Screening for Escherichia coli O157:H7 in Illinois

Objective: To determine the incidence of infection with Escherichia coli O157:H7 in a tertiary referral center in Chicago, where a similar study had been performed in 1984, to evaluate cases of disease reported to the Illinois Department of Public Health (IDPH) in 1993, and to determine laboratory practices used to detect this infection throughout the state.
Methods: During a 6-month period in 1993, all stool specimens at Rush-Presbyterian-St Luke's Medical Center (RPSLMC) were tested for E. coli O157:H7. Reports of diagnosed E. coli O157:H7 cases investigated by IDPH were also reviewed. A survey of 73 hospitals in the Chicago area was performed to determine routine culturing practices, specifically, the selection of stool specimens for evaluation for this pathogen.
Results: In the RPSLMC survey, two cases were identified among 1985 samples (incidence 0.1%), similar to the 0.08% incidence detected in a similar study conducted at the same institution in 1984. Through passive surveillance, the IDPH received 44 reports of E. coli O157:H7 in 1993. The hospital survey revealed that, in the seven labs testing all stool specimens for E. coli O157:H7, an incidence of 16/8137 specimens (0.2%) was determined.
Conclusions: These data suggest that sporadic E. coli O157:H7 remains uncommon in Illinois and that the incidence may not have changed over a 9-year period. The low yield and substantial cost of culturing all stools suggest that only specimens from patients with bloody diarrhea should be evaluated routinely in areas of low endemicity.     

Design and Simulation of Active Biochip System

To solve the problems existing in passive biochip systems, we designed a novel active biochip system. This system introduces negative pressure and controlling devices to adjust the antigen-antibody reaction on the nitrocellulose membrane. Computational simulation demonstrated that this system is a rapid, stable, robust and practical system that may enhance the efficiency of antigen-antibody reactions and improve the repeatability and accuracy of biochip analysis.     

Efficacy of recombinant granulocyte colony-stimulating factor (rhG-CSF) in experimental colitis

Inflammatory bowel disease is associated with mucosal neutrophil recruitment and activatation, mediated in part by arachidonic acid metabolites. G-CSF attenuates the immune response to sepsis and ameliorates glycogen storage disease Ib-related colitis. These actions may be effected through the shedding of neutrophil adhesion molecules, or inhibition of proinflammatory mediator synthesis. Immune complex colitis was used to evaluate the effect of rhG-CSF on colonic mucosal inflammation, neutrophil recruitment and the generation of eicosanoids. Immune complex colitis was induced in White New Zealand rabbits. Animals were pretreated with rhG-CSF either 24 h before induction, or at induction, with dosages of 50 and 200 μg/kg. rhG-CSF caused a time- and dose-dependent neutrophilia in all animals. Pretreatment with rhG-CSF resulted in increased tissue myeloperoxidase levels, despite a histologically similar mucosal polymorphonuclear cell infiltrate between treated and control colitis groups. Leukotriene B₄ (LTB₄) and thromboxane B₂ (TXB₂) dialysis fluid levels were lower in treated animals, in particular in the groups receiving two doses (LTB₄: both P < 0.01; TXB₂: both P < 0.01. Prostaglandin E₂ (PGE₂) levels in dialysis fluid of the rhG-CSF-treated animals showed no difference from controls. In this model of experimental colitis, high-dose therapy with G-CSF resulted in a marked decrease of proinflammatory mediators, but mucosal generation of the protective PGE₂ was preserved. These results suggest that prolonged high-dose therapy with G-CSF may have anti-inflammatory effects in colitis.     

术苓健脾胶囊对TNBS诱导的大鼠实验性结肠炎的作用及机制

探讨术苓健脾胶囊（术苓）对2,4,6-三硝基苯磺酸（TNBS）诱导的大鼠实验性结肠炎的作用及其机制。采用2.5%TNBS灌肠制备大鼠实验性结肠炎模型。将大鼠随机分为正常组、模型组、肠炎宁（180 mg/kg）组以及术苓低剂量（40 mg/kg）、高剂量（120 mg/kg）组。造模后药物治疗7 d后处死大鼠。其间每日记录大鼠体重,观察大鼠疾病活动状态。实验结束后,取结肠组织进行HE病理学分析、检测结肠组织中髓过氧化物酶（MPO）酶活、诱导型一氧化氮合酶（iNOS）、炎性细胞因子（IL-6、IL-1β、IFN-γ、IL-10）及紧密连接蛋白（occludin、ZO-1）的表达水平,并检测血清中炎性细胞因子（IL-6、IL-1β）的含量。结果表明,与模型组相比,术苓给药显著缓解了TNBS造模引起的体重下降、疾病活动指数（DAI）升高,缓解了结肠组织的缩短、水肿以及病理学损伤,减少了炎性细胞浸润、隐窝的破坏与杯状细胞的丢失,降低了结肠组织MPO酶活性、iNOS与炎性细胞因子的水平,增加了结肠紧密连接蛋白的表达,同时降低了血清中的炎性因子的含量。结果表明,术苓通过降低炎性因子水平,增加肠道紧密...     

5-氨基水杨酸灌肠对大鼠免疫性结肠炎的影响

目的 探讨5-氨基水杨酸(5-ASA)灌肠对大鼠三硝基苯磺酸(TNBS)诱导的结肠炎的作用.方法用TNBS诱发大鼠结肠炎.造模7天后,用不同剂量的5-ASA(25、50、100mg·kg-1·d-1)开始灌肠.观察大鼠粪隐血(OB)反应强度、结肠大体形态和组织学改变,并检测肠黏膜髓过氧化物酶(MPO)活性.结果 5-ASA灌肠可明显降低结肠黏膜损伤指数(CMDI)、OB反应强度、MPO活性及组织学评分(HS),各剂量组间有一定的量效关系.结论 5-ASA灌肠对TNBS诱导的大鼠结肠炎有保护作用,且与剂量有一定关系.     

Acute cytomegalovirus infection modulates the intestinal microbiota and targets intestinal epithelial cells

Primary and recurrent cytomegalovirus (CMV) infections frequently cause CMV colitis in immunocompromised as well as inflammatory bowel disease (IBD) patients. Additionally, colitis occasionally occurs upon primary CMV infection in patients who are apparently immunocompetent. In both cases, the underlying pathophysiologic mechanisms are largely elusive - in part due to the lack of adequate access to specimens. We employed the mouse cytomegalovirus (MCMV) model to assess the association between CMV and colitis. During acute primary MCMV infection of immunocompetent mice, the gut microbial composition was affected as manifested by an altered ratio of the Firmicutes to Bacteroidetes phyla. Interestingly, these microbial changes coincided with high-titer MCMV replication in the colon, crypt hyperplasia, increased colonic pro-inflammatory cytokine levels, and a transient increase in the expression of the antimicrobial protein Regenerating islet-derived protein 3 gamma (Reg3γ). Further analyses revealed that murine and human intestinal epithelial cell lines, as well as primary intestinal crypt cells and organoids represent direct targets of CMV infection causing increased cell death. Accordingly, in vivo MCMV infection disrupted the intestinal epithelial barrier and increased apoptosis of intestinal epithelial cells. In summary, our data show that CMV transiently induces colitis in immunocompetent hosts by altering the intestinal homeostasis.     

GM-CSF-producing CCR2+CCR6+ Th17 cells are pathogenic in dextran sodium sulfate-induced colitis model in mice

Although excessive immune responses by Th17 cells, a helper T cell subset, are implicated in the pathogenesis of inflammatory bowel disease (IBD), the mechanism by which its localization in an inflamed colon is regulated remains unclear. Chemokines and their receptors are involved in the pathogenesis of IBD, however, the relative significance of each receptor on Th17 cells remains unknown. We generated C–C motif chemokine receptor 2 (CCR2) knockout (KO) and CCR6 KO mice in the syngeneic background using the CRISPR/Cas9 system and found that the phenotypes of experimental colitis worsened in both mutant mice. Surprisingly, the phenotype of colitis in CCR2/CCR6-double knockout (CCR2/6 DKO) mice was opposite to that of the single-deficient mice, with significantly milder experimental colitis (p < .05). The same was true for the symptoms in CCR6 KO mice, but not in wild type mice treated with a CCR2 inhibitor, propagermanium. Colonic CCR2⁺CCR6⁺ Th17 cells produced a potentially pathogenic cytokine GM-CSF whose levels in the gut were significantly reduced in CCR2/6 DKO mice (p < .05). These results suggest that GM-CSF-producing CCR2⁺CCR6⁺ Th17 cells are pathogenic and are attracted to the inflamed colon by either CCR2 or CCR6 gradient, which subsequently exacerbates experimental colitis in mice.     

吉林省吸血蠓昼夜活动节律观察

笔者对吉林省8种优势种群吸血蠓的昼夜活动节律进行了观察.结果表明:华库蠓、孔库蠓、伊库蠓、原野库蠓、亚单带库蠓、淡角库蠓属于晨昏活动型蠓种;明边库蠓属于夜间活动型蠓种;浑江铗蠓属于白天活动型蠓种.     

Delivery of a normal newborn after intensive medical treatment for an acute exacerbation of ulcerative colitis during pregnancy: A case report

(Received for publication on Sept. 21, 1998; accepted on May 27, 1999)