• Environmental Mutagens and Carcinogens
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• v.19 no.2
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• pp.102-107
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• 1999

A population monitoring studies for assessing the genotoxicity of occupationally exposed mixed organic solvents to printers were performed by using the chromosome aberration assay and the cytokinesis-blocked micronucleus assay. The incidence of chromosome aberrations and micronuclei was studied in the peripheral blood lymphocytes of 51 male printers and their matched controls in Seoul area. Smoking habits and duration of employment were taken into account. The frequencies of micronucleus in peripheral lymphocytes of printers were significantly different in comparision with control subjects. Also there were significant increase in the frequencies of micronucleus by duration of exposure. The frequencies of chromosome aberrations showed no significant differences between printers and their matched controls.

• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.451-457
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• 2002

The purpose of the present experiment was to investigate the micronuclei (MN) frequency in cytokinesis-blocked (CB) cells after various doses of gamma-rays in two species (fish and fowl) and so to contribute to the clarification of the question whether these species are suitable as a target organism in the test system. The frequencies of binucleated cells, and gamma-ray-induced MN in CB cells at several doses were measured in three donors of two species. No binucleated cell was noted in erythrocyte. The peaks of binucleated lymphocyte formation were found at a concentration of 2% phytohaemagglutinin (PHA) and $3{\mu}g/m{\ell}$ cytochalasin B (Cyt-B) in fish at 144 hours after incubation and 2% PHA and $6{\mu}g/m{\ell}$ Cyt-B in fowl at 72 hours after incubation. But the micronucleus counts failed to show any evidence of radiation damage. Measurements performed after irradiation showed a dose-related decrease in the formation of binucleated cells in each of the donors studied. Results indicated that the assays were not suitable for this due to blastization inhibition (binucleation failure) after irradiation. We concluded that the use of CB cell from fish and fowl for detecting the results of mdiation exposure was highly questionable.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.487-492
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• 1993

정상인 말초혈액임파구 및 C57BL/6마우스 비장임파구에 $^{60}Co{\gamma}-rays$를 in vitro상태에서 조사한 후 500개 또는 1000개의 cytokinesis-blocked(CB) lymphocytes의 미세핵(micronuclei)의 발생빈도를 측정하였다. 방사선조사량에 따라 미세핵의 발생빈도는 증가하였으며 linear-quadratic model로 측정한 결과 선량반응곡선의 식은 인체의 경우 $Y=(0.31{\pm}0.049)D+(0.0022{\pm}0.0002)D^2+13.19$($r^2=1.000$)이었으며, 마우스의 경우 $Y=(1.31{\pm}0.264)D+(0.0015{\pm}0.0006)+8.7$($r^2=0.988$)이었다(Y는 1000개의 CB cell 당 미세핵발생빈도, D는 cGy로 표시되는 조사선량). 인체 말초혈액임파구에 대한 마우스 비장임파구의 상대적 생물학적 효과(relative biological effectiveness)는 미세핵의 발생율이 세포당 0.05~0.8의 범위에서 $1.84{\pm}0.48$이었다. 미세핵분석법은 인체 및 동물의 방사선 피폭시 간편하고 빠른 생물학적 선량측정법으로 사용될 수 있을 것이다.

• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.243-249
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• 2004

The cytokinesis-block micronucleus (CBMN) assay in combination with FISH technique using chromosome-specific centromeric probes for chromosome 1 and 4 was performed in mitogen stimulated human lymphocytes which were exposed to x-radiation to identify different sensitivity of chromosomes to the induction of micronuclei(MN) and aneuploidy by radiation. The frequencies of micronucleated cytokinesis-blocked(MNCB) cells and MN in binucleated lymphocytes(BN) increased with the increase in radiation dose. A significant induction of aneuploidy of chromosome 1 and 4 were found. The frequency of aneuploidy of chromosome 1 and 4 in the control were 9 per 2,000 BN cells and this increased to 47 and 71 following irradiation at a dose of 1 and 2 Gy, respectively. The induction of aneuploidy of chromosome 1 was higher than that of chromosome 4. The frequency of aneuploid BN cells with MN exhibiting positive centromere signal for either chromosome 1 and/or 4 increased in a dose dependent manner, and that for chromosome 1 is higher than that for chromosome 4. Among the total induced MN in irradiated lymphocytes, smaller proportion of MN exhibit centromeric signal of chromosome indicating that radiation-induced MN are mainly originated from chromosomal breakage rather than chromosomal non-disjunction. These results suggest that x-radiation can induce aneuploidy and supports the finding that chromosome vary in their sensitivity to aneuploidy induction by x-irradiation.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.256-260
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• 2015

Purpose: Mefenamic acid (MEF) as a non-steroidal anti-inflammatory drug is used as a medication for relieving of pain and inflammation. Radiation-induced inflammation process is involved in DNA damage and cell death. In this study, the radioprotective effect of MEF was investigated against genotoxicity induced by ionizing radiation in human blood lymphocytes. Materials and Methods: Peripheral blood samples were collected from human volunteers and incubated with MEF at different concentrations (5, 10, 50, or $100{\mu}M$) for two hours. The whole blood was exposed to ionizing radiation at a dose 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis blocked binucleated lymphocyte. Results: A significant decreasing in the frequency of micronuclei was observed in human lymphocytes irradiated with MEF as compared to irradiated lymphocytes without MEF. The maximum decreasing in frequency of micronuclei was observed at $100{\mu}M$ of MEF (38% decrease), providing maximal protection against ionizing radiation. Conclusion: The radioprotective effect of MEF is probably related to anti-inflammatory property of MEF on human lymphocytes.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.333-338
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• 2003

Cytogenetic and hematological analysis was performed in bovine peripheral blood from the regions around Wolsong nuclear power plant and control area. The frequency of micronuclei (MN) in peripheral blood lymphocytes from cattle was used as a biomarker of radiobiological effects resulting from exposure to environmental radiation. An estimated dare of radiation was calculated by a best fitting linear-quadratic model based on the radiation-induced MN formation from the bovine lymphocytes exposed in vitro to radiation over the range from 0 Gy to 4 Gy. MN rates in lymphocytes of cattle from Wolsong nuclear power plant and control area were 9.87/1,000 and 9.60/1,000, respectively. There were no significant differences in MN frequencies and hematological values in cattle between Wolsong and control area. The study indicates that the MN assay is a rapid, sensitive and accurate method that can be used to monitor a large population exposed to radiation.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.303-309
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• 2019

Tritium is an important nuclide that must be monitored for radiation safety management. In this study, HTO was orally administered to rats at the level of 37 kBq ($1{\mu}Ci$) or 370 kBq ($10{\mu}Ci$) to examine tissue distribution and excretion levels. After sacrifice, wet and dry tissue samples were weighed and analyzed for tissue free-water tritium (TFWT) and organically bound tritium (OBT). The mean tissue concentrations of TFWT (OBT) were 30.9 (17.8) and 4.4 (8.1) Bq/g on days 7 and 13 at the 37 kBq level and 30.8 (64.6) Bq/g on day 17 at the 370 kBq level. To assess the cytogenetic damage due to tritium exposure, a cytokinesis-blocked micronucleus (MN) assay was performed in blood samples from rats exposed to HTO for 14 and 21 days after oral administration. There was no significant difference in the MN frequencies between the control and exposed rats.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.10
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• pp.4409-4419
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• 2015

The Bhopal gas tragedy involving methyl isocyanate (MIC) is one of the most horrific industrial accidents in recent decades. We investigated the genotoxic effects of MIC in long-term survivors and their offspring born after the 1984 occurrence. There are a few cytogenetic reports showing genetic damage in the MIC-exposed survivors, but there is no information about the associated cancer risk. The same is true about offspring. For the first time, we here assessed the micronucleus (MN) frequency using cytokinesis-blocked micronucleus (CBMN) assay to predict cancer risk in the MIC-affected population of Bhopal. A total of 92 healthy volunteers (46 MIC-affected and 46 controls) from Bhopal and various regions of India were studied taking gender and age into consideration. Binucleated lymphocytes with micronuclei (BNMN), total number of micronuclei in lymphocytes (MNL), and nuclear division index (NDI) frequencies and their relationship to age, gender and several lifestyle variabilities (smoking, alcohol consumption and tobacco-chewing) were investigated. Our observations showed relatively higher BNMN and MNL (P<0.05) in the MIC-affected than in the controls. Exposed females (EF) exhibited significantly higher BNMN and MNL (P<0.01) than their unexposed counterparts. Similarly, female offspring of the exposed (FOE) also suffered higher BNMN and MNL (P<0.05) than in controls. A significant reduction in NDI (P<0.05) was found only in EF. The affected group of non-smokers and non-alcoholics featured a higher frequency of BNMN and MNL than the control group of non-smokers and non-alcoholics (P<0.01). Similarly, the affected group of tobacco chewers showed significantly higher BNMN and MNL (P<0.001) than the non-chewers. Amongst the affected, smoking and alcohol consumption were not associated with statistically significant differences in BNMN, MNL and NDI. Nevertheless, tobacco-chewing had a preponderant effect with respect to MNL. A reasonable correlation between MNL and lifestyle habits (smoking, alcohol consumption and tobacco-chewing) was observed only in the controls. Our results suggest that EF and FOE are more susceptible to cancer development, as compared to EM and MOE. The genotoxic outcome detected in FOE reflects their parental exposure to MIC. Briefly, the observed cytogenetic damage to the MIC-affected could contribute to cancer risk, especially in the EF and FOE.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.323-327
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• 2004

The purpose of the present experiment was to investigate the micronuclei(MN) frequency in cytokinesis-blocked(CB) cells after various doses of gamma-rays in pig (Landrace, male, 3-month-old) and so to contribute to the clarification of the question whether these species are suitable as a target organism in the test system. The frequencies of binucleated cells, and gamma-ray-induced MN in CB cells at several doses were measured in three donors. The peaks of binucleated lymphocyte formation(22%) were found at a concentration of 2% phytohaemagglutinin(PHA) and $4{\mu}g/ml$ Cytochalasin B(Cyt-B) in pig at 72 hours after incubation. Measurements performed after irradiation showed a dose-related increases in MN frequency in each of the donors studied. When analysed by linear-quadratic model the line of best fit was $y=0.0183D+0.0124D^2+0.0133$(y = number of MN/CB cells and D=irradiation dose in Gy). In conclusion, the results demonstrate that it appears feasible to use pig as target organisms in the micronucleus test to estimate the cytogenetic damage caused by ionizing radiations or, potentially, chemical compounds.

• Journal of Radiation Protection and Research
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• v.29 no.1
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• pp.9-15
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• 2004

Firstly, we compared the two staining techniques, Giemsa and Acridine orange, to determine micronuclei on samples of cultures of five healthy human peripheral blood lymphocytes after ${\gamma}-irradiation\;(^{137}Cs)$ in dose ranges of 0 to 800cGy. It was found that the Acridine orange staining method gives more reliable results than the usual Giemsa staining method in micronucleus tests. Moreover, the frequency of micronuclei in cytokinesis-blocked human B-lymphocytes was studied after in vitro irradiation in dose ranges of 0 to 50cGy. After setting and separating the B-lymphocytes, the frequency of radiation-induced micronuclei were observed as the end-point markers for the low-dose radiation dosimetry after staining with Giemsa and Acridine orange dyes. The micronuclei frequency in B-lymphocytes was significantly elevated from 10 to 30cGy ${\gamma}-irradiation$. The determination of micronuclei in B-lymphocytes after staining with Acridine orange was higher than that of Giemsa. The frequency of micronuclei in B-lymphocytes was observed to be at least two times higher than those of T-lymphocytes Giemsa in dose increasing. Therefore, the determination of low-dose radiation-induced micronuclei in B-lymphocytes after staining with Acridine orange is likely to have the greatest potential in the estimation of low dose radiation exposure.