Publications by authors named "Graaf Y"

Sero-epidemiological case control studies have observed positive relations between infections with Chlamydia pneumoniae, Helicobacter pylori or cytomegalovirus (CMV) and the occurrence of coronary artery disease (CAD) and stroke. Moreover, positive relations between 'infection burden' and CAD and the role of inflammation have recently been described. However, the relations between infection, inflammation and the occurrence of peripheral arterial disease (PAD) have not been reported so far.

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Background: Elevated serum levels of homocysteine are considered a risk factor for cardiovascular disease. It has been suggested that homocysteine is a late stage predictor of adverse cardiovascular events, which might explain reported controversies in literature. The objective of the present study was to study the relationship between homocysteine levels and the stage of atherosclerotic disease.

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Background And Purpose: Epidemiological studies have shown an increased risk of venous thrombosis in women taking third-generation oral contraceptives, ie, those containing the progestogens desogestrel or gestodene. This study assesses the risk of ischemic stroke with several types of oral contraceptives.

Methods: A multicenter, population-based, case-control study was performed in 9 Dutch centers in women aged 18 to 49 years.

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Objectives: To determine if cardiovascular disease may be a risk factor in the development of chronic idiopathic axonal polyneuropathy (CIAP).

Methods: In this incidence case-control study, the prevalence of cardiovascular disease and risk factors in 97 patients with CIAP (mean age 67.5 (SD 7.

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Background: Prediction of complications is an essential part of risk management in surgery. Knowing which patients are at high risk of developing complications will contribute to the quality and cost reduction of surgery.

Methods: All patients admitted to a general surgical ward during a 1-year interval were followed until 30 days after discharge.

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In this study, the authors investigated whether combined information on reproductive factors has additive value to the single reproductive factor age at menopause for assessing endogenous estrogen exposure and cardiovascular mortality risk in postmenopausal women. They conducted a population-based cohort study that included 9,450 postmenopausal women from Nijmegen, the Netherlands, who were aged 35--65 years at enrollment in 1975, with a median follow-up of 20.5 years.

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It remains often uncertain whether the use of illicit substances has contributed to the aetiology of psychosis. Gas chromatography-mass spectrometry can be used to detect them in hair of the head. Given a monthly growth rate between 1.

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Rationale And Objectives: To compare selenium- versus phosphor-based digital chest imaging for visualization of various anatomic regions of the chest.

Methods: Thirteen observers analyzed pairs of posteroanterior (PA) and lateral chest radiographs of 63 patients. One radiograph in each pair was obtained with a digital selenium chest radiography system, and the other with a storage phosphor-based technique.

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Background: An association between the use of oral contraceptives and the risk of myocardial infarction has been found in some, but not all, studies. We investigated this association, according to the type of progestagen included in third-generation (i.e.

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Objective: Several studies have reported an association between abdominal aortic dilatation and peripheral arterial occlusive disease. Narrowing of aortic diameter, also called abdominal aortic hypoplasia, and peripheral arterial occlusive disease have received insufficient attention. Precise estimates of the relationship between aortic hypoplasia and peripheral arterial occlusive disease are lacking.

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Background: Although the prognosis of acute sinusitis is important, little is known about it and the factors predicting its course in a general practice population.

Objective: To determine the course of acute sinusitis and factors predicting it in adults in general practice.

Methods: The prognostic value of demographic and clinical factors and the patient's emotional state, for example anxious or depressed, were determined prospectively by means of multivariate analysis.

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Rationale And Objectives: To evaluate the effect of dose reduction on diagnostic performance by using a digital chest imaging system in which amorphous selenium serves as the x-ray detector.

Methods: Two hundred forty-seven patients were examined with the selenium system. Three sets of images were made in each patient: one set with a standard x-ray dose, one set with 55% of the standard dose, and one set with 35% of the standard dose.

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Neural network-based screening (NNS) of cervical smears can be performed as a so-called "hybrid screening method," in which parts of the cases are additionally studied by light microscope, and it can also be used as "pure" NNS, in which the cytological diagnosis is based only on the digital images, generated by the NNS system. A random enriched sample of 985 cases, in a previous study diagnosed by hybrid NNS, was drawn to be screened by pure NNS. This study population comprised 192 women with (pre)neoplasia of the cervix, and 793 negative cases.

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Objective: To derive and evaluate diagnostic determinants of gastro-oesophageal malignancy as a means of helping family physicians select patients for 'open-access' gastroscopy. In this multicenter study, 861 consecutive patients were investigated with first-time gastroscopy (study population). Another 1153 patients were studied during the next 6 years (validation population).

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Background And Aim Of The Study: Approximately 82,000 Björk-Shiley convexo-concave (BSCC) 60 degree prosthetic heart valves were implanted in patients worldwide between 1979 and 1986. Outlet strut fractures (OSF) of some of the valves were first reported shortly after their introduction. Here, the determinants of OSF are examined, and the between-country variation and long-term risk are assessed.

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Background: Previous reports on the incidence of schizophrenia in immigrant groups to The Netherlands were based on hospital data.

Aims: To compare the incidence of psychotic disorders in the immigrant groups to that in natives.

Method: Two-year first-contact incidence study in The Hague.

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Objective: To assess the difference in costs between PAPNET-assisted and conventional microscopy of cervical smears when used as a primary screening tool.

Study Design: We performed time measurements of the initial screening of smears by four cytotechnologists in one laboratory. Time was measured in 816 conventionally screened smears and in 614 smears with PAPNET-assisted screening.

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Information on the life expectancy of Bjork-Shiley convexo-concave (BScc) valve recipients is necessary when considering prophylactic replacement. However, little is known about the late results after valve replacement with BScc valves. We describe long-term survival and its determinants of the Dutch BScc cohort and compare mortality figures with those of the general population and those used in guidelines for prophylactic replacement.

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Objective: To determine the reproducibility of the PAPNET scanning station (Neuromedical Systems, Inc., Suffern, New York, U.S.

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Purpose: To evaluate whether and to what extent greater number of projection images obtained at three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography versus conventional digital subtraction angiography (DSA) causes overestimation of internal carotid arterial (ICA) stenosis.

Materials And Methods: DSA (two or three projections), rotational angiography (16 or 32 projections), and 3D TOF MR angiography (12 projections) were performed in 47 stenotic ICAs of 38 symptomatic patients. Two observers independently measured maximum stenosis, and the mean differences among MR angiography, DSA, and rotational angiography were compared.

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Studies from Denmark and the USA have reported a strong correlation between the seasonal pattern for stillbirths and the seasonal birth pattern for people who develop schizophrenia. It has been suggested that the correlation could be caused by a common seasonal factor (e. g.

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In the evaluation of diagnostic tests emphasis is placed on the evaluation of a particular diagnostic test in order to estimate it's sensitivity, specificity, or area under the 'receiver operating characteristic' curve (so called test research). This kind of test research is only useful in situations in which a diagnosis is set by one test (i.e.

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Objective: To determine the prevalence of hypercholesterolaemia and the use of lipid-lowering medication in patients with a manifest vascular disease.

Design: Prospective, cross-sectional.

Methods: In patients who visited the University Medical Centre Utrecht, the Netherlands, for the first time with a manifestation of atherosclerosis in the period 1 September 1996-15 November 1998, we determined by a single measurement of the cholesterol if they were eligible for lipid-lowering medication according to the cholesterol cut-off value mentioned in the new Dutch cholesterol guidelines (1998) of the Dutch Institute for Health Care Improvement.

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Background: For the surgical treatment of gastrooesophageal reflux disease (GORD), laparoscopic Nissen fundoplication has largely replaced the open procedure. Retrospective and prospective non-randomised studies have shown similar results after laparoscopic Nissen fundoplication compared with the open procedure.

Methods: In a multicentre randomised trial candidates for surgical treatment of GORD were randomly assigned to either laparoscopic or open 360 degrees Nissen fundoplication.

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