大肠杆菌生产的霍乱毒素B亚单位

应用遗传工程技术,获得一株高效表达霍乱毒素B亚单位的工程大肠杆菌菌株,该菌株在501发酵罐培养,B亚单位产量达20—40μg/ml,且能分泌至胞外。将工程菌产生的B亚单位经亲和层析纯化,获得了电泳纯制品,其分子量、N端氨基酰末端分析、抗原性、与天然的B亚单位完全相同。工程菌产生的B亚单位具有很好的免疫原性,可用于构建防治霍乱及毒源性大肠杆菌腹泻的制剂及半抗原的载体。     

霍乱弧菌无毒肠毒素A~-B~+基因在大肠杆菌的表达

应用DNA体外重组技术,成功地将霍乱弧菌毒素(CT)基因,在大肠杆菌中改建成CTA~-B~+基因克隆。组构的pMM-CTB重组质粒,在大肠杆菌中能高表达CTB亚单位,并能分泌到细胞外。     

蒙药“心室Ⅱ号”中微量锗的测定

以丁基罗丹明B与锗钼杂多酸形成的三元配合物,测定了对冠心病有较好疗效的蒙药“心室Ⅱ号”中锗的含量。提出了高灵敏度测定痕量锗的新方法,显色体系的表观摩尔吸光系数为5.6×10~5L/mol·cm,锗含量在0～7ug/25mL范围内服从比尔定律,回收率为96％～106％     

预防伤寒及霍乱二价口服疫苗的构建

将含有产生无毒的霍乱毒素B亚单位基因之重组质粒pMM-CTB,转移至口服安全、有效的伤寒疫苗林Ty21a中。获得的Ty21a(pMM-CTB)这个菌株,能稳定地产生CT-B亚单位,分泌至胞外,具有与霍乱弧菌产生的CT-B亚单位有相同的抗原性,且它仍保持了伤寒疫苗株Ty21a的抗原性,对半乳糖的敏感性及在体内存留时间的生物特性。应用它与杀死的霍乱弧菌全细胞构建成二价疫苗,具有对伤寒和霍乱很好的免疫原性。     

THE EXPRESSION OF ENTEROTOXIN A~-B~+ GENE OF V. cholerae IN E. coli

The cloning in E. coli of a cholerae toxin gene that is A~-B~+ has been successfully constructed by using DNA recombinant techniques. E. coli cells carrying the recombinant plasmid pMM-CTB have been shown to produce a large amount of CTB subunits which are secreted as extracellular proteins.     

B SUBUNIT OF CHOLERA TOXIN PRODUCED IN Escherichia coli

An engineered E. coli strain containing high expression level of CT-B subunits has beenobtained by the application of recombinant DNA techniques. The B subunit can be secretedinto the medium and reaches 20- 40 μg/ml when this strain is incubated in a 50 1 fermenta-tion tank. The CT-B subunit purified with affinity chromatography in E. coli has the samecharacters as the natural CT- B subunit in molecular weight, N terminal amino acid analysisand antigenicity. The CT-B subunit has good immunogenicity and can be used as a preparation for protect-ing against diarrhea caused by V. cholera and enterotoxigenic E. coli. It can also be usedas a vector for hepatins.     

呼和浩特蒙,汉,回三民族儿童头发中锌铁铜镁钙含量比较研究

测定了呼和浩特市地区１８７名不同民族、不同性别７岁健康儿童头发中Ｚｎ、Ｆｅ、Ｃｕ、Ｍｇ、Ｃａ含量。结果发现同地区同年龄同性别不同民族儿童头发中上述五种元素含量有一定的区别。     

CONSTRUCTION OF A BIVALENT ORAL VACCINE FOR PREVENTION OF TYPHOID FEVER AND CHOLERA DIARRHEA

A recombinant plasmid pMM-CTB containing the gene for production of the nontoxic B subunit of Vibrio cholera was transferred into a safe, effective and attenuated oral vaccine Ty21a strain of Salmonella typhi. The resulting Ty21a(pMM-CTB) could steadily produce CT-B subunit that was secreted extracellularly and had the same antigenicity as CT-B produced by V. cholera. Furthermore, the characteristics of the antigenicity, the persistance in mice and the galactose sensitivity possessed in the strain of Ty21a were also retained in Ty21a (pMM-CTB). A bivalent vaccine containing Ty21a (pMM-CTB) and the killed whole cell of V. cholera was then constructed which had good immunogenecity for typhoid fever and cholera diarrhea.