[Molecular typing of the tick-borne encephalitis virus isolated from patients with different-infection severities in the south of Russia's Far East]. / Molekuliarnoe tipirovanie shtammov virusa kleshchevogo éntsefalita, vydelennykh ot liudei s razlichnoi stepen'iu tiazhesti infektsii na territorii iuga Dal'nego Vostoka Rossii.

The thick-borne encephalitis virus (TBEV), which is widespread in the Eurasian continent, belongs to the Flaviviridae family, Flavirus genus, and comprises the Far Eastern, Siberian and West European subtypes. It was for the first time that the gene part of the E 24 strain envelope glycoprotein of TBEV, which caused infection in residents of the South of Russia's Far East, was analyzed. It was established that the TBEV Far-Eastern subtype causes different-severity disease cases ranging from the focal ones with the lethal outcome to latent infection forms. On the basis of the phylogenetic analysis, the Far-Eastern subtype was shared between 4 sub-clusters, 2 of which constitute a majority of the analyzed TBEV strains.

[Changes in the immune status parameters and their correction in various forms of tick-borne encephalitis]. / Izmenenie pokazatelei immunnogo statusa i ikh korrektsiia pri raznykh formakh kleshchevogo éntsefalita.

Comparative investigation of immune status indices in patients with fever form of vernal encephalitis (group 1), with inapparent form with prolonged antigenemia (group III) and with short-term antigenemia (group II) was performed for the first time. Total 99 patients were under investigation. It was shown that in group I selective damage of immune system at T-level took place. In patients of group III immune system at all levels was less involved and humoral factor were changes. In patients in group II no significant change in immune system were registered. Activity of different immune correctors (thimalin, 4-iodoantipirine, leukinferon) was investigated in vitro. This preparations had stimulating effect in blood samples of patients with decreased immune status. In the patients with unchanged immune status no effect was demonstrated. The most prominent effect was revealed in the case of 4-iodoantipirine--interferon inducer.

[Experimental tick-borne encephalitis in golden hamsters treated with specific immunotherapy]. / Eksperimental'nyi kleshchevoii éntsefalit u zolotistykh khomyachkov na fone spetsificheskoi immunoterapii.

Efficiency of various protocols of specific immunoglobulin treatment was evaluated in golden hamsters inoculated with two Far Eastern tick-borne encephalitis (TBE) strains. After a low therapeutic dose (0.1 ml) of immunoglobulin, corresponding to total dose (60 ml) per course, all parameters (survival, immunogenicity, pathomorphology of the brain) deteriorated in animals infected with both strains. A higher dose (0.2 ml) corresponding to total dose of 120 ml notably improved all the studied parameters. The efficiency of specific immunoglobulin depends on the clinical and pathogenetic characteristics of TBE, determined by the properties of TBE strains. The results validate therapy and prevention of TBE by high-titer immunoglobulin in adequate total dose, monitored by blood analyses for TBE antigen and evaluations of the time course of IgM antibodies.

[Apoptosis as a mechanism for the cytopathic action of tick-borne encephalitis virus]. / Apoptoz kak mehanizm tsitopaticheskogo deistviia virusa kleshchevogo éntsefalita.

The ability of tick-borne encephalitis (TBE) virus to cause programmed cell death (apoptosis) in viral infection of newborn mice and of two cell cultures is studied. The time course of virus antigen accumulation detected by enzyme immunoassay and of endonuclease fragmentation of nuclear DNA detected by agarose gel electrophoresis is compared. All three TBE strains differing by the source of isolation and biological characteristics can cause oligonucleosomal fragmentation of DNA of brain cells of two-day white mice and of SPEV cells in acute infection. In VERO-E6 cells the same three strains caused a latent infection; accumulation of virus antigen was not associated with endonuclease fragmentation of DNA or any other signs of cytopathic destruction. These data indicate that TBE virus can cause programmed cell death both in vitro and in vivo, which is apparently one mechanism of the cytopathic effect of the virus.