Protein-free Diet Research Articles

Long-term outcome of a child with hyperinsulinism- hyperammonaemia syndrome

Methods A male infant was born at 38 gestational weeks with birth weight of 3.605 kg. He presented with convulsion at 28 days of life. Physical examination was unremarkable. He was initially treated as meningoencephalitis. CT brain was unremarkable. Bacterial and viral cultures were negative. Plasma glucose upon admission was 1.2 mmol/l with negative urine ketone. Glucose infusion was high up to 12.1 mg/kg/min. Two sets of critical samples were obtained during hypoglycaemia. Workup for metabolic diseases was unremarkable. But ammonia levels were persistently high up to 252353 umol/l. Octreotide injection was started to achieve euglycaemia. Protein free diet was tried but without success in lowering ammonia levels. Octreotide was later switched to oral diazoxide and hydrochlorothiazide. Full enteral feeding was established with stable glucose levels. Results Genetic analysis showed a mutation in axon 10; Asn410I1e (N410I), a mutation of AAC to ATC at codon 410. The diagnosis of hyperinsulinism-hyperammonaemia syndrome was confirmed. We follow the child until he is 6 years of age. Home blood glucose monitoring prevented him from hypoglycaemia. Fasting test was performed every year to fine tune his diazoxide dosage. He remained seizure free while ammonia levels remained high up to 123-218 μmol/l. Formal developmental assessment performed at 5 years of age showed delay in cognitive and speech development for 11.5 years, and attention-deficit hyperactivity syndrome.

Biochemical markers of bone metabolism in children with cow’s milk allergy

IntroductionPatients with cow's milk allergy (CMA) and following a cow milk protein-free diet for a long time are potentially at risk of developing bone abnormalities. To assess the balance between bone formation and resorption processes, we determined serum concentrations of osteocalcin (OC), bone alkaline phosphatase (BALP), C-terminal telopeptide of type I collagen (CTX), fetuin-A, osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) in children with CMA.Material and methodsThe study included 50 prepubertal children with diagnosed cow's milk allergy, who were under systematic medical and nutritional care at the Institute of Mother and Child and 40 healthy counterparts as a control group. The concentrations of bone metabolism markers were determined by immunoenzymatic assays.ResultsThe diets of all investigated children were correct in terms of phosphorus and magnesium contents but deficient in terms of calcium and vitamin D. Serum OC and CTX as well as fetuin-A concentrations were similar in both studied groups. The BALP activity was significantly (p < 0.05) higher in children with cow's milk allergy than in the controls. Serum OPG concentration was comparable in both groups, but the RANKL level was higher (p < 0.05) in CMA children than in healthy ones. Hence, the ratio of OPG/RANKL was lower in children with CMA.ConclusionsOur study demonstrates slight disturbances in the profile of bone metabolism markers in growing children with CMA. The increase in RANKL level and decrease in OPG/RANKL ratio may contribute to intensification of bone resorption in these patients.

Conversion of High and Low Pollen Protein Diets Into Protein in Worker Honey Bees (Hymenoptera: Apidae)

Adequate protein levels are necessary to maintain strong honey bee [Apis mellifera (L.)] colonies. The aim of this study was to quantify how pollens with different crude protein contents influence protein stores within individual honey bees. Caged bees were fed one of three diets, consisting of high-protein-content pollen, low-protein-content pollen, or protein-free diet as control; measurements were made based on protein content in hemolymph and fat body, fat body weight, and body weight. Vitellogenin in hemolymph was also measured. Bees fed with high crude protein diet had significantly higher levels of protein in hemolymph and fat bodies. Caged bees did not increase pollen consumption to compensate for the lower protein in the diet, and ingesting approximately 4 mg of protein per bee could achieve levels of 20 microg/microl protein in hemolymph. Worker bees fed with low crude protein diet took more time in reaching similar protein content of the bees that were fed with high crude protein diet. The data showed that fat bodies and body weight were not efficient methods of measuring the protein status of bees. The determination of total protein or vitellogenin concentration in the hemolymph from 13-d-old bees and protein concentration of fat bodies from 9-d-old bees could be good indicators of nutritional status of honey bees.

Induction of immune tolerance to caseins and whey proteins by oral intubation in mouse allergy model

This study was designed to evaluate the effect of oral tolerance of caseins (CSN) and whey proteins (WP) in alleviating the allergic response to cow's milk proteins in Swiss albino mice raised on a milk protein-free diet. Oral tolerance was induced by feeding mice with 20 mg of CSN or WP once in a day for 4 days consecutively before immunization with respective protein by intraperitoneal (i.p.) injections (20 μg 200 per μl of PBS) using 2% of alum Al(OH)3 as adjuvant. Three weeks later, oral tolerance induction was analysed in humoral and cellular compartments of CSN- and WP-fed versus saline-fed control mice groups by measuring seric and intestinal antibody responses, mRNA abundance in splenic tissue and cytokine secretion patterns. The specific serum immunoglobulin-E (IgE) levels were significantly suppressed (p < 0.05), while sIgA was enhanced in these groups when compared with their respective saline-fed mice. Moreover, the mRNA levels of interferon-γ (IFN-γ) and interleukin-4 (IL-4) in both CSN- and WP-tolerized mice were found to be significantly decreased, while the abundance of interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) was increased significantly, as compared to respective control groups. Finally, cytokine profiles indicated a reciprocal decrease in IL-4 and IFN-γ versus an increase in IL-10 secretions in supernatants of cultured splenocytes of tolerized mice. Taken together, these results clearly showed that oral administration of cows' milk caseins and whey proteins can induce significant hyposensitization in mice, with the participation of suppressor cytokines.

Use of markers to determine the ileal digestibility of amino acids for swine

Many markers can be used in digestibility assays for swine, but needs to be evaluated before its use. An assay was carried out with the objective of measuring the coefficients of ileal apparent (CIAD) and standardized digestibility (CISD) of amino acids in meat and bone meal for swine using different markers. Eight crossbred barrows were equipped with T-cannulas in the distal ileum. Four animals received a free protein diet and another four received a diet containing meat and bone meal as the only protein source in the diet. The treatments consisted in evaluating the chromic oxide, acid-insoluble ash naturally occurring in the diet, cellulose and lignin as markers to determine the apparent and standardized digestibility of the amino acids contained in the meat and bone meal. All data were submitted to analysis of variance and means were compared using the Tukey test, with a significance of 5%. The CIAD, obtained using chromic oxide as external marker, were lower (P&lt;0.05) than those obtained when acid insoluble ash, lignin and cellulose were used as markers, observing differences for all the amino acids evaluated. Similarly, the CISD from all the studied amino acids were lower (P&lt;0.05) when the chromic oxide was used for determining the indigestibility factor. It is concluded that chromic oxide used as a external marker, to determine the coefficients of apparent and standardized ileal digestibility of the amino acids of the meat and bone meal, is most appropriate than the acid insoluble ash naturally occurring in diets, lignin and cellulose.

Diet formulation techniques and lysine requirements of 1- to 22-day-old broilers

Two experiments were carried out to compare two techniques (amino acid supplementation and dilution) for formulating experimental diets for pre-starter (1 to 8 days) and starter (8 to 22 days) broiler chicks and to estimate digestible lysine requirements using the dose-response method. In each experiment, 1,200 male Cobb 500 chickens were randomly distributed according to a 5x2 factorial arrangement (lysine level x formulation technique) with six replicates of 20 birds each. For the supplemented diet, a basal diet was formulated to meet the nutritional requirements, then L-lysine HCl was added to achieve digestible lysine levels of 0.975, 1.082, 1.189, 1.296 and 1.403% in the pre-starter diets and 0.840, 0.932, 1.024, 1.116 and 1.208% in the starter diets. For the diluted diet, a diet high in crude protein (CP) and relatively low in lysine was formulated and to which was added a protein-free diet until lysine levels were similar to those described above for the supplemented diet. The results suggest that the dilution technique favored the performance potential and better met lysine requirements compared with the supplementation technique. Lysine levels required for optimal feed conversion ratio of broilers during the pre-starter and starter phases were estimated at 1.361 and 1.187%, which are equivalent to lysine intake of 0.340 and 0.797 g/day, respectively.

L-glutamate secretion in the pancreatic juice involves transport and metabolism of neutral amino acids in exocrine pancreas

Introduction: The pancreas efficiently absorbs amino acids (AA) for the synthesis of enzymes, but also secrets free AA in the pancreatic juice. Under free protein diet (FPD), the AA release on the pancreatic juice (PJ) may play an important role on the homeostasis maintenance of the small intestine. Aims: The aim of this study was to analyze acinar synthase and secretion of L-glutamate (Glu), the most concentrated AA in PJ. Materials & methods: Expression of enzymes involved in Glu synthesis, AA concentration and ptotein localization were performed. Results: Two glutaminase isoforms (gls1 and gls2) are expressed in the pancreas, and the mRNA levels of gls2 and of the alanine aminotransferase 1 (gpt) were elevated in animals receiving (FPD). These results suggest Glu may be synthesized in the exocrine pancreas from L-glutamine (Gln) and L-alanine (Ala) and that the dietary protein content can modulate the expression of enzymes involved in the synthesis of Glu. The secretory mechanism of Glu to PJ does not involve zymogen granules vesicles (ZGV). Glu and its precursors were not concentrated in ZGV but were found at high concentrations in the cytoplasmic fraction, suggesting the secretory mechanism does not involve exocytosis. Immunofluorescence of pancreatic tissue suggested that the Naâo-dependent Glu transporter EAAT1 (Slc1a3) localizes proximal to the apical membrane of acinar cells and may be involved in the secretion of Glu. Conclusion: These preliminary results suggest a new mechanism for Glu concentration and secretion on the PJ, as well a recycling of neutral AA (Ala, Gln) and Glu between the pancreas and intestine.

Abstract 214: Protein Restriction Attenuates Intimal Hyperplasia and Alters Blood Lipid Profiles

Introduction Dietary restriction (DR: reduced enteral intake without malnutrition) diminishes the acute phase response to surgical stress in preclinical models. We hypothesized that short-term preoperative protein-free DR would attenuate the vascular response to injury (intimal hyperplasia: IH) while perturbing systemic circulating lipids. Methods After 2 weeks of 60% fat kcal diet, 8 week old B6D2F1/J mice had ad lib access to a complete 10% fat kcal diet (n=10) or a reduced calorie, protein-free diet (DR group, n=10) 1 week before induction of IH, then an ad lib complete diet. IH was induced via a validated model placing a nylon suture tie around the distal carotid artery and external 35g needle mandrel (outer diameter=0.14mm). Subsequent removal of the mandrel created a focal area of stenosis (~78% lumen diameter/~85% flow reduction). 4 weeks later, tissues were harvested for morphology and immunohistochemistry for CD45. Separately, serum was collected from mice fed a complete or DR diet for 1 week absent any surgical stress (n=20/group) for mass spectrometry-based lipidomics. Results DR mice showed less intimal area (p = 0.032) vs controls with statistically equivalent intimal leukocyte infiltration. DR mice also had significantly larger internal elastic lamina length (p = 0.003), a remodeling measure. DR serum exhibited significant decreases in certain classes of circulating lipids, including a collapse of multiple triglyceride types. Conclusions One week of protein-free DR dramatically decreased circulating lipids and attenuated arterial IH. Preoperative dietary manipulations may offer a practical means of extending durability of vascular interventions.

The mean dietary protein intake at different stages of chronic kidney disease is higher than current guidelines

The actual dietary protein intake of adults without and with different stages of chronic kidney disease is not known. To evaluate this we performed cross-sectional analyses of 16,872 adults (20 years of age and older) participating in the National Health and Nutrition Examination Survey 2001-2008 who completed a dietary interview by stage of kidney disease. Dietary protein intake was assessed from 24-h recall systematically collected using the Automated Multiple Pass Method. Complex survey analyses were used to derive population estimates of dietary protein intake at each stage of chronic kidney disease. Using dietary protein intake of adults without chronic kidney disease as the comparator, and after adjusting for age, the mean dietary protein intake was 1.30 g/kg ideal body weight/day (g/kgIBW/d) and was not different from stage 1 or stage 2 (1.28 and 1.25 g/kgIBW/d, respectively), but was significantly different in stage 3 and stage 4 (1.22 and 1.13 g/kgIBW/d, respectively). These mean values appear to be above the Institute of Medicine requirements for healthy adults and the NKF-KDOQI guidelines for stages 3 and 4 chronic kidney disease. Thus, the mean dietary protein intake is higher than current guidelines, even after adjusting for age.

Double-blind placebo-controlled food challenges in children with alleged cow’s milk allergy: prevention of unnecessary elimination diets and determination of eliciting doses

BackgroundChildren with cow’s milk allergy (CMA) need a cow’s milk protein (CMP) free diet to prevent allergic reactions. For this, reliable allergy-information on the label of food products is essential to avoid products containing the allergen. On the other hand, both overzealous labeling and misdiagnosis that result in unnecessary elimination diets, can lead to potentially hazardous health situations. Our objective was to evaluate if excluding CMA by double-blind placebo-controlled food challenge (DBPCFC) prevents unnecessary elimination diets in the long term. Secondly, to determine the minimum eliciting dose (MED) for an acute allergic reaction to CMP in DBPCFC positive children.MethodsAll children with suspected CMA under our care (Oct’05 - Jun’09) were prospectively enrolled in a DBPCFC. Placebo and verum feedings were administered on two randomly assigned separate days. The MED was determined by noting the ‘lowest observed adverse effect level’ (LOAEL) in DBPCFC-positive children. Based on the outcomes of the DBPCFC a dietary advice was given. Parents were contacted by phone several months later about the diet of their child.Results116 children were available for analysis. In 76 children CMA was rejected. In 60 of them CMP was successfully reintroduced, in 2 the parents refused introduction, in another 3 the parents stopped reintroduction. In 9 children CMA symptoms reappeared. In 40 children CMA was confirmed. Infants aged ≤ 12 months in our study group have a higher cumulative distribution of MED than older children.ConclusionsExcluding CMA by DBPCFC successfully stopped unnecessary elimination diets in the long term in most children. The MEDs form potential useful information for offering dietary advice to patients and their caretakers.

Nasally Administered Lactobacillus rhamnosus Accelerate the Recovery of Humoral Immunity in B Lymphocyte-Deficient Malnourished Mice

The ability of nasally administered Lactobacillus rhamnosus CRL1505 to accelerate the recovery of respiratory B cell-mediated immunity against pneumococcal infection in replete malnourished mice was evaluated. Weaned mice were malnourished after consumption of a protein-free diet for 21 d. Malnourished mice were fed a balanced conventional diet (BCD) for 7 d (BCD group) or a BCD for 7 d with supplemental L. rhamnosus CRL1505 by the nasal route during the last 2 d (BCD+Lr group). Nonreplete malnourished and normal mice were used as the malnourished (MNC) and the well-nourished (WNC) control groups, respectively. Mice were challenged with Streptococcus pneumoniae at the end of each dietary treatment. The immune response was studied before the challenge and at different times postinfection. The MNC mice had less resistance to pneumococcal infection, fewer mature and immature B cells in lung and spleen, and a reduced production of specific antibodies compared with WNC mice. The BCD treatment did not induce a complete normalization of the number B cell populations and antibody amounts. However, the BCD+Lr group had normal numbers of spleen and lung B cells. Moreover, the BCD+Lr mice had a significantly lower susceptibility to S. pneumoniae infection and higher amounts of anti-pneumococcal antibodies. Although further studies are necessary to clarify the effect of malnutrition and nasally administered lactobacilli in other immune cell populations involved in the protection against respiratory pathogens, this work gives evidence of the importance of using nasal priming with probiotics to accelerate the recovery of respiratory immunity in immunocompromised malnourished hosts.

Prediction of apparent, standardized, and true ileal digestible total and reactive lysine contents in heat-damaged soybean meal samples1

Forty-two individually housed entire male pigs weighing 37.5 ± 0.15 kg (mean ± SEM) were used in a randomized block design having 7 dietary treatments (n = 6). The dietary treatments were 5 semisynthetic diets containing 350 g/kg of soybean (Glycine max) meal (SBM) with variable heat treatments (0, 7, 14, 21, and 28 min autoclaved at 135°C), a protein free (N-free) diet, and an enzymatically hydrolyzed casein (EHC) diet. Heat treatment linearly decreased (P < 0.001) total Lys content from 27.5 to 19.2 g/kg and reactive Lys content from 23.4 to 11.7 g/kg. Apparent, standardized, and true ileal digestible total and reactive Lys contents linearly decreased (P < 0.001) with increasing severity of heat treatment and were accurately predictable (P < 0.001) from total and reactive Lys content in heat-damaged SBM. These data indicate that excessive heat processing of SBM reduced both the content (P < 0.001) and digestibility (P < 0.001) of total and reactive Lys in SBM.

A Preoperative Protein Free Diet Protects Against Renal Ischemia and Reperfusion Injury

Background: Ischemia and reperfusion (I/R) injury is a serious and common complication of organ transplantation. Previously we showed that both two weeks of 30% dietary restriction and three days of preoperative fasting protects against renal I/R injury. In the present study, we investigated whether the protective effect was induced by a reduction of calories, or by absence of a specific food component. Materials and methods: Male C57BL/6 mice (n= 6/group) had ad libitum access to diets free of protein-, methionine-, tryptophan-,leucine, carbohydrate or fat before induction of renal I/R injury. Renal I/R injury was induced by clamping both kidneys during 37 minutes. After removing the clamp, I/R injury was assessed by serum urea levels and signs of animal discomfort. Mice fed ad libitum control diets and pair-fed (PF) controls for the deficient diets were used as control. Results: A 14 day preoperative protein-, methionine-, tryptophan- or leucine-free diet protected against renal I/R injury. PF controls revealed that mice on modified diets restricted their calorie intake by 30%. Since we previously showed that 30% dietary restriction for 14 days induces protection against I/R injury the effect of individual dietary components could not be separated from the effect of DR. Three days of 30% DR does not induce protection against I/R injury. Therefore we administered these diets during 3 preoperative days, and found that only the protein-free diet protected against renal I/R injury. Conclusion: A three day preoperative protein-deficient diet protects against renal I/R injury. These data show that the absence of protein is responsible for the protection induced by DR.

Modulation of the immuno-coagulative response in a pneumococcal infection in malnourished mice nasally treated with Lactobacillus casei

We studied the systemic effects of the intranasal administration of Lactobacillus casei on the immuno-coagulative response in pneumoccocal infection in immunocompromised mice. Weaned mice consumed a protein-free diet (PFD) for 21 days and were therefore malnourished. Malnourished mice were fed a balanced conventional diet (BCD) for 7 days (BCD group) or a BCD for 7 days with nasal administration of viable L. casei on days 6 and 7 (BCD+LcN group). The malnourished control mice (MNC) received a PFD, whereas the well-nourished control mice (WNC) continually consumed a BCD. At the end of the treatment period, the mice were infected with Streptococcus pneumoniae. At different times after infection, we analysed the following parameters: global coagulation system, activation of coagulation, coagulation inhibitors, platelet count, leukocyte count and myeloperoxidase (MPO) activity, total proteins, albumin and acute phase proteins (APPs). The MNC group showed greater impairment in the coagulation tests and an increase in the positive APPs. These parameters were normalized by the L. casei treatment. However, the number of leukocytes, decreased by malnutrition, was improved only by the administration of L. casei. After infection, the BCD+LcN group showed similar results to those of the WNC group for most of the haemostatic parameters. The BCD+LcN group did not show significant variations in the prothrombin time or in the level of anticoagulant protein C, but showed higher levels of fibrinogen, platelets, albumin, leukocytes and MPO activity compared with the different experimental groups. The intranasal administration of L. casei was effective in modulating the pro-inflammatory aspects of coagulation without affecting coagulation itself.

Gut luminal endogenous protein: Implications for the determination of ileal amino acid digestibility in humans

The true ileal digestibility assay provides the most informative measure of digestibility to assess bioavailability of amino acids in foods for humans. To determine 'true' estimates of ileal amino acid digestibility, requires that endogenous amino acids present in digesta at the terminal ileum be quantified. The amounts of endogenous amino acids in ileal digesta can be determined after feeding an animal or human a protein-free diet (traditional approach) or by various methods after giving a protein-containing diet. When the protein-free method has been applied with adult human subjects an overall mean value (three separate studies) for endogenous ileal nitrogen flow of 800 mg N/d has been reported. This value is considerably lower than a comparable value obtained after feeding protein of 1852 mg N/d (mean of four separate studies), and thus endogenous ileal N and amino acids should be measured under conditions of protein alimentation. There is some confusion concerning the terminology used to define digestibility, with the term "true" digestibility having different adopted meanings. Here, true amino acid digestibility is defined as apparent amino acid digestibility corrected for the basal amino acid losses determined after giving either a protein-free or a protein-containing diet. Basal losses should be determined at a defined dry-matter and protein intake. The protein-free diet approach to determining endogenous amino acids is considered unphysiological and basal losses refer to ileal endogenous amino acid flows associated with digesta dry-matter flow, and not including "specific" effects of dietary factors such as non starch polysaccharides and anti nutritional factors. Arguments are advanced that the enzyme hydrolysed protein/ultra filtration method may be suitable for routine application with a cannulated pig model, to obtain physiologically-valid basal estimates of ileal endogenous amino acids to allow calculation of true ileal amino acid digestibility in the pig, and then prediction (via statistical relationships) of true coefficients of amino acid digestibility in humans.

Dietary selection by gilthead sea bream (Sparus aurata) provided with unbalanced mixed-macronutrient feeds dispensed from self-feeders

We investigated dietary self-selection in gilthead sea bream using a multiple-choice self-feeding system. To this end, five groups of 15 fish (154g BW) were distributed among 500-l tanks and allowed to self-feed from 3 self-feeders, each of which distributed feeds composed of combinations of macronutrients. Three different selection ranges of protein (P), carbohydrate (C) and fat (F) (expressed as percentage of total macronutrients) were tested: in phase 1, PF (75%–25%, respectively), PC (75%–25%) and CF (85%–15%); in phase 2, PF (60%–40%), PC (75%–25%) and CF (60%–40%); and in phase 3, PF (60%–40%), PCF (20%–50%–30%) and PC (90%–10%). In addition, the effect of P deprivation on energy intake was tested. The results revealed that, despite the different selection ranges in each phase, the macronutrient composition of the selected diets did not differ significantly during the experiments, being on average 63.7±0.6% P, 15.5±1.7% F and 20.6±1.15% C. When sea bream were restricted to self-feeding on a protein-free diet for 10days, and were only given the CF (60%–40%) diet, the fish sustained their average energy intake (260.0±37.7kJ/kg BW/day), which did not differ statistically from the average energy intake during the previous three experimental phases (284.6±26.9kJ/kg BW/day). In conclusion, sea bream were able to compose and defend a balanced diet by selecting from three incomplete diets, and the fish were also able to maintain their energy intake for a short period of time when allowed to self-feed on a protein-free diet.

Not any type of rice performs equally to improve lactose-induced diarrhea characteristics in rats: is amylose an antidiarrheal factor?

The effectiveness of different types of rice in relation to their ability to accelerate diarrhea recovering was evaluated in a rat model of osmotic diarrhea (OD). Animals (90-100 g) received protein free diet until reaching up to 20% weight loss, followed by lactose rich diet (LRD) to induce osmotic diarrhea. Rats presenting osmotic diarrhea were divided into 4 groups, which received lactose rich diet for 4 days from 8 am to 8 pm, and one of three experimental products containing 6% rice flour differing in amylose content during the night: high (HA), intermediate (IA), and low (LA). A group fed stock diet containing equivalent amount of lactose was taken as control and allowed to recover spontaneously. Amylose and viscosity (cp at 25 °C, 10 rpm) of final products were determined. Effectiveness was expressed as the ratio between percentages of normal vs. diarrheic stools during the treatment. Fecal characteristics in this rat model improved only as result of feeding high amylose content (HA) type of rice. In this experimental model of osmotic diarrhea in young rats, the antidiarrheal effects of rice were strongly dependent on the type of diet used and appear to be related to its amylose content.

Apparent and true digestibility of protein and amino acid in feedstuffs used in Nile Tilapia feed as determined by the technique of dissection

The objective of this study was to determine the coefficients of apparent and true digestibility of protein and amino acids of five feedstuffs (corn, wheat bran, soybean meal, corn gluten meal and fish meal) in 900 sex-reversed Nile tilapia (Oreochromis niloticus) of the Thai strain during the growth phase, with an initial weight of 315±8.45 g. A total of 750 fish were distributed according to a randomized block design (repetitions in time) into five treatments with six replicates of 25 fish each. The remaining 150 fish were fed a protein-free diet to measure endogenous protein and amino acid losses in order to determine the true digestibility of these components. Each tested diet contained a single protein source, which consisted of one of the evaluated feedstuffs. Digestibility was indirectly estimated using chromic oxide at 0.50% as marker. Digesta was collected from the last 5 cm of the distal intestine (between the ileal-rectal valve and the anus) using the dissection technique. Apparent digestibility coefficients of protein and amino acids were, on average, 74.69 and 73.62% for corn, 73.74 and 72.81% for wheat bran, 86.01 and 84.66% for soybean meal, 85.19 and 84.29% for corn gluten meal, 76.74 and 75.56% for fish meal, respectively. True digestibility coefficients of protein and amino acids were, on average, 85.21 and 83.97% for corn, 84.41 and 83.74% for wheat bran, 87.22 and 87.51% for soybean meal, 87.97 and 87.34% for corn gluten meal, and finally 79.58 and 78.44% for fish meal, respectively.

Effect of tomato and Tocopherols intake on IgE level

The aim of this research was to evaluate the effect of tomato and tocopherols intake on IgE level in Lamina Propria of intestinal villi.An experimental rat model of protein malnutrition at weaning was used. Rats of Wistar strain were fed a protein‐free diet until they lost 25% of their initial body weight. This feeding procedure develops an allergic state. Re‐feeding was performed by the administration of an experimental diet containing 20% casein as the only source of protein (Re‐nourished group=R). Other experimental groups received this diet plus tomato (R+T) – equivalent to 200g/day for an adult man of 70kg‐ or plus a tocopherols mix (á, â, ã, ä) equivalent to those present in tomato fruit (R+Tph), added to drinking water during 35 days.Results showed that Lamina Propria of intestinal villi of R+T group presented higher % of IgE+ B cells compared to R (99±8; 62±11) and intake of tocopherols mixture reverted that situation lowering the levels to 31±6. These results would suggest that tomato could be an allergenic food as tested in this model. Instead, tocopherols were effective to alleviate the basal allergic status.

Surgical Stress Resistance Induced by Single Amino Acid Deprivation Requires Gcn2 in Mice

Dietary restriction, or reduced food intake without malnutrition, increases life span, health span, and acute stress resistance in model organisms from yeast to nonhuman primates. Although dietary restriction is beneficial for human health, this treatment is not widely used in the clinic. Here, we show that short-term, ad libitum feeding of diets lacking essential nutrients increased resistance to surgical stress in a mouse model of ischemia reperfusion injury. Dietary preconditioning by 6 to 14 days of total protein deprivation, or removal of the single essential amino acid tryptophan, protected against renal and hepatic ischemic injury, resulting in reduced inflammation and preserved organ function. Pharmacological treatment with halofuginone, which activated the amino acid starvation response within 3 days by mimicking proline deprivation, was also beneficial. Both dietary and pharmacological interventions required the amino acid sensor and eIF2α (eukaryotic translation initiation factor 2α) kinase Gcn2 (general control nonderepressible 2), implicating the amino acid starvation response and translational control in stress protection. Thus, short-term dietary or pharmacological interventions that modulate amino acid sensing can confer stress resistance in models of surgical ischemia reperfusion injury.