Search PubMed⌕ Search

Biomedical subjects

J M Guillaumin

Publications and source records attributed to J M Guillaumin.

33 records · Page 2Linked to original sources
PubMed1984

Kinetics of the histological changes in lymphoid organs and of the T-cell inducing capacity of serum in mice treated with Imuthiol (sodium diethyldithiocarbamate).

Sodium diethyldithiocarbamate ( Imuthiol ) triggers in mice an increased production of T-cell recruiting factors and an early and prolonged hyperplasia in the T-cell dependent areas of peripheral lymphoid organs, partially independent from thymus modification. The data confirm previous findings on the role of an extrathymic factor and are consonant with the notion of a feedback regulation to control T-cell differentiation.

Animals↗
PubMed1983

A balanced brain asymmetry modulates T cell-mediated events.

Partial ablation of the left fronto-parietal cerebral cortex decreases the number of spleen T cells, impairs IgG-alpha SRBC and T mitogen-induced responses, and delays the response to alloantigens. In contrast, these events are increased following a symmetric lesion of the right neocortex. The findings extend previous results showing that the neocortex modulates NK activity and the efficacy of T cell-specific serum factors. B cells and macrophages are not affected. In these assays, mice subjected to ablation of one lateral cerebral neocortex serve as controls for symmetrically lesioned mice, in addition to no surgery or sham-operated controls. The findings suggest that brain lateralization for cognitive processes should be extended to T cell immune recognition. The phenomenon is present at a population level.

Animals↗
PubMed1983

The production of T-cell-inducing factors in mice is controlled by the brain neocortex.

The synthesis of factors that monitor the expression of the Thy-1 cell surface component by marker-negative precursor cells requires an intact left cerebral cortex, whereas the activity of sodium diethyldithiocarbamate, an immunopotentiator that increases this synthesis, seems to require an intact right neocortex. These results suggest a role for the cerebral cortex in the coordinated interregulation of lymphocyte subclasses. The finding extends previous information suggesting relationships between the central nervous system and the T-cell arm of the immune system.

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↗
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

Isoprinosine as an immunopotentiator.

Isoprinosine is a compound developed for antiviral use. The effects of isoprinosine on mouse responses to sheep red blood cells were studied over a wide range of doses, from 0.5 microgram/kg to 5 g/kg, i.p. administered at the time of i.v. immunization or as pretreatment for 7 days before antigenic stimulus. Low doses, 50 microgram/kg to 50 mg/kg, significantly increased the numbers of IgM- or IgG-spleen antibody-forming cells. Large doses, such as the LD50 (5 g/kg) or pretreatments where unable to impair mouse immune responsiveness. Isoprinosine (< 500 mg/kg/day) orally administered at time of or one day after immunization stimulated immune responses. In vitro addition of isoprinosine to spleen lymphocytes augmented PHA- or Con A-induced proliferation over a concentration range from 10 to 150 microgram/ml, whereas isoprinosine had no effect in the absence of mitogens. These data, and the lack of immunodepressing effect, suggest that there is a need for further evaluation of isoprinosine as an immunopotentiator.

Adjuvants, Immunologic↗
PubMed1979

Differentiation and regulation of lymphocyte populations: evidence for immunopotentiator-induced T cell recruitment.

Isoprinosine, the p-acetaminobenzoic acid salt of inosine dimethylaminoisopropanol (1:3 molar ratio) and sodium diethyldithiocarbamate are two immumopotentiators which share an ability to induce in vivo acquisition of a specific T-cell marker by undifferentiated precursor lymphoid cells of healthy nu/nu mice, without affecting the B-cell lineage. Serum from treated nu/nu mice tested in dual assays, contains a selective inducer of prothymocytes.

Adjuvants, Immunologic↗
PubMed1977

[Sodium diethyldithiocarbamate is a stimulating agent of immunity].

A single dose of DTC was administered, in a dose-range from 0.6 mg/kg to 25 mg/kg, to mice immunized with 10(8) sheep red cells (SRC). All doses strongly enhanced plaque-forming spleen cell (PFC) responses, when given either 18 h before, simultaneously to, 6 h or 24 h after SRC immunization. However, the higher levels of immunostimulation were attained by DTC doses above 5 mg/kg. DTC-induced immunopotentiation was not accompanied by untoward effects, such as acute toxicity, splenomegalia or modifcations in counts of viable spleen lymphocytes.

Animals↗
PubMed1976

[Cachexia in mice induced by a fraction of Brucella melitensis. Modification by levamisole or by diethyldithiocarbamate of soda].

The PMF fraction of B. melitensis creates a wasting disease in newborn mice (J. infect. Dis., 1973, 127, p. 139). Administered to adult mice, PMF induces a 4 to 8 g loss of weight in 20 g mice and more markedly in males than in females. Treatment with Levamisole (LMS) suppresses this difference in response to PMF and restores normal weight in 24 days. Diethyldithiocarbamate (DDC), another immunostimulant sulfur derivate, abolishes the emaciating effect of PMF. Furthermore, DDC is an anabolizing agent which increases the weight of normal or PMF-treacted mice above the mean level of normal untreated control mice.

Animals↗
PubMed1976

Potentiation of T-cell mediated immunity by levamisole.

Cell-mediated immunity is a requirement for recognition and elimination of cells and for prevention or treatment of a variety of diseases. Therefore, the development of a product potentially active in increasing immunity involves its testing in assays specific for cell-mediated immunity. The effectiveness of a single administration of levamisole was demonstrated in the rejection of isografts in a male to female C57BL/6 system, and on the enhancement of levels of the delayed type hypersensitivity (DTH) to sheep red cells (SRBC). Indeed, in five on nine tests, an injection of 25 mg/kg of levamisole to female recipients either on the day of grafting or 7 days after grafting resulted in a RT50% rejection time of 25 days, compared with 46 days in untreated controls. Levamisole administered at the time of immunization with various doses of SRBC elicited earlier, higher and more sustained DTH levels than in untreated controls. Such induction of T-cell activation was accompanied by a switch on anti-SRBC antibodies from IgM to IgG. These findings confirm and extend data evidencing the ability of levamisole to recruit and activate T cells for an increased or restored cell-mediated immunity.

Animals↗
PubMed1976

[Biological properties and chemical composition of a soluble fraction of Brucella abortus. Monospecific A or M antigens].

ABS, the supernatant of smooth B. abortus phenol-protected suspensions, is a protein, lipid, sugar and ARN complex containing all amino acids found in phenol-water fractions from B. abortus and B. melitensis. ABS is non-toxic and immunizes mice against B. abortus challenge. Chromium chloride easily binds ABS to sheep erythrocytes (E ABS) for a specific and accurate passive hemagglutination test in brucellosis. E ABS are agglutinated by all antisera to fractions of B. abortus or B. melitensis, but not by the monospecific anti M serum. A study of the antigenic relationships between ABS and phenol-water fractions from smooth brucella strains leads to the isolation of sub-fractions fron the phenol precipitates of B. abortus or of B. melitensis that could contain only A or M antigens which react only with their respective monospecific A or M serum.

Amino Acids↗
PubMed1976

[Passive hemagglutination, lymphoblastic transformation, and leukocyte migration applied to the diagnosis of brucellosis].

Passive hemagglutination test (HP) after binding of ABS antigen to SRBC by chromium chloride, lymphocyte transformation (TTL) and inhibition of leukocyte migration (TML) tests were compared to tube agglutination and complement fixation tests, and to clinical symptoms for diagnosis of brucellosis. Both TTL and TML persist for years after contact with brucella. HP is the most reliable serologic test.

Antibodies, Bacterial↗
PubMedDate not supplied

Human Sertoli cells in vitro. Lactate, estradiol-17 beta and transferrin production.

Human Sertoli cell parameters, namely lactate, estradiol-17 beta, and transferrin production, were determined after a 24-hour incubation with either human follicle stimulating hormone (FSH) or dbcAMP in the presence or absence of testosterone plus a phosphodiesterase inhibitor (1-methyl-3-isobutylxanthine; MIX). Testicular tissues were obtained from 10 young patients (mean age, 29 years); using a 3-step enzymatic treatment, Sertoli cell enriched preparations (> 92%) were studied after 4 days as primary cultures. No significant changes in lactate, estradiol-17 beta, and transferrin outputs have been observed according to age in patients ranging in age from 16 years to 47 years. Sertoli cell production of the compounds is controlled by testosterone plus MIX; FSH (or dbcAMP) treatment only slightly improves their synthesis. It is suggested that human Sertoli cell function, as far as the parameters measured in this study are concerned, is likely regulated by cAMP-dependent and independent pathways.

Adolescent↗