• Korean Journal of Veterinary Pathology
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• v.3 no.2
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• pp.77-82
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• 1999

Testicles of nine-week-old male CBA/J mice were X-ray irradiated (1 Gy or 2 Gy) and were mated one week later with untreated virgin 12-week-old females of the same strain. The 1-Gy offspring (88 males and 62 females), 2-Gy offspring (100 males and 93 females) and additional offs pring (83 males and 84 females) were treated once subcutaneously with 0.1 mg/g body weight of urethane at 6 weeks of age. These three groups of off offspring showed similar incidences of lung tumors in both sexes. Depending on the doses of paternal X-ray irradiation, increasing incidences of adenocarcinoma were observed in the male 1-Gy and 2-Gy offspring groups. An increased multiplicity of lung carcinomas was observed in the male 2-Gy progeny that was statistically significant when compared with the control group. The results indicate that prezygotic testicular X-ray exposure of patemal animals causes the shift of adenoma-carcinoma sequence towards malignancy in the progeny.

• Archives of Pharmacal Research
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• v.18 no.3
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• pp.146-152
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• 1995

To achieve a better understanding of the effects on behavioral safety caused by possible neuroprotective doses (50 mg/kg, p.o.) of dextromethorphan HBr (DM), several motor activity measures were monitored in two generations of mice through a long-term period of ten months. Adult male mice (G1), in the presence of DM, developed behavioral tolerance after an initial suppression period. Prenatally exposed, second generation (G2) mice formed two groups, prenatal exposure alone (G2C) and prenatally exposed with additional postnatal exposure (G2T). In the presence of DM, group G2T was characterized by significant behavioral impairment; while G2C exhibited behavioral activation. These results suggest that more attention should be given to the prenatal effects of DM on a developing organism.

• Journal of Life Science
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• v.11 no.2
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• pp.181-189
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• 2001

Cytokines are hormone-like proteins which mediate and regulast inflammatory and immune responses. Transforming growth factor -$\beta$1(TGF-$\beta$) plays an important role in the control of the immune response and wound healing, and in the development o various tissues and organs, Nitric oxide(NO) is major messenger molecule regulating immune function and blood vessel dilation and serving as a neurotransmitter in the brain and peripheral nervous system. Also, NO is to be a potent mutagen that cause mutation in the p53 tumor suppressor gene in early phases of human gastric carcinogenesis. The purpose of this study was to investigate the effect of Helicobacter phlori lystes, lipopolysaccharide (LPS), and Staphylococcus enterotoxin B(SEB) on production of TGF-$\beta$1 and NO by human fibroblasts. Primary cultured human fibroblasts were incubated with H. pylori lysates(Hp), LPs, SEB, Hp+LPS, Hp+SEB, Hp+LPS+SEB. Cultured supernatants that were collected at 24, 48 and 72 hr were assessed for TGF-$\beta$1 by enzyme-linked immunosorbent assay and NO production by quantification of nitrite ion. TGF-$\beta$1 production in fibroblasts exposed with Hp, LPS or SEB for 48 hrs was enhanced, but for 72 hrs inhibited. Its production by doble exposure such as Hp+LPS, Hp+SEB, Hp+LPS+SEB was lowered in comparison with single exposure of Hp in cases of 24 and 48 hrs incubation, but for 72 hrs decreased in Hp vaculoating toxin(+), increased in Hp vacuolating toxin(-). No production in fibroblasts increaed at all doses of LPS. But its production by exposure of SEB increased or decreased according to dose and incubation time. Also, NO production by Hp vacuolating toxin(+) increased at all doses, but its production by Hp vacuolating toxin(-) decreased. Its production by doble exposure such as Hp+LPS, Hp+SEB, Hp+LPS+SEB decreased in comparison with single exposure Hp Therefore, quantities pf TGB-$\beta$1 and NO released by human fibroblasts shows differences according to kinds of stimulants. Also, in care stimulated with same kinds of stimulants, its productions exhibit quantitative differences according to exposure times. These results suggest that the decreased of TGF-$\beta$1 in fibroblasts by mixed exposure with Hp producing vacuolating toxin and bacterial toxins such as LPS and SEB may effect negatively in healing of host tissue and increased of NO by infection oh H. pylori may related to the increased susceptibility for human gastric carcinogenesis.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.357-363
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• 2022

This study aims to improve the safety inspection awareness of occupational exposure and help radiation safety management by analyzing radiation exposure doses by occupational type of radiation related-workers and radiation workers. Radiation-related workers and radiation workers were classified into three occupations (radiological technologist, doctors, and nurses). A nominal risk coefficient based on ICRP 103 was used to calculate the probability of causing side effects of the lungs due to exposure doses. As a result of analyzing the exposure dose of all workers for one year, the exposure dose of radiological technologist among radiation-related workers was 1.63 ± 2.84 mSv, doctors 0.12 ± 0.22 mSv, and nurses 0.59 ± 1.08 mSv. The one-year deep dose for radiation workers was 2.44 ± 3.30 mSv for radiological technologists, 0.19 ± 0.26 mSv for doctors, and 0.12 ± 0.00 mSv for nurses. Due to this dose, the probability of causing side effects in the lungs was 1.2 per 100,000 radiological technologist, 0.096 doctors, and 0.06 nurses. In this study, it is believed that the probability of side effects on lungs by occupation of radiation exposure dose will be studied and used as useful data for radiation safety management in relation to probabilistic effects in the future.

• Toxicological Research
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• v.18 no.1
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• pp.99-106
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• 2002

The United States Environmental Protection Agency (EPA) characterized the cancer hazard of di(2-ethylhexyl)-phthalate (DEHP) as a B2 group (probable human carcinogen) and proposed "Guide-lines for Carcinogen Risk Assessment". This guidelines proposed alternative methods for analyzing carcinogen dose-response data and for extrapolating the effects of observed at high dose to predict that might occur at lower doses relevant to human exposure. This proposed guidelines state that "If in a particular case, the evidence indicated a threshold, as in the case of carcinogenicity being secondary to another toxicity that has a threshold, the margin of exposure analysis for toxicity is the same as is done for a non-cancer endpoint". DEHP is excellent candidate for reconideration under the new guidelines for carcinogen risk assessment (John Doull et al., 1998). This study is conducted about risk assessment for infant exposure on DEHP in powdered milk wing methodology in EPA's new guideline on carcinogenic risk assessment. Estimated cancer risk of DEHP in powdered milk and cow milk is 2.83$\times$$10^5$ (using cancer potency: 1.4$\times$$10^2$/ (mg/kg/day)) as mean and MOE is 12075 (using selected NOEL 20 mg/kg/day) as mean. mg/kg/day) as mean.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.120-125
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• 2004

Exposure to volatile disinfection by-products (DBPs) such as chloroform included in chlorinated tap water can occur during household activities via inhalation as well as ingestion and dermal absorption. This study was conducted to examine the significance of inhalation route of exposure since humans are unintentionally exposed to volatile DBPs while staying home. Two sets of experiments were carried out in an apartment to measure: 1) the variation of chloroform concentrations in the living room air following kitchen activities (cooking and dish-washing); and 2) the variation of chloroform concentrations in the bathroom and living room following showering. Cooking, dish-washing, and showering all contributed to the elevation of household chloroform levels. Even a few minutes of natural ventilation resulted in the reduction of the chloroform levels to the background. Estimates of daily chloroform doses and lifetime cancer risks suggested that inhalation of household air during staying home be a major route of exposure to chloroform and that ingestion be a minor one in Korean people. It is also suggested that ventilation be a simple and important measure of mitigating human exposure to volatile DBPs indoors.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.4
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• pp.537-548
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• 2020

Currently, radioactive waste for disposal has been restricted to low and intermediate level radioactive waste generated during operation of nuclear power plants, and these radioactive wastes were managed and disposed of the 200 L and 320 L of steel drums. However, it is expected that it will be difficult to manage a large amount of decommissioning waste of the Kori unit 1 with the existing drums and transportation containers. Accordingly, the KORAD is currently developing various and large-sized containers for packaging, transportation, and disposal of decommissioning waste. In this study, the radiation exposure doses of workers and the public were evaluated using RADTRAN computational analysis code in case of the domestic on-road transportation of new package and transportation containers under development. The results were compared with the domestic annual dose limit. In addition, the sensitivity of the expected exposure dose according to the change in the leakage rate of radionuclides in the waste packaging was evaluated. As a result of the evaluation, it was confirmed that the exposure dose under normal and accident condition was less than the domestic annual exposure dose limit. However, in the case of a number of loading and unloading operations, working systems should be prepared to reduce the exposure of workers.

• Journal of radiological science and technology
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• v.44 no.2
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• pp.109-115
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• 2021

In this study, a physical evaluation of internal radiation exposure in children was conducted using nuclear medicine test(Renal DTPA Dynamic Study) to simulate the distribution and effects of the radiation throughout the tracer kinetics over time. Monte Carlo simulations were performed to determine the internal medical radiation exposure during the tests and to provide basic data for medical radiation exposure management. Specifically, dose variability based on changes in the tracer kinetic was simulated over time. The internal exposure to the target organ (kidney) and other surrounding organs was then quantitatively evaluated and presented. When kidney function was normal, the dose to the target organ(kidney) was approximately 0.433 mGy/mCi, and the dose to the surrounding organs was approximately 0.138-0.266 mGy/mCi. When kidney function was abnormal, the dose to the surrounding organs was 0.228-0.419 mGy/mCi. This study achieved detailed radiation dose measurements in highly sensitive pediatric patients and enabled the prediction of radiation doses according to kidney function values. The proposed method can provide useful insights for medical radiation exposure management, which is particularly important and necessary for pediatric patients.

• Development and Reproduction
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• v.25 no.4
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• pp.293-298
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• 2021

Di(2-ethylhexyl)phthalate (DEHP) could induce metabolic disorders through interfering with thyroid homeostasis. Therefore, we evaluated the effects of short term to environmental relevant doses of DEHP on thyroid hormones. Four week old Sprague-Dawley (SD) rats were treated with vehicle (corn oil), and DEHP 0.75, 7.5, and 150 mg/kg/day. The rats were treated with once daily by oral gavage and were sacrificed with after 1 week. They were measured body weight and relative thyroid weight, serum thyroid hormones and histological changes of thyroid. There was no difference in body weight between the control and DEHP exposed rats. Relative thyroid weight in DEHP 150 mg/kg/day treated group was significantly lower than control. Serum thyroxine levels was decreased in rats exposed to 0.75 and 150 mg/kg/day DEHP. No histological changes were observed in the thyroid of rats administered DEHP compared to control. Exposure to DEHP at environmental relevant levels, even short-term exposure, can cause hypothyroidism in adolescent rats even the exposure period is relative short.

• Progress in Medical Physics
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• v.26 no.4
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• pp.267-272
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• 2015

In this study, the reduction of dose and risk was evaluated from using automatic mA control in 4D CT scan of patients whose organ movement was considered for gated radiotherapy. The organ doses, CTDI, effective doses from 4D CT with and without using automatic mA control were evaluated using CT-Expo program for each 10 patients of liver and lung cancer, and the risk of exposure induced death and loss of life expectancy were evaluated using PCXMC program. It was founded that there were 26.8%, and 15.5% dose reduction in organ doses and CTDI for liver and lung cancer patients and 16.5% and 19.8% risk reduction in liver and lung cancer patients. The organ doses and effective doses were evaluated for the parameter of each patient used in CT scans, and risks considering age and gender could be evaluated. It was founded that there were 21.2% dose reduction and 18.2% risk reduction in 4D CT scan using AEC for liver and lung cancer patients.