• Journal of Radiation Protection and Research
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• 제40권1호
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• pp.65-72
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• 2015

방사선 노출에 따른 피부손상의 기본이론들은 정립되어 있지만, 정확한 기전에 관해서는 알려지지 않은 실정이다. 본 연구에서는 감마선 조사 후 용량 및 시간에 따라 돼지 피부의 장애를 육안 및 조직학적인 변화를 통해 평가하고 cyclooxygenase(COX)-2 발현 정도를 비교하고자 하였다. 미니돼지의 등 쪽 피부에 20-70 Gy 감마선을 국소조사 후 12 주 동안 육안적인 변화를 관찰하고 생검을 통해 조직학적인 변화를 관찰하였다. 방사선 조사 후 피부의 기저세포층에서의 세포자멸사와 표피층의 두께 변화를 평가하였고 COX-2 발현 정도를 면역염색을 통하여 비교하였다. 방사선 조사 후 피부 장애는 용량이 증가할수록 피부손상이 더욱 심하였으며 초기에 발적 소견을 보이다가 50 Gy 이상 조사군에서는 미란과 궤양으로 이어졌다. 조직학적인 변화는 육안적인 소견과 일치하였다. 방사선 조사 후 3일부터 기저세포에서 세포자멸사가 관찰되었으며 기저세포수의 감소가 유발되었으며 이러한 변화는 용량이 증가할수록 더욱 증가하였다. 방사선 조사 후 표피층의 두께는 3일 무렵에 일시적으로 증가하다가 점차 감소하였으며 20, 30, 40 Gy 조사 군에서는 다시 회복되는 소견이 관찰되었으나 50, 70 Gy 조사 군에서는 다시 회복되지 못하고 표피창의 두께 소실을 보였다. 방사선 조사 후 피부에서의 COX-2 발현은 피부손상정도와 일치하게 관찰되었다. 방사선 조사 후 COX-2 발현은 방사선의 용량이 증가할수록 발현이 증가하였고 시간이 증가할수록 증가하였다. 이러한 조직학적인 변화와 함께 방사선 손상을 일으키는 신호전달에 관여하는 COX-2 발현이 방사선조사 용량에 비례하여 증가하며 이러한 단백질의 발현은 피부손상과 관련성이 높은 것으로 사료된다.

• 한국축산식품학회지
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• 제30권3호
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• pp.397-402
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• 2010

Pork is an excellent source of essential nutrients such as protein. However, pork can trigger hypersensitivity and serum albumin of pork is known as major allergen. In this study, to evaluate the effect of gamma irradiation on the allergenicity of porcine serum albumin (PSA), PSA solution was irradiated at 3, 5, 7, 10, 15, and 20 kGy. The changes in the ability of PSA to bind IgG and patient's serum caused by gamma irradiation were observed by ci-ELISA and immunoblotting. SDS-PAGE was used for measuring the conformational change of gamma-irradiated PSA. The ability of 3-kGy-irradiated PSA to bind p-IgG and patient's serum was decreased to 30% and 15%, respectively. The binding ability showed no significant differences among all irradiated samples. SDS-PAGE showed that the irradiated PSA bands were degraded and aggregated. Immunoblotting of irradiated PSA revealed that IgG and patient's serum were rarely recognized at 3 kGy. Therefore, gamma irradiation could be applied to less-allergenic pork products.

• Journal of Ecology and Environment
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• 제37권4호
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• pp.195-200
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• 2014

The chances of accidental exposure are augmented as the application of ionizing radiation increases in various fields. Such accidental exposures may occur at nuclear power plants, laboratories, and hospitals. Cytogenetic assays have been used for estimating radiation dose in the situation of the accidents. The micronucleus assay has several advantages over the other cytogenetic methods as it is simple and fast. The present study aimed at investigation of the micronuclei frequencies in cytokinesis-block cells in human blood lymphocytes after ${\gamma}$-irradiation and at establishment of a standard dose response relationship. The samples of peripheral blood were obtained from 6 different donors aged between 24 and 30 years old. The bloods were irradiated in vitro with 0-5 Gy. A linear quadratic dose-response equation was obtained by scoring the micronuclei in binucleated cells; $y=27.87x^2+46.13x+2.08$ ($r^2=0.99$). Irradiation caused a significant decrease in the nuclear division index. Necrotic and apoptotic cells increased in number after irradiation in a dose-dependent manner. In conclusion, the conventional cytokinesis-block micronucleus assay has proven to be the great technique in biological dosimetry. Dose-response calibration curve derived from CMBN assay could be used to estimate the exposure dose during a radiological emergency.

• Radiation Oncology Journal
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• 제1권1호
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• pp.69-77
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• 1983

20 cases of midline pineal tumors and 3 suprasellar germinomas received radiation therapy at Yonsei University Medical College, Severance hospital from 1971 to 1982 were reviewed. 12 cases were pathologically proved; 10 germinomas, 1 pineoblastoma, and 1 pineocytoma. 11 cases received radiotherapy without biopsy confirmation. Although treatment fields varied from small field to whole brain irradiation, but not to the spinal cord, most patients received 4000-5000 rads irradiation to the primary tumor site. 17 patients are alive without evidence of disease and 5 year actuarial NED survival is 73.2%. 9 of 10 biopsy proved germinomas and all 6 presumed germinomas are alive and well. Optimum radiation dose, adequate irradiation field, tumor response to radiation observed in serial CT scan and role of radiation therapy in the management of pineal tumors are also discussed.

• 한국지역사회생활과학회지
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• 제14권3호
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• pp.13-19
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• 2003

The purpose of this study was to investigate the UVA radiation protection effects of summer hats currently on the market with the purpose of making it possible to choose a hat with suitable UVA protection. Twelve different summer hats from the market were selected for the experiment. The results are summarized as follows: It is more effective to wear a hat than not wear a hat to block UVA radiation. Summer hats with the greatest degree of protection, from highest to lowest, are cotton, straw2, and straw1. In the area of the forehead, which is rarely influenced by the irradiation angle, the cotton hat was the most effective in protecting from UVA radiation because the material density was greater than that of the straw hats. A hat with a 8.5 cm brim was more effective at blocking UVA radiation on the jaw than 6 cm, 4 cm, and 0 cm wide brims, but it still couldn't block the radiation completely. Irradiation amounts at 11:00 AM on the forehead, jaw! s and left and right cheeks were lower than amounts measured on the back of the neck. This revealed that irradiation amounts depend on the shape of the hat and time of day. A hat with a brim encircling the head was found to be more effective in blocking UVA radiation than a hat with only a front or side brim.

• 방사선산업학회지
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• 제8권1호
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• pp.53-57
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• 2014

The kenaf is quickly developing as a renewable resource. Kenaf can be grown under a wide range of weather conditions. Modification of kenaf fiber by graft polymerization provides a significant route to alter the chemical properties, including surface hydrophilicity or hydrophobicity. In this study, kenaf fiber surfaces were grafted with acrylic acid as a hydrophilic group using electron beam irradiation. The grafting rate increased with an increase in grafting time. The FT-IR results confirmed that acrylic acid was successfully grafted onto the kenaf fibers. The wettability of the kenaf fiber was increased, accompanied by acylic acid grafting on the fiber surface. According to the permeability test result, it was found that acrylic acid grafted kenaf fiber reinforced cement composite was more reduced than non-grafted kenaf fiber reinforced cement composite.

• 방사선산업학회지
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• 제4권4호
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• pp.365-372
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• 2010

Irradiation has been recognized as a highly suitable tool to aid in the formation of hydrogel. The radiation process has various advantage, such as easy process control and the lack of necessity for initiators and crosslinker. In this study, the hydrogel containing the citrus fermentation gel for the wound healing were successfully synthesized. The strength of hydrogel was increased as a function of a increasing the concentration of citrus and the irradiation doses. In addition, this hydrogel have been evaluated by the cytotoxicity and animal experiment.

• 한국축산식품학회지
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• 제28권1호
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• pp.69-75
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• 2008

본 연구는 면역력이 약한 영유아 및 면역결핍환자를 위한 아이스크림을 개발하기 위하여 시판중인 바닐라 아이스크림의 품질을 여러 선량의 감마선 조사 후에 평가하였다. 감마선 조사에 의해 바닐라 아이스크림의 일반성분(수분, 지방 및 단백질) 및 지방산의 함량변화는 유의적으로 차이가 없었다. 또한 감마선 조사에 의해 바닐라 아이스크림의 명도, 적색도 및 황색도는 약간 감소하였고, TBARS를 이용한 지질산패도를 측정한 결과 5 kGy 이상의 조사선량에서 산패도가 증가하였다. 감마선 조사에 의한 바닐라 아이스크림의 관능검사 결과 색 변화는 유의적으로 차이가 없었으나 향, 맛, 전체적인 기호도가 조사선량에 따라 감소하였으며, 특히 5 kGy 이상에서는 심각한 차이를 보였다. 따라서 바닐라 아이스크림의 품질변화를 최소화 하기 위한 최적조사선량은 3 kGy 이하인 것으로 판단되며 감마선 조사기술과 특정 향 및 항산화제 첨가 등의 병용처리를 통한 품질 개선 실험이 필요하다고 판단된다.

• 생명과학회지
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• 제16권2호
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• pp.180-185
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• 2006

일품벼(Oryza sativa L. cv. Ilpoombye)에 고선량 감마선을 조사한 후 벼 잎의 생리적 손상과 항산화 효소인 superoxide dismutase (SOD)의 isoenzyme 수준에서의 유전자 발현 및 효소활성 변화와의 연관성을 조사하였다. 500 Gy의 감마선 조사는 24 h 이내에 벼 잎의 단백질, 엽록소, 그리고 카로테노이드의 함량을 유의적으로 감소시켰으며 특히 엽록소는 대조구에 비해 26% 이상 감소하였다. 반면에 SOD isoenzyme들의 유전자 발현은 감마선 조사 후 6 h부터 24 h까지는 전반적으로 대조구보다. 높게 유지되었으나 48 h부터 현저히 감소되어 72h에는 모든 isoenzyme들의 유전자 발현 이 대조구보다. 낮았다. 그러나 isoenzyme들의 효소활성은 조사구에서 일부 CuZn-SOD isoenzyme들의 경우 48 h까지 대조구보다. 약간 높았지만 72h에는 모두 현저히 감소하였다. 따라서 본 연구에 사용된 500 Gy의 고선량 감마선은 단백질, 엽록소, 그리고 카로테노이드 함량의 감소를 초래하며, 조사 후 초기단계에는 이러한 생리적 손상과 무관하게 일시 적으로 SOD isoenzyme들의 유전자 발현을 증가시키지만 72 h 이후에는 유전자 발현과 효소활성을 동시에 감소시키면서 산화스트레스에 의한 생리적 손상을 유도하는 것으로 생각된다.

• Molecules and Cells
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• 제25권1호
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• pp.105-111
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• 2008

Radiotherapy is an important treatment for many malignant tumors, but there are recent reports that radiation may increase the malignancy of cancer cells by stimulating expression of type IV collagenases. In this study, we examined changes in matrix metalloproteinase (MMP) inhibitors, such as the tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2 and RECK, in response to irradiation in Panc-1 pancreatic cancer cells. Irradiation increased RECK protein levels but not mRNA levels, whereas no significant changes were found in TIMP-1 and TIMP-2. The enhanced RECK protein levels were associated with an increase in MMP inhibitory activity. However, irradiation slightly but reproducibly increased the invasiveness of the Panc-1 cells. Like irradiation, treatment of Panc-1 cells with transforming growth factor $(TGF)-{\beta}1$ led to a 2-fold increase in RECK protein levels. Transient transfection with Smad3 also increased RECK protein levels, but transfection with Smad7 markedly reduced them. Stable expression of Smad7 and treatment with SB431542, an inhibitor of $TGF-{\beta}$ receptor I kinase, abolished $TGF-{\beta}1$- and radiation-mediated effects on RECK. Furthermore, irradiation increased levels of phosphorylated Smad3. We conclude that radiation post-transciptionally enhances RECK protein levels in Panc-1 cells, at least in part, via $TGF-{\beta}$ signaling, and that irradiation increases Panc-1 invasiveness via a mechanism that may not be linked to MMP-2 activity.