Development of a PCR-based method for diagnostics of mycoses

Since the express-diagnostics of mycoses in immune-deficit patients still remains an acute problem, we developed an effective test system (Kan-Am) to detect DNA Candida albicans, which is a leader in the list of causative agents of candidosis. A comparison study of three PCR-systems used to detect a broad spectrum of fungoid pathogens was carried out, and a universal system (FungAm), which ensures the detection of DNAs of above 78 strains of 25 types of pathogenic fungi, was selected. The results of clinical testing of the species-specific and universal PCR-systems are well confirmed by the culture method, and they are indicative of the efficacy of applying them for the diagnostics of mycoses in neonatology. The use of the mentioned systems is a promising factor for the express-diagnostics of mycoses in immunodeficiency patients. The high sensitivity of the method makes it possible to detect 10 to 100 cells of a causative agent in 100 mcl of the examined biological material, which is compatible with the culture method. A kit of dry reagents (IonoMix) designed for an accelerated sample preparation and isolation, from them, of DNAs on the basis of Chelex-100 and of proteinase K was worked out; the kit is portable and meant for a long-term storing.     

Insertion of transposon P(lacW) with gradual expression of reporter genes

In Drosophila, insertions of the P?lacW? transposon led to uncommon expression patterns of the reporter genes white and lacZ: gene activity was gradually reduced in the neighboring cells along the dorsal-ventral or proximal-distal axes. Using in situ hybridization, the gradual gene expression was shown to be caused by P?lacW? insertions in regions 40A (lines G1 and G2) and 69C (line G3) of the Drosophila genome. The expression patterns of genes lacZ and white were similar in eye cells of each line. In salivary gland polytene cells of G3 flies, the lacZ expression was also gradually reduced, which indicates the existence of a mechanism maintaining the gene activity gradient during endomitosis.     

Allele variants of Borrelia afzelii found by sequencing of the chromosome gene p66

Sequencing of gene p66 fragments of 246-337 p.b. was performed in 45 isolates of Aorrelia afzelii isolated from different transmitting agents and reservoir hosts within the habitation area of the spirochaeta. At least seven allele variants of the pathogenic agent were found indifferent natural foci of the disease. The extent of similarity between the nucleotide sequences of the isolates of the same allele variant was 99.9-100%; the extent of similarity between different allele variants was 98.9-99.7%. It was found that the majority of genovariants of A. afzelii (with respect to 5S-23S) incorporated several different allele variants of gene p66, all allele variants being found in the two genogroups (VS461 and NT28) of the pathogenic agent.     

Prevalence of type III secretion system genes in cholera vibrios from different serogroups

Prevalence of vcs genes coding the type III secretion system (T3SS) in cholera vibrios of different serogroups isolated in Russia and neighboring countries was studied for the first time. Virulent strains of O1 and O139 serogroups as well as toxigenic Vibrio cholerae strains of other serogroups contained no T3SS genes. Unlike mentioned strains, 29.2% of atoxigenic non O1/non O139 cholera vibrios isolated from patients in Russia and neighboring countries contained the T3SS genes cluster, which might contribute to the pathogenic properties of these strains.     

Catalytic properties of Na+-translocating NADH:quinone oxidoreductases from Vibrio harveyi, Klebsiella pneumoniae, and Azotobacter vinelandii.

The catalytic properties of sodium-translocating NADH:quinone oxidoreductases (Na+-NQRs) from the marine bacterium Vibrio harveyi, the enterobacterium Klebsiella pneumoniae, and the soil microorganism Azotobacter vinelandii have been comparatively analyzed. It is shown that these enzymes drastically differ in their affinity to sodium ions. The enzymes also possess different sensitivity to inhibitors. Na+-NQR from A. vinelandii is not sensitive to low 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO) concentrations, while Na+-NQR from K. pneumoniae is fully resistant to either Ag+ or N-ethylmaleimide. All the Na+-NQR-type enzymes are sensitive to diphenyliodonium, which is shown to modify the noncovalently bound FAD of the enzyme.     

Effects of a medium pH on the ability of Chinese hamster cells to repair radiation injuries]

In experiments with Chinese hamster cells at exponential and stationary growth phases, it has been shown that the postirradiation incubation of irradiated cells in a medium with low pH (up to 6.0) promotes the recovery of cells from potentially lethal damages; it has also been found that the recovery from sublethal radiation damages does not depend on the medium pH. The long-term incubation of nonirradiated cells with low pHc causes death of part of cells.     

Intensification of antibacterial and antiviral nonsusceptibility and of the immune response with an officinal RNA preparation]

Sodium nucleinate increased essentially the insusceptibility of mice to pathogenic escherichia, strain O26, Pr. vulgaris, Ps. aeruginosa, Ser. marcescens, and produced a total stimulating effect on the nonspecific bacterial resistance; analogous stimulating activity was found in the homologous low polymeric RNA from the liver. Sodium nucleinate intensified the insusceptibility of the animals to the tick-born encephalitis and encephalomyelitis viruses, and increased the antibody-forming cells count. The side-effect of heat-inactivated vaccine from pathogenic escherichia was reduced in animals inoculated with sodium nucleinate preliminarily.