Study On Expression And Forensic Application Of The NF-KB During Injurey In The Rat Brain

Background and Objective: The estimation of injury interval remains to be a very complex problem in forensic pathology.Although lots of indexes were used to measure the injury interval, no standard was satisfied, especially in case of brain injury.Currently, the injury interval was estimated according to multiple factors. Brain injury is a common injury, NF-κB in virtually all human tissues and organs, and its expression is very stable and in the event of injury in the early days, their expression levels began to increase [141,620]. Thus NF-κB expression of the determination may be a forensic inference injury time meaningful way. To investigate the expression of NF-κB during brain injury time.Methods:(1)Material: Eighty SD rats (from Chong Qing University of Medical Sciences Experimental Animal Center) were divided into experimental group, sham-surgery group and normal control group randomly. The model of local moderate brain contusion was established by the free-falling-body impact device according to the Feeney method. (2)The samples surrounding the lesion were harvested at different time points.(3)The brain tissue of paraffin wax slices were prepared for HE staining and microscope observation.(4)The expression of NF-κB at different time were detected by immuonhistochemical technique.(5)The results were analyzed by SPSS 11.0 software.Results: (1) 0n postinjury hour 1 ,weak expression of NF-κB was detected in the injured area.(2)on postinjury hour 12, area of NF-κB positive cells increased(274.72±0.9471 );(3)On postinjury hour 24 , The erea of NF-κB positive cells in response to the peak was (299.4000±1.5476);Thereafter , expression of NF-κB decreased and was detected in the injured area on postinjury day 10.(4) The expression of NF-κB in postmortem group was similar with postinjury 24 hours group(P﹥0.05)。Conclusion:After brain contusion, the expression of NF-κB varied regularly. The expression of NF-κB increased immediately after injury, then reached to a peak at three to five days after injury, finally decreased. The level of NF-κB can be used as a supplement index to estimate the injury interval in brain contusion. These results suggest that NF-κB may play a major role in the injured–induced .