[Expression of the NS1 gene of tick-borne encephalitis virus in gram-negative bacteria from the mouse nasopharynx]. / Ekspressiia gena NS1 virusa kleshchevogo éntsefalita v gramotritsatel'nykh bakteriiakh--obitateliakh nosoglotki myshei.

Bacteria were isolated from the nasopharynx of BALB/c mice and electroporated with pUR290(NS1)2 containing two copies of tick-borne encephalitis virus (TBEV) strain Sofjin NS1 under the control of the lac promoter. The plasmid persisted in transformants for at least ten passages. The NS1 gene expression was detected in Gram-negative enterobacteria via immunoblotting with monoclonal antibodies against TBEV nonstructural glycoprotein NS1. Recombinant NS1 was detected in bacterial cells and in the culture medium. Intranasal immunization with recombinant bacteria activated production of antibodies against NS1 in serum of BALB/c mice. The humoral immune response to NS1 failed to protect immunized mice from a TBEV challenge.

[Involvement of the common shrew, Sorex araneus (Insectivora, Soricidae), in circulation of the tick-borne encephalitis virus in south-western Siberia]. / Uchastie obyknovennoi burozubki Sorex araneus (Insectivora, Sorcidae) v tsirkuliatsii virusa kleshchevogo entsefalita na iuge zapadnoi Sibiri.

We presented the data on the abundance of immature instars of the taiga tick Ixodes persulcatus Schuize on the common shrews Sorex araneus L. in natural foci of tick-borne encephalitis in the south of Western Siberia. Basing on the results of virological and serological studies we demonstrated a low effectiveness of this host species as a donor of disease agent strains, which are predominant in the territory under study, for ticks feeding on shrews. The analysis of samples taken from the young shrews in winter and spring using reverse RNA transcription with polymerase chain reaction and ELISA revealed occurRence of subvirion components of the tick-borne encephalitis (RNA and capsid protein E) ether in brain, liver or spleen in 90 percent of shrews (n = 42). Neither hemagglutination antigen nor infectious virus have been detected. We discussed a possible epizootic role of the maintenance of non-infectious tick-borne encephalitis virus in overwintering animals.

[A comparison of the immune response induced by DNA or by an inactivated vaccine against tick-borne encephalitis]. / Sravnenie immunnogo otveta, indutsirovannogo DNK ili inaktivirovannoi vaktsinoi protiv kleshchevogo éntsefalita.

BALB/c mice were immunized with recombinant plasmid DNA pSVK3-ENS1 and pcDNAI-NS3 containing, respectively, genes E-NS1 and NS3 of tick-borne encephalitis (TBE) virus. Antibodies to TBE virus proteins were detected in the blood sera of the immunized animals by the method of the enzyme immunoassay. Though the titers of virus-specific antibodies in the sera of mice immunized with protein vaccines exceeded those registered after immunization with DNA vaccines, essential protective immunity was observed after the use of both vaccines.

[Preparation and properties of monoclonal antibodies to tick-borne encephalitis viral nonstructural proteins]. / Poluchenie i svoistva monoklonal'nykh antitel k nestrukturnym belkam virusa kleshchevogo entsefalita.

Hybridomas secreting monoclonal antibodies (Mab) to tick-borne encephalitis (TBE) virus are obtained. Immunodiffusion showed that 3 Mabs to TBE protein NS3 belong to class IgM and the rest to IgG1. Mabs to TBE protein NS1 were tested in hemagglutination inhibition, complement fixation, neutralization, and protection tests. Only 1 hybridoma produced Mab specific for protein NS1 of TBE strain Sofyin, the rest reacted with the common antigenic determinants of nonstructural TBE complex.

[Time course of changes in tuberculosis epidemiological parameters in Iakutia over 12 years (1983-1994)]. / Dinamika osnovnykh épidemiologicheskikh pokazateleí tuberkuleza v Iakutii za 12 let (1983-1994gg).

In the past 12 years, there were 1.3- and 1.9-fold reductions in the total morbidity rates of tuberculosis and its spread, respectively. However, its morbidity among children showed 3-fold increases. The reduction rate of bacterial excretion became much slower in the past 4 years. Tuberculosis mortality rates tended to rise. At the moment of study, the basic tuberculosis epidemiological parameters were 1.3-1.5 times higher than those in the Russian Federation. At the same time there was a decrease in the efficiency of antituberculous work at all levels.

[Recurrence of pulmonary tuberculosis in adults in the areas of the Republic of Sakha (Iakutia)]. / Retsidivy tuberkuleza legkikh u vzroslykh v ulusakh Respubliki Sakha (Iakutia).

The dynamics in recurrences of pulmonary tuberculosis was analyzed in the areas of Yakutia. The social and clinical characteristics of patients with recurrences and their treatment outcomes are presented in the paper. Recurrences of pulmonary tuberculosis were found to occur more frequently in the areas having a poor epidemiological tuberculosis situation and among socially unprotected groups of the population. Under these conditions, recurrences may occur in 30 years or more after clinical cure of tuberculosis. To treat patients with recurrences in the area presents great difficulties.

Antibodies against tick-borne encephalitis virus (TBEV) non-structural and structural proteins in human sera and spinal fluid.

Western immunoblotting of the serum and spinal fluid of patients with tick-borne encephalitis (TBE) revealed the presence of antibodies against non-structural and internal virion proteins. Antibodies against different viral proteins have been shown to appear 8 days postinfection and to circulate for more than 2 months in case of acute TBE. Antibodies against structural glycoprotein E and non-structural glycoprotein NS1 do not prevail over antibodies against other kinds of viral proteins. The large viral non-structural proteins NS5 and NS3 and small hydrophobic proteins NS2A and NS4B can cause an effective immune response as well. There is no strong correlation between immune response spectrum and fever or meningitis forms of disease. However, sera of patients with chronic TBE contained IgM antibodies to virus-specific proteins more than 1 year later and IgG antibodies with very low titers (if any).