[Correlation between the receptor specificity of pandemic influenza A (H1N1)pdm09 virus strains isolated in 2009-2011 and the structure of the receptor-binding site and the probability of fatal primary viral pneumonia].

The receptor specificity (RS) of pandemic influenza A(H1N1) pdm09 virus strains deposited into the State Collection of Viruses of the Russian Federation, D. I. Ivanovsky Research Institute of Virology, Ministry of Health and Social Development of Russia, in the 2009-2010 and 2010-2011 epidemic seasons to a panel of 9 sialoglycopolymers (SGP). The strains were divided into 3 groups according to the W(3/6) index proposed by the authors, which was equal to the amount of reactivities to unbranched alpha2-3-SGP to that of reactivities to unbranched alphal-6-SGP: W(3/6) < or = 1.0; 1.0 < W(3/6) < or = 1.5. The W(3/6) < or = 1.5 group showed a predominance of a2-3-RS, attended by the high incidence of fatal primary viral pneumonias (FPVP) (60.0%) and amino acid replacements in the HA1 receptor-binding site (RBS) (80.0%): D222{G, N} and Q223R. The 1.0 < W(3/6) < or = 1.5 group was characterized by mixed alpha2-3/alpha2-6-RS with the incidence of FPVP (29.7%) and amino acid replacements in the HA1 RBS (40.5%) (D222{G, N, V} and Q223), respectively. In the W(3/6) < or = 1.0 group, alpha2-6-RS was prevalent, FPVPs were absent and amino acid replacements in HA1 RBS (D222{G, E}) were seen only in 6.0% of cases. The number of strains with increased specificity to alpha2-3-sialosides increased in the 2010-2011 epidemic season as compared to the previous season. With their further spread among the population, there may be a rise in cases of severe primary viral pneumonias with possible fatal outcomes, which can be, however, accompanied by a decrease in the capacity of mutants to air-dropwise transmission.

Effects of dehydroepiandrosterone sulfate on the conversion of corticosterone into 11-dehydrocorticosterone in stress: a regulatory scheme.

In male rats, repeated but not single exposures to stress increased the conversion of corticosterone (CS) to 11-dehydrocorticosterone (11-DHCS), particularly on the background of administration of dehydroepiandrosterone sulfate (DHEAS). Naltrexone given 20 min before DHEAS at a dose of 0.1 mg/kg, at which it selectively blocks mu opioid receptors, prevented this effect of DHEAS, which is evidence that it is mediated by mu opioid receptors. This action of DHEAS involved endogenous ACTH and was thus mediated by central regulatory mechanisms. Our results, along with published data, lead to the first proposed scheme for the physiological regulation of the interconversion of CS and 11-DHCS in conditions of repeated stress with the involvement of DHEAS and mu opioid receptors.

[Dynamics organ blood flow in rats in postnatal ontogenesis].

In the 4-, 13-, 30-, and 65- 90-day-old Wistar rats the voluminous blood flow rate was measured in liver, kidney, small intestine wall, and in the predominantly white gracilis muscle of femur. A LAKK-01 laser-Doppler flowmeter and its cutaneous (for kidney) and needle (for other organs) probes were used; they provided estimation of blood flow (per organ mass unit) to the tissue depth of about 1 mm. It has been found that the blood flow rates (per organ mass unit fall in liver, intestine, and even more in muscle, whereas increase in kidney, particularly for the first month of life. Calculations show that in adult rats as compared with the 4-day-old pups (with their mass exceeding 22 times) the blood flow to muscle, liver, intestine, and kidney should rise 14, 17, 18 and 43 times, respectively.

[Dehydroepiandrosterone sulfate effect at the conversion of corticosterone to 11-dehydrocorticosterone in stress conditions: the scheme of regulation].

It had been shown that the reaction of conversion of corticosterone (CS) to 11-dehydrocorticosterone (11-DHCS) was increased in chronic intermissions, but not in sharp stress influences in male rats, especially under dehydroepiandrosterone sulfate (DHEAS) employment. The injection of naltrexone 20 min before DHEAS in dose 0.1 mg/kg which selectively blocked the mu-opiate receptors canceled this effect that indicated the participation of in-opiate receptors in such regulation. The DHEAS effect realized through the endogenous ACTH, and such was of the central nature. On the base of ourselves and the literature dates we intraduced the scheme of DHEAS- and mu-opiate-dependent regulation of CS/11-DHCS interchangings.

[Native and renatured oligomer-dependent epitopes of intracellular influenza virus nucleocapsid protein].

Intracellular NP oligomers have been shown to react with some anti-NP monoclonal antibodies (mAbs) in radio-immnoprecipitation, immunoblotting, and dot immunoassay. Soluble NP monomers obtained after thermal dissociation of NP oligomers are not recognized by mAbs unlike the NP monomers whose concentration increased by about 100-fold due to transfer to the nitrocellulose membrane after polyacrylamide gel electrophoresis. The findings demonstrated that in the intact NP oligomers there were epitopes determined by their quaternary structure. These oligomer-dependent epitopes may be renaturated in vitro under the conditions allowing for a concentration-dependent NP-NP association.

[Relationship of nuclear import of influenza virus nucleoprotein polymers to their conformational status].

It has been earlier shown that in the cells infected with influenza virus, the molecules of nucleoprotein (NP) are polymers that differ in their conformational maturity and stability. The present investigation has studied the ability of different conformational forms of NP polymers to migrate into the nucleus. Conformationally mature compact NP oligomers are shown to predominantly import into the nucleus. In contrast, unstable, loose, and conformationally immature NP multimers accumulate in the cytoplasm and do not migrate into the nucleus. The present investigation is the first evidence for that that the conformational maturity of influenza virus NPs is essential for their nuclear traffic and, hence, for participation in the transcription and replication of viral genomes.

[The denydroepiandrosterone sulfate thyroid activation through the mu-opioid receptors under cold influences].

Denydroepiandrosterone-sulfate (DHEAS) effects on total thyroxine (tT4), total triiodothyronine (tT3), and free thyroxine (tT4) levels were studied in male rats under single or repeated (for 19 days, 1 hr a day) cold influences, as well as participation of mu-opioid receptor effects in DHEAS (30 mg/kg). It was shown that the increased tT4 and tT3 levels under repeated cold influences were more obvious after DHEAS injections. The opioid antagonist naltrexone in the dose 0.1 mg/kg reversed the DHEAS effect. These data suggest involvement of mu-opioid receptors in that thyroid activation. Under a single cold influence DHEAS did not produce the effects at tT4, or tT3 levels, and the action of mu-opioid receptor blocker in this situation was not manifested. The fT4 levels were obviously increased both under repeated or single cold influences, but the DHEAS and naltrexone actions were absent.

[The muscular blood flow in rats in ontogenesis as measured by the needle probe laser Doppler flowmeter "LAKK-01"].

In anesthetized Wistar rats of the age of 4, 13, 30 and 90 days, blood flow in m. gracilis was measured with the aid of laser-Doppler flowmeter "LAKK-01" with a needle probe. The sharpest postnatal falling of a muscular blood flow was revealed in the first month of life. Features of measurement of the blood flow and biological background by a needle probe in skeletal muscles of rats of various age described.

[Two types of NP-NP associations in influenza virus-infected cells].

Two types of NP-NP associations are shown to form in the influenza virus-infected cells. Early NP synthesis gives rise to NP associations stabilized by relatively weak bonds. These structures are designed as NP multimers. The high protease- and heat-sensitivities allow NP-multimers to be regarded as incompletely folded proteins. Post-translationally, NP-multimers transform to compact NP associations (NP oligomers) that are relatively highly heat-and protease-resistant. The NP-multimers untransformed to the folded compact NP-oligomers accumulate in the cells and partially degraded. Whether both types of NP-NP associations may be of significance is under discussion.

[Effect of Panavir on influenza A virus reproduction].

Mitogenic properties of panavir, as well as its effect on the grippe virus reproduction in cell systems in vitro and the effect on the survival of mice with the experimental grippe infection were studied. It was shown that panavir had no cytotoxic action whereas it was characterized by pronounced mitogenic activity and subsequently could be considered as a perspective immunomodulator. Under in vitro conditions with the use of relatively high doses for the cell contamination with the grippe virus, panavir lowered the virus production in the cell systems. When the contaminating doses were low, panavir inhibited the virus production detected at the early stages of the infection. In the in vivo studies on mice with the experimental grippe infection panavir showed antigrippe activity against both the romantadine resistant and the remantadine nonresistant populations of the grippe A virus.

[Mitotic activity of pial microvascular endothelium rat in postnatal ontogenesis].

Mitotic activity of endothelium in pial microvessels has been studied with the aid of intra-vessel autoradiography in 4-, 12- and 30-day old rats using these parameters: number of labeled nuclei per vessel or per 100 mcm of its length, or per 1 mm2 endothelial surface area, as well as number of vessels with labeled endothelium cells. The first parameter was independent of vessel diameter. The other parameters had highest value in the pericapillary vessels in all rats. These values decrease with rat age. The highest rate of brain growth was revealed after reaching the greatest mitotic endothelium activity in pial bed.

[Temporary acquisition of intra-chain disulphide bonds by nucleocapsid protein of influenza virus].

The in vitro reducing agents were shown to promote the NP-NP association and to stabilize the NP oligomers, which dissociate when heated in non-reducing buffer. This confirms that non-covalent linkages in electrophoresis stabilize the influenza virus NP oligomers. The mobility of pulse-labeled and chased NPs in PAGE as well as their sensitivity to protease were investigated. The S-S bonds reduce at later stages of conformational maturation of NP; the disulfide-containing NP transforms itself into an NP free of S-S bonds with non-covalently linked NP-oligomers being subsequently formed. Presumably, the early disulfide-dependent stage in NP maturation is needed for the correct NP-NP association and for the protection of early monomeric NPs against protease action.

[Proliferative activity of blood microvascular endothelium of intestinal mesentery during rat postnatal ontogenesis]. / Proliferativnaia aktivnost' éndoteliia krovenosnykh mikrososudov kishechnoi bryzheiki u krys linii Vistar v postnatal'nom ontogeneze.

The study of mitotic activity of mesenteric microvascular endothelium cells (EC) in 4-, 12-, and 30-day old rats has been carried out using following parameters: number of labeled nuclei per vessel, or per 100 microm of vascular length, or per 1 mm2 of endothelial surface area, as well as shares of labeled EC and of vessels with labeled EC, have been estimated. The highest density of labeled nuclei was revealed in the pericapillary vessels in all rats. Its values were significantly higher in 12-day-old rats and were the lowest in 30-day-old ones.

[Physicians and the population on the reforming of public health (based on sociological research data)]. / Vrachi i naselenie o reformirovanii zhdravookhraneniia (po dannym sotsiologicheskogo issledovaniia).

A sociological analysis of the opinions of physicians and population on public health reforms was carried out during the period of active introduction of obligatory medical insurance in Russia, that is, in July-August 1994 and 1995. A total of 4000 questionnaires distributed among the population and 2500 among physicians were analyzed using the random cluster and typological proportional sampling. The paper presents statistical data disclosing the opinion of the population and physicians on the process of introducing obligatory medical insurance as the priority improvement in the activity of outpatient health centers and on other reforms in public health. Analysis of public opinion demonstrated the difficulties of the present period and the reserves in improving the reformation of public health which may be used to ensure guaranteed volume of medical care rendered to the population.

[Determination of specific hepatitis A markers by a radioimmunological method with autoradiographic recording of the results]. / Opredelenie spetsificheskikh markerov gepatita A radioimmunologicheskim metodom s avtoradiograficheskoi registratsiei rezul'tatov.

The possibility of determining specific markers of hepatitis A by a simple variant of radioimmunoassay on a polyethylene film with autoradiographic recording of the results was demonstrated. The high sensitivity of the method, an extremely simple procedure, no necessity of special radiometric apparatuses, visual demonstration and reliability of the results recommend it for hepatitis A diagnosis.

[Antigenic determinant study of the hemagglutinin in the composition of influenza viruses A subtype H1N1 by an indirect solid-phase radioimmunological analytical method]. / Izuchenie antigennykh determinant gemaggliutinina v sostave virusov grippa A podtipa H1N1 metodom nepriamogo tverdofazovogo radioimmunologicheskogo analiza.

A comparative study of antigenic determinants of influenza A virus, subtype H1N1, hemagglutinins isolated in 1947-1953 and in 1977-1979 was carried out. The competitive capacity of 8 virus strains for antibody of 4 hyperimmune antisera to A/Fm/1/47, A/Moscow/Pan/52, A/USSR/090/77, and A/Brazil/11/78 viruses was studied by solid-phase radioimmunoassay (SPRIA) in two modifications: in the homologous and heterologous systems. The analysis of competition in the heterologous system permits one to study isolated subpopulations of antibody homologous to viruses fixed on the solid phase. The combination of both modifications allows investigations of a wider spectrum of antibodies than those possible in the homologous system alone. The results of the study showed the antigenic determinants of hemagglutinin exposed on the surface of particles of different influenza A virus strains to differ in their capacity to stimulate antibody synthesis. The analysis of the time course of changes in the antigenic properties of hemagglutinin regions of similar structure in various viral strains may facilitate prognosing of evolution of virus strains of the same subtype.

[Analysis of heterogenous populations of antihemagglutinating antibodies in hyperimmune sera against influenza virus by indirect solid-phase radioimmunoassay]. / Analiz geterogennykh populiatsii antigemaggliutiniruiushchikh antitel v giperimmunnykh syvorotkakh k virusu grippa metodom nepriamogo tverdofazovogo radioimmunologicheskogo issledovaniia.

Populations of antihemagglutinating antibodies in hyperimmune rabbit sera to influenza A/PR8/34, A/Moscow/PAN/52, and A/Swine Iowa/15/31 viruses were examined by indirect competitive solid phase radioimmunoassay (SPRIA). Under conditions of competitive assay with immobilized virus homologous to the serum under test, not all subpopulations of cross-reacting antibodies in the sera are identified. Competition in the system of immobilized heterologous virus identifies a fuller spectrum of cross-reacting antibody. A composite analysis of the sera under both variants of competition showed each of the sera to contain a heterogenous population of antibodies interacting to various extents with determinants of a number of heterologous viruses classified, according to 1971 Nomenclature, as viruses with H0, H1, and Hsw1 hemagglutinin subtypes. The identification of cross-reacting antibodies permitted a conclusion on the existence of both antigenic determinants on the surface of hemagglutinin molecules of the viruses under study and an analysis of their variability. The pattern of changes of similar determinants in transition from viruses of one subtype to viruses of another subtype is characteristic of the drift type.

[Use of indirect solid-phase radioimmunological analysis for studying the antigenic properties of influenza virus]. / Primenenie nepriamogo tverdofaznogo radioimmunologicheskogo analiza dlia izucheniia antigennykh svoistv virusa grippa.

A method of indirect radioimmunoassay (RIA) for investigation of influenza virus antigenic properties and serum titrations was developed. The method is based on the detection of immobilized specific antigen-antibody complexes using 125I-labeled antispecies IgG. Antigen immobilization is done on the surface of polychlorvynil plate wells at alkaline pH, 37 degrees C for 2 hours. As compared with RIA in solution, the solid-phase RIA is a rapid method, the entire reaction taking 5 hours. The method is highly sensitive (dozen ng), reproducible, and economic. The latter property is important for screening of paired sera during epidemiological surveys of large groups of human population, since the small amount of the blood required may be collected from a finger and not from a vein of the patient. Experiments on competitive inhibition of antigen-antibody reaction done by the solid phase RIA permit quantitative evaluation of antigenic relationships among different influenza virus strains.

[Detection of the determinants of influenza virus H3 hemagglutinin by the technic of radioimmunologic analysis]. / Vyiavlenie determinant gemaggliutinina H3 virusov grippa metodom radioimmunologicheskogo analiza.

The interrelations between H3/73 hemagglutinin of human influenza virus and the other 16 mammalian and avian hemagglutinin subtypes (a total of 50 strains) were studied by the method of radioimmunologic analysis (RIA). The antigenic relations of H3, Hav7 and Heq2 were confirmed, certain common determinants were also found in H3/73 hemagglutinin and avian viral Hav6 and Hav9 hemagglutinins. No interrelations were revealed with previously circulating human influenza viruses H0, H1, H2 as well as with swine influenza virus and avian viruses Hav1-Hav5, Hav8. It has been shown that the H3/73 determinant in some avian viruses evolves similarly to drift-variants of human influenza virus. The method can be recommended for fine analysis of influenza virus antigenic structure as it allows detecting small antigenic quantities.