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Biomedical subjects

G R Owens

Publications and source records attributed to G R Owens.

At least 19 recordsLinked to original sources

Public screening for lung disease: experience with the NIH Lung Health Study.

The Lung Health Study is the first major initiative of the National Heart, Lung, and Blood Institute in screening for and intervention in early lung disease. The objective of the study is to identify cigarette smokers who have early disease and determine whether an intervention program of smoking cessation and bronchodilator therapy will alter the course of their disease. After an extensive screening program, 5,887 participants have been randomized to one of three groups: usual care, intervention with smoking cessation and the use of a placebo inhaler, and intervention with smoking cessation and the use of ipratropium bromide. All participants will be followed for 5 years. Preliminary data from the screening indicate that chronic obstructive pulmonary disease is more prevalent than was previously recognized, that it is widespread in women as well as men, and that it is far more common in young individuals than was thought. Approximately two-thirds of the study participants have hyperreactive airways. Preliminary data from the Lung Health Study indicate that screening for lung function can be carried out in a cost-effective manner.

Adult

The effect of obliterative bronchiolitis on breathing pattern during exercise in recipients of heart-lung transplants.

The more rapid and shallow ventilation pattern seen during exercise in patients with obstructive and/or restrictive lung disease has been attributed by some investigators to the effects of vagal afferents from intrapulmonary receptors. Recipients of heart-lung transplants (HLTR) offer a unique opportunity to test this hypothesis since they have denervated lungs and may develop obliterative bronchiolitis after organ rejection. We thus compared the ventilation responses to incremental bicycle ergometry of five HLTR with relatively normal pulmonary function (HLTR-N) and four with bronchiolitis obliterans (HLTR-O). We compared the slopes of the linear portion of the tidal volume versus inspired minute ventilation relationship of both groups. The rate of rise of tidal volume (VT) (slope of VT versus VI) was greater in HLTR-N (0.31 +/- 0.004) than in HLTR-O (0.023 +/- 0.007) (p less than 0.05). This corresponded to a slower increase in respiratory rate (RR) (slope of RR versus Vl/cm) in HLTR-N (0.055 +/- 0.005) than in HLTR-O (0.083 +/- 0.019) (p less than 0.01). Furthermore, values for VT, inspiratory time (TI), and duty cycle (TI/Ttot) measured during exercise at the VT break point were all significantly lower in the HLTR-O than in HLTR-N. We also evaluated the ability of HLTR with lung disease to regulate their ultimate level of ventilation during maximal exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

The short-term effects of smoke exposure on the pulmonary function of firefighters.

The short-term effects of smoke inhalation have been little studied. This study evaluated whether firefighters experience a significant change in spirometric values following exposure to smoke from a fire. Sixty firefighters from the city of Pittsburgh completed a questionnaire (Medical Research Council) and underwent spirometric testing following exposure to house fires. The group contained 25 current smokers, 14 ever smokers, and 21 never smokers. Firefighters reporting cough, phlegm, breathlessness, and chest illnesses were more likely to be current or ever smokers than never smokers. Mean spirometric data obtained before exposure, after a minimum of four off-duty days, showed the following: FVC, 4.50 +/- 0.60L (90 percent of predicted); FEV1, 3.65 +/- 0.56L (96 percent of predicted); FEV1/FVC, 81 +/- 8 percent (106 percent of predicted); FEF25-75%, 3.71 +/- 1.13L/s (96 percent of predicted); and PEF, 7.95 +/- 1.70L/s (87 percent of predicted). After exposure, spirometry was performed on 22 firefighters. All spirometric values decreased after exposure; however, a significant decline was only seen in two indices, the FEV1 and FEF25-75%. This decline was small (3 to 11 percent). Two firefighters experienced an exaggerated decline in spirometric values after exposure, compared to the group as a whole. Neither age, smoking history, location of firefighting, intensity of smoke exposure, or use of a self-contained breathing apparatus explained the reasons for the greater decline in these two individuals. Thus, while firefighters do experience a small decrease in pulmonary function after exposure to house fires, there appears to be a small subgroup of firefighters who develop more substantial and potentially clinically important decreases in pulmonary function after smoke exposure.

Adult

Giant-cell interstitial pneumonia and hard-metal pneumoconiosis. A clinicopathologic study of four cases and review of the literature.

We report four cases of giant-cell interstitial pneumonia that occurred in association with exposure to hard metals. All patients presented with chronic interstitial lung disease and had open-lung biopsies that revealed marked interstitial fibrosis, cellular interstitial infiltrates, and prominent intraalveolar macrophages as well as giant cells displaying cellular cannibalism. We also review the literature to determine the sensitivity and specificity of giant-cell interstitial pneumonia for hard-metal pneumoconiosis. Although hard-metal pneumoconiosis may take the form of usual interstitial pneumonia, desquamative interstitial pneumonia, and giant-cell interstitial pneumonia, the finding of giant-cell interstitial pneumonia is almost pathognomonic of hard-metal disease and should provoke an investigation of occupational exposure.

Adult

Ventilation and breathing pattern during progressive hypercapnia and hypoxia after human heart-lung transplantation.

The effects of human pulmonary denervation on the ventilatory responses to progressive hyperoxic hypercapnia and isocapnic hypoxia as well as the effect on resting breathing pattern were evaluated in nine female heart-lung transplant (H-LT) recipients. The results were compared to those obtained from 10 normal women of comparable age and stature. Testing was performed 2 to 37 months after H-LT (median, 7.5 months). Cardiac function was normal in all H-LT recipients. None of the patients had spirometric evidence of airway obstruction, while six had a restrictive pattern with forced vital capacities less than 80% of predicted values. Resting minute ventilation (VE), tidal volume (VT), and ventilatory drive (VT/TI) in the H-LT recipients were not significantly different from those of the normal subjects. Inspiratory time (TI), however, was significantly shorter in the H-LT patients (1.64 +/- 0.2 versus 2.09 +/- 0.13 s, p = 0.035), and resting breathing frequency (F) tended to be greater in the H-LT recipients (16.27 +/- 2.04 versus 12.82 +/- 0.53 breaths/min, p = 0.052). The overall ventilatory response to hypercapnia was reduced after H-LT (0.91 +/- 0.17 versus 1.5 +/- 0.27 L/min/mm Hg CO2, p less than 0.043), as was the F response (0.2 +/- 0.09 versus 0.65 +/- 0.13 breaths/min/mm Hg CO2, p less than 0.01). The VT and VT/TI responses to hypercapnia did not differ between the H-LT recipients and normal subjects. There were no significant differences between the two groups with respect to the responses to progressive hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Breathing during wakefulness and sleep after human heart-lung transplantation.

To study the effects of pulmonary denervation on breathing during sleep, sleep studies were conducted on seven heart-lung transplant recipients (H-LT) and a comparable number of sex-matched normal subjects of similar age. Four of the H-LT patients had a restrictive pattern on spirometry. The time since transplantation ranged from 45 to 1,102 days. There were no significant differences between the groups with respect to total sleep time or distribution of sleep stages. There were no significant differences between the H-LT recipients and normal subjects with respect to baseline awake oxyhemoglobin saturation (SaO2) or the nadirs of SaO2 during REM and non-REM sleep, the absolute number and frequency (number per hour of sleep) of apneas, hypopneas, desaturation events, both over the whole night of study or separately during non-REM and REM sleep. Across wakefulness and all sleep stages, the H-LT patients tended to have shorter total respiratory cycle times (Ttot) (p = 0.052) and more rapid breathing frequency (F) than the normal subjects. This was associated with significantly shorter inspiratory times (Tl) (p less than 0.001) and smaller duty cycles (Tl/Ttot) (p less than 0.005) in the H-LT recipients. During non-REM and REM sleep, F tended to be higher in the H-LT recipients with pulmonary restriction than in the nonrestricted patients. There were no significant differences between the H-LT recipients and the normal subjects with regard to the periodicity of breathing, either in terms of timing parameters or breath amplitude.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Evidence of an altered pattern of breathing during exercise in recipients of heart-lung transplants.

Recipients of heart-lung transplants represent an unusual opportunity to study the regulation of ventilation, because the neural pathways between the lungs and the central nervous system are disrupted in these patients. We compared the ventilation response in seven recipients of heart-lung transplants who had normal pulmonary function and seven recipients of heart transplants, all of whom performed incremental bicycle ergometry. The level of ventilation in recipients of heart-lung transplants was similar to that in heart-transplant recipients for equivalent levels of carbon dioxide production. Arterial pH and partial pressure of carbon dioxide at maximal exercise were normal and not significantly different in the two groups, also suggesting that levels of ventilation were appropriate in both groups. However, the rate of the rise in respiratory rate for increasing levels of ventilation was significantly lower in recipients of heart-lung transplants than in heart-transplant recipients, and the initial increase in tidal volume was more rapid in the former group than in the latter. Thus, recipients of heart-lung transplants have an appropriate level of ventilation during exercise as the result of a disproportionate increase in tidal volume at a reduced respiratory rate. We speculate that intrapulmonary receptors are important in regulating the pattern, but not the absolute level, of ventilation during exercise.

Acid-Base Equilibrium

Asbestosis among electricians.

In a cross-sectional study of a small group of non-shipyard electricians, the prevalence of asbestosis, defined as irregular opacities of at least 1/0 profusion, was found to be 15% overall and 25% after 20 years of service. Irregular opacities occurred more frequently among smokers. Cost estimates for asbestos-related disease should include construction electricians in the populations at risk.

Adult

Comparison of arm and leg ergometry in patients with moderate chronic obstructive lung disease.

Exercise testing is traditionally performed with leg exercise on either a treadmill or a bicycle ergometer. Many of these tests are terminated before dyspnoea occurs because of leg fatigue, arthritic pain, or claudication. A study was carried out to determine whether arm ergometry testing might serve as an alternative method to leg testing in eight patients with chronic obstructive lung disease. The patients had mild to moderate dyspnoea on exertion and required bronchodilator treatment. They had smoked an average of 62 pack years and had a mean FEV1 of 1.88 l. Arm and leg ergometry yielded similar levels of maximum ventilation (arm 47.2, leg 48.6 l/min), maximum heart rates (126 v 124 beats/min), maximum tidal volume (1.5 v 1.6 l), and respiratory rate (30 v 29 breaths/min); but maximum oxygen consumption (1120 v 966 ml/min), maximum power output (62 v 26 w), and oxygen pulse (9.1 v 7.8 ml/beat) were all higher with leg than with arm ergometry. In addition, ventilation and heart rate at a given level of oxygen consumption were higher for arm than for leg work during both submaximal and maximal exercise. It is concluded that arm ergometry offers an alternative testing method to leg testing in patients with moderate chronic obstructive lung disease.

Arm

DLco in COPD.

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Humans

Pulmonary hypertension in the CREST syndrome variant of systemic sclerosis.

Pulmonary hypertension (PHT) occurred in 59 (9%) of 673 systemic sclerosis patients seen between 1963 and 1983. In 30 patients, all with the CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), the pulmonary hypertension was isolated, i.e., independent of other pulmonary or cardiac conditions. In 20 patients, isolated PHT was demonstrated by cardiac catheterization. All had normal or only mildly decreased lung volumes, and mild or no pulmonary interstitial fibrosis on chest roentgenogram. In comparison with 287 CREST syndrome patients without PHT, these 20 patients had markedly reduced diffusing capacity for carbon monoxide (DLCO) (mean 39% of predicted normal). In 6 patients, the low DLCO antedated clinical evidence of PHT by 1-6 years. At autopsy there was marked intimal fibrosis with hyalinization and smooth muscle hypertrophy in the small- and medium-sized arteries, without significant parenchymal fibrosis or inflammation. Patients with isolated PHT did not respond favorably to vasodilators and had a very poor prognosis, with a 2-year cumulative survival rate of 40%. A DLCO less than 45% of predicted in the absence of pulmonary interstitial fibrosis may be an important predictor of the subsequent development of isolated PHT.

Calcinosis

Elevated pleural fluid glucose: a risk for tension hydrothorax.

We have presented a case of tension hydrothorax that developed after hyperosmolar hyperalimentation fluids were infused into the pleural space through a misplaced jugular venous line. The hyperosmolar state of the pleural fluid appears to have played a prominent role in the development of the tension hydrothorax. We believe there is a risk of tension hydrothorax in any clinical situation in which the pleural fluid glucose concentration is significantly higher than the serum concentration.

Adult

Long-term prognosis of survivors of Pneumocystis carinii pneumonia. Structural and functional correlates.

Limited data exist detailing the long-term sequelae of Pneumocystis pneumonia. Open lung biopsies were obtained in seven renal transplant recipients within 48 hours of the onset of respiratory failure. Biopsy specimens and simultaneous chest roentgenograms were graded without clinical information according to the severity of alveolar damage and pulmonary infiltrates, respectively. Evaluation of pulmonary function and exercise physiology were performed 15 to 21 months after their illness. Pulmonary function indices were normal except FRC (2.65 +/- 0.56 L or 77 +/- 16 percent of predicted) and Dsb (20.0 +/- 7.2 ml/min/mm Hg or 79 +/- 19 percent of predicted). Two patients developed arterial desaturation with exercise. Alveolar damage scores correlated with later exercise arterial desaturation (r = 0.88, p less than 0.05). Simultaneous roentgenographic scores correlated with later abnormalities of Dsb (r = 0.81, p less than 0.05). Mild residual abnormalities of pulmonary function were found in five of seven adult survivors of Pneumocystis pneumonia. These abnormalities correlated with pathologic and radiographic features of the acute illness.

Adult

Role of inflammation in the lung disease of systemic sclerosis: comparison with idiopathic pulmonary fibrosis.

Alveolar inflammation is thought to underlie the development of pulmonary fibrosis in several forms of diffuse lung disease including the connective tissue diseases. The relationship between inflammation and the clinical manifestations of systemic sclerosis (scleroderma), such as skin and lung involvement, is less clear. We therefore evaluated 14 never-smoking patients with systemic sclerosis with pulmonary involvement by bronchoalveolar lavage (BAL) and compared the results with those found in eight nonsmoking patients with idiopathic pulmonary fibrosis (IPF) and eight normal subjects. The patients with scleroderma also underwent gallium citrate Ga 67 scanning. We found that patients with scleroderma and pulmonary involvement have alveolitis that appears to wane with time. In addition, patients with systemic sclerosis have a cellular profile in lavage fluid that appears to differ from that of patients with IPF. Finally, we found a significant correlation between BAL cellular recovery and the single-breath carbon monoxide diffusing capacity in patients with systemic sclerosis but not in patients with IPF. We conclude that inflammation may play an important role in the pathogenesis of the pulmonary disease of scleroderma and that different mechanisms may lead to fibrosis in IPF and scleroderma.

Adult

Pulmonary involvement in systemic sclerosis (scleroderma).

One hundred sixty-five nonsmoking systemic sclerosis patients were evaluated by pulmonary function testing. Restrictive lung disease and an isolated reduction of the diffusing capacity of carbon monoxide were the most frequent abnormalities. Patients with the CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias) had a similar frequency and severity of pulmonary involvement compared with the patients who had diffuse scleroderma. CREST syndrome patients with restrictive lung disease rarely had the anticentromere antibody and had more skin and joint involvement of their hands, compared with other CREST syndrome patients. Dyspnea and rales were most commonly found in patients with restrictive lung disease. Fibrosis, shown on chest radiograph, and pulmonary function abnormalities correlated poorly with each other. Dyspnea was associated with restrictive disease, and rales were more commonly found in patients with fibrosis. Patients with a restrictive abnormality had the worst prognosis, with a 5-year survival rate of 58%, although death from pulmonary causes was uncommon. Comparison of these nonsmoking patients with 137 scleroderma patients who smoked, seen during the same time period, revealed more frequent and severe obstructive changes in smokers. Smoking patients with restrictive lung disease had more severe disease than nonsmoking patients. The single breath diffusing capacity for carbon monoxide was significantly decreased in the patients who smoked compared with the nonsmokers. These data confirm that pulmonary function abnormalities are common in patients with systemic sclerosis including CREST syndrome. Smoking appears to have an additive deleterious effect on pulmonary function and should be strongly discouraged.

Calcinosis