Captopril but not acebutolol, prazosin or indomethacin decreases postexercise proteinuria.

Strenuous physical exercise causes transient proteinuria and renal hemodynamic changes: decrease of renal blood flow and to a lesser extent of the glomerular filtration rate, and an increase of the filtration fraction. However, the mechanisms of these modifications are still poorly understood. In order to elucidate them we performed maximal exercise tests on 8 untrained healthy volunteers after inhibition of the renin-angiotensin system (RAS) by captopril, the sympathetic nervous system by a beta-blocking drug (acebutolol) or an alpha-blocking drug (prazosin) and the prostaglandin system by indomethacin. Urinary albumin excretion was measured in every subject first at rest (AB) and then after exercise (AA) performed successively without and with blockade by each of theses drugs. AA-AB difference in the captopril test (12.04 +/- 6.11 micrograms/min) compared to that in the control test (68.91 +/- 25.18 micrograms/min) was significantly reduced (p less than 0.02). This difference remained unchanged after acebutolol (59.87 +/- 21.91 micrograms/min, p = 0.62), prazosin (35.23 +/- 27.80 micrograms/min, p = 0.21) and indomethacin (55.21 +/- 28.43 micrograms/min, p = 0.35). There was a negative correlation between the lowering of AA elevation and the rise in plasma renin activity in the captopril test (r = 0.64; p less than 0.03). Only acebutolol decreased systolic blood pressure significantly. These results suggest that the RAS plays a major role in postexercise proteinuria. We hypothesize that stimulation of this system induces an increase of efferent glomerular artery constriction and consequently of glomerular transcapillary pressure and the filtration fraction. Captopril seems able to prevent these hemodynamic changes.

[Reliability of the transcutaneous PO2 measurement in the adult by the TCM 1 radiometer electrode]. / Fiabilité de la mesure de la PO2 transcutanée chez l'adulte par l'électrode radiometer TCM 1.

The accuracy of transcutaneous PO2 measurements (PtcO2; Radiometer TCM 1) was evaluated by comparison with arterial PO2 (PaO2) on 115 recordings in 35 patients: 20 during exercise testing (group I) and 14 during assisted ventilation at different FIO2 values (group II). The correlation coefficient between PaO2 and PtcO2 was satisfactory (r = 0.977; n = 115). However PaO2 and PtcO2 mean values were significantly different in group I, and in group II at 45% FIO2. The analysis of variance showed that the difference between PaO2 and PtcO2 was significant among the patients but did not vary with exercise and FIO2 changes (group I: F19 = 6.28, p less than 0.001; group II: F19(19) = 2.54, p less than 0.025). In the adult, transcutaneous PO2 measurement by TCM 1 radiometer electrode seems to be interesting in the context of monitoring blood gases with exercise and assisted ventilation. The significant variation with arterial PO2 sometimes registered should make one cautious in the interpretation of accurate measurements.

[Contribution of nocturnal polygraphy to the diagnosis of Pickwickian syndrome. 10 cases]. / Apport de la polygraphie nocturne au diagnostic du syndrome de Pickwick. A propos de 10 observations.

The authors studied a series of 10 obese patients with respiratory failure referred for treatment because of sleep disorders and diurnal, sometimes uncontrollable, episodes of somnolence. 8 parameters were recorded in the polygraphic study performed during a night of hospitalization: electroencephalogram, electrocardiogram, electro-oculogram, chin electromyogram, thoracic movements, and nasal and buccal air flows. SaO2 and transcutaneous PO2 were recorded simultaneously. A sleep apnea syndrome was diagnosed in 6 of the 10 patients, whose apnea index was markedly above the limit of 5 apneas per hour. The apnea index was below 5 in the other 4 patients. Most patients with sleep apnea syndrome suffer from obstructive apneas of varying duration taking up as much as 48% of total sleep time. The cardiorespiratory effects of these events are apparent, with a drop in PO2 and SaO2 and a decrease in heart rate at the end of apnea. Polygraphic studies seem useful in the diagnosis of the pickwickian syndrome. They allow the type of apnea and its effects to be specified and thus guide treatment.

[Asbestos exposure and pleural calcification : functional effects in 34 patients]. / Exposition asbestosique et calcifications pleurales : appréciation du retentissement fonctionnel chez 34 sujets.

Respiratory function disturbances were evaluated in 34 patients, mostly retired naval shipyard workers, with asbestos-related pleural calcifications. All patients had spirography tests, while 20 of them were studied by CO transfer in steady-state and measurements of arterial gases. Results were correlated with previous clinical history (chronic bronchopathy and/or pleural effusions), smoking habits, and the duration of exposure to asbestos dust. Patients with no previous history had mean spirographic values close to the normal (VC: 96% of lower limits; TC: 113%, mean VEMS/CV: 72.5%). Previous clinical history had a very much more marked effect on spirographic results than on gas exchanges: whereas CO transfer and blood gases were usually fairly normal (97% of normal for TCO and DuCO, mean PaO2 at 78 mmHg, mean PaCO2 at 34,5 mmHg), many patients had markedly altered altered values. A clear correlation was found for TCO, DuCO, Du a and PaCO2 with the duration of exposure. This suggests that in some cases there is a certain degree of pulmonary fibrosis associated with the pleural thickening.

[Oxygen enrichers and different ways of using them]. / Enrichisseurs d'oxygène et différents modes d'utilisation.

Different ways of using oxygen enrichers have been studied. First, the performances of two different devices were tested: the results were very similar to the constructors' previsions. Second, oxygen concentrations in venturi masks connected to enrichers were measured with a mass spectrometer. The authors suggest to adjust the flow delivered by enrichers at 3 liters/min for any type of venturi mask. Pharyngeal oxygen concentration curves show the reliability of masks connected to enrichers compared to other modes of administration (nasal cannulae, nasal catheter).