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排序方式: 共有10000条查询结果,搜索用时 281 毫秒
931.
932.
Si-Cheng Liang Guang-Bo Ge Yang-Liu Xia Dong Pei-Pei Wang Ping 《Xenobiotica; the fate of foreign compounds in biological systems》2017,47(6):498-504
1.?Finding and developing inhibitors of catechol-O-methyltransferase (COMT) from natural products is highly recommended. Daphnetin, a naturally occurring catechol from the family thymelaeaceae, has a chemical structure similar to several potent COMT inhibitors reported previously. Here the potential of daphnetin and its Phase II metabolites as inhibitors of COMT was investigated with human liver cytosol (HLC).2.?Daphnetin and its methylated metabolite (8-O-methyldaphnetin) were found to inhibit COMT-mediated dopamine O-methylation in a dose-dependent manner. The IC50 values for daphnetin (0.51~0.53?μM) and 8-O-methyldaphnetin (22.5~24.3?μM) were little affected by changes in HLC concentrations. Further kinetic analysis showed the differences in inhibition type and parameters (Ki) between daphnetin (competitive, 0.37?μM) and 8-O-methyldaphnetin (noncompetitive, 25.7?μM). Other metabolites, including glucuronidated and sulfated species, showed negligible inhibition against COMT. By using in vitro–in vivo extrapolation (IV-IVE), a 24.3-fold increase in the exposure of the COMT substrates was predicted when they are co-administrated with daphnetin.3.?With high COMT-inhibiting activity, daphnetin could serve as a lead compound for the design and development of new COMT inhibitors. Also, much attention should be paid to the clinical impact of combination of daphnetin and herbal preparations containing daphnetin with the drugs primarily cleared by COMT. 相似文献
933.
Over the past decade, management of the T1 renal mass has focused on nephron‐sparing surgery. Robotic partial nephrectomy has played an increasing role in the technique of preserving renal function by decreasing warm ischemia time, as well as optimizing outcomes of hemorrhage and fistula. Robot‐assisted partial nephrectomy is designed to provide a minimally‐invasive nephron‐sparing surgical option utilizing reconstructive capability, decreasing intracorporeal suturing time, technical feasibility and safety. Ultimately, its benefits are resulting in its dissemination across institutions. Articulated instrumentation and three‐dimensional vision facilitate resection, collecting system reconstruction and renorrhaphy, leading to decreased warm ischemia time while preserving oncological outcomes. The aim of the present review was to present our surgical sequence and technique, as well as review the current status of robot‐assisted partial nephrectomy. 相似文献
934.
935.
Yan Xu Guoyuan Liang Guangshu HuYan Yang Jinzhao GengPunam K. Saha 《Computerized medical imaging and graphics》2012,36(1):11-24
Quantification of coronary arterial stenoses is useful for the diagnosis of several coronary heart diseases. Being noninvasive, economical and informative, computed tomographic angiography (CTA) has become a common modality for monitoring disease status and treatment effects. Here, we present a new method for detecting and quantifying coronary arterial stenosis in CTA using fuzzy distance transform (FDT) approach and a new coherence analysis of observed data for computing expected local diameter. FDT allows computing local depth at each image point in the presence of partial voluming and thus, eliminates the need for binarization, commonly, associated with inclusion of additional errors. In the current method, coronary arterial stenoses are detected and their severities are quantified by analyzing FDT values along the medial axis of an arterial tree obtained by its skeletonization. A new skeletal pruning algorithm has been developed toward improving the quality of medial axes and thereby, enhancing the accuracy of stenosis detection and quantification. Further, we have developed a new method to estimate “expected diameter” along a given arterial branch using a new coherence analysis of observed diameter values along the branch. The overall method is completed in the following steps - (1) fuzzy segmentation of coronary artery in CTA, (2) FDT computation of coronary arteries, (3) medial axis computation, (4) estimation of observed and expected diameters along arteries and (5) detection of stenoses and quantification of arterial blockage. The performance of this method has been quantitatively evaluated on a realistic coronary artery phantom dataset with randomly simulated stenoses and the results have been compared with a binary distance transform based and a conventional binary algorithm. The method has also been applied on a clinical CTA dataset from thirteen heart patients and the results have been compared with an expert's quantitative assessment of stenoses. Results of the phantom experiment indicate that the new method (error: 0.53%) is significantly more accurate as compared to both binary distance transform based (error 2.11%) and conventional binary (error 3.71%) methods. Also, the results of the clinical study indicate that the new FDT-based method (kappa coefficient = 87.9%) is highly in agreement with the expert's assessments and, in this respect, outperforms the other two methods (kappa coefficients = 75.2% and 69.5%). 相似文献
936.
目的:探讨眼底炫彩成像(MCI)联合光相干断层扫描成像(OCT)在视网膜动脉阻塞(RAO)的快速诊断及分类中的应用。方法:对本院2018-02/2020-07诊断为RAO的患者19例19眼进行回顾性研究。所有患者在经过眼科检查后确诊为RAO,均为单眼发病,其中视网膜中央动脉阻塞(CRAO)13眼,视网膜分支动脉阻塞(BRAO)5眼,睫状视网膜动脉残留的CRAO 1眼。所有患者行最佳矫正视力、裂隙灯、OCT、MCI、FFA及视野检查及分析。结果:经裂隙灯检查,12眼(63%)出现瞳孔对光反射迟钝或消失,16眼(84%)可发现全部或部分后极部视网膜苍白水肿,10眼(53%)可发现视网膜动脉变细。行FFA检查的患者为10例(53%),其余9例未行检查,其中6例患有严重的系统性疾病,2例拒绝检查、1例有药物过敏史。所有患者经MCI及OCT检查可发现特征性眼底表现,OCT特征性改变为弥漫性内层视网膜反射增强与MCI图像绿色缺血区域形成严密的一对一关系。结论:联合MCI及OCT检查可快速确诊RAO,而且结合两者的图像特征可更精确辨认出视网膜缺血区域,有助于疾病分类及预后判断。 相似文献
937.
938.
Feng Liang Wu Zhong Jun Liu Xiao Guang Liu Shao Min Yang Liang Jiang Feng Wei Miao Yu 《The spine journal》2014,14(1):e11-e15
Background contextPolyostotic fibrous dysplasia (PFD) seldom involves the thoracic spine and usually presents with back pain.PurposeTo describe an extremely rare presentation of an uncommon disease.Study design/settingWe present a case report from a university hospital.MethodsWe report a case of symptomatic thoracic PFD associated with myelopathy and pathologic fracture. A thorough search of PubMed/MEDLINE was performed for the terms “polyostotic fibrous dysplasia,” “spine,” and “neurological deficit.”ResultsThe patient was treated by posterior laminectomy, vertebroplasty, and pedicle screw fixation and fusion. Satisfactory results were achieved, and there were no complications.ConclusionsIn the spine, PFD may lead to pathologic fracture and myelopathy even after adolescence. Vertebroplasty with or without decompression and fixation may be the appropriate option for cases with myelopathy. 相似文献
939.
940.
目的:探究胫骨横向搬移术联合负压引流(VSD)技术治疗糖尿病足的疗效及其对血管生成相关因子水平的影响.方法:根据治疗方法不同将60例糖尿病足患者分为观察组(n=28)和对照组(n=32).对照组采用VSD技术治疗,观察组在对照组的基础上采用胫骨横向搬移术治疗.观察两组的治疗效果,对比治疗前及治疗后3个月患肢踝肱指数(ABI)、视觉模拟评分法(VAS)评分、足部血流指标(足背动脉内径、足背动脉血流速度)及血清血管生成相关因子[血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)、表皮生长因子(EGF)]水平.结果:观察组的临床有效率为89.29%,高于对照组的59.38%(P<0.05);治疗后,观察组ABI以及VEGF、bFGF、EGF水平均高于对照组(P<0.05),且足背动脉内径及血流速度均大于对照组(P<0.05),而VAS评分低于对照组(P<0.05).结论:胫骨横向搬移术联合VSD技术治疗糖尿病足的临床疗效高于单用VSD,可能与其增加血管生成因子的表达水平、改善足部血供相关. 相似文献