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Biomedical subjects

B E Sheffy

Publications and source records attributed to B E Sheffy.

At least 19 recordsLinked to original sources
PubMed1985

Nutrition and metabolism of the geriatric dog.

Sixteen 10-12-year-old and eight 1-year-old dogs were studied over a two year period to determine comparative differences in physiological response to 4 diets varying in protein content and percentages of energy contributed by protein. The ability of old dogs to utilize nutrients as supplied by these foods was not significantly different from that of young adult dogs. Except for indices of mitogenic stimulation and serum urea nitrogen (SUN) other physiological parameters studied were not affected by the diet fed. Regardless of diet, old dogs had significantly higher serum levels of cholesterol, phosphorus and alkaline phosphatase and had lower indices of mitogenic stimulation than did young dogs.

Aging↗
PubMed1983

Effect of antioxidants on the proliferative response of canine lymphocytes in serum from dogs with vitamin E deficiency.

The in vitro effect of vitamin E and 3 other antioxidants--ethoxyquin, 2-mercaptoethanol, and ascorbic acid--on proliferation of canine lymphocytes was examined. Lymphocytes from 2 groups of dogs given a vitamin E-deficient diet or whelped from a bitch fed such a diet were cultured with pooled samples of serum from dogs fed a vitamin E-deficient diet or whelped from a bitch fed such a diet, or normal canine serum, and stimulated with phytohemagglutinin. Added vitamin E enhanced the responsiveness in serum from the dogs with vitamin E deficiency, but not in normal canine serum. A similar effect was noted with added ethoxyquin and 2-mercaptoethanol. Ascorbic acid had no effect on proliferation in either serum pool. These results indicated that depressed lymphocyte responsiveness seen with serum from vitamin E-deficient dogs may, at least in part, be due to a loss of antioxidant activity in this serum.

Animals↗
PubMed1979

Influence of vitamin E and selenium on immune response mechanisms.

Vitamin E and selenium have both been shown to have immunostimulatory effects in a variety of species when administered in quantities in excess of established deitary requirements. Responses to each nutrient appeared to be independent of the nutrition of the other. Deficiencies of vitamin E and selenium conversely caused suppression of the immune response system, particularly, cell mediated mechanisms. Suppression was shown to be associated with serum factors coating lymphocytes from dogs deficient in vitamin E and selenium. Oral supplementation with vitamin E transformed or removed the suppressive factors, dietary selenium had no effect. In vitro peripheral lymphocyte blast transformation tests corroborated observations of in vivo studies. Reducing agents and synthetic anti-oxidants eliminated suppressive effects in vitro. Suppression was most marked in dogs fed diets highest in polyunsaturated fatty acid (PUFA) content, providing conditions most conductive to lipid peroxidation in vivo. The essential fatty acids linoleic and arachidonic have been shown to similarly influence immunoregulatory mechanisms in vivo. The effect may be a direct one since plasma membrane fluidity of lymphoid cells increases the probability of modification of cell--antigen interactions by PUFA. However, their effect may also be an indirect one. PUFA are known precursor substances of E anf F type prostaglandins which have been shown to affect immediate and delayed hypersensitivity by stimulating synthesis of cyclic AMP. More definitive studies are needed to resolve this question.

Animals↗
PubMed1978

Nutrition and the immune response.

Vitamin E--selenium deficiency in dogs resulted in complete suppression of lymphocyte responsiveness to stimulation with mitogens. Depressing effects on neutralizing antibody synthesis were also noted. A serum factor associated with the inability of lymphocytes to respond has been isolated and partially purified. The suppressor factor can be removed or transformed by both in vivo and in vitro vitamin E supplementation.

Animal Nutritional Physiological Phenomena↗
PubMed1978

An improved procedure for genetic selection against hip dysplasia in dogs.

Rapid weight gain can educe hip dysplasia of dogs with normal hip joints. It is proposed that progeny whose parents have "excellent genotypes" would not be susceptible to this stress and would develop normal hip joints. The method for reducing the incidence of hip dysplasia in dogs would be to use stress to identify carriers (parents) and potential carriers (progeny), and select for breeding only dogs with proved genotypic value and those progeny with the best hip joint conformation.

Animals↗
PubMed1975

Experimental in utero infection of fetal pigs with a porcine parvovirus.

In utero infection of fetuses of six specific-pathogen-free large white sows at 35, 48, 55, 72, 99, and 105 days was studied. The fetuses were infected by direct inoculation of porcine parvovirus into the amniotic sac. The inoculation consisted of 0.25 ml of tissue culture fluid containing 10(5.5) mean tissue culture infective doses per ml of porcine parvovirus strain G10/1. Fetuses of one uterus horn were infected, whereas fetuses in the opposite horn were given 0.25 ml of noninfected cell culture material. No clinical signs of infection were observed; however, all sows developed antibodies 7 to 9 days postinfection. A total of 24 virus-inoculated fetuses and 20 control fetuses were studied. Fetuses infected at 35, 48, and 55 days of gestation died between about 5 and 22 days after infection. Virus was isolated from their organs and fetal blood. Virus spread to control fetuses but did not cause death and mummification or stimulate antibody production. Fetuses from sows infected at 72, 99, and 105 days of gestation survived. They developed high antibody titer in utero. Control piglets remained antibody free.

Amnion↗