[Microflora of gastric mucosa, its properties and role in the development of acute and chronic gastritis].

Gastric microflora was studied in 28 patients suffering acute and chronic gastritis with reference to the factors of pathogenicity and sensitivity to antibacterial preparations. A total of 55 bacterial species were isolated The microflora was dominated by streptoccoci while Helicobacter pylori occurred rather rarely 27.3 +/- 6.5% of the isolated strains showed urease activity 36.3 +/- 6.5% natural or acquired virulence, 45.5 +/- 6.7% resistance to eradication therapy.

[Oligonucleotide derivatives in the nucleic acid hybridization analysis. II. Isothermal signal amplification in process of DNA analysis by minisequencing].

The isothermal amplification of reporter signal via limited probe extension (minisequencing) upon hybridization of nucleic acids has been studied. The intensity of reporter signal has been shown to increase due to enzymatic labeling of multiple probes upon consecutive hybridization with one DNA template both in homophase and heterophase assays using various kinds of detection signal: radioisotope label, fluorescent label, and enzyme-linked assay. The kinetic scheme of the process has been proposed and kinetic parameters for each step have been determined. The signal intensity has been shown to correlate with physicochemical characteristics of both complexes: probe/DNA and product/DNA. The maximum intensity has been observed at minimal difference between the thermodynamic stability of these complexes, provided the reaction temperature has been adjusted near their melting temperature values; rising or lowering the reaction temperature reduces the amount of reporting product. The signal intensity has been shown to decrease significantly upon hybridization with the DNA template containing single-nucleotide mismatches. Limited probe extension assay is useful not only for detection of DNA template but also for its quantitative characterization.

[Hepatitis C virus genotyping using 5 nuclease real-time PCR and probes with oligodeoxyinosine linkers].

Hepatitis C virus (HCV) infection is a major cause of severe liver disease including liver cirrhosis and hepatocellular carcinoma. Genotyping became fundamental in the clinical assessment of patients with hepatitis C because the genotype of the hepatitis C virus determines the chance of therapeutic response and duration of treatment. We developed a new real-time PCR assay for genotyping of HCV with increased specificity due to a novel approach to dual-labeled probe design using oligodeoxyinosine linkers. The assay allows genotypes 1, 2, 3 to be distinguished and genotypes 4-6 with high specificity to be blocked. The analytical sensitivity (150 IU/ml) can be implemented. Of the 285 clinical samples genotyped using the developed assay, 45% were genotype 1; 6%, genotype 2; 49%, genotype 3. No discordant results with 5-UTR sequencing and commercial genotyping assays were obtained.

[Development of uncompetitive exogenous internal amplification control for real-time PCR based on UFA method].

An uncompetitive exogenous internal amplification control method (EIAC) was developed on the basis of short synthetic DNA segment, whose amplification can be detected in real time by UFA spectroscopy principle. The EIAC was shown to be useful as internal control in diagnostic test systems based on DNA or RNA detection by multiplex real-time PCR. It can be applied to assess the quality of extracted DNA or RNA, and also to detect and study the factors causing PCR inhibition and earlier plateau effect.

[Chronic gastroduodenal erosions: clinical and pathogenetic characteristics, classification, differential treatment]. / Khronicheskie gastroduodenal'nye érozii: kliniko-patogeneticheskaia kharakteristika, klassifikatsiia, differentsirovannoe lechenie.

The etiology of chronic (complete) gastroduodenal erosions is not quite clear and is apparently multifactorial. A total of 100 patients with chronic gastroduodenal erosions were examined and divided into 5 representative groups, 20 pts each. For objective evaluation of the significance of various (probable) etiological and pathogenetic factors in development of chronic erosions, monotherapies with drugs with known pharmacodynamic effects were used (ranitidine, double and triple antihelicobacter protocols, dalargin, trental). Triple antihelicobacter protocol and trental proved to be the most effective in the treatment of chronic erosions (90 and 85%, respectively). Dalargin and double antihelicobacter protocol caused disappearance of complete erosions in 50% patients and ranitidine in only 15%. Analysis of the frequency of erosion epithelialization and Helicobacter pylori eradication under the effect of antibiotics showed a clear-cut positive correlation (r = 0.9) between these parameters, which indicated an important role of Helicobacter pylori in the pathogenesis of chronic gastroduodenal erosions. Moderate antihelicobacter activity of dalargin was revealed for the first time. The results of this study indicate that the majority of complete erosions are an individual nosological entity. Microcirculatory disorders in the antral part of the gastric mucosa and its contamination with Helicobacter pylori play an important role in the disease development; decreased cytoprotection and local immunity in the antral part of the stomach are also. The acidopeptic factor cannot cause complete erosions but is one of conditions for their formation.