1,542 research outputs found

    Etude des propriétés d’adsorption et de désorption du Plomb (Pb) et du Cadmium (Cd) par les sédiments d’une lagune tropicale en présence d’Allylthiourée

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    Les métaux plomb (Pb) et cadmium (Cd) s’accumulent dans les réseaux trophiques aquatiques et peuvent présenter une menace pour la santé humaine et la faune. Une littérature relativement abondante existe sur la concentration totale de ces métaux dans les lagunes ivoiriennes. Cependant, aucune information n’est  disponible pour prédire leur toxicité potentielle. Cette étude avait pour objectif de déterminer l’influence de la matière organique sur l’adsorption du plomb et du cadmium par les sédiments de la baie de Cocody. Les résultats ont montré que les grandes quantités d’allylthiourée (de matière organique) empêchent le cadmium de s’adsorber sur les sédiments aux concentrations de cadmium supérieures à 1 mg/L, augmentant sa concentration dans la colonne d’eau. Aucune  conclusion claire n’a été tirée pour le plomb. Les résultats ont aussi montré que les sédiments de la baie de Cocody sont très contaminés en cadmium et en plomb, mais que les fractions solubles à l’eau sont très faibles. Des études complémentaires d’adsorption-désorption prenant en compte des études cinétiques sur beaucoup plus d’échantillons de sédiments permettront de mieux comprendre le comportement et la toxicité des métaux dans la lagune Ebrié.Mots clés : Métaux traces, matière organique, adsorption, désorption, Estuaire

    Sample size determination for bibliographic retrieval studies

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    <p>Abstract</p> <p>Background</p> <p>Research for developing search strategies to retrieve high-quality clinical journal articles from MEDLINE is expensive and time-consuming. The objective of this study was to determine the minimal number of high-quality articles in a journal subset that would need to be hand-searched to update or create new MEDLINE search strategies for treatment, diagnosis, and prognosis studies.</p> <p>Methods</p> <p>The desired width of the 95% confidence intervals (W) for the lowest sensitivity among existing search strategies was used to calculate the number of high-quality articles needed to reliably update search strategies. New search strategies were derived in journal subsets formed by 2 approaches: random sampling of journals and top journals (having the most high-quality articles). The new strategies were tested in both the original large journal database and in a low-yielding journal (having few high-quality articles) subset.</p> <p>Results</p> <p>For treatment studies, if W was 10% or less for the lowest sensitivity among our existing search strategies, a subset of 15 randomly selected journals or 2 top journals were adequate for updating search strategies, based on each approach having at least 99 high-quality articles. The new strategies derived in 15 randomly selected journals or 2 top journals performed well in the original large journal database. Nevertheless, the new search strategies developed using the random sampling approach performed better than those developed using the top journal approach in a low-yielding journal subset. For studies of diagnosis and prognosis, no journal subset had enough high-quality articles to achieve the expected W (10%).</p> <p>Conclusion</p> <p>The approach of randomly sampling a small subset of journals that includes sufficient high-quality articles is an efficient way to update or create search strategies for high-quality articles on therapy in MEDLINE. The concentrations of diagnosis and prognosis articles are too low for this approach.</p

    mTCTScan: a comprehensive platform for annotation and prioritization of mutations affecting drug sensitivity in cancers

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    Cancer therapies have experienced rapid progress in recent years, with a number of novel small-molecule kinase inhibitors and monoclonal antibodies now being widely used to treat various types of human cancers. During cancer treatments, mutations can have important effects on drug sensitivity. However, the relationship between tumor genomic profiles and the effectiveness of cancer drugs remains elusive. We introduce Mutation To Cancer Therapy Scan (mTCTScan) web server (http://jjwanglab.org/mTCTScan) that can systematically analyze mutations affecting cancer drug sensitivity based on individual genomic profiles. The platform was developed by leveraging the latest knowledge on mutation-cancer drug sensitivity associations and the results from large-scale chemical screening using human cancer cell lines. Using an evidence-based scoring scheme based on current integrative evidences, mTCTScan is able to prioritize mutations according to their associations with cancer drugs and preclinical compounds. It can also show related drugs/compounds with sensitivity classification by considering the context of the entire genomic profile. In addition, mTCTScan incorporates comprehensive filtering functions and cancer-related annotations to better interpret mutation effects and their association with cancer drugs. This platform will greatly benefit both researchers and clinicians for interrogating mechanisms of mutation-dependent drug response, which will have a significant impact on cancer precision medicine.published_or_final_versio

    A cross-sectional study of the number and frequency of terms used to refer to knowledge translation in a body of health literature in 2006: a Tower of Babel?

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    <p/> <p>Background</p> <p>The study of implementing research findings into practice is rapidly growing and has acquired many competing names (<it>e.g</it>., dissemination, uptake, utilization, translation) and contributing disciplines. The use of multiple terms across disciplines pose barriers to communication and progress for applying research findings. We sought to establish an inventory of terms describing this field and how often authors use them in a collection of health literature published in 2006.</p> <p>Methods</p> <p>We refer to this field as knowledge translation (KT). Terms describing aspects of KT and their definitions were collected from literature, the internet, reports, textbooks, and contact with experts. We compiled a database of KT and other articles by reading 12 healthcare journals representing multiple disciplines. All articles published in these journals in 2006 were categorized as being KT or not. The KT articles (all KT) were further categorized, if possible, for whether they described KT projects or implementations (KT application articles), or presented the theoretical basis, models, tools, methods, or techniques of KT (KT theory articles). Accuracy was checked using duplicate reading. Custom designed software determined how often KT terms were used in the titles and abstracts of articles categorized as being KT.</p> <p>Results</p> <p>A total of 2,603 articles were assessed, and 581 were identified as KT articles. Of these, 201 described KT applications, and 153 included KT theory. Of the 100 KT terms collected, 46 were used by the authors in the titles or abstracts of articles categorized as being KT. For all 581 KT articles, eight terms or term variations used by authors were highly discriminating for separating KT and non-KT articles (p < 0.001): implementation, adoption, quality improvement, dissemination, complex intervention (with multiple endings), implementation (within three words of) research, and complex intervention. More KT terms were associated with KT application articles (n = 13) and KT theory articles (n = 18).</p> <p>Conclusions</p> <p>We collected 100 terms describing KT research. Authors used 46 of them in titles and abstracts of KT articles. Of these, approximately half discriminated between KT and non-KT articles. Thus, the need for consolidation and consistent use of fewer terms related to KT research is evident.</p

    Asian-variant intravascular lymphoma in the African race

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    Intravascular Large B-cell lymphoma (IVLBCL) is an exceptionally rare form of non-Hodgkin lymphoma (NHL) distinguished by the preferential growth of neoplastic cells within blood vessel lumen. Challenging to detect and deemed disseminated at diagnosis, this condition is characterized by a highly aggressive, inconspicuous course with a high mortality rate. We describe the case of a 48 year-old African-American female presenting with a two month history of low-grade fevers and malaise. Laboratory data was notable for anemia, thrombocytopenia, elevated liver function tests, and hematuria. An extensive work-up for infectious, rheumatologic and malignant causes was negative. Her symptoms progressed and within two weeks, she was admitted for disseminated intravascular coagulation (DIC). Her course was complicated by diffuse pulmonary hemorrhage and ultimately, care was withdrawn. Autopsy identified widespread CD-20 positive intravascular large B-cell lymphoma with significant hepatosplenic involvement, characteristic of the Asian variant IVLBCL. This case uniquely highlights development of the Asian variant IVLBVL in a previously undescribed race. Identified by its intraluminal vascular growth pattern, IVLBCL generally spares lymphatic channels. Diagnosis and differentiation of this condition from other hematological malignancies via skin, visceral and bone marrow biopsy is imperative as anthracycline-containing chemotherapies may significantly improve clinical outcomes. This article outlines the common presentation, natural course, and treatment options of IVLBCL, along with the histopathology, immunohistochemistry, and chromosomal aberrations common to this condition

    Identifying quality improvement intervention publications - A comparison of electronic search strategies

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    Abstract Background The evidence base for quality improvement (QI) interventions is expanding rapidly. The diversity of the initiatives and the inconsistency in labeling these as QI interventions makes it challenging for researchers, policymakers, and QI practitioners to access the literature systematically and to identify relevant publications. Methods We evaluated search strategies developed for MEDLINE (Ovid) and PubMed based on free text words, Medical subject headings (MeSH), QI intervention components, continuous quality improvement (CQI) methods, and combinations of the strategies. Three sets of pertinent QI intervention publications were used for validation. Two independent expert reviewers screened publications for relevance. We compared the yield, recall rate, and precision of the search strategies for the identification of QI publications and for a subset of empirical studies on effects of QI interventions. Results The search yields ranged from 2,221 to 216,167 publications. Mean recall rates for reference publications ranged from 5% to 53% for strategies with yields of 50,000 publications or fewer. The 'best case' strategy, a simple text word search with high face validity ('quality' AND 'improv*' AND 'intervention*') identified 44%, 24%, and 62% of influential intervention articles selected by Agency for Healthcare Research and Quality (AHRQ) experts, a set of exemplar articles provided by members of the Standards for Quality Improvement Reporting Excellence (SQUIRE) group, and a sample from the Cochrane Effective Practice and Organization of Care Group (EPOC) register of studies, respectively. We applied the search strategy to a PubMed search for articles published in 10 pertinent journals in a three-year period which retrieved 183 publications. Among these, 67% were deemed relevant to QI by at least one of two independent raters. Forty percent were classified as empirical studies reporting on a QI intervention. Conclusions The presented search terms and operating characteristics can be used to guide the identification of QI intervention publications. Even with extensive iterative development, we achieved only moderate recall rates of reference publications. Consensus development on QI reporting and initiatives to develop QI-relevant MeSH terms are urgently needed

    Use of Aspirin postdiagnosis improves survival for colon cancer patients

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    Background: The preventive role of non-steroid anti-inflammatory drugs (NSAIDs) and aspirin, in particular, on colorectal cancer is well established. More recently, it has been suggested that aspirin may also have a therapeutic role. Aim of the present observational population-based study was to assess the therapeutic effect on overall survival of aspirin/NSAIDs as adjuvant treatment used after the diagnosis of colorectal cancer patients. Methods: Data concerning prescriptions were obtained from PHARMO record linkage systems and all patients diagnosed with colorectal cancer (1998-2007) were selected from the Eindhoven Cancer Registry (population-based cancer registry). Aspirin/NSAID use was classified as none, prediagnosis and postdiagnosis and only postdiagnosis. Patients were defined as non-user of aspirin/NSAIDs from the date of diagnosis of the colorectal cancer to the date of first use of aspirin or NSAIDs and user from first use to the end of follow-up. Poisson regression was performed with user status as time-varying exposure.Results:In total, 1176 (26%) patients were non-users, 2086 (47%) were prediagnosis and postdiagnosis users and 1219 (27%) were only postdiagnosis users (total n=4481). Compared with non-users, a survival gain was observed for aspirin users; the adjusted rate ratio (RR) was 0.77 (95% confidence interval (CI) 0.63-0.95; P=0.015). Stratified for colon and rectal, the survival gain was only present in colon cancer (adjusted RR 0.65 (95%CI 0.50-0.84; P=0.001)). For frequent users survival gain was larger (adjusted RR 0.61 (95%CI 0.46-0.81; P=0.001). In rectal cancer, aspirin use was not associated with survival (adjusted RR 1.10 (95%CI 0.79-1.54; P=0.6). The NSAIDs use was associated with decreased survival (adjusted RR 1.93 (95%CI 1.70-2.20; P<0.001). Conclusion: Aspirin use initiated or continued after diagnosis of colon cancer is associated with a lower risk of overall mortality. These findings strongly support initiation of a placebo-controlled trial that investigates the role of aspirin as adjuvant treatment in colon cancer patients

    Molecular Characterization of the Mouse Superior Lateral Parabrachial Nucleus through Expression of the Transcription Factor Runx1

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    The ability to precisely identify separate neuronal populations is essential to the understanding of the development and function of different brain structures. This necessity is particularly evident in regions such as the brainstem, where the anatomy is quite complex and little is known about the identity, origin, and function of a number of distinct nuclei due to the lack of specific cellular markers. In this regard, the gene encoding the transcription factor Runx1 has emerged as a specific marker of restricted neuronal populations in the murine central and peripheral nervous systems. The aim of this study was to precisely characterize the expression of Runx1 in the developing and postnatal mouse brainstem.Anatomical and immunohistochemical studies were used to characterize mouse Runx1 expression in the brainstem. It is shown here that Runx1 is expressed in a restricted population of neurons located in the dorsolateral rostral hindbrain. These neurons define a structure that is ventromedial to the dorsal nucleus of the lateral lemniscus, dorsocaudal to the medial paralemniscal nucleus and rostral to the cerebellum. Runx1 expression in these cells is first observed at approximately gestational day 12.5, persists into the adult brain, and is lost in knockout mice lacking the transcription factor Atoh1, an important regulator of the development of neuronal lineages of the rhombic lip. Runx1-expressing neurons in the rostral hindbrain produce cholecystokinin and also co-express members of the Groucho/Transducin-like Enhancer of split protein family.Based on the anatomical and molecular characteristics of the Runx1-expressing cells in the rostral hindbrain, we propose that Runx1 expression in this region of the mouse brain defines the superior lateral parabrachial nucleus
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