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Biomedical subjects

R Ellis

Publications and source records attributed to R Ellis.

At least 37 records · Page 2Linked to original sources
PubMed1987

Phytate:zinc and phytate X calcium:zinc millimolar ratios in self-selected diets of Americans, Asian Indians, and Nepalese.

The literature indicates that phytate:zinc and phytate X calcium:zinc millimolar ratios of a diet may provide useful indexes of the bioavailability of dietary zinc. However, there is little information on the phytate:zinc and phytate X calcium:zinc millimolar ratios for total human diets. We have therefore determined the phytate:zinc and phytate X calcium:zinc millimolar ratios of self-selected diets of 29 American omnivores, 23 American vegetarians, 30 Asian Indian immigrant vegetarians, and 26 Nepalese lactating vegetarians. Criteria for selection of subjects were: good health, no extreme dietary habits, and no intake of nutrient supplements. According to the limited literature, the suggested critical values for phytate:zinc and phytate X calcium:zinc millimolar ratios in animal diets and retrospective calculations from human diets are greater than 10 and greater than 200, respectively. The mean phytate:zinc and phytate X calcium:zinc millimolar ratios of American omnivorous diets in the present study were less than 10 and 200, respectively. Confirmation of the critical molar ratios as indexes of the bioavailability of zinc in human diets has not been established by experimentation. However, if the data from animal studies are applicable to human diets, the present study suggests that phytate has little influence on zinc bioavailability of most American diets. In contrast, the mean phytate:zinc and phytate X calcium:zinc millimolar ratios of all vegetarian diets were above the proposed critical levels. Those data, therefore, suggest that phytate might increase the risk of impaired zinc bioavailability for vegetarians consuming a relatively high level of calcium.

Biological Availability↗
PubMed1986

Vaccines made from recombinant yeast cells.

Production of polypeptide and protein antigens through recombinant DNA technology in prokaryotic and certain eukaryotic cells in culture is facilitating the development of new vaccines that are safe, efficacious, and economically feasible to manufacture. A current example is that of human hepatitis B vaccine that, to the present, has been produced commercially using hepatitis B viral surface antigen (HBsAg) purified from the plasma of human carriers chronically infected with the virus. Production of plasma-derived vaccine is limited by the available supply of suitable carrier plasma and by the need to apply highly technical procedures to purify the antigen as well as to ensure inactivation of all infectious agents that might be present in human plasma.

Animals↗
PubMed1985

Thermogenic and metabolic consequences of thyroid hormone treatment in brown and white adipose tissue.

Male rats were treated with triiodothyronine in the drinking water for 12 days. In vitro rates of isoprenaline stimulated lipolysis were significantly greater in brown but not white adipose tissue. Rates of [14C]glucose incorporation into triacylglycerols were significantly reduced in BAT (brown adipose tissue) and WAT (white adipose tissue) under basal and isoprenaline stimulated conditions. In a second experiment, hyperthyroid animals showed impaired weight gain, despite increased food intake during 19 days' treatment. Energy expenditure on days 5 and 12, and BAT core temperature differences (TBAT - TCORE) on day 19, were significantly greater than in control animals. Epididymal white fat pad weight was reduced and interscapular brown fat pad weight increased by triiodothyronine treatment.

Adipose Tissue↗
PubMed1985

Microinjected ras family oncogenes stimulate DNA synthesis in quiescent mammalian cells.

Oncogenes of the ras family stimulate DNA synthesis when microinjected into quiescent mouse and hamster fibroblasts, as detected by in situ autoradiography. The molecularly cloned genomes of Harvey and Kirsten sarcoma viruses, the cloned Harvey ras gene, and the product of the v-ras gene, the p21v-rasH protein, stimulate DNA synthesis in quiescent cells. This stimulation is comparable to the stimulatory activity of the microinjected SV40 T-antigen-coding gene. The demonstration that these oncogenes can stimulate transient DNA synthesis in quiescent cells is relevant to understanding the mechanism by which these genes are able to transform cells in vitro and induce tumors in animals.

Animals↗
PubMed1985

Measurement of plasma catecholamine concentrations. An assessment of anxiety.

This study was designed to assess the value of measurement of plasma catecholamine concentrations as an objective index of anxiety. A preliminary study was undertaken on 11 healthy volunteers (medically qualified), to determine if venous cannulation per se produced any change in plasma catecholamine concentrations. There were no changes in plasma catecholamine concentrations in the 2 h following insertion of an i.v. cannula, suggesting that venous cannulation did not induce a measurable stress response. A second study was performed on 48 surgical patients who were asked to rate their perceived anxiety on a linear analogue scale immediately before premedication and immediately before induction of anaesthesia. Venous blood was obtained at the same time as these ratings. There were no significant changes in perceived anxiety or plasma noradrenaline concentrations following premedication. However, compared with values before premedication, there was a mean percentage increase in plasma adrenaline concentration of 40% before induction of anaesthesia. A significant correlation was shown between mean percentage change in Linear Analogue Anxiety Score and mean percentage change in plasma adrenaline concentrations (r = 0.32).

Adolescent↗
PubMed1978

Fever of undetermined origin: role of cytomegalovirus and Epstein-Barr virus.

Roles of various infections, neoplasms and granulomatous diseases in fever of unknown origin were studied in 22 patients. Bacterial infections were responsible in seven (32 percent), herpes viruses in five (23 percent), neoplasms in four (18 percent) and granulomata in two (9 percent) cases. Patients with herpes infections had initially no clinical or routine laboratory clues to viral involvement, and were given an intensive workup for 5 to 15 days. The diagnosis was made on the basis of cytomegalovirus or Epstein-Barr virus lgM antibody titers.

Adolescent↗