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M C Bene

Publications and source records attributed to M C Bene.

98 records · Page 6Linked to original sources
PubMedDate not supplied

Expression of IL-2alpha and IL-2beta receptors on the membrane surface of human sperm.

Cytokines are secreted proteins that act as local immunological mediators. Increased seminal cytokine concentrations are associated with fertility problems. The purpose of the present study was to investigate the presence of IL-2alpha, and IL-2beta receptors on fresh and isolated sperm by flow cytometry and transmission electron microscopy. Twenty sperm samples from oligospermic men were incubated with CD25, a mouse monoclonal antibody specific for IL-2alpha-chain receptor, and CD122, a mouse monoclonal antibody specific for IL-2beta-chain receptor. The strong initial fluorescence intensity and, subsequently, a labeling index yielded by CD25 and CD122 decreased in sperm centrifuged on a Percoll gradient (p < .05). The expression of CD25 and CD122 correlated negatively with fresh sperm concentration, but in sperm centrifuged on a Percoll gradient there was no correlation. Labeling with CD25 and CD122 antibody was evident on the head and the middle piece in fresh sperm, while in sperm centrifuged on a Percoll gradient a weak labeling was observed only on the principal piece. The authors have identified and localized cytokine receptors on human sperm for the first time. Cytokine receptors may be involved in the regulation of pathophysiological events in sperm cell functions and male infertility. The exact pathway involved in modulation of these receptors requires further investigation. These results contribute to the understanding of cytokine-sperm relationships.

Flow Cytometry↗
PubMedDate not supplied

Lectin-binding sites on human sperm during acrosome reaction: modifications judged by electron microscopy/flow cytometry.

Biochemical surface modifications occur during the capacitation and acrosome reaction of human sperm and among those, variations in the expression of carbohydrates moieties. A sequential study was performed with electronic microscopy and flow cytometry techniques, where the binding of 4 lectins was assessed on normal human sperm samples during in vitro induction of the acrosome reaction with calcium ionophore A-23187. Triticum vulgaris agglutinin (WGA) was shown to bind strongly the whole surface of sperm before induction of the acrosome reaction, and in lesser amounts after incubation with calcium ionophore. Arachis hypogea agglutinin (PNA) and mostly Concanavalia ensiformis agglutinin (Con-A) and Ulex europaeus agglutinin (UEA-1) binding evolved in an opposite pattern with an increase of the labeling parallel to that of GB24 antibody binding. Electron microscopy showed that the fluorescence patterns observed correlated with increased access to the inner membrane of the acrosome. This was significant 60 min after the induction of acrosome reaction. Lectin binding could be a useful tool to examine the ability of sperm samples to undergo the acrosome reaction.

Acrosome↗
PubMedDate not supplied

Complex investigation of Graves'-Basedow disease: case report.

This paper relate a patient case, age 42, female sex, which was complex immuno-morphologically investigated, on thyroid fragments, surgically obtained. The patient was previously diagnosed with Graves'-Basedow disease; the relapses after conventional therapy, orientated the case for surgical treatment--subtotal thyroidal resection. Using polyclonal and monoclonal antibodies, we may confirm that the disease is fully active. Graves'-Basedow disease is the most common form of autoimmune thyroiditis, responsible for the majority of the cases of hyperthyroidism, affecting young women. It was suspected, many years ago and recently demonstrated that the hyperthyroidism is involved in the development of the autoimmune response, by increasing the immune reaction of the organism. Some effects of the antithyroid drugs are mediated by the decrease of the specific stimulator antibodies (long-acting thyroid stimulator), commonly found in Graves'-Basedow disease.

Adult↗
PubMedDate not supplied

Lymphocyte subpopulations in an experimental model of axial and peripheral enthesiopathies.

We report a study of lymphocyte subsets in experimental arthritis induced in Wistar Furth rats by native human type II collagen and muramyl dipeptide. This experimental arthritis shares similarities with both the spondyloarthropathies and rheumatoid arthritis. Peripheral blood T lymphocytes, primarily the CD4+ cells (p = 0.01), were lower in arthritic rats than in the controls, although the difference in the CD4/CD8 ratio was not statistically significant. Splenic CD4 cells were significantly (p = 0.03) more numerous in arthritic rats, while the numbers of MHC class II positive cells (p = 0.002) and kappa-bearing B-cells (p = 0.0004) were significantly lower. Determination of peripheral blood and spleen lymphocytes subsets could therefore be used for the assessment of arthritis and for the evaluation of therapeutic agents. Thymic T-cell differentiation does not appear to be impaired in this model. These results differ from the peripheral blood disturbances described in the active stages of human rheumatoid arthritis and are more similar to those reported in ankylosing spondylitis patients. However, the absence of alterations in the Peyer's patches suggests that pathogeneic mechanisms involving mucosal areas and exogenous intestinal antigens are not reproduced in this model.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMedDate not supplied

[Levels of IgA rheumatoid factors in seropositive rheumatoid polyarthritis. Absence of correlation with disease activity or pejorative course].

Rheumatoid factors of the IgA isotype directed to human IgG Fc fragment were assayed, using an Elisa test, in the serum of 30 patients with seropositive rheumatoid arthritis and in the synovial fluid of 9 of them. A high incidence was found in the serum (90%) and synovial fluids (77%). Clinical, radiological and biological parameters of each patients were recorded at the time of the assay, and two years later. There was no statistically significant association between IgA rheumatoid factors levels and other parameters, nor with a pejorative evolution. However, a significant negative correlation was observed between IgA rheumatoid factors levels and the duration of the disease, suggesting that IgA rheumatoid factors are predominantly produced at the earliest stages of rheumatoid arthritis.

Adult↗