The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Jian Guo - One of the best experts on this subject based on the ideXlab platform.
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Clinical usefulness of the Oxygen Uptake efficiency in pulmonary embolism
European Respiratory Journal, 2014Co-Authors: Jinming Liu, Shujuan Chen, Wenlan Yang, Jian GuoAbstract:OBJECTIVES We sought to study the Oxygen Uptake efficiency, an index of cardiopulmonary functional reserve that can be based upon a submaximal exercise effort, in pulmonary embolism (PE) by performing the cardiopulmonary exercise test (CPET). METHODS The cardiopulmonary exercise test with simultaneous respiratory gas measurement were performed in fifty PE patients and fifty healthy individuals. All subjects also underwent the pulmonary function test (PFT). RESULTS (1) In compared with the controls, the PE patients had lower peak Oxygen Uptake (peakVO 2 ), Oxygen Uptake efficiency slope (OUES), Oxygen Uptake efficiency plateau (OUEP) and Oxygen Uptake efficiency at anaerobic threshold (OUE@AT) (P 2 /VE) at warming up, AT and peak exercise but the rest, indicated statistically lower than the controls. The OUE in normal subjects increased as unloaded exercise began, and then increased further to OUEP just before the AT. Thereafter, the OUE decreased gradually until peak exercise. In contrast, the rate of changes of the OUE in PE patients was relatively mild during exercise. (3) OUES, OUEP, OUE@AT correlated strongly with peakVO 2 and DL CO %pred (r=0.712,0.404,0.414; p CONCLUSIONS The Oxygen Uptake efficiency of patients with PE decreases. The OUE is an objective, reproducible measure of cardiopulmonary reserve that does not require a maximal exercise effort. Therefore, OUE could be helpful to assess exercise performance in PE patients that unable to perform a maximal exercise test in early recovery stage.
Michiaki Hiroe - One of the best experts on this subject based on the ideXlab platform.
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Effects of isosorbide dinitrate on Oxygen Uptake kinetics in cardiac patients.
Medicine and science in sports and exercise, 1998Co-Authors: Akira Koike, Takashi Yajima, Yoshiharu Koyama, Noritaka Shimizu, Hiroshi Kano, Kazuo Kobayashi, Koichi Taniguchi, Fumiaki Marumo, Michiaki HiroeAbstract:Purpose Although nitrates are known to improve indices of exercise capacity in patients with coronary artery disease, their effects on Oxygen Uptake kinetics during the onset of exercise have not been clarified. We evaluated the acute effects of isosorbide dinitrate on the kinetics of Oxygen Uptake during the onset of exercise at a constant work rate in patients with coronary artery disease. Methods We studied 14 patients with coronary artery disease who performed 6 min of low-intensity exercise at a constant work rate on a cycle ergometer 30 min after oral administration of 10 mg of isosorbide dinitrate or placebo in a double-blind, crossover manner. Oxygen Uptake was calculated from breath-by-breath analysis of respired gases. The time constant of Oxygen Uptake kinetics during the onset of exercise was determined by fitting a single exponential function to the Oxygen Uptake response. Results Heart rate was significantly increased at rest, and systolic blood pressure was significantly decreased both at rest and during exercise after administration of isosorbide dinitrate. The time constant of Oxygen Uptake was significantly shorter (the kinetics were faster) after administration of isosorbide dinitrate (39.4+/-10.1 vs 44.5+/-10.5 s, P = 0.038). Conclusions Isosorbide dinitrate was found to speed the kinetics of the increase in Oxygen Uptake during constant work-rate exercise. The time constant of Oxygen Uptake, which reflects the rapidity of cardiovascular adaptation at the onset of exercise, seems to be a useful parameter of the effectiveness of therapy in patients with coronary artery disease.
Ju-chang Huang - One of the best experts on this subject based on the ideXlab platform.
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Study of Oxygen Uptake by tidal river sediment
Water Research, 1999Co-Authors: Guanghao Chen, I-man Leong, Jian Liu, Ju-chang HuangAbstract:Abstract This paper presents a study on the kinetics of chemical and biological Oxygen Uptakes within tidal river sediment and thereby modelled the Oxygen Uptake by the sediment. Sediment cores were taken from a major tidal river, the Shing-Mun River in Hong Kong. Characterization of the core found that the sediment contained high concentrations of iron and organic matter. The kinetics within the sediment were investigated with a set of batch tests using dispersed subsamples taken from different depths of the core. The results showed that the chemical Oxygen Uptake followed zero-order kinetics with respect to sediment quantity, and its Uptake rate coefficient varied less with the depth. The mean value of the coefficient was found to be 8.25×10 −4 day −1 . The batch tests also confirmed that the biological Oxygen Uptake rate in the sediment can be described by a Monod function of dissolved Oxygen (DO). It was also found that potential bioactivity of the sediment was kept constant in its 10-cm thick upper layer. Based upon these results, the concept of a hybrid benthic biofilm was introduced to develop a model of the sediment Oxygen Uptake (SOU). To verify the proposed SOU model, comparisons of experimental data with model predictions were conducted, which showed that the proposed SOU model perfectly fitted the experimental results at different water temperatures ranging from 11 to 27°C.
Augusto Shinya Abe - One of the best experts on this subject based on the ideXlab platform.
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Oxygen Uptake in snakes: is there a reduction in fossorial species?
Comparative Biochemistry and Physiology Part A: Physiology, 1994Co-Authors: Tobias Wang, Augusto Shinya AbeAbstract:Abstract Oxygen Uptake of the fossorial blind snake ( Typhlops reticulatus ) and the semifossorial coral snake ( Micrurus ibiboboca ) was measured at 20 and 30°C. Oxygen Uptake of blind snakes was within the normal range, whereas Oxygen Uptake of coral snakes was in the lower end of values reported for snakes. The results do not support the hypothesis of reduced Oxygen Uptake in fossorial reptiles.
A. L. Garden - One of the best experts on this subject based on the ideXlab platform.
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Test-retest reliability of the Oxygen Uptake efficiency slope in surgical patients.
Anaesthesia, 2011Co-Authors: B. J. Phypers, D. Robiony-rogers, Ruth M. Pickering, A. L. GardenAbstract:The Oxygen Uptake efficiency slope is a measure of cardiopulmonary fitness, that can be obtained from a sub-maximal cardiopulmonary exercise test. It has been evaluated in medical patients but its reliability in surgical populations remains uncertain. We conducted a test-retest study with the aim of establishing the reliability of the Oxygen Uptake efficiency slope in relation to that of the anaerobic threshold and peak Oxygen Uptake, in general surgical patients. Twenty-six patients over 60 years old completed two symptom-limited, incremental cycle ergometry tests within 7 days. The mean (SD) anaerobic threshold was 13.0 (3.0) mlO(2) .kg(-1) .min(-1) . There were no significant differences between mean test and retest values of anaerobic threshold (p = 0.50), peak Oxygen Uptake (p = 0.76) or Oxygen Uptake efficiency slope (p = 0.42). Reliability coefficients (95% CI) for the anaerobic threshold, Oxygen Uptake efficiency slope and peak Oxygen Uptake were 66.7% (45.3-87.9%), 89.0% (81.0-96.9%) and 91.7% (85.7-97.8%), respectively. The Oxygen Uptake efficiency slope was determined easily in all patients and found to have excellent reliability. Its clinical utility in determining pre-operative fitness warrants further evaluation.
