10CM短柱快速分离3-MH的实验研究

本研究在改进后短程序基础上,对氨基酸分离柱进行了改进。改进后的分离柱长为10cm。比原来20cm长柱分离3—MH的时间缩短了近1/2。实验所得的(回收率为97.59%,分离度0.89±0.02。变异系数1.17)这些指标较国外用其它方法所得的结果有良好的相关性。多次测定结果说明长柱与短柱比较无明显差异。证明了短柱对3—MH含量无影响。这一改进所建立的方法大大地缩短了样品的分析时间,节约了大量进口试剂,开展这方面的工作将有利益提高严重烧伤、创伤后蛋白质代谢和营养学等方面的研究水平。     

鹤顶兰胚囊发育过程中微管变化的共焦显微镜观察

光镜的观察确定了鹤顶兰（Ｐｈａｉｕｓ ｔａｎｋｅｒｖｉｌｌｉａｅ （Ａｉｔｏｎ） Ｂｌ．）胚囊发育属单孢子蓼型。应用免疫荧光标记技术及共焦镜观察了胚囊发育过程中微管分布的变化。当孢原细胞初形成时,细胞内的微管呈网状分布。之后,孢原细胞体积增大发育为大孢子母细胞。大孢子母细胞延长,进入减数分裂Ⅰ。微管由分裂前的网状分布变为辐射状排列。二分体的两个细胞内的微管分布一样,呈辐射状。四分体的近珠孔端的３ 个大孢子解体,细胞内的微管消失。靠合点端的功能大孢子内有许多微管呈网状分布。当功能大孢子进入第一次有丝分裂时,细胞内的微管由网状变为辐射状,从核膜伸展至周质。再经两次有丝分裂形成八核胚囊。在核分裂之前微管一般是呈网状分布并紧包围着核。在分裂期间二核和四核胚囊都呈极性现象,微管系统也呈极性分布。微管在八核胚囊内的分布变化情形特别复杂。首先,八核分别作不同程度的移动,其中两个核移向胚囊中央,珠孔端和合点端的３ 个核分别互相靠拢,形成３ 个区,即中央区、反足区和卵器区。胚囊未形成区时,８ 个核都被网状分布的微管包围着。当胚囊明显分成区时,反足区内的微管仍作网状分布。中央区的微管分布则趋疏松,形成篮形结构,包围着液泡和两个极核。在     

GPS2 Is Required for the Association of NS5A with VAP-A and Hepatitis C Virus Replication

Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is a component of the replication complex associated with various cellular proteins. It has been reported that G protein pathway suppressor 2 (GPS2) is a potential NS5A-binding factor, as identified in a yeast two-hybrid screens of human cDNA library using viral proteins as baits [1]. In this study, we demonstrated the interaction between GPS2 and NS5A in mammalian cells by coimmunoprecipitation analysis and found that both exogenously and endogenously expressed GPS2 interacted with NS5A of genotype 1b and 2a. Mutagenesis study demonstrated that Domain I of NS5A and coiled-coil domain of GPS2 are responsible for the interaction. Knockdown of GPS2 in hepatoma cell lines suppressed the replication of HCV RNA, which can be rescued by the expression of an RNAi-resistant GPS2. Furthermore, overexpression of GPS2 enhanced the association of NS5A with a proviral cellular factor, human vesicle-associated membrane protein-associated protein A (VAP-A), while knockdown of GPS2 disrupted interaction between VAP-A and NS5A. Taken together, our results suggest that GPS2 acts as a bridge between NS5A and VAP-A and is required for efficient HCV replication.     

核糖核酸酶抑制因子对H_2O_2损伤的大鼠神经胶质瘤细胞系C6的影响

核糖核酸酶抑制因子 (ribonucleaseinhibitor,RI)是广泛存在于哺乳动物细胞浆中的一种酸性糖蛋白 .为了进一步了解RI的功能 ,根据RI分子结构富含巯基的特点 ,研究了RI对过氧化氢(H2 O2 )损伤的大鼠神经胶质瘤细胞 (C6 )的影响 .用不同浓度的H2 O2 分别作用于转染有RIcDNA并且RI过表达的C6细胞和正常C6细胞 ,对比损伤前后 2者的细胞存活率、LDH漏出量、细胞内GSH和MDA含量差别 ,以及细胞内抗氧化酶类GPX、CAT和GST活性的差别 .结果表明 ,与正常C6细胞相比 ,RI过表达的C6细胞在H2 O2 作用下存活率高 ,LDH漏出量、MDA含量明显减少 ,而细胞内GSH较多 ;RI过表达的C6细胞在损伤前后均表现出更强的CAT和GST活性 .提示RI具有抗氧化功能 ,能够减轻H2 O2 所致的细胞过氧化损伤 .     

清洁级SD大鼠血液生理生化指标的测定

目的建立清洁级SD大鼠血液生理生化正常值。方法应用动物芯片血球计数仪测试常规血细胞计数;采用全自动生化测定仪对清洁级SD大鼠的血液28项生化指标进行测定,并进行统计分析雌雄差异显著性检验。结果建立了清洁级SD大鼠血液生理和28项血液生化参考值,ALB、AST/ALT、AG雌雄之间差异显著;血液血球计数雌雄差异不显著。结论比较详细的建立了清洁级SD大鼠的血液生理生化指标参考值,为其应用提供基础数据。     

用于筛选直链淀粉含量为中等的籼稻品种的分子标记

用PCR AccⅠ分子标记检测方法 ,检测了来自不同地区的 6 3个栽培水稻品种 (系 )蜡质基因第 1内含子剪接供体 1位碱基是G或是T。另外 ,还测定了这些水稻成熟种子的直链淀粉含量。结果显示该位置是G碱基的水稻品系成熟种子中直链淀粉含量均高于 2 0 % ,该位置是T的均低于 18%。在杂交育种过程中 ,这一分子标记可用于预测水稻植株种子的直链淀粉含量。对高直链淀粉含量的水稻亲本与中等直链淀粉含量的水稻亲本之间 5个籼型杂交组合F2 群体的分析表明 ,蜡质基因第 1内含子 1位碱基是G或是T与水稻种子中直链淀粉含量的高或低是紧密连锁 ,共同分离的。这些结果表明PCR AccⅠ分子标记检测方法可用于选育中等直链淀粉含量的籼稻新品系     

魔芋葡甘露寡糖的制备、化学结构及对胰岛NO自由基释放量的影响

魔芋精粉经 β 甘露聚糖酶酶解成寡糖后 ,用活性炭柱进行分离纯化 ,以不同浓度 (5 % ,10 % ,2 0 % )的乙醇洗脱 .研究不同洗脱组分对链脲佐菌素 (STZ)诱导糖尿病模型的胰岛NO自由基释放量的影响 .发现 1mg ml以 5 %乙醇洗脱的寡糖可以使胰岛培养液中的NO自由基释放量平均下降2 5 4 % (P <0 0 5 ) ,0 1mg ml以 5 %乙醇洗脱的寡糖使NO自由基水平下降 2 0 % (P <0 0 5 ) .结果表明 ,5 %乙醇洗脱的魔芋寡糖对保护胰岛免受链脲佐菌素 (STZ)的破坏有一定的作用 .用凝胶色谱、红外光谱、元素分析、核磁共振光谱、质谱等方法初步分析了 5 %乙醇洗脱的魔芋寡糖的化学结构 .发现该糖是一种四糖 ,分子量为 6 6 6 .其推测性结构式为 :β D Man(1→ 4 ) β D Man(1→ 4 ) β D Glc(1→ 4 )α D Man ,β D Man(1→ 4 ) β D Glc(1→ 4 ) β D Man(1→ 4 )α D Man或 β D Glc(1→ 4 ) β D Man(1→4 ) β D Man(1→ 4 )α D Man .     

Brief communication: Prenatal and early postnatal stress exposure influences long bone length in adult rat offspring

Stress during the prenatal and early postnatal periods (perinatal stress, PS) is known to impact offspring cognitive, behavioral, and physical development, but effects on skeletal growth are not clear. Our objective was to analyze effects of variable, mild, daily PS exposure on adult offspring long bone length. Twelve pregnant rat dams were randomly assigned to receive variable stress from gestational days 14–21 (Prenatal group), postpartum days 2–9 (Postnatal), both periods (Pre–Post), or no stress (Control). Differences in adult offspring tibia and femur length were analyzed among treatment groups. Mean tibia length differed among groups for males (P = 0.016) and females (P = 0.009), and differences for femur length approached significance for males (P = 0.051). Long bone length was shorter among PS‐exposed offspring, especially those exposed to postnatal stress (Postnatal and Pre–Post groups). Results persisted when controlling for nose–tail length. These differences might reflect early stunting that is maintained in adulthood, or delayed growth among PS‐exposed offspring. This study suggests that PS results in shorter long bones in adulthood, independently of effects on overall body size. Stunting and growth retardation are major global health burdens. Our study adds to a growing body of evidence suggesting that PS is a risk factor for poor linear growth. Am J Phys Anthropol 149:307–311, 2012. © 2012 Wiley Periodicals, Inc.     

Applying a socio-ecological green network framework to Xi’an City,China

Landscape and Ecological Engineering - Green–blue space loss and fragmentation are particularly acute in Chinese cities due to rapid urbanization, large ring-road system and the following...