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Biomedical subjects

A R Walker

Publications and source records attributed to A R Walker.

At least 253 records · Page 14Linked to original sources
PubMed1988

Breath methane and large bowel cancer risk in contrasting African populations.

Breath methane has been measured in 1016 people from four populations resident in Southern Africa which experience widely different risks of bowel cancer and other colonic diseases. Highly significant differences in the proportion of subjects with detectable methane in breath were found; % producers--rural black 84, urban black 72, white 52, Indian 41 (chi 2 121 p less than 0.001 3 df). There was a slight preponderance of female producers over male (female producers 63%, males 57%) and an age trend with fewer producers in the older age groups in the urban blacks and Indians, these comparisons being significant when tested by stepwise logistic regression analysis. Bowel cancer risk, determined from a variety of sources, was lowest in rural blacks, greatest in whites, with intermediate rates for urban blacks and Indians. Methane production in the human colon shows significant interethnic differences but which bear no relation to bowel cancer risk in these populations.

Adolescent↗
PubMed1987

Gastric cancer. Some aspects of epidemiology, risk factors, treatment and survival.

Gastric cancer mortality has fallen sharply in many Western populations, yet world-wide it probably remains the single commonest cancer. A diet rich in salted or smoked food and low in vitamin C contributes to its pathogenesis, while the environmental type of atrophic gastritis and intestinal metaplasia are consistently associated and may represent precursors of malignant change. Better food preservation may have a protective effect. Since patients with gastric cancer usually present with incurable disease and survive for only a few months, only those likely to live long enough to benefit from surgery should be operated upon. In the small proportion of patients who have curable disease, extended lymph node dissection increases morbidity and has not convincingly been shown to prolong survival. The palliation offered by surgery, and particularly that achieved by chemotherapy and radiation, deserves further study. Screening for gastric carcinoma seems unlikely to decrease mortality.

Female↗
PubMed1987

Cancer prevention, detection and survival--how hopeful is the outlook?

Recent overall appraisals of cancer occurrence, detection, treatment and survival have noted: rising incidences; relatively steady mortality rates; and disappointingly small improvements in survival time (the magnitudes of which are controversial). In this review attempts have been made to answer questions on countermeasures--principally, what could be done, and what is likely to be done. It is concluded, broadly, that in Western populations the only ameliorative changes likely are reductions in frequency and intensity of cigarette smoking, and improvements in early detection of certain cancers by screening procedures. Accordingly, the outlook is very unpromising. Claims of halving cancer mortality by the year 2000 would seem to be hyperbole. As to developing populations, frequencies of certain cancers (oesophageal, liver and cervix) are likely to fall, but they will be replaced by increases in cancers characteristic of Western populations. Yet rises in incidence of diet-related cancers (breast, colorectal, and possibly prostate) may be retarded by slow rises in socio-economic state.

Forecasting↗
PubMed1987

Dietary fibre and mineral metabolism.

Current dietary recommendations urge, inter alia, an increased consumption of fibre-containing foods. Some experimental studies made on various animals and man indicate that the associated increases in intakes of fibre and phytic acid may prejudice mineral status respecting calcium, magnesium, iron and zinc. An examination has been made of the experimental evidence, also of the epidemiological evidence on numerous types of populations, past and present, developing and developed. It has been concluded that diets high in fibre, characteristically do not have meaningful ill effects on well-being or unequivocally enhance morbidity. In particular populations in certain regions where deleterious effects have been reported it is judged that local factors, not wholly understood, are in operation. In assessing the extent of the benefit to be derived from the dietary changes urged, results must be viewed holistically and not in isolation. It is believed that the beneficial effects respecting reduced pronenesses to various degenerative diseases are likely to far outweigh the possible adverse effects of reduced bioavailability of mineral nutrients.

Animals↗