体外分离培养人脐静脉内皮及内皮下间充质干细胞

目的:建立人脐静脉内皮及内皮下间充质干细胞体外培养和扩增的方法,探讨其生物学特性,建立间充质干细胞体外培养扩增体系。方法:实验于2006-04/2006-09在辽宁医学院解剖学实验室完成。解剖细胞培养室为无菌百级培养间。正常健康产妇顺产或剖宫产的新生儿脐带由辽宁医学院附属第一医院提供,产妇及其家属均知情同意,并经医院伦理委员会批准。实验方法:①体外分离和培养贴壁细胞:无菌条件下取正常健康产妇分娩或剖宫产脐带,将其用预热PBS充分洗涤去血渍后,从脐静脉一端插入留置针,用预热PBS冲净静脉腔血后,用止血钳夹闭另一端,注入经预热至37℃的Ⅰ型胶原酶,置于37℃水浴箱中消化,30min后放出胶原酶,并用PBS冲洗血管腔,收集消化液和冲洗液,400r/min离心10min,吸弃上清液,重悬于M199培养基(含体积分数为0.15的胎牛血清,2mmol/L谷氨z酰胺,2μg/L碱性成纤维细胞生长因子,100U/mL青霉素,100U/mL链霉素)。以5×108L-1密度接种于6孔培养板中,置于37℃、体积分数为0.05的CO2饱和湿度培养箱中培养,48h后全量换液,以后每3d全量换液。待细胞80%融合时,0.25%胰酶消化,按1×108L-1传代培养。②间充质干细胞生长曲线的测定:取传代培养细胞,按2×107L-1密度接种于24孔培养板内,每天取3孔,将细胞消化计数,连测8d,绘制间充质干细胞生长曲线。③间充质干细胞表面抗原检测:在24孔塑料培养板内放置无菌的盖玻片,每孔中种植108L-1第2代细胞悬液1mL。采用免疫细胞化学方法进行细胞表面抗原检测。结果:①间充质干细胞的形态学观察:接种的细胞48h后细胞完全贴壁生长,其镜下形态有呈椭圆形、多角形的内皮细胞以及呈梭形的成纤维样细胞,有的形成漩涡状生长的集落。②间充质干细胞生长曲线的分析:传代培养的潜伏期约为24～36h,细胞倍增时间约为30～36h,对数增殖期约为二三天,对数增殖期后第5天进入平台期。③间充质干细胞表面抗原特性:免疫细胞化学分析结果显示,间充质干细胞表面抗原cd166、cd44阳性,而vWF阴性,说明分离获得的细胞具有间充质干细胞的特点。结论:所建立的分离和培养方法可获取人脐静脉黏附细胞中一组独特的细胞群,具有间充质干细胞的生物学特性。     

肾移植术后卡氏肺囊虫肺炎5例回顾性分析

目的:观察肾移植术后卡氏肺囊虫肺炎的发生率及治疗效果。方法:选择2003-01/2005-12在中山市人民医院行肾移植的患者112例,患者均知情同意。按是否使用猪抗人淋巴细胞免疫球蛋白分为2组,基础免疫抑制组(n=68)给予环孢素A/他克莫司 吗替麦考酚酯 强的松;抗体诱导组(n=44)给予猪抗人淋巴细胞免疫球蛋白 环孢素A/他克莫司 吗替麦考酚酯 强的松。两组共发生卡氏肺囊虫肺炎5例,其中基础免疫抑制组2例,抗体诱导组3例。5例患者通过普通抗感染治疗,3～7d病情未见好转,遂行支气管镜活检 深部吸痰培养,尽早明确病原体,指导抗菌治疗。比较两组患者卡氏肺囊虫肺炎的发生率,并观察其治疗效果。结果:5例卡氏肺囊虫肺炎患者全部进入结果分析,无脱落。①5例患者经支气管纤维镜肺组织活检确诊为卡氏肺囊虫肺炎,发生率为4.46%,其中抗体诱导组6.82%(3/44)明显高于基础免疫抑制组2.94%(2/68)。②5例卡氏肺囊虫肺炎中2例合并金黄色葡萄球菌感染。以复方磺胺甲恶唑为基础药物进行综合治疗,3例患者临床治愈出院,随访3个月,移植肾及肺功能正常;死亡2例。③5例患者治疗期间均无排斥反应发生。④在发病初期5例患者的CD4/CD8平均值为1.02±0.15,3例治愈患者的CD4/CD8平均值为1.42±0.23,在恢复过程中逐渐升高。2例死亡患者的CD4/CD8平均值为1.10±0.21。结论:早期支气管纤维内镜活检对肾移植术后卡氏肺囊虫肺炎的诊断非常重要,早期诊断、早期治疗是治愈的关键。猪抗人淋巴细胞免疫球蛋白可增加肾移植术后卡氏肺囊虫肺炎的发生率。     

差速贴壁技术对大鼠脑皮质星形胶质细胞纯化率的影响

目的:观察差速贴壁技术对星形胶质细胞纯化率的影响,旨在建立一套可靠的大鼠脑皮质星形胶质细胞的取材分离、纯化培养技术。方法:实验于2006-06/08在泰山医学院生命科学研究所完成。实验材料:出生2～3d的Wistar大鼠,雌雄不拘,由泰山医学院生命科学研究所实验动物中心提供。实验方法:选用出生二三天的Wistar大鼠进行脑皮质星形胶质细胞原代培养。实验分两组培养:常规培养组和差速贴壁培养组。差速贴壁培养组分别于15,30min取出,轻轻翻转培养瓶,将上清液移至另一培养瓶中,放入培养箱中继续培养。7～10d后传代,待细胞分层生长后,置于37℃摇床中250r/min振荡18h,倒掉上清液,D-Hank’s液洗3次后,加入0.25%胰酶消化,倒置显微镜下观察,待细胞突起回缩后加入含血清的培养基终止消化,用吸管反复吹打使细胞从瓶壁上脱落,细胞悬液1000r/min离心5min后,弃上清液,加入含体积分数为0.2血清的DMEM培养基混悬沉淀,接种入预先涂有L-多聚赖氨酸的培养瓶中继续培养。采用双重免疫荧光法鉴定星形胶质细胞纯度,测定积分吸光度值判断星形胶质细胞的生长状况。结果:①应用差速贴壁技术培养星形胶质细胞可明显提高星形胶质细胞纯度[常规培养组:(82±3)%,差速贴壁培养组15min:(94±2)%,差速贴壁培养组30min:(95±2)%,P<0.01]。差速贴壁需要充分的时间,15min组和30min组在提高星形胶质细胞纯度方面无明显差别。②差速贴壁培养组星形胶质细胞积分吸光度值高于常规培养组(常规培养组:528±25,差速贴壁培养组15min:972±17,差速贴壁培养组30min:996±35,P<0.05)。结论:①差速贴壁技术可明显提高星形胶质细胞纯化度,并且星形胶质细胞生长状态明显优于常规培养方法。②最佳差速贴壁时间为15min,过长差速贴壁时间对提高星形胶质细胞纯度无明显影响。     

人白细胞介素24mRNA在瘢痕疙瘩中的表达及意义

目的:从基因水平测量瘢痕疙瘩组织中白细胞介素24的表达水平,探讨白细胞介素24在瘢痕疙瘩发生、发展过程中的作用和意义。方法:实验于2005-10/2006-09在广东医学院整形外科研究所完成。①选取2004-06/2005-10广东医学院附属医院整形外科收治的患者,瘢痕疙瘩标本12例,正常瘢痕标本10例,行巨乳缩小、除皱术、植皮等患者正常皮肤标本12例,患者均知情同意且自愿捐献标本,实验经医学伦理委员会批准。标本取材部位为颜面、前胸、四肢等,切取后液氮保存。②低温条件下切取秤量组织,采用Trizol法提取总RNA。电泳鉴定总RNA完整性,并统一调整总RNA含量为10g/L,-70℃储存。RT-PCR二步法合成cDNA。③以正常皮肤、正常瘢痕为对照,以GAPDH作为扩增内参照基因,将正常皮肤、正常瘢痕和瘢痕疙瘩各类标本总RNA反转录的cDNA模板浓度调整相对一致进行扩增反应。以白细胞介素24mRNA与GAPDHmRNA的光密度积分值之比作为各类组织标本中白细胞介素24的相对含量,比较白细胞介素24mRNA在正常皮肤、正常瘢痕及瘢痕疙瘩组织中的表达情况。结果:①各类组织标本中总RNA抽提结果:正常皮肤、正常瘢痕和瘢痕疙瘩组织中抽提总RNA经甲醛变性凝胶电泳后显示较清晰的18s和28s条带,经紫外分光光度计测定A260/A280≈2.0。②各类组织标本中白细胞介素24mRNA的表达:白细胞介素24和GAPDH基因表达产物通过RT-PCR方法得到的特异性DNA片段长度分别为173bp和577bp。瘢痕疙瘩的白细胞介素24mRNA与GAPDHmRNA的吸光度比值明显低于正常皮肤、正常瘢痕(0.577±0.113,1.070±0.185,1.139±0.195;t=7.436×10-8～4.745×10-8,P均<0.01),正常皮肤与正常瘢痕白细胞介素24mRNA的相对表达量基本一致(t=0.405,P>0.05)。结论:瘢痕疙瘩的形成可能与白细胞介素24在组织中的表达降低有关。提示采用基因疗法提高早期瘢痕疙瘩中白细胞介素24的含量与活性,可能为瘢痕疙瘩的康复治疗提供有效途径。     

小鼠皮肤超氧化物歧化酶活性与枸杞多糖的干预

目的:观察枸杞多糖对皮肤胶原代谢和自由基产生的影响,探讨其抗皮肤衰老的作用。方法:实验于2005-06/2006-05在广东医学院整形外科研究所完成。①实验材料:清洁级昆明小鼠60只,月龄2个月,体质量16～24g,雌雄各半。②实验分组:将小鼠随机分为正常对照组、衰老模型组和抗衰老模型组,每组20只。③实验干预:模型组每日用D-半乳糖溶液皮下注射制造衰老模型,用量和时间为80mg/(kg·d)7d,120mg/(kg·d)14d,140mg/(kg·d)14d,180mg/(kg·d)7d。正常对照组每日注射同体积的生理盐水。抗衰老模型组在注射D-半乳糖期间以枸杞多糖灌胃,剂量为20mg/(kg·d),正常对照组和衰老组则以同体积的生理盐水代之灌胃。④实验评估:42d后切取小鼠颈背部皮肤,测定超氧化物歧化酶活力、羟脯氨酸和丙二醛含量。结果:56只小鼠进入结果分析(4只死亡)。①小鼠皮肤超氧化物歧化酶活力:与正常对照组相比,衰老组和抗衰老组小鼠皮肤超氧化物歧化酶活力降低,差异有显著性意义(P<0.01);抗衰老组与衰老模型组比较,超氧化物歧化酶活力增加,差异有显著性意义(P<0.01)。②与正常对照组相比,衰老组和抗衰老组小鼠皮肤羟脯氨酸和丙二醛含量增加,差异有显著性意义(P<0.01);抗衰老组与衰老组比较,羟脯氨酸和丙二醛含量均降低,差异有显著性意义(P<0.01)。结论:枸杞多糖改善皮肤老化的作用与提高小鼠皮肤超氧化物歧化酶活力,降低羟脯氨酸、丙二醛含量,影响胶原代谢有关。     

中国人胚胎肝组织来源纤溶酶原kringle5基因的克隆与序列分析

目的：分离、克隆和测定中国人纤溶酶原Kringle5功能区基因，为进一步研究其功能奠定基础。方法：实验于2002—06／2003-05在广州医学院金域医学检验中心完成。①实验材料：国人胚肝组织取自广州医学院第一附属医院的流产胚胎（取得家属同意，并经广州医学院第一附属医院伦理委员会批准）。pET21a（＋）载体购自Novagen公司，大肠杆菌BL21（DE3）为医学检验中心保存。引物均由上海生工合成。②实验方法：从国人胚肝组织中提取mRNA，用反转录-聚合酶链反应方法将人纤溶酶原Kringle5的cDNA扩增出来，克隆到pET21a（＋）载体中测序。（D实验评估：采用紫外分光光度仪和琼脂糖凝胶电泳分析胚肝组织总RNA的抽提结果；经琼脂糖凝胶电泳鉴定Kringle5的反转录-聚合酶链反应扩增结果；pET-Kringle5重组质粒的酶切鉴定；序列测定。结果：①胚肝组织提取总RNA结果：提取的总RNA经紫外分光光度仪测得A260nm/A80nm〉1．8，A60nm，A270nm〉1.2，表明无蛋白残留；电泳结果显示提取的总RNA有明显的28S、18S两条带，说明RNA基本完整。②Kringle5的反转录-聚合酶链反应扩增结果：人Kringle5 cDNA片段长为240bp，加上引物设计的2个酶切位点，总长度为258bp，聚合酶链反应产物长度与该长度一致，符合预期结果。③）pET-Kringle5重组质粒的构建和酶切鉴定结果：用引物所带的限制性内切酶BamH Ⅰ、NdeⅠ双酶切，结果有250bp左右条带出现。④序列测定结果：证实国人纤溶酶原Kringle5功能区基因被成功克隆，序列分析证实为该基因，未发现有基因突变或多态性现象，但第153位核苷酸与文献比较存在碱基替代现象，其组成的密码子由于遗传的简并性，所编码的氨基酸相同，并未造成氨基酸组成的改变。结论：中国人纤溶酶原Kringle5功能区cDNA基因编码序列与国外文献报道的相应序列可能存在碱基替代现象。     

骨髓干细胞移植对心肌梗死大鼠血流动力学指标和心脏功能的影响

目的:心肌梗死所致的细胞缺失和瘢痕形成是心力衰竭乃至死亡的病理基础,目前药物治疗、介入治疗和外科手术均不能替代坏死心肌和彻底改善心脏功能。观察骨髓干细胞移植对心肌梗死大鼠血流动力学指标和心功能的影响。方法:实验于2005-03/2006-10在哈尔滨医科大学附属第一医院细胞移植中心完成。①实验动物:SD雄性大鼠60只作为细胞移植的受体,随机数字表法分成假手术组、心肌梗死组、细胞移植组,20只/组。另取SD雄性幼鼠10只作为骨髓干细胞的供体。实验过程中对动物的处置符合动物伦理学标准。②实验方法:取幼鼠股骨骨髓,Percoll分离后收取细胞层,加入含体积分数为0.1的胎牛血清、100IU/mL青霉素、100g/mL链霉素的DMEM营养液,差速贴壁法分离骨髓干细胞,达80%～90%融合时采用胰酶 乙二胺四乙酸消化传代。向含有第3代骨髓干细胞的培养液中加入5-氮杂胞嘧啶核苷进行诱导,3周后行BrdU标记,离心后配制成1×1012L-1的细胞悬液用于移植。心肌梗死组、细胞移植组大鼠建立心肌梗死模型,假手术组未结扎冠状动脉。细胞移植组吸取0.2mL骨髓干细胞悬液注射到瘢痕组织中,心肌梗死组注入等量干细胞培养液基质,假手术组不予任何移植处理。③实验评估:术后4周,利用导管和心动超声技术检测各组大鼠左室舒张末期内压、左室收缩末期内压、左室压力最大变化值、左室压力最小变化值、等容时间常数和心率。结果:术后4周,与假手术组比较,心肌梗死组左室收缩末期内压、左室压力最大变化值、左室压力最小变化值均明显降低(P<0.01),左室舒张末期内压、等容时间常数均明显增高(P<0.01);与心肌梗死组比较,细胞移植组以上各项指标均明显好转(P<0.01)。结论:骨髓干细胞移植到瘢痕心肌组织中,能改善心肌梗死后大鼠的血流动力学参数和心脏功能。     

Evaluation of an automated microbiologic blood culture device for detection of bacteria in platelet components

BACKGROUND: Automated culture methods have been used by several investigators to detect bacterial contamination of cellular blood components. We investigated several factors affecting detection by automated culture of bacteria in platelet concentrates (PCs).These factors included the initial contamination level in PCs, the PC sample volume, the PC sample time, and the white cell level in relation to bacteria levels in the PCs. STUDY DESIGN AND METHODS: Staphylococcus epidermidis or Escherichia coli was inoculated into freshly prepared PCs or white cell-reduced PCs to yield colony-forming unit (CFU) levels of 10, 1, or 0.1 per mL. At the time of inoculation (t=0) and at t=6, t=24, and t=48 hours, 0.5, 1.0, and 2.0 mL samples of the contaminated PCs were transferred into culture bottles. The presence of bacteria in the culture bottles was subsequently monitored by an automated blood culturing instrument. Bacteria levels in the PC at the time of first automated culture detection were determined by quantitative plating. RESULTS: E. coli was detected in 92 percent of experiments when 1.0- or 2.0-mL samples were taken at t=6 hours. At t=24 hours, 100-percent detection was observed with all tested inoculation volumes; however, by that time,>10(7) CFU per mL of bacteria were present in every PC. For S. epidermidis, 89 percent and 83 percent of contaminated PCs were detected with a t=24 hour sampling time and 2.0- or 1.0-mL sampling volume. Seven of 36 PCs with a 2.0-mL sampling volume and 10 of 36 PCs with a 1.0-mL sampling volume contained>10(6) CFU per mL of S. epidermidis at the time of first detection. CONCLUSION: Data from this preliminary evaluation suggest that sampling times of 24 hours or more would be necessary to provide confidence in detection of E. coli or S. epidermidis in PCs using this culture method.     

Aetiological factors for oral manifestations of HIV

OBJECTIVES: Describe the oral diseases in HIV-infected individuals in London, UK and identify social and medical factors related to the presence of specific oral diseases.
DESIGN: Cross-sectional analytic study.
SETTING: Dental clinics.
SUBJECTS: Consecutive sample of 456 patients with HIV infection.
METHODS: Social and medical history and clinical examinations. Univariate and logistic regression analysis.
OUTCOMES: Presence of HIV-associated oral disease.
RESULTS: 80% of patients with AIDS and 50% of patients with HIV had a specific oral disease. The most common diseases were hairy leukoplakia (30%), erythematous candidiasis (24%), pseudomembranous candidiasis (14%), angular chielitis (6%), necrotising periodontal disease (8%) and non-recurrent ulceration (6%).
CONCLUSIONS: The presence of erythematous candidiasis was not related to advanced HIV disease. Pseudomembranous candidiasis, hairy leukoplakia and mucosal ulceration were significantly associated with advanced HIV disease. Smoking was also identified as a strong aetiological factor in oral diseases. Longitudinal studies are required to further explore the prognostic significance of oral diseases in HIV infection.     

Manipulation of liver regeneration with macrophages to influence the hepatic progenitor cell niche

Insufficient regeneration of the adult liver is believed to cause failure to recover from severe liver disease. An undifferentiated cell population with stem-cell-like qualities known as hepatic progenitor cells (HPCs) is hypothesised to have a central role in regeneration of the adult liver during massive or chronic liver disease. Stem cells in other organ systems are believed to reside in a specialised microenvironment or niche that supports their maintenance and function. The existence of a hepatic stem cell niche might provide a means of therapeutically manipulating endogenous HPCs in vivo as a regenerative therapy.To investigate the physiological potential of HPCs to regenerate the mammalian liver, we have established a novel model of hepatocellular injury and HPC activation using genetic manipulation of hepatocytes. After hepatocyte senescence and death in this model (AhCre Mdm2^flox), HPCs expand and bring about the complete regeneration of the liver parenchyma.We demonstrate that a stereotypical niche, consisting partly of macrophages, exists in both animal models and correlating human disease. Using cell tracking, we show active recruitment of extrahepatic macrophages into this niche during injury. In health, intravenous injection of macrophages results in macrophage engraftment to the liver niche, with subsequent HPC activation and changes to liver structure and function.Within the niche, macrophages use paracrine signalling to control both HPC proliferation and cell fate via TWEAK (tumour-necrosis-factor-like weak inducer of apoptosis) and the Wnt signalling pathway, respectively. After hepatocellular injury, macrophages ingest hepatocyte debris, and release Wnt which promotes HPC differentiation into hepatocytes. TWEAK is vital for HPC proliferation in the AhCre Mdm2^flox model of regeneration. Here, the absence of TWEAK signalling results in liver failure and mortality.This work has demonstrated for the first time the ability of a solid organ to fully regenerate in the adult mammal from progenitor cells, and additionally highlights mechanisms by which this process can be modulated by either small molecule or cell therapy.FundingUniversity of Edinburgh.