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Biomedical subjects

I A Golubenko

Publications and source records attributed to I A Golubenko.

7 recordsLinked to original sources

[Ribonuclease of Bacillus intermedius 7 P. Purification by chromatography on phosphocellulose and several characteristics of the homogeneous enzyme].

A new procedure for isolation of homogenous ribonuclease of Bac. intermedius from a commercial source is described. The yields of 140 mg of RNAse from 200 g of the enzymic powder were attained. The amino acid composition of the enzyme was determined. The RNAse contains neither the sulfhydryl groups nor the disulfide bonds and has only one histidine residue. At the same time the amount of aromatic amino acid residues is relatively high. The enzyme is highly resistant to heat and acid treatment but is less stable in an alkaline solution. The pH optimum of the RNAse for the RNA digestion is 8,5; the temperature optimum for this reaction is 37 degrees. A spectrophotometric method for the RNAse activity assay using polyA as a specific substrate was developed. The purified product provides a suitable starting material for structural studies.

Amino Acids↗

[Extracellular nuclease of Bacillus mesentericus].

Bacillus mesentericus is found to secrete three type of nucleases: alkaline ribonuclease (EC 2.7.7.17), acidic ribonuclease (EC 2.7.7.17) and Ca2+-activated exonucleease (EC 3.1.4.7). These nucleases are purified and characterized. They are similar to those from Bac. subtilis in main biochemical and physico-chemical properties and in their chromatographical behaviour. Studying physiological functions of Bac. mesentericus extracellular nucleases, it is shown that bacteria, which are capable to produce extracellular nucleases, utilize exogenous RNAs and a bit worse, DNAs as a single and additional source of nitrogen or phosphorus. In view of this it is believed that extracellular nucleases participate in bacteria nutrition.

Bacillus↗

[The results of conducting a rapid assessment of the situation in relation to intravenous narcotic abuse in the city of Rostov-on-Don].

The main aspects of the spread and intravenous use of drugs in the city, contributing to the transmission of HIV infection among users of intravenous drugs (UID) have been studied. Anonymous questionnaires were distributed among 61 UID; of these, 50 were males (82%) and 11 were females (18%), mainly at the age of 19-35 years. In addition, sociological study was carried out among 582 persons; 61% of them were under 18 years of age, 18% were aged 19-25 years, 13% were aged 26-35 years. The drug users regarded their individual risk of getting HIV infection as insignificant in 23% of cases, slight in 21% of cases, high in 15% of cases, and 15% believed they were at no risk. As shown by the results of the sociological study, 91% of the respondents believed that the problem of drug addiction was topical in the city. The analysis of data obtained from physicians treating drug addicts and from the Head Office of Public Health made it possible to calculate that the number of UID in the city was about 9,000-10,000 persons. Taking into account the results of the rapid evaluation of the situation, the development of the draft program of "diminishing the harm" of the intravenous use of drugs is now in progress.

Adolescent↗

[Preparation of extracellular ribonuclease from Bacillus subtilis].

The paper describes a method for isolating alkaline ribonuclease from the culture liquid Bacillus subtilis KP 349 which involved: submerged cultivation of the producer on complex and synthetic nutrient media with optimized RNase activity, acid treatment of the total culture liquid, and filtration through perlite. Further treatment may include either spray drying of the culture liquid filtrate or its concentration in a vacuum evaporator, dialysis of the concentrate against distilled water, and dialyzate lyophilization. As a result, commercial RNase preparations with activities of 30--60 thous. and 160--300 thous. units/g, respectively, were obtained. The enzyme purification was carried out by chromatography and rechromatography on phosphocellulose columns. The resultant RNase of Bac. subtilis had a specific activity of 41--44 thous. units/mg protein, contained no nonspecific phosphodiesterase, DNase, acid or alkaline phosphomonoesterases.

Bacillus subtilis↗

[The effect of a syringe-exchange program on a decrease in the risk of HIV infection among intravenous narcotic abusers in the city of Rostov-on-Don].

The necessity and effectiveness of introducing the program of the exchange of syringes for intravenous drug users as a preventive and antiepidemic measure are discussed. Preventive and antiepidemic measures within the concept of harm reduction are described. The comparative analysis of materials obtained as a result of two sociological questionings, carried out in 1997-1998 among the representatives of the community (random nonrepeating choice) and in the middle of 1999 among the participants of the program revealed that the participants of the program had statistically significant changes in risky behavior patterns during the use of injection drugs.

Adolescent↗

[Nucleic acids utilized as the main source of bacterial nutrition].

Secretion of DNases and RNases, respectively, was found in saprophyte bacteria isolated from nature and growing on media containing DNA and RNA. Serratia marcescens and Bacillus subtilis with a high nuclease activity can assimilate RNA and DNA as the main source of nutrition. Ser. marcescens with a nuclease which attacks both DNA and RNA can grow equally well on these acids. Bac. subtilis has a higher activity of RNase and grows better on RNA.

Bacillus subtilis↗