重组人生长激素在体外对人直肠癌细胞株HR8348增殖的影响

目的　探讨重组人生长激素 (rhGH )在体外对人直肠癌细胞增殖的影响。方法　实验分为对照组、rhGH组、奥沙利铂 (L OHP)组和rhGH +L OHP组 4组 ,利用体外细胞培养、MTT比色技术及流式细胞仪等方法 ,测定不同浓度的rhGH对人直肠癌细胞株HR83 48细胞倍增时间、细胞抑制率、细胞周期、增殖指数 (PI)和DNA抑制率的影响。结果　rhGH在体外不促进HR83 48细胞的分裂增殖 ,rhGH组与对照组比较 ,以及rhGH +L OHP组与L OHP组比较 ,其差异均无统计学意义 (P>0 .0 5 ) ;rhGH +L OHP组与对照组比较及rhGH +L OHP组与对应的rhGH组配对比较 ,细胞倍增时间明显延长 ,细胞抑制率增加 ,阻滞于G0 ～G1期的细胞数增加 ,S期和G2 ～M期细胞明显减少 ,PI明显降低 ,DNA抑制率显著升高 (P<0 .0 1,S期P<0 .0 5 )。结论　rhGH在体外不促进直肠癌细胞的分裂增殖。     

25-Hydroxyvitamin D3 metabolism in a human leukemia cell line

Summary 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) is a potent inducer of monocytic differentiation of the human promyelocytic leukemia cell line, HL-60. We have noted that 25-hydroxyvitamin D₃ (25(OH)D₃) in high doses is also capable of promoting monocytic differentiation of this cell line. To test the possibility that the latter activity is due to conversion of 25OHD₃ to 1,25(OH)₂D₃ by HL-60, we exposed HL-60 cells to 25OHD₃ and analyzed the products by HPLC and radioreceptor assay. When chromatographed in the traditional solvent system (isopropanol-hexane), a new peak appears which migrates with authentic 1,25(OH)₂D₃. However, in a solvent system containing dichloromethane, 90% of the peak migrates with another metabolite, 19-Nor-10-Keto-25OHD₃ (19-Nor-25OHD₃). Production of this metabolite is enhanced by living cells and is synthesized by both virgin HL-60 and those which have undergone differentiation. We next determined if authentic 19-Nor-25OHD₃ also promotes differentiation of this cell. As assessed by appearance of the monocyte-specific surface antigen (63D3) and macrophage-specific esterase activity, we find that this metabolite does, in fact, induce monocytic differentiation of HL-60 with a potency of approximately 1/200 that of 1,25(OH)₂D₃ and similar to that of 25OHD₃. In agreement with the effect upon cell maturation, 19-Nor-25OHD₃ displaces³H-1,25(OH)₂D₃ from its HL-60 receptor with an efficiency comparable to 25OHD₃. Hence, HL-60 cells convert 25OHD₃ to 19-Nor-25OHD₃, and 19-Nor-25OHD₃ induces monocytic differentiation of HL-60 with comparable efficiency to its precursor, 25OHD₃.     

子宫内膜癌术前放疗对Bcl-2,bax表达的影响

目的探讨Bcl-2，bax与子宫内膜癌的相关性及术前放疗对其表达影响。方法从2002年10月-2006年10月在我科住院的子宫内膜癌患者中筛选符合纳入标准的病例50倒。取其刮宫内膜癌组织标本、放疗且术后内膜癌标本。分为放疗前组、放疗后组，采用免疫组织化学方法检测Bcl-2，bax的表达，并观察表达的变化。结果BcL-2表达放疗后（64．0％）较放疗前（82．0％）减弱，差异有显著性（P〈0．01）；bax蛋白表达放疗后（76．0％）较放疗前（62．0％）增强，差异有显著性（P〈0．01），结论①子宫内膜癌的发生过程中与癌基因及抑癌基因Bcl-2,bax有密切的关系。②子宫内膜癌患者放疗前后癌组织中Bcl-2，bax表达水平发生了明显的改变，放射治疗可能是通过诱导细胞凋亡起到抗肿瘤作用的。③子宫内膜癌为放射敏感性肿瘤。     

Biochemical and ultrastructural alterations produced by miconazole and econazole in Trypanosoma cruzi

Miconazole and econazole, two fungicide imidazole derivatives, completely inhibited growth of Trypanosoma cruzi (Tulahuen strain) at concentrations of about 20 muM. Culturing of T. cruzi in the presence of lower doses of imidazole derivatives produced: decrease of 5,7-diene sterol content in epimastigotes (including ergosterol); disappearance of the nuclear chromatin, vacuolization and decrease in the electron density of the cytoplasm; selective surface alterations as revealed by an increased response to wheat-germ- and phytohemagglutinin. At variance with the effect of miconazole on Candida (De Nollin et al. (1977) Antimicrobial. Agents Chemother. 11, 500-513), miconazole and econazole, under the experimental conditions used, did not increase the rate of hydrogen peroxide generation by T. cruzi.     

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.     

黄连素对缺血再灌注心肌细胞损伤的保护作用

目的　研究黄连素对新生大鼠心肌细胞缺血再灌注损伤的保护作用。方法　取体外培养的新生大鼠心肌细胞于缺氧 2 4h复氧 1h造成缺血再灌注 ( I/ R)模型 ,观察细胞损伤情况 ;并将黄连素以 1.5× 10 - 6 m ol/ L、1.5× 10 - 5m ol/ L、1.5× 10 - 4 mol/ L 三种浓度分别加入培养基中 ,预处理 2 4h后 ,再置于上述缺氧复氧环境中培养 ,检测以上不同条件下细胞上清液中的乳酸脱氢酶 ( L DH)、丙二醛 ( MDA)、超氧化物歧化酶 ( SOD)含量 ,并检测各组细胞的凋亡率。结果　与正常对照组相比 ,缺血及再灌组细胞上清液中 L DH、MDA含量明显升高 ( P<0 .0 1) ,SOD活力则显著降低 ( P<0 .0 1) ,缺血组和再灌组凋亡率均升高明显 ( P<0 .0 1)。而用黄连素预处理后缺血及再灌组的 L DH、MDA显著低于用药前 ( P<0 .0 1) ,SOD则高于单纯缺血和再灌组 ( P<0 .0 1) ,上述作用在本实验黄连素浓度为 1.5× 10 - 6 m ol/ L～ 1.5× 10 - 4 mol/ L 范围内 ,随浓度升高而更加明显。特别是用黄连素 1.5× 10 - 5mol/ L 浓度预处理后 ,缺血组和再灌组的细胞凋亡率分别是 14.4%和 2 0 % ,分别与用药前 ( 17.4%和 41% )比较有显著性差异 ( P<0 .0 1)。结论　黄连素对缺血再灌心肌细胞有保护作用 ,其作用与浓度有一定依赖关系     

生物化学与细胞生物学课程整合的探讨

为了适应新世纪教学内容和课程体系改革的要求,我校借鉴美国哈佛大学医学院的经验,将生物化学与细胞生物学两门课程整合为“细胞的化学与生物学”。整合后在减少两个学科间重复内容、增加学科间联系、减少学时、早期接触临床、培养学生分析解决问题的能力、创新能力等方面有了很大改进,为这两门课程的改革开辟了新途径。     

A new method for application of force to cells via ferric oxide beads

 We describe a new method that uses straightforward physics to apply force to substrate-attached cells. In this method, collagen-coated magnetic ferric oxide beads attach to the dorsal surface of cells via receptors of the integrin family, and a magnetic field gradient is applied to produce a force. In this paper we present a complete characterization of the method in a configuration that is easy to use, in which a permanent magnet provides a fairly uniform gradient over a relatively large area. This allows a fairly uniform average force that can be controlled in magnitude, direction, and duration to be applied to a large number of cells. We show how to determine the applied force per cell by measuring the force per unit volume of magnetic bead, the distribution of bead diameters, and the distribution of beads per cell. We also show how to calculate the force per unit volume of bead in a three-dimensional region near the permanent magnet on the basis of field measurements, and present results for three of the magnets. An upward force applied to fibroblasts by this method produces a measurable time-dependent increase in attachment of cytoskeletal actin filaments to the force application points, and an increase in actin cross-linking. This is accompanied by an actin-dependent retraction of the force-induced upward movement of the dorsal surface of the cells. Received: 27 February 1997 / Received after revision: 10 August 1997 / Accepted: 1 September 1997     

小牛胸腺肽治疗乙型肝炎的疗效研究

本文报告了小牛胸腺肽(CTP)治疗乙肝患者50例(慢迁肝23例,慢活肝16例,重症肝炎11例)和HBsAg携带者10例的结果,CTP对消除或减轻临床症状和体征,改善肝功能具有明显的疗效,对慢迁肝,慢活肝和重症肝炎的治疗效果基本相同,各组间无显著性差异。对HBV血清学指标无重要改变,对HBsAg携带者疗效不侍。并对剂景、疗程与疗效的关系进行了讨论。