American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Nov 1999
Acid-induced lung injury. Protective effect of anti-interleukin-8 pretreatment on alveolar epithelial barrier function in rabbits.
Although prior experimental work has demonstrated that anti-interleukin-8 (anti-IL-8) therapy reduces lung endothelial injury after acid instillation, there is no information regarding the effect of anti-IL-8 on the function of the alveolar epithelial barrier after acid-induced lung injury. Therefore, the primary objective of this study was to determine the effect of acid-induced lung injury on the function of the alveolar epithelium, and secondly to determine whether pretreatment with anti-IL-8 attenuates acid-induced injury to the lung epithelial barrier. Hydrochloric acid (pH = 1.5 in 1/3 normal saline) was instilled into the lungs of anesthetized, ventilated rabbits. ⋯ Pretreatment with anti-IL-8 antibody significantly reduced the acid-mediated increase in bi-directional transport of protein across the alveolar epithelium and restored alveolar fluid clearance to normal. The results indicate that acid instillation causes injury to the alveolar epithelial barrier that can be distinguished from the injury to the lung endothelium. Furthermore, pretreatment with anti-IL-8 therapy prevents acid-induced alveolar epithelial injury, a finding of potential clinical importance.
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Am. J. Respir. Crit. Care Med. · Nov 1999
Case ReportsHypersensitivity pneumonitis from Pezizia domiciliana. A case of El Niño lung.
A previously healthy woman developed severe dyspnea and was found to have restrictive lung disease and evidence of alveolitis. Open lung biopsy revealed extrinsic allergic alveolitis (hypersensitivity pneumonitis). ⋯ This is the first described case of hypersensitivity pneumonitis cause by P. domiciliana. We speculate that unprecedented rainfall and flooding of the patient's basement as a result of El Niño rains produced ideal factors for the growth of this fungus.
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Am. J. Respir. Crit. Care Med. · Nov 1999
Association of asthma control with health care utilization and quality of life.
Asthma severity and level of asthma control are two related, but conceptually distinct, concepts that are often confused in the literature. We report on an index of asthma control developed for use in population-based disease management. ⋯ Qualitatively similar results were found for control problems assessed relative to the past month and relative to the past year. Asthma control is an important "vital sign" that may be useful both for population-based disease management as well as for the management of individual patients.
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Am. J. Respir. Crit. Care Med. · Nov 1999
The effects of trazodone with L-tryptophan on sleep-disordered breathing in the English bulldog.
Obstructive sleep apnea hypopnea syndrome (OSAHS) is a prevalent disorder, for which there are no universally effective pharmacotherapeutics. We hypothesized that in OSAHS, excitatory serotoninergic influences are important for maintaining patency of the upper airway in waking, and that in sleep, reduced serotoninergic drive plays a significant role in upper airway collapse and OSAHS. The previously reported small responses in humans with OSAHS to serotoninergics may relate, in part, to study design and the drugs/doses selected. ⋯ During REMS, the RDI was 31.4 +/- 6.1 events/h (placebo) and 11.5 +/- 4.3 (highest dose), p = 0.002. Trazodone/ L-tryptophan dose-dependently reduced sleep fragmentation, p = 0.03, increased sleep efficiency, p = 0.005, enhanced slow-wave sleep, p = 0.0004, and minimized sleep-related suppression of upper airway dilator activity, p < 0.02. Trazodone with L-tryptophan can treat sleep-disordered breathing (SDB) in an animal model of OSAHS; the effectiveness of this therapy may be related to increased upper airway dilator activity in sleep and/or enhanced slow-wave sleep.
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Am. J. Respir. Crit. Care Med. · Nov 1999
Effect of hypercapnia on maximal voluntary ventilation and diaphragm fatigue in normal humans.
Relatively little is known about the combined effects of hypercapnia and fatigue on the human diaphragm. We examined the effects of acute hypercapnia and fatigue in seven subjects by measuring changes in transdiaphragmatic pressure (Pdi) elicited by cervical magnetic stimulation after 2 min maximal voluntary ventilation (MVV) while breathing air and also with the inspired PCO(2) increased to 8% for 12 min before and during the MVV. Diaphragm strength was assessed before and at 0, 20, 40, 60, and 90 min after the MVV in both studies with the subjects breathing air. ⋯ The changes in TwPdi at 20 to 90 min were not significantly different between the control and CO(2) runs. The decrease in TwPdi at 0 min after MVV, however, was greater (15%) in the hypercapnic run than in the control run (8.1%) (p < 0.05) when compared with baseline valves. Hypercapnia does not intensify long lasting fatigue but may reduce diaphragm contractility immediately after MVV.