Evaluation of Oxidative DNA Damage Using an Alkaline Single Cell Gel Electrophoresis (SCGE) Comet Assay, and the Protective Effects of N-Acetylcysteine Amide on Zearalenone-induced Cytotoxicity in Chang Liver Cells

Changgeun Kang,Hyungkyoung Lee,Yong-San Yoo,Do-Yun Hah,Chung Hui Kim,Euikyung Kim,Jong Shu Kim 한국독성학회 2013 Toxicological Research Vol.29 No.1

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 μM) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 μM). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

Protective Effects of Houttuynia cordata Thunb. on Gentamicin-induced Oxidative Stress and Nephrotoxicity in Rats

Changgeun Kang,Hyungkyoung Lee,Do-Yun Hah,Jung Ho Heo,Chung Hui Kim,Euikyung Kim,Jong Shu Kim 한국독성학회 2013 Toxicological Research Vol.29 No.1

Development of a therapy providing protection from, or reversing gentamicin-sulfate (GS)-induced oxidative stress and nephrotoxicity would be of great clinical significance. The present study was designed to investigate the protective effects of Houttuynia cordata Thunb. (HC) against gentamicin sulfate-induced renal damage in rats. Twenty-eight Sprague-Dawley rats were divided into 4 equal groups as follows: group 1, control; group 2, GS 100 mg/kg/d, intraperitoneal (i.p.) injection; group 3, GS 100 mg/kg/d, i.p. + HC 500 mg/kg/d, oral; and group 4, GS 100 mg/kg/d i.p. + HC 1000 mg/kg/d, oral administration). Treatments were administered once daily for 12 d. After 12 d, biochemical and histopathological analyses were conducted to evaluate oxidative stress and renal nephrotoxicity. Serum levels of creatinine, malondialdehyde (MDA), and blood urea nitrogen (BUN), together with renal levels of MDA, glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) were quantified to evaluate antioxidant activity. Animals treated with GS alone showed a significant increase in serum levels of creatinine, BUN, and MDA, with decreased renal levels of GSH, SOD, and CAT. Treatment of rats with HC showed significant improvement in renal function, presumably as a result of decreased biochemical indices and oxidative stress parameters associated with GS-induced nephrotoxicity. Histopathological examination of the rat kidneys confirmed these observations. Therefore, the novel natural antioxidant HC may protect against GSinduced nephrotoxicity and oxidative stress in rats.

Protective Effects of Houttuynia cordata Thunb. on Gentamicin-induced Oxidative Stress and Nephrotoxicity in Rats

Kang, Changgeun,Lee, Hyungkyoung,Hah, Do-Yun,Heo, Jung Ho,Kim, Chung Hui,Kim, Euikyung,Kim, Jong Shu Korean Society of ToxicologyKorea Environmental Mu 2013 Toxicological Research Vol.29 No.1

Development of a therapy providing protection from, or reversing gentamicin-sulfate (GS)-induced oxidative stress and nephrotoxicity would be of great clinical significance. The present study was designed to investigate the protective effects of Houttuynia cordata Thunb. (HC) against gentamicin sulfate-induced renal damage in rats. Twenty-eight Sprague-Dawley rats were divided into 4 equal groups as follows: group 1, control; group 2, GS 100 mg/kg/d, intraperitoneal (i.p.) injection; group 3, GS 100 mg/kg/d, i.p. + HC 500 mg/kg/d, oral; and group 4, GS 100 mg/kg/d i.p. + HC 1000 mg/kg/d, oral administration). Treatments were administered once daily for 12 d. After 12 d, biochemical and histopathological analyses were conducted to evaluate oxidative stress and renal nephrotoxicity. Serum levels of creatinine, malondialdehyde (MDA), and blood urea nitrogen (BUN), together with renal levels of MDA, glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) were quantified to evaluate antioxidant activity. Animals treated with GS alone showed a significant increase in serum levels of creatinine, BUN, and MDA, with decreased renal levels of GSH, SOD, and CAT. Treatment of rats with HC showed significant improvement in renal function, presumably as a result of decreased biochemical indices and oxidative stress parameters associated with GS-induced nephrotoxicity. Histopathological examination of the rat kidneys confirmed these observations. Therefore, the novel natural antioxidant HC may protect against GSinduced nephrotoxicity and oxidative stress in rats.

KT 인터넷 장비의 순환전류 해석 및 대책

김창근(Kim Changgeun),차한주(Cha Hanju) 대한전기학회 2006 대한전기학회 학술대회 논문집 Vol.2006 No.10

본 논문은 KT 인터넷 장비의 서비스 중단 및 낙뢰 시 소손이 되는 원인이 인터넷 장비 내 보안접지와 통신접지간의 의도하지 않는 연결에 의한 순환전류임을 제시한다. 아울러 장비 오동작에 대한 대책으로 대단위 접지 보강공사가 아닌 순환전류 저감 대책을 제시하며 그 대책에 의한 장비 오동작 감소사례를 소개한다. 제시한 방법에 따른 장비 개선 전후의 순환전류량을 실험파형으로써 보여준다.

다문화교육의 사회정의론적 쟁점과 방향

김창근 ( Kim Changgeun ) 단국대학교 분쟁해결연구센터 2019 분쟁해결연구 Vol.17 No.2

사회정의론적 관점에서 다문화교육의 주된 쟁점은 재분배 패러다임과 인정 패러다임 간의 역할과 지위에 관한 것이다. 재분배 일원론, 인정 일원론과 차이의 정치, 재분배와 인정의 관점적 이원론은 각각의 논지와 다문화교육의 일정한 논점을 가지고 있다. 하지만, 다문화교육의 확장을 위해서는 첫째, 재분배와 인정의 필요성이 통합적으로 인식되도록 해야 한다. 현실에서 보면, 경제적 구조에서 기인하는 불평등의 문제도 시정해가야 하며, 새로운 사회적 갈등이 야기되는 문화특수성의 문제도 해결해가야 하기 때문이다. 둘째, 다문화교육은 재분배와 인정 패러다임을 넘어 정치적 차원에서의 동등한 참여가 규범적·절차적으로 확보되도록 강조해야 한다. 그것은 다양한 구성원의 참여의 평등성을 보장하는 원칙을 의미한다. 다양한 개인을 주변화하고 배제하지 않도록 의사결정 과정과 구조를 바꾸어가는 노력이 상호인정과 사회적 지위 평등을 이루는 것이기 때문이다. 이는 시민권, 공공의 의사결정 방법, 정치영역에서의 대표 등과 같은 정치적 민주주의의 실천과 함께 추구되어야 한다. 셋째, 다문화교육은 변혁적·사회적 행동적 접근으로서 사회정의를 위한 책무성을 강조해야 한다. 그것은 교환적 정의, 보상적 정의, 세대 간 정의이다. 이에 기반한다면 다문화시대에 사회정의가 보다 굳건히 추구될 수 있을 것이다. The main issue in the social justice perspective of multicultural education is the role and the status of the redistributive paradigm and the recognition paradigm. The redistributive monism, the politics of recognition and difference, the perspectival dualism of the redistribution and the recognition have each argument and a certain point of multicultural education. However, for the expansion of multicultural education, we must, first recognize the need for redistribution and recognition.In reality, it is necessary to correct the problem of inequality caused by the economic structure and to solve the problem of cultural specificity caused by new social conflicts. Secondly, we must emphasize the importance of multicultural normative and procedural access to equal participation on the political level beyond the redistribution and recognition paradigm. It means the principle that guarantees the various members’ equality of participation. This is because that efforts to change the decision-making process and structure so as not to divert and exclude diverse individuals result in mutual recognition and social status equality. These efforts should be pursue together with practice of political democracy, such as civil rights, public decision-making, the reprentative of political territory. Thirdly, Multicultural education should emphasize accountability for social justice as an approach for transformative and social action. It is interchangeable justice, compensatory justice, and intergenerational justice. Based on this, we can firmly pursue social justice in a multicultural era.

포스트 코로나 시대, 한반도 통일교육의 방향: 한반도 평화와 공존의 의미 변화를 중심으로

김창근 ( Kim Changgeun ) 단국대학교 분쟁해결연구센터 2021 분쟁해결연구 Vol.19 No.3

이 논문은 코로나19를 지나면서 나타나고 있는 국제관계 패러다임의 변화가 한반도 평화·공존의 의미에 주는 내용을 바탕으로 포스트 코로나 시대 한반도 통일교육의 방향을 제언하였다. 첫째, 통일교육은 포괄안보의 관점에서 다양한 한반도 평화의 의미와 융합적 접근을 강조해야 한다. 한반도 평화 이슈의 다차원성과 한반도 지역의 시·공간적인 평화·공존의 의미가 새롭게 설명되어야 한다. 기존 남북한 협력의 차원을 넘어 ‘한반도라는 상위의 미래 정체성’에 대한 인식 위에 새로운 남북한 협력의 의제가 상상되어야 한다. 둘째, 통일교육은 한반도 지속가능개발을 위한 남북한 평화·공존 협력의 연결과 활성화를 강조해야 한다. 한반도 지속가능개발을 위한 남북경협의 인식과 실천이 강조되어야 한다. 남북한 주민의 삶의 문제와 연관지어 일상적 평화가 강조되어야 하며, 일상적 작은 평화를 큰 평화로 연결하려는 노력이 한반도 평화·공존의 토대가 된다는 점이 부각되어야 한다. 셋째, 통일교육은 한반도 평화·공존의 규범과 레짐의 활성화를 위한 남북한 및 국제협력의 필요를 강조해야 한다. 남북한 생명·안전 공동체로서의 연결성의 의미가 우선 부각되어야 하며, 북한 비핵화가 한반도 평화체제의 구조 변경과 병행되어야 한다는 점이 인식되어야 한다. 북한 비핵화 대화·외교와 함께 구조적 차원에서의 한반도 평화체제를 구축하려는 정부의 역할이 강조되어야 하며, 한반도 평화·공존 협력을 위한 국제 공공외교의 중요성이 부각되어야 한다. This article suggested the direction of unification education for the Korean peninsula in the post-corona era based on the changes in the international relation paradigm appearing after the COVID-19 in the meaning of peace and coexistence on the Korean Peninsula. First, unification education should emphasize the meaning of peace on the Korean Peninsula and a convergent approach from the perspective of comprehensive security. The multidimensionality of the peace issue and the meaning of temporal and spatial peace and coexistence on the Korean peninsula must be newly explained. In addition, a new agenda for inter-Korean cooperation must be imagined on the basis of the recognition of the “superior future identity as the Korean Peninsula” beyond the current cooperative dimension. Second, unification education should emphasize the connection and vitalization of peace and coexistence cooperation between the two Koreas for sustainable development. The recognition and practice of the inter-Korean economic cooperation for sustainable development on the Korean Peninsula should be emphasized. Furthermore, the peace in the ordinary lives should be emphasized in relation to the problems of the North and South Korean residents’ lives, and it should be highlighted that the efforts to connect the peace in the ordinary lives build the foundation for establishing peace and coexistence on the Korean Peninsula. Third, unification education should emphasize the need for inter-Korean and international cooperation to revitalize the norm and regime for peace and coexistence on the Korean Peninsula. The meaning of the connection as a life-safety community between North and South Korea must first be highlighted, and it must be recognized that the denuclearization of North Korea must go hand in hand with restructuring of the peace regime on the Korean Peninsula. In addition to North Korea’s denuclearization dialogue and diplomacy, the South Korean government’s role in establishing a peace regime on the Korean Peninsula at a structural level should be emphasized, and the importance of international public diplomacy for peace and coexistence and cooperation on the Korean Peninsula should be highlighted.

Evaluation of Oxidative DNA Damage Using an Alkaline Single Cell Gel Electrophoresis (SCGE) Comet Assay, and the Protective Effects of N-Acetylcysteine Amide on Zearalenone-induced Cytotoxicity in Chang Liver Cells

Kang, Changgeun,Lee, Hyungkyoung,Yoo, Yong-San,Hah, Do-Yun,Kim, Chung Hui,Kim, Euikyung,Kim, Jong Shu Korean Society of ToxicologyKorea Environmental Mu 2013 Toxicological Research Vol.29 No.1

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 ${\mu}M$) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 ${\mu}M$). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

DCLR 을 사용한 다중루프 제어시스템 설계를 위한 해석적 방법

김창근(Kim Changgeun),전대웅(Daewoong Chun),이지태(Jietae Lee),이기홍(Kihong Lee),이문용(Monyong Lee) 제어로봇시스템학회 2001 제어로봇시스템학회 국제학술대회 논문집 Vol.2001 No.10

모폴로지와 비선형 확산을 이용한 영상 분할

김창근(Changgeun Kim),유재명(Jaemyeong Yoo),이귀상(Gueesang Lee) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.2Ⅱ

영상을 유사한 특성을 갖는 영역 단위로 분할하는 작업은 다양한 영상 처리를 위한 전처리 과정으로 사용되고 있다. 본 논문에서는 모폴로지(morphology)와 비선형 확산(Non-Linear Diffusion)을 이용한 영상 분할 방법을 제안한다. 초기에 LUV 색상공간에 모폴로지를 응용한 재구성 (Reconstruction)에 의한 닫힘(Closing) 연산과 비선형 확산(Non-Linear Diffusion)을 통해 실험 영상을 획득한다. 이 영상에서 칼라 영상의 기울기(Gradient) 정보를 획득하고 마커(Marker) 정보를 이용한 워터쉐드(Watershed) 알고리즘을 적용하여 영상을 효과적으로 분할한다. 그레이 영상과 칼라 영상을 대상으로 한 실험에서 제안 방법이 영상을 효과적으로 분할함을 확인 하였다.

Optimization of Ultrasound-Assisted Pretreatment for Accelerating Rehydration of Adzuki Bean (Vigna angularis)

( Hyengseop Kim ),( Changgeun Lee ),( Eunghee Kim ),( Youngje Jo ),( Jiyoon Park ),( Choongjin Ban ),( Seokwon Lim ) 한국미생물생명공학회 2024 Journal of microbiology and biotechnology Vol.34 No.4

Adzuki bean (Vigna angularis), which provides plant-based proteins and functional substances, requires a long soaking time during processing, which limits its usefulness to industries and consumers. To improve this, ultrasonic treatment using high pressure and shear force was judged to be an appropriate pretreatment method. This study aimed to determine the optimal conditions of ultrasound treatment for the improved hydration of adzuki beans using the response surface methodology (RSM). Independent variables chosen to regulate the hydration process of the adzuki beans were the soaking time (2-14 h, X₁), treatment intensity (150-750 W, X₂), and treatment time (1- 10 min, X₃). Dependent variables chosen to assess the differences in the beans post-immersion were moisture content, water activity, and hardness. The optimal conditions for treatment deduced through RSM were a soaking time of 12.9 h, treatment intensity of 600 W, and treatment time of 8.65 min. In this optimal condition, the values predicted for the dependent variables were a moisture content of 58.32%, water activity of 0.9979 a_w, and hardness of 14.63 N. Upon experimentation, the results obtained were a moisture content of 58.28 ± 0.56%, water activity of 0.9885 ± 0.0040 a_w, and hardness of 13.01 ± 2.82 g, confirming results similar to the predicted values. Proper ultrasound treatment caused cracks in the hilum, which greatly affects the water absorption of adzuki beans, accelerating the rate of hydration. These results are expected to help determine economically efficient processing conditions for specific purposes, in addition to solving industrial problems associated with the low hydration rate of adzuki beans.