Effect of Perioperative Immuno-Enhanced Enteral Nutrition on Inflammatory Response,Nutritional Status,and Outcomes in Head and Neck Cancer Patients Undergoing Major Surgery

Administration of imunno-enhanced nutritional support may decrease postoperative morbidity, mortality, and infectious complications in cancer patients. The aim of this study was to verify that perioperative enteral diet, enriched with the nutrients arginine, ribonucleic acid (RNA), and ω-3 fatty acids improves outcomes of head and neck cancer patients undergoing major surgery. Forty patients with squamous cell carcinoma of the head and neck were studied. Group 1 received no preoperative nutritional support, whereas Group 2 received an oral formula with nutrients arginine, RNA, and ω-3 fatty acids. After surgery, Group 1 received a standard enteral formula, whereas Group 2 received an enriched enteral formula. Albumin (g/dl), prealbumin, fibrinogen, CRP, Il-6, and TNFa were measured 5 days before and 8 days after surgery. No statistically significant difference was observed for all the evaluated markers between postoperative and preoperative levels for both groups. The rate of complications was significantly reduced in the total number of patients receiving immunonutrition and in the particular subgroup of well-nourished patients receiving an immuno-enhanced diet. Perioperative enteral immuno-enhanced feeding in head and neck cancer patients undergoing major surgery may influence the postoperative outcomes by reducing the frequency rate of infections and wound complications.     

Effect of perioperative immuno-enhanced enteral nutrition on inflammatory response, nutritional status, and outcomes in head and neck cancer patients undergoing major surgery

Administration of immuno-enhanced nutritional support may decrease postoperative morbidity, mortality, and infectious complications in cancer patients. The aim of this study was to verify that perioperative enteral diet, enriched with the nutrients arginine, ribonucleic acid (RNA), and ω-3 fatty acids improves outcomes of head and neck cancer patients undergoing major surgery. Forty patients with squamous cell carcinoma of the head and neck were studied. Group 1 received no preoperative nutritional support, whereas Group 2 received an oral formula with nutrients arginine, RNA, and ω-3 fatty acids. After surgery, Group 1 received a standard enteral formula, whereas Group 2 received an enriched enteral formula. Albumin (g/dl), prealbumin, fibrinogen, CRP, Il-6, and TNFa were measured 5 days before and 8 days after surgery. No statistically significant difference was observed for all the evaluated markers between postoperative and preoperative levels for both groups. The rate of complications was significantly reduced in the total number of patients receiving immunonutrition and in the particular subgroup of well-nourished patients receiving an immuno-enhanced diet. Perioperative enteral immuno-enhanced feeding in head and neck cancer patients undergoing major surgery may influence the postoperative outcomes by reducing the frequency rate of infections and wound complications.     

Influence of dietary fats and vitamin E on plasma and hepatic vitamin A and beta-carotene levels in rats fed excess beta-carotene

Effects of different dietary lipids and excess vitamin E on plasma and hepatic concentrations of beta-carotene were evaluated in rats fed diets containing a large excess (0.2%) of beta-carotene. Male weanling Wistar Kyoto rats were fed beta-carotene-supplemented diets containing various dietary lipids as follows: Group I, a saturated fat (coconut oil); Group II, a monounsaturated fat (olive oil); Group III, a polyunsaturated fat rich in omega-6 fatty acids (safflower oil); Group IV, same as Group III plus vitamin E; and Group V, a polyunsaturated fat rich in omega-3 fatty acids (menhaden oil). All diets contained 2% safflower oil to provide sufficient amounts of linoleic acid (an essential fatty acid). Rats were killed after six weeks of feeding the various diets, and the concentrations of beta-carotene and vitamin A were determined in plasma and liver. Plasma vitamin A levels were not altered by any of the dietary lipids or by an excess of vitamin E. The concentrations of beta-carotene in plasma were the lowest in rats fed the diet containing menhaden oil. The feeding of the diet containing an excess of vitamin E also resulted in a significant decrease in plasma beta-carotene concentration. Similarly, the hepatic beta-carotene concentration was also reduced to about one-half in rats fed the diet containing an excess of vitamin E. Liver beta-carotene concentration was higher in Groups II and III than in the other three dietary groups. Hepatic vitamin A concentrations were also affected by the type of dietary fat.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of glutamine on intestinal mucosal integrity and bacterial translocation after abdominal radiation

This study evaluates the effect of oral glutamine on intestinal mucosal integrity and bacterial translocation in rats. 80 animals were randomised into four groups: group 1 (chow diet and water), group 2 (chow diet and glutamine 3%), group 3 (radiation, chow diet and water), group 4 (radiation, chow diet and glutamine 3%). Groups 1 and 2 were fed for 5 days, then sacrificed. Groups 3 and 4 were fed for 12 days, irradiated on the 5th day and sacrificed on 1st, 3rd and 7th post-radiation days. Cultures from the mesenteric lymph nodes (MLN), portal vein (PV) and aorta (A) were taken and two tissue samples were also taken from the terminal ileum for light and electron microscopic examination. In non-radiated rats glutamine did not alter the histologic parameters of villous height (VH), mitoses per crypt (M/C) and muscle thickness (MT). Group 3 rats had severe mucosal damage associated with a significant decrease of VH (p < 0.0001) and M/C (p < 0.01) on 1st and 3rd post-radiation days respectively. In contrast, group 4 rats maintained their mucosal structure and had a significant increase of VH and M/C (p < 0.0001) on post-radiation days 1 and 3. Bacterial translocation in MLN was 87.5% (p < 0.002) and 75% (p < 0.04) on 1st and 3rd post-radiation days respectively in group 3, and fell significantly to 12.5% (p < 0.002) in group 4. The data demonstrate that glutamine helps maintain the integrity of the intestinal mucosa and thereby reduces the incidence of bacterial translocation following abdominal irradiation.     

Effect of early postoperative enteral immunonutrition on wound healing in patients undergoing surgery for gastric cancer

BACKGROUND & AIMS: One of the most frequent complications in patients with cancer and malnutrition is the surgical wound healing delay or failure. Some studies have shown that arginine improves wound healing in rodents and in healthy human beings. The main objective of this study was to assess the effect of early postoperative enteral immunonutrition on the wound healing process in patients undergoing surgery for gastric cancer. METHODS: Sixty six patients with gastric cancer were randomized to receive early postoperative enteral immunonutrition (formula supplemented with arginine, omega-3 fatty acids and ribonucleic acid (RNA)) or an isocaloric-isonitrogenous control. Assessment of wound healing process: (1) Quantification of hydroxyproline deposition in a subcutaneously placed catheter, (2) occurrence of surgical wound healing complications. RESULTS: Sixty patients were analyzed. Patients fed with immunonutrition (n=30) showed higher local hydroxyproline levels (59.7 nmol (5.0-201.8), vs. 28.0 nmol (5.8-89.6) P=0.0018) and significantly lower episodes of surgical wound healing complications (0 vs. 8 (26.7%) P=0.005) when compared to patients fed with the control formula (n=30). CONCLUSIONS: Early postoperative enteral nutrition with a formula supplemented with arginine, omega 3 fatty acids and RNA increased hydroxyproline synthesis and improved surgical wound healing in patients undergoing gastrectomy for gastric cancer.     

Effects of Three-Month Feeding High Fat Diets with Different Fatty Acid Composition on Myocardial Proteome in Mice

Westernized diet is characterized by a high content of saturated fatty acids (SFA) and a low level of omega-3 polyunsaturated fatty acids (PUFA), often accompanied by an imbalance in the omega-6/omega-3 PUFA ratio. Since increased intake of SFA and n-6 PUFA is considered as a cardiovascular disease risk factor, this study was conducted to determine whether a three-month dietary supplementation of high-fat diets (HFDs) with saturated fatty acids and a significant proportion of various n-6 and n-3 PUFA ratios would affect the architecture and protein expression patterns of the murine heart. Therefore, three HFD (n = 6) feeding groups: rich in SFA, dominated by PUFA with the n-6/n-3–14:1, and n-6/n-3–5:1, ratios were compared to animals fed standard mouse chow. For this purpose, we performed two-dimensional electrophoresis with MALDI-ToF mass spectrometry-based identification of differentially expressed cardiac proteins, and a histological examination of cardiac morphology. The results indicated that mice fed with all HFDs developed signs of hypertrophy and cardiac fibrosis. Animals fed SFA-rich HFD manifested the most severe cardiac hypertrophy and fibrosis lesions, whereas less pronounced changes were observed in the group of animals that ingested the highest amount of omega-3 FA. In general, all HFDs, regardless of FA composition, evoked a comparable pattern of cardiac protein changes and affected the following biological processes: lipid metabolism and FA β-oxidation, glycolysis, TCA cycle, respiratory chain, myocardium contractility, oxidative stress and PUFA eicosanoid metabolism. However, it should be noted that three proteins, namely IDH3A, LDHB, and AK1, were affected differently by various FA contents. High expression of these myocardial proteins found in the group of animals fed a HFD with the highest n-3 PUFA content could be closely related to the observed development of hypertrophy.     

Diets rich in polyunsaturated fatty acids: effect on hepatic metabolism in rats

OBJECTIVE: We investigated the effect of diets rich in omega-6 and omega-3 fatty acids on hepatic metabolism. METHODS: Male Wistar rats, just weaned, were fed ad libitum for 8 wk with one of the following diets: rat chow (C), rat chow containing 15% (w/w) soybean oil (S), rat chow containing 15% (w/w) fish oil (F), and rat chow containing 15% soy bean and fish oil (SF; 5:1, w/w). Casein was added to the fatty diets to achieve the same content of protein (20%) as the control chow. The rats were killed by decapitation, and the hepatic tissue was removed and weighed. Tissue lipid, glycogen, and protein content, in vivo lipogenesis rate, and adenosine triphosphate citrate lyase and malic enzyme activities were evaluated. Plasma total lipids, triacylglycerol, and cholesterol concentrations were assessed. RESULTS: Body weight gain was higher in F and SF than in C and S rats. Liver weight, lipid content, and lipogenesis rate increased in F and SF rats, although adenosine triphosphate citrate lyase activity decreased. Glycogen concentration decreased in S, F, and SF rats compared with C rats. Plasma total lipids and triacylglycerol concentrations were lower in F and SF than in C rats. Total and high-density lipoprotein cholesterol (HDL-C) plasma levels decreased in F rats, with maintenance of the total:HDL-C ratio. In SF rats, an increase in HDL-C led to a lower total:HDL-C ratio. CONCLUSIONS: These results indicated that an enrichment of the diet with omega-3 polyunsaturated fatty acids produces hypolipidemia but may cause changes in liver metabolism that favor lipid deposition. They also suggested that the addition of a small amount of eicosapentaenoic and docosahexaenoic polyunsaturated fatty acids to an omega-6-rich diet further improve the circulating lipid profile, in comparison with an omega-3-rich diet, but it does not prevent excess liver lipid accumulation.     

Effect of palatable diet on growth, caloric intake and endocrine-metabolic profile in weanling rats with dorsomedial hypothalamic lesions

Weanling male Sprague-Dawley rats received bilateral electrolytic lesions in the dorsomedial hypothalamic nuclei (DMNL rats); sham-operated rats served as controls. All animals were fed lab chow for 15 postoperative days. At that time they were subdivided into two groups each. One DMNL and one control group continued to be fed lab chow until the termination of the experiment on postoperative day 116. A second DMNL and control group were fed a high-fat diet and 32% sucrose solution (HF/SS diet). All DMNL rats showed reduced body weight and linear growth, but the HF/SS diet depressed these parameters further below the levels of the chow-fed groups. Both DMNL and control rats fed HF/SS had more carcass fat, heavier epididymal fat pads, more carcass fat per calories eaten, higher plasma levels of glucose, glycerol and free fatty acids but lower insulin levels than chow-fed DMNL rats and controls. This occurred in the face of lower body weights and caloric intake. Neither growth hormone nor insulin showed lesion effects. Rats with DMNL exhibited the same inverse relationship between plasma insulin and free fatty acids as controls. The data indicate that DMNL rats respond to the HF/SS diet essentially like sham-operated controls, i.e., they develop dietary obesity. Although they do show some small deficits, their lipogenic capacity is actually significantly greater than that of HF/SS-diet fed controls.     

The impact of arginine on bacterial translocation in an intestinal obstruction model in rats

BACKGROUND & AIMS: Arginine has been shown to have multiple beneficial metabolic and immunologic effects in stress situations. Supplementation of arginine has been shown to promote wound healing and intestinal mucosal recovery after trauma, ischemia or intestinal resection. Bacterial translocation has also been evaluated although with conflicting results and using different assessing techniques. Therefore, the aim of this study was to evaluate the effects of arginine on bacterial translocation in an intestinal obstruction model in rats using Escherichia coli labeled with 99mTechnetium. METHODS: Male Wistar rats (250-350 g) were randomized to receive conventional chow, diet supplemented with pure arginine or diet supplemented with an immunonutrition enteral formula, enriched with arginine, omega-3 fatty acid and RNA. After 7 days, the animals were anesthetized. Terminal ileum was isolated and a ligature was placed around it. E. coli labeled with 99mTechnetium (99mTc-E. coli) was inoculated into the intestinal lumen (terminal ileum). After 24 h, the animals were sacrificed. Blood, mesenteric lymph nodes (MLN), liver, spleen and lungs were removed for radioactivity determination. RESULTS: Arginine supplementation (300 mg/day, 600 mg/day or present in the enteral formula) reduced the level of bacterial translocation when compared with the control group (p<0.05). This was shown by significantly decrease uptake of 99mTc-E. coli in blood, MLN, liver, spleen and lungs of the animals in the experimental groups (p < 0.05). CONCLUSIONS: These results have shown that arginine was able to decrease bacteria translocation despite intestinal obstruction. There are several mechanisms which might explain the role of arginine and these will be the subject of future studies.     

Fish oil alters T-lymphocyte proliferation and macrophage responses in Walker 256 tumor-bearing rats

OBJECTIVE: We investigated the effect of the dietary ratio of omega-6 to omega-3 polyunsaturated fatty acids (PUFAs) from postweaning until adulthood on T-lymphocyte proliferation, T-lymphocyte subpopulations (helper and cytotoxic), and production of cytotoxic mediators by macrophages in tumor-bearing rodents. METHODS: Weanling male Wistar rats received a normal low-fat (40 g/kg of diet) chow diet or a high-fat (300 g /kg) diet that included fish or sunflower oil or blends of fish and sunflower oils to yield omega-6:omega-3 PUFA ratios of approximately 6:1, 30:1, and 60:1 ad libitum. After 8 wk, 50% of rats in each group were inoculated with 1 mL of 2 x 10(7) Walker 256 cells. Fourteen days after tumor inoculation, animals were killed and lymphocytes and macrophages were obtained for study. RESULTS: The diets richest in omega-6 PUFA resulted in higher proliferation of thymus, spleen, and gut-associated lymphocytes compared with the chow diet irrespective of tumor burden. In contrast, the fish oil diet resulted in lower proliferation of thymus and spleen lymphocytes compared with the chow diet. Diets rich in omega-6 PUFA decreased the proportion of CD8+ lymphocytes. In non-tumor-bearing and tumor-bearing rats, hydrogen peroxide production by macrophages was highest in rats that consumed diets high in omega-3 PUFAs. Superoxide and nitric oxide production were little affected by the dietary ratio of omega-6 to omega-3 PUFAs. CONCLUSION: Dietary omega-6 and omega-3 PUFA contents alter immune function in non-tumor-bearing and tumor-bearing rats. The omega-3 PUFAs decreased T-cell proliferation but increased hydrogen peroxide production compared with omega-6 PUFAs. Decreased tumor growth and cachexia and increased survival previously reported for fish oil in Walker 256 tumor-bearing rats may be related to improved macrophage function rather than to improved T-cell function.     

Influence of Dietary Fats Upon Systolic Blood Pressure in the Rat

Studies were performed to determine whether feeding diets with differing fatty acid content and composition had an influence on systolic blood pressure in the rat. Weanling male rats were fed standard laboratory chow (2.9% fat in total), or synthetic diets (10% fat in total) containing fish oil, butter, coconut oil or corn oil, for 5 weeks. Coconut oil and butter diets were rich in saturated fatty acids, whilst fish oil and corn oil were rich in the n-3 and n-6 unsaturated fatty acids respectively. Systolic blood pressure was measured using an indirect tail-cuff method at the end of the feeding period, and compared to a group of weanling rats.

Feeding the different diets did not alter the growth of the rats, so all animals were of similar weights at the time of blood pressure determination. Control (chow fed) animals, at nine weeks of age, had higher systolic blood pressures than the weanling, baseline control group. Fish oil fed rats had similar pressures to the chow fed rats. Corn oil fed rats had significantly lower systolic pressures than the controls. The rats fed the diets rich in saturated fatty acids (butter and coconut oil) had significantly higher blood pressures than all other groups. Systolic blood pressure was found to be significantly related to the dietary intakes of saturated and unsaturated fatty acids. The dietary intake of linoleic acid was significantly higher in corn oil fed rats than in other groups. Systolic blood pressure was inversely related to linoleic acid intake. Feeding a diet rich in saturated fatty acids significantly increases blood pressure in the rat. A high intake of n-6 fatty acids, and in particular linoleic acid, appears to have a hypotensive effect. Prenatal exposure of the rats to a maternal low protein diet, abolished the hypertensive effects of the coconut oil diet and the hypotensive effect of the corn oil diet upon young adult females. The intrauterine environment may, therefore, be an important determinant of the effects of these fatty acids on blood pressure in later life.     

Monounsaturated and omega-3 but not omega-6 polyunsaturated fatty acids improve hepatic fibrosis in hypercholesterolemic rabbits

OBJECTIVE: Although the influence of saturated fatty acids, monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), lipids, cholesterol levels, and other blood lipids has been established, few studies have examined the influence of these dietary lipids on the composition and histologic damage of organs in situations of hypercholesterolemia. Biliary lipids come from the liver, and this organ is essential in cholesterol homeostasis; thus, it may be helpful to evaluate the inter-relations among biliary, hepatic lipids, and hepatotoxic effects in situations of hypercholesterolemia with different dietary lipids. This study investigated whether administration of diets differing in fatty acid profiles (omega-3 PUFA, omega-6 PUFA, or MUFA) influence the content of biliary lipids, the lithogenic index of gallbladder bile, and the development of hepatic fibrosis in hypercholesterolemic rabbits. METHODS: Thirty rabbits were randomized to one of five groups. A control group received rabbit chow for 80 d. The remaining four groups received a 50-d diet that contained 3% lard and 13% cholesterol to provoke hypercholesterolemia. After this period, three groups were fed for another 30 d on a diet enriched with omega-6 PUFAs, MUFAs, and omega-3 PUFAs, respectively. Liver, bile, and plasma lipid compositions, lipid peroxidation in hepatic mitochondria, and histologic hepatic lesions were analyzed. RESULTS AND CONCLUSIONS: There was a beneficial effect of MUFA and omega-3 PUFA on hepatic fibrosis in hypercholesterolemic rabbits because both dietary fats led to recovery from hepatic lesions. However, because intake of omega-3 PUFA provoked lithogenic bile in rabbits, MUFA intake would be more advisable.     

Lipid profile of rats fed high-fat diets based on flaxseed, peanut, trout, or chicken skin

OBJECTIVE: Dietary saturated fatty acids are associated with coronary disease. Conversely, dietary monounsaturated polyunsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) seem to exert a protective effect. This study evaluated the lipid profile of rats fed high-fat (HF) diets, with fat added as different sources of PUFA (flaxseed and trout), MUFA (peanut), and saturated fatty acid (chicken skin). METHODS: Adult male Wistar rats were placed into six dietary groups (n = 10): control (normal); high fat, with 1% cholesterol, 10% soy oil, and 5% lard; and four groups fed similar HF diets, with 10% lipid as trout, flaxseed, peanut, or chicken skin. After 28 d the animals were killed. Blood, livers, and adipose tissue samples were collected. RESULTS: A higher level (P < 0.05) of total serum cholesterol was observed in rats fed the normal diet (93.57 +/- 14.95 mg/dL) compared with those fed the HF diet (67.57 +/- 12.54 mg/dL). Total cholesterol levels in rats fed the flaxseed diet were lower (P < 0.05) than in rats fed the other fats. No difference was observed in cholesterol levels between groups fed the peanut and chicken skin diets (P > 0.05). Animals fed the peanut diet showed decreased body weight gain than did animals in the other treatment groups. There were large lipid and cholesterol depositions in livers of rats fed the HF diet. Lipid deposition in adipose tissue followed the same dietary fatty acid profile, i.e., high levels of omega-3 PUFA in the flaxseed group, high levels of MUFA in the peanut and chicken skin groups and high levels of omega-6 PUFA in the trout group. CONCLUSIONS: These data indicate that flaxseed is promising for dietary manipulation of hyperlipidemia.     

Dietary supplementation of conjugated linoleic acid reduces colon tumor incidence in DMH-treated rats by increasing apoptosis with modulation of biomarkers

OBJECTIVES: We investigated the effects of conjugated linoleic acid (CLA) on tumor incidence, apoptosis, eicosanoid formation, 1,2-diacylglycerol (DAG), and fatty acid profiles of colonic mucosa in 1,2-dimethylhydrazine-treated rats fed different types of dietary fats. METHODS: One hundred twenty male 7-wk-old Sprague-Dawley rats were assigned to a beef tallow (BT) diet or a fish oil (FO) diet; each group was further divided into two groups, one with CLA supplementation (BTC and FOC) and the other without (BT and FO). All groups were fed for 30 wk on experimental diets that contained 12% (w/w) dietary fat (including 1% CLA for the BTC and FOC groups) and were intramuscularly injected with 1,2-dimethylhydrazine for 6 wk, for a total dose of 180 mg/kg of body weight. RESULTS: Rats fed the FOC, BTC, or FO (omega-3 fatty acids, mainly docosahexaenoic acid) showed a reduced incidence of tumors, increased apoptotic index values (P < 0.05), and lower levels of eicosanoids (prostaglandin E(2) and thromboxane B(2)) and DAG in colonic mucosa (P < 0.05). CLA and docosahexaenoic acid were incorporated into membrane phospholipids and significantly reduced the distribution of arachidonic acid in colonic mucosal phospholipids. Because CLA and omega-3 fatty acids reduced tumor incidence and levels of cell response regulators (prostaglandin E(2), thromboxane B(2), and DAG), they may share at least one common path of action in promoting the apoptotic process of colon carcinogenesis. CONCLUSIONS: These results suggested that increased apoptosis by dietary CLA may be attributed, at least in part, to changes in arachidonic acid metabolism in rats. Therefore, CLA may have anticarcinogenic effects by inducing apoptosis through modification of signal transduction in colonic mucosal cells.     

Dietary glutamine enhances cytokine production by murine macrophages

To examine the effects of dietary glutamine on cytokine production by macrophages, mice were fed for 2 wk on a control diet that included 200.0 g casein/kg providing 19.6 g glutamine/kg or a glutamine-enriched diet that provided 54.8 g glutamine/kg partly at the expense of casein. There were no differences in weight gain between animals fed the two diets. The plasma concentrations of a number of amino acids differed according to the diet fed; this variation largely reflected the variation in the levels of the different amino acids in the diets. Plasma glutamine concentration was not significantly affected by dietary glutamine level. The production of three cytokines, tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6, was greater for lipopolysaccharide-stimulated macrophages from mice fed the glutamine-enriched diet. Thus, increasing the amount of glutamine in the murine diet enhances the ability of macrophages to respond to stimulation, at least in terms of cytokine production. These observations suggest that increasing the availability of glutamine orally could promote immune responses involving macrophage-derived cytokines.     

Dietary fat (virgin olive oil or sunflower oil) and physical training interactions on blood lipids in the rat

OBJECTIVE: We investigated whether the intake of virgin olive oil or sunflower oil and performance of physical exercise (at different states) affect plasma levels of triacylglycerols, total cholesterol, and fatty acid profile in rats. METHODS: The study was carried out with six groups of male rats subjected for 8 wk to a diet based on virgin olive oil (three groups) or sunflower oil (three groups) as dietary fat. One group for each diet acted as sedentary control; the other two groups ran in a treadmill for 8 wk at 65% of the maximum oxygen consumption. One group for each diet was killed 24 h after the last bout of exercise and the other was killed immediately after the exercise performance. Triacylglycerols, total cholesterol, and fatty acid profile were analyzed in plasma. Analysis of variance was used to test differences among groups. RESULTS: Animals fed on virgin olive oil had lower triacylglycerol and cholesterol values. Physical exercise reduced these parameters with both dietary treatments. Fatty acid profile showed higher monounsaturated fatty acid proportion in virgin olive fed oil animals and a higher omega-6 polyunsaturated fatty acid proportion in sunflower oil fed animals. Physical exercise reduced the levels of monounsaturated fatty acids with both diets and increased the proportions of omega-3 polyunsaturated fatty acids. CONCLUSIONS: Results from the present study supported the idea that physical exercise and the intake of virgin olive oil are very good ways of reducing plasma triacylglycerols and cholesterol, which is desirable in many pathologic situations. Concerning findings on fatty acid profile, we had results similar to those of other investigators regarding the effect of different sources of dietary fat on plasma. The most interesting results came from the effect of physical exercise, with significant increases in the levels of omega-3 polyunsaturated fatty acids, which may contribute to the antithrombotic state and lower production of proinflammatory prostanoids attributed to physical exercise.     

Whole-protein-based enteral formula stimulates intestinal ornithine decarboxylase activity more than single amino acids but does not affect mucosal adenosine triphosphate content in early postsurgical refeeding.

BACKGROUND: To restore intestinal integrity after starvation and trauma, luminal nutrients are essential. Specific nutrients such as glutamine support mucosal proliferation and energy metabolism. The aim of this study was to compare effects of enteral formula vs specific amino acids on ornithine decarboxylase (ODC) activity and adenine nucleotide metabolism in jejunal mucosa. METHODS: Male Wistar rats (240 to 280 g) were starved for 48 hours and subjected to intestinal transection, gastrotomy, and jejunal instillation of 5mL nutrient solution. In the first experiment, standard enteral formula (EF) was compared with isonitrogenous formula supplemented with the glutamine precursor, alpha-ketoglutarate (alpha-KG). In a second experiment, 2% glutamine was compared with isonitrogenous ornithine alpha-KG, arginine alpha-KG, glycine and diluted standard enteral formula (EF), or saline. The ODC activity, adenosine triphosphates (ATP), and RNA and protein in the jejunal mucosa were analyzed 2 hours after surgery. RESULTS: The ODC peak in jejunal mucosa in animals treated with EF was higher than when supplemented with alpha-KG (p < .05). Compared with specific amino compounds, EF resulted in a significantly higher ODC peak and no differences were seen between the different specific amino acids. Differences seen in ATP or energy charge between the groups were not significant. CONCLUSIONS: Immediate postoperative enteral feeding by standard EF results in rapid increase of ODC activity. This response was attenuated when the enteral nutrition was supplemented with alpha-KG and was absent when isonitrogenous single amino acids were administered. We found no significant effects on ATP content in the small bowel mucosa by supplementing the diet with alpha-KG.     

Absorption of very-long-chain saturated fatty acids in totally hydrogenated fish oil

Partially hydrogenated fish oil (PHFO) contains a high amount of trans fatty acids (TFA). Total hydrogenation results in a minimal amount of TFA, but a high content of very-long-chain saturated fatty acids (VLCSFA). Absorption and metabolism of VLCSFA from totally hydrogenated fish oil (THFO) were studied in rats. Groups of eight rats were fed one of four diets containing 40 g soyabean oil (SBO)/kg (low-fat diet), 150 g SBO/kg (SBO diet), 40 g PHFO/kg (PHFO diet) or 40 g THFO/kg (THFO diet) for 4 weeks. A lower absorption coefficient of the fat content was found in the THFO group (61 %) compared with the other groups (PHFO 95 %, SBO 99 %, low fat 98 %; which was mainly due to reduced absorption of VLCSFA. A reduced weight gain was found for the THFO group compared with the other groups, but this was only significant when compared with the SBO group Faecal fat excretion (dry weight) was markedly increased in the THFO group (47 %), which was 2.4, 4.8 and 8.3 times higher compared with the groups fed PHFO, SBO and low-fat diets respectively. Serum total cholesterol was reduced for the PHFO and THFO groups whereas serum triacylglycerol was increased for the PHFO group compared with the other groups Animals fed THFO diet had an increased content of 20:0 and 22:0 in the serum triacylglycerol fraction whereas only 20:0 was increased in the serum phospholipid fraction The low absorption coefficient of THFO must be considered if this fat is to be used for consumption by animals or man.     

Nutritional support in acute pancreatitis

PURPOSE OF REVIEW: This review explores the role of enteral and parenteral nutrition in severe acute pancreatitis and discusses the potential benefits of glutamine, omega-3 fatty acids, arginine and selenium together with probiotics and prebiotics in these patients. In addition, the method of refeeding during the convalescent period is also examined. RECENT FINDINGS: A complex picture is emerging in which enteral nutritional support may be important early in the course of the disease with parenteral nutrition being used more as a backup and possibly only after the systemic inflammatory response has peaked. Nasogastric feeding, sometimes supplemented by parenteral nutrition, is as efficacious as nasojejunal feeding. An individualized approach, in which strategies of nutritional support are tailored to patient response, is gaining currency. Data regarding specialized formulae are mixed but the use of prebiotics is showing promise and is worthy of further exploration. In the convalescent period, preliminary data also indicate that the risk of pain developing is no greater if a light diet is instituted rather than clear fluids. SUMMARY: Nutritional support in acute pancreatitis remains challenging and controversial with a number of different and unexpected approaches, including the use of nasogastric feeding and dual enteral and parenteral nutrition support, being adopted in recent clinical trials.     

Suppression of altered hepatic foci development by a high fish oil diet compared with a high corn oil diet in rats

Effects of low corn oil, high corn oil, and high fish oil diets on altered hepatic foci development in female Sprague-Dawley rats were investigated. Rats assigned to Groups 1-4 were initiated with saline as the control and those assigned to Groups 5-7 were initiated with diethylnitrosamine (DEN 15 mg/kg) at 24 hours of age. After weaning, all rats, except those in Group 1, received 500 ppm phenobarbital (PB) in their diet as tumor promoter for three months. Altered hepatic foci development was significantly lower in DEN-initiated rats fed the high fish oil + PB diet than in DEN-initiated rats fed the high corn oil + PB diets. Liver weight and relative liver weight were significantly greater in rats fed the high fish oil + PB diet than in rats fed the other diets, and hepatic biotransformation/detoxification enzyme activities were greater in rats fed the fish oil + PB diets than in rats fed the other diets. These results suggest that the effect of a high fish oil diet on altered hepatic foci may occur through regulation of hepatic biotransformation/detoxification enzyme activities, leading to alteration in the tumor-promoting action of PB. Dietary lipid significantly affected the hepatic phospholipid fatty acid composition of rats. n-3 polyunsaturated fatty acids were incorporated into membrane phospholipid at the expense of n-6 polyunsaturated fatty acids. A high fish oil diet caused greater oxidative stress in rats, as measured by plasma vitamin E level, red blood cell glutathione status, liver lipid peroxidation, and hepatic glutathione reductase activity. Pearson's correlation analysis indicated that the foci number was negatively correlated to the liver thiobarbituric acid-reactive substance and 7-pentoxyresorufin O-dealkylase activity, and the foci area was negatively correlated to the liver thiobarbituric acid-reactive substance activity (p < 0.05) in rats of groups that developed foci. These results suggest that the type of dietary lipid is the more important determinant for gamma-glutamyl transpeptidase-positive foci development than the amount of dietary lipid when rats consumed approximately the same amount of calories in all the dietary groups, and the underlying mechanisms may be partially ascribed to the antioxidant/oxidation status and biotransformation/detoxification system of rats.