[Evolutionary variability of influenza B viruses in Russian Federation in 2005-2012].

Specific traits of influenza B viruses circulation in Russia and worldwide in 2005-2012 were studied and the amount of influenza B viruses in the whole population of influenza viruses isolated in Russia was estimated. The trend toward antigenic drift for both Victoria and Yamagata lineages was characterized. The genetic analysis revealed amino acid changes that influenced the antigenic properties of the viruses. The match of the epidemic isolates and vaccine strains was corroborated.

[Etiological characteristics of the influenza epidemics of 2006-2009 in the Russian Federation (according to the data of the Research Institute of Influenza, North-Western Branch, Russian Academy of Medical Sciences)].

The basic trends in the evolution of influenza A and B in the Russian Federation during the epidemic seasons of 2006-2009 were studied on the basis of an antigenic analysis of 1774 Influenza isolated at the Research Institute of Influenza (RII), North-Western Branch, Russian Academy of Medical Sciences, and sent from resting bases (the regional centers of the Russian Inspectorate for the Protection of Consumer Rights and Human Welfare, which collaborate with the RII). Although the trends in the substitution of representative strains generally coincide with the world patterns, the authors revealed some specific features of the antigenic drift of influenza viruses in the Russian Federation and regional varieties. Data on some biological properties and those of the antigenic analysis of the first pandemic influenza A(H1NI)v strains isolated at the RII from Saint Petersburg patients in July-August 2009 are also given in the paper.

[Molecular characteristic of influenza virus A H5N1 Strains isolated from poultry in Kurgan Region in 2005].

During the latter half of 2005 a widespread outbreak caused by influenza highly pathogenic H5N1 virus among wild and domestic birds occurred in Russia. As pathogenicity level is a polygenic feature and majority of individual genes of influenza A viruses contribute to pathogenicity of influenza viruses to birds, animals and humans. Nucleotide sequencing of the entire genome of influenza H5N1 virus isolates obtained in Kurgan region (Western Siberia) was performed. Structure of viral proteins was analyzed according to the predicted amino acid sequences. HA receptor-binding site of A/chicken/Kurgan/05/2005 and A/duck/Kurgan/08/2005 strains was typical for avian influenza viruses and contained Glu and Gly at positions 226 and 228, respectively. Structure of the cluster of positively charged amino acid residues at the cleavage site was identical for all isolates: QGERRRKKR. According to the data of neuraminidase structure analysis NA of the H5N1 isolates tested was suggested to belong to Z genotype. Amino acid residues typical for birds were revealed in 30 out of 32 positions of M1, M2, NP, PA and PB2 proteins determining host range specificity. One strain isolated in Kurgan contained lysine in position 627 of PB2 protein. Kurgan isolates was shown to have remantadine-sensitive genotype. Glutamic acid was found at position 92 of NS1 protein in both strains indicating virus resistance to interferon. Phylogenetic analyses allowed relating Kurgan isolates to subclade II of clade II of highly pathogenic H5N1 influenza viruses.

Etiology of influenza viruses isolated in Russia from 1998 up to present time.

Influenza epidemic events in Russia from 1998 up to 2005 were associated with the circulation of influenza A (H3N2), A (H1N1) and B viruses. The antigenic analysis revealed that the evolution of A (H3N2) viruses proceeded as following: A/Sydney/05/97-->A/Panama/2007/99-->A/Fujian/411/02-->A/Wellington/01/04; A (H1N1) viruses: A/Bayern/07/95-->A/Bejing/262/95-->A/New Caledonia/20/99; B viruses evolved as two distinct lineages: Victoria- and Yamagata-like viruses. Our results have shown that the evolution in Russia coincided the World trends.

[Analysis of etiology of influenza-like morbidity and monitoring influenza epidemic of 1998-1999 by laboratory diagnosis methods]. / Analiz étiologicheskoi struktury grippopodobnoi zabolevaemosti i monitoring épidemii grippa 1998-1999 gg. s ispol'zovaniem metodov laboratornoi diagnostiki.

The etiological structure of influenza-like was analyzed in the population in cities and towns and in Russia as a whole in November 1998 to April 1999 by the findings of immunofluorescence and serological surveys of patients with acute respiratory viral infections (ARVI). By the results of both tests, the proportion of the incidence of influenza A (H3N2) was largest, the decreasing order in their significance was as follows: adenoviruses, type 3 parainfluenza virus, RSV, influenza B virus, influenza A(H1N1), types 2 and 1 parainfluenza virus. All influenza viruses A(H1N1) were isolated in Samara in February 1999. Three of them were similar to the reference strain A/Johannesburg/82/96 in antigenic properties, two strains appeared to be its drift variants. No A/Beijing/262/95 (H1N1)-like viruses recommended for incorporation as part of vaccines were detected. All influenza A(H3N2) viruses were drift variants of strain A/Sydney/05/97, and all influenza B viruses were similar to the reference strain B/Harbin/07/94 in antigenic structure.

[The etiological structure of the morbidity from influenza and other ARDs on the territory of Russia in the season of 1997-1998]. / Etiologicheskaia struktura zabolevaemosti grippom i drugimi ORZ na territorii Rossii, sezon 1997--1998 gg.

The antigenic properties of 51 strains of influenza virus A(H1N1), isolated in different cities of Russia during the epidemic of 1998, were studied. Most of these strains (49) proved to be similar to virus A/Bern/07/95 in the antigenic structure of hemagglutinin, but 2 strains isolated in Ulan-Ude were found to be closely related to new antigenic variants of this virus: A/Beijing/262/95 and A/Fukuoka/c7/98. The analysis of the antigenic structure of influenza-like diseases (ILD) in different cities of Russia revealed that adenoviruses causing up to 10.9-14.6% of all acute respiratory virus infections dominated at the pre- and post-epidemic periods. RS-viruses, parainfluenza viruses of types 2 and 3 circulated during the whole season (their proportion was 5.1-6.6%). The intensity of the circulation of influenza viruses A(H1N1) and A(H3N2) increased, starting from January, and continued till April 1998; its peak was observed in February-March in most of the cities of Russia (up to 37.5-41.6% according to the results of immunofluorescent diagnostics and 53-73% of ILD according to the results of the hemagglutination inhibition test). The occurrence of influenza B during this season was very low.

[Influenza C: the immunological aspects of the problem]. / Gripp C: immunologicheskie aspekty problemy.

The use of the complex of methods for the characterization of cell-mediated and humoral immunity to influenza C virus has made it possible to establish that with the increase of the age of children and, simultaneously, with the increase of the number of persons found to be seropositive to influenza C the asymptomatic forms of this infection occur more frequently. Practically all examined adults selected by random choice have proved to be immune to this infective agent. The results of this investigation indicate that influenza C virus constantly circulates among the population.

[Enhanced antitumor action of 5-fluorouracil when used in combination with 4-methylmercaptopyrazolo[3,4-d]pyrimidine 1-nucleoside]. / Povyshenie protivoopukholevogo deistviia 5-ftoruratsila pri kombinirovannom primenenii s 1-nukleozidom 4-metilmerkaptopirazolo[3,4-d]pirimidina.

Mice BDF1 with L 1210 or mice BALB/c with plasmacytoma MOPS-406 after pretreatment with ineffective doses of 1-beta-D-ribofuranosyl-4-methylmercaptopyrazolo(3,4-d)pyramidin e (25 to 100 mg/kg per 5 days) were treated with 5-fluorouracil at the optimal dose 100 mg per day. This combination produced a 1.5-2-fold or 2 to 4 fold enhancement of the antitumour effect of 5-fluorouracil without simultaneous increase of lethal toxicity.

[Ribamidyl (ribavirin) as a modulator of the biological action of arabinosylcytosine and methotrexate]. / Ribamidil (ribavirin) kak moduliator biologicheskogo deistviia arabinoziltsitozina i metotreksata.

Administration of ribamidyl (Rb) prior to Ara-C to intact mice or mice with implanted tumours enhanced Ara-C toxicity. The growth of tumours (plasmacytoma MOPC-21, adenocarcinoma of the small intestine (strain AKATON), mammary adenocarcinoma 755 (Ca 755) resistant to Ara-C or Rb was inhibited after coadministration of these drugs. The augmentation of toxic and antitumour effects of Ara-C by Rb is similar to the described effect of high doses of thymidine. This is in accordance with the enhancement of the intracellular pool of thymidine phosphates under the action of Rb. The toxicity of methotrexate in vivo was increased by coadministration with Rb. This effect may be connected with a decrease in purine precursors pool under the action of Rb.

[Ribamidil as a modulator of the toxic effect of 5-fluorouracil]. / Ribamidil kak moduliator toksicheskogo éffekta 5-ftoruratsila.

The in vitro experiments on CaOv cells demonstrated that ribamidyl (ribavirine) (Rb) enhances the intracellular pool of pyrimidine precursors of DNA. This was the basis for studies of its modifying effect on the antitumour activity of antimetabolites. In experiments with intact hybrid mice F1 (CBA+C57B1) the five times administration of ribavirine increase sharply the toxicity of 5-FU. The data should be taken into consideration when combining Rb with antimetabolites in clinical practice.