442 research outputs found
Antonio Venditti. Sculture e disegni
No full textMonografia dedicata allo scultore molisano Antonio Venditti, attenta soprattutto a ricostruire gli anni di formazione , le esperienze condotte nella stagione di adesione al Movimento Arte Concreta e poi a quelle dei primissimi anni Sessanta. Una lettura critica che guarda con attenzione al contesto culturale che connota la Napoli dell'immediato secondo dopoguerra
New Insight on the In Vitro Effects of Melatonin in Preserving Human Sperm Quality
No full textSpermatozoa (SPZ) are sensitive to stressful conditions, particularly oxidative stress, which alters their quality; thus, the use of protective molecules as an antioxidant is encouraged. Herein, we used melatonin (MLT) to investigate its in vitro effects on human sperm parameters under conditions of oxidative stress induced by cadmium (Cd). Fifteen human semen samples were divided into control, Cd-treated, MLT-treated, and Cd+MLT-treated groups and analyzed after 30 min, 6 h, and 24 h of exposure. Results showed a time-dependent decrease in SPZ motility, DNA integrity, and increased apoptosis induced by oxidative stress, and these effects were counteracted by MLT co-treatment. Based on these data, we further explored additional parameters just at 24 h. The induced oxidative stress, highlighted by the increased lipid peroxidation, reduced the percentage of SPZ able to undertake acrosome reaction and altered the levels and localization of some protein markers of motility (PREP, RSPH6A), morphology (DAAM1), and acrosome membrane (PTMA, IAM38); all these effects were counteracted by MLT co-treatment. Interestingly, MLT alone was able to ameliorate motility at 30 min of incubation compared to the control, while at 24 h, it prevented the physiological alteration in terms of motility, DNA integrity, and apoptosis. Collectively, the data encourage MLT use as an integrative molecule to ameliorate human gamete quality when compromised by stressful conditions
Acoustic Resonator for Mitigation Actions on Underground Railway Lines
No full textNoise pollution caused by underground railway lines is particularly strong in open sections, where levels of noise equal to or superior to noise produced by traffic reach the surrounding receivers. In order to minimise the acoustic impact, it is not always possible, for aesthetic or structural reasons, to build ad-hoc noise barriers. It is therefore necessary to consider less invasive actions that can reduce noise close to its source, taking into account the fact that noise produced by train transit is mainly due to the wheel-track contact. In this paper an acoustic resonator is presented, designed to reduce noise produced by the wheel-track contact in the Rome underground railway lines. Considering that the train emission spectrum, measured close to the permanent way, has a peak around 350 Hz, the acoustic resonator was tuned on this frequency interval and designed using the space between the safety gangway and the support plane of the railway line. The value of the resonator’s absorption coefficient was verified experimentally on a prototype built for the purpose
Prothymosin alpha expression in the vertebrate testis: a compatrative review
No full textProthymosin alpha (PTMA) is a highly acidic, intrinsically disordered protein that was first extracted from rat thymus and characterized as an immunogenic factor but soon detected in a variety of mammalian tissues. The presence of a nuclear localization signal and the adoption of a peculiar random-coil conformation are among the reasons behind its interaction with several molecular partners, hence at this time PTMA is known to be a very conserved and widely expressed molecule, involved in numerous and diverse biological processes. Only few studies have tried to weigh its possible involvement in reproduction, specifically in male gametogenesis: first reports have suggested that PTMA might be associated with the proliferative and early-meiotic phases of mammal spermatogenesis. Some years later, a comparative project on vertebrate spermatogenesis reported the isolation, for the first time, of prothymosin in a non-mammalian species, the amphibian Pelophylax esculentus. PTMA transcript and protein are localized in the germinal compartment, from spermatocytes to spermatozoa. A congruent pattern has been highlighted in studies on the fish Torpedo marmorata and Danio rerio, and in the mammal Rattus norvegicus, in which the expression of PTMA has been found in meiotic and post-meiotic germ cells inside testicular cysts and tubules. Moreover, its presence has been confirmed in rat and human spermatozoa (associated with the acrosome); its retention in the apical region of the head after the acrosome reaction revealed a striking conservation of the pattern during phylogenesis and suggested a possible role for the protein in gametogenesis and in fertilization
Male Reproduction: Regulation, Differentiation and Epigenetics
No full textThe production of good-quality spermatozoa (SPZ) is one of the most intricate and far from being completely understood developmental processes during postnatal life [...
Subcellular localization of Prolyl Endopeptidase (PREP) during the first wave of rat spermatogenesis and in rat and human sperm.
No full textProlyl endopeptidase (PREP) is an enzyme which cleaves several peptide hormones and neuropeptides on the carboxyl side of proline residues and is involved in many biological processes, including cell proliferation and differentiation, glucose metabolism, learning, memory and cognitive disorders. PREP has also been identified as a binding partner of tubulin, suggesting the involvement of endopeptidase in microtubule-associate processes, independent of its peptidase activity. Furthermore, several reports have implied PREP participation in both male and female reproduction-associated mechanism. We, herein assess a potential association of PREP to the morphogenesis of rat testis, profiling its localization versus tubulin, during the first wave of spermatogenesis and in the adult gonad (from 7 to 60 dpp). We show that, in mitotic phases, PREP shares its localization with tubulin in Sertoli cells, gonocytes and spermatogonia. Later, during meiosis, both proteins are found in spermatocytes, and in the cytoplasm of Sertoli cells protrusions, surrounding the germ cells, while, during spermiogenesis, they both localize in the cytoplasm of round and elongating spermatids. We also found that this enzyme has a peculiar nuclear localization, in the proliferating cells in all phases of analysis. Finally, they are expressed in the flagellum of mature gametes, as corroborated by additional immunolocalization analysis on both rat and human sperm. Our data support the hypothesis of the fundamental role of PREP in reproduction and in cytoskeletal organization during mammalian testis morphogenesis and gamete progression
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