【摘要】 了解细胞内自由钙离子浓度([Ca2+]i)的变化规律是探知细胞乃至相关生物组织生存及健康状况的手段,而采用时-频分析方法则可获得其变化规律中较多的深层次信息。为了更好了解癌细胞与正常细胞内[Ca2+]i变化规律间的差异以及各自的特征,选取3种癌细胞和4种正常细胞作为实验对象。首先,用荧光试剂对各细胞样品进行负载,再用激光扫描共聚焦显微镜对细胞内的荧光强度进行测量,以获得细胞内[Ca2+]i的时域数据;接着,对时域数据进行时-频分析,并给出时-频分布函数的等值线图。结果表明,虽然癌细胞和正常细胞内[Ca2+]i的变化在时-频域内均有连续出现和离散出现的两类谱带,但癌细胞与正常细胞间的差异却是明显的。差异主要表现在:癌细胞中连续谱带的宽度大于正常细胞连续谱带的宽度,癌细胞中只有1条离散谱带,而正常细胞中却有2条离散谱带;不同癌细胞中离散谱带的中心频率相同,而不同正常细胞离散谱带的中心频率却各不同;癌细胞离散谱带中各频谱分量的相对振幅大于正常细胞各频谱分量的相对振幅。这些结果既为鉴别癌细胞提供一个新的指标,也为认识不同正常细胞的健康状况提供新的参考数据,同时可为电磁波的生物学窗效应机理研究奠定生物学自身的内禀依据。更多还原

【Abstract】 Variation of intracellular free calcium concentration([Ca²⁺]_i) is one parameter to evaluate physiological status of cells and relative tissues.Time-frequency analysis is an effective tool to learn the information of the [Ca²⁺]_i in depth-level.In this paper,three kinds of cancer cells and four kinds of normal cells were used as experimental objects.The cells were loaded by fluorescent reagent,and then the fluorescent intensity in the cells was measured by laser scanning confocal microscope.The data in time domain were acquired and treated by time-frequency analysis.The distribution function in time-frequency domain PMH_x（t,f） was obtained and shown by contours diagram.The results indicate that there are two kinds of spectrum of the [Ca²⁺]_i variation either in cancer cells or in normal cells,the first is continuously appearing spectrum in the measured time,the second is discontinuously appearing spectrum in the measured time,but there are large difference between the variations of cancer cells and normal cells:（1） the width of the continuously appearing spectrum in cancer cells is greater than that in normal cells;（2） there is one discontinuously appearing spectrum in cancer cells,but there are two discontinuously appearing spectrum in normal cells;（3） the centre frequency of the discontinuously appearing spectrum in cancer cells is different from that in normal cells;（4） the relative amplitude of the discontinuously appearing spectrum in cancer cells is greater than that in normal cells.These results provide a method to detect cancer cells as well as the basis for studying mechanisms of biological window-effects of electromagnetic waves.更多还原