Biomedical subjects

Y van der Graaf

Publications and source records attributed to Y van der Graaf.

At least 19 recordsLinked to original sources

PubMed1995

Urinary excretions of high molecular weight beta-thromboglobulin and albumin are independently associated with coronary heart disease in women, a nested case-control study of middle-aged women in the Diagnostisch Onderzoek Mammacarcinoom (DOM) Cohort, Utrecht, Netherlands.

Increased plasma levels of beta-thromboglobulin, a platelet activation marker, are observed in coronary artery disease. Urinary albumin excretion, a marker of endothelial cell perturbation, is related to cardiovascular disease in diabetes. To test the value of these markers in predicting forthcoming coronary disease, the relations between urinary excretions of high molecular weight beta-thromboglobulin (HMW-beta TGf) and albumin and subsequent coronary disease in a cohort of 15,484 middle-aged women were investigated in a nested case-control study. Baseline questionnaire data and urine samples were available from a breast cancer screening program in Utrecht during 1982-1985. Cases were Utrecht hospital admissions for myocardial infarction (n = 50) or angiographically confirmed coronary disease (n = 28) from 1982-1985 to 1990-1991. Classifying events occurred a median of 5.1 years after baseline. Controls were a random sample from the cohort, individually case matched for baseline examination date and age, at a 1:2 ratio. HMW-beta TG/creatinine ratios (ng/mmol, mean +/- standard error) were 5.3 +/- 0.3 in cases and 4.7 +/- 0.3 in controls; albumin/creatinine ratios (mg/mmol, median) were, respectively, 0.37 and 0.22. Crude odds ratios for classification in the highest compared with the lowest tertiles of HMW-beta TG/creatinine and albumin/creatinine distributions were elevated for cases compared with controls: HMW-beta TG/creatinine odds ratio = 2.4, 95% confidence interval 1.1-5.0; albumin/creatinine odds ratio = 2.1, 95% confidence interval 1.0-4.1. These relations persisted after adjustment for smoking, hypertension, Quetelet index, and menopausal status. Both urinary HMW-beta TG and albumin excretion are markers of coronary disease risk in middle-aged women, indicating that increased platelet activation and endothelial cell perturbation precede coronary heart disease events in women.

Adult↗

PubMed1995

The results of denatured homologous vein grafts as conduits for secondary haemodialysis access surgery.

OBJECTIVES: To determine the value of denatured homologous vein grafts as a conduit for secondary haemodialysis access. DESIGN: Retrospective clinical study. SETTING: 2 University Hospitals. MATERIALS AND METHODS: One-hundred-and-twenty-five patients received 195 grafts over a period of five years. Fifty-six first grafts (45%) functioned without complications throughout the study period of 5.8 years. MAIN RESULTS: Primary patency was 57% after 1 year and 25% after 3 years of follow-up. Of the initial grafts, 69 (55%) needed 161 interventions, for thrombosis (n = 59), stenosis (n = 43), failure beyond repair (n = 40), aneurysm (n = 12), infection (n = 4), steal syndrome (n = 1), and other causes (n = 2). Secondary patency was 76% at 1 year and 52% at 3 years of follow-up. A major advantage of these grafts was the low rate (2.6%) of infection. Aneurysm formation occurred 17 times in 195 grafts (8.7%). CONCLUSIONS: Denatured homologous vein graft is a good alternative in secondary access surgery.

Arteriovenous Shunt, Surgical↗

PubMed1995

Efficacy and toxicity of two doses of trimethoprim-sulfamethoxazole as primary prophylaxis against Pneumocystis carinii pneumonia in patients with human immunodeficiency virus. Dutch AIDS Treatment Group.

The efficacy and toxicity of trimethoprim-sulfamethoxazole (TMP-SMZ) as primary prophylaxis against Pneumocystis carinii pneumonia (PCP) for patients with human immunodeficiency virus (HIV) infection was assessed by comparing the effects of two dosages (480 or 960 mg once a day) of the drug. The multicenter trial involved 260 HIV-infected patients with CD4 cell counts < 0.2 x 10(9)/L and no history of PCP. Patients were randomly assigned to the treatment groups. After a median follow-up of 376 days (range, 1-1219), none of the patients developed PCP. Most adverse reactions that required discontinuation were seen within the first month of TMP-SMZ use and were seen more frequently and earlier in the 960-mg group (hazard ratio, 1.4; 95% confidence interval, 0.95-2.02; P = .007). For patients with HIV infection, 480 mg of TMP-SMZ is as efficacious as but less toxic than 960 mg of the drug for primary prophylaxis against PCP.

Acquired Immunodeficiency Syndrome↗

PubMed1995

Digital chest imaging using a selenium detector. A simulated diffuse interstitial pulmonary disease detection study.

RATIONALE AND OBJECTIVES: To assess the diagnostic performance of a new digital chest imaging system based on a selenium detector in the detection of simulated diffuse interstitial pulmonary disease (DIPD). METHODS: Diffuse interstitial pulmonary disease was simulated by superimposing plastic sheets containing small radio-paque objects (birdseed) on an anthropomorphic chest phantom. the number of sheets was varied from 0 to 4 to simulate the degree of pathology. Eighty conventional radiographs and 80 images with the selenium detector were obtained under comparable conditions. Six observers were asked to indicate the presence of DIPD using a five-level scale of confidence. The total 160 chest images were analyzed using receiver operating characteristic curves. RESULTS: There was no significant difference in detection performance between the conventional and the digital images (95% confidence interval). CONCLUSIONS: None of the observers assessed the diagnostic performance of the digital chest images as significantly different from that of the conventional system. The interobserver differences were higher than the differences between digital and conventional chest images.

Humans↗

PubMed1995

Haemorrhagic-ischaemic lesions of the neonatal brain: correlation between cerebral visual impairment, neurodevelopmental outcome and MRI in infancy.

The relationship between the degree of cerebral visual impairment, established using the acuity card procedure, and the extent of neurological sequelae was assessed in 65 at-risk neonates in a prospective follow-up study. MRI and CT scans were performed in all infants with severe neurological sequelae. 11 of 12 children with an acuity at or below the 10th centile at 18 months developed cerebral palsy: the underlying condition was extensive cystic leukomalacia in all. An acuity above the 10th centile was no guarantee of normal development, as 10 out of 52 such infants developed cerebral palsy. MRI and CT scans showed that periventricular high signal intensity in the occipital area was a non-specific finding with regard to visual function. Extensive periventricular white matter loss and involvement of the striate/parastriate cortex was found in the most severely visually impaired infants.

Brain Ischemia↗

PubMed1995

Impact of urbanization on detection rates of eating disorders.

OBJECTIVE: The purpose of this study was to examine the incidence of anorexia nervosa and bulimia nervosa among patients in primary care and to evaluate the impact of urbanization, age and sex differences, and changes over time. METHOD: During 1985-1989, 58 general practitioners, trained in diagnosing eating disorders, registered all of their patients who had diagnoses of anorexia nervosa and/or bulimia nervosa according to strict criteria. The study population (N = 151,781) was 1% of the population of the Netherlands; the distribution of sexes, ages, geographical locations, and degrees of urbanization in the study group was representative of the Dutch population. Main outcome measures were rates of newly detected cases and age-adjusted rate ratios. RESULTS: The crude annual incidence rate of detected cases in primary care per 100,000 person-years was 8.1 for anorexia nervosa and 11.5 for bulimia nervosa. The incidence of bulimia nervosa was lowest in rural areas, intermediate in urbanized areas, and highest in large cities (6.6, 19.9, and 37.9, respectively, per 100,000 females per year); no rural-urban differences for anorexia nervosa were found. Pronounced sex and age differences in incidence rates were observed. Over the 5-year period, there was no time trend in the incidence of anorexia nervosa, but the incidence of bulimia nervosa tended to increase. CONCLUSIONS: The incidence rates of eating disorders--as defined by detection rates in primary care--are higher than previously reported. Urbanization seems to be a risk factor for bulimia nervosa but not for anorexia nervosa.

Adolescent↗

PubMed1995

Digital chest imaging with a selenium detector: comparison with conventional radiography for visualization of specific anatomic regions of the chest.

OBJECTIVE: The purpose of this study was to compare a new digital chest radiography system that uses amorphous selenium as the X-ray detector with conventional radiography for the visualization of various anatomic regions of the chest as a first phase of testing image quality. MATERIALS AND METHODS: Six observers analyzed pairs of posteroanterior chest radiographs of 40 patients. One radiograph in each pair was obtained with a conventional chest film changer, and the other was obtained with the digital selenium chest radiography system. Each observer rated the visibility and the radiographic quality of 12 different anatomic regions. RESULTS: The observers rated visualization obtained with the digital system as better than that obtained with the conventional system in four regions (right lower lobe, upper lobes, ribs, and soft tissue), as better than or equal to that obtained with the conventional system in four regions (retrocardiac, retrodiaphragmatic, hilum, and upper mediastinum), and as equal to that obtained with the conventional system in four regions (horizontal fissure, carina, azygoesophageal recess, and thoracic spine). Some observers had a strong preference for the digital images, whereas others showed no preference. The conventional system was not ranked high for any region (2880 observations, p < .01, sign test). CONCLUSION: The digital selenium chest radiography system performs well in a clinical setting, providing visualization of anatomic structures that is better than or at least equal to that provided by standard screen-film images.

Humans↗

PubMed1994

Prospective study of sentinel headache in aneurysmal subarachnoid haemorrhage.

Retrospective surveys of patients with subarachnoid haemorrhage suggest that minor episodes with sudden headache (warning leaks) may precede rupture of an aneurysm, and that early recognition and surgery might lead to improved outcome. We studied 148 patients with sudden and severe headache (possible sentinel headache) seen by 252 general practitioners in a 5-year period in the Netherlands. Subarachnoid haemorrhage was the cause in 37 patients (25%) (proven aneurysm in 21, negative angiogram in 6, no angiogram done in 6, sudden headache followed by death in 4). 103 patients had headache as the only symptom, 12 of whom proved to have subarachnoid haemorrhage (6 with a ruptured aneurysm). Previous bouts of sudden headache had occurred in only 2. Other serious neurological conditions were diagnosed in 18. In the remaining 93, no underlying cause of headache was found; follow-up over 1 year showed no subsequent subarachnoid haemorrhage or sudden death. In this cohort, acute, severe headache in general practice indicated a serious neurological disorder in 37% (95% CI 29-45%), and subarachnoid haemorrhage in 25% (18-32%). 12% (5-18%) of those with headache as the only symptom. The notion of warning leaks as a less serious variant of subarachnoid haemorrhage is not supported by this study. Early recognition of subarachnoid haemorrhage is important but will probably have only limited impact on the outcome in the general population.

Acute Disease↗

PubMed1994

Single-leg strut fractures in explanted Björk-Shiley valves.

A retrospective follow-up study in the Netherlands on the risk of fracture of Björk-Shiley convexo-concave valves concluded that prophylactic replacement is advisable for certain groups of patients. We have examined valves explanted from twenty-two patients because they met epidemiological criteria for reoperation, with or without the presence of moderate cardiac impairment, or because there were other cardiac complaints not related to the valve. No information was available before explanation to suggest a valve defect. All patients survived their operations. Of the twenty-four valves, seven (29% [95% CI 13-52]) had fracture of one of the legs of the outlet strut (single-leg strut fracture [SLF]). Two other valves had features that suggested fatigue defects. As in the previous study, 70 degrees valves had the highest risk of SLF (five of sixteen, two aortic and three mitral). However, two of eight 60 degrees valves (both aortic) also had SLF. Current hazard calculations and explanation recommendations may need to be revised. Since several of the defective valves were welded by the same person, knowledge of manufacturing details may help in estimation of fracture risk for an individual patient.

Adult↗

PubMed1994

Ruptured aortic aneurysm: early postoperative prediction of mortality using an organ system failure score.

Ruptured abdominal aortic aneurysm (AAA) is a personal and public health catastrophe because of the high and unimproving mortality rate, increasingly long intensive care unit (ICU) stay and rising hospital costs. Criteria are needed to identify patients with a poor prognosis so that treatment and resources may be directed to those with a better outlook. This retrospective study reviews perioperative variables, outcome and length of ICU stay for 99 consecutive patients with operated ruptured infrarenal AAA between 1985 and 1992 who reached the ICU alive. Early death (within 48 h) occurred in 20 per cent using 24 ICU days and late death (after 48 h) occurred in 29 per cent using 420 ICU days; neither type of death could be predicted before operation. Multiple organ failure, the cause of 93 per cent of late deaths, was assessed for each patient 48 h after operation using an organ system failure score. There was a strong positive correlation between organ system failure score and mortality rate (P < 0.00001); all 20 patients with more than two failing organ systems died. If used in decision making the score would have saved 43 per cent of the ICU days associated with late mortality. Withdrawing postoperative treatment at an early stage in accordance with an organ system failure score may be a defensible and cost-effective option.

Aged↗

PubMed1994

Mortality rates associated with operative treatment of infrarenal abdominal aortic aneurysm in The Netherlands.

Information on surgery for non-ruptured and ruptured infrarenal abdominal aortic aneurysm (AAA) in all hospitals in The Netherlands in 1990 was obtained from the Dutch National Medical Registration Foundation. The operation rate in the population over the age of 50 years was 30.3 per 100,000 for non-ruptured AAA and 16.8 per 100,000 for ruptured aneurysm. The hospital operative mortality rate for non-ruptured AAA surgery was 6.8 per cent in 1289 patients and for ruptured aneurysm 43.6 per cent in 709. For non-ruptured AAA the mortality rate almost doubled per age group of 10 years, whereas the influence of age was less significant for ruptured lesions. The operative mortality rate for non-ruptured aneurysm in university hospitals exceeded that in other hospitals, but no difference was found for emergency surgery on ruptured AAA. Nationwide results give a more representative picture of the true mortality rate associated with operation for aortic aneurysm. Such data are important for planning future treatment strategy and for evaluating the efficacy of screening.

Adolescent↗

PubMed1994

Cerebral visual impairment in cerebral palsy: relation to structural abnormalities of the cerebrum.

In patients with cerebral palsy (CP), cerebral visual impairment (CVI) is frequently found in addition to ophthalmological disorders. Lesions in the visual areas are found in CT scans of CP patients with CVI. The aim of the present study was to determine the prevalence of these specific findings in CP patients with CVI. CT scans of 49 cerebral palsy patients were studied; CVI was diagnosed in 36 patients; in 13 patients, visual acuity was normal. In 8 patients, comparison with an MRI scan was possible (6 with CVI, 2 with normal acuity). The CT scans were scored according to the criteria used by Van Nieuwenhuizen (1987): normal, abnormalities of the white matter adjacent to the posterior horns of the lateral ventricles, abnormalities of the white matter located under the visual cortex, abnormalities of the visual cortex and abnormalities elsewhere. Abnormalities in the visual areas were found in 15% of the normal acuity group and in 53% of the CVI group. In 17 of the 19 CVI patients with abnormalities in the visual areas, the lesions were located in the white matter surrounding the posterior horns (89%). MRI imaging revealed the same abnormalities as the CT scans in 6 patients, but in one patient the abnormality was seen in more detail and in one patient the lesion in the occipital area was seen only on MRI. MRI examination seems to detect at least as many, but in some cases even more specific lesions in CVI patients compared to CT scanning, but the numbers were too small to allow any definitive conclusions to be drawn.

Adolescent↗

PubMed1994

Polyneuropathy associated with monoclonal gammopathy of undetermined significance. A prospective study of the prognostic value of clinical and laboratory abnormalities.

The natural course of polyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS) is not well known. We therefore studied 32 untreated patients for a period of 5 years. Fifteen patients had an IgM M-protein, 15 an IgG and two an IgA. There was a male predominance, a mean age of onset at the end of the sixth decade and sensory signs were more pronounced than motor deficits. On entry into the study and during the 5 years of follow-up, we quantified the neuropathy in a standard way: totals of motor and sensory scores; vibration perception threshold; tapping tests; quantified Romberg test; electrophysiological parameters. A significant difference in the natural history between the polyneuropathy associated with IgM-MGUS and IgG/IgA-MGUS was found for the motor and sensory sum scores, the vibration perception threshold and the tapping tests. The polyneuropathy in IgM-MGUS is more progressive, with significantly more weakness and sensory signs, indicating that the neuropathies associated with IgM-MGUS and IgG/A-MGUS may be two different entities. A rapid progression of the neuropathy was found in five patients. We found no predictive factors for this severe progression of the neuropathy of these five patients. Of these five, three (two IgM, one IgG) developed a non-Hodgkin lymphoma.

Electrophysiology↗

PubMed1994

Relation between neonatal cranial ultrasound abnormalities and cerebral visual impairment in infancy.

A prospective follow-up study was conducted of a cohort of 65 at-risk neonates to assess the predictive value of neonatal cranial ultrasound abnormalities for cerebral visual impairment in infancy. Visual function was assessed using the acuity card procedure and behavioural visual responses were tested. Normal visual function was found in controls as well as in infants with small haemorrhages or mild leukomalacia. Infants with large haemorrhages performed poorly at 40 weeks postmenstrual age, but recovered to within the normal range in the first half year. In contrast, of the infants with extensive cystic leukomalacia, four of nine preterm infants and three of four term infants were severely visually impaired at 18 months. In the more mature infants, the cystic lesions extended deeper into the subcortical white matter, and this appeared to be associated with a worse visual outcome. Cystic leukomalacia proved to be highly predictive of cerebral visual impairment in infancy.

Cerebral Hemorrhage↗

PubMed1994

Measuring ataxia: quantification based on the standard neurological examination.

To quantify ataxia in a simple way four tests were developed and analysed, based on the neurological examination: a tapping test for the arms (test 1), another one for the legs (test 2), a quantified finger-to-nose test (test 3), and a modified Romberg test (test 4). All tests were performed by 115 volunteers, 13 patients with cerebellar ataxia and 25 patients with sensory ataxia due to neuropathy. The test-retest repeatability was excellent. Tests 1, 2 and 4 were age-dependent, with lower scores above age 65. On test 1, 2 and 4 both groups of patients performed worse than controls; the correlation with the ataxia scale of Nobile-Orazio and the modified disability Rankin scale was good (P < 0.05). Although test 3 could differentiate between sensory and cerebellar ataxia, it was not useful for quantifying the degree of ataxia. To determine the practical value of the four tests, 11 patients performed the tests for a second time after a follow up period of 16 months. The results indicate that tests 1, 2 and 4 are sensitive for the detection of ataxia and of changes in its severity.

Adult↗

PubMed1994

Chronic idiopathic axonal polyneuropathy: a five year follow up.

Seventy five patients with chronic idiopathic axonal polyneuropathy (CIAP) were studied for five years. The standardised and quantified neurological examination shows that progression of CIAP is slow, and handicap, if present, is not severe. During the follow up period a definite cause of the neuropathy was found in only four patients (two hereditary motor and sensory neuropathy type 2, one sensory chronic inflammatory demyelinating polyneuropathy, one alcoholic neuropathy). At the end of the follow up CIAP was not related to malignancy or gammopathy. Routine repetition of laboratory tests was not informative and these tests should be performed on clinical grounds only.

Aged↗

PubMed1993

Evaluation of electrophysiological and clinical tests in an exploratory trial of Org 2766 in motor neuron disease.

Twenty four patients with motor neuron disease (MND) participated in a double-blind, placebo-controlled trial with the ACTH 4-9 analog, Org 2766. Patients were examined three times during an 8 week treatment period, using a summated score for several manually and functionally tested muscles (sum score), myometry, jitter, fibre density (FD), macro motor unit potential (MUP), and supramaximal evoked muscle action potentials. No differences were found between Org 2766 and placebo treated patients. In an open 1 yr follow-up study, 5 out of 13 patients treated with Org 2766 died; the others showed continued progression of weakness. The methods used for assessment of muscle function were compared. The highest interest reliability was obtained in the sum score and myometry. Mean differences that might be detectable were relatively small for the sum score and myometry, and large for FD and MUP. We concluded that clinical function testing and myometry are superior to electromyographic measurements for assessment of changes in MND patients.

Action Potentials↗

PubMed1993

Chronic idiopathic polyneuropathy presenting in middle or old age: a clinical and electrophysiological study of 75 patients.

The clinical and electrophysiological features were prospectively studied of 75 patients (46 men and 29 women) with chronic polyneuropathy presenting in middle or old age in whom a diagnosis could not be made even after extensive evaluation and a follow up of six months. The mean age at the onset of symptoms was 56.5 years. The clinical features of chronic idiopathic polyneuropathy are heterogeneous. On clinical grounds 44 patients had a sensorimotor, 29 patients a sensory, and two patients a motor polyneuropathy. The overall clinical course in chronic idiopathic polyneuropathy was slowly progressive. None of the patients became severely disabled. Electrophysiological and nerve biopsy studies were compatible with an axonal polyneuropathy. Antibodies against myelin associated glycoprotein, gangliosides, and sulphatides were assessed in 70 patients and found to be negative.

Age of Onset↗