体外反搏对血液流变性和血小板聚集性的影响

观察４０例心脑血管疾病患者体外反搏前后血液流变性和血小板聚集性变化。结果表明，反搏后全血比及还原比粘度、血浆粘度有不同程度的下降（Ｐ＜０．０５～０．０１）。反搏治疗后，１～５ｍｉｎ血小板聚集率、最大聚集率和最大聚集速度较反搏前均明显降低（Ｐ＜０．０５～０．０１），而５ｍｉｎ解聚率则明显增加（Ｐ＜０．０５）。提示体外反搏治疗不仅影响血液动力学，而且明显降低血液粘度，对血小板聚集功能有明显抑制作用。     

急性脑梗塞患者血浆内皮素与血小板内钙含量和聚集关系的探讨

本文用放射免疫分析测定了１６例急性脑梗塞病人的血浆内皮素，用比浊法测定了血小板聚集，用Ｆｕｒａ－２／ＡＭ荧光技术测定了血小板内游离Ｃａ＾２＋含量。急性脑梗塞病人血浆内皮素明显升高（Ｐ〈０．０１），血小板聚集率增设增高（Ｐ〈０．０１），血小板内Ｃａ２＾＋含量增高（Ｐ〈０．０１），且观察到ＡＤＰ诱导的血小板聚集与血小板内Ｃａ＾２＋含量之间呈正相关（ｒ＝０．７８，Ｐ〈０．０１），而血浆内皮素与血小反聚集     

Vortex Shedding in Steady Flow Through a Model of an Arterial Stenosis and Its Relevance to Mural Platelet Deposition

In this study, the development of unsteady vortical formations in the separated flow region distal to a stenosis throat is presented and compared with the platelet deposition measurements, to enhance our understanding of the mechanisms involved in platelet kinetics in flowing blood. Qualitative and quantitative flow visualization and numerical simulations were performed in a model of a streamlined axisymmetric stenosis with an area reduction of 84% at the throat of the stenosis. Measurements were performed at Reynolds numbers (Re), based on upstream diameter and average velocity, ranging from 300 to 1800. Both the digital particle image visualization method employed and the numerical simulations were able to capture the motion of the vortices through the separated flow region. Periodic shedding of vortices began at approximately Re=375 and continued for the full range of Re studied. The locales at which these vortices are initiated, their size, and their life span, were a function of Re. The numerical simulations of turbulent flow through the stenosis model entailed a detailed depiction of the process of vortex shedding in the separated flow region downstream of the stenosis. These flow patterns were used to elucidate the mechanisms involved in blood platelet kinetics and deposition in the area in and around an arterial stenosis. The unsteady flow development in the recirculation region is hypothesized as the mechanism for observed changes in the distribution of mural platelet deposition between Re=300, 900, and 1800, despite only a marginal variation in the size and shape of the recirculation zone under these flow conditions. © 1999 Biomedical Engineering Society. PAC99: 8719Uv, 8710+e     

Ultrastructural myeloperoxidase activity and expression of myeloid-associated antigens in acute lymphoblastic leukemia

Ultrastructural myeloperoxidase (MPO) activity and myeloid-associated antigen (MyAg) expression were investigated in 12 adult patients with acute lymphoblastic leukemia (ALL). Ultrastructural MPO was detected by 3 different methods. Immunophenotyping was performed by flow cytometry, using a series of monoclonal antibodies. Ultrastructural MPO-positive blast cells were detected in 6 patients (50%). In 5 of these 6 patients, the methods detecting both MPO and platelet peroxidase (PPO) activities found MPO-positive blast cells more frequently than those detecting MPO activity alone. In 2 patients (17%), at least one kind of MyAg was positive. Ultrastructural MPO activity was detected more frequently than MyAg expression in ALL patients. This method of detecting PPO and MPO is recommended for detection of ultrastructural MPO-positive ALL.     

探讨血小板计数在血泵离体实验中的意义

为了探讨血小板计数在血泵离体实验中的意义。我们用两种滚压泵分成两组，作5对16小时离体长时间转流实验，血样本为转前作对照组、转流4h后每隔2h抽1次。测定项目：血小板计数、游离血红蛋白。结果：两组血小板计数值均随转流时间延长而呈线性逐渐增加，各时点值与前时点比（P＜0．05），有显著差异，两组游离血红蛋白量也随转流时间延长而呈线性增加。血小板计数与游离血红蛋白呈直线回归相关关系。结论；在血泵离体转流实验中，血小板计数可反映血细胞碎片的数量，因此可作为一项评价血泵离体溶血性能的客观指标。     

中性粒细胞对洗涤血小板聚集功能的影响

目的:观察非激活或激活的中性粒细胞(PMN)对洗涤血小板聚集功能的影响。方法:采用Born方法测定血小板聚集功能。结果:非激活的PMN(5×10⁹cells/L)上清液对ADP和花生四烯酸(AA)诱导的血小板聚集具有显著抑制作用,阿司匹林可增强这种抑制作用;肉豆寇佛波醇(fMLP)及血小板活化因子(PAF)激活的PMN悬液或其上清液均能活化血小板聚集,且PMN悬液的诱聚作用比其上清液更强;阿司匹林对fMLP或PAF激活的PMN悬液或其上清液均无明显抑制作用。结论:不同状态(非激活或激活状态)的PMN对正常血小板的反应性表现出完全相反的作用,即非激活的PMN抑制血小板反应性,而激活的PMN则具有促血小板活化聚集作用。     

体外血栓形成后血液的流变性变化及体外血栓形成试验的规范化操作

目的:观察体外模拟血栓形成后剩余血液的流变学变化,并探讨体外血栓形成试验的规范化操作。方法:采用30例健康人静脉血液,一部分抗凝后测定血液流变学指标和血细胞计数,另一部分不抗凝,于Chandler环内模拟血栓形成后,再测定剩余血液的血细胞计数及流变学指标,包括血液表观粘度、红细胞聚集指数、红细胞变形指数、血小板最大聚集率、血小板粘附率和血浆纤维蛋白原含量等。结果:体外模拟血栓形成后剩余血液的表观粘度,血小板计数、白细胞计数及纤维蛋白原含量均显著降低(P<0.01);血小板粘附率、最大聚集率也显著降低(P<0.01);但红细胞计数、压积和变形指数变化不明显(P>0.05)。结论:模拟血栓形成后剩余血液的流变性发生了显著变化,尤以血小板数量、血小板聚集性和粘附性以及血浆纤维蛋白原含量的变化更加突出。规范体外血栓形成试验的操作方法,有利于提高该试验的准确性和可靠性。     

Bileaflet Aortic Valve Prosthesis Pivot Geometry Influences Platelet Secretion and Anionic Phospholipid Exposure

The clinical histories of the Medtronic Parallel (MP) and St. Jude Medical (SJM) Standard valves suggest pivot geometry influences the thrombogenic characteristics of bileaflet prostheses. This work studied the effects of various pivot geometries on markers of platelet damage in a controlled, in vitro apparatus. The Medtronic Parallel valve, two St. Jude Medical valves, and two demonstration prostheses were used to study the effects of bileaflet pivot design, gap width, and size on platelet secretion and anionic phospholipid expression during leakage flow. A centrifugal pump was used to drive blood through a circuit containing a bileaflet prosthesis. Samples were taken at set time intervals after the start of the pump. These samples were analyzed by cell counting, flow cytometry, and enzyme-linked immunosorbant assay. No significant differences were observed in platelet secretion or anionic phospholipid expression between experiments with the SJM 27 Standard regular leaker, the SJM 20 regular leaker, and the MP 27 valves. Significant differences in platelet secretion and anionic phospholipid expression were observed between a SJM 27 Standard regular leaker and a SJM 27 high leaker valve. These studies suggest that leakage gap width within bileaflet valve pivots has a significant effect on platelet damage initiated by leakage flow. © 2001 Biomedical Engineering Society. PAC01: 8719Uv, 8719Tt, 8380Lz, 8768+z     

噻氯匹定对脑梗塞患者血小板聚集功能和血液流变学的影响

以50例脑梗塞为观察组，45例健康人为对照组，观察噻氯匹定对脑梗塞血小板聚集功能和血液流变学的影响。（1）治疗前，观察组血小板聚集率（PAR）非常显著地高于对照组（P＜0.01），（2）治疗后，观察组PAR非常显著地低干治疗前（P＜0.01），与对照组比较已无显著性差异（P＞0．05），（3）观察组各亚组治疗后PAR大多非常显著地低于治疗前（P＜0．01）。（4）观察组治疗前后血液流变学指标无显著性变化（P＞0．05），（5）神经功能缺损评分：治疗前15．8±0．98；治疗后8．2±5.4，差异有非常显著意义（P＜0．01）。