Comparative immunochemical analysis of specific beta globulins of the "pregnancy zone" of the humans and other mammals]

By means of the immunodiffusion method it was shown that human pregnancy-specific beta-globulin, as well as analogous beta-globulins in the pregnancy serum of mammal animals (rat, guinea-pig) had an individual antigenic structure. During pregnancy the blood serum of the allied species (rat, mouse) contained immunologically similar beta-globulins which apparently were synthesized in the placenta.     

Immunochemical identification and physico-chemical characteristics of specific alpha 2 globulin of human granulocytes]

The antigen which has alpha 2-globulin mobility was identified immunochemically in leukolysate and pus extract. This antigen was localized in polymorphonuclear leukocytes by the immunofluorescence technique in the blood of healthy donors. The alpha 2-globulin of granulocytes (alpha 2GG) is not identical to lactoferrin, lysozyme, granulocyte elastase, fibronectin, fetal hemoglobin, amyloid P-component of the serum. The molecular mass of alpha 2GG is equal to 50 +/- 8 Kd. in the pus extract. The biological role of alpha 2GG is unknown.     

A comparative analysis of the biological activity of an acid-extractable brain protein and fibroblast growth factors]

An acid-soluble protein was isolated from bovine brain tissue using a combination of 5% HClO4 acidic extraction, cation-exchange chromatography and heparin-Sepharose affinity chromatography. This preparation had a biological activity similar to that of the fibroblast growth factor (FGF). It has stimulated neurite outgrowth in organotypic culture of chicken embryo dorsal root ganglia and also has stimulated a proliferation of human embryonic fibroblasts in the culture. The biological activity of isolated preparation was totally inhibited by anti-bFGF antibodies, while anti-aFGF antibodies had no effect. The bFGF showed a neurite stimulating activity in the organotypic culture that was completely abolished by the anti-bFGF, IgG, while the aFGF was inactive. This data, as well as cationic properties of isolated protein and its heparin-binding ability, enable us to postulate a high degree of homology of the brain acid-soluble protein and the bFGF. At the same time the relations of the isolated growth factor and other brain-derived heparin-binding growth factors are yet to be established.     

Fusion of protoplasts in Streptomyces antibioticus

The analysis of Streptomyces antibioticus recombinants isolated under non-selective conditions for stability of inheritance of parental properties demonstrated the existence of non-stable diploids and stable haploid recombinants. Also, genetic analysis of heteroclones isolated on selective medium after plating spores of regenerants was conducted. The results of analysis of haploid recombinant and heteroclones pointed to linkage of genetic loci and the possibility to use the technique of protoplast fusion for establishment of genetic map of S. antibioticus.     

Repair of radiation induced DNA damages in unicellular green algae

Two cell repair systems--photoreactivation and repair of single-strand DNA breaks have been studied using unicellular green algae as a test-system. Effects of the genotype and the intensity of pico/second UV-laser irradiation on the degree of the photoreactivation have been investigated. It has been shown that the lower intensity (I = 8.10(6) W/cm2) effects less the inactivation of living cells comparing with I = 30.10(6) W/cm2, regardless of the genotype. The clearly expressed higher potentials of strains LARG-1 and 260 to produce and repair alterations of the cyclobutane-pyrimidine dimers type have been established. An analysis of DNA degradation during gamma rays irradiation and after incubation has been carried out for investigation the relationship between strains radioresistance and repair of single-strand break. It has been shown that high efficiency of the repair system is characteristic of the resistant strain obtained from chronically irradiated population.     

Structural changes of chromatin during proto-oncogene activation by cycloheximide: dose-effect]

The level of expression of cellular proto-oncogens c-myc and c-fos in rat liver has been studied as a function of protein synthesis rate (cycloheximide dose). Activation of proto-oncogens has been established to be initiated by 50% inhibition of nuclear protein synthesis. This promotes a certain level in chromatin structural rearrangements which is manifested, in particular, in decreasing activity of chromatin cleavage by Ca2+, Mg(2+)-DNAase and increasing degree of chromatin condensation. A role of topoisomerase II in chromatin structural rearrangements during proto-oncogen activation is postulated.