[The effects of benzene poisoning on expression of multidrug resistance 1 gene and P-glycoprotein in bone marrow mononuclear cells of C57BL/6 mice].

OBJECTIVE: To investigate the effects of benzene poisoning on the expression of multidrug resistance 1 (MDR1) gene and P-glycoprotein (P-gp) in the bone marrow mononuclear cells (BMMNCs) of C57BL/6 mice. METHODS: C57BL/6 mice were randomly divided into control group (n = 24), low-dose group (n = 24), medium-dose group (n = 24), and high-dose group (n = 24) to receive corn oil, 25 mg/kg benzene, 50 mg/kg benzene, or 100 mg/kg benzene by gavage, once daily, 5 days/weeks, for 4 weeks. The mice were sacrificed on day 12, 26, or 29 of poisoning. Peripheral blood routine test was performed; real-time quantitative PCR was used to measure the MDR1 gene expression in BMMNCs; Western blot was used to measure the P-gp expression in BMMNCs. RESULTS: On day 12, the red blood cell count and hemoglobin level in the high-dose group were significantly lower than those in the control group, low-dose group, and medium-dose group (P < 0.01 or P < 0.05). On day 26, the white blood cell count in the high-dose group was significantly lower than those in the control group, low-dose group, and medium-dose group (P < 0.01 or P < 0.05). At each time point, the mRNA expression of MDR1 gene in the low-dose group, medium-dose group, and high-dose group was significantly lower than that in the control group (P < 0.01). On day 26, the P-gp expression in the high-dose group was significantly lower than those in the control group, low-dose group, and medium-dose group, and the P-gp expression in the medium-dose group was significantly lower than that in the low-dose group (P < 0.01 or P < 0.05). On day 29, the P-gp expression in the low-dose group, medium-dose group, and high-dose group was significantly lower than that in the control group (P < 0.05). CONCLUSION: Benzene poisoning can affect the expression of MDR1 gene and P-gp, which may be one of the mechanisms of benzene hematotoxicity.

[Occupational acute dimethylformamide poisoning: an analysis of 16 cases].

OBJECTIVE: To analyze the clinical features and diagnostic points of occupational acute dimethylformamide (DMF) poisoning and to explore the mechanism of occupational acute DMF poisoning. METHODS: A comprehensive analysis was performed on the clinical data of 16 cases of occupational acute DMF poisoning, including symptoms, signs, and laboratory testing results. RESULTS: The main clinical features of occupational acute DMF poisoning were digestive system impairments, especially abdominalgia. Hemorrhagic gastroenteritis was not found by gastroscopy. There was no significant correlation between the degree of abdominalgia and alanine aminotransferase level (r(s) = 0.109, P>0.05). CONCLUSION: Abdominalgia is recommended to be one of the reference indices for the diagnosis and degrading of occupational acute DMF poisoning, The mechanism of DMF poisoning remains unclear but it is considered to be related to methyl isocyanate, the intermediate product of DMF metabolism.

[Influence of MDR1 gene C3435T on peripheral white blood cell counts in workers exposed to benzene].

OBJECTIVE: To explore the effects of MDR1 C3435T on the peripheral white blood cell counts in workers exposed to benzene. METHODS: One hundred and twenty-one benzene-exposed workers and 110 healthy controls without benzene exposure were enrolled in this study. White blood cell counts influenced by the polymorphism of MDR1 gene were analyzed. RESULTS: The frequency of MDR1 3435 C/C, C/T, T/T in healthy controls was 37.27%, 46.36%, 16.37%, respectively, and it was 38.84%, 41.33%, 19.83% in the benzene-exposed workers, respectively. The frequency of the MDR1 gene was also not significantly different between benzene exposed workers and controls. Subjects exposed to benzene with MDR1 3435 mutation genotype (T/T) had the significantly lower WBC [(5.46 ± 1.51) × 10(9)/L] than those carrying wild type (C/C) and heterozygous (C/T), whose WBC were (6.08 ± 1.28) × 10(9)/L (P = 0.044). CONCLUSION: P-glycoprotein encoded by MDR1 gene may be implicated into the hematotoxicity of benzene. Subjects carrying MDR1 3435 T/T genotype may have a higher risk of benzene poisoning.

[High-resolution melting: a analysis for genotyping of MDR1 C3435T in benzene-exposed workers].

OBJECTIVE: Using high resolution melting (HRM) to analysis MDR1 C3435T in people exposed to benzene. METHODS: Restriction fragment length polymorphism (RFLP) was utilized to detect the polymorphism of MDR1 3435 in 121 benzene-exposed workers, and the results were compared with the HRM in 10% samples and were confirmed with direct sequencing for six people in them. RESULTS: By direct sequencing, consistent results of benzene-exposed workers with RFLP or HRM were got. The new high resolution melting curve analysis is more efficient, more convenient, and cheaper than RFLP. CONCLUSION: High-resolution melting analysis provides a valid approach to efficiently detect DNA genetic diagnosis, which is suitable for detect susceptible genes in occupational surveillance.

[Application of micronucleus test of buccal mucosal cells in assessing the genetic damage of workers exposed to acrylonitrile].

OBJECTIVE: To investigate the application of micronucleus test of buccal mucosal cells in monitoring the genetic effect of acrylonitrile in the population exposed to the acrylonitrile. METHODS: Forty-one healthy male workers in a chemical factory in Shanghai were selected as the low concentration acrylonitrile exposed group while forty-seven healthy male workers in an acrylonitrile factory in Shanghai were selected as the intermediate concentration acrylonitrile exposed group. At the same time, thirty-one male workers who had no toxicant exposure and lived in the same community were selected as the control group. The micronucleus test in buccal mucosal cells and lymphocytes were used respectively for assessing the genetic damage status of these men. RESULTS: The rate of micronucleus in buccal mucosal cells in both acrylonitrile groups (the low concentration group: 3.68% +/- 2.72%; the intermediate concentration group: 4.00% +/- 2.38%) was significantly higher than that in the control group (2.03% +/- 2.20%) (P < 0.05). The rate of micronucleus in the intermediate concentration group (4.23% +/- 3.34%) was significantly higher than that in the control group (2.48% +/- 1.46%) (P < 0.05). There was the correlation between the micronucleus test of buccal mucosal cells and the micronucleus test of the lymphocytes in the peripheral blood in the acrylonitrile exposed population (r = 0.299-0.359, P < 0.05). CONCLUSION: The micronucleus test of buccal mucosal cells replacing the micronucleus test of the lymphocytes in the peripheral blood can be used as one of the screening indexes in the surveillance of the genetic damage in the acrylonitrile exposed population.

[Study on mitochondrial DNA damage in peripheral blood nucleate cells of the workers exposed to acrylonitrile].

OBJECTIVE: To study the potential aging effect on workers exposed to acrylonitrile (ACN). METHODS: The deletion rates of mitochondrial DNA (mtDNA) in peripheral blood nucleate cells of 47 exposed workers and 47 non-exposed workers (as control), as well as 12 old people and 12 young people were measured with polymerase chain reaction (PCR). RESULTS: The positive rates of mtDNA deletion in peripheral blood nucleate cells were 17.02% in the workers exposed to ACN and 25.00% in group of old people. However, the mtDNA deletion was not detected in the control group and young people. CONCLUSIONS: ACN could induce mtDNA deletion in peripheral blood nucleate cells of the exposed workers. There may be a potential molecular effect of occupational ACN exposure on workers' aging.