动物造模,药效评价,颅脑火器伤 z-bio 2024-09-20 388

　　(1) Method of replication: Hybrid dogs, regardless of gender, weighing 15-20kg. After intravenous injection of pentobarbital sodium anesthesia at a dose of 30mg/kg body weight, tracheal intubation was performed. Place the dog on the shooting target platform, fix its head at the target hole, wait for the eyelash reflex to recover, and use a small caliber rifle (bullet model 5.56mm, weight 2.57g) at a distance of 25m to injure it. The impact point is located at the posterior part of the forehead, indicating a penetrating injury; If the impact point is located on the forehead, it is a brain tangent injury. After shooting, use a multi-channel physiological recorder to record changes in vital signs such as heart rate, blood pressure, cerebral blood flow, and electrocardiogram every 30 minutes. Animals with respiratory pauses can be given assisted breathing until spontaneous breathing is restored. Measure intracranial pressure at 30 minutes, 1 hour, and 3 hours after injury, and record the animal's survival time after injury. Animals can be euthanized by deep anesthesia at different time points of 30 minutes, 1, 2, 4, 6, 8, and 12 hours after injury, or whole brains can be taken after animal death for HE or immunohistochemical staining to observe histopathological changes after injury.

　　(2) Model features: After injury, the eyelash reflex disappears in dogs, and most animals experience respiratory arrest. When spontaneous breathing is restored, the frequency slows down, and some exhibit sighing or tidal breathing. After animal injury, both sides of the pupils appear dilated, with a duration ranging from seconds to minutes. Heart rate slows down, some animals experience arrhythmia, and blood pressure drops. The electroencephalogram shows a straight line and can last for 5-15 minutes, followed by varying degrees of recovery. The cerebral blood flow map shows insufficient blood supply to the brain, and intracranial pressure rises in a stepped manner. The survival time varies from 1.5 to 10 hours. Histopathology showed that 30 minutes after injury, the endothelial cells of the blood vessels around the wound (contusion area) were significantly swollen, with increased vacuoles and basement membrane rupture. Swelling of nerve cells, degeneration of organelles, swelling and degranulation of rough endoplasmic reticulum. Neurocorticospinal laxity and degeneration. Due to the disruption of the blood-brain barrier, vascular cerebral edema is caused. As time goes on, the damage worsens, and some nerve cells show degeneration and necrosis.

　　(3) Comparative medicine selects experimental guns with high accuracy, resulting in a relatively constant trajectory and good repeatability of the injury model, and a longer survival time for animals after injury. Its physiological and pathological changes are in line with the characteristics of modern traumatic brain firearm injuries, providing an ideal experimental animal model for further research on traumatic brain firearm injuries. The animal model of penetrating injury can be used as a short-term physiological indicator for measurement and ballistic pathology research. Tangential brain injury can be used for more in-depth observation of physiological and biochemical indicators, as well as exploring the secondary pathological injury mechanism of cranial firearm injury at the molecular level.