Our previous studies revealed the polycyclic aromatic hydrocarbon and phthalic acid esters were the major organic pollutants in the Jialing River and Yangtze River in the Three Gorges area, and they might cause the to...Our previous studies revealed the polycyclic aromatic hydrocarbon and phthalic acid esters were the major organic pollutants in the Jialing River and Yangtze River in the Three Gorges area, and they might cause the toxicity in male fertility when combined. Thus we used di-n-butyl phthalate (DBP) and Benzo(a)pyrene (Bap) as their representatives respectively to explore their effects on the spermatogenesis in male rats. Male Sprague Dawley rats were randomly divided into 4 groups and respectively exposed to corn oil, Bap (5 mg/kg/d), DBP (250 mg/kg/d), and combined doses of Bap (5 mg/kg/d) and DBP (250 mg/kg/d) for 90 days. We observed a significant increase in the stillbirth rate after Bap and combined treatments, while the mean area of seminiferous tubules was reduced after Bap, DBP and combined treatments. Bap and combined treatment had a sup- pressing effect on meiosis in germ cells, which reduced the haploid contents and the ratio between haploid and diploid but increased the tetraploid and diploid contents and the ratio between hap- loid and tetraploid. These effects were more obvious in the combined group. Furthermore, the ex- pression of a number of proteins was changed, of which was associated with the oxidative stress and cAMP/PKA signaling pathway. Our results suggest that Bap has significant toxic effects on male fertility, while the combined treatment of Bap and DBP has more toxic effects.展开更多
The Three Gorges Reservoir （TGR）, formed by China＇s Yangtze Three Gorges Project, is the largest lake in the world, but there is too little information available about fecal contamination and waterborne pathogen im...The Three Gorges Reservoir （TGR）, formed by China＇s Yangtze Three Gorges Project, is the largest lake in the world, but there is too little information available about fecal contamination and waterborne pathogen impacts on this aquatic ecosystem. During two successive 1-year study periods （July 2009 to July 2011）, the water quality in Wanzhou watershed of the TGR was tested with regard to the presence of fecal indicators and pathogens. According to Chinese and World Health Organization water quality standards, water quality in the mainstream was good but poor in backwater areas. Salmonella, Enterohemorrhagic Escherichia coli （EHEC）, Giardia and Cryptosporidium were detected in the watershed. Prevalence and concentrations of the pathogens in the mainstream were lower than those in backwater areas. The estimated risk of infection with Salmonella, EHEC, Cryptosporidium, and Giardia per exposure event ranged from 2.9 × 10 -7 to 1.68 × 10-5 , 7.04 × 10-10 to 2.36 × 10-7 , 5.39 × 10-6 to 1.25 × 10-4 and 0 to 1.2 × 10-3 , respectively, for occupational divers and recreational swimmers exposed to the waters. The estimated risk of infection at exposure to the 95% upper confidence limit concentrations of Salmonella, Cryptosporidium and Giardia may be up to 2.62 × 10-5 , 2.55 × 10-4 and 2.86 × 10-3 , respectively. This study provides useful information for the residents, health care workers and managers to improve the safety of surface water and reduce the risk of fecal contamination in the TGR.展开更多
文摘Our previous studies revealed the polycyclic aromatic hydrocarbon and phthalic acid esters were the major organic pollutants in the Jialing River and Yangtze River in the Three Gorges area, and they might cause the toxicity in male fertility when combined. Thus we used di-n-butyl phthalate (DBP) and Benzo(a)pyrene (Bap) as their representatives respectively to explore their effects on the spermatogenesis in male rats. Male Sprague Dawley rats were randomly divided into 4 groups and respectively exposed to corn oil, Bap (5 mg/kg/d), DBP (250 mg/kg/d), and combined doses of Bap (5 mg/kg/d) and DBP (250 mg/kg/d) for 90 days. We observed a significant increase in the stillbirth rate after Bap and combined treatments, while the mean area of seminiferous tubules was reduced after Bap, DBP and combined treatments. Bap and combined treatment had a sup- pressing effect on meiosis in germ cells, which reduced the haploid contents and the ratio between haploid and diploid but increased the tetraploid and diploid contents and the ratio between hap- loid and tetraploid. These effects were more obvious in the combined group. Furthermore, the ex- pression of a number of proteins was changed, of which was associated with the oxidative stress and cAMP/PKA signaling pathway. Our results suggest that Bap has significant toxic effects on male fertility, while the combined treatment of Bap and DBP has more toxic effects.
基金supported by the Key Project of Chinese Ministry of Education (No. 211150)the Natural Science Foundation Project of CQ CSTC (No. cstc 2013 JCY-JA20011)+1 种基金the China Postdoctoral Science Foundation (No. 20110491855)the Science and Technology Projects of Chongqing Municipal Education Commission, China (No. KJ111115)
文摘The Three Gorges Reservoir （TGR）, formed by China＇s Yangtze Three Gorges Project, is the largest lake in the world, but there is too little information available about fecal contamination and waterborne pathogen impacts on this aquatic ecosystem. During two successive 1-year study periods （July 2009 to July 2011）, the water quality in Wanzhou watershed of the TGR was tested with regard to the presence of fecal indicators and pathogens. According to Chinese and World Health Organization water quality standards, water quality in the mainstream was good but poor in backwater areas. Salmonella, Enterohemorrhagic Escherichia coli （EHEC）, Giardia and Cryptosporidium were detected in the watershed. Prevalence and concentrations of the pathogens in the mainstream were lower than those in backwater areas. The estimated risk of infection with Salmonella, EHEC, Cryptosporidium, and Giardia per exposure event ranged from 2.9 × 10 -7 to 1.68 × 10-5 , 7.04 × 10-10 to 2.36 × 10-7 , 5.39 × 10-6 to 1.25 × 10-4 and 0 to 1.2 × 10-3 , respectively, for occupational divers and recreational swimmers exposed to the waters. The estimated risk of infection at exposure to the 95% upper confidence limit concentrations of Salmonella, Cryptosporidium and Giardia may be up to 2.62 × 10-5 , 2.55 × 10-4 and 2.86 × 10-3 , respectively. This study provides useful information for the residents, health care workers and managers to improve the safety of surface water and reduce the risk of fecal contamination in the TGR.
