Curcumin-Induced DNA Damage and Inhibited DNA Repair Genes Expressions in Mouse–Rat Hybrid Retina Ganglion Cells (N18)

Curcumin is reported to be a potent inhibitor of the initiation and promotion of many cancer cells. We investigated to examine whether or not curcumin induce DNA damage in mouse–rat hybrid retina ganglion cell line N18 cells. The Comet assay showed that incubation of N18 cells with 10, 25 and 30 μM of curcumin led to a longer DNA migration smear (Comet tail). The DNA gel electrophoresis showed that 20 μM of curcumin for 24 and 48 h treatment induced DNA damage and fragments in N18 cells. The real time PCR analysis showed that 20 μM of curcumin for 48 h treatment decreased ATM, ATR, BRCA1, 14-3-3σ, DNA-PK and MGMT mRNA, and ATM and MGMT mRNA expression were inhibited in a time-dependent manner. Our results indicate that curcumin caused DNA damage and inhibited DNA repair genes which may be the factors for curcumin-inhibited cell growth. H.-F. Lu and J.-S. Yang are contributed equally to this study.     

Identity of an ABA-activated 46 kDa mitogen-activated protein kinase from <Emphasis Type="Italic">Zea mays</Emphasis> leaves: partial purification,identification and characterization

Mitogen-activated protein kinase (MAPK) cascades have been shown to be important components in abscisic acid (ABA) signal transduction pathway. In this study, a 46 kDa MAPK (p46MAPK) induced by ABA was partially purified from maize (Zea mays) by Q-Sepharose FF, Phenyl-Sepharose FF, Resource Q, Mono QTM 5/50 GL, poly-l-lysine-agarose, and Superdex 75 prep-grade columns, and was identified as ZmMAPK5 (gi|4239889) by the matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry. Furthermore, the kinase showed optimal activity at pH 8.0, 30°C, and 10 mM MgCl₂; the K _m for myelin basic protein (MBP) substrate and ATP were 0.13 μg μl⁻¹ and 62 μM, respectively. MBP was the preferred substrate, of which the threonine residue was phosphorylated. Finally, the kinase was found to respond to diverse extracelluar stimuli. These results enable us to further reveal the function of the ZmMAPK5 in ABA signaling. The authors Haidong Ding and Aying Zhang contributed equally to the work.     

国产伏立康唑治疗侵袭性真菌感染6例临床观察

目的观察国产伏立康唑治疗恶性血液病患者侵袭性真菌感染（IFI）的临床疗效和安全性。方法以国产伏立康唑治疗6例发生于恶性血液病患者的侵袭性真菌感染,观察疗效及不良反应。结果6例患者中,有效4例,其中完全反应3例,部分反应1例。1例用药第6天出现低钾血症。结论国产伏立康唑是治疗恶性血液病患者侵袭性真菌感染的安全有效的药物,     

斑马鱼干扰素基因工程菌发酵条件及稳定性研究

采用液体传代的方法,研究表达斑马鱼干扰素(IFN)工程菌株pRSET-B-zIFN的遗传稳定性,并对其发酵工艺进行了优化.结果表明,构建的工程菌株遗传稳定性良好,在没有选择压力的情况下,传代100次质粒稳定性仍然保持100%,菌落形态及生长情况与原代菌无明显区别,SDS-PAGE结果显示zIFN表达量无明显差异.发酵条件研究表明,工程菌在LB培养基中,接种量为1%,诱导剂终浓度为0.1 mmol/L,zIFN的表达量最高.     

重组磷脂酰丝氨酸合成酶的分离纯化及酶学性质研究

利对重组枯草芽孢杆菌(pBES-pss)表达的磷脂酰丝氨酸合成酶进行分离纯化及酶学性质研究.pBES-pss发酵后的粗酶液经硫酸铵盐析、中空纤维膜除盐浓缩、SP-Sepharose HP离子交换层析和Sephadex G-75凝胶层析,基本获得电泳纯的重组磷脂酰丝氨酸合成酶,比活力可达13.62 U/mg,分子量约为53 kD.酶学性质研究表明,该酶催化卵磷脂水解反应的最适pH8.0,最适温度为35℃.稳定性研究表明:该酶在pH 6.5～9.5 区间和低于45℃温度下稳定.表面活性剂及金属离子对该酶水解活性的影响结果表明,SDS、Tween20、Tween80对该酶有抑制作用,Triton X-100对该酶有增强作用;Mg2+、Zn2+、K+对该酶有抑制作用,Ca2+、Mn2+和EDTA对该酶有增强作用.     

中国苜蓿植物资源概述

综述了中国苜蓿属植物资源、品种资源及利用概况,并对苜蓿植物资源的进一步利用前景进行了探讨。     

噬菌体裂解酶的抗菌特性

摘要：噬菌体裂解酶是一类细胞壁水解酶,可水解肽聚糖,造成细菌的破裂。裂解酶一般具有两到三个结构域,参与对底物的催化和结合。作为一种新型的杀菌制剂,裂解酶已被越来越多地应用于化脓链球菌、肺炎链球菌、金黄色葡萄球菌等革兰氏阳性细菌病的治疗。与抗生素治疗相比,裂解酶不易使细菌产生抗性且作用相对专一,这可能是解决现在日趋严重的细菌耐药性的一种可行方法。另外,裂解酶还具有高效性,作用协同性,且自身抗体不削弱其作用等优势,使之成为未来预防、控制致病菌一种可能的新途径。     

固定化脂肪酶催化毛油合成生物柴油

本研究开发了一种用石油醚提取毛油的工艺,研究了以提取的毛油和甲醇为原料,用固定化Candida sp.99-125脂肪酶催化合成脂肪酸甲酯(FAMEs)的可行性。同时考察了磷脂对固定化酶活性、反应起始速率、固定化酶使用批次的影响以及毛油和精炼油对固定化酶使用批次等的影响。研究结果表明,用磷脂质量分数为1%的石油醚悬液浸泡过的脂肪酶比仅用石油醚浸泡过的脂肪酶初始转酯化速率显著下降。当大豆油中无磷脂时,15min时FAMEs的产率为26.2%;磷脂质量分数为5%时,FAMEs降为12.4%。当大豆油中磷脂质量分数小于1%时,固定化酶使用10个批次,FAMEs产率无明显变化。固定化脂肪酶催化石油醚浸提得到的大豆和小桐子毛油,经过10个批次反应FAMEs产率都保持在70%以上,该固定化酶直接催化毛油生产生物柴油具有良好的工业化前景。     

晚期糖基化终产物在糖尿病肾病中的病理作用

高糖环境下体内积聚的晚期糖基化终产物(advanced glycation end products,AGEs)是糖尿病慢性并发症的主要致病因素.AGEs可通过对蛋白的修饰直接作用于机体或通过受体介导的作用影响机体.本文就AGEs的来源、病理生理作用,尤其是在糖尿病肾病(diabetic nephropathy,DN)发生发展中的作用及治疗干预作一综述.     

Expression of the calcium-activated potassium channel in upper and lower segment human myometrium during pregnancy and parturition

Background  

Large conductance calcium-activated potassium channel (BKCa) plays an important role in the control of uterine contractility during pregnancy. The change from uterine quiescence to enhanced contractile activity may be associated with the spatial and temporal expression of BKCa within myometrium. The objectives of this study were to examine the expression of BKCa alpha- and beta-subunit in upper segment (US) and lower segment (LS) regions of uterus, and to investigate for the possibly differential expression of these proteins in US and LS myometrium obtained from three functional states: (1) non-pregnant (NP); (2) term pregnant not in labour (TNL) and (3) term pregnant in labour (TL).