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At least 1,009 records · Page 56Linked to original sources
PubMed1981

Association between celiac disease and lung disease.

An association has been suggested between celiac disease and diffuse interstitial lung disease of the hypersensitivity pneumonitis type in several reports from Europe. The present report consists of a study of 18 North American, biopsy-proved celiac patients, who were compared with an equal number of control subjects balanced for age, sex, and smoking. The celiac patients showed no evidence of interstitial lung disease as assessed by chest roentgenograms and pulmonary function tests. However, a history of asthma or chronic cough was present in a higher proportion of the celiac than control subjects. Also the celiac patients showed objective evidence of airway obstruction, as demonstrated by differences between the two groups in FEV1 (P less than 0.05) and Vmax 50% and Vmax 25% (P less than 0.01 and less than 0.05, respectively). These results confirm a recent report questioning whether there is truly a relationship between celiac disease and interstitial lung disease. Nevertheless, our findings suggest an association between celiac disease and airway obstruction.

Antigen-Antibody Complex↗
PubMed1983

How does lung structure affect gas exchange?

The lung is characterized morphologically by establishing a very large surface and an exceedingly thin barrier between air and blood. A model for relating these structural features to the lung's gas exchange function is first developed. It is then shown that DO2 estimated by morphometry is about two times larger than that estimated by physiology; there are possible reasons for this. Comparing animals of high activity (dog, horse) with corresponding species of lower activity (man, cow) reveals that DO2 is proportional to O2 needs. The mechanical properties of the lung are discussed which allow such a large surface with such a thin barrier to be maintained lifelong. Surfactant properties of the lining layer are important factors in stabilizing the alveolar surface. Repair processes are also essential and require metabolic activities of the cells lining the barrier. The case of adult respiratory distress syndrome is used to illustrate the consequences of severe damage to the cell linings of alveoli: the barrier is thickened, and a good part of the alveolar surface is flooded by edema fluid, so that gas exchange is severely impaired.

Animals↗
PubMed1987

Pulmonary involvement in systemic sclerosis. Association with anti-Scl 70 antibody and digital pitting.

The association of clinical and serologic features of 34 patients with systemic sclerosis was examined. Anti-Scl 70 antibody was found to identify patients with abnormal pulmonary function, particularly impaired diffusion (p less than 0.005), as well as patients with digital pitting scars (p less than 0.025). In addition, the presence of digital pitting scars correlated with impaired diffusion (p less than 0.005), suggesting that interstitial pulmonary disease in systemic sclerosis may, like digital pitting, be secondary to vascular pathology. Anticentromere antibody-positive patients were less likely to have abnormalities of pulmonary function (p less than 0.001).

Autoantibodies↗
PubMed1989

The discriminatory value of the P(A-a)O2 during exercise in the detection of asbestosis in asbestos exposed workers.

Asbestosis is commonly associated with abnormalities of gas transport but since most asbestos workers are smokers and smokers also commonly have abnormalities in P(A-a)O2, the actual specificity and sensitivity of the P(A-a)O2 has been unknown. The P(A-a)O2 was measured at rest and exercise in 92 asbestos-exposed patients. These patients were divided into five groups based on their x-ray and pulmonary function status; normal, CAO, CAO and pleural disease, pleural disease alone and asbestosis with or without CAO. The P(A-a)O2/VO2(mm Hg)/L of O2 was the most discriminatory measurement of gas transport between groups, with mean values of 14.45 +/- 9.24 for normal, 19.04 +/- 10.52 for CAO, 16.85 +/- 8.94 for CAO and pleural disease and 34.07 +/- 21.54 for asbestosis with or without CAO. The P(A-a)O2/VO2 was of high specificity if greater than 35 mm Hg/L of O2 with only two out of 65 patients without asbestosis being considered abnormal. It was of low sensitivity in that only nine out of 27 patients with asbestosis would be detected if this were the sole criterion for diagnosis.

Asbestosis↗
PubMed1989

Volume adjustment of mechanics and diffusion in interstitial lung disease. Lack of clinical relevance.

Relationships of lung mechanics and diffusion to lung volume were examined in 38 patients with interstitial lung disease to determine whether patterns of reduction relate to severity of disease, distinguish histologic characteristics or predict prognosis for reversibility. Normal volume-related values for both mechanics and diffusion were seen throughout the range of severity of disease. The ratio of mechanics to lung volume did not correlate with the ratio of diffusion to lung volume in the same patient. Volume relationships of mechanics and diffusion failed to distinguish pathologic predominance of fibrosis or inflammation/granulomas. These ratios failed to predict reversibility in patients who had repeated tests. These results suggest that in patients with interstitial lung disease the significance of "volume-adjustment" of mechanics and diffusion should be viewed with caution; these parameters do not appear to contribute to the assessment of pathophysiology or correlate with clinical spectrum of interstitial lung diseases.

Female↗
PubMed1989

Pulmonary artery medial hypertrophy in cocaine users without foreign particle microembolization.

A reduction in the DCO has been reported among "free-base" cocaine smokers. We reviewed the pulmonary histopathology in 20 deaths due to cocaine intoxication for either parenchymal or vascular abnormalities which might explain this physiologic finding. Pulmonary artery medical hypertrophy in the absence of foreign particle microembolization was present in four of 20 cases (20 percent). Hemosiderin-laden macrophages were found in seven of 20 cases (35 percent). These abnormalities were not seen in a matched control group. We conclude that in the absence of foreign particle microembolization, pulmonary artery medial hypertrophy occurs among cocaine users, although the mechanism of these vascular changes is unknown. In addition, occult alveolar hemorrhage occurs more frequently among cocaine users than is clinically recognized.

Adult↗
PubMed1990

Pentoxifylline improves pulmonary gas exchange.

Pentoxifylline is a xanthine derivative with hemorrheologic and vascular properties that may improve gas exchange in patients with chronic obstructive pulmonary disease (COPD). We tested this hypothesis in 12 patients with COPD (mean FEV1 = 40 percent predicted; mean DCO, 8.6 ml/min/mm Hg) randomly divided into a treatment and control group and six healthy volunteers. Following establishment of baseline DCO and maximum expiratory flow volume (MEFV) curve values, each subject in the treatment and healthy groups took 400 mg of pentoxifylline three times a day for 12 weeks. Weekly DCO and MEFV curves were measured before treadmill exercise in both COPD groups and before and after exercise in the healthy group. The MEFV curve parameters from the final three weeks of therapy did not differ significantly from baseline values. During this time, however, the treatment COPD group's resting DCO rose by 8.2 +/- 2.4 percent over baseline level (p less than 0.01). Treadmill walk time increased from 17.7 +/- 2.9 minutes to 23.2 +/- 2.9 minutes (p less than 0.02). This was accompanied by improved exercise oxygen saturation measured by oximetry (SoxiO2). Premedication SoxiO2 fell from 92.8 +/- 1.2 percent to 88.6 +/- 2.5 percent during exercise, and from 94.4 +/- 1.1 percent to only 91.8 +/- 1.0 percent after 12 weeks of medication (p less than 0.05). No such improvement was noted in the control COPD group. Although the healthy group's resting SoxiO2 and DCO did not change during treatment, their exercise DCO increased significantly from 36.3 +/- 3.1 ml/min/mm Hg to 41.8 +/- 3.5 ml/min/mm Hg (p less than 0.001). These data demonstrate that pentoxifylline improves gas exchange, possibly by increasing cardiac output, and/or by raising mixed venous PO2, and/or by improving blood flow to underperfused alveoli.

Adult↗
PubMed1990

Pulmonary edema in severe falciparum malaria. Hemodynamic study and clinicophysiologic correlation.

This study was performed to extend the knowledge of the pathogenesis of PE in severe falciparum malaria. Sequential hemodynamic studies were conducted in 13 patients with severe falciparum malaria. Seven patients developed PE, while the other six patients had NPE. Two patients died, one in each group. Hemodynamic changes were found in both groups, including an initial reduction in SVR and PVR, along with an increased CI and variable values (normal and increased) of PCWP. All abnormalities persisted for at least two days; changes in PVR lasted especially longer (throughout five days). The initial hemodynamic changes cannot predict the development of PE; however, heavy parasitemia of more than 60 percent and severe hypoalbuminemia were found to be more common in PE than NPE. Of three patients with PE who had normal PCWP, one died, with postmortem findings of increased pulmonary capillary permeability. The increased PCWP which was found in the other four cases of PE was proven to be volume overload without evidence of CHF. It was concluded that the pathophysiologic changes in severe falciparum malaria were systemic and pulmonary vasodilation. The abnormal pulmonary vascular change was found to be the cause of PE. Volume overload and hypoalbuminemia could aggravate further pulmonary capillary leakage in these cases.

Adult↗
PubMed1993

Physiological and biomechanical aspects of rowing. Implications for training.

The drag force on a racing shell increases with the square of velocity corresponding to a 3.2 power increase in energy expenditure. However, the metabolic cost increases with only an approximately 2.4 power function of shell velocity. During international races the metabolic cost corresponds to an oxygen uptake of 6.7 to 7.0 L/min over 6.5 min. The relative anaerobic contribution to 6.5 min of 'all-out' rowing has not been determined but is estimated to range from 21 to 30%. Because of the large muscle mass involved in rowing, blood variables reach extreme values: adrenaline 19 nmol/L; noradrenaline 74 nmol/L; pH 7.1; and bicarbonate 9.8 mmol/L. Because of the static component of the rowing stroke at the catch, blood pressure increases to near 200mm Hg, and the heart of oarsmen has adapted to this load by increasing wall thickness and internal diameters. The maximal oxygen uptake of oarsmen may reach 6.6 L/min and ventilation 243 L/min. Arterial oxygen tension decreases by 20mm Hg during 'all-out' rowing corresponding to a decrease in pulmonary diffusion capacity. A force of approximately 800 to 900N is developed on the oar. Force generation during rowing is relatively slow, 0.3 to 0.4 sec. Oarsmen are strongest in low velocity movement with 70 to 75% slow twitch fibres in skeletal muscle. Data indicate that rowing technique and training may improve explaining why results become approximately 0.7 sec faster per year.

Altitude↗