Molecular evidence of fetal-derived chromosome 21 markers (STRs) in transcervical samples

Transcervical cells (TCCs), collected by flushing or aspiration at 8–13 weeks of gestation, were analysed for the presence of fetal-derived DNA sequences. DNA extracted from maternal peripheral blood, TCC samples, and placental tissue was amplified by the polymerase chain reaction (PCR) to detect small tandem repeat (STR) markers specific to chromosome 21. STR products of fetal origin could be clearly observed in four TCC samples. TCC samples collected by flushing or aspiration were also analysed by fluorescent in situ hybridization (FISH) using X and Y probes simultaneously: 46,XY cells could be detected in all TCC samples obtained from mothers with male fetuses.     

Isolating fetal nucleated red blood cells from maternal blood: The baylor experience—1995

In our previous work we have isolated fetal cells from maternal blood and used fluorescent in situ hybridization (FISH) for chromosome-specific probes to detect aneuploidy. Current efforts in the Baylor College of Medicine programme are focusing on obtaining consistency in flow-sorting methodology and on determining sensitivity and specificity. To this end, systematic evaluation of five glycophorin A (gly A) antibodies all produced agglutination, leading us to abandon the use of gly A antibodies for positive selection of fetal cells. Conversely, we have found LDS-751 to be useful for nuclear selection. CD45 negative selection can best be accomplished by the use of flasks coated with goat antibodies against mouse antibodies. Positive selection by flow sorting for either CD71⁺ cells or gamma-globin-positive cells seems to be successful. Using these two approaches, we have recently detected male (fetal) cells in pregnancies in which the fetus was 46, XY in 10 of 18 and in 12 of 14 cases, respectively.     

连城太阳能光伏产业发展现状与战略选择

太阳能光伏产业是21世纪备受世界各国重视的高新技术产业之一,拥有广阔发展前景,基于对太阳能光伏产业链、国内太阳能光伏产业现状的分析及连城太阳能光伏产业现状与面临挑战的分析,提出连城太阳能光伏产业发展战略。     

国内外光伏发电站环境影响评价方法简析

综述光伏发电技术现状,分析比较国内外光伏发电项目的环境影响和评价要求,简述我国的国家风光储输示范工程、敦煌10MAP太阳能光伏发电工程及保加利亚Betapark有限公司4MW光伏发电项目,对比远离城区的光伏电站、城市地区的光伏电站及光伏建筑一体化在施工期、运行期及服务期满后的评价因子,提出国内光伏发电环境影响评价的主要评价因子为生态、固废、噪声、电磁辐射等,为我国光伏电站设计、建设、运行管理及环境保护提供依据,完善国内光伏发电站环境影响评价。     

First trimester diagnosis of Gaucher disease in a fetus with trisomy 21

A 38-year-old lady, who had a previous infant with type 2 Gaucher disease, underwent prenatal diagnosis by chorionic villus sampling at 9 weeks' gestation. Results on the fresh villus revealed a 47,XY,+21 karyotype and a marked deficiency (2 per cent of control) of β-glucosidase activity. Following termination, villus material was cultured which initially revealed only a partial enzyme deficiency and a normal female karyotype, i.e., maternal cells. A subsequent culture contained 47,XY, + 21 cells which were deficient in β-glucosidase activity, thus confirming the diagnosis. The results in this interesting case illustrate the potential dangers of maternal cell contamination in cultured villus cells.