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Biomedical subjects

A Bouhuys

Publications and source records attributed to A Bouhuys.

At least 55 records · Page 3Linked to original sources
PubMed1975

Byssinosis: airway responses in textile dust exposure.

The inhalation of textile dusts causes bronchoconstriction in textile workers and in healthy experimental subjects. The airway responses to these dusts are potentiated by propranolol and inhibited by an antihistamine drug and by ascorbic acid. Administration of 20 mg disodium cromoglycate by spinhaler 30 minutes prior to challenge with hemp dust or hemp dust extract protected a small number of subjects against the airway constrictor effect, mostly those with a large acute reduction in flow rates. Textile dust extracts contain a histamine-releasing agent, which explains their airway constrictor effect. This agent is a highly water-soluble, heat-stable, low-molecular-weight compound which has not yet been chemically identified. In the prevention and control of byssinosis, the administration of drugs such as ascorbic acid or disodium cromoglycate should be considered in addition to engineering methods.

Adult↗
PubMed1975

Lung function in textile workers.

Acute changes in ventilatory function during a workshift with exposure to hemp, flax, and cotton dust were measured on Mondays in a group of 61 textile workers, all working on carding machines. In addition, single-breath diffusing capacity (DLCOSB) was measured before dust exposure on Monday in 30 of the 61 workers. Large acute reductions during dust exposure were recorded in maximum expiratory flow rate at 50% VC (MEF50%), ranging from 38 to 22%. Acute reductions of FEV1-0 were considerably smaller, ranging from 17 to 9%. There was a statistically significant increase in residual volume (RV) with very small and insignificant changes in total lung capacity (TLC). Although preshift FEV1-0 and FVC were decreased, DLCOSB was within normal limits. Plethysmographic measurements in six healthy volunteers exposed to hemp-dust extract confirmed the results obtained in textile workers, that is, that TLC does not change significantly during dust-induced airway constriction and that maximum expiratory flow rate at 50% VC (MEF50%) is a more sensitive test than FEV1-0 in detecting acute ventilatory changes caused by the dust extract.

Adult↗
PubMed1975

Measurement of axial diffusivities in a model of the bronchial airways.

Values for the effective axial diffusivity D for laminar flow of a gas species in the bronchial airways have been obtained as a function of the mean axial gas velocity u by experiment measurements of benzene vapor dispersion in a five generation glass tube model of the bronchial tree. For both inspiration and expiration D is seen to be approximately a linear function of u over the range of Reynolds' numbers 30-2,000 corresponding to peak flows in bronchial generations 0-13 under resting breathing conditions. The diffusivity for expiration is seen to be approximately one-third that for inspiration due presumably to increased radial mixing at bifurcations during expiration. The effective diffusivities relative to the molecular diffusivity can be expressed by the formulas D/Dmol = 1 + 1.08 NPe for inspiration and D/Dmol = 1 + .37 N-Pe for expiration. These velocity dependent diffusivities help to explain the short transit times of gas boluses from mouth to alveoli and will aid in the analysis of airway gas mixing by mathematical transport equations.

Bronchi↗
PubMed1975

Contractile responses of the guinea-pig trachea in vitro: modification by prostaglandin synthesis-inhibiting drugs.

Prostaglandins (PG) E2 and F2alpha, characterized by thin-layer chromatography and bioassay, were released from guinea-pig trachea contracted with acetylcholine or histamine. Inhibition of contraction with atropine or mepyramine, or by the removal of calcium, abolished the prostaglandin release. PGE2 and PGF2alpha were also released after gentle mechanical irritation of the mucosal surface, but not the adventitial surface, of the trachea. This release of prostaglandins occurred in the absence of calcium and was prevented by treatment of the trachea with indomethacin. Incubation (20 minutes) of tracheal spirals with indomethacin (0.6 mug/ml) 1) reduced the basal tension of the spiral; 2) reduced responses to low doses of histamine, serotonin, acetylcholine, barium or potassium; and 3) increased responses to high doses of these agonists. These effects lasted despite washout but were reversed by the addition of arachidonic acid. Subthresholdquantities of PGF2alpha after indomethacin treatment restored responses to minimally effective doses of the agonists. Aspirin (50 mug/ml), 5,8,11,14-eicosatetrayonic acid (2 mug/ml) and sodium salicylate (100 mug/ml) had effects similar to indomethacin (0.6 mug/ml). Alterations produced with 5,8,11,14-eicosatetrayonic acid and sodium salicylate were reversed with washing. Restoration of resting tension after indomethacin did not qualitatively change the results. Indomethacin at higher doses (greater than 30 mug/ml) inhibited responses to all histamine doses but this effect was reversible with washing. The results suggest that basal tension of the guinea-pig trachea may be due to an intramural production of PGF2alpha and that during the development of active tension, prostaglandins E2 and F2alpha are released which modulate the intensity of the contraction.

5,8,11,14-Eicosatetraynoic Acid↗