[Analysis of structural divergence of H1N1 serotype influenza virus individual genes]. / Analiz strukturnoi izmenchivosti individual'nykh genov épidemicheskikh shtammov virusa grippa serotipa H1N1.

A comparative structural analysis of H1N1 influenza virus isolated in 1977 (the A/USSR/90/77 strain) and H1N1 isolates of 1947 (the A/FM/1/47 strain) and 1950 (the A/FW/1/50 strain) have been carried out by oligonucleotide mapping of individual viral RNA segments. Seven of eight genes of A/USSR/90/77 strain have a high degree of homology with corresponding genes of A/FW/1/50 strain, especially the genes coding the NP and P2 proteins. At the same time the gene coding matrix (M) protein has higher structural similarity to the corresponding gene of A/FM/1/47 strain. Based on the results presented one may conclude that the A/USSR/90/77 epidemic strain is a recombinant virus.

[Identification of the hemagglutinating antigens of the influenza virus by immunoenzyme analysis]. / Identifikatsiia gemaggliutiniruiushchikh antigenov virusa grippa metodom immunofermentnogo analiza.

Highly active test sera detecting the presence of virus antigen both in concentrated and purified preparations and in allantoic virus cultures directly adsorbed on the solid phase have been proposed for successful identification and detection of influenza A and B virus variants. After direct sorption of purified and concentrated virus preparations, the test sera to influenza A (H1N1, H2N2, H3N2) virus detect the virus antigen in a concentration of 8 ng/ml, test sera to influenza B virus in a concentration of 40 ng/ml. After sorption on the solid phase of allantoic virus cultures the test sera detected influenza A virus antigen in a dose of 0.25-1 agglutinating units (AU), and antigen of influenza B virus in a dose of 1-2 AU.

[Oligopeptides of the nucleocapsid proteins of influenza A viruses]. / Oligopeptidy belkov nukleokapsida virusov grippa A.

The method of oligopeptide mapping has shown the presence of similar oligopeptides in nucleocapsid proteins of various influenza viruses, and at the same time diverse oligopeptides in different viruses. This indicates shifts in the sequences of aminoacid residues in various influenza viruses. Various oligopeptide composition of nucleoprotein is marked not only in the viruses with shift hemagglutinin differences (H1 and H3), but also in the drift-variants of viruses (H0-H1).

[Heterologous system of immunoenzyme analysis for the diagnosis of human rotavirus infection and its comparison with RNA electrophoresis]. / Geterologichnaia sistema immunofermentnogo analiza dlia diagnostiki rotavirusnoi infektsii cheloveka i ee sopostavlenie s élektroforezom RNK.

On the basis of porcine rotavirus a heterologous EIA test system was worked out and tested for diagnosis of human rotavirus infection. A high sensitivity and specificity of the test system was demonstrated, its results were compared with those of electron microscopy, diffuse precipitation test, and RNA electrophoresis. Out of 201 specimens (fecal filtrates) collected from children ranging in ages from 14 days to 10 years, rotavirus antigen was detected in 68 (33.8%) RNA electrophoresis demonstrated the rotaviruses circulating in Moscow to have basically the same electrophoretic type, although rotaviruses with other electrophoretic types, including the "short" electrophoretic type, were also detected.

[Etiological study of the fatal cases in the period of the influenza A epidemic of 1977-1978]. / Izuchenie étiologii letal'nykh sluchaev v period épidemii grippa A 1977-1978 gg.

The etiology of the disease, the age structure of fatalities, the time of death were studied in 34 fatal cases in the period of influenza A (H1N1) epidemic in December 1977-February 1978 and in 33 fatal cases during influenza A/Victoria/3/75 (H3N2) epidemic in January-March, 1975 (data from some autopsy offices of Kiev). The results of the investigation of the etiology by immunofluorescence and the histological methods were mostly similar. The polyetiological structure of the diseases in the influenza epidemic of 1975 and rather monoetiological one in the influenza epidemic of 1977-1978 were observed. In 1975, fatal cases were found mostly in 2 age groups: infants under 1 year and adults over 20, in 1977-1978 in 4 age groups: infants under 1, children of 1-3, over 9, and adults. In both epidemics the maximum number of fatal cases coincided with the beginning of a decline in the epidemic wave and subsequently they were registered evenly for over one month. A high infection rate with a new influenza A virus variant (H1N1) was found among normal subjects in all age groups.

[Antigenic determinants of human influenza viruses among the influenza viruses isolated from animals]. / Antigennye determinanty virusov grippa cheloveka v sostave grippoznykh virusov, vydelennykh ot zhivotnykh.

Comparative studies of the antigenic properties of hemagglutinin (HA) of animal and human viruses revealed both similarities between them and complete differences in the composition of antigenic determinants. Avian influenza viruses A/chicken/Kamchatka/12/71, A/pintail/Primorie/730/76, and A/bat/Alma-Ata/73/77 were completely identical with human strains of influenza virus. Influenza A/horse/Miami/63 contains one antigenic determinant H3.1.HA of A/tern/Turkmenia/18/73 (Hav7) viruses has a peculiar set of antigens. Apart from two antigenic determinants H3.1 and H3.3 inherent in human virus strains, HA of A/tern/Turkmenia/18/73 virus contains an antigenic determinant the population of antibodies to which shows no relation to HA of subtypes Hav2-Hav9.

[Determination of the antigenic specificity of the neuraminidase of influenza viruses]. / Opredelenie antigennoi spetsifichnosti neiraminidazy virusov grippa.

The principal possibility of using beta-propiolactone-inactivated and lyophilized antigens of influenza A and B viruses and of mouse immune ascitic fluids to them for the determination of the antigenic specificity of neuraminidase has first been established. A simpler and easier method requiring no expensive reagents: inhibition of influenza virus release from erythrocytes was tested. This method is as specific as the labour-consuming and difficult test of neuraminidase activity inhibition, and allows a rapid and accurate identification of the type of neuraminidase of influenza viruses of various origins to be made.

[Circulation of viruses of the California serocomplex (Bunyaviridae, Bunyavirus) in the central and southern parts of the Russian plain]. / Tsirkuliatsiia virusov serokompleksa kaliforniia (Bunyaviridae, Bunyavirus) v tsentral'noi i iuzhnoi chastiakh Russkoi ravniny.

Seventy strains of California group viruses were isolated in the Central and Southern territories of the Russian plain situated in the Southern taiga, mixed forest, broad-leaved forest, forest-steppe, steppe, and semiarid zones. Sixty-three of these were isolated from 873,300 mosquitoes, 4 from patients, and 3 from rodents. 57.1% of strains were isolated from Aedes communis and the associated species, 28.5% from Aedes excrucians and associated species, and rarely from other mosquito species. The mosquito infection rate was the highest in the Southern taiga zone: 0.0103%, this value decreasing towards the Southern areas. Out of 70 isolated strains 42.3% were identified as the Inkoo virus, 47.2% wer ejust referred to the California group, and only 2.8% were Tahyna and snowshoe hare viruses. The findings of serological screening of the population correlate with the results of virological studies of mosquitoes. Population morbidity is mainly caused by the Inkoo virus in the Southern taiga and mixed and broad-leaved forest, by Inkoo and Tahyna viruses in the steppe and forest-steppe zones, and by Tahyna virus in semiarid zone.

[Distribution of viruses from the Californian encephalitis serogroup (Bunyaviridae, Bunyavirus) in the northern expanses of Russia]. / Rasprostranenie virusov serogruppy Kaliforniiskogo éntsefalita (Bunyaviridae, Bunyavirus) v severnykh shirotakh Rossii.

The study was carried out in 1983-1991 and covered a territory of about 10 x 10(6) km2 in various physico-geographic areas (East Fennoscandia, Northern Russian Plain, West Siberia, Central Siberia, North-Eastern Siberia, and Northern Pacific Region) in the Arctic, Subarctic, Northern-Central-Southern taiga, forest-steppe, and steppe in Northern Russia. A total of 251 strains were isolated from 1391,900 mosquitoes, identified as the California group snowshoe hare (83), Inkoo (44), and Tahyna (2) viruses; 122 strains were not completely identified. Some of the strains with uncommon antigenic composition can be natural reassortants. Fifty-two percent of strains were isolated from Aedes communis and the associate species of mosquitoes, other hosts were A. excrucians (8%), A. cantans (6.25%), A. flavescens (6.25%), A. ciprius (6.25%), A. punctor (4.5%), A. vexans (4.5%), A. cataphylla (3.6%), A. nigripes (3.6%), and A. hexodontus (2.6%). The infection rate of mosquitoes was 0.009% in the tundra, 0.012% in forest-tundra, 0.01% in Northern taiga, 0.02% in Central taiga, 0.017% in Southern taiga, 0.026% in forest-steppe, and 0.097% in steppe. The epidemic season is one month in the tundra (from the beginning of July till the beginning of August), two months in Northern taiga (July-August), and three months in Central taiga (from the second half of June till the beginning of September). The highest infection rate of mosquitoes was observed at the end of the epidemic season in all regions. SSH strains prevailed to the East from the Enisei river, whereas to the West and in the Subarctic regions INK virus predominated, SSH being rare; in the taiga the distribution was quite the opposite. TAH virus was virtually absent. Human morbidity was observed in all territories studied. The immune stratum of adult population is about 30% in the tundra and forest-tundra and about 50% in Northern and Central taiga.

[Standardization of preparations intended for the serodiagnosis of arboviruses]. / Standartizatsiia preparatov, prednaznachenykh dlia serodiagnostiki arbovirusov.

As the result of our research work, 3 reference preparations have been first obtained and studied in accordance with all requirements of biological standardization. These preparations are the national standard of yellow fever antiserum and immune ascitic fluids (IAF) used as reference reagents: IAF to tick-borne encephalitis virus and IAF to Japanese encephalitis virus. The new preparations are stable, possess sufficient specific activity and can be used as standard preparations for the identification of the above-mentioned viruses.