人TRAIL基因cDNA的克隆及其在COS—7细胞中的表达

ＴＲＡＩＬ(ＴＮＦｒｅｌａｔｅｄａｐｏｐｔｏｓｉｓｉｎｄｕｃｉｎｇｌｉｇａｎｄ)是最近克隆的肿瘤坏死因子(ＴＮＦ)家族的新成员,由于它的蛋白质结构和生物学效应类似于ＦＡＳ/ＡＰＯ1Ｌ,因此,也被称为ＡＰＯ2Ｌ。在低浓度下,ＴＲＡＩＬ能迅速地诱导多种肿瘤细胞系的?..     

High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

Background

Short rotation coppice willow is a potential lignocellulosic feedstock in the United Kingdom and elsewhere; however, research on optimising willow specifically for bioethanol production has started developing only recently. We have used the feedstock Salix viminalis × Salix schwerinii cultivar 'Olof' in a three-month pot experiment with the aim of modifying cell wall composition and structure within the stem to the benefit of bioethanol production. Trees were treated for 26 or 43 days with tension wood induction and/or with an application of the cellulose synthesis inhibitor 2,6-dichlorobenzonitrile that is specific to secondary cell walls. Reaction wood (tension and opposite wood) was isolated from material that had received the 43-day tension wood induction treatment.

Results

Glucan content, lignin content and enzymatically released glucose were assayed. All measured parameters were altered without loss of total stem biomass yield, indicating that enzymatic saccharification yield can be enhanced by both alterations to cell wall structure and alterations to absolute contents of either glucan or lignin.

Conclusions

Final glucose yields can be improved by the induction of tension wood without a detrimental impact on biomass yield. The increase in glucan accessibility to cell wall degrading enzymes could help contribute to reducing the energy and environmental impacts of the lignocellulosic bioethanol production process.     

羌活与宽叶羌活的群体遗传结构和种间分化研究

为了合理利用羌活和宽叶羌活的药用植物资源,同时保护其物种多样性,该研究利用SSR分子标记技术对羌活与宽叶羌活邻域及异域分布的23个自然种群,共计227个个体进行多样性和种间分化研究.结果显示:(1)两个物种具有中等水平的遗传多样性;羌活的平均等位基因数(Na)、有效等位基因数(Ne)和期望杂合度(He)分别为2.603...     

非酒精性脂肪肝大鼠PPARα基因表达及脂代谢和胰岛素水平的变化

目的观察非酒精性脂肪肝（NAFLD）大鼠肝组织中PPARα基因的表达,并用PPARct激动剂进行干预,探讨其与胰岛素抵抗、脂代谢紊乱的关系。方法大鼠随机分为①正常对照组、②高脂模型组、③PPARα激动剂干预组,利用高脂饮食建立大鼠非酒精性脂肪肝模型。12周后,检测大鼠血脂、肝功能、血糖、胰岛素水平及胰岛素抵抗指数;RT-PCR法分析PPARα基因的表达;观察肝脏的形态学改变。结果PPARa激动剂可降低NAFLD大鼠转氨酶、血脂水平及胰岛素抵抗指数,可促进NAFLD大鼠中PPARa基因的表达;肝脏形态学明显改善。结论PPARα激动剂能改善NAFLD大鼠脂质代谢紊乱,有明显的保肝降酶作用,具有适度的胰岛素增敏作用。PPARα及其配体在NAFLD发病机制及治疗中的进一步深入研究,将为临床防治NAFLD提供新的思路。     

蒙古高原岩黄芪属植物的分支分类学研究

以蒙古高原岩黄芪属植物为对象, 应用徐克学的最大同步法, 探讨了蒙古高原岩黄芪属(豆科)植物的系统演化, 并根据分支分类结果对蒙古高原岩黄芪属进行了系统学处理。作者首次将蒙古高原岩黄芪属分为岩黄芪亚属、半灌木岩黄芪亚属(新拟)和无刺岩黄芪组、丛枝岩黄芪组、无茎岩黄芪组、半灌木岩黄芪组等4 个组。本文对蒙古高原岩黄芪组的划分符合苏联植物志(1945)中的观点。     

Deletion of the glutamate carboxypeptidase II gene in mice reveals a second enzyme activity that hydrolyzes N-acetylaspartylglutamate

Glutamate carboxypeptidase II (GCPII, EC 3.14.17.21) is a membrane-bound enzyme found on the extracellular face ofglia. The gene for this enzyme is designated FOLH1 in humans and Folh1 in mice. This enzyme has been proposed to be responsible for inactivation of the neurotransmitter N-acetylaspartylglutamate (NAAG) following synaptic release. Mice harboring a disruption of the gene for GCPII/Folh1 were generated by inserting into the genome a targeting cassette in which the intron-exon boundary sequences of exons 1 and 2 were removed and stop codons were inserted in exons 1 and 2. Messenger RNA for GCPII was not detected by northern blotting or RT-PCR analysis of RNA from the brains of -/- mutant mice nor was GCPII protein detected on western blots of this tissue. These GCPII null mutant mice developed normally to adulthood and exhibited a normal range of neurologic responses and behaviors including mating, open field activity and retention of position in rotorod tests. No significant differences were observed among responses of wild type, heterozygous mutant and homozygous mutant mice on tail flick and hot plate latency tests. Glutamate, NAAG and mRNA for metabotropic glutamate receptor type 3 levels were not significantly altered in response to the deletion of glutamate carboxypeptidase II. A novel membrane-bound NAAG peptidase activity was discovered in brain, spinal cord and kidney of the GCPII knock out mice. The kinetic values for brain NAAG peptidase activity in the wild type and GCPII nullmutant were Vmax = 45 and 3 pmol/mg/min and Km = 2650 nm and 2494 nm, respectively. With the exception of magnesium and copper, this novel peptidase activity had a similar requirement for metal ions as GCPII. Two potent inhibitors of GCPII, 4,4'-phosphinicobis-(butane-1,3 dicarboxilic acid) (FN6) and 2-(phosphonomethyl)pentanedioic acid (2-PMPA) inhibited the residual activity. The IC50 value for 2-PMPA was about 1 nm for wild-type brain membrane NAAG peptidase activity consistent with its activity against cloned ratand human GCPII, and 88 nm for the activity in brain membranes of the null mutants.     

The energy budget of Porcellio spinicornis Say (Porcellionidae, Isopoda) under laboratory conditions

The rate of energy flow in Porcellio spinicornis was investigated in a select group of a laboratory population. The consumption, assimilation and production were calculated to be 1 233, 1 002 and 304 cal/year, respectively, in the male, and 1 261, 1 198 and 429 cal/year, respectively, in the female. Ignoring loss due to mortality, and applying the population density of 2 295 m2 in the laboratory colony, the isopod population should consume 2 861.8 kcal m-2 year-1, resulting in an assimilation of 2 524.5 kcal m-2 year-1 and a total productivity of 841.1 kcal m-2 year-1.     

The possible role of 10398A and 16189C mtDNA variants in providing susceptibility toT2DM in two North Indian populations: a replicative study

The role of mitochondria in causing diseases is becoming evident as more and more studies are focusing on this organelle of the cell. This is largely attributed to its reactive oxygen species (ROS) production property. In the context of diabetes, ROS is suggested to trigger different forms of insulin resistance involving different mechanisms. The suggestive role of a mtDNA variant G10398A in increasing ROS production and the impaired response to oxidative stress due to T16189C variant is worth addressing as genetic susceptibility factors in type 2 diabetes mellitus (T2DM). A case control study on 312 T2DM cases and ethnically matched 466 controls involving two North Indian populations, referred as cohort 1 and cohort 2 (in a replicative study), was undertaken to test such a genetic association. A statistically significant association was observed for 10398A allele in both the cohorts [cohort1 (OR = 2.67 95% CI 1.77–4.00); cohort2 (OR = 1.76 95%CI 1.12–2.77)]. The analysis of G10398A/T16189C haplotypic combinations revealed that 10398A/16189C haplotype provides a risk in both the cohorts. To sum up the study suggests that 10398A and 16189C alleles provide susceptiblity to T2DM independently as well as together.