【作者】 徐万龙；

【导师】 白靖平；

【作者基本信息】 新疆医科大学 ， 外科学， 2010， 硕士

【摘要】 目的：观察成年比格犬脊柱三维适形调强放疗(IMRT)和普通放疗对犬脊髓中Fas、HSP70的影响及意义。方法：选用雄性成年比格犬16只,随机数字表法随机分成4组(IMRT组：50 Gy组4只,70 Gy组4只；普通放疗组：50 Gy组4只,70 Gy组4只),模拟犬胸9-10椎体肿瘤,在20 d内对其胸9-10椎体给予放疗,并于放疗3个月后活杀取材,取各犬相同节段、相同部位(胸9-10)脊髓。采用蛋白组学方法筛选放疗前后犬脊髓中的差异蛋白,采用HE染色观察各组犬脊髓神经元的形态,采用TUNEL法定量测定各组犬脊髓中神经元凋亡情况,采用SABC免疫组织化学法测定各组犬脊髓中Fas、HSP70蛋白表达量,采用RT-PCR方法半定量测定各组犬脊髓中Fas、HSP70 mRNA表达量。结果：①蛋白组学方法筛选出Fas、HSP70蛋白为放疗前后的差异蛋白。②相同放疗剂量,比格犬行为学评分IMRT组优于普通放疗组。③HE染色结果提示放疗3个月后可观察到脊髓放疗后的迟发损伤,IMRT组脊髓神经元以可逆性损伤为主,而普通放疗组多以不可逆性凋亡性损伤为主。④相同放疗剂量,IMRT组脊髓神经元凋亡指数低于普通放疗组；相同放疗剂量,IMRT组凋亡促进蛋白Fas蛋白表达量、mRNA表达量明显低于普通放疗组,而凋亡抑制蛋白HSP70蛋白表达量、mRNA表达量明显高于普通放疗。⑤脊髓神经元凋亡指数与Fas/HSP70比值呈正相关。结论：①放疗3个月后脊髓中存在着明显的放疗迟发反应。②Fas、HSP70两个蛋白参与了放疗后脊髓神经元凋亡的过程,而且Fas/HSP70比值是决定放疗后神经元是否发生凋亡的主要因素之一。③脊柱IMRT的脊髓生物安全性远优于普通放疗。更多还原

【Abstract】 Objective:By comparing the spine intensity modulated radiation therapy (IMRT) and the conventional radiation therapy of the beagle spinal cord neurons to demonstrate the biological safety of IMRT of the spinal cord. Methods:Select purebred beagles and sixteen were randomly divided into four groups. Mimic a beagle clinical model of tumor in the ninth and tenth thoracic vertebrae. Then four groups beagle were irradiated by two different models of IMRT and conventional radiation therapy, and the total irradiation doses were 50 Gy and 70 Gy in 20 days. The samples of spinal cord were taken out on the 3th month after radiation.2-DE technique was used to identify the differential protein in the spinal cord after spine IMRT and conventional radiation therapy. The samples were observed by the hematoxylin and eosin stain. The expression of Fas, HSP70 and Fas, HSP70mRNA were evaluated in spinal cord neurons by immunohistochemistry and RT-PCR. Terminal deoxynucleotidyl transferase mediated dUTP nick and labeling (TUNEL) technique was used to examine the apoptotic cells in the spinal cord. Results:①The differential proteins of Fas and HSP70 were identified by the 2-DE technique in the spinal cord after spine IMRT and conventional radiation therapy.②Compared with the IMRT group, the score of the ethology in the conventional radiation therapy group was higher following the same dose.③The late radiotherapy response of the spinal cord neurons was obviously observed on the 3th month. The neurons in the spinal cord of IMRT group were mainly reversible injury, but the conventional radiation therapy ones were mainly apoptosis.④Compared with the IMRT group, the apoptosis rate of the spinal cord neurons and the expression of Fas and FasmRNA in the conventional radiation therapy group increased obviously following the same dose.⑤The expression of HSP70 and HSP70mRNA descended. The numerus of Fas/HSP70 was positively correlated with the apoptosis rate of the spinal cord neurons. Conclusion:①The late radiotherapy response of the spinal cord neurons was existing on the 3th month.②Fas and HSP70 taken part in the apoptosis process of the spinal cord neurons after the radiation therapy. The numerus of Fas/HSP70 was a definitive factor to the apoptosis of the spinal cord neurons.③Biological safety of spinal cord in the IMRT group was much better than in the conventional radiation therapy group.更多还原