Carlo Foresta

Bio: Carlo Foresta is an academic researcher from University of Padua. The author has contributed to research in topics: Male infertility & Sperm. The author has an hindex of 64, co-authored 433 publications receiving 15807 citations. Previous affiliations of Carlo Foresta include University of Sfax & Polaris Industries.

Y chromosome microdeletions and alterations of spermatogenesis.

Abstract: 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.

Male infertility: role of genetic background

Abstract: Male infertility represents one of the clearest examples of a complex disease with a substantial genetic basis. Numerous male mouse models, mutation screening and association studies reported over the last few years reveal the high prevalence of genetic causes of spermatogenic impairment, accounting for 10-15% of severe male infertility, including chromosomal aberrations and single gene mutations. Natural selection prevents the transmission of mutations causing infertility, but this protective mechanism may be overcome by assisted reproduction techniques. Consequently, the identification of genetic factors is important for appropriate management of the infertile couple. However, a large proportion of infertile males are diagnosed as idiopathic, reflecting poor understanding of the basic mechanisms regulating spermatogenesis and sperm function. Furthermore, the molecular mechanisms underlying spermatogenic damage in cases of genetic infertility (for example Yq microdeletions) are not known. These problems can be addressed only by large scale association studies and testicular or spermatozoal expression studies in well-defined alterations of spermatogenesis. It is conceivable that these studies will have important diagnostic and therapeutic implications in the future. This review discusses the genetic causes of male infertility known to date, the genetic polymorphisms possibly associated with male infertility, and reports novel results of global gene expression profiling of normal human testis by microarray technology.

Deletion and expression analysis of AZFa genes on the human Y chromosome revealed a major role for DBY in male infertility

Abstract: Three distinct regions, designated AZFa, b and c from proximal to distal Yq, are required for normal spermato-genesis in humans. Deletions involving AZFa (deletion interval 5C/D) seem to occur less frequently in infertile men and to be associated with a more severe testicular phenotype, with almost complete absence of germ cells. AZFa contains three genes, named USP9Y, DBY and UTY, and presents high homology with the mouse Delta Sxr (b) interval, deletion of which causes a severe spermatogenic impairment. However, the specific role of these genes in human spermatogenesis is still unknown and it is not clear which of them is responsible for the AZFa phenotype. Here we describe a complete sequence map of the AZFa region, the genomic structure of AZFa genes and their deletion analysis in a large number of infertile men characterized by well-defined spermatogenic alterations. Both USP9Y and DBY may cause severe testiculopathies, but DBY appears to be the major AZFa candidate. DBY is frequently deleted in infertile patients and its absence produces severe spermatogenic damage leading to a significant reduction of germ cells or even to their complete absence. Expression analysis of AZFa genes and their X-homologues revealed ubiquitous expression for all of them except DBY; this gene produces a long transcript which is ubiquitously expressed in addition to a shorter transcript which is only expressed in the testis, suggesting a specific role for DBY in the spermatogenic process. This hypothesis is further supported by the high similarity of DBY to other DEAD box proteins belonging to the PL10 subclass.

Vitamin D deficiency.

Abstract: admission. This proportion could already be greater in some parts of the country and may increase if referrals of cases of self-poisoning increase faster than the facilities for their assessment and management. The provision of social work and psychiatric expertise in casualty departments may be one means of preventing unnecessary medical admissions without risk to the patients. Dr Blake's and Dr Bramble's figures do not demonstrate, however, that any advantage would attach to medical teams taking over assessment from psychiatrists except that, by implication, assessments would be completed sooner by staff working on the ward full time. What the figures actually suggest is that if assessment of overdoses were left to house doctors there would be an increase in admissions to psychiatric units (by 19°U), outpatients (by 5O°'), and referrals to social services (by 140o). So for house doctors to assess overdoses would provide no economy for the psychiatric or social services. The study does not tell us what the consequences would have been for the six patients who the psychiatrists would have admitted but to whom the house doctors would have offered outpatient appointments. E J SALTER

Molecular Physiology of P2X Receptors

Abstract: P2X receptors are membrane ion channels that open in response to the binding of extracellular ATP. Seven genes in vertebrates encode P2X receptor subunits, which are 40–50% identical in amino acid ...