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Biomedical subjects

G Delespesse

Publications and source records attributed to G Delespesse.

At least 145 records · Page 8Linked to original sources
PubMed1983

Genetic deficiency of C4 presenting with recurrent infections and a SLE-like disease. Genetic and immunologic studies.

A young girl presenting with recurrent pulmonary infections and atypical lupus erythematosus was totally deficient in C4. In one sister, also deficient in C4, the same symptoms developed. Results of family studies were consistent with an autosomal recessive mode of transmission and with linkage of the genes determining C4 deficiency to those of the major histocompatibility complex. The patient's serum and red cells were Chido- and Rodgers-negative. Humoral and cellular immunity were normal, except for a low lymphocyte response in mixed lymphocyte culture. The cellular function of the patient's polymorphonuclear leukocytes was normal, for both phagocytosis and bactericidal activity using Candida albicans. However, in the presence of C4-deficient serum, opsonin generation and bactericidal indexes were diminished. These defects were completely reversible upon addition of purified C4.

Child, Preschool↗
PubMed1983

Direct action of cyclosporin A on human B-lymphocytes with regard to immunoglobulin production.

Highly purified preparations of human B-lymphocytes were cultured with or without cyclosporin A (CyA; 1 microgram/ml) for 8 days with pokeweed mitogen (PWM) in the presence of helper factors or with Epstein-Barr virus (EBV). The amounts of IgG, IgM, IgA and IgE produced in cultures were measured by radioimmunoassays or by reverse hemolytic plaque-forming cell assays. The results demonstrate that whereas CyA had a strong suppressive effect on the production of immunoglobulins (Ig) by PWM-activated B-cells, it had an enhancing effect on EBV-activated B-cells. It is concluded that CyA has a direct effect on human B-lymphocytes and that it may suppress or enhance their activation depending on the stimulant employed to trigger the cells.

B-Lymphocytes↗
PubMed1982

Characterization of immunoregulatory T lymphocytes in insulin-dependent diabetic children by means of monoclonal antibodies.

Monoclonal antibodies of the OKT series were used to identify total T lymphocytes (OKT3+) and their helper (OKT4+) and suppressor-cytotoxic (OKT8+) and suppressor-cytotoxic (OKT8+) subsets in 34 insulin-dependent diabetic children and in 39 young healthy controls. The diabetics have a moderate but significant reduction of the proportions of total T lymphocytes at the expense of the T helper subset; the proportion of suppressor-cytotoxic cells are normal. These abnormalities of the lymphocyte subpopulations are not related to the duration of diabetes, the control of the disease nor to the presence of autoimmune phenomena. The latter were found in 51.4% of patients.

Adolescent↗
PubMed1982

Characterization of immunoregulatory T cells during pregnancy by monoclonal antibodies.

T Lymphocyte subpopulations were characterized by means of monoclonal antibodies in 44 pregnant women at different stages of gestation, and in 45 healthy controls. In the pregnant subjects, there is a small but significant reduction of the whole circulating T Lymphocytes and of their T helper subset identified respectively by OKT3 and OKT4 monoclonal antibodies. There is no influence of pregnancy on the proportions of T cytotoxic-suppressor cells (OKT8 positive) nor of lymphocytes bearing Ia antigen. Low counts of circulating cells with a thymocyte phenotype (OKT6 positive) are found in the two groups of subjects. It is concluded that pregnancy has a marginal effect on maternal immunocompetence.

Antibodies, Monoclonal↗
PubMed1982

Characterization of immunoregulatory T lymphocytes during ageing by monoclonal antibodies.

Monoclonal antibodies of the OKT series were used to identify T lymphocytes (OKT3+) and their inducer (OKT4+) and suppressor-cytotoxic (OKT8+) subsets in the peripheral blood mononuclear cells (PBMC) of 32 healthy old-aged people more than 70 years old (16 men and 16 women) compared to 47 adults (29 men, 18 women) less than 40 years old. The absolute lymphocyte count in the peripheral blood was not significantly influenced by age or sex. Both the proportions and the absolute numbers of T3+ and T4+ cells were significantly lower in aged than in young participants. The proportions but not the absolute counts of OKT8+ cells were higher in the elderly. Most interesting is the influence of sex and these parameters. Old women have normal numbers and proportions of T3+, T4+ and T8+ cells when compared to young women. The latter have a significantly higher proportion of T8+ cells than young adult males. Old men have a striking reduction of both the numbers and proportions of OKT3+ and OKT4+ cells when compared with young men and with women. In addition, old men have an elevated proportion, but a normal absolute number, of OKT8+ cells. The responses of PBMC to phytohaemagglutinin extent (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) are reduced to the same extent in ageing male and female subjects when compared to young adults. In the older group, the magnitude of the lymphocyte response to PHA and Con A but not to PWM is negatively correlated with the proportions of OKT8+ cells. Surprisingly, these correlations are observed only in old women but not in old men. The latter finding excludes the possibility that the age-associated decline of the lymphocyte response to T cell mitogens is secondary to an imbalance between T4+ and T8+ lymphocytes.

Adult↗
PubMed1981

Influence of oral zinc supplementation on the lymphocyte response to mitogens of normal subjects.

Oral zinc sulfate was given for 1 month to 83 normal subjects distributed in four groups according to age (20 to 40; 40 to 60), sex, and oral contraception. Their in vitro lymphocyte response to phytohemagglutinin and Concanavalin A, and their serum zinc and copper levels were measured before and after treatment. They were compared in 20 untreated subjects. Zinc treatment significantly increased the lymphocyte response to phytohemagglutinin and Concanavalin A. In the group of women aged 40 to 60, this resulted in a normalisation of the response to Concanavalin A. The response to zinc was related to the starting value of lymphocyte stimulation obtained by phytohemagglutinin, i.e., in low responders this was enhanced whereas in high responders it tended to be reduced. Treatment increased serum zinc and had no effect on serum copper. There was no correlation between serum zinc or copper and the lymphocyte response. The beneficial effect of zinc supplementation on the lymphocyte response does not result from a correction of latent zinc deficiency.

Adult↗
PubMed1980

Circulating immune complexes in bronchial asthma.

Soluble immune complexes were detected by a sold phase Clq binding assay in forty-two out of 106 well studied asthmatic patients (39.6%) and in eleven out of 145 age-matched controls (8%; P < 0.01). Clinical significance of immune complexes has been evaluated by comparing the following parameters in patients with and without such complexes: age, sex, duration of disease, IgE-mediated allergy (RAST, skin test), precipitins (Aspergillus, Candida albicans, Thermoactinomycetes), corticodependency, lung function tests, associated symptoms (hivernal bronchitis, urticaria, eczema,...), desenstization treatment, serum concentration in immunoglobulin in G, A, M and E. Immune complexes were found more frequently in female than in male patients. The prevalence of immune complexes was higher in patients treated by hyposensitization therapy and in cases with precipitating antibodies against thermophilic actinomycetes and Aspergillus.

Adult↗
PubMed1980

Differential responses to mitogen stimulation in lymphocytes from normal individuals and Lesch-Nyhan patients: influence of the bicarbonate buffer system.

Three patients affected with the Lesch-Nyhan syndrome were found to have normal levels of immunoglobulins, normal numbers of circulating B and T cells and normal IgG secretion in vitro in response to polyclonal activators. However, when cultures were performed in the absence of a bicarbonate buffer system, the proliferative response to several T cell stimulants (phytohaemagglutinin, concanavalin A and streptokinase-streptodornase) was impaired in Lesch-Nyhan cells as judged from the incorporation of labelled thymidine, uridine and leucine. This situation could be abolished by incubation in a 5% CO2 atmosphere and even reversed by supplementation of bicarbonate to the culture medium. Blocking the de novo purine synthesis by Methotrexate resulted in a more pronounced inhibition of the mitogenic response in Lesch-Nyhan lymphocytes than in normal cells. The differences in proliferative response between normal and Lesch-Nyhan lymphocytes with regard to culture conditions point to the critical role of the de novo pathway in lymphocyte stimulation.

Adolescent↗
PubMed1980

Circulating immune complexes in old people and in diabetics: correlation with autoantibodies.

Circulating immune complexes (CIC) were detected by a solid-phase radioassay in 34% of fifty-three insulin-dependent diabetics (IDD) as compared to 18% of forty-five non-insulin-dependent diabetics (NIDD) and 14% of 173 control subjects. In control subjects, the prevalence of CIC increased with age and was higher in males than in females. In IDD, immune complexes were found with the highest frequency before the age of 30 and after 50. There was no significant difference between the incidence of CIC in old IDD and their age-matched controls. The same sera were also tested for the presence of the following autoantibodies; nuclear , thyroid, gastric, smooth and striated muscle; mitochondria, sub-maxillary and adrenal gland and liver-kidney microsome. Sera containing at least one antibody were found in 16.4% of controls, 55.3% of IDD and 40% of NIDD. The prevalence of autoantibodies increased with age in controls but not in IDD. Islet cell antibodies were present in 28.5% of IDD and 2.9% of control subjects; they were more frequent in young patients. CIC and autoantibodies were statistically associated both in controls and IDD; in the patients, CIC were associated not only with islet cell antibodies but also with other autoantibodies. The possible relation between autoimmunity, degenerative vascular diseases and CIC is discussed.

Adult↗
PubMed1980

In vitro response of human peripheral blood lymphocytes of protein A. DNA synthesis and generation of cells synthesizing the three major classes of Ig.

Increased DNA synthesis and immunoglobulin secretion was observed in human peripheral blood lymphocytes (PBL) cultured in vitro with soluble protein A from Staphylococcus aureus (Sp-A). Optimal Ig secretion was obtained in 6 day cultures containing 1 x 10(6) cells/ml and 10 microgram/ml Sp-A. The presence of 5 x 10(-5) M 2-mercaptoethanol in the culture medium as well as careful selection of foetal calf serum were needed for optimal results. In response to Sp-A stimulation, the three main classes of immunoglobulins were secreted by PBL. In some individuals, concentration of Sp-A optimal for IgG and IgM secretion inhibited IgA production. Immunoglobulin-containing cells were less abundant (0.5--5% of total cells) and smaller in Sp-A than in PWM-stimulated cultures (5--15%). The data suggest that Sp-A and PWM stimulated different subsets of circulating lymphocytes.

Cells, Cultured↗
PubMed1979

Distribution of beta-adrenergic receptors on human lymphocyte subpopulations.

A technique is described allowing the quantification and the characterization of specific beta-adrenergic receptors in intact living human lymphocytes. 125I-Iodohydroxybenzylpindolol, a potent beta-adrenergic antagonist was used to label specific binding sites on unfractionated lymphoid cells and on purified subpopulations of T (F1 and F2) and B cells. F1 and F2 were obtained by filtration through nylon wool column as previously described (Delespesse et al., 1976), they differ in their response to mitogens, and in their interactions with adherent cells and B cells. 125I-HYP binding to unfractionated lymphocytes was a saturable, stereospecific and rapid process with a dissociation constant of 2.5 10(-10) M and a binding capacity of 400--600 sites/cell. Bindings on unfractionated lymphocytes, purified B cells and T cells of the F2 fraction were similar. No detectable binding was noted on T cells from the F1 fraction. Enriched T cells obtained by a rosetting technique displayed 200 receptors/cell.

Adrenergic beta-Agonists↗
PubMed1979

Circulating immune complexes in various thyroid diseases.

In a study of 171 patients with various thyroid diseases, circulating immune complexes (CIC), measured by a C1q solid phase radioassay, were detected in 26% of the patients as compared to 8% of the control subjects. CIC were found in 33--55% of the patients with a well defined thyroid autoimmune disorder (Hashimoto's goitre, asymptomatic thyroiditis, spontaneous myxoedema and Graves' disease) and also in the same proportion of patients with diffuse goitre. CIC were correlated to the presence of serum antibodies to microsomal thyroid antigen but not to their titre. No relationship was observed between CIC and the age or sex of the patients and the presence of exophthalmos, or between CIC and the different thyroid function tests or serum anti-thyroglobulin antibodies. CIC were found in untreated patients as well as in those treated with prednisone, methimazole or thyroxine.

Adolescent↗
PubMed1979

[Incidence of antispermatozoidal antibodies in the serum of fertile women (author's transl)].

The authors describe a simple and reproducible-microagglutination technique for the detection of antispermatozoa antibodies. A positive reaction is detected in 2 p. 100 of women with a normal fertility (12/516), in 10 p. 100 of pregnant women (4/40) and in 32.5 p. 100 of patients with recurrent abortions. There is no relation between anti-HLA antibodies and the sperm agglutinating activity of a serum.

Abortion, Habitual↗