Biomedical subjects

C Grimaud

Publications and source records attributed to C Grimaud.

At least 73 records · Page 4Linked to original sources

PubMed1975

Bronchoconstrictor effects of a deep inspiration in patients with asthma.

A deep inspiration from functional residual capacity to total lung capacity, performed at a low flow rate by a group of 40 unselected adult patients with asthma, yielded an immediate and transient increase (71 per cent, P smaller than 0.001) in specific airway resistance. In 2 of the 40, deep inspiration provoked an attack of asthma. The effect of deep inspiration can be attributed to a vagal bronchoconstrictor reflex, because it was prevented or decreased in most of the cases by inhalation of an anticholinergic drug. Beta-adrenergic blockade by propranolol potentiated in a minority of subjects the bronchoconstrictor response to deep inspiration. Deep expiration also induced a bronchoconstrictor effect, which was weaker than that of deep inspiration. It follows that functional studies of asthmatics may be biased if the technique requires maximal respiratory maneuvers.

Adolescent↗

PubMed1975

[The role of afferent barosensory neurons in respiratory and bronchomotor control].

Ventilatory and bronchomotor responses to baroreceptor afferent stimulation were studied in anaesthetized rabbits breathing spontaneously. The stimuli used were either the increase in carotid sinus pressure or the electrical stimulation of the cut central end of the aortic nerve. Respiratory effects of aortic barodenervation were also studied. Normoxic, normocapnic steady state was verified by repeated measurement of PO2, PCO2 and pH in arterial blood. Stimulation of both aortic and carotid baroreceptors provoked an early decrease of tidal volume and total pulmonary resistances without change in respiratory frequency. Aortic nerve stimulation induced an important and slowly adapting ventilatory and bronchomotor effect, whereas changes in carotid sinus pressure produced slight variation in respiratory parameters. Aortic nerve section resulted in an early and prolonged increase of total pulmonary resistances. Surgical or chemical (atropine) vagotomy did not change the bronchodilation observed under stimulation of the carotid sinus; however this effect was suppressed by intravenous injection of propranolol. This observation shows the importance of the sympathetic outflow in the genesis of bronchomotor responses following baroreceptor stimulation. In conclusion the baroreceptor stimulation provokes simultaneous decrease of both ventilation and total pulmonary resistances; aortic nerves seemed to exert permanent control on bronchomotor tone.

Animals↗

PubMed1975

[The "small airways disease" and its early diagnosis].

The "small airways disease" constitutes the initial, silent step of chronic obstructive bronchopneumopathies and remains misknown for a long time. Discussion is made of an anatomic and physiologic definition of these small airways and authors insist on the concept of MEAD's equal pressure point. The classical technics of functional study (spirometry, determination of the resistances in the airways) are of poor help for evidencing the lesions of these airways; more specifical technics have been advanced (flow-volumes curves, frequency-dependence of the compliance...). Their meaning and their place in the detection and diagnosis of chronic obstructive bronchopneumopathies is presently object of numerous discussions.

Bronchi↗

PubMed1975

[The maximary expiratory flow-volume curve].

The maximal expiratory flow-volume curve is obtained by recording simultaneously, in the course of a forced expiration, the volume in abscissa and the flow in ordinate. Mention is made of the various recording technics and also of the ways for quantifying the results (determinations of the instantaneous flows at various volumes). The clinical applications of the flow-volume curves are taken in consideration. The advantages and inconvenients of this method are discussed.

Age Factors↗

PubMed1974