American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jun 1999
Clinical Trial Controlled Clinical TrialInhalation of dry powder mannitol improves clearance of mucus in patients with bronchiectasis.
Bronchiectasis is a disease characterized by hypersecretion and retention of mucus requiring physical and pharmacologic treatment. Recently we reported that inhalation of dry powder mannitol markedly increases mucociliary clearance (MCC) in asthmatic and in healthy subjects (Daviskas, E., S. D. ⋯ Mean (+/- SEM) clearance with mannitol was 34.0 +/- 5.0% versus 17.4 +/- 3.8% with control and 11.7 +/- 4.4% with baseline in the whole right lung (p < 0.0001). The mean number of coughs induced by mannitol was 49 +/- 11. In conclusion, inhalation of dry powder mannitol increased clearance of mucus and thus has the potential to benefit patients with bronchiectasis.
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Am. J. Respir. Crit. Care Med. · Jun 1999
Comparative StudyA novel, short, and simple questionnaire to measure health-related quality of life in patients with chronic obstructive pulmonary disease.
A novel, short, and simple questionnaire, the Airways Questionnaire 20 (AQ20), has been developed to measure and quantify disturbances in the health-related quality of life (HRQoL) of patients with asthma or chronic obstructive pulmonary disease (COPD). The AQ20 has 20 items with yes/no responses, and should take 2 min to complete and score. The purpose of this study was to assess the discriminative properties and responsiveness of the AQ20 in patients with COPD. ⋯ The change in the AQ20 showed a moderate to strong correlation with each dimension of the SGRQ and CRQ (rs = 0.56, -0.52, respectively), but no significant correlation was noted with the FEV1. In conclusion, the AQ20 may have discriminative properties and responsiveness that are similar to more complex questionnaires such as the SGRQ and CRQ. Because it is short and can be quickly answered and scored, the AQ20 may be useful in studies with limited time for HRQoL assessments.
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Am. J. Respir. Crit. Care Med. · Jun 1999
Review Case ReportsNylon flock-associated interstitial lung disease.
A work-related interstitial lung disease has been diagnosed in workers at five nylon flock facilities in three different states and a Canadian province. The National Institute for Occupational Safety and Health hosted a workshop at which consulting pulmonary pathologists reviewed lung tissue samples from all the cases for which lung biopsy material was available (15 of 20 cases known in January 1998). After independent review and scoring of these lung tissue specimens, the pathologists reached consensus that the histopathological findings revealed a characteristic lesion-a lymphocytic bronchiolitis and peribronchiolitis with lymphoid hyperplasia represented by lymphoid aggregates. ⋯ Six of the cases improved after removal from workplace exposure without medical treatment. Six others, who had recovered with medical treatment and removal from the workplace, had relapses in both symptoms and objective findings after attempting to return to nylon flock work. With this and other evidence supporting the existence of chronic interstitial pneumonitis associated with nylon flock processing, workshop participants recommended surveillance for early identification of affected workers and their removal from further workplace exposure.
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Am. J. Respir. Crit. Care Med. · Jun 1999
Analysis of the Kveim-Siltzbach test reagent for bacterial DNA.
The sarcoid spleen-derived reagent for the Kveim-Siltzbach test (KST) elicits a sarcoid-specific, granulomatous, cutaneous response used to establish the diagnosis of sarcoidosis. In the context of the ongoing discussion of a bacterial cause of sarcoidosis we asked the question whether bacterial DNA could be found in the KST reagent. ⋯ Neither KST reagents, the control preparation, nor the spleen yielded a positive signal, indicating that the preparations are free of bacterial contamination. Because the KST reagent elicits granuloma, these results do not support the hypothesis of a bacterial cause of sarcoid granuloma.
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Am. J. Respir. Crit. Care Med. · Jun 1999
Case ReportsPrevention of human diaphragm atrophy with short periods of electrical stimulation.
We determined whether prolonged complete inactivation of the human diaphragm results in atrophy and whether this could be prevented by brief periods of electrical phrenic nerve stimulation. We studied a subject with high spinal cord injury who required removal of his left phrenic nerve pacemaker (PNP) and the reinstitution of positive-pressure ventilation for 8 mo. During this time, the right phrenic nerve was stimulated 30 min per day. ⋯ On the previously nonfunctioning side, there were substantial changes in VT (from 220 to 600 ml) and tdi (from 0.18 to 0.34 cm). On the side that had been stimulated, neither VT nor tdi changed appreciably (VT from 770 to 900 ml; tdi from 0.25 to 0.28 cm). We conclude that prolonged inactivation of the diaphragm causes atrophy which may be prevented by brief periods of daily phrenic nerve stimulation.