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Biomedical subjects

M Colvin

Publications and source records attributed to M Colvin.

79 records · Page 5Linked to original sources
PubMedDate not supplied

Health and safety in the Lesotho Highlands Dam and Tunnel Construction Program.

To review health and safety practices and to determine the occupational health status of dam workers in the Lesotho Highlands, a health and safety audit and a health study of 258 workers was undertaken. The workers were administered respiratory health questionnaires and underwent chest x-rays and lung function and audiometric testing. The audit revealed a low level of awareness of health and safety issues at all levels of management and a lack of occupational medicine and industrial hygiene systems. Noise-induced hearing loss occurred among 92% of the study subjects. Among the 158 dam construction workers, 5.4% had pneumoconiosis. With poorly developed laws and regulatory bodies, unsophisticated trade unions, and little client supervision, health and safety had a low priority in this construction project. Recommendations are made that are pertinent to health and safety management where international companies are operating in developing countries.

Cross-Sectional Studies↗
PubMedDate not supplied

Intensive cyclophosphamide (NSC-26271) therapy for solid tumors.

Cyclophospamide was given in two dose schedules to 25 patients with a variety of nonlymphoid solid tumors. Eleven patients were given 18 courses of cyclophosphamide at a total dose of 60 mg/kg. Sixteen patients received 26 courses at a total dose of 100 mg/kg. Two patients were treated with both regimens. Partial responses were achieved in two patients treated with 60-mg/kg dose of cyclophosphamide. One of these patients had osteogenic sarcoma and the other had renal carcinoma. The higher dose also produced two partial responses, one in a patient with anaplastic carcinom a of the lung and the other in a patient with anaplastic carcinoma of the lung and the other in a patient with embryonal testicular carcinoma. Mean leukocyte counts fell to a nadir of 1400 cells/mm after 60 mg/kg while they dropped to below 1000 cells/mm for 5 days after 100 mg/kg of cyclophosphamide. Mean platelet counts remained above 150,000 platelets/mm after both cyclophosphamide schedules. In fective complications were documented aftter three of the 18 courses at 60 mg/kg and after ten of the 26 courses at 100 mg5kg. In the latter group, there were three episodes of bacteremia, including one death from pseudomonas sepsis. Nonhematologic toxicity noted with the 100-mg/kg dose of cyclophosphamide included rare instances of electrocardiogram changes and serum enzyme alterations compatible with myocardial toxicity. The intensive cyclophosphamide therapy did not appear to result in an increased antitumor response in malignancies usually considered to be refractory to alkylating agents.

Adolescent↗
PubMedDate not supplied

Glutathione conjugation with phosphoramide mustard and cyclophosphamide. A mechanistic study using tandem mass spectrometry.

The conjugations of cyclophosphamide and of phosphoramide mustard with glutathione are shown to be catalyzed by hepatic cytosolic glutathione-S-transferases. Cyclophosphamide conjugation is also catalyzed by microsomal glutathione-S-transferases, both in intact microsomes and after solubilization and immobilization. Deuterium isotope labels are used to test whether chloride is directly displaced by glutathione in the enzyme-catalyzed conjugations, or whether conjugation takes place via symmetrical cyclic aziridinium ions. Tandem mass spectrometry with high energy collisional activation is shown to provide reliable analysis of the isotope-labeling patterns in the conjugated products. This experiment leads to the conclusion that the aziridinium ion is opened in the conjugation of phosphoramide mustard in both the enzyme-catalyzed and the chemical reactions. Cyclophosphamide, on the other hand, is shown to be conjugated through direct displacement of chloride.

Animals↗