Vol 49, No 6 (2004)

Protease-encoding nucleotide sequences of 27 HIV-1 variants isolated in Russia and other CIS countries from seropositive intravenous drug-users were analyzed. None of the above persons did ever take antiretroviral drugs. The nucleotide sequences were shown to belong to subtypes A and to be have a high degree of genetic homogeneity (0.00-3.23; mean - 1.38 ± 0.79). No isolates contained any primary mutations of resistance to protease inhibitors. At the same time, above one half of the isolates bore the V771 substitution, which, according to published data, is the secondary mutation of resistance that conditions a higher resistance to Nelfinavir. Moreover, the substitution was associated with 2 synonymous mutations in triplets 31 and 78, which denotes a single origin for all V771 variants.

Biological properties of H1V-1 laboratory strains and isolates were studies and compared with research results of the nef gene fragment obtained from their proviral DNA and RNA as well as from RNA and HIV-1 DNA isolated immediately from the blood of patients at early HIV stages. The electrophoresis pattern as well as the results of determination of nucleotide sequences showed that the HVI-1 RNA nef gene of rapid/high laboratory strains of HIV isolates and RNA obtained from patients at late infection stages had a 135-nucleotide inner deletion. The phenomenon can be regarded is proof of that nef gene structure, if violated, causes an enhanced virulence of and an intensified multiplication of the virus (according to laboratory markers) observed at late HIV stages, which triggers, at least in a number of cases, the infection aggravation.

The Siberian subtype of the tick-borne encephalitis virus (TEV) is different from the Far-East subtype by a moderate virulence observed in Siberian hamsters and by a low infection development rate (100 strains were compared). No differences were found in neuro-invasiveness. Clinical findings and experiments with monkeys denote the ability of the Siberian subtype to provoke severe forms of tick-borne encephalitis (TBE). The inflammationanddegenerative changes were localized in the brain cortex, subcortical ganglions, nuclei of medulla oblongata, in the cortex and nuclei of the cerebellum as well as in the anterior horns of the spinal cord. 18 disease cases triggered by the Siberian TEV subtypes in residents of the Western and Eastern Siberia and of Central Russia (Yaroslavl Region), including 7 acute TBE cases (5 lethal outcomes), as well as 11 chronic TBE cases are analyzed. The viral RNA was found in the cortex, medulla oblongata, horn and in the cervical part of the spinal cord of those diseased of acute TBE. Sequences of genotyped strains were presented to Gen Bank, NCBI (AY363846-AY363865).

Pulmonary tissues of red-grey voles, Clethrionomys rufocanus from Shkotovo District and Maritime Territory were investigated. rt-PCR was used to detect the hantavirus nt-222 M-segment genome and nt-403 mitochondrial DNA fragment. A new genetic variant of the PUUV virus named as "Shkotovo", that is different from other PUUV strains by 18-23%, was shown to be circulating in red-grey voles. A phylogenetic analysis denoted 2 PUUV subgroups with their rodent-host branching into C.graleolus and C.rufocanus.

Control tests and subsequent comparative analysis of their results related with the detection of anti-hepatitis С virus (anti-HCV) by different ELISA systems were made at a laboratory of the "Vector-Best" Company, Novosibirsk (A), a clinical diagnostic laboratory of Infection Clinical Hospital No. 1, No. 1 (B), and at a laboratory of chronic viral infections of Andjaparidze Institute of Viral Drugs of the Russian Academy of Medical Sciences (C). Two thousand three hundred and fifty blood sera of donors and 236 blood sera of patients with acute and chronic renal pathology were examined. The comparative research made at the above facilities by different ELISA systems produced diversified results. An analysis of 2350 blood samples from donors made in 3 ELISA systems at laboratory A showed divergence in 19 (0.8%) cases. At laboratories В and C, 5 ELISA systems (a set of 236 samples) denoted differences in 28 (11.9%) cases. Significant variances were registered in confirmation of disputable results of ELISA with immunoblot, which is apparently related with differing criteria applicable to confirming the positive results from using the confirmative tests. A possibility is discussed of using different ELISA systems in screening examination.