Objective To investigate the effects of fluoride on lipid peroxidation, DNA damage and apoptosis in human embryo hepatocyte L-02 cells. Methods Lipid peroxide (LPO) level, reduced glutathione (GSH) content, DNA damage...Objective To investigate the effects of fluoride on lipid peroxidation, DNA damage and apoptosis in human embryo hepatocyte L-02 cells. Methods Lipid peroxide (LPO) level, reduced glutathione (GSH) content, DNA damage, apoptosis, and cell cycle analysis were measured after in vitro cultured L-02 cells were exposed to sodium fluoride at different doses (40 μg/mL, 80 μg/mL, and 160 μg/mL) for 24 hours. Results Fluoride caused an increase of LPO levels and a decrease of GSH content in L-02 cells. There appeared to be an obvious dose-effect relationship between the fluoride concentration and the observed changes. Fluoride also caused DNA damage and apoptosis and increased the cell number in S phase of cell cycle in the cells tested. There was a statistically significant difference in DNA damage and apoptosis when comparing the high dose of fluoride treated cells with the low dose of fluoride treated cells. Conclusion Fluoride can cause lipid peroxidation, DNA damage, and apoptosis in the L-02 cell experimental model and there is a significant positive correlation between fluoride concentration and these pathological changes.展开更多
Objective To design and develop a novel, sensitive and versatile method for in vivo foot printing and studies of DNA damage, such as DNA adducts and strand breaks. Methods Starting with mammalian genomic DNA, singl...Objective To design and develop a novel, sensitive and versatile method for in vivo foot printing and studies of DNA damage, such as DNA adducts and strand breaks. Methods Starting with mammalian genomic DNA, single-stranded products were made by repeated primer extension, these products were ligated to a double-stranded linker having a randomized 3 overhang, and used for PCR. DNA breaks in p53 gene produced by restriction endonuclease AfaI were detected by using this new method followed by Southern hybridization with DIG-labeled probe. Results This randomized terminal linker-dependent PCR (RDPCR) method could generate band signals many-fold stronger than conventional ligation-mediated PCR (LMPCR), and it was more rapid, convenient and accurate than the terminal transferase-dependent PCR (TDPCR). Conclusion DNA strand breakage can be detected sensitively in the gene level by RDPCR. Any lesion that blocks primer extension should be detectable.展开更多
To investigate the association between temperature and daily mortality in Shanghai from June 1, 2000 to December 31, 2001. Methods Time-series approach was used to estimate the effect of temperature on daily tota...To investigate the association between temperature and daily mortality in Shanghai from June 1, 2000 to December 31, 2001. Methods Time-series approach was used to estimate the effect of temperature on daily total and cause-specific mortality. We fitted generalized additive Poisson regression using non-parametric smooth functions to control for long-term time trend, season and other variables. We also controlled for day of the week. Results A gently sloping V-like relationship between total mortality and temperature was found, with an optimum temperature (e.g. temperature with lowest mortality risk) value of 26.7癈 in Shanghai. For temperatures above the optimum value, total mortality increased by 0.73% for each degree Celsius increase; while for temperature below the optimum value, total mortality decreased by 1.21% for each degree Celsius increase. Conclusions Our findings indicate that temperature has an effect on daily mortality in Shanghai, and the time-series approach is a useful tool for studying the temperature-mortality association.展开更多
Objective To determine the best statistical distribution of concentration data of major air pollutants in Shanghai. Methods Four types of theoretic distributions (lognormal, gamma, Pearson V and extreme value) were...Objective To determine the best statistical distribution of concentration data of major air pollutants in Shanghai. Methods Four types of theoretic distributions (lognormal, gamma, Pearson V and extreme value) were chosen to fit daily average concentration data of PM10, SO2 and NO2 from June 1, 2000 to May 31, 2003 in Shanghai by using the maximum likelihood method. The fit results were evaluated by Chi-square test. Results The best-fit distributions for PM10,SO2 and NO2 concentrations in Shanghai were lognormal, Pearson V, and extreme value distributions, respectively. Conclusion The results can be further applied to local air pollution prediction and control, e.g., the probabilities exceeding the air quality standard and emission source reduction of air pollutant concentration to meet the standard.展开更多
Objective To obtain the exposure-response functions that could be used in health-based risk assessment of particulate air pollution in China. Methods Meta analysis was conducted on the literatures on air particulate m...Objective To obtain the exposure-response functions that could be used in health-based risk assessment of particulate air pollution in China. Methods Meta analysis was conducted on the literatures on air particulate matter and its adverse health outcomes in China and worldwide. Results For each health outcome from morbidity to mortality changes, the relative risks were estimated when the concentration of air particulate matter increased to some certain units. Conclusion The exposure-response functions recommended here can be further applied to health risk assessment of air particulate matter in China.展开更多
To study the relationship between ambient air pollution and daily mortality of SARS in Beijing. Methods The approach of time-series Poisson regression was used to assess the relationship between daily SARS mort...To study the relationship between ambient air pollution and daily mortality of SARS in Beijing. Methods The approach of time-series Poisson regression was used to assess the relationship between daily SARS mortality, ambient air pollution, and other factors from April 25 to May 31, 2003 in Beijing. Results An increase of each 10 μg/m3 over a 5-day moving average of PM10, SO2 and NO2 corresponded to 1.06 (1.00-1.12), 0.74 (0.48-1.13) and 1.22 (1.01-1.48) relative risks (RRs) of daily SARS mortality, respectively. The relative risks (RRs) values depended largely on the selection of lag days. Conclusion The daily mortality of SARS might be associated with certain air pollutants in Beijing.展开更多
The present article reports the genotoxic potential of rapeseed oil cooking fume investigated by a battery of short-term tests (Ames test, SCE/V79 in vitro and mice micronucleus in vivo test). The results showed that ...The present article reports the genotoxic potential of rapeseed oil cooking fume investigated by a battery of short-term tests (Ames test, SCE/V79 in vitro and mice micronucleus in vivo test). The results showed that the cooking fume contained mutagenic activity. In the presence of S9 mix, an increase in the number of the Salmonella TA98 was observed at doses ranging from 1.0 to 5.0 mg/plate, and the SCE frequencies of V79 cell were markedly raised at doses ranging from 0.05 to 0.5 mg.ml-1. The positive result was also obtained in mice micronucleus assay, the mice had inhaled the cooking fume a week earlier. The frequency of mice bone marrow MN-PCE was increased and it showed a remarkable time-dose-response relationship during the 4 weeks exposure. The results suggested that this cooking fume exposure may be a risk factor of lung cancer in Chinese women.展开更多
Primary rat hepatocytes were cultured using different in vitro models and the enzym e leakage,albumin secretion,and cytochrome P4 5 0 1A(CYP1A) activity were observed.The re- sults showed that the level of L DH was ...Primary rat hepatocytes were cultured using different in vitro models and the enzym e leakage,albumin secretion,and cytochrome P4 5 0 1A(CYP1A) activity were observed.The re- sults showed that the level of L DH was decreased over time in culture.However,on day5 ,L DH showed a significant increase in monolayer culture (MC) while after day 8no L DH was detectable in sandwich culture (SC) . The levels of AST and AL T did not change significantly over the inves- tigated time. The CYP 1A activity was gradually decreased in a time- dependent manner in MC and SC.The decline of CYP1A was faster in MC than in SC.This effectwas partially reversed by us- ing cytochrom e P4 5 0 (CYP4 5 0 ) inducer such as Omeprazol and3- m ethylcholanthrene(3- MC) and the CYP1A induction was always higher in MC than in SC.In bioreactor basic CYP1A activity was preserved over2 weeks and the highest album in production was observed in bioreactor fol- lowed by SC and MC. Taken together,it was indicated each investigated model had its advantages and disadvantages. It was also underlined thatvarious in vitro models may address different ques- tions.展开更多
Microcystis aeruginosa is the dominant algae in most of the eutrophicated lakes in China. It can produce cyclic heptapeptides, known as microcystins, which can cause liver damage in wild and domestic animals. In this ...Microcystis aeruginosa is the dominant algae in most of the eutrophicated lakes in China. It can produce cyclic heptapeptides, known as microcystins, which can cause liver damage in wild and domestic animals. In this paper, a two-stage transformation assay for demonstrating the carcinogenic effects of the algal toxins is reported. The cell strain used in this assay was derived from embryos of Syrian golden hamster and the algal toxins were extracted from Microcystis aeruginosa, termed microcystis raw toxin (MRT). To elucidate its promoting activity, the target cells were first exposed to a low dosage of 3-mcthylcholanthrene (MCA) and then to MRT. The results showed that MRT significantly enhanced the MCA-initiated cell transformation, and a dose-response relatinnship was observed, but it failed to induce transformation of SHE cells not pretreated by MCA. These results suggest that the MRT play an important role in the malignant transformation of SHE cells. MRT may thus be a tumor promoter, and this transformation assay with SHE cells may be used to predict tumor prompting activity of environmental chemicals, before long-term in vivo two-stage carcinogenesis experiments are carried out.展开更多
The mutagenicity of diesel exhaust particles (DEP) was studied by using Salmonella typhimurium strains TA98 and TA100o in vitro and mice micronucleus in vivo test. DEP from six kinds of medium and heavy-duty diesel ve...The mutagenicity of diesel exhaust particles (DEP) was studied by using Salmonella typhimurium strains TA98 and TA100o in vitro and mice micronucleus in vivo test. DEP from six kinds of medium and heavy-duty diesel vehicles, which were made in China and imported, were tested. The vehicles were operated under free accelerating condition. The results showed that the DEP contained mutagenic activity. An increase in the number of the Salmonella TA98 was observed in the presence and especially in the absence of S9 mix. Positive results were also obtained from mice micronucleus assay. The frequency of mice bone marrow micronucleated polychromatic erythrocytes (M PCE) was increased and it showed a definite dose-response relationship. Comparing the different types of the vehicles,we found that the mutagenicity of DEP from domestic made vehicles was stronger than that from the imported ones展开更多
基金The work was supported by grants from the National Nature Science Foundation of China (No. 30271155) China national key basic research and development program (No. 2022CB512908).
文摘Objective To investigate the effects of fluoride on lipid peroxidation, DNA damage and apoptosis in human embryo hepatocyte L-02 cells. Methods Lipid peroxide (LPO) level, reduced glutathione (GSH) content, DNA damage, apoptosis, and cell cycle analysis were measured after in vitro cultured L-02 cells were exposed to sodium fluoride at different doses (40 μg/mL, 80 μg/mL, and 160 μg/mL) for 24 hours. Results Fluoride caused an increase of LPO levels and a decrease of GSH content in L-02 cells. There appeared to be an obvious dose-effect relationship between the fluoride concentration and the observed changes. Fluoride also caused DNA damage and apoptosis and increased the cell number in S phase of cell cycle in the cells tested. There was a statistically significant difference in DNA damage and apoptosis when comparing the high dose of fluoride treated cells with the low dose of fluoride treated cells. Conclusion Fluoride can cause lipid peroxidation, DNA damage, and apoptosis in the L-02 cell experimental model and there is a significant positive correlation between fluoride concentration and these pathological changes.
基金This work was supported by the National Natural Science Foundation of China (Grant No.30070648).
文摘Objective To design and develop a novel, sensitive and versatile method for in vivo foot printing and studies of DNA damage, such as DNA adducts and strand breaks. Methods Starting with mammalian genomic DNA, single-stranded products were made by repeated primer extension, these products were ligated to a double-stranded linker having a randomized 3 overhang, and used for PCR. DNA breaks in p53 gene produced by restriction endonuclease AfaI were detected by using this new method followed by Southern hybridization with DIG-labeled probe. Results This randomized terminal linker-dependent PCR (RDPCR) method could generate band signals many-fold stronger than conventional ligation-mediated PCR (LMPCR), and it was more rapid, convenient and accurate than the terminal transferase-dependent PCR (TDPCR). Conclusion DNA strand breakage can be detected sensitively in the gene level by RDPCR. Any lesion that blocks primer extension should be detectable.
文摘To investigate the association between temperature and daily mortality in Shanghai from June 1, 2000 to December 31, 2001. Methods Time-series approach was used to estimate the effect of temperature on daily total and cause-specific mortality. We fitted generalized additive Poisson regression using non-parametric smooth functions to control for long-term time trend, season and other variables. We also controlled for day of the week. Results A gently sloping V-like relationship between total mortality and temperature was found, with an optimum temperature (e.g. temperature with lowest mortality risk) value of 26.7癈 in Shanghai. For temperatures above the optimum value, total mortality increased by 0.73% for each degree Celsius increase; while for temperature below the optimum value, total mortality decreased by 1.21% for each degree Celsius increase. Conclusions Our findings indicate that temperature has an effect on daily mortality in Shanghai, and the time-series approach is a useful tool for studying the temperature-mortality association.
基金This work was supported by Shanghai Municipal Committee of Science and Technology through grant 03DZ05052.
文摘Objective To determine the best statistical distribution of concentration data of major air pollutants in Shanghai. Methods Four types of theoretic distributions (lognormal, gamma, Pearson V and extreme value) were chosen to fit daily average concentration data of PM10, SO2 and NO2 from June 1, 2000 to May 31, 2003 in Shanghai by using the maximum likelihood method. The fit results were evaluated by Chi-square test. Results The best-fit distributions for PM10,SO2 and NO2 concentrations in Shanghai were lognormal, Pearson V, and extreme value distributions, respectively. Conclusion The results can be further applied to local air pollution prediction and control, e.g., the probabilities exceeding the air quality standard and emission source reduction of air pollutant concentration to meet the standard.
基金The current work was co-funded by Energy Foundation through grant G-0212-06632 and Shanghai Municipal Committee of Science and Technology through grants 03DZ05052 and 03ZR14009.
文摘Objective To obtain the exposure-response functions that could be used in health-based risk assessment of particulate air pollution in China. Methods Meta analysis was conducted on the literatures on air particulate matter and its adverse health outcomes in China and worldwide. Results For each health outcome from morbidity to mortality changes, the relative risks were estimated when the concentration of air particulate matter increased to some certain units. Conclusion The exposure-response functions recommended here can be further applied to health risk assessment of air particulate matter in China.
基金The current work was funded by Shanghai Municipal Committee of Science and Technology through grants 03DZ19612 and03DZ05052.
文摘To study the relationship between ambient air pollution and daily mortality of SARS in Beijing. Methods The approach of time-series Poisson regression was used to assess the relationship between daily SARS mortality, ambient air pollution, and other factors from April 25 to May 31, 2003 in Beijing. Results An increase of each 10 μg/m3 over a 5-day moving average of PM10, SO2 and NO2 corresponded to 1.06 (1.00-1.12), 0.74 (0.48-1.13) and 1.22 (1.01-1.48) relative risks (RRs) of daily SARS mortality, respectively. The relative risks (RRs) values depended largely on the selection of lag days. Conclusion The daily mortality of SARS might be associated with certain air pollutants in Beijing.
文摘The present article reports the genotoxic potential of rapeseed oil cooking fume investigated by a battery of short-term tests (Ames test, SCE/V79 in vitro and mice micronucleus in vivo test). The results showed that the cooking fume contained mutagenic activity. In the presence of S9 mix, an increase in the number of the Salmonella TA98 was observed at doses ranging from 1.0 to 5.0 mg/plate, and the SCE frequencies of V79 cell were markedly raised at doses ranging from 0.05 to 0.5 mg.ml-1. The positive result was also obtained in mice micronucleus assay, the mice had inhaled the cooking fume a week earlier. The frequency of mice bone marrow MN-PCE was increased and it showed a remarkable time-dose-response relationship during the 4 weeks exposure. The results suggested that this cooking fume exposure may be a risk factor of lung cancer in Chinese women.
文摘Primary rat hepatocytes were cultured using different in vitro models and the enzym e leakage,albumin secretion,and cytochrome P4 5 0 1A(CYP1A) activity were observed.The re- sults showed that the level of L DH was decreased over time in culture.However,on day5 ,L DH showed a significant increase in monolayer culture (MC) while after day 8no L DH was detectable in sandwich culture (SC) . The levels of AST and AL T did not change significantly over the inves- tigated time. The CYP 1A activity was gradually decreased in a time- dependent manner in MC and SC.The decline of CYP1A was faster in MC than in SC.This effectwas partially reversed by us- ing cytochrom e P4 5 0 (CYP4 5 0 ) inducer such as Omeprazol and3- m ethylcholanthrene(3- MC) and the CYP1A induction was always higher in MC than in SC.In bioreactor basic CYP1A activity was preserved over2 weeks and the highest album in production was observed in bioreactor fol- lowed by SC and MC. Taken together,it was indicated each investigated model had its advantages and disadvantages. It was also underlined thatvarious in vitro models may address different ques- tions.
文摘Microcystis aeruginosa is the dominant algae in most of the eutrophicated lakes in China. It can produce cyclic heptapeptides, known as microcystins, which can cause liver damage in wild and domestic animals. In this paper, a two-stage transformation assay for demonstrating the carcinogenic effects of the algal toxins is reported. The cell strain used in this assay was derived from embryos of Syrian golden hamster and the algal toxins were extracted from Microcystis aeruginosa, termed microcystis raw toxin (MRT). To elucidate its promoting activity, the target cells were first exposed to a low dosage of 3-mcthylcholanthrene (MCA) and then to MRT. The results showed that MRT significantly enhanced the MCA-initiated cell transformation, and a dose-response relatinnship was observed, but it failed to induce transformation of SHE cells not pretreated by MCA. These results suggest that the MRT play an important role in the malignant transformation of SHE cells. MRT may thus be a tumor promoter, and this transformation assay with SHE cells may be used to predict tumor prompting activity of environmental chemicals, before long-term in vivo two-stage carcinogenesis experiments are carried out.
文摘The mutagenicity of diesel exhaust particles (DEP) was studied by using Salmonella typhimurium strains TA98 and TA100o in vitro and mice micronucleus in vivo test. DEP from six kinds of medium and heavy-duty diesel vehicles, which were made in China and imported, were tested. The vehicles were operated under free accelerating condition. The results showed that the DEP contained mutagenic activity. An increase in the number of the Salmonella TA98 was observed in the presence and especially in the absence of S9 mix. Positive results were also obtained from mice micronucleus assay. The frequency of mice bone marrow micronucleated polychromatic erythrocytes (M PCE) was increased and it showed a definite dose-response relationship. Comparing the different types of the vehicles,we found that the mutagenicity of DEP from domestic made vehicles was stronger than that from the imported ones
