• Journal of Radiation Protection and Research
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• v.22 no.3
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• pp.153-160
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• 1997

The frequencies of ${\gamma}$-ray-induced micronuclei (MN) in cytokinesis-blocked (CB) lymphocytes at several doses were measured in three donors of human and C57BL/6 mice. Measurements performed after irradiation showed a dose-related increases in MN frequency in each of the donors studied. The relative sensitivity of mouse in spleen lymphocytes (SLs) compared with human peripheral blood lymphocytes (PBLs) was estimated by best fitting linear-quadratic model based on the radiation-induced MN data over the range from 0 cGy to 400 cGy. In the case of MN frequency with 0.2 per CB cell, the relative sensitivity of mouse SLs was 1.67. Compared with the radiation-induced MN formation in the PBLs of human, the SLs of mouse were more radiosensitive. Using this MN assay with human PBLs and mouse SLs, studies were performed to determine whether the water fraction of ginseng (Panax ginseng C.A.Meyer) against radiation-induced MN in human PBLs after in vitro irradiation (3Gy) and in SLs of C57BL/6 mice after in vivo irradiation (3Gy). The frequency of MN in human PBLs was reduced by water fraction of ginseng (0.5mg/ml of medium) both pre-and post treatment (p<0.0l) in vitro. In addition, the frequency of MN in mouse SLs was also reduced by pretreatment of ginseng (2mg/ml of drinking water for 7days) in vivo. The data suggested that the ginseng may reduce cell damage caused by ${\gamma}$-rays in vitro and in vivo. Further studies are needed to characterize better the protective nature of ginseng extract, its fractions and compounds.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.74-81
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• 2000

Purpose: The purpose of this study was to develop in vivo dosimetries using both chromosomal aberrations and micronuclei in mice to assess biological effects of radiations. Materials and Methods: Five each mice were irradiated with 0, 1, 2, 3, 4, 5, 10 Gy of Cs-137 gamma-rays. We scored numbers of chromosomal aberrations in metaphase spreads and numbers of micronuclei in bone marrow smears under light microscope, and obtained the dose-response relationships. We also examined the relationship between the two dose-response curves. Results: The frequency of both chromosomal aberrations and micronuclei increased with dose, in a linear-quadratic manner The delta, beta, and alpha coefficients were 0.0176, 0.0324, and 0.0567 for metaphase analysis (r=1.0, p<0.001) and 0.0019, 0.0073, and 0.0506 for micronuclei assay (r=1.0, p<0.001). The frequency of chromosomal aberrations and micronuclei in different radiation doses was significantly correlated (r=0.99, p<0.01). Conclusion: In vivo dosimetry using either metaphase analysis or micronucleus assay was feasible in mice. These methods could be useful to evaluate biological effects of radiation.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.99-104
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• 2001

To determine if micronucleus (MN) assay could be used to predict the absorbed dose of victims after accidental radiation exposure, we carried out to assess the absorbed dose depending on the numerical changes of MN in human peripheral blood lymphocytes after $^{60}Co\;{\gamma}-rays$ exposure in the range of 0.25 to 1 Gy, respectively. The MNs were observed at very low doses, and the numerical changes according to doses. Satisfactory dose-effect calibration curve is observed after low dose irradiation of human lymphocytes in vitro. When plotting on a linear scale against radiation dose, the line of best fit was $Y=(0.02{\pm}0.0009)+(0.033{\pm}0.010)D+(0.012{\pm}0.012)D^2$. The dose-response curve for MN induction immediately after irradiation was linear-quadratic and has a significant relationship between the frequencies of MN and dose. These data show a trend towards increase of the numbers of MN with increasing dose. The number of MN in lymphocytes that were observed in the control group is $0.1610{\pm}0.0093/cell$. Accordingly, MN assay in human peripheral lymphocytes could be a useful in viva model for studying radio-protective drug sensitivity or screening test, microdosimertic indicator and radiation-induced target organ injury. Since MN assay is simple, rapid and reproducible, it will also be a biodosimetric indicator for individual dose assessment after accidental exposure.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.525-533
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• 1998

Purpose: Radiation adaptive response in human peripheral lymphocytes and mouse bone marrow cells was investigated using both metaphase analysis and micronucleus assay. We assessed the correlation between both tests. Materials and Methods: Two groups of the human peripheral lymphocytes and mouse bone marrow cells were exposed to low dose (conditioning dose, 0,18 Gy) or high dose (challenging dose, 2 Gy) ${\gamma}$-rays. The other 4 groups were exposed to low dose followed by high dose after several time intervals (4, 7, 12, and 24 hours, respectively). The frequencies of chromosomal aberrations in metaphase analysis and micronuclei in micronucleus assay were counted. Results: Chromosomal aberrations and micronuclei of preexposed group were lower than those of the group only exposed to high dose radiation. Maximal reduction in frequencies of chromosomal aberrations were observed in the group to which challenging dose was given at 7 hour after a conditioning dose (p<0.001). Metaphase analysis and micronucleus assay revealed very good correlation in both human lymphocytes and mouse bone marrow cells (r=0.98, p<0.001 ; r=0.99, p=0.001, respectively). Conclusion: Radiation adaptive response could be induced by low dose irradiation in both human lymphocytes and mouse bone marrow cells. There was a significant correlation between metaphase analysis and micronucleus assay.

• 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.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.112-117
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• 1993

Background Radioiodine ($^{131}I$), a major component of nuclear fallout and a valuable therapeutic agent for thyrotoxicosis and thyroid cancer, has been regarded as a mutagen or a carcinogen without any convincing evidence. To evaluate the genotoxicity of radioiodine ($^{131}I$) we performed a micronuclei test in mice bone marrow. Materials and methods : Mice (ICR strain, $25{\sim}30 g$) were divided to 4 groups: control, group 1 (0.17 mCi/kg, usual therapeutic dose for thyrotoxicosis), group 2 (1.67 mCi/kg, usual therapeutic dose for thyroid cancer), and group 3 (16.67 mCi/kg, usual accumulated dose causing bone marrow suppression). $^{131}I$ was administered intraperitoneally. Ten mice of each group were sacrificed at days 1 and 3. Bone marrow were smeared and stained with May-Grunwald Giemsa method. One thou-sand polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) were counted under the light microscope, and the number of micronucleated PCEs were recorded. Results : The frequency of micronuclei in PCE (and NCE in parenthesis) in the control group was $0.25{\pm}0.07$ ($0.23{\pm}0.07$)% in day 1 and $0.24{\pm}0.07$ ($0.21{\pm}0.07$)% in day 3. Those in group 1 was $0.27{\pm}0.1$ ($0.23{\pm}0.09$)% in day 1 and $0.28{\pm}0.07$ ($0.25{\pm}0.06$)% in day 3. Micronuclei was noted in $0.29{\pm}0.08$ ($0.26{\pm}0.09$)% in day 1 and $0.31{\pm}0.05$ ($0.29{\pm}0.06$)% in day 3 in group 2, and in $0.32{\pm}0.06$ ($0.25{\pm}0.09$)% in day 1 and $0.33{\pm}0.08$ ($0.3{\pm}0.06$)% in day 3 in group 3. There was no difference in the frequency of micronuclei between each groups (p> 0.05). Conclusion : Radioiodine ($^{131}I$) did not cause any genotoxicity in mice bone marrow even at the large dose (16.67 mCi/kg).

• Nuclear Engineering and Technology
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• v.27 no.4
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• pp.635-643
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• 1995

핵의학(nuclear medicine )이 란 방사성 및 안정 핵종의 동위원소표지 화합물을 인체에 투여하여, 관심장기의 형태 및 기능을 평가하여 해부학적 또는 생리학적 상태를 진단, 치료하는 의학의 전문 분야이다. 핵의학에 이용되던 방사성 핵종은 1960년대 까지만 해도 $^{131}$ I이 주였으나 1970년대 부터는 $^{99}$Mo -$^{99m}$ Tc 발생기와 $^{99m}$ TC으로 표지된 방사성의 약품이 활발히 이용되면서 $^{131}$ I을 대신하게 되었다. 원자로-생산핵종들의 특성은 중성자가 과잉이어 붕괴시 배타입자를 방출하는 점으로, 이것이 각종 질병의 치료에 이용되고 있다. 특히 각종 표시 화합물의 성질을 이용하여 원하는 부위에 방사선을 집중시킬 수 있음이 외부조사보다 유리한 점이다. 방사성핵종을 이용한 악성종양의 치료에 가장 성공적인 것은 분화된 갑상선 암환자에서 $^{131}$ I을 사용한 것이며, 갈색세포종 등에 $^{131}$ I-MIBG도 효과적이다. 악성종양의 골전이 치료에 베타선을 방출하는$^{32}$P, $^{186}$ Re, $^{153}$ Sm 등이 이용되었다. 종양의 동맥에 주입하여 세동맥이나 모세혈관에 걸리는 기름, 교진 또는 입자에 의한 치료에 $^{131}$ I-lipiodol, ethiodol, $^{32}$P 또는$^{90}$ Y흡사 ceramic resin 미소구 $^{166}$ Ho 유산중합체 미소구 등이 이용된다. $^{166}$ Ho, $^{198}$ Au, $^{32}$P, $^{90}$ Y, $^{169}$ Er, $^{186}$ Rc, $^{131}$ I, $^{211}$ At 등 의 방사성 핵종의 교질, 미소구 또는 단세포군 항체표지 형태로 직접 종양내 또는 공동이나 체강에 투여하는 치료법이 있다. 류마치스 관절염의 슬관절에 $^{165}$ Dy colloid를 주사하는 $^{166}$ Ho-MAA도 활발히 이용되고 있다.

• Journal of Radiation Protection and Research
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• v.22 no.1
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• pp.1-7
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• 1997

Radiation protection by post-irradiation injection of the ginseng extract in mice was studied. Male ICR mice, 7 weeks old, were orally injected with ginseng extrat(100mg/kg) for 10 days, and with physiologocal saline as the control. Immediately after final injection, mice were whole body irradiated with 5.08Gy(Cs-137 ${\gamma}$-ray, central dose rate : 654Gy/h) which induced Bone marrow death. At 24h after irradiation, micronucleus test and metaphase analysis in bone-marrow were carried, blood cell were counted and the survival rate were carried for 30 days after the irradiation. Stimulated recovery by the extract was observed in thrombocyte count, but that phenomenom was not showed in the erythrocyte and leucocyte counts. The 30-day survival ratio was 5% and 65% for the control and experimental group. Frequencies of micronuclei per 1000 polychromatic erythrocytes were 79.5${\pm}$1.5 in experimental group, 185.9${\pm}$35.8 in control. And Abnormal chromosomes per 50 metaphases were 112 in experimental group and 143 in control.

• Journal of Veterinary Clinics
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• v.21 no.3
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• pp.286-290
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• 2004

Cytogenetic and hematological analysis was performed in peripheral blood of pig in the vicinity of Yeonggwang nuclear power station and control area. The frequency of micronuclei (MN) in peripheral blood lymphocytes from pig was used as a biomarker of radiobiological effects resulting from exposure to environmental radiation. An estimated dose of radiation was calculated by a best fitting linear-quadratic model based on the radiation-induced MN formation from the swine lymphocytes exposed in vitro to radiation over the range from 0 Gy to 4 Gy. MN rates in lymphocytes of pig from Yeonggwang nuclear power station and control area were 10.60/1,000 and 11.10/1,000, respectively. There were no significant differences in MN frequencies and hematological values in pig between Yeonggwang and control area. The study indicates that the MN assay in lymphocyte of pig is a rapid, sensitive and accurate method that can be used to monitor a large population exposed to radiation.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.364-368
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• 2003

Cytogenetic and hematological analysis was performed in peripheral blood from the cattle associated with abnormal delivery around nuclear power plant 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 dose of radiation was calculated by best fitting linear-quadratic model based on the radiation-induced MN data over the range from 0 Gy to 4 Gy from the bovine lymphocytes with in vitro irradiation. MN rates in live malformed calf, dams of malformed calves and other cattle living in the same barn from the regions around nuclear power plant, and cattle in control area were 9/1000, 10.8/1000, 13.3/1000 and 10.0/1000, respectively. There were no significant differences in MN frequencies and hematological values between the cattle associated with abnormal delivery around nuclear power plant area and those of control area. This study indicates that the congenital abnormalities near nuclear power plant seemed to be caused by other aetiology.