University of Siena

About: University of Siena is a education organization based out in Siena, Italy. It is known for research contribution in the topics: Population & Cancer. The organization has 12179 authors who have published 33334 publications receiving 1008287 citations. The organization is also known as: Università degli studi di Siena & Universita degli studi di Siena.

Intuitionistic Formal Spaces — A First Communication

Abstract: The notion of formal space was introduced by Fourman and Grayson [FG] only a few years ago, but it is only a recent though important step of a long story whose roots involve such names as Brouwer and Stone and whose development is due to mathematicians from different fields, mainly algebraic geometry, category theory and logic.

Epidemiology of cardio-renal syndromes: workgroup statements from the 7th ADQI Consensus Conference

Abstract: Sean M. Bagshaw, Dinna N. Cruz, Nadia Aspromonte, Luciano Daliento, Federico Ronco, Geoff Sheinfeld, Stefan D. Anker, Inder Anand, Rinaldo Bellomo, Tomas Berl, Ilona Bobek, Andrew Davenport, Mikko Haapio, Hans Hillege, Andrew House, Nevin Katz, Alan Maisel, Sunil Mankad, Peter McCullough, Alexandre Mebazaa, Alberto Palazzuoli, Piotr Ponikowski, Andrew Shaw, Sachin Soni, Giorgio Vescovo, Nereo Zamperetti, Pierluigi Zanco, Claudio Ronco and for the Acute Dialysis Quality Initiative (ADQI) Consensus Group

Insulin-dependent diabetes in men is associated with hypothalamo-pituitary derangement and with impairment in semen quality

Abstract: BACKGROUND: The objective of the study was to investigate the hypothalamo-pituitary–testicular axis and sperm structure at the transmission electron microscope (TEM) level in men affected by insulin-dependent diabetes. METHODS: Twenty-two diabetic men and 24 controls were recruited. GnRH (100 µg) was administered and FSHand LH-induced secretion was evaluated. Semen samples were collected and sperm concentration and motility were determined using a Makler chamber. Ejaculated sperm were fixed and observed with a TEM. RESULTS: The response of gonadotrophins to GnRH was significantly lower in diabetics than in control men. Sperm motility was also significantly lower. At the electron microscope level, sperm from diabetics exhibited a higher percentage of immaturity- and apoptosis-related defects than sperm from controls. CONCLUSIONS: The reduced response of gonadotrophins to GnRH in diabetic men may indicate a decreased acute releasable pool of pituitary gonadotrophins. The results of TEM examination showed that sperm from men with diabetes presented severe structural defects in comparison with sperm from controls. It is possible that the reproductive impairment recognized in men with diabetes could be the result of interference by the disease on the hypothalamo-pituitary–testicular axis at multiple levels, as indicated by the reduced gonadotrophin response to appropriate stimuli and by the abnormal ultrastructure of ejaculated sperm. The defective spermatogenesis may be the consequence of a direct testicular effect of the disease.

Cloning of the gene for ocular albinism type 1 from the distal short arm of the X chromosome

Abstract: Ocular albinism type 1 (OA1) is an X–linked disorder characterized by severe impairment of visual acuity, retinal hypopigmentation and the presence of macromelanosomes. We isolated a novel transcript from the OA1 critical region in Xp22.3–22.2 which is expressed at high levels in RNA samples from retina, including the retinal pigment epithelium, and from melanoma. This gene encodes a protein of 424 amino acids displaying several putative transmembrane domains and sharing no similarities with previously identified molecules. Five intragenic deletions and a 2 bp insertion resulting in a premature stop codon were identified from DMA analysis of patients with OA1, indicating that we have identified the OA1 gene.