低强度恒磁场并环磷酰胺对小鼠S180肉瘤生长的影响

背景目前临床已有利用强磁场的高热效应及低强度磁场治疗恶性肿瘤,多为整体对磁处理因素的反应.低强度恒磁场-永磁贴敷法对接种动物肿瘤生长的作用如何?目的探讨敷磁对小鼠S180肉瘤生长的影响,并观察与抗肿瘤药物(环磷酰胺)联合应用有无协同作用.设计完全随机对照实验研究.单位中国医科大学附属第一医院理疗科.材料本研究于中国药品生物制品检验所进行,实验动物为昆明小鼠,合格证号[1998]106,由中国药品生物制品检验所提供.干预将接种S180肉瘤后的昆明小鼠80只随机分为空白对照组、单纯敷磁片组、单纯环磷酰胺组和敷磁加环磷酰胺组,每组20只.单纯敷磁片组、单纯环磷酰胺组采用直径8.0mm,厚1.2 mm的钕-铁-硼稀土永磁材料贴敷于接种瘤苗处中心,磁感强度0.10～0.11T.空白对照组、单纯环磷酰胺组采用与前两组同样大小未充磁的稀土材料,贴敷部位相同.单纯环磷酰胺组、敷磁加环磷酰胺组用0.5g/L环磷酰胺水溶液,经口投药(0.04mL/kg),1次/d,连续8 d.空白对照组、单纯敷磁片组每天经口给予同样数量的生理盐水作对照处理,连续8d.各组均于第9天停止上述处理,第10天处死,称体质量及瘤质量,计算抑瘤率,并对瘤体进行病理检查.主要观察指标①各组小鼠的体质量及瘤质量.②瘤体病理学表现.结果单纯环磷酰胺组和敷磁加环磷酰胺组体质量低于空白对照组和单纯敷磁片组,差异有显著性意义(P均＜0.05).各组瘤质量除单纯环磷酰胺、敷磁加环磷酰胺两组间差异无显著性外,其他各组间瘤质量差异均有非常显著性(q=4.76～12.73,P均＜0.01).单纯敷磁片组、单纯环磷酰胺组和敷磁加环磷酰胺组抑瘤率分别为39.7%,65.7%,68.7%.单纯环磷酰胺、敷磁加环磷酰胺组瘤体包膜完整,纤维组织间有少许血管增生,瘤细胞大片坏死,中心部细胞分解液化,残存的瘤细胞核分裂少见.结论敷磁和环磷酰胺均有抑制肿瘤生长的作用,二者抑瘤率无显著差异,联合应用不能提高抑瘤率,提示该磁场强度下与抗肿瘤药物环磷酰胺联合应用无协同作用,不能增加对接种瘤的抑瘤效果.

Effects of low-intensity constant magnetic field combined with cyclophosphamide on the growth of S180 sarcoma in mice

BACKGROUND: The hyperthermia effect of the strong magnetic field and low-intensity magnetic field are introduced clinically in the treatment of malignant tumor at present, most of which are the integrate reactions to the magnetic managing factors. What the effects does low-intensity constant magnetic field-strapping and application with permanent magnet have on the growth of tumor in the inoculated animals?OBJECTIVE: To investigate the effects of the magnet for application on the growth of S180 sarcoma in mice and to observe whether there is synergism in the combination of magnet for application and anti-tumor drug (cyclophosphamide, CTX).DESIGN: A completely randomized controlled trial.SETTING: The study was performed in the Department of Physiotherapy, the First Affiliated Hospital of China Medical University.MATERIALS: The study was carried out in National Institute for the Control of Pharmaceutical and Biological Products. Animals were Kunming mice with the certification number of [ 1998 ] 106 were provided by National Institute for the Control of Pharmaceutical and Biological Products.INTERVENTIONS: Eighty Kunming mice inoculated with S180 sarcoma were randomly divided into control group, magnet for application group(magnet group), CTX group, and magnet for application + CTX group(magnet + CTX group) with 20 mice each. Nd-Fe-Boron rare earth permanent magnetic material(8.0 mm in diameter and 1.2 mm in thickness) was applied in the center of the inoculated tumor onto the mice of both magnet group and magnet + CTX group with the magnetic intensity of 0. 10 - 0. 11 T. The same rare earth material was applied onto the same place in the mice of control group and CTX group without magnetism. 0.5 g/L CTX aqueous solution was used in the mice of CTX and magnet + CTX group through oral administration(0.04mL/kg) once a day for 8 days continuously, and same volume of normal saline was used through oral administration once a day in mice of control and magnet groups for 8 days continuously. The intervention was terminated on the 9th day and mice of each group were executed on the 10th day followed by weighing body mass and tumor mass to calculate the tumor-inhibition rate. The tumor was pathologically examined as well.RESULTS: The body mass of CTX and magnet + CTX group was significantly lower than that of control and magnet groups( P＜0.05). There were significant differences in tumor mass among each group except that between CTX and magnet+CTX groups(q=4.76-12.73, P ＜0.01) .The tumor-inhibition rates of magnet group, CTX group and magnet + CTX group were 39.7%, 65.7% and 68.7% respectively. In the CTX and magnet CTX group, the tumor had integral membrane, few blood vessels proliferated in fibrous tissues, big pieces of tumor cell necrosis with decomposition and liquefaction of central cells, and few residual tumor cells divided in nuclei.CONCLUSION: Both magnet for application and CTX have inhibitive effects on tumor growth with no significant difference in tumor-inhibition rate. The combinative application can not increase the tumor-inhibition rate,suggesting that there is no synergism in the combinative application with CTX, and no enhancement in the tumor-inhibitive effects on inoculated tumor under this magnetic intensity.