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Z V Shevtsova

Publications and source records attributed to Z V Shevtsova.

47 records · Page 3Linked to original sources
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[A trial of a hepatitis A cultured inactivated vaccine on rhesus macaques].

In this work experimental model of hepatitis A virus (HAV) infection in macaques rhesus was used. In 6 seronegative monkeys immunized with the inactivated vaccine (3 injections of 0.3 micrograms of viral protein each at an interval of 1 month) pronounced antibody response was observed. The dynamics and titers of anti-HAV antibodies were similar to those in 5 rhesus macaques which received the active virus. But, in contrast to the latter, no IgM antibodies were detected in the immunized animals. Three months after the end of immunization the monkeys were resistant to challenge with a HAV strain pathogenic for humans (10(3) - 10(4) ID50). The monkeys had no morphological changes in the liver and no rise in the serum alanine-amino transferase activity, but exhibited transient excretion of the virus in feces, as well as stimulation of anti-HAV antibodies (in the absence of IgM antibodies). The vaccine under test proved to be safe, immunogenic and produced a protective effect.

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[Spontaneous coronavirus infection in monkeys].

A high level of the spread of coronavirus (CV) infection among hamadryas baboons and macaques of different species (about 50%), both resident in the animal house and imported, has been established. The tropism of CV to the gastrointestinal and respiratory tracts has been demonstrated. The course of spontaneous CV infection is accompanied by enterocolitis and/or pneumonia with periodic exacerbations, or takes the inapparent form. Cases of virus persistence have also been noted. Infected macaques exhibited an increase in the titers of antibodies to their own CV strain isolated from these animals, as well as to antigenically related human CV strain 0043. Spontaneous CV infection in monkeys may be used for solving some obscure problems of the pathogenesis and epidemiology of CV infection in humans.

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[The experimental coronavirus infection of monkeys].

The coronavirus (CV) infection has been reproduced on monkeys (Macaca mulatta) for the first time. The strain CVRM 281, obtained from rhesus monkey who died of the spontaneous CV injection, has been used for the infection. The experimental CV infection has a chronic current with periodical relapses and virus persistence. Gastrointestinal tract (enterocolitis) and respiratory tract (pneumonia) are damaged exhibiting characteristic histological lesions. The monkey model of the CV injection can be used to solve obscure questions of human one.

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[The properties of simian coronavirus].

Properties of 20 coronavirus (CV) isolates obtained from spontaneously infected Papio hamadryas and rhesus monkeys were investigated. Two of them were selected as simian CV prototype strains-CVRM 281 (rhesus monkey) and CVP 250 (Papio hamadryas), and can be offered as candidates to the Coronaviridae family. They are closely related to each other, but differ in some biological properties and polypeptides. These strains belong to the 2nd antigen group of mammalian CV with the prototype strain HCV OC 43 but differ from the latter. The strain CVRM 281 induces experimental CV infection which can be used as a model for investigations of some obscure aspects of human infection. The properties of these viruses suggest their usefulness for diagnostic purposes.

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[Experimental models of hepatitis A in macaques using viral strains isolated from man and monkeys].

Experimental hepatitis A (HA) models were obtained in macaca monkeys (15 M. fascicularis and 4 M. mulatta) by means of the strains of hepatitis A virus (HAV) isolated from the feces of a patient (HAV-H) and of spontaneously infected M. Mulatta (HAV-MM) and green monkeys Cercopithecus aethiops (HAV-CA). Irrespective of the strains used all seronegative macaca monkeys developed HA after intravenous-oral inoculation with the following patterns: elevation of the serum alanine aminotransferase level, HAV shedding in feces, seroconversion with the appearance of anti-HAV IgM and morphological changes in the liver characteristic of acute hepatitis. HAV in fecal samples and elevation of alanine aminotransferase were periodically detected. Periods of their discovery varied from 5-22 to 15-47 days and those of morphological changes in the liver from 9-24 to 40-83 days. The results of the experiments show that experimental HA models in Macaca monkeys are no less adequate than the previous ones developed in chimpanzees (Pan troglodytes), marmosets (Saguinus mystax) and owl monkeys (Aotus trivirgatus), but they are more readily available. Both strain HAV-H and strains from monkeys can be used for HA modelling. The models are expected to be used for studying yet unsolved problems of pathogenesis and immunogenesis, as well as for testing vaccines and antiviral drugs.

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[Preparation and characteristics of cultured strains of hepatitis A virus from humans and monkeys].

Cultural strains of hepatitis A virus (HAV) have been isolated from spontaneously infected Macaca mulatta (HAV-MM), Papio hamadryas (HAV-PH), African green monkeys Cercopithecus aethiops (HAV-CA), and patients (HAV-H). The strains replicate in continuous cells lines AGMK, 4647, Vero, and FRhk-4. AGMK and 4647 cells are the most permissive at 32 degrees C. Virus propagation was not associated with the cytopathic effect and could be detected by enzyme immunoassay (EIA), immune electron microscopy (IEM), and molecular hybridization method (MHM). The morphological and antigenic properties of the above monkey and human strains did not differ in EIA and IEM with polyclonal antibodies and for one most conservative genome sites in the VP1 domain. Cultural strains retained their pathogenicity for monkeys. HAV strains are proposed to be used as HAV antigen in immunological tests and for hepatitis A induction in monkeys.

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[An experimental study of immunity to hepatitis A in monkeys].

In this work the experimental model of hepatitis A on monkeys, adequate to human hepatitis A, was used. Ten monkeys (6 Macaca mulatta and 4 Cercopithecus aethiops) were reinfected with different doses of hepatitis A virus (HAV) a year after recovery from spontaneous and experimental hepatitis A. The monkeys were completely resistant to the inoculation of the virus in moderate doses (10(3) ID50). The inoculation of HAV in large doses (10(4)-10(5) ID50) induced a mild form of this infection in the animals with a transient rise in the level of serum alanin aminotransferase and HAV shedding in feces, but in the absence of morphological changes in the liver. It should be specially pointed out that after the reinfection of monkeys virus shedding in feces was observed, which may be of great epidemiological importance. After reinfection the absence of IgM and a pronounced rise in the titers of IgC antibodies were observed.

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[Characteristics of experimental models of hepatitis A in Papio hamadryas].

Hepatitis A (HA) was induced in 14 Papio hamadryas by strain VHA-PH isolated from this species of monkeys with spontaneous infection, strain VHA-MM isolated from Macaca mulatta, and a unique strain VHA-H3 isolated from a patient; this latter strain is pathogenic for Macaca mulatta in experiment. All infected seronegative animals developed a disease with virological, serological, biochemical, and morphological signs characteristic of human HA, but the duration of these signs manifestation varied. Virus in the feces and an increased level of SGPT were detected periodically starting from days 3-26 to 24-135, and in 4 monkeys even later (up to days 163-238). Morphologic changes in the liver, typical of acute hepatitis, were observed from days 10-46 to days 16-130. Strain VHA-H3 is less pathogenic for papios. HA models on Papio hamadryas infected with strains VHA-PH and VHA-MM can help solve many research and practical problems.

Alanine Transaminase↗
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[Secondary infection with hepatitis A in Rhesus monkeys after experimental inoculation].

Time course of specific humoral immunity is studied in 186 Macaca mulatta spontaneously infected with hepatitis A virus (HAV). Immunity parameters are characterized quantitatively and qualitatively and their similarity to those in human hepatitis A (HA) is demonstrated. Repeated HA was reproduced in 12 seropositive Macaca mulatta infected with HAV-MR in high doses. The disease was characterized either by periodical virus release with feces for 1.5-2 months (10(4) ID50) or by that together with a notable increase of SGPT for 1.5-4 months (10(5) ID50) without morphologic changes in the liver, indicating a lesser severity of infection. Reinfection was associated with a rapid expressed increase of class G anti-HAV titers to 20,000-74,000 and no class M antibodies. Virus release with feces in the absence of the main specific diagnostic criterion, IgM antibodies, may be epidemiologically significant. Hyperimmune sera from monkeys with reinfection are intended to be used as the antibody component of immune diagnostic agent.

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