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Biomedical subjects

G R Matsevich

Publications and source records attributed to G R Matsevich.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

[Variability of the HIV-1 nef regulatory gene and its association with different HIV stages].

Biological properties of HIV-1 laboratory strains and isolates were studies and compared with research results of the nef gene fragment obtained from their proviral DNA and RNA as well as from RNA and HIV-1 DNA isolated immediately from the blood of patients at early HIV stages. The electrophoresis pattern as well as the results of determination of nucleotide sequences showed that the HVI-1 RNA nef gene of rapid/high laboratory strains of HIV isolates and RNA obtained from patients at late infection stages had a 135-nucleotide inner deletion. The phenomenon can be regarded is proof of that nef gene structure, if violated, causes an enhanced virulence of and an intensified multiplication of the virus (according to laboratory markers) observed at late HIV stages, which triggers, at least in a number of cases, the infection aggravation.

Base Sequence↗
PubMedDate not supplied

[Results of examining wild monkeys for the presence of smallpox antibodies and smallpox group viruses].

The results of examinations of sera, blood and organs of different species of monkeys from some Asian and African countries for the presence of antibody to smallpox and viruses of the smallpox group. Significant titers of smallpox antibodies (antihemagglutinins virus-neutralizing and, in some cases, precipitating antibody) were found in a considerable number of monkeys shot near foci with human cases (Equatorial province of Zair Republic). In the same monkeys kidney tissues yielded 3 isolates of smallpox virus group two of which were indistinguishable in the laboratory tests from variola virus. On the basis of these data it is concluded that smallpox viruses circulate among wildlife monkeys in some areas of Equatorial Africa. Further studies along these lines are necessary.

Africa↗
PubMedDate not supplied

[Reverse transcriptase of the human immunodeficiency virus: cloning, expression in Escherichia coli, purification of the enzyme, and production of monoclonal antibodies].

To express HIV-1 reverse transcriptase in E. coli a number of genetic constructions containing reverse transcriptase and virus protease nucleotide sequences was obtained. The products of expression were characterized; monoclonal antibodies to reverse transcriptase were produced. The purification of reverse transcriptase was carried out. The substantial proteolysis of reverse transcriptase during purification was shown. The purified preparation is predominantly, an active protein with Mr 57 kDa. Some properties of this protein differed from the reverse transcriptase isolated from HIV.

Amino Acid Sequence↗
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[Immunoenzyme test systems for detecting the HIV antigen and a trial of their use in examining HIV-infected subjects].

The results of the development and trials of two variants of EIA test system for the detection of HIV-1 antigen using biotinated HIV-antibody and streptavidin-peroxidase or biotin-beta-lactamase enzyme complexes are presented. These diagnostic preparations proved to be highly sensitive and specific allowing the detection of the antigen in the blood of HIV-infected subjects.

Evaluation Studies as Topic↗
PubMedDate not supplied

[The strain features of the HIV-1 circulating in the USSR based on data from a study of its properties in cell cultures].

Both variants of HIV-1 reported in the literature: slow/low and rapid/high types, were detected among the strains isolated from the subjects examined in 4 foci of HIV-1 infection in the south of the RSFSR and Byelorussia. All the 17 strains isolated in the southern RSFSR foci belonged to the slow/low type and had a low and unstable replication potential in donor peripheral blood mononuclear cells and in MT-4 cell line. All of them were isolated from subjects with asymptomatic infection and from children with initial clinical manifestations of the disease. Only one strain isolated in Byelorussia belonged to the rapid/high type. Its replicative activity was very similar to that of the classical HIV-1--HTLV-IIIB strain. Long-term (up to 7 months) propagation of slow/low strains did not result in any increase of their replicative activity. The capacity to form syncytia was found not only in the rapid/high type strains but also in the majority of slow/low strains under study.

Cell Line↗
PubMedDate not supplied

[Stability of the main components of an EIA test system for the serodiagnosis of HIV infection].

The stability of two most important components of the EIA test system for diagnosis of HIV infection, an immunosorbent (HIV antigen adsorbed on polystyrene plates) and antispecies peroxidase conjugate, was studied. The possibility to prolong the shelf life of the test system for at least up to 6 months was demonstrated. At the same time, it is proposed to supplement the existing methods of production control with the conjugate thermostability test developed by the authors who believe that this will allow to exclude conjugates with insufficient stability from the test system kit.

AIDS Serodiagnosis↗
PubMedDate not supplied

[Detection and quantitative determination of antigen to the human immunodeficiency virus during development of a test-system for the serodiagnosis of AIDS].

One of the variants of IFA using a conjugate on the basis of anti-HIV-IgG was used for control of the content of human immunodeficiency virus (HIV) antigen at different stages of production of a test system for serodiagnosis of AIDS. This method permits HIV antigen quantitation in virus lysates, its nonpurified concentrates, and in native culture fluid in titres from 2000 to 60,000 and from less than 27 to greater than 729, respectively. In most cases, high titres of antigen in the liquid fraction of the culture corresponded to high values of the antigen-containing cells on the basis of immunofluorescence data and signs of intensive HIV production in electron microscopic culture control. The authors developed a method allowing to determine the antigen titre in the study material using only one dilution (1:9) of it in IFA technique.

AIDS Serodiagnosis↗
PubMedDate not supplied

[Use of an immune blotting method (western) for studying viral antigens and for detecting antibodies to viral proteins].

The technique of the procedure and the results of the use of immune ("western") blotting method for studies on viral antigens and detection of antibodies to individual proteins of viral particles are described. The possibility of detection and study of individual viral antigens in the whole plasma of patients or carriers is demonstrated by the example of HBs antigen of human hepatitis B virus. The method of immune blotting was used for screening of human sera for the detection of antibodies to the AIDS virus proteins. The sera under study positive for antibodies to AIDS virus by preliminary solid-phase enzyme-immunoassay were shown to contain actually the antibodies to different proteins of AIDS virus. The antibody levels to individual AIDS virus proteins varied in different sera. Some sera positive for antibodies to AIDS virus by the solid-phase enzyme-immunoassay contained no antibody to AIDS virus proteins but reacted with cellular proteins present in the antigen. The immune blotting method was also used for determinations of the spectrum of antibodies in animal sera produced by immunization with different viral antigens.

Animals↗
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[Development and practical use of new experimental models of the various forms of herpetic infection].

New experimental models of neurological herpes in cotton rats and genital herpes in male guinea pigs have been developed which are more adequate to the corresponding human diseases, and models of ophthalmic herpes in rabbits and guinea pigs have been improved. These models may be used for screening and evaluation of the effectiveness of drugs for herpes. A high activity against herpes of bromovinyldeoxyuridine and acyclovir has been verified, a marked therapeutic effect of Soviet monophosphates ara-A, ara-C, and original silur preparation in some forms of herpes infection has been demonstrated.

Animals↗