Search PubMed⌕ Search

Biomedical subjects

R N Butler

Publications and source records attributed to R N Butler.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Metabolic phenotypes and colorectal neoplasia.

It now appears likely that the development of colonic adenomas and carcinomas involves a series of steps in which environmental or endogenous carcinogens induce or promote neoplasia through the accumulation of multiple, specific genetic mutations. Genetic predisposition to this process may take the form of inherited defects in control of cellular proliferation as in familial polyposis coli, or genetically determined polymorphism which affects enzyme activities relevant to the production or detoxication of carcinogens. Genetic effects may also influence levels of hormones and/or their target cell receptors which regulate the metabolic and proliferative activity of colonocytes. This review highlights data suggesting a role for polymorphism associated with xenobiotic acetylation, hydroxylation, and conjugation with glutathione in the metabolism of potential carcinogens, as well as for dehydroepiandrosterone in the metabolic control of cell proliferation. The study of genetically determined polymorphism in colorectal cancer may provide new insights into the epidemiology of cancer and result in new methods for the detection of higher risk groups.

Acetylation↗
PubMedDate not supplied

Glutathione concentrations and glutathione S-transferase activity in human colonic neoplasms.

Tissue concentrations of glutathione (GSH) and the activity of glutathione S-transferases (GST) are relevant to the inactivation of a variety of xenobiotics including carcinogens and anti-neoplastic drugs. In this study, GSH concentrations and GST activity were determined in 25 adenomatous polyps removed at colonoscopy, and in cancer and uninvolved 'normal' mucosa from 58 operative specimens containing colon cancer. We also examined the relationship between GSH concentrations, GST activity and rates of cell proliferation as assessed by flow cytometry. Concentrations of GSH were significantly higher in adenomas (P = 0.001) and cancer (P = 0.001) than in uninvolved mucosa while GST activity was significantly higher in cancer (P = 0.007). There was a positive relationship between GSH concentrations and GST activity in adenomas (P = 0.001) but not in uninvolved mucosa (P = 0.06) or cancer (P = 0.4). Concentrations of GSH and GST activity were independent of results from flow cytometry. The higher concentrations of GSH in colonic neoplasms and the raised activity of GST in cancer may contribute to their resistance to anti-neoplastic drugs.

Adenoma↗
PubMedDate not supplied

Hearing and age: research challenges and the National Institute on Aging.

Just as the ear trumpet once symbolized the elderly, so do contemporary approaches to hearing loss in the aged reflect many of the major themes in geriatrics and gerontology today. This paper begins by describing the National Institute on Aging (NIA) with particular emphasis on activities relevant to hearing in the elderly. Next, several areas of research interest, including the typology of presbycusis and related conditions, the epidemiology of auditory impairment in old age, the design of testing and research, and the rehabilitation of the hearing-impaired elderly, are addressed. The NIA and the National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) are coordinating their efforts to stimulate investigation of these and related topics.

Aged↗
PubMedDate not supplied

Pharmacy's contribution to geriatric care.

It is clear that we currently lack the scientific knowledge necessary to deal with the vast array of problems, both physical and mental, which so often arise as a result of multipathology and its management by multiple-drug use. This lack of fundamental knowledge in the area of drug use, alteration in drug use, and aging reflects, to some degree, the historical neglect of research on the prolems that confront the elderly. Pharmacists can and should take an active part in developing the scientific and clinical data base to ensure better management of drug use among the elderly.

Aged↗
PubMedDate not supplied

Public Interest Report No. 27 : The need for teaching geriatric medicine.

Geriatric medicine, the body of knowledge relating to human aging and associated pathological conditions, must be incorporated systematically and comprehensively into American medical education. Students must be exposed to aging in the context of normal human development and be aware that some diseases present differently in the old.

Aging↗
PubMedDate not supplied

The life review: an unrecognized bonanza.

Historically, doctors have not entertained a broad enough view of the total human life cycle. While much attention has been focused on infancy, childhood, adolescence and adulthood as times of growth and change, we have all but ignored the later years and the often marvelous characteristics of "the survivors." The use of standardized methods for evaluating the mental and physical status of old people has deprived both practitioners and patients of the richness of life-long experiences. By taking the time to attentively listen to their patients' reflections of the past, physicians can help advance our growing understanding of human aging and expand the repertoire of mechanisms that are useful in clinical practice.

Aged↗