Dietary protein effects on gallstone formation

Semipurified lithogenic diets for hamsters contain casein as the protein source. Since substitution of soy protein isolate for casein reduces serum cholesterol concentrations in several species, we studied replacement of casein by soy protein for effects on gallstone formation. Feeding soy protein consistently resulted in a significantly reduced incidence of gallstones. Switching to a soy-based diet after induction of gallstones resulted in dissolution of a significant percentage of the stones. Partial substitution of soy for casein gave results intermediate between 100% casein and 100% soy. The lysine/arginine ratio of the proteins may be responsible for the observed differences in cholelithiasis. The reduction in lithogenicity associated with feeding soy protein appears to be mediated primarily through decreased secretion of cholesterol into bile.     

Contingent take-home incentive: Effects on drug use of methadone maintenance patients.

Examined contingent methadone take-home privileges for effectiveness in reducing on-going supplemental drug use of methadone maintenance patients. 53 new intakes were randomly assigned to begin receiving take-home privileges after 2 consecutive weeks of drug-free urines or to a noncontingent procedure in which take-homes were delivered independently of urine test results. The contingent procedure produced more individuals with at least 4 consecutive weeks of abstinence (32 vs 8%); 28% of noncontingent Ss also achieved abstinence after shifting to the contingent procedure. Lower baseline rate of drug-free urines was strongly associated with successful outcome, whereas the type of drug abused (cocaine vs benzodiazepines) did not influence outcomes. Findings support a recommendation for using contingent take-home incentives to motivate abstinence during methadone maintenance treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chemically mediated interactions among juvenile mosses as possible determinants of their community structure

A field study of the distribution patterns of six closely related species of mosses along a complex altitudinal gradient found evidence suggesting differential aggressiveness among juveniles rather than evidence of differential competitive abilities among adults of the species. Work by Bopp (1963, 1968) on the moss phytohormone, factor H, suggests a means by which such interactions might be mediated. An experimental system is proposed through which the effect of patterns of early moss development upon the determination of moss community structure may be assessed.     

Iron chelating polypropylene films: Manipulating photoinitiated graft polymerization to tailor chelating activity

Transition metals, especially iron, enhance the oxidative degradation of lipids. Nonmigratory metal chelating active packaging can inhibit lipid oxidation and meet consumer demand for ‘cleaner' labels. Recently, the development of iron chelating films prepared by photoinitiated graft polymerization of acrylic acid on polypropylene (PP‐g‐PAA) was reported. The objective of this study was to tailor the chelating activity of PP‐g‐PAA by manipulating graft conditions. Carboxylic acids graft density and PAA graft thickness increased with graft time and acrylic acid concentration, with carboxylic acids density of up to 143 ± 32 nmol cm^?2, PAA graft thickness of ～6–18 μm, and ligand (carboxylic acid) to metal (Fe²⁺) binding ratio of ～4–5. Reducing photoinitiator graft density decreased this ratio to ～2–2.5, suggesting that graft chain density influences chelating activity. This work demonstrates the ability to tailor chelating activity of PP‐g‐PAA with potential applications in active packaging, chelation therapy, and water purification. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39948.     

Optimization of human plasma 1H NMR spectroscopic data processing for high-throughput metabolic phenotyping studies and detection of insulin resistance related to type 2 diabetes

Optimizing NMR experimental parameters for high-throughput metabolic phenotyping requires careful examination of the total biochemical information obtainable from (1)H NMR data, which includes concentration and molecular dynamics information. Here we have applied two different types of mathematical transformation (calculation of the first derivative of the NMR spectrum and Gaussian shaping of the free-induction decay) to attenuate broad spectral features from macromolecules and enhance the signals of small molecules. By application of chemometric methods such as principal component analysis (PCA), orthogonal projections to latent structures discriminant analysis (O-PLS-DA) and statistical spectroscopic tools such as statistical total correlation spectroscopy (STOCSY), we show that these methods successfully identify the same potential biomarkers as spin-echo (1)H NMR spectra in which broad lines are suppressed via T2 relaxation editing. Finally, we applied these methods for identification of the metabolic phenotype of patients with type 2 diabetes. This "virtual" relaxation-edited spectroscopy (RESY) approach can be particularly useful for high-throughput screening of complex mixtures such as human plasma and may be useful for extraction of latent biochemical information from legacy or archived NMR data sets for which only standard 1D data sets exist.     

Factors associated with serum polybrominated diphenyl ether (PBDE) levels among school-age children in the CHAMACOS cohort

Polybrominated diphenyl ethers (PBDEs) are a class of flame retardants historically used in textiles, furniture, and electronic products. Recent studies have documented widespread PBDE exposure to humans, with higher levels measured in children than adults. We analyzed 10 tri- to hepta-BDE congener levels in blood collected from 7-year old Mexican-American children living in an agriculture community in California (n = 272). The most frequently detected PBDE congeners in child serum were BDE-47, -99, -100, and -153, all of which were measured in >99% of the children. We used multiple linear regression models to examine associations between child total PBDE levels (ng/g lipid) and determinants of exposure. Factors positively associated with higher PBDE levels in the children were total PBDE levels in maternal serum during pregnancy, duration of exclusive breastfeeding, and having no safe places to play in their neighborhood. Child BMI was inversely associated with serum PBDE levels (regression p-values <0.05). Our findings confirm that exposure to the penta-BDE mixture is ongoing, and that Mexican-American children living in California may be experiencing higher PBDE exposure from their environment compared to children sampled from the general U.S. population. Additional research is needed to assess the health impacts of these exposures.