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Biomedical subjects

G Bounous

Publications and source records attributed to G Bounous.

13 recordsLinked to original sources

The effect of dietary amino acids on immune reactivity.

The plaque-forming cell response and serum antibody titres to sheep red blood cells (SRBC) were enhanced in mice fed diets moderately deficient in the amino acids phenylalanine-tyrosine. These diets sustained normal growth during a 4 week study period. More severe limitation of phenylalanine-tyrosine or multiple essential amino acid restriction gave rise to a slight increas in the delayed hypersensitivity reaction to SRBC. These latter diets usually limit growth; nevertheless the humoral immune response to SRBC was not significantly depressed except in the mice fed a diet (diet 7) with severe restriction of seven essential amino acids. These results suggest that dietary restriction may suppress the production or function of an inhibitory cell, such as a suppressor T cell, whilst not affecting the effector cell to the same degree.

Amino Acids

Enhanced 5-F.U. mortality in rats eating definded formula diets.

Rats eating nutritionally adequate defined-formula diets (D.F.D) before and following lethal i.p. injection of 5-fluorouracil exhibit increased mortality and shorter survival time than rats eating conventional Purina rat chow. Neither the presence of proteins in hydrolyzed form nor the nitrogen level in the D.F.D appear to be the crucial factor of enhanced lethality. The possible mechanisms and implications of the phenomenon are discussed.

Animal Feed

The role of diet on 5-fluorouracil toxicity.

In three experiments performed at two month intervals, rats eating a nutritionally adequate defined-formula diet (DFD) exhibit a remarkable similarity in the response to 5-FU as measured by survival time, leukopenia and weight loss. Conversely, the corresponding control groups eating the standard Purina rat food show a different degree of tolerance to 5-FU, which varies from a level similar to that of the DFD groups to twice that value. It is suggested that certain protective factors against 5-FU toxicity present in natural food are absent in formula diets produced on the basis of standard requirements for normal growth and nutrition. The present studies indicate that such protective factors are neither vegetable fibers nor arachidonic acid. The importance of food intake in experimental toxicology and clinical pharmacology is emphasized.

Animals

Immunostimulation by a formula-defined diet.

A formula-defined diet (diet 3, table 1) acted as an adjuvant as an adjuvant in the response of the immune system to SRBC in the rat. Similar minimum and maximum antibody levels were measured in both males and females. In the males, the maximum was reached with diet 3 alone while females required the complementary action of diet 3 and LPS mR 595.

Adjuvants, Immunologic

Intestinal brush border enzymes after short-term mesenteric ischemia.

The total activities of sucrase, trehalase, amino-peptidase, and gamma-glutamyltransferase in the isolated brush border of the entire small bowel are reduced to 35, 55, 33, and 21 per cent, respectively, of control values (p less than 0.001) 2 hours after a 45 minute occlusion of the superior mesenteric artery. Since brush border proteins are also reduced by ischemia to 42 per cent of control, enzymatic activity when expressed as U/mg protein is significantly reduced only in the case of gamma-glutamyltransferase, to 48 per cent of control.

Animals

[Essential diet in extensive cervico-facial surgery].

A prospective nutritional study was undertaken on 26 patients submitted to pharyngo-laryngectomy with pre-operative irradiation. Three diets were compared, given through a naso-gastric Levine tube. The first diet being the hospital blenderized diet, the second one Flexical, and the third one, Flexical Control. There was no significant difference between Flexical and Flexical Control, but the biological parameters and the clinical evolution militate in favor of a widespread use of the Flexical method. The authors recommend the use of controlled defined diet as compared to the hospital blenderized diet and the more sophisticated and more expensive method as the intravenous hyperalimentation.

Amino Acids

Use of an elemental diet in animals during treatment with 5-fluorouracil (NSC-19893).

Rats eating a diet containing casein hydrolysate (10% wt/wt)(diet 3) instead of whole casein (diet 1) exhibited increased tolerance to nine consecutive daily injections of 15 mg/kg of 5-fluorouracil (5-FU). The relative nutritional efficiency of diet 3 was significantly higher during 5-FU treatment. Serum albumin levels measured after 5-FU treatment dropped by only 2.7% in diet 3 groups and by 13.5% in diet 1 groups. Serum albumin values for rats on the control diet (Purina lab chow) were comparable to those on diet 1. No 5-FU-related mortality was observed in any of the groups. Intestinal brush border enzymes were determined in a group of rats on diet 1. At the end of 5-FU treatment statistically significant changes were observed: sucrase dropped to 30% of control and leucylnaphthylamide-hydrolyzing activity dropped to 19% of control. The activity of gamma-glutamyltransferase did not change significantly. It is postulated that under these circumstances a mixture with a prevalence of free amino acids (casein hydrolysate) could be more readily absorbed than a corresponding mixture containing a larger proportion of oligopeptides.

Animals

Dietary protection during radiation therapy.

Eighteen patients receiving Cobalt 60 irradiation for abdominal or pelvic malignancies were assigned at random to eat either a semi-hydrolyzed diet (Flexical: 10 g % casein hydrolsate; 14 g % triglycerides, 20% of which medium chain; 66% disaccharides) or a normal diet. There are no significant differences between these two groups with respect to age and the ratio of ideal to actual caloric intake. The patients in the control group received on the average a total of 3900 rd and those in the Flexical group 4040 rd. Generally, Flexical appeared to have a significant positive effect on body weight. In addition, radiation-induced diarrhea was not a problem in the Flexical group. In the latter group, serum proteins including immunoglobulins remained essentially unchanged during therapy while a moderate but significant fall was observed in all control patients. No significant difference between the two groups was observed with respect to peripheral blood hematocrit, red and white cell counts. However, the drop in blood lymphocytes following irradiation was significantly less in the Flexical group. The mechanisms of radioprotection are discussed. These preliminary data indicate that the nutritional and perhaps the immunological status of cancer patients receiving intensive irradiation can be maintained by dietary measures.

Abdominal Neoplasms