Genetic association study of adiposity and melanocortin-4 receptor (MC4R) common variants: Replication and functional characterization of non-coding regions

Common genetic variants 3′ of MC4R within two large linkage disequilibrium (LD) blocks spanning 288 kb have been associated with common and rare forms of obesity. This large association region has not been refined and the relevant DNA segments within the association region have not been identified. In this study, we investigated whether common variants in the MC4R gene region were associated with adiposity-related traits in a biracial population-based study. Single nucleotide polymorphisms (SNPs) in the MC4R region were genotyped with a custom array and a genome-wide array and associations between SNPs and five adiposity-related traits were determined using race-stratified linear regression. Previously reported associations between lower BMI and the minor alleles of rs2229616/Val103Ile and rs52820871/Ile251Leu were replicated in white female participants. Among white participants, rs11152221 in a proximal 3′ LD block (closer to MC4R) was significantly associated with multiple adiposity traits, but SNPs in a distal 309 LD block (farther from MC4R ) were not. In a case-control study of severe obesity, rs11152221 was significantly associated. The association results directed our follow-up studies to the proximal LD block downstream of MC4R. By considering nucleotide conservation, the significance of association, and proximity to the MC4R gene, we identified a candidate MC4R regulatory region. This candidate region was sequenced in 20 individuals from a study of severe obesity in an attempt to identify additional variants, and the candidate region was tested for enhancer activity using in vivo enhancer assays in zebrafish and mice. Novel variants were not identified by sequencing and the candidate region did not drive reporter gene expression in zebrafish or mice. The identification of a putative insulator in this region could help to explain the challenges faced in this study and others to link SNPs associated with adiposity to altered MC4R expression. © 2014 Evans et al

Help-Seeking Barriers Among Sexual and Gender Minority Individuals Who Experience Intimate Partner Violence Victimization

Sexual and gender minority (SGM) individuals experience intimate partner violence (IPV) victimization at disproportionate rates compared to cisgender and heterosexual individuals. Given the widespread consequences of experiencing IPV victimization, intervention and prevention strategies should identify readily accessible and culturally competent services for this population. SGM individuals who experience IPV victimization face unique individual-, interpersonal-, and systemic-level barriers to accessing informal and formal support services needed to recover from IPV. This chapter reviews IPV victimization prevalence rates among SGM individuals in the context of minority stress and highlights unique forms of IPV victimization affecting this population, namely identity abuse. The literature on help-seeking processes among IPV survivors in general and help-seeking patterns and barriers specifically among SGM individuals who experience IPV victimization in the context of minority stress (e.g., discrimination, internalized stigma, rejection sensitivity, identity concealment) are discussed. How minority stressors at individual, interpersonal, and structural levels act as barriers to help-seeking among SGM individuals experiencing IPV victimization is presented. The chapter concludes with a review of emerging evidence for interventions aimed at reducing help-seeking barriers among SGM individuals who face IPV victimization and a discussion of future directions for research on help-seeking barriers in this population

Diagnosis and Management of Infected Total Knee Arthroplasty§

Infection following total knee arthroplasty can be difficult to diagnose and treat. Diagnosis is multifactorial and relies on the clinical picture, radiographs, bone scans, serologic tests, synovial fluid examination, intra-operative culture and histology. Newer techniques including ultrasonication and molecular diagnostic studies are playing an expanded role. Two-stage exchange arthroplasty with antibiotic cement and 4-6 weeks of intravenous antibiotic treatment remains the most successful intervention for infection eradication. There is no consensus on the optimum type of interval antibiotic cement spacer. There is a limited role for irrigation and debridement, direct one-stage exchange, chronic antibiotic suppression and salvage procedures like arthrodesis and amputation. We examine the literature on each of the diagnostic modalities and treatment options in brief and explain their current significance