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Biomedical subjects

C Foresta

Publications and source records attributed to C Foresta.

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

Pathogenesis of persistent infertility in men after varicocelectomy.

With a view to investigating the cause of persistent infertility, the authors studied a group of 27 patients who had, previously, undergone surgical ligation of the spermatic vein for varicocele and infertility. Of these subjects, who failed to father after surgery, 12 presented persisting varicocele at the clinical examination. In 6 cases, the seminal fluid was positive for U. Urealyticum. One patient had orchiepididymitis; in one spermioagglutinating antibodies were found, in one the female partner was found to be infertile. Even preoperatively, three subjects had pathologically high gonadotropin levels, an important sign of testicular parenchyma alteration. In three subjects only there were no pathological findings to explain persistent infertility.

Adult↗
PubMed1982

Andropause: incidence and pathogenesis.

One hundred forty-five male volunteers, 60 to 91 years old, without any hepatic, renal, or metabolic pathology, and not under any steroid therapy for at least 1 year were studied. Plasma luteinizing hormone (LH), Follicle Stimulating hormone (FSH), Testosterone (T), 17-beta-Estradiol (E2), Androstenedione (A), Maximal increase (MI) of LH and FSH after luteinizing hormone releasing hormone (LHRH) (50 gamma iv), and pulsations (P) of LH and FSH over a 3 hr period were measured by radioimmunoassay (RIA). The patients were divided in four groups according to LH and T levels. Group I: (46% of our subjects) showed no signs of hypogonadism with normal LH, T, E2, A, MI of LH and FSH, and normal P-LH, P-FSH. Group II: (15%) with high LH but normal T, showed high FSH, MI-LH, MI-FSH, P-LH, and P-FSH, but normal A and E2. Group III: (22%) with classical signs of hypergonadotropic hypogonadism (high LH and low T) showed high FSH, MI-LH, MI-FSH, and P-FSH, normal P-LH and E2, but low A. Group IV: (16.5%) with signs of hypogonadotropic hypogonadism (low LH and low T) had also low MI-LH, MI-FSH and A, but normal FSH, P-LH, P-FSH, and E2. Contrarily to menopause in women, andropause is not an obligatory event in men, and when it does occur, its pathogenesis and hormonal aspects are very variable.

Aged↗
PubMed1982

Male hypogonadism in aorto-iliac arteriopathies.

In 43 patients affected by aorto-iliac arteriopathies, gonadotropins, testosterone, androstenedione serum levels were measured to verify the presence of a testicular alteration secondary to ischemia. Important signs of testiculopathies (increased gonadotropins and decreased testosterone serum levels) were observed in patients with flow alteration of the internal spermatic artery and in patients with obstructions of the common iliac. Plasma androstenedione levels were not decreased while the A/T ratio was increased in hypotestosteronemic patients. Ischemia might determine a functional block of 17 beta reductase enzyme, necessary to convert androstenedione to testosterone. The impotentia coeundi, which affected about 50% of our patients is not related to testosteronemia.

Adult↗
PubMedDate not supplied

Possible significance of transferrin levels in seminal plasma of fertile and infertile men.

Human seminal plasma contains large amounts of transferrin, which is a protein secreted mostly by Sertoli cells. It has been suggested that the concentration of transferrin may serve as a possible clinical marker of Sertoli cell function. Therefore the concentration of this protein in human seminal plasma from fertile and infertile men has been evaluated in order to find a relationship between transferrin concentrations and human semen parameters and plasma FSH levels. Findings show that seminal transferrin in subjects with oligozoospermia or azoospermia is significantly lower than in controls, and that it is strongly related to sperm count. Results also indicate that transferrin secretion can be impaired when plasma FSH levels are still normal, suggesting that seminal transferrin is an early and specific marker of Sertoli cell function. These results, however, do not clarify whether impairment of transferrin secretion by Sertoli cells is due to an organic dysfunction or to an organic secretory alteration.

Follicle Stimulating Hormone↗
PubMedDate not supplied

Paracrine and endocrine roles of insulin-like factor 3.

Insulin-like factor 3 (INSL3) is expressed in Leydig cells of the testis and theca cells of the ovary. This peptide affects testicular descent by acting on gubernaculum via its specific receptor leucine-rich repeat-containing G protein-coupled receptor 8 (LGR8). From initial animal data showing the cryptorchid phenotype of Insl3/Lgr8 mutants, an extensive search for mutations in INSL3 and LGR8 genes was undertaken in human patients with cryptorchidism, and a frequency of mutation of 4-5% has been detected. However, definitive proofs of a causative role for some of these mutations are still lacking. More recent data suggest additional paracrine (in the testis and ovary) and endocrine actions of INSL3 in adults. INSL3 circulates at high concentrations in serum of adult males and its production is dependent on the differentiation effect of LH. Therefore, INSL3 is increasingly used as a specific marker of Leydig cell differentiation and function.

Animals↗
PubMedDate not supplied

Identification of functional binding sites for progesterone in rat Leydig cell plasma membrane.

Steroid hormones influence cell functions by binding to intracellular receptors and then acting within the nucleus. There is now evidence that steroids affect cell functions also via interaction with plasma membrane receptors in a number of different cell types. In this regard, progesterone appears to be one of the most active steroids. In this paper, we evaluate the effects of progesterone on rat Leydig cell functions, determining variations of ion homeostasis and testosterone production. This steroid was able to effect a depolarization of the plasma membrane that was due to an influx of sodium (Na+) from the external medium since it was absent when extracellular Na+ was iso-osmotically substituted with choline chloride or sucrose. The determination of intracellular sodium concentration ([Na+]i) with the Na+ -sensitive fluorescent dye sodium-benzofuran-isophtalate (SBFI) confirmed these observations. Progesterone did not modify Leydig cell intracellular calcium concentration ([Ca2+]i) at any dose tested. Furthermore, using a cell impermeant progesterone conjugate, we demonstrated that progesterone was able to stimulate Leydig cell steroidogenesis in a dose-dependent manner. The exclusion of calcium (Ca2+) from the extracellular medium did not modify the depolarizing action of progesterone and its steroidogenetic effect while in Na+ -free medium (sucrose supplemented) progesterone-stimulated effects were completely blunted. Finally, using fluorescence microscopy with a fluorescein isothiocyanate-coupled cell impermeant progesterone conjugate, we identified plasma membrane binding sites for progesterone in rat Leydig cells. These results suggest that rat Leydig cells possess progesterone receptors located on the plasma membrane, which when occupied achieves a plasma membrane depolarization, dependent on an influx of Na+ from the external medium, and the subsequent activation of steroidogenesis.

Animals↗
PubMedDate not supplied

Circulating endothelial progenitor cells in subjects with erectile dysfunction.

Erectile dysfunction (ED) is often the first clinical sign of endothelial dysfunction and may precede overt cardiovascular diseases. Bone marrow-derived endothelial progenitor cells migrate into the peripheral circulation to promote endothelial repair. The number of circulating progenitor cells is reduced in patients with cardiovascular risk factor. The objective of our study was to determine the number of these cells in patients with ED both with and without cardiovascular risk factors. These subjects have lower number of circulating progenitor cells, confirming the existence of an endothelial dysfunction and supplying the evidence that ED may be the first symptom of an endothelial damage.

Adult↗
PubMedDate not supplied

PDE-5 inhibitor, Vardenafil, increases circulating progenitor cells in humans.

Bone marrow-derived endothelial progenitor cells (EPCs) originate from haematopoietic stem cells in bone marrow and migrate into the peripheral circulation to promote endothelial repair and neovascularization. The number of circulating progenitor cells is reduced in patients with cardiovascular risk factor. The aim of our study was to determine the number of these cells in healthy patients and to evaluate the effect of Vardenfil, a phosphodiesterases-5 (PDE-5) inhibitor, in the number of circulating EPCs. In our study, we found a significant increase in the number of these cells after the drug administration.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMedDate not supplied

Age-matched cavernous peak systolic velocity: a highly sensitive parameter in the diagnosis of arteriogenic erectile dysfunction.

Recently it has been reported that there is a strict correlation between erectile dysfunction (ED) and cardiovascular diseases, but the importance of such relationship still needs to be addressed. Ultrasonographic peak systolic velocity (PSV), is considered a reliable parameter for the diagnosis of arteriogenic ED. However, the cut-off value of PSV<30 cm/s has sufficient sensitivity only in the diagnosis of advanced arteriogenic ED and it is not representative of peripheral vascular alterations. In the present study, we set up an age-adjustment of PSV - calculated with the formula PSV <6.73+age x 0.7 - that permits a more accurate diagnosis of vascular aetiology in ED patients and may predict the presence of carotid wall alterations. We studied 179 consecutive subjects (mean age 52 years, range 23-79 years), with a history of ED of at least 6 months, by means of penile colour doppler ultrasonography (P-CDU) and common carotid arteries colour doppler ultrasonography (CCA-CDU) between June 2003 and September 2004. Statistical analysis was carried out with the statistical software R. PSV and CCAD values showed a statistically significant negative correlation. Age adjustment further improved this relationship permitting to identify an age-dependent PSV cut-off given by the formula PSV <6.73+age x 0.7. The age-adjusted PSV cut-off allows an accurate interpretation of vascular aetiology in ED patients and predicts the presence of carotid wall alterations, from the intima-media pathologic thickness to the plaque formation, with high values of both sensitivity and specificity.

Adolescent↗
PubMedDate not supplied

Effects of naloxone on gonadotropin secretion in Klinefelter syndrome.

To study the opioid control on LH and FSH secretion in Klinefelter subjects (KS), the response of gonadotropin to an opioid antagonist, naloxone, was examined in 8 KS (age range 25-35 yrs) and in 8 age matched normal men. In 6 KS with low testosterone plasma levels, naloxone infusion were also performed after treatment with testosterone enanthate, 200 mg i.m. every 3 weeks for 4 months. FSH did not show any important variation in KS and in normal men during naloxone infusion. In KS the percentage of naloxone induced LH increase was significantly lower than in controls and there was no correlation between testosterone plasma levels and LH increase after naloxone infusion. LH increases after naloxone infusion were not significantly different before and after testosterone treatment. The increases of naloxone induced LH plasma levels, before and after testosterone treatment, correlated well between themselves (r = 0.93-p less than 0.01). Plasma levels decreased in all patients after testosterone treatment, but only in two was there a return to normal range. There is a clearly positive linear correlation between the percentage of LH decrease after testosterone treatment and LH increase after naloxone infusion (r = 0.81; p less than 0.01). After testosterone therapy FSH plasma levels fall by 63 +/- 15% in all patients and did not show any important variation after naloxone infusion. In conclusion, our data are in agreement with the hypothesis that in Klinefelter's syndrome an alteration of opioid control on gonadotropin secretion may exist. This alteration does not appear to be due to androgen deficiency, but rather it may be caused by genetic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

A simple nephelometric method for measuring the progressive motility and collecting motile spermatozoa.

A simple method for collection and measurement of the progressive motility of spermatozoa was developed. The procedure consists of the spectrophotometric measurement of the increase in optical absorbance produced by the upward migration of spermatozoa in a high density medium of Ficoll 400. The suspension containing migrated spermatozoa may be used as a purified population of uniformly motile and undamaged spermatozoa.

Animals↗
PubMedDate not supplied

Calcitonin in human seminal plasma and its localization on human spermatozoa.

We determined the calcitonin (CT) levels in peripheral plasma and in seminal fluid of 15 normal human subjects: the concentration of the hormone in seminal fluid was about 30 times higher than the concentration found in peripheral plasma. We also studied the localization of calcitonin on human spermatozoa by means of an indirect immunofluorescent technique, using an anti-human CT rabbit serum and a fluorescein-isothiocyanate conjugated goat anti-rabbit immunoglobulins serum. A bright fluorescence was observed at the middle piece and neck, while the tail's principal piece was weakly stained. With an anti-human CT rabbit serum pre-absorbed with human CT no fluorescent staining was detectable. These findings demonstrate that calcitonin is localized onto spermatozoa and suggest a potential role for calcitonin in the calcium dependent-mechanisms of spermatozoa.

Adult↗
PubMedDate not supplied

Evidence of sperm nuclear chromatin heterogeneity in ex-cryptorchid subjects.

Ex-cryptorchid subjects are frequently affected by infertility, even if the usually determined seminal parameters are still within the normal range. We evaluated in this study, in 14 ex-unilateral cryptorchid adult males (22-28 years), with normal sperm concentration, morphology and viability, the resistance of sperm nuclear chromatin to denaturation, using the fluorochrome acridine orange, which fluorescences green when bound to native DNA (double stranded) and red when bound to denaturated DNA (single stranded). Our findings demonstrate that the percentage of green-stained cells with acridine orange was significantly lower in our patients than in controls (p less than 0.001). We therefore suggest that the chromatin of ex-cryptorchid subjects' spermatozoa has a decreased resistance to denaturation and we hypothesize that this finding may explain the infertility of these patients, when the common seminal parameters are still within the normal range.

Acridine Orange↗
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↗