247 research outputs found

    Fatal cardiotoxicity related to halofantrine: a review based on a worldwide safety data base

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    <p>Abstract</p> <p>Background</p> <p>Halofantrine (HF) was considered an effective and safe treatment for multi-drug resistant falciparum malaria until 1993, when the first case of drug-associated death was reported. Since then, numerous studies have confirmed cardiac arrythmias, possibly fatal, in both adults and children. The aim of the study was to review fatal HF related cardiotoxicity.</p> <p>Methods</p> <p>In addition, to a systematic review of the literature, the authors have had access to the global safety database on possible HF related cardiotoxicity provided by GlaxoSmithKline.</p> <p>Results</p> <p>Thirty-five cases of fatal cardiotoxicity related to HF, including five children, were identified. Females (70%) and patients from developing countries (71%) were over-represented in this series. Seventy-four percent of the fatal events occurred within 24 hours of initial exposure to HF. Twenty six patients (74%) had at least one predisposing factor for severe cardiotoxicity, e.g., underlying cardiac disease, higher than recommended doses, or presence of a concomitant QT-lengthening drug. All (100%) of the paediatric cases had either a contraindication to HF or an improper dose was given. In six cases there was no malaria.</p> <p>Conclusion</p> <p>A distinction should be made between common but asymptomatic QT-interval prolongation and the much less common ventricular arrhythmias, such as torsades de pointes, which can be fatal and seem to occur in a very limited number of patients. The majority of reported cardiac events occurred either in patients with predisposing factors or with an improper dose.</p> <p>Therefore, in the rare situations in which HF is the only therapeutic option, it can still be given after carefully checking for contraindications, such as underlying cardiac disease, bradycardia, metabolic disorders, personal or family history of long QT-interval or concomitant use of another QT-prolonging drug (e.g., mefloquine), especially in females.</p

    The emergence of enterovirus D68 in England in autumn 2014 and the necessity for reinforcing enterovirus respiratory screening.

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    In autumn 2014, enterovirus D68 (EV-D68) cases presenting with severe respiratory or neurological disease were described in countries worldwide. To describe the epidemiology and virological characteristics of EV-D68 in England, we collected clinical information on laboratory-confirmed EV-D68 cases detected in secondary care (hospitals), between September 2014 and January 2015. In primary care (general practitioners), respiratory swabs collected (September 2013-January 2015) from patients presenting with influenza-like illness were tested for EV-D68. In secondary care 55 EV-D68 cases were detected. Among those, 45 cases had clinical information available and 89% (40/45) presented with severe respiratory symptoms. Detection of EV-D68 among patients in primary care increased from 0.4% (4/1074; 95% CI 0.1-1.0) (September 2013-January 2014) to 0.8% (11/1359; 95% CI 0.4-1.5) (September 2014-January 2015). Characterization of EV-D68 strains circulating in England since 2012 and up to winter 2014/2015 indicated that those strains were genetically similar to those detected in 2014 in USA. We recommend reinforcing enterovirus surveillance through screening respiratory samples of suspected cases

    Interleukin-1 polymorphisms associated with increased risk of gastric cancer

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    Helicobacter pylori infection is associated with a variety of clinical outcomes including gastric cancer and duodenal ulcer disease. The reasons for this variation are not clear, but the gastric physiological response is influenced by the severity and anatomical distribution of gastritis induced by H. pylori. Thus, individuals with gastritis predominantly localized to the antrum retain normal (or even high) acid secretion, whereas individuals with extensive corpus gastritis develop hypochlorhydria and gastric atrophy, which are presumptive precursors of gastric cancer. Here we report that interleukin-1 gene cluster polymorphisms suspected of enhancing production of interleukin-1-beta are associated with an increased risk of both hypochlorhydria induced by H. pylori and gastric cancer. Two of these polymorphism are in near-complete linkage disequilibrium and one is a TATA-box polymorphism that markedly affects DNA-protein interactions in vitro. The association with disease may be explained by the biological properties of interleukin-1-beta, which is an important pro-inflammatory cytokine and a powerful inhibitor of gastric acid secretion. Host genetic factors that affect interleukin-1-beta may determine why some individuals infected with H. pylori develop gastric cancer while others do no

    Delayed-Onset Hemolytic Anemia in Patients with Travel-Associated Severe Malaria Treated with Artesunate, France, 2011–2013

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    French Artesunate Working GroupInternational audienceArtesunate is the most effective treatment for severe malaria. However, delayed-onset hemolytic anemia has been observed in ≈20% of travelers who receive artesunate, ≈60% of whom require transfusion. This finding could discourage physicians from using artesunate. We prospectively evaluated a cohort of 123 patients in France who had severe imported malaria that was treated with artesunate; our evaluation focused on outcome, adverse events, and postartesunate delayed-onset hemolysis (PADH). Of the 123 patients, 6 (5%) died. Overall, 97 adverse events occurred. Among the 78 patients who received follow-up for >8 days after treatment initiation, 76 (97%) had anemia, and 21 (27%) of the 78 cases were recorded as PADH. The median drop in hemoglobin levels was 1.3 g/dL; 15% of patients with PADH had hemoglobin levels of <7 g/dL, and 1 required transfusion. Despite the high incidence of PADH, the resulting anemia remained mild in 85% of cases. This reassuring result confirms the safety and therapeutic benefit of artesunate

    Quantification of the efficiency of treatment of Anopheles gambiae breeding sites with petroleum products by local communities in areas of insecticide resistance in the Republic of Benin

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    <p>Abstract</p> <p>Background</p> <p>The emergence of <it>Anopheles </it>populations capable of withstanding lethal doses of insecticides has weakened the efficacy of most insecticide based strategies of vector control and, has highlighted the need for developing new insecticidal molecules or, improving the efficacy of existing insecticides or abandoning those to which resistance has emerged. The use of petroleum products (PP) against mosquito larvae had an immense success during early programmes of malaria control, but these compounds were abandoned and replaced in the 1950s by synthetic insecticides probably because of the high performances given by these new products. In the current context of vector resistance, it is important to elucidate the empirical use of PP by quantifying their efficiencies on resistant strains of <it>Anopheles</it>.</p> <p>Methods</p> <p>Larvae of <it>Anopheles </it>Ladji a local resistant strain were exposed to increasing concentrations of various PP (kerosene, petrol and engine oils) for 24 hours and the lethal activities recorded. The highest concentration (HiC) having no lethal activity (also referred as the NOEL or no effect level) and the lowest concentration (LoC<sub>100</sub>) yielding 100% mortality were rated for each PP on the Ladji strain. Prior to laboratory analysis, KAP studies were conducted in three traditional communities were insecticide resistance is clearly established to confirm the use of PP against mosquitoes.</p> <p>Results</p> <p>Laboratory analysis of petrol, kerosene and engine oils, clearly established their lethal activities on resistant strains of <it>Anopheles </it>larvae. Contrary to existing references, this research revealed that exposed larvae of <it>Anopheles </it>were mostly killed by direct contact toxicity and not by suffocation as indicated in some earlier reports.</p> <p>Conclusion</p> <p>This research could serve as scientific basis to backup the empirical utilisation of PP on mosquito larvae and to envisage possibilities of using PP in some traditional settings where <it>Anopheles </it>have developed resistance to currently used insecticides.</p

    Trophic plasticity in Antarctic echinoderms: an adaptive trait with implications at ecosystem wide scale?

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    editorial reviewedClimate change is expected to have many adverse biological effects in Antarctica, including perturbation of feeding habits and energy fluxes. Food availability and predator/prey interactions are considered major factors dictating survival of Antarctic fauna, and foraging strategies have been shown to drive population evolution in some taxa. Whenever facing environmental changes, all organisms are expected to have some intrinsic ability to adapt. At shorter than evolutionary timescales, ecological plasticity in general, and trophic plasticity (i.e. the ability to display different feeding habits according to variation in environmental conditions) in particular, could be important adaptive mechanisms. There is increasing evidence that many key Antarctic benthos members show a high degree of trophic plasticity. It could prove to be a beneficial trait, allowing those species to shift their diet and match the new environments they will face in the future. However, diet shifts may also have detrimental aspects, such as feeding on items whose quality or nature are not optimal for the consumers. Ultimately, trophic plasticity could have important consequences at wider biological organisation levels, as it could modulate secondary production by those taxa, as well as the way they interact with other taxa through trophic relationships. Assessing trophic plasticity in Antarctic zoobenthos is therefore a promising avenue to shed light on how environmental change can shape organisms’ roles in ecosystem functioning. In this talk, we will focus on how trophic tracers (stables isotope ratios of C, N and S) can help delineating feeding plasticity in selected echinoderm (sea star and sea urchin taxa) in both Antarctic and Subantarctic coastal marine ecosystems

    Influence of Polymorphism in the Genes for the Interleukin (IL)-1 Receptor Antagonist and IL-1β on Tuberculosis

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    Several lines of evidence suggest that host genetic factors controlling the immune response influence infection by Mycobacterium tuberculosis. The proinflammatory cytokine interleukin (IL)-1β and its antagonist, IL-1Ra (IL-1 receptor agonist), are strongly induced by M. tuberculosis and are encoded by polymorphic genes. The induction of both IL-1Ra mRNA and secreted protein by M. tuberculosis in IL-1Ra allele A2–positive (IL-1Ra A2+) healthy subjects was 1.9-fold higher than in IL-1Ra A2− subjects. The M. tuberculosis–induced expression of mRNA for IL-1β was higher in subjects of the IL-1β (+3953) A1+ haplotype (P = 0.04). The molar ratio of IL-1Ra/IL-1β induced by M. tuberculosis was markedly higher in IL-1Ra A2+ individuals (P < 0.05), with minor overlap between the groups, reflecting linkage between the IL-1Ra A2 and IL-1β (+3953) A2 alleles. In M. tuberculosis–stimulated peripheral blood mononuclear cells, the addition of IL-4 increased IL-1Ra secretion, whereas interferon γ increased and IL-10 decreased IL-1β production, indicative of a differential influence on the IL-1Ra/IL-1β ratio by cytokines. In a study of 114 healthy purified protein derivative–reactive subjects and 89 patients with tuberculosis, the frequency of allelic variants at two positions (−511 and +3953) in the IL-1β and IL-1Ra genes did not differ between the groups. However, the proinflammatory IL-1Ra A2−/IL-1β (+3953) A1+ haplotype was unevenly distributed, being more common in patients with tuberculous pleurisy (92%) in comparison with healthy M. tuberculosis–sensitized control subjects or patients with other disease forms (57%, P = 0.028 and 56%, P = 0.024, respectively). Furthermore, the IL-1Ra A2+ haplotype was associated with a reduced Mantoux response to purified protein derivative of M. tuberculosis: 60% of tuberculin-nonreactive patients were of this type. Thus, the polymorphism at the IL-1 locus influences the cytokine response and may be a determinant of  delayed-type hypersensitivity and disease expression in human tuberculosis

    Conduire le changement en bibliothèque

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    Comment conduire le changement de manière efficace dans le contexte très particulier introduit par les révolutions du numérique et des réseaux dans les bibliothèques ? Comment assurer le bon fonctionnement d’un équipement lorsque le rythme des changements à conduire s’accélère ? Ce volume apporte des éléments de réponses pratiques, tirées de réalisations concrètes et propose une réflexion plus générale sur les modalités du management en bibliothèque, centrée sur la notion émergente, dans les institutions publiques, d’organisation apprenante

    Identification of the Homeobox Protein Prx1 (MHox, Prrx-1) as a Regulator of Osterix Expression and Mediator of Tumor Necrosis Factor α Action in Osteoblast Differentiation

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    Tumor necrosis factor α (TNF-α) promotes bone loss and inhibits bone formation. Osterix (Osx, SP7) is a transcription factor required for osteoblast (OB) differentiation because deletion results in a cartilaginous skeleton. We previously described a TNF suppressor element in the Osx promoter that was used to isolate nuclear proteins mediating TNF inhibition of OB differentiation. Nuclear extracts from TNF-treated pre-OBs were incubated with the TNF suppressor element for protein pull-down, and tryptic fragments were analyzed by mass spectrometry. Chromatin immunoprecipitation (ChIP) assay confirmed eight bound transcription factors. One protein, the paired related homeobox protein (Prx1), had been shown previously to have a critical role in limb bud formation and skeletal patterning. PCR revealed Prx1 expression in primary stromal cells (MSCs), C3H10T1/2 cells, and MC3T3 preosteoblasts. TNF stimulated a 14-fold increase in mRNA for Prx1, rapid cell accumulation in MC3T3 cells, and expression in periosteal and trabecular lining cells in vivo. Transient expression of Prx inhibited transcription of Osx and RUNX2. Expression of the Prx1b isoform or Prx2 decreased Osx and RUNX2 mRNA and OB differentiation in preosteoblasts. Silencing of Prx1 with siRNA abrogated TNF suppression of Osx mRNA and increased basal Osx expression. Electrophoretic mobility shift revealed Prx1b as the preferred isoform binding the Osx promoter. These results identify the homeobox protein Prx1 as an obligate mediator of TNF inhibition of Osx and differentiation of OB progenitors. Activation of Prx1 by TNF may contribute to reduced bone formation in inflammatory arthritis, menopause, and aging. © 2011 American Society for Bone and Mineral Research
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