Bone is the second most commonly transplanted tissue worldwide,with over four million operations using bone grafts or bone substitute materials annually to treat bone defects.However,significant limitations affect cur...Bone is the second most commonly transplanted tissue worldwide,with over four million operations using bone grafts or bone substitute materials annually to treat bone defects.However,significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma,cancer,infection and arthritis.Developing bioactive three-dimensional(3D)scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering(BTE).A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts.However,individual groups of materials including polymers,ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone.Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds.This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers,hydrogels,metals,ceramics and bio-glasses in BTE.Scaffold fabrication methodology,mechanical performance,biocompatibility,bioactivity,and potential clinical translations will be discussed.展开更多
Patients with long-standing inflammatory bowel disease(IBD)involving at least 1/3 of the colon are at increased risk for colorectal cancer(CRC).Advancements in CRC screening and surveillance and improved treatment of ...Patients with long-standing inflammatory bowel disease(IBD)involving at least 1/3 of the colon are at increased risk for colorectal cancer(CRC).Advancements in CRC screening and surveillance and improved treatment of IBD has reduced CRC incidence in patients with ulcerative colitis and Crohn’s colitis.Most cases of CRC are thought to arise from dysplasia,and recent evidence suggests that the majority of dysplastic lesions in patients with IBD are visible,in part thanks to advancements in high definition colonoscopy and chromoendoscopy.Recent practice guidelines have supported the use of chromoendoscopy with targeted biopsies of visible lesions rather than traditional random biopsies.Endoscopists are encouraged to endoscopically resect visible dysplasia and only recommend surgery when a complete resection is not possible.New technologies such as virtual chromoendoscopy are emerging as potential tools in CRC screening.Patients with IBD at increased risk for developing CRC should undergo surveillance colonoscopy using new approaches and techniques.展开更多
Irritable bowel syndrome(IBS) is an extremely prevalent but poorly understood gastrointestinal disorder. Consequently, there are no clear diagnostic markers to help diagnose the disorder and treatment options are limi...Irritable bowel syndrome(IBS) is an extremely prevalent but poorly understood gastrointestinal disorder. Consequently, there are no clear diagnostic markers to help diagnose the disorder and treatment options are limited to management of the symptoms. The concept of a dysregulated gut-brain axis has been adopted as a suitable model for the disorder. The gut microbiome may play an important role in the onset and exacerbation of symptoms in the disorder and has been extensively studied in this context. Although a causal role cannot yet be inferred from the clinical studies which have attempted to characterise the gut microbiota in IBS, they do confirm alterations in both community stability and diversity. Moreover, it has been reliably demonstrated that manipulation of the microbiota can influence the key symptoms, including abdominal pain and bowel habit, and other prominent features of IBS. A variety of strategies have been taken to study these interactions, including probiotics, antibiotics, faecal transplantations and the use of germ-free animals. There are clear mechanisms through which the microbiota can produce these effects, both humoral and neural. Taken together, these findings firmly establish the microbiota as a critical node in the gut-brain axis and one which is amenable to therapeutic interventions.展开更多
Evidence is increasing that the integrity of sperm DNA may also be related to implantation failure and recurrent miscarriage （RM）. To investigate this, the sperm DNA fragmentation in partners of 35 women with recurr...Evidence is increasing that the integrity of sperm DNA may also be related to implantation failure and recurrent miscarriage （RM）. To investigate this, the sperm DNA fragmentation in partners of 35 women with recurrent implantation failure （RIF） following in vitro fertilization, 16 women diagnosed with RM and seven recent fathers （control） were examined. Sperm were examined pre- and post-density centrifugation by the sperm chromatin dispersion （SCD） test and the terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） assay. There were no significant differences in the age of either partner or sperm concentration, motility or morphology between three groups. Moreover, there were no obvious differences in sperm DNA fragmentation measured by either test. However, whilst on average sperm DNA fragmentation in all groups was statistically lower in prepared sperm when measured by the SCD test, this was not seen with the results from the TUNEL assay. These results do not support the hypothesis that sperm DNA fragmentation is an important cause of RIF or RM, or that sperm DNA integrity testing has value in such patients. It also highlights significant differences between test methodologies and sperm preparation methods in interpreting the data from sperm DNA fragmentation tests.展开更多
Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hyperte...Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hypertension, is in part due to morphological changes occurring in chronic liver diseases. This results in rerouting of blood flow away from the liver through collateral pathways to low-pressure systemic veins. Through a variety of computed tomographic, sonographic, magnetic resonance imaging and angiographic examples, this article discusses the appearances and prevalence of both common and less common portosystemic collateral channels in the thorax and abdomen. A brief overview of established interventional radiologic techniques for treatment of portal hypertension will also be provided. Awareness of the various imaging manifestations of portal hypertension can be helpful for assessing overall prognosis and planning proper management.展开更多
文摘Bone is the second most commonly transplanted tissue worldwide,with over four million operations using bone grafts or bone substitute materials annually to treat bone defects.However,significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma,cancer,infection and arthritis.Developing bioactive three-dimensional(3D)scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering(BTE).A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts.However,individual groups of materials including polymers,ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone.Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds.This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers,hydrogels,metals,ceramics and bio-glasses in BTE.Scaffold fabrication methodology,mechanical performance,biocompatibility,bioactivity,and potential clinical translations will be discussed.
基金澳大利亚研究委员会(ARC)基金The Lexicon Project:Analysing Pedagogical Naming Systems from Different Cultures to Reconceptualise Classroom Practice and Advance Educational Theory(项目编号:DP140101361)全国教育科学"十三五"规划2018年度青年专项课题"形式与功能:中美芬数学课堂关键教学行为比较研究"(项目编号:EHA180480)的阶段性成果
文摘Patients with long-standing inflammatory bowel disease(IBD)involving at least 1/3 of the colon are at increased risk for colorectal cancer(CRC).Advancements in CRC screening and surveillance and improved treatment of IBD has reduced CRC incidence in patients with ulcerative colitis and Crohn’s colitis.Most cases of CRC are thought to arise from dysplasia,and recent evidence suggests that the majority of dysplastic lesions in patients with IBD are visible,in part thanks to advancements in high definition colonoscopy and chromoendoscopy.Recent practice guidelines have supported the use of chromoendoscopy with targeted biopsies of visible lesions rather than traditional random biopsies.Endoscopists are encouraged to endoscopically resect visible dysplasia and only recommend surgery when a complete resection is not possible.New technologies such as virtual chromoendoscopy are emerging as potential tools in CRC screening.Patients with IBD at increased risk for developing CRC should undergo surveillance colonoscopy using new approaches and techniques.
基金Financial support was provided by the following sources to convene a meeting of the CONSORT Group in Montebello Canada+9 种基金in January 2007:the American Society of Clinical OncologyBMJCanadian Institutes for Health ResearchJohnson & JohnsonThe LancetNordic Cochrane CentrePLoS Medicine UK Cochrane Centreand UK National Co-ordinating Centre for Research Methodology.DM is supported by a University of Ottawa Research Chair.国家重点基础研究发展计划(973计划)项目资助(No.2006CB504602)。
文摘背景:对于与随机对照试验(randomized controlled trial,RCT)有关的学术会议论文或期刊中发表的文章来说,清楚、明了、信息量充足的摘要是十分重要的,因为读者经常仅仅根据报告的摘要对一个临床试验作出评价。为此,我们需要对"临床试验报告的统一标准(Consolidated Standards of Reporting Trials,CONSORT)声明"进行扩充,制定一个期刊与学术会议论文摘要中报告RCT的必备条目清单。今后在任何期刊发表的论文或学术会议论文摘要中,作者对RCT结果的报告都要包含这些内容。方法与结果:我们根据现有的质量评价工具和基于经验的证据总结出一个条目清单。运用三轮修正式德尔菲法(modified-Delphi process)进行条目筛选。邀请共计109人参与电子网络调查,反馈率为61%。调查结果于2007年1月在加拿大蒙特贝罗举行的CONSORT小组会议中公布,与会的26人中有临床试验实施人员、统计学家、流行病学家以及生物医学编辑。经过讨论最终确定条目,随后对其进行修订以保证这些条目体现了会议期间以及会后的讨论思路。摘要CONSORT建议RCT报告的摘要需要有一个结构化的格式,其中应该包括具体的试验目的、试验设计(随机分配的方法、盲法或遮蔽等)、研究对象(对象描述、随机分组的样本量以及用于分析的样本量)、每组实施的干预、实施的干预对主要疗效结果的影响及其危害、试验结论、试验注册名称和编号以及资金来源。本文对每一条能够找到例子的纳入条目都配有良好报告范例、基本原理以及证据等,十分明了易懂,因此我们建议与清单同时使用。结论:摘要CONSORT旨在改善期刊与学术会议中发表的论文摘要的质量,这将有助于摘要提供详尽清晰的信息,这些信息能够帮助读者对试验的有效性和试验结果的适用性做出正确的评价。
基金Supported by Science Foundation Ireland,No.SFI/12/RC/2272,No.02/CE/B124,No.07/CE/B1368Health Research Board No.HRA_POR/2011/23Brain and Behaviour Research Foundation No.20771
文摘Irritable bowel syndrome(IBS) is an extremely prevalent but poorly understood gastrointestinal disorder. Consequently, there are no clear diagnostic markers to help diagnose the disorder and treatment options are limited to management of the symptoms. The concept of a dysregulated gut-brain axis has been adopted as a suitable model for the disorder. The gut microbiome may play an important role in the onset and exacerbation of symptoms in the disorder and has been extensively studied in this context. Although a causal role cannot yet be inferred from the clinical studies which have attempted to characterise the gut microbiota in IBS, they do confirm alterations in both community stability and diversity. Moreover, it has been reliably demonstrated that manipulation of the microbiota can influence the key symptoms, including abdominal pain and bowel habit, and other prominent features of IBS. A variety of strategies have been taken to study these interactions, including probiotics, antibiotics, faecal transplantations and the use of germ-free animals. There are clear mechanisms through which the microbiota can produce these effects, both humoral and neural. Taken together, these findings firmly establish the microbiota as a critical node in the gut-brain axis and one which is amenable to therapeutic interventions.
文摘Evidence is increasing that the integrity of sperm DNA may also be related to implantation failure and recurrent miscarriage （RM）. To investigate this, the sperm DNA fragmentation in partners of 35 women with recurrent implantation failure （RIF） following in vitro fertilization, 16 women diagnosed with RM and seven recent fathers （control） were examined. Sperm were examined pre- and post-density centrifugation by the sperm chromatin dispersion （SCD） test and the terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） assay. There were no significant differences in the age of either partner or sperm concentration, motility or morphology between three groups. Moreover, there were no obvious differences in sperm DNA fragmentation measured by either test. However, whilst on average sperm DNA fragmentation in all groups was statistically lower in prepared sperm when measured by the SCD test, this was not seen with the results from the TUNEL assay. These results do not support the hypothesis that sperm DNA fragmentation is an important cause of RIF or RM, or that sperm DNA integrity testing has value in such patients. It also highlights significant differences between test methodologies and sperm preparation methods in interpreting the data from sperm DNA fragmentation tests.
文摘Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hypertension, is in part due to morphological changes occurring in chronic liver diseases. This results in rerouting of blood flow away from the liver through collateral pathways to low-pressure systemic veins. Through a variety of computed tomographic, sonographic, magnetic resonance imaging and angiographic examples, this article discusses the appearances and prevalence of both common and less common portosystemic collateral channels in the thorax and abdomen. A brief overview of established interventional radiologic techniques for treatment of portal hypertension will also be provided. Awareness of the various imaging manifestations of portal hypertension can be helpful for assessing overall prognosis and planning proper management.
