Abstract: Objective To compare the expression of tumor necrosis factor-α（TNF-α） between brain and peripheral organs after cerebral contusion in order to provide the scientific theoretical basis for forensic pathological diagnosis and wound age estimation. Methods Brain and peripheral organs including heart, liver, spleen, lung, kidney tissues of 45 SD rats after the cerebral contusion were obtained and TNF-α of these tissues were analyzed with immunohistochemistry methods. Results TNF-α was detected at 1 h in brain, reaching maximum at 6 h and 3 d after the cerebral contusion, and then decreased but still kept at high expression level at 7 d. TNF-α was detected at 1 h after the cerebral contusion in heart, liver, spleen, lung and kidney tissues. The number of cells expressing TNF-α increased gradually, reaching maximum at 3 d after the contusion of brain, and then decreased but still kept at high expression level at 7 d. Conclusion Besides the change of cerebral contusion, this study considered both the brain and peripheral organs. It is helpful for forensic pathological diagnosis and wound age estimation after contusion of brain.

Key words: forensic pathology, brain injuries, tumor necrosis factor-?琢, rats