Effects of 2(RS)-n-propylthiazolidine-4(R)-carboxylic acid on 4-hydroxy-2-nonenal-induced apoptotic T cell death

4-Hydroxy-2-nonenal (HNE), the aldehydic product of lipid peroxidation, is associated with multiple immune dysfunctions, such as HIV and hepatitis C virus infection. HNE-induced immunosuppression could be due to a decrease in CD4+ T lymphocyte activation or proliferation. Glutathione (GSH) is the most abundant endogenous antioxidant in cells, and an adduct between HNE and GSH has been suggested to be a marker of oxidative stress. Our earlier studies showed that HNE induced cytotoxicity and Akt inactivation, which led to the enhancement of FasL expression and concomitantly decreased cellular FLICE-like inhibitory protein (c-FLIP(S)) levels. In this study, we found that HNE caused intracellular GSH depletion in Jurkat T cells, and we further investigated the role of 2(RS)-n-propylthiazolidine-4(R)-carboxylic acid (PTCA), a GSH prodrug, in attenuating HNE-induced cytotoxicity in CD4+ T lymphocytes. The results show that PTCA protected against HNE-induced apoptosis and depletion of intracellular GSH. PTCA also suppressed FasL expression through increasing levels of Akt kinase as well as antiapoptotic c-FLIP(S) and decreasing the activation of type 2 protein serine/threonine phosphatase. Taken together, these data demonstrate a novel correlation between GSH levels and Akt activation in T lymphocyte survival, which involves FasL down-regulation and c-FLIP(S) expression through increasing intracellular GSH levels. This suggests that PTCA could potentially be used in the treatment of oxidative stress-induced immunosuppressive diseases.     

辛伐他汀在大鼠体内药动学性别差异的研究

目的:研究Wistar大鼠单次灌服辛伐他汀后体内药代动力学的性别差异。方法:利用高效液相色谱方法检测大鼠血浆中辛伐他汀浓度,采用非房室模型法计算各自药动学参数。结果:雌、雄大鼠体内Cmax分别为(144.66±22.31)ng·mL~(-1)和(165.91±52.50)ng·mL~(-1);t_(1/2)分别为(4.74±1.19)h和(14.98±6.64)h;AUC_(0-10)分别为(0.990±0.19)μg.h·mL~(-1)和(0.726±0.15)μg·h·mL~(-1);AUC0-∞分别为(1.62±0.47)μg·h·mL~(-1)和(2.19±0.62)μg·h·mL~(-1);MRT分别为(9.69±1.60)h和(23.08±8.89)h,经t-检验,雌、雄大鼠主要药动学参数t_(1/2)、AUC_(0-10)、MRT均有统计学显著性差异(p<0.01)。结论:辛伐他汀在大鼠体内的药代动力学存在明显的性别差异,辛伐他汀在雌性大鼠体内代谢较快。     

根据蛋白质互作网络预测前列腺癌相关蛋白质的细致功能

对于功能部分已知的前列腺癌相关蛋白质,提出了一种基于Gent Ontology的功能特异的子网构建方法来细化其功能注释。结果显示该方法能够以很高的精确率为前列腺癌相关蛋白质预测更为精细的功能。预测的相关蛋白质的功能对于指导实验研究前列腺癌的分子机制具有重要的价值。     

Morphological differentiation among populations of Sarotherodon melanotheron melanotheron Rüppell 1852 across the West African Lagoon systems (Benin,Cameroon, Nigeria,Togo)

Morphometric variation among populations of Sarotherodon melanotheron melanotheron across its natural range (Mahin, epe, Lekki, Apese, Kuramo, Lagos, Iyagbe, Ologe, Badagry, Yewa – Nigeria; Be Lagoon – Togo; Idenau – Cameroon, Aheme – Benin; Portonovo – Benin) were studied to assess the level of differentiation of one of the populations that is currently isolated from the rest, the Apese Lagoon population. S. m. melanotheron showed subtle differentiation from some of the other lagoon populations. However, the pattern of variation did not reflect the level of geographical barriers or geographical distance among populations. The characters that form the basis of the differentiation observed were mostly those related to feeding, vision and respiration.     

Influences on the antimicrobial activity of surface-adsorbed nisin

The efficacy of the antimicrobial peptide nisin was examined after adsorption to silica surfaces. Three protocols were used to evaluate nisin's activity against adhered cells ofListeria monocytogenes: bioassay usingPediococcus pentosaceous FBB 61-2 as the sensitive indicator strain; visualization and enumeration of cells by microscopic image analysis; and viability of adhered cells as determined by lodonitrotetrazolium violet uptake and crystallization. The activity of adsorbed nisin was highly dependent upon conditions of adsorption. The highest antimicrobial activity of adsorbed nisin occurred with high concentrations of nisin (1.0 mg ml^–1) and brief contact times (1 h) on surfaces of low hydrophobicity. Sequential adsorption of a second protein (-lactoglobulin or bovine serum albumin) onto surfaces consistently resulted in decreased nisin activity. These data provide direction for the development of applications to limit microbial attachment on food contact surfaces through the use of adsorbed antimicrobial peptides.     

Dynamics of Forest Landscape Patterns Along the Main Road in Xishuangbanna

In this paper, we investigated dynamics of forest landscape along the main roads in Xishuangbanna from 1976 to 1988, and from 1988 to 2003, using FRAGSTATS software and the GIS technology, based on the results interpreted from the Landsat MSS TM ETM imageries in 1976, 1988, 2003. Some representative quantitative indices of landscape diversity, including mean patch area, percent of landscape , perimeter-area fractal dimension , aggregation , Shannon′s diversity index , and Shannon′s equality index were used to describe the changes in the spatial pattern of landscape elements. Comparing with whole region of Xishuangbanna during last 27 years , the results showed that the man-made landscape (rubber plantation) and non-forested landscape along the main road expanded faster and their percentage were greater, whereas the natural landscape ( primitive forest patches) reduced faster and its percentage was smaller . There were obviouseffects of road on landscape which the forest coverage was decreased , and rubber plantation landscape was increased with the distance from the road . The natural forest landscape had been fragmented. Especially, the tropical seasonal rain forest was affected severely, while the area and contagion of rubber plantation and shrub increased. The whole landscape pattern along the main road tended to be diversiform, equal and fragmented. The landscape was still dominated by natural landscapes but this dominance was weakening . A case study about the displacement of landscape patch centroids showed that the spatial centroids of many types of landscape, including rubber plantation, tropical seasonal rain forest, mountain rain forest, shrub and non-forested land had moved away from the road. All of these changes in landscape pattern would lead the deterioration of these region environments.     

KRAB型锌指蛋白在高等脊椎动物胚胎发育和肿瘤发生、发展中的调控功能

KRAB型锌指蛋白(KRAB-ZFPs)最早出现于四足类脊椎动物, 且进化非常迅速, 是人类基因组编码的最大转录因子家族。尽管当前对此家族蛋白发挥调控功能的分子机制已有较为深入的研究, 但关于此家族蛋白所具备的高等脊椎动物特有的调控功能目前尚无全面系统的认识。文章对KRAB型锌指蛋白在高等脊椎动物的胚胎发育及肿瘤发生、发展中发挥的调控功能进行综述, 以期丰富对该家族蛋白在不同生理、病理过程中调控功能的认识, 为今后更深入的理论和应用研究打下坚实基础。     

双光子激发荧光各向异性度的成像

荧光各向异性度 (fluorescence anisotropy) 测量可以获得荧光分子的转动速度信息,进而了解分子质量、结构、以及与周边环境的相互作用情况 . 围绕一台双光子激发扫描荧光成像系统,通过改变外光路和图像记录与处理程序,从而实现了双光子激发荧光各向异性度成像,并针对一些典型样品和体系,展示了该方法的应用 . 实验中观察了 FITC 荧光分子、 FITC 结合的 CD44 抗体分子及与肿瘤细胞表面受体结合的 FITC-CD44 抗体分子 . 测量结果表明,不同分子质量、不同微观环境状态下的荧光分子,其各向异性度大小不同,在各向异性度图中能够被明显区分 . 荧光各向异性度成像能够定量测量样品微区的各向异性度值,并以二维图像的形式直观表达,是各向异性度测量与成像技术的良好结合 .     

基于温度-伤害度关系分析酿酒葡萄根系及芽抗寒性

采用差热分析系统(DTA)对8个主栽酿酒葡萄品种的芽和根系进行低温放热分析(LTE),建立各品种芽、根系韧皮部及木质部的温度-伤害度(LT-I)回归方程,评估不同品种的根系及芽抗寒性.结果表明： 8个品种的根系韧皮部伤害度50%的温度从高到低为马瑟兰>品丽珠>赤霞珠>小芒森>霞多丽>蛇龙珠>贵人香>熊岳白;不同品种木质部伤害度50%的温度从高到低为马瑟兰>霞多丽>赤霞珠>小芒森>品丽珠>蛇龙珠>贵人香>熊岳白;芽伤害度50%的温度从高到低为赤霞珠>小芒森>蛇龙珠>品丽珠>霞多丽>贵人香>马瑟兰>熊岳白.利用模糊隶属函数值法综合评价根系及芽的抗寒性,马瑟兰根系的抗寒性最差,熊岳白根系的抗寒性最好;赤霞珠、品丽珠、小芒森和蛇龙珠芽的抗寒性最差,贵人香和熊岳白芽的抗寒性最好.     

破色期番茄果实均一化cDNA沉默文库的构建和功能基因筛选模型的初步建立

番茄果实的成熟是由多基因精细调控的一个过程．利用破色期番茄果实,根据复性动力学原理在mRNA水平进行均一化操作使高丰度和低丰度的mRNA丰度接近．然后把均一化之后mRNA反转录得到cDNA,再与基因沉默载体pTRV重组,最后把构建好的载体通过电转化的方法转入到GV3101农杆菌中,从而建立起破色期番茄果实均一化cDNA沉默文库．通过番茄果实中病毒诱导基因沉默技术,对cDNA沉默文库进行初步筛选,从而确定功能基因筛选模型．在模型建立阶段,以番茄红素合成途径相关的PDS基因作为内标基因,在100个混合农杆菌样中,成功筛选到了PDS基因．