[Synthesis of oligodeoxyribothymidylate derivatives containing alkylating groups and residues of biotin, for directed modification of chromatin]. / Sintez proizvodnogo oligodezoksiribotimidilata, soderzhashchego alkiliruiushchuiu gruppu i ostatok biotina, dlia napravlennoi modifikatsii khromatina.

An oligodeoxythymidylate derivative bearing an alkylating group at the 5'-end and biotin at the 3'-end (RCl-(pdT)16-bio) was synthesized. This reagent alkylates polyA-tracts of DNA in HeLa nuclei specifically via complementary complexes with single-stranded segments of DNA and by the preliminary treatment of chromatin with S1-nuclease, since the reaction is inhibited by an excess of the corresponding free oligothymidylate. The reagent will be used to study the distribution of local unwinded parts of polyA-repeats of DNA in human chromatin by the electron microscopy.

Analysis of atomospheric carcinogens and their cofactors.

Problems in the sampling and analysis of a variety of key air pollutants have been considered. The pollutants of primary interest were those with carcinogenic, mutagenic or cofactor activity. These include benzo[a]pyrene, polynuclear aromatic hydrocarbons, aldehydes, alkylating agents, amines, chloromethyl ethers, epoxides nitrosamines, nitrogen dioxide, nitrates, sulfate and sulfite. Screening tests of the analytical and bioassay types were also discussed; a large variety of these tests were summarized in tables. Concentrations of benzo[a]pyrene in urban atmospheres, in highly polluted atmospheres and effluents, and in a large variety of environment mixtures were reported.