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Biomedical subjects

S M Klimenko

Publications and source records attributed to S M Klimenko.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

[Electron microscopic study of the interaction of influenza virus murine peritoneal macrophages].

Electron microscopic study of mouse peritoneal macrophages infected with influenza virus showed typical phenomena of phagocytosis (absorption, invagination of plasma membrane, and formation of phagosomes) to occur at early stages of virus-cell interaction, up to 2 hours. At later stages, from 3 to 24 hours postinfection, virus particles were completely absent and virus antigen was present in most cells indicating the distruction of phagocytized virus. These observations confirm an important role of macrophages in antiviral immunity.

Animals↗
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[Chronic infection of cells with tick-borne encephalitis virus. Additional characteristics of the provirus].

The paper presents additional characteristics of HEp-2 cells cronically infested with tick-borne encephalitis virus, Sofyin strain (Hep-2-Sof). On the basis of the inhibition analysis, the method of molecular hybridization, and transfection, HEp-2-Sof cells were shown to contain dozens of DNA-transcripts of tick-borne encephalitis virus integrated into nucleoplasm DNA and into the fraction of repeated sequences. Their transcription is mediated by a polymerase sensitive to L-amanitine.

Amantadine↗
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[Electron microscopic analysis of the individual genes of the influenza virus].

The lengths of fragments of influenza virus strain A/USSR/90/77 (H1N1) genome RNA separated by electrophoresis and treatment with 0.25 M glyoxal solution were measured. The number of nucleotides of these fragments was estimated in regard to marker ribosomal 16 S and 23 S E. coli RNA. The results were compared with analogous data obtained by other methods.

Base Sequence↗
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[Morphological study of a mixed alphavirus infection].

In combined paired cultivation of 8 Venezuelan equine encephalomyelitis virus, multiploid virions formed in 17.8% of cases. Five clones with this effect were used in mixed infections with clones of Semliki Forest and Sindbis viruses. In these infections changes in virions of the virus progeny were observed in 20% and 16.6%, respectively. Mixed cultivation of pairs of Sindbis and Semliki Forest viruses resulted in formation of multiploid virions in 42.8%. Besides, in two mixed populations formed upon combined multiplication of the latter viruses virions of unusual shapes were found: rounded, oval, elongated, and triangular designated as polymorphic.

Animals↗
PubMedDate not supplied

[Structural study of influenza A virus virions using cryogenic methods].

The method of cryospalling was used to study formation of influenza A virus virion on the plasma membrane and to study the inner topography of virus membrane. This method is significantly superior to the others in that cryofixation of the native material constitutes one of its steps. The experiments showed that all budding virus particles were characteristically elongated and virions separating from the membrane acquired spherical shape. The mechanism of this phenomenon is discussed. Characteristics of four types of spalls of isolated virions are presented. An assumption is made with regard to the nature of intramembrane particles on the E-plane of influenza virion lipid membrane.

Freeze Fracturing↗
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[Biological and genetic properties of a polyploid-forming mutant of the Venezuelan equine encephalomyelitis virus].

Some genetic and biological properties of the multiploid -forming mutant of Venezuelan equine encephalomyelitis virus as well as of standard and multiploid virions isolated from its population were analysed. The mutant steadily retained the capacity for formation of multiploid virions comprising up to 20% of the population both in passages in CEF culture and in the progeny of multiploid and standard virions. Owing to this, the concentration of multiploid virions in the population of this mutant remains at a constant level. Formation of multiploid virions compensates for the temperature-sensitive defect inherent in the standard virions which is associated with later stages of virus replication.

Animals↗
PubMedDate not supplied

[Electron microscopic study of the genome homology of simian adenoviruses].

DNA homologies of simian adenoviruses SA7, SV20, SV30, SV38, and SA7(C8), clone 230, were studied. The genomes of SV20, SV30, and SV38 differ from each other insignificantly (at least 85% of homology), but from the SA7 genome significantly (50-70% of homology). DNAs of SV20, SV30, and SV38 contain four main regions of melting in 90% formamide: two terminal A-T-rich regions are located symmetrically on the termini of the molecules, and two on the right parts of the molecules. SA7 virus DNA differs from that of the three above-mentioned viruses by the A-T composition and contains only two regions of melting on the right part of the molecule under similar denaturating conditions. SV20, SV30, and SV38 DNAs contain the inverted terminal repetitions of the order of 147 nucleotides long, and SA7 DNA contains considerably longer inverted terminal repetition: 230 nucleotides.

Adenoviridae↗
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[Multiploid virions of the Venezuelan equine encephalomyelitis virus. Isolation and properties].

Multiploid virions present in the population of multiploid-forming mutant of Venezuelan equine encephalomyelitis (VEE) virus were isolated from preparations of purified and concentrated virus by methods of zonal centrifugation in glycerin density gradient or gel filtration through biogel A-150 m. The portion of multiploid particles in such preparations reached 70%-90%. The isolated multiploid virions retained their morphology, infectivity and hemagglutinating activity. The multiploid particles were found to differ from standard virions in the sedimentation rate and buoyant density.

Animals↗
PubMedDate not supplied

[Study results and the unresolved problems in the epidemiology and prevention of parenteral viral hepatitis in Russia].

Great differences in the activity of the epidemic process of hepatitis B (HB), the occurrence of HBsAg among the population of different regions of Russia (in the central and northwestern regions among 1.8-2.4% of the population, in Tuva among 9.8% of the population, in Yakutia among 11.6% of the population) and considerable differences in the occurrence of HBeAg among HBsAg carriers in these regions (antibodies to delta virus have been detected in 1.3-5.5% of carriers of this antigen in the European part of Russia and in 21.0% of carriers in Tuva) are shown. The structure of the transmission routes of HB virus, the proportion of the artificial and natural routes of its transmission are analyzed. The data on the frequency of cases of perinatal and intrafamily HB virus infection in regions with different activity of the epidemic process, as well as the data on effectiveness of measures for the prevention of posttransfusion HB and parenteral infection during therapeutic and diagnostic interventions, are given. The results of the use of Engerix B vaccine among 2,500 persons belonging to groups of risk are presented. The proportion of hepatitis C (HC) cases among patients with different kinds of acute and chronic viral hepatitis among the population of different regions and the occurrence of anti-HC antibodies among the population of different regions of Russia (in Moscow and St. Petersburg among 1.1-1.2% of the population, in North Caucasia among 4.5% of the population), as well as in high risk groups (3.1% among medical personnel, 19.4% among drug addicts, 25% among patients of hemodialysis wards, ets), are considered. The structure of transmission routes of HC virus is analyzed, the possible measures for the prophylaxis of HC virus infection are considered.

Adolescent↗
PubMedDate not supplied

[The isolation of the herpesvirus from yaks during the epizootic in Mongolia in 1990].

Strains of virus belonging, according to the results of electron microscopic examinations, to the herpes virus family, were isolated in Vero cell culture from the organs and aphtha secretions in the buccal cavity of yaks developing the disease during an epizootic (more than 500 animals) in Khubsugul aimak (Mongolian village) in Mongolia, 1990. Virus-neutralizing antibodies were detected in the blood sera of the sick animals. The isolated strains differ from herpes viruses affecting man. No infection could be induced by materials of the sick animals in cows and oxen of different breeds in Mongolia. Seroepidemiological surveys are planned because of the mass character of the disease and its repeated occurrence.

Animals↗
PubMedDate not supplied

[Morphological analysis of a cell system, infected with different strains of the human immunodeficiency virus].

Cell systems infected with 63 strains of types 1 and 2 HIV virus (HIV-1 and HIV-2) were examined under electron microscope. HIV virions were most frequently detected near the cell membrane or budding from it. In the cytoplasm HIV occurred only in vacuole-like formations. Accumulations of mature virions were seen in the cell-to-cell space. Mature particles of HIV-1 and HIV-2 differed by their morphology from oncoviral C particles and were similar rater to the Visna/Medi type Lentiviruses. Morphological analysis of HIV strains isolated in Russia demonstrated their similarity to be foreign HIV strains.

Cell Line↗
PubMedDate not supplied

[Expression of human immunodeficiency virus gag antigens and formation of virus-like particles in a cell culture, infected with recombinant vaccinia virus strains (an electron-microscopic study)].

The synthesis of gag antigens of human immunodeficiency virus (HIV) by recombinant vaccinia virus strains containing the expressed genes gag and gag-pol and the capacity of these proteins to formation of virus-like particles during infection of various cell cultures were studied. The recombinant strain containing the truncated gag gene (p48gag) was shown to effectively synthesize gag polypeptides and to form immature virus-like particles during infection of all the cell cultures tested (CV-1, Hep-2, HT-29). The morphogenesis of mature virus-like particles was detected by electron microscopy only in infection of Hep-2 cells with a strain containing a complete gag-pol sequence of HIV.

Animals↗