Development of focal infection model result from infected root canal-associated bacteria on compromised hosts.

局灶性感染模型的开发是由受损宿主上受感染的根管相关细菌引起的。

基本信息

批准号：
12557161
负责人：
EBISU Shigeyuki
金额：
$ 7.94万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

Correlation between Cyclosporin A (CsA)-induced immunosuppression and untreated or residual periapical lesions has been investigated 3 dimensionally with time, and histopathological analysis were performed. CsA treatment significantly inhibited lesion expansion.. Agter withdrawal of CsA, the lesion increased in size to a same extent in a control group. In addition, histopathological observation revealed that the difference of CsA administration volume did not affected much. However, CsA treatment induced intercellular substance in fibrous tissue to be voluminous, especially in 20mg/Kg/day administration group.In vitro, biofilm forming capacity of 7 infected root canal-associated bacterial (RCB) species to gutta-percha points (GP) was investigated morphologically. Enterococcus faecalis formed most frequently biofilm, but Fusobacterium uncleatum or Propionibacterium acnes did not form it at all. The biofilm forming capacity of 5 RCB species to extraradicular GPs on beagle dogs were evaluated by bacteriologic technique. E. faecalis identified in 71.4% of the examined samples, and was most suitable biofilm forming bacterium in extraradicular area. According to their results, compromised-animals to be administrated methylpredonisolon acetate were prepared for investigation of bacteremia by which planktonic bavteria detached from extraradicular E. faecalis biofilm caused. For 4 weeks administration, bacteremia was not induced, whereas planktonic E. faecalis cells insertion of about 10^3 times biofilm bacteria on GP in vitro in the periapical lesion became continuously bacteremia. Drug concentration and administration period were further studied, and we are continuously searching bacteremia caused by extraradicular biofilm on compromised-animal.

环孢素 A (CsA) 诱导的免疫抑制与未经治疗或残留的根尖周病变之间的相关性已随时间进行了 3 维研究，并进行了组织病理学分析。 CsA治疗显着抑制病灶扩张。在撤除CsA后，对照组的病灶大小增加到相同程度。此外，组织病理学观察显示，CsA给药量的差异并没有太大影响。然而，CsA治疗导致纤维组织中的细胞间质大量增加，尤其是在20mg/Kg/天的给药组中。体外，7种受感染的根管相关细菌（RCB）物种对古塔胶点（GP）的生物膜形成能力进行了形态学研究。粪肠球菌最常形成生物膜，但不沟梭杆菌或痤疮丙酸杆菌根本不形成生物膜。通过细菌学技术评估了 5 种 RCB 物种对比格犬根外 GP 的生物膜形成能力。 71.4%的检测样本中检出了粪肠球菌，它是根外区域最合适的生物膜形成细菌。根据他们的结果，准备了要施用醋酸甲泼尼龙的受损动物，用于研究浮游细菌从根外粪肠球菌生物膜上脱离所引起的菌血症。给药4周，未诱发菌血症，而浮游粪肠球菌细胞在根尖周病灶体外插入GP上约10^3倍生物膜细菌，则持续菌血症。进一步研究了药物浓度和给药时间，并不断寻找受损动物根外生物膜引起的菌血症。