Hardeman M R, Dobbe J G, Ince C
Laboratory for Clinical Hemorheology, Academic Medical Center, University of Amsterdam, The Netherlands.
Clin Hemorheol Microcirc. 2001;25(1):1-11.
The Laser-assisted Optical Rotational Cell Analyzer (LORCA) is unique in its capacity to measure at least two important hemorheological parameters, i.e., deformability of red blood cells (RBC) as well as their aggregation behaviour. In this communication the main principles and characteristics of the aggregometer mode of this instrument are described. Via syllectometry (i.e., laser backscatter versus time), the method allows the measure of both static and kinetic parameters of the aggregation process, e.g., total extent of aggregation, aggregation half time and a combination of these, defined as aggregation index. When the syllectogram deviates from that representing normal rouleaux formation, e.g., in the case of RBC clump formation, this is signalled by a fit error. Maximal flexibility is obtained by various options like an automated re-iteration procedure (which enables to measure the aggregation tendency and/or the aggregate stability) and aggregation at low shear rate. Experiments dealing with reproducibility, stability and sensitivity of the instrument are described. The latter include a few "classic" methods for inducing subtle changes in RBC aggregation behaviour both regarding cellular factors (heat treatment) and changes in medium constituents (fibrinogen, dextrans).It can be concluded that the aggregometer mode of the LORCA considerably increases the feasibility of this instrument for hemorheological investigations.
激光辅助光学旋转细胞分析仪（LORCA）在测量至少两个重要血液流变学参数方面独具特色，即红细胞（RBC）的变形能力及其聚集行为。在本通讯中，描述了该仪器凝集仪模式的主要原理和特点。通过集光测定法（即激光背散射与时间的关系），该方法能够测量聚集过程的静态和动态参数，例如聚集的总程度、聚集半衰期以及这些参数的组合，定义为聚集指数。当集光图偏离代表正常缗钱状形成的图形时，例如在红细胞团块形成的情况下，会通过拟合误差发出信号。通过各种选项可实现最大灵活性，如自动重复程序（能够测量聚集趋势和/或聚集体稳定性）以及低剪切速率下的聚集。描述了有关该仪器的重现性、稳定性和灵敏度的实验。后者包括一些“经典”方法，用于在细胞因素（热处理）和介质成分变化（纤维蛋白原、右旋糖酐）方面诱导红细胞聚集行为的细微变化。可以得出结论，LORCA的凝集仪模式大大提高了该仪器用于血液流变学研究的可行性。
