OBJECTIVE To detect the immunoreaction after osteoblast xenotransplantation and to investigate the possibility of heterogenic osteocyte transplantation and tissue engineered bone reconstruction. METHODS: Rat osteoblasts were isolated by two-part bony digestion/elements in culturing, and incubated in vitro at 37 degrees C, 5% carbon dioxide for 5 days until they multiplied and formed a monolayer on the bottom of dish. Twenty-eight rabbits were divided into 3 groups. Autograft of osteoblasts(group A), xenograft of osteoblasts(group B) and normal saline(group C) were implanted into the rectus abdominus muscle. The immunological and histological observations were performed after 1, 2, 4 and 8 weeks of transplantation. RESULTS: Cultured cells reached confluence within 5 days and was identified as osteoblasts by ALP staining and Bon kossa staining. The result of host versus graft reaction was negative. In group B, specific antibody reaction was detected 2 weeks and 4 weeks after transplantation. Cell mediated cytotoxicity was detected after 2 weeks, reached the peak value 4 weeks later, and then began to decline 8 weeks later. HE staining showed mass inflammatory cells and no ectopic ossification after 8 weeks. CONCLUSION: Heterogenic osteoblast transplantation will lead to an obvious change in host humoral and cellular immunity and lost the ability of bone formation. So, it can not be used for the reliable cell sources for osteocyte transplantation or tissue-engineering bone reconstruction.
Although the current postgraduate education system is gradually improving, there are still some problems in the education mode of postgraduate, especially medical postgraduates in China. The current education mode lacks the ability to stimulate students’ potential to the greatest extent and cultivate talents who can develop comprehensively and focus on a certain direction, and lacks the ability to cultivate “four-faceted” scientific and technological workers who can advance to the breadth and depth of science. In view of the above problems, this paper explores the postgraduate education mode based on the close clinical-basic medicine combination on the basis of the tutor system, and summarizes the successful experience obtained in the process of practical teaching, aiming to provide a high quality reference for the medical postgraduate education.
Objective To observe the characteristics of collateral circulation blood flow of ipsilateral ophthalmic artery in patients with internal carotid artery occlusion. Methods The imaging data of 20 patients with internal carotid artery occlusion were analyzed retrospectively. There were 11 males and 9 females, aged from 30 to 65 years, with an average age of (45±3) years. All the patients underwent digital subtraction angiography and transcranial Doppler examination, and 6 patients underwent simultaneous magnetic resonance angiography. The blood supply and collateral circulation of the ipsilateral ophthalmic artery were observed . Results All the patients had unilateral internal carotid artery occlusion. The blood supply of the ipsilateral internal carotid artery and ophthalmic artery comes from the collateral circulation between the middle meningeal artery branches of the external carotid artery and the ophthalmic artery in 18 patients (90.0%); it also comes from the anterior communicating artery of the contralateral internal carotid artery in 16 patients (80.0%); and the posterior communicating artery of the contralateral internal carotid artery in 12 patients (60.0%), respectively. Conclusion The blood flow of the ipsilateral ophthalmic artery mainly comes from the middle meningeal artery branch of the ipsilateral external carotid artery, also comes from the anterior and posterior communicating arteries of the contralateral internal carotid artery.