Corynebacterium diphtheriae nontoxigenic strain carrying the gene of diphtheria toxin

Among 828 C. diphtheriae nontoxigenic cultures isolated in different region of Russia in 1994-2002, 114 cultures (13.8%) had the gene of diphtheria toxin (gene tox) and were thus called nontoxigenic tox-carrying (NTTC) strains. All NTTC strains were found to belong to biovar mitis and formed neither normal, nor "defective" diphtheria toxin. The most of NTTC strains (94%) belonged to ribotype "Moskva", not occurring among C. diphtheriae toxigenic strains. The incapacity of NNTC strains of forming diphtheria toxin was caused by mutation: the deletion of one nucleotide which led to the shift of the open reading frame and to the formation of the stop codon. The results of these studies are indicative of the fact that a sufficiently homogeneous and isolated group of C. diphtheriae nontoxigenic strains is spread in Russia. These strains carry the nonexpressing gene of diphtheria toxin and are of no epidemic importance in diphtheria infection.     

New recombinant variant of human immunodeficiency virus of type 1, subtype envB/envA, isolated in Novosibirsk

The nucleotide sequence of the variant of human immunodeficiency virus of type 1 (HIV-1), mostly widespread on the territory of the Novosibirsk region, was determined. The analysis of the nucleotide sequence confirmed that this variant belonged to HIV-1 of subtype A. The HIV-1 recombinant variant of subtype envB/envA with the recombination area within the second conservative region C2 of gene env, so far unknown, was detected and characterized. In HIV-1 the area at the beginning of gene env (5'-env) was found to belong to subtype B and the sequence at the end of gene env (3'-env), to subtype A. The analysis of the amino acid sequence of the third variable region of gene env demonstrated that the viruses under study belonged to macrophagotropic "slow/low" variants, characterized by low replication speed. The analysis of nucleotide sequences of the isolated variants of HIV-1 revealed their close genetic relationship with HIV-1 isolates circulating on the territory of Ukraine.     

Neutrophils and antioxidant activity of cervical secretion in women with the acute inflammation in the upper section of the reproductive tract

The functional activity of neutrophils, peroxidation products and antioxidative activity of cervical secretion in women with the acute inflammatory process in the upper section of the reproductive tract were under study. The most pronounced changes in the function of neutrophils were observed in women with the low antioxidative activity of cervical slime.     

Influence of the activation of the immune system cells on the parameters of lipid metabolism in macrophages

The influence of tumor necrosis factor a (TNF-alpha) and media, conditioned by activated macrophages and lymphocytes and containing a complex of biologically active compounds (including cytokines), on the parameters of lipid metabolism in macrophages was studied. The addition of recombinant TNF-alpha and immunocompetent cell-conditioned media to mouse peritoneal macrophages culture stimulated labelled oleate incorporation into cholesterol esters and triglycerides, as well as labelled glycerine incorporation into cholesterol esters, but inhibited labelled cholesterol incorporation into cholesterol esters. One of the mechanisms of the influence of activated immunocompetent cells on cholesterol metabolism in macrophages was, supposedly, the stimulation of sphigmomyelinase activity by a complex of anti-inflammatory cytokines produced by these cells on their activation.     

Age-related features of cataractogenesis in salmon fry. 3. Age-related dynamics of liver lipid composition during cataractogenesis

When studying the cataract pathogenesis in salmon fry, we found changes in the content of individual; phospholipid fractions and fatty acid composition in the liver of diseased and healthy fish. The age-related changes correlated with the increased antioxidant activity and decreased liver content of malondialdehyde.     

Peripheral pool of CD8+ T-cells contains lymphocytes with antigen-specific receptors that recognize syngeneic MHC class II molecules

The capacity of T-lymphocytes to recognize "nonself" and tolerating "self" is formed as a result of positive and negative selection in the thymus. While obtaining and testing specificity of T-hybridomas, we demonstrated that the major part of peripheral pool of CD8+ T-lymphocytes carried receptors specific to "self" MHC class II molecules. Such an unexpected specificity of receptors has been found in some T-cell hybridomas produced by fusion of activated peripheral CD8+ T-lymphocytes with a tumor partner transfected by the coreceptor CD4 gene. The reactivity to "self" is not an experimental artifact due to an increased avidity of interaction of the hybridoma cells with antigen-presenting cells. Also, it is not an expression of reactivity of T-cells to superantigens, products of endogenous viruses of mouse breast cancer. The formation of a pool of such T-cells involves both cells with double receptor specificity and cells coexpressing two alpha-chains of T-cell receptor. Their appearance in the periphery can be due to the capacity of thymocytes differentiating in the direction of CD4+ cells to avoid negative selection via change of expression of coreceptor CD4 to CD8.     

Evolutionary transformations of ontogenesis in anuran amphibians

A review of the recent published data on ontogenesis of direct developing and marsupial frogs. The development of these representatives of anuran amphibians seems to be evolutionary advanced and considerably differs from the development of species traditionally used in amphibian embryology.     

Age-related characteristics of cataractogenesis in salmon fry. II. Biochemical characteristics of eye lens during cataractogenesis

We studied biochemical features of the lipid and phospholipid composition and patter of fatty acid spectra in lenses of one and two year old salmons bearing cataracts. The lipid complex of lenses of diseased fish underwent significant changes. Cataractogenesis was accompanied by enhanced free radical oxidation and accumulation of malone dialdehyde in lenses of salmons of various age. The intensification of oxidative processes was synchronized with the decreased level of antioxidant protection (reduced glutathione, vitamins A and E). The activity of Ca(2+)-dependent proteolytic enzymes in lenses was determined and its decrease in the case of cataract was shown.     

Immobilization of champagne yeasts by inclusion into cryogels of polyvinyl alcohol for preventing cell escape from carrier matrix

Wine champagnizing, a process involving the use of champagne yeasts immobilized by inclusion into cryogels of polyvinyl alcohol, has been studied. Treatment of yeast cells with the autoregulatory factor d1 was proposed as a means of preventing the cell escape from the carrier matrix. Such a treatment inhibited growth and proliferation processes in yeasts cells, without affecting the activity of fermentation; the resulting champagne had the same organoleptic and chemical characteristics as its counterparts obtained using traditional techniques.