1,241 research outputs found
In acute lung injury, inhaled nitric oxide improves ventilation-perfusion matching, pulmonary vascular mechanics, and transpulmonary vascular efficiency
AbstractAcute respiratory distress syndrome continues to be associated with significant morbidity and mortality related to ventilation-perfusion mismatch, pulmonary hypertension, and right ventricular failure. It has been suggested that inhaled nitric oxide, which is a selective pulmonary vasodilator, may be effective in the treatment of acute respiratory distress syndrome; however, the effects of nitric oxide on cardiopulmonary interactions are poorly understood. We therefore developed a model of acute lung injury that mimics the clinical syndrome of acute respiratory distress syndrome. In our model, inhaled nitric oxide significantly reduced pulmonary artery pressure, pulmonary vascular resistance, and pulmonary vascular impedance. In addition, inhaled nitric oxide improved transpulmonary vascular efficiency and ventilation-perfusion matching, which resulted in increased arterial oxygen tension. Although arterial oxygen tension increased, oxygen delivery did not improve significantly. These data suggest that by improving ventilation-perfusion matching and arterial oxygen tension while lowering pulmonary vascular resistance and impedance, nitric oxide may be beneficial in patients with acute respiratory distress syndrome. However, additional measures to enhance cardiac performance may be required. ( J THORAC CARDIOVASC SURG 1995;110: 593-600
The Aquatic Toxicity of Organic Compounds to Embryo-Larval Stages of Fish and Amphibians
Aquatic toxicity tests were conducted on 11 organic compounds considered hazardous to water resources. The toxicity of each compound was evaluated using embryo-larval stages of two to eight fish and amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. The animal test species exhibited varying degrees of sensitivity to the selected toxicants. Combined frequencies for mortality and teratogenesis at 4 days posthatching gave LC50 ranges of 3.66 to 8.25 mg/L for benzene, 1.16 to 22.42 mg/L for carbon tetrachloride, 0.11 to 1.20 mg/L for chlorobenzene, 2.03 to \u3e 68 mg/L for chloroform, 3.01 to 5.56 mg/L for 1,2-dichlorobenzene, 2.54 to .34 mg/L for 1,2-dichloroethane, 13.16 to \u3e 48 mg/L for methylene chloride, 0.002 to 0.64 mg/L for nitrobenzene, 0.04 to .32 mg/L for phenol, 0.02 to 0.85 mg/L for toluene, and 3.53 to 3.77 mg/L for m-xylene. The species which exhibited the greatest susceptibility to organic compounds were the rainbow trout, Rana pipiens, and Rana temporaria. The more sensitive amphibian species generally were those which normaly are restricted to aquatic or moist terrestrial habitats, whereas the more tolerant amphibians included those semi-aquatic and terrestrial species which appear to be more broadly adapted ecologically. Of the 11 test compounds, nitrobenzene, toluene, chlorobenzene, and phenol were the most toxic. The least toxic organics included dichloroethane and methylene chloride. For three chlorinated alkanes, including methylene chloride (CH2Cl2), chloroform (CHCl3), and carbon tetrachloride (CCl4), toxicity was found to 1ncrease with the degree of chlorination. Concerning several aromatic hydrocarbons, benzene always was found to be less toxic than its monosubstituted analogs. Toxicity of the 11 compounds was further evaluated by calculating toxicant concentrations which produced embryo-larval mortality and/or teratogenesis at frequencies of 10% (LC10) and 1% (LC1). The LC values, used to estimate toxicity thresholds, ranged from \u3c 0.l for nitrobenzene to 69.9 Îźg/L for methylene chloride. A limited number of toxicity tests were performed to determine whether embryo-larval bioassays are suitable to assess effects of transitory chemical exposures, such as those resulting from intermittent discharges or accidental spills of chemicals into water resources. Results indicated that Rana pipiens embryos were sufficiently sensitive to quantify effects produced by short-term exposures to chloroform. Animals tested during the earliest embryonic stage appeared to be less tolerant than organisms exposed later in development
An Innovative Interactive Modeling Tool to Analyze Scenario-Based Physician Workforce Supply and Demand
Effective physician workforce management requires that the various organizations comprising the House of Medicine be able to assess their current and future workforce supply. This information has direct relevance to funding of graduate medical education. We describe a dynamic modeling tool that examines how individual factors and practice variables can be used to measure and forecast the supply and demand for existing and new physician services. The system we describe, while built to analyze the pathologist workforce, is sufficiently broad and robust for use in any medical specialty. Our design provides a computer-based software model populated with data from surveys and best estimates by specialty experts about current and new activities in the scope of practice. The model describes the steps needed and data required for analysis of supply and demand. Our modeling tool allows educators and policy makers, in addition to physician specialty organizations, to assess how various factors may affect demand (and supply) of current and emerging services. Examples of factors evaluated include types of professional services (3 categories with 16 subcategories), service locations, elements related to the Patient Protection and Affordable Care Act, new technologies, aging population, and changing roles in capitated, value-based, and team-based systems of care. The model also helps identify where physicians in a given specialty will likely need to assume new roles, develop new expertise, and become more efficient in practice to accommodate new value-based payment model
Study protocol: A cross-sectional survey of clinicians to identify barriers to clinical practice guideline implementation in the assessment and treatment of persistent tic disorders
INTRODUCTION: Eight members of the International Parkinson\u27s Disease and Movement Disorders Society Tic and Tourette Syndrome Study Group formed a subcommittee to discuss further barriers to practice guideline implementation. Based on expert opinion and literature review, the consensus was that practice variations continue to be quite broad and that many barriers in different clinical settings might negatively influence the adoption of the American Academy of Neurology and the European Society for the Study of Tourette Syndrome published guidelines.
OBJECTIVES: 1) To identify how clinical practices diverge from the existing American Academy of Neurology and European Society for the Study of Tourette Syndrome guidelines, and 2) to identify categories of barriers leading to these clinical care gaps.
METHODS AND ANALYSIS: This article presents the methodology of a planned cross-sectional survey amongst healthcare professionals routinely involved in the clinical care of patients with persistent tic disorders, aimed at 1) identifying how practices diverge from the published guidelines; and 2) identifying categories of barriers leading to these clinical care gaps. Purposeful sampling methods are used to identify and recruit critical persistent tic disorders stakeholders. The analysis will use descriptive statistics
Comparative, cross-sectional study of the format, content and timing of medication safety letters issued in Canada, the USA and the UK
Objectives To assess consistency in the format and content, and overlap of subject and timing, of medication safety letters issued by regulatory health authorities to healthcare providers in Canada, the USA and the UK. Design A cross-sectional study comparing medication safety letters issued for the purpose of alerting healthcare providers to newly identified medication problems associated with medications already on the market. Setting Online databases operated by Health Canada, the US Food and Drug Administration and the UK Medicines and Healthcare products Regulatory Agency were searched to select medication safety letters issued between 1 January 2010 and 31 December 2014. Format, content and timing of each medication safety letter were assessed using an abstraction tool comprising 21 characteristics deemed relevant by consensus of the research team. Main outcome measures Main outcome measures included, first, characteristics (format and content) of medication safety letters and second, overlap of subject and release date across countries. Results Of 330 medication safety letters identified, 227 dealt with unique issues relating to medications available in all three countries. Of these 227 letters, 21 (9%) medication problems were the subject of letters released in all three countries; 40 (18%) in two countries and 166 (73%) in only one country. Only 13 (62%) of the 21 letters issued in all three countries were released within 6 months of each other. Conclusions Significant discrepancies in both the subject and timing of medication safety letters issued by health authorities in three countries (Canada, the USA and the UK) where medical practice is otherwise comparable, raising questions about why, how and when medication problems are identified and communicated to healthcare providers by the authorities. More rapid communication of medication problems and better alignment between authorities could enhance patient safety
Determinants of medication adherence to antihypertensive medications among a Chinese population using Morisky medication adherence scale
<b>Background and objectives</b> Poor adherence to medications is one of the major public health challenges. Only one-third of the population reported successful control of blood pressure, mostly caused by poor drug adherence. However, there are relatively few reports studying the adherence levels and their associated factors among Chinese patients. This study aimed to study the adherence profiles and the factors associated with antihypertensive drug adherence among Chinese patients.<p></p>
<b>Methods</b> A cross-sectional study was conducted in an outpatient clinic located in the New Territories Region of Hong Kong. Adult patients who were currently taking at least one antihypertensive drug were invited to complete a self-administered questionnaire, consisting of basic socio-demographic profile, self-perceived health status, and self-reported medication adherence. The outcome measure was the Morisky Medication Adherence Scale (MMAS-8). Good adherence was defined as MMAS scores greater than 6 points (out of a total score of 8 points).<p></p>
<b>Results</b> From 1114 patients, 725 (65.1%) had good adherence to antihypertensive agents. Binary logistic regression analysis was conducted. Younger age, shorter duration of antihypertensive agents used, job status being employed, and poor or very poor self-perceived health status were negatively associated with drug adherence.<p></p>
<b>Conclusion</b> This study reported a high proportion of poor medication adherence among hypertensive subjects. Patients with factors associated with poor adherence should be more closely monitored to optimize their drug taking behavior
Cognitive Information Processing
Contains research objectives and reports on five research projects.Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 36-039-AMC-03200(E)National Science Foundation (Grant GK-835)National Institutes of Health (Grant 2 P01 MH-04737-06)National Aeronautics and Space Administration (Grant NsG 496
Dynamic usage of alternative splicing exons during mouse retina development
Alternative processing of pre-mRNA plays an important role in protein diversity and biological function. Previous studies on alternative splicing (AS) often focused on the spatial patterns of protein isoforms across different tissues. Here we studied dynamic usage of AS across time, during murine retina development. Over 7000 exons showed dynamical changes in splicing, with differential splicing events occurring more frequently in early development. The overall splicing patterns for exclusive and inclusive exons show symmetric trends and genes with symmetric splicing patterns that tend to have similar biological functions. Furthermore, we observed that within the retina, retina-enriched genes that are preferentially expressed at the adult stage tend to have more dynamically spliced exons compared to other genes, suggesting that genes maintaining retina homeostasis also play an important role in development via a series of AS events. Interestingly, the transcriptomes of retina-enriched genes largely reflect the retinal developmental process. Finally, we identified a number of candidate cis-regulatory elements for retinal AS by analyzing the relative occurrence of sequence motifs in exons or flanking introns. The occurrence of predicted regulatory elements showed strong correlation with the expression level of known RNA binding proteins, suggesting the high quality of the identified cis-regulatory elements
Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC
Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H âÎł Îł, H â Z Zâ â4l and H âW Wâ âlνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of âs = 7 TeV and âs = 8 TeV, corresponding to an integrated luminosity of about 25 fbâ1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined ďŹts probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson
Standalone vertex ďŹnding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at âs = 7 TeV collected with the ATLAS detector at the LHC during 2011
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