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Biomedical subjects

A W Musk

Publications and source records attributed to A W Musk.

169 records · Page 10Linked to original sources

Pulmonary elastic recoil and diffusing capacity in subjects with intermediate concentrations of alpha-1 antitrypsin.

Serum from 224 males investigated in a prospective study of respiratory disorders in a recently established asbestos industry has been estimated for alpha-1 antitrypsin (AAT) concentration by single radial immunodiffusion. Mean AAT concentration was 213-4 mg/dl). No subject with a markedly reduced level was found. A comprehensive range of lung function tests sensitive to changes anticipated in emphysema at a preclinical stage, included measurements of diffusing capacity and pulmonary elastic recoil. The 26 subjects with AAT concentration less than 150 mg/dl, were regarded as likely to comprise a majority of genotypes MZ and SS, and the 19 subjects with AAT concentration greater than 300 mg/dl were considered to comprise mainly MM. No difference in pulmonary function could be demonstrated between these two groups. Evidence of diminished pulmonary elastic recoil was found in nine smoking subjects whose AAT concentrations were normal and also in one young non-smoking subject with moderately severe asthma, whose AAT concentration was 140 mg/dl. It is concluded that in a male working population, evidence of diminished pulmonary elastic recoil is not a function of AAT concentration.

Adult↗

Loss of pulmonary elastic recoil in workers formerly exposed to proteolytic enzyme (alcalase) in the detergent industry.

Sixty-seven workers in the detergent industry whose exposure to proteolytic enzyme ceased in 1969 have been examined clinically and functionally. By comparison with 42 lightly and moderately exposed subjects, 13 heavily exposed subjects showed significant loss of pulmonary elastic recoil as evidenced by increased lung volumes and increased pulmonary compliance, but there were no differences in airways resistance or other parameters of lung function. No difference was found between the two groups in relation to symptoms on exposure, current exercise tolerance, skin reactivity to the proteolytic enzyme alcalase, trypsin inhibitor capacity, and other features. An increased clinical grade of breathlessness was associated with evidence of airways obstruction, but not of altered elastic recoil. Comparison of the data on lung mechanics with results obtained in 1970 suggests that partial recovery of pulmonary elastic recoil may have occurred in some cases. It is also suggested that diminished elastic recoil, in the absence of impairment of transfer factor at rest, may reflect altered physical properties of the lung fibre network without loss of effective surface area available for gas exchange.

Adult↗

Insoluble and soluble allergens from wheat grain and wheat dust: detection of IgE binding in inhalant and ingestion allergy.

The need for better in vitro testing for wheat allergy particularly involved correlating clinical evidence of Type I hypersensitivity with laboratory detection of specific IgE antibodies in serum. We report here an improvement in this relationship by the use of a modified method for RAST (Radioallergosorbent test), involving nitrocellulose as the solid phase and alkali (or ethanol) for extraction of allergens and treatment of discs. Serum IgE reactions with the full range of wheat grain and dust proteins were studied using this method and the results were related to wheat allergies due to flour ingestion and the inhalation of flour, pollen or grain dust.

Adult↗

Asbestos-induced release of a human alveolar macrophage-derived neutrophil chemotactic factor.

Neutrophils accumulate in the alveoli of asbestos-exposed individuals. In determining whether asbestos fibers induce the release of neutrophil chemotactic factor (NCF) from human alveolar macrophages, alveolar macrophages (10(6) cell/mL) obtained by bronchoalveolar lavage from six non-asbestos-exposed control subjects were exposed to crocidolite (0.1 and 1 mg/mL), chrysotile (1 mg/mL), or medium alone for 4 h, and NCF activity was measured in the supernatants in a 48-well microchemotaxis chamber with polycarbonate membrane filters (pore size, 3 microns) and purified human neutrophils. Alveolar macrophages in medium alone released negligible amounts of NCF (4 +/- 1 neutrophils per high-power field [N/HPF]). When macrophages were exposed to crocidolite (0.1 and 1 mg/mL), significant NCF release occurred (43 +/- 9 and 105 +/- 32 N/HPF, respectively; p less than 0.01 for each amount compare to alveolar macrophages cultured in medium alone). Chrysotile (1 mg/mL) induced similar NCF release (96 +/- 14 N/HPF; p less than 0.01 compared to unstimulated alveolar macrophages). Partial characterization of the NCF by Sephadex G-25 fine gel filtration demonstrated a molecular size of less than 1,000 daltons. These results show that human alveolar macrophages release NCF after exposure to asbestos. Release of NCF by alveolar macrophages in asbestos-exposed individuals may play a central role in the pathogenesis of asbestosis.

Asbestos↗

Predictions of future cases of asbestos-related disease among former miners and millers of crocidolite in Western Australia.

In a cohort of 6502 male and 410 female former workers from the crocidolite (blue asbestos) mining and milling works at Wittenoom, Western Australia, there were 94 cases of malignant mesothelioma (12 cases of peritoneal mesothelioma), 141 cases of lung cancer and 356 successful compensation claims for asbestosis to the end of 1986. After adjusting for measured covariate effects by means of proportional hazards regression analysis, smooth curves were fitted to the resulting "underlying" incidence rates for malignant mesothelioma, lung cancer and asbestosis, separately, and for mortality of any cause. By the use of these curves and individual risk estimates, predictions have been made of the future incidence of these diseases to the year 2020. With the assumption that all subjects who were not known to be dead or departed overseas still were alive at December 31, 1986, and excluding persons of more than 85 years of age, the number of new cases of mesothelioma is expected to rise to a peak of around 25 cases per year in 2010, with an expected total number of 692 cases of mesothelioma (95% confidence interval [CI], 394-990 cases) between 1987 and 2020. A total of 2898 deaths (95% CI, 2284-3511 deaths) of any cause is expected in the same period. New cases of lung cancer and asbestosis are expected to continue at roughly the current rates of eight and 17 cases per year, respectively, before declining after the year 2000, leading to totals of 183 cases (95% CI, 34-335 cases) and 482 cases (95% CI, 236-728 cases), respectively, being expected by the year 2020. Predictions that were based on the censoring of subjects at the date that they last were known to be alive resulted in slightly higher, but probably less accurate, estimates.

Adult↗