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Biomedical subjects

G Bounous

Publications and source records attributed to G Bounous.

At least 19 recordsLinked to original sources
PubMed1999

Competition for glutathione precursors between the immune system and the skeletal muscle: pathogenesis of chronic fatigue syndrome.

The chronic fatigue syndrome (CFS) is typically associated or follows a recognized or presumed infection. Abnormalities of both humoral and cellular immunity have been demonstrated in a substantial proportion of patients with CFS. The most consistent findings are of impaired lymphocyte responses to mitogen. As an antioxidant, glutathione (GSH) is essential for allowing the lymphocyte to express its full potential without being hampered by oxiradical accumulation. Hence, protracted challenge of the immunocytes may lead to cellular GSH depletion. Because GSH is also essential to aerobic muscular contraction, an undesirable competition for GSH precursors between the immune and muscular systems may develop. It is conceivable that the priority of the immune system for the survival of the host has drawn to this vital area the ever-diminishing GSH precursors, thus depriving the skeletal muscle of adequate GSH precursors to sustain a normal aerobic metabolism resulting in fatigue and eventually myalgia.

Exercise↗
PubMed1993

Whey proteins as a food supplement in HIV-seropositive individuals.

On the basis of numerous animal experiments, a pilot study was undertaken to evaluate the effect of undenatured, biologically active, dietary whey protein in 3 HIV-seropositive individuals over a period of 3 months. Whey protein concentrate was prepared so that the most thermosensitive proteins, such as serum albumin which contains 6 glutamylcysteine groups, would be in undenatured form. Whey protein powder dissolved in a drink of the patient's choice was drunk cold in quantities that were increased progressively from 8.4 to 39.2 g per day. Patients took whey proteins without adverse side effects. In the 3 patients whose body weight had been stable in the preceding 2 months, weight gain increased progressively between 2 and 7 kg, with 2 of the patients reaching ideal body weight. Serum proteins, including albumin, remained unchanged and within normal range, indicating that protein replenishment per se was not likely the cause of increased body weight. The glutathione content of the blood mononuclear cells was, as expected, below normal values in all patients at the beginning of the study. Over the 3-month period, glutathione levels increased in all 3 cases. In conclusion, these preliminary data indicate that, in patients who maintain an adequate total caloric intake, the addition of "bioactive" whey protein concentrate as a significant portion of total protein intake increases body weight and shows elevation of glutathione (GSH) content of mononuclear cells toward normal levels. This pilot study will serve as a basis for a much larger clinical trial.

Body Weight↗
PubMed1991

Whey proteins in cancer prevention.

Epidemiological and experimental studies suggest that dietary milk products may exert an inhibitory effect on the development of several types of tumors. Some recent experiments in rodents indicate that the antitumor activity of the dairy products is in the protein fraction and more specifically in the whey protein component of milk. We and others have demonstrated that whey protein diets result in increased glutathione (GSH) concentration in a number of tissues, and that some of the beneficial effects of whey protein intake are abrogated by inhibition of GSH synthesis. Whey protein is particularly rich in substrates for GSH synthesis. We suggest that whey protein may be exerting its effect on carcinogenesis by enhancing GSH concentration.

Animals↗
PubMed1991

The biological activity of undenatured dietary whey proteins: role of glutathione.

This study compared the effects of different sources of whey protein concentrate (20 g/100 g diet) and of casein on the spleen, liver, and heart glutathione content of C3H/HeJ mice, and on the immune response of their spleen cells to sheep red blood cells. Body weight curves were similar in all dietary groups. Our data indicate that the humoral immune response is highest in mice fed a dietary whey protein concentrate exhibiting the highest solubility (undenatured conformation) and a greater relative concentration of the thermolabile bovine serum albumin and immunoglobulins. In addition, the mice fed this type of whey protein concentrate exhibit higher levels of tissue glutathione. The presence in the serum albumin fraction of glutamylcysteine groups (rare in food protein) and the specific intramolecular bond as related to the undenatured conformation of the molecule are considered to be key factors in the glutathione-promoting activity of the protein mixture.

Animals↗
PubMed1990

Marathon runners: the intestinal handicap.

Intestinal complications following strenuous, protracted physical activity have been increasingly recognized. Diarrhea, sometimes associated with blood loss, described in marathon runners does not appear to be a common diarrhea but rather the clinical expression of ischemic enteropathy. On the basis of experimental evidence and some clinical data, it is suggested that prefeeding an elemental semi-hydrolyzed diet might reduce the incidence and severity of this intestinal handicap in marathon runners. Perhaps, more importantly, the potentially adverse effects of acute ischemic enteropathy on the cardiovascular system might be accordingly reduced.

Cardiovascular System↗
PubMed1990

Dietary milk proteins inhibit the development of dimethylhydrazine-induced malignancy.

This study investigated the influence of two formula diets containing 20 g/100 g diet of either whey protein concentrate or casein, or Purina mouse chow on 1,2-dimethylhydrazine (DMH)-induced colon carcinoma in A/J mice. Four weeks after the 24th DMH treatment the incidence of tumour and tumour area in the whey protein-fed mice was substantially less in comparison to either the casein or Purina groups. The Purina group exhibited the greatest tumour burden. At the end of the experiment all animals continuously fed the whey protein diet were found to be alive, whereas 33% of those on the casein or Purina diet had died. Animals fed Purina diet for 20 weeks and then switched to either milk protein diet for a further 8 weeks exhibited a decrease in tumour burden as compared to those animals fed the Purina diet continuously. Body weights were similar in all dietary groups. In conclusion, a whey protein diet appears to significantly influence the development of chemically induced colon tumours and the short-term survival of mice.

Adenocarcinoma↗
PubMed1989

Elemental diets in the prophylaxis and therapy for intestinal lesions: an update.

The recognition of potentially noxious physiologic substances in the intestinal milieu prompted the use of an "elemental" semihydrolyzed formula diet in the prophylaxis of experimental acute ischemic enteropathy. Elemental diets have been used in the management of a variety of digestive diseases. An elemental diet protects the intestinal mucosa of rodents from radiation injury and facilitates mucosal healing. Clinical trials have shown the benefits of this form of treatment in the prevention of acute radiation enteropathy and in the therapy for delayed radiation enteropathy and Crohn's disease.

Acute Disease↗
PubMed1989

The influence of dietary whey protein on tissue glutathione and the diseases of aging.

This study compared the effects of a whey-rich diet (20 g/100 g diet), with that of Purina mouse chow or casein-rich diet (20 g/100 g diet), on the liver and heart glutathione content and on the survival of old male C57BL/6NIA mice. The study was performed during a limited observation period of 6.3 months. In mice fed the whey protein-rich diet between 17 months and 20 months of age, the heart tissue and liver tissue glutathione content were enhanced significantly above the corresponding values of the casein diet-fed and Purina-fed mice. Mice fed the whey protein diet at the onset of senescence at 84 weeks, exhibited increased longevity as compared to mice fed Purina mouse chow over the 6.3 month observation period extending from the age of 21 months (corresponding to a human age of 55 years) to 26-27 months of age (corresponding to a human age of 80 years), during which time 55% mortality was observed. The corresponding mean survival time of mice fed the defined casein diet is almost identical to that of Purina-fed controls. Body weight curves were similar in all three dietary groups. Hence a whey protein diet appears to enhance the liver and heart glutathione concentration in aging mice and to increase longevity over a 6.3 month observation period.

Aging↗
PubMed1989

Immunoenhancing property of dietary whey protein in mice: role of glutathione.

The spleen cells immune response to sheep red blood cells of C3H/HeJ mice fed a 20 g whey protein/100 g diet is substantially higher than that of mice fed an equivalent casein diet of similar nutritional efficiency. The present study indicates that the observed immunoenhancing effect of the whey protein mixture is dependent on the overall amino acid pattern resulting from the contribution of all its protein components. Whey protein contains substantially more cysteine than casein. Dietary cysteine is considered to be a rate limiting substrate for the synthesis of glutathione which is necessary for lymphocyte proliferation. Our studies show that enhancement of host humoral immune response is associated with greater and more sustained production of splenic glutathione during the antigen driven clonal expansion of the lymphocyte in whey protein fed mice in comparison to mice fed the equivalent casein or the cysteine-enriched casein diet. Hence the efficiency of dietary cysteine in inducing supernormal glutathione levels is greater when it is delivered in the whey protein than as free cysteine. Administration of S-(n-butyl) homocysteine sulfoximine, which reduces splenic glutathione level by half, produces a 4-5 fold drop in the humoral immune response of whey protein diet-fed mice. This is further evidence of the important role of glutathione in the immunoenhancing effect of dietary whey protein.

Animals↗
PubMed1988

Evolutionary traits in human milk proteins.

Human milk has the lowest concentration of protein of any mammalian species. Since the rate of growth of the offspring is negatively related to the protein content of the milk, the time required to double the birth weight is greater in the infant than in any other mammal in which it has been measured. Similarly, in weaned animals, a low protein diet increases the time required to reach maximal growth, senescence and natural death. Human milk protein has the highest whey protein to casein ratio than the milk of any other mammalian species. Our previous experiments have shown that mice fed a 20% whey protein diet exhibit increased resistance to Streptococcus pneumoniae and a humoral immune response significantly higher than that of mice fed most of the commercially available animal and plant proteins in nutritionally similar and adequate formula diets. Other studies have demonstrated that mean and maximal longevity of hamsters fed a 20% whey protein diet is increased in comparison with those fed commercial laboratory feed or a supplemented casein diet of similar nutritional efficiency. Thus, the low protein content and the prevalence of whey protein, which are characteristic features of human milk, are both associated with slow body growth and increased longevity. For human infants, mother's milk is the first and, for most, the only food ingested for a considerable period of time. We, therefore, propose that a trace of Nature's design for the offspring and the evolution of the species can be found in mother's milk.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

The immunoenhancing property of dietary whey protein concentrate.

The plaque-forming cell response to sheep red blood cells was found to be enhanced in mice fed a formula diet containing 20 g lactalbumin/100 g diet in comparison to mice fed equivalent formula diets of similar nutritional efficiency containing 20 g/100 g diet of either casein, soy, wheat or corn protein, egg albumin, beef or fish protein, Spirulina maxima, or Scenedesmus protein, or Purina mouse chow. This effect was manifest after 2 weeks and persisted for at least 8 weeks of dietary treatment. Mixing lactalbumin with either casein or soy protein in a 20 g protein/100 g diet formula significantly enhanced the immune response in comparison to that of mice fed diets containing 20% soy protein or casein.

Adjuvants, Immunologic↗
PubMed1988

Dietary whey protein inhibits the development of dimethylhydrazine induced malignancy.

This study investigates the influence of two formula diets containing 20 g/100 g diet of either whey protein concentrate or casein or Purina mouse chow, on the humoral immune responsiveness and dimethylhydrazine induced colon carcinogenesis in A/J mice. After 20 weeks of dimethylhydrazine treatment, the number of plaque forming cells per spleen, following intravenous inoculation with 5 X 10(6) sheep red blood cells, was nearly three times greater in the whey protein-fed group than in the casein-fed mice although both values were substantially below normal. After 24 weeks of dimethylhydrazine treatment the incidence of tumors in the whey protein-fed mice was substantially lower than that in mice fed either the casein or Purina diet. Similarly, the tumor area was less in the whey protein group in comparison to either the casein or Purina groups, with some difference between casein and Purina groups. Body weight curves were similar in all dietary groups. In conclusion, a whey protein diet appears to significantly inhibit the incidence and growth of chemically induced colon tumors in mice.

1,2-Dimethylhydrazine↗
PubMed1986

Pancreatic proteases and oxygen-derived free radicals in acute ischemic enteropathy.

The specific susceptibility of the intestinal mucosa to low blood flow states is related to the "physiologic" makeup of the intestinal milieu. Pancreatic proteases appear to play a crucial role in the ischemic autodigestion of the intestinal mucosa. Moreover, trypsin can activate the conversion of xanthine dehydrogenase into superoxide radicals producing xanthine oxidase. Oxygen-derived free radicals account for at least part of the damage to the postischemic intestinal mucosa.

Animals↗
PubMed1985

Differential effect of dietary protein type on the B-cell and T-cell immune responses in mice.

The effect of 20 g/100 g diet of lactalbumin (L), casein (C), soy (S) and wheat (W) protein on the immune responsiveness of C3H/HeN mice has been investigated by measuring the humoral immune response to the T cell-independent antigen, TNP-Ficoll. The humoral immune response of mice fed the L diet was found to be higher than that of mice fed the C, S and W diets. On the other hand, delayed-type hypersensitivity, and splenic cell mitogen responses to phytohemagglutinin and concanavalin A did not differ among mice fed the various diets. Similarly, the type of diet did not appear to influence host resistance to Salmonella typhimurium. It is postulated that the type of protein in the diet influences directly the intrinsic capacity of the B lymphocytes to respond to an immunogenic stimulus.

Analysis of Variance↗
PubMed1985

Mechanism of altered B-cell response induced by changes in dietary protein type in mice.

The effect of 20 g/100 g dietary lactalbumin (L) or casein (C) diets or a nonpurified (NP) diet on the immune responsiveness of C57Bl/6J, C3H/HeJ and BALB/cJ mice has been investigated by measuring the response to the T cell-independent antigen, TNP-Ficoll. To investigate the possible influence of dietary protein type on the supply of B lymphocytes, bone marrow lymphocyte production has been examined by a radioautographic assay of small lymphocyte renewal and an immunofluorescent stathmokinetic assay of pre-B cells and their proliferation. The humoral response of all mice fed the L diet was found to be higher than that of mice fed the C diet or nonpurified diet. A similar pattern of dietary protein effect in (CBA/N X DBA/2J) F1 mice carrying the xid defect was observed following challenge with sheep red blood cells (SRBC). An even greater enhancing effect of dietary L was noted in normal (DBA/2J X CBA/N) F1 mice after immunization with SRBC, but in contrast, the normal large-scale production of B lymphocytes in mouse bone marrow was independent of the type of dietary protein. Dietary protein type did not affect blood level of minerals and trace metals. The free plasma amino acid profile essentially conformed to the amino acid composition of the ingested protein, suggesting that the changes in plasma amino acid profile might be a crucial factor in diet-dependent enhancement or depression of the B-cell response.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Acute necrosis of the intestinal mucosa with high serum levels of diamine oxidase.

A patient with acute necrosis of the intestinal mucosa and high serum diamine oxidase activity is described. The 71-year-old woman, with a history of hypertension and cardiovascular and peripheral arteriosclerotic disease, presented with acute epigastric pain, vomiting, and a deteriorating hemodynamic condition. Serum level of the intestinal enzyme diamine oxidase (DAO) obtained on admission, approximately 24 hr after the onset of symptoms, was 7.4 times above the normal value. An exploratory laparotomy performed 6 hr later revealed cyanosis and areas of transmural necrosis involving the entire small bowel. The bowel was not resected because of the extent of lesion. Thirty hours after the first sample was taken and 2 hr before death, the serum DAO level was only slightly above normal. It is suggested that this biochemical marker could provide a valuable tool for the early diagnosis of intestinal ischemia.

Acute Disease↗
PubMed1983

Influence of dietary protein type on the immune system of mice.

The effect of graded amounts of dietary lactalbumin (L), casein (C), soy (S), wheat (W) protein and Purina rodent chow (stock diet) on the immune responsiveness of C3H/HeN mice has been investigated by measuring the specific humoral immune response to sheep red blood cells (SRBC), and horse red blood cells (HRBC) as well as the nonspecific splenic cell responsiveness to phytohemagglutinin (PHA) and concanavalin A (Con A) after stimulation with Mycobacterium bovis, strain BCG. The nutritional efficiency of these diets was normal and similar. The immune response of mice fed the L diets, was found to be almost five times higher than that of mice fed the corresponding C diets. The humoral immune response of mice fed C, S, and W diets was substantially lower than that of mice fed stock diet, whereas that of mice fed L diet was higher. The above-described immune effect of all tested proteins was obtained at 20 g/100 g concentration with no further increments with 30- and 40 g/100 g protein in the diet. Mitogen responsiveness to PHA and Con A in L diet-fed mice was only slightly higher than that of C diet-fed mice. Little difference in immune responses was noted among mice fed C, S or W protein diets. The principal factor responsible for the observed immune effect does not appear to be the availability or concentration of single essential amino acids but rather the composite effect of the specific amino acid distribution in the protein.

Amino Acids↗