NADPH is a specific inhibitor of protein import into glyoxysomes

We have studied the import of proteins into glyoxysomes in vitro and show that this process is specifically inhibited by NADPH. NADPH affects both binding and translocation of proteins into glyoxysomes, and inhibition is determined by the ratio of NADP⁺ to NADPH. The site of action of NADPH is most likely within the glyoxysome because (1) pretreatment of glyoxysomes with NADPH, followed by re-isolation of the organelles prior to the import assay, resulted in inhibition of import that could be restored by the addition of NADP⁺; (2) low concentrations of NADPH inhibited binding of proteins to broken glyoxysome membranes. The sensitivity of protein import to inhibition by NADPH declines as glyoxysomes are converted to leaf-type peroxisomes. A model is proposed that speculates on a possible role for NADPH in regulating protein import into plant peroxisomes.     

Post-ART Symptoms Were Not the Problem: A Qualitative Study on Adherence to ART in HIV-Infected Patients in a Mozambican Rural Hospital

Objective

The objective of this qualitative study was to explore how clinical symptoms may affect adherence to antiretroviral therapy (ART) in HIV patients, and to explore factors, perceptions and attitudes related to adherence to therapy.

Design

A qualitative study was carried out in the context of the prospective cohort study “Evaluation of Immune Reconstitution Following Initiation of Highly Active Antiretroviral Treatment in Manhiça, Mozambique”. In-depth Interviews were conducted twice in a sub-sample of the study cohort (51 participants), at six-month intervals.

Results

Most participants (73%) knew that AIDS is a chronic disease and that ART does not cure it. Nine participants (18%) were non-adherent at some point and two (4%) abandoned ART. All participants but five reported having symptoms after starting ART, mainly attributed to pills needing time to act and body’s reaction to the treatment. In spite of the perceived severity of the symptoms, only two people reported they discontinued the treatment due to symptoms. Almost all participants reported feeling comfortable with the HIV clinic organization and procedures, but afraid of staff being hostile if they did not follow the rules or if the health worker visited their home. Family was one of the most important source of support according participants. Almost all participants with children said that a decisive factor to follow the treatment was the desire to be able to look after them.

Conclusions

Experiencing symptoms after starting treatment was not a barrier to adherence to ART. Factors related to adherence included control measures set up by the health facility (exhaustive follow up, support, information) and family and community support. Indirect ART-related expenses did jeopardise adherence.     

Spatially varying selection shapes life history clines among populations of Drosophila melanogaster from sub‐Saharan Africa

Clines in life history traits, presumably driven by spatially varying selection, are widespread. Major latitudinal clines have been observed, for example, in Drosophila melanogaster, an ancestrally tropical insect from Africa that has colonized temperate habitats on multiple continents. Yet, how geographic factors other than latitude, such as altitude or longitude, affect life history in this species remains poorly understood. Moreover, most previous work has been performed on derived European, American and Australian populations, but whether life history also varies predictably with geography in the ancestral Afro‐tropical range has not been investigated systematically. Here, we have examined life history variation among populations of D. melanogaster from sub‐Saharan Africa. Viability and reproductive diapause did not vary with geography, but body size increased with altitude, latitude and longitude. Early fecundity covaried positively with altitude and latitude, whereas lifespan showed the opposite trend. Examination of genetic variance–covariance matrices revealed geographic differentiation also in trade‐off structure, and Q_ST‐F_ST analysis showed that life history differentiation among populations is likely shaped by selection. Together, our results suggest that geographic and/or climatic factors drive adaptive phenotypic differentiation among ancestral African populations and confirm the widely held notion that latitude and altitude represent parallel gradients.     

The involvement of interleukin-1 and interleukin-4 in the response of human annulus fibrosus cells to cyclic tensile strain: an altered mechanotransduction pathway with degeneration

Introduction  

Recent evidence suggests that intervertebral disc (IVD) cells derived from degenerative tissue are unable to respond to physiologically relevant mechanical stimuli in the 'normal' anabolic manner, but instead respond by increasing matrix catabolism. Understanding the nature of the biological processes which allow disc cells to sense and respond to mechanical stimuli (a process termed 'mechanotransduction') is important to ascertain whether these signalling pathways differ with disease. The aim here was to investigate the involvement of interleukin (IL)-1 and IL-4 in the response of annulus fibrosus (AF) cells derived from nondegenerative and degenerative tissue to cyclic tensile strain to determine whether cytokine involvement differed with IVD degeneration.     

Avian biodiversity in the coastal wetlands of the Okahukura Peninsula

The Tapora Landcare Group, operating on the Okahukura Peninsula, has the long-term goal of making this region predator fenced. The aim of this study was to obtain information on the current status of avian biodiversity and the bird community across the band of coastal wetlands on the Okahukura Peninsula. Bird counts were conducted and playback lures used to detect three cryptic wetland species: fernbirds (Bowdleria punctata); spotless crakes (Porzana tabuensis); and banded rails (Gallirallus philippensis). Fernbirds and banded rails were detected at seven of the eight wetland sites sampled whereas spotless crakes were detected at two sites. The native species with the highest relative abundance across the eight sites were silvereyes (Zosterops lateralis) and South Island pied oystercatchers (Haematopus finschi). Changes in avian biodiversity over time in the region can now be monitored, and comprehensive long-term data on the status of avian biodiversity over time obtained.     

Socio-Cultural Aspects of Chagas Disease: A Systematic Review of Qualitative Research

Background

Globally, more than 10 million people are infected with Trypanosoma cruzi, which causes about 20 000 annual deaths. Although Chagas disease is endemic to certain regions of Latin America, migratory flows have enabled its expansion into areas where it was previously unknown. Economic, social and cultural factors play a significant role in its presence and perpetuation. This systematic review aims to provide a comprehensive overview of qualitative research on Chagas disease, both in endemic and non-endemic countries.

Methodology/Principal Findings

Searches were carried out in ten databases, and the bibliographies of retrieved studies were examined. Data from thirty-three identified studies were extracted, and findings were analyzed and synthesized along key themes. Themes identified for endemic countries included: socio-structural determinants of Chagas disease; health practices; biomedical conceptions of Chagas disease; patient''s experience; and institutional strategies adopted. Concerning non-endemic countries, identified issues related to access to health services and health seeking.

Conclusions

The emergence and perpetuation of Chagas disease depends largely on socio-cultural aspects influencing health. As most interventions do not address the clinical, environmental, social and cultural aspects jointly, an explicitly multidimensional approach, incorporating the experiences of those affected is a potential tool for the development of long-term successful programs. Further research is needed to evaluate this approach.     

Living Situation Affects Adherence to Combination Antiretroviral Therapy in HIV-Infected Adolescents in Rwanda: A Qualitative Study

Introduction

Adherence to combination antiretroviral therapy (cART) is vital for HIV-infected adolescents for survival and quality of life. However, this age group faces many challenges to remain adherent. We used multiple data sources (role-play, focus group discussions (FGD), and in-depth interviews (IDI)) to better understand adherence barriers for Rwandan adolescents. Forty-two HIV positive adolescents (ages 12–21) and a selection of their primary caregivers were interviewed. All were perinatally-infected and received (cART) for ≥12 months. Topics discussed during FGDs and IDIs included learning HIV status, disclosure and stigma, care and treatment issues, cART adherence barriers.

Results

Median age was 17 years, 45% female, 45% orphaned, and 48% in boarding schools. We identified three overarching but inter-related themes that appeared to influence adherence. Stigma, perceived and experienced, and inadvertent disclosure of HIV status hampered adolescents from obtaining and taking their drugs, attending clinic visits, carrying their cARTs with them in public. The second major theme was the need for better support, in particular for adolescents with different living situations, (orphanages, foster-care, and boarding schools). Lack of privacy to keep and take medication came out as major barrier for adolescents living in congested households, as well the institutionalization of boarding schools where privacy is almost non-existent. The third important theme was the desire to be ‘normal’ and not be recognized as an HIV-infected individual, and to have a normal life not perturbed by taking a regimen of medications or being forced to disclose where others would treat them differently.

Conclusions

We propose better management of HIV-infected adolescents integrated into boarding school, orphanages, and foster care; training of school-faculty on how to support students and allow them privacy for taking their medications. To provide better care and support, HIV programs should stimulate caregivers of HIV-infected adolescents to join them for their clinic visits.     

Tuberculosis in Migrant Populations. A Systematic Review of the Qualitative Literature

Background

The re-emergence of tuberculosis (TB) in low-incidence countries and its disproportionate burden on immigrants is a public health concern posing specific social and ethical challenges. This review explores perceptions, knowledge, attitudes and treatment adherence behaviour relating to TB and their social implications as reported in the qualitative literature.

Methods

Systematic review in four electronic databases. Findings from thirty selected studies extracted, tabulated, compared and synthesized.

Findings

TB was attributed to many non-exclusive causes including air-born transmission of bacteria, genetics, malnutrition, excessive work, irresponsible lifestyles, casual contact with infected persons or objects; and exposure to low temperatures, dirt, stress and witchcraft. Perceived as curable but potentially lethal and highly contagious, there was confusion around a condition surrounded by fears. A range of economic, legislative, cultural, social and health system barriers could delay treatment seeking. Fears of deportation and having contacts traced could prevent individuals from seeking medical assistance. Once on treatment, family support and “the personal touch” of health providers emerged as key factors facilitating adherence. The concept of latent infection was difficult to comprehend and while TB screening was often seen as a socially responsible act, it could be perceived as discriminatory. Immigration and the infectiousness of TB mutually reinforced each another exacerbating stigma. This was further aggravated by indirect costs such as losing a job, being evicted by a landlord or not being able to attend school.

Conclusions

Understanding immigrants’ views of TB and the obstacles that they face when accessing the health system and adhering to a treatment programme-taking into consideration their previous experiences at countries of origin as well as the social, economic and legislative context in which they live at host countries- has an important role and should be considered in the design, evaluation and adaptation of programmes.     

Measures of linkage disequilibrium among neighbouring SNPs indicate asymmetries across the house mouse hybrid zone

Theory predicts that naturally occurring hybrid zones between genetically distinct taxa can move over space and time as a result of selection and/or demographic processes, with certain types of hybrid zones being more or less likely to move. Determining whether a hybrid zone is stationary or moving has important implications for understanding evolutionary processes affecting interactions in hybrid populations. However, direct observations of hybrid zone movement are difficult to make unless the zone is moving rapidly. Here, evidence for movement in the house mouse Mus musculus domesticus × Mus musculus musculus hybrid zone is provided using measures of LD and haplotype structure among neighbouring SNP markers from across the genome. Local populations of mice across two transects in Germany and the Czech Republic were sampled, and a total of 1301 mice were genotyped at 1401 markers from the nuclear genome. Empirical measures of LD provide evidence for extinction and (re)colonization in single populations and, together with simulations, suggest hybrid zone movement because of either geography-dependent asymmetrical dispersal or selection favouring one subspecies over the other.