Immunotoxicological consequences of perinatal chemical exposures

The developing immune system may be especially vulnerable to the toxic effects of immunotoxicants. A number of chemicals has been identified that affect the developing immune system. Yet, so far there are no immune parameters included in current guidelines for developmental or reproductive toxicity testing. It is recommended that such guidelines are updated so that also the developing immune system is evaluated as a potential target of toxicity during developmental stages.     

Surface plasmon resonance (BIACORE) detection of serum antibodies against Salmonella enteritidis and Salmonella typhimurium

We have used a surface plasmon resonance biosensor (BIACORE 3000) to detect serum antibodies in chickens having current or recent infections. Three well-defined Salmonella flagellar recombinant DNA antigens reflecting Salmonella enteritidis (H:g,m flagellin) and Salmonella typhimurium (H:i and H:1,2 flagellins) expressed in Escherichia coli were each immobilized in a single flow cell of a biosensor chip. Glutathione-S-transferase was immobilized on the surface of another flow cell to monitor non-specific binding. Sera collected from chickens with no history of Salmonella infection, and from chickens infected with Salmonella serotypes infantis, pullorum, gallinarum were used to test the performance of the system. The sensitivity exhibited to a range up to 900 arbitrary response units (RU) for the most positive S. typhimurium serum at a dilution of 1/40. Sera from Salmonella infantis, Salmonella pullorum and Salmonella gallinarum infected birds gave responses less than the cut-off point, which was determined as the averaged response of sera from specific pathogen-free chickens plus three times the standard deviation. A positive response was obtained when these sera and whole blood were fortified with S. enteritidis and S. typhimurium positive serum. The sensitivity, specificity, precision and reproducibility obtained suggested that this approach could be used for detecting past or present infection with a range of pathogens in animals.     

新疆家犬体内存在细粒棘球绦虫G1(羊)株和G6(骆驼)株的分子证据

目的收集家犬体内的细粒棘球绦虫成虫以建立新疆棘球蚴病的分子流行病学资料. 方法对家犬体内成虫细胞色素c氧化酶Ⅰ基因序列进行测定以确定其亚株型. 结果所有感染犬体内成虫的基因型为G1型.特别是1条家犬体内发现存在细粒棘球绦虫G1(羊)株和G6(骆驼)株混合感染的情况. 结论在新疆阻断羊犬和羊骆驼循环圈是预防棘球蚴病的重要措施.作为终末宿主的家犬与人类的感染密切相关,对感染犬的管理应该加强.     

Subacute effects of hexabromocyclododecane (HBCD) on hepatic gene expression profiles in rats

Hexabromoyclododecane (HBCD), used as flame retardant (FR) mainly in textile industry and in polystyrene foam manufacture, has been identified as a contaminant at levels comparable to other brominated FRs (BFRs). HBCD levels in biota are increasing slowly and seem to reflect the local market demand. The toxicological database of HBCD is too limited to perform at present a solid risk assessment, combining data from exposure and effect studies. In order to fill in some gaps, a 28-day HBCD repeated dose study (OECD407) was done in Wistar rats. In the present work liver tissues from these animals were used for gene expression profile analysis. Results show clear gender specificity with females having a higher number of regulated genes and therefore being more sensitive to HBCD than males. Several specific pathways were found to be affected by HBCD exposure, like PPAR-mediated regulation of lipid metabolism, triacylglycerol metabolism, cholesterol biosynthesis, and phase I and II pathways. These results were corroborated with quantitative RT-PCR analysis. Cholesterol biosynthesis and lipid metabolism were especially down-regulated in females. Genes involved in phase I and II metabolism were up-regulated predominantly in males, which could explain the observed lower HBCD hepatic disposition in male rats in this 28-day study. These sex-specific differences in gene expression profiles could also underlie sex-specific differences in toxicity (e.g. decreased thyroid hormone or increased serum cholesterol levels). To our knowledge, this is the fist study that describes the changes in rat hepatic gene profiles caused by this commonly used flame retardant.