[Experience in the search of new prolonged-action radiation-protective agents]. / Opyt izyskaniia novykh radiozashchitnykh veshchestv prolongirovannogo deistviia.

The cysteamine derivative-guanidinoethanesulfanylthiosulfuric acid was demonstrated to have radioprotective properties protecting mice against X-rays and fission neutron irradiation hazard. Radioprotective efficacy shows itself for 2 hours after i.p. and p.o. administration of the preparation. It was established an opportunity of the prolonged protective action of gammaphos as a result of its cross-linking to dextran. The preparation has a radioprotective action on X-ray and neutron irradiation.

[The effect of phenol derivatives on the antimutagenic activity of dextran]. / Vliianie proizvodnykh fenola na antimutagennuiu aktivnost' dekstrana.

The effects of dextran + hydrazine or amino derivative of dibunol and of dextran + cystafos derivatives with different degree of modification of their molecules on the mutagenic activity of gamma irradiation were studied using the micronucleus test in polychromatophilic erythrocytes of the mouse bone marrow. The effects of these compounds on differentiation of the erythroid series has also been studied. The mutagenic activity of gamma irradiation was most markedly inhibited by the copolymer dextran and the amino derivative dibunol. The optimal structure of copolymers was 1 heterocyclic link per 3 non-oxidized links of dextran, while the increasing number of active links in the dextran molecule insignificantly enhanced its antimutagenic effect. The studied compounds effectively protected erythropoiesis.

[Antimutagenic activity of dextran gammaphos derivatives]. / Antimutagennaia aktivnost' dekstranovykh proizvodnykh gammafosa.

In experiments with V-79 Chinese hamster cell culture the influence of dextran gammaphos derivatives on the mutagenic effects of gamma-radiation was studied by the number of cells with micronuclei and fragmented nuclei. Products of interaction between gammaphos and dialdehyde dextran were shown to have a higher antimutagenic activity than gammaphos.

[The antimutagenic activity of compounds of modified polyglucin]. / Antimutagennaia aktivnost' soedinenii modifitsirovannogo poligliukina.

The effect of modified polygluquin compounds on gamma-irradiated nuclei of V-79 Chinese hamster cells has been studied. Antimutagenic properties of the compounds are determined by aldehyde groups and oxidized chains.

[Isolation and characteristics of endonuclease tightly bound to alpha-polymerase from the rat liver]. / Vydelenie i kharakteristika éndonukleazy, zhestko sviazannoi s alpha-polimerazoi pecheni krysy.

Three major polypeptides are found in purified DNA polymerase alpha from rat liver: 160, 77 and 58 kDa. The electrophoretic analysis has identified polypeptide 160 kDa as the catalytically active subunit of DNA polymerase alpha. The other two polypeptides showed no DNA polymerase activity. Individual polypeptide p77 kDa purified by sodium dodecyl sulfate polyacrylamide gel electrophoresis was used to produce antibodies in rabbits. Immunoblot analysis indicated that the complex DNA polymerase alpha-3'-5'-exonuclease contained polypeptide p77 kDa. To elucidate the function of the p77 kDa protein we have prepared an immunoabsorbent column with antibodies against the p77 kDa polypeptide. The antibody column purified p77 kDa protein was homogeneous according to sodium dodecyl sulfate gel electrophoresis. The activity of alpha-polymerase was increased approximately 10-fold as a result of purification of DNA polymerase alpha from the p77 kDa protein. The in vitro experiments showed the identity of the p77 kDa polypeptide to endonuclease. It cleaved both single-stranded and double-stranded DNA. The function of endonuclease p77 kDA in complex with DNA polymerase alpha remains obscure.