American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jun 1996
Comparative StudyInfluence of sleep onset on upper-airway muscle activity in apnea patients versus normal controls.
Current evidence suggests that patients with obstructive sleep apnea (OSA) may have augmented pharyngeal dilator muscle activity during wakefulness, to compensate for deficient anatomy. However, the isolated effect of sleep on the activity of these muscles (comparing OSA patients with controls) has not been studied. We therefore determined waking levels of genioglossus (GG) and tensor palatini (TP) muscle activity (% of maximum electromyographic [EMG] activity) in 10 OSA patients and eight controls, and then assessed the impact of the first two breaths of sleep (theta electroencephalographic [EEG] activity) following a period of stable wakefulness. ⋯ However, three OSA patients demonstrated small increments in GG EMG at sleep onset despite falling TP EMG and obstructive apnea or hypopnea. We conclude that sleep onset is associated with significantly larger decrements in TP muscle EMG activity in OSA patients than in controls, which may represent a loss of neuromuscular compensation that is present during wakefulness. However, our results for the GG muscle were more variable, and did not always support this hypothesis.
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Am. J. Respir. Crit. Care Med. · Jun 1996
Clinical TrialEffect of uridine 5'-triphosphate plus amiloride on mucociliary clearance in adult cystic fibrosis.
Cystic fibrosis (CF) is characterized by abnormal airway epithelial electrolyte transport leading to viscous airway secretions that are difficult to clear. By enhancing Cl- secretion onto and blocking Na+ absorption from the airway surface, treatment with aerosolized uridine 5'-triphosphate (UTP) plus amiloride may improve the rheology of airway secretions and enhance mucociliary clearance in patients with CF. After performing safety studies of aerosolized UTP/amiloride in adult patients with CF, we investigated the effects of inhaled vehicle and UTP/amiloride on mucociliary clearance of [99mTc] iron oxide particles from the airways of adult patients with CF (n = 14). ⋯ Mean baseline peripheral clearance rates during the first 40 min of clearance measurements were significantly less in patients with CF than in normal subjects (mean +/- SE: 0.30 +/- 0.05 versus 0.54 +/- 0.07%/min, respectively; p = 0.01). Aerosolized UTP and amiloride in combination improved mucociliary clearance from the peripheral airways of the CF lungs to near normal values (0.51 +/- 0.09%/min; p = 0.04) during this period. These data support the concept for the use of UTP in combination with amiloride as therapy to improve clearance of secretions from the lungs of patients with CF.
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Am. J. Respir. Crit. Care Med. · Jun 1996
Clinical TrialClarithromycin regimens for pulmonary Mycobacterium avium complex. The first 50 patients.
Intermediate results of the first 50 patients treated with clarithromycin (CLARI) regimens for Mycobacterium avium-intracellulare (MAI) lung disease were evaluated. Patients were HIV negative, and pretreatment isolates were susceptible to CLARI. Patients received CLARI 500 mg twice daily, ethambutol, rifampin (RMP), or rifabutin (RBT) and initial streptomycin, and they were treated until culture-negative 1 yr. ⋯ Of 23 patients who are alive and were culture-negative a mean of 12.0 mo while receiving therapy, all remain culture-negative without therapy a mean of 19.1 mo. Despite reduced CLARI serum levels in patients also receiving RMP, 10 of 13 patients (77%) receiving this regimen were successfully treated. Although not directly compared with previous regimens, the success of this regimen strongly suggests it is superior to previous non-CLARI-containing regimens.