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The article presents the results of a study of the effectiveness of wheat flour containing selenium in organic form. The organic form of trace element was achieved by transformation of selenium in selenium-methionine (Se-Met) at germination of wheat grains, moistened with a solution of sodium selenite. To determine the effectiveness of selenium- containing supplements experimental investigations were carried out on Long white rats with initial body weight 50 ± 2 g. The duration of the experiment was 30 days. The research model included four groups of animals: control group--animals were fed a complete vivarium diet; group 1--a model of selenium deficiency, which was achieved by feeding selenium-deficient food (grain growh in the Chita region of the Trans-Baikal Territory Zabaikalsky Krai); group 2--animals were administered selenium supplement in the form of enriched flour (0.025 µg Se per 50 g body weight of the animal) on the background of selenium-deficient diet; group 3--animals were treated with a high dose of selenium in the form of a solution of sodium selenite intragastrically through a tube (0.15 µg Se per 50 g body weight). Selenium-containing additive on the background of selenium-deficient diet had a positive impact on the appearance and behavior of animals, the body weight gain per head after 10 days in group 2 amounted to 47.9 g that was 4 fold larger than in rats of group 1. The study of selenium content showed that in the blood, liver, lungs and heart of rats treated with the additive on the background of selenium-deficient diet (group 2), selenium level did not differ from those in the control group and was within physiological norms. The experiment showed that selenium deficiency and rich in selenium rich diet has a significantly different effect on the studied parameters of oxidative-antioxidative status. The activity of blood glutathione peroxidase in animals of group 2 (did not differ from that in group 3) was almost 2 fold higher than in blood of control animals and was seven fold higher than that in blood of animals kept on selenium deficient diet (35.57 ± 3.36 µmol/g per 1 min) A similar dependence was established when studying the activity of glutathione reductase. It has been revealed thatthe oxidative-antioxidative status of animals from experimental groups 1 and 3 was lower than from control group and group 2. Thus, blood antioxidant activity in animals receiving diet with selenium deficiency and high dose of this trace element, was less than in the control group by 43.1 and 25.4%, respectively. Liver MDA level in animals kept on a diet with selenium deficiency exceeded the value of this indicator in the group 2 more than 1.5 fold (110.5 ± 10.70 vs. 72.5 ± 4.30 nmol/mg). When using selenium-containing supplement, this parameter decreased to the control level. In blood plasma of the animals of group 2 total antioxidant activity increased by about five times as compared with the indicators of animals kept on selenium-deficient diet, and was 25% higher than in control. Thus, the introduction of a selenium supplements in the deficient diet contributes to the development of endogenous antioxidants that suppress lipid oxidation. High biological effectiveness of supplements containing organic form of selenium has been proved.

Blood samples of 60 patients and 19 staff members were tested for serological markers of hepatitides B (HBV) and C (HBC) using the Vector-Best JSC enzyme immunoassay kits. HBV and HBC markers were found in 25 in 30% of patients and in 15.8 and 5.3% of staff members, respectively. Part of the sera with HBV and HBC markers were tested for the HBV and HBC RNAs by polymerase chain reaction. The findings confirm that donors should be more thoroughly tested for hepatitis markers, as well as the patients and staff of hematology departments.

Diastereomers of oligonucleotide ethyl phosphotriesters were separated by high-performance complementary (affinity) chromatography on a column with the immobilized complementary oligonucleotide. The elution buffer contained 0.18 M K2HPO4, pH 7.5, and 30% acetonitrile. The temperature of the separation was a few degrees lower than Tm of corresponding oligonucleotide complexes. The diastereomers separated completely or partially were: d[GCC(Et)AAACA], d[GCCA(Et)AACA], d[GCAA(Et)ACA], d[GCC(Et)A(Et)AACA], d[GCC(Et)AA(Et)ACA], d[GCCA(Et)A(Et)ACA], d[GCC(Et)A(Et)A(Et)ACA].

The bisulphite-catalysed transamination of cytosine residues by means of ethylenediamine generally used for the natural nucleic acids modification has been extended on relatively short synthetic oligonucleotides. One of the aminoalkyloligonucleotides thus obtained has been used for preparing a biotinylated hybridisation probe.

The hemagglutinin gene primary structure of influenza virus A/Riga/9977/86 (H3N2) belonging to the "Coen/84" antigenic subgroup was determined by primer sequencing. A comparative analysis confirmed that the reversions of amino acids in the late stages of the H3 influenza virus subtype antigenic drift became more frequent and the antigenic variants remained in epidemic circulation longer. The possible role of some mutations is discussed.

Kinetic values of the BamHI endonuclease interaction with synthetic oligonucleotides, containing some defects, have been determined. These defects were: the absence of the one internucleotide phosphate in the GGATCC sequence; substitution of a phosphate linkage by a methylphosphonate one; 5'-protruding end of the double-stranded oligonucleotide substrate. Some modifications resulted in the increase of the initial rates of cleavage due to higher Vmax values for these substrates. Several structural defects in the oligonucleotide substrates have been shown to intensity the formation of productive complexes with the enzyme, which can be explained by the significant role of the polynucleotide chain kinks in the recognition process. Studies on oligonucleotides with different defects made it possible to reveal the phosphate groups essential for the interaction with BamHI endonuclease.

The interaction of bifunctional ATP derivatives, Appp5'[NH-(CH2) n-NH]ppp5'A (n = 0 or 2-8) with tyrosyl-, valyl-, lysyl-, tryptophanyl-tRNA synthetases and creatine kinase was investigated. ATP derivatives don't inhibit the tRNA aminoacylation catalyzed by tyrosyl-tRNA synthetase. These derivatives behave as mixed-type inhibitors with respect to ATP in the case of valyl- and lysyl-tRNA-synthetases. In the case of the other enzymes all analogs of ATP manifest competitive inhibition towards ATP. The affinity of all ATP derivatives to tryptophanyl-tRNA synthetase does not differ significantly (Ki = 0.2 divided by 0.6 mM). The Ki values for these derivatives in the case of creatine kinase are also very similar with the exception of A5'ppp-NH-(CH2)3-NH-ppp5'A. The Ki value for this derivative is one order of magnitude lower than for other ones. The affinity reagents received by periodate oxidation of bifunctional ATP analogs derivatives of di-, tetra- and heptamethylenediamine modify non-identical subunits of creatine kinase with different velocities, but modification of M- and M'-subunits proceeds independently. An analogues derivative of trimethylenediamine interacts simultaneously with two centers of the dimeric form of kinase forming non-equivalent complexes. The covalent attachment of the reagent to one subunit of creatine kinase does not except the complex formation and covalent binding of bifunctional ATP analogs with the other subunit of the dimer, but results in a one order of magnitude decrease in affinity of the ATP derivative to the nonmodified centre of the enzyme. These data permit to evaluate the distance between ATP binding sites of creatine kinase in its dimeric form as 5-6 A approximately. Such a distance between active sites may be the reason for the higher activity of the M- and M'-creatine kinase subunits taken separately as compared to the enzyme dimeric form.