Diffusing capacity

About: Diffusing capacity is a research topic. Over the lifetime, 2712 publications have been published within this topic receiving 92633 citations. The topic is also known as: diffuxion capacity & diffusing capacity.

Plasma Hsp90 levels in patients with systemic sclerosis and relation to lung and skin involvement: a cross-sectional and longitudinal study.

Abstract: Our previous study demonstrated increased expression of Heat shock protein (Hsp) 90 in the skin of patients with systemic sclerosis (SSc). We aimed to evaluate plasma Hsp90 in SSc and characterize its association with SSc-related features. Ninety-two SSc patients and 92 age-/sex-matched healthy controls were recruited for the cross-sectional analysis. The longitudinal analysis comprised 30 patients with SSc associated interstitial lung disease (ILD) routinely treated with cyclophosphamide. Hsp90 was increased in SSc compared to healthy controls. Hsp90 correlated positively with C-reactive protein and negatively with pulmonary function tests: forced vital capacity and diffusing capacity for carbon monoxide (DLCO). In patients with diffuse cutaneous (dc) SSc, Hsp90 positively correlated with the modified Rodnan skin score. In SSc-ILD patients treated with cyclophosphamide, no differences in Hsp90 were found between baseline and after 1, 6, or 12 months of therapy. However, baseline Hsp90 predicts the 12-month change in DLCO. This study shows that Hsp90 plasma levels are increased in SSc patients compared to age-/sex-matched healthy controls. Elevated Hsp90 in SSc is associated with increased inflammatory activity, worse lung functions, and in dcSSc, with the extent of skin involvement. Baseline plasma Hsp90 predicts the 12-month change in DLCO in SSc-ILD patients treated with cyclophosphamide.

Primary pulmonary hypertension: a national prospective study

Abstract: A national registry was begun in 1981 to collect data from 32 centers on patients diagnosed by uniform criteria as having primary pulmonary hypertension. Entered into the registry were 187 patients with a mean age (+/- SD) of 36 +/- 15 years (range, 1 to 81), and a female-to-male ratio of 1.7:1 overall. The mean interval from onset of symptoms to diagnosis was 2 years. The most frequent presenting symptoms included dyspnea (60%), fatigue (19%), and syncope (or near syncope) (13%). Raynaud phenomenon was present in 10% (95% of whom were female) and a positive antinuclear antibody test, in 29% (69% female). Pulmonary function studies showed mild restriction (forced vital capacity [FVC], 82% of predicted) with a reduced diffusing capacity for carbon monoxide (DLCO), and hypoxemia with hypocapnia. The mean (+/- SD) right atrial pressure was 9.7 +/- 6 mm Hg; mean pulmonary artery pressure, 60 +/- 18 mm Hg; cardiac index, 2.3 +/- 0.9 L/min X m2; and pulmonary vascular resistance index, 26 +/- 14 mm Hg/L/min X m2 for the group. Although no deaths or sustained morbid events occurred during the diagnostic evaluation of the patients, the typically long interval from initial symptoms to diagnosis emphasizes the need to develop strategies to make the diagnosis earlier.

A Standardized Breath Holding Technique for the Clinical Measurement of the Diffusing Capacity of the Lung for Carbon Monoxide

Abstract: Previous publications from this laboratory have described (1, 2) a modification of the Krogh breath holding technique for measuring the pulmonary diffusing capacity for carbon monoxide (DL) .6 This test can be performed quickly and simply and does not require arterial blood analyses. It has recently (2) been shown to provide an index of pulmonary diffusing capacity similar to that given by the DLo2 method of Lilienthal, Riley, Proemmel, and Franke (3) and the "steady state" method of Filley, MacIntosh, and Wright (4). The purpose of the present report is to enumerate some of the factors that affect DL, to describe a standardized technique for its measurement, and to present

Relative importance of diffusion and chemical reaction rates in determining rate of exchange of gases in the human lung, with special reference to true diffusing capacity of pulmonary membrane and volume of blood in the lung capillaries.

Abstract: An equation, i/Dm + i/θVc = i/Dl, has been derived which relates the measured pulmonary diffusing capacity (Dl), the true diffusing capacity of the pulmonary membrane (Dm), the rate of uptake of CO...