52 research outputs found

    Early Mortality and AIDS Progression Despite High Initial Antiretroviral Therapy Adherence and Virologic Suppression in Botswana

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    Background Adverse outcomes occurring early after antiretroviral therapy (ART) initiation are common in sub-Saharan Africa, despite reports of high levels of ART adherence in this setting. We sought to determine the relationship between very early ART adherence and early adverse outcomes in HIV-infected adults in Botswana. Methods This prospective cohort study of 402 ART-naïve, HIV-infected adults initiating ART at a public HIV clinic in Gaborone, Botswana evaluated the relationship between suboptimal early ART adherence and HIV treatment outcomes in the initial months after ART initiation. Early adherence during the interval between initial ART dispensation and first ART refill was calculated using pill counts. In the primary analysis patients not returning to refill and those with adherence \u3c0.95 were considered to have suboptimal early adherence. The primary outcome was death or loss to follow-up during the first 6 months of ART; a secondary composite outcome included the primary outcome plus incident opportunistic illness (OIs) and virologic failure. We also calculated the percent of early adverse outcomes theoretically attributable to suboptimal early adherence using the population attributable risk percent (PAR%). Results Suboptimal early adherence was independently associated with loss to follow-up and death (adjusted OR 2.3, 95% CI 1.1–4.8) and with the secondary composite outcome including incident OIs and virologic failure (adjusted OR 2.6, 95% CI 1.4–4.7). However, of those with early adverse outcomes, less than one-third had suboptimal adherence and approximately two-thirds achieved virologic suppression. The PAR% relating suboptimal early adherence and primary and secondary outcomes were 14.7% and 17.7%, respectively. Conclusions Suboptimal early adherence was associated with poor outcomes, but most early adverse outcomes occurred in patients with optimal early adherence. Clinical care and research efforts should focus on understanding early adverse outcomes that occur despite optimal adherence

    Improving T-Cell Assays for the Diagnosis of Latent TB Infection: Potential of a Diagnostic Test Based on IP-10

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    Background There is a need for simple tools such as the M.tuberculosis specific IFN-γ release assays (IGRA) to improve diagnosis of M.tuberculosis-infection in children. The aim of the study was to evaluate the performance of an IP-10 and IL-2 based tests for the diagnosis of M.tuberculosis-infection in recently exposed children from Nigeria. Methodology and Principal Findings Samples were obtained from 59 children at high risk of infection with M.tuberculosis (contacts of adults with smear and culture-positive tuberculosis) and 61 at low risk (contacts of smear-negative/culture-positive tuberculosis or community controls). IP-10 and IL-2 was measured in plasma after stimulation of whole-blood with M.tuberculosis specific antigens and mitogen. Previously developed criteria for positive IP-10 and IL-2 tests were used and the diagnostic performances of the IP-10 and IL-2 tests were compared with the Quantiferon In-Tube (QFT-IT) and the Tuberculin Skin Tests (TST). In response to M.tuberculosis specific antigens, the high-risk children expressed significantly higher levels of IP-10 (1358 pg/ml[IQR 278–2535 pg/ml]) and IL-2 (164 pg/ml[11–590 pg/ml]) than low risk groups 149 pg/ml(25–497 pg/ml), and 0 pg/ml(0–3 pg/ml), respectively. There was excellent agreement (>89%,k>0.80) between IP-10, IL-2 tests and QFT-IT, better than with TST (>74%,k>0.49). The IP-10 and IL-2 responses were strongly associated with M.tuberculosis exposure and with grade of infectiousness of the index cases (p<0.0001). IP-10, IL-2, and TST but not QFT-IT was associated with age of the child in the low risk groups (p<0.02). Conclusions/Significance IP-10 is expressed in high levels and results of the IP-10 test were comparable to the QFT-IT. IL-2 was released in low amounts in response to the antigens and not in response to the mitogen therefore IL-2 seems a less useful marker. We have demonstrated that IP-10 and possibly IL-2 could be alternative or adjunct markers to IFN-γ in the diagnosis infection with M.tuberculosis

    Temporal Dynamics of Interferon Gamma Responses in Children Evaluated for Tuberculosis

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    BACKGROUND: Development of T-cells based-Interferon gamma (IFNgamma) assays has offered new possibilities for the diagnosis of latent tuberculosis infection (LTBI) and active disease in adults. Few studies have been performed in children, none in France. With reference to the published data on childhood TB epidemiology in the Paris and Ile de France Region, we considered it important to evaluate the performance of IGRA (QuantiFERON TB Gold In Tube(R), QF-TB-IT) in the diagnosis and the follow-up through treatment of LTBI and active TB in a cohort of French children. METHODOLOGY/PRINCIPAL FINDINGS: 131 children were recruited during a prospective and multicentre study (October 2005 and May 2007; Ethical Committee St Louis Hospital, Paris, study number 2005/32). Children were sampled at day 0, 10, 30, 60 (except Healthy Contacts, HC) and 90 for LTBI and HC, and a further day 120, and day 180 for active TB children. Median age was 7.4 years, with 91% of the children BCG vaccinated. LTBI and active TB children undergoing therapy produced significant higher IFNgamma values after 10 days of treatment (p = 0.035). In addition, IFNgamma values were significantly lower at the end of treatment compared to IFNgamma values at day 0, although the number of positive patients was not significantly different between day 0 and end of treatment. CONCLUSIONS/ SIGNIFICANCE: By following quantitative IFNgamma values in each enrolled child with LTBI or active TB and receiving treatment, we were able to detect an increase in the IFNgamma response at day 10 of treatment which might allow the confirmation of a diagnosis. In addition, a decline in IFNgamma values during treatment makes it possible for clinicians to monitor the effect of preventive or curative therapy

    AtriplaR/anti-TB combination in TB/HIV patients. Drug in focus

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    Co-administration of anti-tuberculosis and antiretroviral therapy is often inevitable in high-burden countries where tuberculosis is the most common opportunistic infection associated with HIV/AIDS. Concurrent use of rifampicin and several antiretroviral drugs is complicated by pharmacokinetic drug-drug interaction. Pubmed and Google search following the key words tuberculosis, HIV, emtricitabine, tenofovir efavirenz, interaction were used to find relevant information on each drug of the fixed dose combination AtriplaR RESULTS: Information on generic name, trade name, pharmacokinetic parameter, metabolism and the pharmacokinetic interaction with Anti-TB drugs of emtricitabine, tenofovir, and efavirenz was obtained. Fixed dose combination of emtricitabine/tenofovir/efavirenz (ATRIPLAR) which has been approved by Food and Drug Administration shows promising results as far as safety and efficacy is concerned in TB/HIV co-infection patients, hence can be considered effective and safe antiretroviral drug in TB/HIV management for adult and children above 3 years of age

    Tuberculosis and HIV Co-Infection

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    Tuberculosis (TB) and HIV co-infections place an immense burden on health care systems and pose particular diagnostic and therapeutic challenges. Infection with HIV is the most powerful known risk factor predisposing for Mycobacterium tuberculosis infection and progression to active disease, which increases the risk of latent TB reactivation 20-fold. TB is also the most common cause of AIDS-related death. Thus, M. tuberculosis and HIV act in synergy, accelerating the decline of immunological functions and leading to subsequent death if untreated. The mechanisms behind the breakdown of the immune defense of the co-infected individual are not well known. The aim of this review is to highlight immunological events that may accelerate the development of one of the two diseases in the presence of the co-infecting organism. We also review possible animal models for studies of the interaction of the two pathogens, and describe gaps in knowledge and needs for future studies to develop preventive measures against the two diseases

    The reconstruction of the first copper-smelting processes in Europe during the 4th and the 3rd millennium BC: where does the oxygen come from?

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    International audienceFrom the end of Chalcolithic times (end of the 4th millennium BC) up to the end of the Bronze Age (1st millenium BC), copper production increases dramatically in Western Europe. However, due to the scarcity of technology-related archaeological data, the technological background sustaining the transition to mass production modes remains poorly understood. The main archaeological clues concerning metal production stem from the metallurgical waste, namely copper slags. Those complex materials may be a genuine chemical footprint of the process. In particular, it may bring new insights on one main issue of the process reconstruction: the origin of the oxygen in the system. A new analytical methodology based on both mass-balance calculation and quantification of Fe3+ contents in copper slags (Mössbauer spectroscopy, electronic microprobe and Synchrotron μ-XANES at the Fe-K-edge) has been set up. This methodology enables us to distinguish between the solid and gaseous sources of oxygen in a broad range of working conditions, thus yielding new features for the understanding of the first smelting processes dealing with copper sulphides in Western Europe 4000 years ago

    Petrographic and chemical investigation of the earliest copper smelting slags in Italy: towards a reconstruction of the beginning of copper metallurgy

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    The systematic analysis or reanalysis of all reported occurrences of the early copper smelting in Northern Italy has been carried out by a joint Italian-French collaboration. Several ltalian Neolithic, Eneolithic, and Early Bronze Age sites are reported in the literature as having produced copper smelting slags, though only a handful of samples have been properly characterized to date. All slags available for analysis have been fully investigated by XRD, optical microscopy, SEM-EDS, and PIXE. The results indicate that: (I) the reported occurrences of Liguria and some of Tuscany are actually not related to copper smelting; (2) most slag occurrences from the Alps were actually produced during copper smelting from sulphide minerals, indicating diffuse extractive metallurgy during the 3rd millennium BC, (3) different sites show different degrees of reaction advancement and copper extraction efficiency, pointing to non-standard extraction processes and smelting conditions. The mineralogical, chemical, and textural results are discussed with reference to the other known European occurrences of Eneolithic copper smelting

    The mystery of plattenschlake in protohistoric copper smelting: early evidence at the Early Bronze Age site of Saint Veran, French Alps

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    Thin low viscous plate slags, the so-called Plattenschlacke, are one of the 3 types of slags systematically encountered at Middle and Late Bronze Age copper smelting sites in the Alps. The two other types are coarse cake-like slags, and finely crushed slag sand. The exact origin of these different types of slags within the smelting process, and particularly that of the Plattenschlacke is still debated: do they belong to the same unique smelting step, or do they refer to separate operations? With respect to this issue, the Early Bronze Age (EBA) copper production site of Saint-V\ue9ran (Hautes-Alpes, France), one of the earliest copper mass production centre in the Alps, occupies an exceptional situation. Indeed, it provides not only one of the first evidence of Plattenschlacke in the Alps, but also Plattenschlacke is the only type of slags produced there. This paper aims at exploring further the "Plattenschlacke mystery" by proposing a reconstruction of the smelting process performed at Saint-V\ue9ran during the EBA, on the basis of thorough analytical investigation of the local Plattenschlacke. Conventional (OM, SEM-EDS, PIXE) as well as more unusual analytieal techniques were used, including Raman micro-spectrometry, Rietveld refmement on X-ray diffraction patterns, as well as micro-XANES
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