Investigation on apoptosis of neuronal cells induced by Amyloid beta-Protein

Objective: To construct a PC12 cell strain with neuronal differentiation, and observe the apoptosis and pro-liferation activity effects induced these cells by Amyloid beta-Protein (Aβ3-43). Methods: 1) PC12 cells in logarithmic growth phase were subcultured for 24 h. After the culture fluid was changed, the cells were treated with Rat-β-NGF and cultured for 9 days. 2) Neuronal differentiation of PC 12 cells in logarithmic growth phase were divided into four groups:control group (0), experimental group (1), experimental group (2) and experimental group (3). The concentrations of Aβ in the four groups were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μmol/L, respectively. The cells were harvested at 24, 48 and 72 h later and stained with AnnexinV-FITC/PI after centrifugation and washing. Then flow cytometry was conducted to examine the apoptosis percentage. 3) NGF-induced PC12 cells were selected and Aβ with different concentrations was added. The final concentrations of Aβ were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μmol/L, respectively. After the cells were incubated in an atmosphere of 5% CO2 at 37 ℃ in an incubator for 72 h, the OD values were examined. Results: 1)Neuronal differentiated PC12 cell lines were successfully established. 2) Flow cytometric examination indicated that Aβ(1.25, 2.5, and 5.0 μmol/L) could effectively induce apoptosis of neuronal-differented cells at the 24 h, 48 h and 72 h time points. 3) Aβ (0-5.00 μmol/L) had no obvious effect on proliferation or restraining of the neuronal differentiation of the PC 12 cells after a 72 h interacting process. Conclusion: This investigation revealed successful neuronal differentiation of the PC12 cell strain. The induction of apoptosis of the neurocytes by various concentrations of Aβ was observed and the in-fluence of Aβ on induced proliferation of PC 12 cells by Rat-β-NGF was revealed. This study may provide basis for future research on the molecular cure of AD and interdiction of AD evolution.     

贵州2种负蝗核型和C—带的比较研究

研究了短额负蝗AtractomorphasinensisI .Bol.和云南负蝗AtractomorphayunnanensisBietXia的核型和C—带。结果表明 :2种负蝗的染色体数目均为 2n(♂ ) =18+XO =19,全部为端部着丝粒染色体 :核型公式 2n(♂ ) =2X =19t ,NF =19,都属“4B”核型 ,按相对长度 ,它们的染色体都可分成L ,M 2组 ,都具有着丝粒C带。云南负蝗后期Ⅰ染色体组绝对长度总和 (4 9 91± 0 37μm)比短额负蝗的 (4 2 5 0± 0 34 μm)长 ;但结构异染色质总量 (2 8 38± 0 2 2 % )却比短额负蝗的 (38 96± 0 16 % )少。     

新时代下的老年痴呆病

阿尔兹海默病(Alzheimer's)是一种已知几乎一个世纪的脑遇行性病变,最常见于老年人,以记忆和其它高级思维活动的严重障碍为特征,称之为老年痴呆。此病的原因和治疗尚不清楚。有两种因素使得老年痴呆病成为热门主题,一是此病患者在西方世界所占比重正在增加,其中3/4在英国和美国,目前已进入60岁。到本世纪末,随着出生率的下降,人口中老年人所占的比例将上升到20%,其中至少1/20将患老年痴呆病。因素之二是出现了遗传和分子生物学技术。     

从自谦词看英汉礼貌差异

英语和汉语都大量使用称谓语,但汉语中所使用的自谦词语的数要大大高于英语,并造成跨文化交际中的不可避免的欠额翻译现象,从而反映出两种语言系统的称谓语的礼貌使用上存在显著差异。本文就此作了分析。     

中频电源中晶闸管故障分析

晶闸管是晶闸管中频电源的关键部件，本文首先分析了品闸管中频电源的工作原理，然后分析了晶闸管中频电源中晶闸管故障的原因，最后提出了一些保护措施。     

随机利率下全连续式增额寿险模型的责任准备金

以即时给付的一类增额寿险为研究对象，对利率的随机性采用反射布朗运动建模，在保证利率恒正的情况下，给出连续缴费模式下时刻s时责任准备金的一般表达式。     

绿茶多酚对拟痴呆模型小鼠学习记忆活动和AchE活性的影响

目的建立D-半乳糖与Aβ25～35诱导的拟痴呆(Alzheimer's diaease,AD)模型小鼠,观察绿茶多酚对其学习记忆活动和AchE活性的影响.方法皮下注射D-半乳糖(120 mg/kg,连续给药12周),并在第7周时,侧脑室注射Aβ25～35(4 nmol/L),建立AD模型小鼠.利用跳台法和水迷宫方法评价绿茶多酚对AD模型小鼠学习记忆障碍的改善作用;并测定血液和脑组织中AchE的活性.结果绿茶多酚明显延长模型小鼠跳台潜伏期,减少跳台错误次数;缩短游出迷宫时间和减少进入盲端的错误次数,而对脑组织和血浆AchE活性无明显影响.结论绿茶多酚对D-半乳糖与Aβ25～35诱导的AD模型小鼠学习记忆障碍具有改善作用,其作用可能与脑内AchE活性无关.