颈动脉注射血吸虫虫卵建立兔脑肉芽肿模型的研究

Preliminary study to create an animal model of cerebral granuloma by injecting Schistosoma japonicum eggs through the carotid artery

目的通过颈动脉注射血吸虫虫卵建立家兔脑肉芽肿模型。方法实验组家兔10只,行全脑放疗(20GY,单次照光)破坏血脑屏障;照光后7d,通过颈动脉注射血吸虫虫卵悬浮液1ml建模。阴性对照组10只,全脑放疗后7d经颈动脉注射生理盐水1ml。空白对照组10只,不进行任何处理。术后使用抗生素预防感染,观察3组动物临床表现。30d后行MRI检查。取脑组织做病理切片,观察脑组织大体标本及病理改变。结果实验组2只、阴性对照组1只家兔死于放疗后并发症。实验组8只家兔术后均出现轻度食欲不振,体重下降,1周后症状逐渐消失;8只出现呆滞、嗜睡等精神症状。阴性对照组家兔术后均食欲下降,1周后症状消失,无异常精神症状。空白对照组未见异常。MRI检查实验组增强T1WI见脑膜线状强化4例,脑组织内见结节状强化2例。对照组未见明显异常。脑组织大体标本及病理切片检查实验组8只家兔均出现血管炎,7只出现脑水肿,6只病理切片见肉芽肿结节,5只出现脑膜炎。阴性对照组及空白对照组未见脑水肿及肉芽肿结节(阴性对照组1只出现血管周围炎)。结论经颈动脉注射血吸虫虫卵建立的家兔脑肉芽肿模型出现相应的组织病理变化及临床表现,符合实验要求。

Objective To create a model of cerebral granuloma in rabbits via injection of Schistosoma japonicum eggs through the carotid artery. Methods Rabbits were divided into three groups with 10 animals in each group.Rabbits in the experimental group received whole brain radiation（20GY,single fraction）to disrupt the blood-brain barrier.A week later,those rabbits were directly injected with a suspension of Schistosoma japonicumeggs（0.9mg,1ml）via the carotid artery.Rabbits in the negative control group received whole brain radiation and a week later were injected with normal saline（1ml）via the carotid artery.Rabbits in the blank control group were not treated.Antibiotics were given to the first two groups after the injection.Clinical manifestations were observed in the 3groups.Magnetic resonance imaging（MRI）was performed on all of the rabbits 30 days post-injection,and then brain tissues were collected for pathological examinations. Results Two rabbits in the experimental group and 1in the negative control group died of complications after radiotherapy.Eight rabbits in the experimental group had a slight loss of appetite and weight loss after the injection,but the symptoms disappeared after 1week.Eight rabbits exhibited mental symptoms,including sluggishness and lethargy.Nine rabbits in the negative control group had a loss of appetite that disappeared after 1week but none had abnormal mental symptoms.There were no abnormalities in the blank control group.MRI of the experimental group revealed nodular or patchy enhancement in 2animals and linear meningeal enhancement in 4according to enhanced T1-weight images.Obvious abnormalities were not noted in the negative control group and blank control group.Gross specimens and pathological sections exhibited perivascular inflammation in 8animals in the experimental group,cerebral edema in 7,granulomatous nodules in 6,and meningitis in 5.However,cerebral edema and granulomatous nodules were not noted in thenegative control group and blank control group,except for 1animal in the negative control group that exhibited perivascular inflammation. Conclusion A rabbit model of granuloma was created by injecting S.japonicumeggs into the carotid artery.This model revealed corresponding histopathological changes and clinical manifestations,thus meeting the requirements for experimentation.