Rats have been placed for periods from two hours to 22 days in a chamber, the atmosphere of which was enriched in CO2 (FICO2: 0.10). The acute phase of hypercapnia induces multidirectional changes of many plasma amino acids. Some of these changes lessen or become of an opposite direction during the first days of exposure; most of them disappear when the hypercapnic acidosis is partly compensated. The variety of these reactions seems due to the fact that CO2 brings into play various mechanisms of synthesis, circulation and catabolism.

Alanine↗

PubMedDate not supplied

[Effects of non-occupational air pollutants on the tracheo-bronchial mucosa (bronchial cancer excepted)].

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Air Pollutants↗

PubMedDate not supplied

[A micromethod for determination of nicotine and cotinine in blood and urine by gas chromatography. Results obtained from various smokers].

The determination of nicotine and cotinine in plasma and urines of smokers is carried out by gas-chromatography with an Ucon-Polar 50 HB 2000 alkalinized column and a specific N detector, using diphenylamine as internal standard. The technique for extraction and chromatographic analysis is developed. The limit values for a correct determination are : 0,2 ng for nicotine and 1 ng for cotinine. The results show that the transit of nicotine and cotinine into the blood is very fast. They confirm the rapidity of the urinary excretion of nicotine, the slowness of that of cotinine, and the relation between the eliminated amounts and the urinary flow.

Adult↗

PubMedDate not supplied

[Kinetics of the compensation of respiratory acidosis induced by experimental chronic hypercapnia in man (author's transl)].

Four groups of male volunteers have been exposed in a tight climatical chamber to PICO2 of 14, 21, 28 and 32 torr; exposure periods varied from two to 30 days, between two reference periods in normal air. The results deal with the evolution of arterial blood acid-base equilibrium and that of renal response in relation to PICO2. In all exposures, the carbon dioxide alveolar overload increases by several torr during the first 24 hours on account of attenuation of the initial hyperventilation. Kinetics of the respiratory acidosis compensation differs according to hypercapnia which is moderate (PICO2 of 14 and 21 torr) or relatively severe (PICO2 of 28 and 32 torr). The decrease in arterial pH lessens as early as the 24th hour at PICO2 28 and 32 torr, and only after two days at PICO2 14 and 21 torr. The renal response is characterized by a significant increase in aciduria during the first 24 hours at PICO2 28 and 32 torr; the changes are smaller and start latter at PICO2 14 torr.

Acidosis, Respiratory↗

PubMedDate not supplied

[Mucociliary function and its alteration by certain irritants (author's transl)].

Mucociliary clearance is usually estimated in vivo by the measurement of mucus transfer or by clearance of radio-active tracers previously deposited in the airways. These methods are relatively difficult and complex so that for routine studies measures are usually made of ciliary activity. To clarify the consequences of changes in activity the authors have established the relationship between the speed of mucus transport and the frequency of ciliary beating. From their own studies and from evidence in the literature they show how the clearance function of mucociliary activity can be disturbed by a fall in temperature and humidity, by viral infection, by atmospheric pollutants such as sulphur dioxide, nitrogen dioxide and aldehydes and by tobacco smoking. They indicate the beneficial effects obtained by the administration of beta adrenergic compounds and the limits of efficiency of mucolytic agents. They examined the pathophysiological consequences of the slowing down or arrest of mucus drainage with particular reference to the proliferation of infectious agents and their penetration into respiratory mucus membranes.

Adrenergic beta-Agonists↗