The developmental effects of media-ideal internalization and self-objectification processes on adolescents’ negative body-feelings, dietary restraint, and binge eating

Despite accumulated experimental evidence of the negative effects of exposure to media-idealized images, the degree to which body image, and eating related disturbances are caused by media portrayals of gendered beauty ideals remains controversial. On the basis of the most up-to-date meta-analysis of experimental studies indicating that media-idealized images have the most harmful and substantial impact on vulnerable individuals regardless of gender (i.e., “internalizers” and “self-objectifiers”), the current longitudinal study examined the direct and mediated links posited in objectification theory among media-ideal internalization, self-objectification, shame and anxiety surrounding the body and appearance, dietary restraint, and binge eating. Data collected from 685 adolescents aged between 14 and 15 at baseline (47 % males), who were interviewed and completed standardized measures annually over a 3-year period, were analyzed using a structural equation modeling approach. Results indicated that media-ideal internalization predicted later thinking and scrutinizing of one’s body from an external observer’s standpoint (or self-objectification), which then predicted later negative emotional experiences related to one’s body and appearance. In turn, these negative emotional experiences predicted subsequent dietary restraint and binge eating, and each of these core features of eating disorders influenced each other. Differences in the strength of these associations across gender were not observed, and all indirect effects were significant. The study provides valuable information about how the cultural values embodied by gendered beauty ideals negatively influence adolescents’ feelings, thoughts and behaviors regarding their own body, and on the complex processes involved in disordered eating. Practical implications are discussed

Receptor-targeted liposome-peptide-siRNA nanoparticles represent a novel and efficient therapeutic approach to prevent conjunctival fibrosis.

There is increasing evidence that the Myocardin-related transcription factor/Serum response factor (MRTF/SRF) pathway plays a key role in fibroblast activation and that knocking down MRTF can lead to reduced scarring and fibrosis. Here, we have developed a receptor-targeted liposome-peptide-siRNA nanoparticle as a non-viral delivery system for MRTF-B siRNA in conjunctival fibrosis. Using 50 nM siRNA, the MRTF-B gene was efficiently silenced by 76% and 72% with LYR and LER nanoparticles, respectively. The silencing efficiency was low when non-targeting peptides or siRNA alone or liposome-siRNA alone were used. LYR and LER nanoparticles also showed higher silencing efficiency than PEGylated LYR-P and LER-P nanoparticles. The nanoparticles were not cytotoxic using different liposomes, targeting peptides, and 50 nM siRNA. Three-dimensional fibroblast-populated collagen matrices were also used as a functional assay to measure contraction in vitro, and showed that MRTF-B LYR nanoparticles completely blocked matrix contraction after a single transfection treatment. In conclusion, this is the first study to develop and show that receptor-targeted liposome-peptide-siRNA nanoparticles represent an efficient and safe non-viral siRNA delivery system that could be used to prevent fibrosis after glaucoma filtration surgery and other contractile scarring conditions in the eye

Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

Determining Steady-State Kinetics of DNA Polymerase Nucleotide Incorporation

Polymerase enzymes catalyze the replication of DNA by incorporating deoxynucleoside monophosphates (dNMPs) into a primer strand in a 5′ to 3′ direction. Monitoring kinetic aspects of this catalytic process provides mechanistic information regarding polymerase-mediated DNA synthesis and the influences of nucleobase structure. For example, a range of polymerases have different capacities to synthesize DNA depending on the structure of the inserted dNMP (natural or synthetic) and also depending on the templating DNA base (modified vs. unmodified). Under steady-state conditions, relative rates depend on the deoxynucleoside triphosphate (dNTP) residence times in the ternary (polymerase-DNA-dNTP) complex. This chapter describes a method to measure steady-state incorporation efficiencies by which polymerase enzymes insert dNMPs into primer-template (P/T) oligonucleotides. The method described involves the use of a primer oligonucleotide 5′ radiolabeled with [γ-32P]ATP. Significant established applications of this experiment include studies regarding mechanisms of nucleotide misincorporation as a basis of chemically induced DNA mutation. Further, it can provide information important in various contexts ranging from biophysical to medical-based studies.ISSN:1064-3745ISSN:1940-602

A vicious cycle among cognitions and behaviors enhancing risk for eating disorders

© 2017 The Author(s). Background: Establishing the sequence in which risk factors for eating disorders (ED) emerge would enable more effective ED prevention. Thus, in our study we investigated reciprocal and indirect associations between three cognitive and behavioral ED determinants (appearance orientation, appearance worries, and dieting) emphasized in the transdiagnostic model of ED. Methods: Data were collected in a non-clinical group of adolescents at Time 1 (T1),and then 2-months (Time 2, T2) and 13-months later(Time 3, T3). Participants (N=1260) aged 13-19 completed a questionnaire encompassing their nutrition behaviors, beliefs about appearance, health and well-being. Weight and height were measured objectively. Results: Higher levels of appearance orientation (T1) were associated with higher levels of appearance worries (T2) which in turn predicted dieting (T3). Dieting (T1) predicted higher levels of appearance orientation (T2) which in turn predicted higher levels of appearance worries (T3). Higher levels of appearance worries (T1) were associated with higher levels of appearance orientation (T2) which in turn predicted dieting (T3). Also, higher levels of appearance worries (T1) were associated with dieting (T2), and higher levels of appearance orientation (T3). Conclusions: The three transdiagnostic model variables formed a vicious cycle. Therefore, higher levels of one of ED determinants (appearance orientation, appearance worries or dieting) increase the likelihood of the elevated levels of two other ED determinants at follow-ups and thus enhances the risk for ED