Plasma and Urinary Amino Acid-Derived Catabolites as Potential Biomarkers of Protein and Amino Acid Deficiency in Rats

Objective: Dietary intakes must cover protein and essential amino acid (EAA) requirements. For this purpose, different methods have been developed such as the nitrogen balance method, factorial method, or AA tracer studies. However, these methods are either invasive or imprecise, and the Food and Agriculture Organization of the United Nations (FAO, 2013) recommends new methods and, in particular, metabolomics. The aim of this study is to determine total protein/EAA requirement in the plasma and urine of growing rats. Methods: 36 weanling rats were fed with diets containing 3, 5, 8, 12, 15, and 20% protein for 3 weeks. During experimentation, urine was collected using metabolic cages, and blood from the portal vein and vena was taken at the end of the experiment. Metabolomics analyses were performed using LC-MS, and the data were analyzed with a multivariate analysis model, partial least Squares (PLS) regression, and independent component-discriminant analysis (ICDA). Each discriminant metabolite identified by PLS or ICDA was tested by one-way ANOVA to evaluate the effect of diet. Results: PLS and ICDA allowed us to identify discriminating metabolites between different diet groups. Protein deficiency led to an increase in the AA catabolism enzyme systems inducing the production of breakdown metabolites in the plasma and urine. Conclusion: These results indicate that metabolites are specific for the state of EAA deficiency and sufficiency. Some types of biomarkers such as AA degradation metabolites appear to be specific candidates for protein/EAA requirement.     

Leptin and Ob-Rb receptor isoform in the human digestive tract during fetal development

CONTEXT: Leptin, partially produced by the stomach, is a hormone involved in energy balance and regulation of food intake. It also regulates some digestive functions through its functional receptor Ob-Rb expressed by gastrointestinal epithelial cells. OBJECTIVE: The objective of the study was to investigate the temporal and spatial appearance of Ob-Rb in the human digestive tract and leptin in the stomach. DESIGN: The esophagus, stomach, and intestine samples of 7- to 24-wk-old human fetuses and adult mucosae were studied by RT-PCR, immunohistochemistry, and Western blot. Leptin was measured by RIA in amniotic fluids at 16-33 wk gestation. RESULTS: All mucosae expressed Ob-Rb (mRNA and/or protein) between 7 and 9 wk gestation. Leptin protein appeared by 8 wk in the gastric mucosa, whereas leptin mRNA was detected around 11 wk. Leptin levels in amniotic fluids were significantly higher during the second than during the third trimester. Overall, Ob-Rb immunoreactivity was higher in young fetuses, during the period corresponding to the formation of gastric buds and primitive intestinal crypts and the beginning of differentiation of epithelial cell types, than in the oldest. Leptin added to culture medium of gastrointestinal explants from 10- to 12-wk-old fetuses appeared to affect DNA synthesis as compared with controls, indicating that leptin receptor functionality was developing. CONCLUSIONS: The strong expression of leptin, in amniotic fluid when fetuses begin swallowing then in the gastric mucosa, and the early presence of Ob-Rb in mucosae suggest a possible role for leptin, exerted endoluminally and in a paracrine pathway, in the developmental process (growth and/or maturation) of the human digestive tract.     

Aplasia cutis congenita: a conservative approach of a case with large,extensive skin,and underlying skull defect

Aplasia cutis congenita is a disease in which skin, bone, and dura mater can be absent. In majority of the cases it affects the scalp. We report a baby girl born at term with a large scalp and skull defect measuring 9 × 10 cm. Conservative treatment led to complete epithelization.     

Toxicological aspects of trans fat consumption over two sequential generations of rats: Oxidative damage and preference for amphetamine

Chronic consumption of processed food causes structural changes in membrane phospholipids, affecting brain neurotransmission. Here we evaluated noxious influences of dietary fats over two generations of rats on amphetamine (AMPH)-conditioned place preference (CPP). Female rats received soybean oil (SO, rich in n-6 fatty acids (FA)), fish oil (FO, rich in n-3 FA) and hydrogenated vegetable fat (HVF, rich in trans fatty acids (TFA)) for two successive generations. Male pups from the 2nd generation were maintained on the same supplementation until 41 days of age, when they were conditioned with AMPH in CPP. While the FO group showed higher incorporation of n-3 polyunsaturated-FA (PUFA) in cortex/hippocampus, the HVF group showed TFA incorporation in these same brain areas. The SO and HVF groups showed AMPH-preference and anxiety-like symptoms during abstinence. Higher levels of protein carbonyl (PC) and lower levels of non-protein thiols (NPSH) were observed in cortex/hippocampus of the HVF group, indicating antioxidant defense system impairment. In contrast, the FO group showed no drug-preference and lower PC levels in cortex. Cortical PC was positively correlated with n-6/n-3 PUFA ratio, locomotion and anxiety-like behavior, and hippocampal PC was positively correlated with AMPH-preference, reinforcing connections between oxidative damage and AMPH-induced preference/abstinence behaviors. As brain incorporation of trans and n-6 PUFA modifies its physiological functions, it may facilitate drug addiction.     

Interleukin-23 and its correlation with disease activity,joint damage,and functional disability in rheumatoid arthritis

The purpose of this study was to compare the serum interleukin (IL)-23 levels between rheumatoid arthritis (RA) patients and healthy controls and to determine the correlation of IL-23 levels with disease activity, joint damage and functional disability in RA. Serum samples were obtained from 45 patients with RA and 45 healthy controls. The enzyme-linked immunosorbent assay method was used for quantitative analysis of IL-23. All the RA patients were assessed for disease activity based on the 28-joint disease activity score, joint damage based on modified Sharp score, and functional ability using the Health Assessment Questionnaire–Disability Index. The mean serum IL-23 level was much higher among the RA patients (24.50 ± 13.98 pg/mL) compared to the controls (5.98 ± 3.40 pg/mL; p < 0.01). There was a significant positive relationship between IL-23 levels and disease activity and questionnaire scores (p = 0.003 and 0.020, respectively). On logistic regression analysis, IL-23 levels were significantly higher in patients with moderate to high disease activity (p = 0.008, odds ratio = 1.073, 95% confidence interval = 1.019–1.130) and patients with significant functional disability (p = 0.008, odds ratio = 1.085, 95% confidence interval = 1.021–1.153). RA patients have significantly higher levels of serum IL-23. The IL-23 levels correlate well with disease activity and functional disability but not with radiographic joint damage.     

Exploring isoxazoles and pyrrolidinones decorated with the 4,6‐dimethoxy‐1,3,5‐triazine unit as human farnesyltransferase inhibitors

Unprecedented triazinyl‐isoxazoles were afforded via an effective cycloaddition reaction between nitrile oxides and the scarcely described 2‐ethynyl‐4,6‐dimethoxy‐1,3,5‐triazine as dipolarophile. The biological evaluation of the newly synthesized compounds showed that the inhibition of human farnesyltransferase by zinc complexation could be improved with triazine‐isoxazole moieties. The replacement of the isoxazole unit by a pyrrolidin‐2‐one was detrimental to the inhibitory activity while the pyrrolidin‐2‐thione derivatives conserved the biological potential. The potential of selected compounds to disrupt protein farnesylation in Chinese hamster ovary (CHO) cells transfected with pEGFP‐CAAX was also evaluated.