逍遥散对抑郁模型大鼠海马中枢神经递质含量及BDNF和TrkB表达的影响

目的 探讨逍遥散对抑郁模型大鼠海马中神经递质(5-HT、NE、DA)的含量及海马脑源性神经营养因子(BDNF)和其受体型酪氨酸蛋白激酶B(TrkB)表达的影响,揭示逍遥散抗抑郁的机制.方法 将SD雄性大鼠50只随机分为正常组,模型组,盐酸氟西汀组(3 mg/kg),逍遥散高、低剂量组(14、7 g/kg).除正常组外,对其余各组大鼠进行56 d的孤养加慢性应激刺激,第29天起灌胃给药,连续给药28 d,给药结束后解剖大鼠取海马.采用放免法测定大鼠海马中神经递质5-HT、DA、NE的含量变化;采用免疫组化法检测海马中BDNF和TrkB阳性神经元面密度值的变化.结果 与正常组相比,模型组大鼠海马中5-HT、DA、NE的含量显著下降,BDNF和TrkB阳性神经元面密度值显著减小(P＜0.01),与模型组相比,逍遥散高、低剂量可以显著增加海马中5-HT、DA、NE的含量,明显提高BDNF和TrkB阳性神经元面密度值(P＜0.05或P＜0.01).结论 逍遥散可明显改善抑郁模型大鼠的抑郁状态,其机制与其可增加相关神经递质的含量,增强BDNF和TrkB表达有关.     

强迫游泳大鼠海马组织5-羟色胺受体mRNA的表达

目的探讨强迫游泳大鼠海马组织中5-羟色胺（5-HT1A）受体激活物抑制因子-1（1mRNA）的表达。方法随机将雄性Wistar大鼠分为对照组、1d应激组、14d应激组和28d应激组,建立强迫游泳应激模型。用化学发光法测定血清皮质醇浓度,用逆转录聚合酶链式反应（RT-PCR）方法检测海马5-HT1A受体mRNA的变化。结果（1）对照组、1d应激组、14d应激组和28d应激组血清皮质醇浓度分别为（0．64±0．09）μg／dL、（1．14±0．19）μg／dL（1．98±0．40）μg／dL、（0．95±0．14）μg／dL。（2）强迫游泳大鼠海马5HT1A受体mRNA表达相对水平分剐为1．501±0．257、1．141±0．120、0．681±0．056,与对照组相比较,差异具有统计学意义（P〈0．05）。结论强迫游泳大鼠海马中5-HT1A受体mRNA表达降低。     

大肠杆菌表面CS3菌毛展示随机肽库的构建

目的:在肠毒素性大肠杆菌CS3菌毛表面构建 10肽随机肽库．方法:首先将原有的单酶切CS3菌毛呈现载体改造为双酶切载体,并证实改造后的载体能正确形成CS3菌毛．同时设计合成2条寡核苷酸序列,链1含有1个10肽随机编码序列(NNS)10, 链2可与链1的3′端互补．两条链经过退火、延伸、酶切和回收与经过同样酶切的呈现载体连接,连接产物纯化后分多次电击转化,获得随机肽库．随机挑选10个克隆进行测序并对测序结果进行分析．结果:获得1个库容量为1．8×106大小的随机肽库．测序结果显示,所构建肽库的基本框架与预期设计相符,4个寡核苷酸出现的频率也与理论值相接近．结论:在肠毒素性大肠杆菌CS3菌毛表面成功构建库容量为1．8×106大小的10肽随机肽库．为下一步利用肽库进行筛选奠定了基础．     

动物源性粪肠球菌Ebp菌毛亚单位蛋白多抗的制备及其对生物被膜形成的影响

目的 研究制备动物源粪肠球菌Ebp菌毛亚单位蛋白多克隆抗体及其可能的免疫学作用。方法 运用生物信息学软件对粪肠球菌菌毛EbpA、EbpB和EbpC蛋白的抗原表位进行预测,发现6个抗原表位,将其构建重组质粒,表达、纯化,免疫新西兰大白兔后获得了6个菌毛亚单位多克隆抗体,再进行抗体特异性和生物膜阻断分析。结果 6个菌毛亚单位重组蛋白与预测的分子量相符,均对新西兰大白兔具有免疫原性,EbpA1、EbpA2、EbpA3、EbpB1、EbpC1和EbpC2亚单位蛋白多克隆抗体效价经双向免疫琼脂扩散实验检测分别达到1∶16、1∶8、1∶32、1∶32、1∶64和1∶64。经WB检测和生物膜阻断试验,6个多克隆抗体均具有抗原特异性和野生菌株生物膜阻断作用,而且以EbpA1、EbpC1和EbpA3的生物膜阻断作用最强。结论 粪肠球菌EbpA1、EbpC1和 EbpA3亚单位蛋白可能为粪肠球菌免疫预防和治疗奠定基础。     

口腔细菌黏附机制的研究进展

口腔细菌黏附的机制是口腔微生物学和生态学的研究热点之一,近年来,随着分子生物研究水平的提高,口腔细菌黏附机制的研究在分子水平上有了较大的进展.细菌表面的黏附蛋白和受体以及菌毛和胞外多糖都参与细菌间的共聚及细菌对牙表面的黏附.材料表面的获得性薄膜、粗糙度、表面电荷和疏水性等特性也能影响细菌的定植和黏附.本文就细菌和材料两个方面对口腔细菌黏附的机制及控制细菌黏附的方法作一综述.     

Evidence for reduced dentate gyrus and fimbria volume in bipolar II disorder

Objectives: Dentate gyrus (DG)‐dependent inhibition of the stress response might play an important role in mood disorders. During stress, hippocampal projections traversing the fimbria, a white matter bundle on the hippocampal surface, inhibit the hypothalamic–pituitary–adrenal (HPA) axis. The aim of the present study was to measure the volumes of the DG–cornu ammonis 4 (DG–CA4) and fimbria in patients with bipolar II disorder (BD‐II) and healthy controls using a recently developed magnetic resonance imaging (MRI)‐based technique. Methods: Thirty‐seven individuals with a DSM‐IV diagnosis of BD‐II and 42 healthy controls underwent 3‐Tesla MRI. Hippocampal subfield volumes were estimated using a novel segmentation algorithm implemented in FreeSurfer. Results: In patients with BD‐II there was a significant reduction in the volume of the left [analysis of covariance (ANCOVA), F = 7.84, p = 0.006] and total (left + right) (F = 4.01, p = 0.047) DG–CA4 and left (F = 4.38, p = 0.040) and total (F = 4.15, p = 0.045) fimbria compared to healthy controls. Explorative analyses indicated a smaller left CA2–3 volume in subjects with BD‐II compared to healthy controls, and a reduced left fimbria volume in unmedicated patients compared to medicated patients and controls. Conclusions: Our results provide evidence for the involvement of the DG and fimbria in BD‐II. Longitudinal studies of the DG and fimbria with assessments of the HPA axis in BD‐II are warranted.     

骨髓基质细胞对缺血／再灌注损伤海马片的保护作用

目的:探讨骨髓基质细胞对缺血/再灌注海马片的保护作用。方法:缺血/再灌注的大鼠海马片与骨髓基质细胞联合培养。观察海马片细胞死亡及细胞超微结构变化。结果:海马片细胞死亡及超微结构破坏以单纯缺血组最明显,条件培养液组次之,联合培养组最轻。结论:骨髓基质细胞可能通过分泌可溶性营养分子发挥对缺血/再灌注海马片的保护作用;两者的联合培养使骨髓基质细胞对损伤海马片的保护作用显著增强。     

人、鼠神经干细胞的生物特性比较

目的:比较分析体外人及小鼠神经干细胞原代培养的生长特性。方法:用无血清培养与单细胞克隆技术对人及鼠胚胎脑组织进行分离、培养。借用光镜、免疫组织化学对其鉴定,应用透射电镜对不同生长时期神经干细胞生物学特性进行观察。结果:人和鼠胚胎分离的细胞具有连续分化及克隆能力,克隆球与早期的原始细胞神经上皮干细胞蛋白(nestin)抗原呈阳性。诱导后成熟分化的细胞胶质纤维酸性蛋白(GFAP)及神经丝-200(NF-200)抗原呈阳性。小鼠神经干细胞电镜结果:1周时,细胞发育较为原始,核大胞质少,细胞器不发达,未观察到细胞突起及神经元与星形胶质细胞具备的特征。培养2周后,其电镜结果与1周结果无明显区别。继续培养到4周,见大部分细胞内出现空泡样变性,部分细胞表现出神经元及星形胶质细胞的一些特征。另外在克隆求内观察到类似细胞连接样结构。而人神经干细胞特性与小鼠神经干细胞相似,空泡样变性比小鼠神经干细胞更为明显。人与鼠神经干细胞经诱导分化10d后,见到典型的神经元及星形胶质细胞特征。结论:人及鼠神经干细胞具有很强的增殖能力,生物特性相似。     

Habituation of the acoustic startle response following lesion of the medial septal nucleus

Adult male rats were subjected to one of three surgical procedures: total lesions of the medial septal nuclei (TMS), partial lesions of the medial septal nuclei (PMS), and lesions of the dorsal fimbria (FM), as an attempt to determine the role of the septo-hippocampal relationship in habituation of the acoustic startle response. The initial startle amplitude of the TMS group was approximately three times that of the other groups, but rapidly decreased to the level of the other experimental groups and thereafter habituated at similar slow rates. Unlike animals with hippocampal lesions, all animals with hippocampal afferent damage displayed overdays savings of habituation. Following nine days without startle stimulation, startle amplitudes of the TMS groups had returned to their initial level while the PMS, FM and Control groups exhibited nonsignificant recovery. Differences in rates of habituation and amplitude of startle responses were attributed to loss of hippocampal input, and increased hippocampal output over intact pathways, respectively.