Reduced field-of-view MRI with two-dimensional spatially-selective RF excitation and UNFOLD.

When the region of interest (ROI) is smaller than the object, one can increase MRI speed by reducing the imaging field of view (FOV). However, when such an approach is used, features outside the reduced FOV will alias into the reduced-FOV image along the phase-encoding direction. Reduced-FOV methods are designed to correct this aliasing problem. In the present study, we propose a combination of two different approaches to reduce the acquired FOV: 1) two-dimensional (2D) spatially-selective RF excitation, and 2) the unaliasing by Fourier-encoding the overlaps using the temporal dimension (UNFOLD) technique. While 2D spatially-selective RF excitation can restrict the spins excited within a reduced FOV, the UNFOLD technique can help to eliminate any residual aliased signals and thus relaxes the requirement for a long RF excitation pulse. This hybrid method was implemented for MR-based temperature mapping, and resulted in artifact-free images with a fourfold improvement in temporal resolution.     

Effects of acute electromagnetic field exposure and movement restraint on antioxidant system in liver,heart, kidney and plasma of Wistar rats: A preliminary report

Purpose:?The aim of the present study was to evaluate the early effects of acute (2?h) exposure to extremely low frequency electromagnetic fields (ELF-EMF), as well as movement restraint (MR) and the combination of both on the antioxidant systems in the plasma, liver, kidney, and heart of rats.

Materials and methods:?Twenty-four adult male Wistar rats were divided in two groups, restrained and unrestrained. The restrained animals were confined into an acrylic tube for 120?min. Half of the animals of each group were exposed to ELF-EMF (60?Hz, 2.4?mT) during the period of restriction. Immediately after treatment, reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and thiobarbituric acid reactive substances (TBARS) were measured in tissues.

Results:?GSH concentration was significantly lower in the heart of all experimental animals when compared to the control group; furthermore, the decrease was higher in the liver of restrained animals. SOD activity was lower in the plasma of restrained and EMF exposed animals compared to unrestrained rats. There were no significant differences in CAT activity and TBARS levels among all the experimental groups vs. the control group.

Conclusion:?Two hours of 60?Hz EMF exposure might immediately alter the metabolism of free radicals, decreasing SOD activity in plasma and GSH content in heart and kidney, but does not induce immediate lipid peroxidation. Oxidative stress induced by movement restraint was stronger than that produced by EMF.     

还原型辅酶Ⅰ(NADH)对PC12细胞鱼藤酮损伤的分子调控

为探讨NADH对PC12细胞线粒体鱼藤酮损伤的修复机制，采用细胞毒实验、免疫荧光和流式细胞仪检测细胞在鱼藤酮损伤前后细胞增殖基因（c-myc、c-erbB-2）、抗凋亡基因（bcl－2）、抑癌基因（p53）、细胞快反应基因（c-fos）相关蛋白和细胞增殖核抗原（PCNA）的表达。结果表明，鱼藤酮能明显抑制PC12细胞增殖，下调c-erbB-2、c-myc、bcl-2和p53基因的表达；NADH可以抑制鱼藤酮对PC12细胞线粒体的毒性作用，上调细胞bcl-2c、c-myc、c-erbB－2基因和PCR的表达，提示鱼藤酮可能通过控线粒体磷酸化过程和下调细胞增殖基因（c-rebB-2、c－myc）、抗凋亡基因（bcl-2），上调快反应基因(c-fos）表达致使细胞损伤，NADH抑制鱼藤酮对PC12细胞的损伤可能与bcl-2、c-myc、c-erbB-2和p53表达调控有关。     

NADH抗肝细胞氰化物损伤的实验研究

为分析NADH在保护正常肝细胞氰化物缺氧性损伤中的作用，在L02细胞组织培养基中加入3mmol／LKCN后立即加入0－600μg/ml的NADH，培养0．5、2、4h后检测细胞凋亡和Bcl－2家族蛋白的表达。另取L02细胞发3组进行实验，实验组I为对照组，实验组Ⅱ、Ⅲ加3mmol/LKCN后分别加入不含和含有NADH（400μg/ml）的RPMI1640培养2h，检测3组Bcl-XL,Bax,Bcl-2蛋白，并取样进行透射电观察细胞形态。结果显示，NADH对氰化细胞凋亡率的抑制作用呈剂量依赖性，在浓度400－600μg/ml时达平台，并且能够上调Bcl-2及Bcl-XL蛋白表达，下调Bax蛋白表达；电镜观察可见损伤后细胞呈凋亡和坏死改变。提示NADH具有明显抗肝细胞氰化物损伤作用，其作用机制可能与Bcl-2、Bcl-XL蛋白表达的上调及和Bax蛋白表达的下调有关。     

辅酶NADH保护和修复细胞损伤的研究

探讨辅酶NADH增加能量代谢水平、修复细胞损伤、提高细胞应激反应的能力和降低化疗药物、放射线对正常组织的毒性损伤作用,探讨NADH细胞保护的分子调控机制,为今后临床多种疾病的细胞保护治疗提供新的防治途径。     

一些硝基化合物的燐光特点

研究了13种硝基化合物及其还原产物的燐光性质?蠖嗍趸衔镉袩?但强度比相应还原产物(对-硝基苯胺除外)都低。硝基取代位置影响燐光强度,有对位>邻位>间位的关系。硝基化合物的燐光波长比相应还原产物的燐光波长长,即硝基化合物的最低三线态比还原产物低。硝基化合物与相应产物燐光位移能差绝对值有对位>邻位>间位,且成直线关系。大多数硝基化合物还原后燐光寿命延长。     

还原型谷胱甘肽在原发性肝癌介入治疗后保肝作用中的临床应用

目的 探讨还原型谷胱甘肽在原发性肝癌介入治疗后的保肝作用.方法 回顾性分析2010年1月-2013年6月收治的原发性肝癌患者110例,按照随机数字表法分为对照组50例和治疗组60例,均给予肝动脉化学性栓塞和灌注治疗.对照组,静脉滴注维生素C 2.0g,维生素B6 0.2 9,肌苷2.0 g,以及支链氨基酸250 ml,每日1次,术后连续使用l周;治疗组,在前述基础用药上加用还原型谷胱甘肽1.8 9,以5％葡萄糖溶液250 ml配伍静脉滴注.同时检测术前和术后1周各项肝功能指标,进行两组间比较.结果 治疗前两组肝功能、病情无明显差异.介入治疗1周后,治疗组和对照组转氨酶(ALT、AST)、总胆红素(TBIL)均明显升高(P＜0.05),血清前白蛋白(PA)均明显降低(P＜0.05);治疗组各项指标变化明显优于对照组(P＜0.05).结论 还原型谷胱甘肽能明显改善原发性肝癌介入治疗引起的肝功能损害,有很好的临床应用价值.     

辅酶NADH抑制人肝细胞株L02化疗凋亡损伤的作用

为研究辅酶NADH对顺铂（DDP）诱导的肝细胞凋亡的抑制作用及其分子机制，采用透射和扫描电镜检测肝细胞超微结构改变，碘化丙啶染色流式细胞术检测细胞凋亡，RT－PCR检测p53和bcl-2基因表达变化，并用紫外分光光度法测定凋亡分子caspase-3和caspase－8活性水平的改变。结果显示，与DDP组比较，NADH／DDP组典型凋亡超微形态改变不明显，细胞凋亡明显下降，p53基因表达下降，bcl-2基因表达上升，caspase-3和caspase-8活性维持在低水平。提示NADH具有明显抑制DDP诱导肝细胞凋亡的作用。     

还原型谷胱甘肽对急性有机磷农药中毒肝损害的保护作用

目的探讨还原型谷胱甘肽对急性有机磷农药中毒肝损害的保护作用。方法将164例急性有机磷农药中毒肝损害患者分为对照组与观察组,每组各82例。给予对照组患者常规治疗,观察组患者在常规治疗基础上给予还原型谷胱甘肽静点,比较两组治疗总有效率及肝功能指标的差别。结果治疗后观察组治疗总有效率为92.7%,显著高于对照组的69.5%,两者比较,差异有显著统计学意义(P<0.01);治疗后观察组患者天冬氨酸氨基转移酶、丙氨酸氨基转移酶、谷氨酰转肽酶及总胆红素显著低于对照组(P<0.05)。结论还原型谷胱甘肽治疗急性有机磷农药中毒肝损害,可显著改善患者肝功能,提高疗效。     

DWI of the spinal cord with reduced FOV single‐shot EPI

Single‐shot echo‐planar imaging (ss‐EPI) has not been used widely for diffusion‐weighted imaging (DWI) of the spinal cord, because of the magnetic field inhomogeneities around the spine, the small cross‐sectional size of the spinal cord, and the increased motion in that area due to breathing, swallowing, and cerebrospinal fluid (CSF) pulsation. These result in artifacts with the usually long readout duration of the ss‐EPI method. Reduced field‐of‐view (FOV) methods decrease the required readout duration for ss‐EPI, thereby enabling its practical application to imaging of the spine. In this work, a reduced FOV single‐shot diffusion‐weighted echo‐planar imaging (ss‐DWEPI) method is proposed, in which a 2D spatially selective echo‐planar RF excitation pulse and a 180° refocusing pulse reduce the FOV in the phase‐encode (PE) direction, while suppressing the signal from fat simultaneously. With this method, multi slice images with higher in‐plane resolutions (0.94 × 0.94 mm² for sagittal and 0.62 × 0.62 mm² for axial images) are achieved at 1.5 T, without the need for a longer readout. Magn Reson Med 60:468–473, 2008. © 2008 Wiley‐Liss, Inc.     

Creating a library of generalized Fourier sampling patterns for irregular 2D regions of support.

Multiple-region MRI (mrMRI) represents a generalization of the Shannon sampling theorem to permit sparse k-space sampling whenever the scanned object or its high-contrast edges are confined to multiple known regions. Use of an optimal mrMRI sampling pattern produces an image with root-mean-squared (RMS) noise over the supporting regions equal to the RMS noise in a conventional Fourier image with the same total area of support. Analytical solutions for such sampling patterns have been described previously for all arrangements of two or three (noncollinear) supporting regions. This work describes a robust numerical method for creating a library of optimal and near-optimal mrMRI sampling patterns for more complicated geometries. The average noise amplification over all sampling patterns in the demonstration library was only 4%, with 30% of the sampling patterns resulting in no noise amplification whatsoever.     

Fast maximum intensity projection algorithm using shear warp factorization and reduced resampling.

Maximal intensity projection (MIP) is routinely used to view MRA and other volumetric angiographic data. The straightforward implementation of MIP is ray casting that traces a volumetric data set in a computationally expensive manner. This article reports a fast MIP algorithm using shear warp factorization and reduced resampling that drastically reduced the redundancy in the computations for projection, thereby speeding up MIP by more than 10 times.     

还原型辅酶Ⅰ(NADH)拮抗阿霉素心肌线粒体毒性的机制

为探讨还原型辅酶Ⅰ（NADH）对阿霉素（Dox）心肌线粒体毒性的拮抗作用及其机制，建立原代培养的乳鼠心肌细胞和SD大鼠心肌受阿霉损伤的模型，采用MTT比色法、激光共聚焦显微镜、透射电镜和生物氧耗电极检测器检测线粒体形态和功能改变。结果显示，Dox组心肌细胞杀伤率增高，而NADH／Dox组心肌细胞杀伤作用明显下降，Dox诱发的心肌细胞线粒体结构损害表现为肿胀、裂解、嵴断裂直至溶解，加入NADH后线粒体结构明显得到保护，Dox组和NADH／Dox组MMP和ROS荧光强度有显著性差异,Dox可明显损害线粒体氧化磷酸化功能，Dox组与NADH／Dox组S3值、RCI值和ADP／O值比较，两者差异有显著性意义。提示NADH能够明显拮抗Dox所致的心肌线粒体毒性损伤作用，对线粒体结构和功能起保护作用。     

还原型谷胱甘肽对异甘草酸镁治疗酒精性肝炎疗效的影响

 目的 探究还原型谷胱甘肽对异甘草酸镁治疗酒精性肝炎疗效的影响。方法 选择2014年1－12月酒精性肝炎患者140例,按随机数字表法分为实验组和对照组,每组70例。对照组给予异甘草酸镁注射液治疗,实验组在对照组治疗基础上加用还原型谷胱甘肽注射液。以4周为一疗程,观察并记录两组患者肝功能指标丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、谷氨酰转肽酶(GGT)、总胆红素(TBIL)。结果 治疗后实验组肝功能指标ALT、AST、GGT、总胆红素水平优于对照组,具有统计学意义(P<0.05)。实验组有效率(94.29%)高于对照组(81.43%),差异有统计学意义(P<0.05)。治疗后实验组无不良反应发生;对照组不良反应发生率为10%,高于实验组(P<0.05)。结论 还原型谷胱甘肽可以提高异甘草酸镁治疗酒精性肝炎的效果。