甲醛对暴露工人外周血淋巴细胞的遗传损伤作用

目的评价甲醛对暴露工人外周血淋巴细胞染色体和DNA损伤水平。方法选择65名甲醛暴露工人和非甲醛暴露工人70名为研究对象，采用甲基纤维素法和单细胞凝胶电泳法，分析其外周血淋巴细胞微核发生率和DNA断裂损伤。结果暴露组工人外周血淋巴细胞微核发生率、DNA断裂损伤的细胞数，与对照组比较，差异有统计学意义（P〈0．05），并有随工龄、暴露浓度增加而增高的趋势。但甲醛浓度为0．5mg／m^3～3．11mg／m^3时，DNA断裂损伤细胞与对照组比较，差异无统计学意义（P〉0．05）。结论甲醛暴露可导致工人外周血淋巴细胞染色体和DNA断裂损伤明显增高，DNA断裂可望成为暴露人群的早期效应标志物和致癌机制之一。     

The Salmonella Mutagenicity Assay: The Stethoscope of Genetic Toxicology for the 21st Century

Objectives

According to the 2007 National Research Council report Toxicology for the Twenty-First Century, modern methods (e.g., “omics,” in vitro assays, high-throughput testing, computational methods) will lead to the emergence of a new approach to toxicology. The Salmonella mammalian microsome mutagenicity assay has been central to the field of genetic toxicology since the 1970s. Here we document the paradigm shifts engendered by the assay, the validation and applications of the assay, and how the assay is a model for future in vitro toxicology assays.

Data sources

We searched PubMed, Scopus, and Web of Knowledge using key words relevant to the Salmonella assay and additional genotoxicity assays.

Data extraction

We merged the citations, removing duplicates, and categorized the papers by year and topic.

Data synthesis

The Salmonella assay led to two paradigm shifts: that some carcinogens were mutagens and that some environmental samples (e.g., air, water, soil, food, combustion emissions) were mutagenic. Although there are > 10,000 publications on the Salmonella assay, covering tens of thousands of agents, data on even more agents probably exist in unpublished form, largely as proprietary studies by industry. The Salmonella assay is a model for the development of 21st century in vitro toxicology assays in terms of the establishment of standard procedures, ability to test various agents, transferability across laboratories, validation and testing, and structure–activity analysis.

Conclusions

Similar to a stethoscope as a first-line, inexpensive tool in medicine, the Salmonella assay can serve a similar, indispensable role in the foreseeable future of 21st century toxicology.     

含铬鱼肉质遗传毒理学检测与评价

目的探讨含铬鱼可食性及铬的毒理学特性。方法以氯化铬0.5mg/Cr/kg饵料喂饲鲤鱼2个月,以全鱼为受试物,不同剂量给小鼠一次灌胃,观察2周。结果急性毒性实验证明该样品为无毒物质。遗传毒理学检测,小鼠骨髓嗜多染微核试验阴性;小鼠睾丸染色体畸变分析未见染色体损伤;小鼠伤寒沙门氏菌/微粒体试验(Ames)在不加与加S9代谢活化系统的条件下,对Ames试验菌株均呈阴性结果。结论铬对鱼无致突变作用,从遗传毒理学角度认为食用是安全的。     

Diet/Genetic Interactions and Their Effects on Inflammatory Markers

The importance of a healthy diet to living well is well recognized. A growing array of experimental, epide-miological, and clinical studies have revealed an association between pro-inflammatory responses and the progression of numerous serious disease states, including the metabolic syndrome, type 2 diabetes, and cardiovascular diseases. Further studies have established a "diet/genetic interaction" that further modulates markers of inflammation, producing both positive and negative effects, depending on the net changes in gene expression. Yet, there are few studies that reveal the mechanisms underlying this modulation of the inflammatory response. Highlighted here are several such recent and ongoing studies that investigate the mechanisms underlying the effects of diet/genetic interactions on inflammatory biomarkers, followed by a discussion of to what extent these interactions may translate into healthier aging and increased longevity. Whether these interactions translate into healthier aging and increased longevity remains to be determined; however, the prospects are enticing.     

Ozone Toxicology

Rats, rabbits, and monkeys were exposed to mercury vapor (1 mg/cu m) for four hours, and uptake and distribution of mercury in the brain was compared with that of animals injected intravenously with the same dose of mercury as mercuric salts. Vapor-exposed animals showed a brain content about ten times higher than the injected animals. The results indicate that the higher uptake in brain following vapor exposure is a general phenomenon in mammals.