[The organizational aspects of laboratory diagnostics of acute conditions: a lecture].

The article presents data concerning the prevalence of acute diseases and conditions in the Russian Federation. The main requirements are exposed concerning the laboratory diagnostics of acute conditions. The results of analysis of regulating documents concerning this issue are presented. The list of optimal laboratory tests and organizational options to be implemented in laboratory testing of patients with acute diseases and conditions in medical institutions is developed. The role and importance of principles of evidence medicine in choosing an optimal list of laboratory analysis to diagnose the acute conditions is demonstrated.

[Significance of the operational test parameters in selection of a diagnostic test for Helicobacter infection]. / Znachenie operatsionnykh kharakteristik testa pri vybore metoda diagnostiki infektsii Helicobacter pylori.

The group of 89 patients was examined, 63 of them suffered by a duodenal ulcerative disease, 11--by gastric ulcerative disease and 15--by chronic gastritis. It was conducted the comparison of the following indices: sensitivity, specificity, relationship of probability and diagnostic efficiency of histological, cytological methods, urease and respiratory tests, method of polymerase chain reaction, qualitative and quantitative definition of antibodies of the class IgG in serum blood to H. pylori by a method of enzyme immunoassay and Western-blot for H. pylori infection diagnostics was carried out. The results show that in choice of a diagnostic method of infection H. pylori it is better to use such characteristics as sensitivity and specificity, which more objectively reflect the diagnostic possibilities of each test.

[Laboratory diagnosis of hepatitis C]. / Laboratornaia diagnostika gepatita C.

Laboratory algorithm for the diagnosis of viral hepatitis C (HVC) is proposed. Blood sera are screened for antiHVC by third-generation EIA and PCR of HVC RNA. Positive result of PCR is diagnostically significant. In case of positive EIA and negative PCR the serum is to be analyzed in immunoblotting. If immunoblotting is not carried out, the diagnosis is made on the basis of estimated values of hepatitis C probability attached to diagnostic EIA kit used in clinical laboratory. When evaluating the positive result, the increase in optic density (OD) of analyzed samples is compared with the cutoff OD. In OD higher than 9 and below 1.5 the probability of disease is 92.6 and 11.8%, respectively. Patients with doubtful results of serological tests are to be regularly checked up for 1 year, with laboratory tests (immunoblotting and PCR) repeated every 3 months. Complex laboratory diagnosis by biochemical and serological methods and PCR should be carried out in groups at a high risk of HVC.

[Laboratory diagnosis in tuberculosis]. / Laboratornaia diagnostika tuberkuleza.

The most reliable signs of tuberculosis infection is detection of M. tuberculosis complex in biological fluids and biopsy specimens from focus of lesions. The sensitivity of laboratory diagnostic methods is different for different biological materials, which dictates the utilization of a complex laboratory approach, including microscopy, bacteriological methods, detection of specific IgG, IgM, IgA, and polymerase chain reaction.

[Metabolic and structural properties of extrachromosomal DNA in mammalian cells]. / Metabolicheskie i strukurnye svoistva vnekhromosomnykh DNK v kletkakh mlekopitaiushchikh.

Discrete bands of free DNAs of approximately 25 kbp were detected in human cell cultures. According to electrophoretic shifts induced by single and double strand breaks, they from topological isoforms (supercoiled, open, and linear). Long-term labeling (24 h) of growing and quiescent cultured cells by [3H]thymidine indicates differences of free versus chromosomal DNAs including (i) significantly lower specific radioactivity in growing cells, (ii) higher specific radioactivity in quiescent cells, and (iii) resistance to fluorodeoxyuridine labeling. During apoptosis of cultured Namalwa cells, heterogeneous fragments are formed which differ from free DNAs. Crosslinking of nascent RNA with DNA template by 8-methoxypsoralen indicated slight transcriptional activity of free DNAs.