Using chimeric piggyBac transposase to achieve directed interplasmid transposition in silkworm Bombyx mori and fruit fly Drosophila cells

The piggyBac transposon has been long used to integrate foreign DNA into insect genomes. However, undesirable transgene expression can result from random insertions into the genome. In this study, the efficiency of chimeric Gal4-piggyBac transposase in directing integration onto a DNA target plasmid was evaluated in cultured silkworm Bombyx mori Bm-12 and fruit fly Drosophila Schneider 2 (S2) cells. The Gal4-piggyBac transposase has a Gal4 DNA-binding domain (DBD), and the target plasmid has upstream activating sequences (UAS) to which the Gal4 DBD can bind with high affinity. The results indicate that, in the Bm-12 and S2 cells, transpositional activity of Gal4-piggyBac transposase was increased by 4.0 and 7.5 times, respectively, compared to controls, where Gal4-UAS interaction was absent. Moreover, the Gal4-piggyBac transposase had the ability of directing piggyBac element integration to certain sites of the target plasmid, although the target-directing specificity was not as high as expected. The chimeric piggyBac transposase has the potential for use in site-directed transgenesis and gene function research in B. mori.     

血清CA-19-9测定对胰腺癌的诊断价值

目的：寻求胰腺癌的诊断方法，方法：用免疫放射分析法（IRMA）检测血清CA－19－9含量，106例血清CA－19－9含量3700u/L，进行追踪随访，结果：106例中，胰腺癌66例，结肠癌15例，胆管癌13例，肺癌9例，结论：检测血清CA－19－9含量，有利于胰腺癌的诊断和与结肠癌，胆管癌，肺癌等恶性肿瘤的鉴别。     

微量全血单细胞凝胶电泳技术在身体机能评定中的应用

单细胞凝胶电泳技术是一种在单细胞水平上检测有核细胞DNA损伤与修复的方法.本文总结了该实验技术的基本原理、方法及应用现状.改进的微量全血单细胞凝胶电泳技术具有敏感性高、取材方便、费用低、实验周期短等优点,对于运动中身体机能的评定具有重要的意义。     

吸烟对体育专业学生外周血淋巴细胞DNA损伤的研究

目的：用慧星试验检测体育专业学生吸烟所诱发的DNA损伤。方法：选体育专业15名吸烟学生（平均烟龄10．3支／天，1．4年）和8名不吸烟的对照组学生。用彗星试验检测了两组对象外周血淋巴细胞DNA的迁移。结果：实验结果表明吸烟组的平均彗星尾长为2．75μm，明显高于对照组（1．2μm），差异有显著性（P＜0．01）。平均彗星尾相为3．66，明显高于对照组（2．14），差异有显著性（P＜0．01）。吸烟组平均长尾核的百分率为27．74％，明显高于对照组的5．55％，差异有显著性（P＜0．01）。结论：体育专业吸烟学生外周血淋巴细胞的DNA有不同程度的损伤。     

Antigens of diagnostic and prophylactic importance inEntamoeba histolytica

Summary  Amoebiasis, caused by an enteric protozoanEntamoeba histolytica, is one of the major parasitic diseases of mankind. Current estimate suggests that the parasite infects about 10% of the world population at any given time. There is an urgent need to characterize the antigenic molecules ofE. histolytica, and find out antigens which have both immunodiagnostic and prophylactic potential against amoebiasis. The results of somatic antigen analysis, using sera from immune or infected individuals, indicated that the wholeE. histolytica trophozoites, are highly complex and heterogeneous in nature and both immunodiagnostic and immuno prophylaxis activity remain mainly in a surface associated 29 kDa glycoprotein ofE. histolytica. Future studies at molecular level particularly, genes responsible for expression of this protein, their homology with other proteins and structure analysis will give better understanding about this polypeptide. Studies on excretory secretory antigens, clearly demonstrated thatE. histolytica like many organisms, also liberates certain antigenic moieties into the culture medium during in vitro cultivation and this antigen has similar diagnostic values like the conventional somatic antigens. It is important that the ESA should be prepared from the supernatant after collecting the cell and use for immunodiagnosis of amoebiasis. This is an additional source of antigen which will help in carrying out more tests using the same reagents. Further studies are needed to clarify the location of these molecules on the parasite, along with detailed biochemical and immunological characterization and their relation with the pathogenesis. This was presented at the symposium on “Recent Trends in Tropical Disease Research”, held at Sevagram on 5-6 September, 1997.     

注射用盐酸头孢吡肟的RP-HPLC测试

建立注射用盐酸头孢吡肟含量测定的RP-HPLC方法。ODS色谱柱250×4.6mm（i.d.）5μm;0.04mol/L醋酸铵（冰醋酸调节pH至5.0）-甲醇（92：8）为流动相,流速为1.0ml/min,检测波长为256nm。流速为1.0ml/min。盐酸头孢吡肟在10.5～84.0μg/ml浓度范围内,其峰面积与浓度呈良好线性关系（r=0.9993）,精密度RSD为0.5%。平均回收率为98.90%,RSD为0.34%,检测限为1.5ng。本法简便、快速、准确、专属性强,可用于注射用盐酸头孢吡肟的含量测定及有关物质检查。     

异烟肼片含量测定方法的改进

以甲基橙代替乙氧基黄叱精指示剂，用溴酸钾法测定异烟肼含量，讨论了温度、被测液酸度、体积、滴定速度等因素对测定结果的影响。测得异烟肼平均回收率为１００．０８％，ＲＳＤ＝０．２４％。经与九○年版中国药典法比较，所得结果一致，本法具有终点易观察，滴定操作时不必控制温度等优点。     

管碟法研究臭牡丹提取物抑菌活性

采用管碟法研究臭牡丹根和茎的水提取物对四种试用菌的抑菌效果.结果表明臭牡丹提取物对大肠杆菌、枯草杆菌、金黄色葡萄球菌和放线菌均具有不同程度的抑菌作用,抑菌效果随提取液浓度的加大而增强.根提取物的抑菌效果总体比茎好.大肠杆菌、枯草杆菌在浓度为8.0mg/mL时具抑菌效果,而放线菌和金黄色葡萄球菌在浓度为4.0mg/mL具抑菌效果.根提取物对金黄色葡萄球菌、大肠杆菌的抑菌能力随着pH的增大而减小;放线菌则相反.     

蛇足石杉生物碱的提取与测定

研究蛇足石杉生物碱的提取工艺.整个工艺是:用酸浸提、微波加热、蒸馏、萃取、反萃取、脱色等分离技术从蛇足石杉中提取石杉碱,最后定性定量检测.结果表明:(1)微波加热处理可提高石杉碱的提取率;(2)萃取和反萃取相结合,使用旋转蒸发仪蒸馏有助于分离石杉碱;(3)用碘化铋钾试液对提取的生物碱进行饱和滴定,然后烘干称量,再根据化学反应式来计算生物碱含量,是一种较好的近似测定方法;(4)根据标准样品的直线回归方程,利用紫外分析仪测定石杉碱甲含量是一种经济高效的方法;(5)洪江市塘湾镇的蛇足石杉的石杉碱甲的含量为0.085‰,粗提物中石杉碱甲的百分含量为26.1%.