骨髓单核细胞与心肌样细胞移植对兔心肌梗死面积影响的对比研究

目的评价骨髓单核细胞与心肌样细胞移植对心肌梗死面积影响是否具有差异。方法提取、分离、培养骨髓单个核细胞,向心肌样细胞定向诱导分化。心肌梗死模型制作2周后沿梗死周边区域注射100!l培养基或骨髓单个核细胞、心肌样细胞各3×108/100!l。移植前、后4周心脏超声检查,TTC染色评价梗死面积。结果①诱导后骨髓基质细胞(MSC)呈现心肌样细胞超微结构特征,PCR检查表达心肌收缩、舒张特异性蛋白肌球蛋白重链(β-MHC)、受磷蛋白(PHO)、心房颗粒(ANP)。②与对照组相比,细胞移植能降低梗死面积,心肌样细胞移植组效果更好[(35.17±1.76)%、(28.61±1.24)%和(22.82±3.12)%,P<0.05]。结论MSC可定向分化心肌样细胞,心肌样细胞移植在改善心肌细胞坏死,降低梗死面积方面效果优于骨髓单个核细胞移植。     

心肌样细胞与内皮祖细胞联合移植治疗兔心肌梗死心室重构的实验研究

目的:评价心肌样细胞和内皮祖细胞联合移植对心肌梗死心室重构疗效是否优于单一细胞移植。方法:体外骨髓穿刺提取、分离、培养骨髓间充质干细胞(mensenchymal stem cell,MSC),向心肌样细胞和内皮祖细胞定向诱导分化。心肌梗死模型制作成功2周后,随机分为对照组、心肌样细胞组、内皮祖细胞组、联合移植组,沿梗死周边区域注射100μl培养基或心肌样细胞、内皮祖细胞、二者混合悬液各3×1012/L。移植前、后4周心脏超声检查,TTC染色评价梗死面积、氯胺T氧化法测定血浆、心肌组织羟脯氨酸(hydroxyproline,Hyp)含量及基质金属蛋白酶含量。结果:①诱导后MSC呈现心肌样细胞超微结构特征,PCR检查表达β-肌球蛋白重链(β-myosin heavy main,β-MHC)、受磷蛋白(phospholamban,PLB)、心房钠尿肽(atrial natriuretic polypeptide,ANP);内皮祖细胞呈"铺路石"外观,高表达CD133并随时间推移表达逐步下降。②与对照组相比,细胞移植能改善心功能(P0.05),降低梗死面积(P0.05),血浆羟脯氨酸含量(P0.05),心肌组织羟脯氨酸(P0.05)基质金属蛋白酶(MMP-9)含量(P0.05),联合细胞移植组效果更好。结论:MSC可定向分化心肌样细胞和内皮祖细胞,两者联合移植能够更好降低梗死面积、改善心室重构,效果优于单一细胞移植。     

骨髓基质细胞移植对心肌纤维化的干预

目的:评价骨髓基质细胞移植对心肌梗死后心肌间质纤维化的影响。方法:30只日本大耳白兔,随机分为细胞移植组、药物治疗组、对照组,体外骨髓穿刺提取、分离、培养骨髓基质细胞,心肌梗死模型制作成功2周后沿梗死周边区域注射细胞悬液100μl(细胞移植组)或DMEM培养基100μl(对照组)或给予安体舒通20mg,bid,服用1个月(药物治疗组)。各组实验前、后4周经心脏超声检查,氯胺T氧化法测定血浆、组织羟脯胺酸含量,TTC染色评价梗死面积。结果:细胞移植组血浆、组织羟脯胺酸含量[(22.79±1.69)mg/L、(1.59±0.89)μg/mg]均低于对照组[(40.16±2.31)mg/L、(3.59±0.19)μg/mg]、药物治疗组[(34.24±1.98)mg/L、(2.67±0.81)μg/mg],均P<0.05。实验后4周时,细胞移植组心功能有所提高[LVEF(56.91±2.04)%],与对照组[(32.49±1.29)%]、药物治疗组[(53.22±2.13)%]比较,均P<0.05;梗死面积[(22.82±3.12)%]有所下降,与对照组[(29.73±2.11)%]、药物治疗组[(28.61±1.24)%]比较,均P<0.05。结论:细胞移植后可抑制心肌胶原合成、抑制心肌局部间质纤维化,是细胞移植心功能改善机制之一。     

人脂肪间充质干细胞治疗大鼠急性心肌梗死的实验研究

目的:探讨人脂肪间充质干细胞(HADMSCs)移植于大鼠缺血心肌后的增殖分化情况及心功能改善情况。方法:通过结扎法建立心肌梗死模型,1周后将BrdU标记的HADMSCs通过经心外膜注射至心梗移植组梗死心肌,行超声心动图检查。建模后5周行HE染色观察心肌梗死情况,TTC染色计算左室梗死面积百分比,免疫组织化学检测HADMSCs移植后的存活和分布情况及心肌特异性蛋白的表达。结果:超声检查心梗移植组左心室收缩末期内径、舒张末期内径均小于心梗对照组,而射血分数均大于心梗对照组(P0.05);TTC染色结果显示心梗移植组左室梗死面积百分比[(23.6±4.3)%]小于心梗对照组左室梗死面积百分比[(32.4±5.6)%](P0.05)。心肌组织免疫组织化学结果显示带有BrdU标记的移植细胞在心梗周边区域存活,且特异性肌钙蛋白呈阳性表达。结论:HADMSCs能够在大鼠梗死心肌内存活,并分化为心肌样细胞,减小梗死面积,改善心功能。     

骨髓间充质干细胞体外定向诱导内皮祖细胞的实验研究

目的:研究兔骨髓间充质干细胞(mensenchymal stem cell,MSC)在体外定向诱导分化为内皮祖细胞(endothelial progenitor cell,EPC)的状况。方法:取兔髂骨骨髓,经密度梯度离心法分离并培养骨髓间充质干细胞,实验组细胞在内皮细胞生长添加剂、血管内皮生长因子、成纤维细胞生长因子等诱导条件下定向分化为内皮祖细胞。对照组不干预,继续培养。结果:实验组细胞集落接近融合时形态呈现“鹅卵石”样或“铺路石”样外观,流式细胞仪检测发现实验组细胞较对照组高度表达CD133、CD34(P<0．05)。结论:体外诱导可使骨髓间充质干细胞分化为内皮祖细胞,并有效扩增。     

多种细胞移植治疗大鼠心肌梗死后功能性室壁瘤的疗效比较

目的:观察比较骨髓间充质干细胞(MSCs)、5-氮杂胞苷(5-Aza)诱导分化的心肌样细胞及2种细胞联合移植治疗大鼠心肌梗死后功能性室壁瘤的疗效.方法:体外培养大鼠的MSCs,及用5-Aza诱导成的心肌样细胞.结扎大鼠冠状动脉左前降支,形成心肌梗死,4周后用超声心动图检测并筛选形成功能性室壁瘤者,分4组:A组(n=10),在室壁瘤瘤部及周边部点状注射MSCs(106～107个);B组(n=10),注射心肌样细胞(106～107个);C组(n=10),联合移植MSCs和心肌样细胞(106～107个);D组(n=10)为对照组,注射0.9%氯化钠.术后4周用超声心动图和血流动力学方法测定大鼠的心功能.另外,用组织学方法评价细胞移植后毛细血管密度,Masson氏三色染色法测量室壁瘤范围.结果:心脏彩超结果显示,与D组相比,A组、B组和C组的左室舒张内径、左室收缩内径均明显缩小(P<0.05),短轴缩短率及左室射血分数明显增大(P<0.05),且C组优于A组和B组(P<0.05),A组和B组比较,差异无统计学意义(P>0.05).血流动力学检测结果显示,与D组相比,A组、B组和C组的左室舒缩压差和左室正负最大变化速率均明显增高(P<0.05),其中C组增高最明显(P<0.05),A组和B组比较,差异无统计学意义(P>0.05).苏木精-伊红染色血管计数结果显示,A组(3.452±0.168/高倍视野)和C组(3.383±0.129/高倍视野)的毛细血管密度高于D组(1.827±0.052/高倍视野)(P<0.05),B组(1.917±0.038/高倍视野)与D组比较,差异无统计学意义(P>0.05).Masson氏三色染色法评价室壁瘤范围(%)结果显示,A组[(21.32±0.90)%]、B组[(22.14±0.74) %]和C组[(21.98±0.51) %]的室壁瘤范围小于D组[(25.70±1.71) %],差异有统计学意义(P<0.05).结论:MSCs移植,心肌样细胞移植,及二者联合移植对大鼠室壁瘤均有修复作用,联合MSCs和心肌样细胞移植改善心功能及心室重构方面效果优于单项细胞移植.     

人受体活性修饰蛋白1基因修饰间充质干细胞对兔心肌梗死后心室重构的作用

目的探讨腺病毒介导人受体活性修饰蛋白1(hRAMP1)基因转染间充质干细胞(MSC)移植对心肌梗死后心肌纤维化和心室重构的影响及可能机制。方法建立心肌梗死再灌注兔模型,随机分为hRAMP1组(高表达hRAMP1基因的MSC移植,n=10)、MSC组(无基因修饰的单纯MSC移植,n=10)和对照组(生理盐水注射,n=10)。Western blot检测心肌梗死后1、3、7和28d心肌梗死局部基质金属蛋白酶9(MMP-9)和hRAMP1蛋白表达水平;同时行2,3,5三苯基氯化四氮唑染色检测心肌梗死面积,心肌组织Masson染色评价心肌梗死后胶原沉积和纤维化程度;超声心动图评价28d时左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室射血分数(LVEF)及短轴缩短率(FS)。结果细胞移植后,与对照和MSC组相比,hRAMP1组的LVEF[(57.2±6.3)%比(36.2±2.2)%、(45.3±5.4)%]和FS[(29.2±2.4)%比(13.5±1.4)%、(19.4±2.4)%]均升高(均P<0.05),而LVESD[(7.9±0.8)比(12.7±0.9)、(10.4±0.9)mm]和LVEDD[(12.7±1.2)比(17.3±2.4)、(16.3±1.1)mm]、心肌梗死面积、胶原容积分数均明显降低,胶原沉积减少。免疫印迹结果显示,hRAMP1组MMP-9蛋白表达较对照、MSC组明显增高。结论 hRAMP1移植通过促进梗死区心肌组织MMP-9表达,降低梗死区胶原沉积,抑制心肌纤维化,进而改善心室重构,提高心功能。     

细胞因子微球加强骨髓间充质干细胞移植对猪心肌梗死的疗效

目的 通过观察血管内皮生长因子(VEGF)缓释明胶微球与自体骨髓间充质干细胞(MSC)联合移植于猪心肌梗死模型梗死周边区3周后MSC的生存情况,结合磁共振成像(MRI),阐明改善局部微环境对自体MSC移植于缺血心肌后转归的影响,并直观评价MRI对移植MSC在体示踪及半定量分析的可靠性.方法 以乳化冷凝法制备VEGF缓释明胶微球并评价其缓释性能.成年中华小型猪12头,抽取髂骨骨髓并制备自体MSC,以顺磁性氧化铁颗粒(SPIO)和4',6-二脒基-2-苯基吲哚(4',6-Diamidino-2-phenylindole dihydrochloride,DAPI)标记细胞.按照随机化表将动物分为MSC移植组及MSC-VEGF缓释微球联合移植组.开胸结扎冠状动脉左前降支制备小型猪心肌梗死模型后第14天,直视下经心外膜于MSC组动物心肌梗死周边区注射MSC(9×107),于MSC-VEGF缓释微球组注射MSC(9×107)及VEGF缓释明胶微球(含9 μg人重组VEGF165).细胞和(或)微球移植后24 h及21 d,磁共振FGRE序列T2*像检测干细胞移植点低信号区的面积及信号强度.病理组织学检测细胞移植区域心肌组织毛细血管密度及干细胞存活情况.结果 明胶微球平均粒径为(104.0±22.6)μm,体内、外缓释VEGF均可达到10 d以上.小型猪心肌梗死模型建立后第14天,梗死区面积为33.6%±8.9%.细胞移植后24 h,MSC注射点于MRI显示为边界清晰的卵圆形T2*低信号区,细胞移植3周后,两组注射点T2*低信号区面积均减小(P<0.05),其与正常心肌组织间的信号对比度均减低(P<0.05).MSC-VEGF缓释微球组移植点毛细血管密度高于MSC组[(15.2±5.4)个/高倍视野比(10.2±5.0)个/高倍视野,t=2.43,P<0.05].MSC-VEGF缓释微球组MSC注射点移植细胞数多于MSC组[(354±83)个/高倍视野比(278±97)个/高倍视野,t=3.14,P<0.05],而MSC凋亡率则小于MSC-VEGF缓释微球组[(6.4±4.1)%比(11.9±4.8)%,t=2.97,P<0.05].结论 VEGF缓释明胶微球可以改善移植于缺血心肌区3周后MSC的生存情况.移植干细胞所生存的微环境是影响其转归的重要因素.MRI对于移植干细胞位置的在体示踪是可靠的,但不能作为对移植细胞定量或半定量分析的依据.     

血管内皮生长因子基因转染内皮祖细胞移植于大鼠缺血心肌的研究

目的:将编码有血管内皮生长因子基因的腺病毒(Ad.VEGF)转染诱导培养的骨髓内皮祖细胞(EPCs),移植于大鼠缺血心肌,评价其对心功能的保护和促血管再生作用。方法:Ficoll离心分离大鼠骨髓单个核细胞,诱导培养EPCs;在50倍的转染倍数(病毒数/靶细胞)下,用Ad.VEGF转染诱导的EPCs。然后将其移植于结扎冠状动脉前降支的Lewis大鼠缺血心肌内(组Ⅰ),同时设置单纯细胞移植组(组Ⅱ)和基因治疗组(组Ⅲ),以注射磷酸盐缓冲液的大鼠为对照组(组Ⅳ)。术后4周通过血流动力学指标评价其对心功能的保护作用;另外通过免疫组化染色观察移植细胞存活、分化和血管再生情况。结果:骨髓EPCs移植于缺血心肌4周后,缺血区的移植细胞部分分化为血管内皮细胞,组Ⅰ心功能明显好于组Ⅱ、组Ⅲ和组Ⅳ(P<0.01),在促血管新生方面,组Ⅰ也明显优于以上3组[组Ⅰ(32.2±3.5)、组Ⅱ(17.6±2.7)、组Ⅲ(19.4±3.3)、组Ⅳ(5.9±1.2)个/高倍视野]。结论:转染Ad.VEGF后的EPCs移植于缺血心肌后,可促进缺血心肌再血管化,更好地保护和改善心脏功能。     

大鼠骨髓干细胞移植对慢性心力衰竭模型缺血心肌的影响

目的探讨骨髓干细胞(bone marrow mesenchymal stem cell,MSC)移植对慢性心力衰竭大鼠模型心肌瘢痕周边及远隔区心肌的影响。方法制作心力衰竭大鼠模型,4周后分为细胞移植组(将5×10~6MSC注射到梗死后心肌)和对照组(注射等体积磷酸缓冲液),每组7只。组织多普勒评价室壁运动。Tunel染色检测心肌细胞凋亡情况。RT-PCR及Western杂交检测Bax、Bcl2基因和蛋白表达。结果细胞移植组在心肌瘢痕区观察到血管形成。与对照组相比,治疗后21 d移植组大鼠心肌收缩及舒张期纵向峰值速度在左室前壁、后壁、前室间隔及二尖瓣水平均显著升高[左室前壁收缩峰值速率为(0.67±0.02)cm/s对(0.31±0.02)cm/s,P<0.0013;左室前壁舒张峰值速率为(1.26±0.04)cm/s对(0.4±0.01)cm/s,P<0.001];移植组大鼠心肌凋亡细胞减少[(9.2±1.1)个/mm~2对(28.5±3.6)个/mm~2,P<0.001];瘢痕远隔区细胞比对照组细胞减小[(29.5±1.6)μm~2对(78.5±3.9)/μm~2,P<0.001]。与对照组相比,移植组大鼠心脏Bax基因和蛋白表达降低,Bcl2基因和蛋白表达升高。结论MSC移植改善瘢痕边缘缺血心肌血供,增强缺血心肌功能;拮抗细胞凋亡,防止远隔区细胞肥大。     

消化系恶性肿瘤病人LAK细胞和NK细胞功能与表型的变化

通过观察20例正常人和24例消化系恶性肿瘤病人外周血自然杀伤细胞(NK)和淋巴因子激活的杀伤细胞(LAK)的活性变化,以及加用重组白细胞介素2(rIL-2)刺激前后T淋巴细胞表型变化。结果发现肿瘤病人的NK细胞活性明显下降,但经rIL-2激活后LAK细胞活性得到明显提高,其溶解率接近正常水平。肿瘤病人的总T淋巴细胞(CD_(3+))和辅助/诱导T淋巴细胞(CD_(4+))水平低于正常,但抑制/杀伤淋巴细胞(CD_(8+))水平正常。辅助/诱导淋巴细胞与抑制/杀伤淋巴细胞之比为1.18,低于正常水平(1.55)。经加入rIL-2培养后,CD_(3+)和CD_(8+)淋巴细胞的比率明显升高并达正常水平。而在正常人此变化不明显,且加用rIL-2培养与不加者无显著差异。IL-2受体的表达正常人与肿瘤病人无异。结果显示胃肠道恶性肿瘤病人的免疫机制受到抑制,但能被IL-2提高至正常水平。     

Robust measurement of telomere length in single cells

Measurement of telomere length currently requires a large population of cells, which masks telomere length heterogeneity in single cells, or requires FISH in metaphase arrested cells, posing technical challenges. A practical method for measuring telomere length in single cells has been lacking. We established a simple and robust approach for single-cell telomere length measurement (SCT-pqPCR). We first optimized a multiplex preamplification specific for telomeres and reference genes from individual cells, such that the amplicon provides a consistent ratio (T/R) of telomeres (T) to the reference genes (R) by quantitative PCR (qPCR). The average T/R ratio of multiple single cells corresponded closely to that of a given cell population measured by regular qPCR, and correlated with those of telomere restriction fragments (TRF) and quantitative FISH measurements. Furthermore, SCT-pqPCR detected the telomere length for quiescent cells that are inaccessible by quantitative FISH. The reliability of SCT-pqPCR also was confirmed using sister cells from two cell embryos. Telomere length heterogeneity was identified by SCT-pqPCR among cells of various human and mouse cell types. We found that the T/R values of human fibroblasts at later passages and from old donors were lower and more heterogeneous than those of early passages and from young donors, that cancer cell lines show heterogeneous telomere lengths, that human oocytes and polar bodies have nearly identical telomere lengths, and that the telomere lengths progressively increase from the zygote, two-cell to four-cell embryo. This method will facilitate understanding of telomere heterogeneity and its role in tumorigenesis, aging, and associated diseases.Telomeres are the ribonucleoprotein structures that cap and protect linear chromosome ends from genomic instability and tumorigenesis (1, 2). Intriguingly, telomere shortening protects against tumorigenesis by limiting cell growth (3, 4), but also can impair tissue regenerative capability and cell viability (5, 6).Thus far, most assays of telomere length measure average telomere length from aggregates of many cells derived from dissected tissues, cultured cells, or blood (7). Telomere restriction fragment (TRF) determination (1, 8), a Southern blot-based technique, remains the “gold standard” for determining absolute telomere length, but requires a large amount of starting material (0.5–5 µg DNA) and several days for processing. Moreover, the requirements for gel electrophoresis and hybridization limit the scalability of this assay. Recently, a quantitative PCR (qPCR)-based method for telomere length measurement was developed, providing the convenience and scalability of PCR (9). Although the DNA requirement (35 ng) for qPCR is significantly less than TRF, it still relies on populations of cells to derive sufficient amount of DNA.Quantitative FISH (Q-FISH) allows sensitive visualization of relative telomere length from individual cells and individual telomeres, but this method requires many cells or metaphase arrested cells, which precludes its application to many sample types, including postmitotic cells, senescent cells, and other nondividing cells, and when only one actual cell is required to test. In addition, preparing chromosome spreads requires significant technical skill, and only proliferating cells within a population reach metaphase stage, so this analysis potentially biases the estimates of telomere length for a given cell population (10–12). High-throughput Q-FISH, flow FISH, and single telomere length analysis can be used for telomere measurement of dividing, nondividing, and senescent cells, but these methods also require large cell populations (13–15).The ability to measure telomere length in single cells rather than relying upon average telomere length in cell populations or the entire tissue enables the study of biological heterogeneity on a cell-by-cell basis, an issue of fundamental importance for studies of aging, development, carcinogenesis, and many other diseases. Here, we demonstrate an accurate determination of telomere length in individual cells, with the resolution and scalability of the qPCR telomere length assay.The basis of qPCR is that within a given cell, the ratio of the copy number of telomere repeats to the copy number of a multicopy reference gene is fixed (3), and this method, because of its simplicity, has been widely used to investigate a variety of telomere shortening-associated diseases (7), even sensitive enough to identify mild telomere dysfunction resulting from chronological life stress (16, 17). We adapted qPCR to measure telomere length in individual cells by using a preamplification step that specifically targets both the telomere and multicopy genes, followed by a qPCR assay to obtain telomere to reference gene (T/R) ratio. A single-cell telomere (SCT) length measurement method (SCT-pqPCR) runs robustly, and shows an identical T/R ratio for two sister blastomeres from two-cell–stage mouse embryos. The average result from SCT-qPCR with multiple single cells is linearly correlated to Q-FISH, TRF, and conventional qPCR assays designed for a large number of cells. The heterogeneity of telomere length among several populations of cells by SCT-pqPCR run on multiple single cells is consistent with—and sometimes superior to—results obtained by Q-FISH. Application of SCT-pqPCR to study telomere length during early embryo development, aging, and cancer demonstrate the value of this single-cell telomere length assay method.     

Processivity of peptidoglycan synthesis provides a built-in mechanism for the robustness of straight-rod cell morphology

The propagation of cell shape across generations is remarkably robust in most bacteria. Even when deformations are acquired, growing cells progressively recover their original shape once the deforming factors are eliminated. For instance, straight-rod-shaped bacteria grow curved when confined to circular microchambers, but straighten in a growth-dependent fashion when released. Bacterial cell shape is maintained by the peptidoglycan (PG) cell wall, a giant macromolecule of glycan strands that are synthesized by processive enzymes and cross-linked by peptide chains. Changes in cell geometry require modifying the PG and therefore depend directly on the molecular-scale properties of PG structure and synthesis. Using a mathematical model we quantify the straightening of curved Caulobacter crescentus cells after disruption of the cell-curving crescentin structure. We observe that cells straighten at a rate that is about half (57%) the cell growth rate. Next we show that in the absence of other effects there exists a mathematical relationship between the rate of cell straightening and the processivity of PG synthesis—the number of subunits incorporated before termination of synthesis. From the measured rate of cell straightening this relationship predicts processivity values that are in good agreement with our estimates from published data. Finally, we consider the possible role of three other mechanisms in cell straightening. We conclude that regardless of the involvement of other factors, intrinsic properties of PG processivity provide a robust mechanism for cell straightening that is hardwired to the cell wall synthesis machinery.     

特应性皮炎的免疫学发病机制

特应性皮炎是慢性复发性炎症性皮肤疾病，发病机制复杂，其中变态反应因素在发病机制中扮演着重要角色。目前认为Th1／Th2平衡失调是特应性皮炎重要的发病机制。本文围绕这一机制综述T细胞、树突状细胞、角质形成细胞及IgE在特应性皮炎发病机制中的作用。     

Regenerative medicine for the treatment of heart disease

Heart failure is a major cause of mortality worldwide with a steady increase in prevalence. There is currently no available cure beyond orthotopic heart transplantation, which for a number of reasons is an option only for a small fraction of all patients. Considerable hope has therefore been placed on the possibility of treating a failing heart by replacing lost cardiomyocytes, either through transplantation of various types of stem cells or by boosting endogenous regenerative mechanisms in the heart. Here, we review the current status of stem and progenitor cell‐based therapies for heart disease. We discuss the pros and cons of different stem and progenitor cell types that can be considered for transplantation and describe recent advances in the understanding of how cardiomyocytes normally differentiate and how these cells can be generated from more immature cells ex vivo. Finally, we consider the possibility of activation of endogenous stem and progenitor cells to treat heart failure.     

白藜芦醇对人肾癌细胞增殖和细胞周期的影响

目的探讨白藜芦醇（Res）对人肾癌细胞786-0（以下简称肾癌细胞）增殖和周期的影响。方法分别采用12.5、25、50、100μmol/L的白藜芦醇（Res）作用于肾癌细胞24 h;并设空白对照组。流式细胞仪检测细胞细胞周期。结果各浓度Res对肾癌细胞增殖均具有明显的抑制作用,表现为G1期及G2期细胞比例明显降低,S期比例明显升高,与对照组比较,P均〈0.05。Res 12.5μmol/L与25、50及100μmol/L比较,P均〈0.05;但25μmol/L与50、100μmol/L比较,P〉0.05。12.5μmol/L的Res抑制作用明显,当浓度达到25μmol/L时,抑制作用达最强;而继续升高浓度不能提高抑制作用。结论 Res对人肾癌细胞增殖有抑制作用,且具有剂量依赖性。     

骨髓干细胞移植在心血管疾病中的应用

近年来的研究表明，骨髓干细胞向心肌细胞分化已成为可能，动物模型及临床应用均证实，将骨髓干细胞移植于受损心肌可改善心肌缺血及心脏功能。     

Exposure of blood from patients with sickle cell disease to air changes the morphological, oxygen-binding, and sickling properties of sickled erythrocytes

We collected venous blood samples from 7 steady-state patients with homozygous sickle cell disease under venous oxygen pressure without exposure to air (UnExp-blood) and compared the morphological, oxygen-binding, and sickling properties with those of SS cells in aliquots of the same venous blood samples that were oxygenated in room air or at a PO2 near 180 mmHg (Exp-blood). Results showed that (1) upon deoxygenation under nitrogen, UnExp-blood generated a significantly higher percentage of elongated reversibly sickled cells (RSCs) than did Exp-blood; (2) upon gradual oxygenation of completely deoxygenated sickled cells, RSCs in UnExp-blood converted to discocytes at a higher oxygen pressure than did those in Exp-blood; (3) the degree of hysteresis between the sickling/desickling curves of UnExp-blood was greater than that of Exp-blood; and (4) deoxy-Hb S in hemolysate prepared from SS cells in UnExp-blood polymerized without a delay time, while those from Exp-blood polymerized with a distinct delay time. The in vivo properties of RSCs significantly changed upon oxygenation. We also found that the various properties of blood samples collected from patients with SCD by the ordinary method were similar to those of Exp-blood, probably because such blood samples are exposed to oxygen through air in the needle, syringe, and Vacutainer. Once SS cells were oxygenated, the in vivo properties of RSCs could not be recovered by partial deoxygenation to venous oxygen pressure.     

Propagation of large numbers of T cells with natural killer cell markers

Summary. Previously, a subset of T cells co-expressing the NK cell antigen CD56 has been described. These CD3⁺CD56⁺ cells are rare in peripheral blood collections and have been poorly characterized. We have developed culture conditions which allow for the rapid expansion of CD3⁺CD56⁺ cells. The protocol for cellular expansion includes the addition of interferon-gamma on day O, interleukin-1, interleukin-2 and a monoclonal antibody against CD3 on day 1 to peripheral blood lymphocytes. Cells of the CD3⁺CD56⁺ phenotype increased up to 6000-fold using this protocol after 16 d in culture. These cells have been characterized by flow cytometry and have been found to express the alpha, beta T cell receptor, co-express the CD5 and CD8 antigens and do not express the CD16 antigen. Morphologically, these cells cannot be distinguished from NK cells. CD3⁺CD56⁺ killer cells lyse a variety of tumour cells with intermediate activity between CD3^?CD56⁺ NK cells and CD3⁺CD56^? T cells.     

肺干细胞研究进展

干细胞研究是现代医学领域研究热点之一.肺部疾病所导致的不同程度呼吸系统病理改变和功能受损,都伴随着肺组织的修复和重塑过程.对于肺部疾病的干细胞研究和应用尚有许多问题有待进一步的明确和探索.肺干细胞包括了肺组织自身的干细胞修复和肺外组织来源的干细胞修复.肺组织内的干细胞包括肺内上皮性干细胞、肺问充质干细胞、肺侧群细胞;其中肺内上皮性干细胞又包括了基底细胞、Clara细胞、Ⅱ型肺泡上皮细胞、"芽孢"样细胞.肺外组织来源的干细胞修复包括骨髓间充质干细胞和造血干细胞.干细胞治疗方法在临床上有巨大的应用前景.