[Molecular epidemiology of HIV-infection in drug addicts of Southern Ural]. / Molekuliarno-epidemiologicheskaia kharakteristika ochagov VICH-infektsii sredi narkomanov na Iuzhnom Urale.

The analysis of HIV-1 variants circulating among drug addicts in 16 settlements of the Sverdlov, Chelyabinsk and Orenburg regions (72, 90 and 42 patients respectively) was carried out. As shown by the serological analysis, the spread of HIV-1 variant IDU-A among the drug addicts in this area continued in this area and could be detected in 99.5% of the samples (203 out of 204 samples). These data were confirmed by the results of the analysis of 35 samples by the Heteroduplex Mobility Assay for genes env and gag. The analysis of nucleotide sequences of gene env revealed that HIV-1 variants in the Southern Urals, where the greatest outbreak of HIV infection in Russia had been registered, were genetically related to viruses of subtype A, detected earlier in this group of risk in other regions of Russia, as well as in Ukraine, Belarus and other East European countries.

[Development of HIV infection epidemic among intravenous drug users in the Sverdlovsky region]. / Razvitie épidemii VICh-infektsii sredi potrebitelei in"ektsionnykh narkotikov v Sverdlovskoi oblasti.

The Sverdlovsky region takes the fourth place among the 89 subjects of the Russian Federation by the number of registered cases of HIV infection. Drug addiction has reached an excessive scale in this region: according to the data of express evaluation carried out by the Regional Narcological Hospital and the Regional AIDS Center, not less than 7-8% of persons aged 15-30 years constantly use injection drugs. The large-scale epidemic of injection drug addiction has led to the rapid spread of HIV among addicts. The first penetration of HIV into this population took place in 1996 and, starting from the year 2000, rapid, development of the epidemic began, taking the character of an avalanche. The peak of new cases of HIV infection fell on 2001 (9,230 cases were registered). The concentrated stage of the epidemic development is observed in the region at present, the prevalence of HIV infection among drug addicts being 13.8%. Children born from HIV-infected drug addicted mothers now represent a new risk group due to great difficulties in the prophylaxis of the vertical virus transmission.

[The potentials for the comprehensive diagnosis of viral encephalitis in Sverdlovsk Province]. / Vozmozhnosti kompleksnoi diagnostiki virusnykh éntsefalitov v Sverdlovskoi oblasti.

The suggested scheme of laboratory tests helped identify the etiology of viral encephalitides in 65.9% of cases. Diagnosis of tick-borne encephalitis was confirmed by laboratory findings in 93.6% of cases. Patients with Californian encephalitis were detected in the Sverdlovsk region for the first time. A rather high rate of detection of antibodies to Tahyna virus was revealed in the examined population: up to 60%. Influenza origin of encephalitis was recognized in 6.2% of cases, Lyme's disease was diagnosed in 9.3%.

[Antihemagglutinin exhaustion reaction in studying the activity of arbovirus antigenic preparations]. / Reaktsiia istoshcheniia antigemaggliutininov v izuchenii aktivnosti antigennykh preparatov arbovirusov.

A modification of serological tests, the antihemagglutinin exhaustion test, was developed for the study of capacity of different fractions of the antigenic preparations of tick-borne encephalitis and western equine encephalomyelitis viruses to react with antibody. The test is simple to perform, highly sensitive and specific which permits within a very short time to examine the antigenic activity of practically all, including non-hemagglutinating, virus fractions obtained by gel chromatography and ultracentrifugation. Significant functional heterogeneity of virus particles in interaction with antibody was established. Non-hemagglutinating virions were capable of binding antihemagglutinins. The intensity of interaction with antibody of the most active virus fractions in the HI and CF tests was considerably higher than that of nonfractionated preparations.

Buoyant density of some togaviruses in sucrose density gradient and capacity of their haemagglutinin fractions to interact with antibody.

The buoyant densities of Western equine encephalomyelitis virus (an Alphavirus) and tick-borne encephalitis (TBE) virus (a Flavivirus) antigens prepared by different methods were studied. Sucrose density centrifugation revealed a heterogeneity in the density of the virions. The sedimentation pattern and height of peaks of the haemagglutinating activities and infectivity, other conditions being equal, depended both on the virus species and properties of its strains and on the mode of preparation and treatment of the virus-containing material. Different haemagglutinating antigen fractions differed in their capacity to interact with specific antibody. It was suggested that the kinetics of a serological reaction and its result depend on the functional activity of the antigen preparation and, in particular, on the proportion in the reaction mixture of virus particles with a dissimilar antigenic structure.

[Avidity criteria in assessing the functional activity of antigens, antibodies and non-specific serum inhibitors on a model of the kinetic reaction of hemagglutination suppression with arboviruses]. / Kriterii aviditeta v otsenke funktsional'noi aktivnosti antigenov, antitel i nespetsificheskikh syvorotochnyk ingibitorov na modeli kineticheskoi reaktsii podavleniia gemaggliutinatsii s arbovirusami

The functional activity of some arboviruses of groups A and B, of the antibodies and serum inhibitors was studied on a model of the kinetic hemagglutination inhibition test (HAI) by different avidity criteria (velocity, completeness and stability of formation of a neutral complex). The avidity indices of the antigens, antibodies and the inhibitors proved to depend on the group, species and strain peculiarities of the arboviruses, the method of preparation of the antigen, the biological species of the donor of the immune and normal blood sera, the method of treatment of the sera and a number of other factors. There proved to be no constan-correlation between the avidity of the strain and the avidity of the serum immune to it. Inhibitors of the normal rabbit and human sera were not less effective in comparison with the specific antibodies to a number of viral strains of tick-borne encephalitis and Japanese encephaliti or even exceeded them by the avidity indices to the antigens in the HAI test. The most active (functionally) strains can be recommended for obtaining high-quality viral (antigenic and serum) preparations.