Mitochondrial myopathy: correlation between oxidative defect and mitochondrial DNA deletions at single fiber level

In situ hybridization combined with immunohistochemical techniques has been applied to study patients affected by mitochondrial myopathies with large mitochondrial (mt)DNA deletions. All patients' muscle biopsies showed ragged red fibers (RRFs) and cytochrome oxidase (COX) deficiency. Two digoxygenin-labeled, polymerase chain reaction (PCR)-amplifed DNAs were used as probes. One probe was designed to hybridize only with wild-type mtDNAs, while the other recognized both wild-type and deleted mtDNAs. Concomitant immunocytochemical analysis using antibodies against subunits II, III, (encoded by mtDNA) and IV (encoded by nuclear DNA) of COX was carried out. In our patients deleted mtDNAs are overexpressed in COX-negative RRFs, while wild-type mtDNAs are decreased in the same fibers. Immunohistochemistry studies show that COX IV is overexpressed in RRFs and that COX II and COX III subunits are still present. Deleted mtDNAs are spatially segregated in muscle fibers, where they interfere with the local population of normal mitochondrial genomes, causing a regional deficiency of the mitochondrial respiratory activity.This work was supported by the Associazione Amici del Centro Dino Ferrari     

The durability of small-diameter rods in lumbar spinal fusion

The use of a small-diameter rod in lumbar fusion offers a lower hardware profile and reduced implant bulk. Concern has been raised, however, about the ability of smaller rods to withstand the cyclic loads placed on them until fusion is achieved. This study is a retrospective radiographic review designed to evaluate the durability of a 4.75-mm diameter rod in the early postoperative period before fusion healing. Examination of postoperative radiographs revealed two instances of rod failure that occurred more than 24 months after operation among 85 cases of pedicle screw instrumentation followed for an average of 32 months. Based on these preliminary data, the benefits of a small-diameter rod can be obtained without an increased incidence of rod failure during the initial healing period.     

Love,Trust, and HIV Risk Among Female Sex Workers and Their Intimate Male Partners

Objectives. We examined correlates of love and trust among female sex workers and their noncommercial male partners along the Mexico–US border.Methods. From 2011 to 2012, 322 partners in Tijuana and Ciudad Juárez, Mexico, completed assessments of love and trust. Cross-sectional dyadic regression analyses identified associations of relationship characteristics and HIV risk behaviors with love and trust.Results. Within 161 couples, love and trust scores were moderately high (median 70/95 and 29/40 points, respectively) and correlated with relationship satisfaction. In regression analyses of HIV risk factors, men and women who used methamphetamine reported lower love scores, whereas women who used heroin reported slightly higher love. In an alternate model, men with concurrent sexual partners had lower love scores. For both partners, relationship conflict was associated with lower trust.Conclusions. Love and trust are associated with relationship quality, sexual risk, and drug use patterns that shape intimate partners’ HIV risk. HIV interventions should consider the emotional quality of sex workers’ intimate relationships.While public health interventions continue to be grounded in tenets of risk and disease, there is growing recognition of the importance of emotions such as love and trust in shaping the health behaviors of diverse populations. Unprotected sex allows for transmission of HIV and other sexually transmitted infections (STIs) but often carries emotional meanings of trust and commitment that impede condom negotiation even among individuals with high knowledge and self-efficacy.1–4 Research has consistently found female sex workers’ condom use to be less frequent with their noncommercial male partners than with clients, which has been linked to intimacy, love, and trust.5–7 Similarly, drug-using couples may share syringes and engage in additional known HIV risk behaviors to convey support and emotional closeness.8,9 Although much of this research is qualitative, some quantitative work has confirmed associations between perceptions of intimacy and condom use among sex workers and clients10 and men who have sex with men.11Quantitative researchers have attempted to operationalize emotions into theoretical constructs for empirical research.12 Sternberg’s “triangular” theory posits that love comprises 3 components: intimacy (feelings of emotional closeness between partners), passion (physical attraction and sexual consummation), and commitment (decisions that partners make about maintaining relationships).13,14 Taken together, these components combine to generate different kinds of love.13,15,16Another important aspect of intimate relationships, trust is conceptualized as a belief in the integrity of a partner. Trust may be based on individuals’ assessments of their partners’ benevolence and honesty17 and subjective feelings of security within relationships.18,19 To measure trust quantitatively, Larzelere and Huston developed a dyadic trust scale that correlated with love and relationship quality.17A rich body of ethnographic scholarship has highlighted the importance of companionate relationships and love in diverse global contexts,20–22 but quantification of emotional constructs are largely absent from settings outside the Western middle-class experience. Most quantitative studies of love and trust have focused on privileged populations who do not experience the burden of disease that disproportionately affects socially marginalized couples. Existing studies among US populations have also suggested that women and men value components of these emotions differently,23–25 yet the implications of these potential gender differences for HIV prevention among vulnerable couples remains underexplored.Our study of love and trust among sex workers and their noncommercial partners is situated in 2 Mexican border cities: Tijuana, Baja California, south of San Diego, California (population 1.6 million), and Ciudad Juárez, Chihuahua, adjacent to El Paso, Texas (population 1.3 million). Both cities have areas where sex work and drug use are concentrated,26 lending to the conceptualization of the border as an HIV risk environment27 characterized by poverty, unemployment, violence, and availability of illicit drugs.28 Research has documented substantial overlap in risky sexual and injection drug use behaviors among marginalized female sex workers29 who often turn to sex work as a last option for supporting themselves and their dependents.30Drawing on Connell’s conceptualization of gender as a relational process influenced by structural and sociocultural factors,31 our previous qualitative and ethnographic inquiry into sex workers’ intimate partnerships in these cities proposed that emotions are shaped by the HIV risk environment of the border. Structural conditions bring partners together into relationships that provide critical material and emotional support. In light of limited economic opportunities, couples form tacit agreements regarding women’s engagement in sex work. In the process, women emerge as primary wage earners, alienating men from traditional gender roles as providers and shifting gender dynamics. To cope, partners mostly avoid communicating about sex work or disclosing HIV risk to protect the emotional integrity of the relationship.32We also found that these couples’ relationships range in emotional intensity from friendship and care to transformative experiences of love. Regardless, most couples demarcate their primary relationships from sex work by engaging in unprotected sex. Among couples who inject drugs, sharing syringes together (but not with others) often reinforces trust and care.33 Concerns of mistrust and infidelity also reduced couples’ interest in alternative HIV-prevention technologies such as pre-exposure prophylaxis.34In light of the central role of emotions in our qualitative research with these couples, we attempted to quantify constructs of love and trust and identify associated relationship traits and HIV risk behaviors in our larger cohort. We hypothesized that markers of relationship quality (e.g., higher satisfaction, lower conflict) and unprotected sex within primary relationships would be associated with higher love and trust, whereas extradyadic HIV risk behaviors (e.g., concurrent sexual partners, syringe sharing with others) would be associated with lower love and trust.     

Comparison of Cepheid® Xpert Flu and Roche RealTime Ready Influenza A/H1N1 Detection Set for detection of influenza A/H1N1

Objective

To compare two influenza polymerase chain reaction (PCR) methods.

Thiocarbohydrazide-crosslinked chitosan as a bioinspired corrosion inhibitor for protection of stainless steel in 3.5% NaCl

A facile single-step synthesis was performed to cross-link chitosan with thiocarbohydrazide to yield thiocarbohydrazide-chitosan (TC-Cht) which was for the first time evaluated as an inhibitor for corrosion of stainless steel in 3.5% NaCl solution. A comprehensive electrochemical analysis employing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and cyclic voltammetry (CV) was undertaken and showed that the TC-Cht acts by adsorption on the steel surface and exhibits mixed type behavior with predominantly cathodic nature. The adsorption of TC-Cht molecules on the surface of stainless steel followed the Langmuir isotherm. The TC-Cht showed a high inhibition efficiency of >94% at 500 mg L^?1 concentration. Surface investigation using SEM and EDX supported the inhibitor adsorption on the steel surface.