[Influenza viruses and atherosclerosis: the role of atherosclerotic plaques in prolonging the persistent form of influenza infection]. / Virusy grippa i ateroskleroz: rol' ateroskleroticheskikh bliashek v podderzhanii persistentnoi formy grippoznoi infektsii.

It was established that viral particles, like low-density lipoproteins (LDLP), when subjected to some modification changes, lost their ability to be internalized by tissue somatic cells and acquired tropism to macrophage cells. The data, obtained by us by using the polymerase chain reaction (PCR) method, made it possible to assert that atherosclerotic plaques, isolated from vessels of patients with ischemic heart disease (IHD) who underwent coronary bypass, contained RNA of the A(HINI) and AH3N3) influenza viruses. Whereas, the vessel portions, undamaged by atherosclerosis, did not contain any genetic substances of influenza viruses. It was for the first time that an experimentally supported understanding was expressed on that the atherosclerotic plaques serve as a "reservoir" for influenza viruses. It is also suggested that the mentioned plaques can be the carriers of influenza viruses for a long time, thus, prolonging the persistent form of influenza infection in the human body.

[Influenza virus infection in progressing atherosclerosis]. / Infektsiia virusami grippa pri progressiruiushchem ateroskleroze.

AIM: To study relationship between influenza virus infection and activity of clinical presentations of atherosclerosis. METHODS AND RESULTS: Average blood level of IgG to influenza A virus was significantly higher in patients with progressing forms of ischemic heart disease then in patients without objective signs of exacerbation of atherosclerotic process. Mean titles of antibodies to parainfluenza virus and adenoviruses were similar in both groups of patients. Direct detection of viral DNA by polymerase chain reaction was carried out in samples of aortic wall taken during coronary artery bypass surgery with the use of primers for hemagglutinin of H1N1, H3N2 viruses. RNA of influenza virus was found in these samples. CONCLUSION: The presence of viral RNA in vascular atherosclerotic lesions could be indicative of possible pathogenetic role of influenza infection in progression of clinical course of atherosclerosis.

[Molecular epidemiology of rotaviruses circulating among residents of St. Petersburg from 1986 through 1991]. / Molekuliarnaia epidemiologiia rotavirusov, tsirkulirovavshikh sredi naseleniia Sankt-Peterburga v period s 1986 po 1991.

The results of screening of 510 patients with acute gastrointestinal diseases over the period of 1986 to 1991 are presented. Rotaviruses were shown to be the infection agents in 112 (60%) children and 76 (40%) adults. The phoretyping of the isolated strains revealed cocirculation of 17 different phoretypes of rotaviruses: 8 "long" and 9 "short" ones. At the same time, two predominant phoretypes were found to alternately circulate in various epidemic seasons. The "long" phoretypes were found to be equally prevalent among adults and children, whereas the "short" phoretype rotaviruses were isolated mainly from children. The cyclic pattern of circulation of rotavirus phoretypes and genetic changeability of these viruses as a factor determining the prevalence of rotaviral infection are discussed.

[Comparative study of genomes of present-day influenza A and B viruses]. / Sravnitel'noe izuchenie genomov sovremennykh virusov grippa A i B.

The electrophoretic mobility of RNA fragments was used to study epidemic influenza viruses A and B as compared with the reference strains and virological findings. Among those tested, there was a further drift involving both the genes coding glycosylated proteins and internal and non-structural proteins. The analysis of atypical isolates showed their reassortant nature.

[Study of the nature and mechanism of action of virus neutralizing inhibitors of the blood]. / Izuchenie prirody i mekhanizma deistviia virusneitralizuiushchikh ingibitorov syvorotki krovi.

Low-density lipoproteins (LDL, d 1.0.40-1.053 g/ml) and high-density lipoproteins (subfraction 3 of HDL, d 1.210 g/ml) were isolated by preparative ultracentrifugation at the NaBr density gradient. The findings have led to the conclusion that LDL or beta-LP are not thermolabile, but they represent a thermoresistant serum virus-inhibiting factor. At the same time HDL3 has pronounced thermolabile properties. The mechanisms of action of the above factors are explained in the paper.

[Features of interepidemic influenza A and B viruses]. / Osobennosti mezhépidemicheskikh virusov grippa A i B.

The comparison of interepidemic influenza viruses with the pathogens of resultant influenza epidemics has revealed that they belong to the same type (subtype) of influenza virus. A definite correlation has been found between the antigenic specificity of haemagglutinin of epidemic and interepidemic strains. The antigenic structure of the interepidemic viruses and the pathogens of further epidemics of influenza B viruses have been found to be completely identical. The interepidemic A(H1N1) isolates have been shown to be antigenic analogues of the causative agents of influenza A(H1N1) during the previous epidemics. Despite the time and place of their isolation, as well as the etiology of the previous and subsequent epidemics, the interepidemic influenza A(H3N2) viruses have been ascertained to be similar to the reference A/Bangkok/1/79.

[The receptor-mediated endocytosis of influenza viruses and low-density lipoproteins by tissue cells]. / Retseptoroposredovannyi éndotsitoz virusov grippa i lipoproteidov nizkoi plotnosti kletkami tkanei.

The experimental data obtained by immunological, immunomorphological, biochemical, and virological methods are presented which substantiate a concept that various strains of influenza virus under study may penetrate tissue cells at sites of high affinity usually meant for low-density lipoproteins (LDLP) providing the cells with cholesterol for construction of outer and inner membranes. A computer analysis of a bank of data on the primary structure of proteins (the package of GENBER programme) revealed significant similarity of amino acid sequences between the area of viral hemagglutinin site attachment to cells and corresponding amino acids comprising apoB LDLP. The presented proofs are a convincing example of virus particles mimicry realized at the molecular level and give new concepts concerning the mechanisms of virus penetration into body cells which are important for the development of a principally new approach to creation of highly effective antiviral compounds. Moreover, the observed phenomenon may serve for explanation of the nature and mechanism of action of the so-called thermostable virus-neutralizing blood serum inhibitor.

[Long-term carriers of genomic structures of the influenza virus in the blood leukocytes of children with congenital pathology of central nervous system]. / Dlitelnoe nositelstvo genomnykh struktur virusa grippa v leikotsitakh krovi detei s vrozhdennoi patologiei tsentralnoi nervnoi sistemy.

Children with central nervous abnormality were followed up for a long time (180 days). The clinical samples (nasal swabs, blood samples) were investigated for influenza virus antigens or RNA detection by virologic and molecular biological techniques. No viral isolate was found throughout the follow-up. The use of the polymerase chain reaction made it possible to reveal the long-term persistence (for 180 days) of NS- and genes of influenza A (H1N1) viruses in the leukocytes and of HA-gene in the nasal swabs. No NS-gene was found in the nasal swabs. The polymerase chain reaction appears to be more effective for the diagnosis of persistent influenza infection that the conventional techniques--immunofluorescence and enzyme-linked immunosorbent assay (ELISA).

[Polymorphism of current human influenza A and B virus population]. / Polimorfizm populiatsii sovremennykh virusov grippa A i B cheloveka.

During the past years, the etiological situation has been significantly complicated. It is characterized by simultaneous circulation of A(H1N1), A(H3N2) and influenza B viruses and by the isolation of reassortant strains and viruses, which are atypical in relation to the process of their natural variability. The antigenic properties of epidemic strains and unusual isolates were investigated. The marked heterogeneity of the A(H3N2) influenza viruses was demonstrated. It was determined by the circulation of several antigenic variants during the epidemic. Two separate antigenic lineage of the influenza B viruses--b/Victoria/2/87 and B/Yamagata/16/88--cocirculated in our country in 1991. Since 1986, all the influenza A(H1N1) viruses have been considered to be varieties of the reference strain A/Taiwan/1/86. A direct correlation was found between some atypical viruses and the vaccine strains previously used.

[Immunomorphological changes in the mouse brain after intracerebral administration of a neurotropic strain of influenza virus]. / Immunomorfologicheskie izmeneniia v golovnom mozge myshei pri intratserebral'nom vvedenii neirotropnogo shtamma virusa grippa.

The work dealt with intracerebral inoculation of 150 mice with neurotropic strain of influenza virus A/WSN/33. Virological and immunohistochemical study of virus localization in the mice brain was carried out. It was shown that virus reproduction in ependymal lining cells and plexus choroideus epithelium is followed by destruction of cells and uptake of disintegration products by macrophages. Since the influenza infection is followed by a large number of macrophages involved in gene expression of the main histocompatibility complex, the development of autoimmune reaction with the formation of autoantibodies to brain specific antigens can't be ruled out.

Effective inhibition of viral reproduction by hydrophobised antiviral antibodies.

A method is proposed for the inhibition of viral reproduction in cells by means of fatty-acylated antiviral antibodies which, in contrast to the unmodified antibodies, have the ability to enter the cells. The potential of this technique is demonstrated in experiments involving inhibition of the reproduction of various strains of influenza virus and respiratory syncytial virus.

Fatty acid acylated antibodies against virus suppress its reproduction in cells.

A method for suppression of virus reproduction in cells using fatty acylated antiviral antibodies, which in contrast to non-modified antibodies are capable of intracellular penetration, has been suggested. The addition of stearoylated antiviral antibodies to influenza A/Chili virus-infected cells causes a 100-fold suppression of virus reproduction. Non-modified antibodies do not produce any effect on virus reproduction.

[Antigenic anachronism of influenza viruses A(H2N2) in Leningrad in 1980. II. The laboratory characteristics of influenza A/Leningrad/80 viruses]. / Antigennyi anakhronizm virusov grippa A(H2N2) v Leningrade v 1980 g. Soobshchenie II. Laboratornaia kharakteristika virusov grippa A/Leningrad/80.

As indicated by the results of the hemagglutination inhibition (HAI) test, influenza viruses A/Leningrad/80 contain hemagglutinin (HA), similar to that of virus A/Singapore/1/57 (H2N2). Neuraminidase contained in viruses A/Leningrad/80 belongs to serological subtype N2 and is similar to that of virus A/Singapore/1/57 (H2N2). No differences in the polypeptide composition of the virus-induced proteins of viruses A/Leningrad/527/80, A/Leningrad/549/80, A/Leningrad/553/80 and virus A/Singapore/1/57 used as reference have been detected in the study of their electrophoretic mobility in polyacrylamide gel, as well as the mobility of duplexes obtained by the hybridization of the virion and complement RNA of viruses A/Leningrad/553/80 and A/Singapore/1/57. The results of the HAI test with antisera to purified HA indicate that virus A/Leningrad/549/80 contains HA similar to that of viruses A(H2N2) isolated in 1957, but not in 1964. The HAI test with the sera of polecats having the infection permits the differentiation of viruses A/Leningrad/80 from epidemic viruses A(H2N2) isolated in 1957-1965, including reference virus A/Singapore/1/57. In relation to the latter, the isolates of 1980 are older antigenic mutants. The isolates of 1980 are distinguished from virus A(H2N2), isolated in 1975 from the system of persisting influenza infection in a tissue culture, by mutation in NS-gene and the properties of RNA-polymerase. The authenticity of the isolation of viruses A(H2N2) in Leningrad in 1980 has been proved.