• Journal of Environmental Health Sciences
• /
• v.23 no.4
• /
• pp.9-15
• /
• 1997

This experiment was carried out to examine the roles of selenium in arsenic- and chromium-induced oxidative stress, which results in chromosomal damage, such as sister chromatid exchange (SCE) and chromosomal aberration (CA). For this purpose, the frequency of CA and SCE related to the level of 0xidative stress were analyzed. Selenium decreased the frequency of CA induced by As. In order to evaluate the effect of selenium on clastogenic factors, media from As- and Cr-treated cells were ultrafiltered and added again to cells in the presence or absence of selenium. Selenium decreased the frequency of SCE by As and Cr. This observation indicates the possibility of presence of clastogenic factor. In addition, the clastogenic factor would be involed in oxidative stress since selenium decreased the level of oxidative stress. Thus, it is suggested that selenium may play a role as an anti-clastogenic effector by preventing the oxidative stress, thereby decreasing the frequency of Asand Cr-induced chromosomal damage.

• The Korean Journal of Nuclear Medicine
• /
• v.27 no.1
• /
• pp.118-122
• /
• 1993

To evaluate the genotoxic effect of $^{131}I$, lymphocytes from 9 patients who underwent large dose (150 mCi) $^{131}I$ therapy after total thyroidectomy were studied for sister chromatid exchanges (SCE) before and after their first radioiodine treatments. Frequency of SCE (FSCE) was counted in chromosomes of 30 lymphocytes in each patients, and was expressed as numbers of SCE per cell. Numbers of leukocytes were also observed during $^{131}I$ therapy. Pretreatment FSCE ($4.2{\pm}0.7$) was not different from the control ($3.8{\pm}0.4$, p=0.17). However, the frequency was significantly elevated after $^{131}I$ administration (at the second day, $7.9{\pm}0.8$, p<0.001) and was diminished but still significantly elevated after a week (at 9th day, $6.4{\pm}0.6$, p<0.001). While counts of leukocytes in the peripheral blood showed no change (p> 0.05). In conclusion, chromatids of human lymphocytes were significantly damaged after $^{131}I$ treatment without any bone marrow supression. And the repair of SCE was not complete within one week.

• Journal of Preventive Medicine and Public Health
• /
• v.19 no.2 s.20
• /
• pp.244-251
• /
• 1986

Sister chromatid exchanges(SCEs) and cell cycle kinetics were proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity in short-term cultures of phytohema-gglutinin(PHA)-stimu1ated human 1ymphocytes. Therefore, this study was performed to investigate the relation between the cytotoxic effects and sister chromatid exchanges. The resultes are summarized as follows: 1) The frequency of SCEs per cell are $13.1{\pm}2.8$ in the lower concentration of $6.25{\times}10^{-9}M\;and\;75.8{\pm}8.2$ in the highest concentration of $1.00{\pm}10^{-7}M$. Mitotic index is decreased in the higher concentration of mitomycin C. The result indicates that mitomycin C led to a dose dependent increase in SCE frequency, but decease in mitotic index. 2) Chromosomal analysis was performed on metaphase cells that have divided one, two, and three or more times for cell cycle kinetics by fluorescence-plus-Giemsa(FPG) technique. According to the increased concentration of mitomycin C, the proportion of metaphase cells in the first are profoundly increased but the cells of third division are greatly decreased. 3) The frequency of SCEs per chromosome by chromosomal group are decreased gradually from A group to G group. But relationships between specific chromosomal group and SCE frequency are not found.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.14 no.2
• /
• pp.144-150
• /
• 2016

Purpose: Glyphosate is a widely used non-selective herbicide. Previous studies have shown that glyphosate has genotoxicity, and that even low-doses of glyphosate can cause DNA damage. Melatonin is a hormone produced and secreted by the pineal gland that is known to be a potent anti-carcinogen, anti-oxidant, and genetic protector. This study was conducted to investigate the genoprotective effect of melatonin against glyphosate in human blood lymphocytes. Methods: Human peripheral blood was obtained from 15 young, healthy volunteers and cultured under four different toxicologic conditions. The four groups consisted of a control group, glyphosate only group (300 ng/mL), glyphosate with low level of melatonin group ($50{\mu}M$), and glyphosate with high level of melatonin group ($200{\mu}M$). The mean Sister Chromatid Exchange (SCE) frequency of each group was then analyzed. Results: Glyphosate exposed groups had a higher mean SCE frequency ($10.33{\pm}2.50$) than the control group ($6.78{\pm}2.31$, p<0.001). Interestingly, the group that received a low-level of melatonin had a lower mean SCE frequency ($8.67{\pm}2.58$) than the glyphosate-only group, while the group that received a high level of melatonin had a much lower mean SCE frequency ($8.06{\pm}2.50$) than the glyphosate-only group. There was statistical significance. Conclusion: Melatonin exerted a potent gene protective effect against the genotoxicity of glyphosate on human blood lymphocytes in a dose-dependent fashion.

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

• Clinical and Experimental Reproductive Medicine
• /
• v.23 no.3
• /
• pp.379-384
• /
• 1996

This study was undertaken to investigate the sister chromatid exchange (SCE) frequency and embryonic development after exposure to cryoprotectants and vitrification of mouse zygotes. Mouse IVF zygotes were cryopreserved by vitrification using vitrification solution, EFS40 (40% ethylene glycol, 30% Ficoll and 0.3 M sucrose in phosphate buffer saline containing 10% FBS). After mouse zygotes were exposed to EFS40 at $25^{\circ}C$ for 30 sec., they were immediately plunged into $LN_2$ or cultured for cryoprotectant toxicity test without freezing. The results obtained in these experiments were summarized as follows: After thawing, survival rates to the 2-cell stage of zygotes exposed to or vitrified in EFS 40 (98.5%, 95.2%) were not significantly difference compared with that of control (100%). However, the developmental rates upto blastocyst and hatching blastocyst in vitrified groups (66.7, 50.0%) were lower than those of control (93.9, 81.8%) or exposed group (94.0, 78.8%) (p<0.05). When the influence of vitrification and exposure to cryoprotectant on the in vitro development of mouse zygotes was assessed by the SCE frequency, the SCE frequency in exposed ($20.2{\pm}2.1$) to or vitrified embryos ($21.4{\pm}3.2$) was higher than that in control embryos ($16.8{\pm}1.5$). These results suggest that the frequency of SCE was increased after cryoprotectant exposure or Vitrification although developmental rates of zygotes upto blastocysts and /or hatching blastocysts were not afected by cryoprotectant.

• Journal of Korean Biological Nursing Science
• /
• v.2 no.2
• /
• pp.90-101
• /
• 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 Preventive Medicine and Public Health
• /
• v.20 no.1 s.21
• /
• pp.1-9
• /
• 1987

Sister chromatid exchanges (SCEs) observed by means of bromodeoxyuridine substitution and fluorescence plus Giemsa (FPG) technique were proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity in short-term cultures of phytohaemagglutinin (PHA)-stimulated human lymphocytes. Therefore, this study was carried out to investigate the relation between anticancer agents and cytotoxic effects. Chromosomal analysis was performed on metaphase cells that had divided one, two, or three or more times after treatment for SCEs, mitotic indices (MI) and cell cycle kinetics by FPG technique. The results indicate that anticancer agents led to a dose dependent increase in SCE frequency except methotrexate. But, highly inhibited mitotic indices and delayed cell cycle kinetics were observed except for cyclophosphamide. The author suggest that the difference of SCE frequency is due to the differences in the cytotoxic action of anticancer agents, but although the induction of SCEs has a correlation with cell cycle delay, in some cases the induction of SCEs is not always related to cell cycle delay because of different cytotoxic action of anticancer agents.

• Korean Journal of Food Science and Technology
• /
• v.31 no.3
• /
• pp.823-830
• /
• 1999

The suppressing effects of crude extracts of three Korean teas, persimmon leaf tea extract (PLTE), green tea extract (GTE) and oolong tea extract (OTE), were studied on the induction of sister chromatid exchange (SCE) in cultured Chinese hamster ovary cells. When cells were treated with tea extract after mitomycin C (MMC) treatment, the frequency of MMC-induced SCEs were decreased at the high concentration $(1000\;{\mu}g/mL)$ of PLTE in the presence of S9 mix and at low concentrations $(20{\sim}80\;{\mu}g/mL)$ of PLTE in the absence of S9 mix, Whereas GTE and OTE showed suppressing effects on the MMC-induced SCEs at low concentrations $(10{\sim}20\;{\mu}g/mL)$ for OTE and $160\;{\mu}g/mL$ for GTE only in the presence of S9 mix. MMC-induced SCEs were decreased by post-treatment with each tea extracts with S9 mix in the G1 phase of the cell cycle. These results suggest that PLTE, GTE and OTE could have bio antimutagenic activities, and also suggest that PLTE might have unknown antimutagenic components which would be responsible for the inhibitory effect against direct acting mutagenicity.

• Journal of Preventive Medicine and Public Health
• /
• v.31 no.4 s.63
• /
• pp.616-627
• /
• 1998

In order to evaluate the cytogenetic hazard among hospital workers potentially exposed to low dose of radiation, the analysis of chromosome aberrations(CA) and sister chromatid exchanges(SCE) in lymphocytes were performed in 79 hospital workers and 79 non-exposed workers. The mean frequency of chromosomal exchange and deletion(respectively, $0.20\times10^{-2}/cell\;and\;0.39\times10^{-2}/cell$) in the exposed group were significantly higher than those$(0.07\times10^{-2}/cell\;and\;0.23\times10^{-2}/cell)$ in control group. The frequency of sister chromatid exchanges was 5.04/cell in the control vs. 6.57/cell in the exposed group. There were also significant differences in the mean frequencies of CA and SCE adjusted for age, sex, smoking, drinking between two groups. There were no evidence of significant increase of CA and SCE according to the department or duration of employment. But the frequency of cells having chromosome aberration was significantly higher in the exposed group than in the control group related to duration of employment. There was no dose-effect relationship between the cumulative doses and the frequency of CA and SCE. But in the case of last 1 yr cumulative dose, there were evidence of significant dose-dependant increase of chromosome type CA and percentage of cells with aberration. The result suggest that there is cytogenetic hazard in risk group like hospital workers handling low dose radiation. And the analysis CA and SCE are useful biological indicators for the exposure of low dose level of radiation.