1,595 research outputs found

    Hepatotoxicity and effectiveness of a Nevirapine-based antiretroviral therapy in HIV-infected patients with or without viral hepatitis B or C infection in Cameroon

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    Background: Coinfection with hepatitis B virus (HBV) or hepatitis C virus (HCV) in HIV-infected patients receiving a commonly used nevirapine-based antiretroviral therapy is a major concern for African clinicians owing to its high prevalence, the infrequent testing and treatment of viral hepatitis, and the impact of liver disease on the tolerability and effectiveness of anti-HIV treatment. We compared the hepatotoxicity and the immunological, virological and clinical effectiveness of a nevirapine-based antiretroviral therapy between patients infected with HIV only and patients coinfected with hepatitis B or C virus in Cameroon. Methods: A retrospective cohort study was conducted among HIV-1-infected patients. Plasma HBV DNA and HCV RNA were tested in positive or indeterminate samples for HBsAg or HCV antibodies, respectively. All patients received nevirapine and lamivudine plus stavudine or zidovudine. Results: Of 169 HIV-1-infected patients with a median baseline CD4 count of 135 cells/mm(3) (interquartile range [IQR] 67 218), 21% were coinfected with HBV or HCV. In coinfected patients, the median viral load was 2.47 x 107 IU/mL for HBV (IQR 3680-1.59 x 10(8)) and 928 000 IU/mL for HCV (IQR 178 400-2.06 x 10(6)). Multivariate analyses showed that the risk of hepatotoxicity was 2-fold higher in coinfected patients (p < 0.01). The response to antiretroviral therapy was however comparable between monoinfected and coinfected patients in terms of CD4 cell count increase (p = 0.8), HIV-1 viral load below 400 copies/mL (p = 0.9), death (p = 0.3) and death or new AIDS-defining event (p = 0.1). Nevirapine was replaced by a protease inhibitor in 4 patients owing to hepatotoxicity. Conclusion: This study suggests that the nevirapine-based antiretroviral therapy could be used safely as first-line treatment in patients with low CD4 cell count in Africa despite frequent coinfections with HBV or HCV and infrequent testing of these infections. Although testing for HBV and HCV should be systematically performed before initiating antiretroviral therapy, transaminases elevations at baseline or during treatment should be a decisive argument for testing when hepatitis status is unknown

    Kypho-IORT - a novel approach of intraoperative radiotherapy during kyphoplasty for vertebral metastases

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    <p>Abstract</p> <p>Background</p> <p>Instable and painful vertebral metastases in patients with progressive visceral metastases present a common therapeutic dilemma. We developed a novel approach to deliver intraoperative radiotherapy (IORT) during kyphoplasty and report the first treated case.</p> <p>Methods/Results</p> <p>60 year old patient with metastasizing breast cancer under chemotherapy presented with a newly diagnosed painful metastasis in the 12<sup>th </sup>thoracic vertebra. Under general anaesthesia, a bipedicular approach into the vertebra was chosen with insertion of specially designed metallic sleeves to guide the electron drift tube of the miniature X-ray generator (INTRABEAM, Carl Zeiss Surgical, Oberkochen, Germany). This was inserted with a novel sheet designed for this approach protecting the drift tube. A radiation dose of 8 Gy in 5 mm distance (50 kV X-rays) was delivered. The kyphoplasty balloons (KyphX, Kyphon Inc, Sunnyvale) were inflated after IORT and polymethylmethacrylate cement was injected. The whole procedure lasted less than 90 minutes.</p> <p>Conclusion</p> <p>In conclusion, this novel, minimally invasive procedure can be performed in standard operating rooms and may become a valuable option for patients with vertebral metastases providing immediate stability and local control. A phase I/II study is under way to establish the optimal dose prescription.</p

    Smc5/6 coordinates formation and resolution of joint molecules with chromosome morphology to ensure meiotic divisions

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    During meiosis, Structural Maintenance of Chromosome (SMC) complexes underpin two fundamental features of meiosis: homologous recombination and chromosome segregation. While meiotic functions of the cohesin and condensin complexes have been delineated, the role of the third SMC complex, Smc5/6, remains enigmatic. Here we identify specific, essential meiotic functions for the Smc5/6 complex in homologous recombination and the regulation of cohesin. We show that Smc5/6 is enriched at centromeres and cohesin-association sites where it regulates sister-chromatid cohesion and the timely removal of cohesin from chromosomal arms, respectively. Smc5/6 also localizes to recombination hotspots, where it promotes normal formation and resolution of a subset of joint-molecule intermediates. In this regard, Smc5/6 functions independently of the major crossover pathway defined by the MutLγ complex. Furthermore, we show that Smc5/6 is required for stable chromosomal localization of the XPF-family endonuclease, Mus81-Mms4Eme1. Our data suggest that the Smc5/6 complex is required for specific recombination and chromosomal processes throughout meiosis and that in its absence, attempts at cell division with unresolved joint molecules and residual cohesin lead to severe recombination-induced meiotic catastroph

    Updating known distribution models for forecasting climate change impact on endangered species

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    To plan endangered species conservation and to design adequate management programmes, it is necessary to predict their distributional response to climate change, especially under the current situation of rapid change. However, these predictions are customarily done by relating de novo the distribution of the species with climatic conditions with no regard of previously available knowledge about the factors affecting the species distribution. We propose to take advantage of known species distribution models, but proceeding to update them with the variables yielded by climatic models before projecting them to the future. To exemplify our proposal, the availability of suitable habitat across Spain for the endangered Bonelli’s Eagle (Aquila fasciata) was modelled by updating a pre-existing model based on current climate and topography to a combination of different general circulation models and Special Report on Emissions Scenarios. Our results suggested that the main threat for this endangered species would not be climate change, since all forecasting models show that its distribution will be maintained and increased in mainland Spain for all the XXI century. We remark on the importance of linking conservation biology with distribution modelling by updating existing models, frequently available for endangered species, considering all the known factors conditioning the species’ distribution, instead of building new models that are based on climate change variables only.Ministerio de Ciencia e Innovación and FEDER (project CGL2009-11316/BOS

    Small-molecule inhibition of STOML3 oligomerization reverses pathological mechanical hypersensitivity

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    The skin is equipped with specialized mechanoreceptors that allow the perception of the slightest brush. Indeed, some mechanoreceptors can detect even nanometer-scale movements. Movement is transformed into electrical signals via the gating of mechanically activated ion channels at sensory endings in the skin. The sensitivity of Piezo mechanically gated ion channels is controlled by stomatin-like protein-3 (STOML3), which is required for normal mechanoreceptor function. Here we identify small-molecule inhibitors of STOML3 oligomerization that reversibly reduce the sensitivity of mechanically gated currents in sensory neurons and silence mechanoreceptors in vivo\textit{in vivo}. STOML3 inhibitors in the skin also reversibly attenuate fine touch perception in normal mice. Under pathophysiological conditions following nerve injury or diabetic neuropathy, the slightest touch can produce pain, and here STOML3 inhibitors can reverse mechanical hypersensitivity. Thus, small molecules applied locally to the skin can be used to modulate touch and may represent peripherally available drugs to treat tactile-driven pain following neuropathy.This study was funded by DFG collaborative research grant SFB958 (projects A09 to K.P. and G.R.L., A01 to V.H. and Z02 to J.S.). Additional support was provided by a senior ERC grant (grant number 294678 to G.R.L.) and by the NeuroCure Cluster of Excellence (to V.H., G.R.L. and J.F.A.P.). K.P. was supported by a Cecile-Vogt Fellowship (MDC). S.P. was supported by a Marie Curie Fellowship from the European Union (grant number 253663 Touch in situ). C.P. received a Ph.D. fellowship from the University of Cagliari. J.F.A.P. was funded by a European Research Council (ERC) starting grant (ERC-2010-StG-260590), the DFG (FOR 1341, FOR 2143), the Berlin Institute of Health (BIH) and the European Union (FP7, 3x3Dimaging 323945). R.K. was supported by an ERC Advanced Investigator grant (294293-PAIN PLASTICITY). D.H. was funded by the Berlin Institute of Health (BIH). E.St.J.S., L.E. and M.M. were supported by an Alexander von Humboldt Fellowship

    The Cytotoxic Necrotizing Factor of Yersinia pseudotuberculosis (CNFy) is Carried on Extracellular Membrane Vesicles to Host Cells

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    In this study we show Yersinia pseudotuberculosis secretes membrane vesicles (MVs) that contain different proteins and virulence factors depending on the strain. Although MVs from Y. pseudotuberculosis YPIII and ATCC 29833 had many proteins in common (68.8% of all the proteins identified), those located in the outer membrane fraction differed significantly. For instance, the MVs from Y. pseudotuberculosis YPIII harbored numerous Yersinia outer proteins (Yops) while they were absent in the ATCC 29833 MVs. Another virulence factor found solely in the YPIII MVs was the cytotoxic necrotizing factor (CNFy), a toxin that leads to multinucleation of host cells. The ability of YPIII MVs to transport this toxin and its activity to host cells was verified using HeLa cells, which responded in a dose-dependent manner; nearly 70% of the culture was multinucleated after addition of 5 mu g/ml of the purified YPIII MVs. In contrast, less than 10% were multinucleated when the ATCC 29833 MVs were added. Semi-quantification of CNFy within the YPIII MVs found this toxin is present at concentrations of 5 -10 ng per mu g of total MV protein, a concentration that accounts for the cellular responses see

    Morpholino Gene Knockdown in Adult Fundulus heteroclitus: Role of SGK1 in Seawater Acclimation

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    The Atlantic killifish (Fundulus heteroclitus) is an environmental sentinel organism used extensively for studies on environmental toxicants and salt (NaCl) homeostasis. Previous research in our laboratory has shown that rapid acclimation of killifish to seawater is mediated by trafficking of CFTR chloride channels from intracellular vesicles to the plasma membrane in the opercular membrane within the first hour in seawater, which enhances chloride secretion into seawater, thereby contributing to salt homeostasis. Acute transition to seawater is also marked by an increase in both mRNA and protein levels of serum glucocorticoid kinase 1 (SGK1) within 15 minutes of transfer. Although the rise in SGK1 in gill and its functional analog, the opercular membrane, after seawater transfer precedes the increase in membrane CFTR, a direct role of SGK1 in elevating membrane CFTR has not been established in vivo. To test the hypothesis that SGK1 mediates the increase in plasma membrane CFTR we designed two functionally different vivo-morpholinos to knock down SGK1 in gill, and developed and validated a vivo-morpholino knock down technique for adult killifish. Injection (intraperitoneal, IP) of the splice blocking SGK1 vivo-morpholino reduced SGK1 mRNA in the gill after transition from fresh to seawater by 66%. The IP injection of the translational blocking and splice blocking vivo-morpholinos reduced gill SGK1 protein abundance in fish transferred from fresh to seawater by 64% and 53%, respectively. Moreover, knock down of SGK1 completely eliminated the seawater induced rise in plasma membrane CFTR, demonstrating that the increase in SGK1 protein is required for the trafficking of CFTR from intracellular vesicles in mitochondrion rich cells to the plasma membrane in the gill during acclimation to seawater. This is the first report of the use of vivo-morpholinos in adult killifish and demonstrates that vivo-morpholinos are a valuable genetic tool for this environmentally relevant model organism
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