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M L Renoux

Publications and source records attributed to M L Renoux.

13 recordsLinked to original sources
PubMed1988

Mononuclear phagocytes from patients with active systemic lupus erythematosus down-regulate the specific in vitro reactivity of autologous lymphocytes to double-stranded DNA.

Peripheral mononuclear cells (MNC) from patients with systemic lupus erythematosus (SLE) are hyporesponsive in vitro. In order to study the role of mononuclear phagocytes (m phag) in regulating the in vitro responses of autologous lymphocytes, the MNC from 16 SLE patients (eight active, eight inactive) and 14 healthy controls were stimulated in vitro with PHA or dsDNA. The proliferative response to PHA was tested by 3H-thymidine incorporation on day 4 and the response to dsDNA using a specific haemolytic plaque assay. Indomethacin, an inhibitor of prostaglandin (PG) synthesis by m phag, was added into the cultures to test the presence of suppressive m phag acting through a PG-mediated pathway. Indomethacin augmented the proliferative response to PHA in active SLE cultures and not in inactive SLE or controls. In six of 13 SLE cultures, dsDNA totally or partly suppressed anti-dsDNA plaque-forming cell (PFC) generation. Indomethacin restored or enhanced the PFC response to dsDNA in active SLE and not in inactive SLE or controls. M phag depletion by plastic adherence prevented the effects of indomethacin. These results show that m phage exerting a suppressive activity on PHA-induced lymphocyte proliferation and on anti-dsDNA antibody production are found in cultures from active SLE and generally not in inactive SLE or healthy individuals. PHA being primarily a T-cell stimulator, the m phag suppressive activity observed in PHA-stimulated cultures is exerted on T cells. On the other hand, in two active SLE cultures depleted of T cells by OKT3 antibody, indomethacin still could enhance the PFC response to dsDNA, showing that in vitro suppressive m phag can act directly on B cells from patients with active SLE.

Adult↗
PubMed1978

The anti-anaphylactic action of tiaramide hydrochloride.

Tiaramide hydrochloride (THC) is a new basic, non-steroidal, anti-flammatory drug. Its anti-anaphylactic action has been investigated using rat mast cells. It was found that THC exerts a strong inhibitory action on antigen-induced and compound 48/80-induced histamine release from rat peritoneal mast cells in a fluorometric assay. Compound 48/80-induced vasodilatation in rat skin is inhibited by prior intradermal injection of THC, as measured by blueing of skin due to intravascular Evans blue dye. THC also inhibits radio-labeled serotonin release from compound 48/80-challenged rat mast cells. In these experimental systems a similar action was exerted by disodium cromoglycate, but higher drug concentrations were needed. Further studies are needed to determine the exact mode of action of this drug and its eventual clinical use in the field of allergic diseases.

Anaphylaxis↗
PubMed1977

Rosette-forming mast cells in rat anaphylaxis. Immunological characteristics of mast cell rosettes.

Peritoneal mast cells from immunized rats can form rosettes with antigen-coated sheep red blood cells. The receptor responsible for this active rosette formation is shown to be IgE cytophilic antibody: rosettes are inhibited by previous contact of mast cells with antigen, or with anti-IgE antiserum; the kinetics of mast cell rosettes following a primary immunization with ovalbumin and Bordetella pertussis vaccine is similar to the kinetics of reaginic antibody response. Furthermore, a reaginic serum can induce passive rosette formation. There is no correlation between cell-bound and circulating IgE.

Animals↗
PubMed1976

[Effect of a polyvitamin preparation on the immune response to antibodies. Demonstration of the immunostimulating activity of propylene glycol].

Humoral antibody to sheep erythrocytes was studied by plaque forming cell and hemagglutinin assays in mice receiving a polyvitaminic preparation containing vitamins A, D, E, and C. A statistically significant increase in PFC on days 6, 12 and 18 after immunization, and an increase in hemagglutinin titers was observed in animals treated with this vitamin containing solution. These results are interpreted as an immunostimulating activity of the preparation. Nevertheless, as shown by the results obtained with each component injected separately, a major proportion of the immunostimulating activity seems to be related to propylene glycol, a simple compound contained as an hydrodispersant in the preparation. Further studies of the immunostimulating properties of propylene glycol are now in progress in our laboratory.

Adjuvants, Immunologic↗
PubMed1976

[Mast-cell rosettes in the immunized rat].

After stimulation by ovalbumin + Bordetella pertussis, rat peritoneal mast cells can form rosettes with antigen-coated erythrocytes. This phenomenon is inhibited by previous incubation of mast cells with antigen; it is attributed to apparition of membrane-bound anaphylactic antibody. The variations of percentage of rosette forming mast cells during the course of immunization are reported and compared with P.C.A. titers.

Animals↗
PubMed1975

Binding of human IgE immunoglobulin to rat mast cells. A study by means of three independent techniques.

The binding of human myeloma IgE immunoglobulin on rat mast cells was studied by three independent techniques. A mixed agglutination reaction with anti-IgE-coated Sephadex granules demonstrated that only human IgE-coated rat mast cells were clearly agglutinated. This binding is strong (50% agglutination) in 3 min and progresses for 30 min (95% agglutination). Autoradiographic studies with 125I-labelled human serum proteins demonstrated the selective formation of grains on mast cells incubated with labelled IgE. Upon action of anti-IgE antiserum on IgE-coated rat mast cells, the mast cells released up to 47.5% of their total histamine content in a fluorometric histamine assay. A relationship was established between sensitizing doses of human IgE and histamine release. These results bring evidence for a binding of human IgE on rat mast cells and imply the existence of receptors for this immunoglobulin on mast cell membrane.

Animals↗
PubMedDate not supplied

[Detection of circulating immune complexes in lupus erythematosus by precipitation test with polyethylene glycol and complement consumption test (author's transl)].

Immune complexe-like materials have been detected by a precipitation test with polyethylene glycol (PEG test) in the sera of 14 (93.3 p. 100) of 15 patients with active SLE, in 11 (44.0 p. 100) of 25 patients with inactive SLE, in 5 (83.3 p. 100) of 6 patients with widespread DLE and 3 (42.9 p. 100) of 7 patients with localized DLE. A good correlation was demonstrated between the value of PEG test and the complement consumption activity measured by an anticomplementary method in the cases of SLE, but it was not clear in the cases of DLE. The anticomplementary activity has been observed in the macromolecular fractions obtained by gel filtration on Sephadex G-200 of serum samples from one patient with active SLE and one patient with widespread DLE. As the value of PEG test had shown a tendency to increase with the antinuclear antibody titer if the titer was higher than 1 : 128, it is probable that the antinuclear factors were the important elements of the composition of circulating immune complexes in the cases of SLE. Contrarily, in several DLE patients, PEG test was positive despite lacking antinuclear antibody. In most cases, no significant decrease of PEG titers after DNase action was recorded, suggesting the participation of complexes containing antigens different from DNA.

Adult↗