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Biomedical subjects

C L White

Publications and source records attributed to C L White.

At least 145 records · Page 8Linked to original sources
PubMed1977

Sulphur-selenium studies in sheep. I. The effects of varying dietary sulphate and selenomethionine on sulphur, nitrogen and selenium metabolism in sheep.

Sulphur, selenium and nitrogen metabolism were studied in Merino wethers fed for 35-day periods on semipurified diets in which the sulphur content was increased to either 0-07 or 0-20% by the addition of sodium sulphate. At both levels of sulphur, additions of selenium as DL-selenomethionine increased the basal level of selenium (0-02 microgram/g) to 0-06, 0-09 and 0-67 microgram/g. Both levels of dietary sulphur supported positive sulphur balances but a reduction in sulphur intake per se resulted in a significant depression in dry matter digestibility (P less than 0-05), apparent nitrogen digestibility (P less than 0-05), nitrogen balance (P less than 0-01), sulphur balance (P less than 0-05) and plasma sulphate-sulphur (P less than 0-05) and wool (P less than 0-01) selenium levels. Selenium balance was not affected by differences in sulphate-sulphur intake. Selenium balances (P less than 0-001), plus the selenium levels in plasma (P less than 0-001), and wool (P less than 0-001) were significantly different at the different levels of selenium supplementation. A positive selenium balance was achieved when the selenium intake was approximately 37 microgram/day, regardless of sulphur treatment. The validity of using plasma and/or wool selenium levels as indices of the selenium status of sheep is questioned.

Animals↗
PubMedDate not supplied

The effect of zinc deficiency on the body composition of rats.

Body composition and the levels of some plasma metabolites were measured in zinc deficient and control rats with the aim of assessing the nature of the metabolic defects resulting from zinc deficiency. Two experiments, lasting 15 and 20 d, were carried out using 52 immature rats. Zinc deficient animals were fed a diet of 1-2 mg Zn/kg. Pair fed and ad libitum control rats received the same diet with 100 ppm zinc added to the drinking water. Feed intake and growth rate were measured, and the carcasses were analyzed for protein, fat, and ash. In each experiment, a group of rats were killed on d 1 to provide pretreatment values and to allow for estimates of net deposition of carcass components. Lactate, urea, and zinc were assayed in plasma, as well as zinc concentration in carcasses and liver. The main effect of zinc deficiency was to reduce feed intake and efficiency of feed conversion, resulting in a reduced proportion of carcass fat. However, when adjustments were made for difference in body wt because of the reduced feed efficiency, zinc deficiency per se resulted in an increase in the proportion of fat in the carcass. Plasma lactate concentration was unchanged, but urea concentration increased in both pair fed and zinc deficient rats relative to ad libitum fed control animals. The results indicate that a defect in protein synthesis and an increase in energy expenditure, perhaps resulting from increased protein turnover, underlies the reduced growth and efficiency of feed conversion of zinc deficiency.

Animals↗
PubMedDate not supplied

The role of cortical connectivity in Alzheimer's disease pathogenesis: a review and model system.

Here we review current evidence in support of the cortical disconnection/cortical connectivity model of Alzheimer disease (AD) pathogenesis, a model which predicts that one of the first events in AD is damage to the entorhinal cortex and/or subiculum resulting in the disconnection of the hippocampal formation and neocortex, and the subsequent progression of the disease in a stepwise fashion along cortico-cortical connections. Much of the evidence for this model has been obtained from studies involving the limbic system where investigators have demonstrated a precise correspondence between established patterns of connectivity and the degenerative changes associated with AD. In addition, some studies of the distribution of neuritic plaques (NP) and neuro-fibrillary tangles (NFT) in the neocortex and subcortical structures have yielded corroborative data. The validity of the cortical disconnection/connectivity model in the neocortex remains to be established or refuted. We propose that testing of this model can be accomplished with systematic studies of the laminar and regional distribution of NP and NFT in a series of sequentially interconnected cytoarchitectural regions that also form part of two functional hierarchies--the paralimbic and occipitotemporal visual systems. To adequately control for variation between brains affected by AD, it is imperative that such studies be conducted in a large but varied population of AD cases exhibiting differences in several variables, including clinical and/or neuropathological severity of the disease, temporal duration of the disease, and clinical/neuropsychological profile. We believe that further understanding of the relationship between characteristic AD pathology and intrinsic anatomico-functional circuits will contribute not only to our comprehension of AD pathogenesis but also to our general knowledge of the human brain.

Alzheimer Disease↗
PubMedDate not supplied

Workplace injury experience of female coal miners in the United States.

Analysis of the 1978-1980 accident history of female coal miners collected by the Mine Safety and Health Administration (MSHA) has identified significant differences in injury severity due to mine type, source and nature of injury, geographic region, age class, and part of body injured. Approximately 4% of all female coal workers were involved in a lost-time accident as compared to 7% for males; female workers lost approximately 1.1 days each as compared to 2.4 days for males; and 0.01% of the female work force were fatally injured as compared to 0.05% among males. Most injuries to both female and male workers involved back sprains. The majority of remaining injuries are sprains and fractures to joints and bones of the limbs.

Accidents, Occupational↗
PubMedDate not supplied

Providers' and consumers' perceptions of quality health care.

This article describes a study that explored perceptions of quality health care among physicians, nurses, patients, and hospital administrators. A self-report questionnaire evaluating interpersonal relationships, needs fulfillment, and education as dimensions of health care was developed. Results indicated that all groups differed in their perceptions of quality health care. Staff development educators should be particularly mindful of such differences. Making nurses aware of these differences during orientation and continuing education programs can assist them more effectively to deliver quality nursing care and meet patients' perceived needs.

Attitude of Health Personnel↗