Biomedical subjects
Publications and source records attributed to A De Graaf.
"The 1993 Netherlands Fertility and Family Survey shows that parental divorce has an impact on (the attitudes towards) relationships of young adults. Children of divorced parents leave home at an earlier age and have a stronger preference for cohabitation. Once a relationship (cohabitation or marriage) has started, it is more likely to end in separation or divorce." (SUMMARY IN ENG)
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A high-resolution in situ hybridization method is described for localizing epidermal growth factor (EGF)-receptor transcripts in nuclei of A431 epidermoid carcinoma cells. The method is based upon the use of ultra-small gold particles in combination with silver enhancement. The RNA of the EGF-receptor was detected mainly around the nucleoli. After removal of the DNA using nucleases and high salt extraction, the RNA of the EGF-receptor appears to be associated with the nuclear matrix. The RNA of the EGF-receptor was observed in close contact with the SC-35 splicing protein, but no exact colocalization was observed. These results demonstrate that high resolution pre-embedding in situ hybridization in combination with immunocytochemistry, both using ultra-small gold as a detection method, provides a powerful tool to unravel the organization of nuclear processes.
Data from the 1993 Netherlands Fertility and Family Survey are analyzed. Results show that "three out of every four women aged 18-42 years use some method of birth control. Some 10% is pregnant or wants to become pregnant, 5% is infecund and 10% does not use a method for other reasons. Compared with the previous surveys, held in 1982 and 1988, more women use the pill, whereas the popularity of the IUD has decreased.... Among women in their thirties sterilization has decreased, but that is related to the fact that women nowadays have their children at a later age....Furthermore it can be concluded that of the women who have no male partner, 50% used some reliable method of birth control (pill, IUD or condom)." (SUMMARY IN ENG)
We investigated the cellular composition and the major histocompatibility complex (MHC) class II antigen expression in the draining lymph node and the tumour during potentiation of the immune response by intralesional bacillus Calmette-Guérin (BCG) administration in the line 10 hepatocellular carcinoma in the strain 2 guinea-pig. Five days after its injection BCG induced a ninefold increase in the number of draining lymph node cells and an increased MHC class II expression. This increased MHC class II expression was mostly due to the selective increase of B cells in the lymph nodes, and to a lesser extent to the increase of T cells expressing MHC class II antigens. Taking into account this nine-fold increase, intralesional treatment of BCG increased considerably the number of T helper/inducer (anti-CT7) and T suppressor/cytotoxic (anti-CT6) lymph node cells expressing MHC class II antigen. The percentage of tumour-infiltrating T cells expressing MHC class II antigen in the tumour was higher than the percentage of T cells in the regional draining lymph node of non-treated guinea-pigs, indicating the presence of activated T cells in the tumour. After treatment with BCG no further increase in MHC class II expression was measured in the tumour, nor was any phenotypical change of the tumour-infiltrating T cells found. In conclusion, with the use of two-colour flow cytofluorometry we have shown that the potentiation of the already existing immune response to line 10 is accompanied by a considerable increase in T helper/inducer, T suppressor/cytotoxic cells and MHC class II antigen in the regional lymph node. Whether this is essential for the potentiation of the immune response causing tumour regression and long-lasting immunity is a subject for further study.
"This article examines whether women who experienced parental divorce behave differently with respect to leaving the parental home, cohabitation, marriage and birth than women who grew up in families with both natural parents.... Data are used from the Netherlands Fertility Survey conducted in February 1988....[Results show that] women who [lived] with one of the natural parents were more likely to have left home than women who [lived] with both natural parents. Women from one-parent families also cohabited more than women from two-parent families....For the divorce-rates no significant difference between the two categories of women was found.... Married women aged 18-37 who grew up in one-parent families have fewer children than other women." An English-language version of this article is available from the publisher. (SUMMARY IN ENG)
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The effect of experimentally induced cholestasis on the amount of phosphoenolpyruvate carboxykinase (PEPCK) was studied immunohistochemically in rat liver parenchyma. In control liver, the enzyme was mainly localized periportally and, although the enzyme content was much reduced, this distribution pattern was maintained up to 2 weeks after ligation of the common bile duct. At 4 and 8 weeks after ligation the enzyme content in parenchymal cells remained low, but became distributed homogeneously throughout the liver parenchyma. This suggests that after bile duct ligation, gluconeogenesis from lactate is impaired. This may well be the cause of the adaptive changes to enhance the glycogenolytic capacity of parenchymal cells to maintain as far as possible a constant blood glucose level.
Male Wistar rats received a single i.p. injection of [3H]ethylnitrosourea (140 mg/kg) and were killed after 2 h, 1, 3, 6, 28 or 56 days. DNA of the following organs was isolated and analysed for the presence of 12 different ethylated bases and ethylphosphotriesters: brain, lung, liver, spleen, kidney, intestine, testis and bone marrow. At 2 h after injection the extent of DNA ethylation was found to be heterogeneous: highest in liver and lowest (3-4 times lower) in testis and brain. The rates at which O2- and O4-ethylthymine and the ethylphosphotriester dTp(Et)dT were lost, were very low in all organs except intestine and spleen. Most likely, loss in the latter organs is exclusively due to cell turnover. The rate of O6-ethylguanine repair strongly varied from organ to organ: high in liver, very low in testis and brain and intermediate in the other organs. In none of the DNAs were significant amounts of imidazole ring-opened 7-ethylguanine found. Our results strengthen the notion that a substantial part of carcinogen-induced DNA damage is of a highly persistent nature and might contribute to the carcinogenic process long after the original exposure has occurred.
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Rat (Rattus norvegicus) and spiny mouse (Acomys cahirinus) are closely related murinoid species that mainly differ in the developmental timing of birth. A comparison between the developmental profiles of some characteristic enzymes of the liver of both species was carried out to elucidate the question to what extent are these enzymic profiles and hence the maturation of the liver related to the timing of birth? It was found that these organotypic enzymes first become detectable at the same developmental stage in both species. Likewise, the weaning phase of the enzymic profiles occurs at the same developmental time point in both species. It is argued that both the first appearance and the weaning increase in enzyme activity levels occur at endogenously programmed timepoints with only superimposed effects of hormones. In contrast, the perinatal phase of the enzymic profile is completely dependent on the developmental timing of birth and therefore appears not to be anchored to a particular developmental timepoint, but rather to be dependent on birth-associated (hormonal) adaptation. In accordance with this hypothesis it was found that the morphological development of the liver proceeded independent of the timing of birth. Furthermore, the hormonal regulation of the investigated enzymes was found to be the same in both species. Despite the more advanced state of morphological development of the liver in the spiny mouse at birth, it was found that the inducibility of organotypic gene expression by hormones in spiny mouse fetuses was as limited as in rat fetuses. This observation therefore suggests that the intra-uterine environment is responsible for the limited inducibility of enzymes before birth.
This article deals with relationships and childbearing as observed in the 1983 survey of the well-being of the population (WBP'83), a survey in which a sample of Dutch citizens aged 18 years and over was interviewed. The demographic part of the survey can be considered as a continuation of the Netherlands Fertility Surveys 1977 and 1982 (NFS'77 and NFS'82) as well as the 1980 survey on the well-being of the population (WBP'80). As the fertility surveys consist of interviews with women of reproductive ages, only the well-being surveys are of particular interest as they also consist of interviews with older women and with men. As cohabitation is on the increase and many youngsters expect ever to cohabit, one could wonder whether these phenomena will result in a continuing decrease of marriages or in a delay of marriages until older ages. The latter hypothesis would seem to make more sense, since the majority of the interviewed persons, even among the youngest, is already married or expects to do so. After the sharp decreases in the average number of children per person, a more stable pattern can be observed in the youngest generations. The expected ultimate numbers of children to persons born in the 1950s and early 1960s are, on average, just below the level of replacement. However, a somewhat lower level can even be expected, as research on the reliability of fertility expectations shows that many women, expecially (still) childless women, overestimate their future number of births. The fertility expectations of men and women show remarkable agreement. However, men do not know the future number of children they expect to have in more cases than women. This implies that the men's answers are less suitable for quantitative calculations.
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This study is concerned with the reliability of birth expectations in the Netherlands. The data are from four nationwide surveys: the National Survey on Fertility of 1969, the Netherlands Survey on Fertility and Parenthood Motivation of 1975, and the Netherlands Fertility Surveys of 1977 and 1982. These data permit the reliability of birth expectations data to be evaluated at the aggregate level only. Variations in the reliability of the data among the four surveys, and in the reliability of short- and long-term expectations, are analyzed. The results suggest that "asking for birth expectations in surveys in the Netherlands makes sense in so far that birth expectations can be used in...hypotheses for population forecasts." The precise ways of doing this are currently being studied at the Central Bureau of Statistics. (summary in ENG)
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This article is concerned with the effect of non-response on the quality of results from the Netherlands Fertility Survey of 1977. "The description of the non-response extends to reasons for non-response, the number of visits paid by the interviewers, some characteristics of the municipality of residence of the women and some demographic characteristics. These final data, as at October 1st, 1977, were obtained by writing to the municipal population registers. The non-response turned out to be 25.5%. It occurred particularly in the western part of the country and in more urbanized areas." (summary in ENG)