Biomedical subjects

M L Hortas

Publications and source records attributed to M L Hortas.

3 recordsLinked to original sources

PubMed1995

CD4+ cells in human ejaculates.

Using flow cytometry, we studied the expression of the CD4 antigen within the different cells present in human ejaculate, both in spermatozoa and round cells. In all, 20 samples of semen were obtained from fertile males; in 11 of these, we detected the presence of leukocytes, using the peroxidase test. Swim-up was performed for the analysis of the spermatozoa. From our results it may be concluded that there is no expression of the CD4 antigen on the surface of human spermatozoa or on CD45- ejaculate cells (epithelial and germinal cells). However, we did detect the presence of the CD4 antigen on the surface of the leukocyte cells (CD45+). A better characterization of these CD45+ cells made it apparent that the CD4+ cells of ejaculate are composed of T lymphocytes (helper/inducer T lymphocytes) and monocytes. Thus we may conclude that human spermatozoa do not express the CD4 antigen, the cell surface receptor for human immunodeficiency virus. However, we did detect CD4+ T lymphocytes and CD4+ monocytes in semen.

CD4 Antigens↗

PubMed1995

Influence of incubation on the chromatin condensation and nuclear stability of human spermatozoa by flow cytometry.

Flow cytometry analysis was used for the accurate and objective evaluation of sperm chromatin condensation and chromatin stability of sperm nuclei. It was also possible to determine the influence of incubation on sperm chromatin. Different types of spermatozoa were studied: unprocessed spermatozoa at 1 and 45 min after ejaculation, after swim-up (migrated), spermatozoa incubated for 6 h in non-capacitating conditions (aged), or in B2 medium (capacitated) or B2 medium followed 1 h later with A23187 (reacted). All types of spermatozoa were analysed before and after treatment with various decondensation agents: sodium dodecyl sulphate (SDS), SDS plus EDTA and SDS plus disulphide-reducing agent [dithiotreitol (DTT)]. Sperm nuclei were enzymatically isolated and stained with propidium iodide. Three flow cytometric parameters were then measured: forward light scatter (cellular size), side light scatter (cellular complexity) and fluorescence (uptake of propidium iodide). Fluorescence was the most suitable parameter to study the degree of condensation and resistance to decondensation of DNA in the spermatozoa. Unprocessed spermatozoa 1 min after ejaculation underwent decondensation by all assessed treatments (anionic detergent, chelating or disulphide-reducing agents). Unprocessed spermatozoa 45 min after ejaculation and migrated spermatozoa did not undergo decondensation with SDS treatment, but decondensation occurred after treatment with SDS+EDTA or SDS+DTT. Spermatozoa incubated for 6 h under both non-capacitating (aged spermatozoa) and capacitating conditions (capacitated spermatozoa) and reacted spermatozoa were decondensed only after treatment with SDS+DTT.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcimycin↗

PubMed1995

Undetectable expression of genomic progesterone receptor in human spermatozoa.

The expression of genomic progesterone receptor in human ejaculated spermatozoa was investigated. Spermatozoa from 10 fertile donors who exhibited normal semen parameters were analysed. Indirect immunofluorescence and an enzyme immunoassay using monoclonal antibodies against genomic progesterone receptor were used. Different types of spermatozoa were studied: fresh, post-swim-up (migrated), capacitated and post-artificial induction of the acrosome reaction by calcium ionophore A23187. Progestin receptor-rich T47D human breast cancer cells were used as a positive control, and progestin receptor-poor MDA-MB-231 human breast carcinoma cells were used as a negative control. Genomic progesterone receptor was not detected in fresh, migrated, capacitated and post-acrosome reaction induction human spermatozoa and MDA-MB-231 cells by either indirect immunofluorescence or enzyme immunoassay. However, in T47D cells a mean concentration of 1043.2 +/- 125.2 fmol genomic progesterone receptor/mg protein was observed by enzyme immunoassay, and indirect immunofluorescence results were positive using both flow cytometry and fluorescence microscopy. These findings suggest that the effect of progesterone on human spermatozoa is not mediated by genomic progesterone receptor.

Antibodies, Monoclonal↗