Serum Carotenoids and Pediatric Metabolic Index Predict Insulin Sensitivity in Mexican American Children

High concentrations of carotenoids are protective against cardiometabolic risk traits (CMTs) in adults and children. We recently showed in non-diabetic Mexican American (MA) children that serum α-carotene and β-carotene are inversely correlated with obesity measures and triglycerides and positively with HDL cholesterol and that they were under strong genetic influences. Additionally, we previously described a Pediatric Metabolic Index (PMI) that helps in the identification of children who are at risk for cardiometabolic diseases. Here, we quantified serum lycopene and β-cryptoxanthin concentrations in approximately 580 children from MA families using an ultraperformance liquid chromatography-photodiode array and determined their heritabilities and correlations with CMTs. Using response surface methodology (RSM), we determined two-way interactions of carotenoids and PMI on Matsuda insulin sensitivity index (ISI). The concentrations of lycopene and β-cryptoxanthin were highly heritable [h2 = 0.98, P = 7 × 10–18 and h2 = 0.58, P = 1 × 10–7]. We found significant (P ≤ 0.05) negative phenotypic correlations between β-cryptoxanthin and five CMTs: body mass index (− 0.22), waist circumference (− 0.25), triglycerides (− 0.18), fat mass (− 0.23), fasting glucose (− 0.09), and positive correlations with HDL cholesterol (0.29). In contrast, lycopene only showed a significant negative correlation with fasting glucose (− 0.08) and a positive correlation with HDL cholesterol (0.18). Importantly, we found that common genetic influences significantly contributed to the observed phenotypic correlations. RSM showed that increased serum concentrations of α- and β-carotenoids rather than that of β-cryptoxanthin or lycopene had maximal effects on ISI. In summary, our findings suggest that the serum carotenoids are under strong additive genetic influences and may have differential effects on susceptibility to CMTs in children

How changes in white matter might underlie improved reaction time due to practice

Why does training on a task reduce the reaction time for performing it? New research points to changes in white matter pathways as one likely mechanism. These pathways connect remote brain areas involved in performing the task. Genetic variations may be involved in individual differences in the extent of this improvement. If white matter change is involved in improved reaction time with training, it may point the way toward understanding where and how generalization occurs. We examine the hypothesis that brain pathways shared by different tasks may result in improved performance of cognitive tasks remote from the training

White matter and reaction time: Reply to commentaries

We appreciate the many comments we received on our discussion paper and believe that they reflect a recognition of the importance of this topic worldwide. We point out in this reply that there appears to be a confusion between the role of oscillations in creating white matter and other functions of oscillations in communicating between neural areas during task performance or at rest. We also discuss some mechanisms other than the enhancement of white matter that must influence reaction time. We recognize the limited understanding we have of transfer and outline some future directions designed to improve our understanding of this process

Zooming in on Barrett oesophagus using narrow-band imaging: an international observer agreement study

Background Several classifications of mucosal morphology have been proposed in Barrett oesophagus using narrow-band imaging (NBI). We evaluated a simplified classification in which only the regularity of mucosal and vascular patterns were evaluated. Aim To assess the inter and intraobserver agreement and the correlation with histology of a simplified NBI classification of mucosal morphology in Barrett oesophagus combining the experience of two referral centres. Methods Two hundred NBI images [57 high-grade intraepithelial neoplasia (HGIN)/early cancer (EC)] were evaluated twice by four NBI-experienced and four nonexperienced endoscopists in the field of NBI. Endoscopists assessed each image for: quality, suspicion for dysplasia, and regularity of mucosal and vascular patterns. Observer agreement was assessed using kappa statistics. Results Overall interobserver agreement for the items evaluated was 'moderate' and varied between 0.42 and 0.44. Overall intraobserver agreement was 'moderate' to 'substantial' (kappa 0.60-0.62). There were no significant differences in agreement between expert and nonexpert endoscopists. Endoscopist correctly identified 71% of the images containing HGIN/EC. Of the areas without HGIN/EC, 68% were correctly identified as not suspicious. Again, there were no significant differences between experts and nonexperts. Conclusion Our proposed, simplified classification for Barrett mucosal morphology has a moderate interobserver and a moderate to substantial intraobserver agreement. The lack of differences in agreements between expert and nonexpert endoscopists suggests a short learning curve. The disappointing rate for correctly indentifying HGIN/EC, questions, however, whether detailed inspection of Barrett oesophagus with NBI can replace histological sampling. Eur J Gastroenterol Hepatol 21: 1068-1075 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkin