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Biomedical subjects

Y van der Graaf

Publications and source records attributed to Y van der Graaf.

At least 19 recordsLinked to original sources
PubMed1992

A controlled trial of aerosolized pentamidine or trimethoprim-sulfamethoxazole as primary prophylaxis against Pneumocystis carinii pneumonia in patients with human immunodeficiency virus infection. The Dutch AIDS Treatment Group.

BACKGROUND: Primary prophylaxis against Pneumocystis carinii pneumonia (PCP) is recommended for patients with human immunodeficiency virus (HIV) infection if their CD4 cell counts are below 200 per cubic millimeter (0.2 x 10(9) per liter). Either aerosolized pentamidine or trimethoprim-sulfamethoxazole (co-trimoxazole) is commonly prescribed for prophylaxis, but the relative efficacy and toxicity of these agents are unknown. METHODS: We conducted a multicenter trial involving 215 HIV-infected patients with no history of PCP but with CD4 cell counts below 200 per cubic millimeter. The patients were randomly assigned to one of three regimens: aerosolized pentamidine once a month, 480 mg of trimethoprim-sulfamethoxazole once a day (80 mg of trimethoprim and 400 mg of sulfamethoxazole), or 960 mg of trimethoprim-sulfamethoxazole once a day (160 mg and 800 mg, respectively). The cumulative incidence of PCP was estimated by Kaplan-Meier survival analysis. RESULTS: After a mean follow-up of 264 days, 6 of the 71 patients in the pentamidine group had a confirmed first episode of PCP (11 percent), whereas none of the 142 patients in the two trimethoprim-sulfamethoxazole groups had PCP (P = 0.002). However, adverse events that required discontinuation of the medication were much more frequent in the trimethoprim-sulfamethoxazole groups (17 and 18 patients) than in the pentamidine group (2 patients). The adverse reactions occurred significantly sooner in the group given 960 mg of trimethoprim-sulfamethoxazole than in the group given 480 mg (mean time, 16 vs. 57 days; P = 0.02). CONCLUSIONS: For patients with HIV infection, trimethoprim-sulfamethoxazole taken once a day is more effective as primary prophylaxis against PCP than aerosolized pentamidine administered once a month, although adverse drug reactions are more frequent with trimethoprim-sulfamethoxazole.

AIDS-Related Opportunistic Infections↗
PubMed1992

Risk of strut fracture of Björk-Shiley valves.

The incidence of and factors that predispose to outlet strut fracture of Björk-Shiley heart valves are still not known. To obtain such information a retrospective cohort study was conducted on all 2303 patients in the Netherlands with a 60 degrees convexo-concave (60 degrees CC) or a 70 degrees convexo-concave (70 degrees CC) Björk-Shiley heart valve. Patients have been followed-up for a mean of 6.6 years (range 1-4271 days). 42 cases of mechanical failure due to outlet strut fracture have been recorded-6 of the 7 patients with fracture of the aortic valve died, as did 18 of the 35 patients with fracture of the mitral valve. Multivariate analysis identified wide opening angle (70 degrees), large valve size (greater than or equal to 29 mm diameter), and young age (less than 50 years) as risk factors for outlet strut fracture. For large 70 degrees CC mitral valves the cumulative risk of outlet strut fracture after 8 years was 17.4% (95% CI 9.1-31.6). Unlike previous findings, this excessive risk applied to late as well as to early batches of valves. In patients with a large 60 degrees CC mitral valve the cumulative risk after 8 years was 4.2% (95% CI 2.7-6.5). The incidence rate of outlet strut fracture in 60 degrees CC and 70 degrees CC valves (aortic and mitral) was constant over time. Overall survival since implantation was better for patients with 60 degrees CC prostheses than for those with 70 degrees CC prostheses; the adjusted hazard ratio for mortality for patients receiving a 70 degrees CC prosthesis was 1.5 (95% CI 1.1-2.0). Together with the low (24%) necropsy rate, this ratio suggests that the reported incidence of strut fracture for the 70 degrees CC valves is an underestimate. The data indicate that prophylactic replacement of 60 degrees CC and 70 degrees CC valves is advisable for selected groups of patients. Since the case-fatality rate is 50% for emergency replacement of faulty valves, patients suspected of Björk-Shiley heart-valve failure should be referred without delay to a cardiothoracic centre.

Adult↗
PubMed1992

Endarterectomy of the superficial femoral artery: a procedure worth reconsidering.

The preferred management of superficial femoral artery occlusive disease remains unresolved. The oldest technique for restoring vascular continuity, endarterectomy, has been largely replaced by bypass operations and percutaneous transluminal angioplasty. We have continued to perform semi-closed endarterectomy in selected cases and review here a series of 231 consecutive cases in 197 patients treated during the last 10 years. The indication for the endarterectomy was disabling claudication in 186 operations (80%), rest pain in 21 (9%) and gangrene in 24 (11%). The superficial femoral artery abnormality consisted of 1-10 cm occlusion in 52 cases (23%), > 10 cm occlusion in 96 (41%), single stenosis in 21 (9%), multiple stenoses in 28 (12%) and it was unknown in 34 cases (15%). Postoperative mortality was 0.8% with a complication rate of 10%. Five year cumulative primary patency was 71% overall, 75% in patients with disabling claudication, 61% in those with rest pain and 46% in those with gangrene. Eight year patency was 55% (S.E. 5.4%). No difference in 5-year cumulative patency was seen between treatment for stenosis or occlusion (74 and 70%, respectively). The results of earlier studies and the current study raise the question of whether endarterectomy should be the first treatment of choice in obstructive lesions of the superficial femoral artery. The results of endarterectomy are better than can be achieved with angioplasty and compare well with the results of femoropopliteal bypass. Endarterectomy has specific advantages above femoro-popliteal bypass: the autologous saphenous vein is spared for future use and in case of failure of the endarterectomy, femoro-popliteal bypass remains possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

The prevalence of cerebral visual disturbance in children with cerebral palsy.

Assessment of visual acuity using the visual acuity card procedure in 164 children with cerebral palsy revealed low visual acuity in 71 per cent. Results of ophthalmological examination were available for 74 of these patients, but could not explain adequately the low visual acuity of 36 of the 43 patients (84 per cent) assessed by both the acuity card procedure and other techniques. There is a high probability that cerebral visual disturbance is present in these patients. Awareness of visual disability when compiling a programme of visual and neurodevelopmental stimulation for children with cerebral palsy is essential.

Adolescent↗
PubMed1992

Grating-acuity in children. Normal values of visual acuity in children up to 13 years as assessed by the acuity card procedure.

The acuity card procedure proved to be a useful method for assessing visual acuity in children. Normal values of visual acuity measured by this method had already been assessed in children up to four years. To enable application of the test in older children this study obtained values in a group of 396 normal children, aged three months to 13 years. The mean curve as well as the 10th centile was calculated in different age groups. A considerable variation of acuity values causing a 'dip' in the 10th centile was found in the ages 18 to 24 months. A smaller 'dip' was found in the ages 48 to 52 months. This has to be attributed to behavioural properties connected with age. The results obtained in the group of children under four years of age corresponded fairly well with other studies. In schoolchildren a fair agreement could also be found between the data obtained using the acuity card procedure and the data obtained with the Landolt-C rings. Obtaining normal values for the acuity card procedure in children covering a wide age range facilitates recognition of visual handicap in children who are difficult to assess.

Adolescent↗
PubMed1990

Contribution of the cytobrush to determining cellular composition of cervical smears.

A study was made of the contribution of the cytobrush to determining the composition of the cervical smear. From a population of women screened in The Netherlands in 1987, 733 women were selected whose smears for the second time in a row lacked endocervical cells. Note was made of method of contraception, age of the woman, and day of the menstrual cycle. A control group was formed of women whose smears contained endocervical cells. Highly significant differences were found in the results between the two groups. Two new samples were collected, one made with the modified wooden Ayre spatula, the other with the cytobrush from the research group. The number of smears containing endocervical cells increased from 44% (by spatula alone) to 79% (spatula plus cytobrush). The cytobrush alone produced a high percentage of unsatisfactory smears (17.5%) due to a low content of squamous epithelial cells. No differences could be observed in the rate of cellular atypia because of the small number of cases.

Cell Count↗
PubMed1988

Cervical cancer survival in Nijmegen region, The Netherlands, 1970-1985.

Survival rates were computed for 359 women diagnosed with invasive cervical cancer between 1970 and 1985. The 5-year survival rate for the entire group was 67%. Survival was better in the period 1976-1980. Extension of the tumor and age at diagnosis were important prognostic factors. The effects of clinical stage, age at diagnosis, and year of diagnosis were studied simultaneously with the proportional hazards model. The hazard rate increased with increasing age and increasing clinical stage. Year of diagnosis had effect on survival only in case of IIB tumors. For the other clinical stages there was no significant effect on survival of year of diagnosis.

Adult↗
PubMed1988

Population screening for cervical cancer in the region of Nijmegen, The Netherlands 1976-1985.

In this study the results of a 9-year cervical screening program in the region of Nijmegen, The Netherlands are presented. All women aged 35 through 54 were invited every 3 years for a cervical smear. Overall attendance rates were 74%, 67%, and 63% at first, second, and third screening, respectively. The number of histologically confirmed severe epithelial abnormalities discovered in women who were screened for the first time was 3.8 per thousand smears, 1.0 per thousand in women who were screened twice and 0.7 per thousand in women who were screened three times in the program. Three years after the start of the screening program the incidence of invasive squamous cell cancer started to decline in the women aged 35 through 54 years. On the basis of the results of this study we may conclude a screening policy with an interval of 3 years to be a safe procedure. Whether this interval is the most efficient cannot be concluded. We have the impression that an interval of 4 to 6 years may lead to comparable results.

Adult↗
PubMed1988

The effectiveness of cervical screening: a population-based case-control study.

The cervical smear histories of 36 women with invasive cervical cancer were compared to those of 120 age-matched controls, drawn from local registrar's offices. Of the cases 47% were screened at least once, while for the controls this figure was 68%. The relative risk of getting invasive cervical cancer for women screened at least once compared to women who were never screened was 0.32. The most important confounding factor was age at first intercourse. Contrary to other studies however, it was found that women who were younger when having first intercourse were screened more often. After correcting the relative risk of screened vs unscreened for age at first intercourse, the relative risk became 0.22. When the length of the interval since the last smear was considered, the relative risk was 0.18 when the smear was made between 2 and 5 years earlier and 0.30 when this smear was made more than 5 years earlier. These results support the assumption that screening is effective in the prevention of invasive cancer of the uterine cervix. Even a screening interval of more than 5 years provides considerable protection.

Adult↗
PubMed1988

Cervical cancer mortality in the Netherlands.

In this study cervical cancer mortality figures for the period 1936-1985 were evaluated. Trends in age-specific rates were analysed by separating the variations attributable to age at death, period of birth and period of death. Cervical cancer mortality has been decreasing since 1960 and this decline has become more rapid since about 1975. Organized screening, which began in 1976 could be responsible for the acceleration in the decline, but since the decline was already evident before screening was started, other factors must play a role. It seemed likely that a fall in incidence or an improvement in early diagnosis were responsible for the decline. Cohort analysis showed an increased risk for younger age groups but since the observations were derived from few five-year age-specific mortality rates no firm conclusions about future trends can be made.

Adult↗
PubMed1987

False negative rate in cervical cytology.

All women in Nijmegen, The Netherlands, with a histological diagnosis of severe dysplasia, or carcinoma in situ, or invasive carcinoma were investigated to see whether they had participated in a population screening programme. Within two years of diagnosis of a negative cervical smear, 45 women were found to have histologically confirmed severe epithelial abnormality of the cervix. From the same population as these apparently false negative cases, the number of true positive cases was available, and hence the sensitivity of cervical screening for severe dysplasia, or carcinoma in situ, and invasive carcinoma could be assessed. This was found to be 83% after two years. The laboratory procedures which led to the high sensitivity for the cervical cytodiagnosis were analysed. Experienced sample takers and cytotechnologists are very important and can reduce sample and screening errors. A good administrative system is necessary to guarantee proper follow up for women with abnormal findings in their cervical smears.

Adult↗
PubMed1986

Effect of population screening for cancer of the uterine cervix in Nijmegen, The Netherlands.

Since the introduction of a population screening program for cervical cancer in 1976, more than 85% of the female population between the ages of 35 and 54 years in the region of the city of Nijmegen, The Netherlands, has been screened. At first screening, severe epithelial abnormalities were diagnosed in 4.4 per 1,000 women, at second screening, in 1.5 per 1,000; and at third screening, in 1.0 per 1,000. The population screening program led to a marked increase in the detected number of carcinomata in situ. The number of cases of squamous cell cancer diagnosed in the first screening period did not increase. Once the population was screened, the detection rate of invasive squamous cell cancer in the group of women ages 35 through 54 decreased from 18.6 per 10(5) during the period prior to the screening to 9.0 per 10(5) after the first screening and 3.3 per 10(5) after the second screening. For the women above age 54, the incidence of invasive cancer was reduced by 58% after the second screening. The number of invasive cancers diagnosed in women under age 35 remained relatively small in spite of the large number of cases of carcinoma in situ.

Adult↗
PubMedDate not supplied

Cervical screening revisited.

Some of the achievements of cervical screening in the reduction of morbidity and mortality in different countries are briefly reviewed, along with a consideration of some of the aspects of cervical cancer screening programs. The latter include the organization of the program (e.g., whether it is organized by the national health authorities), the protection afforded by routine screening, the assurance of quality in cervical sampling and in the screening program, the screening interval, the age groups to be screened, the compliance of women to present themselves for screening and of health care personnel to provide appropriate follow-up and/or treatment for the lesions diagnosed, the problem of false positives and its relation to overdiagnosis and overtreatment and, finally, the cost effectiveness. It is concluded that a centrally organized and well supervised cervical screening program, cautiously executed and with all involved parties closely cooperating, can be a cost-effective means of combatting cervical cancer.

Carcinoma in Situ↗
PubMedDate not supplied

The influence of sample takers on the cellular composition of cervical smears.

In a population-based cervical cancer screening program, the performances of five sample takers and their influence on the cellular composition of the smears and the numbers of epithelial abnormalities diagnosed were analyzed. As measured by the presence of endocervical columnar cells, there were remarkable variations in the quality of the smears between sample takers and between years of sampling. There was also a positive relationship between the presence of endocervical columnar cells in the smear and the number of epithelial abnormalities found. A lower quality of smear was reflected by a lower incidence of epithelial atypical changes found, both between sample takers and by a single sample taker over a period of time. These findings show that sample takers influence the cellular composition of smears and, therefore, the diagnostic outcome of smear screening. Their competence in executing their tasks must be frequently reviewed.

Adult↗