降纤酶治疗心源性脑栓塞疗效观察

目的 探讨降纤酶治疗心源性脑栓塞的临床疗效和安全性。方法 对32例心源性脑栓塞病人给予降纤酶10u加0．9％氯化钠250ml中静滴,每天1次,10天为1疗程。用药期间监测血浆纤维蛋白原、血液粘度、凝血酶原时间、血小板聚集率及肝肾功能。结果 临床疗效显著,总有效率84．4％,在发病24h内给药部效率92．3％;血浆纤维蛋白原、血液粘度、血小板聚集率均明显降低（P＜0．05）。结论 降纤酶治疗心源性脑栓塞疗效确切,副作用小,安全可靠。早期、足量使用效果更佳。     

Optimization of conditions for the production of pullulan and high molecular weight pullulan by Aureobasidium pullulans

Aureobasidium pullulans had a maximum yield coefficient of pullulan (Y _p/s=0.24) with an initial pH of the culture broth of 6.5 in a shake-flask culture. In a batch culture, the maximum pullulan yield coefficient of 0.30 was obtained at the aeration rate of 0.5 vvm. A yeast-like form and mycelial form of cells were found at the culture broth with pH controlled at 4.5 with a maximum yield coefficient of pullulan of 0.27. However, a high portion (35%) of high molecular weight pullulan (M _w>2 000 000) was produced at pH 6.5 with a yeast-like morphology of the cells.     

具有抗氧化活性的酸性菟丝子多糖H2的研究

从药用植物菟丝子 (CuscutachinensisLam .)的种子中经碱液提取所得的粗多糖CHC ,经进一步分离纯化得一酸性纯多糖H2 ,其分子量大于 1.0× 10 6,利用化学方法和光谱分析方法对其结构进行了研究。多糖H2由 1,6_linked_β_DGalp、1,4_linked_β_DGalp、1,4_linked_β_DGalA和 1,2or 4_linked_β_L_Rhap构成主链 ,并在部分1,6_linked_β_DGalp残基的O_3位和 1,2or 4_linked_β_L_Rhap残基的O_4或O_2形成分枝点 ,以末端半乳糖构成末端。侧链由末端半乳糖 ,1,6_linked_β_DGalp、1,4_linked_β_DGalp和 1,3,6_linked_β_DGalp残基构成 ,连接于主链的1,6_linked_β_DGalp残基的O_3位。阿拉伯糖残基 1,5_linkedAra、1,3,5_linkedAra、末端Ara以及末端鼠李糖残基存在于多糖分子H2的外周 ,连接于侧链和主链的 1,6_linked_β_DGalp残基的O_3位。此外 ,药理研究结果显示 ,H2能减少自由基引起的对大鼠成嗜铬细胞瘤PC12神经细胞系的损伤 ,明显提高细胞的存活率     

PCR-ELISA检测HBV DNA的研究

目的:建立一种敏感、特异的乙型肝炎病毒(HBV)DNA检测方法。方法:应用PCR扩增技术和核酸杂交技术结合酶促显色技术(即PCRELISA技术)来检测血清中的HBVDNA。结果:应用PCRELISA技术能够检出许多PCR琼脂糖凝胶电泳所检测不到的HBVDNA,大大地提高了检出率,而且,特异性强。结论:PCRELISA方法灵敏度高,特异性强,检测结果数据化,不受主观因素的影响 。     

鼎湖山森林群落的光能利用效率

本文研究了鼎湖山自然保护区,亚热带季风常绿阔叶林和针叶阔叶混交林的光能利用效率。根据群落的垂直结构和成层现象,应用红外线CO_2气体分析法,分层测定了主要植物22种58株的光合速率.计算了群落的生产力;用量子传感器分层测定了两个群落的光合有效辐射,并计算其光能利用效率。结果表明:阔叶林总生产力的光能利用效率为14.28%,混交林为12.01%,说明了不同森林类型对光能资源的利用效率。     

应用荧光抗体染色技术对感染鲢鱼组织中病原菌的观察

河弧菌III生物型(Vibrio fluvialis biovar III)是近年来流行于国内广大养殖地区的一种严重的淡水鱼类细菌出血性败血病的病原川,然而对该病的病理学、被感染鱼组织中细菌的定位和侵袭情况至今尚无正式报道.       

杨属植物新分类群(一)

杨树在我国各省、区均有分布,尤以山地和北方较为普遍。多数种类具有喜光、耐寒、耐旱、速生、易繁殖、适应性强、用途广的特点,是我国营造平原地区用材林、防护林、水土保持和四旁绿化的优良树种,深受生产单位和群众的喜爱,近年来对杨树的栽培更为重视,许多平原地区,把杨树作为大力发展的速生树种之一。实践证明,杨树对绿化祖国,改造自然,保证农业高产稳产,迅速满足社会主义建设所需大量木材起到了积极作用。     

Structural basis for juvenile hormone biosynthesis by the juvenile hormone acid methyltransferase

Juvenile hormone (JH) acid methyltransferase (JHAMT) is a rate-limiting enzyme that converts JH acids or inactive precursors of JHs to active JHs at the final step of JH biosynthesis in insects and thus presents an excellent target for the development of insect growth regulators or insecticides. However, the three-dimensional properties and catalytic mechanism of this enzyme are not known. Herein, we report the crystal structure of the JHAMT apoenzyme, the three-dimensional holoprotein in binary complex with its cofactor S-adenosyl-l-homocysteine, and the ternary complex with S-adenosyl-l-homocysteine and its substrate methyl farnesoate. These structures reveal the ultrafine definition of the binding patterns for JHAMT with its substrate/cofactor. Comparative structural analyses led to novel findings concerning the structural specificity of the progressive conformational changes required for binding interactions that are induced in the presence of cofactor and substrate. Importantly, structural and biochemical analyses enabled identification of one strictly conserved catalytic Gln/His pair within JHAMTs required for catalysis and further provide a molecular basis for substrate recognition and the catalytic mechanism of JHAMTs. These findings lay the foundation for the mechanistic understanding of JH biosynthesis by JHAMTs and provide a rational framework for the discovery and development of specific JHAMT inhibitors as insect growth regulators or insecticides.     

Cloning and Structure Analysis of rbcS Gene from Wild Soybean

About 1 kb fragment of rbcS (ribulose 1, 5-bisphosphate carboxylase small subunit) gene in wild soybean (Glycine soja, Ji 50017) was amplified from total DNA by PCR assay. Sequence analysis of the fragment indicated that 1089 bp sequenced included the whole coding region for Rubisco small snbunit. The rbcS gene in wild soybean encoded a precursor composed of a transit peptide of 55 amino acids and a mature protein of 123 amino acids. There were two introns found in the rbcS gene as other dicotyledonous species previously sequenced. Comparison of DNA sequences showed high degree homology of rbcS genes between wild soybean and cultivated soybean (Glycine max var. wayne). Some changes of amino acids emerged from the diverse nucleotides did not affect the function of the small subunit. These results may contribute some basic data in molecular biology to study the origin and evolution of soybean.