• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.949-956
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• 2021

The purpose of this paper is to evaluate whether tungsten nanoparticles have a shielding effect on scattered light generated at high doses as an alternative material to lead used to shield scattered light in electron beam therapy. A plate was manufactured to set the position of the dosimeter and the size of the radiation field to be constant. The glass dosimeter was placed at 12 points, which were 1, 2, and 4 cm apart from the center of the field of 10 × 10 cm² in the cross direction. A total of 12 types of tungsten nanoparticle shields were developed with a thickness of 0.75 mm to 4.00 mm and a size of 10 × 10 cm² using 0.4, 0.75, and 1 mm materials. Using a linear accelerator, measurements were made four times at 6 MeV and four times at 12 MeV, and the dose intensity was investigated at 100 MU. The 4 mm shielding plate showed the highest shielding effect at 1 cm from the irradiation field. The 1 mm shielding plate at 2 cm from the irradiation field had the lowest shielding effect. As the thickness of the tungsten shielding plate increased, the electron beam's shielding effect increased sharply. It was confirmed that tungsten nanoparticles can reduce the amount of scattered light generated by electron beam therapy. Therefore, this study will provide basic data when follow-up studies are conducted on the shielding ability of tungsten nanoparticles.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.659-667
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• 2017

The present study was designed to evaluate the antioxidant activity and radioprotective effects of Naringin and Naringenin in ${\gamma}$-irradiated mice. The antioxidant activity of Naringin and Naringenin was evaluated by 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Healthy female BALB/c mice were administered Naringin and Naringenin orally ($90{\mu}M/dose$ and $180{\mu}M/dose$) for 7 consecutive days prior to ${\gamma}$-irradiation (6 Gy). Naringenin displayed a much higher antioxidant activity in ABTS and FRAP than naringin. ${\gamma}$-irradiation resulted in cellular damage with decreased spleen and thymus indices and white blood cells (WBC) count. Additionally, ${\gamma}$-irradiation significantly increased lipid peroxidation and decreased the levels of antioxidant enzymes and glutathione (GSH) in the liver tissue. Strikingly, prior administration of Naringenin resulted in considerable prevention of these symptoms. Protection against ${\gamma}$-irradiation-induced cellular damage by Naringenin is likely due to its higher its antioxidant activity. Together, these results confirm that Naringenin is a potent antioxidant and radioprotector.

• Radiation Oncology Journal
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• v.17 no.4
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• pp.314-320
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• 1999

Purpose : Paclitaxel is a chemotherapeutic agent with potent microtubule stabilizing activity that arrests cells in $G_2$-M phase. Because $G_2$ and M are the most radiosensitive phase of the cell cycle, paclitaxel has potential role as a cell-cycle specific radiosensitizer. This study was peformed to see the effects of paclitaxel on the radiation-induced damage of gastric mucosa of the rat. Materials and Methods : The rats were divided into the three groups i.e., paclitaxel alone group, radiation alone group and, a combination of paclitaxel and radiation in combined group. A single intraperitoneal infusion of paclitaxel (10 mg/kg) was done in paclitaxel alone group. In radiation alone group, a single fraction of irradiation (8 Gy, x-ray) to the whole abdomen and, a combination of a single fraction of irradiation (8 Gy, x-ray) to the whole abdomen was given 24 hrs after paclitaxel infusion In combined group of paclitaxel and radiation. The incidence of mitosis and apoptosis as well as histologic changes of the gastric mucosa were evaluated at 6 hrs, 24 hrs, 3 days and 5 days after treatment. Results : The number of the mitosis was not increased by paclitaxel infusion. The incidence of the apoptosis was similar from 6 hrs to 3 days after paclitaxel infusion and was decreased at 5 days. Paclitaxel induced minimal glandular dilatation and cellular atypia of gastric mucosa at 24 hrs and 3 days. In irradiation group, the incidence of apoptosis was $6.0\%$ in 6 hrs and $1.25\%$ in 24 hrs after irradiation and minimal glandular dilatation and cellular atypia were noted throughout the experimental period. The incidence of apoptosis in the combined group of paclitaxel and irradiation ($4.5\%$) was significantly higher than irradiation alone group ($1.25\%$) at 3 days (p<0.05). Conclusion : Paclitaxel had no mitotic on mitotic arrest in gastric mucosa of the rat. Increased number of apoptosis in combined paclitaxel and irradiation group suggested the additive effects of paclitaxel on irradiation.

• Radiation Oncology Journal
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• v.13 no.4
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• pp.321-330
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• 1995

Purpose : To evaluate whether the early pulmonary irradiation can prevent or decrease the pulmonary damage and contribute to improve ultimate survival in paraquat lung. Materials and Methods : From Jun. 1987 to Aug. 1993, thirty patients with paraquat poisoning were evaluated. Fourteen of these patients were received pulmonary irradiation(RT). All of the patients were managed with aggressive supportive treatment such as gastric lavage, forced diuresis, antioxidant agents and antifibrosis agents. Ingested amounts of paraquat were estimated into three groups(A : minimal 50cc). Pulmonary irradiation was started within 24 hours after admission(from day 1 to day 11 after ingestion of paraquat). Both whole lungs were irradiated with AP/PA parallel opposing fields using Co-60 teletherapy machine. A total of 10Gy(2Gy/fr. x 5days) was delivered without correction of lung density. Results : In group A, all patients were alive regardless of pulmonary irradiation and in group C, all of the patients were died due to multi-organ failure, especially pulmonary fibrosis regardless of pulmonary irradiation. However, in group B, six of 7 patients($86{\%}$) with no RT were died due to respiratory failure, but 4 of 8 patients with RT were alive and 4 of 5 patients who were received pulmonary irradiation within 4 days after ingestion of paraquat were all alive though radiological pulmonary change. One patient who refused RT after 2Gy died due to pulmonary fibrosis. All 3 patients who were received pulmonary irradiation after 4 days after ingestion were died due to pulmonary fibrosis in spite of recovery from renal and hepatic toxicity Conclusion : It is difficult to find out the effect of pulmonary irradiation on the course of the paraquat lung because the precise plasma and urine paraquat concentration were not available between control and irradiation groups. But early pulmonary irradiation within 4 days after paraquat poisoning with aggresive supportive treatment appears to decrease Pulmonary toxicity and contribute survival in patients with mouthful ingestion of paraquat who are destined to have reversible renal and hepatic damage but irreversible pulmonary toxicity.

• Radiation Oncology Journal
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• v.6 no.2
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• pp.283-288
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• 1988

However, long-term results of retrospective studies suggest that, for the great majority of individuals, mastectomy or conservative surgery with radiation therapy were be equally effective. The results at 5 and 10 years from prospective randomized trials indicate that survival following primary radiation therapy for early breast cancer is equivalent to that fellowing mastectomy. When competently Performed, Primary radiation therapy gives highly satisfactory cosmetic results and acceptably low rates of local tumor recurrence. A number of controversial issues remain concerning patient evaluation and selection and the optimal techniques of treatment, both surgical and radiotherapeutic. In addition, further work is needed to clearity the best way to integrate primary radiotherapy with adjuvant systemic treatment. And further follow-up of these patients with primary radiation therapy for early beast cancer will be required for ultimate proof of the relative merits. A case which was conservative surgery and radical irradiation of early breast cancer with review of literatures will be done.

• The Journal of the Korea Contents Association
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• v.13 no.1
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• pp.287-293
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• 2013

Dandelion(Taraxacum officinale), an oriental herbal medicine, has been shown to favorably affect choleretic, antioxidative and protection of gastric mucosa. The protective effects of common dandelion leaf and root extract were investigated by irradiation in Sprague-Dawley rats. Male SD rats, 6weeks, were orally injected with dandelion extract(100mg/kg) for 10days. Immediately after final injection, rats were whole body irradiated with 10Gy used irradiation facility(Elekta Linac, Sweden). At 24h-15days after irradiation, complete blood counted test and apoptosis in jejunal crypt cell. Stimulated recovery by the extract was observed in platelet but was not showed in the erythrocyte and leucocyte. The jejunal crypt cells were protected significantly(p<0.05) and the radiation-induced apoptosis was reduced(p<0.05). The survival rate were carried for 15days, the survival ratio was 15% and 85% for the control and experimental group. Observations intestinal inhibition of cell death, intestinal mucosa and tissue decreased systemic inflammation and vacuole. Base on these data, we propose that dandelion may be a useful radioprotector, especially since it is a relatively nontoxic natural product.

• Radiation Oncology Journal
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• v.23 no.4
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• pp.211-216
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• 2005

Purpose: It has been reported that all-trans retinoic acid (ATRA) can inhibit glioma growing in vitro. However, clinical trials with ATRA alone in gliomas revealed modest results. ATRA has been shown to increase radiosensitivity in other tumor types, so combining radiation and ATRA would be one of alternatives to increase therapeutic efficacy in malignant gliomas. Thus, we intended to know the role of catalase, which is induced by ATRA, for radiosensitivity if radiation-reduced reactive oxygen species (ROS) is removed by catalase, the effect of radiation will be reduced. Materials and Methods: A rat glioma cell line (36B10) was used for this study. The change of catalase activity and radiosensitivity by ATRA, with or without 3-amino-1, 2, 4-triazole (ATZ), a chemical inhibitor of catalase were measured. Catalase activity was measured by the decomposition of $H_2O_2$ spectrophotometrically Radiosensitivity was measured with clonogenic assay. Also ROS was measured using a 2, 7-dichlorofluorescein diacetate spectrophotometrically. Results: When 36B10 cells were exposed to 10, 25 and $50{\mu}M$ of ATRA for 48 h, the expression of catalase activity were increased with increasing concentration and incubation time of ATRA. Catalase activity was decreased with increasing the concentration of AT (1, $10{\mu}M$) dose-dependently. ROS was increased with ATRA and it was augmented with the combination of ATRA and radiation. ATZ decreased ROS production and increased cell survival in combination of ATRA and radiation despite the reduction of catalase. Conclusion: The increase of ROS is one of the reasons for the increased radiosensitivity in combination with ATRA. The catalase that is induced by ATRA doesn't decrease ROS production and radiosensitivity.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.161-169
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• 2024

This study confirmed the radioprotective effects of a mixed extracts of Hottuynia, Perilla Frutescens, and Camellia Sinnensis as natural radioprotectors on the prostate, small intestine, and liver of SD rats. It is known that Hottuynia, Perilla Frutescens, and Camellia Sinnensis have antioxidant effects on the prostate, small intestine, and liver, respectively.In this study, SD rats were irradiated with 8 Gy of gamma rays to confirm the radioprotective effects of a mixed extracts of Hottuynia, Perilla Frutescens, and Camellia Sinnensis. After radiation irradiation, histological analysis of the prostate, small intestine, and liver was performed. After radiation irradiation, histological analysis of the prostate, small intestine, and liver was performed. In the case of the prostate, the HPC+IR Group had less prostate damage and better recovery due to radiation compared to the IR Group. It was confirmed that the prostate size of the HPC+IR Group was 11.48%p and 24.54%p higher than the IR Group on 1st and 7th days. In the case of the small intestine, the HPC+IR Group had less radiation-induced small intestinal damage and recovery was better than the IR Group. The length of small intestine villus in the HPC+IR Group was confirmed to be 23.73%p and 24.27%p higher than the IR Group on the 1st and 7th days. In the case of the liver, the HPC+IR Group had less liver damage due to radiation and had better recovery than the IR Group. This was confirmed through the hepatic portal vein and surrounding cells. The results of this study are considered to be used as basic data for research on natural radiation protection using mixed extracts.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2003.10a
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• pp.89-89
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• 2003

고사리(Pteridium aquilinum)는 봄철에 어린싹을 삶아 물에 담구었다가 먹거나 건조시켜 저장해서 이용하는데 현재 유통되고 있는 건고사리는 수확, 건조 및 저장 중에 비위생적인 관리 둥에 의해 미생물의 중식 및 해충의 발생 등으로 품질이 크게 저하되어 저장상 많은 어려움을 안고 있다. 살균, 살충을 위한 방사선의 식품에의 이용은 그 건전성과 경제적 타당성이 인정되어 여러나라에서 실용화 되고 있다. 방사선 조사된 건고사리는 선행연구에서 재수화성이 증대되었고, 조리에 의한 연화시간이 단축되어 에너지 절감의 효과가 있었다. (중략)

• Radiation Oncology Journal
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• v.23 no.2
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• pp.116-122
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• 2005

Purpose: Histone deacetylase inhibitors (HDIs) are emerging as potentially useful components of anticancer therapy and their radiosensitizing effects have become evident. Specific HDAS are now available that preferentially inhibit specific HDAC classes; TSA inhibits Class I and II HDACs, and SK7041 inhibits Class I HDACs. Materials and methods: We tested the differential radiosensitization induced by two different classes of HDIs in HeLa cells. We next tested the hypothesis that p53 expression in cancer cells may influence the susceptibility to HDIs by using pharmacologic modification of the p53 status under an isogenic background. Results: It is interesting that p53 expression in the HeLa cells clearly increased the degree of radio-sensitization by TSA compared to that of the class I specific inhibitor SK7041. This suggests that p53 may, in part, be responsible for the mechanistic role for the greater radiosensitization induced by Class I & II inhibitors compared to that of the class I specific inhibitors. Thus, these studies are useful in distinguishing between events mediated solely by the Class I HDACS versus those events involving the other classes of HDACS as well. Conclusion: The anticancer efficacy of targeting Class I and II HDACS, in conjunction with radiation therapy, may be further enhanced by the restoration of p53 expression.