Benjamini Y, Bitterman N
Department of Statistics, School of Mathematics, Tel-Aviv University, Israel.
Undersea Biomed Res. 1990 May;17(3):213-21.
Animal models are widely used for the study of CNS oxygen toxicity, but confusion still exists regarding the proper statistical approach to the analysis of the data. This paper is based on data collected from unanesthetized, free-moving rats with chronically implanted cortical electrodes for continuous EEG monitoring, exposed to 5 or 6 ATA oxygen. The index measured for CNS oxygen toxicity is the duration of the latent period preceding the appearance of well-defined electrical discharges in the EEG. At both oxygen pressures studied, the duration of the latent period is not distributed normally, and variability within the groups is not homogeneous. Transformations of the latent period data were found to enhance normality, and the speed of appearance of the discharges in the EEG, which is the reciprocal of the time, seems to be a simple, useful index for CNS oxygen toxicity in rats. Two experimental designs were compared: repeated measurements vs. single exposure. No advantage was demonstrated for the use of each rat as its own control as against the comparison between data from groups of rats. Rats can be used more than once in such research, but not more than once in a single study where individual observations are assumed to be independent, since there is some positive correlation between the first and second exposures to hyperbaric oxygen in individual rats; however, the level of sensitivity of the groups is not significantly different.
动物模型被广泛用于中枢神经系统氧中毒的研究，但在分析数据的适当统计方法上仍存在困惑。本文基于从长期植入皮层电极以进行连续脑电图监测的未麻醉、自由活动的大鼠收集的数据，这些大鼠暴露于5或6个绝对大气压的氧气中。用于衡量中枢神经系统氧中毒的指标是脑电图中明确的放电出现之前的潜伏期持续时间。在所研究的两种氧压下，潜伏期持续时间的分布都不正常，且组内变异性不均匀。发现对潜伏期数据进行变换可增强正态性，并且脑电图中放电出现的速度（即时间的倒数）似乎是大鼠中枢神经系统氧中毒的一个简单而有用的指标。比较了两种实验设计：重复测量与单次暴露。与大鼠组数据之间的比较相比，将每只大鼠作为自身对照并未显示出优势。在这类研究中，大鼠可以多次使用，但在假设个体观察独立的单个研究中不能超过一次，因为个体大鼠第一次和第二次高压氧暴露之间存在一定的正相关性；然而，各组的敏感性水平没有显著差异。
