二噁英的毒性与防治

分析了二英的化学结构与毒性的关系，二英的来源，对人体健康的潜在危害以及可能造成的环境污染，提出了防治措施。     

Renatal diagnosis of mosaic tetrasomy 12p/trisomy 12p by fluorescent in situ hybridization in amniotic fluid cells: A case report of pallister–killian syndrome

A prenatally detected case of a rare mosaic tetrasomy 12p/trisomy 12p is reported, presenting as the well-known accessory isochromosome 12p and a supernumerary single 12p marker in 17/24 and 6/24 clones of cultured amniotic fluid cells, respectively. The chromosomal nature of both marker chromosomes was investigated in cultured amniotic fluid cells by fluorescent in situ hybridization with various probes: the 12-centromeric probes pa12H8 and D12Z3, a whole chromosome 12 paint, and the chromosome 12p-specific paint M28. DNA analysis revealed a maternal origin of the extra 12p material. After counselling, the parents requested termination of pregnancy. Inspection and autopsy of the fetus revealed many of the dysmorphisms and internal structural abnormalities of the Pallister–Killian syndrome.     

基于原代培养背角无齿蚌鳃细胞的镉毒性效应评价

为了探究淡水贝类背角无齿蚌鳃细胞的原代培养途径，并阐释其在评价水体Cd²⁺毒性效应上的潜力，本研究比较了不同酶分解方法（链霉蛋白酶、胰蛋白酶）的鳃细胞存活率差异，并分析了L-15培养基中不同血清浓度（10% FBS、20% FBS）对鳃细胞存活率的影响，细胞置于20℃生化培养箱中培养.进而根据Cd²⁺对鳃细胞的LC₂₅值设定0.0625、0.125、0.25、0.5和1.0 mg·L^-1 5个Cd²⁺理论浓度梯度，对原代培养的鳃细胞进行24 h暴露，分析了细胞活力、总超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和酸性磷酸酶（AcP）的变化特征.结果表明：0.025%链霉蛋白酶在4℃分解16 h的鳃细胞存活率为98.2%±0.2%，显著高于0.25%胰蛋白酶在26℃分解30 min的89.4%±3.5%鳃细胞存活率（p<0.05）；L15培养基加入10% FBS的细胞存活率总体显著高于添加20% FBS的细胞存活率（p<0.05）.在上述较佳的分解和血清浓度组合条件下，细胞培养120 h后，其存活率仍高达90.1%±4.7%.鳃细胞活力随着Cd²⁺浓度的增加而降低，两者之间呈显著的线性负相关（p<0.05）；随着Cd²⁺浓度的增加，SOD和AcP含量总体增加，而CAT含量呈现出"诱导-抑制"的变化趋势.本研究初步建立了较为适宜的背角无齿蚌鳃细胞的原代培养方法，并揭示了其原代培养鳃细胞的细胞活力及SOD、CAT、AcP水平，具有作为评价水环境Cd²⁺毒性/污染的生物指标的潜力.     

Assay of some volatile compounds in human exhalation

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Detection of low-grade mosaicism in fetal cells isolated from maternal blood

Recovering and analysing fetal erythrocytes from maternal blood is being pursued for non-invasive prenatal genetic diagnosis. We report the observation of 46, XY/47, XXY mosaicism in fetal cells from a woman whose first-trimester chorionic villus sampling (CVS) initially showed only 46, XY. Only after exhaustive (500 cells) analysis were four XXY cells found in cultured villi.     

Extraction of DNA from amniotic fluid cells for the early prenatal diagnosis of genetic disease

Ten-ml samples of amniotic fluid were taken from pregnancies being terminated at 8–14 weeks' gestation. DNA was extracted from the amniotic cells by sequential centrifugation and analysed using the polymerase chain reaction (PCR). Fifteen samples were analysed for evidence of maternal contamination using Mfd5 oligo-nucleotide primers for repeat polymorphisms. Ten amniotic fluid samples were tested for the Delta-F₅₀₈ deletion characteristic of cystic fibrosis to demonstrate a diagnostic application for the technique. In each case, DNA extracted from fetal tissue from the same pregnancy was included in the controls. In 14 of the 15 cases tested with the Mfd5 primers, both the amniotic fluid DNA and the fetal DNA showed no evidence of contaminating DNA. In one case, neither the amniotic fluid cells nor the fetal cells yielded results. In nine of the ten cases tested with the Delta-F₅₀₈ primers, the amniotic fluid cell DNA provided accurate information about the genetic status of the fetus; in the tenth, the fetal DNA failed to amplify. The results indicate that adequate DNA can be extracted from amniotic fluid from 8 weeks' gestation onward and these samples are suitable for prenatal diagnosis using PCR.     

Flow sorting of fetal erythroblasts using intracytoplasmic anti-fetal haemoglobin: Preliminary observations on maternal samples

Monoclonal antibody to fetal haemoglobin (a₂γy₂) has been proposed as a fetal-specific reagent. We developed an intracellular staining protocol that combines fluorescein isothiocyanate or phycoerythrin conjugated anti-γ with the DNA binding dye Hoechst 33342 to identify and flow sort fetal erythroblasts from maternal blood. Our preliminary observations on anti-γ-positive cells sorted from four different pregnant women are described here, using fluorescence in situ hybridization (FISH) with chromosome-specific probes to identify fetal cells. Our data demonstrate that far fewer candidate fetal cells are sorted with this protocol than by current cell surface staining methods that employ the monoclonal antibody CD71. This results in increased fetal cell sorting purities. With this protocol, standard FISH techniques require modification due to the rigorous fixation with 4 per cent paraformaldehyde. Our initial data indicate the promise of this approach.     

Immediate prenatal diagnosis of Zellweger syndrome by direct measurement of very long chain fatty acids in chorionic villus cells

We report a gas chromatographic-mass spectrometric method which allows the very long chain fatty acids content of trophoblastic tissue to be directly measured in samples collected by biopsy between 8 and 11 weeks of gestation. This method has been successfully applied to the detection of fetal Zellweger syndrome in two pregnant women who had previously delivered affected infants. In one of them, increased concentrations of C26:0 (0.254 versus 0.108±0.035 μ/mg proteins) and C24:0 (1.32 versus 0.815±0.325 μ/mg proteins) in trophoblast indicated that the fetus had Zellweger syndrome, a diagnosis confirmed by pathological findings after abortion. In the second case, the pregnancy was allowed to proceed, on the basis of normal concentrations of very long chain fatty acids in trophoblastic tissue, and its outcome was actually a healthy newborn.     

极低频电磁场对健康影响的流行病学调查及人体测试研究进展

流行病学调查结果表明，环境的极低频电磁场暴露与人群某些肿瘤，如白血病、乳腺癌、脑肿瘤等，以及生殖、神经、心血管和内分泌等系统疾患的发病相关，这些结果在一定程度上得到实验室人体测试的支持。然而，极低频电磁场对健康影响的确切效应，迄今尚未能作出结论，亟等进一步开展多层次、多水平的研究。