白藜芦醇通过调节 SIRT1/AMPK 信号通路保护氧-葡萄糖剥夺大鼠皮质神经元

目的：探讨白藜芦醇对单次和双次氧-葡萄糖剥夺(oxygen-glucose deprivation, OGD)原代皮质神经元沉默信息调节因子1(silent information regulator 1, SIRT1)、AMP 活化的蛋白激酶(AMP-activated protein kinase, AMPK)活性和 ATP 含量的影响及其可能的神经保护机制。方法皮质神经元取自18 d Wistar 大鼠胚胎,原代培养成功后通过2次OGD 制作体外反复缺血模型。采用台盼蓝染色法检测细胞存活率,蛋白质印迹法检测 SIRT1和磷酸化 AMPK 表达,去乙酰化酶荧光检测法检测 SIRT1活性,生物发光测定法检测 ATP 含量。结果与对照组比较,白藜芦醇(0．5μmol/L)预处理能显著增高单次和双次 OGD 后存活率(P 均<0．001)、ATP 含量(P 均=0．004)、SIRT1活性(单次：P =0．001;双次：P =0．002)以及 SIRT1(单次：P =0．029;双次：P =0．023)和磷酸化 AMPK (P 均=0．001)表达水平。结论白藜芦醇对单次和双次 OGD 皮质神经元均具有神经保护作用,其机制可能与上调 SIRT1/AMPK 通路和降低能量需求有关。     

Heterogeneity of rat cardiac cells of defined origin in single cell culture

Cells derived from tissue containing different elements of the conduction system of the neonatal rat heart have been isolated and maintained separately in culture. The autorhythmic cells are of three morphological types, one of which has not previously been described, and the distribution of these types is dependent on the anatomic origin of the cells. The heterogeneity in morphology and intrinsic rate of contraction is consistent with in vivo observations.     

Effects of doxorubicin, mitomycin C, and ethanol on Hep-G2 cells in vitro

There are conflicting results for experiments aimed at determining whether anticancer drug therapy of human hepatocellular carcinoma prolongs the survival rate effectively. The purpose of this study was to assess the effect of low concentrations of doxorubicin, mitomycin C, and ethanol on cell replication (cell number and proliferation), and cell apoptosis of cultured human hepatocellular carcinoma (Hep-G2) cells. After 1 day of exposure doxorubicin inhibited cell replication initially by 72%, but a partial recovery of the cell number was observed. Mitomycin C inhibited to the same extent but without recovery. Ethanol reduced the cell number even further, the maximum inhibition (12 days after exposure) being 96.4%. After 3 days of exposure all three agents stopped cell replication at a level of 2%–4% of the control (P < 0.001). Cell apoptosis was activated most strikingly by mitomycin C (5 μg/ml) after 1 day of exposure and by ethanol (150 μl/ml) after 3 days of exposure. Two-way repeated-measures analysis of variance showed statistically significant differences, with ethanol being the most significant followed by mitomycin C doxorubicin, and the control (P < 0.01). Thus, a low dose of ethanol combined with an exposure time of up to 3 days appears to be an effective regimen to control growth of human hepatocellular carcinoma cells in vitro. The strong induction of apoptosis by ethanol might be of additional benefit for a local application in vivo. Received: 3 April 1998  / Accepted: 30 September 1998     

1，6－二磷酸果糖对培养心肌细胞膜缺氧－再灌注损伤的保护作用

用培养的原代心肌细胞建立缺氧－再给氧方法，对缺氧６０分钟、１２０分钟及缺氧后再给氧３０及６０分钟时心肌细胞搏动、ＬＤＨ活性、（５１）￣Ｃｒ释放率、苔盼蓝摄取率、扫描电镜观察及１，６－二磷酸果糖对其影响进行了研究。结果显示：缺氧２小时可引起心肌细胞搏动频率减慢，再给氧后搏动频率加快；ＬＤＨ活性、（５１）￣Ｃｒ释放率和苔盼蓝摄取率增加，电镜显示心肌细胞膜受损。１，６－二磷酸果糖对心肌细胞膜具有保护作用。     

刺槐素在SH-SY5Y细胞氧-葡萄糖剥夺和小鼠脑缺血再灌注中的神经保护作用

目的 探讨刺槐素在SH-SY5Y细胞氧-葡萄糖剥夺和小鼠脑缺血再灌注中的神经保护作用.方法 培养神经母细胞瘤细胞SH-SY5Y,分为正常培养组、氧-葡萄糖剥夺(oxygen-glucose deprivation,OGD)组以及刺槐素小剂量组(1μmol/L)、中剂量组(5μmol/L)和大剂量组(10 μmol/L),复氧24 h后应用噻唑蓝染色法测定细胞存活率,乳酸脱氢酶(lactate dehydrogenase,LDH)法测定LDH漏出率.60只C57小鼠随机分为假手术组、脑缺血再灌注组以及小剂量组、中剂量组和大剂量刺槐素组,每组12只.采用线栓法制作大脑中动脉闭塞模型,缺血再灌注时给予刺槐素腹腔注射(小、中、大剂量组分别为6.25、12.5和25 mg/kg).再灌注后24 h时进行神经功能评分,应用2,3,5-氯化三苯基四氮唑染色检测脑梗死体积.结果 体外实验显示,1 μmol/L、5μmol/L和10 μmol/L刺槐素组SH-SY5Y细胞存活率分别为(90.34±6.87)％(P=0.000)、(85.47 ±2.24)％ (P=0.001)和(81.79±1.77)％(P=0.008),均显著高于OGD组的(70.62± 8.89)％.1μmol/L、5μm/L和10 μm/L刺槐素组SH-SY5Y细胞LDH漏出率分别为(159.11 ±13.11)％ (P=0.021)、(155.12±24.72)％(P=0.011)和(160.92 ±7.83)％ (P =0.027),均显著低于OGD组的(180.35±10.60)％.体内实验显示,大剂量刺槐素组神经功能评分显著低于与脑缺血再灌注组[(1.67±0.85)分对(2.50±0.55)分;P=0.018].小剂量、中剂量和大剂量刺槐素组梗死体积分别为(24.14±7.10)mm3、(17.18±3.19)mm3和(12.86±1.88)mm3,均显著小于脑缺血再灌注组的[(48.81±9.48) mm3](P均=0.000).结论 体外和体内实验均显示,刺槐素具有神经保护作用.     

人参培养细胞中粗多糖的提取分离及其理化特性

人参(Panax ginseng)是我国传统的珍贵药材,利用人参细胞培养方法产生人参皂甙类有用成分已有不少报道。现代医药学研究表明,人参多糖有较强的药理活性,如刺     

Cell-killing Activity and Kinetic Analysis of a Novel Antitumor Compound NC-190, a Benzo[a]phenazine Derivative

A novel antitumor compound, N-β-dimethylaminoethyl 9-carboxy-5-hydroxy-10-methoxybenzo[a]-phenazine-6-carboxamide sodium salt (NC-190), was evaluated for antitumor activity in vitro against cultured tumor cell lines, and the kinetics of cell killing was elucidated. NC-190 strongly inhibited the growth of all of 3 murine tumor cell lines, 7 human tumor cell lines and 2 normal cell lines. With continuous exposure, the 50% inhibition concentrations were in the range of 0.005–0.06 μg/ml, except for KATO-III (2.15 μ g/ml). By colony-forming assay, concentrations of NC-190 giving 90% cell kill (IC₉₀) at various exposure times were obtained with HeLa S3 cells. The plot of IC₉₀exposure time on a log-log scale was linear for NC-190 with a slope of -1, which is typical for cell cycle phase-nonspecific agents. A 2 h treatment with NC-190 induced a rapid reduction in cell viability at doses of more than 3 μ g/ml. At the dose where colony formation was completely inhibited, cell viability was persistently reduced to below 20% during the cell culture period. NC-190 cauced a dose- and time-dependent reduction in DNA synthesis. The inhibitions of RNA and protein synthesis were less than that of DNA synthesis. Spectroscopic studies of NC-190 mixed with calf thymus DNA demonstrated that NC-190 was capable of interacting with DNA. However, DNA thermal denaturation studies suggested that intercalation of NC-190 was weak in comparison with those of classical intercalating drugs.     

胃癌干细胞的分离、鉴定及其特性

背景：近年来随着肿瘤干细胞的深入研究,越来越多的证据表明肿瘤干细胞是恶性肿瘤转移复发的原因,因此分离鉴定出肿瘤干细胞对阐明肿瘤发病机制和研发抗肿瘤药物具有重要意义。 目的：分离培养胃癌干细胞,并检测胃癌干细胞的生物学特性。 方法：收集16例胃癌患者术中切除肿瘤组织,采用组织块贴壁培养法和酶消化培养法从肿瘤组织中分离胃癌干细胞,倒置显微镜下观察细胞形态,绘制生长曲线,并观察成骨成脂诱导分化能力。 结果与结论：两种方法均能够分离出胃癌干细胞,在显微镜下可以发现细胞形态为长梭形或多角样,细胞增殖生长达到融合时,呈漩涡状、放射状排列。从细胞生长曲线可以看出,1-3 d为潜伏期,4-9 d为对数增殖期,10 d后进入生长平台期。流式细胞仪检测结果显示：第3代胃癌干细胞高表达细胞表面标志物CD90、CD29、CD44,而低表达CD34、CD45、HLA-DR。第3代胃癌干细胞经成骨诱导后可见钙化结节,成脂诱导后细胞胞浆开始出现微小明亮的脂肪滴。结果表明胃肿瘤组织内存在肿瘤干细胞,且与正常细胞有相似的形态、生物特性以及多向分化能力,可能参与胃癌的发生、发展。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Absence of mutagenic effects of continuous and pulsed ultrasound in cultured (AL) human-hamster hybrid cells.

Mutagenic effects of continuous and pulsed ultrasound were looked for using an in vitro assay system, the A_L hybrid, that is up to 100 times more sensitive for mutagens such as x-rays and neutrons than the assays used previously to evaluate ultrasound. Cells in suspension in rotated plastic test tubes were insonated with continuous wave ultrasound at I MHz, I_SPTP, = 0.62–40 W/cm² for 0–40 min. Cells attached in the central region of culture flasks received pulsed exposures at f_c = 2.5 MHz, PRF = 1 kHz, 2 and 8 cycles per pulse, with p_ = 1.2 MPa (I_SPTA = 31–180 mW/cm²) for 0–30 min. Although these exposures were cytotoxic (the plating efficiency was decreased to 65% by the highest doses), induction of mutation, if any occurred, was less than would be expected in this test system from 10–30 cGy of x-ray.     

Mechanism underlying potentiation by progesterone of the kainate-induced current in cultured neurons

The effect of the neurosteroid progesterone on the kainate receptor-mediated response was studied in cultured chick spinal cord neurons using the whole-cell voltage-clamp recording technique. Progesterone rapidly and reversibly potentiates the kainate-induced current in a dose-dependent manner, with an EC₅₀ of 35 μM and a maximal potentiation of 30%. Potentiation of the kainate response by extracellularly applied progesterone is not significantly affected by inclusion of a saturating concentration of progesterone in the electrode buffer, indicating that progesterone acts at the extracellular surface of the membrane. Furthermore, progesterone enhances the kainate maximal response with little effect on the kainate EC₅₀.