In situ measurement of free radical formation during the thermal decomposition of grape seed oil using “spin trapping” and electron paramagnetic resonance spectroscopy

The generation of free radical intermediates as a result of the oxidative degradation of lipid molecules during the heating of grape seed oil has been established by a combination of “spin trapping” and electron paramagnetic resonance spectroscopy. The effects of temperature on the rates of formation and decomposition of the adduct with the spin trapN-t-butyl-α-phenylnitrone (PBN) have been investigated over the temperature range 105–180°C. The results show that PBN can be used for studies of free radical processes in oils in situ in the spectrometer cavity at temperatures up to 180°C.     

Mutation in the M1 domain of the acetylcholine receptor alpha subunit decreases the rate of agonist dissociation

We describe the kinetic consequences of the mutation N217K in the M1 domain of the acetylcholine receptor (AChR) alpha subunit that causes a slow channel congenital myasthenic syndrome (SCCMS). We previously showed that receptors containing alpha N217K expressed in 293 HEK cells open in prolonged activation episodes strikingly similar to those observed at the SCCMS end plates. Here we use single channel kinetic analysis to show that the prolonged activation episodes result primarily from slowing of the rate of acetylcholine (ACh) dissociation from the binding site. Rate constants for channel opening and closing are also slowed but to much smaller extents. The rate constants derived from kinetic analysis also describe the concentration dependence of receptor activation, revealing a 20-fold shift in the EC50 to lower agonist concentrations for alpha N217K. The apparent affinity of ACh binding, measured by competition against the rate of 125I-alpha-bungarotoxin binding, is also enhanced 20-fold by alpha N217K. Both the slowing of ACh dissociation and enhanced apparent affinity are specific to the lysine substitution, as the glutamine and glutamate substitutions have no effect. Substituting lysine for the equivalent asparagine in the beta, epsilon, or delta subunits does not affect the kinetics of receptor activation or apparent agonist affinity. The results show that a mutation in the amino-terminal portion of the M1 domain produces a localized perturbation that stabilizes agonist bound to the resting state of the AChR.     

Nonessential fatty acids in formula fat blends influence essential fatty acid metabolism and composition in plasma and organ lipid classes in piglets

The online version of the original article can be found at     

Drosophila engrailed can substitute for mouse Engrailed1 function in mid-hindbrain, but not limb development

The Engrailed-1 gene, En1, a murine homologue of the Drosophila homeobox gene engrailed (en), is required for midbrain and cerebellum development and dorsal/ventral patterning of the limbs. In Drosophila, en is involved in regulating a number of key patterning processes including segmentation of the epidermis. An important question is whether, during evolution, the biochemical properties of En proteins have been conserved, revealing a common underlying molecular mechanism to their diverse developmental activities. To address this question, we have replaced the coding sequences of En1 with Drosophila en. Mice expressing Drosophila en in place of En1 have a near complete rescue of the lethal En1 mutant brain defect and most skeletal abnormalities. In contrast, expression of Drosophila en in the embryonic limbs of En1 mutants does not lead to repression of Wnt7a in the embryonic ventral ectoderm or full rescue of the embryonic dorsal/ventral patterning defects. Furthermore, neither En2 nor en rescue the postnatal limb abnormalities that develop in rare En1 null mutants that survive. These studies demonstrate that the biochemical activity utilized in mouse to mediate brain development has been retained by Engrailed proteins across the phyla, and indicate that during evolution vertebrate En proteins have acquired two unique functions during embryonic and postnatal limb development and that only En1 can function postnatally.     

Association between bleomycin hydrolase and Alzheimer's disease in caucasians

A recent study showed modest evidence for an increased frequency of the bleomycin hydrolase (BH) V/V genotype in Alzheimer's disease (AD) patients compared with non-demented controls. To test this hypothesis, we examined this polymorphism in 621 rigorously evaluated patients and 502 control subjects (all caucasian) but were unable to detect an association between BH and AD even after controlling for age, gender, and apolipoprotein E (ApoE) genotype. We conclude that this polymorphism does not account for inherited susceptibility to AD in the populations represented in this sample.     

Randomized trial of contingent prizes versus vouchers in cocaine-using methadone patients.

Contingency management (CM) interventions frequently utilize vouchers as reinforcers, but a prize-based system is also efficacious. This study compared these approaches. Seventy-four cocaine-dependent methadone outpatients were randomly assigned to standard treatment (ST), ST plus a maximum of $585 in contingent vouchers, or ST plus an expected average maximum of $300 in contingent prizes for 12 weeks. CM participants achieved longer durations of abstinence (LDA) than ST participants, and CM conditions did not differ significantly in outcomes or amount of reinforcement earned. Although long-term abstinence did not differ by group, LDA during treatment was the best predictor of abstinence at 9 months. Thus, reinforcement with prizes was similar to voucher CM in promoting LDA, which is associated with posttreatment benefits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A preliminary study of clinical interventions in custody & access disputes.

Reviewed, retrospectively, 30 custody and access dispute cases (8 assessments, 22 arbitrations, and 10 mediations) and analyzed factors associated with each procedure. The factors examined were based on parents' views of their dispute, as recorded in an initial intake questionnaire completed preintervention. Findings suggest that couples who resolve their dispute through mediation tend to be more child-focused, future-oriented, positive about themselves, and helpful in providing suggestions for dispute resolution than parents involved in an assessment process. (French abstract) (6 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Multiple objective shift allocation model

This paper is concerned with a production planning problem of allocating production items to production shifts on production lines in a multiple objective decision environment. The problem is modeled and solutions are generated using integer goal programming techniques. Objectives are formulated not only in terms of minimizing the sum of deviations from goal target levels, but also in terms of minimizing the maximum deviation. Test results indicate that the model structure and solution process utilized can provide decision makers with a good set of representative solutions in a rather complex multiple objective decision environment.     

Dear Sheila: An experimental study of the effectiveness of written communication as a form of psychotherapy.

42 college students who responded to an announcement for a writing therapy study were randomly assigned to 1 of 3 groups. The writing therapy group wrote letters describing their problems to a psychotherapist whose written replies contained behaviorally oriented responses. Reassuring responses were written to the problem letters of Ss in a reassurance control group. A 2nd control group was asked to count the frequency of occurrence of specific problem behaviors and mail them to the therapist, who did not reply. 10 Ss in the writing therapy group and 8 in each of the control groups completed the 4-mo treatment period. The decrease in the number of problems (as measured by the Mooney Problem Check List) was significantly greater in the writing therapy group than in the 2 control groups. Analysis of demographic data revealed that more males than females dropped out of the study, and a significantly greater proportion of the dropouts were from lower-class families. It is concluded that writing therapy may be useful and appeal to students who do not feel able to use traditional student counseling services. (PsycINFO Database Record (c) 2010 APA, all rights reserved)