Effect of local hyperthermia induced by nanometer magnetic fluid on the rabbit VX2 liver tumor model

Hyperthermia induced by magnetic nanoparticles is a recent therapeutic approach for local targeting of hyperthermia and thermoablation and is a promising treatment of malignant tumors.The purpose of this study is to evaluate the potential and therapeutic effect of magnetic fluid hyperthermia on the rabbit VX2 liver tumor model.Rabbits bearing liver tumors 14 days after tumor implantation were randomly divided into five groups of 10 cases each,including three control groups and two hyperthermia groups.Hyperthermia was carried out immediately after a single intratumoral injection of uncoated water-based Fe3O4 magnetic fluid under an alternating magnetic field only once as one hyperthermia group and repeated hyperthermia after 5 days as the other treated group.The distribution of magnetic fluid was evaluated by CT scanning.All animals were sacrificed 4 weeks after tumor implantation.The therapeutic effect was determined by tumor size and macroscopic and pathological examination of the liver tumor.The local higher density imaging of intratumoral magnetic fluid deposits compared to the surrounding tissue was clearly observed by CT scanning.Twenty-eight days after tumor implantation,the tumor maximal diameter and tumor volume of two hyperthermia were both significantly less than those of control groups (P＜0.05).Tumor volume inhibition by single or repeated hyperthermia compared to the three control groups was 71.93-79.91% and 92.34-94.46% (P＜0.05),respectively.Under a microscope,coagulation necrosis was observed in the heated area,which had a clear boundary line with the surrounding tissue.The intratumoral distribution of magnetic nanoparticles,especially in the area of necrosis,appeared much more homogenous than in the untreated ones.This study demonstrates that hyperthermia induced by direct intratumoral injection of magnetic fluid can be used safely,and a well-homogenized distribution of high intratumoral temperature without heating adjacent to normal tissue can be achieved.     

DSA 联合 CT 引导下经皮肝穿刺兔 VX2 肝癌模型制作

摘要: 目的 探讨 DSA 联合 CT 引导下经皮肝穿刺兔 VX2 肝癌模型制作的可行性。方法 40 只新西兰白兔随机分 成 A、B 两组,每组 20 只,A 组在 DSA 联合 CT 引导下将兔 VX2 肿瘤组织块经皮肝穿刺接种于兔左肝内,B 组通过 开腹法种植 VX2 肿瘤组织块,于接种后第 2 周、4 周行全身 MR 检查,后处死实验兔行原位、异位肿瘤肉眼观察。结 果 A 组建模成功率 90% ,有 1 只出现异位种植,未发现腹水及死亡,平均手术时间( 17. 3 ± 5. 2) min; B 组建模成 功率 85% ,有 3 只出现腹水,2 只死亡,无异位种植发生,平均手术时间( 50. 7 ± 11. 3) min,,两组手术时间比较差异 有统计学意义( P ＜ 0. 05) 。结论 DSA 联合 CT 引导下经皮肝穿刺制作兔 VX2 肝癌模型方法简单、建模成功率高、 手术操作时间短。     

Study of alternate cooling and heating treatment induced tumor microvasculature injury

Tumor microvasculature is important to tumor growth, metastasis and thus tumor treatment outcome. The alternate cooling and heating treatment has been confirmed to have advantages over single treatment of cooling or heating. The degree of tumor microvasculature damage induced by the alternate cooling and heating treatment and the mechanisms underlying are studied in this paper. The response of the tumor microvasculature to different treatments including alternate cooling and heating is observed in vivo thro...     

城市综合体三联供系统应用分析

城市三联供系统是一项既经济又环保的优化方案。文中阐述了城市综合体的负荷特点和三联供系统的运行特点,并以湖南省某城市综合体为例,在估算建筑物的冷热电负荷的基础上,提出了三联供系统应用于该类建筑的可行性和系统设备配置及运行方式选择的最优化方案。比较三联供系统与常规市电供电系统的经济和环保效益,结果表明:三联供系统应用于城市综合体有效实用。三联供系统有更大的收益率,充分体现出燃气发电清洁能源的环保特点。     

光动力疗法对兔肝癌肿瘤微血管密度及血管内皮细胞生长因子的影响

目的：研究光动力疗法对兔肝＇VX2移植癌模型的抑瘤作用及其可能的机制,为临床应用 PDT 治疗肝癌提供依据;方法用15只新西兰白兔制成VX2细胞肝癌模型。以血卟啉衍生物（HPD）为光敏剂观察PDT的抑瘤效果,应用免疫组化染色检测VEGF及MVD的表达水平;结果 PDT对肿瘤明显的杀伤作用;PDT组中VEGF及Mr＇VD的表达水平显著的低于对照组（p〈0.05）;结论 PDT可抑制兔肝VX2移植癌中肿瘤灶VEGF的生成,减少肿瘤灶内MVD。PDT抗肿瘤血管形成是其抑制肿瘤生长的一个重要机制。     

腹水浓缩回输术治疗顽固性腹水的疗效研究

目的探讨腹水浓缩回输术治疗肝硬化顽固性腹水的疗效。方法采用病例对照研究,在常规护肝利尿基础上,对67例进行腹水浓缩回输治疗,观察治疗前后临床表现、生化指标的变化及并发症发生率。结果经腹水浓缩回输术治疗后的病例,体重、腹围均明显好转,尿量增多,肾功能改善,白蛋白明显提升,并发症发生率降低,显效率明显提高。结论能有效地减轻患者痛苦,节约输注外源性白蛋白的费用,减少利尿剂用量。     

大黄苷元对大鼠药物代谢酶CYP2A6、CYP3A4活性的影响

研究大黄苷元对大鼠体内药物代谢酶CYP2A6、CYP3A4活性的影响,以预测大黄与临床常用药物的相互作用.大鼠分组,分别灌胃不同质量浓度大黄苷元、质量分数0.5%羧甲基纤维素钠(CMC-Na)、苯巴比妥钠(PB)、地塞米松(DEX)、β-奈黄酮(β-NF)和酮康唑(KET),取各给药组给药后24 h的肝微粒体(RLM)与CYP2A6、CYP3A4的探针底物香豆素、睾酮进行体外温孵,通过高效液相色谱法分别测定各底物的代谢产物7-羟基香豆素、6β-羟基睾酮的生成量,考察大黄苷元对CYP2A6、CYP3A4活性的影响.大黄苷元高、中、低剂量给药组代谢产物7-羟基香豆素的生成量高于空白给药组和KET给药组,均有统计学意义(P0.05)、(P0.01),大黄苷元高剂量给药组代谢产物6β-羟基睾酮的生成量高于空白给药组和KET给药组,均有统计学意义(P0.05)、(P0.01).随着大黄苷元给药剂量的增加,7-羟基香豆素、6β-羟基睾酮的生成量均随之增加.大黄苷元对CYP2A6、CYP3A4均有诱导作用,并且随着大黄苷元剂量的增加,其对CYP2A6、CYP3A4诱导作用均增强.