[Topical trends of improving the sanitary-and-epidemiological protection of different territories from bringing extra dangerous viral infections into them and from disseminating such infections]. / Aktual'nye napravleniia sovershenstvovaniia sanitarno-épidemiologicheskoi okhrany territorii ot zavoza i rasprostraneniia osobo opasnykh virusnykh infektsii.

The state-of-art related with the sanitary-and-epidemiological protection of different territories from bringing into them extra dangerous viral infections and from disseminating such infections (which is a topical issue now addressed by WHO, CIS and the Russian Federation) is elucidated in the paper. Possible trends of perfecting the sanitary-and-epidemiological protection of territories in Russia are under discussion. A differential list of extra dangerous viral infections is defined within the framework of the sanitary-and-epidemiological protection of territories.

Congener-specific patterns and toxic assessment of polychlorinated biphenyls in resident and migratory birds from Southern India and Lake Baikal in Russia.

Concentrations of polychlorinated biphenyls (PCBs), including non-, mono-, and di-ortho congeners, were determined in migratory and resident birds collected from India and Lake Baikal in Russia. In the 11 different species examined, total PCBs concentrations were in the range of 11-4500 ng/g (wet wt). IUPAC 105, 118, 138, 153, and 180 were the predominant congeners in almost all the birds. White-cheeked tern collected from India and common tern collected from Lake Baikal showed high PCBs concentrations of 4400 ng/g (wet wt) and 4500 ng/g (wet wt), respectively, and accumulated relatively high ratios of penta-CBs (IUPAC 118, 105, 99). Toxic equivalents (TEQs) of non- and mono-ortho PCB congeners in birds collected from India and Lake Baikal were in the range of 1.5-56 and 2.8-370 pg/g wet wt, respectively. Toxic assessment results led by calculated TEQs of the transfer to eggs from female birds revealed that TEQs in most of migratory and resident birds were comparable to the lowest observable effect level (LOAEL) of chicken which is a highly sensitive species against dioxin-like compounds. Calculated transfer TEQs to eggs of common tern collected from Lake Baikal in autumn, however, exceeded the LOAEL of CYP1A induction in bald eagle embryos and ED50 of that in pheasant embryos, suggesting that embryo toxicity by coplanar PCBs in some avian species breeding in Lake Baikal is possible.

[Filovirus haemorrhagic fevers: Ebola fever]. / Filovirusnye gemorragicheskie lichoradki: lichoradka Ebola.

Epidemiological issues, clinical course and laboratory diagnostics of Ebola haemorrhagic fever are reviewed. The structural features of virions and genetic variants of the virus are described along with ecology of Ebola virus. The data on Ebola fever global morbidity are also presented.

[Dynamics of expression of Marburg and Ebola virus antigens in infected Vero cells ]. / Dinamika ékspressii antigenov virusov Marburg i Ebola v infitsirovannykh kletakh Vero.

Time course of Marburg and Ebola virus antigens expression in Vero cells was studied by indirect immunofluorescence test. The maximum accumulation of virus specific antigens in Vero cells infected with a high dose was observed after 48-54 h of incubation. It is essential for laboratory diagnosis that virus specific antigens can present as incorporations of different shape and size, starting from small hardly discernible granules (immediately after the virus adsorption) to large lumps, cords, accumulations, and diffuse fluorescence.

[The use of monoclonal antibodies for detecting the common antigenic determinants of Brucella spp. and Yersinia enterocolitica O:9]. / Ispol'zovanie monoklonal'nykh antitel dlia vyiavleniia obshchikh antigennykh determinant Brucella spp. i Yersinia enterocolitica O:9.

Monoclonal antibodies (McAb) 2AH10, specifically reacting with protein preparations having mol. wt. of 18 and 38 kD and not interacting with brucellar lipopolysaccharide (LPS) and protein-polysaccharide antigen, have been obtained. As shown with the use of McAb 2AH10, Brucella spp. and Yersinia enterocolitica O:9 possess common antigenic determinants, localized not only in the area of their LPS, which is generally known, but also in the area of their outer cell-wall proteins with mol. wt. 18 and 38 kD. The sensitivity of the solid-phase enzyme immunoassay and the latex agglutination test with the use of McAb 2AH10 is essentially higher in the detection of B. abortus and B. suis, than B. melitensis and B. rangiferi, as well as Y. enterocolitica O:9. Essential differences observed in the detected concentrations of different Brucella species and Y. enterocolitica O:9 are seemingly linked with different expression of specific antigenic determinants, detected with the use of McAb 2AH10 in the corpuscular antigens under study.

[Neutralizing morbillivirus antibodies in the population of the Baikal seal Phoca sibirica]. / Neitralizuiushchie morbillivirus antitela v populiatsii baikal'skikh nerp Phoca sibirica.

The antibodies neutralizing Baikal seal morbillivirus (BSMV) were studied in sera from 148 normal Baikal seals (Phoca sibirica). The virus-neutralizing antibodies were demonstrated in sera of 61.5% of the animals examined. A comparative analysis of antibodies in NT and cell-ELISA method is presented. The role of BSMV in morbidity and mortality of seals (Phoca sibirica) is discussed.

Molecular and serological studies on the recent seal virus epizootics in Europe and Siberia.

The virus epizootics which occurred in seals in both Europe and Siberia during 1987/1988 were caused by two different morbilliviruses, referred to as phocid distemper virus (PDV) 1 and 2, respectively. Molecular and serological studies have shown that the European virus is quite distinct from canine distemper virus (CDV), its closest relative in the morbillivirus group. Analysis of tissues obtained from infected seals from a wide geographical distribution over Northern Europe showed that the infectious agent (PDV 1) was identical in all cases. Nucleotide sequence analysis of one of the virus genes suggested that this virus has evolved away from CDV over a long time period and is most probably an enzootic virus of marine mammals. In contrast, the virus (PDV 2) which caused the deaths of many Siberian seals was indistinguishable, both serologically and at the molecular level, from CDV and must have originated from a land source.

[Ebola virus reproduction in cell cultures]. / Reproduktsiia virusa Ebola v kletochnykh kul'turakh.

Ebola-Zaire virus production in Vero and BGM cells was studied. The CPE developed in both cell cultures. The cell monolayer destruction by 80-90% was seen at a low multiplicity of infection in 7-8 days after virus inoculation. An overlay composition was developed for virus titration using plaque assay. The plaque production was shown to be directly proportional to the virus dose. The curve of Ebola virus production in Vero cell culture fluid was determined. At a multiplicity of infection of 0.01 PFU/cell, the maximum virus titer of 10(6.4) PFU/ml was reached in 7 days postinfection. Specific antisera were generated by inoculation of guinea pigs. Indirect immunofluorescent assay was used for testing of virus-specific antigen and antibody.

[An experimental infection of the seal Phoca sibirica with the morbilli virus]. / Eksperimental'noe infitsirovanie nerpy Phoca sibirica morbillivirusom.

A Baikal seal (Phoca sibirica) was experimentally infected with Baikal seal morbillivirus (BSMV) isolated from Baikal seals during an epizootic in 1987-1988. The seal was infected with BSMV with an infectious titer of 10(7.0) TCD50/ml, and daily observations of the animal clinical condition were made. The virus-specific antibodies in the seal serum were determined by ELISA and virus neutralization test. The clinical picture showed a mild infection. The ELISA-active antibodies were detected 10 days postinfection and reached the maximum in 20 days. Virus-neutralizing antibodies were detected in 16 days after infection, reached the maximum titer of 1:640 in 20 days and remained at this level for 39 days (the observation period). These data indicate that BSMV can induce a disease in the natural host with production of virus-neutralizing antibodies. The results of this work and the earlier reports show that the epizootic in Baikal seals was induced by BSMV.

[The isolation of the morbilli virus from the Baikal seal Phoca sibirica and its preliminary characterization]. / Vydelenie morbillivirusa ot baikal'skoi nerpy Phoca sibirica i ego predvaritel'naia kharakteristika.

A morbillivirus was isolated from the organs of a seal (Phoca sibirica) which had died during 1987-1988 epizootic in Baikal. This Baikal seal morbillivirus (BSM) was adapted to Vero cell cultures in which it induced a cytopathic effect developing to complete destruction of the monolayer. Typing of BSM was done by indirect immunofluorescence test and enzyme immunoassay using antibodies to distemper and measles viruses. A method for virus concentration and purification was developed. According to electron microscopic examinations, the virus virions were spherical particles of heterogeneous sizes over 100 nm in diameter. The clinical picture of seal infection, pathological anatomy and histopathology are described. A possible role of BSM in the epizootics of Baikal seals is discussed.

[Antibodies to morbilli virus of the Baikal seal in its natural host]. / Antitela k morbillivirusu baikal'skoi nerpy u prirodnogo khoziaina.

Morbillivirus of Baikal seal (BSM) was isolated from organs of a dead animal during 1987-1988 epizootic of Baikal seal (Phoca sibirica). A method of cellular enzyme immunoassay for testing for virus-specific antibodies was developed using BSM. The method was used for antibody detection in sera of 115 apparently normal seals collected in the spring of 1989. Antibody to BSM were found in sera from 75 animals. Examinations of seropositive animals of different age and sex were carried out. The results obtained indicate a possible role of BSM in the epizootic.

[Characteristics of different recombinants of the Philippine variety of influenza virus H3N2]. / Kharakteristika razlichnykh rekombinantov filippinskoi raznovidnosti virusa grippa H3N2.

The paper presents the results of generating influenza virus recombinants by hybridization of the laboratory A/PR8/34 strain with epidemic A/Philippines 2/82 virus and studies of a number of their biological properties. A highly temperature-sensitive recombinant with mutational damages in the hemagglutinin gene was detected.

Investigation about the surface structure of some viruses by the freeze-etching and freeze-drying methods.

An electronmicroscopic study of a suspension of Venezuelan equine encephalomyelitis (VEE) virus by freeze-drying and freeze-etching methods showed that glycoprotein peplomers are located on the surface of the lipoprotein shell. These peplomers are trimeric in shape and form a regular icosahedral surface lattice corresponding to T = 4. The modes of glycoproteins clustering for the two clones of VEE are different. Venezuelan equine encephalomyelitis (VEE) virus belongs to the alpha-viruses of the toga-virus family. Virions of VEE virus have the icosahedral nucleocapsid surrounded by a lipoprotein envelope (peplos) and contain single-stranded RNA. During budding, alpha-virus nucleocapsid acquires a host cell lipid membrane in which virus specific glycoproteins are built in (Bonsdorff et al. 1975, Harrison et al. 1974). Earlier the surface peplomer clustering was investigated only for the sindbis virus (Bonsdorff et al. 1975, Bonsdorff et al. 1978).

[Electron paramagnetic resonance study of the structural characteristics of the envelope of the Venezuelan equine encephalitis virus]. / Izuchenie strukturnykh kharakteristik obolochki virusa venesuél'skogo éntsefalomielita loshadei metodom élektronnogo paramagnitnogo rezonansa.

The method of electron paramagnetic resonance and spin labels was used to study the structural characteristics of Venezuelan equine encephalomyelitis virus envelope and cell membranes of chick embryo fibroblasts. The virus envelope lipids form a bilayer structural typical of biological membranes. The lipid bilayer of virions is more rigid than the cytoplasmic membrane of chick embryo fibroblasts. Investigation of interaction of a small hydrophilic molecule with Venezuelan equine encephalomyelitis virus particles showed free water to be absent in the virions. A structural translation was detected at 25 degrees-30 degrees C in the virion membrane. The role of membrane structures in virus reproduction is discussed.

The surface structure of Venezuelan equine encephalomyelitis virus.

An electronmicroscopic study of a suspension of Venezuelan equine encephalomyelitis (VEE) virus by freeze-drying and freeze-etching methods showed that glycoprotein peplomers are located on the surface of the lipoprotein shell. These peplomers are organized with trimer clustering in a T = 4 icosahedral surface lattice. The mode of glycoprotein clustering for the two clones of VEE are different.

Properties of virions and ribonucleoproteins of Venezuelan equine encephalomyelitis virus.

The physicochemical properties of Venezuelan equine encephalomyelitis (VEE) virus and of its ribonucleoprotein (RNP) were studied. Upon purification in a discontinuous or linear sucrose gradient, the losses of infectivity were small (25%), and 96% of cellular proteins were removed. The purified virus was homogeneous with respect of sedimentation rate (s20, w = 265 S). The CsCl gradient was unsuitable for purification of infectious virus because the latter was destroyed at high CsCl concentrations. Buoyant density of the virus in CsCl after formaldehyde fixation was 1.21--1.22 g/cm3. Treatment of the virus with 1% Nonidet P-40 proved to be the most effective method for isolation of the RNP. The structures thus obtained contained practically all of the viral RNA and about 20% of viral proteins, and were homogeneous with respect of sedimentation rate (153 S) and buoyant density (1.40--1.42 g/cm3 in CsCl after formaldehyde fixation). The RNPs were sensitive to ribonuclease.