Gene Chi-Wai Man

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STUDY OBJECTIVE To evaluate the relationship between obstructive sleep apnea (OSA) and ventilatory responsiveness to carbon dioxide in both men and women. DESIGN An analysis of 219 patients referred to an university-based sleep center between 1989 to 1994 was conducted (104 with OSA and 115 without OSA; 43 women and 176 men). These patients had spirometry(More)
To evaluate the efficacy of a mild anxiolytic, alprazolam, in relieving dyspnea, we conducted a randomized, placebo-controlled double-blind study on patients with chronic obstructive lung disease. Twenty-four patients had alprazolam (0.5 mg bid) or placebo administered for one week, followed by placebo for one week, then either placebo or alprazolam for the(More)
This study was undertaken to define the mechanism for the respiratory inhibition observed during high-frequency oscillatory ventilation (HFOV). The effects of HFOV on the activities of single units in the vagus (Vna) and phrenic nerves (Pna) were examined in pentobarbital-anesthetized dogs. The animals were either ventilated by intermittent(More)
Through its ability to cause lipid peroxidation, nitrogen dioxide (NO2) may affect the functional properties of both the pulmonary epithelium and endothelium. We evaluated this possibility in 13 mongrel dogs by exposing these animals to 200 or 400 ppm NO2 for 1 h. The changes in pulmonary epithelial permeability (using a radioaerosol technique), FRC, and(More)
Cardiac output (Q) was measured with the thermodilution technique at 4 points during the respiratory cycle in dogs. Boluses of an ice-cold solution were injected at mid- and end-inspiration while the animals were on intermittent positive-pressure ventilation (IPPV) or after induction of positive end-expiratory pressure (PEEP), with and without induction of(More)
This study was undertaken to determine the influence of 1) the left atrial receptors (LA) on the ability of the carotid sinus baroreceptors (CS) to regulate heart rate and 2) the CS on the reflex increase in heart rate mediated by the LA. The LA were stimulated by stretching the pulmonary vein-atrial junctions in dogs anesthetized with alpha-chloralose.(More)
1. The effects of an acute sustained increase in pulmonary venous pressure induced by partial obstruction of the mitral valve on the activity of the four types of pulmonary receptors, namely, slowly adapting, rapidly adapting, pulmonary C-fibre and bronchial C-fibre receptors, were studied in the dog. 2. Fifteen slowly adapting receptors, eleven rapidly(More)
1. The effect of pulmonary venous congestion on tracheal tone was studied in dogs anaesthetized with alpha-chloralose. Pulmonary venous congestion was produced by partial obstruction of the mitral valve to increase left atrial pressure by 10 mmHg. Tracheal tone was measured in vivo by an isometric force displacement method. 2. Tracheal tone increased by 6.3(More)