NO sorption, in-crystal nitrite and nitrate production with arylamine oxidation in gas-solid single crystal to single crystal reactions.

A bridging nitrite and a nitrate counter anion per Co2 site are generated in-crystal and an arylamine group on the ligand scaffold is oxidised to a nitro group when nitric oxide (NO) is chemisorbed by molecular crystals of cobalt complexes.

Enhanced nutrient supply to very low birth weight infants is associated with higher blood amino acid concentrations and improved growth.

BACKGROUND & AIMS: Customized nutrient supply is vital to ensure optimal growth among very low birth weight infants (birth weight < 1500 g). The supply of amino acids is especially important due to their impact on protein synthesis and growth. The objectives of this study were to evaluate the impact of enhanced nutrition on growth, blood concentrations of amino acids, and explore possible associations between amino acid concentrations and common neonatal morbidities. We hypothesized higher amino acids levels and growth velocity among infants on enhanced nutrient supply. METHODS: This randomized controlled trial was performed in three university neonatal intensive care units in Oslo, Norway. Fifty very low birth weight infants were randomized to a control or intervention group. Within 24 h after birth, infants in the intervention group received enhanced supply of energy, amino acids, lipids, long-chain polyunsaturated fatty acids and vitamin A, whereas the control group received a standard nutrient supply. The intervention continued until 52 weeks postmenstrual age or until a body weight of 5.5 kg was reached. Amino acid analyses were performed at birth, day 3, 5 weeks of age and 5 months corrected age. Detailed information about nutrient intake, morbidities, blood amino acid concentrations and growth velocity were collected from 44 infants (6 infants excluded). High-performance liquid chromatography was used for amino acid analysis. RESULTS: The intervention group (n = 23) received higher supply of proteins, with higher blood concentrations of amino acids measured at 5 weeks of age, and improved growth velocity (mean 17.4 vs 14.3 g/kg/day, p < 0.001) at 36 weeks postmenstrual age, compared to the control group (n = 21). The correlation between concentrations of branched chain amino acids (leucine, isoleucine and valine) and growth was stronger and more positive among infants: a) in the control group (correlation coefficient ≥ 0.68, p ≤ 0.004); b) born with birth weight appropriate for gestational age (correlation coefficient ≥ 0.53, p ≤ 0.009) and c) not diagnosed with septicemia (correlation coefficient ≥ 0.63, p ≤ 0.005). CONCLUSION: Enhanced nutrient supply to very low birth weight infants led to higher blood amino acid concentrations and improved growth. The correlations between amino acid concentrations and growth velocity were weaker in the intervention group as compared to the control group. This could reflect an upper threshold for protein synthesis and growth with our intervention, whereas a potential for further growth with increasing amino acid supply was possible for the control group. CLINICAL TRIAL REGISTRATION NO: NCT01103219.

An LC-MS/MS method to quantify acylcarnitine species including isomeric and odd-numbered forms in plasma and tissues.

Acylcarnitines are intermediates of fatty acid and amino acid oxidation found in tissues and body fluids. They are important diagnostic markers for inherited diseases of peroxisomal and mitochondrial oxidation processes and were recently described as biomarkers of complex diseases like the metabolic syndrome. Quantification of acylcarnitine species can become challenging because various species occur as isomers and/or have very low concentrations. Here we describe a new LC-MS/MS method for quantification of 56 acylcarnitine species with acyl-chain lengths from C2 to C18. Our method includes amino acid-derived positional isomers, like methacrylyl-carnitine (2-M-C3:1-CN) and crotonyl-carnitine (C4:1-CN), and odd-numbered carbon species, like pentadecanoyl-carnitine (C15:0-CN) and heptadecanoyl-carnitine (C17:0-CN), occurring at very low concentrations in plasma and tissues. Method validation in plasma and liver samples showed high sensitivity and excellent accuracy and precision. In an application to samples from streptozotocin-treated diabetic mice, we identified significantly increased concentrations of acylcarnitines derived from branched-chain amino acid degradation and of odd-numbered straight-chain species, recently proposed as potential biomarkers for the metabolic syndrome. In conclusion, the LC-MS/MS method presented here allows robust quantification of isomeric acylcarnitine species and extends the palette of acylcarnitines with diagnostic potential derived from fatty acid and amino acid metabolism.

Absorbing TiO x thin film enabling laser welding of polyurethane membranes and polyamide fibers.

We report on the optical properties of thin titanium suboxide (TiO x ) films for applications in laser transmission welding of polymers. Non-absorbing fibers were coated with TiO x coatings by reactive magnetron sputtering. Plasma process parameters influencing the chemical composition and morphology of the deposited thin films were investigated in order to optimize their absorption properties. Optical absorption spectroscopy showed that the oxygen content of the TiO x coatings is the main parameter influencing the optical absorbance. Overtreatment (high power plasma input) of the fiber surface leads to high surface roughness and loss of mechanical stability of the fiber. The study shows that thin substoichiometric TiO x films enable the welding of very thin polyurethane membranes and polyamide fibers with improved adhesion properties.

Hepatic methionine homeostasis is conserved in C57BL/6N mice on high-fat diet despite major changes in hepatic one-carbon metabolism.

Obesity is an underlying risk factor in the development of cardiovascular disease, dyslipidemia and non-alcoholic fatty liver disease (NAFLD). Increased hepatic lipid accumulation is a hallmark in the progression of NAFLD and impairments in liver phosphatidylcholine (PC) metabolism may be central to the pathogenesis. Hepatic PC biosynthesis, which is linked to the one-carbon (C1) metabolism by phosphatidylethanolamine N-methyltransferase, is known to be important for hepatic lipid export by VLDL particles. Here, we assessed the influence of a high-fat (HF) diet and NAFLD status in mice on hepatic methyl-group expenditure and C1-metabolism by analyzing changes in gene expression, protein levels, metabolite concentrations, and nuclear epigenetic processes. In livers from HF diet induced obese mice a significant downregulation of cystathionine ß-synthase (CBS) and an increased betaine-homocysteine methyltransferase (BHMT) expression were observed. Experiments in vitro, using hepatoma cells stimulated with peroxisome proliferator activated receptor alpha (PPARα) agonist WY14,643, revealed a significantly reduced Cbs mRNA expression. Moreover, metabolite measurements identified decreased hepatic cystathionine and L-α-amino-n-butyrate concentrations as part of the transsulfuration pathway and reduced hepatic betaine concentrations, but no metabolite changes in the methionine cycle in HF diet fed mice compared to controls. Furthermore, we detected diminished hepatic gene expression of de novo DNA methyltransferase 3b but no effects on hepatic global genomic DNA methylation or hepatic DNA methylation in the Cbs promoter region upon HF diet. Our data suggest that HF diet induces a PPARα-mediated downregulation of key enzymes in the hepatic transsulfuration pathway and upregulates BHMT expression in mice to accommodate to enhanced dietary fat processing while preserving the essential amino acid methionine.