Biomedical subjects

M Rossato

Publications and source records attributed to M Rossato.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Progesterone induces capacitation in human spermatozoa.

Mammalian sperm acrosome reaction is a prerequisite for oocyte fertilization, and to date the mechanisms regulating this event are still unclear. Recent studies have demonstrated that human follicular fluid is able to induce an influx of extracellular calcium and acrosome reaction in capacitated spermatozoa. More recently these effects have been attributed to progesterone. The results of our study demonstrated that progesterone is able to trigger the capacitation, acrosome reaction, and fertilizability in human spermatozoa through a calcium mediated mechanism, suggesting a clinical use of this steroid in the treatment of spermatozoa for the different techniques of assisted fertilization.

Acrosome↗

PubMedDate not supplied

Epidermal growth factor receptors (EGFR) localization in human testis.

An indirect immunofluorescence technique was used to detect and localize epidermal growth factor receptors (EGFR) in human testicular biopsies in different testicular diseases. Monolateral biopsies from twelve infertile subjects were studied from qualitative/quantitative points of view and were examined by immunofluorescence study with anti-EGFR monoclonal antibody. Two different patterns of EGFR expression were observed: a very weak presence of EGFR was detectable on Sertoli cells, peritubular basal structures, and interstitial compartment in testicular biopsies showing a normal spermatogenic status; and an important increase in EGFR expression was observed on the cytoplasm of Sertoli cells and on peritubular basal structures in biopsies exhibiting various degrees of hypospermatogenesis and in a case of Sertoli cells only syndrome. Germ cells did not show EGFR immunolocalization. EGFR seems to be present on different testicular target cells. EGFR expression increases on peritubular and Sertoli cells in the presence of significant tubular damage.

Adult↗

PubMedDate not supplied

[Microdeletions of the Y chromosome in cryptorchidism and in idiopathic male infertility].

We investigated the possible role of Y chromosome microdeletions in regions previously shown to be important for male germ cell development in unilateral ex-cryptorchid subjects manifesting important bilateral testiculopathy, in order to clarify whether cryptorchidism could be the expression of an intrinsic congenital testicular abnormality. Microdeletion analysis of the Y chromosome long arm was performed by polymerase chain reaction and confirmed by Southern blot in 40 selected unilateral ex-cryptorchid patients with azoospermia or severe oligozoospermia sustained by severe bilateral testiculopathy (Sertoli cell-only syndrome and severe hypospermatogenesis, respectively), 20 unilateral ex-cryptorchid men with moderate oligozoospermia and normal function of the descended testis, 110 patients affected by severe idiopathic primary testiculopathies, 20 patients affected by moderate idiopathic testiculopathy and, as controls, 50 patients affected by known causes of testiculopathy and 50 fertile controls. Eleven out of the 40 (27.5%) unilateral ex-cryptorchid patients affected by bilateral testiculopathy and 28 out of 110 (25.4%) patients affected by severe idiopathic primary testiculopathy showed microdeletions in the Y chromosome long arm, while all other subjects were normal. Male relatives of patients with deletions were also normal. Microdeletions were distributed in different regions of the Y chromosome long arm, including known regions involved in spermatogenesis (DAZ and RBM genes, AZFa, b and c regions) and other still poorly defined loci. No difference in localization of deletions was evident between ex-cryptorchid and idiopathic patients. Microdeletions in the Y chromosome may be responsible for bilateral severe testicular damage: the clinical consequence, other than idiopathic azoospermia and severe oligozoospermia, may also be unilateral cryptorchidism, probably due to altered testicular responses to mechanisms regulating testicular descent.

Biopsy, Needle↗

PubMedDate not supplied

Possible significance of seminal zinc on human spermatozoa functions.

This study has been performed to investigate the possible role of seminal zinc in the regulation of human spermatozoa functions. Sperm cells from fertile men were washed and pooled, and in each cellular suspension we determined: a) spermatozoal uptake of zinc, b) effects of different albumin concentrations on cellular zinc content, c) effects of zinc and albumin on spermatozoal O2 consumption, d) effects of different zinc concentrations on albumin induced acrosome reaction. We observed that increases of extracellular zinc cause corresponding increases of spermatozoal zinc and that albumin exerts an important chelating effect, even at very low concentrations, on cellular zinc content. Zinc also possesses a reversible inhibitory effect on spermatozoa O2 consumption in a dose-related way, and albumin is able to reverse this effect. Albumin-induced acrosome reaction was also significantly reduced by addition of different zinc concentrations. Our findings reveal that zinc exerts an important influence on human spermatozoa functions and suggest that zinc may be involved in the mechanisms that maintain spermatozoa in the transitory quiescent state until penetration in the female reproductive tract.

Acrosome↗