Histological changes in the normal rat brain after gamma irradiation
Histological changes in the normal rat brain after gamma irradiation
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DOI：
10.1007/bf01420308
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发表时间：
1996-01-01
影响因子：
2.4
通讯作者：
Steiner, L
中科院分区：
文献类型：
--
作者：
Kamiryo, T;Kassell, NF;Steiner, L
在伽马手术后的不同时间点观察Wistar大鼠顶叶皮质的辐射诱导的变化。使用4 mm准直器在放射线等中心处给予最大剂量50、75和120戈伊。常规组织化学和免疫细胞化学分析，并利用计算机辅助显微镜检查灌注固定的脑组织。照射剂量为50戈伊，在3个月引起顶叶皮质星形胶质细胞的形态学变化。12个月时血管扩张明显;扩张的毛细血管壁中观察到纤维蛋白沉积。在12个月的观察期内，没有观察到伊文思蓝从血管渗漏到组织中，也没有观察到坏死。75戈伊剂量的照射在1个月内导致星形胶质细胞的形态学改变。3个月时观察到血管扩张和毛细血管增厚。75戈伊照射后4个月观察伊文思蓝渗漏和坏死情况。此时，小动脉壁因内膜下纤维蛋白和透明物质积聚而增厚;这有时导致管腔闭塞。在4个月时观察到显著的半球肿胀，在120戈伊剂量下的照射在3天内引起星形胶质细胞形态的变化。3周时观察到伊文思蓝渗漏到组织中。在该时间点，血管舒张变得明显，在辐照皮质中观察到稀疏。4周时观察到坏死，但没有观察到明显的肿胀。综上所述，这些结果表明伽玛刀照射后正常脑组织的时间依赖性和剂量依赖性变化。这些结果提供了一个基础，衡量的影响，伽玛手术的区域的功能组织。加强对放射外科的细胞反应的理解将有助于开发和评估伽马手术的未来应用。
Radiation-induced changes in the parietal cortex of Wistar rats were observed at various time points after gamma surgery. Maximum dosages of 50, 75, and 120 Gy were given at the iso-center of the radiation using a 4-mm collimator. Conventional histochemical and immunocytochemical analyses, and computer-assisted videomicroscopy were utilized to examine perfusion-fixed brain tissue.Irradiation at a dosage of 50 Gy elicited morphological changes of astrocytes in the parietal cortex at 3 months. Vasodilatation became obvious at 12 months; fibrin deposition was observed in the dilated capillary wall. Neither leakage of Evans Blue from the vasculature into the tissue nor necrosis was observed across the 12 month observation period.Irradiation at a dosage of 75 Gy resulted in morphological changes of astrocytes within 1 month. Dilatation of vessels and capillary thickening were observed at 3 months. Evans Blue leak age and necrosis were observed at 4 months after 75 Gy irradiation. At this time, the walls of arterioles became thickened by subintimal accumulation of fibrin and hyaline substance; this sometimes resulted in occlusion of the lumen. Significant hemispheric swelling was observed at 4 months.Irradiation at a dosage of 120 Gy elicited changes in astrocytic morphology within 3 days. Evans Blue leakage into the tissue was observed by 3 weeks. Vasodilatation became marked at this time point and rarefaction was observed in the irradiated cortex. Necrosis was observed at 4 weeks, however, no significant swelling was observed.Taken together, these findings demonstrate time-dependent and dosage-dependent changes in normal cerebral tissue after Gamma Knife irradiation. These results provide a basis for gauging the impact of gamma surgery in regions of eloquent tissue. An enhanced understanding of the cellular responses to radiosurgery will contribute to developing and evaluating future applications for gamma surgery.