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Biomedical subjects

A Bouhuys

Publications and source records attributed to A Bouhuys.

At least 19 recordsLinked to original sources

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

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

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

Growth and decay of pulmonary function in healthy blacks and whites.

We recorded maximum expiratory flow-volume curves in 3046 healthy persons, blacks and whites, age 7 and over--a representative population of lifetime nonsmokers except for some black adult males, who were healthy smokers or ex-smokers. We computed regression equations for lung function measurements (FVC, FEV1.0, FEV10/FVC, PEF, MEF 50% and MEF 25%) as a function of age, height and weight terms for eight subgroups (by sex and race, and for children or adults). Objective statistical criteria were used to select the optimal equations. Simple linear regressions on age and height are inaccurate, in particular for young adults and for the elderly. Weight affects most function measurements: lung function first increases with weight ('muscularity effect') and decreases with further increases in weight ('obesity effect'). The regression equations allow more accurate prediction of normal lung function. In addition, the lower 95% confidence limits are closer to the predicted values and are valid regardless of height, weight and age within each subgroup.

Adolescent

Tachyphylaxis to beta-adrenoceptor agonists in guinea pig airway smooth muscle in vivo and in vitro.

Beta-Adrenoceptor tachyphylaxis was induced by incubating spirally cut guinea pig tracheas with isoproterenol (2.4 x 10(-7) M) for 20 min. This incubation reduced the relaxant effects of catecholamines but not of dibutyryl cyclic AMP, theophylline or sodium nitrite. Tracheas incubated with norepinephrine, phosphodiesterase inhibitors or cyclic nucleotides became tachyphylactic to isoproterenol. Pretreatment with indomethacin prevented induction of tachyphylaxis. Incubation with adenosine, methoxamine or sodium nitrite did not induce beta-adrenoceptor tachyphylaxis. When we gave isoproterenol intramuscularly to guinea pigs, airway sensitivity to aerosolized histamine was unchanged but the toxicity of parenterally administered histamine was increased. A prolonged treatment with isoproterenol reduced airway sensitivity to histamine aerosols; this reduced sensitivity was reversed by indomethacin. Thus, beta-adrenoceptor tachyphylaxis may not explain increased toxicity of parenteral histamine after isoproterenol treatment. Elevated levels of cyclic AMP and an increased synthesis of prostaglandins may result in diminished response to beta-receptor stimulation.

Adrenergic beta-Agonists

Lung function, respiratory disease, and smoking in families.

Respiratory symptoms, disease and lung function were studied in 376 families with 816 children who participated in a survey in three USA towns. Parental smoking had no effect on children's symptoms and lung function. Also, there was no evidence that passive smoking affected either lung function or symptoms of adults. There was no association between prevalence of self-reported cough and/or phlegm in parents and their children. There was a highly significant association between the prevalence of wheeze in parents and their younger children, for whom parents reported this symptom. Wheeze in children was also significantly associated with a parental history of asthma, and lung function was lower in children with a family history of asthma. Even after accounting for height, weight, age, sex and race, children's lung function correlated significantly with parents' lung function. However, the contribution of familial factors (i.e., parents' lung function, smoking, and history of asthma) to children's lung function is small compared to the effects of height, weight and age.

Adolescent