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Biomedical subjects

L MacLean

Publications and source records attributed to L MacLean.

26 records · Page 2Linked to original sources
PubMed1979

Respiratory abnormalities among grain elevator workers.

Twenty-two grain workers with respiratory symptoms and lung function abnormalities were studied. Our findings suggest that grain dust asthma probably has an allergic basis, even though skin tests and precipitin studies were negative using extracts of grain dust. Hypersensitivity pneumonitis and grain dust fever were not found in any of the subjects. We found that grain dust can cause airflow obstruction in two ways: first by inducing asthma, probably through immunologic mechanisms, and second, by causing industrial chronic bronchitis.

Adult↗
PubMed1978

A respiratory survey of cedar mill workers. II. Influence of work-related and host factors on the prevalence of symptoms and pulmonary function abnormalities.

The influence of certain work-related and host factors on the prevalence of respiratory symptoms and pulmonary function abnormalities in 405 red cedar workers and 187 control workers was examined. In cedar workers, but not in controls, the prevalence of chest symptoms increased with duration of exposure. The decline in pulmonary function with increasing duration of exposure was also more marked in cedar workers, but in both groups smoking was a more important determinant. Substantial proportions of cedar workers and, to a lesser extent, controls noted improvement of cough and wheeze, and particularly of conjunctivitis and rhinitis, when away from work. No deterioration, however, was found in pulmonary function during the work week in either exposure group. Atopic status was unrelated to the prevalence of chest symptoms or pulmonary function abnormalities; it was more common in workers with conjunctivitis and rhinitis, particularly in the cedar group. Similarly, Pi phenotype did not appear to influence the occurrence of either symptoms or lung function abnormalities.

Adult↗
PubMed1975

Beclomethasone dipropionate in asthma.

Beclomethasone dipropionate aerosol therapy can replace or diminish systemic corticosteroid therapy in the majority of asthmatics. In a clinical trial of 41 patients with perennial asthma, the 10 who had not required long-term corticosteroid therapy improved symptomatically and in pulmonary function. Of the 31 who had required prolonged systemic corticosteroid therapy 12 were able to discontinue oral prednisone therapy, 15 were able to decrease the maintenance dose of prednisone and only 4 were unable to decrease the dose; all maintained satisfactory lung function and some showed improvement. Discontinuation of systemic corticosteroid therapy was accomplished more readily in patients whose daily maintenance dose was less than 15 mg and who had been taking the drug for less than 3 years. Side effects consisted of a "dry throat" in seven patients, two of whom had throat infections with Candida albicans. Recurrence of rhinitis after discontinuation or reduction of systemic corticosteroid therapy was noted in 11 patients.

Administration, Oral↗
PubMedDate not supplied

Longitudinal study of workers in an aluminum smelter.

We conducted a 6-y follow-up study that included workers in an aluminum smelter in British Columbia. Of the original cohort, 951 workers left the industry and 985 workers participated in both studies. Comparison of those who left and those who remained showed that those who left were (1) older, (2) had a slightly higher prevalence of respiratory symptoms, and (3) had lower lung function; this was especially true for workers who were 50 + y of age at the time the initial study was conducted. Analyses were conducted only on 586 male workers who did not change their job location or smoking habits between the initial and the follow-up study. Potroom workers in the "high-exposure" group had a significant reduction in the prevalence of cough, but experienced an increase in the prevalence of wheeze. There was no significant difference in the annual decline in forced expiratory volume in 1 sec and forced vital capacity between the potroom workers and controls. In general, older workers and smokers had a greater decline in lung function compared to younger workers and nonsmokers. Leukocyte count done during the initial study was found to be an independent predictor of longitudinal decline in lung function. The lack of exposure effect on longitudinal decline in lung function could be due to "healthy worker" effect and improvement in the working condition of the smelter.

Adult↗