• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.88-99
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• 1998

This study was undertaken to find out the bio-effects due to be a radiation fractionated exposure. The experimental animals were divided into the control group and the radiation exposure groups of 20cGy, 40cGy and 80cGy with 220 male Sprague-Dawley rats at 6 weeks old. The radiation exposure groups were fractionated exposed from each 20cGy, 40cGy and 80cGy for every 5 days. The chromosome aberrations, the frequency of SCE, the changes of body weight, hematological values and enzyme activities were investigated for the fractionating exposure times and the time after fractionated exposure. The results were summarized as follows 1. The body weight of the radiation exposure groups were significantly decreased compared with control group according to the increasing fractionated exposure times, and it was the lowest values at the immediately after the end of the fractionating exposed, but it was recovered with the level of control group at 3rd weeks gradually increased 1st week after fractionated exposure. 2. The values of WBC, RBC, Hb and Hct in the radiation exposure groups were significantly decreased than those the control group, but the values of GOT, GPT, ALP, and LDH in the radiation exposure groups were significantly increased than those of the control group. 3. The frequency of chromosomal aberration were increased according to the increasing fractionated exposure dose, and it showed the highest at 5th days after fractionated exposed. The types of chromosomal aberration were occurred such as a numerical abnormality, deletion, break and duplication, it was not recovered immediately and maintained high frequency than the control group. 4. The frequency of SCE were significantly increased according to the increasing fractionated exposure dose in 20cGy, 40cGy and 80cGy groups. But it was recovered the level of control group at 7th days after fractionated exposure. According to the above results, this study could confirm that the frequency of chromosomal aberration and SCE were increased with fractionated exposure dose, the other hand, the changes of body weight, hematological values and enzyme activity values were significantly affected according to the increasing fractionated exposure dose.

• Journal of Radiation Protection and Research
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• v.19 no.1
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• pp.51-68
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• 1994

It is good method to use frequency of chromosome aberration in Lymphocytes for a biological dosimetry in cases of accidental exposure to radiation. But in cases of past exposure, biological dosimetry is limited because the frequency of aberration decreases by time after exposure. To provide a basic data for estimation of past radiation exposure, the changing pattern of frequency of unstable chromosome aberration by time interval after exposure was studied. Observation was made on peripheral lymphocytes of 41 blood samples from 20 patients treated for uterine cervical carcinoma and endometrial carcinoma. The patients received 50.4Gy radiation to whole pelvis. Elapsed times after the completion of radiation therapy were 1 day, 3, 6, 9, 12, 24, 52, 104, 156, 208, 260 and 520 weeks. All the blood sample were microcultured. The Ydr, Qdr and Qdra were calculated from frequency of unstable aberration. Ydr did not decrease for 3 weeks after radiation therapy, and thereafter, decreased very rapidly and reached 0.05 at two years after radiation therapy and decreased very slowly until 5 years after radiation therapy. Relationship between unstable chromosome aberration and time interval after radiation therapy was described as $Ydr=0.259{\times}exp(-0.0429T)+0.0560{\times}exp(-0.00106T)$ (time in weeks) Qdr remained constant at 1.51 until 24 weeks after radiation therapy and then decreased to 1.17 at 52 weeks. Therafter, it did not change. Qdra remained constant at 1.10 for 12 weeks after radiation therapy and decreased to 0.81 at 52 weeks. Thereafter, it remained constant. Two superimposed exponential Ydr disappearance rate suggests that it is possible to calculate the past exposure dose. When the elapsed time after exposure is short, Qdr and Qdra are useful papameters for biological dosimetry for past radiation exposure.

• Environmental Mutagens and Carcinogens
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• v.17 no.1
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• pp.17-22
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• 1997

We observed the frequency of chromosome aberrations induced by UVB irradiations, and the suppressing effect of tannic acid on chromosome aberrations induced by UVB irradiations in CHL cells, which is a phenolic compound, a hydrolysate of tannin and a components of green tea. UVB doses used for the frequency of chromosome aberrations were from 0.2 to 1.6 KJ/m$^2$ and tannic acid concentrations were from 1.16 $\mu$g/ml to 37.50 $\mu$g/ml. For the observation of suppressing effect of tannic acid on UVB-induced chromosome aberrations, UVB dose was 1.6 KJ/m$^2$ and tannic acid concentrations were 1.0, 2.0, 4.0 $\mu$g/ml. In our study, tannic acid was treated for 24 hours in CHL, cells after UVB irradiation without S9 mix or for 6 hours with S9 mix. From this study, we obtained the following results : (1) The frequency of chromosome aberrations UVB induced were dose-dependently increased. (2) The tannic acid did not induce chromosome aberrations in cultured Chinese hamster cells. (3) UVB-induced chromosome aberrations were suppressed by tannic acid at every concentration from 1.0 $\mu$g/ml to 4.0 $\mu$g/ml with or without metabolic activation. These results suggest that the tannic acid acts as an inhibitor to UVB-induced clastogenicity of the cultured cell.

• Journal of Radiation Protection and Research
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• v.26 no.2
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• pp.101-111
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• 2001

To study the relationship between the DNA content of human chromosomes and their involvement in radiation-induced structural chromosome aberrations, the frequencies of translocations and dicentrics induced in human lymphocytes after in vitro exposure to 2Gy of x-tay were analysed by fluorescence in situ hybridization(FISH). Single whole chromosome probes(WCP), specific for chromosomes 1, 2, 4, 7, 8, 9, and 21 and triple combination of probes tot chromosome 1, 2 & 4 were used separately. A significant deviation of the frequency of symmetrical translocation and dicentrics from a DNA-proportional distribution was observed. Chromosomes 2, 7, 8, 9 and 21 were less frequently involved in the formation of symmetrical translocations and dicentrics than expected, whereas chromosomes 1 and 4 were more frequently involved. Chromosome 2 and 4 showed a higher frequency of acentric fragments. When triple combination probe for chromosome 1, 2 & 4 was used, no differences were found between the observed and expected frequency of exchange type aberrations. The results showed that the frequency of radiation-induced chromosome aberrations was not proportional to DNA contents, suggesting the difference in the susceptibility to specific aberrations among individual chromosomes. The results also indicated that the FISH technique with combination of probes for chromosome 1, 2 & 4 was useful for radiation biodosimetry.

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.164-165
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• 2009

See Full Text

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.05a
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• pp.66-66
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• 2002

• Journal of Environmental Health Sciences
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• v.21 no.3
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• pp.67-76
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• 1995

The frequencies of chromosome aberrations and sister chromatid-exchanges in peripheral blood lymphocyte of 44 nurses handling anticancer drugs were compared with those in 44 age-match controls. The frequencies of dicentric chrdmosome were $2.4\times 10^{-3}$ in the exposed and $0.5\times 10^{-3}$ in the control. The frequencies of sister cromatid exchanges in the exposed were slightly higher (5.68 SCEs/cell) than those in the control (5.04 SCEs/cell). The frequencies of chromosome aberrations and sister cromatid exchanges were not associated with duration of drug handling and types of anticancer drugs, but associated with use of safety cover.

• Journal of Plant Biology
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• v.8 no.1_2
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• pp.1-4
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• 1965

Beta-ray irradiation effects on structural changes of the chromosomes in root tip of rye, Secale cereale L., seedlings, particularly the frequency of chromosome bridge induction at anaphase stage treated with radioactive sulfur (S35) solutions were studied in this experiment. Among the four different concentrations of isotope solution, the lowest one, 0.4$\mu$c solution, has shown weak effect on the induction of chromosome aberration. On the other hand, higher concentration, 25.6$\mu$c solution, induced higher frequency of chromosome bridge induction as much as 4.3%. Concerning the relationship between the ages of after treatment and the ranges of concentration, the higher concentrations showed more pronounced effects than the lower ones.

• Toxicological Research
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• v.14 no.2
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• pp.211-216
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• 1998

In order to evaluate the mutagenic potential of SDK(skin decontamination kit) produced by Agency for Defense Development(ADD), were performed Salmonella typhimurium reversion assay, chromosomal aberration test on chinese hamster ovarian cells and in vivo micronucleus assay using mouse bone marrow cells according to the established regulation of Korean Food and Drug Administration. In the reverse mutation test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 did not in-crease the number of revertant at any of the concentration tested in this study. SDK did not increase the number of cells having structural or numerical chromosome aberration in cytogenetic test. In mouse micronucleus test, no significant increase in the occurrence oj micro nucleated polychromatic erythrocytes were observed in ICR male mice intraperitoneally administered with SDK. These results indicate that SDK has no mutagenic effects under these experimental conditions.

• Toxicological Research
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• v.17 no.1
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• pp.1-6
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• 2001

To determine whether ozone is genotoxic at environmentally relevant exposure level, B6C3F1 mice were exposed to 0.5 ppm ozone for 12 weeks, 6 hr/day. Chromosomal aberration, supravital micronucleus and hprt mutation assays were performed. The percentage of abnormal cells was significantly increased at 0.5 ppm ozone when compared to unexposed control in chromosome aberration assay. Significant increase in the frequencies of micro nucleated reticulocytes and 6-thioguanine-resistant ($TG^r$) lymphocytes was also observed in supravital micronucleus assay using peripheral blood and lymphocyte hprt mutation assay, respectively. The results indicate, that under our experimental conditions, 0.5 ppm ozone are genotoxic in exposed B6C3F1 mice.