Molecular cytogenetic characteristics of chromosome imbalance in cells of spontaneous human abortion fetuses with low proliferative activity in vitro

Karyotyping of noncultivated cells of 60 first-trimester spontaneous abortions (blighted ova and missed abortions) was carried out using fluorescence in situ hybridization (FISH) with centromere-specific DNA probes for all chromosomes of the karyotype. Conventional cytogenetic study of these abortions was impossible because of cell culture failures. The algorithm is proposed for molecular cytogenetic FISH analysis of interphase karyotypes. Chromosome abnormalities were found in 32 fetuses (53.3%). In groups of missed abortions and blighted ova, the frequency of numerical chromosome abnormalities was 50 and 60%, respectively. Both the numerical chromosome abnormalities typical of spontaneous human abortions (autosomal trisomies, sex chromosome aneuploidy, and polyploidy) and a relatively rare type of genomic imbalance unidentifiable by standard cytogenetic analysis (autosomal monosomies 7, 15, 21, and 22 in mosaic state) were observed. The frequency of these type of chromosome abnormalities comprised 19% of all known karyotype abnormalities determined in spontaneously perished embryos. Note that the level of confined placental mosaicism in embryos with low cell proliferative activity was 25%, which is substantially higher than the corresponding parameter (1-2%) determined by prenatal diagnosis of chromosome abnormalities in developing embryos. The results of interphase FISH analysis of cells with low proliferative activity in vitro suggest that the pathology of early fetal development and missed abortion in humans are associated with a wider spectrum of chromosome abnormalities.     

Lectin histochemistry for detecting cadmium-induced changes in the glycosylation pattern of rat placenta

Cadmium (Cd) is an industrial and environmental pollutant that produces toxic effects on gametogenesis, pre- and post-implantation embryos, and the placenta. Because the effects of acute Cd intoxication on the placenta are not well understood, we investigated changes in its glycosylated components in Cd treated dams at days 4, 7, 10 and 15 of gestation using lectin histochemistry. CdCl₂ was administered to pregnant rats; control animals received sterile normal saline. Placentas were processed for DBA, Con A, SBA, PNA, UEA-I, RCA-I and WGA lectin histochemistry to evaluate changes in the carbohydrate pattern of the placenta that might modify cell interactions and contribute to embryonic alterations. Lectin binding was analyzed in the yolk sac; trophoblast giant cells; trophoblast I, II and III; spongiotrophoblast cells and endovascular trophoblast cells in the chorioallantoic placenta. Our lectin binding patterns showed that Cd caused alteration of SBA and DBA labeling of trophoblast-derived cells, which suggested increased expressions of α and β GalNAc. Cd also caused decreased UEA-1 binding affinity, which indicated fewer α-L-Fuc residues in placentas of Cd treated dams. The nonreactivity in trophoblast I of the control placentas incubated with Con-A contrasted with the labeling in placentas of experimental dams, which indicated increased expression of terminal α-D-Man, and α-D-Glc residues. We found that Cd altered the reactivity of placenta to several lectins, which indicated modification of the glycotype presented by the fetal component of the placenta. We report that Cd exerts a deleterious effect on the glycosylation pattern of the placenta.     

Design of mutant variants of horse cytochrome <Emphasis Type="Italic">c</Emphasis> by analysis of informational structure method and testing its biological activity

Informational structure of cytochrome c was investigated using the ANIS method (Analysis of Informational Structure Method). Mutant variants of cytochrome c gene were constructed on the basis of data from the ANIS method. The mutations carry substitutions reducing electron-transport activity of cytochrome c in the mitochondrial respiratory chain. These mutant genes were obtained and expressed in the bacterial system. The biological activity of the obtained cytochrome c mutant variants interacting with complexes III and IV of the respiratory chain in the system of rat liver mitoplasts.