Vol 48, No 5 (2003)

The most promising trends of using monoclonal antibodies (Mabs) in virology research of the viral hemorrhagicfevers' agents are related with studying viral antigen structure and with developing diagnostic preparations for indicating and identifying infectious agents of the mentioned pathologies. The methodological specificity of obtaining the Mabs to viral hemorrhagic-fevers' agents as well as data on its practical use are discussed.

A study of distributions of different genetic variations (subtypes) of hepatitis С virus (HCV), circulating in the territories of Yekaterinburg and Chelyabinsk among infected population categories of different social statuses and age, is reported in the paper. The predominance of 1 b subtype was shown in the HCV-infected patients at the hemodialysis center (HDC) and at the pediatric oncohematology center (OHC), 83.3% and 84.6% respectively. The summarized results of examinations of patients conducted at HCV-infection departments (97 persons) did not reveal any essential differences between the data, obtained for Moscow and Saint-Petersburg, concerning the distributions of HCV subtypes. However, according to an analysis made in cities of the Urals region, the prevalence of 1b subtype in Chelyabinsk was 2-fold higher than that of 3a subtype, whereas in Yekaterinburg there was an equal ratio (1:1) between the above subtypes. Besides, unequal distributions of HCV subtypes were registered in different age groups. 3a subtype was found to be predominant in patients aged 15 to 27, and prevalence of 1b subtype persisted in persons aged below 15 and above 27. The conclusion is that the redistributed occurrence rates of separate HCV subtypes, with their spectrum in mentioned territories being preserved, is associated with a growing number of young drug-addicts who are more often get infected with 3a subtype.

New water-soluble antiviral chemical agents, containing 10 to 30% of adamantane derivatives (amino-, aminopropyl-adamantane-, aminomethyl- and rimantadine), which were conjugated with polycarboxylic matrixes of the divinyl ether and maleic anhydride copolymers (DIVEMA), were developed. The polymeric drugs exhibited a low cytotoxicity (4 to 10 times less than rimantadine) and a wide spectrum of antiviral activity against influenza viruses, including both the remantadine-resistant strains of A/PR/8/34 (H1N1) and the B/Saint-Petersburg strain/71/77 as well as against herpes viruses of type 1, parainfluenza viruses of types 1 and 3 and RS-virus. A reduction of the viral infection titer in their reproduction in sensitive cells' cultures was more than 2.0 Ig ID50. Complete inhibition of viral-specific syntheses, registered by immune-enzyme assay (IEA) and by hemagglutination test was observed at low infection doses ranging from 1 to 100 Юи. The efficiency of the antiviral effect depends on a drug's molecular weight and a structure of chemical bonds between the adamantane nucleus and the polymeric matrix.

Experimental data are reported on the antiviral activity of peptide immune-modulator "Gepon" in infections caused by herpes simplex virus (HSV), types 1 and 2, in vitro and in vivo. The drug proved to be non-toxic and did not possess any viricidal action. Its antiviral effect was registered in experiments with a multiple-infection cells' culture. The maximal effect was a 100-fold reduction of the viral titer when it was used in a concentration of 6.25 meg/ I as a preventive measure 24 hours before triggering the infection. The mentioned drug's effect was reliably higher than its use within a treatment scheme (1 hour after the infection onset). "Gepon" possessed the reliable protecting qualities (36% of protection with a mean increase of the infected mouse life by 1.9 days) in experiments with intraperitoneally infected mice (10 LD50/mouse of HSV, type 2), when the drug was administered in doses of 0.1 and 1 meg/mouse.

Data on changing contents of blood-lymphocytes' subpopulations in patients with ophthalmoherpes are reported. A higher number of blood cells expressing the surface activation antigens of HLA-DR*, CD71* and CD95*, a lower number of T-helpers and a reduced value of the immune-regulating index were found to be typical of such changes. A more significant increase in the quantity of CD95* lymphocytes, as observed in cases of severe ophthalmoherpes versus its moderate clinical course, could be a prognostication criterion. The essential shifts occurring in the T-cells' population denote the status of tension in the immune response provoked by an intensified reproduction of herpes simplex virus (HSV); at the same time, they are indicative of a certain deficit in the immune-protection mechanisms.

A possibility of using the amplification of gene HN fragment in combination with nucleotide cDNA sequencing for the purpose of identification and strain differentiation of bovine parainfluenza-3 virus was demonstrated. A comparative analysis of the primary structure in the studied HN gene fragment revealed 2 genetic groups among the investigated virus' strains and isolates. Group 1 is made up of Northern American viral strains and of Russian isolates, whose primary structure has a high level of homology to the primary SF-4/32 strain structure; group 2 comprises the virus' Russian isolates with a high level of homology to the mentioned strains to Japanese strains' sequences. The biggest differences between the studied strains and the viral isolates amounted to around 8%, when the nucleotide sequences were compared, and to around 4%, when the corresponding amino-acid sequences were compared.