Bcl-2家族参与β-淀粉样蛋白对PC12细胞的致凋亡作用

目的:研究bcl-2家族(主要是bcl-xl和bax)基因及相关蛋白是否参与水溶性淀粉样蛋白对培养的大鼠嗜铬细胞瘤细胞的毒性作用.方法:应用电镜和DNA电泳判断细胞损伤途径,应用RT-PCR,免疫细胞化学和免疫印迹判断bcl-2家族及其相关蛋白是否参与淀粉样蛋白的损伤作用.结果:10 μmol/L Aβ25-35作用24 h后,电镜和DNA电泳均显示Aβ25-35可以导致PC12细胞凋亡;RT-PCR表明药物作用后6 h,bcl-xl mRNA表达量减少而bax mRNA表达量增加;免疫印迹和免疫细胞化学结果显示药物作用后24h,Bax蛋白增加而Bcl-xl无明显改变.结论:水溶性淀粉样蛋白可以导致神经细胞凋亡,bcl-2家族参与了作用环节,对阿尔茨海默病的发病起着重要的作用.     

Rac1表达调控对髓母细胞瘤Daoy细胞增殖与凋亡的影响

目的 探讨Rac1基因沉默对髓母细胞瘤Daoy细胞株细胞周期、凋亡的影响.方法 将Daoy细胞分为2组:Rac1-shRNA组和对照组,Rac1-shRNA组将Rac1-shRNA质粒转染Daoy细胞,对照组则转染空白质粒.分别用RT-PCR、Western blot及流式细胞仪检测2组Daoy细胞Rac1 mRNA、Rac1蛋白、细胞周期、细胞凋亡率的变化,并进行统计学比较.结果 Rac1 mRNA和Racl蛋白在髓母细胞瘤Daoy细胞株中均有高表达;Rac1基因沉默后Daoy细胞细胞周期受阻于G0～G1期,G0～G1期细胞所占比例明显增加(80.9%±4.9%),而S期所占细胞比例减少(11.8%±2.3%);Rac1-shRNA组Daoy细胞凋亡率为36.7%±3.9%,而对照组为8.5%±0.9%.2组比较差异均有统计学意义(P<0.05).结论 RNA干扰沉默Rac1基因可以抑制Daoy细胞增殖,促进细胞凋亡,Rac1可成为抑制髓母细胞瘤增殖并促进细胞凋亡新的靶点.     

Bcl-2家族参与β-淀粉样蛋白对PC12细胞的致凋亡作用

目的：研究bcl一2家族(主要是bcl-xl和bax)基因及相关蛋白是否参与水溶性淀粉样蛋白对培养的大鼠嗜铬细胞瘤细胞的毒性作用。方法：应用电镜和DNA电泳判断细胞损伤途径，应用RT-PCR，免疫细胞化学和免疫印迹判断bcl-2家族及其相关蛋白是否参与淀粉样蛋白的损伤作用。结果：10μmol／LAβ25-35作用24h后，电镜和DNA电泳均显示Aβ25-35可以导致PCI2细胞凋亡；RT-PCR表明药物作用后6h，bcl-xl mRNA表达量减少而bax mRNA表达量增加；免疫印迹和免疫细胞化学结果显示药物作用后24h，Bax蛋白增加而Bcl-xl无明显改变。结论：水溶性淀粉样蛋白可以导致神经细胞凋亡，bcl-2家族参与了作用环节，对阿尔茨海默病的发病起着重要的作用。     

EGCG对H2O2诱导BV2细胞氧化损伤保护作用机制的研究

目的探讨EGCG对H2O2诱导BV2细胞氧化损伤的保护作用机制。方法以200μmol/L H2O2制备BV2细胞氧化应激损伤模型,用CCK-8法检测不同浓度EGCG(0、1、5、10、20、40、80μmol/L)的保护作用,Ho-echst33258染色法检测细胞的凋亡,Western bloting法检测caspase-9蛋白的表达。结果 10及20μmol/L的EGCG组保护效果较明显;EGCG保护组的凋亡细胞显著少于无保护组;20μmol/L EGCG保护组的caspase-9蛋白表达较无保护组明显下调(P=0.03<0.05)。结论 10及20μmol/L浓度的EGCG对H2O2诱导的BV2细胞损伤模型有保护作用,其机制可能是通过减少caspase-9蛋白的表达,进而部分阻断caspase-9所介导的caspases级联反应,减少BV2细胞的凋亡。     

卡莫司汀对C6胶质瘤细胞凋亡作用机制的研究

目的研究卡莫司汀(BCNU)对胶质瘤凋亡的作用机制。方法取生长状态良好的C6胶质瘤细胞悬液,按1×107个细胞/25μl的密度接种于20只SD大鼠腹股沟区皮下,观察其生长情况。将16只成瘤大鼠随机等分为治疗组与非治疗组,前者按相同剂量隔日腹腔内注射BCNU。治疗2周后处死全部大鼠,取大鼠右侧腹股沟区皮下肿瘤行苏木精-伊红染色和免疫组织化学染色,检测胶质瘤的病理学特征及胶质纤维酸性蛋白(GFAP)、bax和bcl-2蛋白的表达情况,观察瘤细胞凋亡情况。结果C6胶质瘤细胞皮下接种4～5d后,大鼠腹股沟区皮下形成实体瘤;治疗2周,非治疗组和治疗组SD大鼠平均肿瘤质量差异有统计学意义(P<0.01),治疗组肿瘤抑制率为29.6%。肿瘤GFAP表达为阳性;BCNU治疗后bax基本无改变,bcl-2下调明显(P<0.01),bax/bcl-2比值明显增加。结论BCNU腹腔注射治疗大鼠神经胶质瘤导致胶质瘤细胞凋亡,其主要机制可能与下调凋亡蛋白bcl-2的表达和升高bax/bcl-2的比值有关。     

MicRNA-124可能通过PI3K/Akt通路调节缺血脑组织细胞凋亡

目的探讨脑缺血环境下对micRNA-124表达的影响。方法采用Western blot、荧光定量PCR技术检测脑缺血后缺血皮质区不同时间点bax、bcl-2、caspase-3、ROCK1、micRNA-124蛋白或基因的表达水平。结果缺血脑组织细胞micRNA-124基因表达量与调控细胞凋亡指标bax、bcl-2、caspase-3增高一致;bax、bcl-2、caspase-3、ROCK1活化片段蛋白表达量逐渐升高,在随后观察的时点内持续处于高表达状态(P0.01)。结论 micRNA-124可能参与缺氧致脑组织细胞凋亡的过程,其机制可能是通过PI3K/Akt通路,激活或抑制bax、bcl-2、caspase-3、ROCK1其中一个或是多个基因调节缺氧脑组织细胞凋亡。     

重组pIRES-AD7c-NTP质粒的构建表达及其对PC12细胞凋亡的影响

目的构建重组pIRES-AD7c-NTP质粒,探究其对PC12细胞凋亡的影响。方法构建pIRESAD7c-NTP重组质粒,通过脂质体体外转染至PC12细胞内,RT-PCR检测凋亡相关蛋白bcl-2和bax的mRNA表达变化含量变化。结果成功构建pIRES-AD7c-NTP重组质粒并转染至PC12细胞内;重组质粒转染组出现了明显的细胞凋亡,流式细胞仪检测出典型凋亡峰;重组质粒转染组中bcl-2表达低于对照组,bax表达高于对照组。结论 AD7c-NTP重组质粒转染组PC12细胞内bcl-2/bax表达异常,说明AD7c-NTP增加凋亡促进蛋白的表达、同时减少凋亡抑制蛋白的表达,可见AD7c-NTP可导致神经细胞发生凋亡,为后续研究提供实验基础。     

AKT2在胶质瘤细胞中替莫唑胺化疗耐药的作用机制研究

目的研究AKT2基因在U251细胞株中对替莫唑胺化疗耐药中的作用机制。方法体外将慢病毒介导的AKT2-shRNA表达载体转染胶质瘤U251细胞。应用细胞计数试剂盒(CCK8)法检测RNA干扰AKT2后U251细胞对替莫唑胺敏感性的变化情况。流式细胞仪测定沉默AKT2基因表达后各组细胞凋亡的改变情况。AKT2-shRNA干扰胶质母细胞瘤细胞株U251的AKT2表达,进而采用Western blot实验方法,来进一步分析和评价AKT2与MDR-1、MRP-1、MGMT、bcl-2、caspase-3、P53等相关蛋白表达情况和相互调控关系。结果 CCK8法检测结果计算替莫唑胺对U251细胞的半数细胞抑制浓度(IC50)从U251空白对照组的(39.72±2.41)μg/ml、阴性对照组的(39.43±2.24)μg/ml降到(27.23±1.93)μg/ml,AKT2干扰组U251细胞对替莫唑胺药物的IC50值显著降低。流式细胞仪检测凋亡实验显示,与空白对照的U251细胞[调亡细胞(16.95±1.32)%]和转染阴性对照的U251胶质瘤细胞[调亡细胞(17.93±2.29)%]相比,转染AKT2shRNA的U251细胞中早期、晚期调亡细胞明显增加,总调亡细胞达(38.16±4.83)%,干扰组凋亡水平有显著性增强(P0.05)。AKT2-shRNA干扰U251后其凋亡明显增加,Real-time PCR和蛋白印迹实验结果提示bcl-2、survivin、MGMT明显下调,而caspase-3、PTEN、P53、beclin-1明显上调。结论 AKT2可能参与调控bcl-2、caspase-3、P53、survivin、beclin1等凋亡自噬相关蛋白及DNA损伤修复蛋白MGMT的表达,从而介导胶质母细胞瘤细胞株U251对替莫唑胺化疗抵抗。     

F90对胶质母细胞瘤细胞的作用及机制研究

目的探讨表皮生长因子受体（EGFR）抑制剂F90对胶质母细胞瘤（GBM）细胞的抑制作用及其机制。方法采用MTT法检测F90对．GBM细胞的抑制作用，流式细胞术检测细胞凋亡和免疫印迹法（Western Blot）检测蛋白表达。结果F90能明显抑制U251和SHG-44细胞的生长，半数抑制浓度（IC50）分别为（5．8±113）和（5．1±1．2）μmol／L，且呈一定的剂量相关性。F90可以诱导U251细胞的凋亡，抑制U251细胞EGFR的磷酸化及其丝裂原活化的蛋白激酶（MAPK）通路下游信号的活化，下调Bcl-2蛋白的表达，上调P53蛋白的表达。结论F90能有效抑制某些GBM细胞在体外的生长，与Iressa作用强度相当，有可能成为一种新的治疗GBM的药物。     

花生四烯酰多巴胺对H2O2诱导SH-SY5Y细胞氧化应激损伤的保护作用

目的 探讨花生四烯酰多巴胺(N-arachidonoyl dopamine,NADA)对H₂O₂诱导的人神经母细胞瘤SH-SY5Y细胞氧化损伤的保护作用。方法 H₂O₂处理SH-SY5Y细胞制作细胞氧化损伤模型,通过CCK8法检测细胞活力,明确不同水平的NADA对细胞存活的影响,分析NADA对SH-SY5Y细胞的保护作用; 利用生化方法检测丙二醛(MDA)和乳酸脱氢酶(LDH)的水平; 运用DCFH-DA荧光探针检测细胞内氧自由基(ROS)水平; Hoechst33342/PI双染法检测NADA对细胞氧化损伤的保护作用; 蛋白免疫印迹实验检测抗凋亡蛋白bcl-2的表达水平。结果 H₂O₂处理SH-SY5Y细胞可导致细胞活力降低,增加MDA水平和LDH活力,促进ROS的产生,降低抗凋亡蛋白bcl-2的表达,加剧细胞凋亡。NADA可剂量依赖性提高H₂O₂诱导的SH-SY5Y细胞的存活率、降低MDA水平和LDH活力以及ROS的产生,促进抗凋亡蛋白bcl-2的表达,降低细胞凋亡。结论 NADA对H₂O₂诱导的细胞氧化损伤模型具有保护作用,其机制可能是通过抑制胞内氧化应激,促进抗凋亡蛋白bcl-2的表达,从而减少神经细胞凋亡。     

The effect of age of onset of PD on risk of dementia

Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005     

帕金森病运动症状进展分析

目的分析帕金森病(PD)患者运动症状进展特点。方法采用PD统一评分量表(UPDRS)Ⅲ对912例PD患者进行评估。结果与病程1年的患者比较,除病程1~2年的患者外,其他病程患者的UPDRSⅢ评分、强直分、姿势或步态异常分、轴性症状总分、言语分、步态分显著升高(均P0.05),病程5~6年及14年患者的震颤分,病程5~6年、7~8年、9~13年、14年患者的运动迟缓分、姿势分显著升高(P0.05~0.01)。轴性症状进展速度高于UPDRSⅢ评分。结论 PD患者病程早期UPDRSⅢ评分进展快,震颤症状进展独立于其他症状,轴性症状评分较UPDRSⅢ更敏感地反映疾病加重趋势。     

Frequency of accumulation of filaments in adaxonal cytoplasm of Schwann cells of myelinated fibers of rat spinal roots

Summary The frequency of accumulation of 6-nm filaments in the adaxonal cytoplasm of Schwann cells in the 6th lumbar dorsal and ventral roots was evaluated in 4-, 8-, 26- and 45-week-old Sprague-Dawley rats. The frequency was higher in 4- and 8-week-old (growing) rats than in 26- and 45-week old (mature) rats, and also higher in ventral than in dorsal roots in 4-, 8- and 26-week old rats. There were no clusters on certain groups of myelinated fibers according to the size of transverse axonal area, in both the ventral and dorsal roots. Therefore, this accumulation may reflect certain functions of the adaxonal cytoplasm of Schwann cell during natural growth and maturation of the axon and myelin sheath.     

他汀类药物的使用和颅内动脉瘤破裂相关性分析

目的 探讨他汀类药物对颅内动脉瘤破裂的影响。方法 2010年3月至2014年3月收治颅内囊状动脉瘤67例,其中破裂者32例,未破裂者35例。采用多变量Logistic回归评估他汀类药物的使用和颅内动脉瘤破裂的关系。结果 破裂组术前使用他汀类药物4例（12.5%,4/32）,未破裂组16例（45.7%,16/35）。破裂组服用他汀类药物的百分比显著低于未破裂组（P<0.01）。纠正潜在的混杂干扰后（or值: 0.30,95%可信空间:0.12~="" 0.64）显示,颅内动脉瘤破裂与他汀类药物的使用呈显著负相关,也与高血清总胆固醇浓度有关。结论 本结果提示他汀类药物对颅内动脉瘤破裂有一定的预防效果。     

Impact of our understanding of the genetic aetiology of epilepsy

A genetic contribution to aetiology is estimated to be present in up to 40% of patients with epilepsy. It is useful to categorise genetic epilepsies according to the mechanisms of inheritance into Mendelian disorders, non-mendelian or ‘complex’ disorders, and chromosomal disorders. Over 200 Mendelian diseases include epilepsy as part of the phenotype, and the genes for a number of these have been identified recently. These include autosomal recessive progressive myoclonic epilepsies such as Unverricht-Lundborg disease, Lafora disease and the neuronal ceroid lipofuscinoses, and three autosomal dominant idiopathic epilepsies. The last named have been shown to arise from mutations in ion channel genes. Autosomal dominant nocturnal frontal lobe epilepsy is caused by mutations in CHRNA4, benign familial neonatal convulsions by mutations in KCNQ2 and KCNQ3, and generalised epilepsy with febrile seizures plus by mutations in SCN1B. ‘Complex’, familial epilepsies are more difficult to analyse, but evidence has been obtained for loci predisposing to juvenile myoclonic epilepsy on chromosome 6p and 15q. Lastly, the genes underlying several spike-wave epilepsies in mice have been cloned, and three of these encode sub-units of voltage-gated calcium channels. Received: 29 September 1999/Accepted: 7 December 1999     

Function of circle of Willis

Nearly 400 years ago, Thomas Willis described the arterial ring at the base of the brain (the circle of Willis, CW) and recognized it as a compensatory system in the case of arterial occlusion. This theory is still accepted. We present several arguments that via negativa should discard the compensatory theory. (1) Current theory is anthropocentric; it ignores other species and their analog structures. (2) Arterial pathologies are diseases of old age, appearing after gene propagation. (3) According to the current theory, evolution has foresight. (4) Its commonness among animals indicates that it is probably a convergent evolutionary structure. (5) It was observed that communicating arteries are too small for effective blood flow, and (6) missing or hypoplastic in the majority of the population. We infer that CW, under physiologic conditions, serves as a passive pressure dissipating system; without considerable blood flow, pressure is transferred from the high to low pressure end, the latter being another arterial component of CW. Pressure gradient exists because pulse wave and blood flow arrive into the skull through different cerebral arteries asynchronously, due to arterial tree asymmetry. Therefore, CW and its communicating arteries protect cerebral artery and blood–brain barrier from hemodynamic stress.     

肌萎缩侧索硬化三例误诊分析

目的掌握肌萎缩侧索硬化(ALS)的诊断标准,以便早期准确诊断,避免误诊。方法分析3例ALS患者早期被误诊的临床资料。结果 3例患者均以下肢无力发病,逐渐波及上肢或对侧肢体,脊柱MR I示颈部或腰部椎间盘突出压迫硬膜囊,手术治疗后,症状无缓解,病情仍进行性加重,经肌电图检查证实为ALS。结论临床医师应熟知ALS的诊断标准,对患者详细询问病史、认真查体和电生理检查是减少ALS误诊的关键。     

Effects of prevention of afferentation of the development of the chick optic lobe

BONDY, S. C., M. E. HARRINGTON AND C. L. ANDERSON. Effects of prevention of afferentation on the developmentof the chick optic lobe. BRAIN RES. BULL. 3(5) 411–413, 1978.—The effects of unilateral extirpation of the right optic cup of the three-day incubated chick embryo upon the rate of synthesis and the stability of DNA in the non-innervated optic lobe, have been studied. This surgical procedure prevents innervation of the optic lobe contralateral to the removed eye, while the other optic lobe is normally innervated by retinal ganglion cells of the remaining eye. At the 20th day of incubation, the DNA content of the non-innervated lobe was below that of the paired lobe receiving normal innervation. This deficiency of cell number was caused by two events; death of an excess number of neurons formed early in embryogenesis and a reduced rate of glial proliferation in the later stages of incubation.     

腺垂体功能减退症临床特征变化分析

目的探讨腺垂体功能减退症患者的病因结构变化及临床表现。方法回顾性分析我院2013-01—2016-12住院及门诊78例腺垂体功能减退症患者的临床资料。结果男32例(41.03%),女46例(58.97%);诊断时年龄11~89岁,平均62.5岁;鞍区占位(包括术前及术后)52例(66.67%),席汉综合征8例(10.26%),空泡蝶鞍9例(11.65%),病因不明8例(10.26%),垂体-下丘脑发育不良1例(1.28%)。首次就诊科室:纳差厌食、恶心呕吐就诊于消化内科36例(46.15%)最常见。ACTH+TSH+Gn+G激素缺乏为19例最多,占24.36%,ACTH+TSH+Gn缺乏15例,占19.23%。结论腺垂体功能减退症病因结构发生变化,发病人群、首发症状及受累激素也不同,患者女性多于男性,发病年龄偏高,症状不典型,分布于临床多个科室,其中以低钠血症为首发临床表现就诊消化内科最多。     

Standards of instrumentation of EMG

Standardization of Electromyography (EMG) instrumentation is of particular importance to ensure high quality recordings. This consensus report on “Standards of Instrumentation of EMG” is an update and extension of the earlier IFCN Guidelines published in 1999. First, a panel of experts in different fields from different geographical distributions was invited to submit a section on their particular interest and expertise. Then, the merged document was circulated for comments and edits until a consensus emerged.The first sections in this document cover technical aspects such as instrumentation, EMG hardware and software including amplifiers and filters, digital signal analysis and instrumentation settings. Other sections cover the topics such as temporary storage, trigger and delay line, averaging, electrode types, stimulation techniques for optimal and standardised EMG examinations, and the artefacts electromyographers may face and safety rules they should follow. Finally, storage of data and databases, report generators and external communication are summarized.