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121.
Rapid detection of numerical aberrations of chromosomes 13, 18 and 21 in chorionic mesenchymal cells
We have devised and evaluated a rapid screening method for the detection of numerical aberrations of chromosomes13, 18 and 21 in chorionic villus cells. We used non-radioactive in situ hybridization (ISH) with three chromosome-specific probes on overnight-attached mesenchymal cells from chorionic villi. A blind study was performed of 47 karyotypically normal samples, one triploid sample, two samples trisomic for chromosome 21, and two samples from a fetus with putative mosaicism (46/47, +21). All samples were hybridized with the chromosome 18- and 21-specific probes. Thirty samples were additionally hybridized with the chromosome 13-specific probe. The test could be completed within 3-4 days of sampling. In samples disomic with respect to the probed chromosomes, an average of 2 per cent (range 0-9 per cent) had three hybridization signals. By contrast, in the samples trisomic for the probed chromosome(s), 57 per cent (chromosome 13), 51 per cent (chromosome 18), and an average of 74 per cent (55-86 per cent) (chromosome 21) of the nuclei exhibited three signals. In the putative mosaic samples, the number of nuclei with three chromosome 21-specific signals ranged from 41 to 69 per cent. We conclude that this technique rapidly and clearly distinguishes between normal and trisomic/triploid samples, and consequently may be of use in future prenatal diagnosis. 相似文献
122.
A population of 1639 patients were seen for chorionic villus sampling (CVS). Embryonic death was identified at ultrasound in 5.3 per cent of patients. The number of patients undergoing CVS was 1551, with 1416 transcervical procedures and 135 transabdominal procedures. The most common indication for CVS was advanced maternal age. Spontaneous pregnancy losses identified by increased risk of pregnancy loss with increasing aspiration attempts. The total fetal loss for this population was 5.4 per cent with the pregnancy loss estimated due to procedure being 1.2 per cent. Analysis of placentae from patients having CVS and amniocen-tesis showed no differences. Microbiological assessment prior to CVS was similar to previous publications. 相似文献
123.
Wang Liming Zhang Junwu Wu Guanyun Wang Shenwu Fan Yu Huang Youwen Zhao Letian Wang Rongxin Su Jidong Zhang Nijia Long Guifang Li Qi Zou Peng Liang Rong Liang Xu 《黑龙江环境通报》1986,6(2):89-95
By means of chorion biopsy together with restriction endonuclease analysis of fetal DNA, first trimester diagnoses were successfully made in 33 fetuses at risk for Bart's hydrops fetalis. Seven pregnancies with Hb H or hydrops fetalis were therapeutically terminated before 4 months of gestation. Of the 26 pregnancies intended to continue, 18 have come to term with normal deliveries; one with threatened abortion was terminated at the end of the first trimester and, seven are progresssing normally. 相似文献
124.
钼锑抗分光光度法测定总磷的精密度偏性试验分析 总被引:1,自引:0,他引:1
通过钼锑抗分光光度法测定总磷的精密度偏性试验及其结果分析,提出本标准方法用光程10mm比色皿比色测定时,由于测定的灵敏度较低,使总磷低浓度测定的精密度和准确度难于达到标准方法要求;建议钼锑抗分光光度法测定总磷时,最好选用30mm比色皿比色测定. 相似文献
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128.
Compounds in the atmosphere contaminate samples of groundwater. An inexpensive and simple method for collecting groundwater samples is developed to prevent contamination when the background concentration of contaminants is high. This new design of groundwater sampling device involves a glass sampling bottle with a Teflon-lined valve at each end. A cleaned and dried sampling bottle was connected to a low flow-rate peristaltic pump with Teflon tubing and was filled with water. No headspace volume was remained in the sampling bottle. The sample bottle was then packed in a PVC bag to prevent the target component from infiltrating into the water sample through the valves. In this study, groundwater was sampled at six wells using both the conventional method and the improved method. The analysis of trichlorofluoromethane( CFC-11 ) concentrations at these six wells indicates that all the groundwater samples obtained by the conventional sampling method were contaminated by CFC-11 from the atmosphere. The improved sampling method greatly eliminated the problems of contamination, preservation and quantitative analysis of natural water. 相似文献
129.
欧拉观测的大气扩散参数计算方法探析及应用 总被引:2,自引:0,他引:2
根据湍流扩散统计理论,讨论了利用欧拉观测的风速资料求解正态扩散模式中大气扩散参数的计算方法及其实现,并以海南洋埔开关区各稳定度大气扩散参数的计算为实例作了分析。 相似文献
130.