[Expression of caspase-8 after brain injury from fluid percussion in rats].

OBJECTIVE: To provide the evidence of the relationship between brain injury and the time of injury. METHODS: Rats were contused on brain by fluid percussion, then were killed after injury for 15 min, 30 min, 1,3,6,12 h, and 1,4,7,14 d respectively. The expression of caspase-8 were detected by immunohistochemical technology on rat brain section and the results were assessed by image analysis system in the cerebral cortex, thalamus, and hippocampus. RESULTS: The expression of caspase-8 in cortex and hippocampus could be detected in 30 min after injury, increased significantly in 3h, reached apex in 1d after injury, remained 4d before decreased. In addition, the expression of caspase-8 can be detected in 1h after injury and reached apex in 1d after injury, and remained 4d then reduced. CONCLUSION: It seems that the expression of caspase-8 should be a useful target for diagnosis of early brain injury.

Epidemiology of assaultive injuries in areas of Sichuan province, China.

OBJECTIVE: To scrutinize the epidemiological characteristics of assaultive injuries in Sichuan province, China. METHODS: A survey of all cases of assaultive injuries reported by police was performed during 8 years in eight counties of Sichuan province, China. A total of 2862 victims and 2856 offenders were registered. RESULTS: The majority of victims and offenders were young men at the age of 20-39 and only received an education at secondary school or primary school. The largest fraction of these cases took place at farm or by-place during 10.00-11.00 o'clock, 16.00-17.00 o'clock and 20.00-21.00 o'clock. The tangles caused by trifles were the most common factors inducing assaultive injuries and accounted for 42.1 percent of the causes of assaults. Blunt injuries were mainly caused by punching (40%) and kicking (17.2%). About 37.3% of the lesions seriously happened in the regions of face and head. Open wounds accounted for 40.3% of these different injuries. CONCLUSIONS: It is valuable to take some specific measures to prevent and control assaultive injuries according to their territorial characteristics.

[The expression of Fas after fluid percussion brain injury in rats].

OBJECTIVE: To inquire into the pathologic diagnosis and the dating of injuries of light closed encephalon injury. METHODS: Wistar rats were hurt by fluid percussion, and were killed respectively at 15 min, 30 min, 1 h, 3 h, 6 h, 12 h, 1 d, 4 d, 7 d, and 14 d after injury. The expression of Fas in the cerebral cortex, thalamus, and hippocampi was detected by immunohistochemistry and the results were assessed by image analysis system. RESULTS: The results showed that the expression of Fas could be detected in thirty minutes after injury, and then it increased significantly in three hours, reached apex in twelve hours after injury, decreased gradually in four days after injury, and returned to normal in 14 days after injury. CONCLUSION: This research demonstrated that Fas-mediated apoptosis appeared not only around brain trauma but also in the brain tissue far away from the traumatic area. It indicted that Fas expression is a useful target for diagnosis of early brain injury and the regularity of Fas expression could be used as one of indications in deducing the time of brain injury.

[Expression of PDGF-B after fluid percussion brain injury in rats].

OBJECTIVE: To elucidate the changes of PDGF-B chain in the brain injured by fluid percussion. METHODS: The expression of PDGF-B protein was studied by immunohistochemistry and the results were assessed by image analysis system. RESULTS: Enhanced expression of PDGF-B protein induced by fluid percussion injury was seen at 1 h, and its marked up-regulation was noted at 4-7 days, and then the expression became decreased but it remained above the control levels till 14 days after injury. CONCLUSION: Fluid percussion brain injury induced expression of PDGF-B. The regular change pattern of PDGF-B level in time course seems to be of value in estimating the age of brain injury.

[A study on the expression of Snap-25 mRNA in rat poisoned by tetramine].

OBJECTIVE: This study sought to reveal the relationship between Snap-25 and tetramine poisoning in order to approach the mechanism of tetramine poisoning. METHODS: The levels of Snap-25 mRNA in the brain tissues of poisoned SD rats were detected by RT-PCR method. RESULTS: After 1 hour of intoxication, the expression level of Snap-25 mRNA did not change in the rat brain. It increased at day 1 and reached its peak at day 3. The expression level of Snap-25 mRNA begain to descend at day 5, but it was still higher than that in the rat brain tissue of control group. CONCLUSION: In this study the expression of Snap-25 of rat poisoned by tetramine was not markedly increased in the early stage of poisoning, indicating that the symptoms of rat poisoned by tetramine are not induced by the changes of the Snap-25 level. The mechanism of high expression in Snap-25 mRNA probably involves the negative feedback of the body, which may increase the releasing of neurohumor and hence mitigate the symptoms of poisoning.

[The latest research progress on CGRP and its potential application in forensic medicine].

Calcitonin gene-related peptide (CGRP) play a key role in some physiological and pathological progresses. The latest studies indicate that CGRP might involve in some disease progress and has a close relation with wound healing. It is significant to further investigate and then apply it to clinical diagnosis and therapy as well as forensic pathology.