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排序方式: 共有1003条查询结果,搜索用时 312 毫秒
41.
Andrew J Burghardt Jean‐Baptiste Pialat Galateia J Kazakia Stephanie Boutroy Klaus Engelke Janina M Patsch Alexander Valentinitsch Danmei Liu Eva Szabo Cesar E Bogado Maria Belen Zanchetta Heather A McKay Elizabeth Shane Steven K Boyd Mary L Bouxsein Roland Chapurlat Sundeep Khosla Sharmila Majumdar 《Journal of bone and mineral research》2013,28(3):524-536
High‐resolution peripheral quantitative computed tomography (HR‐pQCT) has recently been introduced as a clinical research tool for in vivo assessment of bone quality. The utility of this technology to address important skeletal health questions requires translation to standardized multicenter data pools. Our goal was to evaluate the feasibility of pooling data in multicenter HR‐pQCT imaging trials. Reproducibility imaging experiments were performed using structure and composition‐realistic phantoms constructed from cadaveric radii. Single‐center precision was determined by repeat scanning over short‐term (<72 hours), intermediate‐term (3–5 months), and long‐term intervals (28 months). Multicenter precision was determined by imaging the phantoms at nine different HR‐pQCT centers. Least significant change (LSC) and root mean squared coefficient of variation (RMSCV) for each interval and across centers was calculated for bone density, geometry, microstructure, and biomechanical parameters. Single‐center short‐term RMSCVs were <1% for all parameters except cortical thickness (Ct.Th) (1.1%), spatial variability in cortical thickness (Ct.Th.SD) (2.6%), standard deviation of trabecular separation (Tb.Sp.SD) (1.8%), and porosity measures (6% to 8%). Intermediate‐term RMSCVs were generally not statistically different from short‐term values. Long‐term variability was significantly greater for all density measures (0.7% to 2.0%; p < 0.05 versus short‐term) and several structure measures: cortical thickness (Ct.Th) (3.4%; p < 0.01 versus short‐term), cortical porosity (Ct.Po) (15.4%; p < 0.01 versus short‐term), and trabecular thickness (Tb.Th) (2.2%; p < 0.01 versus short‐term). Multicenter RMSCVs were also significantly higher than short‐term values: 2% to 4% for density and micro–finite element analysis (µFE) measures (p < 0.0001), 2.6% to 5.3% for morphometric measures (p < 0.001), whereas Ct.Po was 16.2% (p < 0.001). In the absence of subject motion, multicenter precision errors for HR‐pQCT parameters were generally less than 5%. Phantom‐based multicenter precision was comparable to previously reported in in vivo single‐center precision errors, although this was approximately two to five times worse than ex vivo short‐term precision. The data generated from this study will contribute to the future design and validation of standardized procedures that are broadly translatable to multicenter study designs. © 2013 American Society for Bone and Mineral Research. 相似文献
42.
Adrian S. Fairey Wassim Kassouf Eric Estey Simon Tanguay Ricardo Rendon David Bell Jonathan Izawa Joseph Chin Anil Kapoor Edward Matsumoto Peter Black Alan So Jean‐Baptiste Lattouf Fred Saad Darrel Drachenberg Ilias Cagiannos Louis Lacombe Yves Fradet Niels‐Erik B. Jacobsen 《BJU international》2013,112(6):791-797
43.
Large Deformation Mechanisms,Plasticity, and Failure of an Individual Collagen Fibril With Different Mineral Content
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Baptiste Depalle Zhao Qin Sandra J Shefelbine Markus J Buehler 《Journal of bone and mineral research》2016,31(2):380-390
Mineralized collagen fibrils are composed of tropocollagen molecules and mineral crystals derived from hydroxyapatite to form a composite material that combines optimal properties of both constituents and exhibits incredible strength and toughness. Their complex hierarchical structure allows collagen fibrils to sustain large deformation without breaking. In this study, we report a mesoscale model of a single mineralized collagen fibril using a bottom‐up approach. By conserving the three‐dimensional structure and the entanglement of the molecules, we were able to construct finite‐size fibril models that allowed us to explore the deformation mechanisms which govern their mechanical behavior under large deformation. We investigated the tensile behavior of a single collagen fibril with various intrafibrillar mineral content and found that a mineralized collagen fibril can present up to five different deformation mechanisms to dissipate energy. These mechanisms include molecular uncoiling, molecular stretching, mineral/collagen sliding, molecular slippage, and crystal dissociation. By multiplying its sources of energy dissipation and deformation mechanisms, a collagen fibril can reach impressive strength and toughness. Adding mineral into the collagen fibril can increase its strength up to 10 times and its toughness up to 35 times. Combining crosslinks with mineral makes the fibril stiffer but more brittle. We also found that a mineralized fibril reaches its maximum toughness to density and strength to density ratios for a mineral density of around 30%. This result, in good agreement with experimental observations, attests that bone tissue is optimized mechanically to remain lightweight but maintain strength and toughness. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR). 相似文献
44.
Cost‐effectiveness analyses (CEA) conducted alongside randomised trials provide key evidence for informing healthcare decision making, but missing data pose substantive challenges. Recently, there have been a number of developments in methods and guidelines addressing missing data in trials. However, it is unclear whether these developments have permeated CEA practice. This paper critically reviews the extent of and methods used to address missing data in recently published trial‐based CEA. Issues of the Health Technology Assessment journal from 2013 to 2015 were searched. Fifty‐two eligible studies were identified. Missing data were very common; the median proportion of trial participants with complete cost‐effectiveness data was 63% (interquartile range: 47%–81%). The most common approach for the primary analysis was to restrict analysis to those with complete data (43%), followed by multiple imputation (30%). Half of the studies conducted some sort of sensitivity analyses, but only 2 (4%) considered possible departures from the missing‐at‐random assumption. Further improvements are needed to address missing data in cost‐effectiveness analyses conducted alongside randomised trials. These should focus on limiting the extent of missing data, choosing an appropriate method for the primary analysis that is valid under contextually plausible assumptions, and conducting sensitivity analyses to departures from the missing‐at‐random assumption. 相似文献
45.
Nuclear translocation of NF-κB is increased in dopaminergic neurons of patients with Parkinson disease
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46.
Lionel Rebibo Jean‐Baptiste Deguines Flavien Prevot David Pérignon Raphaël Sinna Pierre Verhaeghe Jean‐Marc Regimbeau 《International wound journal》2014,11(3):278-282
Treatment of an enterocutaneous fistula is complex and may require multidisciplinary management, especially when associated with a neoplastic process. Here, we describe the case of a 59‐year‐old patient with a squamous cell carcinoma that had invaded the abdominal wall through a chronic enterocutaneous fistula identified 30 years ago. We combined parietectomy with small intestine and colon resection and inguinal lymphadenectomy in order to obtain clear surgical margins. At the same time, plastic surgery involved the implementation of a large bioprosthesis and coverage with a vastus lateralis muscle free flap. 相似文献
47.
48.
Baptiste Leurent Helen Killaspy David P. Osborn Mike J. Crawford Angela Hoadley Diane Waller Michael King 《Social psychiatry and psychiatric epidemiology》2014,49(11):1703-1710
Purpose
Although some studies suggest that art therapy may be useful in the treatment of negative symptoms of schizophrenia, a recent large trial of group art therapy found no clinical advantage over standard care, but the study population was heterogeneous and uptake of the intervention was poor. This study aimed to investigate whether art therapy was more effective for specific subgroups of patients.Methods
Secondary analysis of data from a randomised controlled trial of group art therapy as an adjunctive treatment for schizophrenia (n = 140) versus standard care alone (n = 137). Positive and Negative Syndrome Scale scores at 12 months were compared between trial arms. Interaction between intervention effect and different subgroups, including those with more severe negative symptoms of schizophrenia, and those who expressed a preference for art therapy prior to randomisation, was tested using a linear mixed model.Results
The clinical effectiveness of group art therapy did not significantly differ between participants with more or less severe negative symptoms [interaction for difference in PANSS = 1.7, 95 % CI (?8.6 to 12.1), P = 0.741], or between those who did and did not express a preference for art therapy [interaction = 3.9, 95 % CI (?6.7 to 14.5), P = 0.473]. None of the other exploratory subgroups suggested differences in intervention effect.Conclusions
There was no evidence of greater improvement in clinical symptoms of schizophrenia for those with more severe negative symptoms or those with a preference for art therapy. Identification of patients with schizophrenia who may benefit most from group art therapy remains elusive. 相似文献49.
Elisa De Franco Ccile Saint‐Martin Klaus Brusgaard Amy E. Knight Johnson Lydia Aguilar‐Bryan Pamela Bowman Jean‐Baptiste Arnoux Annette Rnholt Larsen May Sanyoura Siri Atma W. Greeley Raúl Calzada‐Len Bradley Harman Jayne A. L. Houghton Elisa Nishimura‐Meguro Thomas W. Laver Sian Ellard Daniela del Gaudio Henrik Thybo Christesen Christine Bellann‐Chantelot Sarah E. Flanagan 《Human mutation》2020,41(5):884-905
The most common genetic cause of neonatal diabetes and hyperinsulinism is pathogenic variants in ABCC8 and KCNJ11. These genes encode the subunits of the β‐cell ATP‐sensitive potassium channel, a key component of the glucose‐stimulated insulin secretion pathway. Mutations in the two genes cause dysregulated insulin secretion; inactivating mutations cause an oversecretion of insulin, leading to congenital hyperinsulinism, whereas activating mutations cause the opposing phenotype, diabetes. This review focuses on variants identified in ABCC8 and KCNJ11, the phenotypic spectrum and the treatment implications for individuals with pathogenic variants. 相似文献
50.
Gilles Morin Valrie Biancalana Andoni Echaniz‐Laguna Jean‐Baptiste Noury Xavire Lornage Maurizio Moggio Michela Ripolone Raffaella Violano Pascale Marcorelles Denis Marchal Florence Renaud Claude‐Alain Maurage Cline Tard Jean‐Marie Cuisset Jocelyn Laporte Johann Bhm 《Human mutation》2020,41(1):17-37
Calcium (Ca2+) acts as a ubiquitous second messenger, and normal cell and tissue physiology strictly depends on the precise regulation of Ca2+ entry, storage, and release. Store‐operated Ca2+ entry (SOCE) is a major mechanism controlling extracellular Ca2+ entry, and mainly relies on the accurate interplay between the Ca2+ sensor STIM1 and the Ca2+ channel ORAI1. Mutations in STIM1 or ORAI1 result in abnormal Ca2+ homeostasis and are associated with severe human disorders. Recessive loss‐of‐function mutations impair SOCE and cause combined immunodeficiency, while dominant gain‐of‐function mutations induce excessive extracellular Ca2+ entry and cause tubular aggregate myopathy (TAM) and Stormorken syndrome (STRMK). TAM and STRMK are spectra of the same multisystemic disease characterized by muscle weakness, miosis, thrombocytopenia, hyposplenism, ichthyosis, dyslexia, and short stature. To date, 42 TAM/STRMK families have been described, and here we report five additional families for which we provide clinical, histological, ultrastructural, and genetic data. In this study, we list and review all new and previously reported STIM1 and ORAI1 cases, discuss the pathomechanisms of the mutations based on the known functions and the protein structure of STIM1 and ORAI1, draw a genotype/phenotype correlation, and delineate an efficient screening strategy for the molecular diagnosis of TAM/STRMK. 相似文献