三氧化二砷增强ST1571对K562细胞的细胞毒作用

目的 探讨ST1571联合三氧化二砷(arsenie trioxide，ATO)对慢性粒细胞白血病(CML)细胞增殖和凋亡的影响。方法 通过细胞增殖和活力检测、形态学观察、细胞凋亡率和细胞周期检测等方法观察ST1571和ATO对CMI，细胞系K562细胞的增殖抑制与诱导凋亡效应。结果 ST1571和ATO均可抑制K562细胞增殖并诱导其凋亡，并使细胞阻滞于G2／M期；当两药物联合运用时，明显增强对K562细胞增殖的抑制作用，细胞凋亡率也较两药单用组明显增高。结论 ATO能增强ST1571对K562细胞的细胞毒效应和诱导凋亡作用。     

贫血患者血浆可溶性Fas水平变化及其意义

目的 :探讨缺铁性贫血 (IDA)、巨幼细胞性贫血 (MA)、再生障碍性贫血 (AA)等贫血患者血浆可溶性 Fas(s Fas)水平变化及其临床意义。方法 :用酶联免疫吸附实验法 (ELISA)检测 37例贫血患者 (其中 IDA 2 0例、MA 9例、AA 8例 )及 2 5例正常对照血浆 s Fas水平。结果 :巨幼细胞性贫血和再生障碍性贫血患者血浆 s Fas水平显著高于正常对照组 (P<0 .0 5) ,缺铁性贫血患者血浆s Fas水平与正常对照组无显著差别。结论 :血浆 s Fas水平升高可见于多种病理状态及机体免疫失衡 ,s Fas的生物学功能及其对机体免疫、对 Fas/ Fas L凋亡途径的干扰有待于进一步研究     

β细胞凋亡与l型糖尿病关系的研究进展

1型糖尿病 (ｔｙｐｅ 1ｄｉａｂｅｔｅｓｍｅｌｌｉｔｕｓ,Ｔ1ＤＭ) ,也称胰岛素依赖型糖尿病 (ｉｎｓｕｌｉｎｄｅｐｅｎｄｅｎｔ ｄｉａｂｅｔｅｓｍｅｌｌｉｔｕｓ,ＩＤＤＭ) ,是一种Ｔ淋巴细胞介导的自身免疫性疾病 ,表现为胰岛 β细胞的选择性破坏。当 90 %的 β细胞遭自身Ｔ细胞免疫攻击后 ,胰岛素的分泌量绝对不足时 ,就导致出现高血糖。以往的实验证实β细胞的损伤与凋亡密切相关 ,故 β细胞凋亡在Ｔ1ＤＭ发病起因中的作用是目前研究的重点。现仅就近年来这方面的研究进展综述如下。1　Ｔ1ＤＭ胰岛局部存在 β细胞过度凋亡的证据Ｎ…     

脉络膜黑色素瘤脱色素处理后Caspase-3的免疫组化研究

目的 观察凋亡基因Caspase-3在脉络膜黑色素瘤(choroidal melanoma)中的表达及分型与细胞凋亡的关系。方法 收集20例脉络膜黑色素瘤标本，对其进行Caspase-3免疫组织化学染色，观察表达情况及染色强度。结果 Caspase-3在脉络膜黑色素瘤有较好的表达，在梭形细胞型中5例／6例呈阳性表达，在混合型中6例／8例呈阳性表达，在上皮样瘤细胞型中3例／4例呈阳性表达，在坏死型中1例／2例呈阳性表达，且在各型之间没有显著性差异(P＞0．05)。结论 凋亡在脉络膜黑色素瘤中存在；Caspase-3在脉络膜黑色素瘤的发生发展中起重要作用。     

EphB4反义寡核苷酸对人脑胶质瘤细胞增殖、凋亡及迁移的作用

目的观察EphB4反义寡核苷酸(ASODN)对人脑胶质瘤细胞增殖、凋亡及迁移的影响,探讨EphB4的生物学功能。方法人工合成EphB4 ASODN,脂质体转染U87细胞。分别应用RT-PCR以及免疫组织化学染色方法检测EphB4 mRNA和蛋白质,评估阻抑效应;并应用MTT法和流式细胞术检测细胞的增殖和凋亡;采用Boyden侵袭小室法检测细胞迁移和侵袭力。结果(1)由脂质体转染的EphB4 ASODN对U87细胞EphB4 mRNA和蛋白质表达具有不同程度的抑制作用,且呈现一定的时间-剂量依赖性,600nmol/LASODN作用于U87细胞72h,EphB4 mRNA相对表达量为0.30±0.05,EphB4蛋白表达水平亦明显减弱。(2)各实验组EphB4 ASODN对U87细胞增殖均具有抑制作用,呈明显时间-剂量依赖性;以600nmol/LASODN作用72h,U87细胞生长抑制率达到68.70%,而对照组则无明显抑制作用。(3)EphB4 ASODN诱导U87细胞凋亡呈剂量依赖性。(4)EphB4 ASODN组U87细胞的跨膜数为17.82±2.35,与空白对照组及NSODN组比较差异具有统计学意义(P<0.01)。结论EphB4在人脑胶质瘤细胞增殖、凋亡、迁移和侵袭过程中发挥重要作用,可能成为脑胶质瘤基因治疗的一个新靶点。     

红三叶总异黄酮对人乳腺癌MCF-7细胞增殖和凋亡的影响

目的研究红三叶总异黄酮对人乳腺癌MCF-7细胞的生长抑制和凋亡的诱导作用。方法在体外细胞培养下,采用不同质量浓度红三叶异黄酮和5-Fu处理MCF-7细胞,MTT法测定红三叶总异黄酮抑制MCF-7细胞增殖的量-效关系;TUNEL法、流式细胞术分析其细胞凋亡率和周期分布。结果红三叶总异黄酮对MCF-7细胞增殖的抑制作用随药物质量浓度提高和作用时间延长而更加明显,而在低质量浓度时却出现轻微促细胞增殖现象。TUNEL法、流式细胞术分析结果表明,红三叶总异黄酮能诱导MCF-7细胞凋亡,阻滞细胞于G2/M期,降低细胞增殖指数,且这种作用也存在剂量-效应关系。结论红三叶总异黄酮可抑制MCF-7细胞增殖并诱导其凋亡,具有抗肿瘤作用。     

线粒体和细胞凋亡

线粒体在能量代谢和自由基代谢过程中占有十分重要的地位.线粒体产生大量超氧阴离子,并通过链式反应形成活性氧(reactive oxygen species,ROS),当ROS水平较低时,可促进细胞增生;而当ROS水平较高时,使得线粒体MPTP开放,不仅导致跨膜电位崩溃,也使细胞包素C外漏[1].     

Pfizer收购Idun医药公司

世界上最大的制药商Pfizer公司称已就收购Idun医药公司达成协议。后者是一家美国私营企业，致力于发现与开发控制细胞凋亡（一种涉及许多疾病过程的程序性细胞死亡）的药物。     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

持续压力超负荷对兔左心室细胞凋亡的影响

OBJECTIVE: To study the effect of chronic pressure overload on the apoptosis of the left ventricle myocytes in rabbits. METHODS: Rabbit models of chronic pressure overload-induced heart failure were prepared in which dynamic changes of apoptotic myocytes in the left ventricle were observed by way of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. RESULTS: Only a few apoptotic cells was observed in the sham-operated group, while in the experimental group, the apoptotic left ventricle myocytes significantly increased after operation, presenting a peak level between day 3 and day 7. Seven days after the operation, the apoptotic myocytes began to decrease and till day 14, the apoptotic cell number had been smaller than that measured on day 1. When signs of heart failure set in, the apoptotic myocytes were again increased (P<0.001). CONCLUSION: During chronic pressure overload, myocyte apoptosis in the left ventricle is elevated at the early stages and undulates subsequently, with the peak occurring before hypertrophy is obvious.