Flaris N A, Hickey W F
Department of Pathology, Washington University School of Medicine, St. Louis, Missouri.
Am J Pathol. 1992 Dec;141(6):1299-307.
Brain abscesses were produced in the rat by direct intracerebral injection of agarose beads laden with Staphylococcus aureus. The method proved to be easy, reproducible, effective and was associated with a low mortality rate. The histopathologic features of the experimental abscess are similar to other animal models and to human abscesses. The encapsulation of the lesion, macrophage/microglial response, astrocytic activation, and changes in the surrounding brain parenchyma were studied by immunohistochemistry. Edema, diffuse microglial activation and diffuse astrocytosis characterized the early reaction of the injected cerebral hemisphere. After day 10, edema subsided, and the microglial and astrocytic responses became restricted to the area around the lesion. Fibronectin deposition in the capsule preceded the appearance of myofibroblasts, which was concurrent with the beginning of collagen deposition on day 9. Hypervascularity of the capsule appeared as early as day 6 and persisted through day 28. This study suggests that brain abscess formation can be separated into three components: an initial period of edema and glial activation; an intermediate phase of neovascularization and fibronectin deposition; and a final phase of collagen deposition and progressive fibrosis. This new model offers an excellent paradigm for the analysis of neural tissue reaction and de novo fibrous tissue deposition.
通过向大鼠脑内直接注射载有金黄色葡萄球菌的琼脂糖珠来制造脑脓肿。该方法被证明简便、可重复、有效且死亡率低。实验性脓肿的组织病理学特征与其他动物模型以及人类脓肿相似。通过免疫组织化学研究了病变的包囊形成、巨噬细胞/小胶质细胞反应、星形胶质细胞活化以及周围脑实质的变化。水肿、弥漫性小胶质细胞活化和弥漫性星形细胞增多是注射侧大脑半球早期反应的特征。第10天后，水肿消退，小胶质细胞和星形胶质细胞反应局限于病变周围区域。在肌成纤维细胞出现之前，纤维连接蛋白在包囊中沉积，肌成纤维细胞在第9天开始出现，同时胶原蛋白开始沉积。包囊的血管增生最早在第6天出现，并持续到第28天。这项研究表明，脑脓肿形成可分为三个阶段：水肿和胶质细胞活化的初始阶段；新血管形成和纤维连接蛋白沉积的中间阶段；以及胶原蛋白沉积和进行性纤维化的最后阶段。这个新模型为分析神经组织反应和新生纤维组织沉积提供了一个极好的范例。
