牦牛血清转铁蛋白对人红细胞膜氧化损伤的保护作用

牦牛血清中分离纯化的转铁蛋白对人红细胞膜的抗氧化具有保护作用 .方法 :采用黄嘌呤 /黄嘌呤氧化酶、Fe2 + /H2 O2 两个体系产生的O·2 -、OH·对红细胞膜造成氧化损伤 ,通过丙二醛含量、超氧化物歧化酶和谷胱甘肽过氧化酶活性的测定研究牦牛转铁蛋白在抗氧化方面的作用与机制 .结果 :O·2 -和OH·可以造成红细胞膜丙二醛量的显著增加 ,超氧化物歧化酶和谷胱甘肽过氧化酶活性的下降 .当适量不同浓度牦牛血清转铁蛋白在黄嘌呤 /黄嘌呤氧化酶、Fe2 + /H2 O2 两个体系前处理可以抑制丙二醛的产生 ,保护红细胞膜免受丙二醛的氧化损伤并且使超氧化物歧化酶和谷胱甘肽过氧化酶活性升高 .提示 ,牦牛血清转铁蛋白对O·2 -和OH·自由基引起的氧化损伤有保护作用     

高压静电场处理油菜种子的品质影响及模型探讨

研究了高压静电场处理种子在大田生长条件下的长期效应 .结果表明 ,较低电压的处理可提高硫甙含量显著降低含油量 ,而较高电压的处理可降低硫甙含量 ,极显著降低芥酸含量 .采用平面类脂双层模型分析外加高压静电场对植物细胞跨膜电位的影响 ,并探讨其微观机理 ,一定程度上可以解释相关的实验结果     

以秀丽隐杆线虫为模型的玛咖功效评价

先对玛咖进行脱油、水提、冻干,再将所得水提物冻干品与Escherichia coli OP50菌液进行混合,稀释至终质量浓度为1,2mg/mL.以秀丽隐杆线虫(简称线虫)为模型,考察玛咖水提物对线虫的抗氧化作用:经寿命、产卵、吞咽、运动能力实验表明,玛咖水提物对线虫无明显毒性作用,且1,2mg/mL玛咖水提物均能显著延长线虫寿命;由玛咖水提物对线虫热激氧化压力诱导表明,玛咖水提物对线虫体外热激氧化压力有保护作用;通过油红O对脂肪染色表明,玛咖水提物具有一定降脂功效.     

共培养技术及化学絮凝法对小球藻C.vulgaris XJB絮凝的影响

微藻是生物柴油理想的原料,但微藻尺寸较小,细胞密度较低,导致微藻采收困难。为提高微藻的采收率,节约成本,实验采用自絮凝斜生栅藻Scenedesmus sp.-BH与富油小球藻C.vulgaris XJB共培养技术来提高小球藻C.vulgaris XJB的絮凝率,同时与调节p H、添加Fe Cl3和添加壳聚糖3种化学絮凝法对比。结果表明:3种化学絮凝法60 min时的最佳絮凝率分别为84.2%、96.5%和72.9%;共培养最佳条件下小球藻C.vulgaris XJB 60 min时的絮凝率为33.3%,8 h后的絮凝率可达73.2%。共培养条件下小球藻C.vulgaris XJB的絮凝率比化学絮凝法的稍低,但该方法不会引入有害化学物质,后期分离成本低,是一种经济、环保的絮凝方法。     

Alternative exon usage selectively determines both tissue distribution and subcellular localization of the acyl-CoA thioesterase 7 gene products

Acyl-CoA thioesterases (ACOTs) catalyze the hydrolysis of acyl-CoAs to free fatty acids and coenzyme A. Recent studies have demonstrated that one gene named Acot7, reported to be mainly expressed in brain and testis, is transcribed in several different isoforms by alternative usage of first exons. Strongly decreased levels of ACOT7 activity and protein in both mitochondria and cytosol was reported in patients diagnosed with fatty acid oxidation defects, linking ACOT7 function to regulation of fatty acid oxidation in other tissues. In this study, we have identified five possible first exons in mouse Acot7 (Acot7a–e) and show that all five first exons are transcribed in a tissue-specific manner. Taken together, these data show that the Acot7 gene is expressed as multiple isoforms in a tissue-specific manner, and that expression in tissues other than brain and testis is likely to play important roles in fatty acid metabolism. Received 5 February 2007: received after revision 3 April 2007; accepted 19 April 2007     

内质网应激对小鼠脂肪组织的影响

为了探究内质网应激对小鼠白色脂肪组织的影响,通过腹腔注射衣霉素(tunicamycin, TM)诱导小鼠体内内质网应激,构建内质网应激小鼠模型,然后获取小鼠附睾处白色脂肪组织,并采用RT-PCR和Western blot检测白色脂肪组织中内质网应激相关因子的mRNA水平及蛋白表达情况,通过荧光显微镜观察白色脂肪组织细胞的变化,测定甘油三酯、游离脂肪酸含量及脂肪细胞因子和炎症因子分泌情况.结果表明：1.0 mg/kg TM处理72 h诱导小鼠内质网应激效果最佳;内质网应激可以导致白色脂肪组织比例减少,脂肪细胞直径减小,脂解反应增多,脂肪细胞因子分泌减少及炎症反应增多等.该研究结果说明内质网应激可以诱导小鼠脂肪组织中发生脂解,进而介导脂代谢紊乱.     

包裹姜根油的多种纳米颗粒的制备及质量评价

以大豆磷脂、聚乙交酯丙交酯(PLGA)和聚乙二醇(PEG)3种原料成功制备了包裹难溶于水的植物提取物姜根油(GRO)的纳米脂质体、PLGA纳米颗粒和PEG纳米颗粒,并对3种不同载体制备的纳米制剂的形貌、大小、Zeta电位,包封率及物理稳定性等进行了考察.研究结果表明3种纳米颗粒各有优缺点,可以根据不同的条件和不同的需要制备不同的颗粒,为开发新型的难溶药用植物提取物的理想药剂提供了实验依据.     

Evidence for the intracellular accumulation of anandamide in adiposomes

Anandamide is a lipid messenger that carries out a wide variety of biological functions. It has been suggested that anandamide accumulation involves binding to a saturable cellular component. To identify the structure(s) involved in this process, we analyzed the intracellular distribution of both biotinylated and radiolabeled anandamide, providing direct evidence that lipid droplets, also known as adiposomes, constitute a dynamic reservoir for the sequestration of anandamide. In addition, confocal microscopy and biochemical studies revealed that the anandamide-hydrolase is also spatially associated with lipid droplets, and that cells with a larger adiposome compartment have an enhanced catabolism of anandamide. Overall, these findings suggest that adiposomes may have a critical role in accumulating anandamide, possibly by connecting plasma membrane to internal organelles along the metabolic route of this endocannabinoid. S. Oddi, F. Fezza: These authors contributed equally to the study.     

Myelin basic protein: a multifunctional protein

Myelin basic protein (MBP), the second most abundant protein in central nervous system myelin, is responsible for adhesion of the cytosolic surfaces of multilayered compact myelin. A member of the ‘intrinsically disordered’ or conformationally adaptable protein family, it also appears to have several other functions. It can interact with a number of polyanionic proteins including actin, tubulin, Ca²⁺-calmodulin, and clathrin, and negatively charged lipids, and acquires structure on binding to them. It may act as a membrane actin-binding protein, which might allow it to participate in transmission of extracellular signals to the cytoskeleton in oligodendrocytes and tight junctions in myelin. Some size isoforms of MBP are transported into the nucleus and thus they may also bind polynucleotides. Extracellular signals received by myelin or cultured oligodendrocytes cause changes in phosphorylation of MBP, suggesting that MBP is also involved in signaling. Further study of this very abundant protein will reveal how it is utilized by the oligodendrocyte and myelin for different purposes. Received 2 March 2006; received after revision 12 April 2006; accepted 16 May 2006     

高产油脂斯达氏酵母菌株的选育及摇瓶发酵条件的初步研究

以斯达氏油脂酵母Lipomyces starkeyi AS 2．1560为出发菌株．经紫外线诱变选育出了一株高产油脂的优良酵母菌株L．starkeyi M36．通过摇瓶培养,对与菌体产油脂相关的因素进行了单因子试验,确定了摇瓶发酵培养的最佳产油脂条件,碳源为葡萄糖110g／L;氯源为硫酸铵0．6g／L;培养温度30℃;接种量15％;初始pH5．0～7．0;培养144h。最后可得生物量24．2g／L;油脂量14．6g／L．菌油脂肪酸组成分析结果如下：豆蔻酸0．5％,软脂酸35．2％,棕榈油酸4．3％,硬脂酸4．4％,油酸53．0％,亚油酸2．6％．与植物油脂相似．