Metabolite analyses of grain from maize hybrids grown in the United States under drought and watered conditions during the 2002 field season.

Understanding natural variation in the composition of conventional crop germplasms is critical in establishing a baseline for comparison of biotechnology-derived crops. This is particularly relevant to such traits as tolerance to drought stress. Thus, there is both a need to understand the contribution of stress conditions to natural variation in plant nutritional components and to determine whether levels of small molecule metabolites such as osmoprotectants and stress metabolites are also affected. As a first step in developing such information for maize, seven conventional hybrids were grown under different moisture regimens and the impact of moisture on composition was assessed. The regimens included well-watered conditions, water restriction during the vegetative phase, and water restriction during grain fill. Compositional analyses of the harvested grain included assessments of the levels of proximates (moisture, protein, oil, starch) and small molecule metabolites such as fatty acids, free amino acids, organic acids, sugars, total glycerol, glycine betaine, and abscisic acid. Ranges for these analytes were determined across all moisture regimens, and the effect of the different water regimens on these analytes was also evaluated. The number and type of grain analytes that showed statistically significant differences in levels between different water regimens differed quite markedly by maize hybrid. However, the magnitude of mean differences between well-watered and water-restricted samples was typically small, and statistically significant differences for any given analyte were typically observed in only one to three of the seven maize hybrids. Only two analytes, free glutamine and free proline, showed a significant drought-induced difference in at least four maize hybrids.

Impact of genetics and environment on nutritional and metabolite components of maize grain.

The Organization for Economic Co-operation and Development (OECD) recommends the measurement of specific plant components for compositional assessments of new biotechnology-derived crops. These components include proximates, nutrients, antinutrients, and certain crop-specific secondary metabolites. A considerable literature on the natural variability of these components in conventional and biotechnology-derived crops now exists. Yet the OECD consensus also suggests measurements of any metabolites that may be directly associated with a newly introduced trait. Therefore, steps have been initiated to assess natural variation in metabolites not typically included in the OECD consensus but which might reasonably be expected to be affected by new traits addressing, for example, nutritional enhancement or improved stress tolerance. The compositional study reported here extended across a diverse genetic range of maize hybrids derived from 48 inbreds crossed against two different testers. These were grown at three different, but geographically similar, locations in the United States. In addition to OECD analytes such as proximates, total amino acids and free fatty acids, the levels of free amino acids, sugars, organic acids, and selected stress metabolites in harvested grain were assessed. The major free amino acids identified were asparagine, aspartate, glutamate, and proline. The major sugars were sucrose, glucose, and fructose. The most predominant organic acid was citric acid, with only minor amounts of other organic acids detected. The impact of genetic background and location was assessed for all components. Overall, natural variation in free amino acids, sugars, and organic acids appeared to be markedly higher than that observed for the OECD analytes.

The use of complementary and alternative medicine in children with chronic medical conditions.

OBJECTIVES: The objectives of this study were to examine whether progressive medical conditions lead to greater use of complementary and alternative medicine (CAM) as compared with more stable conditions, to see whether disease severity influences CAM use, and to identify the main motivations behind CAM use. METHODS: Subjects were selected from outpatient clinics at Hotel Dieu Hospital. Surveys were conducted by mail and telephone. Medical diagnosis and severity were obtained from medical files. Statistical tests included chi, Kruskal-Wallis, and correlations. RESULTS: One hundred ninety-four children were surveyed. The "progressive" group included 15 patients with Duchenne muscular dystrophy and 22 patients with cystic fibrosis. The "nonprogressive" group included 85 patients with cerebral palsy (CP), 49 with diabetes mellitus, and 23 with spina bifida. Twenty-three percent were using CAM. CP had the highest use; diabetes mellitus had the lowest. Popular therapies included massage and dietary/herbal remedies. Progressiveness had no impact on CAM use. Within the CP group, greater disease severity was associated with higher use (P < 0.001). The main reason for CAM use was to complement conventional medicine. CONCLUSIONS: Disease progressiveness had no impact on CAM use, but severity within the CP group did. Complementing conventional medicine was the main motive. Understanding the reasons and patterns of use of CAM is beneficial in efforts to improve the care of children with chronic medical conditions.

Patterns of complementary and alternative medical therapy use in children diagnosed with autism spectrum disorders.

Previous studies suggest that complementary and alternative medical (CAM) therapy use in children with chronic illnesses is higher than in children in the general population. In this study, we investigated patterns of CAM therapy use in children diagnosed with autism spectrum disorders (ASD, n = 50) as compared to a control population of children with no ASD (n = 50). Over half of the parents in the ASD group reported using, or had used at least one CAM therapy for their child (52%) as compared to 28% of the control group (P = 0.024). Seventy percent of therapies used in the ASD group were biologically based therapies comprised of special diets or supplements, and parents felt that 75% of the therapies used were beneficial.

Solid Phase Synthesis of beta-Peptoids: N-Substituted beta-Aminopropionic Acid Oligomers.

A solid-phase organic synthesis method has been developed for the preparation of N-substituted-beta-aminopropionic acid oligomers or beta-peptoids 1. Treatment of polymer-bound 4-(benzyloxy)benzyl acrylate 2 with primary amines afforded N-substituted beta-alanines 3. Polymer loadings and product conversions were determined by direct cleavage of resin-bound materials and measurement by (1)H NMR with an internal standard. The NMR method was used to establish loading of all resin-bound intermediates including acrylic acid. Acylation with acryloyl chloride followed by Michael addition of primary amines to the acrylamide allowed preparation of di-beta-peptoids. By a linear set of seven reactions, trimeric N-benzyl-beta-aminopropionic acid was prepared in 67% overall yield. Single-bead FT-IR microspectroscopy was used to acquire spectra of the resin bound mono-beta-peptoids, di-beta-peptoids, and acrylamide intermediates. A combinatorial library of defined mixtures of tri-beta-peptoids was prepared by mixing equimolar amounts of the mono-beta-peptoid resins and carrying them through two sequences of the acylation-Michael addition. The identity of a sample mixture was determined by LC-MS analysis of the cleavage product.