Urinary Metabolites as Predictors of Acute Mountain Sickness Severity.

Individuals sojourning at high altitude (≥2,500m) often develop acute mountain sickness (AMS). However, substantial unexplained inter-individual variability in AMS severity exists. Untargeted metabolomics assays are increasingly used to identify novel biomarkers of susceptibility to illness, and to elucidate biological pathways linking environmental exposures to health outcomes.

Influence of Myo-inositol Plus Ethanolamine on Plasmalogens and Cell Viability during Oxidative Stress.

Previously, we demonstrated that treatment of rats with myo-inositol plus ethanolamine (ME) elevated brain ethanolamine plasmalogens (PE-Pls) and protected against phosphine-induced oxidative stress. Here we tested the hypothesis that ME treatment elevates PE-Pls in a neuro-2A (N2A) cell culture system and protects against hydrogen peroxide (HO)-induced oxidative stress, and we assessed the effects of treatments using myo-inositol with or without (+/-) ethanolamine on ethanolamine phospholipids (PLs) and cell viability following HO exposure. Cells were treated with equimolar amounts (500 μM) of myo-inositol, ethanolamine (Etn), or their combination (ME) for 24 h, followed by an additional 24 h exposure to 650 μM HO.

Lipid, water, and protein composition to facilitate kinetic modeling of the auditory pathway.

Environments combining JP-8 jet fuel exposure with heightened ambient noise may accelerate hearing loss induced by noise. To reduce animal use and facilitate kinetic modeling of this military aviation fuel, tissue-specific parameters are required, including water, protein, and lipid content. However, tissues involved in hearing, including cochlea, brainstem, frontal, and temporal lobe, have not been characterized before.

Simultaneous fecal microbial and metabolite profiling enables accurate classification of pediatric irritable bowel syndrome.

Background: We previously showed that stool samples of pre-adolescent and adolescent US children diagnosed with diarrhea-predominant IBS (IBS-D) had different compositions of microbiota and metabolites compared to healthy age-matched controls. Here we explored whether observed fecal microbiota and metabolite differences between these two adolescent populations can be used to discriminate between IBS and health.

Findings: We constructed individual microbiota- and metabolite-based sample classification models based on the partial least squares multivariate analysis and then applied a Bayesian approach to integrate individual models into a single classifier.

Altered gut microbial energy and metabolism in children with non-alcoholic fatty liver disease.

Obesity is becoming the new pediatric epidemic. Non-alcoholic fatty liver disease (NAFLD) is frequently associated with obesity and has become the most common cause of pediatric liver disease. The gut microbiome is the major metabolic organ and determines how calories are processed, serving as a caloric gate and contributing towards the pathogenesis of NAFLD.

The networks of human gut microbe-metabolite associations are different between health and irritable bowel syndrome.

The goal of this study was to determine if fecal metabolite and microbiota profiles can serve as biomarkers of human intestinal diseases, and to uncover possible gut microbe-metabolite associations. We employed proton nuclear magnetic resonance to measure fecal metabolites of healthy children and those diagnosed with diarrhea-predominant irritable bowel syndrome (IBS-D). Metabolite levels were associated with fecal microbial abundances.

Identification of serum analytes and metabolites associated with aerobic capacity.

Studies aimed at identifying serum markers of cellular metabolism (biomarkers) that are associated at baseline with aerobic capacity (VO₂max) in young, healthy individuals have yet to be reported. Therefore, the goal of the present study was to use the standard chemistry screen and untargeted mass spectrometry (MS)-based metabolomic profiling to identify significant associations between baseline levels of serum analytes or metabolites with VO₂max (77 subjects, age range 18-35 years). Use of multivariable linear regression identified three analytes (standard chemistry screen) and twenty-three metabolites (MS-based metabolomics) containing significant, sex-adjusted associations with VO₂max.

Comparative metabolomic and genomic analyses of TCDD-elicited metabolic disruption in mouse and rat liver.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) elicits a broad spectrum of species-specific effects that have not yet been fully characterized. This study compares the temporal effects of TCDD on hepatic aqueous and lipid metabolite extracts from immature ovariectomized C57BL/6 mice and Sprague-Dawley rats using gas chromatography-mass spectrometry and nuclear magnetic resonance-based metabolomic approaches and integrates published gene expression data to identify species-specific pathways affected by treatment. TCDD elicited metabolite and gene expression changes associated with lipid metabolism and transport, choline metabolism, bile acid metabolism, glycolysis, and glycerophospholipid metabolism.

Evidence that plasmalogen is protective against oxidative stress in the rat brain.

The antioxidant capabilities of phosphatidylethanolamine plasmalogen (PlsEtn), in vivo, against lipid peroxidation were investigated via acute phosphine (PH(3)) administration in rats. Oxidative stress was assessed from measures of malondialdehyde and various enzyme activities, while NMR analyses of lipid and aqueous tissue extracts provided metabolic information in cerebellum, brainstem, and cortex. Brainstem had the highest basal [PlsEtn], and showed only moderate PH(3)-induced oxidative damage with no loss of ATP.

Total body water volume for white children and adolescents and anthropometric prediction equations: the Fels Longitudinal Study.

Background: There are few studies of total body water (TBW) volume in children. Such studies are needed, as are new prediction equations for the clinical management of children with renal insufficiency and those receiving dialysis.

Methods: Mixed longitudinal data were from 124 white boys and 116 white girls 8 to 20 years of age.

Administration of myo-inositol plus ethanolamine elevates phosphatidylethanolamine plasmalogen in the rat cerebellum.

Plasmalogens are ether-linked phospholipids highly abundant in nervous tissue. Previously we demonstrated that acute administration of myo-inositol (myo-Ins) + [2-(13)C] ethanolamine ([2-(13)C]Etn) significantly elevated phosphatidylethanolamine plasmalogen (PlsEtn) in rat whole brain. Current experiments investigated the effects of acute myo-Ins+[2-(13)C]Etn administration on [PlsEtn] and the biosynthesis of new Etn lipids using NMR spectroscopy in rat cerebral cortex, hippocampus, brainstem, midbrain and cerebellum.

Studies of myo-inositol and plasmalogen metabolism in rat brain.

Plasmalogens are ether-linked phospholipids that are abundant in nervous tissues. Their biological role is unclear, but may involve membrane structure/function and antioxidant activities. This study further investigates a recent report that chronic administration of myo-inositol in rats increased brain phosphatidylethanolamine plasmalogen (PlsEtn).

NMR-based metabolomics.

Similar to genomics and proteomics which yield vast amounts of data about the expression of genes and proteins, metabolomics refers to the whole metabolic profile of the cell. The focus of this report concerns the use of nuclear magnetic resonance (NMR) spectroscopy for metabolic analyses and, in particular, its use in toxicology for examining the metabolic profile of biofluids. Examples from the literature will demonstrate how 1H NMR and pattern recognition methods are used to obtain the urinary metabolic profile, and how this profile is affected by exposure to various toxicants.

Kinetic analyses of liver phosphatidylcholine and phosphatidylethanolamine biosynthesis using (13)C NMR spectroscopy.

Choline and ethanolamine are substrates for de novo synthesis of phosphatidylcholine (PtdC) and phosphatidylethanolamine (PtdE) through the CDP-choline and CDP-ethanolamine pathways. In liver, PtdE can also be converted to PtdC by PtdE N-methyltransferase (PEMT). We investigated these kinetics in rat liver during a 60 min infusion with (13)C-labeled choline and ethanolamine.