• 한국동물생명공학회지
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• 제37권3호
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• pp.169-175
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• 2022

Bovine mammary epithelial (MAC-T) cells are commonly used to study mammary gland development and mastitis. Lipopolysaccharide is a major bacterial cell membrane component that can induce inflammation. Autophagy is an important regulatory mechanism participating in the elimination of invading pathogens. In this study, we evaluated the mechanism underlying bacterial mastitis and mammary cell death following lipopolysaccharide treatment. After 24 h of 50 ㎍/mL lipopolysaccharide treatment, a significant decrease in the proliferation rate of MAC-T cells was observed. However, no changes were observed upon treatment of MAC-T cells with 10 ㎍/mL of lipopolysaccharide for up to 48 h. Thus, upon lipopolysaccharide treatment, MAC-T cells exhibit dose-dependent effects of growth inhibition at 10 ㎍/mL and death at 50 ㎍/mL. Treatment of MAC-T cells with 50 ㎍/mL lipopolysaccharide also induced the expression of autophagy-related genes ATG3, ATG5, ATG10, ATG12, MAP1LC3B, GABARAP-L2, and BECN1. The autophagy-related LC3A/B protein was also expressed in a dose-dependent manner upon lipopolysaccharide treatment. Based on these results, we suggest that a high dose of bacterial infection induces mammary epithelial cell death related to autophagy signals.

• 대한임상독성학회지
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• 제20권1호
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• pp.25-30
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• 2022

In this study, we report the case of a 59-year-old male patient with organophosphate pesticide poisoning. He visited the local emergency medical center after ingesting 250 ml of organophosphate pesticide. The patient's symptoms improved after the initial intravenous infusion of pralidoxime 5 g and atropine 0.5 mg. However, 18 hours after admission, there was a worsening of the symptoms. A high dose of atropine was administered to improve muscarinic symptoms. A total dose of 5091.4 mg of atropine was used for 30 days, and fever and paralytic ileus appeared as side effects of atropine. Anticholinergic symptoms disappeared only after reducing the atropine dose, and the patient was discharged on the 35th day without any neurologic complications.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1838-1854
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• 2023

This paper presents a hybrid algorithm to solve the multi-objective path planning (MOPP) problem for mobile robots in a static nuclear accident environment. The proposed algorithm mimics a real nuclear accident site by modeling the environment with a two-layer cost grid map based on geometric modeling and Monte Carlo calculations. The proposed algorithm consists of two steps. The first step optimizes a path by the hybridization of improved ant colony optimization algorithm-modified A^* (IACO-A^*) that minimizes path length, cumulative radiation dose and energy consumption. The second module is the high radiation dose rate avoidance strategy integrated with the IACO-A^* algorithm, which will work when the mobile robots sense the lethal radiation dose rate, avoiding radioactive sources with high dose levels. Simulations have been performed under environments of different complexity to evaluate the efficiency of the proposed algorithm, and the results show that IACO-A^* has better path quality than ACO and IACO. In addition, a study comparing the proposed IACO-A^* algorithm and recent path planning (PP) methods in three scenarios has been performed. The simulation results show that the proposed IACO-A^* IACO-A^* algorithm is obviously superior in terms of stability and minimization the total cost of MOPP.

• 대한방사선치료학회지
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• 제25권1호
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• pp.9-14
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• 2013

목 적: 10 MV 이상 고에너지 방사선 치료 시 광핵반응을 통해 광중성자가 발생된다. 광중성자는 방사선하중계수가 X선 보다 커 작은 선량에도 인체에 미치는 영향이 크므로 정확한 선량계산 및 고려가 필요하다. 이에 광자선 에너지 크기와 치료방법에 따른 광중성자의 선량변화를 공간적인 측면에서 비교 분석하였다. 대상 및 방법: 광자선의 에너지 크기에 따른 광중성자의 선량 변화를 측정하고자 동일한 치료부위의 환자를 대상으로 치료 계획을 10 MV와 15 MV conventional plan으로 각각 만들었다. 그리고 치료방법에 따른 차이에 대해 측정하고자 10 MV conventional plan과 10 MV IMRT plan을 각각 만들었다. 검출기의 위치는 광자선원으로부터 isocenter까지의 거리를 100 cm으로 정한 기준점을 $^3He$비례계수기의 중심점에 위치시키고 광중성자 선량을 측정하였다. 또한 중심점을 기준으로 couch의 longitudinal 방향으로 상방, 하방 50 cm 방향으로 각각 $^3He$비례계수기를 위치시켜 위치변화에 따른 선량변화를 측정하여 상용프로그램을 이용하여 분석하였다. 결 과: 에너지 크기에 따른 광중성자의 평균 누적선량은 10 MV, 15 MV conventional RT시 각각 $220.27{\mu}Sv$, $526.61{\mu}Sv$로 15 MV conventional RT가 평균 2.39배의 선량이 증가하였다. 동일한 에너지의 conventional RT와 IMRT의 광중성자의 평균 누적선량은 Conventional RT, IMRT 시 각각 $220.27{\mu}Sv$, $308.27{\mu}Sv$로 IMRT가 1.40배의 선량이 증가하였다. 측정위치에 따른 광중성자의 누적선량은 Conventional RT시 point 2가 3보다 10 MV에서는 약 7.1%, 15 MV에서는 3.0%로 유의하게 높게 측정되었다. 결 론: 고에너지 방사선 치료 시 광중성자에 의한 불필요한 선량을 줄이기 위해 에너지의 선택, 치료 방법의 결정 및 환자의 position을 고려해야 할 것이다. 또한 광중성자의 선량 데이터를 체계화하여 전산화계획 프로그램에 적용되는 방안을 모색하여야 할 것이다. 이는 환자에게 불필요한 선량을 최소화하고 방사선 치료로 인한 2차 암 발생확률과 부작용을 감소시킬 수 있을 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4835-4837
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• 2012

Objectives: To evaluate residual disease in uterine cervical cancer patients treated with teletherapy using combined high dose rate Cobalt-60 brachytherapy. Materials and Methods: A retrospective study of uterine cervical cancer patients, FIGO stages IB-IVB (International Federation of Gynecologists and Obstetricians recommendations), treated by radiotherapy alone between April 1986 and December 1988 was conducted and the outcomes analysed. The patients were treated using teletherapy 50 Gy/25 fractions, five fractions per week to the whole pelvis together with HDR Cobalt -60 afterloading brachytherapy of 850 cGy/fraction, weekly to point A for 2 fractions. Results: The study covered 141 patients with uterine cervical cancer. The mean age was 50.0 years with a range of 30-78 years. The mean tumor size was 4.1 cm in diameter (range 1-8 cm). Mean follow - up time was 2.94 years (range 1 month-6.92 years). The overall incidence of residual locoregional disease was 3.5%. Residual disease, according to stage IIB, IIIB and IVA was present in 2.78%, 3.37% and 50.0%. It was noted that there was no evidence of residual disease in stage IB and IIA cases. Conclusion: Combined teletherapy along with high dose rate Cobalt -60 brachytherapy of 850 cGy/fraction, weekly to point A for 2 fractions resulted in overall 3.5% residual disease and a 96.5% complete response. The proposed recommendation for improving outcome is initiation of measurements for early detection of disease.

• Journal of Radiation Protection and Research
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• 제31권2호
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• pp.69-89
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• 2006

Biological mechanisms for ionizing radiation effects are different at low doses than at high doses. Radiation hormesis involves low-dose-induced protection and high-dose-induced harm. The protective component is associated with a reduction in the incidence of cancer below the spontaneous frequency, brought about by activation of defensive and repair processes. The Linear No-Threshold (LNT) hypothesis advocated by the International Commission on Radiological Protection (ICRP) and the Biological Effects of ionizing Radiation (BEIR) Report VII for cancer risk estimations Ignores hormesis and the presence of a threshold. Cancer incidences significantly less than expected have been found in a large number of epidemiological studies including, airline flight personnel, inhabitants of high radiation backgrounds, shipyard workers, nuclear site workers in scores of locations throughout the world, nuclear power utility workers, plutonium workers, military nuclear test site Participants, Japanese A-bomb survivors, residents contaminated by major nuclear accidents, residents of Taiwan living in $^{60}Co$ contaminated buildings, fluoroscopy and mammography patients, radium dial painters, and those exposed to indoor radon. Significantly increased cancer was not found at doses <200 $mSv^*$. Evidence for radiation hormesis was seen in both sexes for acute or chronic exposures, low or high LET radiations, external whole- or partial body exposures, and for internal radionuclides. The ubiquitous nature of the Healthy Worker Effect (HWE)-like responses in cellular, animal and epidemiological studies negates the HWE as an explanation for radiation hormesis. The LNT hypothesis is wrong and does not represent the true nature of the dose-response relationship, since low doses or dose-rates commonly result in thresholds and reduce cancer incidences below the spontaneous rate. Radiation protection organizations should seriously consider the cost and health implications of radiation hormesis.

• 한국진공학회지
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• 제22권6호
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• pp.285-290
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• 2013

금속 기판 위에 성장한 그래핀은 원자구조와 전자구조 연구에 우수한 기반이 된다. 그래핀은 금소 기판에서 탄소의 surface segregation 이나 chemical vapor deposition으로 성장할 수 있는데, 이 두 방법의 성장 양상에 대한 비교 연구는 아직까지 없었다. 본 연구에서는 surface segregation, 흡착된 에틸렌의 post-annealing, 에틸렌의 high-temperature dose 등 3 방법으로 성장한 그래핀의 성장구조를 주사형 터널링 현미경으로 연구했다. 처음 2종류의 방법에서는 $100nm^2$ 수준의 작은 그래핀 영역이 나타났고, 3 번째 방법에서는 $10^4nm^2$ 보다 큰 그래핀이 육각형 무아레 무늬와 함께 타나났다. 본 연구에서는 에틸렌의 high-temperature dose 방법이 추가적인 분자성장 등에 필요한 넓은 그래핀을 성장하기에 가장 좋은 방법임을 보였다.

• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1511-1516
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• 2020

The Korea Research Institute of Standards and Science (KRISS) established a new standard of the absorbed dose to water in LINAC X-ray beams. To confirm the equivalence of the new standard with other national metrology institutes (NMIs), a bilateral comparison study of the absorbed dose to water in high energy X-ray beams was performed between the KRISS and the National Metrology Institute of Japan (NMIJ). The comparison was made in-directly. Three transfer chambers were calibrated in the high energy X-ray beams by both laboratories and the calibration coefficients were compared. The average ratios of the calibration coefficients of the three transfer chambers obtained by the KRISS to those obtained by the NMIJ were 1.004, 1.006, 1.006, 1.007 for 6, 10, 15 and 18 MV X-ray beams, respectively. The calibration coefficients obtained at the KRISS were higher than those at the NMIJ but they were in good agreement within the expanded uncertainty of 1.0% (k = 2). The results of this study will be used as the evidence for the KRISS standard being comparable with those of other NMIs, temporarily, in the interim period up to finalizing a key comparison study, BIPM.RI(I)-K6 managed by the Consultative Committee for Ionizing Radiation.

• 한국식품과학회지
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• 제52권1호
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• pp.81-88
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• 2020

PGSE의 혈당조절 효과를 평가하기 위하여 제2형 당뇨 동물모델을 이용하여 8주간의 동물실험을 진행한 결과, 고농도 PGSE(600 mg/kg)의 투여는 경구 포도당 내성 및 혈당 수준을 유의적으로 감소시켰으며(p<0.05), 당화혈색소도 유의적으로 낮은 수준을 유지시켰다(p<0.05). 또한, 혈청 인슐린과 렙틴 농도 역시 대조군과 비교하여 PGSE 고농도 처리군에서 유의적으로 감소하였다(p<0.05). PGSE 투여는 db/db 마우스의 골격근에서 인슐린 의존적 세포신호전달경로를 유의적으로 활성화시켰으며, AMPK 인산화를 촉진시키고, 골격근내 포도당 흡수를 위한 GLUT4의 세포막으로의 전이를 대조군 대비 약 1.7배 증가시켰다. 이러한 결과를 근거로 할 때 PGSE는 항 당뇨병 치료제로서의 잠재적 가능성을 가진 것으로 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3461-3464
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• 2012

Methotrexate (MTX) is an important drug for the treatment of childhood acute lymphoblastic leukemia (ALL). However, related toxicity occurs in many organs which may cause interruption of treatment, morbidity, and mortality. Single nucleotide polymorphisms (SNPs) of dihydrofolate reductase (DHFR) and gamma glutamyl hydrolase (GGH) are known to alter their enzymatic activity and thus affect the metabolism of MTX and influence the effectiveness. Therefore, we hypothesized that genetic variations of DHFR and GGH genes may influence the risk of toxicity after high dose MTX. The study population comprised of 105 children with ALL who were treated according to the modified St Jude Total XV protocol. The patients received 2.5 or $5g/m^2$ of MTX for 5 doses during the consolidation phase. Genotyping of DHFR 829C>T and GGH-401C>T was performed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The GGH-401CT and TT genotypes were associated with increased risk of leukopenia and thrombocytopenia after high dose MTX (OR 2.97, 95%CI; 1.24-7.13 and OR 4.02, 95%CI; 1.58-10.26). DHFR 829C>T was not associated with toxicity. In conclusion, the GGH-401CT and TT genotypes were found to increase the risk of severe leukopenia and thrombocytopenia after exposure to high dose MTX for childhood ALL therapy.