甲基丙烯酸环氧丙酯体外诱导的人胚肺成纤维细胞DNA链断裂

甲基丙烯酸环氧丙酯（GMA）导致人胚肺成纤维细胞（HELFs）恶性转化及其潜在致癌机理尚未阐明. 本研究用0.5-5.0 mg·L^-1的GMA给体外培养的HELFs染毒2 h和12 h,或用5.0 mg·L^-1的GMA染毒15 min-24 h, 应用单细胞凝胶电泳技术（彗星试验）对GMA引起的HELFs DNA断裂作用进行了初步探讨. 琼脂糖凝胶电泳及流式细胞仪检测等方法观察了GMA对细胞凋亡的诱导作用. 结果表明, GMA可导致染毒细胞DNA发生剂量和时间依赖性链断裂. 用5.0 mg·L^-1的GMA染毒后仅1 h断裂作用即已显著, 并随染毒时间延长而递增, 至24 h时损伤最为严重. 但在同样条件下未观察到GMA对细胞凋亡的诱导作用. 结果提示GMA导致的非凋亡性DNA链断裂可能是其诱导HELFs恶性转化早期重要的遗传事件之一.     

大黄素对抗顺铂引起的WI-38细胞凋亡

目的　从细胞水平研究大黄素对顺铂引起WI 38细胞凋亡的影响。方法　采用MTT法检测细胞毒性 ,用形态学观察、DNA凝胶电泳及流式细胞仪检测细胞凋亡。结果　WI 38细胞经大黄素和顺铂同时处理 2 2h后 ,30mg·L- 1大黄素可明显减轻顺铂引起的细胞毒性 ,其IC50 值由 (16± 3)mg·L- 1增加至 (34± 6 )mg·L- 1;可明显抑制顺铂引起的细胞形态学改变、核异染色质边集和DNA片段化 ,使顺铂 10和 30mg·L- 1导致的细胞凋亡率由 35 .5 6 %和33.99%降至 9.2 1%和 10 .2 5 % ,S期细胞百分数由6 2 .6 6 %和 4 8.4 6 %降至 4 8.6 7%和 36 .18%。结论　大黄素可对抗顺铂所致WI 38细胞凋亡 ,可能与其对细胞周期的影响有关     

甲基丙烯酸环氧丙酯体外诱导的人胚肺成纤维细胞DNA链断裂

甲基丙烯酸环氧丙酯 (GMA)导致人胚肺成纤维细胞 (HELFs)恶性转化及其潜在致癌机理尚未阐明 .本研究用 0 .5- 5.0 mg· L-1的 GMA给体外培养的 HELFs染毒 2 h和 1 2 h,或用 5.0 mg· L-1的 GMA染毒 1 5min- 2 4 h,应用单细胞凝胶电泳技术 (彗星试验 )对 GMA引起的 HELFs DNA断裂作用进行了初步探讨 .琼脂糖凝胶电泳及流式细胞仪检测等方法观察了 GMA对细胞凋亡的诱导作用 .结果表明 ,GMA可导致染毒细胞 DNA发生剂量和时间依赖性链断裂 .用 5.0 mg· L-1的 GMA染毒后仅 1 h断裂作用即已显著 ,并随染毒时间延长而递增 ,至 2 4 h时损伤最为严重 .但在同样条件下未观察到 GMA对细胞凋亡的诱导作用 .结果提示 GMA导致的非凋亡性 DNA链断裂可能是其诱导 HELFs恶性转化早期重要的遗传事件之一     

维生素E琥珀酸酯体外防护顺铂肝细胞毒性并增强其抗肿瘤细胞增殖活性

目的　研究维生素E琥珀酸酯 (VES)对顺铂(CP)肝细胞毒性及联合用药增强抗肿瘤活性的可能。方法　用二步灌流法分离人和大鼠肝细胞 ,接种于胶原铺被的 96孔板 ,细胞贴壁后 ,分别加入一系列浓度的CP ,VES及CP +VES ,于 4 8h用噻唑蓝(MTT)比色法检测细胞存活率 ,并计算半数抑制浓度 (IC50 ) ;同样方法用于检测CP ,VES及CP +VES对人前列腺癌细胞系DU 14 5和人大肠癌细胞系CCL2 2 9的抗增殖作用。结果　CP ,VES ,CP +VES 1mg·L- 1,CP +VES 5mg·L- 1,CP +VES 10mg·L- 1对人肝细胞的IC50 分别为 2 .35 ,>10 0 ,2 .2 6 ,4 .2 5 ,6 .93mg·L- 1;CP ,VES ,CP +VES 5mg·L- 1,CP +VES 10mg·L- 1,CP +VES 2 5mg·L- 1对大鼠肝细胞的IC50 分别为 4 .70 ,>10 0 ,10 .94 ,17.5 7,2 3.2 4mg·L- 1;CP ,VES ,CP +VES 5mg·L- 1,CP +VES 10mg·L- 1,CP +VES 2 5mg·L- 1对DU 14 5和CCL2 2 9的IC50 分别为6 .36 ,5 5 .36 ,5 .0 4 ,4 .85 ,0 .5 8和 9.5 8,39.4 7,7.2 9,4 .2 2 ,2 .4 3mg·L- 1。结论　VES能明显减低CP所致人和大鼠肝细胞毒性 ,增强CP对DU 14 5和CCL2 2 9细胞的抗增殖作用     

应用Bhas 42细胞转化实验检测环磷酰胺、丝裂霉素C和氨苄西林钠致癌作用

目的采用Bhas 42细胞转化实验检测已知有遗传毒性的化学品在化学致癌中的引发和促生长作用,评价Bhas 42细胞转化实验检测化学品致癌作用的可靠性。方法①通过细胞毒性实验确定环磷酰胺、丝裂霉素C和氨苄西林钠进行Bhas 42细胞转化实验的浓度。②引发实验:细胞接种当日为第0天,第1天换成含有相应最终浓度的受试物或0.5%DMSO的DF5F培养基,培养72 h,第4天换成不含药物的DF5F培养基,培养至第21天。第22天将细胞固定、染色、并计数细胞数大于50的集落数。③促生长实验:接种当日为第0天,第4天换成含有相应受试物或0.5%DMSO的DF5F培养基并连续培养至第14天,期间第7天,第11天更换同样培养基,每15天换成不含药物的DF5F培养基,培养至第21天。第22天固定、染色细胞、计数细胞数大于50的集落数。结果按照70%的细胞存活率以及前期文献结果确定最终浓度为:氨苄西林钠1750 mg·L-1;环磷酰胺1300 mg·L-1;丝裂霉素C 0.01 mg·L-1;3-甲基胆蒽1 mg·L-1,佛波酯0.05 mg·L-1。引发实验结果显示,3-甲基胆蒽,丝裂霉素C和环磷酰胺集落数显著多于空白对照、并且两者比值>2,判定为有引发作用的致癌化学品。促生长实验结果显示,佛波酯集落数显著多于空白对照、并且两者比值大于2,因此判定为有促生长作用的致癌化学品。结论 Bhas42细胞转化实验不仅可以检测出遗传实验可检测出的致癌阳性化学品和非致癌化学品,还可检测出遗传实验结果为假阴性的致癌阳性化学品,可以作为一种快速易操作的致癌物预测体外模型。     

褪黑素对低氧诱导的BV-2小胶质细胞CD45表达增高的抑制作用(英文)

目的　研究褪黑素对低氧激活的小胶质细胞CD4 5表达的影响 ,以探讨褪黑素的抗衰老和抗阿尔茨海默病的作用机制。方法　体外培养BV 2小胶质细胞 ,用终浓度为 2 .0mmol·L- 1的连二亚硫酸钠作用 4 8h ,造成慢性低氧模型 ,药物处理组在低氧的同时给予褪黑素。相差显微镜下观察小胶细质胞形态学变化 ,流式细胞术测定缺氧状态下BV 2小胶质细胞表面CD4 5的表达 ;体外培养BV 2小胶质细胞用终浓度为 0 .0 1,0 .1,1.0 μmol·L- 1的褪黑素作用5min ,加入 2 0mg·L- 1的脂多糖 37℃孵育 12h ,Griess试剂法检测培养上清中NO的含量。结果　连二亚硫酸钠引起的低氧可明显增加BV 2小胶质细胞CD4 5的表达 ,荧光强度增至 2 3.9± 14 .2 (对照组为0 .80± 0 .73) ,低氧也可使小胶质细胞的形态发生阿米巴样变 ,而 0 .0 1,0 .1,1.0 μmol·L- 1的褪黑素可剂量依赖性地减少低氧诱导的CD4 5表达 ,抑制由低氧引起的小胶质细胞的阿米巴样变。但褪黑素对脂多糖诱导的BV 2小胶质细胞培养液中NO的升高无明显抑制作用。结论　褪黑素抑制小胶质细胞的激活与其抗氧化作用密切相关 ,可能是其抗炎和防治阿尔茨海默病作用的重要理论基础     

党参白术提取物分别和合用诱导IEC-6细胞增殖分化的作用

目的　观察党参提取物 (D h)和白术提取物 (B t)对小肠隐窝细胞 (IEC 6 )增殖、分化的作用及其二者配伍对IEC 6细胞增殖的影响。方法　IEC 6细胞培养 2 4h ,加入不同剂量的D h、B t及二者的配伍溶液 ,2 4h后用MTT法观察细胞增殖 ,显微镜观察细胞分化的形态特征。结果　D h在 2 5 0mg·L-1以下剂量时对细胞增殖无影响 ,剂量提高到 5 0 0mg·L-1和 10 0 0mg·L-1时 ,明显促进细胞的增殖。B t各剂量均无促进细胞增殖的作用 ,在 5 0 0mg·L-1和10 0 0mg·L-1剂量时 ,细胞增殖反见减弱。二药配伍后 ,促进细胞增殖的作用明显增强 ,具有一定的剂量依赖关系 ,其效果优于D h ;IEC 6细胞在B t作用下 ,分化程度增高 ,低倍镜下细胞呈典型的上皮细胞形态 ,细胞排列呈条索状 ,部分呈腺管状排列。高倍镜下可观察到隐约有细胞连接样结构 ,上皮细胞似有微绒毛形成的趋势。D h处理的细胞分化程度较低 ,镜下所见多为未分化的梭状细胞 ,且排列不规则 ,无任何形成腺管的趋势和有细胞连接样结构。结论　D h能促进细胞增殖 ,B t可促进细胞分化 ,二者配伍后促进细胞增殖作用明显增强 ,有协同作用     

生技霉素药代动力学性能研究

目的　研究生技霉素药代动力学过程。方法　测定狗口服生技霉素 10mg·kg-1,2 0mg·kg-1,30mg·kg-1血药浓度并与乙酰螺旋霉素比较 ;测定大鼠灌胃生技霉素 40mg·kg-1,80mg·kg-1,12 0mg·kg-1血药浓度及大鼠灌胃生技霉素 40mg·kg-1后尿、胆汁活性产物回收率。血药浓度及尿、胆汁药物浓度以微生物法测定。 3P87程序拟合计算药物动力学参数。结果　狗口服 3组剂量生技霉素 ,结果表明药物吸收较快 ,lag time为 10～ 30min ;Tmax1 43～ 2 44h ;Cmax1 0 2～ 2 94g·L-1;T1/ 2α0 48～ 1 81h ;T1/ 2 β8 40～10 5 2h ;3组剂量AUC值分别为 15 2 5 ,2 3 70 ,31 40mg·L-1·h-1,表明药物在此剂量范围内呈线形药代动力学特征 ;MRT值分别为 8 11,8 38,8 71h ,不随剂量增减而改变。大鼠口服 3组剂量生技霉素 ,Tmax1 5 7～ 2 45h ;Cmax0 39～ 3 14mg·L-1;T1/ 2α 1 36～ 1 77h ;T1/ 2 β15 6 3～2 0 6 4h ;MRT值约为 13 0h。AUC值分别为 8 44、16 5 4、37 5 8mg·L-1·h-1,同样呈线形药代动力学特征。在相同的实验条件下 ,进行狗口服 3组剂量乙酰螺旋霉素药物动力学对比实验 ,测得ASPM药物动力学参数为 :lag time为0 37～ 0 44h ;Tmax1 49～ 2 2 6h ;Cmax 0 87～ 3 34mg2 0 0 0 0 3 0 5收稿 ,2 0 0     

单剂量与多剂量口服罗红霉素缓释片与普通片的犬体药物动力学研究

目的　研究健康家犬单剂量与多剂量口服罗红霉素(Rox)缓释片的药物动力学。方法　采用健康家犬 6只随机交叉单剂量与多剂量口服Rox缓释片与普通片 ,微生物法测定血药浓度 ,应用 3p97程序计算主要药动学参数 ,对AUC0～∞ 、AUC0～T或AUC0～τ的对数值进行方差分析、双单侧t检验等统计学处理 ,以 80 %～ 12 5 %为等效标准 ,评价缓释制剂与普通制剂的生物等效性。结果　单剂量时Rox缓释片的Tmax、Cmax、AUC0～T、AUC0～∞ 和MRT分别为(2 2 5± 0 99)h、(4 2 6± 1 70 )mg·L-1、(2 8 73± 10 4 6 )mg·h·L-1、(34 6 4± 9 5 7)mg·h·L-1和 (15 84± 1 6 3)h ,普通片的上述参数分别为 (1 33± 0 2 6 )h、(6 32± 2 79)mg·L-1、(2 8 6 8± 8 16 )mg·h·L-1、(34 4 9± 5 6 3)mg·h·L-1和 (12 95± 1 5 6 )h。多剂量达稳态时Rox缓释片的Tmax、Cmax、Cmin、AUC0～τ、AUC0～∞ 、Cav、DF和FI分别为(2 5 0± 0 4 5 )h、(4 38± 1 2 5 )mg·L-1、(0 4 9± 0 0 6 )mg·L-1、(2 4 91± 2 38)mg·h·L-1、(39 71± 6 4 8)mg·h·L-1、(1 0 4± 0 10 )mg·L-1、370 4 2 %± 98 4 1%和 15 7 36 %±11 86 % ,普通片的上述参数分别为 (1 4 2±0 38 )h、(6 13± 1 2 6 )mg·L-1、(0 4 3± 0     

铁杉灵芝多糖FⅢ-2对人组织瘤细胞和人外周血白细胞产生炎症性细胞因子的影响(英文)

用放射免疫分析法及逆转录聚合酶链反应法 ,比较研究水不溶性铁杉灵芝多糖 (FⅢ 2 )及其吡啶 氯磺酸修饰产物 (FⅢ 2 S)对人炎症性细胞因子蛋白质及其mRNA产生的影响 .结果表明 ,FⅢ 2 (4 ,4 0或 4 0 0mg·L- 1)显著提高低剂量脂多糖 (LPS) 10mg·L- 1协同佛波醇 14烷酰乙酸盐 (PMA) 2 0 0nmo1·L- 1诱导的人组织瘤THP 1细胞产生肿瘤坏死因子α(TNFα) ,然而明显地抑制高剂量LPSl0 0mg·L- 1协同PMA诱导的THP 1细胞产生TNFα .FⅢ 2 S(4或4 0mg·L- 1)提高无刺激剂细胞产生TNFα ,高浓度FⅢ 2 S(4 0 0mg·L- 1)抑制TNFα产生 .FⅢ 2与FⅢ 2 S提高白介素 8的产生 ,降低刺激剂引起的白介素 1α的产生 .FⅢ 2的抗肿瘤作用可能是与TNFα产生有关 .FⅢ 2对人外周血单核细胞产生各种细胞因子和对THP 1细胞产生细胞因子的机理基本上相同 .结果提示 ,松杉灵芝菌丝体水不溶性多糖在不同的刺激条件下具有双向免疫调节作用 .化学修饰的多糖可改变原多糖对细胞因子产生的调节方向 .     

Analysis of the Transforming Potential of Growth and Differentiation Factors in Syrian Hamster Embryo Cells: Reversible and Irreversible Transformation

The mitogenic growth and differentiation factor (GDFs) oncostatin M (OM), epidermal growth factor (EGF), fibroblast growth factor 4 (FGF-4), platelet-derived growth factor AA (PDGF AA), PDGF AB, and PDGF BB and the anti-mitogenic GDF, transforming growth factor beta one (TGF-beta1), were tested in the 7-day continuous exposure and 24-h transient exposure Syrian hamster embryo (SHE) cell transformation assay to determine their reversible and irreversible transforming potential. OM was negative while EGF, FGF-4, and PDGF AA were positive for statistically significant morphological transformation (MT) in the 7-day exposure SHE cell transformation assay. PDGF AB and PDGF BB (but not EGF, FGF-4, and PDGF AA) were positive for statistically significant MT in the 24-h transient exposure SHE cell transformation assays. TGF-beta1 was not only negative for the induction of MT in the 7-day and 24-h exposure SHE cell transformation assays, but suppressed the spontaneous background transformation response. Investigation of the transformation suppression potential of TGF-beta1 demonstrated that TGF-beta1 was able to irreversibly suppress the transformation potential of a variety of transforming agents including growth factors, Ames assay positive carcinogens, and Ames assay negative carcinogens. PDGF AA and PDGF BB were investigated to better understand the reversible and irreversible transformation response. Differences in the receptors activated, the proteins phosphorylated by the receptors, and immediate early gene expressed were observed in SHE cells treated with either PDGF AA or PDGF BB. Importantly, SHE cells treated with TGF-beta1 and PDGF BB, two GDFs, which modulate SHE cell transformation irreversibly, altered DNA methylation; PDGF AA did not demonstrate this effect. Together these data demonstrate that the SHE cell transformation assay can be utilized to evaluate the transformation potential and mechanism of activation of GDFs.     

Protective effect of BMP-7 against aristolochic acid-induced renal tubular epithelial cell injury

Aristolochic acid nephropathy (AAN) is regarded as a kind of rapidly progressive renal fibrosis caused by the ingestion of herbal remedies containing aristolochic acid (AA). Recent studies showed that bone morphogenetic protein-7 (BMP-7) exerts beneficial effects on acute and chronic kidney injuries induced by different pathological conditions. We examined whether BMP-7 protects human renal tubular epithelial cells (HK-2) against AA-induced injury in vitro. HK-2 cells were cultured with different concentrations of AA and BMP-7 for 48 h. Cell viability was determined by Cell Counting Kit-8 assay and lactate dehydrogenase (LDH) release. The apoptosis rate and the activity of caspase 3 protease were also examined. Epithelial-to-mesenchymal transition (EMT) was determined by cell morphology, E-cadherin and α-smooth muscle actin (α-SMA) protein expression, and TGF-β₁ and collagen III secretion. Additionally, the effect of anti-TGF-β1 antibody on AA-induced EMT was assessed. Our results indicated that BMP-7 significantly increased cell proliferation, decreased apoptosis rate and attenuated activation of caspase-3, resulting in the protection of HK-2 cells from AA-induced cytotoxicity. In addition, studies on EMT revealed that BMP-7 could inhibit AA-induced myofibroblast phenotype and restored the epithelial morphology in a dose-dependent manner. It was partially through reducing the activation of a myofibroblast phenotype and production TGF-β1. Treatment with neutralizing anti-TGF-β1 antibody also blocked AA-induced EMT and collagen III secretion. Together, these observations strongly suggest that BMP-7 is a potent inhibitor of AA-induced renal tubular epithelial cell injury and might be a promising agent for aristolochic acid-induced kidney damage.     

Choline supplementation inhibits diethanolamine-induced morphological transformation in syrian hamster embryo cells: evidence for a carcinogenic mechanism.

DEA, an amino alcohol, and its fatty acid condensates are widely used in commerce. DEA is hepatocarcinogenic in mice, but shows no evidence of mutagenicity or clastogenicity in a standard testing battery. However, it increased the number of morphologically transformed colonies in the Syrian hamster embryo (SHE) cell morphologic transformation assay. The goal of this work was to test the hypothesis that DEA treatment causes morphologic transformation by a mechanism involving altered cellular choline homeostasis. As a first step, the ability of DEA to disrupt the uptake and intracellular utilization of choline was characterized. SHE cells were cultured in medium containing DEA (500 microg/ml), and (33)P-phosphorus or (14)C-choline was used to label phospholipid pools. After 48 h, SHE cells were harvested, lipids were extracted, and radioactive phospholipids were quantified by autoradiography after thin layer chromatographic separation. In control cells, phosphatidylcholine (PC) was the major phospholipid, accounting for 43 +/- 1% of total phospholipid synthesis. However, with DEA treatment, PC was reduced to 14 +/- 2% of total radioactive phospholipids. DEA inhibited choline uptake into SHE cells at concentrations > or = 50 microg /ml, reaching a maximum 80% inhibition at 250-500 microg/ml. The concentration dependence of the inhibition of PC synthesis by DEA (0, 10, 50, 100, 250, and 500 microg/ml) was determined in SHE cells cultured over a 7-day period under the conditions of the transformation assay and in the presence or absence of excess choline (30 mM). DEA treatment decreased PC synthesis at concentrations > or = 100 microg/ml, reaching a maximum 60% reduction at 500 microg/ml. However, PC synthesis was unaffected when DEA-treated cells were cultured with excess choline. Under 7-day culture conditions, (14)C-DEA was incorporated into SHE lipids, and this perturbation was also inhibited by choline supplementation. Finally, DEA (10-500 microg/ml) transformed SHE cells in a concentration-dependent manner, whereas with choline supplementation, no morphologic transformation was observed. Thus, DEA disrupts intracellular choline homeostasis by inhibiting choline uptake and altering phospholipid synthesis. However, excess choline blocks these biochemical effects and inhibits cell transformation, suggesting a relationship between the two responses. Overall, the results provide a plausible mechanism to explain the morphologic transformation observed with DEA and suggest that the carcinogenic effects of DEA may be caused by intracellular choline deficiency.     

Nitric oxide donors prevent while the nitric oxide synthase inhibitor L-NAME increases arachidonic acid plus CYP2E1-dependent toxicity

Polyunsaturated fatty acids such as arachidonic acid (AA) play an important role in alcohol-induced liver injury. AA promotes toxicity in rat hepatocytes with high levels of cytochrome P4502E1 and in HepG2 E47 cells which express CYP2E1. Nitric oxide (NO) participates in the regulation of various cell activities as well as in cytotoxic events. NO may act as a protectant against cytotoxic stress or may enhance cytotoxicity when produced at elevated concentrations. The goal of the current study was to evaluate the effect of endogenously or exogenously produced NO on AA toxicity in liver cells with high expression of CYP2E1 and assess possible mechanisms for its actions. Pyrazole-induced rat hepatocytes or HepG2 cells expressing CYP2E1 were treated with AA in the presence or absence of an inhibitor of nitric oxide synthase L-N(G)-Nitroarginine Methylester (L-NAME) or the NO donors S-nitroso-N-acetylpenicillamine (SNAP), and (Z)-1-[-(2-aminoethyl)-N-(2-aminoethyl)]diazen-1-ium-1,2-diolate (DETA-NONO). AA decreased cell viability from 100% to 48+/-6% after treatment for 48 h. In the presence of L-NAME, viability was further lowered to 23+/-5%, while, SNAP or DETA-NONO increased viability to 66+/-8 or 71+/-6%. The L-NAME potentiated toxicity was primarily necrotic in nature. L-NAME did not affect CYP2E1 activity or CYP2E1 content. SNAP significantly lowered CYP2E1 activity but not protein. AA treatment increased lipid peroxidation and lowered GSH levels. L-NAME potentiated while SNAP prevented these changes. Thus, L-NAME increased, while NO donors decreased AA-induced oxidative stress. Antioxidants prevented the L-NAME potentiation of AA toxicity. Damage to mitochondria by AA was shown by a decline in the mitochondrial membrane potential (MMP). L-NAME potentiated this decline in MMP in association with its increase in AA-induced oxidative stress and toxicity. NO donors decreased this decline in MMP in association with their decrease in AA-induced oxidative stress and toxicity. These results indicate that NO can be hepatoprotective against CYP2E1-dependent toxicity, preventing AA-induced oxidative stress.     

莪术有效成分联合多西他赛抗肺部肿瘤最佳配比初步研究

目的初步确定莪术中有效抗癌成分姜黄素和β-榄香烯联合多西他赛对肺癌细胞生长抑制的最佳质量浓度配比。方法体外培养LLC细胞,通过MTT实验研究不同质量浓度姜黄素和β-榄香烯联合多西他赛单独及配伍对LLC细胞的生长抑制作用。采用金氏公式计算q值研究药物联用后的协同效果。结果质量浓度为10mg·L-1的β-榄香烯与质量浓度为40mg·L-1的姜黄素联用,再配伍质量浓度为800μg·L-1的多西他赛后q值最大,即联用后协同效果最明显。结论实验初步筛选出姜黄素和β-榄香烯合用后再与多西他赛联用对LLC细胞生长抑制率最明显的质量浓度组。     

Cell-transforming activity of fourteen chemical agents used in dental practice in Syrian hamster embryo cells

Fourteen chemical agents used in dental practice were assessed for their cell-transforming activity using the Syrian hamster embryo (SHE) cell transformation assay system. The cell-transforming activity was quantitatively assessed by the frequency of morphological transformation (MT) in SHE cells induced by these agents. MT was induced by m-cresol, guaiacol, formaldehyde, sodium hypochlorite, hydrogen peroxide, sodium arsenite, acid fuchsin, and basic fuchsin, but not by p-chlorophenol, p-phenolsulfonic acid, glutaraldehyde, and erythrosine B. Iodine and chlorhexidine exhibited positive and pseudopositive responses, respectively. The chemical agents exhibiting a negative or pseudopositive response neither induced nor enhanced MT even in the presence of exogenous metabolic activation.     

Morphological transformation by 8-hydroxy-2'-deoxyguanosine in Syrian hamster embryo (SHE) cells.

8-Hydroxy-2'-deoxyguanosine (OH8dG) is one of the most prevalent oxidative DNA modifications found in eukaryotic cells. Previous studies have suggested an association between OH8dG formation and carcinogenesis. However, it is unclear whether OH8dG formation results in the necessary genotoxic events for cancer development. In the present study, the formation of OH8dG and its ability to transform Syrian hamster embryo (SHE) cells was examined. Methylene blue, a photosensitizer that in the presence of light can generate singlet oxygen by a type II mechanism, was used to produce oxidative DNA damage (predominantly OH8dG) in SHE cells. Photoactivated methylene blue produced a dose-dependent increase in OH8dG as well as a dose-dependent increase in morphological transformation in SHE cells. SHE cells transfected with DNA that contained increasing concentrations of OH8dG displayed a dose-dependent increase in morphological transformation. Treatment with beta-carotene (a singlet oxygen quencher) inhibited both the formation of OH8dG and the induction of morphological transformation in photoactivated methylene blue-treated SHE cells. These results suggest that formation of OH8dG can induce morphological transformation and provide further support for a role of OH8dG formation in the carcinogenesis process.     

LPS诱导小胶质细胞活化模型的建立及评价

目的探讨不同浓度脂多糖(Lipopolysaccharides,LPS)对小胶质细胞活化作用,建立小胶质细胞活化的模型。方法不同浓度LPS(0.01,0.1,1,10,100mg·L-1)刺激原代纯化的小胶质细胞及BV2细胞株,采用MTT法检测细胞活力;采用细胞免疫化学法观察细胞形态变化。结果 LPS(1mg·L-1)可以明显激活原代小胶质细胞,但不影响细胞活力,OX-42染色显示小胶质细胞胞体变大,轴突变短变多,形似"阿米巴状";LPS(10mg·L-1)可以激活BV2细胞,且不降低细胞活力,镜下观察发现BV2细胞胞体明显增大。结论采用LPS(1mg·L-1)刺激原代小胶质细胞,LPS(10mg·L-1)刺激BV2细胞株,可以建立稳定的小胶质细胞活化模型。     

甲基莲心碱对人脐静脉血管平滑肌细胞增殖及表型调节的影响

目的研究甲基莲心碱对人脐静脉平滑肌细胞增殖及表型调节的影响。方法以0.1,0.5,1.0,5.0μmol·L-1甲基莲心碱处理平滑肌细胞,采用MTT法和流式细胞术观察甲基莲心碱对人脐静脉血管平滑肌细胞增殖的影响。用免疫印迹法检测收缩型平滑肌细胞特异性标志物SM1,calponin 1和α-actin蛋白的表达。结果甲基莲心碱（0.1~5.0μmol·L-1）处理12,24,48 h后,人脐静脉血管平滑肌细胞的增殖具有明显的抑制作用,并具有剂量依赖关系和时间依赖关系。在缺乏甲基莲心碱的干预下,血管平滑肌细胞SM1,calponin 1和α-actin蛋白表达减少,在用0.5,5.0μmol·L-1甲基莲心碱处理48 h后,可显著逆转SM1,calponin 1和α-actin蛋白表达的减少,且具有剂量依赖性。结论甲基莲心碱具有抑制血管平滑肌细胞增殖及表型转化的作用,可用于防治动脉粥样硬化和再狭窄。     

丹参二萜醌对黄嘌呤氧化酶活性的抑制作用(英文)

目的黄嘌呤氧化酶(XOD)抑制剂对痛风或其他XOD诱导的疾病有潜在的治疗作用,因此探讨了从丹参(Salvia miltiorrhiza Bge.)中分离的丹参二萜醌---隐丹参酮(CT)和次甲丹参酮(MT)对XOD的抑制作用。方法在分子氧存在的条件下,XOD催化黄嘌呤产生尿酸和超氧阴离子。在黄嘌呤/XOD的反应媒介中加入CT或MT,通过测量波长290nm处吸光度的增加测定尿酸形成速率。结果CT和MT对XOD有抑制作用,酶动力学曲线Dixon图显示抑制方式是竞争型。CT和MT的Ki值分别为17.8和25.9μmol.L-1,抑制活性与浓度正相关。CT和MT的IC50值分别为70和67μmol.L-1,阳性对照别黄嘌呤醇的IC50值为60μmol.L-1。结论CT和MT对XOD活性有抑制作用,对痛风或其他XOD诱导的疾病可能有一定的治疗作用。