• Toxicological Research
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• v.9 no.1
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• pp.45-60
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• 1993

The present study was carried out to evaluate the cytotoxicity of cadmium on cultured rat fibroblasts. The colorimetric assays of neutral red and tetrazolium MTT, the lactatedehydrogenase activity, the amounts of total protein, the rate of DNA synthesis, the amounts of unscheduled DNA synthesis, the frequency of sister chromatid exchange, the releasing rate of intracellular calcium, and light and electron microscopic studies were performed on cultured rat fibroblasts maintained in the media containing various concentrations of cadmium. The results were as follows: The neutral red(NR) and MTT values were decreased dose-dependently by cadmium, and the NR90, NR50, MTT90 and MTT50 values of cadmium were 0.2mM, 21.5mM, 1.0Mm and 60.0Mm, respectively.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.598-605
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• 2015

The cohesin complex holds sister chromatids together and prevents premature chromosome segregation until the onset of anaphase. Mcd1 (also known as Scc1), the α-kleisin subunit of cohesin, is a key regulatory subunit of the mitotic cohesin complex and is required for maintaining sister chromatid cohesion, chromosome organization, and DNA repair. We investigated the function of Mcd1 in meiosis by ectopically expressing Mcd1 during early meiotic prophase I in Saccharomyces cerevisiae. Mcd1 partially regulated the progression of meiotic recombination, sister chromatid separation, and nuclear division. DNA physical analysis during meiotic recombination showed that Mcd1 induced double-strand breaks (DSBs) but negatively regulated homologous recombination during DSB repair; Mcd1 expression delayed post-DSB stages, leading to inefficiencies in the DSB-to-joint molecule (JM) transition and subsequent crossover formation. These findings indicate that meiotic cells undergo Mcd1-mediated DSB formation during prophase I, and that residual Mcd1 could regulate the progression of JM formation during meiotic recombination.

• Nutritional Sciences
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• v.5 no.3
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• pp.134-145
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• 2002

No Abstract, See Full-text

• Journal of Korean Biological Nursing Science
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• v.2 no.2
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• pp.90-101
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• 2000

This study is being carried out, in two different random sample groups, between 20 men who were radiation exposed workers in the two general hospitals located in "T" city as a experimental group and 20 healthy men who were non-radiation exposed workers as a control group. The occurring frequency of the sister chromatid exchange as a biological dosemeter of radiation were studied. And the age, duration of employment and smoking were used as variable for the experiment. The results are as follows : The frequency of SCE were noticed respectively by each variable : 1) by age as a variable, the frequency were increased notably in radiation exposed workers group rather than a control group(p<0.05). 2) by duration of employment, the difference of the frequency were not recognised significantly in statistical among radiation exposed workers. 3) in smoker the frequency were increased notably in a radiation exposed workers than a control groups(p<0.05). Taking into consideration the above results, the age and smoking could affect the frequency of SCE, however, the size of sample were too small to generalize. Therefore, the following suggestions are recommended to get more accurate result. 1) In order to clarify the correlation in a smoking as variable, finding the volume of smoking and its related factor are necessarily required. 2) In order to confirm the correlation in each variable, adopting of a bigger-sized sample are needed and the study itself also be carried out repeatedly.

• Journal of The Korean Society of Clinical Toxicology
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• v.12 no.1
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• pp.8-13
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• 2014

Purpose: Glyphosate (N-phosphonomethyl glycine) is widely used as an herbicide for weed control in rural areas. It is also readily available for suicide attempts. Glyphosate has high toxicity and negatively affects the human body. The aim of this investigation was to study the genotoxicity of a low-concentration of glyphosate through sister chromatid exchange (SCE) in human blood lymphocytes in vitro. Methods: Primary lymphocyte cultures were obtained from blood samples of 11 males and seven females who had been exposed to glyphosate (0, 100, 200, and 300 ng/mL). The frequency of SCEs was examined and statistical analysis was performed. Results: All doses of glyphosate induced a significant dose-dependent increase in SCE frequency compared with the control group (P<0.001). In particular, the SCE frequency for exposure to low-dose glyphosate was significantly higher in females than in males. Conclusion: According to the result of this study, even a low-dose of glyphosate may damage DNA and females are more vulnerable to glyphosate.

• Journal of The Korean Society of Clinical Toxicology
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• v.14 no.2
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• pp.78-82
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• 2016

Purpose: Green tea is known as a potent anti-oxidant, anti-carcinogen, and genetic protector. Glyphosate (N-phosphonomethyl glycine) is a widely used non-selective herbicide that causes DNA damage. The present study was conducted to investigate the protective effects of green tea in human blood lymphocytes exposed to glyphosate using the Sister Chromatid Exchange (SCE) frequency method. Methods: Peripheral blood was obtained from 10 volunteers and cultured through four different conditions. Four groups were divided into control, glyphosate only (300 ng/mL), glyphosate and low ($20{\mu}m$) concentrations of epigallocatechin gallate (EGCG) and glyphosate and high ($100{\mu}m$) concentrations of EGCG. Results: The glyphosate exposed groups had a higher mean SCE frequency ($10.33{\pm}2.50$) than the control group ($6.38{\pm}2.28$, p<0.001). The low concentrations of EGCG groups had a lower mean SCE frequency ($9.91{\pm}1.93$) than the glyphosate-only group, although this difference was not significant (p=0.219). However, the high concentration group ($9.49{\pm}1.85$) had a significantly lower SCE frequency than the glyphosate-only group (p=0.001). Conclusion: EGCG has a gene protective effect in human lymphocytes exposed to the genotoxicity of glyphosate in the case of high concentrations.

• Toxicological Research
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• v.3 no.1
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• pp.15-26
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• 1987

The mutagenicity of pranoprofen, a new antiinflammatory agent primarily used in Japan, was evaluated by employing several different methods such as the Ames test, micronucleus test, and the sister chromatid exchange test. For the Ames test, various doses of pranoprofen (5 and 1 mg, 100, 10, and 1 ${\mu}$g per plate) were applied, with or without the mammalian liver S-9 fraction, to the S. typhimurium LT2. For the micronucleus test, 24 hours after administering the various doses of pranoprofen (200, 100, and 50 mg/kg) to male mice by aral intubation, the femura of each group were isolated and the bone marrow samples were prepared. The micronucleated red cells and the ratio of the polychromatic versus the normochroomatic cells were counted. For the sister chromatid exchange test, the maximal non-cytotoxic concentrations (10 to 0.1 mM pranoprofen) were applied to the culture media of the Chinese Hamster Ovary (CHO) cells for 24 hrs. The numbers of revertant colonies did not increase with the increasing doses of pranoprofen when teseted with various strains of S. typhimurium. In the micronucleus test employing mice, the pranoprofen was identkfied to be a non-clastogen and a non-spindle poison. In the sister chromatid exchange test employing the cultured CHO cells, the pranoprofen did not increase the incidences of chromosomal abnormality. Based on these results, pranoprofen was found to have no mutagenic activity.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9725-9730
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• 2014

Background: Sister chromatid exchange (SCE) in human peripheral blood lymphocytes is one of the most extensively studied biomarkers employed to evaluate genetic damage subsequent to pesticide exposure. Objective: To estimate the pooled levels of SCE in human peripheral blood lymphocytes among population exposed to pesticide. Materials and Methods: Meta-analysis on the association between SCE frequency and pesticide exposure was performed with STATA 10.0 software package and Review Manager 5.0.24 in this study. Results: The overall means of SCE were 7.88 [95% confidence intervals (95%CI): 6.71-9.04] for exposure group and 6.05 (95%CI: 5.13-6.95) for controls, respectively. There was statistically significant difference in the SCE frequency in human peripheral blood lymphocytes between pesticide-exposed groups and control groups, and the summary estimate of weighted mean difference was 1.69 (95%CI: 1.01-2.38). We also observed that pesticide-exposed population had significantly higher SCE frequency than control groups among smokers, nonsmokers, pesticide applicator, pesticide producer, other exposure population and Asian population in stratified analyses. Conclusions: Data indicate that the SCE frequency in human peripheral blood lymphocytes might be an indicator of early genetic esffects for pesticide-exposed populations.

• Journal of Preventive Medicine and Public Health
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• v.34 no.3
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• pp.269-276
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• 2001

Objectives : To evaluate the internal burden and hazardous effects associated with smoking in middle and high school students. Methods : We analysed urinary cotinine(U-cotinine) concentrations and the frequency of Sister Chromatid Exchanges (SCE). A comparison was done of U-cotinine concentrations and the frequency of SCE in peripheral lymphocytes across school levels (middle vs. high) and smoking types (direct: daily & occasional smoking, indirect; usual indirect & non-smoking), in 122 males. Results : The middle school student group comprised 6.8% daily smokers, 15.9% occasional smokers, 40.9% daily indirect smokers, and 35.4% nonsmokers, while the high school student group comprised 18.0%, 20.5%, 35.7%, and 21.8%, respectively. The U-cotinine concentration and the frequency of SCE among the middle school students were $79.11{\mu}g/l$ and 2.0 per cell, respectively, which were significantly lower than the $146.85{\mu}g/l$ (p=0.078) and 2.6 per cell (p=0.005) of the high school students. Among the 40 direct smokers, these two biomarkers were $236.66{\mu}g/l$ and 2.59 per cell, significantly higher than the $67.33{\mu}g/l$ (p=0.0001) and 2.1 per cell (p=0.003) among indirect smoking groups. The variation in individual U-cotinine concentration ranged widely in both the indirect and direct smoking groups. Conclusion : Urinary cotinine concentrations and the frequency of Sister Chromatid Exchange seem to objectively and effectively evaluate student exposure whether it was direct or indirect smoking. Consequently, these biomarkers may be useful in monitoring the objective efficacy of anti-smoking programs in adolescent populations.

• Journal of Preventive Medicine and Public Health
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• v.23 no.1 s.29
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• pp.1-10
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• 1990

The protective effect of sodium selenite($Na_2SeO_3$) against the cytogenetic toxicity of heavy metals was investigated on human whole-blood cultures in relation to induction of sister chromatid exchange (SCE) in secondary metaphase chromosome. Methylmercury chloride($CH_3HgCl$), cadmium chloride($CdCl_2$), potassium dichromate($K_2Cr_2O_7$), and sodium selenite caused to the typically dose-dependent increase in sister chromatid exchanges (SCEs) by the concentrations ranging from $0.3{\mu}M\;to\;10{mu}M$. However, the inductions of sister chromatid exchanges by methylmercury chloride or cadmium chloride were inhibited by the simultaneous addition of sodium selenite $1.2{mu}M$. The frequencies of SCE were decreased to the level of control in the molar ratios as 2:1, 1:1, 1:2, and 1:4 of selenium selenite vs. methylmercury chloride, and as 1:1 and 1:2 of selenium selenite vs. cadmium chloride, while the frequencies of SCE induced by potassium dichromate were not changed by the addition of sodium selenite in culture condition. Mitotic indices were decreased in the higher concentrations of chemicals and not significantly changed by the simultaneous addition of sodium selenite to the culture condition containing each chemicals.