地高辛素标记的DNA探针快速鉴定产不耐热肠毒素大肠杆菌的研究

用地高辛素标记的６７０ｂＰ－ＬＴ－ＤＮＡ片段作为探针，用菌落原位杂交法对９株标准参考株进行检测，结果全部相符。对７０株从临床分离的菌株也进行菌落原位杂交．并与３２－Ｐ标记的探针进行比较．结果地高辛素探针的特异性为９７．７％，敏感性为１００％，符合率为９８．６％。从含正常肠道菌的粪便中可以直接检出ＬＴ－ＥＴＥＣ而无须经纯培养。定量试验表明本法最低检出量为６ＣｆｕＬＴ－ＥＴＥＣ／斑点。整个检测过程短．仅须２４～３０ｈ。探针的稳定性好，有效期可长达１年。     

rhTPO在大肠杆菌中的表达、纯化及生物活性分析

目的：探讨人促血小板生成素(human thromlbopoietin，hTPO)在大肠杆菌中表达、分离纯化及生物学活性初步鉴定。方法：利用RT-PCR法从人胎肝细胞中扩增目的基因片段，将其定向插入pQE30表达质粒T5启动子下游的多克隆区，转化大肠杆菌M15，得到pQE30-TPO的工程菌，诱导目的蛋白表达、纯化。将表达产物给血小板减少模型小鼠尾静脉注射，观察注射后不同时间血小板量的改变。结果：经异丙基硫代-β-D-半乳糖苷(isopropylthio-β-D-galactoside IPTG)诱导培养，该工程菌可以产生单一特异性的高表达蛋白条带。将纯化后的表达蛋白注射小鼠，结果显示对实验性小鼠血小板减少症具有一定的治疗作用。结论：在大肠杆菌中成功地高效表达了重组hTPO，该产物具有促血小板生成的活性。     

婴幼儿感染性腹泻25例临床分析

婴幼儿感染性腹泻是婴幼儿常见病之一，近年来在病原学方面有明显变迁，以致病性大肠杆菌感染多见，据我院儿科１９８９年的统计结果表明，大肠艾希氏菌和克雷伯氏菌感染明显上升，病程长，病情重，应引起重视，本文就１９８９年１年的婴幼儿感染性腹泻的发病机制与病原学进行了分析。     

Haemolytic uraemic syndrome in the defined population of Northeast of Scotland

Twenty seven cases of haemolytic-uraemic syndrome (HUS) were admitted to the Royal Aberdeen Children's Hospital between 1978 and 1989. All cases were from the defined childhood population of the Grampian region of Northeast of Scotland. Thirteen cases were admitted during the 2-year period 1987–1988 (Group 1). Of the 13 cases, 9 (Group 1a) were admitted within the 11-month period between August 1987 and June 1988, and were from a small area (7 miles radius) within and around the City of Aberdeen. Their mean age was 7.1 years. Twelve cases of HUS were admitted between 1978 and 1986 and 2 cases were admitted in 1989 (total 14 cases; Group 2). Mean age was 3.0 years with no geographical clustering. The average annual incidence for group 2 was 1.25 per 100,000 children 0–16 years old.     

Adhesins of uropathogenic bacteria: Properties,identification and use for new antibacterial strategies

Adherence is a major virulence factor in the complex pathogenesis of urinary tract infections (UTI). Colonization of the urinary tract and subsequent spread of infection ascending to the kidneys depends not only on the expression of adhesins by bacteria but also on the presence of host factors which may either contribute to or inhibit infection. The presence of certain types of adhesins expressed by the bacteria and their interactions with epithelial cells play a role in determining where bacteria localize in the urinary tract, the kind and severity of symptoms and how the disease progresses. The knowledge of the molecular mechanisms underlying adherence may be useful for epidemiological research in the pathogenesis of UTI, for the diagnosis of different types of UTI and, in some cases, for prognosis. Furthermore, attachment to epithelia is a promising target for developing new methods in prophylaxis and therapy.     

消毒剂敌菲特的研究

经全面考察研究,敌菲特缓释消毒灭菌剂具有良好的消毒灭菌效果,对细菌繁殖体、病毒和细菌芽孢均可完全灭活;即使在—20℃低温条件下,对枯黑变种芽孢仍具很好的杀灭效果。此外,该消毒剂基本克服了氯制剂对金属腐蚀性的缺陷;原药性能基本稳定。     

人PD-L2基因克隆及其在大肠杆菌中的表达

目的 克隆人PD-L2基因并构建PD-L2胞外区的原核表达载体，在大肠杆菌中进行表达。方法 以RT-PCR方法从活化的人外周血单个核细胞总RNA中克隆PD-L2基因的cDNA，构建PD-L2胞外区的原核表达载体，在大肠杆菌BL21(ED3)中进行表达并鉴定。结果 克隆到PD-L2基因cDNA编码区全长序列，经DNA测序证明其与已报道的序列一致。进而构建了PD-L2胞外区的原核表达载体，并在大肠杆菌表达，免疫印迹分析表明在IPTG诱导后表达PD-L2胞外区蛋白，相对分子质量Mr为22000，与理论值大小相符。结论 成功克隆PD-L2基因，其胞外区蛋白在大肠杆菌中获得表达，为进一步研究PD-L2功能提供了条件。     

Selection of an Escherichia coli O157:H7 bacteriophage for persistence in the circulatory system of mice infected experimentally

A bacteriophage lytic for Escherichia coli O157:H7 was isolated from bovine manure. Following in-vivo selection, the phage acquired the capacity to persist in the circulatory system of mice for at least 38 days. When mice were infected experimentally with E. coli O157:H7 (10(7) CFU/mouse), simultaneous injection of the mice with phage (10(8) PFU/mouse) cleared E. coli O157:H7 from the mice within 48 h.     

Adhesion inhibitory activity of β-lactoglobulin isolated from infant formulae

β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis.