苏州工业园区土壤与蔬菜中重金属污染调查研究

调查研究苏州市常见的12种蔬菜及土壤,并按照国家标准对蔬菜中重金属污染情况进行了评价。结果表明,苏州市工业园区的蔬菜重金属尚未受到相应土壤重金属污染元素的污染,只有少数蔬菜受到了Zn、Pb的污染。     

甘肃天祝白牦牛肉、奶及制品卫生学监测分析

目的：了解白牦牛肉、奶及制品中重金属、食源性致病菌的污染状况,为预防白牦牛食物链系统食源性疾病的发生提供依据。方法：按GB/T5009.11.12.15-2003及GB/T4789.4.5.6.10.30-2003对白牦牛肉、奶及制品中重金属、食源性致病菌进行检测。结果：白牦牛鲜肉及熟肉制品铅、砷、镉未超标;鲜奶及消毒奶铅、镉污染水平高;鲜肉及鲜奶沙门菌、金黄色葡萄球菌检出率高;肉制品及消毒奶沙门菌、金黄色葡萄球菌检出率明显降低。结论：天祝白牦牛肉、奶及制品存在着重金属及食源性致病菌的污染,应引起天祝白牦牛养殖加工行业的重视,预防食源性疾病的发生。     

Cellular transporters for zinc

Nutritionally essential metals such as zinc are moved into and out of cells by a series of transport proteins or transporters. Their tri-fold purpose is to procure zinc from the environment, to protect cells against zinc toxicity, and maintain ample supplies of zinc for metabolic purposes. Two families of zinc transporters are known: the ZIP family that imports zinc and the ZnT family that functions in releasing zinc or sequestering zinc internally.     

Observations on metal concentrations in tilapia (Oreochromis mossambicus) in reservoirs of south Sri Lanka

Samples of the muscle and liver of tilapia (Oreochromis mossambicus) obtained from the five reservoirs in four catchments in southern Sri Lanka in 1998 were analyzed for 16 elements: As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn by inductively coupled plasma emission spectrophotometry, and Hg by atomic absorption spectrophotometry. The concentrations of Cr, Ni, and Pb were below the detection limits of the instrumental techniques employed in all samples. The elements As, Ca, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Sr, and Zn were detected in the muscle and liver tissue, with Cd detected in some liver samples. There were no statistically significant differences between the individual concentrations of any of the metals and the site from which the tilapia were collected (P>0.05). Furthermore, no statistically significant correlations were found between total length of fish and metal concentration. No elements were found at concentrations of toxicological concern. However, a principal component analysis suggests that the populations of tilapia in the reservoirs may be exposed to different regimes of metals, possibly associated with different catchment land-use patterns.     

水蛭及其养殖基地农药与重金属残留分析

目的：通过对水蛭药材、养殖基地土壤、养殖用水的重金属与农药残留的比较研究,为水蛭的安全规范化生产提供依据和实践。方法:采用等离子发射光谱仪、原子荧光分光光度计和气相色谱仪对水蛭、基地土壤和养殖用水的重金属与农药残留进行了比较分析。结果与结论:除水蛭药材中铅超出国家现行有关标准外,水蛭药材,养殖基地土壤和养殖用水的六六六、DDT和重金属残留各项指标均符合国家标准规定。建议今后在制订国家有关标准时将类似水蛭类等动物的安全限量单独列出。     

报告基因方法监测重金属汞及其化合物的早期毒性

目的：基于热休克信号响应和分泌型碱性磷酸酶（SEAP）报告基因,建立HSE-SEAP-HeLa细胞模型,预测重金属（汞及其化合物）的早期毒性。方法：将pHSE-SEAP质粒转染到人子宫颈癌HeLa细胞中,建立瞬时HSE-SEAP响应模型。热休克（42 ℃,1 h）或重金属化合物（CdCl₂,5 μmol·L^-1,4 h）处理后,在完全DMEM培养基中恢复48 h后,检测细胞上清液中的分泌型碱性磷酸酶的含量（表示该状态下细胞中的热休克蛋白表达量）,同时用MTT方法检测对应浓度下的细胞活性,以验证模型的有效性和重复性。并用亚致死浓度（由MTT实验确定）的无机和矿物汞（HgCl₂,HgS和朱砂）和柳硫汞钠处理细胞,检测诱导的细胞热休克响应。结果：热休克和CdCl₂作用HSE-SEAP-HeLa细胞模型后,细胞上清液中的分泌型碱性磷酸酶的含量显著升高；热休克蛋白表达早于Cd²⁺对细胞活性的降低。4种汞化合物在亚致死浓度均诱导细胞内热休克蛋白的变化,但4种化合物的作用时间和浓度效应不同,显示不同类型的汞化合物早期毒性存在差异。结论：HSE-SEAP-HeLa细胞模型可有效检测重金属诱导的热休克应激作用,并具有良好的重复性,可应用于重金属有关的早期毒性预测或药物毒性评估。     

Effects of various metal ions on the gene expression of iron exporter ferroportin-1 in J774 macrophages

Macrophages play a key role in iron metabolism by recycling iron through erythrophagocytosis. Ferroportin-1 (FPN1) is a transporter protein that is known to mediate iron export from macrophages. Since divalent metals often interact with iron metabolism, we examined if divalent metals could regulate the expression of FPN1 in macrophages. J774 macrophage cells were treated with copper, manganese, zinc, or cobalt at 10, 50, or 100 µM for 16 to 24 h. Then, FPN1 mRNA and protein levels were determined by quantitative real-time PCR and Western blot analyses, respectively. In addition, effects of divalent metals on FPN1 promoter activity were examined by luciferase reporter assays. Results showed that copper significantly increased FPN1 mRNA levels in a dose-dependent manner. The copper-induced expression of FPN1 mRNA was associated with a corresponding increase in FPN1 protein levels. Also, copper directly stimulated the activity of FPN1 promoter-driven reporter construct. In contrast, manganese and zinc had no effect on the FPN1 gene expression in J774 cells. Interestingly, cobalt treatment in J774 cells decreased FPN1 protein levels without affecting FPN1 mRNA levels. In conclusion, our study results demonstrate that divalent metals differentially regulate FPN1 expression in macrophages and indicate a potential interaction of divalent metals with the FPN1-mediated iron export in macrophages.