放疗的生物学评估和优化

随着计划优化和实施技术的完善、临床经验的积累,调强放疗应用越来越多.其生物学评估和优化方法也取得了一些进展,笔者通过系统回顾常用的放射生物学模型来探讨放疗的生物学评估和优化问题,并对涉及调强放疗的内容做了专门的阐述.     

大鼠肾移植模型技术的改进

目的 为开展器官移植的实验研究，建立了大鼠异体肾移植模型。方法使用Wistar大鼠分别作为供者和受者，采用原位低温灌洗，肾动脉带一小段主动脉，肾静脉带一小段下腔静脉、输尿管末端带一直径约为0．5cm的膀胱瓣的供者手术方式；受者主动脉与供者主动脉、受者下腔静脉与供者下腔静脉进行端侧吻合，在受者膀胱上剪去一膀胱瓣与供者相同大小的圆瓣，然后进行一层膀胱吻合。结果 第一阶段为实验探索阶段，经过半年近150次的实验摸索，克服了移植物灌洗、血管吻合、膀胱吻合等技术难关，终于建立了比较稳定的大鼠同种异体肾移植模型。第二阶段为模型成熟阶段，冷热缺血时间、血管吻合的速度以及手术时间都比第一阶段有所缩短。手术成功率为85％左右，动物死亡的原因主要为血管吻合口出血、灌洗不良、休克、血栓形成以及膀胱漏尿致弥漫性腹膜炎等。结论 此模型容易掌握，可以在条件比较简单的实验室开展，除常规显微外科器械外不需要特殊的器械或设备。     

早产儿视网膜病变的动物模型

早产儿视网膜病变(ROP)是一种可引起致盲的视网膜新生血管及纤维组织增生的病变,正逐渐受到国内眼科和新生儿科医师的重视.关于ROP的临床研究取得了很多成果,但是受到研究对象和医学伦理等问题的限制.类似ROP病变的氧诱导视网膜病变(OIR)模型先后在猫、家兔、犬、小鼠、大鼠等动物中建立,后两者由于具有体型小、繁殖快、品种品系多、方法较为成熟且成功率高等特点,得到了广泛的应用.转基因小鼠为ROP的分子遗传学研究提供了理想的途径.此外大鼠中CO2诱导视网膜病变和代谢性酸中毒诱导视网膜病变的方法将有助于研究CO2、酸中毒与ROP的关系.犬视网膜血管对氧的反应比啮齿类动物更加接近人类,但其ROP模型在更多应用之前还有待于深入研究.     

豚鼠内耳磁微粒栓塞缺血模型初探

OBJECTIVE: To set up an inner ear ischemic model in guinea pig with ferromagnetic embolism. METHODS: A magnet was fitted in the external auditory canal and carbonyl iron filings (1%, 1 ml/kg) was injected into jugular, then the inner ear vessels were obstructed by ferromagnetic spheres. Cochlear blood flow (CBF) and number of red blood cells in the stria vessels were used to detect the model's ischemia of cochleae. The slice of temple bone and basal membrane stained by silver nitrate were used for inner ear's histopathological observations. RESULTS: The iron spheres were amassed in the one and two-day-later's model of inner ear vessels, which resulted in embolism. The number of red blood cells in the stria vessels decreased and then recovered to normal level after 4 days, but the CBF decreased to 50% +/- 10% of basic level immediately and recovered to 99% +/- 41% 4 days later. Scattered lesion of out hair cell cilium could be seen in cochleae in eight-day-later's model, and degenerations in different degree were found in vascular stria. CONCLUSION: The methods of inner ear ischemic model with ferromagnetic embolism could be practical and the decrease of CBF was reversible, so it may be an ideal model for studying some ischemic inner ear diseases and evaluating the effects of therapeutic drugs.     

关于急性脑梗死溶栓治疗研究中的几个关键问题

溶栓治疗能迅速、直接地再通阻塞血管，恢复灌注，从而有效缩小梗死面积甚至阻止梗死进一步形成，因此，早期溶栓治疗可能会成为急性脑梗死最重要的治疗方法。因为溶栓治疗涉及的时间窗、溶栓后缺血／再灌注损伤等并发症问题，限制了其广泛应用；而且脑梗死溶栓治疗临床研究设立对照组困难，其基础研究就显得尤为重要。目前溶栓研究中存在动物模型制备、溶栓治疗时机、     

新胆碱酯酶抑制剂对实验性重症肌无力的治疗作用

本文应用实验性重症肌无力模型研究了7种新的胆碱酯酶抑制剂对实验性重症肌无力的治疗作用,其中包括6种二甲氨基甲酸烷氧(烷硫)基苯酯及1种中草药提取物,大多数化合物对乙酰胆碱酯酶有较强的抑制作用,并见到有不同程度的治疗效果。二甲氨基甲酸-3-叔丁基-4〔2-(1-哌啶基)乙氧基〕苯酯不仅明显改善肌无力症状,而且毒性小、副作用较新斯的明轻,值得进一步研究。     

急性软脑膜微循环障碍实验模型的研究

本文报道应用高分子右旋糖酐制成软脑膜微循环障碍的动物实验模型。软脑膜微循环障碍模型的标志;软脑膜微血管血流速度减慢,血液流态呈粒状流或絮状流,血细胞聚集。 将98只家兔分成甲、乙二组。甲组38只,静脉注射平均分子量为25万的高分子右旋糖酐,乙组60只,静脉注射平均分子量为49万的高分子右旋糖酐。实验结果发现,甲组38只家兔仅28只可复制成软脑膜微循环障碍的实验模型,模型复制成功率为73.6％;乙组60只家兔,59只可形成软脑膜微循环障碍实验模型,成功率为98.3％。本实验证明复制动物模型以49万分子量的高分子有旋糖酐为宜。 本实验模型可用于脑微循环障碍和改善脑微循环药物的研究工作。     

实验性腹主动脉瘤瘤体外径与iNOS相关性分析及分期研究

Objective To construct new model of experimental abdominal aortic aneurysm (AAA) and detect the AAA outer diameter and the change of induce nitric oxide synthase(iNOS) in the abdominal aor-tic aneurysm in different period,and analysis the correlation between experimental AAA and iNOS.Methods During the operation of the experiment group,the vascular prosthesis of PTFE was implanted to the rabbit abdominal aorta to form an aneurysm,while sham operation was done in the control group.The tissue of ab-dominal aortic aneurysm was harvested in 1 d,7d,14d,and 28d after operation,respectively.The tissue bo-mogenate concentration of iNOS in the abdominal aortic aneurysm were detected by enzyme linked immu-nosorbent assay (ELISA).Results In experimental group,mean concentration of the tissue bomogenate concentration of iNOS in the abdominal aortic aneurysm in 1 d,7 d,14 d,28 d were (22.129 ±2.518)μ/mL,(27.337±5.321) μ/mL,(36.047±4.584)μ/mL,(44.756±1.799)μ/mL,respectively;In control group,that was (12.499±1.807)μ/mL.The concentration of iNOS in experimental group was significantly higher than that of control group (P < 0.01).The difference during the experimental group all had statisti-cal significance (P < 0.05).Conclusion It is possible that iNOS has some biological function during the formation and progression of the abdominal aortic aneurysm.     

壳聚糖神经干细胞复合物修复大鼠完全性脊髓损伤的组织学观察

目的：探讨壳聚糖与神经干细胞复合物修复成年SD大鼠完全性脊髓损伤的可行性。方法：制作大鼠脊髓完全缺损模型，在形成的缺损中植入壳聚糖与神经干细胞复合物(实验组)，或只植入壳聚糖(对照组)，或不加任何材料(空白组)，术后2、4、8周灌注取材，观察结果。结果：壳聚糖与神经干细胞复合物在植入SD大鼠脊髓完全缺损模型后，能桥接缺损两端脊髓；其内的神经干细胞能存活、迁移并分化成多种形态的神经组织细胞，并诱导神经轴突向复合材料内生长。结论：壳聚糖与神经干细胞复合物有可能桥接并修复大鼠脊髓完全缺损性损伤。