Mechanical haemolysis in shock wave lithotripsy (SWL):: II.: In vitro cell lysis due to shear
Mechanical haemolysis in shock wave lithotripsy (SWL):: II.: In vitro cell lysis due to shear
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DOI：
10.1088/0031-9155/46/4/323
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发表时间：
2001-04-01
影响因子：
3.5
通讯作者：
Sturtevant, B
中科院分区：
文献类型：
--
作者：
Lokhandwalla, M;McAteer, JA;Sturtevant, B
在这项工作中，我们报告了在无空泡的环境中，聚焦冲击波对分离的红细胞(RBC)的损伤。碎石机产生的冲击波被抛物面反射器重新聚焦。这种重新聚焦的波场具有比碎石波场更紧密的焦点(更小的波束宽度和更高的幅度)，其特征是薄膜水听器。通过对流体施加超压来消除空化。使用一种新型的被动空化探测器(HP-PCD)在高超压(高达7 Mpa)下工作，测量了气泡活动引起的声发射。当液体被封闭在压力室中时，在碎石机自由场中测得的典型的双爆炸发射被一系列微弱的信号所取代。在5.5 Mpa的超压下没有测到声发射，用铝箔研究了冲击波的损伤，并具有与暴露条件相对应的明显的变形特征，即点蚀和凹陷伴随起皱。采用抛物面反射器反射冲击波，使悬浮在磷酸盐缓冲盐水(PBS)中的红细胞分别暴露在抛物面反射器和平板反射器的反射波场中，通过抛物面反射器和平面式反射器反射的冲击波产生凹陷和起皱。与未经处理的对照组相比，暴露在抛物面反射器的波场中的溶血增加了四倍，是使用平面反射器的细胞裂解的两倍。最近，我们分析了红细胞在聚焦激波建立的流场中的变形和破裂。本文给出的细胞裂解结果与我们的理论预测是定性一致的，即溶血与冲击强度的梯度直接相关，并验证了剪切是SWL的细胞裂解机制。
In this work we report injury to isolated red blood cells (RBCs) due to focused shock waves in a cavitation-free environment. The lithotripter-generated shock wave was refocused by a parabolic reflector. This refocused wave field had a tighter focus (smaller beam width and a higher amplitude) than the lithotripter wave field, as characterized by a membrane hydrophone.Cavitation was eliminated by applying overpressure to the fluid. A novel passive cavitation detector (HP-PCD) operating at high overpressure (up to 7 MPa) was used to measure acoustic emission due to bubble activity. The typical 'double-bang' emission measured in the lithotripter free-field was replaced by a continuum of weak signals when the fluid was enclosed in a pressure chamber. No acoustic emissions were measured above an overpressure of 5.5 MPa, Aluminium foils were used to study shock wave damage and had distinct deformation features corresponding to exposure conditions, i.e. pitting and denting accompanied by wrinkling. Fitting was eliminated by high overpressure and so was due to cavitation bubble collapse, whereas denting and wrinkling were caused by the reflected shock wave refocused by the parabolic reflector.RBCs suspended in phosphate-buffered saline (PBS) were exposed to the reflected wave field from a parabolic reflector and also from a flat reflector. Exposure to the wave field from the parabolic reflector increased haemolysis four-fold compared with untreated controls and was twice that of cell lysis with the flat reflector. Recently we analysed deformation and rupture of RBCs when subjected to a flow field set up by a focused shock. The cell lysis results presented here are in qualitative agreement with our theoretical prediction that haemolysis is directly related to the gradient of shock strength and validates shearing as a cell lysis mechanism in SWL.