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61.
Quantitative chemical exchange saturation transfer (qCEST) MRI – omega plot analysis of RF‐spillover‐corrected inverse CEST ratio asymmetry for simultaneous determination of labile proton ratio and exchange rate 下载免费PDF全文
Renhua Wu Gang Xiao Iris Yuwen Zhou Chongzhao Ran Phillip Zhe Sun 《NMR in biomedicine》2015,28(3):376-383
Chemical exchange saturation transfer (CEST) MRI is sensitive to labile proton concentration and exchange rate, thus allowing measurement of dilute CEST agent and microenvironmental properties. However, CEST measurement depends not only on the CEST agent properties but also on the experimental conditions. Quantitative CEST (qCEST) analysis has been proposed to address the limitation of the commonly used simplistic CEST‐weighted calculation. Recent research has shown that the concomitant direct RF saturation (spillover) effect can be corrected using an inverse CEST ratio calculation. We postulated that a simplified qCEST analysis is feasible with omega plot analysis of the inverse CEST asymmetry calculation. Specifically, simulations showed that the numerically derived labile proton ratio and exchange rate were in good agreement with input values. In addition, the qCEST analysis was confirmed experimentally in a phantom with concurrent variation in CEST agent concentration and pH. Also, we demonstrated that the derived labile proton ratio increased linearly with creatine concentration (P < 0.01) while the pH‐dependent exchange rate followed a dominantly base‐catalyzed exchange relationship (P < 0.01). In summary, our study verified that a simplified qCEST analysis can simultaneously determine labile proton ratio and exchange rate in a relatively complex in vitro CEST system. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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目的:探讨Ki-67表达与原发性肝癌根治性切除术后行预防性TACE患者预后的关系。方法:采用回顾性队列研究,收集2014年12月—2016年1月福建医科大学孟超肝胆医院150例行原发性肝癌根治性切除术并在术后2个月内行预防性TACE患者的临床病理资料,根据术后肝癌组织病理Ki-67评分分为为低表达组(Ki-67评分≤20%,44例)和高表达组(Ki-67评分20%,106例);分析Ki-67表达量与患者临床病理因素及复发与生存的关系。结果:高表达组肿瘤多发、肿瘤包膜不完整及合并微血管癌栓患者比例明显高于低表达组(均P0.05)。Ki-67高表达与肿瘤多发、肿瘤直径大为影响无瘤生存期的独立危险因素(均P0.05);Ki-67高表达与肿瘤多发、肿瘤直径大、肿瘤包膜不完整、合并微血管癌栓为影响总生存期的独立危险因素(均P0.05);高表达组患者复发率明显高于低表达组(57.9%vs. 37.7%,χ~2=6.777,P0.05),总生存率明显低于低表达组(45.6%vs. 75.9%,χ~2=8.447,P0.05)。结论:Ki-67的表达量对肝癌根治性切除术后行预防性TACE患者的预后有显著影响,高表达者预后不良。 相似文献
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新型冠状病毒肺炎(corona virus disease 2019,COVID-19)自2019年12月爆发以来,由于具有高传染性,迅速在世界各地蔓延,国内外疫情防治形势空前严峻。COVID-19不仅造成肺部、肠道、肾脏等多脏器损害,且部分患者以眼表损害为首发或伴发症状出现,临床上很容易被忽视。COVID-19的眼表损害归属于祖国医学“天行赤眼”范畴,本文结合国内外最新的文献报道,探讨新型冠状病毒(2019 novel corona virus,2019-nCoV)对眼表的损害,阐明其可能机制,并从中西医角度提出可行的治疗措施。 相似文献
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目的:探讨醛-酮还原酶家族7成员A3(AKR7A3)在肺腺癌中的异常表达及与临床病理特征的关系,并探究其临床意义。方法:采用生物信息学数据库分析、免疫组化、Western Blot、Real-time PCR等方法对肺腺癌组织及不同细胞中AKR7A3的表达进行检测与分析。结果:Oncomine数据库分析结果显示,在肺腺癌中,AKR7A3的表达普遍高于正常肺组织,分别为正常肺组织的1.811倍(P=0.022)、1.356倍(P<0.01)、1.413倍(P=0.002)。Kaplan-Meier Plotter数据库分析结果显示,AKR7A3高表达的患者较低表达的患者生存时间缩短,差异具有统计学意义(P=0.003 7)。免疫组化染色显示肺腺癌组织中AKR7A3的表达较癌旁增高,在与临床病理特征的相关性分析中,发现其与肿瘤分化程度(P<0.01)、淋巴结转移情况(P=0.029)以及TNM分期(P<0.01)相关,且会造成患者生存时间缩短(P=0.031)。Cox多因素分析表明AKR7A3可能是影响肺腺癌患者预后的独立危险因素(P=0.012)。Western Blot及Real-time PCR实验提示不同肺腺癌细胞中AKR7A3蛋白及mRNA表达普遍增高。结论:AKR7A3在肺腺癌中表达增高,对预后有不良影响,有促进肿瘤发生发展的作用。 相似文献
67.
Ping Liu Jiang Peng Gong-Hai Han Xiao Ding Shuai Wei Gang Gao Kun Huang Feng Chang Yu Wang 《中国神经再生研究》2019,(8)
Resident and inflammatory macrophages are essential effectors of the innate immune system. These cells provide innate immune defenses and regulate tissue and organ homeostasis. In addition to their roles in diseases such as cancer, obesity and osteoarthritis, they play vital roles in tissue repair and disease rehabilitation. Macrophages and other inflammatory cells are recruited to tissue injury sites where they promote changes in the microenvironment. Among the inflammatory cell types, only macrophages have both pro-inflammatory(M1) and anti-inflammatory(M2) actions, and M2 macrophages have four subtypes. The co-action of M1 and M2 subtypes can create a favorable microenvironment, releasing cytokines for damaged tissue repair. In this review, we discuss the activation of macrophages and their roles in severe peripheral nerve injury. We also describe the therapeutic potential of macrophages in nerve tissue engineering treatment and highlight approaches for enhancing M2 cell-mediated nerve repair and regeneration. 相似文献
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目的分析2014-2018年黄山市淋病的流行特征,为全市的淋病防控工作提供科学依据。方法通过中国疾病预防控制信息系统收集黄山市2014—2018年的淋病数据、人口数据,进行统计分析。结果2014—2018年黄山市累计报告淋病病例761例,年均发病率为11.09/10万,年均增长率为29.14%,发病率呈逐年上升趋势(χ^2趋势=112.29,P<0.05)。淋病的人群分布中,男女报告病例数之比为13.63:1,男女发病率有统计学差异(χ^2=113.18,P<0.05);15~49岁年龄组病例数最多,占85.94%,职业以农民最多,占44.81%;以屯溪区、歙县报告病例数较多,分别占37.45%、23.26%。结论2014—2018年黄山市淋病发病率呈上升趋势,淋病防控形势严峻,需进一步完善各项防控措施。 相似文献
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The significance of hepatobiliary scintigraphy (HBS) for hepatic graft function assessment was established mostly on retrospective studies and was not widely recognized due to the lack of quantitative data and variation in accuracy. This prospective study was performed to investigate the effectiveness of quantitative HBS for assessing hepatocyte dysfunction and biliary complication in liver transplant recipients.In 57 recipients who had undergone orthotopic liver transplantation, a total of 67 dynamic 99mTc-EHIDA scans were performed and quantitative parameters including the hepatocyte extraction fraction (HEF), time to maximum hepatic radioactivity (Tmax), and time for peak activity to decrease by 50% (T1/2) were calculated. The scintigraphic results based on the 3 parameters were compared against the final diagnosis. A ROC curve analysis was carried out to identify the cutoff value of Tmax for diagnosis of biliary stricture. Correlation between the parameters of postoperative HBS and conventional biochemical liver function indices were also analyzed.Quantitative 99mTc-EHIDA HBS had an overall sensitivity of 94.12% (16/17), specificity of 93.33% (42/45), and diagnostic accuracy of 93.55% (58/62) for detecting hepatocyte dysfunction and biliary complication in liver transplant recipients. The recommended cutoff value of Tmax for diagnosis of post-transplant biliary stricture was set at 15.75 min with a sensitivity of 100.0% and a specificity of 94.0%. The scintigraphic parameters (HEF, Tmax) were statistically significantly associated with the conventional liver function parameters.Quantitative 99mTc-EHIDA HBS offers a noninvasive imaging modality with high sensitivity and specificity to diagnose hepatocyte dysfunction as well as distinguish between patients with or without biliary stricture following liver transplantation. Furthermore, HEF and Tmax values obtained from dynamic HBS show good correlation with conventional liver function parameters. 相似文献