A Facile Route to Tailoring Peptide-Stabilized Gold Nanoparticles Using Glutathione as a Synthon

The preparation of gold nanoparticles (AuNPs) of high purity and stability remains a major challenge for biological applications. This paper reports a simple synthetic strategy to prepare water-soluble peptide-stabilized AuNPs. Reduced glutathione, a natural tripeptide, was used as a synthon for the growth of two peptide chains directly on the AuNP surface. Both nonpolar (tryptophan and methionine) and polar basic (histidine and dansylated arginine) amino acids were conjugated to the GSH-capped AuNPs. Ultracentrifugation concentrators with polyethersulfone (PES) membranes were used to purify precursor materials in each stage of the multi-step synthesis to minimize side reactions. Thin layer chromatography, transmission electron microscopy, UV-Visible, 1H-NMR, and fluorescence spectroscopies demonstrated that ultracentrifugation produces high purity AuNPs, with narrow polydispersity, and minimal aggregation. More importantly, it allows for more control over the composition of the final ligand structure. Studies under conditions of varying pH and ionic strength revealed that peptide length, charge, and hydrophobicity influence the stability as well as solubility of the peptide-capped AuNPs. The synthetic and purification strategies used provide a facile route for developing a library of tailored biocompatible peptide-stabilized AuNPs for biomedical applications

Filling America’s Fiber Intake Gap: Summary of a Roundtable to Probe Realistic Solutions with a Focus on Grain-Based Foods

Current fiber intakes are alarmingly low, with long-term implications for public health related to risk of coronary heart disease, stroke, hypertension, certain gastrointestinal disorders, obesity, and the continuum of metabolic dysfunctions including prediabetes and type 2 diabetes. Eating patterns high in certain fibers are known to lower LDL cholesterol and blood pressure, lower blood glucose, and decrease insulin resistance in people with prediabetes and type 2 diabetes; help with both weight loss and maintenance; and improve bowel regularity and gastrointestinal health. With \u3e 90% of adults and children who fall short of meeting their daily fiber recommendations, the 2010 Dietary Guidelines for Americans once again classified fiber as a nutrient of concern. Despite efforts over the past decade to promote adequate fiber through fruit, vegetable, and whole-grain intakes, fiber consumption has remained flat at approximately half the daily recommended amount. The public health implications of inadequate fiber intake prompted the roundtable session Filling America\u27s Fiber Gap: Probing Realistic Solutions, which assembled nutrition researchers, educators, and communicators to identify challenges, opportunities, and realistic solutions to help fill the current fiber gap. The roundtable discussions highlighted the need for both consumer and professional education to improve acceptance for and inclusion of grain-based foods with added fiber as one strategy for increasing fiber intakes within daily energy goals. © 2012 American Society for Nutrition

Guanidinoacetate Methyltransferase (Gamt) Deficiency: Outcomes In 48 Individuals And Recommendations For Diagnosis, Treatment And Monitoring

We collected data on 48 patients from 38 families with guanidinoacetate methyltransferase (GAMT) deficiency. Global developmental delay/intellectual disability (DD/ID) with speech/language delay and behavioral problems as the most affected domains was present in 44 participants, with additional epilepsy present in 35 and movement disorder in 13. Treatment regimens included various combinations/dosages of creatine-monohydrate, L-ornithine, sodium benzoate and protein/arginine restricted diets. The median age at treatment initiation was 25.5 and 39 months in patients with mild and moderate DD/ID, respectively, and 11 years in patients with severe DD/ID. Increase of cerebral creatine and decrease of plasma/CSF guanidinoacetate levels were achieved by supplementation with creatine-monohydrate combined with high dosages of t-ornithine and/or an arginine-restricted diet (250 mg/kg/d L-arginine). Therapy was associated with improvement or stabilization of symptoms in all of the symptomatic cases. The 4 patients treated younger than 9 months had normal or almost normal developmental outcomes. One with inconsistent compliance had a borderline IQ at age 8.6 years. An observational GAMT database will be essential to identify the best treatment to reduce plasma guanidinoacetate levels and improve long-term outcomes. (C) 2013 The Authors. Published by Elsevier Inc. All rights reserved.WoSScopu