• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.268-275
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• 2004

To investigate the potential application of the single-cell gel electrophoresis (SCGE) assay to carp as an aquatic pollution monitoring technique, gill, liver, and blood cells were isolated from carp exposed to a direct-acting mutagen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), or indirect mutagen, $benzo[\alpha]pyrene$ $(B[\alpha]P)$, then the DNA strand breakage was analyzed using the assay. Based on testing 5 different cell isolation methods and 6 electrophoretic conditions, the optimized assay conditions were found to be cell isolation by filter pressing and electrophoresis at a lower voltage and longer running time (at 0.4 V/cm for 40 min). In preliminary experiments, gill and liver cells isolated from carp exposed to MNNG in vitro exhibited DNA damage signals even with 0.5 ppb exposure, which is a much higher dose than previously reported. In the gill cells isolated from carp exposed to 0.01-0.5 ppm MNNG in vivo, significant dose-and time-dependent increases were observed in the tail for 4 days. As such, the linear correlation between the relative damage index (RDI) values and time for each dose based on the initial 48-h exposure appeared to provide effective criteria for the genotoxicity monitoring of direct-acting mutagenic pollution. In contrast, the in vivo exposure of carp to 0.25-1.0 ppm of $B[\alpha]P$ for 7 days resulted in dose-and time-dependent responses in the liver cells, in which 24-h delayed responses for metabolizing activation and gradual repair after 48 h were also observed. Thus, the negative-sloped linear correlation between the RDI and time at each dose based on the initial 48 h appeared to provide more effective criteria for the genotoxicity monitoring of indirect mutagenic pollution.

• Preventive Nutrition and Food Science
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• v.20 no.1
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• pp.52-59
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• 2015

This study was to investigate the preventive effect of taemyeongcheong (TMC, a Korean traditional health drink) on acetaminophen (APAP, 800 mg/kg BW)-induced hepatic damage in ICR mice. TMC is prepared from Saururus chinensis, Taraxacum officinale, Zingiber officinale, Cirsium setidens, Salicornia herbacea, and Glycyrrhizae. A high dose of TMC (500 mg/kg BW) was found to decrease APAP-induced increases in serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase. TMC pretreatment also increased the hepatic levels of hepatic catalase, superoxide dismutase, glutathione peroxidase, and glutathione, and reduced serum levels of the inflammatory cytokines tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-6 in mice administered APAP (P<0.05). TMC (500 mg/kg BW) reduced hepatic mRNA levels of TNF-${\alpha}$, IL-$1{\beta}$, IL-6, COX-2, and iNOS by 87%, 84%, 89%, 85%, and 88%, respectively, in mice treated with APAP (P<0.05). Furthermore, histological observations suggested TMC pretreatment dose-dependently prevented APAP-induced hepatocyte damage. These results suggest that TMC could be used as a functional health drink to prevent hepatic damage.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.312.2-313
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• 2003

The purpose of this study was to report dose-independent pharmacokinetics of KR-31543, a new neuroprotective agent for ischemia-reperfusion damage, after intravenous and oral administration and first-pass effects after intravenous. intraportal, intragastric, and intraduodenal administration in rats. After intravenous (10, 20 and 50 mg/kg) and oral (10, 20 and 50 mg/kg) administration, the pharmacokinetic parameters of KR-31543 were dose-independent. (omitted)

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1773-1777
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• 2016

Diagnostic and therapeutic radiation fields are planned so as to reduce side-effects while maximising the dose to site but effects on healthy tissues are inevitable. Radiation causes strand breaks in DNA of exposed cells which can lead to chromosomal aberrations and cause malfunction and cell death. Several researchers have highlighted the damaging effects of high dose radiation but still there is a lacuna in identifying damage due to low dose radiation used for diagnostic purposes. Blood is an easy resource to study genotoxicity and to estimate the effects of radiation. The micronucleus assay and chromosomal aberration can indicate genetic damage and our present aim was to establish these with lymphocytes in an in vitro model to predict the immediate effects low dose radiation. Blood was collected from healthy individuals and divided into 6 groups with increasing radiation dose i.e., 0Gy, 0.10Gy, 0.25Gy, 0.50Gy, 1Gy and 2Gy. The samples were irradiated in duplicates using a LINAC in the radiation oncology department. Standard protocols were applied for chromosomal aberration and micronucleus assays. Metaphases were stained in Giemsa and 200 were scored per sample for the detection of dicentric or acentric forms. For micronuclei detection, 200 metaphases. Giemsa stained binucleate cells per sample were analysed for any abnormality. The micronuclei (MN) frequency was increased in cells exposed to the entire range of doses (0.1-2Gy) delivered. Controls showed minimal MN formation ($2.0%{\pm}0.05$) with triple MN ($5.6%{\pm}2.0$) frequency at the lowest dose. MN formation increased exponentially with the radiation dose thereafter with a maximum at 2Gy. Significantly elevated numbers of dicentric chromosomes were also observed, even at doses of 0.1-0.5Gy, compared to controls, and acentric chromosomes were apparent at 2Gy. In conclusion we can state that lymphocytes can be effectively used to study direct effect of low dose radiation.

• Journal of Radiation Protection and Research
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• v.48 no.1
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• pp.44-51
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• 2023

Background: Aptamers are currently being used in various fields including medical treatments due to their characteristics of selectively binding to specific molecules. Due to their special characteristics, the aptamers are expected to be used to remove radionuclides from a large amount of liquid radioactive waste generated during the decommissioning of nuclear power plants. The radiological effects on the aptamers should be evaluated to ensure their integrity for the application of a radionuclide removal technique. Materials and Methods: In this study, Monte Carlo N-Particle transport code version 6 (MCNP6) and Monte Carlo damage simulation (MCDS) codes were employed to evaluate the radiological effects on the aptamers. MCNP6 was used to evaluate the secondary electron spectrum and the absorbed dose in a medium. MCDS was used to calculate the DNA damage by using the secondary electron spectrum and the absorbed dose. Binding experiments were conducted to indirectly verify the results derived by MCNP6 and MCDS calculations. Results and Discussion: Damage yields of about 5.00×10^-4 were calculated for 100 bp aptamer due to the radiation dose of 1 Gy. In experiments with radioactive materials, the results that the removal rate of the radioactive ⁶⁰Co by the aptamer is the same with the non-radioactive ⁵⁹Co prove the accuracy of the previous DNA damage calculation. Conclusion: The evaluation results suggest that only very small fraction of significant number of the aptamers will be damaged by the radioactive materials in the liquid radioactive waste.

• Journal of Radiation Protection and Research
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• v.40 no.2
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• pp.110-117
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• 2015

Recently, Due to the increased industry using radiation inspection equipment in the semiconductor, this demand of technology research is increasing. Although semiconductor inspection equipment is using low energy X-ray from 40 keV to 120 keV, Studies of radiation damage about the low energy X-ray are lacking circumstance in our country. Therefore, It is study that BJT (bipolar junction transistor) of one type of semiconductor elements are received radiation damage by low energy X-ray. BJT were used to the NXP semiconductor company's BC817-25 (NPN type), and Used the X-ray generator for the irradiation. Radiation damage of BJT was evaluated that confirm to analyse change of collector-emitter voltage of before and after X-ray irradiation when current gain fixed to 10. X-ray generator of tube voltage was setting 40 kVp, 60 kVp, 80 kVp, 100 kVp, 120 kVp and irradiation time was setting 180s, 360s, 540s into 180s intervals. As the result, We confirmed radiation damage in BJT by low energy X-ray under 120 keV energy, and Especially the biggest radiation damage was appeared at the 80 kVp. It is expected that ELDRS (enhanced low dose rate sensitivity) phenomenon occurs on the basis of 80 kVp. This studies expect to contribute effective dose administration of semiconductor inspection equipment using low energy X-ray, Also Research and Development of X-ray filter.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.135-141
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• 2001

Endocrine disruptors have been implicated in carcinogenesis in animal studies, but carcinogenetic effects on human remain controversial. In order to examine the genotoxicity of two common endocrine disruptors, Bisphenol A and Diethylstilbestrol, cytogenetic endpoints including chromosome aberration (CA), sister chromatid exchange (SCE), micronuclei (MN) analyses and DNA damage by single cell gel electrophoresis (SCGE) were assessed. The effects of Bisphenol A and Diethylstilbestrol on the frequencies of CA and MN were increased in a dose-dependent manner and that of Bispheol A was more significant by Kendall'$\tau$test. Bisphenol A and Diethylstilbestrol also increased the frequency of SCE. Bisphenol A and Diethylstilbestrol induced DNA damage in a dose-dependent manner and the DNA damage induced by Diethylstilbestrol in human blood lymphocytes was more significant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.346-351
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• 2003

Single-cell gel electrophoresis (comet assay) was used to detect DNA single strand break in blood cells from several marine fish species. Three fish species were collected from Georgia coastal area. Mummichog, Fundulus heteroclitus showed higher DNA damage than sea bass, Lateolabrax japonicus and trout, Oncorhynchus masou masou under the same experimental conditions. Mummichogs had more alkaline-labile sites on their DNA than other fish species. The comet assay with mummichog blood cells at pH 12.5 showed a dose-response curve with the increasing concentrations of hydrogen peroxide. While the isolated leucocytes showed no increase of DNA damage after in vitro exposure to 2-methyl-1,4-naphthoquinone (MNQ), erythrocytes showed dose-dependent DNA damage. These results indicate that the comet assay can be applied successfully as a bioassay using erythrocyte for environmental monitoring.

• Korean Journal of Plant Resources
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• v.23 no.3
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• pp.207-213
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• 2010

Hovenia dulcis Thunb fruits were successively extracted with hot water, water, methanol, ethyl acetate, and chloroform. The crude extracts were investigated for potential antioxidant by measuring scavenging against DPPH free radicals, reducing power, superoxide radicals, and protection of protein damage and cultured cells from a lethal dose of hydrogen peroxide ($H_2O_2$). In all chemical assays used, the hot water extract of H. dulcis fruits, which contained $61.14{\pm}2.57$ (Tannic acid mg/g extract, n=3) of total phenolic compounds contents exhibited highest activity in in vitro models of DPPH free radical scavenging activity, reducing power assay, superoxide radical scavenging activity and protection of protein damage. In addition, the hot water extract protected cultured RAW 264.7 macrophages from a lethal dose of $H_2O_2$ and reduced reactive oxygen species level in RAW 264.7 cells.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.126-126
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• 2003

Welding fume (WF) induces pulmonary disease including pneumoconiosis. To investigate whether reactive oxygen species-induced oxidative DNA damage occurs during welding fume exposure and the upregulation of DNA repair mechanisms is accompanied, SPF SD rats were exposed to welding fumes with the concentrations of 65.6${\pm}$2.9 mg/㎥(low dose) and 116.8${\pm}$3.9 mg/㎥ (high dose) of total suspended particulate for 2 hrs per day in an inhalation chamber for a total of 2hrs, 15 or 30 days.(omitted)