154 research outputs found

    Does Alendronate reduce the risk of fracture in men? A meta-analysis incorporating prior knowledge of anti-fracture efficacy in women

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    BACKGROUND: Alendronate has been found to reduce the risk of fractures in postmenopausal women as demonstrated in multiple randomized controlled trials enrolling thousands of women. Yet there is a paucity of such randomized controlled trials in osteoporotic men. Our objective was to systematically review the anti-fracture efficacy of alendronate in men with low bone mass or with a history of prevalent fracture(s) and incorporate prior knowledge of alendronate efficacy in women in the analysis. METHODS: We examined randomized controlled trials in men comparing the anti-fracture efficacy of alendronate to placebo or calcium or vitamin D, or any combination of these. Studies of men with secondary causes of osteoporosis other than hypogonadism were excluded. We searched the following electronic databases (without language restrictions) for potentially relevant citations: Medline, Medline in Process (1966-May 24/2004), and Embase (1996–2004). We also contacted the manufacturer of the drug in search of other relevant trials. Two reviewers independently identified two trials (including 375 men), which met all inclusion criteria. Data were abstracted by one reviewer and checked by another. Results of the male trials were pooled using Bayesian random effects models, incorporating prior information of anti-fracture efficacy from meta-analyses of women. RESULTS: The odds ratios of incident fractures in men (with 95% credibility intervals) with alendronate (10 mg daily) were: vertebral fractures, 0.44 (0.23, 0.83) and non-vertebral fractures, 0.60 (0.29, 1.44). CONCLUSION: In conclusion, alendronate decreases the risk of vertebral fractures in men at risk. There is currently insufficient evidence of a statistically significant reduction of non-vertebral fractures, but the paucity of trials in men limit the statistical power to detect such an effect

    Human Cardiac-Derived Adherent Proliferating Cells Reduce Murine Acute Coxsackievirus B3-Induced Myocarditis

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    BACKGROUND: Under conventional heart failure therapy, inflammatory cardiomyopathy typically has a progressive course, indicating a need for alternative therapeutic strategies to improve long-term outcomes. We recently isolated and identified novel cardiac-derived cells from human cardiac biopsies: cardiac-derived adherent proliferating cells (CAPs). They have similarities with mesenchymal stromal cells, which are known for their anti-apoptotic and immunomodulatory properties. We explored whether CAPs application could be a novel strategy to improve acute Coxsackievirus B3 (CVB3)-induced myocarditis. METHODOLOGY/PRINCIPAL FINDINGS: To evaluate the safety of our approach, we first analyzed the expression of the coxsackie- and adenovirus receptor (CAR) and the co-receptor CD55 on CAPs, which are both required for effective CVB3 infectivity. We could demonstrate that CAPs only minimally express both receptors, which translates to minimal CVB3 copy numbers, and without viral particle release after CVB3 infection. Co-culture of CAPs with CVB3-infected HL-1 cardiomyocytes resulted in a reduction of CVB3-induced HL-1 apoptosis and viral progeny release. In addition, CAPs reduced CD4 and CD8 T cell proliferation. All CAPs-mediated protective effects were nitric oxide- and interleukin-10-dependent and required interferon-γ. In an acute murine model of CVB3-induced myocarditis, application of CAPs led to a decrease of cardiac apoptosis, cardiac CVB3 viral load and improved left ventricular contractility parameters. This was associated with a decline in cardiac mononuclear cell activity, an increase in T regulatory cells and T cell apoptosis, and an increase in left ventricular interleukin-10 and interferon-γ mRNA expression. CONCLUSIONS: We conclude that CAPs are a unique type of cardiac-derived cells and promising tools to improve acute CVB3-induced myocarditis

    Light Chain Separated from the Rest of the Type A Botulinum Neurotoxin Molecule Is the Most Catalytically Active Form

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    Botulinum neurotoxins (BoNT) are the most potent of all toxins. The 50 kDa N-terminal endopeptidase catalytic light chain (LC) of BoNT is located next to its central, putative translocation domain. After binding to the peripheral neurons, the central domain of BoNT helps the LC translocate into cytosol where its proteolytic action on SNARE (soluble NSF attachment protein receptor) proteins blocks exocytosis of acetyl choline leading to muscle paralysis and eventual death. The translocation domain also contains 105 Å -long stretch of ∼100 residues, known as “belt,” that crosses over and wraps around the LC to shield the active site from solvent. It is not known if the LC gets dissociated from the rest of the molecule in the cytosol before catalysis. To investigate the structural identity of the protease, we prepared four variants of type A BoNT (BoNT/A) LC, and compared their catalytic parameters with those of BoNT/A whole toxin. The four variants were LC + translocation domain, a trypsin-nicked LC + translocation domain, LC + belt, and a free LC. Our results showed that Km for a 17-residue SNAP-25 (synaptosomal associated protein of 25 kDa) peptide for these constructs was not very different, but the turnover number (kcat) for the free LC was 6-100-fold higher than those of its four variants. Moreover, none of the four variants of the LC was prone to autocatalysis. Our results clearly demonstrated that in vitro, the LC minus the rest of the molecule is the most catalytically active form. The results may have implication as to the identity of the active, toxic moiety of BoNT/A in vivo

    Mesenchymal Stem Cells Exhibit Firm Adhesion, Crawling, Spreading and Transmigration across Aortic Endothelial Cells: Effects of Chemokines and Shear

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    Mesenchymal stem cells (MSCs) have anti-inflammatory and immunosuppressive properties and may be useful in the therapy of diseases such as arteriosclerosis. MSCs have some ability to traffic into inflamed tissues, however to exploit this therapeutically their migratory mechanisms need to be elucidated. This study examines the interaction of murine MSCs (mMSCs) with, and their migration across, murine aortic endothelial cells (MAECs), and the effects of chemokines and shear stress. The interaction of mMSCs with MAECs was examined under physiological flow conditions. mMSCs showed lack of interaction with MAECs under continuous flow. However, when the flow was stopped (for 10min) and then started, mMSCs adhered and crawled on the endothelial surface, extending fine microvillous processes (filopodia). They then spread extending pseudopodia in multiple directions. CXCL9 significantly enhanced the percentage of mMSCs adhering, crawling and spreading and shear forces markedly stimulated crawling and spreading. CXCL9, CXCL16, CCL20 and CCL25 significantly enhanced transendothelial migration across MAECs. The transmigrated mMSCs had down-regulated receptors CXCR3, CXCR6, CCR6 and CCR9. This study furthers the knowledge of MSC transendothelial migration and the effects of chemokines and shear stress which is of relevance to inflammatory diseases such as arteriosclerosis

    Methods of probing the interactions between small molecules and disordered proteins

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    It is generally recognized that a large fraction of the human proteome is made up of proteins that remain disordered in their native states. Despite the fact that such proteins play key biological roles and are involved in many major human diseases, they still represent challenging targets for drug discovery. A major bottleneck for the identification of compounds capable of interacting with these proteins and modulating their disease-promoting behaviour is the development of effective techniques to probe such interactions. The difficulties in carrying out binding measurements have resulted in a poor understanding of the mechanisms underlying these interactions. In order to facilitate further methodological advances, here we review the most commonly used techniques to probe three types of interactions involving small molecules: (1) those that disrupt functional interactions between disordered proteins; (2) those that inhibit the aberrant aggregation of disordered proteins, and (3) those that lead to binding disordered proteins in their monomeric states. In discussing these techniques, we also point out directions for future developments.Gabriella T. Heller is supported by the Gates Cambridge Trust Scholarship. Francesco A. Aprile is supported by a Senior Research Fellowship award from the Alzheimer’s Society, UK (grant number 317, AS-SF-16-003)

    Liver transplantation: indication and survival

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    O sucesso dos transplantes de fígado certamente seria comprometido se a avaliação pré-operatória dos pacientes não fosse realizada de forma adequada. Isto se justifica devido ao reconhecimento de que o sucesso da cirurgia depende, em princípio, do diagnóstico da doença de base, da determinação de sua extensão e do grau de repercussão sistêmica. No final das décadas de setenta a noventa os progressos da hepatologia na identificação das hepatites virais e no manejo da ascite e da síndrome hepatorrenal melhoraram sobremaneira a expectativa de vida do doente portador de doença hepática crônica. Mas, sem dúvida o transplante ortotópico do fígado (TOF) foi o espetacular avanço da hepatologia moderna. Atualmente o transplante é um tratamento eficaz das hepatopatias crônicas, e o índice de sobrevivência global aos 3 anos é ao redor de 80%. É, portanto, uma alternativa de tratamento indicada nos casos terminais, onde a mortalidade com tratamentos conservadores pode atingir até 70% ao final de 12 meses. Neste artigo, os autores comentam aspectos do TOF, relacionados à indicação e a sobrevida. _________________________________________________________________________________________ ABSTRACT: The success of liver transplantation would be certainly compromised if the pre-operative evaluation was not adequately performed. The success of the liver transplantation depends on the diagnosis of the underlying hepatic disease, the determination of its extension and the degree of systemic repercussion. In the last 30 years, the progress in hepatology, the identification of viral hepatitis and the better management of ascitis and hepatorenal syndrome have increased the life expectancy of patients with chronic liver failure. Undoubtedly, orthotopic liver transplantation represents a great advance in modern hepatology. Nowadays, liver transplantation represents a valid therapeutic option for chronic liver diseases with (and presents) a mean survival rate of about 80% in 3 years. Thus, it is an indicated treatment in situations where the conservative treatment (would) could lead to a (incur) mortality rate as high as 70% in one year. In this article the authors comment (on) various aspects of Orthotopic Liver Transplantation related to indications and survival rates
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