1,355 research outputs found

    Analysis of CAPZA3 localization reveals temporally discrete events during the acrosome reaction

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    In mammals, the starting point of development is the fusion between sperm and egg. It is well established that sperm fuse with the egg through the equatorial/post-acrosomal region. Apart from this observation and the requirement of two proteins (CD9 in the egg and IZUMO1 in the sperm) very little is known about this fundamental process. Actin polymerization correlates with sperm capacitation in different mammalian species and it has been proposed that F-actin breakdown is needed during the acrosome reaction. Recently, we have presented evidence that actin polymerization inhibitors block the movement of IZUMO1 that accompany the acrosome reaction. These results suggest that actin dynamics play a role in the observed changes in IZUMO1 localization. This finding is significant because IZUMO1 localization in acrosome-intact sperm is not compatible with the known location of the initiation of the fusion between the sperm and the egg. To further understand the actin-mediated changes in protein localization during the acrosome reaction, the distribution of the sperm- specific plus-end actin capping protein CAPZA3 was analyzed. Like IZUMO1, CAPZA3 shows a dynamic pattern of localization; however, these movements follow a different temporal pattern than the changes observed with IZUMO1. In addition, the actin polymerization inhibitor latrunculin A was unable to alter CAPZA3 movement.Fil: Sosnik, Julian. University Of Massachussets; Estados UnidosFil: Buffone, Mariano Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; ArgentinaFil: Visconti, Pablo E.. University Of Massachussets; Estados Unido

    Coupling a distributed grid based hydrological model and MM5 meteorological model for flooding alert mapping

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    International audienceThe increased number of extreme rainfall events seems to be one of the common feature of climate change signal all over the world (Easterlin et al., 2000; Meehl et al., 2000). In the last few years a large number of floods caused by extreme meteorological events has been observed over the river basins of Mediterranean area and they mainly affected small basins (few hundreds until few thousands of square kilometres of drainage area) . A strategic goal of applied meteorology is now to try to predict with high spatial resolution the segments of drainage network where floods may occur. A possible way to reach this aim is the coupling of meteorological mesoscale model with high resolution hydrological model. In this work few case studies of observed floods in the Italian Mediterranean area will be presented. It is shown how a distributed hydrological model, using the precipitation fields predicted by MM5 meteorological model, is able to highlight the area where the major floods may occur

    Determination of propofol by GC/MS and fast GC/MS-TOF in two cases of poisoning

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    Two cases of suspected acute and lethal intoxication caused by propofol were delivered by the judicial authority to the Department of Sciences for Health Promotion and Mother-Child Care in Palermo, Sicily. In the first case a female nurse was found in a hotel room, where she lived with her mother; four 10 mg/mL vials and two 20 mg/mL vials of propofol were found near the decedent along with syringes and needles. In the second case a male nurse was found in the operating room of a hospital, along with a used syringe. In both cases a preliminary systematic and toxicological analysis indicated the presence of propofol in the blood and urine. As a result, a method for the quantitative determination of propofol in biological fluids was optimized and validated using a liquid-liquid extraction protocol followed by GC/MS and fast GC/MS-TOF. In the first case, the concentration of propofol in blood was determined to be 8.1 \u3bcg/mL while the concentration of propofol in the second case was calculated at 1.2 \u3bcg/mL. Additionally, the tissue distribution of propofol was determined for both cases. Brain and liver concentrations of propofol were, respectively, 31.1 and 52.2 \u3bcg/g in Case 1 and 4.7 and 49.1 \u3bcg/g in Case 2. Data emerging from the autopsy findings, histopathological exams as well as the toxicological results aided in establishing that the deaths were due to poisoning, however, the manner of death in each were different: homicide in Case 1 and suicide in Case 2

    Evidence of the presence of calcium/calmodulin-dependent protein kinase IV in human sperm and its involvement in motility regulation

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    The mechanisms involved in the regulation of mammalian sperm motility are not well understood. Calcium ions (Ca(2+)) have been suggested to play a key role in the maintenance of motility; nevertheless, how Ca(2+) modulates this process has not yet been completely characterized. Ca(2+) can bind to calmodulin and this complex regulates the activity of multiple enzymes, including Ca(2+)/calmodulin-dependent protein kinases (CaM kinases). Results from this study confirmed that the presence of Ca(2+) in the incubation medium is essential for maintaining human sperm motility. The involvement of CaM kinases in Ca(2+) regulation of human sperm motility was evaluated using specific inhibitors (KN62 and KN93) or their inactive analogues (KN04 and KN92 respectively). Sperm incubation in the presence of KN62 or KN93 led to a progressive decrease in the percentage of motile cells; in particular, incubation with KN62 also reduced sperm motility parameters. These inhibitors did not alter sperm viability, protein tyrosine phosphorylation or the follicular fluid-induced acrosome reaction; however, KN62 decreased the total amount of ATP in human sperm. Immunological studies showed that Ca(2+)/calmodulin-dependent protein kinase IV (CaMKIV) is present and localizes to the human sperm flagellum. Moreover, CaMKIV activity increases during capacitation and is inhibited in the presence of KN62. This report is the first to demonstrate the presence of CaMKIV in mammalian sperm and suggests the involvement of this kinase in the regulation of human sperm motility.Fil: Marin Briggiler, Clara Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Jha, Kula N.. University of Virginia; Estados UnidosFil: Chertihin, Olga. University of Virginia; Estados UnidosFil: Buffone, Mariano Gabriel. Laboratorio de Estudios en Reproducción; ArgentinaFil: Herr, John C,. University of Virginia; Estados UnidosFil: Vazquez, Monica Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Visconti, Pablo E.. University of Massachussets; Estados Unido

    Can public-private partnerships foster investment sustainability in smart hospitals?

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    This article addresses the relationship between Public-Private Partnerships (PPP) and the sustainability of public spending in smart hospitals. Smart (technological) hospitals represent long-termed investments where public and private players interact with banking institutions and eventually patients, to satisfy a core welfare need. Characteristics of smart hospitals are critically examined, together with private actors' involvement and flexible forms of remuneration. Technology-driven smart hospitals are so complicated that they may require sophisticated PPP. Public players lack innovative skills, whereas private actors seek additional compensation for their non-routine efforts and higher risk. PPP represents a feasible framework, especially if linked to Project Financing (PF) investment patterns. Whereas the social impact of healthcare investments seems evident, their financial coverage raises growing concern in a capital rationing context where shrinking public resources must cope with the growing needs of chronic elder patients. Results-Based Financing (RBF) is a pay-by-result methodology that softens traditional PPP criticalities as availability payment sustainability or risk transfer compensation. Waste of public money can consequently be reduced, and private bankability improved. In this study, we examine why and how advanced Information Technology (IT) solutions implemented in "Smart Hospitals" should produce a positive social impact by increasing at the same time health sustainability and quality of care. Patient-centered smart hospitals realized through PPP schemes, reshape traditional healthcare supply chains with savings and efficiency gains that improve timeliness and execution of care

    Bicarbonate is required for migration of sperm epididymal protein DE/CRISP-1 to the equatorial segment and expression of rat sperm fusion ability

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    Numerous studies have demonstrated that sperm capacitation is a bicarbonate-dependent process. In the rat, capacitation has not been studied as much as in other species, mainly because of the difficulties in carrying out functional assays with this animal model. In the present study, we have examined the influence of bicarbonate in the overall rat sperm capacitation process by analyzing involvement of the anion in 1) protein tyrosine phosphorylation, 2) migration of epididymal protein DE (also known as CRISP-1) from the dorsal region to the equatorial segment of the sperm head that occurs during capacitation, and 3) ability of sperm to fuse with the egg. Incubation of sperm under capacitating conditions produced a time-dependent increase in protein tyrosine phosphorylation. This phosphorylation did not occur in the absence of HCO3- and rapidly increased by either exposure of sperm to HCO3- or replacement of the anion by a cAMP analog (dibutyryl-cAMP) and a phosphodiesterase inhibitor (pentoxifylline). The absence of HCO3- also produced a significant decrease in the percentage of cells showing migration of DE to the equatorial segment. This parameter was completely restored by addition of the anion, but dibutyryl-cAMP and pentoxifylline were not sufficient to overcome the decrease in DE migration. Sperm capacitated in the absence of HCO3- were unable to penetrate zona-free eggs independent of the presence of the anion during gamete coincubation. Exposure of these sperm to bicarbonate, or replacement of the anion by dibutyryl-cAMP and pentoxifylline, only partially restored the sperm fusion ability. Altogether, these results indicate that, in addition to its influence on protein tyrosine phosphorylation, bicarbonate is required to support other rat sperm capacitation- associated events, such as migration of DE to the equatorial segment, and expression of the ability of sperm to fuse with the egg.Fil: Da Ros, Vanina Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Munuce, María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Cohen, Debora Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Marin Briggiler, Clara Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Busso, Dolores. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Visconti, Pablo E.. University of Massachussets; Estados UnidosFil: Cuasnicu, Patricia Sara. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

    Central role of soluble adenylyl cyclase and cAMP in sperm physiology

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    Cyclic adenosine 3′,5′-monophosphate (cAMP), the first second messenger to be described, plays a central role in cell signaling in a wide variety of cell types. Over the last decades, a wide body of literature addressed the different roles of cAMP in cell physiology, mainly in response to neurotransmitters and hormones. cAMP is synthesized by a wide variety of adenylyl cyclases that can generally be grouped in two types: transmembrane adenylyl cyclase and soluble adenylyl cyclases. In particular, several aspects of sperm physiology are regulated by cAMP produced by a single atypical adenylyl cyclase (Adcy10, aka sAC, SACY). The signature that identifies sAC among other ACs, is their direct stimulation by bicarbonate. The essential nature of cAMP in sperm function has been demonstrated using gain of function as well as loss of function approaches. This review unifies state of the art knowledge of the role of cAMP and those enzymes involved in cAMP signaling pathways required for the acquisition of fertilizing capacity of mammalian sperm. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.Fil: Buffone, Mariano Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Wertheimer Hermitte, Eva Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Visconti, Pablo E.. University Of Massachussets; Estados UnidosFil: Krapf, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Biología Molecular y Celular de Rosario; Argentina. Universidad Nacional de Rosario; Argentin
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