氯化钴对小鼠NIH3T3细胞增殖和凋亡的影响

目的:观察氯化钴(Cocl2)对体外培养的小鼠NIH3T3细胞增殖和凋亡的影响.方法:首先利用MTT法和流式细胞术检测不同浓度Cocl2对小鼠NIH3T3细胞增殖及凋亡的影响.然后利用免疫印迹检测HIF-1α和凋亡相关蛋白Bcl-2及Bax的表达.结果:(1)MTT结果显示,低于250μ mol/L的Cocl2作用NIH3T3细胞24 h对细胞的增殖活力影响不大,当浓度增加到500μ mol/L以上时会明显抑制细胞的增殖活力.(2)流式细胞仪检测结果显示低浓度Cocl2(≤ 250μ mol/L)并不会引起NIH3T3细胞明显的凋亡和坏死,增加浓度(≥500μmol/L)会导致细胞早期凋亡和坏死增加.3)不同浓度Cocl2作用NIH3T3细胞24 h均可诱导细胞中HIF-1α表达上调,同时Bax/Bcl-2的比值增高.结论:高浓度Cocl2可以抑制小鼠NIH3T3细胞增殖,促进凋亡发生.     

ATM activation in the presence of oxidative stress

The Ataxia-Telangiectasia mutated (ATM) kinase is regarded as the major regulator of the cellular response to DNA double strand breaks (DSBs). In response to DSBs, ATM dimers dissociate into active monomers in a process promoted by the Mre11-Rad50-Nbs1 (MRN) complex. ATM can also be activated by oxidative stress directly in the form of exposure to H₂O₂. The active ATM in this case is a disulfide-crosslinked dimer containing two or more disulfide bonds. Mutation of a critical cysteine residue in the FATC domain involved in disulfide bond formation specifically blocks ATM activation by oxidative stress. Here we show that ATM activation by DSB s is inhibited in the presence of H₂O₂ because oxidation blocks the ability of MRN to bind to DNA . However, ATM activation via direct oxidation by H₂O₂ complements the loss of MRN/DSB-dependent activation and contributes significantly to the overall level of ATM activity in the presence of both DSB s and oxidative stress.Key words: ATM, DNA repair, double-strand break, oxidative stress, ROS     

华南沿海地区西部入海水系中间黄颡鱼的形态变异及地理分化

为探讨不同水系中间黄颡鱼(Pelteobagrus intermedius)的形态差异及地理分化问题,采用形态学方法, 测量12个水系中间黄颡鱼150尾样本的18个形态性状,进行主成分分析.其结果显示,前3个主成分累积贡献率为58.918%,并可将这12个水系的群体分为3簇.华南沿海地区西部诸独立入海小水系中的中间黄颡鱼群体与海南岛群体之间的相似性大于与西江干流群体的相似性.防城港地区3条直接入海的小水系的群体在形态特征上已发生了一定程度的分化,其分化主要表现在吻、眼和尾的变异.     

蚕豆根尖细胞微核技术检测合成氨工业水的遗传毒性

目的:探讨了合成氨工业水处理前后对蚕豆根尖细胞微核率的影响。方法:选取某化工厂生产流程中3个有代表性的水样,同时以蒸馏水(CK)为阴性对照,以不同浓度(0.5、5、50、500μg/L)的环磷酰胺处理为阳性对照,共5个处理组水平,蚕豆根尖细胞微核试验测定其MCN‰。结果:洗煤气水、洗甲醇水可诱导蚕豆根尖细胞产生较高的MCN‰与对照组相比,差异均具有统计学意义(P<0.01),并分别相当于50μg/L和5μg/L环磷酰胺的致突变效应。经处理后的生化出水致突变性显著降低。结论:合成氨工业水具有较强的致突变性,蚕豆根尖细胞微核技术可作为合成氨工业水的遗传毒性检测。     

N-(5-chloro-2-(hydroxymethyl)-N-alkyl-arylsulfonamides as gamma-secretase inhibitors

A series of N-alkylbenzenesulfonamides were developed from a high throughput screening hit. Classic and parallel synthesis strategies were employed to produce compounds with good in vitro and in vivo gamma-secretase activity.     

Synthesis and evaluation of antifungal properties of a series of the novel 2-amino-5-oxo-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile and its analogues

A series of 2-amino-5-oxo-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile and various analogues have been synthesized in excellent isolated yields starting from various arylidenemalononitrile and 3-amino-2-cyclohexen-1-one in 1-propanol as solvent at reflux temperature in the absence of any added catalyst. All the synthesized compounds were evaluated for their antifungal activity. The relationship between functional group variation and biological activity of the evaluated compounds is discussed in the article.     

扁藻多糖的性质及结构特征的研究

利用不同浓度范围的乙醇从培养至平衡期后的扁藻细胞内沉淀分离出不同组分的扁藻多糖级分,对其理化性质和结构特征进行了相应的测定和对比分析。结果表明,经过凝胶层析分离后,乙醇浓度在0%~50%范围时沉淀的扁藻多糖与乙醇浓度为50%~75%范围时沉淀的扁藻多糖相比,前者分子量大、糖含量高、其结合的蛋白质也多,但前者的溶解度和粘度小于后者。两个级分的扁藻多糖的官能团相似,均含有硫酸基和氨基,但其含量不同。所得结果为深入研究扁藻多糖的结构及其实际应用提供了实验依据。