Kimura A, Ikeda H, Yasuda S, Yamaguchi K, Tsuji T
Department of Legal Medicine, Wakayama Medical College, Japan.
Int J Legal Med. 1995;107(4):193-6. doi: 10.1007/BF01428404.
Non-muscle tissues contain 3 myosin heavy chain (MHC) isoforms; MIIA, MIIB1 and MIIB2. MIIA is a non-muscle type isoform distributed in all non-muscle tissues and smooth-muscle, while MIIB1 and MIIB2 are brain-type isoforms distributed mainly in neuronal tissues. The ratio of MIIA and MIIB (A/B ratio) differs between tissues, suggesting that this ratio may be a useful marker for tissue identification. To apply the A/B ratio for tissue identification in forensic practice, we developed a highly sensitive ELISA for quantification of each MHC isoform. At least 100 pg of both MHC isoforms could be detected by the present method. Analysis of the A/B ratio of the cerebrum, cerebellum, liver, kidney, spleen and andrenal gland by the present method indicated that the A/B ratio of the brain tissue (< 0.5) was quite different from other tissues (> 3.0). The A/B ratio could be determined from at least 8 micrograms of fresh tissue sample and 0.1 mg of dried tissue sample stored for 1 month at room temperature. Therefore, the A/B ratio seems to be an excellent marker for identification of the brain tissue.
非肌肉组织含有3种肌球蛋白重链（MHC）异构体；MIIA、MIIB1和MIIB2。MIIA是一种非肌肉型异构体，分布于所有非肌肉组织和平滑肌中，而MIIB1和MIIB2是脑型异构体，主要分布于神经组织中。不同组织中MIIA和MIIB的比例（A/B比例）有所不同，这表明该比例可能是组织鉴定的有用标志物。为了在法医实践中应用A/B比例进行组织鉴定，我们开发了一种高度灵敏的酶联免疫吸附测定法（ELISA）来定量每种MHC异构体。用本方法至少可检测到100 pg的两种MHC异构体。用本方法分析大脑、小脑、肝脏、肾脏、脾脏和肾上腺的A/B比例表明，脑组织的A/B比例（<0.5）与其他组织（>3.0）有很大差异。至少8微克新鲜组织样本和0.1毫克在室温下储存1个月的干燥组织样本即可测定A/B比例。因此，A/B比例似乎是鉴定脑组织的极佳标志物。
