93 research outputs found

    Comparison of the efficacy and safety of rosuvastatin 10 mg and atorvastatin 20 mg in high-risk patients with hypercholesterolemia – Prospective study to evaluate the Use of Low doses of the Statins Atorvastatin and Rosuvastatin (PULSAR)

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    BACKGROUND: Many patients at high risk of cardiovascular disease do not achieve recommended low-density lipoprotein cholesterol (LDL-C) goals. This study compared the efficacy and safety of low doses of rosuvastatin (10 mg) and atorvastatin (20 mg) in high-risk patients with hypercholesterolemia. METHODS: A total of 996 patients with hypercholesterolemia (LDL-C ≄ 3.4 and < 5.7 mmol/L [130 and 220 mg/dL]) and coronary heart disease (CHD), atherosclerosis, or a CHD-risk equivalent were randomized to once-daily rosuvastatin 10 mg or atorvastatin 20 mg. The primary endpoint was the percentage change from baseline in LDL-C levels at 6 weeks. Secondary endpoints included LDL-C goal achievement (National Cholesterol Education Program Adult Treatment Panel III [NCEP ATP III] goal < 100 mg/dL; 2003 European goal < 2.5 mmol/L for patients with atherosclerotic disease, type 2 diabetes, or at high risk of cardiovascular events, as assessed by a Systematic COronary Risk Evaluation (SCORE) risk ≄ 5% or 3.0 mmol/L for all other patients), changes in other lipids and lipoproteins, cost-effectiveness, and safety. RESULTS: Rosuvastatin 10 mg reduced LDL-C levels significantly more than atorvastatin 20 mg at week 6 (44.6% vs. 42.7%, p < 0.05). Significantly more patients achieved NCEP ATP III and 2003 European LDL-C goals with rosuvastatin 10 mg compared with atorvastatin 20 mg (68.8% vs. 62.5%, p < 0.05; 68.0% vs. 63.3%, p < 0.05, respectively). High-density lipoprotein cholesterol was increased significantly with rosuvastatin 10 mg versus atorvastatin 20 mg (6.4% vs. 3.1%, p < 0.001). Lipid ratios and levels of apolipoprotein A-I also improved more with rosuvastatin 10 mg than with atorvastatin 20 mg. The use of rosuvastatin 10 mg was also cost-effective compared with atorvastatin 20 mg in both a US and a UK setting. Both treatments were well tolerated, with a similar incidence of adverse events (rosuvastatin 10 mg, 27.5%; atorvastatin 20 mg, 26.1%). No cases of rhabdomyolysis, liver, or renal insufficiency were recorded. CONCLUSION: In high-risk patients with hypercholesterolemia, rosuvastatin 10 mg was more efficacious than atorvastatin 20 mg at reducing LDL-C, enabling LDL-C goal achievement and improving other lipid parameters. Both treatments were well tolerated

    Development and quantitative analyses of a universal rRNA-subtraction protocol for microbial metatranscriptomics

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    Metatranscriptomes generated by pyrosequencing hold significant potential for describing functional processes in complex microbial communities. Meeting this potential requires protocols that maximize mRNA recovery by reducing the relative abundance of ribosomal RNA, as well as systematic comparisons to identify methodological artifacts and test for reproducibility across data sets. Here, we implement a protocol for subtractive hybridization of bacterial rRNA (16S and 23S) that uses sample-specific probes and is applicable across diverse environmental samples. To test this method, rRNA-subtracted and unsubtracted transcriptomes were sequenced (454 FLX technology) from bacterioplankton communities at two depths in the oligotrophic open ocean, yielding 10 data sets representing ~350 Mbp. Subtractive hybridization reduced bacterial rRNA transcript abundance by 40–58%, increasing recovery of non-rRNA sequences up to fourfold (from 12% to 20% of total sequences to 40–49%). In testing this method, we established criteria for detecting sequences replicated artificially via pyrosequencing errors and identified such replicates as a significant component (6–39%) of total pyrosequencing reads. Following replicate removal, statistical comparisons of reference genes (identified via BLASTX to NCBI-nr) between technical replicates and between rRNA-subtracted and unsubtracted samples showed low levels of differential transcript abundance (<0.2% of reference genes). However, gene overlap between data sets was remarkably low, with no two data sets (including duplicate runs from the same pyrosequencing library template) sharing greater than 17% of unique reference genes. These results indicate that pyrosequencing captures a small subset of total mRNA diversity and underscores the importance of reliable rRNA subtraction procedures to enhance sequencing coverage across the functional transcript pool.Agouron InstituteGordon and Betty Moore FoundationUnited States. Dept. of Energy. Office of ScienceNational Science Foundation (U.S.) (NSF Science and Technology Center Award EF0424599

    Lipoprotein associated phospholipase A2: role in atherosclerosis and utility as a biomarker for cardiovascular risk

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    Atherosclerosis and its clinical manifestations are widely prevalent throughout the world. Atherogenesis is highly complex and modulated by numerous genetic and environmental risk factors. A large body of basic scientific and clinical research supports the conclusion that inflammation plays a significant role in atherogenesis along the entire continuum of its progression. Inflammation adversely impacts intravascular lipid handling and metabolism, resulting in the development of macrophage foam cell, fatty streak, and atheromatous plaque formation. Given the enormous human and economic cost of myocardial infarction, ischemic stroke, peripheral arterial disease and amputation, and premature death and disability, considerable effort is being committed to refining our ability to correctly identify patients at heightened risk for atherosclerotic vascular disease and acute cardiovascular events so that they can be treated earlier and more aggressively. Serum markers of inflammation have emerged as an important component of risk factor burden. Lipoprotein-associated phospholipase A2 (Lp-PLA2) potentiates intravascular inflammation and atherosclerosis. A variety of epidemiologic studies support the utility of Lp-PLA2 measurements for estimating and further refining cardiovascular disease risk. Drug therapies to inhibit Lp-PLA2 are in development and show considerable promise, including darapladib, a specific molecular inhibitor of the enzyme. In addition to substantially inhibiting Lp-PLA2 activity, darapladib reduces progression of the necrotic core volume of human coronary artery atheromatous plaque. The growing body of evidence points to an important role and utility for Lp-PLA2 testing in preventive and personalized clinical medicine

    Evaluation of two commercial global miRNA expression profiling platforms for detection of less abundant miRNAs

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    <p>Abstract</p> <p>Background</p> <p>microRNAs (miRNA) are short, endogenous transcripts that negatively regulate the expression of specific mRNA targets. miRNAs are found both in tissues and body fluids such as plasma. A major perspective for the use of miRNAs in the clinical setting is as diagnostic plasma markers for neoplasia. While miRNAs are abundant in tissues, they are often scarce in plasma. For quantification of miRNA in plasma it is therefore of importance to use a platform with high sensitivity and linear performance in the low concentration range. This motivated us to evaluate the performance of three commonly used commercial miRNA quantification platforms: GeneChip miRNA 2.0 Array, miRCURY Ready-to-Use PCR, Human panel I+II V1.M, and TaqMan Human MicroRNA Array v3.0.</p> <p>Results</p> <p>Using synthetic miRNA samples and plasma RNA samples spiked with different ratios of 174 synthetic miRNAs we assessed the performance characteristics reproducibility, recovery, specificity, sensitivity and linearity. It was found that while the qRT-PCR based platforms were sufficiently sensitive to reproducibly detect miRNAs at the abundance levels found in human plasma, the array based platform was not. At high miRNA levels both qRT-PCR based platforms performed well in terms of specificity, reproducibility and recovery. At low miRNA levels, as in plasma, the miRCURY platform showed better sensitivity and linearity than the TaqMan platform.</p> <p>Conclusion</p> <p>For profiling clinical samples with low miRNA abundance, such as plasma samples, the miRCURY platform with its better sensitivity and linearity would probably be superior.</p

    X-ray Absorption and Reflection in Active Galactic Nuclei

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    X-ray spectroscopy offers an opportunity to study the complex mixture of emitting and absorbing components in the circumnuclear regions of active galactic nuclei, and to learn about the accretion process that fuels AGN and the feedback of material to their host galaxies. We describe the spectral signatures that may be studied and review the X-ray spectra and spectral variability of active galaxies, concentrating on progress from recent Chandra, XMM-Newton and Suzaku data for local type 1 AGN. We describe the evidence for absorption covering a wide range of column densities, ionization and dynamics, and discuss the growing evidence for partial-covering absorption from data at energies > 10 keV. Such absorption can also explain the observed X-ray spectral curvature and variability in AGN at lower energies and is likely an important factor in shaping the observed properties of this class of source. Consideration of self-consistent models for local AGN indicates that X-ray spectra likely comprise a combination of absorption and reflection effects from material originating within a few light days of the black hole as well as on larger scales. It is likely that AGN X-ray spectra may be strongly affected by the presence of disk-wind outflows that are expected in systems with high accretion rates, and we describe models that attempt to predict the effects of radiative transfer through such winds, and discuss the prospects for new data to test and address these ideas.Comment: Accepted for publication in the Astronomy and Astrophysics Review. 58 pages, 9 figures. V2 has fixed an error in footnote

    The Ethics of Ethics Reviews in Global Health Research: Case Studies Applying a New Paradigm

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    With increasing calls for global health research there is growing concern regarding the ethical challenges encountered by researchers from high-income countries (HICs) working in low or middle-income countries (LMICs). There is a dearth of literature on how to address these challenges in practice. In this article, we conduct a critical analysis of three case studies of research conducted in LMICs.We apply emerging ethical guidelines and principles specific to global health research and offer practical strategies that researchers ought to consider. We present case studies in which Canadian health professional students conducted a health promotion project in a community in Honduras; a research capacity-building program in South Africa, in which Canadian students also worked alongside LMIC partners; and a community-university partnered research capacity-building program in which Ecuadorean graduate students, some working alongside Canadian students, conducted community-based health research projects in Ecuadorean communities.We examine each case, identifying ethical issues that emerged and how new ethical paradigms being promoted could be concretely applied.We conclude that research ethics boards should focus not only on protecting individual integrity and human dignity in health studies but also on beneficence and non-maleficence at the community level, explicitly considering social justice issues and local capacity-building imperatives.We conclude that researchers from HICs interested in global health research must work with LMIC partners to implement collaborative processes for assuring ethical research that respects local knowledge, cultural factors, the social determination of health, community participation and partnership, and making social accountability a paramount concern

    STROBE-X: a probe-class mission for x-ray spectroscopy and timing on timescales from microseconds to years

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    We describe the Spectroscopic Time-Resolving Observatory for Broadband Energy X-rays (STROBE-X), a probeclass mission concept that will provide an unprecedented view of the X-ray sky, performing timing and spectroscopy over both a broad energy band (0.2–30 keV) and a wide range of timescales from microseconds to years. STROBE-X comprises two narrow-field instruments and a wide field monitor. The soft or low-energy band (0.2–12 keV) is covered by an array of lightweight optics (3-m focal length) that concentrate incident photons onto small solid-state detectors with CCD-level (85–175 eV) energy resolution, 100 ns time resolution, and low background rates. This technology has been fully developed for NICER and will be scaled up to take advantage of the longer focal length of STROBE-X. The higher-energy band (2–30 keV) is covered by large-area, collimated silicon drift detectors that were developed for the European LOFT mission concept. Each instrument will provide an order of magnitude improvement in effective area over its predecessor (NICER in the soft band and RXTE in the hard band). Finally, STROBE-X offers a sensitive wide-field monitor (WFM), both to act as a trigger for pointed observations of X-ray transients and also to provide high duty-cycle, high time-resolution, and high spectral-resolution monitoring of the variable X-ray sky. The WFM will boast approximately 20 times the sensitivity of the RXTE All-Sky Monitor, enabling multi-wavelength and multi-messenger investigations with a large instantaneous field of view. This mission concept will be presented to the 2020 Decadal Survey for consideration
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