1,846 research outputs found

    ROLE OF ENDOTHELIUM-DERIVED PROSTAGLANDINS IN HYPOXIA-ELICITED ARTERIOLAR DILATION IN RAT SKELETAL-MUSCLE

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    The aims of the present study were to determine the response of rat cremaster muscle first-order arterioles to hypoxia and the role of endothelium-derived prostaglandins in the response. Isolated arterioles were cannulated, pressurized to 65 mm Hg, and studied in a no-flow condition in a bath containing Krebs' bicarbonate solution, pH 7.4, equilibrated with 21% O2-5% CO2-74% N2 (PO2, 150 mm Hg) or 95% N2-5% CO2 (Po2, 15 mm Hg [hypoxia]). Responses to hypoxia and vasoactive substances were studied before and after removal of the endothelium or blockade of prostaglandin synthesis by the administration of indomethacin (10(-5) M). Addition to the suffusion solution of arachidonic acid (10(-7) and 10(-6) M), prostaglandin E2 (10(-9) and 10(-8) M), acetylcholine (10(-8) and 10(-6) M), or sodium nitroprusside 10(-8) M) evoked significanT arteriolar dilation. When the bath Po2 was reduced from 150 to 15 mm Hg, arteriolar diameters increased by 58.8+/-9.3-mu-m (61%). Removal of the endothelium completely inhibited responses to hypoxia, acetylcholine, and arachidonic acid, whereas responses to sodium nitroprusside and prostaglandin E2 remained unaltered. In arterioles with an intact endothelium, indomethacin completely inhibited the responses to hypoxia and arachidonic acid, whereas responses to acetylcholine and sodium nitroprusside were unaltered. These findings support the conclusion that endothelium-derived prostaglandins mediate the arteriolar dilation to hypoxia in rat skeletal muscle arterioles

    'A habitual disposition to the good': on reason, virtue and realism

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    Amidst the crisis of instrumental reason, a number of contemporary political philosophers including Jürgen Habermas have sought to rescue the project of a reasonable humanism from the twin threats of religious fundamentalism and secular naturalism. In his recent work, Habermas defends a post-metaphysical politics that aims to protect rationality against encroachment while also accommodating religious faith within the public sphere. This paper contends that Habermas’ post-metaphysical project fails to provide a robust alternative either to the double challenge of secular naturalism and religious fundamentalism or to the ruthless instrumentalism that underpins capitalism. By contrast with Habermas and also with the ‘new realism’ of contemporary political philosophers such as Raymond Geuss or Bernard Williams, realism in the tradition of Plato and Aristotle can defend reason against instrumental rationality and blind belief by integrating it with habit, feeling and even faith. Such metaphysical–political realism can help develop a politics of virtue that goes beyond communitarian thinking by emphasising plural modes of association (not merely ‘community’), substantive ties of sympathy and the importance of pursuing goodness and mutual flourishing

    Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors

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    Background Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (177Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. Methods We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either 177Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (177Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. Results At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the 177Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the 177Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the 177Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the 177Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. Conclusions Treatment with 177Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the 177Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11

    Fermilab E791

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    Fermilab E791, a very high statistics charm particle experiment, recently completed its data taking at Fermilab's Tagged Photon Laboratory. Over 20 billion events were recorded through a loose transverse energy trigger and written to 8mm tape in the the 1991-92 fixed target run at Fermilab. This unprecedented data sample containing charm is being analysed on many-thousand MIP RISC computing farms set up at sites in the collaboration. A glimpse of the data taking and analysis effort is presented. We also show some preliminary results for common charm decay modes. Our present analysis indicates a very rich yield of over 200K reconstructed charm decays.Comment: 4 pages, 1 figure, LaTe

    Modeling methanogenesis with a genome-scale metabolic reconstruction of Methanosarcina barkeri

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    We present a genome-scale metabolic model for the archaeal methanogen Methanosarcina barkeri. We characterize the metabolic network and compare it to reconstructions from the prokaryotic, eukaryotic and archaeal domains. Using the model in conjunction with constraint-based methods, we simulate the metabolic fluxes and resulting phenotypes induced by different environmental and genetic conditions. This represents the first large-scale simulation of either a methanogen or an archaeal species. Model predictions are validated by comparison to experimental growth measurements and phenotypes of M. barkeri on different substrates. The predicted growth phenotypes for wild type and mutants of the methanogenic pathway have a high level of agreement with experimental findings. We further examine the efficiency of the energy-conserving reactions in the methanogenic pathway, specifically the Ech hydrogenase reaction, and determine a stoichiometry for the nitrogenase reaction. This work demonstrates that a reconstructed metabolic network can serve as an analysis platform to predict cellular phenotypes, characterize methanogenic growth, improve the genome annotation and further uncover the metabolic characteristics of methanogenesis

    Agonism Reloaded: Potentia, Renewal and Radical Democracy

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    This article focuses on the agonistic account of renewal and discusses its place within the broader horizon of radical democracy. It suggests that while the emphasis which agonistic theorists place on difference and popular struggles (particularly social movement politics) ensures some common ground with other theories of radical democracy, their account of renewal also displays some marked differences. The article explores these differences and discusses whether agonism is sufficient to address the limits of the current neoliberal order

    First Observation of the Rare Decay Mode K-long -> e+ e-

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    In an experiment designed to search for and study very rare two-body decay modes of the K-long, we have observed four examples of the decay K-long -> e+ e-, where the expected background is 0.17+-0.10 events. This observation translates into a branching fraction of 8.7^{+5.7}_{-4.1} X 10^{-12}, consistent with recent theoretical predictions. This result represents by far the smallest branching fraction yet measured in particle physics.Comment: 9 pages, 3 figure

    Anti-tumour effects of lanreotide for pancreatic and intestinal neuroendocrine tumours: The CLARINET open-label extension study

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    In the CLARINET study, lanreotide Autogel (depot in USA) significantly prolonged progression-free survival (PFS) in patients with metastatic pancreatic/intestinal neuroendocrine tumours (NETs). We report long-term safety and additional efficacy data from the open-label extension (OLE). Patients with metastatic grade 1/2 (Ki-67 %) nonfunctioning NET and documented baseline tumour-progression status received lanreotide Autogel 120 mg (n=101) or placebo (n=103) for 96 weeks or until death/progressive disease (PD) in CLARINET study. Patients with stable disease (SD) at core study end (lanreotide/placebo) or PD (placebo only) continued or switched to lanreotide in the OLE. In total, 88 patients (previously: lanreotide, n=41; placebo, n=47) participated: 38% had pancreatic, 39% midgut and 23% other/unknown primary tumours. Patients continuing lanreotide reported fewer adverse events (AEs) (all and treatment-related) during OLE than core study. Placebo-to-lanreotide switch patients reported similar AE rates in OLE and core studies, except more diarrhoea was considered treatment-related in OLE (overall diarrhoea unchanged). Median lanreotide PFS (core study randomisation to PD in core/OLE; n=101) was 32.8 months (95% CI: 30.9, 68.0). A sensitivity analysis, addressing potential selection

    Tracking Performance of the Scintillating Fiber Detector in the K2K Experiment

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    The K2K long-baseline neutrino oscillation experiment uses a Scintillating Fiber Detector (SciFi) to reconstruct charged particles produced in neutrino interactions in the near detector. We describe the track reconstruction algorithm and the performance of the SciFi after three years of operation.Comment: 24pages,18 figures, and 1 table. Preprint submitted to NI
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