The characterization of hCG regulation in cultured human amniotic fluid cells

The media from primary cultures and subcultures of second trimester human amniotic fluid (AF) cells were assayed by radioimmunoassay to quantitate production of human chorionic gonadotropin (hCG). Primary AF cultures produce more hCG per cell than do the corresponding subcultures. Sodium butyrate (2 mM) stimulates AF subcultures to produce 5-13 times more hCG per cell or per mg of cellular protein than do untreated subcultures. This stimulatory effect of sodium butyrate is dose dependent between 0 and 5 mM. Addition of sodium butyrate 24 hours after subculture, while stimulating production of hCG during the subsequent 3 days, also results in fewer cells and less protein per culture. This effect on cell growth is also dose-dependent. Previous investigators have proposed that the stimulation of hCG by sodium butyrate in other types of cell cultures is due to an effect of that agent on culture growth. Therefore, in these studies AF cells are allowed to grow to confluency before sodium butyrate was added. Production of hCG was stimulated by sodium butyrate about four-fold during the next 5 days although no significant changes were observed either in number of cells or amount of cellular protein per culture. These results suggest that stimulation of hCG by sodium butyrate is not dependent on its effect on growth of the cultures.     

Normal karyotype in cultured chorionic villus cells,but mosaicism in amniotic and fetal cells

A case with a normal male karyotype in cultured chorionic villus cells, but 46,XY/45,X/ 46,X,i(Yq) mosaicism in amniotic and fetal tissue is reported. The fetus was a phenotypic male. Pathological examination revealed discrete features, which might indicate a syndrome, and histological examination showed large, bright cells in the tubules of the testes. Possible explanations for discordance between the karyotype of embryonic and extraembryonic tissue are discussed.     

Fragile X demonstrated retrospectively in amniotic cells cultured in low folate medium

Chromosome analysis in a boy aged 10 months, with psychomotor retardation, revealed the fragile X-chromosome in lymphocytes and skin fibroblasts cultured in low folate medium (TC 199). Amniocentesis and chromosomal analysis had been carried out during pregnancy because of advanced maternal age. Review of the slides from amniotic fluid cells grown routinely in low folate medium showed the marker X in 10.6 per cent of the metaphases. Possible explanations for the appearance of the marker X in amniotic cell culture are discussed.     

Fumarylacetoacetase activity in cultured and non-cultured chorionic villus cells,and assay in two high-risk pregnancies

We describe further development of the fumarylacetoacetase (FAA) assay for the prenatal diagnosis of tyrosinaemia type 1 using chorionic villus sampling (CVS). We have established a reference range for FAA activity in cultured villus cells and have confirmed previously reported data on the FAA activity in uncultured chorionic villus cells. This should allow confirmation of results using CVS, without the need for further invasive procedures. We report the FAA enzyme stability at −70°C, +4°C, and at room temperature, and we have shown no obvious difference in enzyme activity with gestational age. We have analysed cultured and non-cultured CVS activity of FAA in two pregnancies at risk of tyrosinaemia type 1. In both, the fetus was designated unaffected, and these results were confirmed postnatally.     

室内空气污染对人类健康的影响及防治措施

本文通过论述第三污染源室内空气污染对人类健康的危害,并提出了主要防治措施。     

Circulating ‘trophoblast’ cells in pregnancy have maternal genetic markers

A syncytiotrophoblast-associated antigen identified by the monoclonal antibody (McAb) H315 is detectable on the surface of a low proportion of peripheral blood cells in pregnant women, raising the possibility of a new approach to prenatal diagnosis of genetic disorders. We aimed at verifying the trophoblastic origin of H315⁺ cells and their use for prenatal diagnosis of β-thalassaemia. H315 ⁺ cells were separated from the peripheral blood of pregnant women: the DNA obtained from these cells in two selected cases was shown to have genetic markers indistinguishable from those of the mother and definitely different from the fetus. Our results suggest that H315 antigen is expressed by maternal cells and that prenatal diagnosis on peripheral blood of the mother using H315 McAb is not feasible.     

三丁基锡对正常人胚胎羊膜细胞凋亡的诱导作用

为了探讨三丁基锡(TBT,tributyltin)对正常人羊膜细胞FL(humanamnioticcells)凋亡的诱导作用,进行了流式细胞仪PIAnnexinⅤ双染色检测TBT对FL细胞凋亡的诱导作用,并采用荧光染料FITC标记的特异性的caspase3的抑制剂检测活细胞中caspase3的酶活性.实验结果表明,0、1、2、3、4μmol·L-1浓度的三丁基锡作用于FL细胞2h后,细胞凋亡率和细胞中caspase3酶活性都明显升高,且有良好的剂量效应关系.表明三丁基锡在一定浓度和暴露时间下能够诱导FL细胞的凋亡,而且在此过程中,caspase3起重要作用.     

Prenatal exclusion of metachromatic leukodystrophy by estimation of arylsulphatase a activity in chorion and cultured amniotic fluid cells

Chorion biopsy specimens were used for prenatal assay of arylsulphatase A activity in a pregnant woman whose two children had died from metachromatic leukodystrophy (MLD). As in two subsequent pregnancies chorion arylsulphatase A was in the control range, it was concluded that both fetuses were healthy. Absence of MLD in the fetus from the first pregnancy was confirmed after assay of arylsuphatase A activity in fetal organs. The second pregnancy resulted in delivery of a healthy child.     

A misdiagnosis of X-linked adrenoleucodystrophy in cultured chorionic villus cells by the measurement of very long chain fatty acids

A case is reported of a male fetus at risk of X-linked adrenoleucodystrophy who showed a normal cultured chorionic villus cell very long chain fatty acid (VLCFA) profile but at birth exhibited grossly abnormal plasma and cultured fibroblast VLCFAs. Maternal contamination or a sample mix-up was excluded by chromosome analysis and analysis of polymorphic markers. This is the second report of a fetus affected with this disorder who showed normal cultured chorionic villus cell VLCFAs. It highlights the importance of a proper audit of all prenatal diagnoses to evaluate method reliability.     

Mechanisms of ultraviolet disinfection and chlorination of Escherichia coli: Culturability, membrane permeability, metabolism, and genetic damage

Traditional culture methods may underestimate the tolerance of microorganisms to disinfectants because of the existence of viable but nonculturable or sublethally injured cells after disinfection.The selection of a strict method is crucial for the evaluation of disinfection performance.The actions of 2 typical disinfectants–ultraviolet(UV)and chlorine–on the fecal indicator Escherichia coli were investigated by the detection of culturability,membrane permeability,metabolic activity,deoxyribonucleic acid(DNA),and messenger ribonucleic acid(m RNA).During UV disinfection,the irreversible damages in the cell membrane and cellular adenosine triphosphate(ATP)were negligible at low UV doses(80 m J/cm~2).However,membrane permeability was damaged at low doses of chlorine(5 mg/L),leading to leakage of cellular ATP.Our study showed that a slight lesion in DNA was detected even at high doses of UV(400 m J/cm~2)and chlorine(5 mg/L)treatments.The decay of m RNA was more rapid than that of DNA.The degradation level of m RNA depended on the choice of target genes.After exposure to 50 m J/cm~2UV dose or 5 mg/L chlorine for30 min,the DNA damage repair function(Rec A m RNA)was inhibited.The m RNA involved in the DNA damage repair function can be a potential indicator of bacterial viability.