Fatty acid content of plasma lipids and erythrocyte phospholipids are altered following burn injury

Effects of hydrolyzed collagen alone or in combination with fish oil on the gut microbiome in patients with major burns

Burns are associated with gut dysbiosis. Collagen peptides and omega-3 fatty acids (FAs) are suggested to improve wound healing and the inflammatory response. These are also correlated with microbiome colonization. Therefore, the present study aimed to investigate the effect of hydrolyzed collagen alone or in combination with fish oil on specific species of the gut microbiome in patients with major burns. In this randomized double-blind clinical trial, 57 adults (aged 18-60 years) with 20-45% total body surface area burns were randomised into three groups to receive either 40 gr hydrolyzed collagen +10 ml sunflower oil, 40 g hydrolyzed collagen +10 ml fish oil or placebo, divided into two daily drinks, for two weeks. Gut bacteria were measured using the real-time quantitative polymerase chain reaction (qPCR) method. The mean concentration of Bifidobacterium was significantly reduced in the control (P = 0.002) and collagen (P = 0.005) groups compared with the baseline values, whereas no significant change was observed in the collagen omega-3 group. The Firmicutes to Bacteroidetes ratio decreased significantly in the collagen group (p = 0.002) after supplementation compared to baseline . No significant changes in concentration of Lactobacillus, Enterobacteriaceae, and F.prausnitzii were observed between or within the study groups. Two weeks of supplementation with collagen and omega-3 FAs in patients with major burns did not result in a significant difference in the concentration of bacteria measured between the study groups. However, the addition of omega-3 FAs prevented a significant reduction in gut Bifidobacterium. Future studies are suggested to investigate the potential efficacy of these nutrients in improving the gut microbiota and clinical outcomes in major burns. REGISTRATION NUMBER: IRCT20131125015536N9.

Cardiometabolic disease risk markers are increased following burn injury in children

Introduction

Burn injury in children causes prolonged systemic effects on physiology and metabolism leading to increased morbidity and mortality, yet much remains undefined regarding the metabolic trajectory towards specific health outcomes.

Methods

A multi-platform strategy was implemented to evaluate the long-term immuno-metabolic consequences of burn injury combining metabolite, lipoprotein, and cytokine panels. Plasma samples from 36 children aged 4-8 years were collected 3 years after a burn injury together with 21 samples from non-injured age and sex matched controls. Three different ¹H Nuclear Magnetic Resonance spectroscopic experiments were applied to capture information on plasma low molecular weight metabolites, lipoproteins, and α-1-acid glycoprotein.

Results

Burn injury was characterized by underlying signatures of hyperglycaemia, hypermetabolism and inflammation, suggesting disruption of multiple pathways relating to glycolysis, tricarboxylic acid cycle, amino acid metabolism and the urea cycle. In addition, very low-density lipoprotein sub-components were significantly reduced in participants with burn injury whereas small-dense low density lipoprotein particles were significantly elevated in the burn injured patient plasma compared to uninjured controls, potentially indicative of modified cardiometabolic risk after a burn. Weighted-node Metabolite Correlation Network Analysis was restricted to the significantly differential features (q <0.05) between the children with and without burn injury and demonstrated a striking disparity in the number of statistical correlations between cytokines, lipoproteins, and small molecular metabolites in the injured groups, with increased correlations between these groups.

Discussion

These findings suggest a 'metabolic memory' of burn defined by a signature of interlinked and perturbed immune and metabolic function. Burn injury is associated with a series of adverse metabolic changes that persist chronically and are independent of burn severity and this study demonstrates increased risk of cardiovascular disease in the long-term. These findings highlight a crucial need for improved longer term monitoring of cardiometabolic health in a vulnerable population of children that have undergone burn injury.

A 16-week randomized controlled trial of a fish oil and whey protein-derived supplement to improve physical performance in older adults losing autonomy-A pilot study

BACKGROUND

Low functional capacity may lead to the loss of independence and institutionalization of older adults. A nutritional intervention within a rehabilitation program may attenuate loss of muscle function in this understudied population.

OBJECTIVE

This pilot study assessed the feasibility for a larger RCT of a nutritional supplementation in older adults referred to an outpatient assessment and rehabilitation program.

METHODS

Participants were randomized to receive a supplement (EXP: 2g fish oil with 1500 IU vitamin D3 1x/d + 20-30g whey protein powder with 3g leucine 2x/d) or isocaloric placebo (CTR: corn oil + maltodextrin powder) for 16 weeks. Handgrip and knee extension strength (using dynamometry), physical performance tests and plasma phospholipid n-3 fatty acids (using GCMS) were evaluated at weeks 0, 8 and 16; and lean soft tissue mass (using DXA), at weeks 0 and 16.

RESULTS

Over 2 years, 244 patients were screened, 46 were eligible (18.9%), 20 were randomized, 10 completed the study (6 CTR, 4 EXP). Median age was 87 y (77-94 y; 75% women) and gait speed was 0.69 m/s; 55% had low strength, and all performed under 420m on the 6-minute walk test, at baseline. Overall self-reported compliance to powder and oil was high (96% and 85%) but declined at 16 weeks for fish oil (55%). The EXP median protein intake surpassed the target 1.2-1.5 g/kg/d, without altering usual diet. Proportions of plasma phospholipid EPA and DHA increased significantly 3- and 1.5-fold respectively, at week 8 in EXP, with no change in CTR. Participants were able to complete most assessments with sustained guidance.

CONCLUSION

Because of low eligibility, the pilot study was interrupted and deemed non-feasible; adherence to rigorous study assessments and to supplements was adequate except for long-term fish oil. The non-amended protocol may be applied to populations with greater functional capacity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04454359.

Lipid is heterogeneously distributed in muscle and associates with low radiodensity in cancer patients

BACKGROUND

Low muscle radiodensity is associated with mortality in a variety of cancer types. Biochemical and morphological correlates are unknown. We aimed to evaluate triglyceride (TG) content and location as a function of computed tomography (CT)-derived measures of skeletal muscle radiodensity in cancer patients.

METHODS

Rectus abdominis (RA) biopsies were collected during cancer surgery from 75 patients diagnosed with cancer. Thin-layer chromatography and gas chromatography were used for quantification of TG content of the muscle. Axial CT images of lumbar vertebra were used to measure muscle radiodensity. Oil Red O staining was used to determine the location of neutral lipids in frozen muscle sections.

RESULTS

There was wide variation in RA radiodensity in repeated measures (CV% ranged from 3 to 55% based on 10 serial images) as well as within one slice (CV% ranged from 6 to 61% based on 10 subregions). RA radiodensity and total lumbar muscle radiodensity were inversely associated with TG content of RA (r = -0.396, P < 0.001, and r = -0.355, P = 0.002, respectively). Of the total percentage area of muscle staining positive for neutral lipid, 54 ± 17% was present as extramyocellular lipids (range 23.5-77.8%) and 46 ± 17% (range 22.2-76.5%) present as intramyocellular lipid droplets.

CONCLUSIONS

Repeated measures revealed wide variation in radiodensity of RA muscle, both vertically and horizontally. Low muscle radiodensity reflects high level of TG in patients with cancer. Non-uniform distribution of intramyocellular and extramyocellular lipids was evident using light microscopy. These results warrant investigation of mechanisms resulting in lipid deposition in muscles of cancer patients.

Clinical and biological characterization of skeletal muscle tissue biopsies of surgical cancer patients

BACKGROUND

Researchers increasingly use intraoperative muscle biopsy to investigate mechanisms of skeletal muscle atrophy in patients with cancer. Muscles have been assessed for morphological, cellular, and biochemical features. The aim of this study was to conduct a state-of-the-science review of this literature and, secondly, to evaluate clinical and biological variation in biopsies of rectus abdominis (RA) muscle from a cohort of patients with malignancies.

METHODS

Literature was searched for reports on muscle biopsies from patients with a cancer diagnosis. Quality of reports and risk of bias were assessed. Data abstracted included patient characteristics and diagnoses, sample size, tissue collection and biobanking procedures, and results. A cohort of cancer patients (n = 190, 88% gastrointestinal malignancies), who underwent open abdominal surgery as part of their clinical care, consented to RA biopsy from the site of incision. Computed tomography (CT) scans were used to quantify total abdominal muscle and RA cross-sectional areas and radiodensity. Biopsies were assessed for muscle fibre area (μm² ), fibre types, myosin heavy chain isoforms, and expression of genes selected for their involvement in catabolic pathways of muscle.

RESULTS

Muscle biopsy occurred in 59 studies (total N = 1585 participants). RA was biopsied intraoperatively in 40 studies (67%), followed by quadriceps (26%; percutaneous biopsy) and other muscles (7%). Cancer site and stage, % of male participants, and age were highly variable between studies. Details regarding patient medical history and biopsy procedures were frequently absent. Lack of description of the population(s) sampled and low sample size contributed to low quality and risk of bias. Weight-losing cases were compared with weight stable cancer or healthy controls without considering a measure of muscle mass in 21 out of 44 studies. In the cohort of patients providing biopsy for this study, 78% of patients had preoperative CT scans and a high proportion (64%) met published criteria for sarcopenia. Fibre type distribution in RA was type I (46% ± 13), hybrid type I/IIA (1% ± 1), type IIA (36% ± 10), hybrid type IIA/D (15% ± 14), and type IID (2% ± 5). Sexual dimorphism was prominent in RA CT cross-sectional area, mean fibre cross-sectional area, and in expression of genes associated with muscle growth, apoptosis, and inflammation (P < 0.05). Medical history revealed multiple co-morbid conditions and medications.

CONCLUSIONS

Continued collaboration between researchers and cancer surgeons enables a more complete understanding of mechanisms of cancer-associated muscle atrophy. Standardization of biobanking practices, tissue manipulation, patient characterization, and classification will enhance the consistency, reliability, and comparability of future studies.

Mixed Lipid, Fish Oil, and Soybean Oil Parenteral Lipids Impact Cholestasis, Hepatic Phytosterol, and Lipid Composition

OBJECTIVES

In parenteral nutrition-dependent infants and children, intestinal failure (IF)-associated liver disease (IFALD) remains an important problem. A comparative study was undertaken of parenteral mixed lipid (ML), ω-3 predominant fish oil (FO), and ω-6 predominant soybean oil (SO) emulsions in regards to hepatic phytosterol, neutral lipid, fatty acid (FA) content, and the relationship to cholestasis in piglets.

METHODS

Neonatal piglets received parenteral nutrition, varying in lipid dose (5 or 10 g· kg · day) and formulation: SO5 (n = 5), SO10 (n = 5), FO5 (n = 5), and ML10 (n = 5). On day 14, liver chemistry, bile flow, histology and neutral lipid staining were assessed. Hepatic triglyceride FA content was determined using thin layer and gas chromatography, and phytosterol content was assessed using gas chromatography-mass spectrometry.

RESULTS

SO groups had higher prevalence of biochemical cholestasis (P < 0.04) and lower bile flow (P < 0.0001). Hepatic campesterol, stigmasterol, and β-sitosterol were highest in SO10 (P < 0.0001). Hepatic FA (P < 0.03) and ω-6/ω-3 FA ratio (P < 0.0001) were higher in the SO groups. Neutral lipid accumulation (P = 0.3) and liver histology (P = 0.16) were not different between groups. Univariate predictors of bile flow were: campesterol (r = -0.77, P = 0.001), β-sitosterol (r = -0.74, P = 0.002), stigmasterol (r = -0.74, P = 0.002), ω-6 FA (r = -0.72, P = 0.002), and ω-3 FA (r = 0.59, P = 0.02). Only campesterol independently predicted bile flow.

CONCLUSIONS

ML and FO lipid emulsions reduce cholestasis in association with lowered hepatic phytosterol and lipid content. Lower hepatic phytosterol and ω-6 FA content, and higher ω-3 FA content are hepatoprotective. Multivariate analysis suggests reduced phytosterol accumulation may best explain the hepatoprotective effect of fish oil-containing lipids.

Lipidomic analysis enables prediction of clinical outcomes in burn patients

Recent discoveries have highlighted the novel metabolic functions of adipose tissue in enhancing hypermetabolism after trauma. As the exact function and expression profiles of serum lipids and free fatty acids (FFA) are essentially unknown, we determined the lipidomic expression profile after burn in correlation to clinical outcomes to identify important lipid mediators affecting post-burn outcomes. We conducted a prospective cohort study with 46 adult burn patients and 5 healthy controls at the Ross Tilley Burn Center in Toronto, Canada. Patients were stratified based on major demographic and clinical variables, including age, burn severity, mortality, and sepsis. Serum FFAs and inflammatory markers were measured during acute hospital stay. We found that FFAs were acutely elevated post-burn and returned to baseline over time. Greater burn severity and age were associated with an impaired acute response in unsaturated FFAs and pro-inflammatory cytokines. Elevations in saturated and mono-unsaturated FFAs correlated significantly to increased mortality. In summary, persistent elevation of unsaturated lipids was associated with a functionally altered inflammatory-immunological milieu and worse clinical outcomes. The present lipidomic analysis indicates profound alterations in the lipid profile after burn by characterizing key lipids as potential diagnostic and outcome indicators in critically injured patients.

Skeletal muscle depletion is associated with reduced plasma (n-3) fatty acids in non-small cell lung cancer patients

Upwards of 50% of newly diagnosed advanced lung cancer patients have severe muscle wasting (sarcopenia). Supplementation with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in advanced cancer has been shown to attenuate lean tissue wasting. However, the relationship between muscle mass and plasma (n-3) fatty acids in the absence of supplementation is unclear. We aimed to determine how plasma phospholipid (n-3) fatty acids relate to sarcopenia and change in muscle mass in non-small cell lung cancer patients receiving chemotherapy. Computed tomography images were used to measure muscle mass. Patients were classified as sarcopenic or nonsarcopenic based on sex-specific cutpoints. Change in muscle mass during chemotherapy (2.5 mo) was calculated and patients were divided into quartiles based on the rate of muscle loss or gain. Patients with sarcopenia had lower plasma EPA (16.7 +/- 2.1 micromol/L vs. 31.6 +/- 4.4 micromol/L; P = 0.001), DHA (36.6 +/- 4.0 micromol/L vs. 55.3 +/- 4.0 micromol/L; P = 0.003), and Sigma(n-3) fatty acids (63.6 +/- 5.6 micromol/L vs. 95.0 +/- 7.7 micromol/L; P = 0.002) than nonsarcopenic patients. Patients with maximal muscle loss (mean - 3.5 kg) had lower plasma EPA (12.2 +/- 3.3 micromol/L vs. 35.0 +/- 7.1 micromol/L; P = 0.03), DHA (26.9 +/- 8.7 micromol/L vs. 59.6 +/- 5.3 micromol/L; P = 0.01), and Sigma(n-3) fatty acids (57.8 +/- 13.5 micromol/L vs. 104.6 +/- 11.1 micromol/L; P = 0.005) compared with patients who were gaining muscle (mean +1 kg). Plasma (n-3) fatty acids are depleted in cancer patients with sarcopenia, which may contribute to accelerated rates of muscle loss.

In vivo high-resolution magic angle spinning magnetic resonance spectroscopy of Drosophila melanogaster at 14.1 T shows trauma in aging and in innate immune-deficiency is linked to reduced insulin signaling

In vivo magnetic resonance spectroscopy (MRS), a non-destructive biochemical tool for investigating live organisms, has yet to be used in the fruit fly Drosophila melanogaster, a useful model organism for investigating genetics and physiology. We developed and implemented a high-resolution magic-angle-spinning (HRMAS) MRS method to investigate live Drosophila at 14.1 T. We demonstrated, for the first time, the feasibility of using HRMAS MRS for molecular characterization of Drosophila with a conventional MR spectrometer equipped with an HRMAS probe. We showed that the metabolic HRMAS MRS profiles of injured, aged wild-type (wt) flies and of immune deficient (imd) flies were more similar to chico flies mutated at the chico gene in the insulin signaling pathway, which is analogous to insulin receptor substrate1-4 (IRS1-4) in mammals and less to those of adipokinetic hormone receptor (akhr) mutant flies, which have an obese phenotype. We thus provide evidence for the hypothesis that trauma in aging and in innate immune-deficiency is linked to insulin signaling. This link may explain the mitochondrial dysfunction that accompanies insulin resistance and muscle wasting that occurs in trauma, aging and immune system deficiencies, leading to higher susceptibility to infection. Our approach advances the development of novel in vivo non-destructive research approaches in Drosophila, suggests biomarkers for investigation of biomedical paradigms, and thus may contribute to novel therapeutic development.

n-3 Fatty acid supplementation in burned paediatric patients

AIM

To determine the effect of dietary supplementation with n-3 fatty acids (FA) in paediatric burned patients who had less than 20% of total body surface affected.

METHODS

Burned patients were randomly assigned into two groups, one of them received a supplement of n-3 FA during 5 weeks; the other group was considered as not n-3 supplemented burned group. A third group of no burned patients was selected as control. Blood samples were collected at admission and in burned groups at the final of the study. Plasma and erythrocyte phospholipid FA composition and some biochemical parameters related to the clinical evolution: total plasma proteins and C3 and C4 complement proteins were determined.

RESULTS

In the early post-burn patients, there is an increase in saturated and monounsaturated FAs in plasma phospholipids, and a decrease in polyunsaturated FAs compared with control. These alterations are in favour of proinflammatory response to burn injury. In n-3 FA supplemented group, these changes were further reverted, and a favourable response in the amount of total plasma proteins and in C3 and C4 proteins of the complement system was demonstrated.

CONCLUSION

Dietary n-3 FA supplementation might be beneficial for patients suffering thermal injury.

Solid emulsion gel as a vehicle for delivery of polyunsaturated fatty acids: implications for tissue repair, dermal angiogenesis and wound healing

The paper describes preparation and biological characterization of the solid hybrid biomaterial that was designed for cell-targeted lipid delivery in healing tissues. The material referred to as 'solid emulsion gel' combines a protein-stabilized lipid emulsion and a hydrogel structure in a single compartment. The potential of the omega-3 (n-3)-fatty acids rich solid emulsion gel for tissue repair applications was investigated at the macro-, micro-, molecular and gene expression levels, using human fibroblasts and endothelial cells and a porcine model of full-thickness wounds. Being non-cytotoxic in vitro and in vivo, the biomaterial was found to affect cell metabolism, modulate expression of certain genes, stimulate early angiogenesis and promote wound repair in vivo. The neovascular response in vivo was correlated with upregulated expression of the genes involved in lipid transport (e.g. adipophilin), anti-apoptosis (e.g. heat shock proteins, haem oxygenase 1) and angiogenesis (vascular endothelial growth factor, placental growth factor). Collectively, the results of this study provide first evidence that the angiogenic response provided by solid emulsion gel-mediated delivery of n-3 fatty acids is an alternative to the topical administration of exogenous growth factors or gene therapy, and can be advantageously used for the stimulation of tissue repair in complex wounds.

New oral fat tolerance tests feature tailoring of the polyunsaturated/saturated fatty acid ratio to elicit a specific postprandial response

The impact of dietary fat on postprandial metabolic biomarkers for obesity-related chronic diseases, such as type-2 diabetes and cardiovascular disease, has received significant recent attention. However, there is no standard method to evaluate the postprandial response to dietary fat alone. Our goals were to develop a novel oral fat tolerance test (OFTT) consisting solely of emulsified lipids tailored for specific fatty acid compositions and to evaluate the functionality of specific ratios of polyunsaturated/saturated fatty acid (P/S) loading on postprandial triacylglyceride (TAG) concentrations. Two OFTTs of emulsified lipids were prepared with specific P/S ratios of 0.2 and 2.0. Physical characteristics of the fat blends, including TAG composition, melting point, and emulsion droplet size were quantified. Healthy, older (age > 45 y) men (n = 8) underwent an 8 h postprandial study wherein they received the OFTT treatment (either the P/S ratio of 0.2 or 2.0), with a total lipid load of 1 g/kg subject body mass. All subjects received both treatments separated by at least 1 week. Both the P/S 0.2 and 2.0 OFTT significantly elevated (p < 0.05) blood TAG and free fatty acid concentrations for 8 h without increasing blood glucose or serum insulin concentrations. The predominant fatty acids contained in the P/S 0.2 (palmitic acid, 16:0) and 2.0 (linoleic acid, 18:2(n–6)) OFTT blends were significantly elevated in the blood (p < 0.05) during their respective postprandial periods. We concluded that blood TAGs are elevated in a specific pattern through the administration of novel OFTTs with specific P/S blends without eliciting an insulin or glucose response.

Effect of providing a formula supplemented with long-chain polyunsaturated fatty acids on immunity in full-term neonates

To determine the effect of feeding formula containing long-chain PUFA (LCP) on immune function, healthy term infants were randomised at age 2 weeks to either a standard term formula (Formula; n 14) or the same formula supplemented with the LCP 20 : 4n-6 and 22 : 6n-3 (Formula+LCP; n 16). Peripheral blood was collected at 2 and 6 weeks to measure immune cell response (the rate of [3H]thymidine uptake and cytokine production after stimulation with phytohaemagglutinin (PHA)). Compared with cells from infants receiving only human milk (HM), the rate of [3H]thymidine uptake in response to PHA, but not IL-2 production, was lower for Formula+LCP infants (P < 0.05). Compared with HM-fed infants, Formula-fed infants (but not Formula+LCP infants) produced more TNF-alpha (unstimulated) and had a fewer CD3+CD44+ cells before stimulation and fewer CD11c+ cells post-stimulation (P < 0.05). However, compared with Formula-fed infants, the Formula+LCP infants had an immune cell distribution (higher percentage CD3+CD44+ and CD4+CD28+ cells) and cytokine profile (lower production of TNF-alpha post-stimulation) that did not differ from HM infants. Additionally, it was found that feeding infants formula during the first 10 d of life influenced immune function. These infants had a higher percentage of CD3+, CD4+CD28+, and lower percentage of CD14+ cells and produced more TNF-alpha and interferon-gamma after PHA stimulation than HM-fed infants (P < 0.05). These results demonstrate that early diet influences both the presence of specific cell types and function of infant blood immune cells. Since many diseases have a strong immunological component, these immune changes may be of physiological importance to the developing infant.

Parenteral nutrition providing a restricted amount of linoleic acid in severely burned patients: a randomised double-blind study of an olive oil-based lipid emulsion v. medium/long-chain triacylglycerols

It has been claimed that lipid emulsions with a restricted linoleic acid content can improve the safety of total parenteral nutrition (TPN). The tolerability of TPN and its effects on the metabolism of fatty acids were assessed in this prospective, double-blind, randomised study comparing an olive/soyabean oil long-chain triacylglycerol (LCT) with a medium-chain triacylglycerol (MCT)/LCT; 50:50 (w) based lipid emulsion in two groups (O and M, respectively; eleven per group) of severely burned patients. After resuscitation (48-72 h), patients received TPN providing 147 kJ/kg per d (35 kcal/kg per d) with fat (1.3 g/kg per d) for 6 d Plasma fatty acids, laboratory parameters including liver function tests, and plasma cytokines were assessed before and after TPN. Adverse events encountered during TPN and the clinical outcomes of patients within the subsequent 6 months were recorded. With both lipid emulsions, the conversion of linoleic acid in its higher derivatives (di-homo-gamma-linolenic acid) improved and essential fatty acid deficiency did not appear. Abnormalities of liver function tests occurred more frequently in the M (nine) than in the O (three) group (P = 0.04, Suissa-Shuster test). Seven patients (four from group O and three from group M) died as a consequence of severe sepsis 3-37 d after completion of the 6 d TPN period. When compared with the surviving patients, those who died were older (P = 0.01) and hyperglycaemic at baseline (P < 0.001), and their plasma IL-6 levels continued to increase (P < 0.04). Although fatty acid metabolism and TPN tolerability were similar with both lipid emulsions, the preservation of liver function noted with the use of the olive oil-based lipid emulsions deserves confirmation.

Proton NMR spectroscopy shows lipids accumulate in skeletal muscle in response to burn trauma‐induced apoptosis

Burn trauma triggers hypermetabolism and muscle wasting via increased cellular protein degradation and apoptosis. Proton nuclear magnetic resonance (1H NMR) spectroscopy can detect mobile lipids in vivo. To examine the local effects of burn in skeletal muscle, we performed in vivo 1H NMR on mice 3 days after burn trauma; and ex vivo, high-resolution, magic angle spinning (1)H NMR on intact excised mouse muscle samples before and 1 and 3 days after burn. These samples were then analyzed for apoptotic nuclei using a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. To confirm our NMR and cell biology results, we used transcriptome analysis to demonstrate that burn trauma alters the expression of genes involved in lipid metabolism and apoptosis. Our results demonstrate that burn injury results in a localized intramyocellular lipid accumulation, which in turn is accompanied by burn-induced apoptosis and mitochondrial dysfunction, as seen by the up-regulation of apoptotic genes and down-regulation of genes that encode lipid oxidation and the peroxisomal proliferator activator receptor gamma coactivator PGC-1beta. Moreover, the increased levels of bisallylic methylene fatty acyl protons (2.8 ppm) and vinyl protons (5.4 ppm), in conjunction with the TUNEL assay results, further suggest that burn trauma results in apoptosis. Together, our results provide new insight into the local physiological changes that occur in skeletal muscle after severe burn trauma.

Enteral nutritional supplementation prevents mesenteric lymph node T-cell suppression in burn injury

OBJECTIVE

To determine the effects of an immune-enhancing diet supplemented with glutamine, arginine, fish oil, and dietary nucleotides on mesenteric lymph node T-cell functional disturbances encountered after burn injury in rats.

DESIGN

A prospective animal study.

SETTING

University medical center research laboratory.

SUBJECTS

Adult male Sprague-Dawley rats.

INTERVENTIONS

Rats received a 30%, total body surface, full-thickness burn. Burn-injury rats received the IMPACT diet supplemented with glutamine, arginine, fish oil, and nucleotides or arginine, fish oil, and nucleotides, or an isocaloric/isonitrogenous diet without supplementation with glutamine, arginine, fish oil, or nucleotides.

MEASUREMENTS AND MAIN RESULTS

Two days after injury, we found a significant decrease in the proliferation and interleukin-2 production by mesenteric lymph node T cells derived from rats fed on conventional chow compared with sham rats. The burn-related suppression of mesenteric lymph node T-cell proliferation and interleukin-2 production was prevented when the rats were fed on a high-protein diet rich in glutamine, arginine, fish oil, and nucleotides. We found that the immunostimulatory effects of the enriched diet are dependent on the presence of glutamine, arginine, fish oil, and nucleotides as feeding of rats on the isocaloric/isonitrogenous diet deficient in glutamine, arginine, fish oil, and nucleotides did not prevent the burn-related suppression of mesenteric lymph node T-cell dysfunction. Finally, our studies suggested that immunostimulatory effects of the diet are mediated by prostaglandin E(2) regulation of T-cell activation signaling molecule P59fyn.

CONCLUSION

These results suggest that a diet rich in arginine, fish oil, and nucleotides, with and without glutamine, can effectively prevent T-cell dysfunction encountered after burn injury.

Effect of fish oil on appetite and other symptoms in patients with advanced cancer and anorexia/cachexia: a double-blind, placebo-controlled study

PURPOSE

To determine whether high doses of fish oil, administered over 2 weeks, improve symptoms in patients with advanced cancer and decreased weight and appetite.

PATIENTS AND METHODS

Sixty patients were randomly assigned to fish oil capsules or placebo. Appetite, tiredness, nausea, well-being, caloric intake, nutritional status, and function were prospectively assessed at days 1 and 14.

RESULTS

The baseline weight loss was 16 +/- 11 and 16 +/- 8 kg in the fish oil (n = 30) and placebo (n = 30) group respectively, whereas the baseline appetite (0 mm = best and 10 mm = worst) was 58 +/- 24 mm and 67 +/- 19 mm, respectively (P = not significant). The mean daily dose was 10 +/- 4 (fish oil group) and 9 +/- 3 (placebo group) capsules, which provided 1.8 g of eicosapentaenoic acid and 1.2 g of docosahexaenoic acid in the fish oil group. No significant differences in symptomatic or nutritional parameters were found (P <.05), and there was no correlation between changes in different variables between days 1 and 14 and the fish oil doses. Finally, the majority of the patients were not able to swallow more than 10 fish oil capsules per day, mainly because of burping and aftertaste.

CONCLUSION

Fish oil did not significantly influence appetite, tiredness, nausea, well-being, caloric intake, nutritional status, or function after 2 weeks compared with placebo in patients with advanced cancer and loss of both weight and appetite.

Plasma and neutrophil fatty acid composition in advanced cancer patients and response to fish oil supplementation

Metabolic demand and altered supply of essential nutrients is poorly characterised in patients with advanced cancer. A possible imbalance or deficiency of essential fatty acids is suggested by reported beneficial effects of fish oil supplementation. To assess fatty acid status (composition of plasma and neutrophil phospholipids) in advanced cancer patients before and after 14 days of supplementation (12+/-1 g day(-1)) with fish (eicosapentaenoic acid, and docosahexaenoic acid) or placebo (olive) oil. Blood was drawn from cancer patients experiencing weight loss of >5% body weight (n=23). Fatty acid composition of plasma phospholipids and the major phospholipid classes of isolated neutrophils were determined using gas liquid chromatography. At baseline, patients with advanced cancer exhibited low levels (<30% of normal values) of plasma phospholipids and constituent fatty acids and elevated 20 : 4 n-6 content in neutrophil phospholipids. High n-6/n-3 fatty acid ratios in neutrophil and plasma phospholipids were inversely related to body mass index. Fish oil supplementation raised eicosapentaenoic acid and docosahexaenoic acid content in plasma but not neutrophil phospholipids. 20 : 4 n-6 content was reduced in neutrophil PI following supplementation with fish oil. Change in body weight during the supplementation period related directly to increases in eicosapentaenoic acid in plasma. Advanced cancer patients have alterations in lipid metabolism potentially due to nutritional status and/or chemotherapy. Potential obstacles in fatty acid utilisation must be addressed in future trials aiming to improve outcomes using nutritional intervention with fish oils.