• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.142-148
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• 2001

We studied adaptive response in CHL cells by benzidine dihydrochloride, a derivative of benzidine, which was a major mutagenic agent in dye industry. Chromosome aberration analysis was used for the identification of adaptive response to this mutagen. Adaptive and reactive doses were confirmed by cell proliferation rate curve. Cell proliferation rate curve was obtained from the mitotic indices of cells treated with various concentrations of benzidine dihydrochloride for 24 hours. Marked adaptive responses to benzidine dihydrochloride in the induction of chromosome aberration were observed in CHL cells by pre-treatment with low concentrations of benzidine dihydrochloride (0.0047 mg/$m\ell$ or 0.0094 mg/$m\ell$) for 24 hours following post-treatment with high concentrations (0.0187, 0.0375, 0.075, 0.15 mg/$m\ell$) for 24 hours. These adaptive responses were found mostly in the type of chromatid breaks and chromatid exchanges. There is no difference in these results between two adaptive doses, 0.0047 mg/$m\ell$ and 0.0094 mg/$m\ell$. The amount of adaptive response, however, was dependent on post-treatment doses.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.124-139
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• 2000

This study was performed to investigate monoacetylbenzidine(MABZ) and benzidine(BZ) hemoglobin adducts among workers who worked at benzidine based dye manufacturing company, and exposed by benzidine and benzidine based dye. The hemoglobin adducts were compared with work environment assessment result for evaluating the usefulness of biological monitoring. The mean BZ hemoglobin adducts among the first synthesis worker's hemoglobin adducts were $40.69{\mu}gBZ/g$ Hb and those of dry and packing workers were $22.14{\mu}gBZ/g$ Hb. The mean of MABZ hemoglobin adducts among 1st synthesis workers were $255.84{\mu}gMABZ/g$ Hb, dispersion worker's hemoglobin adducts were $76.17{\mu}gMABZ/g$ Hb and synthesis worker's hemoglogin adducts were $28.66{\mu}gMABZ/g$ Hb. Work environment assessment results during past 3 years were $0.0065mg/m^3$ and $0.5659mg/m^3$ of benzidine based dye concentration in ambient air of drying and packing only. Dye producing process was categorized by the possibility of exposure to benzidine and benzidine based dye. BZ and MABZ hemoglobin adducts were $19.55{\mu}gBZ/g$ Hb, $119.80{\mu}gMABZ/g$ Hb among workers who exposed by benzidine dihydrochloride and $16.32{\mu}gBZ/g$ Hb, $316.56{\mu}gMABZ/g$ Hb among workers who exposed by benzidine based dye. BZ hemoglobin adducts were not detected among control group and MABZ hemoglobin adducts were $5.33{\mu}gMABZ/g$ Hb. The differences between control and other exposed group was statistically significant. But there was no statistically significant differences between benzidine dihydrochloride exposed process and benzidine based dye exposed group. BZ and MABZ hemoglobin adducts were $2.23{\mu}gBZ/g$ Hb, $76.17{\mu}gMABZ/g$ Hb and $3.46{\mu}gBZ/g$ Hb, $21.33{\mu}gMABZ/g$ Hb. So hemoglobin adducts of MABZ were 5 ~ 30 time higher than those of BZ(P<0.003). Above results indicate that work environment assessment didn't detected benzidine and benzidine based dye in ambient air but biological monitoring detected those of hemoglobin adducts. Two group's hemoglobin adducts exposed benzidine dihydrochloride and benzidine based dye were high level but wasn't statistically significant and those were not detected in control group.

• Journal of the Korean Chemical Society
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• v.16 no.1
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• pp.18-24
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• 1972

Benzidine dihydrochloride crystallizes in the triclinic system. The space group is $P_1$. The unit cell dimensions are; a = 4.38${\pm}$0.01, b = 5.76${\pm}$0.01, c = 12.82${\pm}$0.02${\AA}$, $\alpha$ = 101.5${\pm}$0.2, $\beta$ = 99.5${\pm}$0.2, $\gamma$ = 99.5${\pm}$0.2$^{\circ}$; with one molecule per unit cell. The crystal structure has been solved by two dimensional Patterson and by trial and error methods, and refined by means of two dimensional differential synthesis. The bond distances are C-C(*) = 1.40${\pm}$0.02, C-C = 1.52${\pm}$0.02, C-N = 1.51${\pm}$0.03 and N-H${\cdot}{\cdot}{\cdot}$Cl = 3.21${\pm}$0.03${\AA}$. The structure consists of hydrogen bonded molecular layers, extending to the (100) plane, and the hydrogen bonding scheme is similar to that of p-phenylenediamine dihydrochloride. The adhesion between hydrogen bonded molecular layers is due to van der Waals forces.