Substrate specificity of the biotransformation enzymes in a Nocardia erythropolis culture

Substrate specificity of biotransformation enzymes of culture Nocardia erythropolis was studied. Products of transformation of cholesterol and three sterols of microbial origin: ergosterol, ergosta-5,7-dien-3 beta-ol and ergosta-7,22-dien-3 beta-ol was identified with a help of thin-layer chromatography, UV spectrophotometry and mass-spectrometry. It was established, that delta 22-bond in the side chains of sterols and delta 7-bond slows and delta 5-bond makes impossible cleavage of side chains of sterols.     

The brain phospholipids following the irradiation of animals at a high dosage

In experiments with albino mice, rats and guinea pigs the effect of ionizing radiation (100 Gy) on brain phospholipids and their fatty acids has been investigated. Upon the development of manifest behavioural disturbances (2 h after irradiation) phospholipid molecules degrade insignificantly. Some changes in the relative content of phospholipids and their fatty acids are mainly found in the rat synaptosomal fraction: this may be responsible for the disturbances in the sensitivity of the receptor apparatus of cell membranes.     

A cytogenetic study of the human chorion for the purpose of the prenatal diagnosis of hereditary diseases

Cytogenetical investigation of 50 diagnostic chorionic villus samples from women with a high risk of giving birth to babies with chromosomal and genic pathology, and of 128 chorionic samples obtained from medical abortions, both on the 8-12th weeks of gestation was performed by means of original direct chromosomal analysis. Chromosomal anomalies were found in 6 cases of diagnostic chorion biopsies (12%) and in 4 cases (3%) of medical abortions. The former group included 5 embryos with autosomal trisomy (4--Ts21 and 1--Ts13) and one embryo with monosomy 18. The latter group contained 2 embryos with X-chromosome monosomy and 2 other with chromosomal mosaicism. A significant prevalence of the female sex was found in the diagnostic group (sex ratio 0.56), but not in the medical abortion one (sex ratio 1.0). Analysis of routine chromosomal preparations and those after in situ hybridization with X-chromosome alfoid-probe YAP 1-10 revealed polyploidy in average in 0.8-1% chorion cells. The feasible causes of sex ratio distortion in embryos of diagnostic group and factors responsible for the rate of polyploidy are discussed. High reliability of originally elaborated direct "shaking-blotting" method of chromosomal preparations from chorionic villus samples is stressed.     

Combined chemotherapy of experimental infection in neutropenia

A significant decrease in resistance to infections caused by gramnegative pathogens was observed in mice with neutropenia induced by cytostatics. Efficacy of schemes for combined chemotherapy with beta-lactams, aminoglycosides and a novel peptide antibiotic was studied on model infections in mice with neutropenia. In the neutropenic mice with sepsis caused by Pseudomonas the peptide antibiotic administered parenterally in a single dose of 50 micrograms/kg provided high therapeutic activity. In combination with azlocillin, cefotaxime and amikacin the peptide antibiotic has a synergistic therapeutic action.     

Electron microscopic study of the differentiation of decidual cells. I. The ultrastructure of large decidual cells in the antimesometrial portion of the rat decidua

The large decidual cells (LDC) of the antimesometrial part of decidua in rats of 7-9 days of gestation were studied by electron microscope. The decidual tissue has an epithelium-like pattern of organization. The apical surface of LDC is facing the pericapillar space making numerous villi. Lateral surfaces of these cells maintain close contact with each other by means of zona adhaerens, gap junctions, spot desmosomes and simple junctions. Accumulation of electron dense granules measuring from 0.05 to 0.3 mkm is seen in the apical parts of LDC. The Golgi complex and rough endoplasmic reticulum are much developed. The material of rough endoplasmic reticulum is denser than the cell matrix. Disperse chromatin is seen in the nucleus, whereas the granular component is dominanting in the nucleolus. It is concluded that the LDC may have a high metabolic activity, and that the secretion is a mode of fulfilling specific functions of LDC.     

Experimental and biochemical aspects of crystalline lens induction during embryogenesis]

The lens induction is a two-step process and involves morphogenetic influences from the archencepalic endoderm and optic vesicle. One can suggest that the lens induction is primed by specific proteins which are synthesized and secreted by the optic vesicle cells. The proteins-inductors appear to penetrate in the cells and, while interacting (directly or via the cytoplasm) with the nuclei, "programme" the ectodermal cells towards the lens differentiation. The contact interactions and extracellular matrix are of substantial, but not crucial value for the lens induction. The synthesis of specific proteins (crystallins) is to be considered as the most objective criterion of lens differentiation. In vertebrates, there is a lag-period between the moment of lens induction and synthesis of crystallins which is the most long-term in amphibians. The chick embryos constitute an exception and the synthesis of crystallin mRNA occurs in them a few hours after the lens induction. The developing retina loses its capacity to induce lens but stimulates the processes of fiber formation and synthesis of crystallins. A factor was found in the definitive lens epithelium which may be considered as a possible regulator of lens differentiation. On the basis of experiments with heterogenous and native lens inductors, a suggestion is put forward to the effect that the activity of inducing substances is determined by a definite determinant group of the molecule, rather than by the whole molecule.     

Effect of amphotericin B on the energy metabolism of tissue forms of Candida albicans]

Dehydrogenase activity of the tissue form cells of C. albicans during the infection process in albino mice with and without amphotericin B treatment was studied. The strength of the metabolic reactions resulting in accumulation of ATP was evident from the activity of 4 main enzymes, i.e. succinate dehydrogenase, lactate dehydrogenase, alcohol dehydrogenase and glucose-6-phosphate dehydrogenase. The enzymatic activity was determined by the tetrasol method based on formation of diphormazan. Investigation of the fungal cells 10 minutes after the infection showed that preliminary intravenous or intraperitoneal administration of amphotericin B did not change the activity of the tissue forms. The cytochemical characteristics of the fungal cells remained the same as that in the untreated animals. Six hours after infection of the animals treated with amphotericin B administered intravenously the fungus vegetation decreased from 52 to 38 per cent, while in the animals treated with amphotericin B administered intraperitoneally it was suppressed completely. Simultaneously the energy metabolism was also suppressed, the activity of alcohol dehydrogenase being suppressed most significantly. The activity of this enzyme in the cells of C. albicans isolated from the animals treated with the antibiotic administered intraperitoneally was 14 times lower than that in the cells of the culture isolated from the control animals.     

Karyological study of the continuous cell lines. Comparative analysis of the Hela and Detroit-6 cell lines]

Comparison of the results of the karyologic analysis of two Hela cell sublines (HeLa1 and HeLa2), obtained from different sources, and of Detroit-6 cell line has shown that all the lines contain marker chromosomes characteristic of the HeLa cell line. Detroit-6 cell line marker chromosomes are similar to markers of the HeLa subline (HeLa1). At the same time, part of marker chromosomes in the two sublines of HeLa cell line (HeLa1 and HeLa2) are different. These data show that HeLa1 and Detroit-6 cell lines are more similar than two sublines of the same HeLa cell line.