Chimerism and multiple numerical chromosome imbalances in a spontaneously aborted fetus

We report on a case of chimerism and multiple abnormalities of chromosomes 21, Xand Yin spontaneous abortion specimen. To the best our knowledge the present case is the first documented chimera in a spontaneously aborted fetus. The application of interphase fluorescence in situ hybridization (FISH) using chromosome enumeration and site-specific DNA probes showed trisomy X in 92 nuclei (23 %), tetrasomy X in 100 nuclei (25 %), pentasomy of chromosome X in 40 nuclei (10 %), XXY in 36 nuclei (9 %), XXXXXXYY in 12 nuclei (3 %), XXXXXYYYYY in 8 nuclei (2 %), trisomy 21 and female chromosome complement in 40 nuclei (10 %), normal female chromosome complement in 72 nuclei (18 %) out of 400 nuclei scored. Our experience indicates that the frequency of chimerism coupled with multiple chromosome abnormalities should be no less than 1 : 400 among spontaneous abortions. The difficulties of chimerism identification in fetal tissues are discussed.     

The synthesis of nucleic acids in cultivated <Emphasis Type="Italic">Polyscias filicifolia</Emphasis> cells exposed to oxidative stress

The content of nucleic acids in the cell culture of fern-leaf aralia Polyscias filicifolia (Moore ex Fournter) Bailey (Araliaceae) exposed to heat shock (3 h at 45°C) decreased significantly (by 20–30%). The decrease in DNA and RNA contents was even larger (30–40%) after longer heat shock (24 h). Cold (24 h at 7°C) caused an even more dramatic decrease in DNA (by 34.2%) and total RNA (by 48%) contents. To judge from the DNA production rate, the presence of hydrogen peroxide and phenazine methosulfate in the culture exerted a dose-dependent and differently directed action on cell proliferation.     

Abnormal condensation of meiotic chromosomes caused by the mei8 mutation in rye Secale cereale L

Inheritance of two spontaneous meiosis-specific mutations with similar cytologic phenotype was studied. Both mutations were independently obtained from two rye populations (Vyatka variety and weedy rye). Both mutations are recessive, allelic, and monogenically inherited; the corresponding gene is designated mei8. The mutant alleles of the gene cause abnormal meiotic chromosome structure expressed as irregular compaction along the chromosome length, chromatin stickiness at all stages of meiosis, and chromosome fragmentation in anaphase I.     

Effect of ambiol and 2-chloroethylphosphonic acid on the content of phytohormones in potato leaves and tubers

The effects of the antioxidant Ambiol and 2-chlorethylphosphonic acid (2-CEPA) on individual concentrations and concentration ratios of phytohormones, photosynthesis and photophosphorylation rates, sucrose and starch content in tubers, and plant productivity were studied in potato (Solanum tuberosum L). Ambiol increased the ratio of indoleacetic acid (IAA) to abscisic acid (ABA), IAA/ABA, and that of zeatin (Z) and zeatin riboside (ZR) to ABA, (Z + ZR)/ABA. These effects were underlain by an increase in the content of auxins and cytokinins and a decrease in ABA. Unlike Ambiol, 2-CEPA increased the level of ABA, the effect being the most pronounced in the tubers. Ambiol increased the rates of photosynthesis and noncyclic photophosphorylation in chloroplasts isolated from potato leaves. The relation of this phenomenon to auxin and cytokinin accumulation, Ambiol- and 2-CEPA-induced changes in the hormonal balance of potato tubers, carbon metabolism, and plant productivity is discussed.     

Influence of a natural and a synthetic inhibitor of factor XIIIa on fibrin clot rheology

We investigated the origins of greater clot rigidity associated with FXIIIa-dependent cross-linking. Fibrin clots were examined in which cross-linking was controlled through the use of two inhibitors: a highly specific active-center-directed synthetic inhibitor of FXIIIa, 1,3-dimethyl-4,5-diphenyl-2[2(oxopropyl)thio]imidazolium trifluoromethylsulfonate, and a patient-derived immunoglobulin directed mainly against the thrombin-activated catalytic A subunits of thrombin-activated FXIII. Cross-linked fibrin chains were identified and quantified by one- and two-dimensional gel electrophoresis and immunostaining with antibodies specific for the alpha- and gamma-chains of fibrin. Gamma-dimers, gamma-multimers, alpha(n)-polymers, and alpha(p)gamma(q)-hybrids were detected. The synthetic inhibitor was highly effective in preventing the production of all cross-linked species. In contrast, the autoimmune antibody of the patient caused primarily an inhibition of alpha-chain cross-linking. Clot rigidities (storage moduli, G') were measured with a cone and plate rheometer and correlated with the distributions of the various cross-linked species found in the clots. Our findings indicate that the FXIIIa-induced dimeric cross-linking of gamma-chains by itself is not sufficient to stiffen the fibrin networks. Instead, the augmentation of clot rigidity was more strongly correlated with the formation of gamma-multimers, alpha(n)-polymers, and alpha(p)gamma(q)-hybrid cross-links. A mechanism is proposed to explain how these cross-linked species may enhance clot rigidity.     

Expression of the sonic hedgehog gene in human embryos with neural tube defects

BACKGROUND: To estimate the rate of malformations observed during early human development, a series of 38,913 first-trimester abortions were studied. Neural tube defects (NTD) were found in 57 cases. METHODS: A histological study of serial sections performed in 25 embryos revealed a spectrum of axial structure abnormalities. Expression of the SHH gene was studied by in situ hybridization in one case of CRS and in two cases of SB. RESULTS: A cervical notochord duplication was always found in craniorachischisis (CRS, n = 8), but not in spina bifida (SB, n = 10) or diplomyelia (split cord malformation, n = 3). In the embryo with CRS, expression of SHH was found in both domains, corresponding to the duplicated part of the notochord, whereas a single signal was observed in the nonduplicated part. This expression was associated at the cervical level of the open neural tube with a broad SHH expression domain and with two or even three domains in its lumbar region, suggesting multiple functional floor plates. Similarly, in two embryos with SB, two domains of SHH expression were found in the ventral neural tube. CONCLUSIONS: Our findings suggest that notochord splitting in the cervical region might be involved in the pathogenesis of CRS. Interestingly, similar notochord abnormality and altered expression of the shh gene are observed in Lp mice with NTD. This suggests that the Lp gene could be a candidate gene for human CRS. Further studies are needed to establish the primary event responsible for the notochord splitting and for the abnormal expression of the SHH gene in the floor plate in embryos with CRS and SB.     

Genetic analysis of mutation sy2 which causes nonhomologous meiotic synapsis in chromosomes of diploid rye Secale cereale L

Partially nonhomologous (heterologous) synapsis of meiotic chromosomes in a spontaneous desynaptic mutant form of rye is determined by two recessive genes, sy2a and sy2b, that have independent expression and inheritance. The third gene, dominant inhibitor suppressing the mutant phenotype, has been revealed in hybrid combinations between sy2 mutants and lines segregating other meiotic mutants: sy10 (heterologous synapsis), sy1, and sy9 (asynapsis). All three genes determining desynapsis (sy2a, sy2b, and I) were shown to be nonallelic to monogenic mutations sy10, sy1, and sy9, inherited independently of them and expressed at later stages of prophase I than the sy10 gene. The possibility of modifying monogenic segregation of mutation sy2 by gametophyte selection for a locus linked to the gene expressed as sy2 at particular frequencies of recombination between this gene and selected locus is discussed.     

Ultrasound study in the diagnosis of colon obstruction

The authors present the results of their investigations into the use of routine transabdominal sonography and ultrasound irrigoscopy in the diagnosis of acute colon obstruction in 70 patients. In 55 patients, the cause of this pathology was tumor-induced obturation of colon lumen and in 15 cases, the pathology resulted from colon evacuation dysfunction due to congenital abnormalities, acquired stenosis due to inflammatory diseases. Ultrasound irrigoscopy was first applied to determine the presence and degree of colon obstruction and to establish its causes. The procedure and semiotics of ultrasound irrigoscopy and routine transabdominal sonography for this abnormality have been developed and are described in detail. Analysis of the findings has demonstrated that ultrasound irrigoscopy used in the diagnosis of acute colon obstruction is on a par with X-ray irrigoscopy in its informative value and may be widely employed in the used arsenal of diagnostic techniques.     

Changes in the protein spectrum of human kidney anlagen

Extracts of metanephros were studied using two-dimensional electrophoresis in human embryos at the age of 7 to 21 week of intrauterine development. Electrophoregrams show 160 to 190 protein fractions. Fractions have been identified which corresponded to actin, albumin, alpha-chain of tropomyosin, light chains of myosin. The tropomyosin zone fractions were subject to greatest changes during development. Other zones of the embryonic kidney electrophoretogram displayed, predominantly, quantitative changes of polypeptides.     

Effect of glucagon and hydrocortisone on aldolase turnover in the rat liver after total x-irradiation

A study was made of the effect of glucagon and hydrocortisone on aldolase metabolism in rat liver after total-body X-irradiation. The hormonal regulation of the enzyme metabolism in the exposed rats was shown to vary from that of intact animals.