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Biomedical subjects

A Bouhuys

Publications and source records attributed to A Bouhuys.

At least 37 records · Page 2Linked to original sources

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↗

Protective effect of disodium cromoglycate against airway constriction induced by hemp dust extract.

The effect of disodium cromoglycate (DSCG) was studied in 14 healthy subjects following hemp dust extract (HDE) inhalation (10-min exposure). Ten subjects were given 20 mg of DSCG or a placebo and then challenged with dust aerosol at 30 min post-DSCG inhalation. Partial expiratory flow-volume (PEFV) curves were recorded at least 30 min after exposure, and maximum expiratory flow rates at 40% of the control vital capacity [MEF40%(P)] were read from these curves. Significant acute reduction in MEF40%(P) were recorded after HDE alone and after pretreatment with placebo (p less than 0.01). There was considerable protection from a single dose of 20 mg of DSCG against hemp-induced bronchoconstriction although the acute reductions in MEF40%(P) were still statistically significant at 20 and 30 men postexposure. A group of 7 subjects was given 40 mg of DSCG or placebo 30 min prior to HDE inhalation. In another experiment this group was given 20 mg of DSCG four times daily for 2 days, and on the third day challenged with HDE. The protective effect of DSCG is a short-term one: somewhat less protection was seen after 2 days of four times 20 mg of DSCG/day than 30 min after a single dose of 40 mg. Measurement of airway conductance (Gaw) in 6 subjects demonstrated prevention of acute reductions in Gaw at low lung volumes (25% VC) in 4 out of 6 subjects. We suggest that inhalation of 40 mg of DSCG prior to a work shift might be considered as a temporary means of protecting textile workers against the constrictor effects of dust in their work.

Adult↗

Community studies of lung disease in Connecticut: organization and methods.

We have obtained data on respiratory symptoms, enviornmental exposures, and lung function in 3730 residents, aged seven years and over, of a rural and an urban community in Connecticut. We used newly developed computerized techniques of data acquisition. The respondents represent 66.3% of the total populations available for study in the defined geographic areas (75.2% in the rural and 54.7% in the urban community). Door-to-door surveys in defined areas within each community provided information on the nonrespondents. Data on 92% of all residents were obtained in the door-to-door survey areas. Comparisons of respiratory symptoms and smoking habits between respondents and nonrespondents in the door-to-door survey areas, and between respondents living in the door-to-door survey areas and elsewhere in the two towns, led to the conclusion that the data on the respondents are an accurate reflection of the lung disease experienced by the total populations of the two communities.

Adolescent↗

Effect of wool dust on respiratory function.

A group of 252 workers (176 women and 76 men) employed in two wool mills was studied. The mean age of 36 years; mean exposure, 11 years. All women were nonsmokers, and 47 per cent of the men were regular smokers. Ventilatory function was measured by recording maximal expiratory flow-volume curves and forced expiratory volume in 1 sec on the first working day of the week (Monday) before and after the work shift. On maximal expiratory flow-volume curves the flow rates at 50 per cent of the control vital capacity were read. Workers exposed to wool dust for more than 10 years had a higher prevalence of chronic respiratory symptoms than did those with less than 10 years' exposure, but the difference was not significant. Significant reductions during the work shift were found in maximal expiratory flow rates at 50 per cent of the control vital capapity and 1-sec forced expiratory volume, the first test being considerably more sensitive. Workers exposed to wool dust for more than 10 years had signficantly lower than predicted pre-shift values for maximal expiratory flow rates at 50 per cent of the control vital capapcity. Inhalation of wool dust extract caused a significant decrease of maximal expiratory flow rates at 40 per cent of the control vital capacity on partial expiratory flow-volume curves during the 100 min after exposure. Comparison with the same concentration of cotton dust extract revealed a similar effect during the first 40 min after exposure but a significantly larger effect of the cotton dust extract after 40 min. The data suggest that preventive measures, especially medical supervision, are necessary in wool-processing mills to protect workers sensitive to dust.

Adult↗

Lung function among black and white children.

Racial differences in ventilatory lung function were evaluated in a community study of 393 children (158 blacks, 235 whites). Mean forced vital capacity was 18 per cent larger in nonsmoking white males than in nonsmoking black males, and 11 per cent larger in nonsmoking white females than in nonsmoking black females. Similar differences were observed for the 1-sec forced expiratory volume and for the maximal expiratory flow at 50 per cent of the vital capacity. However, when adjusted for lung size (on the basis of forced vital capacity), 1-sec forced expiratory volume and maximal expiratory flow at 50 per cent of the forced vital capacity were larger in the black children compared to the white children. Lung function prediction equations based on race, sex, age, height and weight are presented for healthy nonsmoking children; these allow for an evaluation of normal lung function in both black and white children.

Adolescent↗

Chronic respiratory disease in hemp workers. A follow-up study, 1967-1974.

Many soft-hemp workers with more than 20 years' exposure to dust have chronic respiratory symptoms and obstructive lung function loss. During 7 years of follow-up, these workers had significantly higher occurrences of chronic cough and phlegm and dyspnea than control subjects and a significantly larger annual decline of forced expiratory volume in 1 second (FEV1.0) than control subjects, with a particularly marked difference between 20- to 44-year-old nonsmoking controls and hemp workers. We believe that deterioration of lung function among hemp workers begins before the age of 45 and that it continues even if further exposure to dust ceases. Textile workers should be advised to avoid further exposure to dust at a time when their ventilatory lung function (in the absence of effects of acute exposure) is sufficient to prevent future development of disabling function loss.

Adult↗

Interaction between bronchoconstrictor stimuli on human airway smooth muscle.

In healthy human subjects, the simultaneous aerosol administration of histamine and methacholine results in a pronounced decrease in maximum flow rates on partial expiratory flow-volume (PEFV) curves. When given alone in the same concentrations, these drugs produced no or minimal decreases in flow rates. The results suggest an interaction of histamine and cholinergic stimuli on airway smooth muscle (ASM). This mechanism might explain many experiments where vagal blockade diminished or abolished ASM response to histamine and other stimuli, simply by interfering with histamine-cholinergic interaction at the ASM level. These findings confirm similar findings of animal in vitro experiments. The experiments clearly confirm the sensitivity and value of assessing drug effects prior to a deep breath. Flow-rate changes after a full inspiration, taken from the maximum expiratory flow-volume (MEFV) curve, show either no relationship to the concentration of inhaled methacholine or significantly less effect than that seen on the PEFV curve.

Adult↗