碘帕醇注射液重金属检查方法的改进

目的:改进碘帕醇注射液的重金属检查方法方法:将碘帕醇注射液水浴蒸干后,采用《中国药典》2010年版部附录VIII H重金属检查第二法检查.结果:碘帕醇注射液的原辅料均不干扰重金属的检查,6批样品含重金属均低于百万分之二十,符合国家标准的规定结论:本法无干扰,适用于碘帕醇注射液的重金属检查.     

Bioaccumulation and biochemical markers in feral crab (Carcinus maenas) exposed to moderate environmental contamination—The impact of non‐contamination‐related variables

Moderate contamination is a challenging scenario for ecotoxicologists because of the occurrence of subtle biomarker responses and the increased relevance of non‐contamination related variables. This investigative biomonitoring study was performed in a moderately contaminated coastal system (Óbidos lagoon, Portugal) to examine winter–summer variations on biochemical responses and accumulated metals in Carcinus maenas, searching for associations with environmental and biological factors. Males and females were collected in three sites: Barrosa (BB) and Bom‐Sucesso (BS) in upper lagoon, and the middle lagoon (ML), closer to the lagoon inlet. Water and sediment were monitored for metals (Cu, Mn, Ni, Cr, Cd). Catalase (CAT), glutathione peroxidase (GPx), glutathione S‐transferase (GST), total glutathione content (GSH_t), lipid peroxidation (LPO), and ethoxyresorufin‐O‐deethylase (EROD), as well as Cu, Mn, Ni, Cr and Cd were measured in the crabs' hepatopancreas. Inter‐site differences, though infrequent, pointed to the presence of crab stressors at BB. This was particularly obvious in summer when higher GST as well as lower GSH_t and EROD were found in females, and accompanied by higher Ni accumulation. Seasonal differences of biochemical responses superimposed spatial variations in line with the contrasting winter–summer conditions regarding water quality and, to a lesser extent, with metal bioaccumulation. CAT, GSH_t, and LPO were higher in summer, whereas enhancements of GPx and GST were recorded in winter. Winter increases were in agreement with higher availability of metals in water and enhancement of accumulated levels, particularly in females as emphasized by a bioaccumulation index. On the other hand, increases in summer were mainly driven by non‐contamination related factors. Males and females exhibited different patterns of metal accumulation and biochemical responses, with females being more responsive, as confirmed by a general stress index (IBR). Results recommend gender separation in biomonitoring programs using crabs. The integration of biochemical responses into IBR substantiated data interpretation. This is particularly relevant under moderate contamination allowing for better site‐distinction rather than biochemical responses considered individually. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.     

药食同源品中重金属的检测方法与思考

2002年卫生部发布"既是食品又是药品的物品名单",即规定87种药食同源品可以作为我国保健食品的原料。这些药食同源品的功效成分已有大量研究,但有关其中的重金属检测研究相对较少。而食品安全和保健食品的质量控制是当前国内外关注和需要迫切解决的问题。总结了重金属的多种检测方法,同时就已报道的药食同源品中汞、砷、铅和镉的检测数据进行统计,分析目前的检测现状及存在的问题,为药食同源品作为保健食品的原料选用和质量控制及安全使用提供依据。     

Dietary zinc, copper and selenium, and risk of lung cancer

Zinc, copper and selenium are important cofactors for several enzymes that play a role in maintaining DNA integrity. However, limited epidemiologic research on these dietary trace metals and lung cancer risk is available. In an ongoing study of 1,676 incident lung cancer cases and 1,676 matched healthy controls, we studied the associations between dietary zinc, copper and selenium and lung cancer risk. Using multiple logistic regression analysis, the odds ratios (OR) and 95% confidence intervals (CI) of lung cancer for all subjects by increasing quartiles of dietary zinc intake were 1.0, 0.80 (0.65-0.99), 0.64 (0.51-0.81), 0.57 (0.42-0.75), respectively (p trend = 0.0004); similar results were found for men. For dietary copper, the ORs and 95% CI for all subjects were 1.0, 0.59 (0.49-0.73), 0.51 (0.41-0.64), 0.34 (0.26-0.45), respectively (p trend < 0.0001); similar reductions in risk and trend were observed by gender. Dietary selenium intake was not associated with risk, except for a significant inverse trend (p = 0.04) in men. Protective trends (p < 0.05) against lung cancer with increased dietary zinc intake were also found for all ages, BMI > 25, current smokers, pack-years < or =30, light drinkers and participants without emphysema. Increased dietary copper intake was associated with protective trends (p < 0.05) across all ages, BMI, smoking and vitamin/mineral supplement categories, pack-years < or =30 and 30.1-51.75 and participants without emphysema. Our results suggest that dietary zinc and copper intakes are associated with reduced risk of lung cancer. Given the known limitations of case-control studies, these findings must be interpreted with caution and warrant further investigation.     

Increased uptake of divalent metals lead and cadmium into the brain after kainite-induced neuronal injury

An increase in iron level, number of iron positive cells and ferritin expression has been observed in the rat hippocampus after neuronal injury induced by the excitotoxin, kainate. This is accompanied by an increased expression of divalent metal transporter-1 (DMT1) in the lesioned hippocampus, suggesting that the transporter may be partially responsible for the iron accumulation. DMT1 has a broad substrate range that includes other divalent metals such as lead (Pb) and cadmium (Cd), and the present study was carried out to elucidate the uptake of these metals in the kainate-injected brain. The technique of atomic absorption spectroscopy was used for analyses. Significantly higher lead and cadmium levels were detected in the hippocampus and other brain areas of intracerebroventricular kainate-injected rats treated with lead and cadmium in the drinking water, compared to intracerebroventricular saline-injected rats treated with lead and cadmium in the drinking water. Since very low levels of lead and cadmium are present in the normal animal, these results indicate increased uptake of lead and cadmium into brain areas as a result of the kainate injections. Increased iron levels were also detected in the hippocampus of the kainate-injected rats. The above results show increased uptake of divalent metals into brain areas undergoing neurodegeneration.     

Characterization of metal-resistant plant-growth promoting Bacillus weihenstephanensis isolated from serpentine soil in Portugal

A metal-resistant bacterial strain SM3 isolated from a serpentine soil in the north-east of Portugal was characterized as Bacillus weihenstephanensis based on the morphological and biochemical characteristics and on the comparative analysis of the partial 16S ribosomal DNA sequence. Bacillus weihenstephanensis SM3 showed a high degree of resistance to nickel (1500 mg l(-1)), copper (500 mg l(-1)) and zinc (700 mg l(-1)) and also to antibiotics (ampicillin, penicillin, kanamycin and streptomycin). Strain SM3 has also exhibited the capability of solubilizing phosphate and producing indole-3-acetic acid (IAA) both in the absence and in the presence of metals (Ni, Cu and Zn). A pot experiment was conducted to elucidate the effects of strain SM3 on plant growth and uptake of Ni, Cu or Zn by Helianthus annuus. Inoculation with strain SM3 increased the shoot and root biomass of H. annuus grown in both non-contaminated and contaminated soil. Furthermore, strain SM3 increased the accumulation of Cu and Zn in the root and shoot systems. A batch experiment was also conducted to assess the metal mobilization potential of strain SM3 in soil. Inoculation with this strain increased the concentrations of water soluble Ni, Cu and Zn in soil. Metal solubilization by this bacterial strain may be an important process to promote the uptake of heavy metals by plants. This study elucidates the multifarious role of strain SM3 in plant growth promotion and its metal mobilizing potential.     

Cellular iron status influences the functional relationship between microglia and oligodendrocytes

Previously, we have reported that there is a spatiotemporal relationship between iron accumulation in microglia and oligodendrocytes during normal development and in remyelination following injury. This in vivo observation has prompted us to develop a cell culture model to test the relationship between iron status of microglia and survival of oligodendrocytes. We found that conditioned media from iron-loaded microglia increases the survival of oligodendrocytes; but conditioned media from iron loaded activated microglia is toxic to oligodendrocytes. In the trophic condition, one of the proteins released by iron-loaded microglia is H-ferritin, and transfecting the microglia with siRNA for H-ferritin blocks the trophic response on oligodendrocytes. Lipopolysaccharide (LPS) activation decreases the amount of H-ferritin that is released from microglia and increases the release of the proinflammatory cytokines tumor necrosis factor-alpha and interleukin-1. LPS activation of iron-enriched microglia results in the activation of NF-kB and greater release of cytokines when compared with that of control microglia; whereas treating microglia with an iron chelator is associated with less NF-kB activation and less release of cytokines. These results indicate that microglia play an important role in iron homoeostasis and that their iron status can influence how microglia influence growth and survival of oligodendrocytes. The results further indicate that ferritin, released by microglia, is a significant source of iron for oligodendrocytes.     

Testing of different plants to determine influence of physico–chemical properties and contaminants content on municipal sewage sludges phytotoxicity

This study attempts to evaluate the Phytotoxkit? as a tool for measuring the toxicity of municipal sewage sludges using 10 common plants: mustard, turnip, cress, red clover, cucumber, tomato, radish, sorrel, and spinach. The results were used to determine a germination index (GI) and a median effective concentration (EC) value for each plant. The trace metal and polycyclic aromatic hydrocarbon (PAH) contaminant content and the physical–chemical properties were examined. Most sewage sludges were characterized by an unfavorable electrical conductivity value of about 5.2 mS/cm^?1. The most abundant trace metals were zinc (Zn) at 871–1680 mg kg^?1, manganese (Mn) at 245–661 mg kg^?1, and copper (Cu) at 88.2–161.0 mg kg^?1. The lowest values were determined for cobalt (Co) at 2.9–3.8 mg kg^?1 and cadmium (Cd) at 0.7–3.7 mg kg^?1. The PAH sum was based on 10 individual compounds (USE EPA), and the PAH content ranged from 4.76 to 27.95 mg kg^?1, most of the sewage sludges showing a predomination by carcinogenic PAHs. The GI values, based on seed germination and root growth inhibition bioassays, showed increasing plant sensitivity to the tested sewage sludges in the following order: cress > turnip > mustard > sorrel > tomato > sorgo > red clover > radish > cucumber > spinach. The EC50 sewage sludge values lay in the range 31–404 g/kg of soil, and significant relationships were found for most of the plants between EC50 and the magnesium content (Mg²⁺: α = 0.888–0.924, P = 0.05), calcium content (Ca²⁺: α = 0.813–0.911, P ≤ 0.05), and pH (α = ?0.913–0.948, P = 0.05). In the case of sewage sludge pollutants, significant relationships were found for trace metals such as: strontium (Sr: α = 0.851–0.948, P ≤ 0.05), chromium (Cr: α = 0.858, P ≤ 0.05), and nickel (Ni: α = 0.955, P = 0.05), as well as pyrene (PAHs). © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.     

Risk assessment of pesticides and heavy metals contaminants in vegetables: A novel bioassay method using Daphnia magna Straus

Cucumber and potato samples of known levels of pesticides and heavy metal residues, as respectively measured by gas chromatography and atomic absorption, were subjected to a bioassay method using Daphnia magna in order to assess the potential of the toxic hazard of their contaminants. Based on the estimated lethal time for 50% mortality (LT50) in daphnids, we suggested a classification to categorize toxic hazards in six definite ratings. Either samples of cucumbers (from conventional, greenhouse and organic farming) or potatoes (from conventional and organic farming) were evaluated for toxic hazard of the mixtures of pesticide residues and heavy metals, as well as mixtures of both. Accordingly, a 53.7% of cucumber samples were ranked as “Highly Toxic: HT”; a 18.5% “Moderately Toxic: MT); a 9.3% “Slightly Toxic: ST”; and a 18.5% “Practically Non-Toxic: NT”. For potato samples, the ranking pattern to different classes was: Extremely Toxic: ET (LT50 = <1 h) for 11.1%; Very Toxic: VT (LT50 = 1–<3 h) for 50.0%; HT (LT50 = 3–<12 h) for 13.9%; MT (LT50 = 12–<24 h) for 11.1%; ST (LT50 = 24–48 h) for 0.0%; and NT (LT50 = > 48 h) for 13.9% of the samples bioassayed.