A double-labelling fluorescent assay for concomitant measurements of [Ca2+]i and O2. production in human macrophages.

To measure intracellular free Ca2+ concentration ([Ca2+]i) and superoxide (O2) production in human alveolar macrophages, we used the fluorescent Ca2+ indicator fura-2 and the O2-sensitive dye dihydrorhodamine-123, which becomes fluorescent in its oxidized form, rhodamine-123. We describe a new double-dye technique whereby the kinetics of both [Ca2+]i levels and O2. production can be monitored simultaneously. This technique was developed in the dimethylsulfoxide-differentiated monocytic-like U-937 cell line (not equal to U-937), validated by comparison with single dye measurements and applied to human alveolar macrophages. The chemotactic peptide N-formyl-L-Methionyl-L-Leucyl-L-Phenylalanine induced in both cell types a similar transient elevation in [Ca2+]i, followed within seconds by a sustained increase in O2 production, which was however 4-fold weaker in not equal to U-937 cells. These results indicate that O2 production is an early event following the stimulation of human alveolar macrophages. This new double-dye technique may be relevant to other O2 ion-producing cells and could help to define more precisely the kinetics of the events leading to this biological response.

Comparative study of the ventilatory responsiveness to CO2 in bronchitic and emphysematous patients with chronic respiratory failure.

The comparative ventilatory responsiveness to CO2 was studied in 13 chronic bronchitics and 14 emphysematous patients, all exhibiting respiratory insufficiency and with FEV1 less than 1,500 ml. The gas inhaled was enriched with oxygen (F1O2 =0.6) and contained 6% CO2, and measurements were taken when the patients had reached a stable state. The ratio delta VE/deltaPaCO2, which represents the ventilatory responsiveness to CO2, was higher in the emphysematous patients (1.18+/-0.51 liters-min-1. Torr-1) than in the bronchitics (0.76+/-0.34, p less than 0.025), but the deviation on either side of the mean was large in each group. The ventilatory responsiveness to CO2 was proportional to the initial PaCO2, FEV1, total airways resistance, total pulmonary work and especially to inspiratory mechanical work done on the lung ( r=-0.73, p less than 0.001). The difference in ventilatory responsiveness to CO2 between the bronchitic and emphysematous patients may be explained by the difference in energy expended in breathing. It was not possible to exclude an effect due to a difference in sensitivity within the respiratory centers, since inspiratory mechanical work was not measured during CO2 inhalation. It was thought likely that mechanical factors play a triggering role, in that they cause a fall in ventilatory responsiveness to CO2 and hypercapnia, the latter causing the central hyposensitivity which maintains the retention of CO2.

[Value of pulmonary hemodynamic exploration during muscular exercise in chronic bronchitis?]. / Que peut apporter l'exploration hémodynamique pulmonaire au cours de l'exercice musculaire dans la bronchite chronique

The value of pulmonary haemodynamic tests during physical exercise in chronic bronchitis was shown by the comparison of two groups of patients. In the first group (n=24) the PAP during exercise is lower than 30 torr. In the second it was over 30 torr. The PAP at rest was always lower than 20 torr. The load was 40 to 50 watts, i.e. an average O2 consumption of 500-600 ml.mm-1 m-2. The cardiac output doubled on average in exercise. Both groups varied markedly in their PAP at rest: 13.6 +/- 1.7 torr for the first group and 15.8 +/- 2.4 for the second (p less than 0.001). In fact differences in pressure during exercise (I=25.0 +/- 3.4 torr; II=39.6 +/- 7.4 torr, p less than 0.001) could be explained mainly by the differences of pulmonary vascular resistances (I=0.91 +/- 0.37; II=1.47 +/- 0.61, p less than 0.005): they tended to fall during effort in the first group and increased slightly in the second; and by the much higher increase in the pulmonary "capillary" pressure during exercise in the second group (I=12.5 +/- 4.4 torr; II=19.7 +/- 72 torr, p less than 0.001). The cardiac output during rest and exercise was equal in both groups. The haemo-dynamic "recovery delay" was much higher in the second group. The spirographic shortage was on the whole identical in both groups. PaO2 on average was higher in group I (p less than 0.05) where it improved during exercise (p less than 0.01). The PaO2 of the second group did improve during exercise. The haemodynamic differences were concomitant with the differences in gas exchanges during effort, of well known prognostic significance. As the "foretelling" of PAP in effort from the PAP at rest was quite poor, it appeared that haemodynamic test in effort has a real value in contributing efficiently to the differenciation of the degree in severeness. The threshold of 30 torr for PAP in exercise (and for the load mentioned above) seemed a good discriminating factor.

[Pulmonary aspergillosis. Apropos of 5 anatomo-clinical cases]. / Les aspergilloses pneumoniques. A propos de 5 observations anatomo-cliniques

The authors report five cases of invading and diffuse pulmonary aspergillosis. Clinically they are characterized by a development in a still clear pulmonary field in patients with a lessened organic resistance and under corticosteroid treatment. Necrotic phenomenons occurred very quickly and prognosis was poor. Anatomically, foci were spreading, rapidly necrosing and contained Aspergillus. Diagnosis was based, besides etiological circumstances, on the presence of Aspergillus in sputum and of anti-aspergillus precipitins in serum.