• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.1-17
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• 2000

Carcinogen-DNA adduct analysis has potential for biomonitoring the earliest effects of exposure to many chemical carcinogens. They are the covalent reaction products of electrophiles and nucleophilic sites on DNA and the initial damage to DNA induced by many carcinogens. So many researchers begin to use them as biomarker for monitoring the earliest exposure of carcinogens and develop the effective analytical techniques about them. Randerath, Gupta and coworkers(1981, 1982) has also developed a $^{32}P$-postlabelling method as one among them. A major project for biomonitoring workers with carcinogen-DNA adducts is to develop non-invasive samples instead of tissues of target organs such as baldder and lung. This study use the exfoliated urothelial cells in urine for examine benzidine-DNA adducts. The content of exfoliated urothelial cells is not enough to significantly measure DNA content with spectrophotometer, and require the another way. So firstly washing the collected cells with PBS and 70% ethanol and centrifuge them for removing the crystals in urine, which block the isolation of DNA adducts. And then, measure the total nucleotide after $^{32}P$-postlabelling for calculating RAL. $[{\gamma}-^{32}P]ATP$ using for $^{32}P$-postlabelling, can synthesize with $[^{32}P]H_3PO_4$, and reagent and enzyme mixture (RM, EM), which is very economic in case of requiring a lot of them. Chromatography was composed of two steps. First step was to separate adduct ones from unadducted nucleotide, and secondary step was separate each adduct, which were performed with 4 kinds of solvents and different directions on TLC. With this procedure, we measure the DNA adducts in exfoliated urothelial cells of workers who were employed in benzidine and benzidine-dye company. RAL of adducts were $89.0{\times}10^7$ and $57.0{\times}10^7$ in them. In conclusion, we can significantly measure the DNA adduct in exfoliated urothelial cells by using the above $^{32}P$-postlabelling procedures, and use them to be biomonitoring workers who exposed carcinogens.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.247-255
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• 2014

Objectives: We reviewed the CAREX (CARcinogen EXposure) program designed to estimate the prevalence of occupational exposure to carcinogens and summarized the advantages and limitations of this program. Methods: All literature, including reports on CAREX and the use of CAREX, were reviewed. The keyword search term was CAREX. Additional articles were identified from references cited in articles and reviewed. Results: An exposure information system, CAREX was developed based on data from the Finnish Institute of Occupational Health of Finland and from the US. CAREX has been applied in several countries, including in the EU, in order to estimate national exposure patterns to carcinogens. The initial exposure assessment carried out through CAREX was aimed at estimating exposures over the period of 1990-1993. To estimate the number of workers exposed to carcinogens by using CAREX, reference exposure prevalence from Finland and the United States was computed, which was then reviewed and corrected by national experts. Finally the overall number of workers exposed to carcinogens can be estimated. We found that CAREX has been used in a total of 18 countries. No Asian country has used CAREX. Conclusions: CAREX can be applied not only to estimate the number of workers exposed to carcinogens in Korea, but also to identify high-risk industries with workers most exposed to carcinogens.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.135.2-136
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• 2000

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.29-30
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• 2003

The heavy metal cadmium is a xenobiotic toxicant of environmental and occupational concern and it has been classified as a human carcinogen. Inhalation of cadmiumhas been implicated in the development of emphysema and pulmonary fibrosis, but, the detailed mechanism by which cadmium induces adverse biological effects is not yet known.(omitted)

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.34-34
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• 2001

• Toxicological Research
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• v.13 no.1_2
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• pp.49-54
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• 1997

PCBs are classified as B2 (Probable human carcinogen) based on the induction of hepatocellular carcinomas in rats and mice from IRIS (Integrated Risk Information System). About 20 years ago, PCBs were phased out for electrical use in Korea, but PCBs were continuously used in the other field. Lately, there has been increasing concern on possible effects of contaminated soil to the other environment and human health. The purpose of this study is to determine PCBs level in soil at some site and to assess the human exposure doses according to exposure routes for people living within sites which expected to be exposed to PCBs. Pollution level of PCBs on the site was monitored using gas liquid chromatography. To assess the transport of PCBs in soil to plant and to air, various transfer factors(diffusion coefficient, bioconcentration factor etc.) were considered in simple calculations. To calculate the residential exposure doses by routes, some equations were considered using assumption value, which define inhalation, ingestion (soil, plant) and derreal uptake pathway. Computated results will be used as risk assessment information for human health evaluation on contaminated soil.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1686-1689
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• 2003

The ability of ten probiotic bacteria to bind a common food carcinogen aflatoxin $G_1$,$G_2$ and $B_2$ was assessed. The strains were incubated in vitro with aflatoxins and the toxin residues in the supernatant were measured using high performance liquid chromatography. The aflatoxin $G_1$ binding capacity of the strains was found to strain dependent, most efficient binding of AF$G_1$ was observed by L. acidophilus CU028 and L. brevis CU06 which bound approximately 50%. L. acidophilus CU028 was capable of bind approximately 67% of AF$G_2$, difference in their binding ability showed statistical significance (p>0.05). L. acidophilus CU028 and L. helveticus CU 631 were the best binders and the strains were observed to possess variable AF$B_2$-binding ability in the range was from 38.0% to 55.9%. Lactobacillus acidophilus CU028 was the best common binders of the three types of food carcinogen aflatoxins. The application of binding phenomenon in the removal of mycotoxins from contaminated feeds is urgently needed to improve the safety of feeds.

• BMB Reports
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• v.36 no.1
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• pp.28-34
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• 2003

Breast cancer is the most prevalent cancer among women in Western countries, and its prevalence is also increasing in Asia. The major risk factor for breast cancer can be traced to reproductive events that influence the lifetime levels of hormones. However, a large percentage of breast cancer cases cannot, be explained by these risk factors. The identification of susceptibility factors that predispose individuals to breast cancer (for instance, if they are exposed to particular environmental agents) could possibly give further insight into the etiology of this malignancy and provide targets for the future development of therapeutics. The most interesting candidate genes include those that mediate a range of functions. These include carcinogen metabolism, DNA repair, steroid hormone metabolism, signal transduction, and cell cycle control. We conducted a hospital-based case-control study in South Korea to evaluate the potential modifying role of the genetic polymorphisms of selected low penetrance genes that are involved in carcinogen metabolisms (i.e., CYP1A1, CYP2E1, GSTM1/T1/P1, NAT1/2, etc.), estrogen synthesis and metabolism (i.e., CYP19, CYP17, CYP1B1, COMT, ER-$\alpha$, etc.), DNA repair (i.e., XRCC1/3, ERCC2/4, ATM, AGT, etc.), and signal transduction as well as others (i.e., TGF-$\beta$, IGF-1, TNF-$\beta$, IL-1B, IL-1RN, etc.). We also took into account the potential interaction between these and the known risk factors of breast cancer. The results of selected genes will be presented in this mini-review.

• Toxicological Research
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• v.8 no.1
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• pp.131-137
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• 1992

Sprague-Dawley rats aged six weeks divided into four groups and group 1, 2, 3 and 4 of rats were given an intrapertioneal injection of diethylnitrosamine at 200 mg/kg body weight. Group 4 was Control. Two weeks after beginning of the experiment, group 1 of rats were begun to feed on water containing 0.05% phenobarbital sodium as a promoter for six weeks, and CP-2 were intrapertioneally given to rats of group 2(20mg/kg) and group 3(1mg/kg). Three weeks after beginning of the experiment, partial hepatectomy was performed in all rats. Preneoplastic foci were identified histopathologically by glutathione S-transferase placental form (GST-P) activity. In the Immunohistochemical quantitative analysis of carcinogen-induced foci, it was concluded that CP-2 was not carcinogen.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.336-336
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• 1994

In order to develope the in vitro short term screen-ing method for carcinogen, we studied a purification method for thymine glycol in oxidaized DNA. Thymine glycol (5,6-dihydroxy-5, 6-dihydrothymine) is the major stable radiolysis poduct in thymine by chemical oxidants and ionzing radiation and it is a useful biomarker among oxidized DNA adducts, related with carcinogenests. Standard thymine glycol was prepared by oxidation of 〔$^3$H〕 thymine with KMnO$_4$ followed by purification with HPLC-LSC system and it was assayed by TLC and gas chromatography-MSD. 〔$^3$H〕 DMA adducts was isolated from E. coli (wild type ) treated with oxidative agents such as benzo(a)pyrene, adriamycin, aflatoxin B$_1$ and KBrO$_3$. These oxidative agents generated free radicals in cells by oxidative metabolism. As a result, thymine glycol was produced in cultured E. coli by four chemicals. This result shows that this methodology should be useful tool in screening oxidative carcinogen.