinical trial was performed between January 2009 and January 2012. A total of
220 Moroccan and Turkish adult patients were randomly assigned to mental health workers who
were trained in a cultural module and to those who were not. Drop-out and no-show rates were
registered over a 6- month period after the intake session. Several possible determinants of
outcome were explored by analyzing medical files.
Results
There were no significant differences in drop-out rates (21% versus 12%) and mean no-show
between the intervention and control group. Compared to other studies the rates were relatively
moderate. Language problems predicted a significantly lower drop-out rate in both conditions.
Conclusions
Training in cultural competence did not reduce the drop-out and no-show rates. Possibly there
was no difference between the conditions because the therapists in the usual care condition were
also competent in motivating and treating migrant patients. Implications for future research and
practice are to collaborate more intensively with general practitioners to obtain more insight in the
reasons of drop-out among outpatients in specialized mental health care.
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Clinical intervention
88. Implementation index: an indicator measuring level of
implementation of school-based interventions
Femke van Nassau1, Trynke Hoekstra2,3, Grace Skrzypiec4, Phillip Slee4, Amika Singh1,
Willem van Mechelen1, Johannes Brug3, Mai Chin A Paw2
Department of Public and Occupational Health, VU University Medical Center, The Netherlands
Faculty of Earth and Life Sciences, Department of Health Sciences, VU University, The Netherlands
3
Department of Epidemiology and Biostatistics, VU University Medical Center, The Netherlands
4
School of Education, Flinders University, Adelaide, Australia
1
2
Introduction
Insight into the process of implementation is crucial to explain intervention effectiveness during
implementation. We developed an implementation index score for the school-based Dutch Obesity
Intervention in Teenagers (DOiT) program. The aim of the implementation index was to define a
school-level implementation score.
Methods
Development of the index was based on recommendations of Domitrovich et al. and the
implementation index of Dix et al. We included 44 items divided over six factors; fidelity, dosage
and quality of delivery at both intervention and support level. Items were derived from the selfreported questionnaire of teachers completed after implementation of DOiT. Using Mplus, we
conducted factor coefficient analyses to identify the best combination of items within one factor,
and removing poor indicators. We used standardized coefficient scores to calculate a score for
each of the six factors. We combined the six factor scores into one final index score for each
teacher. Data were then aggregated to school level.
Results
School-level implementation scores were calculated, providing a variation in implementation
between schools. We identified ‘low’ and ‘high’ implementing schools and explored the difference
in index item scores between these two groups, indicating which of the 44 items contributed to
high implementation.
Conclusions
The DOiT implementation index can provide insight into the dynamic nature of implementation
processes and key factors that are expected to be critical for achieving effectiveness during large
scale implementation, allowing translation of research into daily practice.
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Clinical intervention
89. Ablation of colorectal liver metastases by irreversible
electroporation: results of the COLDFIRE-I ablate-andresect study
K. Nielsen1*, H.J. Scheffer2*, A.A.J.M. van Tilborg2, G. Kazemier1, J.M. Vieveen3, J.W.M. Niessen4,
S. Meijer1, M.R. Meijerink2, M.P. van den Tol1.
* contributed equally
Department of Surgery, VU University Medical Center, Amsterdam
Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam
3
Anesthesiology, VU University Medical Center, Amsterdam
4
Pathology, VU University Medical Center, Amsterdam
1
2
Introduction
Irreversible electroporation (IRE) is a new, non-thermal, image guided technique for tumor ablation.
The application of an electric field across cells creates nanopores in the cell membrane, inducing
cell death. Surrounding -acellular- connective tissue is relatively preserved, so the framework
of vulnerable structures such as blood vessels and bile ducts should remain intact. We present
results of the COLDFIRE study: a prospective single centre pilot study of patients with colorectal
liver metastases treated with IRE before surgical resection. The aim was to evaluate safety,
feasibility and (histological) changes of the ablated tissue after IRE.
Methods
Ten patients with resectable CRLM were included. Main exclusion criteria were cardiac arrhythmias
and epilepsy. During laparotomy, the metastases were treated with IRE and resected 60 minutes
later. Safety and feasibility were assessed based on adverse events, laboratory values, technical
success and ultrasound confirmation of the ablation zone. Tissue response was assessed using
triphenyl tetrazolium chloride (TTC) vitality staining and (immuno)histochemical stainings (HE,
complement-3d and caspase-3).
Results
Ten lesions with a mean diameter of 2.4cm were successfully treated with IRE and resected, on
average, 84 minutes later (range 51-153 minutes). One minor adverse event, a mild transient
arrhythmia without hemodynamic consequences, occurred during IRE. Ultrasonography showed
a sharply demarcated hypoechoic ablation zone around the tumor. TTC showed avitality of all
lesions, covering the complete tumor in 8/10 lesions. Immunohistochemistry confirmed
irreversible cell damage in and around the tumor.
Conclusions
This ablate-and-resect study demonstrated physiological and immunohistochemical cell death
caused by IRE of liver metastases of colorectal origin in humans.
VU University Medical Center Science Exchange Day 2014
99
Clinical intervention
90. The structure of the geriatric depressed brain and
response to electroconvulsive therapy
Mardien L Oudega1,2,3, Eric van Exel1,2,3, Max L. Stek1, Mike P. Wattjes4, Wiesje M. van der Flier5,6,
Hannie C. Comijs1,3, Annemieke Dols1, Philip Scheltens2,5, Frederik Barkhof2,4, Piet Eikelenboom1,7,
Odile A. van den Heuvel1,2,8
Department of Psychiatry, VU University Medical Center, Amsterdam
Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam
3
EMGO Institute for Health and Care Research and VU University Medical Center/GGZ inGeest,
Amsterdam
4
Department of Radiology, VU University Medical Center, Amsterdam
5
Department of Neurology and Alzheimer Center, VU University Medical Center, Amsterdam
6
Department of Epidemiology & Biostatistics, VU University Medical Center, Amsterdam
7
Department of Neurology, Academic Medical Center, Amsterdam
8
Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam
1
2
Objective
Electroconvulsive therapy (ECT) is the treatment of choice in severe geriatric depression. High
remission rates may be influenced by specific brain morphology, accompanying geriatric
depression. Our objective was to identify the relationship between brain structure, symptom
profile, and ECT response.
Methods
In a naturalistic cohort of 55 patients with a major depressive disorder, structural magnetic
resonance imaging scans were made prior to ECT. Voxel-based morphometry was applied to
determine regional differences in gray matter (GM) volume between patients and 23 matched
healthy controls.
Results
Depressed patients with psychotic symptoms showed significantly higher remission rates and
smaller regional GM volume of the left inferior frontal gyrus (IFG). Patients with late onset
depression showed smaller regional GM volume of the bilateral lateral temporal cortex. Larger size
of response in the whole patient group was related to smaller pretreatment regional GM volume
of the right lateral temporal cortex, whereas faster speed of response was related to smaller
pretreatment regional GM volume of the right IFG.
Conclusions
ECT is most effective in depressed patients with psychotic symptoms showing smaller GM volume
of the left IFG and bilateral temporal cortex. Smaller volume of the IFG pretreatment was related
to faster treatment response and smaller volume of the right lateral temporal cortex pretreatment
was related to larger response to ECT. These results are possibly explained by the connectivity
between these brain regions and interconnected network which is particularly activated by the
ECT-induced seizures.
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Clinical intervention
91. Hematopoietic stem cell transplantation for Metachromatic
Leukodystrophy
D.F. van Rappard1, J.J. Boelens2, M.S. van der Knaap1, N.I. Wolf1
1
2
Child Neurology, Center for White Matter Disorders, VU University Medical Center
Blood and Marrow Transplantation Program, University Medical Center Utrecht
Introduction
Metachromatic leukodystrophy (MLD) is a severe white matter disease, caused by a deficiency of
the ARSA enzyme. This study aims to evaluate the effectiveness of hematopoietic stem cell
transplantation (HSCT) as a treatment for MLD
Methods
13 MLD patients were followed pre and post HSCT to evaluate clinical outcome and white matter
abnormalities on MRI. MRI’s were evaluated using the modified Loes scoring system for MLD.
Results
Survival: at this moment, 10 out of 13 patients are surviving (median follow up 29 months) with
a 5 year survival probability of 83.5%. A significant difference in survival probability between
symptomatic (69%) (N=7) versus presymptomatic (100%) (N= 6) patients at time of transplantation
was found.
In 2 of the 10 surviving patients, MRI scans showed, after an initial worsening in scores, a final
improvement.
Patients with the late infantile type of MLD exhibited a greater decline in gross motor function
(expressed by higher scores on the GMFC) post HSCT compared to the adult and juvenile onset
type.
Conclusions
A higher overall survival, stabilization or improvement of MRI abnormalities and less decline
in motor function post HSCT are observed for presymptomatic juvenile or adult patients. In
symptomatic late infantile or early juvenile patients, primarily a delay of disease progression, as
opposed to complete halt of the disease, following HSCT was observed.
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101
Clinical intervention
92. The therapeutic potential of IGFBP7 in specific eradication
of leukemic stem cells in acute myeloid leukemia
Han Verhagen1, Dave de Leeuw1, Meyram Çil1, Walter Pouwels1, Arjo Rutten1, Monique Terwijn1,
Patrick Celie2, Gert Ossenkoppele1, Gerrit Jan Schuurhuis1 and Linda Smit1.
1
2
Department of Hematology, VU University Medical Center, Amsterdam
Protein facility, The Netherlands Cancer Institute, Amsterdam
Introduction
Acute myeloid leukemia (AML) is a heterogeneous disease characterized by the accumulation of
abnormal immature myeloid cells in the bone marrow (BM). Despite high remission rates after
chemotherapy treatment, many AML patients experience a relapse which is hard to treat and leads
to a poor overall survival.
The main cause of this present treatment failure is the insufficient eradication of a subpopulation
of chemotherapy resistant leukemic cells with stem cell-like features called leukemic stem cells
(LSC).
We aim to develop novel anti-LSC therapies eradicating LSC while sparing hematopoietic stem cells
(HSC) and the extent to which LSC differ from HSC is therefore of critical importance.
LSC and HSC share a similar immune phenotype, CD34+CD38-, and can be further discriminated
by using leukemia-associated phenotypic markers.
Methods
We have compared gene expression profiles of LSC compared to HSC and of LSC with that of the
bulk of the AML and identified insulin growth factor binding protein-7 (IGFBP7) as differentially
expressed. To elucidate the therapeutic potential of IGFBP7, we have generated rhIGFBP7 to test
whether it can efficiently eradicate LSC in vitro and in vivo.
Results
We show that IGFBP7 induces apoptosis of AML cells, cooperates with chemotherapy and
suppresses the outgrow of chemotherapy resistant cells in vitro.
Conclusions
Altogether, our result suggest that AML patients might benefit from combination therapy
consisting of chemotherapy and IGFBP7 and that this combination might potentially overcome
conventional drug resistance in LSC and the bulk of the AML and thus improve AML patient
survival.
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Clinical intervention
93. Hyperemic and hyperemia free pressure indices have
an equivalent diagnostic accuracy when compared to
myocardial blood flow quantified by H215O PET perfusion
imaging
Guus de Waard MD1, Ibrahim Danad MD1, Ricardo Petraco MD2; Paul Teunissen MD1,
Pieter Raijmakers MD, PhD3, Tim van de Hoef MD4, Adriaan Lammertsma PhD3,
Justin Davies MBBS, PhD2, Paul Knaapen MD, PhD1, Niels van Royen MD, PhD1
Department of Cardiology; iCaR-VU, VU University Medical Center, Amsterdam, The Netherlands
Department of Cardiology; ICCH, Imperial College London, London, United Kingdom
3
Department of Nuclear Medicine; VU University Medical Center Amsterdam, The Netherlands
4
Department of Cardiology; AMC, The Netherlands
1
2
Introduction
Revascularization of intermediate coronary artery stenosis guided by the fractional flow reserve
(FFR) improves clinical outcomes and therefore recommended by clinical guidelines. Recently, it
has been proposed that physiological lesion assessment during resting conditions might render
an equivalent diagnostic performance. This study evaluated the performance of the established
FFR as well as the hyperemia free instantaneous wave-free ratio (iFR), Pd/Pa ratio and finally the iFR
during hyperemia (iFRa) compared them to the non-invasive gold standard, H215O PET perfusion
imaging.
Methods
This study included 49 intermediate coronary stenoses (≥40% diameter) in patients with suspected
coronary artery disease who were scheduled for coronary angiography. H215O PET perfusion
imaging and intracoronary pressure measurements were obtained under both basal conditions
and pharmacologically induced hyperemia. FFR, iFR, iFRa and Pd/Pa were computed and the
diagnostic performance of these pressure indices was then compared to PET perfusion using
predefined cutoff values.
Results
Mean stenosis diameter was 62±15%. Diagnostic accuracy was 78% for FFR, iFR and Pd/Pa, and 71%
for iFRa. Diagnostic agreement as expressed by area under the receiver operator curve was similar
across all physiological indices: 0.85 for FFR, 0.88 for Pd/Pa, 0.86 for iFR and 0.85 for iFRa (P>0.05
for all indices).
Conclusions
Hyperemic and hyperemia free pressure derived intracoronary indices for the assessment of
moderate coronary artery stenosis, have an equivalent diagnostic accuracy when compared to
H215O PET perfusion imaging.
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103
Clinical intervention
94. Intensive combination treatment regimens, including
prednisolone, are effective in treating early rheumatoid
arthritis patients regardless of additional etanercept:
1 year results of the COBRA-light trial
Marieke ter Wee1, Debby den Uyl1, Maarten Boers1,2, Pit Kerstens2,3, Mike Nurmohamed1,2,
Dirkjan van Schaardenburg1,2, Alexandre E. Voskuyl1, Willem F. Lems1,2
VU University Medical Center, Amsterdam
Jan van Breemen Research Institute | Reade, Amsterdam
3
Westfriesgasthuis, Hoorn
1
2
Introduction
Recently, we demonstrated the noninferiority of COBRA-light therapy compared to original COBRA
therapy after 26 weeks in patients with early active RA. Objective: to assess the one-year results
of these two protocolized strategies, aiming minimal disease activity, in terms of disease activity
(DAS44), functional outcome (HAQ), and radiographic progression (SHS), and to assess the effect
of addition of etanercept.
Methods
An open, randomized controlled, noninferiority trial in 164 patients with active early RA, following
a treat-to-target protocol incorporating the addition of etanercept if DAS44 ≥ 1.6 at weeks 26 or 39.
Results
Both groups showed major mean improvements in DAS44 after 52 weeks: –2.40 (± 1.2) in COBRA,
and –2.05 (± 1.0) in the COBRA-light group (ns). Most improvement in DAS44 was reached after
26 weeks treatment: mean decrease in DAS44 between weeks 26 and 52 was 0,2 in COBRA and
0.4 in COBRA-light therapy. In both groups, functional ability improved, and minimal radiological
progression of joints was found. Treatment actually instituted was often less intensive than
required by protocol: of the total population (n=164), 110 patients (67%) required etanercept
(more in COBRA-light), and of those only 57 patients (52%) actually received etanercept.
Conclusion
Intensive treatment with COBRA or COBRA-light therapy both have major, comparable favorable
effects on disease activity, functional ability and radiological outcome after one year in early
RA patients. Protocolized addition of etanercept was often not implemented by treating
rheumatologists, and patients receiving it appeared to have limited added benefit, probably due
to low disease activity levels at initiation of etanercept.
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Clinical intervention
95. The evaluation of a worksite intervention to promote
a healthy lifestyle among employees in two different
organizations
Debbie Wierenga1,2,3, Luuk Engbers1,3 , Pepijn van Empelen3, Willem van Mechelen1,2
Body@Work, Research Centre on Physical Activity, Work and Health, TNO-VUmc, Amsterdam
Department of Public and Occupational Health, EMGO+ Institute for Health and Care Research,
VU University Medical Center, Amsterdam
3
Netherlands Organization for Applied Scientific Research, TNO Expertise Centre Life Style, Leiden
1
2
Introduction
The aim of this study is to systematically evaluate the natural course of implementation of multiple
lifestyle interventions at two worksites (hospital and university). Additionally, the effectiveness of
the programme was assessed in a quasi-experimental controlled trial.
Methods
Quantitative and qualitative data on nine process components were obtained 6 and 12 months
after start of implementation. The impact of the intervention on employee lifestyle behaviour
(physical activity, nutrition, smoking, alcohol use and vitality) was measured at baseline and
12-month follow-up using questionnaires
Results
The programme was implemented partly as planned as 84.9% of all planned interventions were
delivered, which were mainly easily-implemented environmental and educational interventions.
High programme reach (96.6%) and participation (75.1%) was achieved. Satisfaction with the
programme was moderate (6.8 ± 1.1). It appears facilitating if ‘the programme matches employee
needs’, ‘employees have a positive attitude towards implementation’ and ‘employees believe
it is good that their employer thinks about their health’. Effects were found for days of fruit
consumption in the intervention group (β: 0.44 days/week, 95%CI 0.02 to 0.85), and for days of
vegetable intake in the low participation group (β: -0.358, 95%CI -0.691 to -0.026).
Conclusions
This study seems to indicate that the primary precondition for a WHPP in a non-research context is
not that an intervention has to be evidence-based, but it should be easily implemented, at minimal
costs and effort. Implementing lifestyle interventions that target different aspects resulted in high
awareness and participation but only one intervention was actually embedded in the hospitals’
general health policy.
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Clinical intervention
96. Stress reduction through mindfulness meditation, heart
rate variability biofeedback or physical activity:
a randomized trial
J.E. van der Zwan1, W. de Vente2, A.C. Huizink1, S.M. Bögels2, E.I. de Bruin2
1
2
Department of Developmental Psychology, VU University
Research Institute of Child Development and Education, University of Amsterdam
Introduction
World-wide there is a high prevalence of stress; therefore, the need for stress-reducing methods is
high. The purpose of this study was to compare the efficacy of three stress-reducing interventions
— heart rate variability (HRV) biofeedback, mindfulness meditation, and physical activity — on
stress and its related symptoms.
Methods
76 participants (20 males; mean age 25.8, range 18-40) were randomly allocated to HRVbiofeedback, mindfulness meditation, or physical activity. The three interventions consisted of
2 hours psycho-education and introduction to the intervention techniques followed by five weeks
of daily exercises at home. For the HRV-biofeedback condition, exercises consisted of slow breathing
(~6 breaths per minute) while using a HRV-biofeedback device; the mindfulness meditation
exercises consisted of several guided mindful meditations recorded on a CD; for the physical
activity exercises participants were free to choose a vigorous intensity activity of their liking.
Psychological wellbeing, stress, anxiety, depression, and sleep quality were assessed prior to and
after the training (pre-test and post-test), and 6 weeks later (follow up), using questionnaires.
Results
Results indicate an overall beneficial effect consisting of reduced stress, anxiety and depressive
symptoms and improved psychological wellbeing and sleep quality. No significant betweenintervention effect was found on any of the outcome variables.
Conclusions
Results suggest that HRV-biofeedback, mindfulness meditation, and physical activity are equally
effective in reducing stress, anxiety and depressive symptoms and promoting psychological
wellbeing and sleep quality.
106
Clinical – Surveys on Volunteers
97. Cognitive functioning and blood pressure as a function
of age
Kees-Jan Kan1, Suzanne Swagerman1, Annemarie Kraaijeveld1, Eco de Geus12, Dorret Boomsma12
1
2
Department of Biological Psychology, VU University Amsterdam
EMGO+ Institute for Health and Care Research, VU University Medical Center
Introduction
High blood pressure in the elderly is commonly treated with anti-hypertensives, which - as been
suggested recently - enhance cognitive decline and thus threaten mental health. As cognitive
functioning and blood pressure are both age dependent and the relationships are inconclusive, we
aimed to investigate, , using multivariate modelling, the age-dependencies of cognitive functioning
and blood pressure across various well-defined (neuro)cognitive domains in a population based
sample.
Methods
In a population representative sample consisting of 250 males and 347 females between 10 and
86 years old, we measured diastolic and systolic blood pressure and accuracy performance on
17 neurocognitive tests from the Dutch computerized neurocognitive battery.
Results
Subjects with relatively high levels of diastolic and/or systolic blood pressure and elderly tended
to perform relatively poor on the majority of tasks. Once sex and (linear and nonlinear) age effects
were taken into account, correlations between blood pressure and cognitive performance dropped
to near 0. Evidence for an intrinsic relationship between blood pressure and cognitive functioning
was thus absent.
Conclusions
Our results suggest that in the base population high blood pressure does not have negative
consequences for cognitive functioning. Results from recent studies, showing that antihypertensives enhance cognitive decline, need to be taken seriously. Negative effects of antihypertensives on cognitive health should be weighted against their (limited) positive effects on
physical health.
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Diagnostic studies – Patients
98. Two new adult cases with AUTS2 mutations, including
a two basepair deletion, further delineate the AUTS2
syndrome
G. Beunders1, S.A. de Munnik2, N. van der A.3, B. Ceulemans4, E. Voorhoeve1, A.J. Groffen1,
W.M. Nillesen2, E.J.Meijers-Heijboer1, R.F. Kooy3, H.G. Yntema2, E.A. Sistermans1
Department of Clinical Genetics, VU University Medical Center, Amsterdam, The Netherlands
Department of Human Genetics, Radboud university medical centre, Nijmegen, The Netherlands
3
Department of Medical Genetics, University and University Hospital Antwerp, Antwerp, Belgium
4
Department of Neurology- Paediatric Neurology, University Hospital Antwerp and University of,
Antwerp, Belgium
1
2
Introduction
We recently described a new ID syndrome, AUTS2 syndrome that is characterised by low birth
weight, feeding difficulties, intellectual disability, microcephaly and mild dysmorphic features.
All cases thus far were caused by chromosomal rearrangements, mutations at the base pair level
disrupting AUTS2 have not yet been described.
Methods
Here we present the full clinical description of two new adult cases with AUTS2 syndrome found
by diagnostic exome sequencing and array CGH.
Results
The phenotypic features of both male cases include: intellectual disability, microcephaly, feeding
difficulties, dysmorphic features and joint contractures. Both cases have intragenic AUTS2
mutations (one two-basepair deletion in exon 7 and one deletion of exon 6) that are predicted to
cause a frame shift of the full length transcript but are unlikely to affect the shorter 3’ transcript
starting in exon 9 that is expressed in human brain.
Conclusions
The similarities between the phenotypes of both cases are striking and further confirm that AUTS2
syndrome is a single gene disorder with a recognisable phenotype.
108
Diagnostic studies – Patients
99. Comparison of quantitative cardiac perfusion
measurements using PET and CMR
Joost J. Binnerts1†, René A. Kroes2,3†, Lourens F.H.J. Robbers1, Paul F.A. Teunissen1,
Maurits R. Hollander1, Mark B.M. Hofman3, Albert van Rossum1, Paul Knaapen1, Aernout M. Beek1,
Niels van Royen1
Department of Cardiology, VU University Medical Center, Amsterdam
Department of Physics and Medical Technology, Tergooi, Hilversum
3
Department of Physics and Medical Technology, VU University Medical Center, Amsterdam
1
2
Introduction
Positron emission tomography (PET) is currently the non-invasive reference method in quantifying
myocardial blood flow (MBF), a measure commonly used for the detection of coronary artery
disease (CAD).
Quantitative cardiac magnetic resonance perfusion (CMR) may add a safer alternative to provide
objective estimates of cardiac perfusion. This study aims to validate its accuracy against PET in
patients after acute myocardial infarction (AMI).
Methods
First pass perfusion CMR and [15O]H2O-PET imaging was performed and compared on forty-eight
patients who had suffered an AMI and undergone successful primary percutaneous coronary
intervention (PCI).
Results
Preliminary results show poor overall correlation between PET and CMR in 17 patients when
comparing segments. In certain patients, however, PET and CMR perfusion data match reasonably
well. General PET and CMR perfusion data of larger myocardial areas correlate more favourably.
Conclusion
Comparing two separate physical principles like PET and CMR is not a straightforward process.
Differences in slice thickness, segmentation protocol and reproducibility have to be overcome
first. Our initial results suggest that careful slice matching could improve the correlation between
PET and CMR perfusion data.
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Diagnostic studies – Patients
100. Anti-Mullerian hormone serum levels decrease in female to
male transsexual women using testosterone as cross-sex
therapy
M.Caanen1, R.Soleman2, E. Kuijper1, B. Kreukels2, P. Hompes1, M. van Trotsenburg1, F. Broekmans3,
C. Lambalk1
¹Department of Obstetrics and Gynaecology, VU University Medical Center
²Department of Medical Psychology and Medical Social Work, VU University Medical Center
³Department of Obstetrics and Gynaecology, University Medical Center Utrecht
Introduction
Since Polycystic ovary syndrome (PCOS) is associated with elevated AMH levels, it is still unclear
whether this is a consequence of the amount of excessive small follicles or due to
hyperandrogenism, although it is assumed that androgens promote multiple early follicle growth,
of which high AMH levels could be a reflection. The aim of this study therefore is to investigate the
influence of androgenic treatment on AMH levels in women, the female-to-male transsexual served
as a study model.
Methods
22 De novo female-to-male transsexuals treated with cross-sex hormone therapy: 8 weeks of
GnRH-agonist to block endogenous ovarian activity. Subsequently 16 weeks androgenic
stimulation by combination of testosterone (5g/day, transdermally) and an aromatase-inhibitor
(letrozole: 2,5mg/day, orally) plus continuation of the GnRH-agonist. Hormone measurements
were done prior to and and after the androgenic treatment.
Results
After 8 weeks of agonist the serum AMH (µg/L) levels before androgen treatment were normal:
mean 4.4+4.4 and 16 weeks of testosterone/letrozole therapy serum AMH levels were significantly
lowered in all women to a mean of 1.4+2.1, (p=0.000). As expected, androgens were elevated after
treatment.
Conclusions
Prolonged testosterone administration in female-to-male transsexuals, results in a very strong
decline of AMH serum levels rather than an increase as expected. This challenges the earlier idea
that hyperandrogenism in PCOS is a cause of elevated serum AMH levels.
110
Diagnostic studies – Patients
101. Hysterosalpingo-foam sonography (HyFoSy), a new
technique to confirm proximal tubal occlusion after
treatment of a hydrosalpinx by an Essure® device prior
to in vitro fertilization IVF (IVF)
Dreyer K.¹, Mijatovic V.¹, Emanuel M.H.², Hompes P.G.A.¹
¹Department of Reproductive Medicine, VU University Medical Center, Amsterdam
²Department of Gynecology and Obstetrics, Spaarne Hospital, Hoofddorp
Introduction
Proximal occlusion of a hydrosalpinx by hysteroscopic insertion of an Essure® device may offer
a safe and effective alternative to laparoscopic tubectomy prior to IVF. In this pilot study we
investigate the accuracy of HyFoSy compared to hysterosalpingography (HSG) to confirm proximal
tubal occlusion after Essure® treatment for hydrosalpingen.
Methods
In 23 patients, who were treated by Essure® devices for hydrosalpingen prior to IVF, we performed
a HyFoSy as well as a HSG 12 weeks post-procedure.
Results
In 22 out of 23 (96%) patients, the HyFoSy procedure was successful in terms of an adequate filling
of the uterine cavity. One patient refused HSG examination.
In the 21 patients who underwent a successful HyFoSy as well as a HSG, the HyFoSy showed
proximal occlusion in 27 of the 29 treated hydrosalpingen, compared to proximal tubal occlusion
in 28 of the 29 treated hydrosalpingen at HSG.
The mean procedure time of HyFoSy was significantly shorter (6 minutes ± 2) compared to HSG
(11 minutes ± 5) (p = 0,01). Also the mean VAS pain score during HyFoSy (1,7 cm ± 1,9) was
significantly lower compared to HSG (4,3 cm ± 2,3) (p < 0,001)
Conclusions
HyFoSy is a promising new sonographic technique to confirm proximal tubal occlusion, in patients
treated with hysteroscopic placement of Essure® devices for hydrosalpinges, prior to IVF.
HyFoSy can easily be performed at the outpatient clinic by a gynecologist himself. It is less time
consuming, without radiation and HyFoSy is a less painful investigation compared to HSG.
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Diagnostic studies – Patients
102. Altered Proteobacteria Composition in Patients with Acute
Uncomplicated Diverticulitis
A. Eck1, L. Daniels2, M.A. Boermeester2, J.A. Bogaards3, P.H.M. Savelkoul1, A.E. Budding1
Department of Medical Microbiology and Infection Control, VU University Medical Center
Gastrointestinal Surgery, Academic Medical Center, University of Amsterdam
3
Department of Clinical Epidemiology and Biostatistics, VU University Medical Center
1
2
Introduction
There is increasing evidence of the role gut microbiota play in health and disease. Disease specific
variations have been found for a number of intestinal disorders. Yet, little is known about
microbiota variations in acute diverticulitis. Our aim was to characterize the baseline fecal
microbiota composition in patients with a first episode of acute uncomplicated diverticulitis and to
identify differences between diverticulitis patients and controls.
Methods
Patients were diagnosed with diverticulitis and sampled by rectal swabs. To obtain gut microbial
profiles, we used the IS-Pro technique: a high throughput PCR based profiling technique which
combines bacterial species differentiation by the length of the 16S-23S rDNA interspace region
with instant taxonomic classification by phylum specific fluorescent labeling of PCR primers.
Results
We compared 31 patients and 25 controls. Shannon diversity of the phylum Proteobacteria was
significantly higher in patients (p < 0.002). Differences in overall bacterial community composition
were assessed and principal coordinates analysis (PCoA) revealed that in the Proteobacteria
phylum patients were grouped separately from controls. Clinical status was predicted by the
Proteobacteria profile using a partial least squares discriminant analysis (PLS-DA). With crossvalidation specificity was 76% and sensitivity 81%. Considering all phyla, specificity was 84% and
sensitivity 88%.
Conclusions
Diverticulitis patients demonstrate a dysbiosis signature in their intestinal microbiota, evident
in the Proteobacteria phylum. We consider that specific members of this phylum play a role in
the pathophysiology of diverticulitis. Clinical implications may be for treatment, as microbial
stratification may guide antibiotic regimen and for diagnostics, as these species are potential
biomarkers.
112
Diagnostic studies – Patients
103. Assessing Muscle Endurance in Adolescents with Cerebral
Palsy using a Submaximal Repetitions to Fatigue Test
M.M. Eken, MSc1,2, H. Houdijk, PhD2,3, C.A.M. Doorenbosch1,4, H. Dekkers, MD2,
Prof. J.G. Becher, MD, PhD1, A.J. Dallmeijer, PhD1
Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University
Medical Center, Amsterdam
2
Heliomare Rehabilitation, Research and Development, Wijk aan Zee
3 MOVE Research Institute Amsterdam, Faculty of Human Movement Science, VU University,
Amsterdam
4
Academy of Human Kinetic Technology, University of Applied Sciences, The Hague
1
Introduction
The aim of the present study is to compare muscle endurance in adolescents with cerebral palsy
(CP) with typically developing (TD) adolescents using a new protocol based on a submaximal
repetitions-to-fatigue (RTF) test.
Methods
Thirteen adolescents with CP (spastic CP, GMFCS I-II) and fourteen TD adolescents (mean age
(yr:mo): respectively 15:9 and 15:8) performed series of isotonic knee extensions at three different
submaximal torques (~60-90% of maximal voluntary contraction (MVC)) until exhaustion. Load
endurance curves were assessed as the linear relationship between imposed (relative and absolute)
torque and number of repetitions.
Results
No significant difference was observed between relative (%MVC) load endurance curves of CP and
TD adolescents. Load endurance curves of absolute torque (Nm/kg) showed significant higher
torques in the TD adolescents as a function of repetition compared to the CP adolescents.
Conclusions
The load endurance curves of relative torque (%MVC) seems to demonstrate that muscle endurance
is similar in CP and TD adolescents, which is in contrast to earlier reported lower muscle
fatigability in individuals with CP. The load endurance curves of absolute torque (Nm/kg) indicate
a reduced capacity in adolescents with CP to endure loads at similar absolute loading conditions
when comparing to TD adolescents, which is in agreement with clinical observations.
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Diagnostic studies – Patients
104. The hippocampus in multiple sclerosis: Function,
structure and its relation with memory performance
Hanneke E. Hulst1, Menno M. Schoonheim1, Quinten van Geest1, Bernard M.J. Uitdehaag2,
Frederik Barkhof3, Jeroen J.G. Geurts
VU University Medical Center, Neuroscience Campus Amsterdam, Department of Anatomy and
Neurosciences
2
VU University Medical Center, Department of Neurology
3
VU University Medical Center, Department of Radiology
1
Introduction
Multiple sclerosis (MS) is a neuroinflammatory and degenerative disease of the central nervous
system, resulting in physical symptoms and memory impairment. The hippocampus plays an
essential role in memory function and is therefore interesting to study in the context of memory
impairment in MS. Our aim was to investigate structural and functional hippocampal changes in
MS and to identify the most important hippocampal parameter(s) for memory performance.
Methods
Structural MRI, resting-state and task-based functional MRI data were acquired from 57 MS patients
(39 females) and 28 healthy controls (HC, 19 females). Hippocampal volume, hippocampal
lesions, hippocampal activity during a memory task and hippocampal functional connectivity were
determined. A memory composite score was calculated based on a subset of memory tests from
a larger neuropsychological test battery. A linear regression analysis was used to define important
hippocampal parameters for memory function in MS.
Results
Hippocampal volume was significantly smaller in patients with MS compared to HCs, and patients
had one hippocampal lesion on average. Increased hippocampal connectivity was detected between
the left hippocampus and the right posterior cingulum. In this patient group, hippocampal
activation during a memory task was previously shown to be increased in cognitively preserved
and decreased in cognitively impaired patients, but did not differ from controls in the patient
group as a whole. Multivariate regression showed that memory dysfunction in MS was related to
male sex (beta = .41), lower hippocampal activity (task fMRI; beta = .32), and higher hippocampal
functional connectivity with the posterior cingulum (beta = .35; adjusted R2 = 0.32, p < .001).
Conclusions
The unique combination of advanced hippocampal neuroimaging measures showed that
increased hippocampal functional connectivity, decreased hippocampal activity and male sex
were associated with worse memory performance in MS. This underlines the predictive power of
functional measures in MS, and indicates that functional activation and functional connectivity are
two distinct entities to measure memory functioning.
114
Diagnostic studies – Patients
105. Compensatory fronto-parietal hyperactivation during setshifting in unmedicated patients with Parkinson’s disease
Niels J.H.M. Gerrits1,5, Ysbrand D. van der Werf1,2,5, Kim M.W. Verhoef1, Dick J. Veltman4,5,
Henk J. Groenewegen1,5, Henk W. Berendse3,5, Odile A. van den Heuvel1,4,5
Department of Anatomy & Neurosciences, VUmc, Amsterdam
Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of
Arts and Sciences, Amsterdam
3
Department of Neurology, VUmc, Amsterdam
4
Department of Psychiatry, VUmc, Amsterdam
5
Neuroscience Campus Amsterdam (NCA), Amsterdam
1
2
Introduction
Patients with Parkinson’s disease (PD) often suffer from impairments in executive functions, such
as mental rigidity, which can be measured as impaired set-shifting. Previous studies have shown
that set-shifting deficits in PD patients result from a hypo-excitation of the caudate nucleus
and lateral prefrontal cortices. These studies, however, included patients who used dopaminergic
medication and employed set-shifting paradigms in which task performance also depended on
other cognitive mechanisms. To circumvent these potential confounding factors, we tested PD
patients that were not yet using dopaminergic medication and developed a new set-shifting
paradigm.
Methods
Eighteen patients and thirty-five matched healthy controls performed the set shifting task, while
measuring their task-related neural activation with functional MRI.
Results
Behaviourally, PD patients, compared with healthy controls, made more errors on repeat, but not
set-shift trials. There were no group differences in switch costs or normalized switch costs. PD
patients, compared with healthy controls, showed increased task-related activation of the inferior
parietal cortex (IPC) and pre-supplementary motor area (preSMA), and a decreased activation of
the right ventrolateral prefrontal cortex (VLPFC) at set-shift trials. Normalized switch costs, in
addition, correlated in patients, but not in controls, with activation of the right prefrontal cortex.
Conclusions
The data suggest that, despite decreased task-related activation of the right VLPFC, these earlystage unmedicated PD patients do not yet suffer from set-shifting deficits due to compensatory
hyperactivation in the IPC and preSMA.
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Diagnostic studies – Patients
106. Birt-Hogg-Dubé syndrome patients with and without
pneumothorax: findings on chest CT
Johannesma P.C.1, van Waesberghe J.H.T.M.2, Reinhard R.2, Gille J.J.P.3, van Moorselaar R.J.A.4,
Houweling A.C.3, Starink Th.M.5, Menko F.H.3, Postmus P.E.1
Department of Pulmonary Diseases, VU University Medical Center
Department of Radiology, VU University Medical Center
3 Department of Clinical Genetics, VU University Medical Center
4 Department of Urology, VU University Medical Center
5 Department of Dermatology, VU University Medical Center
1
2
Introduction
Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant disorder characterized by
fibrofolliculomas, pulmonary cysts, (recurrent) spontaneous pneumothorax (SP) and renal cancer.
The relationship between pulmonary cysts and pneumothorax in BHD has not been clarified yet.
We compared chest CT findings in BHD patients (N=45) with and without pneumothorax.
Methods
Chest CT findings of 18 BHD patients with a history of (recurrent) SP and 27 BHD patients without
SP were evaluated. The cysts on chest CTs were scored for presence, number, size, shape,
craniocaudal distribution, relation to pleura and abutting to or enclosed lower pulmonary arteries
and veins.
Results
Conclusions
The number of lung cysts in BHD patients with a history of (recurrent) pneumothorax is significantly
higher (p<0.008) compared to that in BHD patients without a history of pneumothorax. The size of
lung cysts is not a benchmark for occurrence or recurrence rate of SP in BHD patients.
116
Diagnostic studies – Patients
107. Clinical cases; Spontaneous pneumothorax at the age of
14. Radiological evidence of Birt-Hogg-Dubé syndrome
Johannesma P.C.1, van den Borne B.E.E.M.2, Nagelkerke A.F.3, van Waesberghe J.H.T.M.4,
Paul M.A. 5, Menko F.H.6, Postmus P.E.1
Department of Pulmonary Diseases , VU University Medical Center
Department of Pulmonary Diseases, Catharina Hospital Eindhoven
3
Department of Pediatrics, VU University Medical Center
4
Department of Radiology, VU University Medical Center
5
Department of Thoracic Surgery, VU University Medical Center
6
Department of Clinical Genetics, VU University Medical Center
1
2
Introduction
In children spontaneous pneumothorax (SP) is far less frequent than in adults with an incidence
of 4/100,000 annually. We present two identical cases of SP at age 14.
Case reports – Results
Patient 1 suffered from 4 episodes of SP treated with respectively thoracoscopic pleurodesis,
pleurarubbing and tube thoracostomy performed twice. CT-chest revealed multiple cysts mainly
in basal parts of the lung (R>L). This combination of recurrent SP and lung cysts indicated Birt
Hogg-Dubé (BHD) syndrome, which was confirmed by FLCN mutation analysis.
Patient 2 suffered from 2 episodes of SP of the right lung treated with respectively pleural rubbing
and pleurectomy during VATS. Chest-CT showed multiple cysts in the basal parts of both lungs
(R>L). Two years later he was referred to VUmc because relatives were diagnosed having BHD
syndrome. Genetic Testing confirmed BHD.
Conclusions
BHD is an autosomal dominant inherited disorder, which clinically manifests as fibrofolliculomas,
renal tumours, lung cysts and (recurrent) pneumothorax (SP). Clinical manifestations of BHD
usually present in adults from the age of 20 onward. SP in pediatric population is relatively rare,
we report here two cases of BHD –genetically confirmed- in two pediatrics with recurrent SP. We
illustrate that BHD should be considered as underlying cause of SP during childhood.
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Diagnostic studies – Patients
108. Primary Spontaneous Pneumothorax: a pilot study on the
frequency of FLCN mutation (Birt-Hogg-Dubé syndrome)
Johannesma P.C.1, Menko F.H.2, Reinhard R.3, van Waesberghe J.H.T.M.3, van Moorselaar R.J.A.4,
Starink Th.M.5, Postmus P.E.1
Department of Pulmonary Diseases , VU University Medical Center
Department of Clinical Genetics, VU University Medical Center
3
Department of Radiology, VU University Medical Center
4
Department of Urology, VU University Medical Center
5
Department of Dermatology, VU University Medical Center
1
2
Introduction
Spontaneous pneumothorax (PSP) is often diagnosed without a known underlying cause. Air filled
cavities (blebs, bullae, cysts, ELC) are found in 90%, predominantly subpleural in apex of the
upper lobes. A disease with (recurrent) pneumothorax, lung cysts in lower lobes and renal cancer
is an autosomal dominant condition due to germline mutations in FLCN gene; the Birt-Hogg-Dubé
syndrome (BHDS). Frequency of BHD in PSP patients is unknown.
Methods
PSP patients (n=509) diagnosed between 1990 and 2012 were invited by letter to the last known
address - to participate in study for evaluation of the presence of BHD. The responders (n=42)
underwent skin examination by a dermatologist, FLCN mutation analysis and chest-CT.
Results
Mean age first PSP was 33.6 years (SD ± 15.2), 75.0% was (former) smoker, 27.5% smoked soft
drugs. Recurrence PSP was 52.5%, mean 2 episodes (range: 1-13).Three patients had pathogenic
FLCN germline mutation (7.1%; 95% CI: 0.0150 ; 0.1948), two had multiple bilateral episodes of
PSP, all three had multiple basal lung cysts. Fibrofolliculomas confirmed in two, none had renal
abnormalities on renal MRI. No basal lung cysts were found on chest CT in patients without
pathogenic FLCN mutation.
Conclusions
BHD might be more common among PSP patients than currently assumed.
118
Diagnostic studies – Patients
109. Chest CT for primary spontaneous pneumothorax (PSP):
findings: Birt-Hogg-Dubé versus non-Birt-Hogg-Dubé
patients
Johannesma P.C.1, van Waesberghe J.H.T.M.2, Reinhard R.2, Gille J.J.P.3, van Moorselaar R.J.A.4,
Houweling A.C.3, Starink Th.M.5, Menko F.H.3, Postmus P.E.1
Department of Pulmonary Diseases, VU University Medical Center
Department of Radiology, VU University Medical Center
3
Department of Clinical Genetics, VU University Medical Center
4
Department of Urology, VU University Medical Center
5
Department of Dermatology, VU University Medical Center
1
2
Introduction
Current guidelines advise chest X-ray in cases of primary spontaneous pneumothorax (PSP).
A disease with high incidence of pneumothorax is Birt-Hogg-Dubé (BHD) syndrome, caused by
germline mutations in the FLCN (folliculine) gene which causes fibrofolliculomas, recurrent SP,
lung cysts and renal cancer.
Methods
We evaluated Chest CT findings of SP patients with or without pathogenic FLCN mutation. Chest
CT’s were scored for presence, number, size, shape, craniocaudal distribution, relation to pleura
and abutting to or enclosed lower pulmonary arteries and veins.
Results
Conclusions
It is possible to differentiate between BHD and non-BHD patients with PSP based on CT findings.
Including chest CT in guidelines for PSP improves detection BHD.
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Diagnostic studies – Patients
110. Novel (ovario)leukodystrophy related to AARS2 mutations
Sietske H. Kevelam1, Cristina Dallabona2, Daria Diodato3,Tobias B. Haack4, Lee-Jun Wong5,
Gajja S. Salomons6, Eline M.Hamilton1, Truus E.M. Abbink1, Nicole I. Wolf1, Massimo Zeviani7,
Adeline Vanderver8,Daniele Ghezzi3, Marjo S. van der Knaap1,9
Department of Child Neurology, VU University Medical Center, The Netherlands
Department of Life Sciences, University of Parma, Italy
3
Unit of Molecular Neurogenetics, IRCCS, Italy
4
Institute of Human Genetics and Helmholtz Zentrum, Germany
5
Department of Molecular & Human Genetics, Baylor College of Medicine, USA
6
Department of Clinical Chemistry, VU University Medical Center, The Netherlands
7
Mitochondrial Biology Unit - MRC,UK
8
Center for Genetic Medicine Research, Department of Neurology,USA
9
Department of Functional Genomics, CNCR, VU University, The Netherlands
1
2
Introduction
The study was focused on leukoencephalopathies of unknown cause with the aim to define a novel
similar phenotype suggestive of a common genetic defect, based on clinical and MRI findings, and
to identify the causal genetic defect.
Methods
Next generation exome sequencing was performed in two unrelated patients with a
leukoencephalopathy. Their MRI findings were compared to available MRIs in a database of
unclassified leukoencephalopathies; 11 patients with similar MRI abnormalities were selected.
Clinical and MRI findings were investigated.
Results
Next generation sequencing revealed compound heterozygous mutations in AARS2 encoding
mitochondrial alanine-tRNA synthetase in both patients. Functional studies in yeast confirmed the
pathogenicity of the mutations in one patient. Sanger sequencing revealed AARS2 mutations in
4 of the 11 additional patients. The 6 patients with mutations had childhood to adulthood onset
signs of neurological deterioration consisting of ataxia, spasticity and cognitive decline with
features of frontal lobe dysfunction. MRIs showed a leukoencephalopathy with involvement of
left-right connections and ascending and descending tracts, and cerebellar atrophy. Females had
ovarian failure.
Conclusions
Mutations in AARS2 have been found in a severe form of infantile cardiomyopathy in two families.
We present 6 patients with a new phenotype caused by AARS2 mutations, characterized by
leukoencephalopathy and, in female patients, ovarian failure, indicating that the phenotypic
spectrum associated with AARS2 variants is much wider than previously reported.
120
Diagnostic studies – Patients
111. Brain activation patterns reflect quality of motor control of
the paretic upper limb after stroke
Floor E. Buma1,2, Joost van Kordelaar3, Matthijs Raemaeckers2, Erwin E.H. van Wegen3,
Dietsje Jolles4, Nick F. Ramsey2, Gert Kwakkel3,5
Centre of Knowledge, Rehabilitation Centre ’De Hoogstraat’, Utrecht
Dept. Neurology & Neurosurgery, Rudolf Magnus Institute of Neuroscience, UMC Utrecht, Utrecht
3
Dept. Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center,
Amsterdam
4
Dept. Leiden Institute for Brain and Cognition, Leiden University, Leiden
5
Amsterdam Rehabilitation Research Center, Reade Centre for Rehabilitation and Rheumatology,
Amsterdam
1
2
Introduction
Patients with stroke often show increased brain activation in ipsilesional and contralesional
secondary sensorimotor areas and cerebellum. However, it is unclear whether these areas can
‘take-over’ lost neurological function to restore quality of motor control after stroke. The present
study investigated how cortical activation patterns are associated with quality of motor control in
terms of smoothness of upper limb movements at week 5 and 26 after stroke.
Methods
In 17 patients, cortical activation levels in 12 regions of interest were determined with fMRI while
a finger flexion-extension task was performed. In the same patients, smoothness of the grasp
aperture was assessed during a reach-to-grasp task by determining the normalized jerk of finger
movements with 3D kinematic analyses. Analyses of variance with post-hoc Pearson correlation
coefficients were conducted to investigate how activation in each region of interest was associated
to smoothness of grasp aperture.
Results
Higher activation in the ipsilesional premotor cortex, insula and cerebellum as well as contralesional
supplementary motor area, insula and cerebellum correlated significantly with more normalized
jerk of grasp aperture at week 5 after stroke.
Conclusions
This study suggests that involvement of secondary sensorimotor areas early after stroke results in
less efficient motor strategies culminating in unsmooth, jerky movements. Additionally recruited
sensorimotor areas may therefore not be able to restore quality of motor control after stroke. This
finding suggests that neurorehabilitation should aim to enhance true neurological recovery of the
primary motor system by optimizing quality of motor control within the first 5 weeks after stroke.
VU University Medical Center Science Exchange Day 2014
121
Diagnostic studies – Patients
112. Diaphragm dysfunction in pulmonary arterial
hypertension patient
E. Manders1,2, P.I. Bonta3, J.J. Kloek4, P. Symersky4, N. Westerhof1, G.J.M. Stienen2,
A. Vonk Noordegraaf1, F.S. de Man1 and C.A.C. Ottenheijm2
Department of Pulmonology, Institute for cardiovascular research, VU University Medical Center,
Amsterdam
2
Department of Physiology, Institute for cardiovascular research, VU University Medical Center,
Amsterdam
3
Department of Pulmonology, Amsterdam Medical Center, Amsterdam
4
Department of Cardiothoracic surgery, Amsterdam Medical Center, Amsterdam
1
Introduction
Recently, it was suggested that patients with pulmonary arterial hypertension (PAH) suffer from
diaphragm dysfunction due to increased loading. To test this, we studied the contractile strength
of diaphragm muscle fibers of PAH-patients. Furthermore, we determined whether diaphragm fiber
contractile strength correlates with in vivo measures of diaphragm function, disease severity and
exercise capacity.
Methods
Mean inspiratory and expiratory pressures (MIP/MEP) were assessed in patients with chronicthromboembolitic pulmonary hypertension (CTEPH, N=8). Diaphragm and non-diaphragm muscle
biopsies were obtained during pulmonary endarterectomie (N=12). For muscle fiber contractile
measurements, triton-permeabilized single fibers were mounted between a force transducer and
a length motor. Maximal active tension (Fmax, normalized to cross sectional area), the rate constant
of force redevelopment (ktr), and active stiffness was measured at saturating Ca2+-concentration
(pCa4.5), while Ca2+-sensitivity was determined at non-saturating Ca2+-concentrations.
Results
Diaphragm fiber F­max was significantly lower compared to non-diaphragm fibers in CTEPH-patients
(141 ± 25 [mN/mm­2] vs. 162 ± 16 [mN/mm­2]). Active stiffness, reflecting the number of cycling
cross-bridges, was not different between groups, while the tension/stiffness ratio, an estimate of
the force per cross-bridge, was significantly lower in diaphragm muscle (2.6 ± 0.2 vs. 3.0 ± 0.5
[a.u.]). The ktr, a measure of cross-bridge cycling kinetics, was significantly lower in diaphragm
fibers (9.0 ± 2.4 vs. 11.2 ± 2.7 [s-1]) and Ca2+-sensitivity, expressed as pCa50, was also significantly
lower in diaphragm muscle fibers (6.10 ± 0.06 vs. 6.14 ± 0.07).
Diaphragm F­max was significantly correlated with MEP ([% of predicted], p = 0.03, r2 = 0.57), 6MWT
([m], p = 0.03, r2 = 0.42) and VO2max ([L/min], p = 0.03, r2 = 0.47). No correlation was found
between diaphragm Fmax and mean pulmonary artery pressure, cardiac output or pulmonary
vascular resistance. Non-diaphragm F­max did not correlate with any of the parameters tested.
Conclusions
Although caution is in order when comparing diaphragm fibers with fibers of other skeletal
muscles, our results suggest that the contractile function of diaphragm muscle fibers is
hampered. The correlations between diaphragm fiber contractile function and exercise parameters
such as 6MWT and VO2max, suggests that diaphragm weakness might contribute to the limited
exercise capacity of CTEPH-patients.
122
Diagnostic studies – Patients
113. Contrast-Enhanced MRI as method to monitor response to
anti-angiogenic therapy
Marcus J.T.1, Pieters - van den Bos I.C.2, de Langen A.J.3,Verdaasdonk R.1
Physics & Medical Technology, Institute for Cardiovascular Research, VU University Medical Center
Radiology, VU University Medical Center
3
Pulmonology, VU University Medical Center
1
2
Introduction
Early monitoring of tumor respons to anti-angiogenic therapy is relevant. Thus the vascular
permeability is to be measured. The aim is to set up a procedure for quantification of this
permeability.
Methods
Dynamic contrast enhanced (DCE) MRI was used with a bolus of extracellular Gd contrast agent
(MagnevistR). This was applied on a patient with colo-rectal liver metastases, and a patient with
non small cell lung cancer. For analysis, a dual compartment tissue model was used: plasma (Vp)
and the extracellular extravascular space (Ve). Contrast concentration in Ve was calculated from
the convolution of the impulse response function and the arterial input function. The transfer
constants between the 2 compartments were calculated: Ktrans and Kep.
Results
Functional maps of permeability parameters Ktrans and Kep were obtained. In the liver metastases,
Ktrans ranged between 0.175 and 0.550 [min-1], displaying heterogeneity within the tumor and
a central region with lowest values (probably central necrosis). Kep ranged between 0.353 and
1.97 [min-1]. In the lung tumor, Ktrans ranged between 0.2 and 0.32 [min-1].
Conclusions
A workflow for quantification of tumor permeability is presented. The spatial heterogeneity within
the tumor needs further exploration. Also, the validity and accuracy of the permeability
parameters are still to be assessed.
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123
Diagnostic studies – Patients
114. Non-invasive assessment of the speed of cardiac
contraction
MJ van Rijssel 1, M.A.J.M. van Eijnatten1, R.M. Verdaasdonk1,2, J.H. Meijer1,2
1
2
Department of Physics and Medical Technology, VU University Medical Center
Institute for Cardiovascular Research, VU University Amsterdam
Introduction
When the electrical conductivity of a human thorax is measured, a signal synchronous with the
heart activity can be obtained. The time derivative of this electrical signal shows a characteristic
pulse around the moment of ejection of the ventricles. The time difference between the peak of
this C-wave (C-point) and the R-point in the ECG, is called the Initial Systolic Time Interval (ISTI).
ISTI shows a substantial variation in practise of about 15-25% of the cardiac cycle. Explorative
research after cardiac surgery and during haemodialysis has shown that ISTI depends on the
circulating blood volume. ISTI is also affected by diseases of the autonomous nervous system
(Parkinson’s disease) and is influenced by training in sports.
Methods
The timing of the C-point was compared with other markers of the cardiac cycle obtained by
echocardiography, in a group of 16 healthy volunteers. Heart rate was varied by the application
of an exercise stimulus on a stationary bicycle. The cycle markers from echocardiography were:
opening and closure of the aortic valves, maximum diameter of the aortic arch and of the
descending aorta.
Results
The C-point coincides with the maximum diameter of the aortic arch over a wide range of heart
frequencies. However, while the other markers show a trend with the RR-interval, the C-point
occurs at a constant time interval after opening of the valves.
Conclusion
The present study links the simply measurable ISTI to the time interval between the maximum
electric activity of the heart and the moment of maximum diameter of the aortic arch during
systole. It shows that the non-invasive ISTI can be used as a diagnostic tool to evaluate the speed
of cardiac contraction in a large variety of clinical and non-clinical situations.
124
Diagnostic studies – Patients
115. Predictive value of diffusion-weighted imaging without
and with contrast-enhanced magnetic resonance imaging
in head and neck squamous cell carcinoma
Daniel P Noij 1, Pim de Graaf , MD PhD1, Petra J.W. Pouwels, PhD2, Redina Ljumanovic, MD PhD1,
Dirk L. Knol, PhD3, Patricia Doornaert, MD4, Remco De Bree, MD PhD5, Jonas A. Castelijns, MD PhD1
Department of Radiology and Nuclear Medicine, VU University Medical Center
Department of Physics and Medical Technology, VU University Medical Center
3
Department of Epidemiology and Biostatistics
4
Department of Radiation Oncology, VU University Medical Center
5
Department of Otolaryngology / Head and Neck Surgery, VU University Medical Center
1
2
Introduction
Several studies have reported on the predictive value of diffusion-weighted imaging (DWI), but
none of these studies compared the predictive value of DWI to contrast-enhanced T1-weighted
imaging (CE-T1WI). We compared the predictive value and interobserver agreement of pretreatment
DWI without and with CE-T1WI in patients with head and neck squamous cell carcinoma (HNSCC)
treated with (chemo)radiotherapy ((C)RT).
Methods
We retrospectively studied 78 patients who underwent pretreatment MRI for HNSCC staging.
ADC-values were calculated with two sets of b-values: 0-750 s/mm2 (ADC750) and 0-1000 s/mm2
(ADC1000). Volume of the tumor and largest lymph node was assessed on T1 by one observer.
Two observers assessed the ADC in two sessions:
without and with the use of CE-MRI. Bland-Altman
plots were used to compare both methods.
We assessed interobserver agreement and
intersession agreement with ICC. ADC-values were
related to progression free survival (PFS) using Cox
regression analysis.
Results
Mean follow-up was 18 ± 9 months. ICC range was 0.81-0.92 in the primary tumor and 0.61-0.83
in lymph nodes. Without using CE-T1WI, ADC-values were lower compared than with CE-T1WI
(P <0.001). Intersession ICC range was 0.84-0.89. Pretreatment primary tumor volume and lymph
node ADC1000 were independent significant predictors of PFS in both sessions (P <0.05).
Conclusions
Pretreatment primary tumor volume and lymph node ADC1000 are significant independent predictors
of PFS in HNSCC treated with (C)RT. PFS can be predicted equally well with ADC-values acquired
without and with using CE-T1WI.
VU University Medical Center Science Exchange Day 2014
125
Diagnostic studies – Patients
116. Cognitive Subtypes in Alzheimer Disease defined by Latent
Class Analysis
N.M.E. Scheltens1, MD, F. Galindo Garre2, PhD, Y.A.L. Pijnenburg1, MD, PhD, A.E. van der Vlies1,
PhD, L.L. Smits1, MSc, T. Koene3, MSc, C.E. Teunissen4, PhD, F. Barkhof5, MD, PhD,
Ph. Scheltens, MD, PhD, W.M. van der Flier1,2, PhD
1
Alzheimer Center and Department of Neurology. Neuroscience Campus Amsterdam,
VU University Medical Center (VUmc) Amsterdam
2
Department of Epidemiology and Biostatistics, VUmc Amsterdam
3
Alzheimer Center and Department of Medical Psychology, VUmc
4
Department of Clinical Chemistry, VUmc Amsterdam
5
Department of Radiology, VUmc Amsterdam
Introduction
We aimed to identify cognitive subtypes in Alzheimer Disease (AD) by performing latent class
analysis (LCA) of neuropsychological test results.
Methods
For LCA we used neuropsychological test results of 938 patients with probable AD. Cluster
membership was analyzed for associations with demographics, APOE genotype, CSF biomarkers
and MRI characteristics.
Results
LCA revealed eight clusters, which were characterized by disease severity and impairment of
specific cognitive domains: mild-memory (MILD-MEM), mild-executive (MILD-EXE), mild-diffuse
(MILD-DIFF), mild-visuoperception-language (MILD-VILA), moderate-memory (MOD-MEM),
moderate-visuospatial (MOD-VISP), moderate-language (MOD-LAN) and severe-diffuse (SEV-DIFF).
MILD-VISP was the youngest, MOD-MEM and SEV-DIFF were least educated. MOD-LAN and SEV-DIFF
had most severe medial temporal lobe atrophy, while global cortical atrophy was most severe in
MOD-VISP. Multinomial logistic regression analysis with MILD-MEM as reference cluster and cluster
membership as dependent variable also revealed an association between APOE e4 negative
genotype and MOD-VISP, higher tau and MOD-LAN, lower ptau and MILD-EXE and MILD-DIFF, more
posterior cortical atrophy and MOD-VISP and SEV-DIFF.
Conclusions
LCA identified eight clusters with distinct cognitive profiles, demonstrating clinical heterogeneity
in AD. Associations with demographics, APOE genotype, tau, ptau and MRI characteristics suggest
biological underpinning.
126
Diagnostic studies – Patients
117. Perturbations during treadmill walking offer opportunities
for functional assessment of ankle stiffness
L.H. Sloot MSc1, K.L. de Gooijer-van de Groep MSc2, H. Kristinsdóttir3, S. van Eesbeek MSc3,
J.H. de Groot PhD2, C.G.M. Meskers MD PhD2, E. de Vlugt PhD3, J. Harlaar PhD1
Department of Rehabilitation, VU Medical Center
Department of Rehabilitation Medicine, Leiden University Medical Center
3
Biomechanical Engineering, Delft University of Technology
1
2
Introduction
Clinical assessment of joint stiffness is performed under passive conditions. Yet, therapy like
botulinum toxin may be targeted at functional improvement. We therefore aimed to develop a
method to quantify joint stiffness during active conditions, i.e. walking.
Methods
The method is to be developed for regular treadmill walking and based on techniques for center of
pressure analysis and leg segment tracking (Optotrak, Northern Digital, Canada) and joint moment
calculation. To estimate ankle stiffness, small ankle rotations need to be applied at any instant of
stance without disturbing the gait pattern and inducing instability.
Results
Initially, a custom dual belt treadmill (Forcelink, the Netherlands) with 3-dimensional force and
moment registration was constructed to apply the perturbations. Timing of the perturbation
was based on the moment of heel strike (recorded from the forces) and a fixed delay based on
previous steps. The perturbations induced an additional 50 Nm (relative to 100 Nm ankle torque
during walking in the unperturbed case). Gait was slightly disturbed but restored within 5 steps.
Conclusion
This unique measurement set-up allows us to measure ankle position and ankle torque by fast
perturbations while walking. This permits us to determine the functional ankle stiffness and the
underlying contributors i.e. connective tissue and (activated) muscle. Assessment of ankle joint
stiffness during active functional conditions will be a valuable expansion of current gait analysis to
direct and evaluate therapy like botulinum toxin.
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127
Diagnostic studies – Patients
118. The coupling of the right ventricle to its load during
exercise in pulmonary hypertension
Spruijt O.A.1, Bogaard H.J.1, de Man F.S.1,, Oosterveer F.1, Groepenhoff H.1, Westerhof N.1,2,
Vonk-Noordegraaf A.1
Department of Pulmonology1 and Physiology2, VU University Medical Center, Amsterdam
Introduction
The aim of this study was to investigate whether coupling of the right ventricle (RV) to its load
deteriorates during exercise in patients with pulmonary hypertension (PH).
Methods
We prospectively included 10 patients with idiopathic pulmonary arterial hypertension and
2 patients with chronic thromboembolic pulmonary hypertension. All subjects underwent a
3 minute’ submaximal (40% of maximal workload) supine exercise protocol with a pulmonary
artery catheter in situ. Resting and exercise hemodynamics were continuously recorded and the
coupling of the RV to its load was assessed using pressure-volume loop analysis at rest and after
3 minutes of sub maximal exercise.
Results
Patients characteristics and resting hemodynamics (median and interquartile range): age 55
(44-62); New York Heart Association (NYHA) functional class: 7 patients NYHA II / 5 patients NYHA
III; mean pulmonary artery pressure 48 (41-50) mmHg; pulmonary arterial wedge pressure 11 (712) mmHg; pulmonary vascular resistance 529 (369-691) dyn∙s/cm5; cardiac index 3,2 (2,8-3,3)
L/min/m2; right atrial pressure 9 (4-11) mmHg.
During exercise, RV contractility (Ees) did not change despite a significant increase in RV afterload
(Ea), resulting in a decrease in RV coupling (Ees/Ea) (figure 1).
Figure 1:
Conclusion
PH patients show a variable but substantial deterioration in coupling of the RV to its load during
exercise. It remains to be determined whether the change in coupling during exercise is related to
disease severity.
128
Diagnostic studies – Patients
119. Altered neural connectivity during an n-back task in
unmedicated Parkinson´s disease patients
James P. Trujillo*1,4, Niels J.H.M. Gerrits*1,5, Dick J. Veltman4,5, Henk W. Berendse3,5,
Ysbrand D. van der Werf1,2,5#, Odile A. van den Heuvel1,4,5#
*,# Both authors contributed equally to this work
Department of Anatomy & Neurosciences, VU University Medical Center (VUmc), Amsterdam
Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts
and Sciences, Amsterdam
3
Department of Neurology, VUmc, Amsterdam
4
Department of Psychiatry, VUmc, Amsterdam
5
Neuroscience Campus Amsterdam (NCA), Amsterdam
1
2
Introduction
Patients with Parkinson’s disease (PD) often suffer from impairments in executive functions. We
investigated these impairments by studying activity and connectivity patterns during a working
memory task in unmedicated PD patients compared with matched healthy controls.
Methods
Sixteen unmedicated patients with PD and 35 matched healthy-controls performed a visuospatial
n-back task while we measured their behavioural performance and neural activity using functional
MRI. Using a region-of-interest (ROI) approach, we assessed group differences in activity in the
bilateral inferior parietal, bilateral dorsolateral prefrontal cortex, and bilateral caudate nucleus.
We furthermore assessed the functional connectivity of the dorsolateral prefrontal cortices, and
the effective connectivity within the fronto-parietal and the fronto-striatal networks.
Results
PD patients, compared with controls, only had marginally lower overall accuracy scores yet showed
increased task-related neural activity in the bilateral dorsolateral prefrontal cortex, bilateral
caudate nucleus and left inferior parietal cortex. We found reduced functional connectivity of the
dorsolateral prefrontal cortices in the PD group, and a more disconnected fronto-parietal network
within in the PD patients compared with controls when assessing effective connectivity.
Conclusions
The findings seem to indicate that the task-related network in patients with PD shows
compensatory hyperactivation in order to maintain behavioural performance in the presence of
network deficits due to altered effective and functional connectivity.
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129
Diagnostic studies – Patients
120. Innovative Molecular Drug Imaging: Pioneering Work in
Children
S.E.M. Veldhuijzen van Zanten1,2, i, M.H.A. Jansen1,2, i, D.G. van Vuurden1,2, M.C. Huisman3,
D.J. Vugts4, O.S. Hoekstra3, G.A.M.S van Dongen3,5, G.J.L. Kaspers1,2
Department of Pediatrics, VU University Medical Center
Neuro-Oncology Research Group, VU University Medical Center
3
Department of Radiology & Nuclear Medicine, VU University Medical Center
4
Department of Nuclear Medicine & PET research, VU University Medical Center
5
Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center
i
Shared first authorship
1
2
Introduction
We are the first to report the use of molecular drug imaging in children. We aim to determine
the feasibility of the procedure and aim to analyzing the therapeutic- and toxic potential of
bevacizumab in these children.
Methods
Three patients, aged 6, 7 and 17 years, diagnosed with diffuse intrinsic pontine glioma (DIPG)
were included after standard treatment with radiotherapy. Each patient received 0.1mg/kg
bevacizumab, labeled with 0.9MBq/kg zirconium-89(89Zr). Whole body PET-CT scans were
performed at 1, 72 and 144 hours post-injection. Researchers closely monitored the feasibility
of the procedure. To determine the tumor uptake and biodistribution of 89Zr-bevacizumab,
Standardized Uptake Values (SUVs) were calculated.
Results
No adverse events occurred during any of the study procedures and scans were of good quality.
Tumor uptake was shown in two out of three patients and was limited to the T1-MRI contrastenhanced part of the tumor, with SUVs of 1.8/15.0 versus 0.4/0.6 in the non-enhancing versus
enhancing part, respectively. The highest 89Zr-bevacizumab uptake in organs was observed in the
liver, followed by the kidneys, lungs, and bone marrow.
Conclusions
Administration of 89Zr-bevacizumab followed by a repeated PET-scan procedure is feasible in
children. Bevacizumab uptake in organs was high in all three DIPG patients. However, only two
patients showed significant bevacizumab uptake in their tumor. Moreover, uptake was limited
to the contrast-enhancing part, suggesting that blood-brain barrier disruption is required for
bevacizumab accessibility. With this first successful introduction of molecular drug imaging in
children with cancer, we emphasize it’s importance in treatment decision-making.
130
Diagnostic studies – Patients
121. Clinical Staging of Major Depressive Disorder:
an empirical exploration
Judith Verduijn, MD1, Yuri Milaneschi, PhD1, Albert M. van Hemert, MD, PhD2, Robert A. Schoevers,
MD, PhD3, Ian B. Hickie, MD, FRANZCP4, Brenda W.J.H. Penninx, PhD1, Aartjan T.F. Beekman, MD, PhD1
Department of Psychiatry and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands
2
Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands
3
University of Groningen, University Medical Center Groningen, Department of Psychiatry,
Groningen, The Netherlands
4
Brain and Mind Institute, University of Sydney, Sydney, Australia
1
Introduction
Clinical staging has been proposed to supplement psychiatric diagnoses. We examined the
construct and predictive validity of a clinical staging model for MDD that distinguishes eight
consecutive stages (0,1A,1B,2,3A,3B,3C,4) based on severity and duration of symptoms, and
number of episodes.
Methods
At baseline 2393 Netherlands Study of Depression and Anxiety participants were assigned to
the eight stages of the model, of them 2069 were followed-up after two years. For construct
validity, differences between stages in clinical characteristics (e.g.: severity, age of onset,
co -morbid anxiety) were studied.
Predictive validity was measured by the extent to which baseline stages predicted 2-year follow-up
outcomes (e.g. MDD presence).
Results
Most clinical characteristics and follow-up outcomes showed a significant linear trend across stages
with later stages having worse outcomes than early stages, confirming validity of the model.
Both construct and predictive validity analyses suggest that the model performs best in the early
(mostly pre-clinical) stages (0,1A,1B,2). However, in the later (clinical) stages (2,3A,3B,3C,4),
validity analyses showed no differences between each consecutive stage, but only between stages
with long-lasting symptoms (3A,4) compared to stages differing in number of episodes (2,3B,3C).
The long-lasting stages had generally the worst outcomes.
Conclusions
This study showed reasonable validity for an MDD staging model that based it stages purely on
clinical characteristics. Results suggest that, contrary to the number of episodes, duration of
exposure to the depressed state best characterizes later stages of MDD. Future studies should test
whether modifications to these later stages improve the validity of the model.
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131
Diagnostic studies – Patients
122. Functional deficits in response inhibition in de novo
Parkinson’s disease
Chris Vriend, MSc1-3, Niels J.H.M. Gerrits, Msc2,3, Henk W. Berendse, MD PhD3,4,
Dick J. Veltman, MD PhD1,3, Odile A. van den Heuvel, MD PhD1-3, Ysbrand D. van der Werf, PhD2,3,5
Department of Psychiatry, VU University Medical Center
Department of Anatomy & Neurosciences, VU University Medical Center
3
Neuroscience Campus Amsterdam, VU/VUmc
4
Department of Neurology, VU University Medical Center
5
Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences
1
2
Introduction
Behavioral impairments in motor response inhibition and initiation are common in Parkinson’s
disease and are associated with reduced impulse control. However, no published study has yet
investigated the behavioral and functional correlates of motor response inhibition in de novo
Parkinson’s disease. Furthermore, the role of dopamine denervation in impulse control remains
under debate.
Methods
Twenty-one de novo Parkinson’s disease patients and 37 matched healthy controls performed a
stop-signal task during fMRI. In addition, 15 patients with Parkinson’s disease underwent [123I]FPCIT dopamine transporter (DaT) SPECT imaging to measure DaT availability in the caudate head,
posterior putamen and nucleus accumbens, as an indicators of striatal dopaminergic denervation.
Results
Patients with Parkinson’s disease were slower on response initiation and inhibition and these
types of slowing were unrelated to each other. Task-related activation of the response inhibition
network, including the inferior frontal gyrus, was reduced. The activity in the inferior frontal gyrus
correlated negatively with motor symptom severity in Parkinson’s disease and positively with
DaT availability in the caudate head.
Conclusions
These findings reveal for the first time that de novo Parkinson patients exhibit functional deficits
in brain areas of the response inhibition network and we tentatively suggest that these deficits are
related to dopaminergic denervation of the caudate head. This study provides insights into the
neural underpinning of impulse control deficits and the possible development of impulse control
disorders in Parkinson’s disease.
132
Diagnostic studies – Patients
123. Force-sarcomere length relations in patients with thin
filament myopathy caused by mutations in NEB, ACTA1
and TPM3
Josine M. de Winter1,3, B. Joureau1, C.T. Pappas2, G.J.M. Stienen4, A. Beggs5, N. Clarke6, H. Granzier3,
C.C. Gregorio2, C.A.C. Ottenheijm1,3
Dept. of Physiology, VU University Medical Center, Amsterdam, The Netherlands
Dept. of Cell Biology, University of Arizona, Tucson AZ, USA
3
Dept. of Physiology, University of Arizona, Tucson AZ, USA
4
Dept. of Physics and Astronomy, VU University, Amsterdam, The Netherlands
5 Division of Genetics and Program in Genomics, The Manton Center for Orphan Disease Research,
Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
6 Institute for Neuroscience and Muscle Research, The Children’s Hospital at Westmead, NSW,
2145, Australia
1
2
Introduction: Mutations in the nebulin gene (NEB), skeletal muscle alpha-actin1 gene (ACTA1),
and alpha-tropomyosin 3 gene (TPM3) lead to thin filament myopathies, such as nemaline
myopathy (NM), congenital fiber type disproportion (CFTD) and cap disease (CAP). A hallmark
feature of these myopathies is muscle weakness. Here, we aimed to elucidate the effect of
NEB, ACTA1 and TPM3 mutations on thin filament length by determining the sarcomere lengthdependence of force.
Methods: Quadriceps biopsies from NM, CFTD, and CAP patients (n=16) with mutations in either
the NEB, ACTA1, or TPM3 were compared to biopsies from controls (n=3). Using permeabilized
muscle fibers, maximal active tension was determined at incremental sarcomere lengths (range
2.0–3.5 µm) to obtain the force-sarcomere length relationship.
Results: The maximal active tension and the force-sarcomere length relationship data are
summarized in the table below (a leftward shift of the force-sarcomere length relation indicates
shorter thin filaments). The classification of severity is based on the age of onset. Data are
presented as mean±SD.
Maximal active tension
(mN/mm2)
CTRL
164±17
Shape of forcesarcomere length
ACTA1
mild form
ACTA1
severe form
NEB
mild form
NEB severe
form
TPM3
mild form
TPM3
severe form
139±27
54±13#
76±5#
18±5#
156±13
95±14#
Un-affected
Modest leftward shift
Modest leftward shift
Marked leftward shift
Un-affected
Un-affected
relation
#
Significantly lower compared to CTRL
Note that, in contrast to patients with ACTA1 and TPM3 mutations, fiber preparations from both
mildly and severely affected NEB patients have a disturbed force-sarcomere length relation.
Conclusions: Our data suggest that mutations in NEB result in the most pronounced changes
in thin filament length. Insights in the mechanisms underlying weakness in patients with thin
filament mutations are necessary to improve specific treatment strategies.
This work was supported by the ERA-NET E-Rare (7th Framework Programme) grant NEMMYOP and a VIDI grant
from the Dutch Organization for Scientific Research.
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133
Diagnostic studies – Patients
124. Is capacity for upper extremity motor recovery fixed after a
first-ever ischemic stroke?
C. Winters, MSc¹, E.E.H. van Wegen, PhD¹, A. Daffertshofer, PhD² and G. Kwakkel, PhD¹,³
Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam,
VU University Medical Center, Amsterdam, The Netherlands.
2
Faculty of Human Movement Sciences, MOVE Research Institute Amsterdam,
VU University, Amsterdam, The Netherlands.
3
Department of Neurorehabilitation, Reade Centre for Rehabilitation and Rheumatology,
Amsterdam, The Netherlands.
1
Introduction
Spontaneous neurological recovery after stroke is a poorly understood process. The aim of the
present paper was to investigate the proposed proportional recovery of upper extremity capacity,
and to identify clinical characteristics of patients who do not fit this model.
Methods
A change in the Fugl-Meyer Assessment (FMA) arm score measured within 72 hours and at six
months poststroke served to define motor recovery. Capacity for FMA recovery was predicted
using the proposed model of maximal potential recovery. Hierarchical cluster analysis was used
to separate non-fitters (i.e., outliers) from fitters. Group comparisons between non-fitters and
fitters were made using clinical determinants measured <72 hours poststroke. Subsequent logistic
regression analysis served to predict patients who may not fit the proposed maximal potential
recovery model.
Results
The majority of patients (~70%; N=146) showed a fixed proportional upper extremity motor
recovery of about 78%. Sixty-five patients had substantially less upper extremity motor
improvement than predicted. These non-fitters had significantly more severe neurological
impairments within 72 hours poststroke (p-values<0.01). Logistic regression analysis revealed that
absence of finger extension, facial palsy, more severe lower extremity paresis, and more severe
type of stroke as defined by the Bamford classification were significant predictors of not fitting the
proportional recovery model of upper extremity motor recovery.
Conclusions
Stroke patients show an almost fixed proportional upper extremity motor recovery. Patients with
more extended infarcts affecting multiple modalities show significantly less spontaneous recovery
than predicted. The neurobiological mechanisms responsible for insufficient spontaneous recovery
require further investigation.
134
Literature Surveys
125. Helminth infections and mrconutrients in schoolchildren:
a systematic review and meta-analysis
Brechje de Gier1,2, Maiza Campos Ponce1, Margot van de Bor2, Colleen M. Doak1, K.Polman1
1
Department of Health Sciences, section Infectious Diseases; VU University Amsterdam
Department of Health Sciences, section Health and Life Sciences; VU University Amsterdam
2
Introduction
Helminth infections and micronutrient deficiencies are both highly prevalent in developing
countries. Neither condition typically causes overt disease but they do lead to indirect morbidity
and impaired physical and cognitive development. We aimed to systematically review current
evidence on the relationship of helminth infections with micronutrient status in schoolchildren
worldwide.
Methods
We included both observational studies and RCTs. We used random effects meta-analysis 1) to
estimate cross-sectional associations between helminths and micronutrient status; 2) to estimate
anthelminthic treatment effects on micronutrient status, and 3) to estimate effects of micronutrient
supplementation on helminth (re)infection.
Results
Meta-analyses of observational studies showed a significant association between helminth infections
and serum retinol (SMD (standardized mean difference) -0.30 [-0.48;-0.13]) but not serum ferritin
(SMD 0.00 [-0.7;0.7]). Conversely, meta-analyses of anthelminthic RCT studies did show a positive
effect on ferritin (SMD 0.14 [0.08;0.20]) but not on retinol (SMD 0.04 [-0.06;0.14]). We did not find
enough studies to pool data on other micronutrients besides ferritin and retinol. When evaluating
helminth (re)infection rates in micronutrient supplementation studies, only multi-micronutrient
interventions showed a modest protective effect (OR 0.77 [0.61; 0.97]).
Conclusions
We found significant associations between helminth infections and micronutrient status in
schoolchildren. Our results showed distinct associations with either serum retinol or serum ferritin.
More evidence is needed to further unravel the interrelationship between helminth infections and
micronutrient status.
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135
Literature Surveys
126. Efficacy of intrauterine insemination in moderate to severe
endometriosis. A systematic review and meta-analysis of
observational data
Lisette van der Houwen1, Anneke Schreurs1, Pam Kaspers2, Roel Schats1, Cornelis Lambalk1,
Peter Hompes1, Velja Mijatovic1
Endometriosis Center, Division of Reproductive Medicine, Department of Obstetrics and
Gynaecology, VU University Medical Center
2
Medical Library, VU Amsterdam University Library
1
Introduction
A systematic review and meta-analysis is conducted to evaluate the efficacy of intrauterine
insemination (IUI), since the role of this treatment in moderate to severe endometriosis patients is
discussed.
Methods
To identify all relevant publications systematic searches were performed in the bibliographic
databases PubMed, EMBASE, Cinhal and The Cochrane Library from inception to September 12th,
2013. Search terms expressing ‘endometriosis’ were used in combination with terms comprising
‘IUI’. Studies including moderate to severe endometriosis patients reporting pregnancy rates after
IUI were independently selected by two reviewers. Studies were excluded if pregnancy was not
specified for moderate to severe endometriosis patients receiving IUI treatment. A weighed mean
pregnancy rate per patient and cycle was calculated by using Microsoft Excel (Neyeloff et al. 2012).
Results
Our search revealed 510 unique citations. Seventeen articles fulfilled our criteria; after exclusion
of one article due to overlapping data and inclusion of our own data, seventeen articles
(12 retrospective; 5 prospective) were included for the analysis. Fourteen studies reported
pregnancy per patient; 165 pregnancies in 474 patients. Thirteen studies reported pregnancy per
cycle; 140 pregnancies in 1088 cycles. The calculated weighed mean pregnancy rate per patient
was 32.3% (95%CI 22.7%-41.9%) and per cycle 12.4% (95%CI 8.1%-16.7%).
Conclusions
This meta-analysis of observational data showed that IUI could be a valuable treatment in moderate
to severe endometriosis. Whether this treatment can be structurally offered prior to IVF must be
investigated in a randomized controlled trial including efficacy, safety and cost-effectiveness.
136
Literature Surveys
127. What is the evidence for physical therapy poststroke?
A systematic review and meta-analysis
J.M. Veerbeek (MSc)1, E.E.H. van Wegen (PhD)1, R.P.S. van Peppen (PhD)2, P.J. van der Wees (PhD)3,
H.J.M. Hendriks (PhD)4, M.B. Rietberg (MSc)1, G. Kwakkel (PhD)1,5
Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam,
VU University Medical Center, Amsterdam
2
Department of Physiotherapy, University of Applied Sciences Utrecht
3
Scientific Institute for Quality of Healthcare (IQ healthcare), Radboud University Nijmegen
Medical Centre
4
Department of Epidemiology, Maastricht University
5
Centre of Neurorehabilitation, Rehabilitation Centre READE, Amsterdam
1
Introduction
Physical therapy (PT) is one of the key disciplines in interdisciplinary stroke rehabilitation. The
aim of this systematic review was to summarize the latest evidence for stroke rehabilitation
interventions in the domain of PT.
Methods
Randomized controlled trials (RCTs) regarding PT in stroke rehabilitation were retrieved through
a systematic search. Low risk of bias RCTs were quantitatively analyzed. Differences between
poststroke phases were explored in subgroup analyses. A best evidence synthesis was performed
for neurological treatment approaches.
Results
The search yielded 467 RCTs (N=25 373), identifying 53 interventions. Strong evidence was found
for positive effects of 13 interventions related to gait, 11 interventions related to arm-hand
activities, 1 intervention for ADL and 3 interventions for physical fitness. Summary Effect Sizes
(SESs) ranged from 0.17 (95%CI 0.03-0.70; I2=0%) for therapeutic positioning of the paretic arm
to 2.47 (95%CI 0.84-4.11; I2=77%) for training sitting balance. There is strong evidence that a
higher dose of practice is better, with SESs ranging from 0.21 (95%CI 0.02-0.39; I2=6%) for motor
function of the paretic arm to 0.61 (95%CI 0.41-0.82; I2=41%) for muscle strength of the paretic
leg. Subgroup analyses yielded significant differences with respect to timing poststroke for 10
interventions. Neurological treatment approaches showed equal or unfavorable effects when
compared to other training regimes.
Conclusions
There is strong evidence for PT interventions favoring intensive high repetitive task-oriented and
task-specific training in all phases poststroke. Effects are mostly restricted to the actually trained
functions and activities. Suggestions for prioritizing PT stroke research are made.
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137
Preclinical disease models
128. Suppression of the Local Renin-Angiotensin System to
reduce Fibrosis
J.J. Akershoek1,2, M. Vlig1, C.D. Richters3,4, R.H.J. Beelen4 and M.M.W. Ulrich1,2
Association of Dutch Burn Centres, Beverwijk
VU University Medical Center, Department of Plastic, Reconstructive and Hand Surgery,
Amsterdam
3
Euro Tissue Bank, Beverwijk
4
VU University Medical Center, Department of Molecular Cell Biology and Immunology, Amsterdam
1
2
Introduction
The healing of burn wounds often results in a hypertrophic scar. This type of scar formation is
probably the result of an exaggerated and prolonged inflammation response. Suppression of the
inflammatory response might result in less fibrosis to the skin. There is an increasing interest in
the role of Renin-Angiotensin System (RAS) in fibrosis. The RAS not only regulates blood pressure,
but is also locally active and plays a role in inflammation and remodelling. The biological active
component of the RAS, Angiotensin II (AngII), can bind to either AngII receptor 1 (AT1) or 2 (AT2)
which respectively has pro- or antifibrotic effects.
Methods
In an animal study, we investigated the role of Captopril, an inhibitor of the RAS, on the healing of
contact burn wounds. The burn wounds (partial thickness) were created on the back of male rats.
Subsequently the animals were treated systemically or locally with Captopril for 14 days.
Results
The wound size increased slightly during the first week in all treatment groups. No difference in
wound closure was observed two weeks after wounding. Furthermore, immunohistological analysis
showed a decreased influx of inflammatory cells at day 7 in the group receiving topical treatment.
Especially the number of neutrophils was reduced, where the number of monocytes showed
no difference between the treatment groups. Both treatment groups showed reduced αSMA
expression compared to the control.
Conclusions
These results indicate that topical treatment with Captopril has potential in suppressing the
inflammatory response in burn wounds, and therefore may contribute to the reduction of fibrosis.
138
Preclinical disease models
129. Toward stem cell based therapy for diseases affecting the
retinal pigment epithelium
Anna Bennis1,2, Theo G.M.F. Gorgels 1, Vivi M. Heine2, Arthur AB Bergen1,3,4
Dept. Molecular Ophthalmogenetics, Netherlands Institute for Neuroscience, Amsterdam
Stem Cell Laboratory, VU University Medical Center, Amsterdam
3
Dept Ophthalmology, Academic Medical Center, Amsterdam
4
Dept Clinical Genetics, Academic Medical Centre, Amsterdam
1
2
Introduction
The retinal pigment epithelium (RPE) is a monolayer of pigmented cells forming a part of the
blood/retina barrier that interacts with the photoreceptors in the maintenance of visual function.
Degeneration of the RPE is involved in multiple retinal diseases, such as age related macular
degeneration (AMD). Future therapies for AMD likely involve tissue engineering, using
transplantation of RPE-like cells which are derived from in vitro differentiating stem cells. The
current protocols are inefficient in the generation of functional RPE cells. We aim to optimize the
protocol for differentiation of stem cells into RPE cells, by gathering and applying data of in vivo
gene expression in the retina.
Methods
Using an optimized 3D-culture system and growth factor protocol, human embryonic stem cells a
re differentiated into RPE. Several techniques are used to assess RPE differentiation states, including
morphology, pigmentation, RT-PCR and immunocytochemistry. We developed a new strategy to
define and characterize the transcriptome of the RPE: we determined the transcriptomes of the
RPE, photoreceptors and choroid. By subtracting possible contaminating RNA of the adjacent
layers, we obtained a purified list of genes specifically expressed in the RPE. We did this for mouse
and human RPE.
Results
We optimized RPE differentiation protocols and determined a set of RPE signature genes that are
found in mouse and human.
Conclusions
The gene expression profiles of the mouse and human RPE are quite similar. We can use these
expression profiles to optimize the characterization of the in vitro RPE differentiation.
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139
Preclinical disease models
130. SPPL2b is dramatically increased in early stages of
Alzheimer’s disease and associates with amyloid plaques
and neurofibrillary tangles
Del Campo M1,2, Wouters D.1, Fluhrer R.3, Schröder B.4, Hoozemans J.5, Teunissen C.E.1
Clinical Chemistry, VU University Medical Center, The Netherlands
Alzheimer center, VU University Medical Center, The Netherlands
3
Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE),
Ludwig-Maximilians Universität, Germany
4
Institute of biochemistry, CAU Kiel University, Germany
5
Pathology, VU University Medical Center, The Netherlands
1
2
Introduction
Alzheimer’s disease (AD) is the most common form of dementia with unknown aetiology
characterized by the presence of amyloid beta (Aβ) plaques and neurofibrillary tangles (NFT).
SPPL2b is an enzyme that can process TNFα and BRI2, substrates involved in Aβ plaque and NFT
formation. Since changes in BRI2 and TNFα were previously identified in early stages of AD, we
aim to investigate whether SPPL2b expression is also changed in AD hippocampus.
Methods
SPPL2b expression levels were quantified in post-mortem human homogenates from AD patients
(n=14) and controls (n=13) by western blot. SPPL2b immunostaining was evaluated on paraffin
sections from AD patients (n = 12) and age-matched controls (n=15).
Results
SPPL2b levels were 10-fold increased (p<0.0001) in AD hippocampus compared to non-demented
controls. SPPL2b was strongly correlated (r=0.785,P<0.000) to Braak stages showing a significant
increased from Braak III to IV, stages in which cognitive impairment starts. Strong SPPL2b
immunoreactivity in the hippocampus was observed in early AD stages (p<0.0001), which was
localised in NFT and Aβ plaques. Preincubation and comparison of staining patterns of SPPL2b
family members proved that the observations were SPPL2b-specific.
Conclusions
We found a dramatically increase of SPPL2b in early stages of AD. SPPL2b processes BRI2 and
TNFα, proteins involved not only in Aβ homeostasis but also in chronic inflammation and NFT
formation. These data reveal a novel potential AD etiological factor that links Aβ plaques and NFT
and thus forms a new and promising target for disease modifying therapies.
140
Preclinical disease models
131. BRI2 protein ectodomain activates critical pathological
pathways involved in early stages of Alzheimer’s disease
Del Campo M.1,2, Oliveira C.R.3, Pereira C.F.3 , Teunissen C.E.1
Clinical Chemistry, VU University Medical Center, The Netherlands
Alzheimer center, VU University Medical Center, The Netherlands
3
Center for Neuroscience and cell biology, University of Coimbra, Portugal
1
2
Introduction
Alzheimer’s disease (AD) is the most common form of dementia pathologically characterized
by the presence of amyloid beta (Aβ) plaques and neurofibrillary tangles (NFT). The BRI2
ectodomain accumulates in Aβ plaques in early stages of AD hippocampus and regulates critical
proteins involved in the initial steps of the amyloid cascade, the prevailing hypothesis about AD
pathogenesis. Here we investigated whether the BRI2 ectodomain activates important pathways
involved in early stages of AD in vitro, including apoptosis, the unfolded protein response (UPR)
and the phosphorylation of glycogen synthase kinase 3 β (GSK3β), which is involved in NFT
formation.
Methods
Non differentiated SH-SY5Y cells were exposed to recombinant BRI276-266. Cell viability was assed
by MTT assay. Apoptosis was examined by analysis of the activity of Caspases 3 and 9. The proand anti-apoptotic proteins Bcl-2 and Bax, the UPR related proteins (GRP78 and Xbp-1) and the
phosphorylation of GSK3β (P- GSK3β) were analysed by western blot.
Results
BRI2 ectodomain led to a 10% cell death, increased Bax/Bcl-2 ratio and increased activity of
caspases 3 and 9, indicating an activation of the apoptosis pathway. Strikingly, BRI2 incubation led
to an increase of the UPR protein Xbp-1 but not of GRP78 suggesting that BRI2 accumulation can
partially activate the UPR. Incubation with BRI2 increased P-GSK3β levels.
Conclusions
Here we show that BRI2 ectodomain, which accumulates in AD tissue, can activate important
molecular pathways involved in early stages of AD including NFT formation and neurodegeneration.
Thus, these data reveal not only a new player in AD pathogenesis but also a novel potential target
for the development of new disease modifying therapies.
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141
Preclinical disease models
132. Identification of proteins directly interacting with the
HELLP-syndrome associated lincRNA using ChIRP
Allerdien Visser1, Roel van der Schors2, Cees Oudejans1, Marie van Dijk1
Department of Clinical Chemistry, Institute for Cardiovascular Research,
VU University Medical Center
2
Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam,
VU University
1
Introduction
Recently, a long non-coding RNA has been identified to be associated with the HELLP-syndrome,
a pregnancy-specific disease. Strong indications exist for the LINC-HELLP RNA to function in the
cell cycle of placental cells. LincRNAs predominantly function through interactions with proteins.
To investigate how the LINC-HELLP RNA exerts its effects on the cell cycle we used Chromatin
Isolation by RNA Purification (ChIRP) to identify the directly interacting proteins. For method
optimization we used a known lincRNA-protein interaction present in placental cells, i.e.
KCNQ1OT1 binding to DNMT1.
Methods
Biotin-labeled morpholinos targeting KCNQ1OT1 (n=2), LINC-HELLP (n=4) or a non-targeting control
morpholino were hybridized to crosslinked and DNAse-treated lysates of a placental cell line.
Subsequently, the hybridized morpholinos were extracted from the lysates using streptavidincoated magnetic beads.
Results
KCNQ1OT1 qRT-PCR and DNMT1 dot blot on the extracted RNA and proteins, respectively, gave
a significantly higher expression in the KCNQ1OT1 morpholino-targeted samples compared to
control, confirming the suitability of the ChIRP method.
Comparing the LINC-HELLP samples to control upregulation of the LINC-HELLP RNA was detected
by qRT-PCR. More interestingly, extracted proteins analyzed by mass spectrometry identified
a protein complex involved in the regulation of RNA stability only present in the LINC-HELLP
morpholino-targeted samples.
Conclusions
By using ChIRP we were able to confirm a known lincRNA-protein interaction (KCNQ1OT1-DNMT1)
as well as identifying a protein complex specifically bound to LINC-HELLP. When the mass
spectrometry results have been validated more insight has been gained upon the specific actions
of the LINC-HELLP RNA in the cell cycle.
142
Preclinical disease models
133. Vanishing White Matter diseased astrocytes inhibit
oligodendrocyte progenitor cell maturation
S. Dooves1,2, N. Land1,2, J.A. van der Kreeke1,2, M.S. van der Knaap1 and V.M. Heine1,2
Center for Children with White Matter Disorder, VU University Medical Center
Stem Cell lab, Neuroscience Campus Amsterdam, VU University/VU University Medical Center
1
2
Introduction
Vanishing White Matter (VWM) is a severe leukoencephalopathy mainly affecting children. VWM
is caused by mutations in eIF2B, a gene involved in translation initiation. Previous research has
shown that mainly the astrocytes and oligodendrocytes of the brain white matter are affected in
these patients. However, it is still unknown what cell type primarily is involved. In this study, we
looked at the effect of VWM mutations in astrocytes on oligodendrocyte progenitor cell (OPC)
maturation.
Methods
Astrocytes from WT and VWM mice are cultured together with WT OPCs for 7 days. OPC maturation
is analyzed by immunostainings and PCR. To investigate whether VWM astrocytes inhibit OPC
maturation through direct contacts or through secreted factors, co-cultures received conditioned
medium from WT and VWM astrocytes. Furthermore, astrocytes from WT mice are cultured
together with VWM OPCs to look at how the VWM mutation specifically effects OPCs.
Results
VWM astrocytes inhibit OPC maturation as is apparent from decreased MBP and MOG expression.
Conditioned medium from VWM astrocytes significantly decreases the number of mature
oligodendrocytes in WT astrocyte-WT OPC cultures. In cultures of WT astrocytes with VWM OPCs
the maturation is normal.
Conclusions
VWM astrocytes inhibit OPC maturation, probably through soluble factors that are secreted into
the medium. In co-cultures of WT astrocytes and VWM OPCs the OPCs maturate normally into
mature oligodendrocyte, suggesting that the maturation defect seen in VWM mice is mainly
caused by defective astrocytes.
VU University Medical Center Science Exchange Day 2014
143
Preclinical disease models
134. C1-esterase inhibitor co-localizes with C3d and C4d and is
produced locally in the myocardium after acute myocardial
infarction
Reindert Emmens1,3,4, Umit Baylan1,3, Benno Naaijkens1,3,5, Rashmi Karia1, Diana Wouters4,
Sacha Zeerleder4,6, Suat Simsek7, Marieke van Ham4, Hans Niessen1,2,3, Paul Krijnen1,3
Department of Pathology, VU University Medical Center, Amsterdam
Department of Cardiac Surgery, VU University Medical Center, Amsterdam
3
ICaR-VU, Institute of Cardiovascular Research, VU University Medical Center, Amsterdam
4
Department of Immunopathology, Sanquin Research, Amsterdam
5
Interuniversity Cardiology Institute of the Netherlands, Utrecht
6
Department of Hematology, Academic Medical Center, Amsterdam
7
Department of Internal Medicine, Alkmaar Medical Center, Alkmaar
1
2
Introduction
Complement is an important contributor to the inflammatory response which damages the cardiac
muscle following acute myocardial infarction (AMI). However, it is not precisely known how this
complement activation is regulated. For instance, the role of endogenous C1-esterase inhibitor
(C1-inh), a compound which inhibits complement activation, has never been described for AMI. In
this study we analyzed the presence of endogenous C1-inh in the heart during AMI.
Methods
C1-inh was visualized immunohistochemically in cardiac tissue of patients who died during various
phases of AMI (combined n=28) and control patients (n=9). Complement activation markers C3d
and C4d were visualized in the same tissue. Serping1 (C1-inh gene) transcription levels were
measured in a rat model of AMI. Ischemia-reperfusion-induced C1-inh production in vitro was
analyzed in endothelial cells and cardiomyoblasts with immunofluorescence microscopy.
Results
Especially during phase 2 AMI (infarct age of twelve hours to five days), a large deposit of
endogenous C1-inh was visible in the infarct core, and correlated strongly with the presence of
C3d and C4d. In the rat AMI model, serping1 transcription levels in the heart were increased from
2 hours till at least 7 days after AMI. Both endothelial cells and cardiomyoblasts were observed to
have an increased quantity of intracellular C1-inh as result of ischemia and reperfusion in vitro.
Conclusions
Endogenous C1-inh is present in the infarct core of AMI patients and coincides with complement
activation. Also, AMI stimulates production of C1-inh locally in the heart, an effect which can be
simulated in vitro.
144
Preclinical disease models
135. Impulse Control Disorders in Parkinson’s disease: from
preclinical model to prevention and treatment
O.A. van den Heuvel1,2,3, C. Vriend1,2,3, Y.D. van der Werf2,3, P. Voorn2,3, J. Booij4, P. Raijmakers5,
H.W. Berendse3,6, T. Pattij2,3
Department of Psychiatry, VU University Medical Center
Department of Anatomy & Neurosciences, VU University Medical Center
3
Neuroscience Campus Amsterdam
4
Department of Nuclear Medicine, Academic Medical Center Amsterdam
5
Department of Radiology & Nuclear Medicine, VU University Medical Center
6
Department of Neurology, VU University Medical Center
1
2
Introduction
Impulse control disorders (ICD) occur in 15-35% of Parkinson’s disease (PD) patients in response to
dopamine replacement therapy (DRT, dopamine agonists > L-Dopa) and have a tremendous impact
on patients and caregivers. The overall aim is to understand, alleviate, and prevent ICD in PD. As
part of a new translational research line, we studied the relationship between dopamine depletion
and impaired response inhibition, both in a rat PD model and in de novo PD patients, and now
aim to bring this line of research to the level of drug development, molecular imaging and clinical
trials.
Methods
Study 1 (preclinical): rat PD model (n=24 rats) using striatal lesions (neurotoxin
6-hydroxydopamine) and the translational response inhibition (Stop-Signal) task Study 2 (clinical):
a) r etrospective longitudinal study (n=31 de novo PD) on the relationship between baseline pretreatment striatal dopamine transporter (DaT) binding (SPECT) and risk to develop ICD after DRT,
b) cross-sectional fMRI study using Stop-Signal task (n=21 de novo PD + 37 controls)
Preliminary results
Study 1: L -Dopa administration after dorsomedial striatal dopamine depletion has limited effects
on measures of response inhibition.
Study 2: a) reduced striatal DaT availability predates the development of ICD after DRT, and
b) task-related activation of the response inhibition network was reduced in PD patients
and correlated positively with striatal DaT availability.
Conclusions
We have a good preclinical experimental set-up to test the effect of DRT on response inhibition.
Also, human data indicate that nigrostriatal dopaminergic degeneration (DaT SPECT) and inhibitory
control (fMRI) might be useful as biomarkers to predict the risk of ICDs in response to DRT in PD.
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145
Preclinical disease models
136. Generation of iPSCs from patients with 4H syndrome
Dwayne Holmes1,2,3, Nicole Wolf1, Marjo S. van der Knaap1,Gerard Pals2 and Vivi Heine1,3
Pediatrics - Child Neurology, VU University Medical Center
Clinical Genetics, VU University Medical Center
3
Stem Cell Lab, VU University
1
2
Introduction
4H syndrome is a childhood neural disorder involving hypomyelination of the central nervous
system, reduced cerebellar volume, and impaired gonadal development. While the exact
pathophysiology of 4H syndrome remains unknown, a mutation in the POLR3 gene was found
responsible for hypo-myelination in leukodystrophies fitting 4H criteria. This raises the possibility
of treating the disorder through a gene correction – cell replacement therapy, as well as creating
in vitro disease models to study 4H pathophysiology.
Methods
Patient and control fibroblasts were converted to induced pluripotent stem cells (iPSCs) using
a lentivirus containing all four reprogramming factors and a reporter gene to signal successful
integration. Around 6 days after transfection, cells were transferred to a new plate and maintained
in a serum/feeder free culture. Within 30 days, colonies with embryonic stem cell-like (ESC)
morphology appeared in culture. Several colonies per fibroblast line were picked and expanded.
Each colony was characterized for pluripotency by checking for ESC associated markers, and an
ability to generate cells from all three germ layers.
Results
iPSCs were successfully generated and characterized for two 4H patients (3 lines each), one
unaffected parent of a patient (2 lines), and two controls (2 and 3 lines, respectively). Cells with
neural rosette morphology were observed on an iPSC line from the healthy parent. When induced
toward neural lineage, these cells expressed early neural markers, as well as producing cells with
more defined neuronal morphology.
Conclusions
iPSCs suitable for further testing and disease modelling have been derived from 4H patient tissue.
146
Preclinical disease models
137. Homocysteine induces apoptosis of arterial smooth
muscle cells via NOX4-produced reactive oxygen
Nynke E. Hahn1,9, Ellis N. ter Horst1,2,3,9,Jessica A. Sipkens1,9, Victor W.M. van Hinsbergh4,9,
Rene J.P. Musters4,9, Coen D.A. Stehouwer10, Jan A. Rauwerda5,9, Jacqueline M. Hornstra4,9,
Yvo M. Smulders7,9, Etto C. Eringa4,9, Kathy K. Griendling10, Hans W.M. Niessen1,6,9,
Paul A.J. Krijnen2,9,
Department of Pathology, VU University Medical Center, Amsterdam
Department of Cardiology, Academic Medical Center, Amsterdam
3
Interuniversitary Cardiology Institute of the Netherlands, Utrecht
4
Department of Physiology, VU University Medical Center, Amsterdam
5
Department of Vascular Surgery, VU University Medical Center, Amsterdam
6
Department of Cardiac Surgery, VU University Medical Center, Amsterdam
7
Department of Internal Medicine, VU University Medical Center, Amsterdam
8
Department of Internal Medicine and Cardiovascular Research Institute Maastricht,
University Medical Center, Maastricht
9
Institute of Cardiovascular Research, VU University Medical Center, Amsterdam
10
Division of Cardiology, Emory University, Atlanta GA, United States of America
1
2
Introduction
Elevated levels of homocysteine (Hcy) form a vascular risk factor and can induce apoptosis of
endothelial cells and vascular smooth muscle cells. Recent studies have shown that NADPH
oxidase (NOX)-mediated reactive oxygen species (ROS) play a role in Hcy-induced apoptosis of
endothelial cells. In this study we have analyzed the effect of Hcy on the different NOX isoforms
and their role in human arterial smooth muscle cells (SMCs).
Methods
Human arterial SMCs isolated from the human umbilical cord were incubated with 100 µM Hcy
for 24 hours and were analyzed for cell viability by determining phosphatidylserine exposure via
Flow cytometry and caspase 3 activity measurements. With use of digital imaging microscopy,
expression of NOX1, 2 and 4 and production of ROS were studied. NOX4 small interference RNA
(siRNA) were used to specify the role of NOX4 in Hcy-induced apoptosis.
Results
Hcy induced a significant increase in phosphatidylserine exposure and caspase 3 activity in arterial
SMC. This was accompanied by a significant translocation of NOX4 from the cytoplasm to (peri)
nuclear regions, coinciding with a significant increase in local ROS production. Hcy did not affect
expression levels, nor subcellular localization of NOX1 and NOX2. Knock-down of NOX4 using
siRNA significantly reduced Hcy-induced (peri)nuclear NOX4 expression, concomitant ROS
production and apoptosis in isolated arterial SMCs.
Conclusion
Pathophysiological concentrations of Hcy induce apoptosis of human arterial SMCs via NOX4
mediated ROS production.
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147
Preclinical disease models
138. MicroRNA-214 controls thyroid hormone levels
by targeting Dio3 in the post-MI heart
Rob Janssen1, Marian Zuidwijk1, Alice Muller1, Alain van Mil2, Ellen Dirkx3, Leon de Windt3,
Cees Oudejans4, Warner Simonides1
Department of Physiology, ICaR-VU, VUmc University Medical Center
Department of Cardiology, University Medical Center Utrecht
3
Department of Cardiology, CARIM School for Cardiovascular Diseases
4
Department of Clinical Chemistry, ICaR-VU, VUmc University Medical Center
1
2
Introduction
Changes in expression of microRNAs (miR), as well as changes in thyroid hormone (TH)
metabolism are associated with remodeling following myocardial infarction (MI). Several studies
suggest that MI-induced upregulation of the TH-inactivating enzyme Dio3 in the left ventricle (LV)
and the associated reduction of tissue TH levels contribute to the development of heart failure.
In this study we addressed the hypothesis that miR-214 plays a role in regulating TH metabolism
following MI by repressing Dio3 mRNA.
Methods
MI was induced in mice by occlusion of the left descending coronary artery. MiRs were isolated
from the remodeling LVand analyzed using qPCR. MiR/target-interaction was analyzed using
luciferase-reporter constructs.
Results
MiR-214 is upregulated in the remodeling LV at
1 week post-MI (A). We confirmed the predicted
repression of Dio3 by miR-214 using a luciferasereporter construct containing the 3’UTR of Dio3 (B).
Additional analysis showed that miR-214 levels
increased from day 5 until 8 weeks post-MI (C),
whereas a previous study showed that Dio3
mRNAlevel was maximal at 3-5 days post-MI, and
subsequently decreased towards a steady elevated
level 8 weeks post-MI. In an additional model
ofcardiac-overloadwe showed that suppression of
miR-214 expression using anti-miR-214 resulted in
increased Dio3 mRNAlevels.
A.
B.
C.
Conclusions
We found that Dio3 mRNA is a target of miR-214.Reciprocal changes in cardiac miR-214 and Dio3
expression were observed in several mouse models. Based on these observations, we hypothesize
that increased expression of miR-214 is aimed at reducing Dio3 activity, thereby preventing an
excessive and potentially lethal reduction of cardiac TH levels.
148
Preclinical disease models
139. Diaphragm muscle weakness in a novel mouse model for
nebulin-based nemaline myopathy
B. Joureau1, J.M. de Winter1, Kelly Stam1, A.H.Beggs2, D. Buck3, GJM Stienen1, H. Granzier3,
C.A.C Ottenheijm1,3.
Department of Physiology, VU University Medical Center Amsterdam,
The Netherlands
2
Division of Genetics and Program in Genomics, The Manton Center for Orphan Disease Research,
Harvard Medical School, Boston, MA, USA
3
Department of Physiology, University of Arizona, Tucson, AZ, USA
1
Introduction
Nemaline myopathy (NM) is the most common non-dystrophic congenital myopathy, and is
characterized by muscle weakness. Seven genes – all coding thin filament proteins - are implicated
in NM. The main form of NM results from nebulin gene (NEB) mutations. Recently, we have
generated a mouse model with a deletion of NEB exon 55, a mutation known to frequently occur
in NM patients.
Importantly, this model allows studying the diaphragm, a muscle whose function is very difficult
to investigate in human NM. It has been postulated that the diaphragm is particularly affected in
NM, and that this explains why many children with NM develop respiratory failure. Here we used
NebΔExon55 mice to test the hypothesis that diaphragm strength is more affected than peripheral
muscle strength.
Methods
Small (diameter: ~70 μm) fiber bundles of m. diaphragm and soleus were dissected from
homozygous NebΔExon55 mice and from wt littermates. Bundles were permeabilized and mounted
between a force transducer and length motor. Sarcomere length was set at 2.3 µm. Fiber bundles
were activated by exposure to solutions with saturating [Ca2+] (pCa 4.5) and non-saturating
[Ca2+] (pCa 5.8). Maximal tension, crossbridge cycling kinetics (ktr), active stiffness and calciumsensitivity of force were determined.
Results Data are summarized in the table below.
Diaphragm
Soleus
NebΔExon55
NebΔExon55
(fraction of wt)
(fraction of wt)
Maximal Tension (pCa 4.5; mN/mm2)
0.27±0.03*,#
0.44±0.02*
Ktr (pCa 4.5; s-1)
0.53±0.03*,#
0.79±0.02*
Active Stiffness (pCa 4.5; mN/mm2)
Calcium Sensitivity (Force at pCa 5.8/4.5)
0.25±0.03*
0.33±0.01*
0.74±0.02*,#
0.85±0.04*
Mean±SEM; * p<0.05 WT vs. NebΔExon55; # p<0.05 Diaphragm NebΔExon55 vs. Soleus NebΔExon55
Conclusions
In line with our hypothesis we observed that the diaphragm muscle is more affected than
peripheral skeletal muscle in this mouse model of nebulin-based NM. We speculate that
preferential diaphragm weakness contributes to respiratory failure in NM.
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149
Preclinical disease models
140. Copy number profiling of human and murine
retinoblastoma
E.I. Kooi1, B.M. Mol1, T. van Harn2, A.C. Moll3, J. Cloos4,5, G.J.L. Kaspers5, H. te Riele1,2, J.C. Dorsman1
Clinical genetics, VU University Medical Center
Division of molecular biology, Dutch cancer institute
3
Ophthalomology, VU University Medical Center
4
Hematology, VU University Medical Center
5
Pediatric oncology, VU University Medical Center
1
2
Introduction
Retinoblastoma (Rb) is a rare but aggressive pediatric cancer that developes in the retina. Tumor
development is initiated by bi-allelic inactivation of RB1, while malignant tumor proliferation is
driven by additional genomic instability. Characterizing the copy number profiles of Rb tumors is
a key step in identifying carcinogenesis networks that drive Rb development.
Methods
Following a comparative oncogenomics approach, in which variants detected in mouse oncogenomes
are used as a biological filter on human oncogenomes, this study aims to identify copy number
alterations driving Rb. Using high-density SNP-array platforms developed for men and mouse, copy
number profiles of an unselected cohort of 74 human Rb samples were determined and of seven
double knockout murine pRb-/-p130-/- tumors.
Results
Strikingly, our data showed that mouse Rb tumors arising from germline bi-allelic inactivated cells
have a copy number stable genome. Only two acquired copy number alterations were detected
in just one single tumor including a focal deletion of the CDH11 locus mapping to 16q loss in
humans. On the contrary, all mouse Rb tumors with somatically acquired bi-allelic mutations
(published data) did show genomic instability. A similar contrast in variability in Rb genomes was
observed in the human Rb cohort, in which genome stability in young hereditary Rbs is more
stable compared to tumors from old non-hereditary Rbs.
Conclusions
In summary, copy number data on both human and murine Rbs show that Rb tumors have variability
in genome stability similar between the two species. Using the murine copy number profiles,
the minimal region of 16q-loss was narrowed down to a single gene level. Furthermore, our data
shows that the different murine mouse models recapitulate human Rb genetics well, advocating
for their exploitation as translational models in Rb-research.
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Preclinical disease models
141. Towards a stem cell transplantation therapy for VWM
Prisca Leferink1,2, Marjo S. Van der Knaap1 and Vivi M. Heine1,2
Center for Children with White Matter Disorders, Pediatrics, VU University Medical Center,
Amsterdam
2
Stem cell laboratory, VU University/VU University Medical Center, Amsterdam
1 Introduction
Vanishing White Matter disease (VWM) is one of the most prevalent genetic childhood
leukoencephalopathies, clinically characterized by neurological deterioration and ataxia. VWM is
linked to mutations in any of the genes encoding for the 5 subunits of the eukaryotic translation
initiation factor 2B (eIF2B), important for protein synthesis. In the VWM brain large regions are
hypomyelinated, the glial cells seem to be predominantly affected, and remyelination is defective.
Therefore, the aim of this project is to develop a patient-specific glial precursor cell (GPC)
transplantation therapy, to possibly repair the pathology and achieve functional recovery of the
remained intact neurons.
Methods
Patient specific induced pluripotent stem cells (iPSCs) are obtained via lentiviral infection of
fibroblasts with transcription factors Oct3/4, Sox2, Klf4 and c-Myc. This leads to nuclear
incorporation of those four genes and the reprogramming back to pluripotent stem cell stage.
These iPSCs still harbor the genetic defect, therefore gene therapy in which the mutation is
corrected is required. The corrected iPSCs will be differentiated into GPCs, after which their
functionality will be evaluated both in vitro in co-cultures with neurons, and in vivo with
transplantation in VWM mouse models.
Results
The human fibroblasts are successfully reprogrammed into iPSCs. Additionally, healthy human
embryonic stem cells (hESCs) have successfully been differentiated into GPCs.
Conclusions
Progress is made towards a stem cell transplantation therapy for VWM, further research is required
to investigate the functionality of both VWM and healthy GPCs.
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151
Preclinical disease models
142. Quantification of IFT-dynein dynamics in C. elegans
J. Mijalkovic1, B. Prevo1, P. Mangeol1, F. Oswald1, E.J.G Peterman1
1
Department of Physics and Astronomy and LaserLab, VU Amsterdam, The Netherlands
Introduction
Cilia are organelles that extend from the surface of most eukaryotic cells, with important roles
in chemo- and mechanosensation. These structures are built and maintained by bidirectional
trafficking of microtubule motors in a specific transport process called Intraflagellar Transport
(IFT). Dysfunctional IFT is associated with several human diseases, including Bardet-Biedl
syndrome and polycystic kidney disease. In C. elegans chemosensory cilia, two types of kinesin-2
motors drive anterograde transport, whereas cytoplasmic dynein 2 (IFT-dynein) is responsible
for retrograde transport. The mechanism and properties of IFT-dynein are relatively poorly
understood. Here we set out to quantify its dynamics in order to gain a better understanding of
the complete IFT mechanism.
Methods
We use MosSCI (Mos1-mediated single copy insertion) to generate mutant nematodes with eGFP
or PA-GFP tagged IFT-dynein at endogenous expression levels. These motor proteins are visualized
and tracked in living C. elegans using fluorescence microscopy, allowing for quantification of
velocities, motor distributions and other parameters. To obtain insight into the behavior of
individual IFT-dynein motors we employed photoactivation of PA-GFP. Subsequent movies were
analyzed using in-house kymograph and single particle tracking software.
Results
Analysis reveals that IFT motor proteins move in groups (trains). IFT-dynein velocity is not constant
along the cilium: motor trains speed up as they depart from the tip and decelerate as they reach
the base. On a single-molecule level, tracking IFT-dynein provides information on behavior such as
run lengths, pausing and turn-arounds.
Conclusions
Our results reveal new quantitative information on IFT-dynein dynamics at endogenous expression
levels in a living organism. Understanding of IFT and dynein activity in vivo at both bulk and
single-molecule level is expected to bring us a step closer to understanding ciliary disorders.
152
Preclinical disease models
143. Neuronal differentiation of iPS cells for disease modeling
Aishwarya. G. Nadadhur1,2, Matthijs Verhage2, Vivi. M. Heine1,2
1
Stem cell lab, VU University/ VU University Medical Center, Amsterdam
Center for Neurogenomics and Cognitive Research (CNCR), VU, Amsterdam
2
Introduction
Induced pluripotent stem cells (iPSCs) are human embryonic stem cell (hESC) like, derived by
reprogramming adult somatic cells (e.g. fibroblasts) with forced expression of specific genes.
The iPSCs are used as in-vitro model to study phenotype of many disorders, as they can be
derived from patient cells and further differentiated into any desired cell type. Our goal is to
study the brain cell (neurons and glia) phenotypes and possible therapy methods of Fragile X
syndrome (FXS) using patient derived iPSCs. Neuroepithelial stem cells (NES) are embryonic neural
precursors, which further differentiate into neurons and glia during development.
Methods
5 iPS cell lines were generated from 2 FXS patient fibroblasts by forced expression of “Yamanaka
factors”. We derived NES cells from hESC and iPSCs based on previously published methods and
also our novel methods. Shortly hESC or iPSCs were neural induced in N2:B27 based medium
and re-plated on PLO/Laminin in same medium with FGF2. These were further differentiated to
GABAergic neurons by induction with Sonic hedgehog, followed by induction with Valporic acid,
after which they were maintained in neurobasal medium with neuronal survival factors.
Results
Characterization of iPSC lines by RNA analysis confirms pluripotency. Comparison of different
populations of NES cells by morphology and expression of neural stem cell markers suggests
presence of different types of NES cells. GABAergic neuronal differentiations show good
expression of dendritic and neuronal markers and also calcium influxes, which suggest culturing
for longer might induce synaptic activity.
Conclusion
It will be interesting to study the phenotype of human iPSC-derived neurons in comparison to hESC
derived control neurons. And, further analysis is required to report different NES cell population
and their individual roles in development.
VU University Medical Center Science Exchange Day 2014
153
Preclinical disease models
144. Microglia phenotyping in pre-active MS lesions
Laura A.N. Peferoen1*, Daphne Y.S. Vogel1,2*, Kimberley Ummenthum1, Marjolein Breur2,
Wouter Gerritsen1, Christien D Dijkstra2, Sandra Amor1,3
Department of Pathology, VU University Medical Center, the Netherlands
Department of Molecular Cell Biology and Immunology, VU University Medical Center,
the Netherlands
3
Department of Neuroimmunology Unit, Blizard Institute, Queen Mary University of London, UK
1
2
Introduction
Multiple Sclerosis (MS) is a complex disease of the central nervous system, characterized by areas
of demyelination and inflammation. Well before any myelin and blood-brain barrier damage,
clusters of activated microglia are noticeable. These clusters are considered to be the first stage
of lesion formation and therefore called ‘pre-active lesions. However, they do not always progress
into full-blown active destructive lesion. This strongly suggest that some regulation exists.
Microglia are the innate macrophages of the brain. Macrophages can fulfil a dual role: proinflammatory (M1) and anti- inflammatory (M2). Here we postulate that a switch from an antiinflammatory to a pro-inflammatory phenotype of microglia in pre-active lesions, may be crucial in
lesion development.
Methods
Human primary isolated microglia are cultured and stimulated to either a M1 or M2 phenotype and
characterized by marker expression and cytokine profile.
By immunohistochemical staining the activation status of microglia in pre-active lesions will be
determined.
Results
In vitro data reveal that human microglia are able to be activated towards pro- and antiinflammatory phenotypes. Typical M2 markers are scarcely observed in pre-active lesions, whereas
M1 markers are abundantly present.
Conclusions
Based on histopathological microglia phenotyping, it is not possible to predict whether a preactive lesion will turn into a demyelinating lesion. This suggests that another intrinsic factor
might control this switch. A possible candidate is the myelin producing oligodendrocyte, not the
victim but maybe the key player in MS lesion formation.
154
Preclinical disease models
145. Endothelial AMPKa2 regulates whole body glucose uptake
Erik van Poelgeest1, Michiel P. de Boer2, Rick I. Meijer2, Erik H. Serné2,
Geerten P. van Nieuw Amerongen1, Erik A. Richter, Benoit Viollet, Victor W.M. van Hinsbergh1,
Yvo M. Smulders2, Etto C. Eringa1
VU University Medical Center, Amsterdam
1
Laboratory for Physiology
2
Department of Internal Medicine Institute for Cardiovascular Research (ICaR-VU)
Introduction
An increase in muscle tissue delivery of glucose and insulin due to insulin-induced vasodilatation
of arterioles and the subsequent increase in muscle microvascular perfusion is known to be a
requisite response to food intake. An impairment of this physiological response could play a role
in the development of both hyperglycemia and hypertension. The energy regulator AMP-activated
Kinase (AMPK) has intriguingly been shown to play a role in the regulation of arteriolar diameter
by the endothelium. We hypothesized that activation of endothelial AMPK for insulin to induce
vasodilatation.
Methods
Using our CreER/Loxp AMPK endothelium-specific inducible knockout mice we investigated
insulin-induced capillary recruitment (contrast enhanced ultrasonography) and whole-body insulin
sensitivity (hyperinsulinemic euglycemic clamp) and oral glucose tolerance tests. Using pressure
myography we explored the mechanism of insulin-induced dilatation in skeletal muscle arterioles.
Results
Strikingly, AMPKEKOα2 mice are glucose intolerant. Systolic blood pressure possibly trends to be
increased. Puzzling, both peripheral insulin sensitivity and capillary recruitment on insulin appear
normal. Tissue-wide AMPKa2-/- mice do show decreased insulin-induced arteriolar dilatation in
vivo and ex vivo as well as peripheral insulin resistance.
Conclusions
Endothelial AMPK could play a role in the development of both glucose intolerance and
hypertension. Further experiments will be done to clarify the mechanism, i.e. in an endothelial
knockout model of both AMPK’s subunits (AMPKEKO α1α2).
VU University Medical Center Science Exchange Day 2014
155
Preclinical disease models
146. Predicting Glycated Haemoglobin in the Non-Diabetic
General Population: a DIRECT Study
Simone P. Rauh1, Martijn W. Heymans1, Marjan Alssema1, Giel Nijpels2, Coen D. Stehouwer3,
Barbara Thorand4, Wolfgang Rathmann5, Christa Meisinger4, Annette Peters4, Tonia Ludwig4,
Charlotte Glümer6, Oluf Pedersen7, Henna Cederberg8, Johanna Kuusisto8, Ewan R. Pearson9,
Paul W. Franks10,11, Femke Rutters1, Jacqueline M. Dekker1
Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care
Research, VU University Medical Center, Amsterdam, The Netherlands
2
Department of General Practice, VU Medical Center, Amsterdam, The Netherlands
3
Department of Internal Medicine and Cardiovascular Research Institute Maastricht,
Maastricht University Medical Centre, Maastricht, The Netherlands
4
Institute of Epidemiology II, Helmholtz Zentrum München - German Research Center for
Environmental Health, Neuherberg, Germany
5
Institute of Biometrics and Epidemiology, German Diabetes Center, Leibniz Center for Diabetes
Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
6
Research Centre for Prevention and Health, Glostrup Hospital, Capital Region of Denmark
7
The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical
Sciences, University of Copenhagen, Denmark
8
Department of Medicine, University of Kuopio and Kuopio University Hospital, Kuopio, Finland
9
Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee,
Scotland, United Kingdom
10
Department of Clinical Sciences, Genetic and Molecular Epidemiology Unit, Lund University,
Skane University Hospital Malmö, Malmö, Sweden
11
Department of Public Health and Clinical Medicine, Umea University, Umea, Sweden
1
Introduction: Recently, glycated haemoglobin (HbA1c) levels have been introduced as diagnostic
criterion for type 2 diabetes. Our study evaluates whether predictors from the previously
developed DETECT-2 screening tool could be used to predict HbA1c levels 6 years later.
Methods: Data from 5,762 initially non-diabetic subjects from three population-based cohorts
(Hoorn Study, Inter99, KORA S4) were used to predict HbA1c levels at follow-up. Using backward
selection, age, BMI, waist circumference, use of anti-hypertensive medication, current smoking
and parental history of diabetes remained in sex-specific linear regression models. To minimize
overfitting of coefficients, we performed internal validation using bootstrapping techniques.
Discrimination and calibration were assessed using classification tables (comparing highest/
lowest 50% HbA1c levels) and calibration graphs. The model was externally validated in 2,765 nondiabetic subjects of the population-based cohort METSIM.
Results: At baseline, mean HbA1c level was 5.6%. During a mean follow-up of six years, 2.3% of
the subjects developed HbA1c levels ≥6.5%. With respect to discrimination, our model classified
60% of the subjects correctly as having high/low HbA1c levels. Calibration plots showed that
predicted HbA1c levels were underestimated in the Inter99 cohort and overestimated in the Hoorn
and KORA cohorts, indicating that the model’s intercept should be adjusted for each cohort to
improve predictions. External validation showed similar model performance in the METSIM cohort.
Conclusions: In the non-diabetic population, simple predictors can be used to discriminate
between future highest and lowest HbA1c levels. Actual HbA1c values are cohort-dependent. As a
next step, for identifying high-risk individuals, current HbA1c levels can be added to the model.
156
Preclinical disease models
147. In Vitro Sonothrombolysis in Whole Blood for Myocardial
No-reflow
S.T. Roos1,2; F.T. Yu3; X. Chen3; O. Kamp1,2; J.J. Pacella3; F.S. Villanueva3
Cardiology department, VUmc, Amsterdam, The Netherlands
ICIN – Netherlands Heart Institute, Utrecht, The Netherlands
3
Center for Ultrasound Molecular Imaging and Therapeutics, Pittsburgh, USA
1
2
Introduction
Acute myocardial infarction can be treated with percutaneous coronary intervention. Adequate
microvascular perfusion is often not restored due to microvascular obstruction (MVO), partly
caused by microvascular microthrombi. This negatively influences clinical outcomes. We tested the
hypothesis that ultrasound (US) mediated microbubble (MB) destruction can achieve microvascular
clot lysis in our in vitro MVO model.
Methods
The model comprised of a phantom vessel containing an intraluminal mesh with 40 µm pores to
simulate a cross section of the microcirculation. Bovine blood microthrombi were injected into the
blood filled system, increasing upstream pressure, measured with an upstream fluid filled
transducer. Partially degassed bovine whole blood and lipid MBs (2x106 MB/ml) were infused at
0.75ml/min. US was delivered at 1 MHz with a variable pulse length and peak-to-peak pressure of
1.5MPa. US was applied for 20 minutes during continuous pressure monitoring, in pulses every
3 seconds to allow MB replenishment between pulses. Control experiments utilized no MB, no US
or saline as the perfusate. Experimental manipulations included the addition of tPA to the blood
perfusate during US and MB delivery. Experiments were repeated 3-7 times.
Results
Upstream pressure decreased progressively during US delivery. US parameters affected the
efficacy; thrombolysis increased with increasing acoustic pressure and duty cycle. Upstream
pressure did not drop completely to zero using whole blood perfusate, when tPA was added
pressure fell close to zero.
Conclusions
High acoustic pressure sonothrombolysis with MB can achieve reperfusion in whole blood, but
with less efficacy than in PBS, suggesting differences in fluid dynamics affect bubble dynamics.
VU University Medical Center Science Exchange Day 2014
157
Preclinical disease models
148. The micro- but not macro-vascular lung endothelium of
pulmonary arterial hypertension patients shows a defective
adaptation to high fluid shear stress
Robert Szulcek1, 3, R.D. Fontijn2, S. Joemai3, A.J. Horrevoets2, K. Hartemink4, C. Dickhoff4,
A. Vonk-Noordegraaf1, H.J. Bogaard1 and G.P. van Nieuw Amerongen3
Department of Pulmonary Diseases,
Department of Molecular Cell Biology and Immunology,
3
Department of Physiology,
4
Department of Lung- and Endocrine Surgery, Institute for Cardiovascular Research (ICaR-VU),
VU University Medical Center, Amsterdam
1
2
Introduction
We hypothesize that endothelial cell activation, injury and death, caused by un-physiological
high levels of fluid shear stress (HSS), is required for the pulmonary vascular remodeling found
in pulmonary arterial hypertension (PAH). Therefore we tested whether pulmonary microvascular
(MVEC) and pulmonary arterial endothelial cells (PAEC) from PAH patients are capable to adjust
their morphology and function to HSS.
Methods
Static cell cultures were compared to cells under HSS (up to 25dyn/cm2). Different flow profiles
(laminar, bifurcation-like) were applied and electrical impedance of the cell layers was recorded to
assess barrier function.
Results
Striking differences were found in structural adaptation to HSS, as control MVEC re-aligned in flow
direction, whereas MVEC from PAH patients failed to align after 72hrs application of HSS.
Specifically, 65.3%±1.4 of the control MVEC elongated and 72.4%±4.4 of them re-aligned within an
angle less than 20˚ relative to the flow direction, whereas only 47.2%±8.5 of PAH MVEC showed
a stretched morphology and oriented randomly to the flow. In contrast, PAH PAEC responded
similarly as control MVEC to HSS challenge. Application of bifurcation-like HSS to PAH MVEC
caused severe cell loss at branch points, while control MVEC and PAH PAEC were able to withstand
those flow patterns. Interestingly, upon HSS stimulation, expression of genes known to play a role
in shear sensing and adaptation, was similarly up-regulated in all PAH and control samples. Under
static culture conditions a two times lower protein expression of the known shear sensor CD31 as
well as an significant increase in Tiam1 and phosphoERK1/2 was found in PAH MVEC and PAEC.
Whereas endothelial barrier function remained unaffected, as PAH and control cells formed similar
barriers with a resistance of 800-1100ohms.
Conclusions
PAH MVEC but not PAEC have a hampered ability to adapt to HSS, which can result in severe
endothelial damage at branch points of the lung microvasculature. These findings imply that
treatment strategies normalizing pulmonary blood flow and/or protect endothelial cells from
injury, could prevent or reverse the vascular remodeling in PAH.
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Preclinical disease models
149. Expression of CORIN and STOX2 and their effect on NODAL
in the first trimester fetal placenta
Hari Krishna Thulluru1,2, Gunilla Kleiverda3, Cees Oudejans1,2, Marie van Dijk1,2
Department of Clinical Chemistry, VU University Medical Center, Amsterdam
Institute for Cardiovascular Research, VU University Medical Center, Amsterdam
3
Department of Gynecology, Flevoziekenhuis, Almere
1
2
Introduction
Our group has previously shown the effect of maternal (decidual) Nodal on feto-placental NODAL
and STOX1 expression indicating their potential maternal-fetal interaction.CORIN, a cardiac protease,
and STOX2, a paralog of preeclampsia (PE) susceptibility gene STOX1, have lately been described
as pre-eclamptic susceptibility genes. Recently, corin deficient mice showed PE like symptoms
while PE patients had low corin levels. STOX2 was found to be downregulated in term PE deciduas.
We therefore sought to investigate if CORIN and STOX2 factors might function in the same pathway
as STOX1 and Nodal.
Methods
CORIN and STOX2 mRNA expression in human first trimester tissues (6-12 gestational weeks) were
measured by qPCR, while STOX2 cellular localization was studied by immunohistochemistry (IHC).
Conditioned media (CM) from decidual cells with CORIN and STOX2 siRNA-mediated knockdown
was placed on placental cells and NODAL expression was measured.
Results
In tissues, CORIN was expressed at higher levels in decidua than in placenta while STOX2 was
expressed almost equally in both. IHC analyses of STOX2 showed predominantly cytoplasmic
signal in placenta and nuclear in decidua tissues. Placental cells that can invade the decidua
also showed nuclear expression. CM of CORIN and STOX2 knockdown in decidua and a decidual
stromal cell line gave downregulated NODAL expression in placental cells.
Conclusions
These preliminary findings demonstrate a potential shared pathway between CORIN, STOX2 and
NODAL in the development of PE.
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159
Preclinical disease models
150. Traction force microscopy: a study of the endothelium
during thrombin-mediated contractility
Erik T. Valent1, Lona J. Kroese1,Ramaswamy Krishnan2, Victor W.M. van Hinsbergh1,
Geerten P. van Nieuw Amerongen1
VU University Medical Center, Institute for Cardiovascular Research, Department of Physiology,
Amsterdam, The Netherlands
2
Beth Israel Deaconess Medical Center, Center for Vascular Biology Research, Boston,
Massachusetts, USA
1 Introduction
Different studies indicate that endogenously generated endothelial contractility plays a key role
in barrier dysfunction. Interestingly, the nature and distribution of these forces remains largely
unknown. With the use of traction force microscopy (TFM), we aim to study the contractions of
endothelial monolayers in thrombin mediated hyperpermeability.
Methods
Previously described TFM methods are used to generate force maps of HUVECs monolayer under
basal and after stimulation with the vaso-active agent thrombin.
Results
Novel overlays of traction force maps with images of the endothelium revealed a heterogenic
force landscape with characteristic punctuated hot spots. These highly dynamic and fluctuating
forces were very time and location dependant and assumed to be the consequence of mechanical
feedback from within the monolayer. Upon thrombin stimulation traction forces were increased
significantly (baseline 47± 2.4 Pa vs thrombin 131± 4.8 Pa) as well as the size of the hotspots.
Intercellular gap formation is typically observed at locations where two force hotspots pull in
opposite direction and when the cell-cell interaction is thorn apart, an area of low traction forces is
formed.
Conclusion
This study shows highly dynamic balancing of forces within resting endothelial monolayers.
During thrombin-mediated contractility, hotspot location and force vector angle are of key
importance in relation to the formation of inter-endothelial gaps.
Funding: Dutch Heart Foundation
160
Preclinical disease models
151. GM-CSF stimulation of monocytes enhances migration over
endothelial cells
Daphne Y.S. Vogel1,2, Priscilla D.A.M. Heijnen1, Marjolein Breur1, Helga E. de Vries 1, Sandra Amor2,3,
Christine D. Dijkstra1
Department of Molecular Cell Biology and Immunology, Neuroscience Campus Amsterdam
VU University Medical Center, Amsterdam, the Netherlands
2
Department of Pathology VU University Medical Center, Amsterdam, the Netherlands
3
Department of Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
1
Introduction
Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous
system. Infiltration of macrophages into the central nervous system is crucial for disease onset
and progression. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to
be essential for the migration of monocytes acrossthe blood brain barrier, since blocking GM-CSF
inhibits clinical signs of experimental autoimmune encephalomyelitis(EAE), an experimental model
for MS. Although the role of GM-CSF in MS is less apparent, GM-CSF can activate monocytes and
macrophages. Higher levels of GM-CSF in cerebrospinal fluid during MS relapses indicate that GMCSF may play an important role in leukocyte recruitment.
Methods
To elucidate which cells produce GM-CSF and express the GM-CSF receptor we performed
immunohistochemistry on MS lesions. GM-CSF receptor is expressed by neurons in the rim of
the lesion, whereas GM-CSF is expressed by inflammatory cells in the perivascular space. To
investigate the effect of GM-CSF on macrophages, the levels of expression of CD40 and mannose
receptor (MR) were determined using flow cytometry to investigate the activation status. GM-CSF
induces the expression of both CD40 and MR on macrophages as shown in active MS lesions.
Next we assessed the migratory capacity of monocytes towards CCL2 in the presence of GM-CSF in
a transwell culture system using a monolayer of human endothelial cells.
Conclusion
Altogether our data indicate that GM-CSF is a potent stimulator of monocyte migration in
human in vitro models, which is supporting the relevance of previous findings in EAE models for
neuroinflammation in human disease.
VU University Medical Center Science Exchange Day 2014
161
Preclinical disease models
152. Faster cross-bridge relaxation rates correlate with increased
tension cost in HCM with the R403Q MYH7 mutation
E. Rosalie Witjas-Paalberends1, Claudia Ferrara2, Beatrice Scellini2, Judith Montag3,
Ger J.M. Stienen1,4, Michelle Michels5, Carolyn Ho6, Theresia Kraft3, Corrado Pogessi2,
Jolanda van der Velden1,7.
Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands
Department of Physiology, University of Florence, Florence, Italy
3
Inst. of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
4
Department of Physics and Astronomy, VU University, Amsterdam, The Netherlands
5
Thorax Center, Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
6
Brigham and Women’s Hospital, Cardiology, Boston, USA
7
ICIN- Netherlands Heart Institute, Utrecht, The Netherlands
1
2
Introduction
The first mutation found to be associated with hypertrophic cardiomyopathy (HCM) is the R403Q
mutation in the gene encoding β-myosin heavy chain. R403Q locates in the globular head of
myosin (S1), responsible for the actin interaction, hence motor function of myosin. According to
the 2-state model of action-myosin interaction total cross-bridge turnover rate can be described
by the sum of the cross-bridge association (fapp)and detachment (gapp) rates. Gapp is equivalent
to the slow rate of cross-bridge relaxation (slow krel­), which equals the energetic cost of tension
generation, i.e. tension cost (expressed by ATP utilization/tension). In the present study we
studied to what extent cross-bridge kinetics in HCM with the R403Q mutation correlated with
cross-bridge energetics.
-1 -1
-2
Tension cost (mmol×L s / kN×m )
Methods & Results
5
Left ventricular multicellular muscle strips and myofibrillar
preparations were isolated from 3 HCM patients with the
4
R403Q(1)
R403Q mutation. 8 HCM sarcomere mutation-negative (HCMsmn)
3
R403Q(2)
patients served as control. In the muscle strips force generating
2
R403Q(3)
capacity and ATP utilization were measured to obtain tension
HCM smn
1
cost and in the myofibrillar preparations cross-bridge kinetics
0
was analyzed. The fraction of mutated R403Q mRNA was
0.0
0.2
0.4
0.6
0.8
analyzed using specific specific restriction digests and realtimeSlow krel (s-1)
PCR.restriction. Compared to HCMsmn tension cost was higher
in the muscle strips of the 3 R403Q patients which showed a positive linear correlation with
relaxation kinetics in the corresponding myofibrillar preparations (figure). Variation in cross-bridge
function among the 3 R403Q patients could not be explained by differences in R403Q mRNA
levels.
Conclusions
Cross-bridge cycling efficiency was decreased in HCM due to the R403Q mutation while crossbridge kinetics was increased. This suggests that the apparent gain in function regarding kinetics
leads to a loss off function with respect to cross-bridge cycling efficiency in HCM due to the
R403Q mutation.
162
Quality of Care – Safety
153. ‘Am I at risk?’: Understanding how health risk information
is (mis)understood
N.M.M. Bogaerts1, O.C. Damman1, M.J. van den Haak2 and D.R.M. Timmermans1
Department of Public and Occupational Health, EMGO Institute for Health and Care Research,
VU University Medical Center
2
Department of Language and Communication, Faculty of Arts, VU University
1
Introduction
Numerous studies have shown that people have difficulty in understanding risk information. To
gain more insight into how people interpret risk information, we conducted a qualitative study
based on the Dutch online cardiometabolic risk assessment www.testuwrisico.nl.
Methods
We conducted 16 semi-structured interviews with people between 45 and 65 years. They completed
the risk assessment while an eye-tracker registered their visual attention. They were then
interviewed for thirty minutes about the risk information they received at the end of the assessment.
Data were analyzed by identifying problems in risk interpretation and by comparing eye-gaze
patterns.
Results
We identified several problems related to risk interpretation. One important problem was that
people perceived relatively high risks (e.g. 25%) as low. They felt that only extreme risks were
reason for worry. People compared their risk to an impossible risk of 100%, and a bar chart
visualization seemed to reinforce this. Another problem was that people had problems deriving
meaning from the (numerical) risk information. They were interested to compare their risk to that
of other people. The test does provide comparative information, but both eye-tracking patterns
and people’s verbalizations showed that this information was not optimally used.
Conclusions
In order to help people derive meaning from health risk information, alternative formats should be
developed and tested. One option could be to test different types of risk comparison information
(e.g. average risk or lowest possible risk).
VU University Medical Center Science Exchange Day 2014
163
Quality of Care – Safety
154. Manual therapy for neck pain?
Barriers and facilitators explored
Marije F. Dikkers1, Marjan J. Westerman1, Sidney M. Rubinstein1, Maurits W. van Tulder1,
Johannes R. Anema2
Department of Health Sciences, VU University
Department of Public and Occupational Health, VU University Medical Center
1
2
Introduction
Treatment of neck pain with manual therapy (MT) appears more effective and cost-effective than
general practitioner (GP) care and physiotherapy (PT). However, referral to MT for neck pain is
relatively low. This study was designed to identify the barriers and facilitators for GPs and
physiotherapists to refer patients with neck pain to MT.
Methods
Qualitative explorative study. Semi-structured interviews with GPs (n=13), physiotherapists (n=10),
manual therapists (n=7) and their patients with neck pain (n=27). Three focus groups with additional
stakeholders (e.g. policy makers) were conducted to validate the interview results. Thematic
analysis was used.
Results
All stakeholders mentioned that it is not clear how MT differs from PT and that there are concerns
about adverse effects of MT for neck pain among patients and practitioners. Practitioners
emphasized patients’ preferences are prominent in their decision making. Another factor is
whether GPs and physiotherapists perceive it is part of their professional role to refer to MT. Both
physiotherapists and GPs mentioned that trust in the quality of care provided by manual therapists
to patients with neck pain is a facilitator. Finally, GPs and physiotherapists mentioned availability
of MT plays a role.
Conclusions
A number of factors were identified that can stimulate or hinder MT referral in GPs’ and
physiotherapists’ neck pain management, such as understanding of the MT domain, professional
role orientation, and inter-professional trust. These factors will be addressed in a subsequent
project to test a strategy to improve the implementation of MT in neck pain management in
primary care.
164
Quality of Care – Safety
155. Changes in error and risk management after CRM training.
Results of a controlled study
P.F. Kemper, Msc1*, M.C. de Bruijne, MD PhD1, C. van Dyck, PhD2, K.L. So, MD3, P. Tangkau, MD4,
C. Wagner, PhD 1,5
Department of Public and Occupational Health, EMGO Institute for Health and Care Research,
VU University Medical Center, Amsterdam
2
Faculty of Social Sciences, Department of Organizational Science, VU University, Amsterdam
3
Department of Intensive Care, Albert Schweitzer Ziekenhuis, Dordrecht
4
Department of Intensive Care, Reinier de Graaf Gasthuis, Delft
5
The Netherlands Institute of Health Services Research (NIVEL), Utrecht
1
Introduction
Crew Resource Management (CRM) is an increasingly applied method in health care in order to
improve patient safety by applying non-technical skills, leading to an optimal use of all resources
in the team and their environment. The present study evaluated the effectiveness of CRM in the
Intensive Care Unit (ICU).
Methods
Six ICUs participated in a paired controlled trial, with one pre-test and two post-test measurements
(after 3 and 12 months). Three ICUs received CRM training and were compared to a matched
control unit. The 2-day classroom-based training was delivered to multidisciplinary groups. All
levels of Kirkpatrick’s evaluation framework were assessed using a mixed method design.
Results
Level I: Participants were very positive directly after the training.
Level II: Attitudes towards behaviour to optimise situational awareness were relatively high at
baseline and remained stable.
Level III: Self-reported behaviour to optimise situational awareness improved in the intervention
group. No changes were found in observed explicit professional oral communication.
Level IV: Patient outcomes were unaffected. Error management culture and job satisfaction
improved in the intervention group. Patient safety culture improved in both control and
intervention units.
Conclusions
Based on the results we can conclude that CRM changes how participants manage errors and risks,
as well as increases job satisfaction. Although self-reported behaviour improved, there was no
change in explicit professional communication, neither did patient outcomes improve. This is an
indication that although CRM provides the fundament for quality improvement, improvements in
clinical outcomes require a further implementation of multiple CRM initiatives.
VU University Medical Center Science Exchange Day 2014
165
Quality of Care – Safety
156. Regional change in DTI parameters due to upgrade of MRI
scanner: effects on TBSS and ROI analysis
Petra J.W. Pouwels1, Frederik Barkhof2, Rudolf M. Verdaasdonk1, Joost P.A. Kuijer1
Department of Physics and Medical Technology, Neuroscience Campus Amsterdam,
VU University Medical Center
2
Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam,
VU University Medical Center
1
Introduction
Diffusion tensor imaging (DTI) is used in many neuroradiological protocols. Repeated DTI
measurements were prospectively acquired on healthy volunteers before and after an upgrade of a
3T MRI scanner to check for possible systematic variation.
Methods
DTI acquisition was performed before and after a hardware upgrade of a GE 3T MRI scanner in
13 male healthy subjects (mean age 33.8 ± 8.6 years). Data were processed with FSL, resulting in
FA (fractional anisotropy), MD (mean diffusivity), AD (axial diffusivity), and RD (radial diffusivity),
followed by TBSS analysis of all parameters.
Results
Pairwise comparison of repeated measurements before the upgrade did not show significant
differences. Pairwise comparison of repeated measurements before and after upgrade (representing
a longitudinal study design) showed significant differences in FA, AD, RD, and MD. At tfcecorrected p<0.01, differences were present in >25% of the skeleton, especially located in the body
of the corpus callosum. In an unpaired groupwise comparison (representing a cross-sectional
study design) still 5% of the skeleton remained significantly different. Bland-Altman plots of values
in selected ROIs show that the deviating values only partially scale with mean values of the DTI
parameters, while no differences in SNR were observed as a result of the upgrade.
Conclusions
Quantitative MRI measures as obtained with DTI are sensitive to scanner modifications, even
when using the same scanning protocol. This emphasizes the need to include healthy subjects as
controls both before and after a scanner upgrade, and to take scanner upgrade into account in the
study design.
166
Quality of Care – Safety
157. Actual and preferred place of death as quality indicators
for palliative care?
De Roo ML1, Miccinesi G.2, Onwuteaka-Philipsen B.D.1, Van Den Noortgate N.3, Van den Block L.4,
Bonacchi A.2, Donker G.A.5, Lozano Alonso J.E.6 , Moreels S.7, Deliens L.1,4, Francke A.L.1,5, on behalf
of EURO IMPACT
Department of Public and Occupational Health, VU University Medical Center, EMGO Institute for
Health and Care Research, Amsterdam, The Netherlands
2
Cancer Prevention and Research Institute (ISPO), Florence, Italy
3
Department of Geriatrics, Ghent University Hospital, Ghent, Belgium
4
End-of-life Care Research Group Vrije Universiteit Brussel and Ghent University, Vrije Universiteit
Brussel, Brussels, Belgium
5
NIVEL, Netherlands Institute for Health Services Research, Utrecht, The Netherlands
6
Public Health Directorate General, Regional Ministry of Health, Government of Castilla y León,
Valladolid, Spain
7
Scientific Institute of Public Health, Public Health and Surveillance, Health Services Research,
Brussels, Belgium
1
Introduction
Dying at home and at the preferred place of death have been suggested as indicators of highquality palliative care. More insight is needed in their usefulness as quality indicators (QIs). We
aim to describe the scores of the existing QIs ‘the percentage of patients dying at home’ and ‘the
percentage of patients who died in their place of preference’ and to assess if they are feasible and
informative.
Methods
A mortality follow-back study was conducted, based on registrations from representative GP
networks regarding home-dwelling patients (n=3752) who died non-suddenly in Belgium, the
Netherlands, Italy and Spain. We assessed relationship between QIs and care characteristics using
logistic regression.
Results
The percentage of home deaths ranged between 35.3% and 50.6% in these countries; whereas
67.8% to 86.0% of patients whose preference was known died at their preferred place. Both QIs
were strongly associated with GP palliative care provision (OR 1.55-13.23 and 2.30-6.63). The QI
on the preferred place of death offers a broader view than the QI concerning home deaths,
considering all preferences met in all locations. GPs did not know the preferences in 39.6% to
70.3%.
Conclusions
GPs know their patients’ actual place of death, making the percentage of home deaths a feasible
QI. However, patients’ preferred place of death was often unknown to the GP. We recommend
using information from relatives if information from GPs on the preferred place of death is lacking.
Timely communication about where patients want to be cared for remains a challenge for GPs.
VU University Medical Center Science Exchange Day 2014
167
Quality of Care – Safety
158. Sport and exercise as markers of health for people with
diabetes
M.S. Stuij, MSc1, dr. A. Elling-Machartzki2, prof. dr. T.A. Abma1
1
2
Department of Medical Humanities, EMGO+ Institute, VU University Medical Center
Mulier Institute
Introduction
An illness may influence people’s sporting behavior and meanings given to sport and exercise.
Our study focuses on narratives around sport, exercise, health and illness of people with diabetes.
Methods
We developed an exploratory questionnaire for people with diabetes based on qualitative pilot
studies. Main topics were (changed) meanings of sport and physical activity and experiences with
medical support. Most of the respondents were recruited via the Dutch Diabetes Association. A
total of 174 people completed the questionnaire (type 1: 82; type 2: 92). Data were analysed using
SPSS.
Results
Most respondents are quite active in sports and physical activity. The (experienced) positive effects
of physical activity on diabetes is an important motivation for both groups. While type 1 diabetics
are more intrinsically motivated (pleasure), people with type 2 more often report that the meaning
of sport and exercise has changed and that they need external advice and support. In general,
most respondents are quite critical about their experienced medical guidance in sport and
exercise.
Conclusions
These (preliminary) results point toward the need for more insight into differences in (changed)
meanings and experiences between patients (type diabetes, socio-demographical, sport history)
and critical issues in the experiences with medical guidance in continuing or taking up sports and
physical activity after diagnosis.
168
Quality of Care – Safety
159. Toward optimal organ at risk sparing in complex
radiotherapy treatments: an exponential trade-off with
tumor volume dose homogeneity
Jim P. Tol, Max Dahele, Patricia Doornaert, Ben J. Slotman, Wilko F.A.R. Verbakel
Department of Radiotherapy, VU University Medical Center, Amsterdam
Introduction
Conventional radiotherapy typically aims for a homogenous dose to the tumor volume (PTV) while
sparing nearby organs at risk (OAR). We quantified and characterized the trade-off between PTV
dose inhomogeneity (IH) and OAR sparing in complex head and neck plans delivered using a
rotational radiotherapy technique.
Methods
13 simultaneous integrated boost plans were created per patient, for 10 patients. PTV boost(B)/elective(E)
optimization priorities were systematically increased. IHB&IHE, defined as (100%-V95%)+V107%
was evaluated against the average of the mean dose to the combined composite swallowing and
combined salivary organs (D-OARcomp). To investigate the influence of OAR size and position
with respect to PTVB/E, OAR dose was evaluated against a modified Euclidean distance (DMB/DME)
between OAR and PTV.
Results
Excellent logarithmic fits described the D-OARcomp/IHB and IHE relationship in all patients (mean
R2=0.98/0.97 respectively). Allowing an increase in average IHB and IHE over a clinically acceptable
range, e.g. from 0.4±0.5 to 2.0±2.0% and 6.9±2.8 to 14.8±2.7%, respectively, corresponded to
a decrease in average dose to the composite salivary and swallowing structures from 30.3±6.5
to 23.6±4.7Gy and 32.5±8.3 to 26.8±9.3Gy. The increased IHE was mainly accounted for by an
increase in V107%, by on average 5.9%. A linear correlation was found between DME and dose
to composite swallowing structures and contralateral parotid and submandibular glands
(R2=0.83,0.89,0.95). Mean ipsilateral parotid dose correlated with DMB (R2=0.87).
Conclusions
OAR sparing is highly dependent on the permitted IHB/IHE. IHE substantially influences OAR doses.
These results are relevant for clinical practice and for future automated treatment-planning
strategies.
VU University Medical Center Science Exchange Day 2014
169
Quality of Care – Safety
160. Exploring treatment delays in the care of patients
diagnosed with ST-segment elevation myocardial
infarction undergoing primary percutaneous coronary
intervention: a cross-sectional study
Joppe Tra1, Ineke van der Wulp1, Martine C. de Bruijne1, Cordula Wagner1
1
Department of Social Medicine, EMGO+ Institute / VU University Medical Center
Introduction
A short delay between symptom onset and treatment for patients diagnosed with ST-segment
Elevation Myocardial Infarction (STEMI) is vital to prevent cardiac damage and mortality. Therefore,
international cardiology guidelines recommend a maximum time span of 90 minutes between first
(para)medical contact and percutaneous coronary intervention (PCI). It is unclear whether patients
are treated within this recommended time span, and what factors are associated with treatment
delays.
Methods
In a cross-sectional study, the time between first electrocardiogram and start of PCI procedure
was measured by means of chart review in seven PCI centres. Patients discharged in 2012 with
a diagnosis of STEMI were included in the study. Data were analysed by means of multivariable
generalized linear models, accounting for clustering of patients in hospitals.
Results
In total, 1017 patient charts were included. The majority of the patients (78.6%) were treated within
90 minutes after conducting the first electrocardiogram (median: 64 minutes). Significantly longer
delays were found among patients of whom their first electrocardiogram was conducted at the
general practitioner (+24 minutes); who had acute heart failure on arrival (+18 minutes); or who
were transported between hospitals for PCI (+15 minutes).
Conclusions
The guideline recommended target for timely treatment of STEMI patients is frequently missed.
In optimising the process of care, direct referral to PCI centres is important. To establish this,
the general public requires education on sign and symptom recognition of STEMI. Additionally,
regional STEMI care networks require strengthening and should include all stakeholders, including
emergency departments and general practitioners.
170
Quality of Care – Safety
161. Policy for the return of clinically relevant individual
research results by Dutch biobanks
Eric Vermeulen1, Martin Boeckhout 2, Rob P.B. Reuzel2, Gerhard A. Zielhuis2, A. Cecile J.W. Janssens3,
Marjanka K. Schmidt4
Department of Clinical Genetics, Section Community Genetics, EMGO Institute for Health and
Care Research, VU University Medical Center Amsterdam
The Netherlands Cancer Institute, Amsterdam
2
Radboud University Medical Center, Nijmegen
3
Erasmus University Medical Center, Rotterdam
4
The Netherlands Cancer Institute, Amsterdam
1
Introduction
Biobanks can return ‘actionable’ individual research results to donors. The Dutch Code of Good
Conduct, self-regulation for biobanks, provides a guideline. Biobanks are advised to formulate
policy for (not) returning individual research results.
Methods
We performed a literature research, two expert meetings and interviews with biobank representatives.
Results
The Dutch professional Code of Good Conduct is restrictive towards the feedback of individual
research findings. The Code proposes that only clinically relevant, validated and actionable results
are fed back and this only if the donor/patient has consented to a return of results.
This leaves unanswered the question how to decide about the clinical relevance in individual cases.
How results should and could be returned is another problem that biobanks have to decide on.
As yet, a few Dutch biobanks have a policy formulated about feedback of research findings and
the return of individual research results takes place on an incidental basis. Several biobanks
experiment with ways to return results through a portal.
Conclusions
In order to facilitate the formulation of feasible ‘return of results policies’ biobanks need
information concerning how to decide about clinical relevance and how to return results to
individual donors.
VU University Medical Center Science Exchange Day 2014
171
Grants Desk VU/VUmc
Academic research is increasingly becoming dependent on extramural
financial support. Many researchers do not make sufficient use of external
sources of funding and grants.
The Grants desk provides:
•Up-to-date knowledge, expertise and capacity to attract appropriate
funding;
•Grants database;
•Advice on national and international grant schemes and funds;
•Support of the entire application process;
•Assistance in the formation of research consortia.
Our priorities and added value:
EU grants (Horizon 2020): most money, most potential, and most bureaucracy
Talent support (Veni-Vidi-Vici-ERC): coach individuals during preparation of personal grants
Grant strategy: strategic advice for individuals and departments
The Grants desk team:
Dr. Leo Klomp
Head grants desk
international grants
National, European and Guido Leerdam, MA
EU-adviser
European and international grants
Linde van Ittersum, MA Grants adviser
National, European and international grants
Jeroen van Leur, LL.M
Legal adviser
Legal advice
Drs. Marco Last
Grants adviser
Personal Grants
Dr. Bart Jordi
Grants adviser
Personal Grants
Contact information:
Building: Faculty of Medicine, room G-526;
Van der Boechorststraat 7-9
T: +31 (20) 444 9923
E: subsidiedesk@vu.nl
W: www.intranet.vu.nl/subsidiedesk/
Index
Subjectgroup Title of subject
Abstract nr./Poster nr.
A
Animal Models 1-13
B
Biomarkers: Clinical 14-25
C
Biomarkers: Experimental and Methods 26-41
D
Biomedical Engineering 42-55
E
Clinical and Epidemiological Surveys 56-80
F
Clinical Intervention 81-96
G
Clinical – Surveys on Volunteers 97
H
Diagnostic Studies – Patients 98-124
I
Literature Surveys 125-127
J
Preclinical Disease Models 128-152
K
Quality of Care – Safety – Auditing 153-161
Nr. of Presenting Title of abstract poster author
56
Aa, H.P.A. van der
A way out of depression in the visually impaired:
results from a path-analysis
E
Emgo+
1
Aarts, E.
Extracting gene-behavior relations in mice using
Markov modeling on longitudinal automated home
cage data
A
NCA
2
Acar, S.
Closer look at the machinery of cilia: Focusing on
the steps of IFT kinesins
A
Laserlab
Suppression of the Local Renin-Angiotensin System
to reduce Fibrosis
J
MOVE
128 Akershoek, J.J.
Subject Research
group Institute
8
Akker, R.F.P.
van den
Microvascular flow disturbances in a rat model
of cardiopulmonary bypass are not caused by
hemodilution
A
ICaR-VU
42
Beekmans, S.V.
Measuring the mechanical response of mouse
brain tissue with Alzheimer Disease in-vivo
D
Laserlab
14
Begieneman, M.P.V. Atrial fibrillation coincides with increased
intravascular depositions of the advanced
glycation end-product Nε-(carboxymethyl)lysine in
the atria of the heart
B
ICaR-VU
129 Bennis, A.
Toward stem cell based therapy for diseases
affecting the retinal pigment epithelium
J
NCA
98
Two new adult cases with AUTS2 mutations,
including a two basepair deletion, further delineate
the AUTS2 syndrome
H
NCA
Beunders, G.
173
Nr. of Presenting Title of abstract poster author
Subject Research
group Institute
99
Binnerts, J.J.
Comparison of quantitative cardiac perfusion
measurements using PET and CMR
H
ICaR-VU
3
Boer, M.P. de
AMPK Activation Regulates Microvascular Perfusion
and Insulin-mediated Vasoreactivity Through
Control Over Endothelin-1 Activity
A
ICaR-VU
4
Bogaards, S.J.P.
MAO-A inhibition reduces basal oxygen
consumption and restores isoprenaline sensitivity
of hypertrophied rat papillary muscle in vitro
A
ICaR-VU
153 Bogaerts, N.M.M.
‘Am I at risk?’: Understanding how health risk
information is (mis)understood
K
Emgo+
26
Broek, E. van den
Structural variant breakpoint detection in advanced
colorectal cancer
C
VUmc CCA
57
Burtman, D
Preoperative anemia alters the probability of
packed red blood cell transfusion in patients
undergoing vascular surgery
E
ICaR-VU
27
Büttler, R.M.
Measurement of serum testosterone,
androstenedione and dehydroepiandrosterone
(DHEA) levels using Isotope-Dilution LiquidChromatography Tandem Mass Spectrometry
(ID-LC-MS/MS)
C
NCA
100 Caanen, M.
Anti-Mullerian hormone serum levels decrease
in female to male transsexual women using
testosterone as cross-sex therapy
H
NCA
130 Campo, M. del
BRI2 protein ectodomain activates critical
pathological pathways involved in early stages of
Alzheimer’s disease
J
NCA
131 Campo, M. del
SPPL2b is dramatically increased in early stages of
Alzheimer’s disease and associates with amyloid
plaques and neurofibrillary tangles
J
NCA
5
Chandrupatla,
D.M.S.H.
Improvement of an experimental rat model
of rheumatoid arthritis for positron emission
tomography
A
VUmc CCA
15
Cohn, M.D.
Fear conditioning, persistence of disruptive
behavior and psychopathic traits: an fMRI study
B
Emgo+
28
Cover, K.S.
A standard benchmark for assessing the
reproducibility of brain atrophy measures in
Alzheimer’s using the ADNI1 data set
C
NCA
81
Dekker, N.A.M.
Microcirculatory changes during goal-directed or
mean arterial pressure-guided fluid therapy in
abdominal surgery
F
ICaR-VU
82
Delden, A.E.Q. van
Unilateral versus bilateral upper limb training after
stroke
F
MOVE
6
Detiger, S.E.L.
Slow BMP-2 release from a fibrin-hyaluronate
hydrogel for intervertebral disc regeneration in a
large animal model
A
MOVE
Identification of proteins directly interacting with
the HELLP-syndrome associated lincRNA using
ChIRP
J
ICaR-VU
132 Dijk, M. van
174
Nr. of Presenting Title of abstract poster author
58
Dijkstra, S.C.
The role of perceived barriers in explaining
socioeconomic differences in adherence to the
fruit, vegetables and fish guidelines in older Dutch
adults.
E
Emgo+
154 Dikkers, M.F.
Manual therapy for neck pain? Barriers and
facilitators explored
K
Emgo+
83
The first Dutch experience with the use of
Strattice™ for single-stage implant based breast
reconstruction
F
MOVE
133 Dooves, S.
Vanishing White Matter diseased astrocytes inhibit
oligodendrocyte progenitor cell maturation
J
NCA
34
De novo elucidation of metabolite clusters and
their genetically influenced protein‑protein
interaction sub‑networks based on a metabolomeand genome‑wide association study
C
Emgo+
101 Dreyer, K.
Hysterosalpingo-foam sonography (HyFoSy), a new
technique to confirm proximal tubal occlusion
after treatment of a hydrosalpinx by an Essure®
device prior to in vitro fertilization IVF (IVF)
H
ICaR-VU
102 Eck, A.
Altered Proteobacteria Composition in Patients
with Acute Uncomplicated Diverticulitis
H
VUmc CCA
59
Eekhout, I.
Longitudinal data analysis with auxiliary item
information to handle missing questionnaire data
E
Emgo+
84
Eilander, M.
Implementation of quality of life in routine
paediatric care for adolescents with type 1
diabetes in the Netherlands: An evaluation study
F
Emgo+
103 Eken, M.M.
Assessing Muscle Endurance in Adolescents with
Cerebral Palsy using a Submaximal Repetitions to
Fatigue Test
H
MOVE
134 Emmens, R.
C1-esterase inhibitor co-localizes with C3d and
C4d and is produced locally in the myocardium
after acute myocardial infarction
J
ICaR-VU
43
Feroldi, F.
Endoscopic polarization sensitive optical
coherence tomography and in vivo animal lung
imaging
D
Laserlab
29
Funke, U.
Preclinical evaluation of [11C]JNJ7777120 as a PET
tracer of histamine H4 receptors in the brain
C
NCA
44
Galgano, G.
Dual-channel multi-photon microendoscope for
labelfree optical diagnosis of diseases
D
Laserlab
104 Geest, Q. van
The hippocampus in multiple sclerosis:
Function, structure and its relation with memory
performance
H
NCA
16
Elevated inflammatory levels in chronic widespread
pain: basal inflammation and innate immune
response
B
Emgo+
Compensatory fronto-parietal hyperactivation
during set-shifting in unmedicated patients with
Parkinson’s disease
H
NCA
Dikmans, R.E.G.
Draisma, H.H.M.
Generaal, E.
105 Gerrits, N.J.H.M.
Subject Research
group Institute
175
Nr. of Presenting Title of abstract poster author
Subject Research
group Institute
125 Gier, B. de
Helminth infections and mrconutrients in
schoolchildren: a systematic review and metaanalysis
I
Emgo+
45
Glas, M.
Towards novel antibiotics: targeting the essential
bacterial cell division protein FtsQ
D
AIMMS
60
Grift, T.C. van de
Body-image in gender dysphoria; concepts of selfperception & physical appearance revisited for
different subtypes
E
NCA
17
Groen, F.L.M. de
Gene-dosage Dependent Overexpression at
the 13q Amplicon Identifies DIS3 as Candidate
Oncogene in Colorectal Cancer Progression
B
VUmc CCA
85
Güçlü, A.
Beneficial effects of aortic valve replacement on
myocardial energetics in aortic valve stenosis
patients
F
ICaR-VU
61
Hamilton, E.M.C.
New insights into the spectrum of genotypes and
phenotypes in Hypomyelination with Atrophy of
the Basal Ganglia and Cerebellum (H-ABC)
E
NCA
62
Hammerschlag, A.R. Functional Gene-Set Analysis of Attention Deficit/
Hyperactivity Disorder (ADHD)
E
NCA
63
Hemmen, J. van
Mental rotation in women with Complete Androgen
Insensitivity Syndrome: an fMRI study
E
NCA
46
Hermans, K.
The effect of medication on fMRI resting state
connectivity in focal epilepsy
D
ICaR-VU
135 Heuvel, O.A.
van den
Impulse Control Disorders in Parkinson's disease:
from preclinical model to prevention and
treatment
J
NCA
86
Heuvel, O.A.
van den
BEWARE: Body awareness training in the treatment
of wearing-off related anxiety in patients with
parkinson’s disease
F
NCA
64
Hoekstra, T.
Latent class growth (mixture) models: How do we
handle predictors of class membership?
E
Emgo+
136 Holmes, D.
Generation of iPSCs from patients with 4H
syndrome
J
NCA
65
Psychological posttraumatic growth in head and
neck cancer survivors
E
Emgo+
137 Horst, E.N. ter
Homocysteine induces apoptosis of arterial
smooth muscle cells via NOX4-produced reactive
oxygen
J
ICaR-VU
66
Efficacy and safety of intrauterine insemination in
patients with moderate to severe endometrisis
E
ICaR-VU
126 Houwen, L. van der Efficacy of intrauterine insemination in moderate
to severe endometriosis. A systematic review and
meta-analysis of observational data
I
ICaR-VU
67
E
Emgo+
176
Holtmaat, C.J.M.
Houwen, L.
van der
Huppertz, C.
The dopaminergic reward system and leisure time
exercise behavior: A candidate allele study
Nr. of Presenting Title of abstract poster author
47
Huseinovic, A.
A yeast genome-wide screen uncovers roles
for chromatin modifications and ubiquitin
homeostasis in acetaminophen toxicity.
D
AIMMS
30
Jager, A.M. de
The blood-derived transglutaminase Factor XIII
forms complexes with Aβ and is both present and
catalytically active in Aβ deposition in cerebral
amyloid angiopathy
C
NCA
138 Janssen, R.
MicroRNA-214 controls thyroid hormone levels by
targeting Dio3 in the post-MI heart
J
ICaR-VU
106 Johannesma, P.
Birt-Hogg-Dubé syndrome patients with and
without pneumothorax: findings on chest CT
H
VUmc CCA
108 Johannesma, P.
Clinical cases; Spontaneous pneumothorax at the
age of 14. Radiological evidence of Birt-HoggDubé syndrome
H
VUmc CCA
109 Johannesma, P.
Primary Spontaneous Pneumothorax: a pilot study
on the frequency of FLCN mutation (Birt-HoggDubé syndrome)
H
VUmc CCA
107 Johannesma, P.
Chest CT for primary spontaneous pneumothorax
(PSP): findings: Birt-Hogg-Dubé versus non-BirtHogg-Dubé patients
H
VUmc CCA
139 Joureau, B.
Diaphragm muscle weakness in a novel mouse
model for nebulin-based nemaline myopathy
J
ICaR-VU
48
Kamsma, D.
Single-molecule Acoustic Pushing (smAP!):
Manipulating single-molecules with ultrasound
D
Laserlab
97
Kan, K.J.
Cognitive functioning and blood pressure as a
function of age
G
NCA
7
Kedar, G.H.
A post docking role of the Synaptotagmin1-C2B
base domain
A
NCA
155 Kemper, P.F.
Changes in error and risk management after CRM
training. Results of a controlled study
K
Emgo+
110 Kevelam, S.H.
Novel (ovario)leukodystrophy related to AARS2
mutations
H
NCA
49
Klaessens, J.H.G.M. Development of a baby friendly non-contact
method for measuring vital signs, first results of
clinical measurements in an open incubator on a
Neonatal Intensive Care Unit
D
ICaR-VU
8
Koning, N.J.
Microvascular flow disturbances in a rat model
of cardiopulmonary bypass are not caused by
hemodilution
A
ICaR-VU
140 Kooi, E.I.
Copy number profiling of human and murine
retinoblastoma
J
VUmc CCA
31
Recommendations on study design and data
analysis for differential gene expression using
RNA-seq
C
VUmc CCA
Brain activation patterns reflect quality of motor
control of the paretic upper limb after stroke
H
MOVE
Kooi, E.I.
111 Kordelaar, J. van
Subject Research
group Institute
177
Nr. of Presenting Title of abstract poster author
Subject Research
group Institute
50
Krumpochova, P.
LC-MS based metabolomics as a tool for studying
the Warburg effect.
D
AIMMS
9
Kuzmin, N.V.
Lipid membranes, oxidative stress and amyloidbeta: Alzheimer’s disease triggering and imaging
with multimodal laser-scanning microscopy
A
NCA
10
Laarse, W.J. van der Numbers of intrinsic cardiac adrenergic cells in rat
heart: effect of hypertrophy
A
ICaR-VU
32
Labots, M.
Less is enough: scaling down protein input for
phosphoproteomics based treatment selection in
patients with advanced solid tumors
C
VUmc CCA
11
Lagerweij, T.
3D imaging of brain tumors
A
VUmc CCA
141 Leferink, P.
Towards a stem cell transplantation therapy for
VWM
J
NCA
68
Ligthart, L.
Prevalence and comorbidity of pain symptoms in
the general population
E
Emgo+
87
Loon, A. van
Effectiveness of an intercultural module: drop-out
and no-show rates in non-Western migrants with
affective disorders.
F
Emgo+
18
Luttmer, R.
Human papillomavirus in sperm of healthy young
men
B
VUmc CCA
33
Malekzadeh, A.
Discovery of biomarkers reflecting progression
pathophysiology for relapse remitting and primary
progressive MS subtypes by applying novel
multiplex aptamer approach
C
NCA
112 Manders, E.
Diaphragm dysfunction in pulmonary arterial
hypertension patients
H
ICaR-VU
113 Marcus, J.T.
Contrast-Enhanced MRI as method to monitor
response to anti-angiogenic therapy
H
ICaR-VU
114 Meijer, J.H.
Non-invasive assessment of the speed of cardiac
contraction
H
ICaR-VU
142 Mijalkovic, J.
Quantification of IFT-dynein dynamics in C.
elegans
J
Laserlab
19
Möller, C.
Basal nuclei are more severely atrophic in
behavioral variant Frontotemporal Dementia
compared to Alzheimer’s Disease
B
NCA
69
Mous, S.E.
Cortical Thickness and Inattention/Hyperactivity
Symptoms in Young Children- The Generation R
Study
E
NCA
143 Nadadhur, A.G.
Neuronal differentiation of iPS cells for disease
modeling
J
NCA
88
Nassau, F van
Implementation index: an indicator measuring
level of implementation of school-based
interventions.
F
Emgo+
51
Nauta, T.
Chronic hypoxia-enforced inhibition of
vascularization; Involvement of HIF1α and HIF2α
D
ICaR-VU
178
Nr. of Presenting Title of abstract poster author
52
Nelemans, B.
The Forces that Shape our Spine: Mechanics in
Somitogenesis
D
MOVE
70
Neter, J.E.
Dietary intake of Dutch food bank recipients
E
Emgo+
89
Nielsen, K.
Ablation of colorectal liver metastases by
irreversible electroporation: results of the
COLDFIRE-I ablate-and-resect study
F
VUmc CCA
115 Noij, D.P.
Predictive value of diffusion-weighted imaging
without and with contrast-enhanced magnetic
resonance imaging in head and neck squamous
cell carcinoma
H
VUmc CCA
90
The structure of the geriatric depressed brain and
response to electroconvulsive therapy
F
NCA
135 Pattij, T.
Impulse Control Disorders in Parkinson's disease:
from preclinical model to prevention and
treatment
J
NCA
144 Peferoen, L.A.N.
Microglia phenotyping in pre-active MS lesions
J
NCA
12
Persoon, C.M.
Neuropeptide secretion in the brain: Insights into
dynamics of dense-core vesicles
A
NCA
71
Plas, A. van der
Palliative care case management in primary care:
A descriptive study about the flexibility, duration
and content of care.
E
Emgo+
Endothelial AMPK_2 regulates whole body glucose
uptake
J
ICaR-VU
Oudega, M.L.
145 Poelgeest, E. van
Subject Research
group Institute
72
Pols-Vijlbrief, R. van Determinants of Undernutrition in Older Adults
der
receiving Home Care
E
Emgo+
34
Pool, R.
De novo elucidation of metabolite clusters and
their genetically influenced protein‑protein
interaction sub‑networks based on a metabolomeand genome‑wide association study
C
Emgo+
156 Pouwels, P.J.W.
Regional change in DTI parameters due to upgrade
of MRI scanner: effects on TBSS and ROI analysis
K
NCA
20
Rain, S.
Altered β-Adrenergic Receptor Signaling
Contributes to the Development of Right
Ventricular Diastolic Dysfunction in Pulmonary
Arterial Hypertension
B
ICaR-VU
73
Rainey, J.F.M.
Measurement properties of questionnaires
assessing participation in children and adolescents
with a disability: a systematic review
E
Emgo+
91
Rappard, D.F. van
Hematopoietic stem cell transplantation for
Metachromatic Leukodystrophy
F
NCA
146 Rauh, S.P.
Predicting Glycated Haemoglobin in the NonDiabetic General Population: a DIRECT Study
J
Emgo+
157 Roo, M.L. de
Actual and preferred place of death as quality
indicators for palliative care?
K
Emgo+
147 Roos, S.T.
In Vitro Sonothrombolysis in Whole Blood for
Myocardial No-reflow
J
ICaR-VU
179
Nr. of Presenting Title of abstract poster author
Subject Research
group Institute
35
Rosenberger, A.F.N. Protein kinase activity profiling of patients with
Alzheimer’s Disease and non-demented controls
reveals pathway changes
C
NCA
36
Ruiz-Zapata, A.M.
Substrate surface alter mechano-responses of
vaginal fibroblasts from prolapsed tissues in
premenopausal women with pelvic organ prolapse
C
MOVE
74
Rutten, S.
Anxiety in Parkinson’s disease: mind = body?
E
NCA
75
Rutters, F.
The association between psychosocial stress and
mortality is mediated by lifestyle and chronic
diseases: the Hoorn Study
E
Emgo+
116 Scheltens, N.M.E.
Cognitive Subtypes in Alzheimer Disease defined
by Latent Class Analysis
H
NCA
13
Schippers, M.C.
Deep brain stimulation of the nucleus accumbens
core affects heroin seeking and impulsivity in rats
A
NCA
76
Schooten, K.S. van
The quantity and quality of daily activities in
relation with fall history and future falls in older
adults
E
MOVE
77
Schutte, N.M.
A twin-sibling study of components of adolescent
physical fitness
E
Emgo+
117 Sloot, L.H.
Perturbations during treadmill walking offer
oppor-tunities for functional assessment of ankle
stiffness
H
MOVE
37
Smit, B.
Quantitating neutrophil oxidative stress by Flow
Cytometry
C
ICaR-VU
78
Spriensma, A.H.
Two-part joint regression modeling to analyze
longitudinal left censored patient reported
outcomes
E
Emgo+
118 Spruijt, Q.A.
The coupling of the right ventricle to its load
during exercise in pulmonary hypertension
H
ICaR-VU
79
Stam, H.
Predictors of dizziness in older persons: a 10-year
prospective cohort study in the community
E
Emgo+
21
Strooper, L. de
Triage of high-risk HPV-positive women by
combined cytology and methylation marker
analysis: complementary clinical performance
B
VUmc CCA
158 Stuij, M.S.
Sport and exercise as markers of health for people
with diabetes
K
Emgo+
80
The sex, age, and cognitive domain dependent
associations between regular voluntary exercise
behavior and cognitive functioning
E
NCA
148 Szulcek, R.
The micro- but not macro-vascular lung
endothelium of pulmonary arterial hypertension
patients shows a defective adaptation to high fluid
shear stress
J
ICaR-VU
149 Thulluru, H.K.
Expression of CORIN and STOX2 and their effect
on NODAL in the first trimester fetal placenta
J
ICaR-VU
180
Swagerman, S.
Nr. of Presenting Title of abstract poster author
159 Tol, J.P.
Toward optimal organ at risk sparing in complex
radiotherapy treatments: an exponential trade-off
with tumor volume dose homogeneity
K
VUmc CCA
160 Tra, J.
Exploring treatment delays in the care of patients
diagnosed with ST-segment elevation myocardial
infarction undergoing primary percutaneous
coronary intervention: a cross-sectional study
K
Emgo+
119 Trujillo, J.P.
Altered neural connectivity during an n-back task
in unmedicated Parkinson´s disease patients
H
NCA
22
Triaging borderline/mild dyskaryotic Pap cytology
with p16/Ki-67 dual-stained cytology testing:
cross-sectional and longitudinal outcome study
B
VUmc CCA
150 Valent, E.T.
Traction force microscopy: a study of the
endothelium during thrombin-mediated
contractility
J
ICaR-VU
127 Veerbeek, J.M.
What is the evidence for physical therapy
poststroke? A systematic review and meta-analysis
I
MOVE
120 Veldhuijzen van
Zanten, S.E.M.
Innovative Molecular Drug Imaging: Pioneering
Work in Children
H
VUmc CCA
23
Velzen, L.S. van
Brain-derived neurotrophic factor and regional
brain volume
B
NCA
38
Verbeek, J.
(Z)-2-(4-[18F]fluoro-2-oxoindolin-3-ylidene)-N-(4methoxyphenyl)hydrazine carbothioamide is an
aberrant P-gp tracer
C
NCA
53
Verdaasdonk, R.
Quantification of air flows produced by medical
equipment disturbing the clean air in the field of
surgery using large field background subtraction
imaging
D
NCA
121 Verduijn, J.
Clinical Staging of Major Depressive Disorder: an
empirical exploration
H
Emgo+
92
Verhagen, H.
The therapeutic potential of IGFBP7 in specific
eradication of leukemic stem cells in acute myeloid
leukemia
F
VUmc CCA
24
Verlaat, W.
Genome-wide DNA methylation profiling reveals
novel biomarkers for early detection of cervical
cancer
B
VUmc CCA
161 Vermeulen, E.
Policy for the return of clinically relevant individual
research results by Dutch biobanks
K
Emgo+
54
Parallel scanning laser ophthalmoscope (PSLO) for
retinal imaging
D
Laserlab
151 Vogel, D.Y.S.
GM-CSF stimulation of monocytes enhances
migration over endothelial cells
J
NCA
55
AFM nanoindentation reveals mechanical
properties of extracellular vesicles from Red Blood
Cells
D
laserlab
Functional deficits in response inhibition in de
novo Parkinson’s disease
H
NCA
Uijterwaal, M.H.
Vienola, K.
Vorselen, D.
122 Vriend, C.
Subject Research
group Institute
181
Nr. of Presenting Title of abstract poster author
Subject Research
group Institute
39
Vries, H.M. de
Large lactate clearance shifts in the first 8 hours
after traumatic brain injury are associated with
increased mortality
C
ICaR-VU
93
Waard, G. de
Hyperemic and Hyperemia Free Pressure Indices
have an Equivalent Diagnostic Accuracy when
Compared to Myocardial Blood Flow Quantified by
H215O PET Perfusion Imaging
F
ICaR-VU
94
Wee, M. ter
Intensive combination treatment regimens,
including prednisolone, are effective in treating
early rheumatoid arthritis patients regardless of
additional etanercept: 1 year results of the COBRAlight trial
F
VUmc CCA
86
Wegen, E.E.H. van
BEWARE: Body awareness training in the treatment
of wearing-off related anxiety in patients with
parkinson’s disease
F
NCA
95
Wierenga, D
The evaluation of a worksite intervention to
promote a healthy lifestyle among employees in
two different organizations
F
Emgo+
40
Wildt, B. van der
Synthesis of a 11C-labeled tissue transglutaminase
inhibitor using a [11C]CO carbonylation reaction
C
NCA
123 Winter, J.M. de
Force-sarcomere length relations in patients with
thin filament myopathy caused by mutations in
NEB, ACTA1 and TPM3
H
ICaR-VU
124 Winters, C.
Is capacity for upper extremity motor recovery
fixed after a first-ever ischemic stroke?
H
MOVE
41
Colorectal cancer candidate biomarkers identified
by tissue secretome proteome profiling
C
VUmc CCA
152 Witjas-Paalberends, Faster cross-bridge relaxation rates correlate with
E.R.
increased tension cost in HCM with the R403Q
MYH7 mutation
J
ICaR-VU
96
Zwan, J.E. van der
Stress reduction through mindfulness meditation,
heart rate variability biofeedback or physical
activity: a randomized trial
F
Emgo+
25
Zwan, M.D.
Diagnostic Value of Amyloid Imaging in Early
Onset Dementia
B
NCA
182
Wit, M. de
Vormgeving: Gerda Lieftink, DPC VUmc
184