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Biomedical subjects

G Bounous

Publications and source records attributed to G Bounous.

At least 37 records · Page 2Linked to original sources

The effect of concentration and type of dietary protein hydrolysates on tumour growth in mice.

The effects of diets containing 12% (W/W) and 28% of casein or lactalbumin hydrolysate on the growth of implanted mammary adenocarcinoma H2712 in C3H-HeJ strain and fibrosarcoma 1038 in DBA-2J strain mice were compared. Our data indicate that amino acid intake in excess of the minimum requirement for normal growth of non-tumour-bearing mice enhances the growth of implanted fibrosarcoma and mammary carcinoma. The effect is not related to protein quality or amino acid distribution and appears to be solely dependent on the amino acid or nitrogen concentration in the diet.

Animals↗

Influence of dietary proteins on the immune system of mice.

The effect of graded amounts of dietary lactalbumin (L) and casein (C) hydrolyzates on the immune responsiveness of C3H/HeN and DBA/2 strain mice has been investigated by measuring both the specific humoral immune response to sheep red blood cells (SRBC) and the nonspecific splenic cell responsiveness to phytohemagglutinin, concanavalin A and Escherichia coli lipopolysaccharide after stimulation with Mycobacterium bovis, strain BCG. The nutritional efficiency of these diets was similar at both 12 and 28% amino acid levels. The immune responses of mice fed the L diets were found to be significantly greater than those of mice fed the corresponding C diets, especially at the 28% level. Furthermore in the mice fed L diet, increasing the concentration of amino acid in the diet from 12 to 28% greatly enhanced immune responsiveness by both parameters measured. In the C-fed mice, a comparable enhancement of mitogen responsiveness with increasing amino acid level of diet was seen, but there was no change in the humoral immune response. The enhancement of immune responsiveness observed in mice fed the 28% L diet was moderately reduced by the addition of phenylalanine to the diet, indicating that the lower level of this amino acid in the L protein may be of some significance. These dietary effects on immune responsiveness were remarkably similar in both mouse strains tested.

Amino Acids↗

Effect of intestinal ischemia on diamine oxidase activity in rat intestinal tissue and blood.

This study examines the effect of increasing duration of intestinal ischemia on the mucosal integrity and the release of the enzyme diamine oxidase from the small intestine. Acute ischemia was produced by the occlusion of the superior mesenteric artery, and the subsequent changes in DNA and 125I-albumin content in the lumen were taken as indices of intestinal lesions. Diamine oxidase activity was measured in the intestinal lumen, mucosa, lymph, and serum. Occlusions of the superior mesenteric artery for periods of more than 60 min resulted in significant leakage of 125I-albumin (i.v.) into the lumen. In contrast, luminal DNA content rose significantly after 15 min of ischemia and continued to increase proportionally with the increased duration of the occlusion up to 120 min. Similarly, diamine oxidase activity was augmented in the lumen after 15 min of occlusion and rose sharply as the ischemic period was lengthened up to 60 min, leveling off thereafter. Increases in the diamine oxidase activity were also observed in the intestinal lymph and serum, reaching levels that were 2.6 and 3.6 times that of the control respectively after 60 min of ischemia. These findings suggest that intestinal ischemia reduces the diamine oxidase content in the intestinal mucosa by desquamation of the surface epithelial cells and by releasing the enzyme into the intestinal interstitial fluid, from which at least a portion is transported to the blood via the lymphatics. The early release of diamine oxidase seems to occur before the mucosal barrier is broken.

Albumins↗

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↗