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排序方式: 共有1013条查询结果,搜索用时 984 毫秒
901.
902.
Dr. Sci. V. S. Baranov V. N. Gorbunova T. E. Ivaschenko N. Yu. Shwed N. S. Osinovskaya T. K. Kascheeva V. M. Lebedev A. V. Mikhailov V. G. Vakharlovsky T. V. Kuznetzova 《黑龙江环境通报》1992,12(7):575-586
From a total of 490 cystic fibrosis (CF) high-risk families under supervision (mostly Russian Slavs from the European part of the country), DNA data including both direct screening for some CF gene(CFTR)mutations(deIF508, G551D and 1677delTA) and allelic polymorphism studies with tightly CF linked DNA markers were collected from 261 families. All full families (129) and 86 CF families with a deceased index child were found to be either fully (42 per cent) or partially (40 per cent) informative for DNA analysis. Prenatal diagnosis (PD) was carried out in 161 CF families. Microvillar enzyme (MVE) assay was applied to all 140 PD at the second trimester either as a single test (88) or in conjunction with DNA analysis (52). The frequency of false-negative results of the MVE assay was 1.3 percent and that of false-positive results, as judged by the albumin meconium test, was 5.0 per cent. Ambiguous results of MVE analysis were found in 30 cases, 12 of which were verified by DNA analysis. Molecular diagnosis of CF at the first trimester was carried out in 21 cases and four pregnancies were terminated. Altogether, 39 pregnancies with a predicted high risk of CF fetuses were terminated. The low average frequency of delF508 in CF chromosomes of Russian Slavs (50 per cent), its remarkable inter-population variation, and the significant proportion of at-risk families without an affected child determine the necessity of combined molecular and biochemical (MVE assay) approaches for efficient prenatal diagnosis of CF in the former U.S.S.R. 相似文献
903.
Dr. Elizabeth J. T. Winsor B. St. John Brown Edwin R. Luther Stephen A. Heifetz J. Philip Welch 《黑龙江环境通报》1987,7(7):485-489
A pregnancy was terminated because of persistently elevated amniotic fluid AFP (+10 S.D.) and an AChE band of low intensity on gel electrophoresis. No fetal anomalies were detected by ultrasonographic examination. Autopsy revealed an apparently normal fetus of about 20 weeks gestation. Attached to the placenta was a small sac containing a fetus papyraceus co-twin of about 8–9 weeks gestation. The small deceased co-twin and its gestational sac were not detected prenatally despite multiple ultrasonographic examinations. The difficulty in the interpretation of apparently conflicting results is emphasized. 相似文献
904.
In the course of a 2-year predictive testing programme for Huntington's disease (HD), six couples from a total of 52 applicants requested prenatal testing. In each case, the pregnancy was in the first or second trimester when the couples were referred for DNA diagnosis. In five cases, exclusion testing was offered; in one case, a person at risk with an increased risk of being a gene carrier requested prenatal diagnosis. In all cases, informative markers for prenatal testing could be determined. Whenever possible, the newer technique of polymerase chain reaction (PCR) for D4S125 was applied to perform rapid prenatal diagnosis. Two couples withdrew before chorionic villus sampling was undertaken; prenatal diagnosis was completed in the remaining four cases. After exclusion testing, two pregnancies were determined to have an increased risk and two fetuses to have a low risk of being HD gene carriers. 相似文献
905.
Harold S. Bernstein Roy A. Filly James D. Goldberg Dr. Mitchell S. Golbus 《黑龙江环境通报》1991,11(6):349-355
This paper reports our experience with 55 fetuses identified in utero to have a cystic hygroma. The outcome of fetuses with an isolated cystic hygroma, cystic hygroma with non-immune hydrops, and cystic hygroma with multiple anomalies was evaluated. Approximately two-thirds of karyotypes were aneuploid, and a strong association of septation and aneuploidy existed. Only five cases, four of which had isolated hygromas, came to term and resulted in live births. Two of these involved small non-septated lesions which resolved in utero. 相似文献
906.
In 226 women requesting chorionic villus sampling (CVS), routine cervical cultures were obtained before the procedure. Transcervical CVS was performed irrespective of the test results. The prevalence of potential pathogens in cervical cultures at our institution is low. Beta haemolytic Streptococcus was cultured in 3 per cent of the women. No pathogenic microorganisms were isolated in 64 per cent of the women. There was no relationship between culture results and the outcome of pregnancy. These observations suggest that adequate antiseptic cleansing of the genital tract is a suitable approach and there is no need to routinely perform cultures before CVS. 相似文献
907.
Hopes are held out for chorion villus sampling, a technique which is gaining more and more importance for the first trimester prenatal diagnosis of chromosomal aberrations and metabolic abnormalities. A variety of inherited skin diseases can be diagnosed postnatally and prenatally (in the second trimester) by ultrastructural diagnostic markers. For evaluation of prenatal diagnosis in the first trimester, we investigated chorionic villi derived from the trophoblast layer of the early pregnancy by light microscopy and conventional electron microscopy. The ultrastructure of the cellular layers covering the villi, i.e., the inner cytotrophoblast and the outer syncytiotrophoblast, as well as that of the connective tissue of the inner extraembryonic mesoderm, are thoroughly described in relation to the ultra-structural changes in certain genodermatoses including epidermolyses and keratinization disorders. We found that chorionic villi have only a few of the characteristics differentiated in skin, and none of the structures which are relevant to the diagnosis of genodermatoses. In our view, the ultrastructural approach is not suitable for first trimester prenatal diagnosis of genodermatoses in chorionic villi. 相似文献
908.
Presumptive maternal cell contamination (MCC) was monitored in identified male cases during cytogenetic comparison of direct techniques and three different culture regimes from 140 thoroughly dissected chorionic villus samples. Of the 66 identified male cases, 11(16·7 per cent) showed MCC, the mean number of cells examined per case being 8·2 (direct) and 14·5 (cultures); in the direct preparations only one of a total of 457 cells examined was female, while preparations from cultures revealed MCC in 11 cases. Four of these had MCC in more than one culture regime and four had only a single female cell. The results showed that (1) dependence on the culture system alone would have given a diagnosis based on maternal cells in one (1·5 per cent) male case, thus underlining the danger of this approach (a similar undetected rate of misdiagnosis being expected in the female cases) and (2) MCC was significantly lower in cultures grown in Chang medium as compared with the other two regimes, McCoy's 5A + 15 per cent fetal calf serum and 1 per cent Ultroser G, and McCoy's 5A + 25 per cent fetal calf serum, the latter expressing the highest level of MCC. 相似文献
909.
Dr. Suprapto H. Sastrowijoto M.D. Phd. Kamiel Vandenberghe Philippe Moerman Joseph M. Lauweryns Jean-Pierre Fryns 《黑龙江环境通报》1994,14(8):770-776
Rhizomelic chondrodysplasia punctata (RCDP) is a sublethal autosomal recessive disorder characterized by skeletal dysplasia, microcephaly, mental retardation, congenital cataracts, joint contractures, skin changes, and failure to thrive. Prenatal ultrasound diagnosis has been reported during the second trimester of pregnancy. Prenatal diagnosis is also possible from the first trimester onwards by demonstration of peroxisomal dysfunction in cultured chorionic villous or amniotic fluid cells. In all cases reported hitherto, the prenatal diagnosis was established after the birth of a previous affected child. In contrast to these studies in pregnant multiparous women at risk for RCDP, we report on the first case of prenatal ultrasound diagnosis of RCDP at 19 weeks' gestation in a primigravida. In addition, a complex cardiac malformation associated with hypoplasia of the thymus (DiGeorge anomaly) is described. 相似文献
910.
PD Dr Ingo Kennerknecht Gotthold Barbi Michael Wolf Mahmoud Djalali Dieter Grab Rainer Terinde Walther Vogel 《黑龙江环境通报》1993,13(10):929-944
An increasing number of cytogenetic prenatal diagnoses are performed on chorionic villus samplings. The accuracy of this method is influenced by chromosomal mosaicism, mostly confined to direct preparation methods. Especially those investigators who have experienced false-negative and false-positive findings propagate the combined use of direct and culture methods. Yet large collaborative studies have shown that in approximately two-thirds of diagnostic cases only one procedure is applied. Moreover, the accuracy of a cytogenetic investigation depends not only on the ontogenetic origin of the tissues investigated, but also on interacting factors such as the ‘a priori risk’ and the ‘predictive value of a cytogenetic finding’. On this basis a differentiated prenatal diagnostic procedure is discussed, including either sole short-term culture (STC), combined STC and long-term culture (LTC), primary amniocentesis (AC), or primary percutaneous umbilical blood sampling (PUBS). The predictive value of the cytogenetic diagnosis from CVS varies significantly dependent on the a priori risk of a chromosome aberration and, in the case of an abnormal karyotype, on the specific chromosome involved. A non-mosaic and ‘non-lethal’ trisomy detected in STC is highly representative of the embryo/fetus, but there are exceptions of limited predictive value, e.g., trisomy 18. Guided by the strategy of an optional follow-up by LTC, AC, or PUBS in 1317 successive CV samplings, we are not aware of a false-negative diagnosis, but probably had one false-positive diagnosis: 47,XXY after STC; 46,XY after LTC. When referring to the rate of fetuses with an unbalanced karyotype expected in the different indication groups, a relative increase of false-positive findings in the very-low-risk group (maternal age ⩽35 years of age) and of false-negative findings in the very-high-risk group (abnormal ultrasonographic findings) of pregnant women when only performing CVS becomes obvious. Because of this dilemma, AC or—especially in the latter group—PUBS might be primarily offered to these indication groups instead of CVS. 相似文献