Search

Some authors attribute recurrences of giant cell tumours to biological factors which are only expressed in some tumours. Grover et al. (1998)suggested that the risk for recurrence is associated with the down-regulation of the nm23-H1 gene. We reviewed the charts of the 154 patients operated on for giant cell tumours of the tendon sheath and selected a group of patients with recurrence (ten cases) and a group of patients who did not have a recurrence after a minimum follow-up of 3 years (13 cases). Immunohistochemical detection of nm23-H1 was performed blindly of the clinical outcome on the paraffin-embedded specimens of these patients and no correlation was found between nm23-H1 expression and the risk for recurrence.

While monitoring birth defects in a registry, statistically significant increases in prevalence occasionally occur. In the European Registration Of Congenital Anomalies (EUROCAT) in the Northern Netherlands 20000 births are monitored every year. For omphaloceles, a steady increase in the prevalence from 0.86 per 10000 live- and stillbirths in 1981-1983 to 3.11 per 10000 live- and stillbirths in 1994 was seen in the three northern provinces of The Netherlands.

The aim of this article is to examine the performance of screening for fetal Down syndrome (DS) in the context of demographic variation in time and place, using population and fertility data for several European countries. Two screening approaches are distinguished: one on the basis of maternal serum screening with human chorionic gonadotropin (hCG) and alpha‐fetoprotein (AFP) in combination with maternal age, and one on the basis of maternal age only. Screening performance, as measured by detection and false‐positive ratios, is shown to be the result of the screening approach chosen and of the demographic characteristics of the population under consideration. A proper distinction between these two determinants of DS screening performance should be made, in order to distinguish between an improvement in screening performance that is brought about by a new screening approach and an improvement that is brought about by demographic change. We recommend that measures of DS screening performance be standardized for demographic variation. The methodology and demographic data presented in this article can be used for this purpose. © 1997 John Wiley & Sons, Ltd.

Abstract: An average cystic fibrosis (CF) carrier frequency of 1 in 25 in Europe is cited in numerous reports, although a great variability in estimated prevalences has been found in different European populations. The estimates of these frequencies were based on numbers of CF patients before identification of the gene in 1989. Here we report the results of a study to determine the carrier frequency of the ΔF508 mutation in The Netherlands by analyzing mouthwashes and matched blood samples from 11 654 blood donors all over the country. We analyzed possible relationships between a number of theoretically explanatory variables and the ΔF508 carrier frequency by means of univariate and multivariate logistic regression. These variables were: distance of the blood banks from the northeastern part of the country (distance); whether the blood donors knew that we were looking for a CF mutation; sex and age of the donor; and number of children of the donor (family size). We detected a ΔF508 carrier frequency of 1 in 42 (95% CI 1/37–1/47) in The Netherlands. If we assume that the relative frequency of the ΔF508 mutation among carriers and patients is comparable in The Netherlands, this gives an estimated overall CF carrier frequency of 1 in 32 (95% CI 1/28–1/36), significantly less than 1 in 25. The univariate logistic regression analysis of the effects of the explanatory variables on the carrier frequency revealed no significant relationships, except for an increase in carrier frequency with increasing distance from the northeastern region. In the multivariate analysis with all five independent variables, distance, age and family size were significantly related to the carrier frequency, but sex and CF information were not. There was a significant interaction between age and family size. In our final model, distance, age and family size were positively related to the carrier frequency, while the interaction of age with family size showed a negative relation. These results confirm that there is a gradient in gene frequency with low frequencies in the northeastern part of the country and high frequencies in the southern part. They also suggest a relation of age and family size with carrier frequency. This relation, however, is too complex to be explained by heterozygote advantage.

Abstract: Objective: In November 1993, Dutch health authorities advised that women planning a pregnancy should take folic acid in the periconceptional period to reduce the risk of fetal neural tube defects. In the autumn of 1995 a national campaign was organized to inform women and health care professionals in a systematic way. Methods: We assessed the awareness and behaviour of women at their first or second antenatal visit in two surveys in the spring of 1994 and the autumn of 1995, in order to evaluate the impact of non-systematic information during that period, and to collect baseline data to evaluate the effect of the national folic acid campaign. The two surveys were carried out in the north and the west of The Netherlands. Results: The proportion of women who had heard of folic acid increased from 28% to 78%. The proportion that used folic acid during any period in pregnancy increased from 7.8% to 26%. The proportion that took folic acid tablets during the whole of the recommended period increased from 0.8 to 4.4%. In the group of women who did not take folic acid, the proportion who did “not like to use anything during pregnancy” decreased, as did the proportion who did “not think it is useful”. Conclusion: In The Netherlands, non-systematic information about periconceptional folic acid use has already led to significant changes in awareness and behaviour before the start of the national folic acid campaign.