Lack of Neuroprotective Effects of High-Density Lipoprotein Therapy in Stroke under Acute Hyperglycemic Conditions

Introduction: The pleiotropic protective effects of high-density lipoproteins (HDLs) on cerebral ischemia have never been tested under acute hyperglycemic conditions. The aim of this study is to evaluate the potential neuroprotective effect of HDL intracarotid injection in a mouse model of middle cerebral artery occlusion (MCAO) under hyperglycemic conditions. Methods: Forty-two mice were randomized to receive either an intracarotid injection of HDLs or saline. Acute hyperglycemia was induced by an intraperitoneal injection of glucose (2.2 g/kg) 20 min before MCAO. Infarct size (2,3,5-triphenyltetrazolium chloride (TTC)-staining), blood–brain barrier leakage (IgG infiltration), and hemorrhagic changes (hemoglobin assay by ELISA and hemorrhagic transformation score) were analyzed 24 h post-stroke. Brain tissue inflammation (IL-6 by ELISA, neutrophil infiltration and myeloperoxidase by immunohisto-fluorescence) and apoptosis (caspase 3 activation) were also assessed. Results: Intraperitoneal D-glucose injection allowed HDL- and saline-treated groups to reach a blood glucose level of 300 mg/dl in the acute phase of cerebral ischemia. HDL injection did not significantly reduce mortality (19% versus 29% in the saline-injected group) or cerebral infarct size (p = 0.25). Hemorrhagic transformations and inflammation parameters were not different between the two groups. In addition, HDL did not inhibit apoptosis under acute hyperglycemic conditions. Conclusion: We observed a nonsignificant decrease in cerebral infarct size in the HDL group. The deleterious consequences of reperfusion such as hemorrhagic transformation or inflammation were not improved by HDL infusion. In acute hyperglycemia, HDLs are not potent enough to counteract the adverse effects of hyperglycemia. The addition of antioxidants to therapeutic HDLs could improve their neuroprotective capacity.     

Monitoring of Altered Free Fatty Acid Metabolic Patterns in Rat Plasma Following Hemorrhagic Stroke

To uncover the physiological changes occurring after hemorrhagic stroke, we analyzed 24 free fatty acids in plasma as tert-butyldimethylsilyl derivatives by gas chromatography-mass spectrometry from control and intracerebral hemorrhage rats. Hematoma volume decreased, and hemorrhage-induced behavioral abnormalities recovered overtime. Altered fatty acid metabolism at 7 days after hemorrhagic stroke spontaneously recovered to normal control levels at 14 days. The deformed star patterns of hemorrhagic stroke group were readily distinguished from the tetracosagonal shape of the control mean. Thus, the present method may be used for monitoring of biochemical and physiological events in hemorrhagic stroke.     

峰值电流达几千安量级的闪电M分量放电特征及机理探讨

利用2009年山东人工触发闪电实验获取的实测雷电流资料、近距离电场和高速摄像资料,分析了6次峰值电流达几千安量级的M分量.6次M分量均对应闪电通道中明显的发光亮度的脉冲式变化,持续时间小于1 ms.M分量的电流波形和近距离电场波形均呈较为对称的V形,且波形的上升时间均为几十微秒,同步记录结果显示,电场先于通道底部电流发生变化且先达到峰值.这些M分量在发生前,闪电通道中存在一定的连续电流,通道的导电性优于先导-回击过程.M分量发生前的闪电 关键词： 闪电 M分量')" href="#">M分量 先导-回击 通道电流     

内源性蛋白质分子成像的研究进展

酰氨质子转移（amide proton transfer, APT）成像是一种新的分子MRI技术,它可用来测量组织中内源性蛋白质. 理论上,APT-MRI信号强度主要取决于游离蛋白质的酰氨质子浓度以及交换速度,而酰氨质子交换速度与组织pH有关. 因此,APT-MRI技术已经被用于无创性中风pH成像（通常pH降低）和肿瘤蛋白质含量成像（通常蛋白质量提高）. 近期对大鼠的实验表明,APT-MRI技术可用来区分放射性坏死和胶质瘤. 该综述文章简要地介绍了APT成像的基本原理以及它在动物模型与临床中风和肿瘤成像中的应用.     

A diethyltartrate-based synthesis of both (−)- and (+)-arundic acid

A diethyltartrate-based synthesis of both enantiomers of the acute ischemic stroke therapeutic agent, arundic acid is presented. Separable diastereomers were obtained through the Johnson-Claisen rearrangement of the chiral vicinal diol based on the diethyltartrate skeleton and were converted separately into the two enantiomers of arundic acid.     

Erythrocyte‐Derived Nanoparticles as a Theranostic Agent for Near‐Infrared Fluorescence Imaging and Thrombolysis of Blood Clots

Ischemic stroke occurs when a blood clot obstructs or narrows the arteries that supply blood to the brain. Currently, tissue plasminogen activator (tPA), a thrombolytic agent, is the only United States Food and Drug Administration (FDA)‐approved pharmacologic treatment for ischemic stroke. Despite its effective usage, the major limitation of tPA that stems from its short half‐life in plasma (≈5 min) is the potential for increased risk of hemorrhagic complications. To circumvent these limitations, herein, the first proof‐of‐principle demonstration of a theranostic nanoconstruct system derived from erythrocytes doped with the FDA‐approved near‐infrared (NIR) imaging agent, indocyanine green, and surface‐functionalized with tPA is reported. Using a clot model, the dual functionality of these nanoconstructs in NIR fluorescence imaging and clot lysis is demonstrated. These biomimetic theranostic nanoconstructs may ultimately be effective in imaging and treatment of blood clots involved in ischemic stroke.     

脑卒中患者血清中钒钼钡铝锶水平的探讨

对１１０名脑卒中患者与对照组血清中钒、钼、钡、铝、锶的含量比较，结果显示：血清锶和钡的含量升高；血清钡和钼的含量降低；而血清铝的含量未见差异。     

脑卒中患者血清中钙镁镉铅铍含量的观察

对１１０例脑卒中患者与正常对照组血清中钙、镁、镉、铅、铍的含量比较。研究结果揭示：血清铍的含量升高，血清钙、镉、铅的含量降低，血清镁的含量两者之间无显著性差异，Ｐ〉０．０５。