74 research outputs found

    A two-year study with cimetidine in the rat: assessment for chronic toxicity and carcinogenicity

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    T. F. (1981). Toxicol. Appl. PharmacoL 61, 119-137. Cimetidine [Am-cyano-N-methyl-N1-{2-[(5-methylimidazol-4-yl)methylthio]ethyl}guanidine] was administered daily for 2 years by gavage to Wistar rats at dose levels of 950, 378, and 150 mg/kg/day. Two groups, one receiving distilled wathr daily and the other not treated, served as controls. Premature deaths occurred when cimetidine was accidentally introduced into the lungs or reached the lungs by seepage from the esophagus via the larynx during intragastric administration but cimetidine treatment did not otherwise affect survival, body weight gain, clinical condition, and hematological, or urinalysis parameters. Raised transaminase levels occurred occasionally during the second year of the study in top dose males and there was a significant increase in mean liver weight in top dose females killed terminally compared with controls. Histopathological observations of the livers of these animals indicated only nonspecific changes. Mean prostate and seminal vesicle weights were significantly lower in all groups receiving cimetidine than in controls and there was dose-related atrophy of the seminiferous tubules and atrophy of the male secondary sex organs. There were no other apparent effects of treatment on nontumor pathology. Overall tumor incidence, after the exclusion of Leydig-cell tumors, was not affected by cimetidine treatment. A significantly higher incidence of benign Leydig-cell tumors in the combined cimetidine-treated groups compared with the combined control groups was confined to rats killed during Weeks 105 and 106 and was not dose related. No meaningful treatmentrelated effects on incidence were observed for any other kind of neoplasm. Cimetidine is a specific, competitive histamine H2-receptor antagonist as defined by Black et al. (1972) and is an effective inhibitor of gastric acid secretion in animals and in man. Cimetidine has been shown to have low acute toxicity and repeated dose studies of up to 12 months duration in rats and dogs have revealed no major adverse effects The present paper presents the results of a 2-year toxicity study in the rat with particular attention to incidences of neoplastic lesions

    Carbon Sequestration in Synechococcus Sp.: From Molecular Machines to Hierarchical Modeling

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    The U.S. Department of Energy recently announced the first five grants for the Genomes to Life (GTL) Program. The goal of this program is to "achieve the most far-reaching of all biological goals: a fundamental, comprehensive, and systematic understanding of life." While more information about the program can be found at the GTL website (www.doegenomestolife.org), this paper provides an overview of one of the five GTL projects funded, "Carbon Sequestration in Synechococcus Sp.: From Molecular Machines to Hierarchical Modeling." This project is a combined experimental and computational effort emphasizing developing, prototyping, and applying new computational tools and methods to ellucidate the biochemical mechanisms of the carbon sequestration of Synechococcus Sp., an abundant marine cyanobacteria known to play an important role in the global carbon cycle. Understanding, predicting, and perhaps manipulating carbon fixation in the oceans has long been a major focus of biological oceanography and has more recently been of interest to a broader audience of scientists and policy makers. It is clear that the oceanic sinks and sources of CO2 are important terms in the global environmental response to anthropogenic atmospheric inputs of CO2 and that oceanic microorganisms play a key role in this response. However, the relationship between this global phenomenon and the biochemical mechanisms of carbon fixation in these microorganisms is poorly understood. The project includes five subprojects: an experimental investigation, three computational biology efforts, and a fifth which deals with addressing computational infrastructure challenges of relevance to this project and the Genomes to Life program as a whole. Our experimental effort is designed to provide biology and data to drive the computational efforts and includes significant investment in developing new experimental methods for uncovering protein partners, characterizing protein complexes, identifying new binding domains. We will also develop and apply new data measurement and statistical methods for analyzing microarray experiments. Our computational efforts include coupling molecular simulation methods with knowledge discovery from diverse biological data sets for high-throughput discovery and characterization of protein-protein complexes and developing a set of novel capabilities for inference of regulatory pathways in microbial genomes across multiple sources of information through the integration of computational and experimental technologies. These capabilities will be applied to Synechococcus regulatory pathways to characterize their interaction map and identify component proteins in these pathways. We will also investigate methods for combining experimental and computational results with visualization and natural language tools to accelerate discovery of regulatory pathways. Furthermore, given that the ultimate goal of this effort is to develop a systems-level of understanding of how the Synechococcus genome affects carbon fixation at the global scale, we will develop and apply a set of tools for capturing the carbon fixation behavior of complex of Synechococcus at different levels of resolution. Finally, because the explosion of data being produced by high-throughput experiments requires data analysis and models which are more computationally complex, more heterogeneous, and require coupling to ever increasing amounts of experimentally obtained data in varying formats, we have also established a companion computational infrastructure to support this effort as well as the Genomes to Life program as a whole.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63164/1/153623102321112746.pd

    The Baryon Oscillation Spectroscopic Survey of SDSS-III

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    The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7. Observations of neutral hydrogen in the Lyman alpha forest in more than 150,000 quasar spectra (g<22) will constrain BAO over the redshift range 2.15<z<3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyman alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance D_A to an accuracy of 1.0% at redshifts z=0.3 and z=0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyman alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D_A(z) and H^{-1}(z) parameters to an accuracy of 1.9% at z~2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.Comment: 49 pages, 16 figures, accepted by A

    Improving physical health and reducing substance use in psychosis - randomised control trial (IMPACT RCT): study protocol for a cluster randomised controlled trial

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    The National Institute for Health Research funds the IMPACT programme at King’s College London and South London and Maudsley NHS Foundation Trust (ref: RP-PG-0606-1049)

    The Baryon Oscillation Spectroscopic Survey of SDSS-III

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    The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg(2) to measure BAO to redshifts z < 0.7. Observations of neutral hydrogen in the Ly alpha forest in more than 150,000 quasar spectra (g < 22) will constrain BAO over the redshift range 2.15 < z < 3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Ly alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance d(A) to an accuracy of 1.0% at redshifts z = 0.3 and z = 0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Ly alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D-A(z) and H-1(z) parameters to an accuracy of 1.9% at z similar to 2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS
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