目的:探讨经介入途径中药白芨提取物作为基因递送载体的可行性.方法:从中药白芨中提取其有效成分-白芨多糖,采用胺化还原法制备阳离子型白芨多糖,体外实验检测该阳离子型多糖对质粒DNA的结合与保护作用,以及阳离子白芨多糖载基因复合物...目的:探讨经介入途径中药白芨提取物作为基因递送载体的可行性.方法:从中药白芨中提取其有效成分-白芨多糖,采用胺化还原法制备阳离子型白芨多糖,体外实验检测该阳离子型多糖对质粒DNA的结合与保护作用,以及阳离子白芨多糖载基因复合物对肝癌细胞系HepG2的转染,进一步通过介入途径经肝动脉给予该复合物,以GFP作为报告基因检测复合物在体内对活体兔肝细胞的转染.结果:所制备的阳离子型白芨多糖载基因复合物可以结合并保护质粒DNA免受DNA酶的降解;体外实验证实该复合物可以转染入体外培养肝癌细胞,以阳离子白芨多糖作为转染载体时转染效率要低于脂质体组,差异具有统计学意义(28.87%±3.27% vs 36.64%±6.87%,P<0.05).采用介入方法经肝动脉给药时复合物能靶向转染入活体兔肝细胞内并实现表达.结论:采用介入途径经肝动脉给药时阳离子白芨多糖载基因复合物可以实现活体肝细胞靶向转染,有望作为一种新型的多聚阳离子型的基因载体在基因治疗中发挥作用.展开更多
The term ＂biogenic amines＂ defines decarboxylation products such as histamine, putrescine, serotonin, tyramine, phenylethylamine, tryptamine and also aliphatic polyamines. They can be detected in both raw and proces...The term ＂biogenic amines＂ defines decarboxylation products such as histamine, putrescine, serotonin, tyramine, phenylethylamine, tryptamine and also aliphatic polyamines. They can be detected in both raw and processed foods. In the recent years, there is a great interest in biogenic amines as they are associated with quality, safety and freshness of some foods, particularly fermented foods. The presence of biogenic amines in foods can also be used as an indicator of hygienic quality. Biogenic amines also cause health hazards due to their toxic effects especially in sensitive individuals. It is therefore important to control and reduce the biogenic amines. The reduction can be brought about by the use of high pressure, irradiation, packaging, additives, starter cultures and by reduction of decarboxylase activity and temperature. This review summarizes the significance, function, occurrence and formation of biogenic amines in different foods and their reduction by different methods.展开更多
目的评价不同分子大小b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)结合物的免疫原性,确定结合物的最适分子大小。方法制备不同活化度的Hib多糖,分别与载体蛋白CRM197以胺还原法制备不同分子大小(K_D)的Hib结合物;此外,利用凝...目的评价不同分子大小b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)结合物的免疫原性,确定结合物的最适分子大小。方法制备不同活化度的Hib多糖,分别与载体蛋白CRM197以胺还原法制备不同分子大小(K_D)的Hib结合物;此外,利用凝胶过滤层析分离Hib结合疫苗原液,收集K_D于0.05~0.25、0.25~0.45之间及大于0.45的结合物组分;分别免疫小鼠,采用间接ELISA法测定小鼠血清中抗Hib多糖IgG抗体滴度,以市售Hib疫苗作为对照。结果不同分子大小Hib结合物第2针及第3针免疫后,K_D0.35组与K_D0.01组诱导的抗体水平相当(P=0.166和0.882),显著高于K_D0.53组(P=0.008和0.031),也高于对照疫苗组;同样K_D0.25组第2针免疫后诱导的抗体滴度也显著高于K_D0.48组(P=0.037)。不同分子大小片段的Hib结合物组分第2针及第3针免疫后,K_D0.05~0.25组抗体水平最高,K_D0.25~0.45组次之,K_D>0.45组最低。结论较高分子大小Hib结合物的免疫原性优于较低分子大小的结合物,在制备Hib结合疫苗时,以分子大小K_D0.20~0.35为宜。展开更多
文摘目的:探讨经介入途径中药白芨提取物作为基因递送载体的可行性.方法:从中药白芨中提取其有效成分-白芨多糖,采用胺化还原法制备阳离子型白芨多糖,体外实验检测该阳离子型多糖对质粒DNA的结合与保护作用,以及阳离子白芨多糖载基因复合物对肝癌细胞系HepG2的转染,进一步通过介入途径经肝动脉给予该复合物,以GFP作为报告基因检测复合物在体内对活体兔肝细胞的转染.结果:所制备的阳离子型白芨多糖载基因复合物可以结合并保护质粒DNA免受DNA酶的降解;体外实验证实该复合物可以转染入体外培养肝癌细胞,以阳离子白芨多糖作为转染载体时转染效率要低于脂质体组,差异具有统计学意义(28.87%±3.27% vs 36.64%±6.87%,P<0.05).采用介入方法经肝动脉给药时复合物能靶向转染入活体兔肝细胞内并实现表达.结论:采用介入途径经肝动脉给药时阳离子白芨多糖载基因复合物可以实现活体肝细胞靶向转染,有望作为一种新型的多聚阳离子型的基因载体在基因治疗中发挥作用.
文摘The term ＂biogenic amines＂ defines decarboxylation products such as histamine, putrescine, serotonin, tyramine, phenylethylamine, tryptamine and also aliphatic polyamines. They can be detected in both raw and processed foods. In the recent years, there is a great interest in biogenic amines as they are associated with quality, safety and freshness of some foods, particularly fermented foods. The presence of biogenic amines in foods can also be used as an indicator of hygienic quality. Biogenic amines also cause health hazards due to their toxic effects especially in sensitive individuals. It is therefore important to control and reduce the biogenic amines. The reduction can be brought about by the use of high pressure, irradiation, packaging, additives, starter cultures and by reduction of decarboxylase activity and temperature. This review summarizes the significance, function, occurrence and formation of biogenic amines in different foods and their reduction by different methods.
文摘目的评价不同分子大小b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)结合物的免疫原性,确定结合物的最适分子大小。方法制备不同活化度的Hib多糖,分别与载体蛋白CRM197以胺还原法制备不同分子大小(K_D)的Hib结合物;此外,利用凝胶过滤层析分离Hib结合疫苗原液,收集K_D于0.05~0.25、0.25~0.45之间及大于0.45的结合物组分;分别免疫小鼠,采用间接ELISA法测定小鼠血清中抗Hib多糖IgG抗体滴度,以市售Hib疫苗作为对照。结果不同分子大小Hib结合物第2针及第3针免疫后,K_D0.35组与K_D0.01组诱导的抗体水平相当(P=0.166和0.882),显著高于K_D0.53组(P=0.008和0.031),也高于对照疫苗组;同样K_D0.25组第2针免疫后诱导的抗体滴度也显著高于K_D0.48组(P=0.037)。不同分子大小片段的Hib结合物组分第2针及第3针免疫后,K_D0.05~0.25组抗体水平最高,K_D0.25~0.45组次之,K_D>0.45组最低。结论较高分子大小Hib结合物的免疫原性优于较低分子大小的结合物,在制备Hib结合疫苗时,以分子大小K_D0.20~0.35为宜。
