目的研究一定功率的超声波对仔鼠学习记忆及海马组织乙酰胆碱酯酶活性的影响,探讨诊断超声的安全性。方法妊娠ICR小鼠40只,随机分为辐照0 m in组(对照组)、辐照10 m in组、辐照20 m in组、辐照30 m in组4组。妊娠第14天应用一定功率的...目的研究一定功率的超声波对仔鼠学习记忆及海马组织乙酰胆碱酯酶活性的影响,探讨诊断超声的安全性。方法妊娠ICR小鼠40只,随机分为辐照0 m in组(对照组)、辐照10 m in组、辐照20 m in组、辐照30 m in组4组。妊娠第14天应用一定功率的连续超声波(3.5 MHz,输出功率1 W)对各组孕鼠进行辐照,待仔鼠生长至30 d和90 d时,从各组仔鼠中随机选出20只进行旷场行为实验,20只进行Y-迷宫分辨学习实验。实验完毕,立即处死仔鼠,取出不同组仔鼠海马组织,测其中的乙酰胆碱酯酶活性。结果与对照组相比,辐照20 m in组和30 m in组小鼠学习能力明显损伤(均P<0.01);辐照20 m in组和30 m in组小鼠脑内乙酰胆碱酯酶活性明显升高(均P<0.01)。结论孕14 d的母鼠接受一定剂量的超声辐照后对仔鼠的学习能力有损伤,这种损伤可能与脑内乙酰胆碱酯酶活性升高有一定的相关性。展开更多
Objective To deliver the naked genes into cells through the bioeffects of cell membrane porous produced by low-frequency ultrasound (US) and to investigate the safety by determining the threshold of cell damage and me...Objective To deliver the naked genes into cells through the bioeffects of cell membrane porous produced by low-frequency ultrasound (US) and to investigate the safety by determining the threshold of cell damage and membrane permeability. Methods The suspension of red cells from chickens, rabbits, rats, and S180 cells was exposed to calibrated US field with different parameters in still and flowing state. Laser scanning confocal microscopy, fluorescent microscopy, scanning electron microscopy, flow cytometry and spectrophotometry were used to examine cell morphology, membrane permeability, enzymes, free radicals, naked gene expression efficiency, threshold of cell damage and cell viability. Results The plasmid of green fluorescent protein (GFP) as a reporter gene was delivered into S180 cells under optimal conditions without cell damage and cytotoxicity. The transfection rate was (35.83±2.53)% (n=6) in viable cells, and the cell viability was (90.17±1.47)% (n=6). Also, malondialdehyde, hydroxyl free radical, alkaline phosphatase, and acid phosphatase showed a S-shaped growth model (r=0.98±0.01) in response to the permeability change and alteration of cell morphology. The constant E of energy accumulation in US delivery at 90% cell viability was an optimal control factor, and at 80% cell viability was the damage threshold. Conclusion US under optimal conditions is a versatile gene therapy tool. The intensity of GFP expression in US group has a higher fluorescent peak than that in AVV-GFP group and control group (P<0.001). The optimal gene uptakes, expression of gene and safety depend on E, which can be applied to control gene delivery efficiency in combination with other parameters. The results are helpful for development of a novel clinical naked gene therapeutic system and non-hyperthermia cancer therapeutic system.展开更多
文摘目的研究一定功率的超声波对仔鼠学习记忆及海马组织乙酰胆碱酯酶活性的影响,探讨诊断超声的安全性。方法妊娠ICR小鼠40只,随机分为辐照0 m in组(对照组)、辐照10 m in组、辐照20 m in组、辐照30 m in组4组。妊娠第14天应用一定功率的连续超声波(3.5 MHz,输出功率1 W)对各组孕鼠进行辐照,待仔鼠生长至30 d和90 d时,从各组仔鼠中随机选出20只进行旷场行为实验,20只进行Y-迷宫分辨学习实验。实验完毕,立即处死仔鼠,取出不同组仔鼠海马组织,测其中的乙酰胆碱酯酶活性。结果与对照组相比,辐照20 m in组和30 m in组小鼠学习能力明显损伤(均P<0.01);辐照20 m in组和30 m in组小鼠脑内乙酰胆碱酯酶活性明显升高(均P<0.01)。结论孕14 d的母鼠接受一定剂量的超声辐照后对仔鼠的学习能力有损伤,这种损伤可能与脑内乙酰胆碱酯酶活性升高有一定的相关性。
文摘Objective To deliver the naked genes into cells through the bioeffects of cell membrane porous produced by low-frequency ultrasound (US) and to investigate the safety by determining the threshold of cell damage and membrane permeability. Methods The suspension of red cells from chickens, rabbits, rats, and S180 cells was exposed to calibrated US field with different parameters in still and flowing state. Laser scanning confocal microscopy, fluorescent microscopy, scanning electron microscopy, flow cytometry and spectrophotometry were used to examine cell morphology, membrane permeability, enzymes, free radicals, naked gene expression efficiency, threshold of cell damage and cell viability. Results The plasmid of green fluorescent protein (GFP) as a reporter gene was delivered into S180 cells under optimal conditions without cell damage and cytotoxicity. The transfection rate was (35.83±2.53)% (n=6) in viable cells, and the cell viability was (90.17±1.47)% (n=6). Also, malondialdehyde, hydroxyl free radical, alkaline phosphatase, and acid phosphatase showed a S-shaped growth model (r=0.98±0.01) in response to the permeability change and alteration of cell morphology. The constant E of energy accumulation in US delivery at 90% cell viability was an optimal control factor, and at 80% cell viability was the damage threshold. Conclusion US under optimal conditions is a versatile gene therapy tool. The intensity of GFP expression in US group has a higher fluorescent peak than that in AVV-GFP group and control group (P<0.001). The optimal gene uptakes, expression of gene and safety depend on E, which can be applied to control gene delivery efficiency in combination with other parameters. The results are helpful for development of a novel clinical naked gene therapeutic system and non-hyperthermia cancer therapeutic system.
