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Biomedical subjects

B Walker

Publications and source records attributed to B Walker.

At least 271 records · Page 15Linked to original sources
PubMed1982

The relevance of occupational medicine.

As the burden-of-illness profile has shifted significantly in recent years, more attention is focused on occupational factors in disease, not only because of past developments and future aspects but mainly because of the numerous practical and theoretical implications and the involvement of many medical and social features.

Female↗
PubMed1981

Occupational exposure to aromatic amines: benzidine and benzidine-based dyes.

Large-scale production of aromatic amines that serve as intermediates in the aniline dye industry began in this country during World War I. In the United States, the first known occupationally induced aromatic amine cancers of the bladder were observed at a dye factory in 1931. Additional cases of benzidine-related bladder cancer was subsequently reported at this same facility and at numerous other dye works in this country and throughout the world. In 1974, the Occupational Safety and Health Administration promulgated a standard to control the production and use of benzidine in the workplace. Although hazards associated with benzidine exposure have been reduced, a carcinogenic risk due to benzidine-based dye exposure is now apparent. In addition, several dyes produced from o-tolidine and o-dianisidine, carcinogenic compounds structurally related to benzidine, have demonstrated metabolism to their respective parent compounds. The history of occupational bladder cancer in the United States is traced and measures taken by the Occupational Safety and Health Administration to reduce exposure to this hazard are described.

Animals↗
PubMed1980

Metabolism and mutagenicity of N-nitroso-2-methoxy-2,6-dimethylmorpholine in hamsters.

N-Nitroso-2-methoxy-2,6-dimethylmorpholine (MeNDMM) was derived from the cyclic form of N-nitroso-(2-hydroxypropyl)(2-oxopropyl)amine (HPOP), a proposed proximate pancreatic carcinogen for the hamster. MeNDMM was metabolized in vivo by noninbred Syrian golden hamsters to HPOP, which was excreted in urine. In vitro metabolism produced HPOP by cytochrome P450-mediated oxidative demethylation. MeNDMM and HPOP were similarly mutagenic in the Ames Salmonella typhimurium assay, in which hamster liver preparations were used for metabolic activation. MeNDMM, due to its metabolism to HPOP, is probably also a pancreatic carcinogen in the hamster.

Animals↗
PubMed1980

Mutagenic activities of oxidized derivatives of N-nitrosodipropylamine in the liver cell-mediated and Salmonella typhimurium assays.

The mutagenic activity of N-nitrosobis(2-oxopropyl)amine (BOP), N-nitroso(2-hydroxypropyl) (2-oxopropyl)amine (HPOP), N-nitrosobis(2-hydroxypropyl)amine (BHP), N-nitrosomethyl-2-oxopropylamine (MOP), and N-nitrosomethyl-2-hydroxypropylamine (MHP) was examined in the Ames liquid incubation assay, using hamster liver homogenate for metabolic activation, and in the hamster liver cell-mediated V79 cell assay. At similar concentrations, the cell-mediated assay showed a greater mutagenic response over background to these nitrosamines than did the bacterial assay. Also, the relative mutagenic potency in the cell-mediated assay (MOP > MHP > BOP > HPOP > BHP) correlated better than that in the Ames assay (HPOP > MHP greater than or equal to BOP = BHP = MOP) with overall carcinogenic potency in the hamster (MOP > BOP > HPOP > BHP). The liver cell-mediated assay may be an important adjunct to the battery of short-term tests for carcinogenicity prescreening.

Animals↗
PubMed1978

Lack of effect of bromocriptine on ACTH levels in patients with bilateral adrenalectomy for pituitary-dependent Cushing's syndrome.

Bromocriptine lowers plasma ACTH levels in patients with pituitary-dependent Cushing's syndrome. It seemed possible that the drug would also be effective in patients who had been adrenalectomised for the disease. The effect of 5.0 mg of bromocriptine on plasma ACTH and prolactin levels in 13 patients, bilaterally adrenalectomised for pituitary-dependent Cushing's syndrome, was therefore studied. In only one patient was a fall in plasma ACTH observed. This may be of doubtful significance since marked spontaneous fluctuation in plasma ACTH levels were found in the five patients tested. Bromocriptine lowered the plasma prolactin in all of the patients, including two with hyperprolactinaemia.

Adolescent↗