Revision of Dietary Reference Intakes for energy in preschool-age children.

Background: Dietary Reference Intakes (DRI) for energy aim to balance energy expenditure at a level of physical activity consistent with health and support adequate growth in children. DRIs were derived from total energy expenditure (TEE) measured by using the doubly labeled water (DLW) method; however, the database was limited in the 3-5-y-old range.

Objective: We reexamined the DRI for energy for preschool-age children.

Methylation at CPT1A locus is associated with lipoprotein subfraction profiles.

Lipoprotein subfractions help discriminate cardiometabolic disease risk. Genetic loci validated as associating with lipoprotein measures do not account for a large proportion of the individual variation in lipoprotein measures. We hypothesized that DNA methylation levels across the genome contribute to interindividual variation in lipoprotein measures.

Dual purpose use of preterm piglets as a model of pediatric GI disease.

Necrotizing enterocolitis (NEC) is the most common gastrointestinal complication in human neonates, yet the pathogenesis of this disease remains poorly understood. A fundamental approach to understanding the etiology and underlying biology of NEC is the use of in vivo experimental animal models, primarly neonatal rodents and pigs. The rodent models using rats and mice have provided a much of the experimental evidence showing the protective influence of breast milk and the role of specific molecular mechanisms involved in the premature innate immune and intestinal injury response.

Dietary supplementation with aromatic amino acids increases protein synthesis in children with severe acute malnutrition.

Although 2 earlier studies reported that aromatic amino acid (AAA) supplementation of children with severe acute malnutrition (SAM) improved whole-body protein anabolism during the early postadmission (maintenance) phase of rehabilitation, it is not known whether this positive effect was maintained during the catch-up growth and recovery phases of treatment. This study aimed to determine whether supplementation with an AAA cocktail (330 mg · kg(-1) · d(-1)) vs. isonitrogenous Ala would improve measures of protein kinetics in 22 children, aged 4-31 mo, during the catch-up growth and recovery phases of treatment for SAM.

Subtypes of irritable bowel syndrome in children and adolescents.

Background & Aims: Pharmacologic treatments for irritable bowel syndrome (IBS) and medical management of symptoms are increasingly based on IBS subtype, so it is important to accurately differentiate patients. Few studies have classified subtypes of pediatric IBS, and conclusions have been challenged by methodologic limitations. We performed a prospective study to investigate the distribution of IBS subtypes among children and adolescents based on stool diary information, and compared subtypes according to demographic and pain characteristics.

Regulation of protein degradation pathways by amino acids and insulin in skeletal muscle of neonatal pigs.

Background: The rapid gain in lean mass in neonates requires greater rates of protein synthesis than degradation. We previously delineated the molecular mechanisms by which insulin and amino acids, especially leucine, modulate skeletal muscle protein synthesis and how this changes with development. In the current study, we identified mechanisms involved in protein degradation regulation.

Impact of new-generation lipid emulsions on cellular mechanisms of parenteral nutrition-associated liver disease.

Parenteral nutrition (PN) is a life-saving nutritional support for a large population of hospitalized infants, and lipids make a substantial contribution to their energy and essential fatty acid (FA) needs. A challenge in the care of these infants is that their metabolic needs require prolonged PN support that increases the risk of PN-associated liver disease (PNALD). In recent years, the emergence of new parenteral lipid emulsions containing different source lipids and FA profiles has created nutritional alternatives to the first-generation, soybean oil-based lipid emulsion Intralipid.

Infant iron status affects iron absorption in Peruvian breastfed infants at 2 and 5 mo of age.

Background: Effects of prenatal iron supplementation on maternal postpartum iron status and early infant iron homeostasis remain largely unknown.

Objective: We examined iron absorption and growth in exclusively breastfed infants in relation to fetal iron exposure and iron status during early infancy.

Design: Longitudinal, paired iron-absorption (⁵⁸Fe) studies were conducted in 59 exclusively breastfed Peruvian infants at 2-3 mo of age (2M) and 5-6 mo of age (5M).

Solid anthropomorphic infant whole-body DXA phantom: design, evaluation, and multisite testing.

Background: Dual-energy X-ray absorptiometry (DXA) requires phantoms for quality control and cross-calibration. No commercially available phantoms are designed specifically for whole-body scanning of infants.

Methods: We fabricated a phantom closely matching a 7-kg human infant in body habitus using polyvinyl chloride (PVC), nylon mix, and polyethylene for bone, lean tissue, and fat, respectively, for evaluating the comparability of instruments used in studies on infant body composition.

The circadian clock in cancer development and therapy.

Most aspects of mammalian function display circadian rhythms driven by an endogenous clock. The circadian clock is operated by genes and comprises a central clock in the brain that responds to environmental cues and controls subordinate clocks in peripheral tissues via circadian output pathways. The central and peripheral clocks coordinately generate rhythmic gene expression in a tissue-specific manner in vivo to couple diverse physiological and behavioral processes to periodic changes in the environment.

Feeding style differences in food parenting practices associated with fruit and vegetable intake in children from low-income families.

Objective: To examine the moderating effects of feeding styles on the relationship between food parenting practices and fruit and vegetable (F & V) intake in low-income families with preschool-aged children.

Design: Focus group meetings with Head Start parents were conducted by using the nominal group technique. Parents completed information on food parenting practices and feeding styles.

Viscera and muscle protein synthesis in neonatal pigs is increased more by intermittent bolus than by continuous feeding.

Background: Continuous and intermittent bolus orogastric feedings are strategies used in infants unable to tolerate normal feeds.

Methods: To determine the effects of feeding modality on protein synthesis in different tissues, neonatal pigs received a balanced formula by orogastric tube as an intermittent bolus feed every 4 h or as a continuous infusion, or were fasted overnight.

Results: As compared with fasting, protein synthesis in gastrocnemius, masseter, and soleus muscles; left ventricle; liver; pancreas; jejunum; and kidney increased in bolus- and continuously fed pigs, but the greatest increase occurred after a bolus meal.

Achieving long-term weight maintenance in Mexican-American adolescents with a school-based intervention.

Purpose: This study evaluated 24-month outcomes of a school-based intensive lifestyle weight management program targeting overweight Mexican-American adolescents.

Methods: We recruited a total of 71 adolescents (32 males; 45.1%) between the ages of 10 and 14 years, at or above the 85th percentile for body mass index (BMI).

Early postnatal nutrition determines adult physical activity and energy expenditure in female mice.

Decades of research in rodent models has shown that early postnatal overnutrition induces excess adiposity and other components of metabolic syndrome that persist into adulthood. The specific biologic mechanisms explaining the persistence of these effects, however, remain unknown. On postnatal day 1 (P1), mice were fostered in control (C) or small litters (SL).

Supplementing monosodium glutamate to partial enteral nutrition slows gastric emptying in preterm pigs(1-3).

Emerging evidence suggests that free glutamate may play a functional role in modulating gastroduodenal motor function. We hypothesized that supplementing monosodium glutamate (MSG) to partial enteral nutrition stimulates gastric emptying in preterm pigs. Ten-day-old preterm, parenterally fed pigs received partial enteral nutrition (25%) as milk-based formula supplemented with MSG at 0, 1.

De novo synthesis is the main source of ornithine for citrulline production in neonatal pigs.

Citrulline is an amino acid synthesized in the gut and utilized for the synthesis of the conditionally essential amino acid arginine. Recently, the origin of the ornithine utilized for citrulline synthesis has become a matter of discussion. Multiple physiological factors may have contributed to the differences found among different researchers; one of these is the developmental stage of the subjects studied.

A hydrogen gas-water equilibration method produces accurate and precise stable hydrogen isotope ratio measurements in nutrition studies.

Stable hydrogen isotope methodology is used in nutrition studies to measure growth, breast milk intake, and energy requirement. Isotope ratio MS is the best instrumentation to measure the stable hydrogen isotope ratios in physiological fluids. Conventional methods to convert physiological fluids to hydrogen gas (H(2)) for mass spectrometric analysis are labor intensive, require special reagent, and involve memory effect and potential isotope fractionation.

Designing serious video games for health behavior change: current status and future directions.

Serious video games for health are designed to entertain while changing a specific health behavior. This article identifies behavioral principles that can guide the development of serious video games focused on changing a variety of health behaviors, including those attempting to decrease risk of obesity and type 2 diabetes. Guidelines discussed include how to develop video games that provide a solid foundation for behavior change by enhancing a player's knowledge and skill, ways in which personal mastery experiences can be incorporated into a video game environment, using game characters and avatars to promote observational learning, creating personalized experiences through tailoring, and the importance of achieving a balance between "fun-ness" and "seriousness.

GLP-2 receptor in POMC neurons suppresses feeding behavior and gastric motility.

Glucagon-like peptides (GLP-1/2) are cosecreted from endocrine L cells in the gut and preproglucagonergic neurons in the brain. Peripheral GLP-2 action is essential for maintaining intestinal homeostasis, improving absorption efficiency and blood flow, promoting immune defense, and producing efficacy in treatment of gastrointestinal diseases. However, it is unknown if CNS GLP-2 plays a physiological role in the control of energy homeostasis.

Ablation of ghrelin receptor in leptin-deficient ob/ob mice has paradoxical effects on glucose homeostasis when compared with ablation of ghrelin in ob/ob mice.

The orexigenic hormone ghrelin is important in diabetes because it has an inhibitory effect on insulin secretion. Ghrelin ablation in leptin-deficient ob/ob (Ghrelin(-/-):ob/ob) mice increases insulin secretion and improves hyperglycemia. The physiologically relevant ghrelin receptor is the growth hormone secretagogue receptor (GHS-R), and GHS-R antagonists are thought to be an effective strategy for treating diabetes.

Abundance of amino acid transporters involved in mTORC1 activation in skeletal muscle of neonatal pigs is developmentally regulated.

Previously we demonstrated that the insulin- and amino acid-induced activation of the mammalian target of rapamycin complex 1 (mTORC1) is developmentally regulated in neonatal pigs. Recent studies have indicated that members of the System A transporter (SNAT2), the System N transporter (SNAT3), the System L transporters (LAT1 and LAT2), and the proton-assisted amino acid transporters (PAT1 and PAT2) have crucial roles in the activation of mTORC1 and that the abundance of amino acid transporters is positively correlated with their activation. This study aimed to determine the effect of the post-prandial rise in insulin and amino acids on the abundance or activation of SNAT2, SNAT3, LAT1, LAT2, PAT1, and PAT2 and whether the response is modified by development.

Adipocyte expression of PU.1 transcription factor causes insulin resistance through upregulation of inflammatory cytokine gene expression and ROS production.

We have reported previously that ETS family transcription factor PU.1 is expressed in mature adipocytes of white adipose tissue. PU.

Enteral leucine supplementation increases protein synthesis in skeletal and cardiac muscles and visceral tissues of neonatal pigs through mTORC1-dependent pathways.

Introduction: Leucine (Leu) activates mammalian target of rapamycin (mTOR) to upregulate protein synthesis (PS).

Results: PS in skeletal muscles, heart, liver, pancreas, and jejunum, but not kidney, were greater in low protein supplemented with Leu (LP+L) than LP, but lower than high protein (HP). In longissimus dorsi muscle, protein kinase B phosphorylation was similar in LP and LP+L, but lower than HP.