• 한국방사선학회논문지
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• 제9권7호
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• pp.523-528
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• 2015

본 연구에서는 단일 초음파 조사와 두 개의 저강도 초음파의 중첩 조사 시 발생하는 가열 특성을 평가하였다. 비교결과 단일 조사 조건보다 중첩 조사에서 보다 우수한 온열 효과를 보였으며 최대 상승 온도도 120-150% 증가하는 것을 확인할 수 있었다. 초음파 조사에 의한 가열 개시 시간이 중첩 조사에서 짧아지며, 최대 가열 온도까지 소요되는 시간 역시 짧아짐을 확인할 수 있었다. 초음파 조사 강도가 커지면 매질의 표면 손상을 유발하는데, 저강도 중첩조사의 경우 표면의 손상없이 동일한 온도 상승 효과를 확인할 수 있었다. 본 연구의 결과를 통하여 초음파 치료 시 적용 강도를 줄일 수 있을 것으로 생각되었으며, 저강도 초음파를 사용함으로써 보다 안전하고 효율적인 초음파 치료가 가능할 것으로 판단된다.

• 대한수의학회지
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• 제45권4호
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• pp.457-464
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• 2005

The irradiation of radioactive ${\gamma}-ray$ induces apoptosis of radiosensitive organs for homeostasis. In this study, we investigated the repair mechanisms for homeostasis in the small intestine after cell damage by $^{60}Co\;{\gamma}-ray$ irradiation. The apoptosis was most frequently observed in the crypt cells of the small intestine after four and six hours by radioactive ${\gamma}-ray$ irradiation, and the frequency of apoptosis was proportional to the amount of irradiation. Also, the number of apoptotic cells was coincident with expression pattern of p53. Interestingly, PCNA (proliferating cell nuclear antigen) which is engaged in DNA replication and repair was expressed in apoptotic cells of small intestinal crypts. Also, it was observed that cell-cycle regulator p21 which is known to induce cell-cycle arrest is co-expressed in the same apoptotic cells of irradiated small intestinal crypt cells. These findings suggest that the co-expression of PCNA and p21 proteins, which may lead to resistance to DNA damage through cell-cycle arrest is closely associated with repair of damaged gastrointestinal cells after ${\gamma}-ray$ irradiation.

• 대한방사선기술학회지:방사선기술과학
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• 제41권3호
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• pp.215-221
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• 2018

Cone beam Computed Tomography(CBCT) is an increasing trend in clinical applications due to its ability to increase the accuracy of radiation therapy. However, this leaded to an increase in exposure dose. In this study, the simulation using Monte Carlo method is performed and the absorbed dose of CBCT is analyzed and standardized data is presented. First, after simulating the CBCT, the photon spectrum was analyzed to secure the reliability and the absorbed dose of the tissue in the human body was evaluated using the MIRD phantom. Compared with SRS-78, the photon spectrum of CBCT showed similar tendency, and the average absorbed dose of MIRD phantom was 8.12 ~ 25.88 mGy depending on the body site. This is about 1% of prescription dose, but dose management will be needed to minimize patient side effects and normal tissue damage.

• Journal of Ginseng Research
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• 제44권6호
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• pp.843-848
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• 2020

This study investigated the inhibitory effect of ginsenoside-Rp1 (G-Rp1) on the ionizing radiation (IR)-induced response in lipopolysaccharide (LPS)-stimulated macrophages and its effects on the malignancy of tumor cells. G-Rp1 inhibited the activation of IR-induced DNA damage-related signaling molecules and thereby interfered with the IR-increased production of nitric oxide (NO) and interleukin (IL)-1β. The inhibitory effect of G-Rp1 increased the survival rate of mice inoculated with CT26 colon cancer cells by suppressing the phenotypic variation of tumor cells induced by conditioned medium obtained from IR- and LPS-treated J774A.1 macrophages.

• 대한방사선기술학회지:방사선기술과학
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• 제23권1호
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• pp.81-89
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• 2000

In the present study, to determine whether the ascorbate protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of ascorbate(240 mg/kg, i.p) pretreatment of mice on the survival ratio, splenic weight, major antioxidant enzymes(SOD, catalase and glutathione peroxidase) activities, glutathione contents and lipid peroxidation in the liver were examined for 2 weeks after whole-body ${\gamma}-irradiation$(6.5 Gy). The 30-day survival ratio Increased from 10% to 47% for mice treated with ascorbate. The ascorbate decreased the extent of loss in splenic weight and stimulated recovery of splenic weight in irradiated mice(p<0.01). On the day of 14 after ${\gamma-irradiation}$, the ascorbate pretreatment produced a slight increase of antioxidant enzymes activities and significantly increased reduced glutathione(GSH) contents(P<0.05) in the liver compared with non-treated group. Pretreatment with the ascorbate significantly decreased GSSG/total GSH ratio(p<0.05) without the change of GSSG in the liver and inhibited the radiation-induced increase in the hepatic malondialdehyde levels(p<0.05). In these results, we found that its radioprotective effect by protecting antioxidant enzyme activities and glutathione contents from radiation induced a decrease, and thereby suppressing lipid peroxidation which is induced by free radicals.

• Nuclear Engineering and Technology
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• 제38권3호
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• pp.231-238
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• 2006

Whole-body exposure to high-dose radiation causes injury involving multiple organs that depends on their sensitivity to radiation. This acute radiation syndrome (ARS) is caused by a brief exposure of a major part of the body to radiation at a relatively high dose rate. ARS is characterized by an initial prodromal stage, a latent symptom-free period, a critical or manifestation phase that usually takes one of four forms (three forms): hematologic, gastrointestinal, or cardiovascular and neurological (neurovascular), depending upon the exposure dose, and a recovery phase or death. One of the most important factors in treating victims exposed to radiation is the estimation of the exposure dose. When high-dose exposure is considered, initial dose estimation must be performed in order to make strategy decisions for treatment as soon as possible. Dose estimation can be based on onset and severity of prodromal symptoms, decline in absolute lymphocyte count post exposure, and chromosomal analysis of peripheral blood lymphocytes. Moreover, dose assessment on the basis of calculation from reconstruction of the radiation event may be required. Experience of a criticality accident occurring in 1999 at Tokai-mura, Japan, showed that ARS led to multiple organ failure (MOF). This article will review ARS and discuss the possible mechanisms of MOF developing from ARS.

• Journal of Radiation Protection and Research
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• 제38권4호
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• pp.179-184
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• 2013

The biological effects of radiation are dependent on the dose rate and dose of radiation. In this study, effects of dose and dose rate using whole body radiation on plasma cytokines and blood count from male BALB/c mice were evaluated. We examined the blood and cytokine changes in mice exposed to a low (3.49m Gy $h^{-1}$) and high (2.6 Gy $min^{-1}$) dose rate of radiation at a total dose of 0.5 and 2 Gy, respectively. Blood from mice exposed to radiation were evaluated using cytokine assays and complete blood count. Peripheral lymphocytes and neutrophils decreased in a dose dependent manner following high dose rate radiation. The peripheral lymphocytes population remained unchanged following low dose rate radiation; however, the neutrophils population increased after radiation. The sera from these mice exhibited elevated levels of flt3 ligand and granulocyte-colony-stimulating factor (G-CSF), after high/low dose rate radiation. These results suggest that low-dose-rate radiation does not induce blood damage, which was unlike high-dose-rate radiation treatment; low-dose-rate radiation exposure activated the hematopoiesis through the increase of flt3 ligand and G-CSF.

• 대한방사성의약품학회지
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• 제9권1호
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• pp.3-8
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• 2023

Parkinson's disease is a neurodegenerative disease caused by damage to brain neurons related to dopamine. Non-clinical animal models mainly used in Parkinson's disease research include drug-induced models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 6-hydroxydopamine, and genetically modified transgenic animal models. Parkinson's diagnosis can be made using brain imaging of the substantia nigra-striatal dopamine system and using a radiotracer that specifically binds to the dopamine transporter. In this study, ¹⁸F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane was used to confirm the image evaluation cutoff between normal and parkinson's disease models, and to confirm model persistence over time. In addition, the efficacy of single or combined administration of clinically used therapeutic drugs in parkinson's animal models was evaluated. Image analysis was performed using the PMOD software. Converted to standardized uptake value, and analyzed by standardized uptake value ratio by dividing the average value of left striatum by the average value of right striatum obtained by applying positron emission tomography images to the atlas magnetic resonance template. The image cutoff of the normal and the parkinson's disease model was calculated as SUVR=0.829, and it was confirmed that it was maintained during the test period. In the three-drug combination administration group, the right and left striatum showed a high symmetry of more than 0.942 on average and recovered significantly. Images using ¹⁸F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane are thought to be able to diagnose and evaluate treatment efficacy of non-clinical Parkinson's disease.

• 한국방재안전학회논문집
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• 제16권4호
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• pp.85-99
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• 2023

현대사회가 고도화되고, 후쿠시마 원전사고 역시 자연재난의 연쇄적인 영향으로 인해 발생함에 따라 복합재난을 고려한 방재계획의 중요성이 나날이 커지고 있다. 그러나 현재 국내의 방사능방재 분야에서 복합재난을 고려한 구체적인 방재계획은 제시되지 않고 있다. 따라서, 본 연구에서는 복합재난의 유형을 분석하여 국내 환경에서 비교적 발생 가능성이 높은 유형을 선정하고, 자연재난 유형별 피해확산이 방사능방재에 미치는 영향을 분석하고자 한다. 복합재난을 고려한 방사능방재 시나리오를 통해 방재계획 수립에 필요한 기준들을 제시하였고, 이러한 기준은 최악의 상황 대비에 활용한다. 이는 실효적인 주민보호조치를 결정하고 이행하는 데에 도움을 줄 수 있을 것으로 판단된다.

• Journal of International Society for Simulation Surgery
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• 제1권2호
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• pp.87-89
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• 2014

An aberrant left hepatic artery is one of the most common variants of hepatic arteries, and its prevalence has been reported 6.5-30%. During D2 lymph node dissection for gastric cancer, an aberrant left hepatic artery arising from left gastric artery is ligated which may lead to hepatic damage. In this case report, a 66-year-old male patient underwent total gastrectomy with D2 lymph node dissection during which the aberrant left hepatic artery was ligated. Post-operative liver function tests revealed elevated liver enzymes, and ischemic changes in the left lateral hepatic section was seen on the CT scan. On retrospective review of preoperative CT images, a replaced left hepatic artery from left gastric artery could have been identified. The information on the presence of aberrant LHA and its supplying area is clinically important when planning curative gastrectomy for gastric cancer, because extended lymph node dissection requires division of the left gastric artery and this may lead to severe liver damage. By using preoperative CT scan, detection of aberrant left hepatic artery could be done.