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C Foresta

Publications and source records attributed to C Foresta.

At least 37 records · Page 2Linked to original sources
PubMed2004

Preliminary data suggest that mutations in the CgRP pathway are not involved in human sporadic cryptorchidism.

In testicular descent to the scrotum, a multistep process, many anatomical and hormonal factors play a role. Cryptorchidism occurs in about 1-2% of males and may cause secondary degeneration of the testes. Animal models have shown that abnormalities, in the calcitonin gene-related peptide (CgRP) activity, could be relevant in the pathogenesis of cryptorchidism. We performed a mutation screening by PCR exon amplification, single-strand conformation polymorphism (SSCP) and sequencing in four candidate genes, CgRPs (alphaCgRP, betaCgRP), their receptor (CgRPR) and the receptor component protein (CgRP-RCP), in 90 selected cases of idiopathic unilateral or bilateral cryptorchidism. Mutation screening of the coding regions and intron-exon boundaries revealed some polymorphic variants but no pathogenic sequence changes. These preliminary data suggest that these genes are not major factors for cryptorchidism in humans.

Adult↗
PubMed2004

Erectile dysfunction: symptom or disease?

Erectile dysfunction (ED) has been defined by the National Institute of Health (NIH) as the inability to achieve and/or to maintain an erection for a sufficiently long period of time so as to permit satisfactory sexual intercourse. ED affects millions of men throughout the world and could have a negative influence on the individual's well-being as well as on the quality of life of affected subjects. Discordant data have been reported on ED epidemiology with prevalence ranging from 12% to 52%, probably depending on the different criteria utilized in the different studies for patient selection. ED is a symptom, sometimes the first, of different pathological conditions. In 15.7% of 45-yr-old patients with vascular ED a dynamic ergometric test has shown electrocardiographic alterations in the absence of any cardiac symptom. In 15% of the patients with ED, high fasting glucose plasma levels are discovered for the first time and in patients with ED and normal fasting glucose plasma levels the prevalence of undiagnosed diabetes mellitus is 12.1% after an oral glucose tolerance test (OGTT). The different risk factors are often additive in the possible development of systemic vasculopathy, neuropathy and ED. ED, underestimated in clinical practice due to archaic prejudice which hinders the patient in spontaneously revealing the problem and the physicians in investigating it, can mark the point where evaluation and prevention of important diseases (such as diabetes, arterial hypertension, atherosclerosis) hitherto unknown by the patients, can begin. The physicians' cultural baggage must include the ability to identify the pathology that can determine ED and the ability to program a specific diagnostic workup. In this paper the different specialists involved in ED diagnosis agreed that a clinical approach which allows the identification of systemic pathologies contributing to the development of ED constitutes an improvement in disease prognosis and may either induce a spontaneous reduction of ED or facilitate its specific treatment.

Adult↗
PubMed2004

Role of androgens in erectile function.

PURPOSE: Erectile response in mammals is centrally and peripherally regulated by androgens. Severe hypogonadism in men usually results in loss of libido and potency. The present studies were designed to evaluate the possible influence of circulating androgens in the regulation of sexual function. MATERIALS AND METHODS: A total of 15 men with severe hypogonadism (testosterone less than 2.0 ng/ml) were recruited. The control group consisted of 20 patients with psychogenic erectile dysfunction. All subjects underwent nocturnal penile tumescence (NPT) and rigidity monitoring during 2 consecutive nights, evaluation of cavernous artery flow using penile color duplex ultrasound (P-CDU), and real-time visually stimulated erection evaluation at baseline and after administration of 50 mg sildenafil or 3 mg apomorphine. NPT, P-CDU and visually stimulated erection were evaluated after 6 months of therapy with a 5 mg daily testosterone patch. RESULTS: NPT analysis in subjects with severe hypogonadism showed a significant decrease in sleep related erections. P-CDU showed a partial erectile response with an alteration of the parameters analyzed, and the visually stimulated erections test was pathological. Administration of 3 mg apomorphine and 50 mg sildenafil has no influence on erectile function. Testosterone treatment for 6 months induced normalization of NPT and P-CDU parameters, and of visually stimulated erection effects with the restoration of a normal response to pharmacological stimulation with apomorphine or sildenafil. CONCLUSIONS: Our results show that testosterone has a key role in the central and peripheral modulation of erectile function even if the accurate testosterone plasma level threshold that may influence these processes remains to be established.

Adult↗
PubMed2003

The human Y chromosome's azoospermia factor b (AZFb) region: sequence, structure, and deletion analysis in infertile men.

Microdeletions of the Y chromosome long arm are the most common mutations in infertile males, where they involve one or more "azoospermia factors" (AZFa, b, and c). Understanding of the AZF structure and gene content and mapping of the deletion breakpoints in infertile men are still incomplete. We have assembled a complete 4.3 Mb map of AZFb and surrounding regions by means of 38 BAC clones. The proximal part of AZFb consists of large repeated sequences organised in palindromes, but most of it is single copy sequence. A number of known and novel genes and gene families map in this interval, and most of them are testis specific or have testis specific transcripts. STS mapping allowed us to identify four severely infertile subjects with a deletion in AZFb with similar breakpoints, therefore suggesting a common deletion mechanism. This deletion includes at least five single copy genes and two duplicated genes, but does not remove the historical AZFb candidate gene RBMY1. These data suggest that other genes in AZFb may have important roles in spermatogenesis. We had no evidence for homologous recombination between large repeats as a possible deletion mechanism, as shown for AZFa and AZFc. However, identical sequences in AZFb and AZFc exist, and this finding could explain deletions found in these regions.

Chromosome Breakage↗
PubMed2003

Erectile function in elderly: role of androgens.

Erectile function progressively declines with age, although most old men's erectile rigidity remains adequate for vaginal intercourses. Recently it has been demonstrated that a significant proportion of men over 60 years of age has a biochemical hypogonadism (defined as below the 2.5th percentile for young men). It is generally accepted that erectile response in mammals is regulated by androgens both centrally and peripherically, but in male ageing a casual relationship between androgen levels and erectile function has not been established yet. The present study was designed to evaluate the possible relationships between circulating androgens and sexual activity in a group of healthy old men without erectile dysfunction. Forty men with a mean age of 68 +/- 6 years (range 61-75 years) were recruited among healthy subjects undergoing periodic health screening. The control group consisted of 30 young volunteers with a mean age of 33 +/- 5 years (range 26-40 years). These subjects had good general health and stable relationship with at least one successful intercourse for week. All subjects performed: 1) hormonal assessment (total testosterone, free testosterone, DHT, FSH and LH); 2) nocturnal penile tumescence monitoring during two consecutive nights. The findings of this study show a significant decrease in frequency, duration and degree of nocturnal erectile episodes in old men with respect to those observed in young controls. The alteration of these parameters was more evident in old subject showing a reduction of testosterone plasma levels. In hypotestosteronemic subjects DHT treatment significantly improved nocturnal penile tumescence parameters even if these still differed from those of controls (p<0.001). On the basis of these observations we hypothesize that hypoandrogenism in old men, also in presence of normal sexual activity, may influence locally the erectile mechanisms. However hypoandrogenism, associated to other conditions negatively influencing the erectile activity, may be an important co-factor in the induction of erectile dysfunction in aging.

Adult↗
PubMed2002

A novel approach for the analysis of DAZ gene copy number in severely idiopathic infertile men.

The deleted-in-azoospermia (DAZ) gene family constitutes the major candidate for the AZFc (azoospermia factor c) phenotype of male infertility, being deleted in about 10% of azoospermic and severely oligozoospermic subjects. Four DAZ genes are arranged in two clusters in AZFc, and standard analysis by PCR cannot distinguish among the different copies. Therefore only deletions of the entire gene cluster can be identified. We developed a PCR amplification-restriction digestion assay able to distinguish from DAZ genes for single nucleotide variants. Then we applied this approach to screen a group of idiopathic infertile men in which the DAZ genes presence was previously assessed by standard PCR analysis. Two patients out of 25 showed deletion of two copies of DAZ (DAZI and 2), suggesting that this mutation was actually the cause of spermatogenic damage. This preliminary screening demonstrates that deletions of copies of DAZ genes may be often found in severely infertile men and it strengthens the role of this gene family in spermatogenesis. Furthermore, this simple method, being able to distinguish among the different DAZ copies, could be used to screen a larger number of patients and to perform a more accurate diagnosis.

Deleted in Azoospermia 1 Protein↗
PubMed2002

Role of seminal osmolarity in the reduction of human sperm motility.

Mammalian sperm at ejaculation are suspended in the seminal plasma, a heterogeneous mixture deriving from the testicular/epididymal fluid and from secretions of seminal vesicles, prostate and bulbourethral glands. Biochemical characteristics of seminal fluid change along the male reproductive tract when considering its inorganic and organic composition and pH but it is known that in each region of the male genital tract seminal osmolarity is higher than that of serum. It has been previously demonstrated that in invertebrate and vertebrate sperm, seminal plasma osmolarity influences sperm motility and activity, and human sperm have been shown to possess osmosensitive calcium entry pathway that controls important functions such as acrosome reaction and oocyte penetration. In the present study, we have determined seminal plasma osmolarity in a large number of normozoospermic fertile and asthenozoospermic infertile subjects correlating it with sperm motility percentages and kinematic characteristics determined utilizing a computerized motion analysis system. Our results confirm that seminal plasma osmolarity is higher than that of serum (336.1 +/- 20.2 vs. 291.1 +/- 6.9 mOsm/L, respectively). Normozoospermic subjects show seminal osmolarity values that are significantly lower with respect to asthenozoospermic patients (317.8 +/- 12.2 vs. 345.2 +/- 22.6 mOsm/L, p<0.001), irrespective of the cause of asthenozoospermia. Seminal plasma osmolarity negatively correlates with sperm progressive motility percentages and kinetic characteristics (curvilinear velocity, linear velocity, linear coefficient and lateral displacements of sperm head). Furthermore, when sperm from fertile subjects were suspended in medium with an osmolarity increasing from 300 to 600 mOsm, sperm motility percentages and kinetics characteristics were progressively reduced and nearly abolished when medium osmolarity was 600 mOsm. On the contrary, when sperm from asthenozoospermic subjects with high semen osmolarity were resuspended in medium with lower osmolarity, sperm motility parameters improved significantly. Sperm motility parameters did not correlate with seminal plasma concentrations of sodium, potassium, chloride with a weak correlation only with seminal calcium concentration. No correlations are present between seminal plasma osmolarity and ionic composition. In conclusion, the present study confirms and extends the knowledge that, in human, seminal plasma osmolarity is higher than that of serum and demonstrates that seminal osmolarity influences sperm motility characteristics and then it may contribute to the pathogenesis of some forms of asthenozoospermia and male infertility.

Humans↗
PubMed2002

[Alteration of spermatogenesis and Y chromosome microdelations. Analysis of the DAZ gene family].

The Y chromosome has a fundamental role in sex determination and regulation of spermatogenesis. Three regions (designated as AZFa, b, and c) on the long arm of this chromosome exist, deletions of which result in severe damage to spermatogenesis with azoospermia or severe oligozoospermia. Recent progresses in molecular biology and extraordinary development of assisted reproduction techniques contributed to the research on this chromosome and the genes involved in spermatogenesis. About 10-15% of subjects affected by azoospermia or severe oligozoospermia carry a deletion in one or more AZF regions, 60% of which involves AZFc. The genes responsible for the testicular phenotype observed in these subjects are DBY and USP9Y for AZFa, RBMY1 for AZFb, and DAZ for AZFc. In this article, the current knowledge on biology and genetics of the Y chromosome are reported with particular interest to deletions found in infertile subjects. Furthermore, the more recent advances on DAZ gene and its role in spermatogenesis and male infertility are discussed.

Animals↗
PubMed2001

Extracellular ATP stimulates estradiol secretion in rat Sertoli cells in vitro: modulation by external sodium.

In this study, we examined the effects of extracellular ATP (ATPe) on [Ca(2+)](i), [Na(+)](i), plasma membrane potential changes and estradiol secretion in rat Sertoli cells. ATPe caused a rapid rise of [Ca(2+)](i) with an initial spike followed by a long lasting plateau. The first rapid spike was dependent on the release of Ca(2+) from internal stores as it also occurred in Ca(2+)-free medium while the long lasting plateau phase was dependent on Ca(2+) influx from the external medium. ATPe stimulated a rapid plasma membrane depolarization that was dependent on an influx of Na(+) from the external medium as demonstrated by plasma membrane potential monitoring in Na(+)-free medium and by [Na(+)](i) measurement with the Na(+)-sensitive fluorescent dye SBFI. ATPe stimulated estradiol secretion in a dose dependent manner and was fully dependent on the presence of Na(+) in the external medium while the presence of Ca(2+) was not necessary. Among the different nucleotides tested, only ATP, ATP-5'-[gamma-thio]triphosphate, UTP, alpha,beta-methylene-ATP were effective in stimulating estradiol secretion. These results demonstrate that rat Sertoli cells possess P2-purinergic receptors belonging to the P2X and P2Y subfamily which activation induces [Ca(2+)](i) and [Na(+)](i) rise and Na(+)-dependent plasma membrane depolarization leading to estradiol secretion.

Adenosine Triphosphate↗
PubMed2001

Evidence for FSH-dependent upregulation of SPATA2 (spermatogenesis-associated protein 2).

Here we report the cloning and characterization of a novel cDNA named spata 2. SPATA2 is the ortholog of PD1, a human testicular protein which has been suggested to play a role in spermatogenesis. The spata 2 sequence reveals an open reading frame encoding a protein of 511 amino acids. Northern blot analysis with rat mRNA demonstrated two distinct transcripts of 2.2 and 4.0 kb. Tagging recombinant SPATA2 with the green fluorescent protein (GFP) and expressing the chimeric polypeptide in HLtat transfected cells indicated that SPATA2 is located in the nucleus. RT-PCR analysis revealed that spata 2 mRNA is expressed in the testis and to a lesser extent in the brain while skeletal muscle and kidney showed a barely visible signal. The same analysis demonstrated that isolated Sertoli cells express spata 2 mRNA. Treating Sertoli cells with FSH in vitro induced remarkable changes in the steady-state level of spata 2 mRNA in a time-dependent manner. In developing testis spata 2 transcripts were first detected 10 days post partum and expression levels increased steadily with age. The ability of FSH to stimulate spata 2 mRNA expression as well as its developmental expression suggests that this protein might play a role in regulating spermatogenesis and thus, according to the Gene Nomenclature Committee, we propose the name SPATA2 (Spermatogenesis associated protein 2) for this protein (or gene).

Amino Acid Sequence↗
PubMed2001

CDY1 analysis in infertile patients with DAZ deletions.

The DAZ (deleted in azoospermia) gene family is considered the major AZFc ("azoospermia factor" c) candidate responsible for male infertility. However, other genes have been recently mapped to this region and they could contribute to the AZFc phenotype. In particular, the testis-specific CDY1 (chromadomain protein 1) gene has one copy within the DAZ cluster and another one at its distal end. Therefore, this gene could be associated with the spermatogenic damage observed in DAZ-deleted patients since at least one CDY1 copy is invariably absent in these patients. In this study, we investigated whether selected infertile patients affected by different testiculopathies caused by DAZ deletions retained CDY1 and if a genotype-phenotype relation could be demonstrated. We found 3 out of 17 patients with absence of both CDY1 copies, while 14 patients have only one CDY1 copy absent. Two out of the 3 patients with deletion of both copies of CDY1 were affected by severe hypospermatogenesis while one patient presented Sertoli cell-only syndrome. Therefore, there was no clear relation between genotype and phenotype, and the loss of the distal copy of CDY1 does not seem to worsen the phenotype of infertile patients with deletion of the DAZ gene cluster. However, a possible contribution of CDY1 in determining the spermatogenic alteration could not be excluded.

Deleted in Azoospermia 1 Protein↗
PubMed2001

Different insulin-like 3 (INSL3) gene mutations not associated with human cryptorchidism.

Cryptorchidism is the most frequent congenital anomaly of the urogenital tract in the male, but its etiology is for the most part unknown. Evidence suggests that a possible genetic cause may be involved. Animal models support this hypothesis, and in particular INSL3 (Leydig insulin-like 3 hormone) has been proposed as putative gene for cryptorchidism, since male mice mutant for Insl3 exhibit bilateral abdominal cryptorchidism due to alteration of gubernaculum development. In this study, we analyzed whether mutations in INSL3 could be associated with human cryptorchidism. Heteroduplex analysis and sequencing of both exons of INSL3 in 65 ex-cryptorchid patients and a group of control subjects allowed us to find four nucleotide changes in the sequence of exon I. These mutations are all single base substitutions from G to A at position 27, 96, 126 and 178. Only the 178G-->A substitution changes codon 60 from alanine to threonine (A60T). All mutations were found in comparable distribution in ex-cryptorchid patients and non-cryptorchid men. Therefore, all mutations represent neutral polymorphisms not associated with phenotype. This study confirms previous observations and demonstrates a novel polymorphism in the INSL3 gene. In contrast to that described for the mutant mouse, these data indicate that mutations of INSL3 do not seem to represent a frequent cause of cryptorchidism.

Adult↗
PubMed2001

Prognostic value of Y deletion analysis. The role of current methods.

Y chromosome microdeletions represent the most frequent genetic alteration in azoospermic and severely oligozoospermic men, and screening for microdeletions in AZFa, b and c are routinely performed in the major andrology and infertility centres. Since patients with Y microdeletions often require intracytoplasmic sperm injection (ICSI), the question of whether the type of the microdeletion present could have prognostic value for the presence of spermatozoa in the ejaculate or in the testes [by testicular sperm extraction (TESE)] is an interesting one. The review of the literature on this topic showed that there is still no clear genotype--phenotype relationship, i.e. similar testicular alterations may be caused by different types of microdeletions, and apparently identical microdeletions may be associated with diverse tubular damage. Even in azoospermic men, the localization of the microdeletion cannot be used as a valid prognostic parameter before TESE--ICSI to identify patients with spermatozoa in their testes. The only finding with absolute negative prognostic value is the presence of complete AZFa--c deletions, which are invariably associated with an absence of spermatozoa. Microdeletions in AZFa or AZFb seem to have promising prognostic value, but more data and gene-specific deletions have to be provided to draw clear conclusions. The absence of a clear genotype--phenotype relationship, and therefore of a prognostic value of Y deletion analysis, is probably due to the current methods used for the screening of the microdeletions. In fact, to date most centres do not use gene-specific markers but instead use anonymous primers that contribute little information to the pathogenic role of the microdeletions.

Gene Deletion↗
PubMed2001

Intracellular calcium store depletion and acrosome reaction in human spermatozoa: role of calcium and plasma membrane potential.

We evaluated the presence and role of internal calcium stores in human uncapacitated spermatozoa by determining the effects of two inhibitors of Ca2+ ATPase of the sarco-endoplasmic reticulum (SERCA-ATPase), thapsigargin and cyclopiazonic acid (CPA) on intracellular calcium concentrations, [Ca2+](i), plasma membrane potential and acrosome reaction. Using a fluorescent conjugate of thapsigargin, we localized internal Ca2+ stores on the acrosome, post-acrosomal region and sperm midpiece. SERCA-ATPase inhibitors induced a rise in [Ca2+](i) both in Ca2+ and Ca2+-free media but under these latter conditions it was reduced with a progressive decline to baseline values; the re-addition of Ca2+-stimulated a rise in [Ca2+](i). This demonstrated that internal Ca2+ store depletion can evoke the opening of Ca2+-channels on sperm plasma membrane, thus showing the existence of "capacitative" Ca2+ entry into these specialized cells. The addition of thapsigargin to human spematozoa induced a dose-dependent increase in acrosome reaction percentages, but only when Ca2+ was present in the external medium. Plasma membrane potential monitoring showed that these inhibitors induced a depolarization dependent on Ca2+ influx from external medium and that this was preceded by a transient hyperpolarization caused by activation of Ca2+-dependent K+ channels. When K+-dependent plasma membrane hyperpolarization was inhibited, the thapsigargin- and CPA-stimulated rise in [Ca2+](i) plasma membrane depolarization and acrosome reaction were abolished. In conclusion, the present study demonstrates that human spermatozoa possess internal Ca2+ stores and that the capacitative Ca2+ entry pathway present in these cells regulates important biological processes that are fundamental for the acrosome reaction.

Acrosome Reaction↗
PubMed2001

Y chromosome microdeletions and alterations of spermatogenesis.

Three different spermatogenesis loci have been mapped on the Y chromosome and named "azoospermia factors" (AZFa, b, and c). Deletions in these regions remove one or more of the candidate genes (DAZ, RBMY, USP9Y, and DBY) and cause severe testiculopathy leading to male infertility. We have reviewed the literature and the most recent advances in Y chromosome mapping, focusing our attention on the correlation between Y chromosome microdeletions and alterations of spermatogenesis. More than 4,800 infertile patients were screened for Y microdeletions and published. Such deletions determine azoospermia more frequently than severe oligozoospermia and involve especially the AZFc region including the DAZ gene family. Overall, the prevalence of Y chromosome microdeletions is 4% in oligozoospermic patients, 14% in idiopathic severely oligozoospermic men, 11% in azoospermic men, and 18% in idiopathic azoospermic subjects. Patient selection criteria appear to substantially influence the prevalence of microdeletions. No clear correlation exists between the size and localization of the deletions and the testicular phenotype. However, it is clear that larger deletions are associated with the most severe testicular damage. Patients with Y chromosome deletions frequently have sperm either in the ejaculate or within the testis and are therefore suitable candidates for assisted reproduction techniques. This possibility raises a number of medical and ethical concerns, since the use of spermatozoa carrying Y chromosome deletions may produce pregnancies, but in such cases the genetic anomaly will invariably be passed on to male offspring.

Chromosome Aberrations↗