Trisomic 22 placenta in a case of severe intrauterine growth retardation

We describe a case in which a trisomic 22 placenta could be the cause of severe growth retardation in a chromosomally normal female fetus. At amniocentesis a mosaic 46,XX/ 47,XX, +22 was observed in amniotic fluid specimens sampled on two different occasions, while fetal blood from a diagnostic cordocentesis revealed a normal chromosome constitution. Postnatal studies showed the consistent presence of trisomic 22 cells in the placenta, while only normal metaphases were found in amnion, blood, and fibroblast cultures.     

Effects of Ca￣（2＋）ions antagonistic to Al￣（3＋）ions poisoning in root growth，cell division and nucleolus in root tip cells of Allium cepa

ＥｆｆｅｃｔｓｏｆＣａ￣（２＋）ｉｏｎｓａｎｔａｇｏｎｉｓｔｉｃｔｏＡｌ￣（３＋）ｉｏｎｓｐｏｉｓｏｎｉｎｇｉｎｒｏｏｔｇｒｏｗｔｈ，ｃｅｌｌｄｉｖｉｓｉｏｎａｎｄｎｕｃｌｅｏｌｕｓｉｎｒｏｏｔｔｉｐｃｅｌｌｓｏｆＡｌｌｉｕｍｃｅｐａＬｉｕＤｏｎｇｈ...     

Effects of Zn2+ on root growth,cell division, and nucleoli of Allium cepa L.

The effects of different concentrations of Zn²⁺ion on root growth,cell division,and nucleoli of Allium cepa were studied. The test Zn²⁺ ion concentration was made up from zinc sulphate (ZnSO₄. 7H₂O) ranging from 10^-7 to 10^-2 mol/L. The solutions were prepared in tap water (pH =6. 5).The results indicated that Zn²⁺ could obviously inhibit root growth at concentrations from 10^-4)to 10^-2 mol/L.Roots treated with zinc sulphate showed the presence of c-mitosis, anaphase bridges,including sticky and fluidized bridges (at 10^-3 to 10^-2 mol/L) , chromosome stickiness, irregularly shaped nuclei, broken nuclei and micronuclei. A toxicity effect was also observed on the nucleoli using silver staining technique after 48h of treatment with 10^-4to 10^-2 mol/L Zn²⁺, e. g,the nucleolar particulate material scattered around the nucleoli in the nucleus of root tip cells.     

Prenatal diagnosis of trisomy 9 mosaicism possibly limited to fetal membranes

In repeat amniotic fluid cultures mosaicism due to trisomy 9 was noted. Autopsy of the aborted female fetus showed a sinus urogenitalis and gonadal dysgenesis with absence of germ cells only. Fetal lymphocytes and skin fibroblasts had a normal karyotype but trisomy 9 was found in cells grown from placenta. It is likely that trisomic cells were limited to fetal membranes.     

Evaluation of prenatal diagnosis by a registry of congenital anomalies

Prenatal diagnosis performed by fetal karyotype and ultrasound scan is now a routine part of antenatal care in many countries. How many fetal anomalies are actually detected by these procedures? We have used our registry of congenital malformations to answer this question. In our region, prenatal diagnosis was performed in 23.1 per cent of fetuses with a chromosomal aberration and in 20.1 per cent of fetuses with non-chromosomal anomalies. Only 6.9 per cent of the pregnancies with fetuses with non-chromosomal anomalies were terminated. The sensitivity of prenatal diagnosis by ultrasonographic examination was much lower for isolated malformations (fetuses with only one anomaly) than for multiple malformed children, 15.3 and 48.3 per cent respectively, chromosomal anomalies excluded.     

对化学品登记要求的数据解释：皮肤致敏重复染毒及致变

本文对化学品登记所要求的部分健康效应数据——皮肤致敏、重复经口染毒、致变做了解释.涉及到的测试参数包括:皮肤致敏、重复(14/28天)经口啮动物毒性、基因突变、染色体畸变和DMA效应.     

Aneuploidy and cystic hygroma detectable by ultrasound

During one year, five second trimester fetuses with cystic hygromata and varying degrees of oedema presented to the authors from hospitals in the West of Scotland. Two fetuses had 45X karyotypes, one each had 47XY+21 and 47XX+18 karyotypes, and the fifth had a normal 46XY karyotype. Fetal oedema detectable by ultrasound, affecting particularly the back of the neck, may be a commoner manifestation of several aneuploid syndromes than has hitherto been recognized.     

Cytogenetic studies of chromium (III) oxide nanoparticles on Allium cepa root tip cells

The current study evaluates the cytogenetic effects of chromium (III) oxide nanoparticles on the root cells of Allium cepa. The root tip cells of A. cepa were treated with the aqueous dispersions of Cr₂O₃ nanoparticles (NPs) at five different concentrations (0.01, 0.1, 1, 10, and 100 μg/mL) for 4 hr. The colloidal stability of the nanoparticle suspensions during the exposure period were ascertained by particle size analyses. After 4 hr exposure to Cr₂O₃ NPs, a significant decrease in mitotic index (MI) from 35.56% (Control) to 35.26% (0.01 μg/mL), 34.64% (0.1 μg/mL), 32.73% (1 μg/mL), 29.6% (10 μg/mL) and 20.92% (100 μg/mL) was noted. The optical, fluorescence and confocal laser scanning microscopic analyses demonstrated specific chromosomal aberrations such as—chromosome stickiness, chromosome breaks, laggard chromosome, clumped chromosome, multipolar phases, nuclear notch, and nuclear bud at different exposure concentrations. The concentration-dependent internalization/bio-uptake of Cr₂O₃ NPs may have contributed to the enhanced production of anti oxidant enzyme, superoxide dismutase to counteract the oxidative stress, which in turn resulted in observed chromosomal aberrations and cytogenetic effects. These results suggest that A. cepa root tip assay can be successfully applied for evaluating environmental risk of Cr₂O₃ NPs over a wide range of concentrations.     

苯作业工人外周血淋巴细胞的细胞遗传学分析

选用外周血淋巴细胞染色体畸变（CA）率和微核细胞（MN）率两项指标对两个厂苯作业工人进行了研究分析,结果表明,在3种平均浓度54,108和219mg/m³,苯接触组和对照组比较CA率和MN率均有显著性差异,且未发现二者间有线性相关,提示二者形成机制不完全相同,且较低浓度下苯的遗传毒性应引起重视。