Effect of various amino acids and ammonium salts in a synthetic culture media on the cholera enterotoxin production

The influence of amino acids and ammonium salts on the production of cholera enterotoxin (CT) by 3 Vibrio cholerae strains of different biovars and serogroups was evaluated. As revealed in this study, toxin formation in each of the strains was quantitatively and qualitatively determined by their individual sets of amino acids. The amino acid compositions ensuring the maximum production of CT by the V. cholerae strains under study were formed. The use of ammonium salts as the only source of nitrogen in the composition of a synthetic nutrient medium for the accumulation of CT was shown to be inexpedient.     

The cell composition in the lymphocyte population and the radiation adaptive response

Using lymphocytes of 5 healthy individuals the ability to adaptive response (AR), cell composition of population after PHA stimulation, changes in cell composition population after irradiation in the dose of 1.0 Gy and after irradiation in adaptive (0.05 Gy) and challenge (1.0 Gy) doses have been studied. AR observed in 2 of the 5 individuals only. After PHA stimulation the persons with AR have the total amount of cells after mitosis or during mitosis (the number of binucleated cells + the number of multinucleated cells + the whole cells with micronuclei + the number of mitotic cells) on average is higher than in persons without AR. In individuals with AR the linear correlation between the number of binucleated cells with micronuclei (on the 1000 scored binucleated cells) and the part of binucleated cells in the population is observed with coefficients of correlation -0.89 and -0.91. In the humans without AR this correlation is absent. The correlation observed permits to suppose that AR may occur at the expense of not only the decrease in number of damaged lymphocytes, but also the increase in the share of not damaged binucleated cell with the stable number of damaged cells.     

Effect of pineal peptide on parameters of the biological age and life span in mice

Female CBA mice were injected with s.c. synthetic tetrapeptide Epithalon from a 6-month age until death. The drug failed to affect the body weight or food consumption, physical activity or behavioural parameters. However, it slowed down the age-related switching off of the estrus function, decreased body temperature, decelerated free redical processes, prolonged the mice life span with an accompanying drop in spontaneous tumour incidence.     

Effect of the gene for bacterial hemoglobin vhb on the effectiveness of the process of Escherichia coli-Streptomyces interspecies conjugation and production of antibiotics in streptomycetes

The bacterial hemoglobin vhb gene was cloned from sliding bacterium Vitreoscilla sp. as an element of the system ensuring survival of this microorganism in an environment that contains insufficient amount of oxygen. The vhb gene was transferred from Escherichia coli to some Streptomyces strains, producers of antibiotics, by the method of intergeneric conjugation using conjugative-integrative plasmid vectors pIH1 and pCH2. The stability of plasmid DNA inheritance was analyzed in the genomes of exconjugants. A positive effect of the vhb gene on processes of conjugation and antibiotic production in a number of examined strains was shown.     

Ontogenetic features of psychophysiological mechanisms of perception of speech emotional component in musically gifted children

Cerebral mechanisms of musical abilities were explored in musically gifted children. For this purpose, psychophysiological characteristics of perception of emotional speech information were experimentally studied in samples of gifted and ordinary children. Forty six schoolchildren and forty eight musicians of three age groups (7-10, 11-13 and 14-17 years old) participated in the study. In experimental session, a test sentence was presented to a subject through headphones with two emotional intonations (joy and anger) and without emotional expression. A subject had to recognize the type of emotion. His/her answers were recorded. The analysis of variance revealed age- and gender-related features of emotional recognition: boys musicians led the schoolchildren of the same age by 4-6 years in the development of mechanisms of emotional recognition, whereas girls musicians were 1-3 years ahead. Musical education in girls induced the shift of predominant activities for emotional perception in the left hemisphere; in boys, on the contrary, initial distinct dominance of the left hemisphere was not retained in the process of further education.     

Characterization of antirubella vaccine in an epidemiological trial

The work was aimed at the evaluation of the antigenic activity and reactogenicity of antirubella vaccine, manufactured by the Serum Institute of India, on the basis of the active observation of 373 children. Vaccinal reactions were registered in 8.8% of the vaccinees. Seroconversion after the injection of the vaccine was 100%. The results of the epidemiological trial demonstrated that the Indian antirubella vaccine was faintly reactogenic and had high antigenic activity.     

Functional activity of mouse peritoneal macrophages contaminated with gram-positive bacteria

The analysis of the functional and enzymatic activity of mouse peritoneal macrophages contaminated with Staphylococcus aureus and Listeria monocytogenes virulent strains is presented. The low bactericidal and digestive activity of these cells with respect to the above-mentioned microorganisms was determined. In this study a decrease in the activity of plasmatic membrane enzymes (5'-nucleotidase and ATP-ase) of macrophages contaminated with S. aureus and L. monocytogenes was observed, which was indicative of the stimulation of phagocytes. A rise in the activity of the oxygen-dependent system of macrophages contaminated with S. aureus and L. monocytogenes was detected by means of the nitro blue tetrazolium test. At the same time a decrease in the intracellular content of nitrogen oxide end metabolites in macrophages was detected with a rise in content of nitrogen oxide in the supernatants.