• Journal of Species Research
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• 제11권4호
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• pp.287-295
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• 2022

Three oxytrichid ciliates, Oxytricha lithofera Foissner, 2016, Pleurotricha curdsi (Shi et al., 2002) Gupta et al., 2003 and Sterkiella tetracirrata Kumar et al., 2015, were isolated from soils and confirmed as new to South Korea. Oxytricha lithofera was identified based on lithosomes, cortical granules, 21-33 adoral zone membranelles, one left (14-21 cirri) and one right (15-18) marginal rows and 5 transverse cirri. Pleurotricha curdsi was identified based on the possession of 2 macronuclear nodules, 2-3 micronuclei, 46-53 adoral zone membranelles, 3 frontal cirri, 5 frontoventral cirri, 5-7 postoral ventral cirri, 2-3 right marginal rows and 5 transverse cirri. Sterkiella tetracirrata was identified with respect 4 macronuclear nodules, 3-6 micronuclei, 25-40 adoral zone membranelles, 3 frontal cirri, 3 postoral ventral cirri, 2 pretransverse cirri, one left (21-30 cirri) and one right (24-30) marginal row and 4 transverse cirri. On the basis of 18S rDNA sequence analyses, we describe the phylogenetic positions of the three species.

• Biomolecules & Therapeutics
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• 제1권2호
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• pp.183-187
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• 1993

The anticlastogenic effect of galangin, flavonoid derivative, was studied in vivo micronucleus test using C57BL/6 mice. The frequencies of micronuclei induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in bone-marrow cells of C57BL/6 mice were significantly decreased by the simultaneous treatment or multiple pre-treatment of galangin. When galangin was orally administered at 0, 0.1, 1.0, or 10.0 mg/kg twice with 24 hr interval, together with intraperitoneally administered MNNG, there were suppressive effects in the tested doses. The most marked suppressive effect was observed in the treatment group of 1.0 mg/kg (64.5%), not in the treatment group of 10.0 mg/kg (36.3%). When galangin was multiply administered at 1/7 or 1 mg/kg for 7 days respectively, galangin showed higher suppressive effect in the treatment group of 1/7 mg/kg (23.5%) rather than in the treatment group of 1 mg/kg (13.5%). In another experiment, galangin was administered at 0.001, 0.01 or 0.1 mg/kg for 1 month respectively. The suppressive effects in one month treatment gradually increased with dose-dependent manner, although suppressive effects were not high. The results showed that galangin was effective in suppressing the frequencies of micronuclei induced by MNNG. Our study indicates that galangin is a potent anticlastogenic agent against MNNG.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6955-6960
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• 2014

Background: The cytokinesis-block micronucleus (CBMN) assay is a standard cytogenetic tool employed to evaluate chromosomal damage subsequent to pesticide exposure. Objectives: To evaluate the pooled levels of total micronuclei (MN) and binucleated cells with micronuclei (MNC) in 1000 binucleated lymphocytes among population occupationally exposed to pesticides and further determine the more sensitive biomarker of CBMN. Materials and Methods: A meta-analysis on the pooled levels of MN and MNC in binucleated lymphocytes among occupationally pesticide-exposed populations was conducted using STATA 10.0 software and Review Manager 5.0.24 in this study. Results: We found significant differences in frequencies of MN and MNC in 1000 binucleated lymphocytes between pesticide-exposed groups and controls, and the summary estimates of weighted mean difference were 6.82 [95% confidence interval (95% CI): 4.86-8.78] and 5.08 (95% CI: 2.93-7.23), respectively. However, when we conducted sensitivity analyses further, only the MN remained statistically different, but not the MNC, the summary estimates of weight mean difference were 2.86 (95% CI: 2.51-3.21) and 0.50 (95% CI: -0.16-1.17), respectively. We also observed pesticide-exposed subjects had significantly higher MN frequencies than controls among smokers and nonsmokers, male and female populations, and American, Asian and European countries in stratified analyses. Conclusions: The frequency of MN in peripheral blood lymphocytes might be a more sensitive indicator of early genetic effects than MNC using the CBMN assay for occupationally pesticide-exposed populations.

• 한국환경성돌연변이발암원학회지
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• 제16권1호
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• pp.19-23
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• 1996

This study was performed by the sister chromatid exchanges (SCEs) and micronuclei (MN) assays to investigate the adaptive response to ultraviolet light (UV) or ethyl methanesulfonate (EMS) in Chinese hamster ovary (CHO) and Sarcoma 180 (S180) cells. The pretreatment with 1 J/m$^2$ UV or 2 mM EMS decreased the frequency of SCEs induced by the treatment with 5 J/m$^2$ UV or 8 mM EMS in CHO cells. The pretreatment with UV (1 or 2 J/m$^2$) or EMS (1, 2 or 3 mM) did not affect the SCEs induced by the treatment with 7 J/m$^2$ UV or 10 mM EMS in S180 cells. On the other hand, the pretreatment with 1 J/m$^2$ UV or 2 mM EMS decreased the frequency of MN induced by the treatment with 5 J/m$^2$ UV or 8 mM EMS in CHO cells. The pretreatment with UV (1 or 2 J/m$^2$) or EMS (1, 2 or 3 mM) did not affect the frequency of MN induced by the treatment with 7 J/m$^2$ UV or 10 mM EMS in S180 cells. It is suggested that there are adaptive responses at the level of chromosome and micronuclei to UV and EMS in CHO cells.

• Journal of Radiation Protection and Research
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• 제24권4호
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• pp.225-230
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• 1999

본 연구는 이온화 방사선이 자주달개비 화분모세포의 미세핵 생성에 미치는 영향을 분석하여 선량-반응 관계를 수립하고자 수행되었다. 자주달개비의 화분모세포는 감수분열을 통하여 4개의 꽃가루로 발전되는 생식세포로서 분열과정 중에 방사선에 노출되면 염색체 조각이 분리되어 미세핵을 형성한다. 감마선 선량이 증가함에 따라 미세핵 생성률도 증가하였으며 특히 50 cGy까지의 선량범위에서 선량별 미세핵 생성률의 최대값은 뚜렷한 선량-반응관계를 보였다. 선량-반응 관계식을 통해 볼 때 1 cGy의 부가적 선량은 100 사분자당 최대 2개씩의 미세핵을 추가로 생성시키는 것으로 나타났다. 화분모세포 미세핵 생성률의 방사선 지표성은 생물학적 방사선량 감시를 위한 필수선결사항일 뿐 아니라 공해물질의 생체 위해성 검증, 수질과 토양의 건전성 평가 등에 대한 응용성을 갖고 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.5229-5232
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• 2012

The incidence of malignant melanoma increases with age. One significiant effect of aging processes is an accumulation of oxidative damage in the genetical material. In this study, the relationship between malignant melanoma and damage in chromosomes and proliferative effectiveness of human peripheral lymphocytes were investigated by the micronucleus (MN) technique. A total of 15 malignant melanoma patients and appropriately matching 15 healthy controls were involved in the study. MN frequencies and proliferative indexes (PI) after non toxic levels of hydrogen peroxide treatment were also measured to determine damaging effect of oxidative stress in genome in addition to measuring the spontenous levels of micronuclei and PI. The patient group had a significantly higher rate of spontaneous MN than the control group (p<0.01). After treatment with $H_2O_2$, MN frequencies in the patient group was significantly decreased (p<0.01) although there was no difference between the treated and untreated results of control group (p=0.29). There was also difference (p<0.01) between the MN frequencies of the patient and the control group either in the spontaneous levels or in the $H_2O_2$ treated groups. The same significant difference persisted when the PI values were compared between patient and control groups. Increase in the MN frequency in patients could mean the alterations in the chromosomal structure which may lead to the chromosome instability and therefore genetic susceptibility to cancer. This increased number of micronuclei can also be used for cytological marker in identifying high risk cases for malignant melanoma.

• Journal of Applied Biological Chemistry
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• 제62권4호
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• pp.355-359
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• 2019

In vivo micronucleus tests were performed to investigate the mutagenic potential of 4-butylaniline and N-butylaniline, which are used in dye intermediates and organic intermediates respectively. Groups of 5 male ICR mice were treated with vehicle or 4-butylaniline for 2 consecutive days by oral gavage at concentrations of 0 (control), 64, 160, 400, and 1000 mg/kg. Statistically significant and dose-dependent increases were found for micronuclei frequencies in male mice (p <0.05). These results suggest that 4-butylaniline can induce genetic effects in the micronuclei of male mouse bone marrow cells. Based on the positive results obtained in cytogenetic analyses of somatic cells in vivo, Globally Harmonized System of Classification and Labelling of Chemicals Category 2 was assigned. N-butylaniline was administered for 2 consecutive days by oral gavage to male ICR mice at dose of 0 (control), 64, 160, 400, and 800 mg/kg. N-butylaniline tested negative for micronuclei induction in mice, although N-butylaniline was associated with micronucleus induction at the highest dose. Based on the negative results obtained for cytogenetic analyses of somatic cells in vivo, "Not Classified" was assigned.

• Korean Journal of Acupuncture
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• 제39권2호
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• pp.54-62
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• 2022

Objectives : The purpose of this study was to evaluate the potential of the test substance, SU-Eohyeol Pharmacopuncture (SUEP), to induce micronuclei in bone marrow cells of Sprague-Dawley (SD) Rats. Methods : The dose range preliminary study was performed first. 1 ml/animal was selected as the high dose of this study. Two additional lower dose levels (0.5 and 0.25 ml/animal) were produced by applying a geometric ratio of 2. In addition, the positive and negative control groups were set. Then, after intramuscular administration (1 ml/animal) of SUEP to 8-week-old male SD rats, an in vivo micronucleus test was performed to evaluate the induction of micronuclei in SD rat bone marrow cells. Results : As a result of the main study, the incidence of micronucleated polychromatic erythrocytes (MNPCE) in polychromatic erythrocytes (PCE) in the test substance SUEP groups was not statistically significantly different from the negative control group. In addition, the ratio of PCE to total erythrocytes in the test substance SUEP groups was not statistically significantly different from the negative control group. In the positive control group, the incidence of MNPCE in PCE was statistically significantly increased when compared to the negative control group. The ratio of PCE to total erythrocytes in the positive control group was not statistically significantly different from the negative control group. Conclusions : Based on these results, the test substance, SUEP, did not have any potential to induce micronuclei formation in bone marrow cells of rats under the conditions of this study.

• Radiation Oncology Journal
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• 제11권1호
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• pp.35-42
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• 1993

원자력 시설 이용 증대에 따른 불의의 방사선 사고에 대비하여 방사선 작업종사자의 피폭시 진단을 위한 검사방법이 필요하다. 이 방법은 검사를 위한 검체의 채취가 용이하고, 짧은 시간내에 간편하게 많은 Sample을 처리하여야 한다는 조건을 만족시켜야 한다. 인체의 다양한 조직 및 세포 중에서 위의 조건을 만족시킬 수 있는 말초 혈액의 림파구는 비교적 방사선에 대한 감수성이 높다고 알려져 있으며, 채집 또한 용이하여 생물학적 선량 측정의 도구로써 이용가치가 높아 방사선 작업 종자사나 피폭 가능성이 있는 사람의 screening test에 사용될수 있다. 정상인에 있어서의 림파구내 미세핵 존재 여부와 방사선 피폭량에 따른 미세핵 발생빈도를 시험관내 실험을 통하여 표준화시켜 향후 방사선 피폭시 피폭선량을 역으로 산출해 낼 수 있는 방사선 장해의 평가 기술 개발의 기초자료를 마련하기 위하여 본 실험을 시행하였다. 정상인으로 부터 혈액을 채취하여 림파구만을 Ficoll-Hypaque gradient 방법으로 추출하여 배양한 다음, 본 치료방사선과의 중성자 치료기 (MC-50, scanditronix)와 Co-60 teletherapy unit(Theratron-780, AECL)를 이용하여 방사선 조사를 시행하였다. Cytokinesis-block method를 이용하여 첫번째 분열을 한 림파구에서 미세핵(Micronucleus)을 현미경을 통하여 계수한 다음, 이의 선량-반응 관계식을 linear-quadratic model을 사용하여 구하고, 이를 근거로 하여 gamma-ray에 대한 중성자의 Relative biological effectiveness (RBE)를 산출하였다. 방사선에 피폭되지 않은 림파구의 미세핵 발생빈도는 binucieated cell한 개당 $0.013{\pm}0.0002$로써 사람에 따라 통계학적으로 큰 차이를 보이지 않았다. 그림 2와 3에서 보는 바와 같이 개개인으로부터 얻은 data는 감마선과 중성자선 모두에서 선량-반응 곡선의 linear-quadratic equation에 잘 일치하였다. 감마선과 중성자선 모두에서 선량에 따른 미세핵의 발생빈도는 선량이 높을수록 비례하여 증가하였는데, 감마선의 경우에는 $r^2=1.000,\;x^2=0.7074$, p=0.95였으며, 중성자선인 경우에는 $r^2=0.996,\;x^2=7.6834$, p=0.11 였다. 이를 linear-quadratic model로 분석하면, 가장 적합한 선은 감마선인 경우에는 y= ($0.31{\pm}0.049)\;D+(0.0022{\pm}0.0002)\;D^2+(13.19{\pm}1.854$) 였으며, 중성자선인 경우에는 y=($0.99{\pm}0.528)\;D+(0.0093{\pm}0.0047)\;D^2+(13.31{\pm}7.309$) 였었다. 감마선에 대한 중성자선의 상대적 생물학적 효과비 (RBE)는 y=aD+$bD^2$+c를 다음과 같은 식으로 변형시켜 계산하였다. $$\frac{[-a{pm}\sqrt{a^2-4b\;(c-y}}]}{2{\times}6}$$ 미세핵 발생빈도가 세포당 0.05와 0.8사이에서의 중성자선의 상대적 생물학적 효과비는 $2.37{\pm}0.17$ 이었다. 이상의 결과를 종합하여 볼 때 선량에 따른 미세핵 발생빈도는 기존의 방사선 감수성 test의 결과와 대동소이하여, 앞으로 방사선 감수성을 측정하는 방법으로 이용할 수 있으며, 또한 실험방법이 비교적 간단하며 짧은 시간에 결과를 도출할 수 있어 생물학적 선량측정 도구로써 널리 이용될 수 있을 것으로 생각되어 진다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1204-1205
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• 2004