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Biomedical subjects

A D Chernousov

Publications and source records attributed to A D Chernousov.

18 recordsLinked to original sources
PubMed1992

[The possibilities of using immunological indices as criteria for determining the stage of HIV infection and the disease prognosis].

The authors studied the immune status of 14 HIV-infected patients, 6 of whom had lymphadenopathy, 4 were diagnosed as having AIDS-related complex and 4, a full-blown AIDS. Analysis of laboratory findings showed that of predictive value are serum levels of immunoglobulin B, a CD4 cell count less than 200, reduced populations of CD20 and CD16 lymphocytes, and a depressed response to pokeweed mitogen. Based on the clinical manifestations and laboratory results, three stages characterizing the immune system in HIV infection have been identified.

AIDS-Related Complex↗
PubMed1989

[Mechanism of the inhibition of proliferation of hapten-modified human and mouse leukemic cells by hapten-specific T-suppressor factor].

T-suppressor-inducer and T-suppressor-effector hybridoma supernatants both regulating the DTH reaction intensity triggered by trinitrophenyl-sulphonic acid (TNPSA) or antigen-dependent proliferation of mice lymph node cells to trinitrophenylated bovine serum albumin, possess and ability to inhibit proliferation of TNPSA-modified human and mice leukaemic cells. This effect is specific, and is caused from antigen binding. This effect is specific, and is caused from antigen binding, idiotype positive T-suppressor factors and is based on a cyclic adenosine monophosphate increase of the concentration in target cells.

Animals↗
PubMed1987

[Model of a stable form of delayed hypersensitivity to chemical allergens].

The injection to mice of a water-soluble form of a chemical allergen (2, 4, 6-trinitrophenylsulfonic acid) in Freund Complete Adjuvant resulted in the development of extremely intensive and persistent (more than 14 weeks) sensibilization which was determined by skin tests. Depending on the challenge, the persistence of skin reactions varied from 48 to 244 hours, but an early component was detected 6 hours after the injection. When this sensibilization method is applied, the effectors of delayed type hypersensitivity are formed in the regional lymph nodes.

Allergens↗
PubMed1986

[Characteristics of 2 types of antigen-binding T suppressors formed during an immune response using T-T hybridomas and their extracts].

Antigen-binding T cells of mice immunized with low doses of syngenic spleen cells modified by 2,4,6-trinitrophenyl sulphonic acid, were fused with BW 5147.3.13 thymoma subclone. Suppressor hybridomas were not identical in their differentiating antigens and functional activity. Extract from Lyt 1-2+ hybridoma suppressed efferent and afferent limbs of delayed type hypersensitivity (DTH) in recipients sensitized with subcutaneous injection of 3 X 10(7) TNP-SC. Extract from Lyt 1+2+ I-hybridoma suppressed only afferent DTH limb. It is suggested that during DTH induction with low doses of hapten-modified cells the generation of different types of antigen-binding DTH T suppressors takes place.

Animals↗
PubMed1983

[Induction of T-suppressors of delayed-type hypersensitivity with a background of T-effector formation].

Administration to mice of 10(5) syngeneic splenocytes modified with trinitrobenzene sulfonic acid leads to the formation of a population of T suppressors which are capable to sorb on a specific antigen. In recipients, these cells suppress only one phase of the induction of delayed type hypersensitivity (DTH). Their precursors are sensitive to the action of low doses of cyclophosphamide. The formation of the suppressors in question occurs during the generation of T effectors of DTH. It is suggested that the suppressors described may be attributed to Tc3 which are activated in the lymph nodes as a result of subcutaneous sensitization with antigen, and which are similar to Tc1 but have the Ly 2+ phenotype.

Animals↗
PubMed1982

[Parallel formation of delayed-hypersensitivity effectors and T-suppressors in the intraperitoneal administration of a massive dose of ram erythrocytes].

Injection of 6 X 10(9) sheep red blood cells (SRBC) to mice led to parallel formation, on days 4-5, of delayed hypersensitivity effector cells (the activity was tested in local transfer experiments) and delayed hypersensitivity T-suppressors preventing sensitization of syngeneic recipients. After massive injection of SRBC the activity of spleen suppressors gave 2 peaks: on days 5 and 14. Five days after massive antigen injection only T-cells capable of sorbing on a specific antigen manifested suppressor activity. On day 14 T-cells capable of sorbing on specific antibodies showed a specific activity, whereas T-cells capable of sorbing on a specific antigen retained only part of their activity. The mechanism of delayed hypersensitivity inhibition following massive antigen injection by suppressors obtained by day 5 is reviewed in terms of Germain and Benacerraf's theory postulating that delayed hypersensitivity is regulated by Ly 2+, I-J+ antiidiotypic suppressors capable of sorbing on specific antibodies and formed upon injection of Ly 1+, I-J+, Id+ inductor cells capable of sorbing on a specific antigen.

Animals↗
PubMed1981

[Genetic restriction on interaction between the effects of delayed hypersensitivity and suppressor cells].

Injection of a massive dose of sheep red blood cells (SRBC) to mice leads to activation of delayed type hypersensitivity (DTH) T suppressors in the spleen. T suppressors inhibit sensitization of syngeneic recipients with an optimal dose of SRBC. They also inhibit sensitization when transferred to syngeneic recipients and to semi-syngeneic strains. An obligatory condition for efficient suppression transfer was H-2 compatibility. Suppressor cells inhibited activation of DTH effector progenitors during the first day after the transfer. However, some of allogeneic cells persist in intact recipients for 4 days. Analysis of the data obtained shows that the absence of suppressions in H-2 incompatible mice is due to genetic restriction of cell interaction rather than to rejection of donors' cells.

Animals↗
PubMed1981

[Regulation of the intensity of delayed-type hypersensitivity to sheep erythrocytes by the K-region of the major histocompatibility complex in mice].

The injection of 6 x 10(9) sheep red blood cells (SRBC) to mice suppressed the delayed type hypersensitivity (DTH) in situ and activated spleen T cells which prevent sensitization of syngeneic recipients. Similar effect was obtained when suppressor cells induced in F1 hybrids were transferred to parental mice. Suppression was also reached in allogeneic strain combination if suppressor cells of donors and recipients shared the major histocompatibility complex (MHC). Studied performed with recombinant and mutant strains revealed that the prerequisite for interaction of DTH suppressors and effectors was the identity of K-region of MHC. Passive transfer of DTH to SRBC was also possible if donors and recipients were identical in K-region of MHC. It is believed that interaction between DTH suppressors and effectors is restricted by a region of MHC whose product takes part in antigen representation.

Animals↗
PubMed1979

[Suppression of delayed hypersensitivity in mice receiving a massive dose of xenogeneic erythrocytes].

The injection of 6x109 sheep red blood cells to mice suppresses delayed-type hypersensitivity (DTH) in situ and activates spleen cells which prevent sensitization of recipients. Preliminary thymectomy of donors and the treatment of cell suspensions with anti-T-globulin abolish suppression of DTH. Pretreatment of mice with low doses of cyclophosphamide (CY) enhances antibody formation and DTH. Higher doses of CY increase the DTH reaction but inhibit antibody formation. The data obtained allow to conclude that suppression of DTH is due to the activity of short-living, intensively proliferating cells of thymic origin and possibly to B cells.

Animals↗
PubMed1979

[Development of delayed hypersensitivity to sheep erythrocytes after separate and combined administration of the antigen and cyclophosphamide].

The ability to the development of delayed hypersensitivity (DHS) to the appropriate antigen was studied in mice treated with large doses of SRBC and cyclophosphamide at varying time prior to the experiment. Suppression of DHS development induced by administering either the cytostatic alone or a large dose of the antigen was examined at the same periods of time. The combined treatment was shown to induce tolerance according to diverse tests for DHS (skin and macrophage migration inhibition tests). At the basis of this tolerance lies genuine deficiency of the appropriate clone of T cells. Administration of cyclophosphamide alone leads to a slight suppression of DHS, while a large dose of the antigen induces a different form of areactivity due to the suppressor cells whose nature is not yet clear.

Animals↗
PubMed1979

[Effect of thymectomy on induction of immunologic tolerance in the effectors of delayed hypersensitivity].

The influence of thymectomy (Tx) on induction of tolerance of delayed type hypersensitivity effectors (DHE) was examined. Tx did not interfere with induction of tolerance to sheep red blood cells (SRBC) achieved with combined injections of the massive dose of the antigen and cyclophosphamide (Cy). Tx resulted in prolongation of unresponsiveness. The injection of mice with the massive dose of SRBC alone also resulted in tolerance formation. However, this type of tolghtly depressed formation of DHE in intact but not in Cy treated mice. The results obtained are in agreement with the idea of the existence of diverse mechanisms of tolerance induction (clonic-deficient and suppressor). These data also suggest the existence of two subpopulations differing in susceptibility to Cy and Tx in DHE effectors and their precursors.

Animals↗
PubMedDate not supplied

[The immunotropic and allergenic activity of hydroxyapatite with an ultrahigh degree of dispersion].

Hydroxyapatite is a well-known biologic material intended for intraosseous implantation which is widely used in practical dentistry. The agent causes no inflammatory reaction at the site of administration and is not characterized by acute or chronic toxicity. The possibility of development of specific contraindications against hydroxyapatite has not yet been studied; such contraindications might be connected with its possible immunotropism and allergenic activity which are to this or that measure present in all materials used for implantation into the bone. Since hydroxyapatite is known as surfactant, we used in our studies its modification characterized by the highest specific surface known at present, and therefore the most biochemically active. "Cold", that is, not exposed to high-temperature treatment ceramics was used in order to prevent reduction of hydroxyapatite reaction capacity. Complex of animal experiments showed that hydroxyapatite cannot possess immunotropic or allergenic characteristics.

Animals↗