[Study of the homogeneity of pulmonary ventilation and perfusion by continuous mass spectrometric analysis of the expired gases].
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Adult↗
Biomedical subjects
P Duroux
Publications and source records attributed to P Duroux.
[Effect of verapamil, nicardipine and disodium cromoglycate on the bronchoconstrictor effects of histamine].
The effects of nicardipine, verapamil and sodium cromoglycate (SCG) on the increase in pulmonary airway resistance (Raw) and decrease in pulmonary dynamic compliance (C.Dyn.) induced by histamine (Hist) (3 and 30 micrograms x kg-1, i.v.) and acetylcholine (ACh) (3 and 30 micrograms x kg-1, i.v.) were investigated in anaesthetized guinea-pigs. The effects of these three agents on the contractile effects of Hist and ACh were tested on isolated tracheal preparations of the guinea pig. Nicardipine (0.3 and 1 mg . kg-1, i.v.) and verapamil (1 mg . kg-1, i.v.) as well as SCG (3 and 10 mg . kg-1, i.v.) partially but significantly inhibited the effects of Hist on Raw. These substances had no effect on Hist-induced decrease in C.Dyn. Nicardipine and verapamil had no effect on ACh-induced bronchoconstriction in vivo. SCG partially but significantly inhibited the effects of ACh (30 micrograms . kg-1) on Raw. In concentrations higher than 3 x 10(-6) M, nicardipine and verapamil inhibited the contractile effects of Hist and ACh on guinea-pig isolated trachea. SCG had no effect on this preparation. The results suggest that nicardipine, verapamil and SCG partially reduce the component of bronchoconstriction associated with stimulation of irritant receptor by Hist. However, the site and mechanism of action of Ca++-entry antagonists remain uncertain.
Acetylcholine↗
Bronchial response to hyperventilation of dry air at room temperature in normals and asthmatics.
The bronchial effects of three levels (25, 40 and 60 1 X min-1) of voluntary isocapnic hyperventilation of dry air at room temperature (20-22 degrees C) have been studied in 18 normal, non-atopic subjects and in 25 nonperennial asthmatics who were asymptomatic and whose airway obstruction at the time of the study was mild, with a peak expiratory flow rate of 6.1 +/- 1.5 (SD) 1 X s-1 vs a predicted 8.4 +/- 1.3 1 X s-1. The bronchial response was assessed by use of maximal expiratory flow-volume curves obtained before and 1, 5, 10 and 15 min after the 5 min hyperventilation challenge. In normal subjects, there was a minimal though significant (p less than 0.001; two-way analysis of variance) fall in maximal expiratory flows which did not increase with the level of hyperventilation and was not accompanied by a fall in forced vital capacity. The bronchial response of asthmatics differed from that in normal: the fall in maximal expiratory flows was significantly greater, associated with a significant fall in forced vital capacity and increased with the level of hyperventilation. Results in 10 asthmatics studied on two different study days were highly reproducible. Sensitivity and specificity are excellent (approximately equal to 1) for the 40 1 X min-1 hyperventilation challenge. Our results suggest that isocapnic voluntary hyperventilation of dry air at room temperature (20-22 degrees C) is a highly satisfactory screening test to detect bronchial hyperreactivity.
Adolescent↗
[Aortic rheumatoid insufficiency. 3 cases and review of the literature].
The authors report on three cases of rheumatoid aortic valve insufficiency. The three patients had classic sero-positive rheumatoid arthritis. In one patient aortic valve insufficiency and pericarditis occurred simultaneously; aortic valve insufficiency appeared in two patients less than two years and in the third patient 17 years after the beginning of arthritis. In the first two cases, the aortic regurgitation evaluated by echocardiography and angiography was not severe enough to require valvular replacement. In the third patient, rheumatoid granuloma of the aortic valve caused fatal aortic insufficiency.
Aged↗