大鼠纤维化肝组织匀浆上清液诱导人脐带间充质干细胞向肝细胞分化的实验研究

目的探讨大鼠纤维化肝组织匀浆上清液对人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,HUCMSCs)向肝细胞分化的诱导作用。方法取健康SD大鼠(体重180~220 g),采用腹腔注射3%硫代乙酰胺生理盐水溶液(200 mg/kg,2次/周,共4周)方法制备大鼠肝纤维化模型,取造模成功的纤维化肝组织用于制备肝纤维化诱导培养基。取第3代HUCMSCs进行分组培养7 d,对照组以含10%FBS的DMEM/F12培养基培养,实验组以含10%FBS及50 g/L肝纤维化诱导培养基上清的DMEM/F12培养基培养。倒置显微镜下观察两组细胞形态学变化;取培养7 d的对照组及实验组细胞,采用Western blot法检测甲胎蛋白(alpha fetoprotein,AFP)、细胞角蛋白18(cytokeratin 18,CK18)、CYP3A4表达情况,采用糖原过碘酸-雪夫(periodic acid-schiff,PAS)染色检测细胞储存糖原的能力,分别采用二乙酰肟比色法及ELISA法测定两组细胞培养液中尿素(blood urea nitrogen,BUN)和白蛋白(albumin,ALB)的含量。结果与对照组长梭形细胞相比,实验组细胞于诱导1 d时即可见到细胞两极回缩,胞体变短;诱导7 d时,细胞呈不规则形或类圆形,胞体丰满。Western blot检测示,对照组细胞未见AFP、CK18、CYP3A4表达;实验组细胞可表达肝细胞特异性标志物AFP、CK18及与代谢功能相关的重要蛋白CYP3A4。对照组上清液中BUN、ALB浓度分别为(0.43±0.07)mmol/L和(8.08±0.41)μg/mL,实验组分别为(2.52±0.20)mmol/L和(41.48±4.11)μg/mL,比较差异均有统计学意义(t=24.160,P=0.000;t=19.810,P=0.000)。PAS染色示,对照组HUCMSCs细胞核呈深蓝色,细胞质呈淡紫色;实验组细胞整个胞体被染成深紫色,细胞核可见。结论大鼠纤维化肝组织匀浆上清液可快速诱导HUCMSCs向肝细胞分化,形成的肝样细胞不仅具备肝细胞表面标志物,同时有肝药酶的表达,并具有储存糖原、合成BUN及分泌ALB的能力,可部分替代肝细胞功能,这可能是干细胞移植改善肝功能的机制之一。     

大鼠MSCs体外分离培养及骨向分化的实验研究

目的:建立骨髓MSCs体外分离培养体系,并进行骨向分化诱导,以证实其多向分化潜能,为骨髓MSCs进一步的临床应用研究提供实验依据。方法:用密度梯度离心法分离大鼠骨髓MSCs,并对其形态学特征进行观察。用诱导剂对骨髓MSCs向成骨细胞进行诱导分化,并进行形态学观察和免疫细胞化学检测。结果:用密度梯度离心法成功分离获得了高纯度的骨髓MSCs。经骨向诱导后,ALP和矿化结节染色阳性。结论:采用密度梯度离心法成功建立了大鼠骨髓MSCs体外分离和培养体系,并能够向成骨细胞分化。     

紫衫醇对大鼠肝纤维化的抑制作用及机制研究

目的:探讨紫衫醇对大鼠肝纤维化的抑制作用及其分子机制。方法:将30只Wistar大鼠随机均分为正常对照组、肝纤维化模型组,肝纤维化模型+紫衫醇组,肝纤维化模型用腹腔注射二甲基亚硝胺每日1次连续7 d诱导,之后,肝纤维化模型+紫衫醇组大鼠给予尾静脉注射紫杉醇液,隔日1次,共3次;实验结束时,处死大鼠观察肝脏病理学和血清学指标变化,及肝组织中肝星状细胞标志物α-SMA的表达。将大鼠肝星状细胞HSC-T6分别用TGF-β1、紫杉醇+TGF-β1处理,以无处理的HSC-T6细胞为对照,分别检测各组细胞纤连蛋白及I、III型胶原m RNA与蛋白的表达。结果:正常对照组肝组织无病理学改变,肝纤维化模型组出现肝纤维化病变,肝纤维化模型+紫杉醇组可见肝组织中度坏死,无明显坏死结节;与正常对照组比较,肝纤维化模型组与肝纤维化模型+紫杉醇组转氨酶、总胆红素(TIBL)、透明质酸(HA)水平均明显升高,白蛋白(ALB)水平明显降低(均P0.05),后者较前者在TBIL、ALB、HA方面有明显改善(均P0.05);正常对照组肝组织无明显α-SMA表达,肝纤维化模型组和与肝纤维化模型+紫杉醇组肝组织均有α-SMA表达,后者的α-SMA阳性细胞数明显少于前者(P0.05);与无处理的HSC-T6细胞比较,TGF-β1与紫杉醇+TGF-β1处理后的HSC-T6细胞纤连蛋白及I、III型胶原m RNA与蛋白均明显上调(均P0.05),后者的上调程度明显低于前者(均P0.05)。结论:紫杉醇可抑制大鼠肝纤维化的产生和发展,机制可能与其抑制肝星状细胞中TGF-β信号通路从而减少肝星状细胞活化有关。     

重组人生长激素对大鼠免疫损伤性肝纤维化的影响

目的 研究重组人生长激素对肝纤维化发生和发展过程的影响。方法 应用尾静脉攻击注射人血白蛋白方法诱导大鼠形成免疫损伤性肝纤维化模型。基础免疫后，在尾静脉攻击注射白蛋白即肝纤维化模型形成的过程中，同时给予外源性的重组人生长激素来干预肝纤维化的发生和发展。攻击注射10周后，观察肝组织病理肝纤维化分级；测定肝组织胆原蛋白含量；检测血清层粘连蛋白和透明质酸的含量和肝功能指标。结果 重组人生长激素能够减轻肝组织病理肝纤维化分级（P＜0．01）；降低胶原蛋白、层粘连蛋白和透明质酸的含量（P＜0．05）；同时改善肝功能（P＜0．05）。结论 重组人生长激素能够阻断或延缓大鼠免疫损伤性肝纤维化的发生和发展，具有一定程度的抗肝纤维化的作用。     

人雪旺细胞促进人脐带间充质干细胞向神经方向分化的研究

目的 观察人雪旺细胞(hSCs)对人脐带间充质干细胞(hUC-MSCs)在脊髓损伤(SCI)体内存活、分化的影响,通过分子生物学技术检测胶质纤维酸性蛋白(GFAP)、髓磷脂碱性蛋白(MBP)与高分子量神经丝蛋白(NF-H)的表达,描述其变化的时间特征.方法 分离、培养及纯化hUC-MSCs和hSCs.取8周龄雌性Wistar大鼠60只,以Impactor Model-Ⅱ型打击器制作脊髓胸10(T10)损伤模型.大鼠随机均分为4组:DMEM对照组(A)、hSCs移植组(B)、hUC-MSCs移植组(C)、hUC-MSCs与hSCs联合移植组(D),各组分别于移植后1、2、3、4周取材.结果 D组可见MBP与核因子(NF)-H染色阳性细胞,其他各组为阴性.A组3种神经标志物在蛋白与mRNA水平的表达量随时间延长均逐渐增高,且GFAP在移植后2周明显增高,MBP与NF-H在移植后3周明显增高[2周与1周GFAP条带灰度比值为1.34,而聚合酶链反应(PCR)所测比值为2.86;3周与1周MBP和NF-H条带灰度比值分别为3.43、4.12,而PCR所测比值分别为6.47、6.78].与对照组相应时间点比较,移植组MBP、NF-H的表达量较高而GFAP的表达量较低,其中D组的MBP、NF-H的表达量最高(D组与A组MBP3周条带灰度比值为2.11,而NF-H3周条带比值为2.11),差异有统计学意义(P＜0.05),但D组GFAP各时间点的表达量差异(各周所测条带灰度比值依次为1.00:1.12:1.13:1.14)无统计学意义(P＞0.05).结论 hSCs可促进hUC-MSCs向神经元与少突胶质细胞方向分化并增强其对胶质瘢痕的抑制作用.     

脾切除对大鼠肝纤维化影响的实验研究

目的 研究脾脏对实验性大鼠肝纤维化的影响，探讨脾切除的应用价值。方法 利用四氯化碳和乙醇诱导Wistar大鼠肝纤维化及肝硬化模型。从造模前、肝纤维化期（早期肝硬化期）、肝硬化期三个层面观察脾切除组、脾大部切除组肝纤维化四项指标与肝组织病理改变的关系，以血常规三项指标动态观测整个实验中脾功能状态，并观察对比脾大部切除前后脾脏病理改变。结果 血清HA、CV、IV、PCⅢ与肝纤维化各个时期病理改变有相关性，血清LN与血清HA、CV、IV、PCⅢ变化趋势相同，但敏感性较差，从敏感性与特异性综合考虑可见血清HA〉CV、IV〉PCⅢ〉LN、PLT、WBC、RBC与脾功能之间有很好的相关性，但敏感性RBC逊于PLT、WBC。脾切除可明显减缓肝纤维化诱导进程，对已形成的肝纤维化模型亦有一定的缓解作用。结论 在减缓和逆转肝纤维化中脾切除术作用明显。当脾脏发生病理改变至脾功亢进时引起贫血，并明显促进肝硬化，似予全部切除为佳。血清肝纤维化四项指标HA、CV、IV、PCⅢ、LN与肝纤维化的病理诊断有良好的一致性，可作为无损伤诊断的依据，推荐前三项指标联合应用。PLT、RBC、WBC与肝纤维化及脾功亢进有较好的相关性，可作为临床评估脾亢分级的参考指标，其中PLT、WBC在肝纤维化及脾功亢进形成过程中变化较早且较为明显。     

重组人肝再生增强因子对肝纤维化大鼠血清透明质酸浓度的影响

目的探讨重组人肝再生增强因子(hALR)对肝纤维化大鼠血清透明质酸浓度的影响.方法建立四氯化碳中毒性及人血白蛋白免疫损伤性两种大鼠肝纤维化模型.模型完成后予不同剂量hALR(50μg·kg-1·d、10μg·kg-1·d)治疗.在不同的时间点留取大鼠血清标本,测定透明质酸浓度.结果在两种模型中hALR治疗组大鼠血清透明质酸浓度在治疗过程中的不同阶段(治疗1、2个月)均明显低于模型组(四氯化碳模型分别为340.7±32.1、234.1±19.5;人血白蛋白模型分别为366.5±32.3、287.3±30.1).高剂量hALR组大鼠血清透明质酸浓度(四氯化碳模型分别为203.3±15.5、134.1±9.8;人血白蛋白模型分别为218.9±15.8、143.1±8.7)均明显低于低剂量组(四氯化碳模型分别为273.3±13.4、186.6±11.3;人血白蛋白模型分别为276.1±23.4、198.7±11.5).结论重组人肝再生增强因子可降低肝纤维化大鼠血清透明质酸含量.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

目的 研究脐带间充质干细胞获得纯化的高效方法及向软骨细胞的分化能力.方法 取人的正常分娩或剖腹产胎儿的脐带,用胶原酶和胰酶初步消化后,将流式细胞仪筛选得到的CD45(-)、CD90(+)细胞作为原代细胞进行培养,并用复合胶原酶差速消化法逐级传代、纯化细胞,每次传代后取部分细胞用作流式细胞仪分析细胞的CD45、CD90阳性比率;对P3代细胞向软骨细胞进行诱导.结果 流式细胞仪检测提示,采用流式细胞仪进行初次筛选并用复合胶原酶差速消化法逐级传代获得的P1、P2、P3代细胞中CD90的阳性率为(80.86±7.85)%、(95.86±3.28)%、(97.15±1.43)%,而CD45的阳性率为(2.53±0.28)%、(0.97±0.48)%、(0.05±0.01)%;向软骨细胞诱导结果提示P3代细胞有向终末软骨细胞分化能力,具有干细胞的特性.结论 采用流式细胞仪进行初次筛选并用复合胶原酶差速消化法能快速获得高纯度的具有向终末软骨细胞分化能力的人脐带间充质干细胞.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

人脐带间充质干细胞获得和纯化及向软骨细胞分化能力的研究

Objective To explore the efficient way to purify and to enrich umbilical cord mesenchymal stem cells which have abilities to differentiate into chondrocytes. Methods Umbilical cord was acquired from new born infants and chopped into 1 mm2 cubics, then they were pretreated with colleganase and trypsin so as to get the mixed cell suspension. CD45(-),CD90(+) cells were acquired from the mixed cell suspension via FCM sorting and were cultured in the medium as umbilical cord mesenchymal stem PO cells. The PO cells were detached and passaged by multiplex collagenase NB4 and the positive rate of CD90 and CD45 of the P1-P3 cells were observeed via FCM ; the P3 cells were induced to differentiated into chondrocytes. Results FCM results showed that the positive rate of CD90 on P1, P2, F3 was (80.86 ± 7.85)%,(95.86± 3.28)%,(97.15± 1.43)%, while the positive rate of CD45 on P1, P2, P3 cells was (2.53 ±0.28)% and (0.97 ± 0.48)% and (0.05 ± 0.01)% respectively; P3 cells had differenciated into chondrocytes. Conclusion FCM presorting and Multiplex collagenase detachment procedures can swiftly acquire highly purified human umbilical cord mesenchymal stem cells which have the ability to differentiate into chondroeytes.     

谷氨酰胺和精氨酸对大鼠肝纤维化的影响

目的:研究谷氨酰胺（Gln）和精氨酸（Arg）对大鼠肝纤维化的影响。方法:CCl4诱导Wistar大鼠6周建立肝纤维化动物模型，共30只动物随机分为对照组、Gln处理组和Arg处理组，每组10只。至8周结束时观察各组大鼠肝脏大体观、胶原蛋白含量和肝纤维化的程度。结果:大鼠肝纤维化模型至8周结束时，无1例死亡。Gln组肝脏纤维化最严重，对照组次之，Arg组最轻。结论:Gln加重了大鼠肝纤维化，而Arg明显减轻大鼠肝纤维化。