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Biomedical subjects

W O Cookson

Publications and source records attributed to W O Cookson.

97 records · Page 6Linked to original sources
PubMed1985

Angiotensin converting enzyme and endotoxin induced lung damage in the mouse.

Acute pulmonary oedema can be induced by intraperitoneal injection of Escherichia coli endotoxin in the mouse. A fall in serum angiotensin converting enzyme activity is found in mice given endotoxin and in patients with septic adult respiratory distress syndrome, and has been proposed as an indicator of lung microvascular injury. Protein concentration and angiotensin converting enzyme activity in serum, lung, and bronchoalveolar lavage fluid were determined in male mice up to eight hours after injection of endotoxin. By six hours the serum protein concentration had increased and the bronchoalveolar lavage fluid protein concentration had fallen, suggesting fluid shift into the lung. Angiotensin converting enzyme activity fell in serum and lung but increased in bronchoalveolar lavage fluid. As these changes in enzyme activity were not paralleled by changes in protein concentration they are unlikely to be a result of fluid shift or protein leak, and may indicate an active role of the enzyme in the response to sepsis.

Animals↗
PubMed1985

Benign and malignant pleural effusions in former Wittenoom crocidolite millers and miners.

Serial plain chest radiographs taken between 1943 and 1982 for 280 claimants for compensation for asbestosis and 32 claimants for malignant pleural mesothelioma from the Wittenoom asbestos industry were reviewed by two observers to identify diffuse pleural thickening and pleural effusion. A pleural effusion which appeared and resolved within two years without radiographic or clinical evidence of underlying malignancy, infection or cardiac failure was seen in 15 cases by reader 1 and 24 cases by reader 2. Eighteen cases of effusion, determined from clinical records to be caused by malignant pleural mesothelioma, were seen by reader 1 and 20 by reader 2. The latent periods between commencing work and the first radiograph showing effusion were much shorter for subjects with benign asbestos pleural effusion than for subjects with effusion due to malignant pleural mesothelioma, although there was considerable overlap in the range. The longest latent period for benign asbestos pleural effusion was 22 years and the shortest period for effusion due to malignant pleural mesothelioma was 12 years. The latent period for benign asbestos pleural effusion was inversely related to total cumulative exposure, whereas that for effusion due to malignant pleural mesothelioma was significantly shorter for subjects who had worked in the mill than for those who had worked in the mine. A long latent period and a history of working in the mill were significant discriminators for a malignant as opposed to a benign basis for an effusion. The appearance of a benign asbestos pleural effusion appeared to be a risk factor for the severity of subsequent diffuse pleural thickening.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Asbestosis and cryptogenic fibrosing alveolitis: a radiological and functional comparison.

This study compares the relationship between lung function and radiological abnormality in 46 subjects with asbestosis and 38 subjects with cryptogenic fibrosing alveolitis. Radiographs were graded separately by two observers according to the 1980 International Labour Organisation criteria for classification of the pneumoconioses. The correlation between the transfer factor of the lungs and the radiographic profusion of small parenchymal opacities was found to be greater in subjects with asbestosis than in subjects with cryptogenic fibrosing alveolitis. At any level of radiological profusion transfer factor was higher in cases with asbestosis than in cases with fibrosing alveolitis. As pleural thickening is seen commonly in asbestosis and may influence lung volumes and the ratio of transfer factor to effective alveolar volume, the results of these measurements were compared only in the cases showing absent or minimal pleural thickening. Both of these variables were higher in the subjects with asbestosis. The results indicate that despite pathological, functional and radiographic similarities, lung function for a given degree of radiographic parenchymal abnormality is better in subjects with asbestosis than in subjects with cryptogenic fibrosing alveolitis, and that changes in the plain chest x-ray appearances in asbestosis correlate more closely with the results of lung function tests.

Asbestosis↗
PubMed1984

Procainamide infusion and acute atrial fibrillation.

We report the use of intravenous procainamide infusion in the treatment of fifteen patients with acute atrial fibrillation. Procainamide was infused at 50 mg/min to a maximum of 20 mg/kg, with blood pressure and electrocardiographic monitoring. Ten patients responded, with a mean dose of 8.7 (standard deviation 4.3) mg/kg, four of these reverting to sinus rhythm after a low dose of less than 5.0 mg/kg. Hypotension was a common concomitant and was seen in four cases, but required termination of the infusion only in a patient with cardiomyopathy. An increase in ventricular rate or conversion to atrial flutter was not seen. Intravenous infusion of procainamide is a safe and moderately effective method of cardioversion in acute atrial fibrillation.

Acute Disease↗
PubMed1983

Pleural thickening and gas transfer in asbestosis.

Anomalies in the ratio of transfer factor to effective alveolar volume as an indicator of pulmonary gas exchange in cases of asbestosis may be related to diffuse pleural thickening. To examine the effect of pleural disease on gas transfer the plain chest radiographs of patients with asbestosis were assessed by two observers for profusion of parenchymal opacities and extent of pleural disease and the results were related to lung function. In 30 cases of category 1 profusion of parenchymal abnormality (according to the ILO international classification of radiographs for pneumoconiosis) transfer factor was independent of the degree of pleural thickening. The ratio of transfer factor to effective alveolar volume correlated directly with the degree of pleural thickening as alveolar volume fell with increasing severity of pleural disease. The results indicate that correcting transfer factor for alveolar volume does not provide an accurate reflection of severity of diffuse parenchymal fibrosis in patients with asbestosis and even minor pleural disease.

Aged↗
PubMedDate not supplied

Changes in blood gas levels after nebuhaler and nebulizer administration of terbutaline in severe chronic airway obstruction.

It has been suggested that patients with severe chronic airway obstruction might suffer dangerous hypoxia after administration of a beta-agonist through an air driven nebulizer. Twenty patients with severe chronic airway obstruction (12 male, mean age 71.1 (SEM 1.5) yr) were monitored with a Biox oximeter and Hewlett-Packard capnometer before and after 4 mg terbutaline was delivered through an air driven nebulizer or Nebuhaler. The eight patients with chronic hypoxia (mean PaO2 6.76 kPa, PaCO2 7.47 kPa. FEV1 0.53 l) experienced a 4.7% increase in oxygen saturation (SaO2) and 2.9% fall in transcutaneous carbon dioxide tension (PtcCO2) (p less than 0.05) during all treatments, followed by a return to initial levels. These changes were attributable to increased ventilation whilst breathing through a mouthpiece. A similar trend was seen in the SaO2 of the twelve normoxic patients (mean PaO2 9.32 kPa, PaCO2 5.34 kPa, FEV1 0.8 l), but there was a sustained fall in PtcCO2 of 3.7% (p less than 0.001) after administration of terbutaline. Inhaled terbutaline in the dosage given did not cause hypoxia in patients with severe chronic airflow obstruction, but nebulizer and Nebuhaler use was associated with a rise in SaO2 related to increased ventilation whilst breathing through a mouthpiece.

Aged↗