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Biomedical subjects

J Darbyshire

Publications and source records attributed to J Darbyshire.

29 records · Page 2Linked to original sources

Cadmium fume inhalation and emphysema.

Lung function and chest radiographs of 101 men who had worked for 1 or more years manufacturing copper-cadmium alloy were compared with those of a referent group matched for age, sex, and employment status. Cigarette consumption was similar in the two groups. The cadmium workers had an excess of abnormalities of lung function and of radiographic changes consistent with emphysema. Classification of the cadmium workers by exposure categories based on either estimated cumulative cadmium exposure or liver cadmium measured by neutron activation analysis showed that abnormalities of lung function were greatest in those with the highest cumulative cadmium exposure or liver cadmium. The difference in the transfer coefficient (KCO) between cadmium workers and referents increased linearly with increasing cumulative exposure without evidence for a threshold. The estimated mean decrement in KCO for a cadmium worker employed 5 or more years with a cumulative exposure of 2000 yr.microgram.m-3 (exposure to the current UK control limit of 50 micrograms.m-3 for a working lifetime of 40 yr) lies between 0.05 and 0.3 mmol.min-1.kPa-1.l-1 (95% confidence interval). This decrement is consistent with the functional and radiological changes of emphysema observed in this group of workers.

Aged↗

A controlled trial of oral hyposensitization in pollen asthma and rhinitis in children.

This study describes the effect of an orally administered grass-pollen vaccine, taken pre-seasonally, on the clinical symptoms of fifty-four children with hay fever, asthma or both, during the 1982 grass-pollen season. Oral mixed grass-pollen vaccine and a matched placebo were randomly allocated to form two matched groups. Although small differences were observed in favour of the active group for both hay fever and asthma, no significant advantage was demonstrated over placebo in terms of symptom scores or additional medication required.

Administration, Oral↗

Examination of operation specimens from patients with spinal tuberculosis for tubercle bacilli.

Operation specimens from 52 Hong Kong patients considered to have tuberculosis of the spine were sent at -78 degrees C to London where they were cultured on two Löwenstein-Jensen medium slopes, a slope of 7H11 medium made selective with antibiotics and in two bottles of selective liquid Kirchner medium. Cultures of M tuberculosis, usually with only scanty colonies, were obtained from 37 of the patients. Pus and caseous matter yielded more positive cultures and more numerous colonies than other specimens, but eight of the 37 patients yielded positive cultures only from tissues lining abscess walls or from bone or intervertebral disc specimens. Cultures in Kirchner medium were never contaminated and twice as many were positive as cultures on the slopes; nine patients had cultures positive only on Kirchner medium. It is recommended that (i) a variety of operation specimens, always including pus or caseous material in volumes of at least 1 ml, should be sent for bacteriology; (ii) specimens should be cultured in selective Kirchner medium, with or without Löwenstein-Jensen slopes; (iii) cultures should be incubated for a minimum of 8-9 wk.

Culture Media↗

Bromocriptine in severe adult asthma--a negative report.

A pilot study had suggested that bromocriptine (a dopamine agonist) might be of benefit in severe asthma, particularly in patients with marked diurnal variation in peak flow. Two studies are reported: (1) a longterm double-blind, controlled trial comparing bromocriptine (B) with placebo (P) in patients with severe asthma and, (2) a withdrawal study in patients who had received known bromocriptine, with apparent benefit, for at least one year. Of 27 patients (16B, 11P) admitted to the double-blind trial only eight (4B, 4P) completed 52 weeks on the trial drug as nine (6B, 3P) had been withdrawn for side-effects, eight (4B, 4P) for failure and two (2B) for both reasons. The results, based on changes in steroid dosage and other medication, daily symptom scores and PEF values, suggest that bromocriptine has little effect in asthma. In addition side-effects were frequent and troublesome. In the withdrawal study, ten patients who had been taking bromocriptine for a year or more were switched to an indistinguishable placebo if their asthma was considered to be stable. The results, of this second study, support the conclusion of the double-blind study, that bromocriptine has little beneficial effect in asthma.

Adult↗

The rapid purification of 3-hydroxybutyrate dehydrogenase and malate dehydrogenase on triazine dye affinity matrices.

3-Hydroxybutyrate dehydrogenase (EC 1.1.1.30) and malate dehydrogenase (EC 1.1.1.37) were purified to homogeneity on a large scale involving only two sequential affinity-chromatography steps on two triazine dye-Sepharose matrices. Recoveries of both enzymes were in excess of 60%. Malate dehydrogenase could also be purified by a combination of triazine dye affinity chromatography and gel filtration on Ultrogel AcA-44, but this offered no significant advantage over the purely affinity procedure.

Chromatography, Affinity↗