236 research outputs found

    Broad Spectrum Antiviral Activity of Favipiravir (T-705): Protection from Highly Lethal Inhalational Rift Valley Fever

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    Background:Development of antiviral drugs that have broad-spectrum activity against a number of viral infections would be of significant benefit. Due to the evolution of resistance to currently licensed antiviral drugs, development of novel anti-influenza drugs is in progress, including Favipiravir (T-705), which is currently in human clinical trials. T-705 displays broad-spectrum in vitro activity against a number of viruses, including Rift Valley Fever virus (RVFV). RVF is an important neglected tropical disease that causes human, agricultural, and economic losses in endemic regions. RVF has the capacity to emerge in new locations and also presents a potential bioterrorism threat. In the current study, the in vivo efficacy of T-705 was evaluated in Wistar-Furth rats infected with the virulent ZH501 strain of RVFV by the aerosol route.Methodology/Principal Findings:Wistar-Furth rats are highly susceptible to a rapidly lethal disease after parenteral or inhalational exposure to the pathogenic ZH501 strain of RVFV. In the current study, two experiments were performed: a dose-determination study and a delayed-treatment study. In both experiments, all untreated control rats succumbed to disease. Out of 72 total rats infected with RVFV and treated with T-705, only 6 succumbed to disease. The remaining 66 rats (92%) survived lethal infection with no significant weight loss or fever. The 6 treated rats that succumbed survived significantly longer before succumbing to encephalitic disease.Conclusions/Significance:Currently, there are no licensed antiviral drugs for treating RVF. Here, T-705 showed remarkable efficacy in a highly lethal rat model of Rift Valley Fever, even when given up to 48 hours post-infection. This is the first study to show protection of rats infected with the pathogenic ZH501 strain of RVFV. Our data suggest that T-705 has potential to be a broad-spectrum antiviral drug. © 2014 Caroline et al

    Carbon storage in soils of Southeastern Nigeria under different management practices

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    <p>Abstract</p> <p>Background</p> <p>Changes in agricultural practices-notably changes in crop varieties, application of fertilizer and manure, rotation and tillage practices-influence how much and at what rate carbon is stored in, or released from, soils. Quantification of the impacts of land use on carbon stocks in sub-Saharan Africa is challenging because of the spatial heterogeneity of soil, climate, management conditions, and due to the lack of data on soil carbon pools of most common agroecosystems. This paper provides data on soil carbon stocks that were collected at 10 sites in southeastern Nigeria to characterize the impact of soil management practices.</p> <p>Results</p> <p>The highest carbon stocks, 7906-9510 gC m<sup>-2</sup>, were found at the sites representing natural forest, artificial forest and artificial grassland ecosystems. Continuously cropped and conventionally tilled soils had about 70% lower carbon stock (1978-2822 gC m<sup>-2</sup>). Thus, the soil carbon stock in a 45-year old <it>Gmelina </it>forest was 8987 gC m<sup>-2</sup>, whereas the parts of this forest, that were cleared and continuously cultivated for 15 years, had 75% lower carbon stock (1978 gC m<sup>-2</sup>). The carbon stock of continuously cropped and conventionally tilled soils was also 25% lower than the carbon stock of the soil cultivated by use of conservation tillage.</p> <p>Conclusion</p> <p>Introducing conservation tillage practices may reduce the loss of soil carbon stocks associated with land conversion. However, the positive effect of conservation tillage is not comparable to the negative effect of land conversion, and may not result in significant accumulation of carbon in southeastern Nigeria soils.</p

    The Classic: Bone Morphogenetic Protein

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    This Classic Article is a reprint of the original work by Marshall R. Urist and Basil S. Strates, Bone Morphogenetic Protein. An accompanying biographical sketch of Marshall R. Urist, MD is available at DOI 10.1007/s11999-009-1067-4; a second Classic Article is available at DOI 10.1007/s11999-009-1069-2; and a third Classic Article is available at DOI 10.1007/s11999-009-1070-9. The Classic Article is © 1971 by Sage Publications Inc. Journals and is reprinted with permission from Urist MR, Strates BS. Bone morphogenetic protein. J Dent Res. 1971;50:1392–1406

    Increased Expression of Toll-Like Receptors by Monocytes and Natural Killer Cells in ANCA-Associated Vasculitis

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    INTRODUCTION: Toll-like receptors (TLRs) are a family of receptors that sense pathogen associated patterns such as bacterial cell wall proteins. Bacterial infections are associated with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). Here, we assessed the expression of TLRs 2, 4, and 9 by peripheral blood leukocytes from patients with AAV, and investigated TLR mediated responses ex vivo. METHODS: Expression of TLRs was determined in 38 AAV patients (32 remission, 6 active disease), and 20 healthy controls (HC). Membrane expression of TLRs 2, 4, and 9, and intracellular expression of TLR9 by B lymphocytes, T lymphocytes, NK cells, monocytes and granulocytes was assessed using 9-color flowcytometry. Whole blood from 13 patients and 7 HC was stimulated ex vivo with TLR 2, 4 and 9 ligands and production of cytokines was analyzed. RESULTS: In patients, we observed increased proportions of TLR expressing NK cells. Furthermore, patient monocytes expressed higher levels of TLR2 compared to HC, and in a subset of patients an increased proportion of TLR4(+) monocytes was observed. Monocytes from nasal carriers of Staphylococcus aureus expressed increased levels of intracellular TLR9. Membrane expression of TLRs by B lymphocytes, T lymphocytes, and granulocytes was comparable between AAV patients and HC. Patients with active disease did not show differential TLR expression compared to patients in remission. Ex vivo responses to TLR ligands did not differ significantly between patients and HC. CONCLUSIONS: In AAV, monocytes and NK cells display increased TLR expression. Increased TLR expression by these leukocytes, probably resulting from increased activation, could play a role in disease (re)activation

    Androgen receptor signaling regulates the transcriptome of prostate cancer cells by modulating global alternative splicing

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    Androgen receptor (AR), is a transcription factor and a member of a hormone receptor superfamily. AR plays a vital role in the progression of prostate cancer and is a crucial target for therapeutic interventions. While the majority of advanced-stage prostate cancer patients will initially respond to the androgen deprivation, the disease often progresses to castrate-resistant prostate cancer (CRPC). Interestingly, CRPC tumors continue to depend on hyperactive AR signaling and will respond to potent second-line antiandrogen therapies, including bicalutamide (CASODEX®) and enzalutamide (XTANDI®). However, the progression-free survival rate for the CRPC patients on antiandrogen therapies is only 8–19 months. Hence, there is a need to understand the mechanisms underlying CRPC progression and eventual treatment resistance. Here, we have leveraged next-generation sequencing and newly developed analytical methodologies to evaluate the role of AR signaling in regulating the transcriptome of prostate cancer cells. The genomic and pharmacologic stimulation and inhibition of AR activity demonstrates that AR regulates alternative splicing within cancer-relevant genes. Furthermore, by integrating transcriptomic data from in vitro experiments and in prostate cancer patients, we found that a significant number of AR-regulated splicing events are associated with tumor progression. For example, we found evidence for an inadvertent AR-antagonist-mediated switch in IDH1 and PL2G2A isoform expression, which is associated with a decrease in overall survival of patients. Mechanistically, we discovered that the epithelial-specific splicing regulators (ESRP1 and ESRP2), flank many AR-regulated alternatively spliced exons. And, using 2D invasion assays, we show that the inhibition of ESRPs can suppress AR-antagonist-driven tumor invasion. Our work provides evidence for a new mechanism by which AR alters the transcriptome of prostate cancer cells by modulating alternative splicing. As such, our work has important implications for CRPC progression and development of resistance to treatment with bicalutamide and enzalutamide

    Caffeic Acid Phenethyl Ester Causes p21Cip1 Induction, Akt Signaling Reduction, and Growth Inhibition in PC-3 Human Prostate Cancer Cells

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    Caffeic acid phenethyl ester (CAPE) treatment suppressed proliferation, colony formation, and cell cycle progression in PC-3 human prostate cancer cells. CAPE decreased protein expression of cyclin D1, cyclin E, SKP2, c-Myc, Akt1, Akt2, Akt3, total Akt, mTOR, Bcl-2, Rb, as well as phosphorylation of Rb, ERK1/2, Akt, mTOR, GSK3α, GSK3β, PDK1; but increased protein expression of KLF6 and p21Cip1. Microarray analysis indicated that pathways involved in cellular movement, cell death, proliferation, and cell cycle were affected by CAPE. Co-treatment of CAPE with chemotherapeutic drugs vinblastine, paclitaxol, and estramustine indicated synergistic suppression effect. CAPE administration may serve as a potential adjuvant therapy for prostate cancer

    Small molecules, big targets: drug discovery faces the protein-protein interaction challenge.

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    Protein-protein interactions (PPIs) are of pivotal importance in the regulation of biological systems and are consequently implicated in the development of disease states. Recent work has begun to show that, with the right tools, certain classes of PPI can yield to the efforts of medicinal chemists to develop inhibitors, and the first PPI inhibitors have reached clinical development. In this Review, we describe the research leading to these breakthroughs and highlight the existence of groups of structurally related PPIs within the PPI target class. For each of these groups, we use examples of successful discovery efforts to illustrate the research strategies that have proved most useful.JS, DES and ARB thank the Wellcome Trust for funding.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nrd.2016.2

    The ineffectiveness of entrepreneurship policy:Is policy formulation to blame?

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    Entrepreneurship policy has been criticised for its lack of effectiveness. Some scholars, such as Scott Shane in this journal, have argued that it is ‘bad’ public policy. But this simply begs the question why the legislative process should generate bad policy? To answer this question this study examines the UK’s enterprise policy process in the 2009–2010 period. It suggests that a key factor for the ineffectiveness of policy is how it is formulated. This stage in the policy process is seldom visible to those outside of government departments and has been largely ignored by prior research. The application of institutional theory provides a detailed theoretical understanding of the actors and the process by which enterprise policy is formulated. We find that by opening up the ‘black box’ of enterprise policy formulation, the process is dominated by powerful actors who govern the process with their interests
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