241 research outputs found

    Determining biokinetic coefficients for the upflow anaerobic sludge blanket reactor treating sugarcane wastewater in hot climate conditions

    Get PDF
    Acknowledgements The managing director of Imam Khomeini (pbuh) Agro-Industry in Shushtar and the laboratory expert of Agro-Industry Treatment Plant are highly appreciated for their cooperation in conducting this study.Peer reviewedPostprin

    Evaluating the Quality of Research into a Single Prognostic Biomarker: A Systematic Review and Meta-analysis of 83 Studies of C-Reactive Protein in Stable Coronary Artery Disease

    Get PDF
    Background Systematic evaluations of the quality of research on a single prognostic biomarker are rare. We sought to evaluate the quality of prognostic research evidence for the association of C-reactive protein (CRP) with fatal and nonfatal events among patients with stable coronary disease. Methods and Findings We searched MEDLINE (1966 to 2009) and EMBASE (1980 to 2009) and selected prospective studies of patients with stable coronary disease, reporting a relative risk for the association of CRP with death and nonfatal cardiovascular events. We included 83 studies, reporting 61,684 patients and 6,485 outcome events. No study reported a prespecified statistical analysis protocol; only two studies reported the time elapsed (in months or years) between initial presentation of symptomatic coronary disease and inclusion in the study. Studies reported a median of seven items (of 17) from the REMARK reporting guidelines, with no evidence of change over time. The pooled relative risk for the top versus bottom third of CRP distribution was 1.97 (95% confidence interval [CI] 1.78–2.17), with substantial heterogeneity (I2 = 79.5). Only 13 studies adjusted for conventional risk factors (age, sex, smoking, obesity, diabetes, and low-density lipoprotein [LDL] cholesterol) and these had a relative risk of 1.65 (95% CI 1.39–1.96), I2 = 33.7. Studies reported ten different ways of comparing CRP values, with weaker relative risks for those based on continuous measures. Adjusting for publication bias (for which there was strong evidence, Egger's p<0.001) using a validated method reduced the relative risk to 1.19 (95% CI 1.13–1.25). Only two studies reported a measure of discrimination (c-statistic). In 20 studies the detection rate for subsequent events could be calculated and was 31% for a 10% false positive rate, and the calculated pooled c-statistic was 0.61 (0.57–0.66). Conclusion Multiple types of reporting bias, and publication bias, make the magnitude of any independent association between CRP and prognosis among patients with stable coronary disease sufficiently uncertain that no clinical practice recommendations can be made. Publication of prespecified statistical analytic protocols and prospective registration of studies, among other measures, might help improve the quality of prognostic biomarker research

    Prognosis research strategy (PROGRESS) 1: a framework for researching clinical outcomes.

    Get PDF
    The PROGRESS series (www.progress-partnership.org) sets out a framework of four interlinked prognosis research themes and provides examples from several disease fields to show why evidence from prognosis research is crucial to inform all points in the translation of biomedical and health related research into better patient outcomes. Recommendations are made in each of the four papers to improve current research standards What is prognosis research? Prognosis research seeks to understand and improve future outcomes in people with a given disease or health condition. However, there is increasing evidence that prognosis research standards need to be improved Why is prognosis research important? More people now live with disease and conditions that impair health than at any other time in history; prognosis research provides crucial evidence for translating findings from the laboratory to humans, and from clinical research to clinical practice This first article introduces the framework of four interlinked prognosis research themes and then focuses on the first of the themes - fundamental prognosis research, studies that aim to describe and explain future outcomes in relation to current diagnostic and treatment practices, often in relation to quality of care Fundamental prognosis research provides evidence informing healthcare and public health policy, the design and interpretation of randomised trials, and the impact of diagnostic tests on future outcome. It can inform new definitions of disease, may identify unanticipated benefits or harms of interventions, and clarify where new interventions are required to improve prognosis

    Prognostic significance of lymphangiogenesis in pharyngolaryngeal carcinoma patients

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Lymphatic vessel spread is considered a major route for head and neck squamous cell carcinoma metastasis. Formation of new lymphatic vessels could facilitate the process, raising the malignant potential of these tumours. Recent identification of lymphatic markers allows the study of the lymphangiogenesis phenomenon. We searched for molecular events involved in the lymphangiogenic process that could have prognostic value in laryngeal/pharyngeal carcinoma patients.</p> <p>Methods</p> <p>104 paraffin-embedded pharyngeal/laryngeal tumour samples were studied. Immunohistochemical analysis of podoplanin and double immunofluorescence analysis of Ki-67 and D2-40 were performed. Lymph vessel density (inside the tumour mass, at its periphery or considered as a whole) and the presence of tumour emboli inside lymphatics were recorded. The proliferative state of endothelial lymphatic cells was evaluated.</p> <p>Results</p> <p>Lymphatic vessels were detected inside the tumour mass (75%) and in the surrounding tissue (80%); some of them in a proliferative state. Tumour emboli were detected in a high proportion of the cases (45%). Lymphatic vessel density was higher in the pharyngeal cases (p = 0.0029), in greater size (p = 0.039), more advanced stage primary tumours (p = 0.006) and in carcinomas of patients with affected nodes (p = 0.019). The presence of tumour emboli and a high global vessel density were indicators of poor prognosis (recorded as death from tumour) in the laryngeal group (p = 0.015 and p = 0.027, respectively), but notably not in the pharyngeal one. Interestingly, high global vessel density showed a negative prognostic value among pathologically staged N0 laryngeal carcinomas (p = 0.03).</p> <p>Conclusions</p> <p>The lymphangiogenic process correlated with aggressive tumour features (pN category, tumour size, tumour stage), but might play different roles in tumours arising from different anatomic sites.</p> <p>Our results suggest that detection of tumour emboli and assessment of global vessel density using the D2-40 antibody, may be useful in the clinical practice, as predictors of reduced survival among pN0 laryngeal carcinoma patients.</p

    Prognosis research strategy (PROGRESS) 4: Stratified medicine research

    Get PDF
    In patients with a particular disease or health condition, stratified medicine seeks to identify thosewho will have the most clinical benefit or least harm from a specific treatment. In this article, thefourth in the PROGRESS series, the authors discuss why prognosis research should form acornerstone of stratified medicine, especially in regard to the identification of factors that predictindividual treatment respons

    Prognostic markers in cancer: the evolution of evidence from single studies to meta-analysis, and beyond

    Get PDF
    In oncology, prognostic markers are clinical measures used to help elicit an individual patient's risk of a future outcome, such as recurrence of disease after primary treatment. They thus facilitate individual treatment choice and aid in patient counselling. Evidence-based results regarding prognostic markers are therefore very important to both clinicians and their patients. However, there is increasing awareness that prognostic marker studies have been neglected in the drive to improve medical research. Large protocol-driven, prospective studies are the ideal, with appropriate statistical analysis and clear, unbiased reporting of the methods used and the results obtained. Unfortunately, published prognostic studies rarely meet such standards, and systematic reviews and meta-analyses are often only able to draw attention to the paucity of good-quality evidence. We discuss how better-quality prognostic marker evidence can evolve over time from initial exploratory studies, to large protocol-driven primary studies, and then to meta-analysis or even beyond, to large prospectively planned pooled analyses and to the initiation of tumour banks. We highlight articles that facilitate each stage of this process, and that promote current guidelines aimed at improving the design, analysis, and reporting of prognostic marker research. We also outline why collaborative, multi-centre, and multi-disciplinary teams should be an essential part of future studies

    Chapter 12: Systematic Review of Prognostic Tests

    Get PDF
    A number of new biological markers are being studied as predictors of disease or adverse medical events among those who already have a disease. Systematic reviews of this growing literature can help determine whether the available evidence supports use of a new biomarker as a prognostic test that can more accurately place patients into different prognostic groups to improve treatment decisions and the accuracy of outcome predictions. Exemplary reviews of prognostic tests are not widely available, and the methods used to review diagnostic tests do not necessarily address the most important questions about prognostic tests that are used to predict the time-dependent likelihood of future patient outcomes. We provide suggestions for those interested in conducting systematic reviews of a prognostic test. The proposed use of the prognostic test should serve as the framework for a systematic review and to help define the key questions. The outcome probabilities or level of risk and other characteristics of prognostic groups are the most salient statistics for review and perhaps meta-analysis. Reclassification tables can help determine how a prognostic test affects the classification of patients into different prognostic groups, hence their treatment. Review of studies of the association between a potential prognostic test and patient outcomes would have little impact other than to determine whether further development as a prognostic test might be warranted
    corecore