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Dive into the research topics where A. M. Van der Laan is active.

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Featured researches published by A. M. Van der Laan.


Netherlands Heart Journal | 2008

Bone marrow cell therapy after acute myocardial infarction: the HEBE trial in perspective, first results.

A. M. Van der Laan; Alexander Hirsch; Robin Nijveldt; P. A. van der Vleuten; W.J. van der Giessen; P. A. Doevendans; Johannes Waltenberger; J. M. ten Berg; W.R.M. Aengevaeren; Jaap Jan Zwaginga; Bart J. Biemond; A. C. Van Rossum; J. G. P. Tijssen; F. Zijlstra; Jan J. Piek

AbstractDuring the last decennium, the role of bone marrow mononuclear cells (BMMC) has been underscored in the healing process after acute myocardial infarction (AMI). Although these cells improve left ventricular recovery after AMI in experimental studies, results from large-scale randomised trials investigating BMMC therapy in patients with AMI have shown contradictory results. To address this issue the HEBE study was designed, a multicentre, randomised trial, evaluating the effects of intracoronary infusion of BMMCs and the effects of intracoronary infusion of peripheral blood mononuclear cells after primary percutaneous coronary intervention. The primary endpoint of the HEBE trial is the change in regional myocardial function in dysfunctional segments at four months relative to baseline, based on segmental analysis as measured by magnetic resonance imaging. The results from the HEBE trial will provide detailed information about the effects of intracoronary BMMC therapy on post-infarct left ventricular recovery. In addition, further analysis of the data and material obtained may provide important mechanistic insights into the contribution of BMMCs to natural recovery from AMI as well as the response to cell therapy. This may significantly contribute to the development of improved cell-based therapies, aiming at optimising post-infarct recovery and preventing heart failure. (Neth Heart J 2008;16:436-9.)


Heart | 2013

Clinical parameters associated with collateral development in patients with chronic total coronary occlusion

N.W. Van Der Hoeven; P.F.A. Teunissen; Gerald S. Werner; Ronak Delewi; Stephan H. Schirmer; Tobias Traupe; A. M. Van der Laan; J. G. P. Tijssen; Jan J. Piek; Christian Seiler; N. van Royen

Objective Well-developed collaterals provide survival benefit in patients with obstructive coronary artery disease (CAD). Therefore, in this study we sought to determine which clinical variables are associated with arteriogenesis. Design Clinical and laboratory variables were collected before percutaneous coronary intervention. Multivariate analysis was performed to determine which variables are associated with the collateral flow index (CFI). Patients Data from 295 chronic total occlusion (CTO) patients (Bern, Switzerland, Amsterdam, the Netherlands and Jena, Germany) were pooled. In earlier studies, patients had varying degrees of stenosis. Therefore, different stages of development of the collaterals were used. In our study, a unique group of patients with CTO was analysed. Interventions Instead of angiography used earlier, we used a more accurate method to determine CFI using intracoronary pressure measurements. CFI was calculated from the occlusive pressure distal of the coronary lesion, the aortic pressure and central venous pressure. Results The mean CFI was 0.39±0.14. After multivariate analysis, β blockers, hypertension and angina pectoris duration were positively associated with CFI (B: correlation coefficient β=0.07, SE=0.03, p=0.02, B=0.040, SE=0.02, p=0.042 and B=0.001, SE=0.000, p=0.02). Furthermore also after multivariate analysis, high serum leucocytes, prior myocardial infarction and high diastolic blood pressure were negatively associated with CFI (B=−0.01, SE=0.005, p=0.03, B=−0.04, SE=0.02, p=0.03 and B=−0.002, SE=0.001, p=0.011). Conclusions In this unique cohort, high serum leucocytes and high diastolic blood pressure are associated with poorly developed collaterals. Interestingly, the use of β blockers is associated with well-developed collaterals, shedding new light on the potential action mode of this drug in patients with CAD.


Journal of Biological Chemistry | 2010

Blocking interferon-beta stimulates vascular smooth muscle cell proliferation and arteriogenesis

Stephan H. Schirmer; Pieter T. Bot; Joost O. Fledderus; A. M. Van der Laan; Oscar L. Volger; Ulrich Laufs; Michael Böhm; Carlie J.M. de Vries; Anton J.G. Horrevoets; Jan J. Piek; Imo E. Hoefer; Niels van Royen

Increased interferon (IFN)-β signaling in patients with insufficient coronary collateralization and an inhibitory effect of IFNβ on collateral artery growth in mice have been reported. The mechanisms of IFNβ-induced inhibition of arteriogenesis are unknown. In stimulated monocytes from patients with chronic total coronary artery occlusion and decreased arteriogenic response, whole genome expression analysis showed increased expression of IFNβ-regulated genes. Immunohistochemically, the IFNβ receptor was localized in the vascular media of murine collateral arteries. Treatment of vascular smooth muscle cells (VSMC) with IFNβ resulted in an attenuated proliferation, cell-cycle arrest, and increased expression of cyclin-dependent kinase inhibitor-1A (p21). The growth inhibitory effect of IFNβ was attenuated by inhibition of p21 by RNA interference. IFNβ-treated THP1 monocytes showed enhanced apoptosis. Subsequently, we tested if collateral artery growth can be stimulated by inhibition of IFNβ-signaling. RNA interference of the IFNβ receptor-1 (IFNAR1) increased VSMC proliferation, cell cycle progression, and reduced p21 gene expression. IFNβ signaling and FAS and TRAIL expression were attenuated in monocytes from IFNAR1−/− mice, indicating reduced monocyte apoptosis. Hindlimb perfusion restoration 1 week after femoral artery ligation was improved in IFNAR1−/− mice compared with wild-type mice as assessed by infusion of fluorescent microspheres. These results demonstrate that IFNβ inhibits collateral artery growth and VSMC proliferation through p21-dependent cell cycle arrest and induction of monocyte apoptosis. Inhibition of IFNβ stimulates VSMC proliferation and collateral artery growth.


Vascular Pharmacology | 2012

Surfing the data tsunami, a bioinformatic dissection of the proangiogenic monocyte

T C T M van der Pouw Kraan; A. M. Van der Laan; Jan J. Piek; Anton J.G. Horrevoets

In this review we compare expression studies on monocyte subsets as an example to show the integrated possibilities of molecular databases and bioinformatic analysis tools. Monocytes have been recognized as cells with great plasticity and differentiation potential that play a pivotal role in revascularization processes, i.e. angiogenesis and arteriogenesis. To gain more insight in the relevant developmental programs, we compared the full-genome mRNA expression profiles of several distinct human monocyte subpopulations previously identified based on surface marker expression. These included classical and non-classical, M1 and M2 macrophages, circulating angiogenic cells (CAC), and non-monocyte-derived endothelial colony-forming cells (ECFC). Their transcriptional profiles revealed distinct and overlapping gene expression signatures and pathways reminiscent of utilization of transcription factors driving polarization into the different monocytic phenotypes. Hierarchical cluster analysis revealed that CAC are most related to M2 macrophages and unstimulated macrophages, and to a lesser extent to classical monocytes, and are quite distinct from M1 macrophages and ECFC. Analysis of the promoter region of CAC-expressed genes suggests that in particular the ETS family of transcription factors is important in CAC development. These analyses show the power of combining multiple datasets with existing databases on biological knowledge, to interpret full genome expression data.


European Heart Journal | 2011

Intracoronary infusion of bone marrow cells and peripheral mononuclear blood cells has no influence on the recovery of myocardial perfusion after acute revascularized myocardial infarction

Lourens Robbers; Robin Nijveldt; A. M. Van der Laan; R. Delewi; Alexander Hirsch; P. A. van der Vleuten; Aernout M. Beek; Jan J. Piek; F. Zijlstra; A. C. Van Rossum


European Heart Journal Supplements | 2010

Left ventricular thrombus following primary percutaneous coronary intervention as assessed by cardiac magnetic resonance imaging in acute myocardial infarction

Ronak Delewi; Robin Nijveldt; A. M. Van der Laan; Alexander Hirsch; P. A. van der Vleuten; Margriet I. Klees; J. G. P. Tijssen; F. Zijlstra; A. C. Van Rossum; Jan J. Piek


European Heart Journal | 2009

Intracoronary infusion of mononuclear cells potentially prevents post-infarct ventricular remodeling in patients with an initial dilated left ventricle : a HEBE substudy

A. M. Van der Laan; P. A. van der Vleuten; Alexander Hirsch; Robin Nijveldt; W.J. van der Giessen; Bart J. Biemond; J. G. P. Tijssen; A. C. Van Rossum; F. Zijlstra; Jan J. Piek; Hebe Investigators


European Heart Journal Supplements | 2010

Limitations of 2-D echocardiography to detect mural thrombus after ST-elevation acute myocardial infarction

Ronak Delewi; Robin Nijveldt; H. de Bruin; Alexander Hirsch; A. M. Van der Laan; J. P. G. Tijssen; A. C. Van Rossum; F. Zijlstra; Jan J. Piek; Bonno N. Bouma


European Heart Journal | 2010

Pericardial effusion following primary percutaneous coronary intervention is associated with the presence of microvascular obstruction

Ronak Delewi; A. M. Van der Laan; Robin Nijveldt; Alexander Hirsch; P. A. van der Vleuten; Margriet I. Klees; J. G. P. Tijssen; F. Zijlstra; A. C. Van Rossum; Jan J. Piek


Atherosclerosis Supplements | 2010

W39 EXPRESSION OF A RETINOIC ACID SIGNATURE IN CIRCULATING CD34 CELLS FROM CORONARY ARTERY DISEASE PATIENTS

T C T M van der Pouw Kraan; Stephan H. Schirmer; Joost O. Fledderus; Perry D. Moerland; Thomas A. Leyen; A. M. Van der Laan; Jan J. Piek; N. van Royen; Anton J Horrevoets

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Jan J. Piek

University of Amsterdam

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F. Zijlstra

Erasmus University Rotterdam

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P. A. van der Vleuten

University Medical Center Groningen

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Ronak Delewi

University of Amsterdam

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