P. A. de Graeff
University of Groningen
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Featured researches published by P. A. de Graeff.
British Journal of Cancer | 2009
P. A. de Graeff; Anne Crijns; S de Jong; Marike Boezen; Wendy Post; E.G.E. de Vries; A.G.J. van der Zee; G. H. de Bock
Background:P53, EGFR and HER-2/neu are the most frequently studied molecular biological parameters in epithelial ovarian cancer, but their prognostic impact is still unequivocal. We performed a meta-analysis to more precisely estimate their prognostic significance.Methods:Published studies that investigated the association between p53, EGFR and HER-2/neu status and survival were identified. Meta-analysis was performed using a DerSimonian–Laird model. Publication bias was investigated using funnel plots and sources of heterogeneity were identified using meta-regression analysis.Results:A total of 62 studies were included for p53, 15 for EGFR and 20 for HER-2/neu. P53, EGFR and HER-2/neu status had a modest effect on overall survival (pooled HR 1.47, 95% CI 1.33–1.61 for p53; HR 1.65, 95% CI 1.25–2.19 for EGFR and HR 1.67, 95% CI 1.34–2.08 for HER-2/neu). Meta-regression analysis for p53 showed that FIGO stage distribution influenced study outcome. For EGFR and HER-2/neu, considerable publication bias was present.Conclusions:Although p53, EGFR and HER-2/neu status modestly influences survival, these markers are, by themselves, unlikely to be useful as prognostic markers in clinical practice. Our study highlights the need for well-defined, prospective clinical trials and more complete reporting of results of prognostic factor studies.
British Journal of Cancer | 2008
P. A. de Graeff; Anne Crijns; K. A. ten Hoor; Harry Klip; H. Hollema; Karin A. Oien; John M.S. Bartlett; G.B.A. Wisman; G. H. de Bock; E.G.E. de Vries; S de Jong; A.G.J. van der Zee
Ovarian cancer is the most frequent cause of death from gynaecological cancer in the Western world. Current prognostic factors do not allow reliable prediction of response to chemotherapy and survival for individual ovarian cancer patients. Epidermal growth factor receptor (EGFR) and HER-2/neu are frequently expressed in ovarian cancer but their prognostic value remains unclear. In this study, we investigated the expression and prognostic value of EGFR, EGFR variant III (EGFRvIII), HER-2/neu and important downstream signalling components in a large series of epithelial ovarian cancer patients. Immunohistochemical staining of EGFR, pEGFR, EGFRvIII, Her-2/neu, PTEN (phosphatase and tensin homologue deleted on chromosome 10), total and phosphorylated AKT (pAKT) and phosphorylated ERK (pERK) was performed in 232 primary tumours using the tissue microarray platform and related to clinicopathological characteristics and survival. In addition, EGFRvIII expression was determined in 45 tumours by RT–PCR. Our results show that negative PTEN immunostaining was associated with stage I/II disease (P=0.006), non-serous tumour type (P=0.042) and in multivariate analysis with a longer progression-free survival (P=0.015). Negative PTEN staining also predicted improved progression-free survival in patients with grade III or undifferentiated serous carcinomas (P=0.011). Positive pAKT staining was associated with advanced-stage disease (P=0.006). Other proteins were expressed only at low levels, and were not associated with any clinicopathological parameter or survival. None of the tumours were positive for EGFRvIII. In conclusion, our results indicate that tumours showing negative PTEN staining could represent a subgroup of ovarian carcinomas with a relatively favourable prognosis.
Diabetologia | 2011
Eberhard Blind; Kristina Dunder; P. A. de Graeff; E. Abadie
Abbreviations CHF Congestive heart failure CHMP Committee for Medicinal Products for Human Use EMA European Medicines Agency FDA Food and Drug Administration MAH Marketing authorisation holder PROactive Prospective Pioglitazone Clinical Trial in Macrovascular Events RECORD Rosiglitazone Evaluated for Cardiovascular Outcomes in Oral Agent Combination Therapy for Type 2 Diabetes SAG Scientific Advisory Group of the EMA SPC Summary of Product Characteristics TZD Thiazolidinedione
Journal of Cardiovascular Pharmacology | 1994
J. Van Wijngaarden; Andries J. Smit; P. A. de Graeff; W. H. Van Gilst; S. A. J. Van Der Broek; D. J. Van Veldhuisen; K. I. Lie; H Wesseling
Cyclooxygenase inhibitors may affect the hemodynamic status of patients with heart failure adversely and may also block the vasodilatory effects of angioten-sin-converting enzyme (ACE) inhibitors in such patients. Relatively low doses of the cyclooxygenase inhibitor acetylsalicylic acid (ASA) are now used routinely in ischemic heart disease, the most important cause of heart failure. Therefore, we investigated the hemodynamic interaction between ASA and captopril in heart failure. In a randomized, cross-over study, 13 patients with congestive heart failure (CHF) who were already receiving maintenance treatment with an ACE inhibitor received a single dose of 25 mg captopril combined with 236 mg ASA or placebo. Peripheral blood flow was studied noninvasively by venous occlusion plethysmography of the calves. Liver blood flow was estimated from indocyanine green (ICG) clearance. Administration of captopril alone significantly decreased blood pressure (BP), and ICG clearance. Calf blood flow remained unchanged. However, after arterial occlusion, hyperemic calf blood flow persisted for longer. Captopril alone did not significantly change the plasma levels of the vasodilating prostaglandins PGI2 and PGE2 or the vasoconstricting thromboxane A2 (TXA2). In contrast, captopril combined with ASA reduced the plasma levels of these vasoactive substances, with significant decreases in PGE2 and TXA2 as compared with captopril alone, yet the hemodynamic alterations after captopril plus ASA were similar to those observed after captopril alone. A single antithrombotic dose of ASA (236 mg) in 13 patients with CHF [New York Heart Association (NYHA) class II-IV] undergoing chronic treatment with ACE inhibitors had no discernible effect on hemodynamic status. These results cannot be extrapolated to chronic ASA administration and must be interpreted with caution with regard to patients in NYHA stage IV of the disease.
British Journal of Cancer | 2006
P. A. de Graeff; Jacqueline A. Hall; Anne Crijns; G. H. de Bock; James Paul; Karin A. Oien; K. A. ten Hoor; S de Jong; H. Hollema; John M.S. Bartlett; Robert Brown; A.G.J. van der Zee
The prognostic impact of p53 immunostaining in a large series of tumours from epithelial ovarian cancer patients in a two-centre study was analysed. The study population (n=476) comprised of a retrospective series of 188 patients (Dutch cohort) and a prospective series of 288 patients (Scottish cohort) enrolled in clinical trials. P53 expression was determined by immunohistochemistry on tissue microarrays. Association with progression-free survival (PFS) and overall survival (OS) was analysed by univariate and multivariate Cox regression analysis. Aberrant p53 overexpression was significantly associated with PFS in the Dutch and Scottish cohorts (P=0.001 and 0.038, respectively), but not with OS in univariate analysis. In multivariate analysis, when the two groups were combined and account taken of clinical factors and country of origin of the cohort, p53 expression was not an independent prognostic predictor of PFS or OS. In this well-powered study with minimal methodological variability, p53 immunostaining is not an independent prognostic marker of clinical outcome in epithelial ovarian cancer. The data demonstrate the importance of methodological standardisation, particularly defining patient characteristics and survival end-point data, if biomarker data from multicentre studies are to be combined.
European Journal of Clinical Pharmacology | 1999
Nicoline Wieringa; P. A. de Graeff; Gt van der Werf; R Vos
AbstractObjectives: To study discrepancies in demographic characteristics between patients participating in pre-registration phase III trials of cardiovascular drugs, registered in the Netherlands, and patient populations in daily practice representing the actual users of the drugs after registration. Methods: Comparison of age and sex distribution in registration files of 15 cardiovascular drugs [angiotensin-converting enzyme (ACE)inhibitors/angiotensin II receptor antagonists, calcium channel blockers, beta-adrenergic blocking agents, vasodilators, HMG-CoA reductase inhibitors and thrombolytics] with patients selected from a general practitioner (GP) registration database, who had received prescriptions for drugs from the therapeutic classes for the registered indications (hypertension, hypercholesterolaemia or angina pectoris) or were diagnosed with myocardial infarction. Moderate discrepancy was defined as more than 10% difference between the populations, large discrepancy by more than 20% difference. Clinical trials were also analysed by region of trial performance with respect to patient selection criteria, differences in male/female ratios and ethnic origin of patients. Results: Phase III clinical trials in registration files of drugs registered for hypertension, angina pectoris and myocardial infarction had a moderate to large under-representation of female patients. Patients aged more than 65 years, who accounted for more than 50% of drug use indicated for hypertension, angina pectoris and myocardial infarction, were under-represented in the clinical trials of drugs registered for all indications. Trials performed in North America included relatively fewer female patients compared with European trials, and showed different patterns in the ethnic origin between indications. Conclusions: Clinically relevant subgroups of cardiovascular patients are under-represented in pre-registration phase III trials. These findings concern major areas of cardiovascular diseases, i.e. hypertension, hypercholesterolaemia, angina pectoris and myocardial infarction. Widely used therapeutic classes of drugs are affected and regional differences in trial performance are present.
Blood Pressure | 1998
F.W. Beltman; Wilfred F. Heesen; Andries J. Smit; Jf May; P. A. de Graeff; T.K. Havinga; F. H. Schuurman; E. van der Veur; K. I. Lie; B. Meyboom-de Jong
The aim of the study was to compare the effects of two long-acting antihypertensive agents, the calcium-antagonist amlodipine and the ACE inhibitor lisinopril, on left ventricular mass and diastolic filling in patients with mild to moderate diastolic hypertension from primary care centres. It is a 1-year prospective, double-blind, randomized, parallel group, comparative study. Patients between 25 and 75 years of age with untreated hypertension with elevated diastolic blood pressure (> or = 95 mmHg) on three occasions (twice on the first visit and once only on the second and third visits) were recruited from a population survey. After 4 weeks placebo run-in 71 patients were randomized to dosages of amlodipine 5-10 mg or lisinopril 10-20 mg, which were titrated on the basis of the effects on blood pressure. Fifty-nine patients completed the study period. Primary endpoints were left ventricular mass index and early to atrial peak filling velocity. Office and ambulatory blood pressure and other echocardiographic measurements were considered secondary. Decrease in blood pressure was equal for both treatment regimens. A statistically significant decrease in left ventricular mass index in both treatment groups was observed: -11.0 g/m2 (95% CI: -6.0, -16.1) in the amlodipine group and -12.6 g/m2 (95% CI: -8.2, -17.0) in the lisinopril group. The higher the baseline value of left ventricular mass before treatment, the more the decrease after treatment. Early to atrial peak filling velocity did not change significantly within the treatment groups: +0.07 (95% CI: -0.01, +0.15) in the amlodipine group and +0.01 (95% CI: -0.06, +0.08) in the lisinopril group. However, analysis of time measurements of the early peak showed significant changes for both treatment groups. No significant differences in primary and secondary endpoints between treatment groups were found. Twelve patients did not complete the study, seven in amlodipine and five in lisinopril, basically due to adverse events. The effects of amlodipine and lisinopril on left ventricular mass and early to atrial filling peak velocity after 1 year of treatment in patients with previously untreated mild to moderate hypertension are similar. Further studies are recommended, particularly with a larger sample size and a follow-up of longer duration.
Journal of Cardiovascular Pharmacology | 1998
Wilfred F. Heesen; F.W. Beltman; Andries J. Smit; Jf May; P. A. de Graeff; T.K. Havinga; F. H. Schuurman; E. van der Veur; B. Meyboom-de Jong; K. I. Lie
We compared, in a prospective double-blind randomized study, the effect of the angiotensin-converting enzyme inhibitor quinapril (QUI) with that of triamterene/hydrochlorothiazide (THCT) treatment on cardiovascular end-organ damage in subjects with untreated isolated systolic hypertension (ISH). End-organ damage measurements, performed initially and after 6 and 26 weeks of treatment, included echocardiographic determination of left ventricular mass index (LVMI) and of diastolic function and measurement of aortic distensibility and peripheral vascular resistance. Blood pressure was significantly reduced in the 44 subjects (21 QUI, 23 THCT) completing the study. Both LVMI and aortic distensibility had changed at 6 weeks, with comparable improvements in both groups. LV diastolic function showed overall no significant changes, although patterns of early filling did differ between the two drug groups. Peripheral vascular resistance appeared to increase between 6 and 26 weeks in THCT subjects only, along with a decreased aortic distensibility. Blood pressure and LV mass were rapidly and markedly reduced in both treatment groups of ISH subjects, paralleled by an improvement of aortic distensibility. In interpreting these results, the pathophysiologic alterations in ISH need to be taken into account, because these differ strongly from those in diastolic hypertension. Results of LV diastolic function and peripheral vascular resistance were less clear but appear to show less favorable changes in the THCT subjects treatment group.
International Journal of Cardiology | 1989
P. A. de Graeff; J.H. Kingma; J.W. Viersma; H Wesseling; Kong I. Lie
We studied the acute and long-term effects of ramipril and captopril in 12 patients with moderate to severe congestive heart failure using an open, parallel design. Drug doses were titrated. Compared with baseline values, maximal haemodynamic and humoral effects after the first dose of both angiotensin converting enzyme inhibitors were similar, but the effects of ramipril (5 mg) demonstrated a slower onset of action and a significantly longer duration than captopril (12.5 mg). After 3 months of treatment a single dose of 5 mg ramipril showed the same 24-hour haemodynamic profile as after the first dose, but the hypotensive effect was less marked. There was no plasma accumulation of ramiprilat. Serum creatinine and potassium remained stable, except for one patient whose renal function deteriorated on captopril treatment. Complex ventricular arrhythmias occurred in 11 patients and were unaffected after treatment with ramipril or captopril. Two patients died suddenly during ramipril therapy and one patient during captopril therapy. In summary, ramipril is an effective, long-acting angiotensin converting enzyme inhibitor, producing long-term haemodynamic effects in patients with congestive heart failure. Using an individualised dosage scheme, neither long-lasting hypotension nor deterioration of renal function occurred. No effect on ventricular arrhythmias was seen.
Naunyn-schmiedebergs Archives of Pharmacology | 1991
J. Van Wijngaarden; René A. Tio; W. H. Van Gilst; P. A. de Graeff; C. D. J. de Langen; H Wesseling
SummaryIn this study, the vasodilating properties of captopril and zofenoprilat, two angiotensin-converting enzyme (ACE) inhibitors containing the sulfhydryl group, are investigated in the isolated rat heart. It is demonstrated that both compounds increase coronary flow in a dose-dependent manner. However, the mean pD2 of zofenoprilat appears to be significantly higher than the mean pD2 of captopril (4.55 ± 0.06 and 3.35 ± 0.02 respectively), indicating that zofenoprilat is about ten times more potent in increasing coronary flow than captopril. Possibly this difference in potency between captopril and zofenoprilat can be explained by their physicochemical properties. Since zofenoprilat is more lipophilic than captopril, its concentration in cardiac and vascular tissues at distribution equilibrium is thought to be higher than the tissue concentration of captopril, which may result in a more pronounced vasodilatory action.The precise mechanism of coronary vasodilation induced by ACE inhibitors containing the sulfhydryl group is not yet understood. Several factors have been proposed, such as stimulation of prostacyclin production. However, in this study, concomitant administration of 10−6 mol/l acetylsalicylic acid shows no antagonism, indicating that under normoxic conditions the vasodilatory effects of captopril and zofenoprilat are independent of the production of vasodilating prostaglandins. Therefore, other factors than stimulation of prostacyclin synthesis seem to be involved, such as prevention of bradykinin breakdown and/or potentiation of endothelium derived relaxing factor (EDRF). Furthermore, despite a marked inhibition of prostacyclin production, 10−6 mol/l acetylsalicylic acid itself has no effect on coronary flow. These results suggest that prostacyclin does not play an important role in the regulation of coronary flow, at least in the normoxic isolated rat heart.