RHEOLOGICAL STUDIES OF SICKLE CELL DISEASE

拟议工作的目标是利用现代流变学 技术结合生化分析，以了解生物物理 镰状细胞贫血的病理生理学基础。 这些知识将 为临床合理开发新药提供依据 治疗。 具体来说，有三大类问题需要解决。 研究：（1）红细胞-内皮细胞相互作用， 使用落射荧光视频显微镜和图像控制流动条件 分析技术。 (2)镰刀红的流动和氧的输送 硅胶毛细管中的细胞与人体中的细胞大小相同 微循环 (3)S血红蛋白凝胶化动力学的控制 (in溶液和整个细胞中）， 条件 与内皮细胞的阻塞性相互作用，缺乏 由于凝胶形成导致的组织氧合和血管闭塞是三种 可能导致临床危机的问题。 的 所提出的技术将检查这些领域中的每一个。 这些调查 需要非常专业的设备-其中一些只有在我们的 laboratories. 通过受控流下红细胞的视频显微镜检查 条件下，我们可以区分细胞是否粘附在流动的壁上， 室或彼此之间的剪切速率。 康贝特人将以 血管壁组合物通过用以下物质涂覆腔室而在粘附中起作用 胶原或在其上培养内皮细胞。 将在氧运输中比较将O2递送到组织的细胞 仿真研究 RBC将是密度分离的SS级分， 来自AS和正常对照的RBC。 研究的变量将包括 O2、pH、渗透压、剪切应力暴露、钙负荷、血影的影响 血红蛋白或膜蛋白的制备和药物修饰。 通过 使用AS和AA RBC和实验操作（增加红细胞 钙，脱水，增加膜结合血红蛋白），我们计划 制作镰状红细胞的模型。 这些模型以及正常和 将从流变学角度研究镰状细胞。 其中一项技术将涉及 在粘度计（Rice Viscometer或Rheometrics）中剪切细胞 流体流变仪）。 将评估它们对剪切力的反应 生物化学 变形性将通过核子过滤来评价 技术，全细胞变形能力变化的动力学将是 介绍了 血红蛋白凝胶在镰状细胞和红细胞中形成的动力学 还将研究开发的模型。

The objectives of the proposed work are to utilize modern rheological techniques combined with biochemical analysis to understand the biophysical basis of the pathophysiology of sickle cell amenia. This knowledge will then provide a basis for the rational development of new clinical treatments. Specifically, three major classes of problems are to be investigated: (1) Red cell - endothelial cell interactions under controlled flow conditions using epi-fluorescent video microscopy and image analysis techniques. (2) Flow of and oxygen transport from sickle red cells in silicone capillaries of the same sizes as found in the human microcirculation. (3) Control of the kinetics of gelation of S hemoglobin (in solution and in the whole cell) upon changes in environmental conditions. Obstructive interactions with endothelial cells, lack of tissue oxygenation and vaso occlusion due to gel formation are three possible problems that could contribute to a clinical crisis. The techniques proposed will examine each of these areas. These investigations require very specialized equipment - some of which is only available in our laboratories. By videomicroscopy of red cells under controlled flow conditions, we can discriminate whether cells adhere to the wall of a flow chamber or to each other at differernt shear rates. We will determine the role vessel wall composition plays in adherence by coating the chamber with collagen or culturing endothelial cells on it. The ability of sickle red cells to deliver 02 to tissue will be compared in the oxygen transport simulation studies. RBCs will be density separated SS fractions and also RBC from AS and normal controls. Variables to study will include the effect of 02, pH, osmolarity, shear stress exposure, calcium loading, ghost preparation and drug modification of hemoglobin or membrane proteins. By using AS and AA RBC and experimental manipulations (increased red cell calcium, dehydration, increased membrane bound hemoglobin) we plan to produce models of the sickle red cell. These models as well as normal and sickled cells will be studied rheologically. One technique will involve shearing the cells in viscometers (Rice Viscometer or the Rheometrics Fluids Rheometer). Their response to shear will be assessed biochemically. Deformability will be evaluated by the nuclepare filtration technique, and the kinetics of whole cell deformability changes will be described. The kinetics of hemoglobin gel formation in sickle cells and in the models developed will also be investigated.