动物造模,缩窄性心包炎 z-bo 2020-08-05 591

　　(1) Reproduction method New Zealand rabbits weighing 1.5 to 2.0 kg, the animals were fixed on their back, and local infiltration anesthesia with 2% procaine. A small incision was made in the middle of the upper abdomen, and about 0.5 g of liver tissue was taken to check the liver water content. Then, a midline incision is made about 2cm, close to the sternum and left side ribs, push the pectoralis muscle to 1.5cm next to the sternum, pull the upper and lower ribs away from the incision of the intercostal muscles to both sides, avoiding the pleura, revealing the bare pericardium. ; Use a No. 7 waist puncture needle to puncture the horizontal position under the xiphoid process to the apex of the heart, and enter the pericardial cavity from the pericardial diaphragmatic surface. Inject the inducer at 1ml/kg body weight (the inducer is prepared as: sterile talcum powder 4g, tetracycline powder 1g, and 1.5% iodine tincture 20ml to make a suspension). The animals were sacrificed 2 weeks after the injection of the inducer. The chest was immediately opened to measure the left and right pleural effusions to observe the thickening of the pericardium and assess the degree of thickening. Take two specimens of myocardium and pericardium for pathological examination. Open the abdominal cavity and measure the ascites, take 2 liver tissue samples, 1 for pathological examination, and 1 for liver tissue water content. Evaluation criteria for the degree of pericardial adhesion and thickening: Grade 0: Normal pericardium: The pericardium is thin and transparent, and there is no adhesion between the pericardium and the myocardium. The vascular network on the myocardial surface can be clearly seen through the pericardium; Grade 1: The pericardium is thickened and whitened, and the pericardium and myocardium There are scattered filamentous adhesions, and larger blood vessels on the surface of the myocardium can be seen through the pericardium; Grade 2: The pericardium thickens and whitens, and the pericardium adheres to the myocardium. The blood vessels are not visible through the pericardium, but the myocardium is visible; Grade 3: Pericardium increases The thickness becomes white, and the myocardium cannot be seen through the pericardium. Measurement and calculation of liver water content: Before and 2 weeks after making the model, take 1 piece of liver tissue of 0.5g size, rinse with physiological saline, absorb the water on the filter paper, weigh it on an analytical balance, and place it in a 60℃ oven for 72 hours , The weight when reaching constant weight is dry weight. Then calculate the following formula: liver water content = (liver wet weight-dry weight) / wet weight × 100%, take the pericardium, myocardium, liver tissue specimens fixed with 10% formaldehyde solution, paraffin embedded section, HE staining, light Observe under the microscope.

　　(2) Features of the model The model is made by injecting the inducer through the chest under local anesthesia, which is simple and easy to implement, has little interference to the animal body, and does not require special care after surgery. The judgment of experimental animal pericardium thickening has also been improved. The traditional method is to make pathological sections of pericardial specimens and observe and compare them under a microscope. Due to the difference between the specimens and the observer's understanding, the judgment of pericardial thickening lacks a unified standard. In this test, the transparency of the rabbit’s normal pericardium is used, and the myocardium and its surface blood vessels are used as a reference to evaluate the thickening of the pericardium. The thickening of the pericardium is relatively quantified, and the judgment of the thickness of the pericardium establishes a relatively clear objective. index. In addition, the rabbits with many animal sources and low prices adopted in this model are experimental animals, which are easy and fast to operate, which is conducive to the large-scale replication of the model. It provides a new animal model for further study of constrictive pericarditis.

　　(3) Comparative Medicine After clinical pericardial constriction, the diastole and contraction of the myocardium are restricted, venous return is blocked, systemic vein congestion, arterial blood supply is insufficient, and important organs are ischemia and hypoxia. This model showed that 2 weeks after injecting the inducer into the pericardial cavity, the animals showed signs of pulmonary and systemic congestion such as thickened pericardium, accelerated breathing, increased pleural fluid, ascites, and liver water content. These manifestations are similar to the clinical signs of constrictive pericarditis. Animal anatomy also shows that rabbits are different from dogs, sheep and other animals. The pleural reflexion of the pleural cavity is very similar to that of humans. There is a bare pleural area of about 1cm2 in front of the pericardium.