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Biomedical subjects

A R Walker

Publications and source records attributed to A R Walker.

At least 127 records · Page 7Linked to original sources
PubMed1996

Diet in the prevention of cancer: what are the chances of avoidance?

In most western populations, cancer causes about a fifth of all deaths, and in developing populations, 5-15%, with the likelihood of further rises. Diet is considered responsible for about a third of cases of cancer and smoking another third. Dietarily, for cancer avoidance, recommendations made include eat less, eat much less fat especially saturated fat, and eat more plant foods, i.e. cereals, but very particularly vegetables and fruit. However, only high consumptions of the latter are consistently associated with a lower risk of cancers, notably of the digestive and respiratory tracts. For each change urged, meaningful compliance will be very difficult, due largely to conservativeness as well as to the higher cost of a 'prudent' diet. Notwithstanding, urges to make dietary changes, particularly relating to plant foods, must be continued, especially with regard to persons familially susceptible and, additionally, with the recognition that the measures recommended also serve to lessen susceptibility to cardiovascular diseases. Compliance, even by a small proportion, could result in large numbers benefiting due to the universality of the burden from cancer.

Adult↗
PubMed1996

Causes of admission of African patients to Gelukspan Hospital, North West Province, South Africa.

An enquiry has been made into the causes of admission in 1994 of African patients to Gelukspan Hospital, North West Province, South Africa. The study concerned 3791 patients of whom 3533 (93.2%) were classifiable. Two groups were not included in this number, namely, 1584 'lodgers' (e.g. mothers of infants), and 1868 females admitted for normal pregnancy. Of the 3533 patients, 940 (26.6%) were aged 14 years and younger; 545 (58.0%) these were boys and 395 (42.0%) were girls. The main causes of their admission were pneumonia, gastroenteritis, trauma, poisoning, and infections. Of the 2593 adults, 1418 (54.7%) were males and 1175 (45.3%) females. Among males, chief causes were pulmonary tuberculosis, trauma and accidents, congestive cardiac failure, psychosis, cancer and diabetes. Of the females, chief causes were pulmonary tuberculosis, trauma and accidents, pregnancy related disorders, gastroenteritis, anaemia and pneumonia. Regarding other diseases, 4.5% of adults were admitted for cancer, and 1.8% for diabetes. The general pattern of admissions is similar to that reported in other rural hospitals. The causes of admissions are discussed, regarding; (i) public health improvements occurring, and (ii) means of promoting further improvements by community self-help, and by help from State health and other services.

Adolescent↗
PubMed1995

Fecal short chain fatty acids in South African urban Africans and whites.

UNLABELLED: Diminished levels for fecal short chain fatty acids (SCFAs) have been linked to occurrence of ulcerative colitis, colorectal polyps, and colon cancer, diseases that are rare or uncommon in African populations. PURPOSE: The aim of this study was to determine fecal SCFA concentrations and fecal pH values in groups of black South Africans (African) and white South Africans (white) subjects. METHODS: Twenty healthy Africans (all women; mean age, 35 years) and 17 healthy whites (7 women; 10 men; mean age, 32 years) were tested. RESULTS: Mean total concentrations of SCFAs in the two groups were 142.1 (+/- 53.9) and 69.2 (+/- 26.0) mmol/kg wet feces, respectively (P = 0.0001). Mean values for Africans were significantly higher in all subfractions except butyrate. There was a significant inverse correlation between fecal pH value and total fecal SCFA concentration (r = 0.704; P = 0.001). CONCLUSION: High concentrations of fecal SCFAs in the African group could protect against chronic bowel diseases.

Adult↗
PubMed1995

Salivary glands and saliva of Amblyomma variegatum ticks: comparison of immatures and adults in relation to the pathogenesis of dermatophilosis.

Salivary glands from immature and adult Amblyomma variegatum were compared for differences in potential components responsible for the systemic aggravation by adult ticks of the skin disease dermatophilosis. Whole salivary glands from adult, nymphal and larval A. variegatum ticks were compared for structural differences by light microscopy and for protein content by gel electrophoresis. Type-2 salivary gland acini from adult ticks at the second stage of feeding contained significantly greater (P < 0.01) proportions of c1 secretory granules than those from either of the immature instars. There was also significantly more area occupied with e secretory granules in the type-3 salivary gland acini from adult ticks compared with larval ticks. Electrophoresis of whole salivary glands showed seven bands present only in the adult material; of these, three were dense bands at 37, 35 and 31 kDA. Electrophoresis of saliva from adult and nymphal A. variegatum obtained by artificial stimulation showed that nine bands were unique to the saliva produced by adults; of these nine bands one was a dense band at 67 kDa. It was concluded that adult salivary material was different from that of immature ticks and that further studies on the relationship between the feeding of adult A. variegatum and dermatophilosis should investigate these components unique to the adults.

Actinomycosis↗
PubMed1995

Dietary advice: from folklore to present beliefs.

Many countries have folklore beliefs about the use of foodstuffs to remedy ill health and to promote long life. Many of the beliefs and practices of the ancients and, more recently, "mothers's views of health" have a basic soundness and are in harmony with present-day advice on the attainment of a prudent diet and life-style.

Diet↗
PubMed1995

Vegetable and fruit consumption: some past, present and future practices.

In Western populations, historically, from early times until the 19th century, diets were composed largely of plant foods-cereals, beans, vegetables and fruit. The huge majority of populations were very poor with restricted food choices. The same situation prevails with most present-day Third World populations, although principally with rural dwellers. In Western populations, in recent times, stemming largely from urbanization and rise in prosperity, and accompanying increased partiality to animal foods, there have been falls in the intake of some plant foods yet rises in others. Potato intake has halved, whereas vegetable consumption has increased only slightly, although that of fruit more so. National consumptions of these foodstuffs vary widely, those in the United Kingdom and United States of American being only about half of those in Mediterranean countries, Spain, Portugal and Greece. In the former countries, present dietary guidelines urge that vegetable consumption be doubled, with fruit up by a half. In southern Africa, consumption of vegetables and fruit by the white population appears similar to those in The USA and UK. Yet in African cities, intake is low due to their cost. In view of the protective role of high vegetable and fruit intake in the combating of coronary heart disease and many forms of cancer, the relatively low consumption of these foodstuffs, especially in the poorer populations, is disappointing, and alas, appears unlikely to rise in the near future.

Diet↗
PubMed1995

Nutritional and dental implications of high and low intakes of sugar.

Currently, in nutrition there are major anxieties over the bearing of high intakes of energy and certain nutrients (e.g. fat, sugar) on health/ill-health. Two questions concern sugar: does a high intake (1) cause a deleterious imbalance or dilution of macro- and micro-nutrients? and (2) does it promote degenerative diseases, in particular dental caries? As to the first question, evidence from a variety of contexts indicates that nutrient intakes are not reduced; rather they are increased. Additionally, one accompaniment of a high sugar intake is a reduced intake of fat, one of the primary aims of nutritional guidelines. However, these do not license excessive sugar consumption. As to sugar and degenerative diseases, evidence is lacking that sugar intake is significantly influential other than for dental caries. An examination of evidence indicates sugar consumption to be a weak factor in caries development; its intake explains little of the variance in caries occurrence. Clearly, additional factors are influential-genetic, exposure to fluoride, and dietary components other than sugar. Early detection of the relatively small proportion of caries-prone individuals by appropriate markers, must be sought.

Adolescent↗
PubMed1995

Is breast cancer avoidable? Could dietary changes help?

In the US, the life time odds of developing breast cancer has reached one in eight, with an incidence rate of 85 per 100,000 world population. The rate is half or less in women in some Mediterranean countries. At the extreme are rural African women whose rate is approximately 5-10 per 100,000. In African, compared with White women, protective factors include (1) reproductive behaviour, namely, slower growth before and after puberty, later age at menarche, high teenage pregnancy, high parity and long periods of lactation and amenorrhoea and (2) a diet of relatively low energy intake and of low-fat and high-fibre contents. In the Mediterranean setting, major dietary protective factors include a relatively low intake of saturated fat and high intakes of monounsaturated fat and of vegetables and fruit. Among White women, a reversion to protective reproductive behaviour is out of the question. Only in respect of diet, could significant avoiding action be taken. Adoption of an African type diet is wholly impracticable. Moreover, even conformation to a former Mediterranean diet, which is already changing, would be difficult, requiring reorientation of fat composition and large rises in intakes of vegetable and fruit. However, with resolution, were such changes made, at least by the very vulnerable, they would help, additionally, to protect against other diet-related cancers, especially colon cancer and against coronary heart disease.

Black People↗