Construction of an acute toxoplasma encephalitis mouse model by the stereotaxic surgery with RH toxoplasma trophozoites / 西安交通大学学报(医学版)

【Objective】 To construct an acute toxoplasma encephalitis mouse model by observing the pathological changes in the hippocampus of mice infected with Toxoplasma gondii strain RH. 【Methods】 The quantitative RH Toxoplasma gondii (100, 500, and 1 000 trophozoites) were injected into the hippocampal CA1 region of mice by the stereotaxic surgery; the survival status of mice was observed. Giemsa staining was used to observe the changes of toxoplasma in mouse ascites and brain tissue homogenates. Nissl staining and HE staining were used to observe the pathological changes of hippocampal nerve tissue. The distribution of Toxoplasma gondii in brain tissue was observed by immunohistochemical ABC method. 【Results】 The RH Toxoplasma gondii infected mice showed obvious symptoms such as arched back, bristling hair, abdominal distension, subtle tremor and hemiplegia on the fourth day of infection. The survival of mice in 100 trophozoites group was longer, no trophozoites of Toxoplasma gondii were found in ascites, a few pseudocysts were found in brain tissue homogenates after infected for 96 hours, and more trophozoites were found after death. Nysl staining and HE staining showed more tissue necrosis foci and loss of nerve cells in CA1 area after infected 144 h. The injury aggravated with the prolongation of infection time. Toxoplasma trophozoites were found in ascites and brain homogenates of mice in 500 and 1000 trophozoites groups. Nissl staining revealed neuronal loss and massive necrosis in the hippocampus. HE staining showed necrosis and inflammatory cell infiltration. The brain tissue injury significantly aggravated compared with 100 trophozoites group. The distribution of Toxoplasma gondii in the necrotic foci was confirmed by immunohistochemistry. 【Conclusion】 The survival of 100 trophozoite mice infected with Toxoplasma gondii strain RH was longer, and the pathological changes of brain tissue gradually aggravated. The damage was relatively confined to the brain tissue, and the mice showed typical symptoms of toxoplasma encephalitis. Therefore, the mouse model of acute toxoplasma encephalitis can be constructed by localized infection of 100 toxoplasma trophozoites, which can lay a foundation for future research on the mechanism of toxoplasma injury to cranial nerves.

Further Experience of Stereotaxic Urokinase Treatment in Spontaneous Intracerebral Hematoma

According to the general principle that a surgical procedure should be as atraumatic as possible several authors proposed stereotaxic urokinase treatment in spontaneous intracerebral hematomas. Authors presented 29 cases of spontaneous intracerebral hematomas which were managed with stereotaxic urokinase treatment including 10 cases of preliminary report on Journal of Korean Neurosurgical Society June 1986. 19 cases were basal ganglia hematomas with or without ventricular rupture, 4 cases were thalamic hematomas with ventricular rupture, 3 cases were subcortical hematomas and 3 cases were intraventricular hematomas. The outcome of the treatment was analysed by the location and amount of hematomas, and the degree of disability of patient on admission and discharge. The outcome was worst in thalamic hematomas than putaminal or subcortical hematomas, and poorer as the amount of hematoma increased. The outcome was bad also in the patient who showed poor neurologic condition on admission. Time requiring hematoma dissapperance with urokinase treatment was estimated by the short term follow up CT scanning. All of the patient except moribund cases showed complete disappearance of hematomas within 10 days after treatment, and mean period was 6.7 days. Rebleeding after the urokinase treatment was noted in 4 cases, which was 2 putaminal, one thalamic and one ventricular hematoma. The cause of rebleeding might be mechanical injury of catheter insertion or too strong negative pressure on aspiration. But in 1 case of intraventricular hematoma, the possible causative factor should be anticoagulant effect of urokinase on the injured vessel. With above result, we concluded that this procedure may be better and safer than conventional craniotomy especially in cases of high risky or elderly patient with deep seated intracerebral hematomas. But the efficacy and safety must be studied further with the exact experimental model of spontaneous intracerebral hematomas.

Controlled Evacuation of Spontaneous Intracranial Hematoma with CT-aided Stereotaxic Urokinase Therapy

Authors describe methods for evacuation of intracerebral and/or intraventricular hematomas with CT-aided stereotaxic infusion of urokinase into the hematoma and controlled drainage. In the past 6 months we performed the procedures in 21 cases during acute(within 3 days) or subacute(between 4 and 14 days) stage after the apoplectic attack. Three dimensional CT images were used to locate the hematoma sites, to assess its volume and to determine stereotaxic coordinates. Under local anesthesia a silicon tube was inserted into the hematoma through burr hole and the hematoma was aspirated with syringe. And then urokinase(6,000IU/5ml saline) was infused into the hematoma and the drain was clipped. There after aspiration and administration were performed repeatedly every 6 hours until the hematoma was completely removed. In cases of intraventricular hematoma a drain was inserted into the ventricle having the main hematoma. As a first trial of hematoma removal, the ventricle was irrigated with urokinase(6,000IU/100ml saline), and the drain was clipped after administration of urokinase(6,000IU/5ml saline). Subsequentry clipping of the drain for 4 hours and drainage of the CSF with the hematoma for 2 hours were repeated under the monitoring of intracranial pressure. Now we review serial changes of CT findings and results of 10 cases which were followed up for at least 4 months' and preliminarily conclude that this procedure may be as good as conventional cranitomy, and safer and less traumatic than any other management especially in cases of intraventricular or deep seated hematomas and elderly or high-risk patients.

Stereotaxic Surgery for Dystonia

Our experienced is based on a series of 5 cases of dystonia who underwent stereotaxic thalamotomy. The immediate good results have been obtained by thalamotomy. We have been able to estimate secondary deterioration on long term results in patients examined 2-5 years postoperatively. Some deterioration is noted patients operated on for athetosis over the age of 20. A pallido-subthalamic lesion is efficient at the beginning of the disease course since it improves motor performance and thereby helps possiblities of intellectual acquirement. Bilateral lesions have done after improved. I.Q. Effects of this treatment specially on spasticity must be discussed among other types of surgery.