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Biomedical subjects

G Renoux

Publications and source records attributed to G Renoux.

At least 55 records · Page 3Linked to original sources
PubMed1981

Neocortical lateralization of NK activity in mice.

The natural killer (NK) reactivity of mouse spleen cells is controlled by the left brain neocortex and not by the right symmetrical brain area. The finding strongly suggests direct relationships between the central nervous system and the immune system, both involved in biological adaptation for the maintenance of homeostasis and body integrity in relation to the external environment.

Animals↗
PubMed1980

[The cerebral cortex regulates immune responses in the mouse].

Ablation of the left cerebral cortex abrogates the production of thymic hormone, reduces the number of spleen T cells and impairs immunization with sheep erythrocytes. In addition, partial decortication inhibits the ability of sodium diethyldithiocarbamate (DTC) to increase the level of circulating thymic hormone, as well as the number of splenic T cells. Therefore, the cerebral cortex would display an important role to maintain body integrity and relations with the external environment, through its effects on the immune system.

Animals↗
PubMed1980

A semi-automated rapid and sensitive microcytotoxicity assay for antibody-mediated cytolysis.

This technique used a Coulter counter to enumerate the target cells remaining after partial lysis with antibody and complement, followed by the destruction of the lysed cells with pronase. Results obtained by this method are compared with those from conventional dye exclusion tests where the final enzymatic step is omitted. Comparisons were made with an anti-Thy-1.2 serum, a monoclonal anti-Thy-1.2 preparation and an anti-H-2k serum. In all cases the semi-automated test gave better results than the dye exclusion test and proved to be highly sensitive and reproducible.

Animals↗
PubMed1980

The general immunopharmacology of levamisole.

The need for treatments to correct an immunological defect, or to restore an impaired immune response asociated with disease or ageing, has led to the development of nonspecific immunoactive agents. Levamisole, a synthetic low molecular weight compound, is the first member of a new class of drugs which can increase the functions of cellular immunity in normal, healthy laboratory animals. The properties of levamisole have contributed to improved understanding of the molecular events which mediate or trigger immune responses. Levamisole can act either as an immunostimulant agent or an immunosuppressive agent. These apparently paradoxical effects depend upon the dose administered, the timing of its administration, the experimental assay used to measure effects, and the host genetic background. Levamisole's potential for opposite effects explains certain apparent inconsistencies observed in experimental or clinical assays. The drug's actions are modulated by the interaction between the T-cell recruiting efficacy of the sulphur moiety and the cholinergic effects of the imidazole ring. The clinical implications resulting from the immunopharmacological properties of levamisole are obvious: one should avoid its use in diseases without known association with an immune defect, and always attempt to correlate clinical data with modifications of immune parameters, since the therapeutic usefulness of correctly administered levamisole parallels improvement in tests of cellular immunity. Immunomodulators act by modifying the functions of the host cells involved in defences against invaders, and the effectiveness of an immunotherapeutic drug is dependent upon characteristics of the individual host. Thus, therapy with such drugs must be individualised; the appropriate agent and dosage should be chosen according to the immune capabilities of individual patients.

Animals↗
PubMed1980

Induction of differentiation of human null cells into T lymphocytes under the influence of serum of mice treated with sodium diethyldithiocarbamate.

Mouse serum collected 24 hr after administration of sodium diethyldithiocarbamate was shown to convert a subset of null cells, not bearing the human T lymphocyte differentiating antigen (HTLA cells) into HTLA+ cells in man. In addition to inducing surface characteristics of T lymphocytes, the serum of treated mice increased functional activities of human peripheral blood lymphocytes, including the response to Con A and the suppressor activity in vitro.

Animals↗
PubMed1980

Administration of DTC gives evidence of a role of the thymus in the control and regulation of factors inducing thymocyte differentiation in the mouse.

Nude (B6) mice, grafted with a syngeneic thymus, are treated 3 wk later with 25 mg/kg of sodium diethyldithiocarbamate (DTC). Serum sampled 24 h afterwards is heated at 56 degrees C for 45 min and tested over a large range of doses for its in vitro capacity to induce Thy-1+ cells in nu/nu spleen cells. Data are compared with the effects of DTC on ungrafted nude mice, and on B6 and C3 mice. Each group comprised 5 to 6 animals. The thymus of B6 mouse abrogates the action of DTC to induce in thymus-less mice two serum factors, active at different concentrations. The serum of DTC-treated C3 mice has an increased T-cell recruiting activity in contrast with the serum of DTC-treated B6 mice. The findings are interpreted as evidencing the extra-thymic origin of one active factor, and a role for the thymus to regulate the synthesis of both factors.

Animals↗
PubMed1979

Genetic and epigenetic control of levamisole-induced immunostimulation.

Antibody responses to a T-cell dependent antigen, sheep red blood cells, were evaluated in mice of various inbred strains, treated or untreated, with levamisole. These responses appear to be under polygenic control, not associated with the H-2 complex, and modified by a Y-linked component and epigenetic factors revealed by aging. Strain, sex, age and the dose of levamisole all in influenced in an interrelated manner the activity of levamisole. Effects varied from inhibited to unchanged or increased antibody-forming cell numbers, without a direct relationship between the genetic regulation of levamisole effectiveness and a genotypic capacity to respond to the antigenic signal. Therefore, a complex relationship between host, antigen and immunopotentiator appears to be responsible for modifying the production of suppressor or helper influences. The present findings may serve as a warning against the uncritical use of levamisole.

Animals↗
PubMed1979

Immunopotentiation and anabolism induced by sodium diethyldithiocarbamate.

Sodium diethyldithiocarbamate, DTC, enhances over a large range of doses macrophage listericidal capacity and T cell activities in terms of increased IgG-antibody forming spleen cells and delayed hypersensitivity levels. Such immunopotentiation is not associated with splenomegalia or increase in lymphocyte counts. Immunopotentiation requires a preexisting link between carbon disulfide and diethylamine, since both moieties were inactive if administered alone or on separate body sites. DTC demonstrates also an anabolic effect on mice emanciated by administering a B. melitensis cell-wall fraction. The role of DTC on hormonal production is discussed in relation to hormone-mediated action on T cell induction.

Adjuvants, Immunologic↗