Ag^(+)/Cys介导的核酸探针级联荧光信号免疫检测法测定玉米和大米中黄曲霉毒素B_(1)

以葡萄糖氧化酶(GOx)催化Ag^(+)/Cys介导的富G-ssDNA/Tb^(3+)核酸探针体系引发荧光强度变化为方法学基础,开发了一种新型ELISA双重级联荧光信号放大系统,对葡萄糖氧化酶具有高的灵敏度响应(低至0.05μg/mLGOx)。将此体系与对GOx负载的纳米微球为信号探针的磁分离免疫体系相结合,建立了一种用于食品中AFB_(1)的高灵敏的双重级联信号放大的荧光免疫检测方法。该方法对AFB_(1)的检出限为0.05 ng/mL,在加标的玉米和大米样品中,添加回收实验结果表明,AFB_(1)的回收率在85.09%~105.2%之间,变异系数(CV)值为6.8%~15.7%。

Effects of Sterigmatocystin, Deoxynivalenol and Aflatoxin G_1 on Apoptosis of Human Peripheral Blood Lymphocytes in vitro

Objective To explore the effects of Sterigmatocystin (ST), Deoxynivalenol (DON) and Aflatoxin G1 (AFG1) on apoptosis of human peripheral blood lymphocytes (HPBLs) in vitro and thus to further elucidate the putative roles of these three mycotoxins on human immunosystem. Methods The effects of ST, DON and AFG1 on apoptosis of HPBLs were studied with cell culture, flow cytometric (FCM) DNA analysis and DNA agarose gel electrophoresis. Results DNA agarose gel electrophoresis results showed the characteristic 'ladder' pattern of apoptosis in HPBLs treated with ST, DON and AFG1. Flow cytometric DNA analysis revealed that typical subdiploid peaks of apoptosis in DNA histogram could be seen in all groups treated with the three mycotoxins. Significant time-effect and dose-effect relationships were found between the apoptosis rates and treatment time as well as concentrations of the three mycotoxins. Conclusion ST, DON and AFG1 can induce apoptosis of HPBLs in vitro and may have some negative effects on human immunosystem.

脱氧雪腐镰刀菌烯醇、黄曲霉毒素G_1对体外培养人外周血淋巴细胞凋亡影响的研究

以细胞培养、流式细胞仪ＤＮＡ含量分析及ＤＮＡ琼脂糖凝胶电泳方法研究了我国食管癌高发区磁县居民粮食中优势污染霉菌毒素脱氧雪腐镰刀菌烯醇（ＤＯＮ）和黄曲霉毒素Ｇ１（ＡＦＧ１）对人淋巴细胞凋亡的影响。流式细胞术（ＦＣＭ）检测结果显示，ＤＯＮ、ＡＦＧ１处理组淋巴细胞出现了典型的亚二倍体凋亡细胞峰，凋亡百分率与毒素作用时间（ＤＯＮ：２～７２小时；ＡＦＧ１：２～２４小时）及剂量（ＤＯＮ：５０～２０００μｇ／Ｌ；ＡＦＧ１：３．１２～２０００μｇ／Ｌ）呈正相关关系。ＤＮＡ琼脂糖凝胶电泳结果表明，ＤＯＮ（１０００μｇ／Ｌ）、ＡＦＧ１（１０００μｇ／Ｌ）处理２４小时淋巴细胞出现特征性的ＤＮＡ＂Ｌａｄｄｅｒ＂条带。因此表明，ＤＯＮ、ＡＦＧ１可诱导和促进体外培养的人外周血淋巴细胞发生凋亡。