新型尿素吸附剂的制备及其对血液中BUN吸附性能分析

首次采用海藻酸锌络合物配位吸附尿素分子,研究了这类络合物在不同条件下对尿素的吸附性能.结果表明海藻酸锌络合物对尿素的吸附主要是通过锌与尿素之间的配位作用进行的.在模拟人体生理介质的水溶液中对尿素的吸附率达74.65±4.71%,对血液中尿素的吸附率达65.25±4.33%.     

枸橼酸铁铵对原代培养的大鼠心肌细胞铜蓝蛋白、膜铁转运辅助蛋白和膜铁转运蛋白表达的影响

目的 观察枸橼酸铁铵(FAC)对原代培养的大鼠心肌细胞铁释放相关蛋白表达的影响,探讨枸橼酸铁铵对心肌细胞铁代谢的影响机制. 方法 以原代培养的乳鼠心肌细胞为材料,分为对照组、20mg/L枸橼酸铁铵组、40mg/L枸橼酸铁铵组和80mg/L枸橼酸铁铵组,每组6个重复.然后检测心肌细胞存活率、搏动频率,免疫组织化学检测铜蓝蛋白(CP)、膜铁转运辅助蛋白(HP)和膜铁转运蛋白(FP1)表达的变化. 结果 各剂量枸橼酸铁铵对大鼠心肌细胞存活率无明显影响;心肌细胞搏动频率减慢,停止跳动的细胞数量明显增加,收缩幅度逐渐降低;随着枸橼酸铁铵浓度的增加,心肌细胞铜蓝蛋白、膜铁转运辅助蛋白和膜铁转运蛋白的表达均增加. 结论 枸橼酸铁铵影响大鼠心肌细胞的生理功能,IRP-IRE可能参与膜铁转运蛋白表达的调控,铜蓝蛋白、膜铁转运辅助蛋白表达的升高可能与铁处理增加细胞的氧化紧张性有关.     

黏膜免疫壳聚糖-多胺转运蛋白D(PotD)DNA纳米微粒对小鼠鼻咽部肺炎链球菌定植的保护作用研究

目的 探讨以壳聚糖包裹的PotD DNA(Chitosan-potD)纳米微粒经鼻黏膜免疫小鼠对肺炎链球菌鼻咽部定植的保护作用.方法 将制备的Chitosan-potD微粒、裸pVAX1-potD重组质粒(裸potD)及pVAX1分别鼻腔免疫小鼠,收集黏膜和血清标本用以检测特异性抗体水平;分离并培养脾淋巴细胞,检测IL-17A、IL-4及IFN-γ的分泌水平;于免疫小鼠鼻腔进行肺炎链球菌攻击,通过菌落计数评估各免疫组对小鼠肺炎链球菌鼻咽部定植的保护作用.结果 Chilosan-potD纳米微粒在小鼠体内诱导产生的抗PotD特异性血清IgG、IgG1、IgG2a、黏膜IgA抗体水平及IL-17A、IL-4、IFN-γ水平与裸potD组及pVAX1组相比均明显升高,且差异具有统计学意义(P<0.05);菌落计数结果 显示,Chitosan-potD微粒组在鼻咽部定植的肺炎链球菌数量显著减少(P<0.05).结论 壳聚糖包裹PotD DNA微粒对肺炎链球菌鼻咽部定植具有免疫保护作用.     

黏膜免疫壳聚糖-多胺转运蛋白D(PotD)DNA纳米微粒对小鼠鼻咽部肺炎链球菌定植的保护作用研究

Objective To prepare the chitosan-potD nanoparticles and to evaluate its protective efficacy against pneumococcal nasopharyngeal colonization. Methods potD gene was amplificated from pneumococcal genome and was inserted into pVAX1 expression vectors to construct pVAX1-potD recombinant plasmid which was then transfected into 293T cell using LipofectAMINE 2000 to analyze transient potD gene expression in vitro by RT-PCR and Western blot. Chitosan-potD nanoparticles were freshly prepared by coacervation methods at each time and the characterizations of the nanoparticles were then evaluated. BALB/c mice were immunized with chitosan-potD, naked potD DNA or pVAX1 for 4 times at two-week intervals. Anti-PotD IgG, IgG1 and IgG2a levels in serum and IgA levels in nasal washes, bronchoalveolar lavage fluids (BALF) and middle ear lavages(MEL) were detected by indirect enzyme-linked immunosorbent assay (ELISA). IL-17A, IL-4 and IFN-γ levels in splenocytes were determined by double sandwich ELISA. Mice were intrannsally challenged with Streptococcus pneumoniae ATCC6303, and Pneumococci were recovered from the nasopharyngeal niche at the fifth day after challenge. Results potD gene was successfully amplificated by PCR and the sequence was confimed to be consistent with that in the Genbank. The pVAX1-potD recombinant plasmid was successfully constructed and was expressed in eukaryocytes in vitro. The mean size and zeta potential of chitosan-potD nanoparticles was 430 nm and + 20.5 mv, respectively. Chitosan-potD nanoparticles were not digested by DNase Ⅰ , while naked potD DNA was completely digested. The levels of antibodies inculding IgG, IgG1, IgG2a, IgA and cytokines including IL-17A, IL-4 and IFN-γ were significantly higher in mice immunized with chitosan-potD nanoparticles than mice with naked potD or pVAX1 ( P <0.05) only. More importantly, much less Pneumococci were recovered from mice immunized with chitosan-potD nanoparticles than the other groups(P <0.05). Conclusion Chitosan-potD nanoparticles significantly enhanced the immunogenicity and protection efficacy of DNA vaccines by intranasal immunization and could be used as a potential mucosal vaccine to prevent pneumococcal infection.     

黏膜免疫壳聚糖-多胺转运蛋白D(PotD)DNA纳米微粒对小鼠鼻咽部肺炎链球菌定植的保护作用研究

Objective To prepare the chitosan-potD nanoparticles and to evaluate its protective efficacy against pneumococcal nasopharyngeal colonization. Methods potD gene was amplificated from pneumococcal genome and was inserted into pVAX1 expression vectors to construct pVAX1-potD recombinant plasmid which was then transfected into 293T cell using LipofectAMINE 2000 to analyze transient potD gene expression in vitro by RT-PCR and Western blot. Chitosan-potD nanoparticles were freshly prepared by coacervation methods at each time and the characterizations of the nanoparticles were then evaluated. BALB/c mice were immunized with chitosan-potD, naked potD DNA or pVAX1 for 4 times at two-week intervals. Anti-PotD IgG, IgG1 and IgG2a levels in serum and IgA levels in nasal washes, bronchoalveolar lavage fluids (BALF) and middle ear lavages(MEL) were detected by indirect enzyme-linked immunosorbent assay (ELISA). IL-17A, IL-4 and IFN-γ levels in splenocytes were determined by double sandwich ELISA. Mice were intrannsally challenged with Streptococcus pneumoniae ATCC6303, and Pneumococci were recovered from the nasopharyngeal niche at the fifth day after challenge. Results potD gene was successfully amplificated by PCR and the sequence was confimed to be consistent with that in the Genbank. The pVAX1-potD recombinant plasmid was successfully constructed and was expressed in eukaryocytes in vitro. The mean size and zeta potential of chitosan-potD nanoparticles was 430 nm and + 20.5 mv, respectively. Chitosan-potD nanoparticles were not digested by DNase Ⅰ , while naked potD DNA was completely digested. The levels of antibodies inculding IgG, IgG1, IgG2a, IgA and cytokines including IL-17A, IL-4 and IFN-γ were significantly higher in mice immunized with chitosan-potD nanoparticles than mice with naked potD or pVAX1 ( P <0.05) only. More importantly, much less Pneumococci were recovered from mice immunized with chitosan-potD nanoparticles than the other groups(P <0.05). Conclusion Chitosan-potD nanoparticles significantly enhanced the immunogenicity and protection efficacy of DNA vaccines by intranasal immunization and could be used as a potential mucosal vaccine to prevent pneumococcal infection.     

N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸对转化生长因子β1介导的心成纤维细胞MMP-1/TIMP-1表达的调节作用

目的:探讨N-乙酰基-丝氨酰-天门冬酰赖氨酰-脯氨酸(AcSDKP)对转化生长因子β_1(TGF-β_1)介导的大鼠心成纤维细胞MMP-1/TIMP-1的调节作用。方法:差速贴壁法分离与获取新生大鼠心成纤维细胞。分别采用免疫细胞化学法和Western印迹法检测心成纤维细胞MMP-1、TIMP-1蛋白表达。结果:TGF-β_1可使心成纤维细胞MMP-1蛋白表达水平下降,而促进TIMP-1蛋白表达,MMP-1/TIMP-1比值下降。AcSDKP可以抑制TGF-β_1对心成纤维细胞MMP-1表达的下调作用,使MMP-1蛋白表达增加,而对TGF-β_1介导的TIMP-1蛋白表达无明显影响,MMP-1/ TIMP-1比值增加。结论:AcSDKP可以通过上调TGF-β_1介导的心成纤维细胞MMP-1蛋白表达并增加MMP-1/ TIMP-1比值,以加速细胞外基质降解,这可能与AcSDKP抗心纤维化的作用有关。     

ERK/c-Fos通路在Ang-(1-7)抑制Ang-Ⅱ诱导大鼠肾系膜细胞株增殖中的作用

目的：研究ERK1/2/c-Fos通路在血管紧张素-（1-7）［Ang-(1-7)］抑制血管紧张素Ⅱ（Ang-Ⅱ）诱导的大鼠肾系膜细胞株（GMCS）增殖中的作用。方法：在培养的大鼠肾系膜细胞(GMC)中，加入不同浓度的Ang-(1-7)与Ang-Ⅱ共同培养，用结晶紫计数法检测GMC数目；Western blotting检测GMC中p-ERK1/2和c-Fos蛋白的表达。结果： Ang-(1-7)呈剂量依赖性地抑制Ang-Ⅱ诱导的GMC数目的增加和GMC内p-ERK1/2和c-Fos蛋白的表达。结论：ERK/c-Fos通路参与Ang-(1-7)抑制Ang-Ⅱ诱导的GMC的增殖。     

17α雌二醇对转基因细胞株(APP/PS1N2a)β-淀粉样蛋白生成的影响

目的 探讨17α雌二醇（ESUB>2/SUB>α）对稳定表达人β-淀粉样前体蛋白（APP）/早老因子-1（PS1）即APP /PS1基因的神经母细胞瘤细胞株（Neuro-2a）（APP/PS1 NSUB>2/SUB>a）β-淀粉样蛋白（Aβ）产生的影响及可能机制。方法 将APP/PS1 NSUB>2/SUB>a细胞用10×10SUP>-9/SUP> mol/L E2α预处理2d,更换培养液后,分别进行如下处理：1.加入不同浓度ESUB>2/SUB> a（25nmol/L、50nmol/L、100nmol/L、200nmol/L）和溶媒（对照组）,用免疫印迹法(Western blotting)检测APP/PS1 NSUB>2/SUB> a细胞内和细胞外的Aβ蛋白水平及细胞BACE1蛋白水平;2.加入 100nmol/L ESUB>2/SUB>α、20nmol/L葡萄糖和5mIU葡萄糖氧化酶（GOX）。24h后,进行二氢乙啶(DHE)染色观察APP/PS1 N2a细胞中活性氧（ROS）含量的变化。结果 不同浓度E2α（25nmol/L、50nmol/L、100nmol/L、200nmol/L）处理后,细胞外Aβ蛋白水     

不同剂量培哚普利对缺血性心功能障碍家兔心功能及ACE2/Ang-(1-9)/Ang-(1-7)轴的影响

 目的: 探讨不同剂量培哚普利对缺血性心功能障碍家兔心功能的影响。方法: 采用结扎冠状动脉前降支的方法制作缺血性心功能障碍家兔模型。利用随机数字表法将30只家兔随机分为培哚普利大、小剂量组和心功能障碍组。大、小剂量组分别给予培哚普利生理盐水溶液(浓度分别为1 g/L、0.33 g/L)2 mL·kg^-1·d^-1灌胃;心功能障碍组给予等量生理盐水灌胃。4周后心脏超声测定心功能;real-time PCR检测血管紧张素转换酶2(angiotensin-converting enzyme 2,ACE2)和血管紧张素2型受体(angiotensin type 2 receptor,AT2R) mRNA表达;ELISA检测家兔血清血管紧张素(angiotensin,Ang)-(1-9)和Ang-(1-7)水平。结果: 与心功能障碍组相比,不同剂量培哚普利均可改善心功能(P<0.01),大剂量培哚普利比小剂量培哚普利改善心功能的效果显著(P<0.05);心功能障碍家兔应用培哚普利后,血清Ang-(1-9)和Ang-(1-7)水平均增高(P<0.01),ACE2和AT2R mRNA表达均增加(P<0.01);与小剂量组相比,大剂量组心肌ACE2和AT2R mRNA表达均增高(P<0.01),血清Ang-(1-9)水平增高(P<0.05),血清Ang-(1-7)水平无明显增加。相关性分析发现,左室射血分数与血清Ang-(1-9)、ACE2及AT2R水平呈正相关关系(P<0.01),与血清Ang-(1-7)水平无相关关系。结论: 大剂量培哚普利较小剂量培哚普利可以更有效改善缺血性心功能障碍家兔心功能,其心功能的改善可能与Ang-(1-9)水平增多,引起AT2R活化相关。