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OBJECTIVE: The objective of this work was to compare the measurement properties of three categorical X-ray scoring methods of knee osteoarthritis (OA), both on semiflexed and extended views. METHODS: In data obtained from trials and cohorts, X-rays were graded using Kellgren and Lawrence (KL), the OA Research Society International (OARSI) joint space narrowing score, and measurement of joint space width (JSW). JSW was analyzed as a categorical variable. Construct validity was assessed through logistic regression between X-ray stages and Western Ontario and McMaster Universities OA Index. Inter-observer reliability was assessed in 50 subjects for extended views by weighted kappa. Intra-observer reliability and sensitivity to change were assessed separately for extended and semiflexed views in 50 patients who had both views performed, over a 30-month interval, by weighted kappa and standardized response mean (SRM). RESULTS: Extended views were available from three trials and two cohorts (1759 X-rays), including one trial in which both extended and semiflexed views (antero-posterior) were obtained. Correlation with clinical parameters was low for the three scoring methods, except for the single community-based cohort. Inter-rater reliability was higher for categorical JSW in extended views (kappa, 0.86 vs 0.56 and 0.48 for KL and OARSI, respectively). Intra-rater reliability was higher for categorical JSW, both in extended views (0.83 vs 0.61 and 0.71) and in semiflexed views (0.89 vs 0.50 and 0.67). Sensitivity to change was also higher for categorical JSW, particularly in semiflexed views (SRM, 0.49 vs 0.22 and 0.34). CONCLUSION: These results indicate categorical JSW, in particular on semiflexed views, may be the preferred method to evaluate structural severity in knee OA clinical trials.  相似文献   
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Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 and 60 years. Molecular and genetic factors that promote oncogenic transformation of odontogenic epithelium to ameloblastoma are strongly linked to dysregulation of multiple genes associated with mitogen‐activated protein kinase, sonic hedgehog, and WNT/β‐catenin signaling pathways. Treatment of ameloblastoma is focused on surgical resection with a wide margin of normal tissue because of its high propensity for locoregional invasion; but this is often associated with significant patient morbidity. The relatively high recurrence rate of ameloblastoma is influenced by the type of molecular etiological factors, the management approach, and how early the patient presents for treatment. It is expected that further elucidation of molecular factors that orchestrate pathogenesis and recurrence of ameloblastoma will lead to new diagnostic markers and targeted drug therapies for ameloblastoma.  相似文献   
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OBJECTIVE: To compare unbiased estimates of short- vs long-term cartilage loss in osteoarthritic knees. METHOD: 441 knees [216 Kellgren Lawrence (KL) grade 2, 225 KL grade 3] from participants of the Osteoarthritis Initiative were studied over a 4-year period. Femorotibial cartilage thickness was determined using 3?T double echo steady state magnetic resonance imaging, the readers being blinded to time points. Because common measurement time points bias correlations, short-term change (year-1 to year-2: Y1?→?Y2) was compared with long-term change (baseline to year-4: BL?→?Y4), and initial (BL?→?Y1) with subsequent (Y2?→?Y4) observation periods. RESULTS: The mean femorotibial cartilage thickness change (standardized response mean) was?-1.2%/-0.8% (-0.42/-0.28) over 1 (BL?→?Y1/Y1?→?Y2),?-2.1%/-2.5% (-0.56/-0.55) over 2 (BL?→?Y2/Y2?→?Y4),?-3.3% (-0.63) over 3 (Y1?→?Y4), and?-4.5% (-0.78) over 4 years. Spearman correlations were 0.33 for Y1?→?Y2 vs BL?→?Y4, and 0.17 for BL?→?Y1 vs Y2?→?Y4 change. Percent agreement between knees showing progression during Y1?→?Y2 vs BL?→?Y4 was 59%, and 64% for BL?→?Y1 vs Y2?→?Y4. The area under the receiver operating characteristic curve was 0.66 for using Y1?→?Y2 to predict BL?→?Y4, and 0.59 for using BL?→?Y1 to predict Y2?→?Y4 change. CONCLUSION: Weak to moderate correlations and agreement were observed between individual short- vs long-term cartilage loss, and between initial and subsequent observation periods. Hence, longer observation periods are recommended to achieve robust results on cartilage loss in individual knees. At cohort and subcohort level (e.g., KLG3 vs KLG2 knees), the mean cartilage loss increased almost linearly with the length of the observation period and was constant throughout the study.  相似文献   
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Research in psychopharmacology for children and adolescents is fraught with ethical problems and tensions. This has practical consequences as it leads to a paucity of the research that is essential to support the treatment of this vulnerable group. In this article, we will discuss some of the ethical issues which are relevant to such research, and explore their implications for both research and standard care. We suggest that finding a way forward requires a willingness to acknowledge and discuss the inherent conflicts between the ethical principles involved. Furthermore, in order to facilitate more, ethically sound psychopharmacology research in children and adolescents, we suggest more ethical analysis, empirical ethics research and ethics input built into psychopharmacological research design.  相似文献   
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