高血压大鼠局灶脑缺血再灌注后X线修复交叉互补组1蛋白表达及DNA片段化损伤

目的　观察肾性高血压大鼠局灶脑缺血再灌注后DNA修复蛋白X线修复交叉互补组 1(XRCC1)蛋白的表达及与DNA片段化损伤的关系。方法　采用双肾双夹法建立肾性高血压大鼠模型 ,在此基础上采用线栓法制作大脑中动脉闭塞模型 ,采用免疫组织化学方法观察假手术组和缺血再灌注后 3h、6h、12h、2 4hXRCC1蛋白表达 ,采用TUNEL方法检测DNA片段化损伤。结果　免疫组织化学染色显示 ,假手术组大脑皮质和海马区出现大量XRCC1表达的阳性细胞 ,再灌注 3h缺血区皮质和海马CA1区XRCC1表达阳性细胞减少 ,即缺血区皮质和海马CA1区XRCC1灰度值升高 ,并一直持续到缺血再灌注 2 4h。缺血再灌注后 3h、6h、12h和 2 4h与假手术组相比差异有显著意义 (P <0 0 5 )。TUNEL染色显示 ,假手术组大脑皮质和海马CA1区未见阳性细胞 ,再灌注 2 4h缺血区皮质和海马CA1区可见较多阳性细胞。结论　脑缺血再灌注后XRCC1蛋白免疫活性下降和DNA修复机制的失败与DNA的片段化损伤及凋亡的发生有关。     

Effect of berberine against cerebral ischemia and reperfusion involving in the methylation of PPARγ promoter

Cerebral ischemia has higher incidence and causes irreversible damage to people. As a traditional drug for anti-inflammation, berberine (BBR) has recently been reported to have protective effect against cerebral ischemia. However, the mechanism has not been explored thoroughly. By employing in vivo and in vitro models for cerebral ischemia and reperfusion, we studied the mechanism of BBR against the ischemia-reperfusion. We found that BBR regulated the expression of peroxisome proliferator-activated receptor (PPARγ) in a specific way upon ischemia-reperfusion injury. BBR enhanced the PPARγ expression during cerebral ischemia-reperfusion. By inhibiting PPARγ activity uisng GW9662, a PPARγ inhibitor, we confirmed that BBR protected the mouse brain against the ischemia in a PPARγ-dependent mechanism. In addition, we found that BBR reduced the overall global methylation, declined the expressions of DNMT1 (DNA methyltransferases 1) and DNMT3a (DNA methyltransferases 3a) in the ischemia-reperfusion and reduced the methylation of PPARγ promoter region. Therefore, our data suggested that PPARγ was one of major targets of BBR, and such BBR-induced PPARγ expression during cerebral ischemia and reperfusion might be correlated to the reduced methylation of PPARγ promoter.     

Differential modulation of apoptosis-associated proteins by ethanol in rat cerebral cortex and cerebellum

Chronic ethanol treatment caused a differential modulation of apoptosis-associated proteins, cytochrome c release, concomitant with procaspase-9 and procaspase-3 activation leading to oligonucleosomal DNA fragmentation in rat cerebral cortex and cerebellum. Caspase-3 proform (32 kDa) showed decreased immunoreactivity in cortex and cerebellum, while the cleaved active fragment (17 kDa) increased significantly in cerebellum after ethanol treatment. Further, chronic ethanol treatment increased caspase-3 activity in cortex and to a higher extent in cerebellum, which was further confirmed by blocking experiments with caspase-3 specific inhibitor, N-acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO). We tested whether activated caspase-3 cleaves downstream substrates such as poly (ADP-ribose) polymerase-1 and protein kinase C-delta (PKC-δ). Western blots showed poly (ADP-ribose) polymerase-1 cleavage to its signature fragment of 85 kDa and decreased levels of PKC-δ in cerebral cortex and cerebellum after ethanol treatment, suggestive of caspase-3 activation. Elevated caspase-3 activity in cerebellum than cortex correlating with cytochrome c, caspase-9, active caspase-3 (p17), poly (ADP-ribose) polymerase-1 and PKC-δ data, suggests a mechanism by which ethanol might be exerting pro-apoptotic events in brain and how selective brain regions such as cerebellum are vulnerable to ethanol neurotoxicity in terms of cell death.     

脑分水岭梗死与脑血管狭窄类型相关性研究

目的针对脑分水岭梗死（CWI）与脑血管狭窄类型的相关性进行统计分析。方法对我院从2005年3月至2010年9月收治的128例脑分水岭梗死病患与同期收治的128例非脑分水岭梗死病患行头颅CT和核磁共振MRI检查,并应用头颅多普勒（TCD）检测颅内血管与脑血管造影DSA显示脑血管,统计分析影像结果。结果128例脑分水岭梗死病患与颈内动脉与脑内动脉狭窄有一定的相关性（P〈0．05）,其中大脑前动脉狭窄42例（32．8％）,大脑中动脉狭窄78例（60．9％）,大脑后动脉狭窄36例（28．1％）,大脑基底动脉狭窄49例（38．3％）,颈内动脉狭窄85例（66．4％）,差异有统计学意义（P〈0．05）。结论脑分水岭梗死与颈内动脉和脑内动脉狭窄有一定的相关性,其中,与颈内动脉和大脑中动脉狭窄关系密切,值得深入研究和讨论。     

心肺脑复苏临床分析

目的探讨心跳呼吸骤停的救治经验,提高心肺脑复苏成功率。方法对我院2008年1月~2009年12月住院病例中29例心跳呼吸骤停患者进行回顾性多因素分析。结果29例心跳呼吸骤停者中,初步复苏成功25例,心肺脑复苏成功7例,康复出院5例,仍在康复中2例。结论心肺脑复苏成功与CPR的及时正确,尽早的电除颤和气管插管,脑复苏的措施及患者原发病密切相关     

脑血管造影在脑血管病变中的应用价值

目的:分析脑血管病变在脑血管造影中的影像学表现特点,讨论脑血管造影显示的脑血管形态学改变在探讨脑血管病变的发病机制、预测临床表现及选择治疗方式中的应用价值.方法:回顾性分析2005年1月-2007年10月行脑血管造影检查并明确诊断为脑血管病变的病例140例,观察各种脑血管病变的造影表现,探讨病变血管的形态学特点与脑血管病变的发生、临床过程、治疗方式等的关系.结果:前交通动脉瘤组中,A1优势征26例(占68.42%),随机选取293例非前交通动脉瘤脑血管造影病例作为对照组.A1优势征11例,两组比较差异具有显著性(P<0.05).脑动静脉畸形组中单支引流静脉的出血率比3支或以上引流静脉明显升高,两组间差异有显著性(P<0.05),不同数量供血动脉组中出血率差异未见显著性(P>0.05).颈内动脉狭窄或闭塞组中前交通动脉或后交通动脉代偿在单、双侧病变中出现率的比较差异有显著性.结论:A1优势征是前交通动脉瘤发生的高危因素.脑动静脉畸形单支引流静脉的出血率明显高于多支引流静脉,供血动脉的数目则不是脑动静脉畸形出血的相关因素.单侧颈内动脉狭窄或闭塞患者经过前交通动脉或后交通动脉的侧支血流代偿,而双侧颈内动脉狭窄或闭塞患者主要是通过后交通动脉的侧支血流代偿.     

丹红注射液对实验性脑缺血大鼠脑毛细血管通透性及脑含水量的影响

目的 研究丹红注射液对大鼠脑缺血所致脑水肿的影响.方法 建立以颈总动脉结扎致大鼠不完全性脑缺血模型,通过伊文氏蓝法和重量法观察丹红注射液对脑毛细血管通透性、脑指数、脑含水量的影响.结果 丹红注射液预防给药可明显降低模型大鼠脑毛细血管通透性、脑含水量和脑指数,减轻脑水肿(P＜0.05).结论 丹红注射液对实验性大鼠脑缺血所致脑水肿有一定的预防作用.     

DNA Self-assembly for Nanomedicine

Self-assembling DNA nanostructures based on rationally designed DNA branch junction molecules has recently led to the construction of patterned supramolecular structures with increased complexities. An intrinsic value of DNA tiles and patterns lies in their utility as molecular pegboard for deterministic positioning of molecules or particles with accurate distance and architectural control. This review will discuss the state-of-art developments in self-assembled DNA nanostructural system. Biomedical aspects of information guided DNA nanostructures will also be summarized. We illustrate both the use of simple DNA artworks for sensing, computation, drug delivery and the application of more complex DNA architectures as scaffolds for the construction of protein and nanoparticle arrays.     

脑出血后迟发性脑水肿的危险因素分析

目的 分析脑出血后迟发性脑水肿的危险因素,为临床自发性脑出血(sICH)患者的治疗提供依据.方法 收集急性sICH患者120例,根据是否出现迟发性脑血肿分为迟发性脑水肿组45例和无迟发性脑水肿组75例.对两者的临床资料进行单因素分析和Logistic多因素回归分析.结果 迟发性水肿组年龄明显低于无迟发性脑水肿组,吸烟史比例、人院血糖、入院时血肿体积、入院NIHSS及纤维蛋白原、MMP-9明显高于无迟发性脑水肿组(P＜0.05).患者人院时血肿体积、人院血糖、纤维蛋白原、MMP-9和入院NIHSS为脑出血后迟发性脑水肿的独立危险因素(P＜0.05).结论 对初发sICH患者,其人院血糖水平、纤维蛋白原、MMP-9、脑血肿体积和NIHSS评分是其发生迟发性脑血肿的独立危险因素,因此密切监测这些危险因素,若出现异常及时针对性处理,可减少迟发性脑水肿的发生风险,改善患者预后.     

Bacterial DNA replication enzymes as targets for antibacterial drug discovery

Introduction: The bacterial replisome is composed of a large number of enzymes, which work in exquisite coordination to accomplish chromosomal replication. Effective inhibition inside the bacterial cell of any of the ‘essential’ enzymes of the DNA replication pathway should be detrimental to cell survival.

Areas covered: This review covers DNA replication enzymes that have been shown to have a potential for delivering antibacterial compounds or drug candidates including: type II topoisomerases, a clinically validated target family, and DNA ligase, which has yielded inhibitors with in vivo efficacy. A few of the ‘replisome’ enzymes that are structurally and functionally well characterized and have been subjects of antibacterial discovery efforts are also discussed.

Expert opinion: Identification of several essential genes in the bacterial replication pathway raised hopes that targeting these gene products would lead to novel antibacterials. However, none of these novel, single gene targets have delivered antibacterial drug candidates into clinical trials. This lack of productivity may be due to the target properties and inhibitor identification approaches employed. For DNA primase, DNA helicase and other replisome targets, with the exception of DNA ligase, the exploitation of structure for lead generation has not been tested to the same extent that it has for DNA gyrase. Utilization of structural information should be considered to augment HTS efforts and initiate fragment-based lead generation. The complex protein–protein interactions involved in regulation of replication may explain why biochemical approaches have been less productive for some replisome targets than more independently functioning targets such as DNA ligase or DNA gyrase.     

Effect of obzidan on cerebral blood flow in acute cerebral ischemia

The effect of obsidan on the local cerebral circulation was studied in cats with normal brain circulation and under acute cerebral ischemia. It was demonstrated that obsidan (0.2 mg/kg) increased local cerebral circulation, while on being given in a dose of 1 mg/kg it lowered it in cats with normal brain circulation. In animals with stroke (both on the side with normal circulation and on the side of cerebral ischemia) obsidan (0.2 mg/kg) significantly decreased the local cerebral circulation and destroyed autoregulation of the brain circulation.     

乙型肝炎后肝硬化患者肝组织中HBcAg、HBV DNA表达及基因芯片检测

目的 用免疫组织化学法、原位分子杂交法、肝炎基因诊断芯片检测99例乙型肝炎后肝硬化患者的肝组织，观察HBcAg和HBV DNA在肝组织中的表达，比较各种方法优缺点。方法 将PCR扩增的HBV DNA探针用点样仪点于玻片介质上，处理后制成基因芯片，收集肝炎后肝硬化组织标本99份，分别用原位分子杂交法，基因芯片检测HBV DNA，免疫组织化学法检测HBcAg。结果 HBcAg阳性67例（67．7％），原位分子杂交HBV DNA阳性53例（53．5％），基因芯片检测阳性46例（46．5％）。32例三种方法检测HBcAg及HBV DNA均阴性。HBcAg颗粒和HBV DNA颗粒在肝组织中呈浆膜型高表达分布，其肝组织病变是活动的。结论 乙型肝炎后肝硬化患者肝组织中有较高的HBV复制率，HBcAg及HBV DNA高表达与肝组织病变活动有关，基因芯片对肝组织中HBVDNA检出率与原位分子杂交结果无显著差异，P＞0．05。     

一种适用于聚合酶链反应的常见念珠菌基因组DNA提取方法的研究

目的介绍一种简单、快速的真菌DNA提取方法,提高真菌DNA提取效率,减少毒性和污染性,以适应临床研究需要。方法同时用溶细胞酶结合Biospin真菌基因组DNA提取试剂盒和十六烷基三甲基溴化铵(CTAB)法,提取白色念珠菌、热带念珠菌、克柔念珠菌和净平滑念珠菌基因组DNA,用A260/A280的比值检测DNA的纯度并计算质量浓度,同时行聚合酶链反应(PCR)以评价其可靠性。结果溶细胞酶结合Biospin真菌基因组DNA提取试剂成功提取所用真菌基因组DNA,其纯度及质量浓度能满足PCR反应的要求。结论用溶细胞酶结合Biospin真菌基因组DNA提取试剂提取DNA,简单、快速、高效,可用于PCR反应。     

硫代磷酸反义寡核苷酸对裸鼠原位移植人胃癌生长和肝转移的影响研究

目的:探讨作用于端粒酶催化亚基的硫代磷酸反义寡核苷酸(ASODN)对裸鼠人胃癌生长和肝转移的影响,为治疗胃癌肝转移提供依据。方法:建立裸鼠人胃癌原位移植肝脏高转移模型,传15代后分别用生理盐水,5-氟尿嘧啶(5-Fu)、ASODN单用及合用进行干预,之后检测各组肿瘤生长及免疫组化指标。结果:与生理盐水组比较,5-Fu、ASODN单药组和合用组原位肿瘤重量明显降低,体积明显缩小,肝转移率、增殖细胞核心抗原及端粒酶阳性率均降低,尤以合用组作用更明显,3组抑瘤率分别为37.52%、58.76%、98.51%。结论:ASODN可抑制裸鼠原发胃癌的生长及肝转移,尤其与5-Fu合用能明显增强其效果。     

钩端螺旋体疫苗研究进展

由致病性钩端螺旋体感染引起的钩端螺旋体病是在全球广泛分布的威胁人类健康和畜牧业生产的常见人畜共患病.防治钩端螺旋体病的最好方法是安全、有效的疫苗.本文对钩端螺旋体灭活疫苗、外膜疫苗、脂多糖疫苗、重组蛋白疫苗和核酸疫苗的研究和应用进行了总结,并介绍了新的疫苗研发思路.     

DNA疫苗佐剂的研究进展

DNA疫苗是一种很有希望的免疫方法,经多途径接种质粒DNA能引起有效的免疫应答,重复给予不会产生抗载体免疫.然而,质粒DNA疫苗在小型实验动物中诱导的免疫应答远强于在人类和其他非人灵长类动物中.已设计多种佐剂通过直接刺激免疫系统或增强DNA表达来提高疫苗的免疫原性,这些佐剂包括免疫协同刺激分子、细胞因子、补体分子、脂质体、核酸、聚合物、纳米粒和微粒类佐剂.此文对DNA疫苗佐剂的研究进展作一综述.     

肺癌原代培养细胞中WWOX第6～8外显子缺失及点突变的研究

目的:探讨肺癌原代培养细胞中的抑癌基因WWOX第6～8外显子的缺失及点突变情况及其与临床病理指标的关系.方法:收集肺癌手术后的肿瘤组织进行原代细胞培养,提取肺癌原代细胞及癌旁正常组织中的RNA;采用RT-PCR和DNA测序方法研究WWOX基因6～8外显子的缺失及点突变情况.结果:20例癌旁正常肺组织及肺癌原代培养细胞中分别检出1例及14例外显子转录本缺失,差别有统计学意义(P<0.01);20例肺癌原代培养细胞标本经测序证实WWOX基因6～8外显子均未发现点突变;WWOX基因6～8外显子缺失率与吸烟、肿瘤组织类型明显相关(P<0.05),但与肿瘤临床分期无关(P>0.05).结论:因WWOX基因第6～8外显子在肺癌的发生发展中具有重要作用,也是肺癌患者吸烟致癌的重要分子标志;点突变不是WWOX基因第6～8外显子失活的主要方式.     

药物小分子与DNA相互作用分析方法概述

DNA是生命活动中最基本的遗传物质,是基因表达和遗传变异的物质基础。DNA由平行堆积的碱基,聚合的阴离子磷酸骨架以及两条由核苷酸链形成的大沟、小沟共同组成了药物分子和蛋白质相互识别的位点。药物小分子与DNA相互作用的方式主要有三种：非共价结合、共价结合和剪切作用。非共价结合又以3种不同的方式进行：     

河北地区糖尿病患者线粒体tRNAleu(UUR)基因A3243G突变的研究

目的 探讨线粒体tRNA^leu(UUR)基因nt3243A→G突变糖尿病(MDM)在河北地区汉族人种的发生率。方法 应用聚合酶链反应/Apa I酶解法检测332例糖尿病(MD)患者的线粒体tRNA^leu(UUR)基因nt3243A→G。结果 332例中5例有此基因突变，这些患者的共同特点是：起病早、消瘦，磺脲类药物继发失效，多伴耳聋。结论 河北地区糖尿病患者线粒体基因tRNA^leu(UUR)A3243G突变率约为1．5％。