三七中人参三醇甙对羊心浦氏纤维动作电位及延迟整流钾电流的影响

三七中人参三醇甙(PTS)2.5μg/ml及5.0μg/ml均能明显延长羊心浦氏纤维动作电位时程(APD)包括APD₃₀,APD₅₀,APD₉₀,对动作电位幅度(APA)无明显影响。双微电极法电压钳实验证明,PTS能明显抑制羊心浦氏纤维延迟整流钾电流(I_x)的峰值,且此种抑制作用呈时间及剂量依赖性。揭示PTS通过阻滞延迟整流钾通道而延长APD。     

9－（2－膦酰甲氧乙基）腺嘌呤及其位置异构体3－（2－膦酰甲氧乙基）腺嘌呤的合成和抗病毒活性研究

９－（２－膦酰甲氧乙基）腺嘌呤及其位置异构体３－（２－膦酰甲氧乙基）腺嘌呤的合成和抗病毒活性研究刘晓辉，王琳，贯宝和，孔漫，张兴权，陶佩珍，陈鸿珊（中国医学科学院、中国协和医科大学药物研究所，北京１０００５０；中国医学科学院、中国协和医科大学医药生物...     

人参皂甙诱导的造血细胞内信号传递途径的研究

目的探讨人参皂甙（ＧＳ）刺激造血祖细胞增殖有关的细胞内信号传递途径。方法采用Ｎｏｒｔｈｅｒｎ印迹杂交法、电泳带移动阻滞实验、抗体胶结合移动实验和紫外放射交联实验。结果ＮｏｒｔｈｅｒｎＢｌｏｔ显示经ＧＳ诱导的人巨核细胞株ＣＨＲＦ２８８、Ｍｅｇ０１和ＭＯ７ｅ细胞的ＧＡＴＡ２ｍＲＮＡ水平增高,分别是未经处理细胞的１．８４,２．４３和１．５２倍。但ＧＡＴＡ１ｍＲＮＡ表达水平低,且ＧＳ处理前后也无明显变化。电泳带移动阻滞实验提示ＧＳ诱导的细胞核内ＧＡＴＡ转录调控蛋白与特定的ＤＮＡ序列结合的活性增高。抗体胶结合移动实验证实与ＤＮＡ结合的主要成分为ＧＡＴＡ２蛋白,紫外放射交联实验确定该复合物的相对分子质量约为５０×１０３,符合ＧＡＴＡ２转录调控蛋白。结论ＧＳ诱导细胞内的信号传递途径与转录因子ＧＡＴＡ２有关,ＧＡＴＡ２有介导ＧＳ刺激造血细胞增殖的作用。     

Antimicrobial peptides: a potential role in ocular therapy

Bacterial pathogens are often involved in contact lens‐related adverse responses. This study aimed to find antimicrobial peptides and proteins that effectively eradicate or inhibit ocular bacteria. The antimicrobials were screened against Gram‐ negative and Gram‐positive bacteria originating from ocular sources. The viability of these ocular bacteria was measured after exposure to the peptides and proteins. Two conditions were used to grow bacteria, low nutrient phosphate‐buffered saline and high nutrient tryptone soya broth. Samples were taken at different times up to 48 h. In low nutrient conditions, protamine was found to be the most effective against all strains. Melittin was very effective against all strains except Serratia and one Pseudomonas isolate which were partially affected. In high nutrient condition, only melittin was effective in killing Staphylococcus aureus. Protamine and the combination of protamine and melittin had the greatest effect in eradicating the bacteria tested in low nutrient condition. Protamine alone and its combination with melittin may have potential therapeutic agents for ocular infections in an era of emerging antibiotic resistance.