[Interdisciplinarity in gerontology: Theoretical problems and practical challenges]. / Interdisziplinarität in der Gerontologie: Theoretische Probleme und praktische Herausforderungen.

Philosophy of science is the theoretical background of this article. Firstly, a definition of interdisciplinarity is given, integrating experiences from longitudinal studies in gerontology and arguing for rejecting the large vocable "interdisciplinarity", because of its overloaded meaning. Secondly, science-oriented, sociopsychological and practical barriers of interdisciplinary work in gerontology are presented, whereby the central statement is that interdisciplinarity is preconditionally dependent on a "culture of understanding". Thirdly, a model of interdisciplinarity in gerontology is shown. In general, this article does not focus on the question whether gerontology is a multidisciplinary, interdisciplinary or transdisciplinary discipline but how the requirement of interdisciplinarity can be successfully implemented. In conclusion, interdisciplinarity is not established due to the subject (of aging) or a methodological approach but evolves based on reciprocal contact between different disciplines, which can be entitled "fair cooperation."

[Quality of life of people with severe dementia in nursing oases: empirical results and methodological implications]. / Lebensqualität von Menschen mit schwerer Demenz in Pflegeoasen: Empirische Ergebnisse und methodische Implikationen.

Nursing oases (NOs) are a variant of segregated care for people with severe dementia in nursing homes. They can be understood as a constant living arrangement in one room for 4-7 persons with a special care concept and environmental design. During the daytime nurses are permanently present. Quality of life (QoL) is the focus because the efficacy of medical and nursing interventions should include measurement of QoL. There is a controversy whether NOs are really different from the traditional caring settings in long-term care. Advocates see NOs as a substantial contribution to improve QoL, especially for people with severe dementia but critics fear a rollback to the era of multibed rooms in nursing homes and emphasize the risk of losing autonomy. This article is differentiated into four parts. Firstly, reasons are given why NOs are an option for a professional and adequate fulfillment of needs for people with severe dementia and a definition of NOs is given. Secondly, selected results of NOs studies in Germany are shown which have mainly documented positive effects. Thirdly, on the background of US American research into Special Care Units methodological questions are discussed. The focus is on designs and the utilization of standardized and non-standardized instruments. In the concluding remarks it is discussed whether QoL is an adequate indicator of a good life for people with severe dementia in long-term care.

Potential involvement of vascular endothelial growth factor in pathophysiology of Turner syndrome.

Vascular endothelial growth factor (VEGF) is a specific growth factor for endothelium but plays also a role in the signaling involved in embryonic endocardial-to-mesenchymal transformation of the endocardial cushions. Furthermore, VEGF is the major vascular permeability factor in both fetal and postnatal life. Overexpression of VEGF during fetal life is associated with fetal hydrops and abnormal endocardial cushion development and therefore with congenital heart defects. Cases of prenatal cervical hygroma like in Turner syndrome show both hydrops and cardiac defects. We hypothesize that excess VEGF formed in the wall of the distended jugular sacs (cervical hygroma's) results in other abnormal features characteristic for Turner syndrome such as short stature and gonadal dysgenesis. This implicates that if excess VEGF could be limited prenatally, the phenotypical expression of Turner syndrome can possibly be reduced.

[Maternal complications of fetal hydrops]. / Maternale complicaties bij hydrops foetalis.

Three women, aged 28, 27 and 25 years, two primigravidae and one woman who had given birth to a hydropic child previously, had four pregnancies with hydrops of the foetus and the placenta: two (in the same patient) due to foetal cardiomyopathy and two with foetal heart block. The patients developed severe oedema and preeclampsia. After the delivery they recovered well. Since the introduction of anti-D rhesus immunoprophylaxis, foetal hydrops has become less frequent. The resulting maternal complications (the maternal hydrops syndrome and enlarged polycystic ovaries) are therefore less well-known. Serious maternal complications occur in around 50% of cases of foetal hydrops. Careful monitoring of the maternal condition in cases of foetal hydrops is therefore warranted.

[Gerontology and nursing care]. / Gerontologie und Pflege.

This paper focuses on questions of the philosophy of science and the scientific development of gerontology and nursing science. First, some aspects of the scientific development in gerontology and nursing science (autonomy, inter- and multidisciplinarity as well as the theory debates) are summarized. In gerontology, problems of the philosophy of science are often neglected. The main focus is on empirical research and the establishment of an scientific infrastructure. In nursing science are questions of the philosophy of science, especially debates about the discipline, are significant. In Germany nursing research and the establishment of a scientific infrastructure are still in the initial stages. Second, on the basis of a content analysis the relevance and status of "nursing/need of care/frailty" in two leading journals ("Zeitschrift für Gerontologie und Geriatrie" and the "Pflege") is shown. Main result is that in nursing science publications regarding the status of the discipline, studies of the motivation, attitudes and behavior of nurses as well as investigations of the professionalization are dominant. In gerontology, the main emphasis is on studies of the changing health service structure, geriatric assessment and qualification. Finally chances of an interdisciplinary exchange between gerontology and nursing science are discussed.

The diagnostic performance of cytogenetic investigation in amniotic fluid cells and chorionic villi.

First-trimester chorionic villus sampling has not reached the popularity of second-trimester amniocentesis in prenatal cytogenetic diagnosis, in contrast to initial expectations. We investigated whether a difference in the diagnostic performances of cytogenetic investigation in amniotic fluid (AF) cells and chorionic villi in favour of AF-cells might justify this. Diagnostic performance was measured as laboratory failure rate, karyotype quality (G-band score, rate of follow-up samples, rate of wrong diagnoses), and karyotype representativity (rate of follow-up samples, rate of wrong diagnoses). From 1993-1999, 11 883 AF-samples were investigated (AF-cells). In chorionic villi, short term culture preparations solely were karyotyped from 1993-1996 (n=3499) (STC-villi), short and long-term culture preparations simultaneously provided a sufficient amount of tissue being available from 1997 onwards (n=1829) ((STC+LTC)-villi). Laboratory failure rates were the same after amniocentesis (0.40%) and chorionic villus sampling (0.50%). G-band scores (mean+/-SD) were equal in AF-cells (373+/-38.1) and LTC-villi (364+/-32.6) but significantly lower in STC-villi (311+/-34.6) (p=0.001). Follow-up sampling rates because of quality reasons were the same in AF-cells (0.14%), STC- villi (0.13%) and (STC+LTC)-villi (0.11%). Two wrong diagnoses turned up among AF-cells. Follow-up sampling rates because of representativity reasons differed significantly between AF-cells (0.10%), (STC+LTC)-villi (1.31%), and STC-villi (1.99%) (p<0.001). However, the ratios of the total numbers of follow-up samples and uncertain or abnormal cytogenetic results in STC, and (STC+LTC)-villi at cytogenetic risks > or =3% (0.132 and 0.160, respectively) were equal to that in AF-cells at risks <3% (0.155). Two wrong diagnoses were made in STC-villi. Diagnostic performance improved in the rank order of STC-villi, (STC+LTC)-villi and AF-cells. At cytogenetic risks > or =3%, (STC+LTC)-villi showed a diagnostic performance equal to that in AF-cells. This might justify a selective use of chorionic villus sampling.

Accuracy of abnormal karyotypes after the analysis of both short- and long-term culture of chorionic villi.

We report in detail the cytogenetic results of 1838 consecutive chorionic villus samples with the availability of both short-term culture (STC-villi) and long-term culture (LTC-villi) preparations in 1561 cases (84.9%). A high degree of laboratory success (99.5%) and diagnostic accuracy (99.8%) was observed; in four cases of low mosaicism, all four associated with the final birth of a normal child, a small risk of uncertainty was accepted. The combined analysis of STC- and LTC-villi reduced follow-up amniocenteses by one-third in comparison with the analysis of STC-villi alone. We believe that the desired level of quality and accuracy of prenatal cytogenetics in chorionic villi can only be achieved when both STC- and LTC-villi are available. We conclude that CVS might then be the mode of prenatal diagnosis of first choice in pregnancies with a high (cytogenetic) risk.

How useful is the in vitro expansion of fetal CD34+ progenitor cells from maternal blood samples for diagnostic purposes?

Fetal cells present in the maternal circulation are a potential source of fetal DNA that can be used for the development of a prenatal diagnostic test. Since their numbers are very low, amplification of fetal cells has been discussed for a long time. So far, most studies have focused on culturing fetal erythroid cells. In this study, we evaluated whether limiting numbers of fetal haemopoietic progenitor cells present in an excess of maternal cells were able to overgrow the maternal component. Therefore, we used a model system in which limiting numbers of male CD34+ umbilical cord blood cells were diluted in 400 000 female CD34+ peripheral blood cells. The number of XY positive cells derived from umbilical cord blood was determined using two-colour in situ hybridization with X and Y chromosomal probes. We demonstrated a 1500-fold relative expansion of male umbilical cord blood cells over the peripheral blood component after three weeks of liquid culture, which also corresponded to the extent of expansion of CD34+ cells derived from 20-week fetal blood. However, application of the same culture protocol to maternal blood samples obtained at 7-16 weeks of gestation showed no preferential growth of fetal haemopoietic progenitor cells. This study, therefore, suggests that fetal primitive haemopoietic progenitor cells do either not circulate in maternal blood before 16 weeks of gestation, or require different combinations/concentrations of cytokines for their in vitro expansion.

Case of 45,X/46,XY mosaicism with non-mosaic discordance between short-term villi (45,X) and cultured villi (46,XY).

We report on a prenatally detected case of discordant non-mosaic karyotypes following chorionic villus sampling. A 45,X karyotype was found in cytotrophoblast cells and a 46,XY karyotype in mesenchymal core cells. A subsequent amniocentesis showed a true 45,X/46,XY mosaicism. Confirmatory studies, including fluorescence in situ hybridization (FISH) in various fetal and placental tissues as well as in the original villi preparations changed the presumed condition of generalized mosaicism with culture confined normality to that of generalized mosaicism with absolute concordance. This case underscores the importance of the investigation of both short-term and cultured villi preparations, the implementation of prenatal FISH studies, and the need for thorough follow-up investigation in cases of discrepant results.

Nasopharyngeal teratoma and mosaic tetrasomy 1q detected at amniocentesis. A case report and review of the literature.

The occurrence of nasopharyngeal teratomas (NPT) is an infrequent event and prenatal detection of such tumors is even rarer. We present a case report and review of the literature (N = 78 cases), in which we describe the cytogenetic, DNA, and pathological findings of a fetus with a mature NPT which was detected prenatally by ultrasound investigation following complaints of severe polyhydramnios by the mother.

Effect of atracurium or pancuronium on the anemic fetus during and directly after intravascular intrauterine transfusion. A double blind randomized study.

BACKGROUND: To determine the effect of atracurium or pancuronium on onset and duration of fetal paralysis, movements and heart rate parameters directly after transfusion, using computer analyzed fetal heart rate recording (c-FHR). METHODS: Double blind randomized study of 23 RhD alloimmunized pregnant women requiring an intravascular intrauterine fetal blood transfusion (IUT) between 24 and 36 weeks. Atracurium was injected in 11 fetuses at 17 IUT's and pancuronium in 12 fetuses at 19 IUT's. For statistical analysis the Mann-Whitney test was used. RESULTS: No statistical differences were found in fetal heart rate and movements between both groups before transfusion. The fetal movements returned more rapidly in the atracurium group when compared to the pancuronium-group (median 24 vs. 57 min, range 6-55 vs. 4-220; (p<0.02). Fetal movements did not hamper the procedure in any case. The atracurium group showed significantly more fetal movements (p<0.01), more accelerations (0<0.05) but no significant reduction of fetal heart rate variability directly after transfusion which was in direct contrast to the pancuronium group. CONCLUSIONS: Neuromuscular blockade with atracurium produces sufficient paralysis for intrauterine transfusion with minimal disturbance of the parameters used to monitor fetal wellbeing after the procedure. Although the routine use of fetal paralysis during IUT may be questionable, we believe that when it is necessary the use of atracurium is the better choice.

The use of in vitro expanded erythroid cells in a model system for the isolation of fetal cells from maternal blood.

The development of a non-invasive prenatal diagnostic test using fetal nucleated red blood cells (NRBCs) isolated from the maternal circulation is hampered by the low frequency of these cells in maternal blood, requiring extensive enrichment procedures before any analytical procedure can be performed. In order to improve and simplify these procedures, we have used in vitro expanded erythroid cells derived from male umbilical cord blood in a model system for the isolation of fetal NRBCs from maternal blood. Erythroblast cells were expanded in vitro to high cell numbers and were immunophenotypically identical to fetal NRBCs isolated from maternal blood. Magnetic activated cell sorting (MACS) isolation procedures were optimized using in vitro expanded male NRBCs diluted up to 1 in 400,000 with female peripheral blood mononucleated cells. The number of recovered male cells was determined using two-colour fluorescence in situ hybridization with X and Y chromosomal probes. Using this model system, an NRBC isolation technique is described. It is based on a one-step MACS enrichment protocol for CD71 positive cells, which showed a significant (Wilcoxon signed ranks test, p<0.05) two-fold higher yield of male NRBCs than previously described MACS methodologies, in which CD71 positive cells were enriched after depletion of other cell types. Application of these isolation strategies to maternal blood samples resulted in a similar improved enrichment of male fetal cells after the direct enrichment of CD71 positive cells.

Periconceptional use of folic acid amongst women of advanced maternal age.

Between February 1994 and February 1997 a group of 881 women completed a questionnaire on the use of folic acid. During the study period the percentage of women who had been informed about the benefits of folic acid rose from 41 per cent to 90 per cent and the percentage taking supplementation rose from 18 per cent to 60 per cent. Nevertheless, few women used folic acid at the right time and dose and although 90 per cent would have been willing to follow recommendations, correct use did not exceed 25 per cent. It is concluded that effective folic acid supplementation requires food fortification rather than information provided by healthcare workers.

Amniocentesis or chorionic villus sampling in multiple gestations? Experience with 500 cases.

500 women with multiple pregnancies underwent amniocentesis or chorionic villus (CV) sampling at our department between January 1988 and July 1997. The aim of this retrospective study was to evaluate the laboratory aspects and the consequences of discordant results in these pregnancies in relation to the method of sampling. Uncertain results in one or both samples, requiring further investigation were more frequent in CV samples (eight times in 163 paired samples, 5 per cent) than in amniotic fluid (AF) samples (once in 298 paired samples, 0.3 per cent). Sampling one fetus twice (erroneous sampling) was seen only once among 163 pregnancies with two CV samples in our study. Cross contamination due to mixed sampling was discovered in two of seven pregnancies that underwent DNA diagnosis in CV and might be a rather regular occuring phenomenon. In none of the 500 pregnancies mixed sampling caused diagnostic dilemmas. A third sampling problem, maternal cell contamination caused a diagnostic problem once among the AF samples. Selective fetal reduction appeared safer after CV sampling than after amniocentesis. Subsequently, CV sampling instead of amniocentesis has become the method of choice for prenatal diagnosis in multiple pregnancies in our department.

Abnormal karyotypes in semi-direct chorionic villus preparations of women with different cytogenetic risks.

Among 3499 cytogenetically investigated semi-direct chorionic villus samples, 219 (6.3 per cent) abnormal karyotypes were encountered. The karyotypes were considered certainly abnormal (generalized abnormal with high probability) in 109 cases (3.1 per cent), and in 110 cases (3.1 per cent) uncertainly abnormal (potentially confined to the placenta), requiring further investigation. Of these 110 uncertain abnormalities, the cytogenetic result turned out to be finally abnormal representing generalized abnormality in 36 cases (32.7 per cent), finally normal representing confined placental mosaicism (CPM) in 69 cases (62.7 per cent), and remained undetermined in 5 instances (4.5 per cent). The rate of the numbers of certainly abnormal and all (certainly + uncertainly) abnormal results, the certainty rate, and that of generalized abnormalities and all abnormalities (generalized abnormalities + CPM cases), the predictive value, are strongly correlated with the cytogenetic risk. Therefore, we advise chorionic villus sampling for cytogenetic investigation only in women with a cytogenetic risk equal to or exceeding that of a 40-year-old pregnant woman. Because of the high rate of prenatal follow-up investigations after the finding of uncertain results in semi-direct villi, semi-direct and cultured villi should be karyotyped simultaneously.