中文摘要：

目的观察低频超声波对人外周血造血干细胞的作用。方法正常人经外周血动员后Baxter CS-3000血细胞分离机采取外周血造血干细胞，分成照射组和对照组。分别于照射后6h，24h，48h用台盼蓝拒染法检测细胞存活率，流式细胞仪检测细胞凋亡，瑞氏染色光镜下观察细胞照射后有无出现凋亡，透射电镜观察照射后细胞的超微结构。结果台盼蓝拒染法结果为不同照射强度和不同照射时间组之间数值差异不显著；流式细胞仪未检测到明显凋亡；瑞氏染色光镜下未观察到细胞凋亡；透射电镜观察结果为照射后细胞的超微结构无明显改变。结论低频低强度超声波对人外周血造血干细胞的生长无明显影响。

英文摘要：

Objective To study the effect of low frequency ultrasound on human peripheral blood hematopoietic stem cells （HSC） , Methods All the HSC were classified into two groups： control and experimental groups. The intensity （20 kHz） of low frequency ultrasound was 0. 03 W/cm^2, 0. 10 W/cm^2 and 0.25 W/cm^2 respectively. The exposure time were 30 and 60 s respectively. The cells were incubated in 24-well culture plates for different time periods （6, 24, 48 h） after sonication and the number of vital cells were tested by typhan blue exclusion. The ratio of apoptosis and morphology of apoptosis were analyzed with flow cytometer （FCM）, Wright＇s stain and transmission electron microscope. Results The result of typhan blue exclusion was ： the difference between the two groups was not significant. FCM, Wright＇s stain and transmission electron microscope did not find apoptosis in the two groups. Conclusions The low frequency and low intensity ultrasound has no significant effect on human peripheral blood HSC.