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Featured researches published by Pieter E. Zondervan.


The Lancet | 2005

Pegylated interferon alfa-2b alone or in combination with lamivudine for HBeAg-positive chronic hepatitis B: a randomised trial

Harry L.A. Janssen; Monika van Zonneveld; Hakan Senturk; Stefan Zeuzem; U.S. Akarca; Yilmaz Cakaloglu; Christopher Simon; Thomas Mk So; Guido Gerken; Robert A. de Man; Hubert G. M. Niesters; Pieter E. Zondervan; Bettina E. Hansen; Solko W. Schalm

BACKGROUND Treatment of HBeAg-positive patients with chronic hepatitis B is not effective in most. A combination of immunomodulatory pegylated interferon alfa-2b and antiviral lamivudine might improve the rate of sustained response. METHODS 307 HBeAg-positive patients with chronic hepatitis B were assigned combination therapy (100 microg/week pegylated interferon alfa-2b and 100 mg/day lamivudine) or monotherapy (100 microg/week pegylated interferon alfa-2b and placebo) for 52 weeks. During weeks 32-52 the pegylated interferon dose was 50 microg/week in both treatment groups. The analyses were based on the modified intention-to-treat population after exclusion of 24 patients from one centre withdrawn for misconduct, ten who lost HBeAg before the study start, and seven who received no study medication. All included patients were followed up for 26 weeks after treatment. FINDINGS 49 (36%) of 136 patients assigned monotherapy and 46 (35%) of 130 assigned combination therapy had lost HBeAg at the end of follow-up (p=0.91). More of the combination-therapy than of the monotherapy group had cleared HBeAg at the end of treatment (57 [44%] vs 40 [29%]; p=0.01) but relapsed during follow-up. Patterns were similar when response was assessed by suppression of serum hepatitis B virus (HBV) DNA or change in concentrations of alanine aminotransferase. Response rates (HBeAg loss) varied by HBV genotype (p=0.01): A, 42 (47%) patients; B, ten (44%); C, 11 (28%); and D, 26 (25%). INTERPRETATION Treatment with pegylated interferon alfa-2b is effective for HBeAg-positive chronic hepatitis B. Combination with lamivudine in the regimen used is not superior to monotherapy. HBV genotype is an important predictor of response to treatment.


Circulation | 2009

The Ross Procedure A Systematic Review and Meta-Analysis

Johanna J.M. Takkenberg; Loes M.A. Klieverik; Paul H. Schoof; Robert-Jan van Suylen; Lex A. van Herwerden; Pieter E. Zondervan; Jolien W. Roos-Hesselink; Marinus J.C. Eijkemans; Magdi H. Yacoub; Ad J.J.C. Bogers

Background— Reports on outcome after the Ross procedure are limited by small study size and show variable durability results. A systematic review of evidence on outcome after the Ross procedure may improve insight into outcome and potential determinants. Methods and Results— A systematic review of reports published from January 2000 to January 2008 on outcome after the Ross procedure was undertaken. Thirty-nine articles meeting the inclusion criteria were allocated to 3 categories: (1) consecutive series, (2) adult patient series, and (3) pediatric patient series. With the use of an inverse variance approach, pooled morbidity and mortality rates were obtained. Pooled early mortality for consecutive, adult, and pediatric patients series was 3.0% (95% confidence interval [CI], 1.8 to 4.9), 3.2% (95% CI, 1.5 to 6.6), and 4.2% (95% CI, 1.4 to 11.5). Autograft deterioration rates were 1.15% (95% CI, 1.06 to 2.06), 0.78% (95% CI, 0.43 to 1.40), and 1.38%/patient-year (95% CI, 0.68 to 2.80), respectively, and for right ventricular outflow tract conduit were 0.91% (95% CI, 0.56 to 1.47), 0.55% (95% CI, 0.26 to 1.17), and 1.60%/patient-year (95% CI, 0.84 to 3.05), respectively. For studies with mean patient age >18 years versus mean patient age ≤18 years, pooled autograft and right ventricular outflow tract deterioration rates were 1.14% (95% CI, 0.83 to 1.57) versus 1.69% (95% CI, 1.02 to 2.79) and 0.65% (95% CI, 0.41 to 1.02) versus 1.66%/patient-year (95% CI, 0.98 to 2.82), respectively. Conclusions— The Ross procedure provides satisfactory results for both children and young adults. Durability limitations become apparent by the end of the first postoperative decade, in particular in younger patients.


Arteriosclerosis, Thrombosis, and Vascular Biology | 2006

In Vivo Characterization and Quantification of Atherosclerotic Carotid Plaque Components With Multidetector Computed Tomography and Histopathological Correlation

Thomas T. de Weert; Mohamed Ouhlous; Erik Meijering; Pieter E. Zondervan; Johanna M. Hendriks; Marc R.H.M. van Sambeek; Diederik W.J. Dippel; Aad van der Lugt

Objective—In a previous in vitro study we have demonstrated that atherosclerotic plaque components can be characterized with multidetector computed tomography (MDCT) based on differences in Hounsfield values (HV). Now we evaluated the use of MDCT in vivo to characterize and quantify atherosclerotic carotid plaque components compared with histology as reference standard. Methods and Results—Fifteen symptomatic patients with carotid stenosis (>70%) underwent MDCT angiography before carotid endarterectomy (CEA). From each CEA specimen 3 histological sections and corresponding MDCT images were selected. The HV of the major plaque components were assessed. The measured HV were: 657±416HU, 88±18HU, and 25±19HU for calcifications, fibrous tissue, and lipid core, respectively. The cut-off value to differentiate lipid core from fibrous tissue and fibrous tissue from calcifications was based on these measurements and set at 60 HU and 130 HU, respectively. Regression plots showed good correlations (R2>0.73) between MDCT and histology except for lipid core areas, which had a good correlation (R2=0.77) only in mildly calcified (0% to 10%) plaques. Conclusions—MDCT is able to quantify total plaque area, calcifications, and fibrous tissue in atherosclerotic carotid plaques in good correlation with histology. Lipid core can only be adequately quantified in mildly calcified plaques.


Journal of Hepatology | 1998

The sequential occurrence of viral mutations in a liver transplant recipient re-infected with hepatitis B: hepatitis B immune globulin escape, famciclovir non-response, followed by lamivudine resistance resulting in graft loss

Robert A. de Man; Angeline Bartholomeusz; Hubert G. M. Niesters; Pieter E. Zondervan; Stephen Locarnini

BACKGROUND/AIMS The purpose of this study was to characterize the clinical, histological and virological events in an orthotopic liver transplant (OLT) recipient with recurrent hepatitis B infection who was initially managed with hepatitis B immune globulin (HBIg) and when viral recurrence occurred, with nucleoside analogue salvage therapy. The aims were to document the mutations occurring in the hepatitis B virus (HBV) polymerase gene as a consequence of HBIg escape, famciclovir non-response and subsequent lamivudine resistance. METHODS Throughout the follow-up of 796 days, the patient was seen at least at 4-week intervals. Clinical, biochemical and virological data were registered according to protocol. HBV DNA was quantified throughout the treatment period. The viral polymerase gene was sequenced from serum samples collected at representative time intervals. Consecutive liver biopsies were scored according to the modified Knodell classification. RESULTS Clinically, the patient was in excellent condition until the development of acute hepatitis during the lamivudine therapy period, 765 days post-OLT. Until this terminal event, serum transaminase activity was only 1-2 times the upper limit of normal with serum bilirubin and prothrombin time within the normal range. Subsequent liver biopsies showed chronic active hepatitis with no signs of fibrosis. The post-mortem biopsy showed severe acute hepatitis B with massive necrosis. The HBV polymerase gene was sequenced during HBIg, famciclovir and lamivudine treatment. One mutation I533L was detected during HBIg treatment. No amino acid changes were selected during famciclovir treatment. Three amino acid changes were selected while the patient was on lamivudine treatment, which include L533I, S559T and M550I. CONCLUSIONS We have documented HBV recurrence in a liver transplant recipient with the emergence of a multidrug resistant HBV which caused graft loss. The primary resistance to famciclovir in spite of therapeutic penciclovir levels may be as a result of a combination of the mutations found in the polymerase region. After 300 days of lamivudine treatment, a drug-resistant population emerged which was associated with a greater than three log increase in HBV DNA and contributed to loss of graft function. This is the first report of such an adverse clinical outcome due to the emergence of a mutant virus as a consequence of immunoprophylactic and antiviral therapy in a liver transplant recipient.


Hepatology | 2007

Peginterferon alpha-2b is safe and effective in HBeAg-positive chronic hepatitis B patients with advanced fibrosis†‡§

Erik H.C.J. Buster; Bettina E. Hansen; Maria Buti; Jean Delwaide; Claus Niederau; P. Michielsen; Robert Flisiak; Pieter E. Zondervan; Solko W. Schalm; Harry L.A. Janssen

Chronic hepatitis B (CHB) patients with advanced fibrosis are often not considered for treatment with peginterferon (PEG‐IFN) because IFN therapy may precipitate immunological flares, potentially inducing hepatic decompensation. We investigated the efficacy and safety of treating hepatitis B e antigen (HBeAg)–positive CHB patients with 52 weeks of PEG‐IFN‐α‐2b (100μg weekly) alone or in combination with lamivudine (100 mg daily). Seventy patients with advanced fibrosis (Ishak fibrosis score 4–6) and 169 patients without advanced fibrosis, all with compensated liver disease, participated in the study. Virologic response, defined as HBeAg seroconversion and hepatitis B virus (HBV) DNA < 10,000 copies/ml at week 78, occurred significantly more often in patients with advanced fibrosis than in those without (25% versus 12%, respectively; P = 0.02). Also patients with cirrhosis (n = 24) exhibited a virologic response more frequently than did patients without cirrhosis (30% versus 14%, respectively; P = 0.02). Improvement in liver fibrosis occurred more frequently in patients with advanced fibrosis (66% versus 26%, P < 0.001). HBV genotype A was more prevalent among patients with advanced fibrosis than among those without (57% versus 24%, P < 0.001). Most adverse events, including serious adverse events, were observed equally as frequently in patients with advanced fibrosis and those without. Fatigue, anorexia, and thrombocytopenia occurred more often in patients with advanced fibrosis than in those without (P < 0.01). Necessary dose reduction or discontinuation of therapy was comparable for both patient groups (P = 0.92 and P = 0.47, respectively). Conclusion: PEG‐IFN is effective and safe for HBeAg‐positive patients with advanced fibrosis. Because PEG‐IFN therapy results in a high rate of sustained off‐therapy response, patients with advanced fibrosis or cirrhosis but compensated liver disease should not be excluded from PEG‐IFN treatment. (HEPATOLOGY 2007.)


Journal of Biomedical Optics | 2004

Raman microspectroscopic mapping studies of human bronchial tissue

Senada Koljenović; Tom C. Bakker Schut; Jan P. van Meerbeeck; Alexander P.W.M. Maat; Sjaak Burgers; Pieter E. Zondervan; Johan M. Kros; Gerwin J. Puppels

Characterization of the biochemical composition of normal bronchial tissue is a prerequisite for understanding the biochemical changes that accompany histological changes during lung cancer development. In this study, 12 Raman microspectroscopic mapping experiments are performed on frozen sections of normal bronchial tissue. Pseudocolor Raman images are constructed using principal component analysis and K-means cluster analysis. Subsequent comparison of Raman images with histologic evaluation of stained sections enables the identification of the morphologic origin (e.g., bronchial mucus, epithelium, fibrocollagenous stroma, smooth muscle, glandular tissue, and cartilage) of the spectral features. Raman spectra collected from the basal side of epithelium consistently show higher DNA contributions and lower lipid contributions when compared with superficial epithelium spectra. Spectra of bronchial mucus reveal a strong signal contribution of lipids, predominantly triolein. These spectra are almost identical to the spectra obtained from submucosal glands, which suggests that the bronchial mucus is mainly composed of gland secretions. Different parts of fibrocollagenous tissue are distinguished by differences in spectral contributions from collagen and actin/myosin. Cartilage is identified by spectral contributions of glycosaminoglycans and collagen. As demonstrated here, in situ analysis of the molecular composition of histologic structures by Raman microspectroscopic mapping creates powerful opportunities for increasing our fundamental understanding of tissue organization and function. Moreover, it provides a firm basis for further in vitro and in vivo investigations of the biochemical changes that accompany pathologic transformation of tissue.


Journal of Viral Hepatitis | 2000

Lamivudine-high dose interferon combination therapy for chronic hepatitis B patients co-infected with the hepatitis D virus.

L. M. M. Wolters; A.B. van Nunen; P. Honkoop; A. C. T. M. Vossen; Hubert G. M. Niesters; Pieter E. Zondervan; R. A. de Man

Currently, the best option for patients with hepatitis delta is interferon alpha therapy for at least one year. To evaluate the effect of the combination lamivudine–high‐dose interferon alpha therapy, we first treated eight patients with chronic hepatitis delta infection with lamivudine for at least 24 weeks; then lamivudine was combined with a high dose of interferon alpha followed by a regular dose (9 MU tiw). Follow‐up was 12 weeks. Virological, biochemical and histological features were evaluated for response to therapy. At baseline, all patients were HBsAg positive in serum and HDV RNA‐(PCR)positive in plasma; HBV DNA was undetectable with the Digene Hybrid Capture assay (limit of detection 1.5 × 106 geq ml–1) in all cases. Transaminases were elevated in all patients; median ALT 68 (range 48–143) IU l–1. Seven of eight patients completed the course; one patient with a pre‐existing sickle cell trait was withdrawn from the trial due to the development of a nephrotic syndrome. The HBsAg‐concentration in serum decreased in two out of seven patients (29%). However, there was no significant decrease in the HBsAg‐concentration in serum during treatment (median 3654 PEU l–1 (range 548–7684) to 5300 PEU l–1 (range 168–19639)). The drop of HDV RNA in plasma from baseline during treatment was not significant. Decrease of HDV RNA was observed in three out of seven patients (43%) (median 105 geq ml–1; range 103–106 to median 103 geq ml–1; range 102–107). Serum ALT did not change as reflected by a median of 68 IU l–1 (range 48–143) at start of therapy to 63 IU l–1 (range 20–171) at the end of therapy. At the end of treatment transaminases had normalised in one patient and decreased in three other patients (improvement in 57%). However, three of these four patients showed a rebound after withdrawal of therapy. The Histology Activity Index (HAI) indicated a drop from a median score of 7 (range 5–9) at baseline to 5 (range 3–8) at the end of treatment, but an increase in fibrosis from a median grade of 2 (range 1–3) at baseline to 3 (range 1–4) at the end of treatment was observed. In conclusion, this study does not yield support for the combination of an HBVsuppressor and 16 weeks of high‐dose interferon for therapy aimed at eradicating the hepatitis delta virus.


Journal of The American Society of Nephrology | 2003

Differential Expression of Heme Oxygenase-1 and Vascular Endothelial Growth Factor in Cadaveric and Living Donor Kidneys after Ischemia-Reperfusion

Francine Brambate Carvalhinho Lemos; Jan N. M. IJzermans; Pieter E. Zondervan; A.M.A. Peeters; Sandra van den Engel; Wendy M. Mol; Willem Weimar; Carla C. Baan

The extent of graft damage after ischemia-reperfusion reflects the balance between deleterious events and protective factors. Heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF) may contribute to cytoprotection by their anti-inflammatory and antiapoptotic properties. For investigating whether HO-1 and VEGF play a role in the adaptive response to ischemia-reperfusion injury after renal transplantation, kidney biopsies were analyzed from living (n = 45) and cadaveric (n = 16) donors, obtained at three time points: at the end of cold storage T(-1), after warm ischemia T(0), and after reperfusion T(+1). The mRNA expression levels of HO-1, VEGF(165), Bcl-2, Bax, and hypoxia inducible factor-1alpha were quantified by real-time reverse transcriptase-PCR, and the HO-1 and VEGF proteins were analyzed by immunohistochemistry. Cadaveric donor kidneys presented higher mRNA expression levels of hypoxia inducible factor-1alpha. In contrast, mRNA expression levels of HO-1, VEGF(165), and Bcl-2 were significantly lower in kidneys from cadaveric donors. Overall, a significant correlation was observed between mRNA expression of Bcl-2 and VEGF(165), between Bcl-2 and HO-1, and between HO-1 and VEGF(165). Moreover, protein expression of HO-1 and VEGF was detected in the same anatomical kidney compartments (glomerulus, arteries, and distal tubules). Renal function at the first week posttransplantation (analyzed by serum creatinine levels) showed a significant correlation with both HO-1 and VEGF mRNA expression, reinforcing the protective role of both genes in the early events of transplantation. It is concluded that the lower expression of HO-1, VEGF(165), and Bcl-2 in cadaveric donor kidneys can reflect a defective adaptation against ischemia-reperfusion injury that may affect their function in the short term.


British Journal of Surgery | 2006

Case-orientated approach to the management of hepatocellular adenoma

D. J. van der Windt; Niels F.M. Kok; S. M. Hussain; Pieter E. Zondervan; I. P. J. Alwayn; R. A. de Man; J. IJzermans

Treatment of suspected hepatocellular adenoma (HA) remains controversial. The aim of this study was to evaluate the management of HA at a time when magnetic resonance imaging (MRI) and computed tomography (CT) are highly sensitive methods for diagnosing HA.


The American Journal of Gastroenterology | 2010

A Randomized Trial of Peginterferon α-2a With or Without Ribavirin for HBeAg-Negative Chronic Hepatitis B

Vincent Rijckborst; Martijn J. ter Borg; Yilmaz Cakaloglu; Peter Ferenci; Fehmi Tabak; Meral Akdogan; Krzysztof Simon; Maria Raptopoulou-Gigi; Necati Örmeci; Pieter E. Zondervan; Elke Verhey; Anneke van Vuuren; Bettina E. Hansen; Harry L.A. Janssen

OBJECTIVES:Hepatitis B e antigen (HBeAg)-negative chronic hepatitis B patients are at high risk of treatment relapse after any antiviral therapy. Combining peginterferon α-2a with ribavirin might improve sustained response rates.METHODS:Overall, 138 HBeAg-negative chronic hepatitis B patients were randomized to receive monotherapy (peginterferon α-2a 180 μg weekly plus placebo) or combination therapy (peginterferon α-2a weekly plus ribavirin 1,000 or 1,200 mg daily, depending on body weight) for 48 weeks. Post-treatment follow-up lasted 24 weeks. Analyses were based on the modified intention-to-treat population after exclusion of five patients.RESULTS:At the end of follow-up, 14 (20%) of 69 patients assigned to monotherapy and 10 (16%) of 64 assigned to combination therapy had a combined response (hepatitis B virus (HBV) DNA <10,000 copies/ml (<1,714 IU/ml) and a normal alanine aminotransferase level, P=0.49). At the end of treatment, more patients had a combined response (25 (36%) vs. 26 (41%) in the monotherapy and combination therapy group, respectively, P=0.60), but subsequently relapsed during follow-up. Serum HBV DNA and hepatitis B surface antigen (HBsAg) levels decreased during treatment (mean change at week 48 compared with baseline −3.9 vs. −2.6 log copies/ml, P<0.001 and −0.56 vs. −0.34 log IU/ml, P=0.23, respectively). HBV DNA levels relapsed after treatment discontinuation; HBsAg remained at end-of-treatment levels. In general, combination therapy was well tolerated, although it was associated with a higher risk of anemia and neutropenia.CONCLUSIONS:Treatment with peginterferon α-2a resulted in a limited sustained response rate in HBeAg-negative chronic hepatitis B patients. Addition of ribavirin did not improve response to therapy.

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Carla C. Baan

Erasmus University Rotterdam

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A. H. M. M. Balk

Erasmus University Rotterdam

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Herold J. Metselaar

Erasmus University Rotterdam

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Jan N. M. IJzermans

Erasmus University Rotterdam

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Robert A. de Man

Erasmus University Rotterdam

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Hugo W. Tilanus

Erasmus University Rotterdam

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Solko W. Schalm

Erasmus University Rotterdam

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Willem Weimar

Erasmus University Rotterdam

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