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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
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pubmed:dateCreated |
1994-7-15
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pubmed:abstractText |
We evaluated whether acute exposure to ozone (O3) enhances or produces exercise-induced asthma (EIA) in asthmatic subjects who have or do not have EIA, according to standardized exercise challenge. Twenty-one otherwise healthy asthmatic subjects, 19 to 40 yr of age, with forced expiratory volume in one second (FEV1) greater than 70% of predicted and methacholine hyperresponsiveness, underwent three 1-h exposures on separate days to 0.10 ppm ozone in filtered air (FA), 0.25 ppm ozone in FA, and FA alone (randomized order, single-blinded, crossover design). Of these subjects, 12 underwent an additional exposure to 0.40 ppm ozone in FA. The subjects performed intermittent light exercise (with mean ventilation of 27 L/min) while in an environmentally controlled chamber (21 degrees C and 40% relative humidity). After each exposure, the subjects rested 1 h in clean air and performed serial postexposure spirometry. The subjects then underwent a standardized exercise challenge in clean air, followed by serial spirometry for 60 min. No significant changes in FEV1 or forced vital capacity (FVC) were found following 1-h exposures to 0, 0.10, and 0.25 ppm ozone (regardless of EIA status). The 12 subjects who underwent all four exposures showed a significant excess reduction in FEV1 (-0.35 +/- 0.37 L or -9.6%) after 1-h exposure to 0.40 ppm O3 (p = 0.017), regardless of EIA status. Postexposure FEV1 returned to baseline levels within 1 h. Postexposure changes in FVC showed similar magnitude and time course but were not statistically significant across exposure conditions or EIA status.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
AIM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
1073-449X
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
149
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1413-9
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8004292-Adult,
pubmed-meshheading:8004292-Asthma, Exercise-Induced,
pubmed-meshheading:8004292-Bronchial Provocation Tests,
pubmed-meshheading:8004292-Dose-Response Relationship, Drug,
pubmed-meshheading:8004292-Exercise Test,
pubmed-meshheading:8004292-Female,
pubmed-meshheading:8004292-Forced Expiratory Volume,
pubmed-meshheading:8004292-Humans,
pubmed-meshheading:8004292-Male,
pubmed-meshheading:8004292-Methacholine Chloride,
pubmed-meshheading:8004292-Ozone,
pubmed-meshheading:8004292-Severity of Illness Index,
pubmed-meshheading:8004292-Single-Blind Method,
pubmed-meshheading:8004292-Time Factors,
pubmed-meshheading:8004292-Vital Capacity
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pubmed:year |
1994
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pubmed:articleTitle |
Pre-exposure to ozone does not enhance or produce exercise-induced asthma.
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pubmed:affiliation |
Department of Medicine, UCLA Medical Center.
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pubmed:publicationType |
Journal Article,
Clinical Trial,
Randomized Controlled Trial,
Research Support, Non-U.S. Gov't
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