Expression Of BDNF In Canines With Craniocerebral Gunshot Wounds

The craniocerebral missile wounds have the characteristic of a high death rate and mutilation rate and are particularly difficult to be managed. They are the most common cause of death in missile injure victims. Since world war two, the craniocerebral missile wounds contributed to 30%~40% of death rate under shield, 10%~20% of casualty rate and 40% of mayhem rate. Up to 50% of deaths caused by missile injury are penetrating missile injuries of the head. It happened not only in wartime, but also in peacetime. The mortality of gunshot wound is more than 60% during times of peace. The common problem of research for craniocerebral missile wounds is difficult to make the animal models because the animals will survive a short time after injury. The aim of this study was to make the canine models of penetrating craniocerebral injury (PCI) and tangent brain injury by the bullets of the small-calibre rifle made in German and test the BDNF expression of cerebral neuronal cells after craniocerebral missile wounds and high energy missile wounds in the extremity of canines. 1. Model establishment and observation of related pbysiopatholog-ical parameters in canines with craniocerebral gunshot woundsAIM To set up the experimental model of canine craniocerebral gunshot wound and examine its feasibility, for further study in craniocerebral gunshot wound. METHODS Sixteen canines, whichwere wounded by the bullets of the small-calibre rifle made in German, were made into penetrating craniocerebral injury (PCI) group (n=10) and tangent brain injury group (n=6). The wounded parameters of bullets were measured, the physiopathological changes of canines were observed. RESULTS The impact velocity and the impact energy of the two groups were recorded. There was no significant difference between two groups. The absorbed energy in the TBI group was more than that in the PCI group (P<0.05). The average survival time of the canines in the tangent brain injury group was longer than that of the PCI group (P<0.05). The heart rate, respiratory frequency, blood pressure and carotid blood flow were reduced, and the intracranial pressure (ICP) was increased obviously in both groups at a few minutes to 1 hour post-wound. There were cerebral vascular dilation, hyperemia, perivascular hemorrhage, ischemia necrosis of the neunons and perivascular edema in the specimen of two groups. CONCLUSION The experimental model showed invariable wound trajectory. The reiteration of the model was good and the survival times were long, especially in the model of the tangent brain injury. 2. Expression brain-derived neurotrophic factor (BDNF) in canines with craniocerebral gunshot woundsAIM To observe the expression of BDNF in cerebral cortex, hippocampus CA2 and brain stem in canines with cranicerebral gunshot wounds. METHODS Twenty canines were divided into normal control and injury group. Using the model of gunshot-injured canine cerebrum made by the bullets of small-caliber rifles made in German, BDNF positive neurons were observed in the contusion trajectory area, the concussion trajectory area, hippocampus, and brain stem at 30 min,l, 2, 4, 6, 8 and 12 h after trauma by immunohistochemical method. The results of the control group and injury group were compared. RESULTS The Expression of BDNF in the injury group was obviously higher than that of the control group. The expression appeared 2-4 hour after trauma (p<0.01).CONCLUSION BDNF plays a positive role in repair of brain injury.In summary, we conclude that using the bullets of the small-calibre rifle made in German, we established the canine models of PCI and tangent brain injury. The canines with PCI or tangent brain injury, especially the tangent brain injury, will survive long time and the model is easy to repeat. Therefore, the models can serve better for the research of craniocerebral missile wounds. The study that BDNF expressed in cerebral neuronal cells after gunshot injury explained the effect of craniocerebral missile wound and the principle of the cerebral secondary...