Tucker J D, Ashworth L K, Johnston G R, Allen N A, Carrano A V
Lawrence Livermore National Laboratory, Biomedical Sciences Division, University of California, Livermore 94550.
Mutat Res. 1988 Mar;204(3):435-44. doi: 10.1016/0165-1218(88)90039-0.
The variation in lymphocyte sister-chromatid exchange (SCE) frequency as a function of time was investigated in nonsmokers and smokers. The smokers were divided into 3 groups depending on their smoking status. The group termed 'smokers' participated in a program to stop smoking but did not reduce or eliminate their use of tobacco; 'smoke enders' successfully completed the smokending program and remained free of tobacco for the duration of the study, while the 'variable' group stopped smoking for a limited time but then resumed smoking. 8 or more blood samples per person were obtained over a period of at least 12 months. The SCE frequencies for each of these groups were compared with each other and with those of two previous longitudinal study groups from our laboratory. The proportion of high-frequency cells (HFCs) was also determined for each sample. The results confirm our previous finding that SCE frequencies and the proportion of HFCs observed in separate samples from the same individual are more likely to be different as the time between samples increases. We also show that smokers have significantly more SCEs and HFCs than do nonsmokers, that SCE frequencies in smokers do not decline for at least 12 months when smoking is stopped, and that among smokers, significant seasonal variation in the SCE frequency occurs. These results provide useful information concerning the effects of smoking upon SCE frequencies, and will be helpful in designing and interpreting the results of long-term human population cytogenetic studies.
我们对不吸烟者和吸烟者淋巴细胞姐妹染色单体交换（SCE）频率随时间的变化情况进行了研究。根据吸烟状况，吸烟者被分为三组。名为“吸烟者”的组参与了戒烟计划，但并未减少或戒掉烟草使用；“戒烟者”成功完成了戒烟计划，并在研究期间一直未接触烟草，而“可变组”则在有限时间内戒烟，但随后又恢复吸烟。在至少12个月的时间里，每人采集了8份或更多血样。将这些组中每组的SCE频率相互比较，并与我们实验室之前的两个纵向研究组的频率进行比较。还测定了每个样本中高频细胞（HFC）的比例。结果证实了我们之前的发现，即来自同一个体的不同样本中观察到的SCE频率和HFC比例，随着样本采集时间间隔的增加，更有可能出现差异。我们还表明，吸烟者的SCE和HFC明显多于不吸烟者，吸烟者戒烟后至少12个月内SCE频率不会下降，而且在吸烟者中，SCE频率存在显著的季节性变化。这些结果提供了有关吸烟对SCE频率影响的有用信息，将有助于设计和解释长期人类群体细胞遗传学研究的结果。
