Prostaglandin A₂-induced Apoptosis is Not Inhibited by Heme Oygenase-1 in U2OS Cells

Kyoung-Won Ko(고경원),Sun-Young Lee(이선영),Ji-Hyun Ahn(안지현),Jaetaek Kim(김재택),In-Kyung Kim(김인경),Ho-Shik Kim(김호식) 한국생명과학회 2008 생명과학회지 Vol.18 No.11

Prostaglandin A₂ (PGA₂)는 사람 골육종 세포인 U2OS 세포주에서 apoptosis와 heme oxygenase (HO)-1의 발현을 함께 유도하였다. PGA₂에 의한 apoptosis는 HO-1의 과도한 발현이나 HO-1에 대한 small interfering RNA에 의한 발현저하에 의하여 변동되지 않았으나 H₂O₂에 의한 세포사망은 HO-1의 발현 수준에 반비례하여 변동되었다. 또한 thiol antioxidant인 N-acetyl-L-cysteine (NAC)은 PGA₂에 의한 세포사망과 HO-1의 발현 증가를 모두 차단하였지만, non-thiol antioxidant인 butylated hydroxyanisole (BHA)과 ascorbic acid는 세포사망과 HO-1의 발현 유도를 차단하지 않았다. 이와 같은 결과들은 PGA₂는 산화성 손상에 의해서가 아니라 PGA₂의 thiol-reactivity에 의하여 apoptosis와 HO-1의 발현을 유도하며, HO-1의 발현은 PGA₂에 의한 apoptosis와는 독립적인 현상이거나 기능적으로 apoptosis 유도의 하부에 위치하고 apoptosis의 진행에는 기여하지 않을 것이라는 것을 시사해 준다. Prostaglandin A₂ (PGA₂), one of cyclopentenone PGs, induced both apoptosis and heme oxygenase (HO)-1 expression in U2OS cells. PGA₂-induced apoptosis was not perturbed by either over-expression or knock-down of HO-1, whereas H₂O₂-induced cell death was inversely modulated by the expression level of HO-1. In addition, N-acetyl-L-cysteine (NAC), a thiol antioxidant, blocked both apoptosis and HO-1 expression induced by PGA₂. But, non-thiol antioxidants like butylated hydorxyanisole (BHA) and ascorbic acid did not block either apoptosis or HO-1-induction. Taken together, these results suggest that PGA₂ induces both apoptosis and HO-1 expression, which are critically related to the thiol-reactivity of PGA₂, but not oxidative stress, and HO-1 expression may be independent or functionally located downstream of apoptosis by PGA₂ without contribution to apoptosis progression.

그래핑 계산기를 활용한 협동학습에서 학생들의 언어적 상호작용 분석에 관한 사례연구 : A Case Study

고호경 한국수학교육학회 2003 수학교육 Vol.42 No.5

The research was aimed at finding the dynamic aspects of the linguistic and social interaction with mathematical concept development using a graphing calculator in collaborative learning. This study was broadly divided into two categories: "Knowledge Construction Statement" for understanding how the verbal interaction works when a graphing calculator is used, and "Teacher's Instructional Role" for the research on the reaction of the students and on the teacher's role as a guide in helping students to construct their knowledge. This research used a case study in a collaborative learning environment. An attempt was made to show clearly how the students interacted with one another in a technology environment using a graphing calculator as a tool. A graphing calculator promoted the students' linguistic interaction and changed the characteristics of the linguistic interaction. Although it didn't show the different aspects completely, some changes of the linguistic traits were perceived.

多樣한 黃芩藥鍼製劑의 安全性 및 效能에 關한 硏究

김호경,마진열,전원경,윤수영,강은정,주혜정,고병섭 한국한의학연구원 1997 한국한의학연구원논문집 Vol.3 No.1

In order to detect the safety and effect of various aqua-acupunctures from Scutellariae Radix, the modifications of boiling, filtration and dilution were employed for the manufacture of aqua-acupunctures. We injected 0.2cc of aqua-acupunctures into Joksamri(足三里) of rat, repeatedly. we compared subacute toxicity of them with saline group, distilled water(D.W.) group, acupuncture group and control group. The results were summarized as follows: 1. The groups were all healthy and alive, and there was no special abnormality in physical condition and autopsy. And there were not any toxic symptoms in repeating application of aqua-acupunctures to the rat, including changes of body weight, organ weight, haematological examination and serum biochemical test. 2. There was slight change of body weight in acupuncture group : We could see significance after 3 days (p<0.05) and after 7 days (p<0.001) in body weight loss. After 9 days, all tested groups were suppressed in body weight increment. 3. Result of organ weight: In Palking aqua-acupuncture(D-2 group), saline group and acupuncture group there were some statistical significance. Especially, acupuncture group revealed significant result in liver and spleen than aqua-acupunctures. From this result, we could suggest that the efficacy of acupuncture was preceded herbal medicine. 4. In serum biochemical test, we examined glucose(GLU), triglyceride(TG) and cholesterol(CHOL). In comparison with control group, the diluted 10 times of hwanggum aqua-acupuncture (× 10 group) was recognized significant decrease of glucose, but the diluted 100 times of Hwanggum aqua-acupuncture (× 100 group), D-2 group, saline group were confirmed significant increment. There was not any meaningful change of CHOL in all of tested group, excepting the acupuncture group was exhibited statistically significant decrease(p<0.05). In TG level all tested group except complex injection of standard compound (CPA group) and HG, there were significant value in statistically. The diluted solution was more significant decrease than Hwanggaum aqua-acupuncture(HG). The mutual relationship of components of aqua-acupuncture tended to decrease level of TG, regardless of its concentration. In acupuncture group, we gained some interesting result in meaningful decrease in TG. 5. Haematological examination showed significant increment of gramulocytes(GR) in all tested groups except Hwanggum aqua-acupuncture. And the diluted solutions of HG expressed very high increment of them(p<0.001). The GR and Mean Corpuscular Volume(MCV) of acupuncture group showed statistical significance.

첨가성분에 따른 부가중합 실리콘 인상재의 세포독성에 관한 연구

조리라,고성희,정경호,김경남 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.3

The purpose of this study was to evaluate the biocompatibility of polyvinyl siloxane impression materials and it's components using cell culture techniques. In the cytotoxicity test, using the culture of L929 mouse fibroblast, the degree of gross cytotoxic effects on the cells by changes in the cell morphology was scored for each materials. And the changes in the cell membrane permeability was tested using the agar overlay test. The results were as follows: 1.The effect of Examix impression material had on cell viability by evaluating survival rates was more severe than any other materials and newly added surfactants. 2.NP-4, nonylphenoxy polyethylene ethanol homologs, showed some cytotoxicity than PC-550 and BYK066. 3.In the test of the changes in cell membrane permeability using the agar overlay method, any cytotoxicity was recorded in silicone base groups. 3.In agar overlay test, Examix and NP-4 showed most response index and lysis index. 4.The application of surfactant such as PC-550, NP-4, and BYK066 might be considered relatively biocompatible.

TiO₂ 담체상에서 귀금속 촉매의 휘발성유기화합물 산화특성

김문찬,강경호,고선환 한국공업화학회 2005 응용화학 Vol.9 No.1

In this study, monometallic Pt and bimetallic Pt-Ru, Pt-Ir were supported to TiO₂. In order to distribute metals uniformly, and Xylene, toluene and MEK were used as reactants. The monometallic or bimetallic catalysts were prepared by the excess wetness impregnation method and were characterized by XPS and BET analysis. As a result, Pt-Ru, Pt-Ir bimetallic catalysts were showed higher conversion than Pt monometallic catalyst. Pt-Ir bimetallic catalyst was showed highest conversion on the TiO₂ support. In the VOCs oxidation, Pt-Ir bimetallic catalyst had multipoint active sites, so it improved the range of Pt metal state. Therefore, bimetallic catalysts were higher conversion of VOCs than monometallic ones. In the kinetics, VOCs oxidation was appeared on the first order reaction. In this study, the use of small amount of Jr to Pt promoted oxidation conversion of VOCs.

Vitamin D deficiency is associated with disease activity in patients with Crohn’s disease

Kyoung Ho Ko,김유선,Bo Kyung Lee,Jong Hyun Choi,Yong Moon Woo,Jin Young Kim,Jeong Seop Moon 대한장연구학회 2019 Intestinal Research Vol.17 No.1

Background/Aims: Previous data suggest that vitamin D has a significant role in inflammatory bowel disease (IBD). We investigated the incidence of vitamin D deficiency in Korean patients with IBD and the correlation between serum vitamin D level and disease activity. Methods: We retrospectively analyzed the medical records of patients with IBD whose serum vitamin D levels were checked. Deficiency of 25-hydroxyvitamin D was defined as <20 ng/mL. Disease activity was evaluated using the partial Mayo score for ulcerative colitis (≥2 defined as active disease) and Harvey-Bradshaw index for Crohn’s disease (≥4 defined as active disease). Results: We enrolled 87 patients with IBD (ulcerative colitis [UC], 45; Crohn’s disease [CD], 42). Among them, 65.5% (57/87) were men, with a mean age of 44.9±15.1 years (range, 18–75 years). The mean duration of disease was 4.7±4.8 years (range, 0.1–17.1 years). Vitamin D deficiency was found in 73.6% (64/87) of patients with IBD. Patients with IBD (mean vitamin D level, 16.3±9.0 ng/mL) showed lower vitamin D level than the healthy control group (mean vitamin D level, 20.4±7.0 ng/mL), with no statistically significant difference (P=0.136). Disease activity was inversely correlated with vitamin D deficiency in patients with CD (P=0.007). However, no correlation was observed in patients with UC (P=0.134). Conclusions: Approximately 75% of Korean patients with IBD showed vitamin D deficiency state. Vitamin D deficiency is associated with disease activity, particularly in patients with CD. (Intest Res 2019;17:70-77)

Who has given up on mathematics? A data analysis

Ko, Ho Kyoung,Choi, Suyoung,Kaji, Shizuo 서울대학교 교육연구소 2021 Asia Pacific Education Review Vol.22 No.4

The newly coined term supoza (giving up mathematics, 수포자, 數抛者) describes a critical social issue that needs to be addressed in South Korea’s educational policy. Although the term has not received precise defnition, it refers to students who have given up on learning mathematics. A precise defnition would require detailing the current supoza situation and identifying its characteristics. This study therefore conducted a statistical investigation of commonalities among students who have given up on learning mathematics; the study results revealed that these students can be characterized by their afective domain for mathematics learning. We found that a statistical model could determine the likelihood that a particular student would report having given up mathematics based on responses to questions related to the afective domain of mathematics learning. This aspect suggests the possibility of understanding supoza with the exclusive use of afective factors and emphasizes the signifcance of the afective domain of mathematics learning. Additionally, this study provides a working example to show how exploratory analysis using big data can be used in relation to mathematical education.

<tex> ${\rm GdBa}_{2}{\rm Cu}_{3}{\rm O}_{7-\delta}$</tex> Coated Conductor on <tex> ${\rm BaZrO}_{3}$</tex> -Buffered IBAD-MgO Template

Kyoung-Pil Ko,Rock-Kil Ko,Sung-Yun Lee,Ho-Kyum Kim,Seung-Hyun Moon,Sang-Soo Oh,Sang-Im Yoo IEEE 2009 IEEE transactions on applied superconductivity Vol.19 No.3

<P>We report a successful fabrication of GdBa2Cu3O7-delta (GdBCO) coated conductor on the ion-beam assisted deposition (IBAD) MgO template with a new buffer layer of BaZrO3 (BZO). The BZO films were deposited on the IBAD-MgO template at various substrate temperatures (T-S) and oxygen partial pressures (PO2) by pulsed laser deposition (PLD). In the broad ranges of T-S and PO2, all BZO layers showed almost uniform in-plane texture (Delta phi of similar to 6 degrees), implying that BZO is an attractive buffer layer. The surface roughness of BZO layer was sensitive to PO2 but not to T-S. On the optimally processed BZO buffer layer with 5.1 nm RMS roughness, GdBCO coated conductor deposited at T-S of 750 degrees C and PO2 of 400 mTorr exhibited Delta phi of 4.4 degrees, T-c,T-zero of 90.3 K, and J(c) of 1.35 MA/cm(2) (77 K, self-field).</P>

Poster Session : PS 0444 ; Infectious Disease ; Mononuclear Syndrome with Acute Hepatitis Diagnosed with Mycoplasma Pneumoniae Infection without Lung Involvement

( Kyoung Ho Ko ),( Young Kyung Yoon ),( Seung Hee Baik ),( Jang Wook Sohn ),( Min Ja Kim ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Although pneumonia has been a hallmark of Mycoplasma pneumoniae infection, it has been also associated with the protean manifestation as extra-pulmonary involvement. Herein, we report a case of mononuclear syndrome with acute hepatitis and erythema multiforme, revealed as M. pneumoniae infection without lung involvement. Case report: A 30-year-old man presented with a 3-day history of skin rash. He had been having high fever and myalgia for 7 days. On admission, physical examination revealed erythema multiforme on trunk and tenderness on right-upper quadrant abdomen. Laboratory examination showed the evidence of mononucleosis-like syndrome. Liver function tests showed aspartate aminotransferase (AST) 504 IU/L, alanine aminotransferase (ALT) 578 IU/ L, r-glutamyl transpeptidase (GGT) 209 IU/L, alkaline phosphatase (ALP) 157 IU/L and total serum bilirubin 1.18 mg/dL. Abdomen computed tomography showed reactive gallbladder wall thickening, and small-sized lymphadenopathy around aorta and portal vein. Chest X-ray showed no signifi cant shadows. On the 8th hospital day, liver function tests were aggravated and he was complaint of abdominal distension due to ascites. Bone marrow biopsy revealed increased plasma cell infi ltration. IgM antibodies for M. pneumoniae were negative by enzyme immunoassay on admission. However, the titer for M. pneumoniae was 1:640 on the 10th hospital day. The patient was initiated on levofi oxacin (500 mg per a day for 17 days) and the symptoms cleared after 3 days. The patient was discharged in good condition. No relapse was noted over a 3-month follow-up period. Conclusion: In conclusion, we report the rare case of M. pneumoniae infection presenting with extra-pulmonary manifestations. Particularly, recognition of this etiologic association is important since specifi c antimicrobial therapy is effective against M. pneumoniae, when bthe patients revealed the various clinical syndromes without pneumonia.

3.5 세대 이동통신 서비스인 WiBro 의 특징과 이동성 기술에 관한 연구

고경호 ( Kyoung Ho Ko ),조치현 ( Chi Hyun Cho ),김경태 ( Kyung-tae Kim ),윤희용 ( Hee Yong Youn ) 한국정보처리학회 2007 한국정보처리학회 학술대회논문집 Vol.14 No.2

WiBro는 휴대 인터넷, 무선 광대역 인터넷, 무선 초고속 인터넷 등으로 풀이된다. 이동전화처럼 언제 어디서나 이동하면서도 초고속으로 인터넷을 이용할 수 있는 서비스로, 한국이 국제 표준화를 주도하고 있는 3.5세대 이동통신 서비스이자 국책사업이다. 기존의 무선인터넷 환경은 이동통신사에서 제공하는 컨텐츠에만 접근이 가능한 폐쇄적인 구조이지만 WiBro를 비롯한 3.5세대의 무선인터넷 서비스로 개방형 구조로 전환된다. 본 논문에서는 WiBro와 WiMAX의 차이점과 시스템의 특징 및 구조에 대하여 알아보고 휴대 인터넷의 핵심 기술인 핸드오버를 WiBro상에서 어떻게 구현했는지에 관해 살펴보고자 한다.