VASCULAR PERMEABILITY AND BRAIN EDEMA IN BRAIN ABSCESS

脑部疾病中浮肿的出现被认为是由于 血脑屏障功能受损，允许血管内 物质扩散到脑实质。脑水肿是一种 严重并发症，如脓肿、脑膜炎和 肿瘤，但产生水肿的机制尚不清楚。这个 该项目的长期目标是将这些机制定义为 可以设计出改进的浮肿治疗方法。这个项目 将研究感染时产生浮肿的机制 大脑的一部分。该项目将采用一种老鼠模型 葡萄球菌性脑脓肿检验细菌假说 产品增加血脑屏障的通透性，以及 促进感染区域的浮肿形成。这个 具体目标是确定：1.当 血脑屏障对血管内的渗透性 物质相比，当白细胞迁移到 脓肿部位；2.脑细胞外时间进程 与血脑相比，空间的大小增加了 屏障变得异常渗透性；3.无论是毒素还是 金黄色葡萄球菌的亚细胞成分可影响 血脑屏障通透性和细胞外间隙 与整个细菌的程度相同。的渗透性 将对整个动物进行血脑屏障的检查 测量血管内示踪剂进入大脑的运动。 白细胞的迁移将通过测量 ~(51)Cr标记的大鼠中性粒细胞进入脑内的运动。这个 细胞外空间的大小将用离子- 一种选择性微电极，它将测量一种 离子导入电极中的四烷基铵离子。这个 毒素和葡萄球菌产品的影响将通过 确定细菌的成分是否产生类似的 血脑屏障通透性和血管大小的变化 与活的葡萄球菌相比，胞外空间。

The presence of edema in brain disease is thought to be due to impaired blood-brain barrier function permitting intravascular substances to diffuse into the brain parenchyma. Brain edema is a serious complication of diseases such as abscess, meningitis, and tumors, but the mechanisms producing edema are unknown. The long-term goal of this project is to define those mechanisms so that improved treatment for edema can be designed. This project will examine the mechanism of edema production in an infection of the brain. The project will employ a rat model of a staphylococcal brain abscess to test the hypothesis that bacterial products increase the permeability of the blood-brain barrier, and promote the formation of edema in an infected region. The specific aims are to determine: 1. The time course when the blood-brain barrier becomes permeable to intravascular substances as compared to when leukocytes migrate into the abscess site; 2. The time course when the brain extracellular space increases in size as compared to when the blood-brain barrier becomes abnormally permeable; 3. Whether toxins or subcellular components of Staphylococcus aureus can affect blood-brain barrier permeability and the extracellular space to the same extent as the whole bacteria. The permeability of the blood-brain barrier will be examined in the whole animal by measuring the movement of an intravascular tracer into the brain. Leukocyte migration will be determined by measuring the movement of 51Cr labelled rat neutrophils into the brain. The size of the extracellular space will be measured with an ion- selective microelectrode which will measure the diffusion of a tetraalkylammonium ion from an ionophoresis electrode. The effect of toxins and staphylococcal products will be measured by determining if components of the bacteria produce similar changes in blood-brain barrier permeability and the size of the extracellular space when compared to live staphylococci.