大鼠实验性牙齿移动诱导中枢立即早期基因c-fos和c-jun的表达与调节

立即早期基因(ｉｍｍｅｄｉａｔｅｅａｒｌｙｇｅｎｅ,ＩＥＧ)ｃｆｏｓ与ｃｊｕｎ在中枢神经系统内的表达与伤害性感或痛觉调制有关。激在数十分钟内作出反应。正畸牙齿移动使患者产生不适或疼痛,这种刺激能否诱导三叉神经脊束核尾侧亚核(Ｖｃ)内ｃｆｏｓ与ｃｊｕｎ的表达,尚未见文献报道。本项实验利用免疫组化技术观察了牙齿移动过程中立即早期基因在中枢的表达及吗啡对其的调节作用。一、材料和方法动物分为实验组和对照组。实验组包括ｃｆｏｓ组、ｃｊｕｎ组和吗啡处理组。矫治器的安装和施力按以往的研究方法进行[1]。动物存活2ｈ后进…     

Dlx1基因在大鼠外胚间充质细胞中表达的研究

目的 探讨Dlxl基因在牙胚发育过程中的调控作用。方法 采用外胚间充质细胞组织块培养法；地高辛标记cDNA原位杂交检测方法和斑点杂交方法，观察Dlxl基因在大鼠外胚间充质细胞，人牙乳头细胞，人牙髓细胞中的表达情况。结果 Dlxl基因在外胚间充质细胞和人牙乳头细胞中mRNA呈强阳性表达，而在牙髓细胞中弱表达。结论 Dlxl基因是牙胚发育过程中重要的调节因子，这种调控作用具有一定的时间性与空间性，它可能主要参与调控早期未分化细胞，而对终末分化细胞作用不显著。     

不同年龄组大鼠正畸力作用下龈沟液中基质金属蛋白酶的表达

目的:观察2个年龄组大鼠牙受正畸力后龈沟液中基质金属蛋白酶-1(matrix metalloproteinase-1,MMP-1)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)含量的变化.方法:选择6周龄和12周龄雌性Wistar大鼠各20只,采用粘结剂联合磨沟周位法在上颌安装正畸加力装置,牵引一侧上颌第一磨牙向近中,另一侧作为对照侧.每周提取大鼠实验牙及对照牙的龈沟液,应用SDS-PAGE、Western印迹和Gel-Doc凝胶成像系统定量检测龈沟液中MMP-1与MMP-9含量的改变.采用SPSS11.0软件包对实验各周龈沟液中MMP-1和MMP-9的含量进行方差分析.结果:6周龄组大鼠和12周龄组大鼠龈沟液中MMP-1及MMP-9含量的基础水平以及在加力第1周时的水平无统计学差异(P＞0.05).但12周龄组比6周龄组稍高.加力早期,12周龄组大鼠MMPs含量增长速度快于6周龄组;后期,12周龄组大鼠较6周龄组大鼠的MMPs含量下降速度慢.结论:12周龄大鼠受正畸力后,龈沟液中MMPs的表达较6周龄组高,12周龄大鼠较6周龄大鼠的正畸牙根吸收可能更严重.     

苯妥英钠和盐酸米诺环素复合膜对大鼠牙周骨再生过程中骨形成蛋白-2表达的影响

目的:观察苯妥英钠和盐酸米诺环素复合膜对实验性大鼠牙周骨开窗缺损再生过程中骨形成情况及BMP-2表达水平的影响.方法:制备含有苯妥英钠和盐酸米诺环素的胶原膜和不含药物的空白膜,分别置于30只Wistar大鼠磨牙区牙周骨开窗缺损内,每组15只.分别于术后10 d(n=7)和21 d(n=8)处死大鼠,取术区组织. HE染色镜下观察缺损区内新生骨样组织形成情况;用免疫组化法检测术后10 d和21 d缺损区内BMP-2的表达情况,比较各组BMP-2平均积分光密度值.结果:术后10 d时,实验组缺损区内被大量成纤维细胞、炎症细胞等占据,多数细胞BMP-2表达呈强阳性,对照组缺损区内细胞量较少,BMP-2表达较弱,二者有显著的统计学差异;术后21 d,实验组内见大量片状成骨,BMP-2表达强度较10 d时减弱,对照组缺损内有少量散在成骨,BMP-2表达较10 d时增强,但二者BMP-2表达不存在显著性差异.结论:苯妥英钠和盐酸米诺环素复合膜可能增强大鼠牙周骨组织再生过程中局部缺损区内BMP-2的表达.     

Immune responses to trichloroethylene and skin gene expression profiles in Sprague Dawley rats

Objective To characterize the immune reaction in SD rats exposed to trichloroethylene （TCE） and to identify the gene expression profiles involved in skin after TCE exposure. Methods Fifteen percent of TCE was injected intradermally into the rat back （100 μL/120 g） at intervals of 7 days. Whole blood was collected 24 h after the fifth or seventh intradermic administration of TCE. The percentages of CD4＋ and CD8＋ of T lymphocytes were measured by a flow cytometer. The concentrations of IFN-gamma and 1L-4 in the serum were semi-quantified by ELISA. Total RNAs of skin samples at 3 h or 24 h after the seventh dose of TCE in SD rats were extracted, and gene expression proftles of these tissues were analyszed by rat toxicology U34 array of Affymetrix. Results Obvious decline of CD4＋ in T lymphocytes was observed in the TCE-administer group. No significant concentration differences in IFN-gamma and IL-4 were found between TCE-treated and control rats. Gadd45a and Mel were significantly up regulated in skin tissue 24 h after TCE exposure. The expression regulation of immune response factors was as active as proteins associated with lipid metabolism and synthesis process in these skin samples of SD rats exposed to TCE. Conclusion T-helper type 1 cells mediate immune response can not be elicited in TCE-treated SD rats, but certain immune disorder can be induced.     

马西替坦联合维利西呱治疗缺氧性肺高压大鼠的作用机制

背景 缺氧性肺高压是一种由慢性缺氧引起的以平均肺动脉压增高为特征的慢性进展性疾病,限制右心室功能,具有严重危害.目的 探讨马西替坦(Macitentan)联合维利西呱(Vericiguat)治疗缺氧性肺高压大鼠的协同作用及机制.方法 将60只雄性SD大鼠随机分为5组:空白组、模型组、Macitentan组(Macitentan 10 mg/kg)、Vericiguat组(Vericiguat 10 mg/kg)、Maci&Veri组(Macitentan 10 mg/kg+Vericiguat 10 mg/kg),每组12只.空白组在非氧舱中饲养,其余各组大鼠在相同环境下10％氧浓度低氧舱中饲养2周,模拟5500 m高原环境.造模完成后,各组每日灌胃相应药物,空白组和模型组灌胃等量0.9％氯化钠注射液,连续2周.在第4周比较大鼠平均肺动脉压、右心肥厚比、右心功能指标,观察右心室、肺小血管病理学改变,检测肺动脉高压相关因子如超氧化物歧化酶(superoxide dismutase,SOD)、重组人骨形态发生蛋白2(bone morphogenetic protein 2,BMP2)、Rho卷曲蛋白激酶2(Rho-associated coiled-coil containing protein kinase 2,ROCK2)、过氧化物酶体增殖剂激活受体α(peroxisome proliferator activated receptor alpha,PPAR-α)、诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)等蛋白的表达.结果 与空白组比较,模型组平均肺动脉压力(mean pulmonary artery pressure,mPAP)、右心室肥厚指数(right ventricular hypertrophy index,RVHI)显著升高,右心室射血分数(right ventricular ejection fraction,RVEF)、右心室缩短率(right ventricular fractional shortening,RVFS)、肺血流加速时间/肺射血时间(pulmonary blood flow acceleration time/pulmonary ejection time,PAT/PET)显著降低(P均<0.01);肺小血管壁(WT％)增厚(P<0.05),SOD、BMP2、PPAR-α表达降低(P<0.05),iNOS、ROCK2表达升高(P<0.05);与模型组比较,联合用药组mPAP、RVHI显著降低,RVEF、RVFS、PAT/PET显著升高(P均<0.01),结果优于马西替坦和维利西呱单独给药组(P<0.05);WT％降低(P<0.01),明显低于马西替坦和维利西呱单独给药组(P<0.05);SOD、BMP2、iNOS、PPAR-α表达升高(P<0.05),ROCK2表达降低(P<0.05),且BMP2表达高于马西替坦和维利西呱单独给药组(P<0.05).结论 马西替坦-维利西呱联合用药对缺氧性肺高压大鼠具有协同保护作用,可降低肺高压、提高心功能、改善肺血管重构和心肌损伤,并改变肺高压相关因子的表达.     

丙戊酸的发现

1962年,法国由Meunier兄弟创立的小型制药企业La Laboratoire Berthier与法国Grenoble大学George Carraz教授合作,通过大鼠测试一系列化合物是否具有镇静催眠作用。2-丙基戊酸（即丙戊酸,1881年合成）在当时的实验中被作为有机溶剂。该项实验中的所有化合物均显示出明显的抗癫痫作用,Meunier兄弟注意到这个有机溶剂并决定做进一步测试,果然很快发现丙戊酸具有良好的抗癫痫作用。于是该实验室开始生产丙戊酸,并投入动物实验。     

Mash1 efficiently reprograms rat astrocytes into neurons简

To date, it remains poorly understood whether astrocytes can be easily reprogrammed into neurons. Mashl and Brn2 have been previously shown to cooperate to reprogram fibroblasts into neurons. In this study, we examined astrocytes from 2-month-old Sprague-Dawley rats, and found that Brn2 was expressed, but Mashl was not detectable. Thus, we hypothesized that Mashl alone could be used to reprogram astrocytes into neurons. We transfected a recombinant MSCV-MASH1 plasmid into astrocytes for 72 hours, and saw that all cells expressed Mashl. One week later, we observed the changes in morphology of astrocytes, which showed typical neuro- nal characteristics. Moreover, β-tubulin expression levels were significantly higher in astrocytes expressing Mashl than in control cells. These results indicate that Mashl alone can reprogram astrocytes into neurons.     

慢性不可预计温和应激大鼠microRNA差异表达谱分析

目的探讨慢性不可预计温和应激大鼠模型microRNA（miRNA）表达谱差异。方法采用慢性不可预计温和应激模型,将16只SD大鼠随机分为对照组和应激组,每组8只,对照组常规饲养,不予任何处理,应激组每天随机予1～2种温和刺激,共6周;造模结束后均采用旷场试验评价大鼠行为,安乐处死,取伏隔核低温保存。采用miRNA测序技术比较两组大鼠miRNA表达差异。结果与对照组比较,慢性不可预计温和应激大鼠有25个miRNA显著下调,2个miRNA显著上调。结论慢性不可预计温和应激可能使大鼠部分miRNA表达发生改变。