【摘要】 目的　探讨利用光敏剂单天门冬酰胺二氢卟酚e6 (NPe6 )的长波长区吸光谱对较深部食管肿瘤作光动力学诊断的可能性 ,以及NPe6的理想剂量和照光时间。方法　雄性日本纯种白兔 12只 ,在全麻下开腹 ,将VX2肿瘤细胞混悬液 (5× 10 6细胞 /ml) 0 1ml种植于食管粘膜下。 1周后将家兔随机分成 4组 (每组 3只 ) ,1组作为对照组 ,其余 3组分别按 1 0、2 5和 5 0mg/kg耳缘静脉注射NPe6 ,给药后 2、4、6和8h用半导体激光内镜荧光观测系统对食管粘膜下肿瘤及周围正常组织中的NPe6荧光进行观察 ,并计算肿瘤组织 /正常组织相对荧光强度 (T/N)比值。结果　各给药组家兔给药后不同时间在食管肿瘤部位发射出较强的NPe6荧光 ,与邻近正常食管呈鲜明对照。食管肿瘤与周围正常组织中NPe6荧光强度随给药后时间增加而减弱 ,但在给药后 2～ 6h ,T/N比值随时间增加而增大。 5 0mg/kg组T/N比值在给药后 4～ 8h明显高于其他 2组 (P <0 0 5 ) ,于 6h时显示最大值 (3 49± 0 32 )。而其他 2组间差异无显著意义 (P >0 0 5 )。对照组家兔的肿瘤及正常组织均未检测出荧光。结论　利用NPe6长波长区吸光谱 ,对较深部食管肿瘤作光动力学诊断是可行的 ,给药剂量为 5 0mg/kg、给药后 6h进行诊断较为适宜。更多还原

【Abstract】 Objective To explore the proper dosage of mono L aspartyl chlorin e6 (NPe6) and proper irradiation time for photodynamic diagnosis of deep seated esophageal tumor, and the possiblity with a long wavelength photodynamic excitation. Methods Japanese white male rabbits were used. After laparotomy under nembutal anesthesia, 0 1 ml of tumor cell suspension consisting of 5×10 6 VX2 cells was injected from the esophageal tunica adventitia into the submucosa of the lower thoracic esophagus in rabbits. A week later, the implanted tumors were 3-5 mm in lateral dimension and 3-4 mm in thickness. The twelve tumor bearing rabbits were divided into four groups (3 in each group). The control group was not treated and the other three were injected i.v. with 1 0, 2 5 and 5 0 mg/kg NPe6, respectively. The fluorescence (675 nm) image was recorded every 2 h up to 8 h by a newly developed diode laser endoscopic fluorescence imaging system after excitation with a 664 nm laser beam (10 mW, 10 s). The fluorescence intensity of tumor and surrounding normal mucosa was analyzed with NIH Image 1 57 software. Results Using the diode laser endoscopic fluorescence imaging system it was able to selectively detect fluorescence from submucosal tumor by comparison with the surrounding normal mucosa after NPe6 injection. The fluorescence intensity correlated with NPe6 dosage. The fluorescence accumulated selectively in the tumor tissue and its relative intensity peaked at 6 h after injection. No fluorescence image was detected in controls. Conclusions NPe6 given intravenously at a dosage of 5 mg/kg and excited with a 664 nm wavelength laser beam 6 h after i.v. injection may induce definitely deep seated esophageal tumor in rabbits, using an endoscopic fluorescence imaging system.更多还原