Past Japanese successes show the way to accomplish future goals

Many parasitic diseases have been eradicated in industrialized countries and well-proven tools and techniques exist to control them. However, the same diseases still cause incalculable ill health and suffering in the developing world. The difficulty remains how best to apply existing solutions where they are most needed. Within a period of 25 years following World War II, Japan eliminated many parasitic diseases and raised national health and living standards to world-leading levels. Gradually, the predominantly community-driven and intersectoral collaborative partnership systems (i.e. private sector, public sector, general public, etc.) and practices that worked in Japan are being extended to Asia and now Africa. These are backed by the provision of substantial human and financial resources from a nation whose population retains the reputation as being the healthiest and longest living in the world.     

Determination of serum glucose by horseradish peroxidase-catalysed imidazole chemiluminescence coupled to a micro-flow-injection system.

The reactivity of flow-injection (FI)-horseradish peroxidase (HRP)-catalysed imidazole chemiluminescence (CL) was studied for continuous determination of hydrogen peroxide (H(2)O(2)) and serum glucose with immobilized glucose oxidase. Light emission by the HRP-catalysed imidazole CL was obtained when immobilized HRP, alkaline imidazole (in Tricine solution, pH 9.3) and H(2)O(2) were reacted at room temperature. The optimal pH for the CL reaction was 9.3 and the optimal concentration of imidazole was 100 micromol/L. When no imidazole was added, the light intensity of the same H(2)O(2) specimen decreased to a level that could not be quantitatively determined. The spectrum of the light emitted by imidazole CL was in the range 400-600 nm with a peak at 500 nm. The calibration equation for determination of H(2)O(2) was y = 9860x(2) + 3830x + 11,700, where y = light intensity (RLU) and x = concentration of H(2)O(2) (micromol/L). The detection limit of H(2)O(2) was 5 pmol, and the reproducibility of the H(2)O(2) assay was 2.3% of the coefficient of variation (H(2)O(2) 48 micromol/L, n = 13). The CL method was successfully applied to assay glucose after on-line generation of H(2)O(2) with the immobilized glucose oxidase column, resulting in good reproducibility (CV = 3.3% and 1.0% for the standard glucose and the control serum, respectively).     

Discovery of PPi-type Phosphoenolpyruvate Carboxykinase Genes in Eukaryotes and Bacteria

Phosphoenolpyruvate carboxykinase (PEPCK) is one of the pivotal enzymes that regulates the carbon flow of the central metabolism by fixing CO₂ to phosphoenolpyruvate (PEP) to produce oxaloacetate or vice versa. Whereas ATP- and GTP-type PEPCKs have been well studied, and their protein identities are established, inorganic pyrophosphate (PP_i)-type PEPCK (PP_i-PEPCK) is poorly characterized. Despite extensive enzymological studies, its protein identity and encoding gene remain unknown. In this study, PP_i-PEPCK has been identified for the first time from a eukaryotic human parasite, Entamoeba histolytica, by conventional purification and mass spectrometric identification of the native enzyme, followed by demonstration of its enzymatic activity. A homolog of the amebic PP_i-PEPCK from an anaerobic bacterium Propionibacterium freudenreichii subsp. shermanii also exhibited PP_i-PEPCK activity. The primary structure of PP_i-PEPCK has no similarity to the functional homologs ATP/GTP-PEPCKs and PEP carboxylase, strongly suggesting that PP_i-PEPCK arose independently from the other functional homologues and very likely has unique catalytic sites. PP_i-PEPCK homologs were found in a variety of bacteria and some eukaryotes but not in archaea. The molecular identification of this long forgotten enzyme shows us the diversity and functional redundancy of enzymes involved in the central metabolism and can help us to understand the central metabolism more deeply.     

Efficient synthesis of 3-O-thia-cPA and preliminary analysis of its biological activity toward autotaxin

The efficient synthesis of 3-O-thia-cPAs (4a-d), sulfur analogues of cyclic phosphatidic acid (cPA), has been achieved. The key step of the synthesis is an intramolecular Arbuzov reaction to construct the cyclic thiophosphate moiety. The present synthetic route enables the synthesis of 4a-d in only four steps from the commercially available glycidol. Preliminary biological experiments showed that 4a-d exhibited a similar inhibitory effect on autotaxin (ATX) as original cPA.     

菲律宾海北部底质沉积中的深海介形类

对琉球群岛东侧的菲律宾海北部海区(27.0°-30.0°N,129.5°-135.5°E)水深1 666 m至6 616 m的123个表层沉积物样品进行了定量微体古生物学研究.仅在38个样品中发现介形类,主要分布在4 000 m以浅水深区.初步鉴定有21属35种,其中Krithe在样品中的出现率和丰度最高,其次常见的还...     

河南西峡盆地晚白垩世含恐龙蛋地层中的介形类

河南西峡盆地含恐龙蛋地层高沟组、马家村组和寺沟组共发现介形类13属(亚属)20种,其中高沟组和寺沟组的介形类为首次报道.文章重点讨论了介形类Talicyridea动物群,其中Talicypridea,Altanicypris,Ruficypris和Lunicypris属的地质历程均限于晚白垩世.依据Talicyprid...     

西藏台错古湖晚第四纪轮藻类及其生态环境、气候变化探讨

西藏台错TT-1剖面厚369 cm,为一套碳酸盐粘土和粘土碳酸盐沉积,地层测年为41.4-4.5 ka,含丰富的轮藻化石,分属于11个轮藻植物群,群落所在地层的碳酸盐和钙质含量分别为80％和33％.从老到新(剖面自下而上):①41.4-26.64 ka(369-319 cm),处于末次冰期间冰阶MIS3a暖期,湖区气候...     

过表达外源ST3Gal I增加MCF-7细胞与胞外基质粘附和侵袭能力

为探讨过表达外源α2,3-唾液酸转移酶（ST3Gal Ⅰ）对乳腺癌MCF-7细胞粘 附和侵袭能力的影响,构建pEGFP-N1-ST3Gal I真核表达载体.采用GenEscortTM Ⅱ包裹后转染MCF-7细胞. MCF-7细胞为3组：未转染组 (M)、转染空质粒组 (P) 和转染ST3Gal I组 (ST3); 荧光显微镜观察融合蛋白EGFP ST3Gal I的表达.采用 半定量RT-PCR、Western印迹法分析转染后MCF-7细胞ST3Gal Ⅰ基因mRNA水平和 蛋白表达水平;流式细胞术分析ST3Gal Ⅰ下游产物细胞表面α2,3-唾液酸含量;采用细胞粘附实验及transwell小室检测转染前后细胞与基质胶Matrigel粘附、迁移和侵袭运动能力的变化.结果表明, 荧光显微镜下P组细胞内绿色荧光呈弥散分 布,而ST3组绿色荧光主要集中在细胞质中,RT-PCR与Western印迹也证实了外源 ST3Gal Ⅰ基因mRNA和蛋白表达均明显增加（P<0.05）,其下游产物细胞表面 α2,3-唾液酸含量明显增加（P<0.05）;与M、P组相比,ST3组表现为粘附、迁移和侵袭能力明显增强（P<0.05）.利用转染技术可明显提高外源ST3Gal Ⅰ在MCF -7细胞表达,明显增加MCF-7细胞与胞外基质（ECM）粘附、迁移和侵袭能力,可形成肿瘤入侵表型,将有望成为治疗乳腺癌转移的新靶点.