Frontal EEG asymmetry moderates the association between attentional bias towards food and body mass index.

High global incidence of obesity has led to efforts to identify factors that may contribute to elevated body mass index (BMI). Studies have shown individuals with obesity tend to display an attentional bias (AB) towards food. Left frontal EEG alpha asymmetry (FA) has been associated with motivation to approach rewards and may heighten reactivity to food cues. The current study thus explored whether the association between AB to food and BMI is moderated by FA. EEG was recorded while 93 female participants watched a video confederate incidentally consume potato chips. Participants subsequently completed a visual-probe task to assess AB towards food. Results revealed that AB was positively associated with BMI when FA was skewed left but not right. Individuals' predisposition to approach appetitive stimuli may interact with a bias to attend to food to facilitate overconsumption in obesogenic food environments. Future studies should examine this interaction in relation to consumption.

Social modeling of eating mediated by mirror neuron activity: A causal model moderated by frontal asymmetry and BMI.

The social modeling of eating effect refers to the consistently demonstrated phenomenon that individuals tend to match their quantity of food intake to their eating companion. The current study sought to explore whether activity within the mirror neuron system (MNS) mediates the social modeling of eating effect as a function of EEG frontal asymmetry and body mass index (BMI). Under the guise of rating empathy, 93 female undergraduates viewed a female video confederate "incidentally" consume either a low or high intake of chips while electroencephalogram (EEG) activity was recorded. Subsequent ad libitum chip consumption was quantified. A first- and second-stage dual moderation model revealed that frontal asymmetry and BMI moderated an indirect effect of model consumption on participants' food consumption as mediated by MNS activity at electrode site C3, a3b3=-0.718, SE=0.365, 95% CI [-1.632, -0.161]. Left frontal asymmetry was associated with greater mu activity and a positive association between model and participant chip consumption, while right frontal asymmetry was associated with less mu activity and a negative association between model and participant consumption. Across all levels of frontal asymmetry, the effect was only significant among those with a BMI at the 50th percentile or lower. Thus, among leaner individuals, the MNS was demonstrated to mediate social modeling of eating, as moderated by frontal asymmetry. These findings are integrated within the normative account of social modeling of eating. It is proposed that the normative framework may benefit from consideration of both conscious and unconscious operation of intake norms.

Heart rate variability reactivity and new romance: Cause or consequence?

There are documented physiological differences between single and coupled individuals during the "honeymoon period" of nascent romantic relationships. One such difference is in autonomic reactivity, specifically heart rate variability (HRV) reactivity. This finding had previously been interpreted as evidence of a stress buffering effect of relationship formation. The present study explored among university women two competing longitudinal hypotheses conceptualizing differences in HRV reactivity as either a cause or a consequence of romantic relationship formation. Results did not support the hypothesis that HRV reactivity changes as a consequence of beginning a new romantic relationship. Instead, lower HRV reactivity predicted greater relationship formation amongst women with low BMI and higher resting HRV. The functioning of the heart therefore predicted the likelihood that an individual would find love. These interactions may be the result of differing success rates of various mating strategies for women with low and high BMI and HRV.

Direct oligonucleotide synthesis onto super-paramagnetic beads.

Super-paramagnetic beads (SPMB)s used for a variety of molecular diagnostic assays are prepared by attaching pre-synthesized oligonucleotides to the surface via a cumbersome and low efficient method of carbodiimide-mediated amide bond formation. To mainstream the process, we describe a novel procedure of direct oligonucleotide synthesis onto the surface of SPMBs (e.g. MyOne Dynabeads). With the many challenges surrounding containment of paramagnetic beads (≤1 µm) during automated oligonucleotide synthesis, we show that by applying a magnetic force directly to the SPMBs we prevent their loss caused by high-pressure drain steps during synthesis. To date we have synthesized 40 mers using a Spacer 9 phosphoramidite (triethylene glycol) coupled to the surface of hydroxylated SPMBs. HPLC analysis shows successful product generation with an average yield of 200 pmol per sample. Furthermore, because of the versatility of this powerful research tool, we envision its use in any laboratory working with conventional synthesis automation, as employed for single columns and for multi-well titer plates. In addition to direct synthesis of oligodeoxynucleotides (DNA) onto SPMBs, this platform also has the potential for RNA and peptide nucleic acid synthesis.

Simultaneous comparison of many triphasic defibrillation waveforms.

Biphasic defibrillation waveforms are now accepted as being more effective at terminating ventricular fibrillation (VF) than monophasic waveforms. If two phases are better than one, this naturally leads to the hypothesis that additional phases improve efficacy. This study tests the hypothesis by adding one additional phase. We examined the efficacy of 18 different triphasic waveforms simultaneously.We tested the rate of recovery, i.e., successful defibrillation, of 21 guinea pigs (820-1,050 g) using triphasic, monophasic and biphasic defibrillation waveforms. The biphasic and monophasic were control waveforms. VF was electrically induced twenty times per animal and a single defibrillation attempt was made using a test waveform VF episode. Every waveform was adjusted to the energy required to defibrillate that animal 50% of the time, using a biphasic waveform as a control. The success rate of each triphasic waveform was pair-wise compared to the biphasic and monophasic control using the adjusted McNemar statistical test.Of the 18 triphasic waveforms tested, two were significantly poorer than the monophasic control (p<0.05). One was superior to the biphasic waveform (p<0.1), but not statistically so. We concluded that, while adding a phase to a monophasic waveform does improve efficacy, adding an additional phase to a biphasic waveform does not necessarily improve efficacy.

Interference of globin genes with biomarker discovery for allograft rejection in peripheral blood samples.

Microarray technology is a powerful tool in the discovery of new biomarkers for disease. After solid organ transplantation, where the detection of rejection is usually made on invasive biopsies, it could be hypothesized that noninvasive transcriptional profiling of peripheral blood will reveal rejection-specific expression patterns from circulating immune cells. However, in kidney transplant rejection, the analysis of gene expression data in whole blood has proven difficult for detecting significant genes specific for acute graft rejection. Previous studies have demonstrated that the abundance of globin genes in whole blood may mask the underlying biological differences between whole blood samples. In the present study, we compared the gene expression profiles of peripheral blood of nine stable renal allograft recipients with seven matched patients having an ongoing acute renal transplant rejection, using four different protocols of preparation, amplification, and synthesis of cRNA or cDNA and hybridization on the Affymetrix platform. We demonstrated that the globin reduction method is not sufficient to unmask clinically relevant rejection-specific transcriptome profiles in whole blood. Applying an additional mathematical depletion of the globin genes improves the efficacy of globin reduction but cannot remove the confounding influence of globin gene hybridization. Sampling of peripheral blood leukocytes alone, without the confounding influence of globin mRNA, provides sensitive and specific peripheral signatures for graft rejection, with many of these signals overlapping with rejection-driven tissue (kidney)-specific signatures from matched biopsies. Similar applications may exist for array-based biomarker discovery for other diseases associated with changes in leukocyte trafficking, activation, or function.

Genome-wide analysis of barcoded Saccharomyces cerevisiae gene-deletion mutants in pooled cultures.

The availability of a near-complete (96%) collection of gene-deletion mutants in Saccharomyces cerevisiae greatly facilitates the systematic analyses of gene function in yeast. The unique 20 bp DNA 'barcodes' or 'tags' in each deletion strain enable the individual fitness of thousands of deletion mutants to be resolved from a single pooled culture. Here, we present protocols for the study of pooled cultures of tagged yeast deletion mutants with a tag microarray. This process involves five main steps: pooled growth, isolation of genomic DNA, PCR amplification of the barcodes, array hybridization and data analysis. Pooled deletion screening can be used to study gene function, uncover a compound's mode of action and identify drug targets. In addition to these applications, the general method of studying pooled samples with barcode arrays can also be adapted for use with other types of samples, such as mutant collections in other organisms, short interfering RNA vectors and molecular inversion probes.

Diverse cellular functions of the Hsp90 molecular chaperone uncovered using systems approaches.

A comprehensive understanding of the cellular functions of the Hsp90 molecular chaperone has remained elusive. Although Hsp90 is essential, highly abundant under normal conditions, and further induced by environmental stress, only a limited number of Hsp90 "clients" have been identified. To define Hsp90 function, a panel of genome-wide chemical-genetic screens in Saccharomyces cerevisiae were combined with bioinformatic analyses. This approach identified several unanticipated functions of Hsp90 under normal conditions and in response to stress. Under normal growth conditions, Hsp90 plays a major role in various aspects of the secretory pathway and cellular transport; during environmental stress, Hsp90 is required for the cell cycle, meiosis, and cytokinesis. Importantly, biochemical and cell biological analyses validated several of these Hsp90-dependent functions, highlighting the potential of our integrated global approach to uncover chaperone functions in the cell.

Assessing the functional nature of binge eating in the eating disorders.

This study explored the functional nature of binge eating through the development of a new self-report instrument called the Binge Eating Adjective Checklist. Participants were 405 adult females who presented to a specialized eating disorders clinic. A subset of participants with bulimia nervosa also completed additional psychometrics and treatment. Those participants who reported greater reductions in negative affective and somatic states during a binge episode were also more distressed on measures of perfectionism, self-esteem, ineffectiveness, and interceptive awareness. They were also less likely to achieve abstinence from bingeing and vomiting over the course of treatment. Thus, the instrument appears to offer a methodology for studying the phenomenology of binge eating and the prediction of therapeutic outcome in bulimia nervosa.

Adolescents with anorexia nervosa: multiple perspectives of discharge readiness.

PROBLEM: Little is known about the conditions that must be in place to help adolescent patients and their families gain the confidence needed to continue recovery at home, following the adolescents' hospitalization for anorexia nervosa. METHODS: Beliefs about discharge readiness were obtained through an open-ended questionnaire following the patients' first weekend pass home from an in-patient unit. The perceptions of patients, parents, and registered nurses were obtained using parallel versions of a questionnaire. FINDINGS: An examination of the responses revealed four themes; medical stability, education, psychological changes, and community resource planning, that were common to all respondents, as well as themes specific to adolescents and to nurses. CONCLUSIONS: The findings suggest that each group of respondents has unique discharge readiness needs and that registered nurses have an important role to play in helping patients and families make the transition home as successful as possible. Implications for nursing practice are highlighted.

A community-based training program for eating disorders and its contribution to a provincial network of specialized services.

The Ontario Community Outreach Program for Eating Disorders is a pilot training project within the eating disorder programs at the University Health Network--Toronto General Hospital (TGH) and the Hospital for Sick Children. This system provides ongoing training, consultation, and research evaluation in areas ranging from prevention through to tertiary care, in the hopes of increasing the capacity of practitioners to respond to the healthcare pressures of those experiencing eating disorders. A total of 3,315 health care practitioners and educators in Ontario participated in community-based training workshops. A pre-post analysis of participants' self-report evaluations was conducted using chi-square analyses. The findings revealed that there was a statistically significant increase in participants' (a) knowledge of eating disorders and of body image issues and (b) level of comfort to either treat clients with eating disorders or teach a curriculum on body image. The contribution of the training program to the development of a provincial network of specialized eating disorder services, designed to promote the public's access to timely and appropriate care for the full spectrum of eating disorders, are discussed.

Evaluation of a school-based program designed to improve body image satisfaction, global self-esteem, and eating attitudes and behaviors: a replication study.

OBJECTIVE: The purpose of the current study was to evaluate the effectiveness of a life-skills promotion program designed to improve body image satisfaction and global self-esteem, while reducing negative eating attitudes and behaviors and feelings of perfectionism, all of which have been identified as predisposing factors to disordered eating. METHOD: A total of 258 girls with a mean age of 11.8 years (intervention group = 182 and control group = 76) completed questionnaires before, and 1 week after, the six-session school-based program, and again 6 and 12 months later. RESULTS: The intervention was successful in improving body image satisfaction and global self-esteem and in reducing dieting attitude scores at post intervention only. The gains were not maintained at the 12-month follow-up. DISCUSSION: The need to assess the influence of health promotion programs on predisposing risk factors, compared with problem-based outcome measures, is discussed.

Selective mood-induced body image disparagement and enhancement effects: are they due to cognitive priming or subjective mood?

OBJECTIVE: The study evaluated the effects of mood induction procedures on body image. METHOD: Eighty female undergraduates participated in combinations of two valences (negative vs. positive) and two types (self-referent vs. other-referent) of mood induction procedures (MIPs). A measure of subjective mood and seven measures of body image were administered before and after the MIPs. RESULTS: Individuals in the self-referent MIP who had high negative body image at the pretest demonstrated increases in negative body image after exposure to the negative valence MIP (a disparagement effect) and decreases in negative body image after exposure to the positive valence MIP (an enhancement effect). This pattern was not evident in the other-referent MIP. Also, changes in negative body image were not appreciably associated with changes in subjective mood. DISCUSSION: The findings yielded support for the cognitive priming hypothesis but not for the subjective mood hypothesis. Further means of examining the cognitive priming hypothesis were outlined.