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Metaphase chromosomes and interphase nuclei from nine amniotic fluid cultures were studied with fluorescence in situ hybridization (FISH). The samples were initially analyzed with routine G-banding and were diagnosed as having true mosaicism (five patients) or pseudomosaicism (four patients). In our study, FISH analysis could provide additional information to distinguish pseudo– from true mosaicism by allowing interphase studies and analysis of an increased number of metaphase spreads. These results suggest a multilinear origin of ‘in situ’ colonies of cells. 相似文献
65.
Maternal cell contamination was assessed in 18 macroscopically blood-stained amniotic fluid samples from male fetuses. The samples were analysed by double-target fluorescent in situ hybridization (ISH) with Y and X chromosome-specific probes. The only sample with an aberrant karyotype (47, XY, +18) was also analysed by hybridization with a chromosome 18-specific probe. An interpretation of extensive maternal cell contamination was made in two samples, one of which was the sample with trisomy 18. ISH with the chromosome 18-specific probe on this latter sample showed that the sensitivity of the ISH method for chromosome enumeration of uncultured amniotic fluid samples may be reduced in bloodstained samples. It was calculated that by using ISH for chromosome enumeration of the two extensively contaminated samples, a case of trisomy 21 might have been overlooked in both samples, while a case of trisomy 18 might only have been overlooked in one of the samples. It is concluded that ISH should not be used for chromosome enumeration of uncultured amniotic fluid samples that are macroscopically blood-stained without further technical developments. 相似文献
66.
Y. Verlinsky N. Ginsberg M. Chmura M. Freidine M. White C. Strom A. Kuliev 《黑龙江环境通报》1995,15(9):831-834
In a routine application of commercially available centromeric DNA probes for the prenatal screening of common trisomies involving the autosomes 13, 18, and 21, and sex chromosomes, four cases of discrepancy between fluorescence in situ hybridization (FISH) results and follow-up cytogenetic analysis were observed from a total of 516 cases of amniocentesis. In three of these cases, the results were false negative, and in one false positive. In this case, amniocentesis was performed because of a positive triple test in a 34-year-old woman with previous infertility treatment. The alpha satellite DNA probe for chromosomes 13/21 revealed five signals in 50 per cent of uncultured amniocytes, while standard cytogenetic analysis showed a normal karyotype. FISH analysis on metaphase chromosomes demonstrated the location of the additional signal in the centromeric region of chromosome 22. This additional signal was also present in the centromeric region of chromosome 22 of the mother, providing evidence for a possible inherited polymorphism in chromosome 22 responsible for unspecific hybridization with the alpha satellite probe for chromosomes 13/21 in this case. The observed polymorphism in centromeric regions may contribute to unreliability of the use of the 13/21 alpha satellite probe for prenatal screening by FISH. 相似文献
67.
Suzanne L. Reeser Alan E. Donnenfeld Robert C. Miller Beatrice S. Sellinger Beverly S. Emanuel Deborah A. Driscoll M.D. 《黑龙江环境通报》1994,14(11):1029-1034
Cytogenetic studies of cultured amniocytes demonstrated a karyotype of 46, XX/47, XX,+mar. A bisatellited, dicentric, distamycin-DAPI negative, NOR-positive marker was present in 76 per cent of the metaphases examined. Similar markers have been associated with cat eye syndrome (CES). We report on the utilization of fluorescence in situ hybridization (FISH) with a 14/22 a-satellite probe and a chromosome 22-specific cosmid for locus D22S9 to determine the origin of the prenatally detected supernumerary marker chromosome. FISH studies demonstrated that the marker is a derivative of chromosome 22 and enabled us to provide the family with additional prognostic information. 相似文献
68.
Prenatal diagnosis of tetrasomy 12p is complicated by the discrimination of the 12p isochromosome from the duplication 21q as well as the level of mosaicism demonstrated in the particular tissue sampled. In this disease, a high percentage of chromosomally abnormal cells are generally found in fibroblastic cells, but lymphocyte karyotypes from the same individual may be normal. We report on the pregnancy of a 37-year-old female who presented to our centre at 16 weeks' gestation for genetic amniocentesis. Sonography of the fetus revealed dextrocardia and diaphragmatic hernia. Chromosome analysis of amniocytes demonstrated mosaicism of a 47,XY,+i(12p) line in 80 per cent of cells and a normal male line (20 per cent), consistent with the Pallister-Killian syndrome. Following termination, a 220 g male fetus of 18 weeks was examined. A flattened nose and low-set ears were noted. In situ hybridization with a chromosome 12 centromeric probe in lymphocytes and skin cells unequivocally confirmed the karyotype and showed the presence of a single centromere in the abnormal chromosome, suggesting a true isochromosome. Chromosome analysis of various fetal tissues was performed and the following percentages of abnormal cells were found: skin 100 per cent, chorion 50 per cent, placenta 30 per cent, and blood 80 per cent. The high frequency of tetrasomic cells in fetal blood at this early gestational age is noteworthy, since most reports of this syndrome show a very low percentage of abnormal cells postnatally. 相似文献
69.
地浸采铀技术与工艺 总被引:8,自引:1,他引:8
地浸采铀是世界上十分先进的采矿技术,其基本原理是对可地浸砂岩型铀矿按一定网度布置工艺钻孔,从注液注孔入地浸液,使地浸液与铀进行充分反应,经铀液孔提出地表,在地表工厂进行萃取铀的过程,地浸法分为酸法和碱法两种,地浸采铀能使低品位砂岩型铀矿成为有工业价值的矿床,由于对环境污染小,已被世界大多数国家广泛采用。但是并非所有的砂岩铀矿都能地浸,只有符合地浸地质-水文评价指标的砂岩铀矿才能地浸。地浸工艺包括钻孔的布置、浸液的配制、地下水的复原和环境保护等方面。我国的地浸采铀于20世纪70年代开始探索,90年代中期开展了大规模的地浸砂岩铀找矿与开采工作,并取得了突破性进展,新疆512矿床是就是利用地浸技术评价与开采的我国第一座大型地浸铀矿山。 相似文献
70.
近年来 ,诸多国家在环境微生物领域先后开展了分子生物学研究方法的建立和生物学评价工作。一些不依靠纯培养的微生物群落的分析方法已得到广泛应用和发展。荧光原位杂交 (FISH)技术 ,具有细胞在测定过程中不被破坏、形状不改变、特异性强、能够真实反映在自然环境下微生物的情况及分布等特点 ,在环境微生物群落探测分析中已逐渐被广泛应用。该技术利用带有荧光标记的特异性寡核苷酸探针 ,与细胞内相应的靶核糖体结合 ,能将微生物探测、鉴定到属和种的水平。运用于硝化细菌、除磷细菌和丝状微生物等废水处理中常见的特征性微生物种群和群落生态学研究中 ,颇为高效。该技术的应用避免了传统培养方法进行鉴定和计数的局限性 ,在环境微生物生态学解析中具有较高应用价值。 相似文献