Research progress on reproductive toxicity and reproductive system tumors induced by environmental endocrine disrupting chemicals / 环境与职业医学

Environmental endocrine disrupting chemicals are a kind of exogenous chemicals that generally exist in the environment, and can disturb the endocrine homeostasis and adversely affect reproductive, immune, neurological, and other functions after entering the body, among which the damage to the reproductive system is the most significant one. Studies have confirmed that the long-term exposure to environmental endocrine disrupting chemicals have irreversible and harmful effects on primordial germ cell growth, reproductive organ development, and reproductive endocrine regulation, and also have obvious correlations with the occurrence and development of various reproductive system tumors. This paper reviewed various reproductive toxicities induced by common environmental endocrine disrupting chemicals in the developmental and reproductive stages, and associated mechanisms involved in the occurrence and development of reproductive system tumors.

Metabonomics analysis of effects induced by PCBs and high fat diet combined expo-sure in SD rats / 军事医学

Objective To explore the effect on metabolism of glucose and lipids, potential toxicity mechanism and possible biomarker candidates by analyzing urine metabonome changes of rats after oral administration of polychlorinated biphenyl congeners( PCBs) and high fat diet alone or in combination.Methods Male SD rats were divided randomly into control group,high fat diet group, PCBs group and combination group of PCBs and high fat diet.Urine samples were collected after 6-week treatment, 1 H NMR spectra were performed and analyzed by principal component analysis ( PCA) . Results The PCA scores plot of urine 1 H NMR data showed that the combined group could be easily distinguished from the other three groups, suggesting great difference in metabolism.The loading plot of the PCA revealed significant increase in the levels of lactate, glucose, creatine, 2-hydroxy-isovaleric acid and reduction in the levels of citrate, succinate, taurine, hippurate and trimethylamine oxide ( TMAO) in the combined exposure group after six-week exposure.Conclusion The altered levels of metabolites induced by combined exposure of PCBs and high fat diet may be related to the injury to mitochondrial function, reduction of energy metabolism in tricarboxylic acid cycle (TAC).These effects possibly lead to perturbations in the metabolism of glucose, lipid and amino acids.The altered metabolites may be considered biomarker candidates of toxicity induced by exposure to PCBs and high fat diet.

Interaction of plant secondary metabolites and organic carbon substrates affected on biodegradation of polychlorinated biphenyl.

Using plant secondary metabolites (PSM) as an inducer to stimulate biodegradation of polychlorinated biphenyl (PCB) is considered a promising strategy to remove PCB from the environment. In this study, the effects of PSM including naringin, salicylic acid or biphenyl on PCB biodegradation using soil isolates were tested in mineral salt medium using either soil organic carbon (MSMS) or glucose (MSMG). In addition, the effects of surfactant hydroxypropyl-b-cyclodextrin (HP-b-CD) were examined. The results indicated that PCB removal was higher in medium with glucose as carbon substrate than in medium with SOC, and further enhanced with biphenyl amendment. However, interactions between salicylic acid and glucose limited PCB removal in treatments using both chemicals as carbon substrate while PCB removal was sustained in treatment using salicylic acid and SOC. Removal of tetra-chlorinated PCB was improved by adding HP-b-CD, suggesting increased bioavailability due to surfactant. These results suggest that interaction of organic carbon substrates could influence PCB degradation in contaminated environments.

Persistent Organic Pollutants and Obesity-Related Metabolic Dysfunction: Focusing on Type 2 Diabetes / 한국역학회지

Even though obesity is a well-established risk factor of type 2 diabetes, there is emerging evidence that persistent organic pollutants (POPs), a variety of lipophilic chemicals accumulated in adipose tissue, may be critically involved in the pathogenesis of type 2 diabetes. Among various POPs, serum concentrations of organochlorine pesticides and polychlorinated biphenyls (PCBs) were the most strongly and consistently linked to type 2 diabetes in both cross-sectional and prospective studies. In particular, obesity did not seem to be related to type 2 diabetes among persons with very low serum concentrations of POPs, suggesting a more fundamental role of chlorinated POPs in the pathogenesis of type 2 diabetes. These POPs were also associated with obesity, insulin resistance, and adverse lipid profiles like high triglyceride and low high-density lipoprotein (HDL) cholesterol among persons without diabetes, all metabolic dysfunctions commonly observed before developing type 2 diabetes. Recent animal studies supported the findings from epidemiological studies. If all these findings on POPs are true, it suggests that any effort to reduce the external and internal exposure to POPs would be necessary to decrease the social burden of type 2 diabetes.

Investigation on Levels of Polychlorinated Dibenzo-p-dioxins,Polychlorinated Dibenzo-p-furan and Polychlorinated Biphenyl in Milk in a City / 环境与健康杂志

Objective To know the levels of polychlorinated dibenzo-p-dioxins(PCDDs),polychlorinated dibenzo-p-furan (PCDFs)and polychlorinated biphenyl(PCBs)in milk and milk powder.Methods From Feb.2007 to Jun.2007,the milk and milk powder samples were collected and PCDDs,PCDFs and PCBs were extracted from the samples by Soxhlet extraction,cleaned up by FMS and quantified by HRGC-HRMS,using isotope dilution methodology.Results PCDDrFs and PCBs were detected in all samples.The mean levels of PCDD/Fs and dl-PCBs TEQ in the milk powder were 0.43 pg/g lipid(median:0.34 pg/g lipid),and in the packed milk were 3.83pg/g)lipid(median:2.04 pg/g lipid).The mean levels of PCDD/Fs and dl-PCBs TEQ in all samples were 2.13 pg/g lipid(median:0.815 pg/g lipid).The levels of PCDD/Fs and dioxin-like PCBs in the detected samples were far below the limitation of EU except of two milk samples,and the levels of PCDD/Fs and dioxin-like PCBs were higher in the packed milk than those in the milk powder.Conclusion Some of the milk and milk powder in the investigated city has been polluted by polychlorinated dibenzo-p-dioxins(PCDDs),polychlorinated dibenzo-p-furan(PCDFs)and polychlorinated biphenyl(PCBs).

Surveillance of polychlorinated biphenyl congeneric patterns in human breast milk from 1973 to 2000 in Osaka, Japan

<p><b>OBJECTIVE</b>Because the analysis of polychlorinated biphenyls (PCBs) in 1970's was performed using a packed column gas chromatograph, with an electron capture detector to determine total-PCB concentration, analytical data obtained by this analysis do not meet the requirement for the risk assessment of PCB congeners. In this context, the present study was carried out to reevaluate the congeneric analysis data by analyzing breast milk fat specimens that have been kept frozen.</p><p><b>METHODS</b>PCB congeners in human breast milk were analyzed by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) using a capillary column for the selected ion monitoring (SIM) of PCBs.</p><p><b>RESULTS</b>Twelve major PCB congeners were detected in breast milk. The concentrations of all congeners of PCBs in breast milk were found to decrease annually, and their changes over time differed greatly for each congener. Between 1973 and 2000, almost no changes in the proportions of the 12 congeners of heptachlorinated biphenyls (HpCBs) and hexachlorinated biphenyls (HxCBs) were found whereas a marked and a slight decrease in the proportion of pentachlorinated biphenyls (PeCBs) and tetrachlorinated biphenyls (TeCBs), respectively, were observed.</p><p><b>CONCLUSIONS</b>The PCB contamination of the Japanese population is estimated to be largely caused by seafood intake, but the proportions of PCB congeners in fish commodities were different from those in breast milk. The absorption, metabolism and therefore the accumulation of PCBs in the human body differ greatly depending on the congener.</p>

Surveillance of Polychlorinated Biphenyl Congeneric Patterns in Human Breast Milk from 1973 to 2000 in Osaka, Japan

Objective: Because the analysis of polychlorinated biphenyls (PCBs) in 1970’s was performed using a packed column gas chromatograph with an electron capture detector to determine total-PCB concentration, analytical data obtained by this analysis do not meet the requirement for the risk assessment of PCB congeners. In this context, the present study was carried out to reevaluate the congeneric analysis data by analyzing breast milk fat specimens that have been kept frozen. Methods: PCB congeners in human breast milk were analyzed by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) using a capillary column for the selected ion monitoring (SIM) of PCBs. Results: Twelve major PCB congeners were detected in breast milk. The concentrations of all congeners of PCBs in breast milk were found to decrease annually, and their changes over time differed greatly for each congener. Between 1973 and 2000, almost no changes in the proportions of the 12 congeners of heptachlorinated biphenyls (HpCBs) and hexachlorinated biphenyls (HxCBs) were found whereas a marked and a slight decrease in the proportion of pentachlorinated biphenyls (PeCBs) and tetrachlorinated biphenyls (TeCBs), respectively, were observed. Conclusions: The PCB contamination of the Japanese population is estimated to be largely caused by seafood intake, but the proportions of PCB congeners in fish commodities were different from those in breast milk. The absorption, metabolism and therefore the accumulation of PCBs in the human body differ greatly depending on the congener.