2，4，6-三硝基苯磺酸诱导小鼠炎症性肠病模型的建立

目的:建立2,4,6-三硝基苯磺酸诱导的结肠炎动物模型,并分析其剂量效应。方法:实验于2006-05/09在南方医院消化内科研究所完成,选用SPF级雌性Balb/c小鼠50只,按随机数字表法分为5组,每组10只,对照组予以300g/L乙醇溶液灌肠1次;其他4组分别给予含25mg/kg,50mg/kg,100mg/kg,150mg/kg2,4,6-三硝基苯磺酸的300g/L乙醇溶液灌肠1次。各组于造模后3,7,21,28d各处死1只小鼠,观察结肠的大体形态。造模后21d观察各组小鼠结肠的病理组织切片,并检测中性粒细胞的髓过氧化物酶活性。结果:造模过程中50,100,150mg/kg2,4,6-三硝基苯磺酸组各死亡2,3,3只小鼠。①各组小鼠造模后的一般情况:对照组及25mg/kg2,4,6-三硝基苯磺酸组小鼠发生一过性的结肠机械损伤表现,出现便血等现象,但3～7d后开始缓解;而50～150mg/kg2,4,6-三硝基苯磺酸组小鼠出现便血,腹泻。②各组小鼠结肠的大体形态及病理组织学观察结果:对照组和25mg/kg2,4,6-三硝基苯磺酸组小鼠肠道在第7天时表现为无粘连,局部充血,肠壁不增厚,未见溃疡,于第3周时局部充血已好转;结肠病理切片大致正常。50～150mg/kg2,4,6-三硝基苯磺酸组小鼠肠道肉眼可见粘连,肠腔增大,充血水肿,溃疡形成,出现肠道增厚,病理切片见黏膜下层水肿,固有层炎症细胞浸润等现象,以上现象于造模4周后开始缓解。其中当2,4,6-三硝基苯磺酸剂量为100mg/kg时作用达到高峰。③各组小鼠的中性粒细胞髓过氧化物酶活性比较:50,100,150mg/kg2,4,6-三硝基苯磺酸组均显著高于对照组[(14.17±3.33,18.50±2.33,18.17±1.50,4.83±2.00)nkat/L,(P<0.01)]。结论:应用含100mg/kg2,4,6-三硝基苯磺酸的300g/L乙醇溶液灌肠是诱导小鼠结肠炎较为理想的方法。     

肠道通透性试验及其临床意义

肠道对大分子物质的通透性试验是评估肠道粘膜屏障功能的方法之一.肠粘膜通透性是指某一特定物质在肠粘膜表面通过非易化扩散方式渗透的能力.肠道对大分子物质的通透性增加,意味着肠道结构有变化,肠道内的细菌或毒素有可能通过肠道屏障进入血循环,引起败血症或毒血症.自从20世纪70年代引入非代谢性寡糖类物质作为肠道通透性试验的示踪物以来,检测肠道粘膜屏障功能的肠道通透性试验已广泛应用于临床[1].     

葡萄糖酸锌对大鼠心肌缺血再灌注损伤的保护作用

目的:观察心肌缺血再灌注损伤过程中血清中一氧化氮的浓度,一氧化氮合酶及铜锌-超氧化物歧化酶的活性,分析葡萄糖酸锌对心肌的保护作用及其可能机制。方法:实验于2005-10/2006-05在锦州医学院药理学实验室进行,50只SD大鼠随机分为5组,即假手术组,缺血再灌注模型组,葡萄糖酸锌167,250,357mg/kg剂量组。采用左冠状动脉下穿线,拉紧丝线引起心肌缺血,放松丝线给予再灌注的方法建立心肌缺血再灌注损伤动物模型,假手术组,完成模型全部操作,只穿线不结扎。葡萄糖酸锌167,250,357mg/kg剂量组,分别以相应剂量葡萄糖酸锌(溶于蒸馏水中,2mL)灌胃,每次2mL,上下午各1次,两次灌胃给药间隔时间为2.5h。于末次灌胃1h后行冠状动脉左前降支结扎30min,再灌注60min。缺血再灌注模型组,给予等容量的生理盐水灌胃,其他处理同上。采用硝酸还原酶化学比色法测定血清中一氧化氮浓度及一氧化氮合酶活性,抽提法测定血清中铜锌超氧化物歧化酶活性。结果:50只大鼠进入结果分析。①模型组大鼠血清中一氧化氮浓度、血清中总一氧化氮合酶、诱导型一氧化氮合酶及铜锌超氧化物歧化酶的活性较假手术组升高,结构型一氧化氮合酶的活性降低(P<0.01～0.05)。②葡萄糖酸锌250,357mg/kg组大鼠血清一氧化氮浓度较模型组升高(P<0.05,0.01);葡萄糖酸锌167,250,357mg/kg组大鼠血清中总一氧化氮合酶的活性及血清中结构型一氧化氮合酶的活性较模型组升高(P<0.01,0.05),血清中诱导型一氧化氮合酶的活性降低(P<0.01,P<0.05);葡萄糖酸锌357mg/kg组大鼠血清中铜锌-超氧化物歧化酶的活性升高(P<0.01)。③血清中铜锌-超氧化物歧化酶活性与一氧化氮浓度呈正相关(r=0.92,P<0.01)。结论:葡萄糖酸锌对缺血再灌注心肌具有保护作用,作用途径可能为:①通过降低诱导型一氧化氮合酶的活性,增强结构型一氧化氮合酶的活性而提高一氧化氮水平。②参与构成铜锌-超氧化物歧化酶,清除自由基。     

FasL^＋组织工程化猪软骨细胞的同种异体移植

目的:探讨表达FasL的猪组织工程化软骨细胞在同种异体内的生长状况和免疫排斥反应。方法:实验于2002-09/2004-03在上海交通大学医学院,上海市免疫学研究所进行。①分离制备猪软骨细胞。②制备FasL 软骨细胞,构建重组pGCEN-FasL反转录病毒载体,转染PA317细胞。经G418筛选获得分泌pGCEN-FasL病毒颗粒的PA317细胞克隆,选择高滴度的病毒液,感染猪软骨细胞。再经过G418筛选获得FasL 的软骨细胞克隆,扩增培养。③FACS检测FasL的表达,应用JAM试验测定FasL 的软骨细胞诱导Fas 的Jurkat细胞及活化的T细胞的凋亡率。同时制备转染pGCEN反转录病毒空载体的软骨细胞为对照。④取FasL 的软骨细胞与可注射性生物材料PluronicF127混合,注射于同种异体猪的腹壁皮下。在第4,5周取材,通过组织病理和免疫组织化学等方法,检测软骨细胞生长和免疫排斥反应。结果:①经转染的软骨细胞表面FasL的表达率为57%。②FasL 的软骨细胞具有明显诱导Fas 细胞和活化的同种异体T细胞的凋亡,最大的凋亡率分别为53.41%,30.38%(效/靶=10∶1),对照组分别为32.27%,13.16%(效/靶=10∶1)。③组织工程化猪软骨结节的结构与正常软骨组织基本一致,可见清晰的软骨凹陷和软骨膜,仅细胞排列较正常软骨略显混乱、不均匀现象。④免疫组织化学染色显示FasL 的组织工程化猪软骨结节的Ⅱ型胶原蛋白分布均匀,形状清楚,与正常软骨比较基本一致。⑤第5周的软骨细胞表面的FasL分子表达明显,周围的炎性细胞浸润相对较少。而对照组的软骨细胞周围可见到大量浸润的炎性细胞。结论:成功构建FasL 软骨细胞并有效表达,抑制免疫排斥反应,为建立同种异体软骨细胞移植的免疫耐受提供了实验依据。     

超声心动图在干细胞移植治疗心脏疾病中的应用

目的:总结超声技术在干细胞移植治疗心脏疾病中的应用,探讨其监测评估价值。资料来源:应用计算机检索Pubmed 1994/2006与超声技术评估干细胞心脏移植及相关心脏组织学内容的文章,检索词为“echocardiography,stem cell transplantation,Doppler tissue image,Tie index,integral ultrasonic backscattering,three-dimension ultrasonic imaging”,限定文献语种为“English”;同时检索中国期刊全文数据库2000/2007相关文章,检索词为“超声心动图,干细胞移植,组织多普勒,Tie指数,超声背向散射积分,三维超声成像”,限定文献语种为中文。资料选择:对资料进行初审,选择超声评估干细胞心脏移植及相关心脏组织学内容的文章,无论观察对象是人或动物,有无对照组均纳入,进一步查找全文,排除重复性研究、陈旧性文献和关联价值不大的文献22篇,重复文献选择近期且发表在较权威杂志者。资料提炼:共检索到相关文献52篇,按以上要求最后纳入30篇文献进行综述。其中13篇论述常规超声心动图在干细胞心脏移植基础和临床研究中的应用,9篇介绍多普勒超声成像衍生的新技术和指标在干细胞心脏移植中的应用,剩余文章介绍超声组织定征和三维超声心动图的应用。资料综合:目前应用于干细胞心脏移植效果评价的超声技术和方法有M型超声、型超声、频谱多普勒、彩色多普勒、心脏造B影、组织多普勒、Tie指数、超声背向散射积分、实时三维超声,其中B型超声和多普勒超声应用较多。超声评价干细胞心脏移植效果的指标多样,可综合应用,且具有具有无创、简便、可重复性操作等优点。结论:近年来新技术的开发和使用进展很快,且各种技术方法之间互为补充,克服不足。随着实时三维超声技术的进一步开发利用,并各种诊断技术指标的综合运用,超声心动图将为干细胞心脏移植提供更客观的评价指标。     

基于小脑模型神经网络控制的步速跟随智能膝上假肢

目的：研究一种能够跟随健康腿步速控制的新型智能膝上假肢（Intelligent above knee prosthesis,IAKP）的控制机制及其实现方法. 方法：首先对国内外IAKP的研究现状及控制机制进行分析,提出了一种新的利用健康腿信号控制假肢步态的方法,设计了基于小脑模型神经网络（Cerebellar model articulation controller,CMAC）控制器的微电脑膝关节系统及相应的实验装置. 结果：步态跟随IAKP的控制可通过基于CMAC的PD监督控制实现步速跟随,并配合基于规则的专家控制来识别行走模式.这种控制方法具有动态记忆和快速随动控制能力,可实现假肢对健康腿步速的实时跟踪. 结论：基于CMAC控制的IAKP可对健康腿步态进行快速识别与跟踪,为进一步研制健康腿步态跟随控制新型IAKP提供了理论与实验基础.     

肠道树突状细胞的特性及功能研究

树突状细胞(DC)是目前所知机体内功能最强的专职性抗原递呈细胞．在肠道内,树突状细胞不但能对致病菌产生免疫应答,而且能对肠腔内共生菌及各类食物蛋白产生免疫耐受．因此,了解DC的功能及相关作用机制对研究肠道免疫屏障具有重要意义．现就肠道树突状细胞在免疫、耐受及疾病发生过程中的作用作一综述,旨在为研究肠道屏障功能提供有益的帮助．     

Association of HLA-DR with susceptibility to and clinical expression of rheumatoid arthritis: re-evaluation by means of genomic tissue typing

The clinical expression of rheumatoid arthritis (RA) varies considerably among individual patients. Genetic variations in human leucocyte antigen (HLA) may influence clinical expression. We re- examined the association of HLA-DR with susceptibility to and clinical expression of RA using genomic tissue typing, since most studies were based on (less reliable) serological techniques. Seventy-eight patients with recent-onset RA, all participating in a clinical trial on therapeutic strategies, were HLA-DR typed by means of low-resolution genomic typing. Cumulative disease activity within the first 3 yr of disease was measured. Of the RA patients, 54% expressed DR4 (DR4+) vs 26% of healthy controls. Rheumatoid factor (RF)-positive patients had a higher cumulative disease activity than RF-negative patients. Patients who were either DR1+ or DR4+ had a higher cumulative disease activity than those who expressed neither DR1 nor DR4. This association was less obvious after correction for RF status. The association of DR52+ (DR3, 5, 6) and a lower cumulative disease activity could also not be demonstrated after correction for RF status. Among RF-negative patients, DR51+ (or DR2+) was associated with a higher cumulative disease activity. Other HLA-DR types (including DR1 and DR4 separately) were not associated with the severity of RA. DR4 was associated with susceptibility to RA in our patients; HLA-DR low-resolution genomic tissue typing did not yield additional information to RF status for the clinical identification of individual patients with a poor prognosis.      

Recombinant human stem cell factor enhances myeloid colony growth from human peripheral blood progenitors

Peripheral blood hematopoietic progenitors (PBHP) are capable of colony growth in vitro. The effect of stem cell factor (SCF), interleukin-6 (IL-6), and basic fibroblast growth factor (bFGF) on myeloid colony proliferation of PBHP was determined. PBHP purified by positive selection with CD34-specific antibody were plated in semisolid agarose with reported plateau doses of interleukin-3 (IL-3), granulocyte- macrophage colony-stimulating factor (GM-CSF), and granulocyte colony- stimulating factor (G-CSF) to enhance myeloid colony growth. Experiments then were done to examine colony growth in response to SCF or with SCF and bFGF and/or IL6. SCF alone in the absence of any other growth factors did not support colony growth. SCF at a determined optimum concentration of 100 ng/mL added to the combination of IL-3, GM- CSF, and G-CSF enhanced colony growth and size relative to proliferation in response to the latter three factors alone (from 78 to 188 total colonies/10(4) PBHP plated and from 10 to 93 large [> 200 cells] colonies/10(4) PBHP plated). Furthermore, addition of bFGF and/or IL-6 to the combination of optimum concentrations of SCF, IL-3, GM-CSF, and G-CSF further enhanced colony number and size in a dose- dependent fashion. Using the optimum combination of all growth factors, we determined that the number of myeloid colony-forming PBHP in whole blood was similar between individuals at about three colonies per milliliter whole blood. We conclude that progenitors capable of responding to the early-acting growth factor, SCF, are represented in PBHP and that the number of circulating myeloid colony-forming PBHP is likely a regulated parameter that may have an important biologic function.