548 research outputs found

    Building Research Capacity in Africa: Equity and Global Health Collaborations

    Get PDF
    Kathryn Chu and colleagues discuss the impact of high-income country investigators conducting research in low- and middle-income countries and explore lessons from the effective and equitable relationships that exist. Please see later in the article for the Editors' Summar

    Evidence for Nodal Superconductivity in LaFePO from Scanning SQUID Susceptometry

    Full text link
    We measure changes in the penetration depth λ\lambda of the Tc6T_c \approx 6 K superconductor LaFePO. In the process scanning SQUID susceptometry is demonstrated as a technique for accurately measuring {\it local} temperature-dependent changes in λ\lambda, making it ideal for studying early or difficult-to-grow materials. λ\lambda of LaFePO is found to vary linearly with temperature from 0.36 to \sim2 K, with a slope of 143±\pm15 \AA/K, suggesting line nodes in the superconducting order parameter. The linear dependence up to Tc/3\sim T_c/3 is similar to the cuprate superconductors, indicating well-developed nodes.Comment: 4 pages, 5 figure

    Nevirapine-Associated Early Hepatotoxicity: Incidence, Risk Factors, and Associated Mortality in a Primary Care ART Programme in South Africa

    Get PDF
    BACKGROUND: The majority of antiretroviral treatment programmes in sub-Saharan Africa are scaling up antiretroviral treatment using a fixed dose first-line antiretroviral regimen containing stavudine, lamivudine, and nevirapine. One of the primary concerns with the use of this regimen is nevirapine-associated hepatotoxicity. METHODOLOGY/PRINCIPAL FINDINGS: Study participants were 1809 HIV-infected, antiretroviral naïve adults initiating nevirapine-based antiretroviral therapy between November 2002 and December 2006. The primary outcome was early hepatotoxicity. Secondary outcomes were associations with hepatotoxicity and mortality at six months. The cumulative proportion of early hepatotoxicity ranged from 1.0-2.0% giving an incidence-rate at 102 days of 3.6-7.6 per 100 person-years. Median time to hepatotoxicity was 32 (IQR 28-58) days. At 12 weeks, only 8% of patients had alanine aminotransferase monitoring at all the time-points recommended by national guidelines. No association was found between age, gender, baseline CD4 count, concurrent tuberculosis infection, prior participation in a prevention of mother-to-child-transmission program, or baseline weight and early hepatotoxicity. There was no association between early hepatotoxicity and mortality. CONCLUSIONS: The cumulative proportion of early hepatotoxicity in nevirapine based antiretroviral therapy was low in this resource-constrained setting. Hepatotoxicity was not associated with mortality. Frequent routine monitoring of alanine aminotransferase proved difficult to implement in this public sector primary care programme. Focused monitoring in the first month may be a more cost-effective and pragmatic option in settings with limited resources. Correlation with clinical signs and symptoms may allow future alanine aminotransferase testing to be dictated by clinical criteria

    AIDS-associated Kaposi's sarcoma is linked to advanced disease and high mortality in a primary care HIV programme in South Africa

    Get PDF
    BACKGROUND: AIDS-associated Kaposi's sarcoma is an important, life-threatening opportunistic infection among people living with HIV/AIDS in resource-limited settings. In western countries, the introduction of combination antiretroviral therapy (cART) and new chemotherapeutic agents has resulted in decreased incidence and improved prognosis of AIDS-associated Kaposi's sarcoma. In African cohorts, however, mortality remains high. In this study, we describe disease characteristics and risk factors for mortality in a public sector HIV programme in South Africa. METHODS: We analysed data from an observational cohort study of HIV-infected adults with AIDS-associated Kaposi's sarcoma, enrolled between May 2001 and January 2007 in three primary care clinics. Paper records from primary care and tertiary hospital oncology clinics were reviewed to determine the site of Kaposi's sarcoma lesions, immune reconstitution inflammatory syndrome stage, and treatment. Baseline characteristics, cART use and survival outcomes were extracted from an electronic database maintained for routine monitoring and evaluation. Cox regression was used to model associations with mortality. RESULTS: Of 6292 patients, 215 (3.4%) had AIDS-associated Kaposi's sarcoma. Lesions were most commonly oral (65%) and on the lower extremities (56%). One quarter of patients did not receive cART. The mortality and lost-to-follow-up rates were, respectively, 25 (95% CI 19-32) and eight (95% CI 5-13) per 100 person years for patients who received cART, and 70 (95% CI 42-117) and 119 (80-176) per 100 person years for patients who did not receive cART. Advanced T stage (adjusted HR, AHR = 5.3, p < 0.001), advanced S stage (AHR = 5.1, p = 0.008), and absence of chemotherapy (AHR = 2.4, p = 0.012) were associated with mortality.Patients with AIDS-associated Kaposi's sarcoma presented with advanced disease and high rates of mortality and loss to follow up. Risk factors for mortality included advanced Kaposi's sarcoma disease and lack of chemotherapy use. Contributing factors to the high mortality for patients with AIDS-associated Kaposi's sarcoma likely included late diagnosis of HIV disease, late accessibility to cART, and sub-optimal treatment of advanced Kaposi's sarcoma. CONCLUSIONS: These findings confirm the importance of early access to both cART and chemotherapy for patients with AIDS-associated Kaposi's sarcoma. Early diagnosis and improved treatment protocols in resource-poor settings are essential

    Ten Years of Experience Training Non-Physician Anesthesia Providers in Haiti.

    Get PDF
    Surgery is increasingly recognized as an effective means of treating a proportion of the global burden of disease, especially in resource-limited countries. Often non-physicians, such as nurses, provide the majority of anesthesia; however, their training and formal supervision is often of low priority or even non-existent. To increase the number of safe anesthesia providers in Haiti, Médecins Sans Frontières has trained nurse anesthetists (NAs) for over 10 years. This article describes the challenges, outcomes, and future directions of this training program. From 1998 to 2008, 24 students graduated. Nineteen (79%) continue to work as NAs in Haiti and 5 (21%) have emigrated. In 2008, NAs were critical in providing anesthesia during a post-hurricane emergency where they performed 330 procedures. Mortality was 0.3% and not associated with lack of anesthesiologist supervision. The completion rate of this training program was high and the majority of graduates continue to work as nurse anesthetists in Haiti. Successful training requires a setting with a sufficient volume and diversity of operations, appropriate anesthesia equipment, a structured and comprehensive training program, and recognition of the training program by the national ministry of health and relevant professional bodies. Preliminary outcomes support findings elsewhere that NAs can be a safe and effective alternative where anesthesiologists are scarce. Training non-physician anesthetists is a feasible and important way to scale up surgical services resource limited settings

    Local measurement of the superfluid density in the pnictide superconductor Ba(Fe1x_{1-x}Cox_{x})2_2As2_2 across the superconducting dome

    Get PDF
    We measure the penetration depth λab(T)\lambda_{ab}(T) in Ba(Fe1x_{1-x}Cox_{x})2_2As2_2 using local techniques that do not average over the sample. The superfluid density ρs(T)1/λab(T)2\rho_s(T)\equiv1/\lambda_{ab}(T)^2 has three main features. First, ρs(T=0)\rho_s(T=0) falls sharply on the underdoped side of the dome. Second, λab(T)\lambda_{ab}(T) is flat at low TT at optimal doping, indicating fully gapped superconductivity, but varies more strongly in underdoped and overdoped samples, consistent with either a power law or a small second gap. Third, ρs(T)\rho_s(T) varies steeply near TcT_c for optimal and underdoping. These observations are consistent with an interplay between magnetic and superconducting phases

    Local measurement of the penetration depth in the pnictide superconductor Ba(Fe0.95_{0.95}Co0.05_{0.05})2_2As2_2

    Get PDF
    We use magnetic force microscopy (MFM) and scanning SQUID susceptometry to measure the local superfluid density ρs\rho_{s} in Ba(Fe0.95_{0.95}Co0.05_{0.05})2_2As2_2 single crystals from 0.4 K to the critical temperature Tc=18.5T_c=18.5 K. We observe that the penetration depth λ\lambda varies about ten times more slowly with temperature than previously published, with a dependence that can be well described by a clean two-band fully gapped model. We demonstrate that MFM can measure the important and hard-to-determine absolute value of λ\lambda, as well as obtain its temperature dependence and spatial homogeneity. We find ρs\rho_{s} to be uniform despite the highly disordered vortex pinning

    Surgical care for the direct and indirect victims of violence in the eastern Democratic Republic of Congo

    Get PDF
    ABSTRACT: BACKGROUND: The provision of surgical assistance in conflict is often associated with care for victims of violence. However, there is an increasing appreciation that surgical care is needed for non-traumatic morbidities. In this paper we report on surgical interventions carried out by Medecins sans Frontieres in Masisi, North Kivu, Democratic Republic of Congo to contribute to the scarce evidence base on surgical needs in conflict. METHODS: We analysed data on all surgical interventions done at Masisi district hospital between September 2007 to December 2009. Types of interventions are described, and logistic regression used to model associations with violence-related injury. RESULTS: 2869 operations were performed on 2441 patients. Obstetric emergencies accounted for over half (675, 57%) of all surgical pathology and infections for another quarter (160, 14%). Trauma-related injuries accounted for only one quarter (681, 24%) of all interventions; among these, 363 (13%) were violence-related. Male gender (adjusted odds ratio (AOR)=20.0, p<0.001), military status (AOR=4.1, p<0.001), and age less than 20 years (AOR=2.1, p<0.001) were associated with violence-related injury. Immediate peri-operative mortality was 0.2%. CONCLUSIONS: In this study, most surgical interventions were unrelated to violent trauma and rather reflected the general surgical needs of a low-income tropical country. Programs in conflict zones in low-income countries need to be prepared to treat both the war-wounded and non-trauma related life-threatening surgical needs of the general population. Given the limited surgical workforce in these areas, training of local staff and task shifting is recommended to support broad availability of essential surgical care. Further studies into the surgical needs of the population are warranted, including population-based surveys to improve program planning and resource allocation and the effectiveness of the humanitarian response
    corecore