• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.206.1-206
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• 2001

No Abstract, See Full Text

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.303-309
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• 2019

Tritium is an important nuclide that must be monitored for radiation safety management. In this study, HTO was orally administered to rats at the level of 37 kBq ($1{\mu}Ci$) or 370 kBq ($10{\mu}Ci$) to examine tissue distribution and excretion levels. After sacrifice, wet and dry tissue samples were weighed and analyzed for tissue free-water tritium (TFWT) and organically bound tritium (OBT). The mean tissue concentrations of TFWT (OBT) were 30.9 (17.8) and 4.4 (8.1) Bq/g on days 7 and 13 at the 37 kBq level and 30.8 (64.6) Bq/g on day 17 at the 370 kBq level. To assess the cytogenetic damage due to tritium exposure, a cytokinesis-blocked micronucleus (MN) assay was performed in blood samples from rats exposed to HTO for 14 and 21 days after oral administration. There was no significant difference in the MN frequencies between the control and exposed rats.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.199-199
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• 2005

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.198-198
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• 2005

• Journal of Radiation Protection and Research
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• v.46 no.1
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• pp.14-23
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• 2021

Background: For radiological protection and control, the International Commission on Radiological Protection (ICRP) provides the nominal risk coefficients related to radiation exposure, which can be extrapolated using the excess relative risk and excess absolute risk obtained from the Life Span Study of atomic bomb survivors in Hiroshima and Nagasaki with the dose and dose-rate effectiveness factor (DDREF). Materials and Methods: Since it is impossible to directly estimate the radiation risk at doses less than approximately 100 mSv only from epidemiological knowledge and data, support from radiation biology is absolutely imperative, and thus, several national and international bodies have advocated the importance of bridging knowledge between biology and epidemiology. Because of the accident at the Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station in 2011, the exposure of the public to radiation has become a major concern and it was considered that the estimation of radiation risk should be more realistic to cope with the prevailing radiation exposure situation. Results and Discussion: To discuss the issues from wide aspects related to radiological protection, and to realize bridging knowledge between biology and epidemiology, we have established a research group to develop low-dose and low-dose-rate radiation risk estimation methodology, with the permission of the Japan Health Physics Society. Conclusion: The aim of the research group was to clarify the current situation and issues related to the risk estimation of low-dose and low-dose-rate radiation exposure from the viewpoints of different research fields, such as epidemiology, biology, modeling, and dosimetry, to identify a future strategy and roadmap to elucidate a more realistic estimation of risk against low-dose and low-dose-rate radiation exposure.

• Journal of Photoscience
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• v.9 no.3
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• pp.37-40
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• 2002

Astronauts are constantly exposed to space radiation at a low-dose rate during long-tenn stays in space. Therefore, it is important to determine correctly the biological effects of space radiation on human health. Space radiations contain various kinds of different energy particles, especially high linear energy transfer (LET) particles. Therefore, we have to study the relative biological effectiveness (RBE) of space radiation under microgravity environment which may change RBE from a stress for cells. Furthermore, the research about space radiation might give us useful information about birth and evolution of life on the earth. We also can realize the importance of preventing the ozone layer from depletion by use of exposure equipment to sunlight at International Space Station (ISS).

• BMB Reports
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• v.36 no.1
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• pp.144-148
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• 2003

During the past 2 decades, radiation tumorigenesis researchers have focused on cellular and molecular mechanisms. We reviewed some of these research fields, since they may specifically relate to the induction of cancer by ionizing radiation. First, radiation-mediated mutation was discussed. Then the initiating event in radiation carcinogenesis, as well as other genetic events that may by involved, is discussed in terms of the possible role of the activation of genes and the loss of cell-cycle checkpoints.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.574-581
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• 2011

A Gram-positive bacterium was isolated from the saline soils of Jangpura (U.P.), India, and showed high-level of radiation-resistant property and survived upto 12.5 kGy dose of gamma radiation. The 16S rDNA sequence of this strain was examined, identified as Bacillus sp. strain HKG 112, and was submitted to the NCBI GenBank (Accession No. GQ925432). The mechanism of radiation resistance and gene level expression were examined by proteomic analysis of whole-cell extract. Two proteins, 38 kDa and 86.5 kDa excised from SDS-PAGE, which showed more significant changes after radiation exposure, were identified by MALDI-TOF as being flagellin and S-layer protein, respectively. Twenty selected 2-DE protein spots from the crude extracts of Bacillus sp. HKG 112, excised from 2- DE, were identified by liquid chromatography mass spectrometry (LC-MS) out of which 16 spots showed significant changes after radiation exposure and might be responsible for the radiation resistance property. Our results suggest that the different responses of some genes under radiation for the expression of radiation-dependent proteins could contribute to a physiological advantage and would be a significant initial step towards a fullsystem understanding of the radiation stress protection mechanisms of bacteria in different environments.

• Genomics & Informatics
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• v.8 no.1
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• pp.34-40
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• 2010

Radiofrequency (RF) radiation might induce the transcription of a certain set of genes as other physical stresses like ionizing radiation and UV. To observe transcriptional changes upon RF radiation, we exposed WI-38, human lung fibroblast cell to 1763 MHz of mobile phone RF radiation at 60 W/kg of specific absorption rate (SAR) for 24h with or without heat control. There were no significant changes in cell numbers and morphology after exposure to RF radiation. Using quantitative RT-PCR, we checked the expression of three heat shock protein (HSP) (HSPA1A, HSPA6 and HSP105) and seven stress-related genes (TNFRSF11B, FGF2, TGFB2, ITGA2, BRIP1, EXO1, and MCM10) in RF only and RF/HS groups of RF-exposed cells. The expressions of three heat shock proteins and seven stress-related genes were selectively changed only in RF/HS groups. Based on the expression of ten genes, we could classify thermal and non-thermal effect of RF-exposure, which genes can be used as biomarkers for RF radiation exposure.

• Journal of Ginseng Research
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• v.35 no.3
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• pp.261-271
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• 2011

Chemical radiation protection is an important strategy to protect living beings against the deleterious effects of radiation. In the present study, the radioprotective effect of hydro-alcoholic extract of Panax ginseng extract (PGR-HAE) was studied on radiation-induced deleterious alterations in Swiss albino mice. Oral administration of such extract (25 mg/kg b wt/day/animal) for 5 consecutive days, half an h. before whole-body exposure to 6 Gy gamma radiation, enhanced the 30 days survival and also inhibited the radiogenic sickness, weight loss and life shortening. PGR-HAE ameliorated radiation induced depletion in blood constituents at different necropsy intervals between 12 h to 30 d, and significantly increased the number of femoral spleen colony forming units that survived after irradiation. Furthermore, it checked depletion of glutathione and antioxidant enzymes (superoxide dismutase, catalase, and glutathione S-transferase) as well as elevation of lipid peroxidation (LPO) level in blood and liver. The significant reduction in the yield of LPO demonstrates that PGR-HAE protects the membranes against radiation-induced oxidative damage. These findings conclude that such plant extract provides significant radioprotection, and it may be potentially valuable in the prevention of injuries caused during planned and unplanned radiation exposure.