8 research outputs found

    Effects of emphysema and chronic hypoxemia on skeletal muscle oxygen supply and demand

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    Skeletal muscle dysfunction in chronic obstructive pulmonary disease (COPD) is a condition in which peripheral skeletal muscle undergoes myopathic changes which impair muscle function, limit physical performance, and can lead to significant disability. While the etiology of the dysfunction is unknown, this study was conducted to test the hypothesis that chronic hypoxemia leads to alterations in oxygen transport and muscle function. A primary objective was to validate elastase-induced emphysema in rats as an animal model of skeletal muscle dysfunction in COPD.Arterial blood gases were used to determine the severity of hypoxemia and sodium dodecyl sulfate- polyacrylamide gel electrophoresis was used to determine the proportions of myosin heavy chain isoforms I, IIa, IIx, and IIb. Measures of microvascular oxygenation and blood flow in the spinotrapezius muscle allowed for determination of both convective and diffusive oxygen supply to the muscle, as well as calculation of muscle oxygen consumption at rest and during electrically stimulated three-minute muscle contractions. Muscle performance measures included peak force, force-time integral, and fatigue index. Due to a presumed rat respiratory virus, which likely resulted in the control group being nearly as hypoxemic as the elastase-induced emphysema group, this study was not able to definitively test the hypothesis that chronic hypoxemia leads to both a diminished supply and demand of oxygen in skeletal muscle. Although many of the results of the present study were not statistically significant, they exhibited consistent trends over time and are likely of physiological significance. All measures of muscle performance were lower in the emphysema group. In addition, spinotrapezius muscle oxygen consumption and blood flow were lower in the emphysema group. The addition of supplemental oxygen during isolated, small-muscle mass exercise did increase the force-time integral by ~18% in both groups, suggesting that muscle work in these hypoxemic animals may be limited by oxygen supply. Thus, the data on muscle fiber type, oxygen consumption and muscle performance suggest that elastase-induced emphysema in rats leads to a similar skeletal muscle dysfunction that is observed in humans with COPD, and indicates that it is a valid animal model of skeletal muscle dysfunction in COPD

    New Investigations of the Alleged Meteorite from Igast, Estonia

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    This paper presents the results of a reinvestigation of the object which allegedly fell at Igast, Estonia, in 1855, and which may be the only example of a meteorite with the chemical composition of a tektite. R is concluded that generally quoted opinions of the artificial nature of this object are based on spurious samples, specifically melted brick and quartz basalt porphyry distributed by a Russian collector. Possibly genuine specimens from this observed fall are in the British Museum, the Paris Museum, and perhaps at the University of Dorpat, Estonia. It is recommended that these specimens be re-examined and that a search for similar objects be made

    Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA)

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    Cross-validation of a Team-Based Learning Student Perception Scale in the United States

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    Entry-level DPT students, who were enrolled in either one of two 3-credit patient/client management courses (i.e., Basic Skills and Cardiopulmonary) over two academic years (2012 and 2013), participated in this study. Of the 132 students in these courses, 115 completed the questionnaire (87% response rate). There were 85 first-year students from the Basic Skills course (43 first year students in 2012 and 42 in 2013) and 30 second-year students from the Cardiopulmonary course (2012). All participants experienced TBL for the first time in their DPT curriculum. The Student Perceptions of TBL scale is a 15-item instrument with two subscales: “preference for TBL” (8 items) and “preference for teamwork” (7 items). Each item was rated on a 5-point Likert-type scale: strongly disagree = -2, disagree = -1, neutral = 0, agree = 1, and strongly agree = 2, with a higher positive score indicating a more favourable perception toward TBL and teamwork

    Fungal Pathogens in CF Airways: Leave or Treat?

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    Potential effector and immunoregulatory functions of mast cells in mucosal immunity

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    Annual Selected Bibliography

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    Amerasia Journal

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