PD98059对人骨髓间质干细胞分化为成骨细胞的影响

目的:探讨胞外信号调节激酶(ERK)信号传导途径对骨髓间质干细胞(MSC)分化为成骨细胞的影响。方法:采用Ficoll-Paque淋巴细胞分离液分离成人MSC,体外扩增,应用地塞米松、β-甘油磷酸钠、vitaminC定向诱导MSC分化为成骨细胞。在成骨诱导液中加入不同剂量的PD98059,观察其对成骨细胞形成的影响。结果:MSC体外扩增15代可获得(3-4)×10¹²个细胞。在成骨诱导液作用下,MSC可在体外定向分化为成骨细胞。不同剂量的PD98059均可抑制MSC分化为成骨细胞,并有剂量依赖关系;同时促使部分细胞转化为脂肪细胞。结论:ERK信号传导途径可能在MSC分化为成骨细胞和脂肪细胞过程中起关键作用。     

人白细胞介素12在哺乳动物细胞中的稳定表达及其生物活性的研究

目的采用遗传基因工程方法获得具有生物活性的人白细胞介素12,探索其治疗肿瘤和慢性肝炎的可行性。方法采用已克隆的国人IL-12基因序列,利用内部核糖体切入位点(IRES)完成IL-12P35、P40双亚基共表达载体的构建,通过转染CHODHFR缺陷细胞,双抗夹心ELISA法筛选阳性克隆,MTX加压扩增,PCR检测其基因整合,T淋巴细胞增殖和诱生γ干扰素实验检测其生物活性。结果获得了稳定高效表达人IL-12的工程细胞系,表达产物为70×103左右的糖蛋白。结论本研究得到的基因重组人IL-12具有良好的生物活性,有强的诱导产生γ干扰素的能力和诱导活化T淋巴细胞增殖能力。     

Activation of MAP kinases,pp90rsk and pp70-S6 kinases in mouse mast cells by signaling through the c-kit receptor tyrosine kinase or FcϵRI: rapamycin inhibits activation of pp70-S6 kinase and proliferation in mouse mast cells

The high-affinity receptor for IgE, Fc_?RI, represents the major cell surface structure through which mast cells express immunologically specific secretory function. By contrast, the stem cell factor receptor (SCFR), which is encoded by c-kit, is essential for normal mast cell development. The signaling pathways initiated by the stimulation of mast cells through the Fc_?RI, which lacks intrinsic kinase activity, and the SCFR, a member of the receptor tyrosine kinase family, generally have been regarded to be distinct. We report here that mouse mast cells stimulated either with SCF or with IgE and specific antigen exhibit a remarkably similar pattern of activation of mitogen-activated protein kinases (MAPK), 90 kDa-S6 kinases (pp90^rsk), and pp70-S6 kinases (pp70-S6K). These results indicate that all three families of protein kinases are associated with the cell surface receptor-dependent activation of secretion, as well as proliferation, in mast cells. We also show that the immunosuppressant rapamycin, but not FK506, can inhibit both SCF-dependent pp70-S6 kinase activation and SCF-dependent proliferation in mouse mast cells, without suppressing IgE- and antigen-dependent mediator release. These findings suggest that the activation of pp70-S6 kinase represents an important link in the stimulation of cell proliferation by SCF. Our results also indicate that the intracellular signaling pathways initiated by stimulation of mast cells through the Fc_?RI or the SCFR exhibit more overlap than has previously been appreciated.     

角膜缘干细胞移植联合丝裂霉素C治疗复发性翼状胬肉

目的 观察自体角膜缘干细胞移植联合丝裂霉素C治疗复发件翼状胬肉的疗效.方法 将58例(62眼)复发性翼状胬肉患者随机分为2组,治疗组(32例,35跟)采用角膜缘于细胞移植联合应用丝裂霉素C;对照组(26例,27眼)单纯采用角膜缘干细胞移植术治疗.术后随访6～30个月并比较疗效.结果 治疗组1眼冉复发,再复发率2.86%;对照组5眼再复发,再复发率18.52%,两组差异具有统计学意义(P<0.05).治疗组角膜创面上皮平均愈合时间为(8.34 ±2.38)d,对照组为(7.21±2.55)d,差异无统计学意义(P>0.05).两组均未发现严重并发症.结论 角膜缘干细胞移植联合应用丝裂霉素C治疗复发性翼状胬肉再复发率低,并发症少,为复发性翼状胬肉安全和有效的治疗方法 .     

氨氯地平抑制氧化型胆固醇诱导的血管内皮细胞凋亡

目的:研究氧化型胆固醇(Triol与25-OH)对人脐静脉内皮细胞凋亡的诱导作用,并观察氨氯地平对氧化型胆固醇诱导内皮细胞凋亡的影响。方法:体外培养人脐静脉内皮细胞,利用光镜、电镜、DNA电泳及流式细胞仪测定作为凋亡检测指标。结果:对照及胆固醇组未检测到细胞凋亡,Triol与25-OH处理组光镜、电镜下可见典型的细胞凋亡形态学改变,电泳示"DNAladder",流式细胞仪检测出现亚二倍体峰,凋亡率分别为32.25%与23.04%,而氨氯地平使其凋亡率分别下降至13.42%与11.77%。结论:氧化型胆固醇(Triol与25-OH)可以诱导人脐静脉内皮细胞发生凋亡,而氨氯地平抑制其凋亡诱导作用。     

中枢神经系统不同部位来源的神经干细胞在体外生长特性的比较

目的 比较相同发育阶段中枢神经系统不同部位来源的神经干细胞在体外的生长特性。方法 胚胎小鼠(E14)于无菌条件下分别分离并收集皮层、纹状体、间脑、中．后脑和脊髓，各部分制备成单细胞悬液，接种在添加有纤维细胞生长因子(FGF)的无血清培养液内，神经干细胞克隆生成后，经免疫细胞化学方法鉴定细胞特性，并在相同条件下进行传代，相差显微镜下观察克隆生成和细胞的迁移特性。结果 在添加有纤维细胞生长因子的无血清培养液中，少量接种的单个细胞会增殖并形成悬浮于细胞培养液中的细胞克隆。这些克隆具有生成新克隆并分化成神经元和胶质细胞的能力。在相同发育阶段，皮层、纹状体、间脑均可生成悬浮的克隆，其中皮层生成的速度最快，纹状体、间脑较慢，中．后脑、脊髓生成克隆的速度最慢；生成克隆后，皮层克隆的贴壁能力最差，贴壁的克隆少有细胞从其底部迁出，纹状体、间脑克隆较易贴壁，贴壁克隆底部有明显的细胞迁出，中．后脑、脊髓生成的克隆不易悬浮，很快贴壁，在贴壁克隆的底部有大量的细胞迁出。结论 在无血清培养液中，神经干细胞可在体外增殖、传代并分化生成神经元和胶质细胞，不同部位来源的神经干细胞在体外生成克隆的速度和细胞迁移性不同，这可能同体内特定部位细胞的发育特性有关。     

血管性痴呆皮肤基底细胞微管的体视学定量研究

目的: 研究血管性痴呆(VD)皮肤基底细胞微管的生物学诊断意义。方法: 使用体视学方法对VD和正常健康老年人皮肤基底细胞微管进行测量, 用图象分析仪进行定量分析。结果: VD组的Vv=2.1926±1.1749、Lv=4.4531±2.4053、Na=2.2356±1.1980, 分别非常显著地高于正常老年组的Vv=1.3515±0.5376、Lv=2.7561±1.0963、Na=1.3781±0.5481; P<0.01。结论: 本研究提示VD患者基底细胞微管定量分析, 有可能为VD诊断提供一种非神经系统的生物学诊断指标。     

三氧化二砷抑制体外培养小鼠气道成纤维细胞增殖及c-myc与c-sis表达

目的：探讨三氧化二砷 (As2O3))对体外培养的小鼠气道成纤维细胞 (FB)增殖及原癌基因c-myc与c-sis表达的影响。 方法： 按不同药物分7组，在体外培养的FB中分别加入浓度为0.25、0.5、1.0、2.0和4.0 μmol/L的As2O3，在1、3、5和7 d后用记数法观察FB生长情况，并用流式细胞仪（FCM）检测不同浓度药物 对各组FB增殖的影响及各组c-myc与c-sis的阳性表达率。 结果： 各种实验浓度的As2O3对FB均有抑制作用，并有时间剂量效应。流式细胞仪分析显示，随着浓度的增高，G1期细胞比例逐渐增高，G2/M期细胞比例降低，浓度为2.0和4.0 μmol/L的As2O3能显著抑制c-myc与c-sis的表达。 结论： As2O3能抑制FB的增生，其机理可能与其下调c-myc与c-sis的表达有关。     

骨髓干细胞动员后归巢梗死心肌的实验研究

目的初步探讨骨髓干细胞动员后归巢梗死心肌的可能机制。方法结扎Wistar大鼠左冠状动脉制作急性心肌梗死(acutemyocardialinfarction,AMI)模型,用干细胞因子(SCF)动员骨髓干细胞,部分大鼠予激素干预治疗,另设AMI组为对照组(A组)。制模后24h杀死大鼠,取出心脏,免疫组化法了解归巢于梗死心肌的CD34细胞数量,心肌组织中炎症趋化因子基质细胞衍生因子(SDF-1)表达量,以及HE染色观察心肌组织学变化。结果应用SCF动员治疗后,AMI 动员组(A1组)大鼠梗死灶内SDF-1表达量明显大于AMI组和AMI 激素 动员组(A2组),同时AMI 动员组(A1组)大鼠梗死灶内CD34阳性细胞数量也明显大于另2组。而AMI 激素 动员组(A2组)的SDF-1表达量最少,其梗死灶内CD34阳性细胞数量也最少。AMI 动员组(A1组)大鼠心肌梗死程度轻,可见CD34阳性的幼稚心肌细胞样细胞。结论应用SCF动员AMI大鼠的骨髓干细胞后,其向梗死灶归巢的能力增强,较多CD34细胞迁移到缺血灶内,并向心肌细胞等分化。骨髓干细胞动员后,心肌梗死灶内SDF-1表达量上调是吸引骨髓干细胞归巢的可能机制之一。     

The instability of membrane markers expressed by human monocytes and macrophages in culture

Surface markers were tested on freshly isolated human monocytes and following their in vitro maturation to macrophages. The markers tested were HLA-DR antigens, receptors for the Fc of IgG and complement as well as membrane markers defined by monoclonal antibodies. The results revealed a dynamic expression of some of the markers on monocytes which was influenced by several variables. The expression of the markers was modulated by the presence of different sera, by treatment with lymphokines and interferon and following the in vitro maturation of monocytes to macrophages. The most unstable marker was found to be the HLA-DR, which was modulated by all these variables. The 63D3 was affected by different sera and culture supernatant, as well as following the maturation of monocytes to macrophages, but not by lymphokines and interferon. One of the markers, the Mac 120, was found to be relatively stable and did not change significantly following the maturation of monocytes to macrophages. The Fc and complement receptors were also stable in their expression under these conditions, but were probably partially blocked in the presence of human serum. These results indicated that at least some of the heterogeneity related to the monocyte population was probably not due to the occurrence of stable subsets of cells, but rather to reversible changes in marker expression.