动物模型 z-bo 2020-08-08 604

　　(1) Reproduction method New Zealand rabbits weighing 2.5-3.5kg are anesthetized with urethane by intraperitoneal injection at a dose of 5ml/kg body weight, and the anesthetized rabbits are fixed on the operating table in a supine position. The anterior wall of the maxillary sinus was cut longitudinally about 1 cm along the midline of the lateral incision, and the subcutaneous and periosteum were separated. From the anterior wall of the maxillary sinus, the opening of the anterior wall was enlarged with piercing forceps. The secretions in the maxillary sinus are taken and sent for bacterial culture. Close the sinus opening and suture the skin. The pure cultures made of Streptococcus pneumoniae (ATCC49619) and Staphylococcus aureus (ATCC25923) were picked in a 0.45% sodium chloride solution and formulated to a concentration of 1 McDonald's unit (3×100000000CFU/ml). The next day after the operation, 1 ml of the above bacterial solution was injected into the maxillary sinus cavity through the bone window with a syringe. At 1, 2, 3, 4, 6, and 8 weeks after the operation, the anterior wall of the maxillary sinus was opened again according to the above-mentioned method, and the secretions of the maxillary sinus cavity were removed for rapid bacterial culture to ensure the successful replication of the model.

　　(2) Model characteristics Before the model was made, no bacteria were detected by routine bacteriological examination of the maxillary sinus cavity of rabbits. In the rabbit maxillary sinusitis model established by this method, the modeling time has a great influence on the changes of the flora in the maxillary sinus. With the prolonged period of experimental maxillary sinusitis, opportunistic pathogens in the body will gradually replace the primary disease bacteria. The bacteria cultured in the animal's maxillary sinus within 2 weeks after the operation are related to the planted bacteria, while the bacteria cultured in the maxillary sinus after 3 weeks are basically opportunistic pathogens in the rabbit itself.

　　(3) Comparative Medicine The rabbit maxillary sinus is similar to human maxillary sinus, and the physiological and pathological conditions of experimental maxillary sinusitis are similar to humans. Therefore, rabbits are often used to make animal models. Whether in adults or children, Streptococcus pneumoniae and Staphylococcus aureus are common aerobic bacteria, so this model uses these two pathogenic bacteria to make molds with clinical practicality. Other research reports have also used experimental animals such as dogs and rodents to replicate experimental maxillary sinusitis models, but the rabbit maxillary sinusitis model replicated by this method is more economical and practical, and has a high model success rate. Previous studies have found that injecting 100 million CFU/ml of bacteria into the maxillary sinus cavity of rabbits can effectively make a model of experimental maxillary sinusitis without causing systemic inflammation in rabbits. There are different methods of modeling, mainly as follows: ①Close the natural opening of the maxillary sinus. ②Inject pathogenic bacteria directly without closing the natural opening. ③Inject pathogenic bacteria at the same time after sealing the sinus orifice. ④The maxillary sinus is inserted into the foreign body. Except for method ②, which is not easy to model, the other methods have a high model success rate. Studies have shown that among these methods, the success rate of modeling in the sinus ostium obstruction group is 84.6%, the success rate of ostium obstruction plus Staphylococcus aureus or Streptococcus pneumoniae group is 100%, and the positive rate of bacterial culture in the simple bacterial group is only 10%, the above results prove that the ostium obstruction and the ostium obstruction plus pathogenic bacteria have a higher success rate of modeling. This model has good practical value in studying the pathogenesis of human maxillary sinusitis, drug treatment, and drug screening.