[Cultivation of cells on a surface covered by microspheres with coupled histones].

The use of histones for modification of the surface intended for cultivation of cells was studied. The work was carried out on the cell line 293 of human embryonic kidney transformed by adenovirus (Ad5) and on the cell line BALB/3T3 clone A31 of mouse spontaneous transformed embryonic fibroblasts. We analyzed interaction of cells with histones of different types put on a hydrophobic surface or on dextran microspheres with diameters of 1.0 microm. It was shown, that all histones studied possessed adhesive ability, but their complexes consisting of total and core histones rendered the best influence on adhesion, morphology and growth of the cells in culture. Thus, cross-linked conjugates of histones immobilized on microspheres promoted in a greater degree formation of a network of cellular structures due to formation of intracellular contacts and simultaneous interaction of cells with several microspheres. Comparing with BALB/3T3 clone A31 the cell line 293 showed significant increase in proliferative activity in 11 days of cultivation on microspheres covered with cross-linked conjugates of histones. Our investigations have shown that the microspheres covered with cross-linked conjugates of histones can be used in the further at creation of the three-dimensional porous matrices intended for in vitro formation of tissue-like cellular structures in them.

[Production and some properties of covalent conjugates of total histone and kanamycin]. / Poluchenie i nekotorye sovistva kovalentnykh kon''iugatov summarnogo gistona s kanamitsinom.

A complex containing total histone and antibiotic kanamycin was produced under optimal conditions using glutaric aldehyde. The obtained water-soluble covalently bound conjugates of these substances were identified by means of enzyme labelled immunoassay and their molecular mass estimated. The validity of new class of highly effective drugs, which may be produced basing on the principles studied, was substantiated considering that histones exhibit the transport properties and are able to augment hematoencephalic barrier permeability.

[Changes in the hemato-encephalic barrier in experimental liver cirrhosis]. / Izmeneniia gematoéntsefalicheskogo bar'era pri éksperimental'nom tsirroze pecheni.

Experiments on 30 Wistar female rats with tetrachloromethane-induced cirrhosis of the liver revealed structural changes in the hematoencephalic barrier presenting as peri- and endocapillary changes and changes in vascular peduncles of astrocytes shown by light and electron microscopy. Hematoencephalic barrier destabilization is conducive to penetration of cerebrotoxins and other metabolic toxins, this explaining the development of hepatic encephalopathy.

[Effect of cAMP modifiers on the cytotoxic activity of macrophages]. / Izuchenie vliianiia modifikatorov cAMP na tsitotoksicheskuiu aktivnost' makrofagov.

The effects of various cAMP modifiers on the changes in the intracellular cAMP level and on the coupling of the cAMP system with realization of macrophage cytotoxicity depending on their functional activity were studied. Nonactivated and activated by E. coli polysaccharides peritoneal macrophages of BALB/c mice and macrophage-like cells of J744 mice were incubated in the presence of cAMP modifiers and further assayed for cytolytic and cytostatic activities. Cells of tetraploid strain of Ehrlich carcinoma G10 were used as target cells. Among other modifiers only dibutyryl-cAMP caused a steady increase of the intracellular nucleotide content, whereas methylisobutylxanthine and isoproterenol in combination with methylisobutylxanthine caused only a temporary increase of the cAMP level. Isoproterenol did not induce any appreciable changes in the intracellular cAMP level. All modifiers under study suppressed the cytotoxic activity of macrophages irrespective of the nature of changes in the intracellular cAMP content. It was assumed that cAMP accomplishes a triggering function in the regulation of the cytotoxic activity of macrophages and that the cAMP system is universal in the regulation of cytotoxicity at various functional states of macrophages.

[Proteinase activity of nuclei from various tissues towards endogenous histones]. / Proteinaznaia aktivnost' iader razlichnykh tkanei v otnoshenii endogennykh gistonov.

The proteinase activities of nuclei isolated from tissues differing in their mitotic activities (brain, thymus, liver, ascite lymphoma) towards the histones and non-histone acid -- extractable proteins were studied. The sensitivity of different histone fractions to nuclear proteinase depends on temperature and time of nuclei incubation under conditions providing for complete dissociation of chromatin proteins from DNA (2 M NaCl--5 M urea). The proteinase activity in the brain and thymus nuclei is revealed only under prolonged (43 hrs) incubation of the nuclei at 25 degrees C, which is accompanied by partial proteolysis of histone H1. Histone H4 from brain nuclei and histone H2a from thymus nuclei are preferably degraded. In the nuclei isolated from the mice ascite cell lymphoma NK/ly and from rat liver the enzyme activity is revealed mainly towards the arginine-enriched histones H3 and H4. The proteolysis of the arginine-enriched histones in tumour cell nuclei is more complete. A high sensitivity to proteolysis was observed for non-histone acid-extractable proteins with low electrophoretic mobility, which were found in brain and tumour cell nuclei.

[Antigenic properties of a preparation of total calf thymus histone]. / Nekotorye antigennye svoistva preparata total'nogo gistona timusa telenka.

Repeated intravenous injection of total histone of calf thymus preparation led to sensitization of experimental animals accompanied by formation of complement fixing antibodies. Sera examination by the complement fixation test demonstrated antigenicity of the total histone preparation protein components to decrease in the following order: nonhistone proteins admixture greater than histone fraction HI greater than mixture of histone fractions H3 : H2b : H2a (1 : 1 : 1). The presence in the total histone preparation of nonhistone protein admixture chiefly conditioned the immunogenic, and possibly, the allergenic activity of the preparation.

[Isolation of cationic proteins from rabbit thrombocytes and study of their bacteriostatic activity]. / Vydelenie kationnykh belkov iz trombotsitov krovi krolikov i izuchenie ikh bakteriostaticheskoi aktivnosti.

Cation-containing proteins, which possessed the bacteriostatic activity against Grampositive microorganism Bacillus subtilis SHGW, were isolated from rabbit thrombocytes by means of selective extraction. These substances were of heterogenous nature (as shown by polyacrylamide gel disc electrophoresis), including two groups of proteins with molecular weight about 8=10-10(3) and 20=30-10(3) daltons. The bacteriostatic activity of each group of these proteins was studied after gel filtration of the total preparation on Sephadex G=75. The group of proteins with molecular weight 8=10-10(3) daltons was responsible for bacteriostatic activity of the total cation-containing protein from thrombocytes.