力生长因子及其E肽对成骨细胞分化的影响

力生长因子(mechano growth factor,MGF)是新近发现的一种生长因子,由Igf-1基因剪接变异产生,拉伸刺激会促使成骨细胞表达力生长因子.比较分析了MGF及其羧基端E肽(MGF-Ct24E)对成骨细胞前体细胞MC3T3-E1分化的影响.结果显示:MGF和MGF-Ct24E具有显著激活胞外信号调节激酶1/2(Erk1/2)的作用,并降低了成骨细胞碱性磷酸酶、Ⅰ型胶原的表达,促进了骨桥蛋白(OPN)的表达,减少了核心绑定因子(corebinding factor1,Cbfα-1)的核转运量,对成骨细胞的分化具有延迟效应,这种效应通过抑制剂PD98059抑制Erk1/2的活化得到逆转;MGF还能显著激活磷脂酰肌醇3-激酶信号通路中的蛋白激酶B(Akt),该活化作用对成骨细胞分化是必需的,钙沉积分析显示长期培养下的细胞MGF促进了矿化节结的形成.这些结果说明,MGF-Ct24E对成骨细胞的分化具有抑制作用,这种作用与Erk1/2的活化有关,MGF因为包含E肽和IGF-1部分,能分别激活Erk1/2和Akt,因此对成骨细胞分化表现出双重效用,在成骨细胞分化早期,具有一定的延迟效应,而在分化晚期对成骨...     

电喷雾萃取电离技术在蛋白质分析中的应用及展望

电喷雾萃取电离技术(extractive electrospray ionization,EESI)是一种能灵敏地电离固体、液体、气体、黏性样品等复杂基体中痕量大分子和小分子的新兴软电离技术．在简要介绍EESI原理的基础上,着重综述其在蛋白质分析中的应用．与商品化质谱仪器配置的电喷雾电离源(electrospray ionization,ESI)不同,EESI能够在常压条件下最大程度地保留蛋白质在样品中的原始构象,并获得大量具有生物活性的蛋白质离子．由此可见,EESI及类似的技术在蛋白质芯片制备、高分辨率氢/氘交换质谱(蛋白质结构分析)、蛋白质计量等方面具有良好的应用前景．本文也对其发展趋势进行了展望．     

唇腭裂矫形修复中的美学研究

本文介绍用双重牙列修复唇腭裂患者面中1/3缺陷,其特点是方法简便、效果明显和患者乐意接受。并提出评判唇腭裂患者的面容面貌改善不能单纯以正常美貌人群中面部指数为标准,而应在介于正常人与唇腭裂患者之间寻找一个能协调、柔和、均衡、匀称的面部指娄作为评判标准。     

Syntaxin蛋白对神经母瘤细胞分化的影响及机制研究

Syntaxin是特异性地分布在神经细胞突触前质膜上的一种多结构域蛋白,它是细胞质膜融合的关键性蛋白,但Syntaxin在神经细胞分化过程中的作用尚未阐明。本实验旨在探讨Syntaxin蛋白对神经母瘤细胞分化的影响及其影响机制。通过在小鼠的神经母瘤细胞（N2a）中过表达不同的Syntaxin蛋白突变体,统计细胞的分化率、突起分支数和突起总长度等参数,来观察Syntaxin蛋白及其突变体对神经细胞分化的影响。通过实验结果得知Syntaxin蛋白促进神经母瘤细胞分化的作用位点在其氨基端的Habc结构域,主要影响细胞的分化突起数目和突起总长度,对细胞分化率无显著作用。     

The effect of PEA on serotonin and catecholamines

Differences of behavior in rats have been noted when using d-amphetamine or β-phenylethylamine (PEA). Both these drugs can disaggregate polyribosomes. It would appear that amphetamine affects both behavior and polyribosomal disaggregation through the release and activity of dopamine, while PEA acts through serotonin and to a lesser degree through norepinephrine and dopamine.     

生物碱抗心律失常的作用及其分子机制

生物碱是广泛存在于生物体内尤其是天然植物中的碱性含氮有机化合物，部分生物碱具有抗心律失常、抗高血压、抗炎以及抗肿瘤等多种生理功能。心律失常是由心脏电生理活动紊乱引起的疾病，是心血管疾病高发病率和死亡率的主要原因，在世界范围内严重威胁人类生命健康。文中综述生物碱在抗心律失常中的作用和分子机制研究进展，并展望其开发应用前景。     

The effect of noise on learning and retention

Thirty one healthy adults (18 women and 13 men, aged 24 to 52 years) were studied in three experimental series. For testing the effect of noise on learning and retention--fixation of the learned--the partly modified method of the laboratory language was used. The experiments were performed in a quiet room at LAeq background noise to 40 dB. Basic microclimatic conditions were also observed. The subjects were tentatively and audiometrically examined. The noise load was a randomly variable noise of LAeq = 81-82 dB. The results of the study (a total of 64 individual tests) showed that the noise load had a negative effect on learning the laboratory language and retention--fixation of the learned.     

The impact of PACS on research and education

Picture Archiving and Communication Systems (PACS) are rapidly evolving and the total digital radiology department may be a reality within the next decade. PACS can have a major impact on the educational and research responsibilities of a medical institution. The possibility of correlating real patient data with existing radiological teaching files opens up numerous possibilities. Multi-institutional research can be strengthened by employing the PACS as the means to the end. This paper discusses the representative examples of how teaching and research can be enhanced with PACS and the technical requirements to achieve the inter-connectivity.     

The effects of feeding and fasting on self-stimulation

The effects of ad libitum feeding and 72 hr fasting on intracranial electrical self-stimulation behaviour (ICSS) were tested in cats. In contrast to previous studies it was found that the opposite manipulations in food intake, i.e. ad libitum feeding fasting, often induced identical changes in lever-pressing rate even in cases of lateral hypothalamic self-stimulation. Both increase and decrease in lever-pressing rate for ICSS could be observed depending rather on the electrically elicited behaviours than the precise anatomical location of the stimulating electrodes. It is concluded that changes in ICSS induced by food intake and food deprivation are probably secondary to the changes in activity level.     

"观察SO2对植物的影响"实验的改进

介绍了对人民教育出版社的高中生物学必修教材第2册103页,实验12“观察二氧化硫对植物的影响”的部分改进。利用洗净的金龙鱼牌5L塑料油瓶和洗净的空矿泉水瓶等废旧物资进行实验操作。材料易于寻找,成本低廉,培养了学生“变废为宝”的节约思想;用NaOH溶液吸收装置内的SO2,避免了环境污染,培养了学生的环保意识。     

终止子的概念与结构之辨析

指出一些生物化学,分子生物学及遗传学方面高等院校教材和著作中,较为普遍存在的关于转录终止子概念与结构的描述和解释方面的错误。