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Biomedical subjects

A Bouhuys

Publications and source records attributed to A Bouhuys.

At least 19 recordsLinked to original sources
PubMed1982

Airway reactivity and exercise in healthy subjects.

The interaction of exercise, methacholine challenge, and beta-adrenergic blockade was investigated in eight healthy subjects. We measured the response to increasing doses of aerosolized methacholine, examining maximum expiratory flow rates. These responses were compared with those obtained on separate days when each methacholine challenge followed submaximal exercise or submaximal exercise in the presence of Beta-blockade. The possible independent effect of increased ventilation (20 +/- 6.7 L/min) was also studied during methacholine challenge. Methacholine-induced bronchospasm was not augmented by exercise alone or by exercise in the presence of beta-blockade, nor was this response significantly altered by hyperventilation during methacholine aerosol challenge. These findings suggest that airway hyperreactivity cannot be induced in healthy subjects by levels of exercise that commonly provoke exercise-induced bronchospasm in asthmatic patients.

Adult↗
PubMed1981

Helium-oxygen flow-volume curves in detecting acute response to hair spray.

The acute effect of hair spray on small airway function was studied in 11 healthy subjects by recording maximum expiratory flow-volume (MEFV) curves while the subjects were breathing first air (Ar) and then a 80% helium-20% oxygen mixture (He). The flow rate response of breathing He compared to Ar (delta MEF50) at 50% of the control forced vital capacity (FVC), and the point of identical flow on Ar and He MEFV curves, known as volume of isoflow (VisoV) were measured. Eight of 11 subjects reacted to the hair spray by demonstrating a decrease in the MEF50 and delta MEF50 although the difference was not significant. However, there was a significant increase in VisoV at 12,20 and 30 min post exposure. VisoV may be a sensitive index in detecting small airway dysfunction following acute exposure to hair spray.

Adult↗
PubMed1981

Lung function changes by ethanol inhalation.

The acute effect of ethanol inhalation on ventilatory capacity was studied in a group of six healthy volunteers and the results were compared to those obtained after the inhalation of a saline solution. There was a significant decrease in flow rates on partial expiratory flow-volume (PEFV) curves up to 90 min after ethanol inhalation. FEV1 values did not change significantly, either after ethanol or saline aerosol. Pretreatment with atropine did not prevent the acute reductions in flow rates in comparison with the reductions without atropine. Pretreatment with disodium cromoglycate (DSCG) considerably diminished the acute reductions of flow rates caused by ethanol inhalation. These results suggest that ethanol in some persons may act, at least partly, through releasing mediators with bronchoconstrictive action.

Administration, Intranasal↗
PubMed1981

Airway reactivity in cotton bract-induced bronchospasm.

Most healthy subjects challenged with cotton bract extract demonstrate some degree of bronchospasm. This response has been associated with the endogenous production of histamine by the inhalation of cotton bract extract. We examined whether this responsiveness reflects increased sensitivity to histamine. Thirty-one healthy subjects were screened for sensitivity to cotton bract extract administered by nebulization. Pulmonary function was measured using partial expiratory flow-volume curves on which flows at 60% of the control vital capacity below total lung capacity were measured (MEF40%(P)). Responders were defined as subjects who exhibited a 20% or greater decrease in MEF40%(P) after 10 min inhaling cotton bract extract. Of those screened, 10 subjects were responders. From the remaining nonresponders, 11 consecutive subjects were selected. The maximal decrease in MEF40%(P) in responders was 40.5 +/- 5.1%, compared to 10.9 +/- 2.2% in nonresponders. The dose-response relationship for histamine was measured in all subjects, using inhalations of progressively more concentrated histamine solutions. The mean +/- SEM threshold for the responders was 38.4 +/- 7.4 mg of histamine per ml, compared to 42.2 +/- 6.8 mg of histamine per ml for responders (difference not significant). The percentage decrease in MEF40%(P) at the threshold dose was 27.6 +/- 3.7% for responders and 32.4 +/- 5.2% for nonresponders (difference not significant). We conclude that healthy subjects sensitive to cotton bract extract do not exhibit increased reactivity to histamine. This suggests that responders are not, in general, subclinical asthmatics, and that the difference between responders and nonresponders to CBE is not due to increased histamine sensitivity among responders.

Adult↗
PubMed1979

Modification of induced airway constriction in healthy subjects.

Unlike asthmatics, healthy persons are relatively unresponsive to airway constrictors. By using partial expiratory flow-volume (PEFV) curves the authors have demontrated, in healthy subjects, dose-related decreases in flow rates following challenge with histamine and methacholine aerosols. With the use of semilogarithmic dose-response curves they have shown that 80 mg oral propranolol augmented, whereas oral pretreatment with 400 mg W10294A (an experimental bronchodilator) decreased, histamine and methacholine-induced airway constriction. However, 300 mg of orally administered aminophylline failed to modify the airway constrictor effects of histamine and methacholine. Moreover, variation was noted in induced airway constriction in healthy subjects with decreases in flow rates being greater in the morning than in the afternoon. The authors conclude that (1) propranolol augments whereas theophylline fails to prevent nonspecific induced airway constriction in healthy subjects. This suggests that the bronchodilator action of theophylline may be unrelated to its phosphodiesterase inhibitory activity, (2) control of volume history, by use of partial expiratory flow-volume curves, is useful in quantifying pharmacologic protection and augmentation of nonspecific induced airway constriction in healthy subjects and (3) conclusions resulting from observations of induced airway constriction in healthy subjects may be dependent upon the effects of diurnal variation.

Adult↗
PubMed1979

Airway responsiveness in workers processing polyester resins.

In 22 employees of a button-manufacturing plant, exposure to polyester resins over an eight-hour work shift resulted in an acute reduction of flow rates on maximum expiratory flow volume (MEFV) curves at MEF50% and MEF25%. In the workers studied, preshift administration of 80 mg of propranolol potentiated, while 1 mg of subcutaneously injected atropine significantly inhibited, the bronchoconstricting effect of the resins, indicating that the autonomic nervous system plays an important role in determining airway smooth muscle response to polyester resins. Although a high prevalence of acute symptoms (cough, shortness of breath, throat and eye irritation) over the work shift was recorded in exposed workers, no high prevalence of chronic respiratory symptoms was found. No definite evidence of chronic airway obstruction was recorded in exposed workers.

Adult↗
PubMed1978

Do present levels of air pollution outdoors affect respiratory health?

A sensitive lung function test does not show difference due to air pollution between lifetime residents in a rural area and those in a small industrial town in Connecticut. Also, there is no evidence that higher air pollutant concentrations elsewhere have any marked effects on the lungs. Severe pollution is dangerous and must be avoided, but at present, air pollution control outdoors does not deserve priority as a means of preventing chronic lung diseases.

Adolescent↗