The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, more...The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, moreover, organic solvents are used in various industrial processes. Organic solvents used in different industrial processes may be associated with hepatotoxicity. Several factors contribute to liver toxicity; among these are: species differences, nutritional condition, genetic factors, interaction with medications in use, alcohol abuse and interaction, and age. This review addresses the mechanisms of hepatotoxicity. The main pathogenic mechanisms responsible for functional and organic damage caused by solvents are: inflammation, dysfunction of cytochrome P450, mitochondrial dysfunction and oxidative stress. The health impact of exposure to solvents in the workplace remains an interesting and worrying question for professional health work.展开更多
Objective: To investigate the influence of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children. Materials and methods: A group of 217 children three to six years of age from a ru...Objective: To investigate the influence of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children. Materials and methods: A group of 217 children three to six years of age from a rural area were given a thorough physical examination and the concentration of lead in blood samples taken from each subject was determined. The indices of lymphocyte immunity (CD^+3CD^+4, CD^+3CD^+8, CD^+4CD^+8, CDˉ3CD^+19) and erythrocyte immunity (RBC-C3b, RBC-IC, RFER, RFIR, CD35 and its average fluorescence intensity) of 40 children with blood lead levels above 0.483 μmol/L were measured and compared with a control group. Results: The blood lead levels of the 217 children ranged from 0.11 μmol/L to 2.11 μmol/L. The CD^+3CD^+4and CD^+4CD^+8 cells were lower (P＜0.01) and the CD^+3CD^+8 cells were higher in the lead-poisoned subjects than those in the control group (P＜0.05). CD^+3 and CDˉ3CD^+19 did not show significant differences. Although the RBC-C3b rosette forming rate was lower and the RBC-IC rosette forming rate was higher in the lead-poisoned group, this difference could not be shown to be statistically significant (P＞0.05). RFIR was found to be lower in the lead-poisoned group (P＜0.01). Compared with the control group, the positive rate of CD35 was not found to be significantly different in a group of 25 lead-poisoned children (P＞0.05), while the average fluorescence intensity was lower in the lead-poisoned group (P＜0.05). Conclusion: Lead exposure can result in impaired immune function oft lymphocytes and erythrocytes in preschool children.展开更多
OBJECTIVE To determine the transcriptional expression of mitochondrial genome （mtDNA） in MGC803 cell lines subjected by various time-phase hypoxic dispositions, and further to discuss the influence of mtDNA transcri...OBJECTIVE To determine the transcriptional expression of mitochondrial genome （mtDNA） in MGC803 cell lines subjected by various time-phase hypoxic dispositions, and further to discuss the influence of mtDNA transcripts on hypoxic resistance to irradiation. METHODS The MGC803 cells exposed to anoxic environment were divided into control group （0 h）, hypoxic group （2 h, 8 h, 16 h, 24 h） and irradiated group after exposing the hypoxia. RTPCR was applied to detect the transcripts of cytochrome oxidase subunit Ⅰ （COI）, NADH dehydrogenase subunit 4 （ND4）, ND5, cytochrome b （cyt-b） and ATPase6 （ATP-6） in MGC803 cell lines at various time-phases of hypoxic, and after X-ray irradiation. Flow cytometry and colony formation assay were conducted to evaluate the cell cycle phase and survival fraction. RESULTS COI and ND4 transcripts of MGC803 cell lines were influenced remarkably by hypoxia. COI transcripts were decreased remarkably with the elongation time of exposing the hypoxic, and reduced to one fourth of its original amount of prehypoxia 24 h after exposing the hypoxia. ND4 transcripts were increased initially, and elevated to two folds 8 h after exposing the hypoxia, and then reduced to one second 24 h after exposing the hypoxia. Hypoxia resulted in G1 phase blockage, especially after hypoxia for 16 h. The survival fraction of MGCS03 ceils exposing the hypoxia in irradiated group showed that as the time of exposing the hypoxic before irradiation is prolonged, the survival fraction of MGC803 cells may have an elevated tendency. CONCLUSION The tumor cells with lower expression levels of the COI and the ND4 after exposing the hypoxic have stronger resistance to the radiation, which indicates that increasing the expression levels of the COI and the ND4 might be advantageous to enhance the sensitivity of hypoxic tumor cells to the radiotherapy.展开更多
文摘The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, moreover, organic solvents are used in various industrial processes. Organic solvents used in different industrial processes may be associated with hepatotoxicity. Several factors contribute to liver toxicity; among these are: species differences, nutritional condition, genetic factors, interaction with medications in use, alcohol abuse and interaction, and age. This review addresses the mechanisms of hepatotoxicity. The main pathogenic mechanisms responsible for functional and organic damage caused by solvents are: inflammation, dysfunction of cytochrome P450, mitochondrial dysfunction and oxidative stress. The health impact of exposure to solvents in the workplace remains an interesting and worrying question for professional health work.
基金Project supported by the Health Bureau of Zhejiang Province(No. 2000A061) and the Natural Science Foundation of ZhejiangProvince (No. 300512) China
文摘Objective: To investigate the influence of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children. Materials and methods: A group of 217 children three to six years of age from a rural area were given a thorough physical examination and the concentration of lead in blood samples taken from each subject was determined. The indices of lymphocyte immunity (CD^+3CD^+4, CD^+3CD^+8, CD^+4CD^+8, CDˉ3CD^+19) and erythrocyte immunity (RBC-C3b, RBC-IC, RFER, RFIR, CD35 and its average fluorescence intensity) of 40 children with blood lead levels above 0.483 μmol/L were measured and compared with a control group. Results: The blood lead levels of the 217 children ranged from 0.11 μmol/L to 2.11 μmol/L. The CD^+3CD^+4and CD^+4CD^+8 cells were lower (P＜0.01) and the CD^+3CD^+8 cells were higher in the lead-poisoned subjects than those in the control group (P＜0.05). CD^+3 and CDˉ3CD^+19 did not show significant differences. Although the RBC-C3b rosette forming rate was lower and the RBC-IC rosette forming rate was higher in the lead-poisoned group, this difference could not be shown to be statistically significant (P＞0.05). RFIR was found to be lower in the lead-poisoned group (P＜0.01). Compared with the control group, the positive rate of CD35 was not found to be significantly different in a group of 25 lead-poisoned children (P＞0.05), while the average fluorescence intensity was lower in the lead-poisoned group (P＜0.05). Conclusion: Lead exposure can result in impaired immune function oft lymphocytes and erythrocytes in preschool children.
基金supported by a grant from the National Natural Science Foundation of China(No.30700979).
文摘OBJECTIVE To determine the transcriptional expression of mitochondrial genome （mtDNA） in MGC803 cell lines subjected by various time-phase hypoxic dispositions, and further to discuss the influence of mtDNA transcripts on hypoxic resistance to irradiation. METHODS The MGC803 cells exposed to anoxic environment were divided into control group （0 h）, hypoxic group （2 h, 8 h, 16 h, 24 h） and irradiated group after exposing the hypoxia. RTPCR was applied to detect the transcripts of cytochrome oxidase subunit Ⅰ （COI）, NADH dehydrogenase subunit 4 （ND4）, ND5, cytochrome b （cyt-b） and ATPase6 （ATP-6） in MGC803 cell lines at various time-phases of hypoxic, and after X-ray irradiation. Flow cytometry and colony formation assay were conducted to evaluate the cell cycle phase and survival fraction. RESULTS COI and ND4 transcripts of MGC803 cell lines were influenced remarkably by hypoxia. COI transcripts were decreased remarkably with the elongation time of exposing the hypoxic, and reduced to one fourth of its original amount of prehypoxia 24 h after exposing the hypoxia. ND4 transcripts were increased initially, and elevated to two folds 8 h after exposing the hypoxia, and then reduced to one second 24 h after exposing the hypoxia. Hypoxia resulted in G1 phase blockage, especially after hypoxia for 16 h. The survival fraction of MGCS03 ceils exposing the hypoxia in irradiated group showed that as the time of exposing the hypoxic before irradiation is prolonged, the survival fraction of MGC803 cells may have an elevated tendency. CONCLUSION The tumor cells with lower expression levels of the COI and the ND4 after exposing the hypoxic have stronger resistance to the radiation, which indicates that increasing the expression levels of the COI and the ND4 might be advantageous to enhance the sensitivity of hypoxic tumor cells to the radiotherapy.
