黑木耳多糖对急性脑缺血/再灌注损伤影响的研究

目的:观察黑木耳多糖(APP)对急性脑缺血大鼠的保护作用并探讨其相关机制。方法:成年雄性SD大鼠给予不同浓度的AAP灌胃20d,每天1次,腹腔注射银杏叶提取物(ginkgo biloba extract,EGb671)作为阳性对照,20d后实施右侧大脑中动脉栓塞(MCAO)建立局灶性脑缺血模型。MCAO60min后复灌,复灌24h后进行Longa神经功能损伤评分,并用2,3,5-氯化三苯基四氮唑(TTC)染色法测定脑梗死面积。复灌48h后用TUNEL免疫组化检测神经元凋亡,测定脑组织线粒体内活性氧簇(ROS)的生成量判断氧化应激水平。结果:黑木耳多糖能降低神经功能损伤评分,减小脑梗死面积,减少神经元凋亡,并且能够使缺血复灌脑组织线粒体ROS生成显著减少。高剂量AAP组的凋亡神经元数量、ROS生成量和阳性对照组相比有显著性差异。结论:黑木耳多糖能够对抗大鼠的局灶性脑缺血损伤,其保护作用和减轻氧化应激水平有关,并优于银杏叶提取物。     

Characterization of the putative tryptophan synthase β-subunit from Mycobacterium tuberculosis

The increasing emergence of drug-resistant tuberculosis （TB） poses a serious threat to the control of this disease. It is in urgent need to develop new TB drugs. Tryptophan biosynthetic pathway plays an important role in the growth and replication of Mycobacterium tuberculosis （Mtb）. The β-subunit of tryptophan synthase （TrpB） catalyzes the last step of the tryptophan biosynthetic pathway, and it might be a potential target for TB drug design. In this study, we overexpressed, purified, and characterized the putative TrpB-encoding gene Rv1612 in Mtb H37Rv. Results showed that Mtb His-TrpB optimal enzymatic activity is at pH 7.8 with 0.15 M Na^＋ or 0.18 M Mg^2＋ at 37℃. Structure analysis indicated that Mtb TrpB exhibited a typical β/α barrel structure. The amino acid residues believed to interact with the enzyme cofactor pyridoxal-5＇-phosphate were predicted by homology modeling and structure alignment. The role of these residues in catalytic activity of the Mtb His-TrpB was confirmed by site-directed mutagenesis. These results provided reassuring structural information for drug design based on TrpB.     

生长激素受体及其介导的信号转导

生长激素受体(growth hormone receptor,GHR)是细胞因子／造血因子受体超级家族的一员。它通过二聚体的形式和生长激素(growth hormone,GH)相结合,然后诱发Janus激酶2(Janus kinase 2,JAK2)等细胞因子酪氨酸磷酸化并通过4条不同的途径将信号传入细胞内从而产生一系列的生理效应。现在了解GHR的结构特征、组织分布的基础上,对其介导的信号转导途径作进一步的阐明。     

Dihydroartemisinin-Piperaquine vs. Artemether-Lumefantrine for First-Line Treatment of Uncomplicated Malaria in African Children: A Cost-Effectiveness Analysis

Background

Recent multi-centre trials showed that dihydroartemisinin-piperaquine (DP) was as efficacious and safe as artemether-lumefantrine (AL) for treatment of young children with uncomplicated P. falciparum malaria across diverse transmission settings in Africa. Longitudinal follow-up of patients in these trials supported previous findings that DP had a longer post-treatment prophylactic effect than AL, reducing the risk of reinfection and conferring additional health benefits to patients, particularly in areas with moderate to high malaria transmission.

Methods

We developed a Markov model to assess the cost-effectiveness of DP versus AL for first-line treatment of uncomplicated malaria in young children from the provider perspective, taking into consideration the post-treatment prophylactic effects of the drugs as reported by a recent multi-centre trial in Africa and using the maximum manufacturer drug prices for artemisinin-based combination therapies set by the Global Fund in 2013. We estimated the price per course of treatment threshold above which DP would cease to be a cost-saving alternative to AL as a first-line antimalarial drug.

Results

First-line treatment with DP compared to AL averted 0.03 DALYs (95% CI: 0.006–0.07) and 0.001 deaths (95% CI: 0.00–0.002) and saved $0.96 (95% CI: 0.33–2.46) per child over one year. The results of the threshold analysis showed that DP remained cost-saving over AL for any DP cost below $1.23 per course of treatment.

Conclusions

DP is superior to AL from both the clinical and economic perspectives for treatment of uncomplicated P. falciparum malaria in young children. A paediatric dispersible formulation of DP is under development and should facilitate a targeted deployment of this antimalarial drug. The use of DP as first-line antimalarial drug in paediatric malaria patients in moderate to high transmission areas of Africa merits serious consideration by health policymakers.     

黄龙大熊猫种群数量及年龄结构调查

１９９６年６￣１０月,在野外采用路线－聚类法对黄龙寺自然保护区内大熊猫种群数量进行了调查。结果表明：保护区内现有大熊猫２３只,竹林内生态密度为０．４３９只／ｋｍ＾２。此外,首次采用了离差平方和聚类的方法,将该种群划分为４个年龄组。其中幼年组个体上占１３．３３％,青年组个体占６．６７％,成年组个体占６０％,老年组个体占２０％。最后还对结果进行了讨论。并提出了保护措施。     

Ordered Hexagonal Nanoplasmonic Au Nanoparticle Arrays: AAO-Assisted Thermal Treatment Synthesis and Application as Surface-Enhanced Raman Scattering Substrates

We have reported on the synthesis of ordered hexagonal Au nanoparticle (NPs) arrays by anodic alumina oxide templates (AAO)-assisted thermal treatment. This simple process has led to the formation of an ordered hexagonal array of Au NPs on the surface of AAO. SERS properties of the ordered hexagonal Au NPs could be obtained by varying the size of Au NPs. Compared with the Au thin film on AAO, the SERS intensity of rhodamine adsorbed on the ordered hexagonal Au NPs was about 1000 times stronger. And the hexagonal Au NPs array films have had stronger Raman-enhanced signal compared to the disorder Au NPs films. Simulations according to the three-dimensional finite-difference time domain (3D-FDTD) have displayed that these electric field enhancements of the ordered hexagonal Au NPs are strongly dependent on the gap distance. Plasmonic ordered hexagonal Au NPs could provide us new platforms to realize novel optoelectronic devices.

     

Interrogation of phosphor-specific interaction on a high-throughput label-free optical biosensor system–Epic® system

The Epic^® system, a high-throughput label-free optical biosensor system, is applied for the biochemical interrogation of phosphor-specific interactions of the 14-3-3 protein and its substrates. It has shown the capability not only for high-throughput characterization of binding rank and affinity but also for the exploration of potential interacting kinases for the substrates. A perspective of biochemical applications for diagnostics and biomarker discovery, as well as cell-based applications for endogenous receptors and viral infection characterization, are also provided.     

五种食用菌氨基酸含量的测定及营养评价

研究测定了五种食用菌中氨基酸的含量,并利用五种非生物学指标对蛋白质的营养价值进行评价。五种食用菌氨基酸种类齐全,必需氨基酸占氨基酸总量的百分比分别达到45.94%、37.62%、42.45%、41.54%、35.98%。茶树菇和姬松茸的限制性氨基酸为半胱氨酸和甲硫氨酸,鸡腿菇、香菇和黑木耳的限制性氨基酸是缬氨酸。不同的评价指标对蛋白质进行营养评价,评价结果会有所差异。