108 research outputs found

    F4-Neuroprostane Effects on Human Sperm

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    Swim-up selected human sperm were incubated with 7 ng F4-neuroprostanes (F4-NeuroPs) for 2 and 4 h. Sperm motility and membrane mitochondrial potential (MMP) were evaluated. The percentage of reacted acrosome was assessed by pisum sativum agglutinin (PSA). Chromatin integrity was detected using the acridine orange (AO) assay and localization of the ryanodine receptor was performed by immunofluorescence analysis. Sperm progressive motility (p = 0.02) and the percentage of sperm showing a strong MMP signal (p = 0.012) significantly increased after 2 h F4-NeuroP incubation compared to control samples. The AO assay did not show differences in the percentage of sperm with dsDNA between treated or control samples. Meanwhile, a significantly higher number of sperm with reacted acrosomes was highlighted by PSA localization after 4 h F4-NeuroP incubation. Finally, using an anti-ryanodine antibody, the immunofluorescence signal was differentially distributed at 2 and 4 h: a strong signal was evident in the midpiece and postacrosomal sheath (70% of sperm) at 2 h, whereas a dotted one appeared at 4 h (53% of sperm). A defined concentration of F4-NeuroPs in seminal fluid may induce sperm capacitation via channel ions present in sperm cells, representing an aid during in vitro sperm preparation that may increase the positive outcome of assisted fertilization

    Effects and Mechanisms Activated by Treatment with Cationic, Anionic and Zwitterionic Liposomes on an In Vitro Model of Porcine Pre-Pubertal Sertoli Cells

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    : Liposomes have been successfully used as drug-delivery vehicles, but there are no clinical studies on improved fertility and the few reported experimental studies have been performed in animal models far from humans. The aim of this paper was to study the effects of treatment with cationic, anionic and zwitterionic liposomes on our superior mammalian model of porcine prepubertal Sertoli cells (SCs) to find a carrier of in vitro test drugs for SCs. Porcine pre-pubertal SCs cultures were incubated with different liposomes. Viability, apoptosis/necrosis status (Annexin-V/Propidium iodide assay), immunolocalisation of β-actin, vimentin, the phosphorylated form of AMP-activated protein Kinase (AMPK)α and cell ultrastructure (Transmission Electron Microscopy, TEM) were analysed. Zwitterionic liposomes did not determine changes in the cell cytoplasm. The incubation with anionic and cationic liposomes modified the distribution of actin and vimentin filaments and increased the levels of the phosphorylated form of AMPKα. The Annexin/Propidium Iodide assay suggested an increase in apoptosis. TEM analysis highlighted a cytoplasmic vacuolisation. In conclusion, these preliminary data indicated that zwitterionic liposomes were the best carrier to use in an in vitro study of SCs to understand the effects of molecules or drugs that could have a clinical application in the treatment of certain forms of male infertility

    Cosmic shear from STIS Pure Parallels: I Data

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    Following the second HST servicing mission in 1997 when the STIS instrument was installed and the capability for parallel observations was enhanced, a substantial archive of non-proprietary parallel data has been accumulating. In this paper, we discuss the use of unfiltered STIS imaging data for a project that requires deep observations along as many independent lines-of-sight as possible. We have developed a technique to determine which datasets in the archive can safely be co-added together and have developed an iterative co-addition technique which enabled us to produce 498 high-quality, deep images. The principal motivation for this work is to measure the Cosmic Shear on small angular scales and a value derived from these data will be presented in a subsequent paper. A valuable by-product of this work is a set of high quality combined fields which can be used for other projects. The data are publicly available at http://www.stecf.org/projects/shear/Comment: 8 pages, 7 figures. accepted for publication in A&

    Black holes, gravitational waves and fundamental physics: a roadmap

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    The grand challenges of contemporary fundamental physics—dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem—all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'

    Do seminal isoprostanes have a role in assisted reproduction outcome?

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    F2-isoprostanes (F2-IsoPs), stereoisomers of prostaglandin F2α generated by the free radical-induced oxidation of arachidonic acid, have been associated with different male infertility conditions. This study aimed to evaluate the role of seminal isoprostane levels and sperm characteristics in the reproductive outcome and embryo quality of 49 infertile couples. Semen analysis was performed following WHO guidelines. Sperm chromatin maturity was detected using an aniline blue (AB) assay, and DNA integrity was assessed using the acridine orange (AO) test. Seminal F2-IsoP levels were quantified by gas chromatography/negative ion chemical ionization tandem mass spectrometry (GC/NICI–MS/MS) analysis. Correlations among variables and their impact on in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) outcome were investigated. F2-IsoP levels are positively correlated with double-stranded DNA sperm (p < 0.001) and negatively correlated with mature sperm chromatin (p < 0.001). Patients with positive outcomes had an increased percentage of sperm with double-stranded DNA, as did patients producing high-quality embryo, who showed higher F2-IsoP levels compared to those detected in the low-quality embryo group. An intriguing relationship between a mild increase in F2-IsoP levels, DNA integrity, and embryo quality seems to indicate that the non-enzymatic oxidation of arachidonic acid can be also a marker of metabolic activity in human semen
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