최과 교정용 스테인리스 강 선재의 신선 가공법이 내식성에 미치는 영향

고영무,모웅남,최한철 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.1

The dental orthodontic wire requires good mechanical properties, such as elastic strength, combined with a high resistance to corrosion. For increasing elastic strength and delaying onset of stress corrosion cracking, drawing methods(one-step and two-step drawing) have been used in this study to extend service life of metal components, However, there is no information on the electrochemical corrosion behavior of drawn wires for orthodontics. To increase elastic strength, good corrosion resistance, and biocompatibility, the electrochemical characteristics of drawn wire have been researched by field emission scanning microscope and potentiodynamic method in 0.9% NaCl solution. The one-step drawn wire showed the formation of rough surface. The hardness and tensile strength of two-step drawn wire increased. Electrochemical measurements showed that, in the case of two-step drawn wire, the corrosion resistance and pitting potential increased compared with two-step drawn wire due to the drawing induced small surface roughness, such as scratch, whereas passivation and active current density decreased as the reduction in area for drawing increased.

스테인리스강 소결체를 이용한 치과용 임플란트 개발(Ⅰ) : 치과용 소결체의 제작과 물성을 중심으로 Fabrication and Physical Properties of Sintered Stainless Steel

최한철,고영무,모웅남 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.3

The first factor to decide the success of dental implantation is sufficient, osseointegration between implant fixture and its surrounding bone tissue. Thus many studies about this have been under actively. In recent, one of them is to increase the roughness of the surface of an implant fixture by treating the surface of an implant fixture in various ways, increase the contact area between an implant fixture and its surrounding bone tissue and so induce a sufficient osseointegration between them. The roughness of the surface on an implant fixture can be increased by coating the smooth surface of an implant fixture with hydroxyapatite or titanium particles or by treating the surface with acid. But these ways can cause the failure of implantation in the long run due to the separatation of coated particles from an implant fixture and sometime; can't attain the sufficient osseointegration because of emitting ion into the surrounding bone tissue. To develop dental implant materials, fabrication and physical properties of sintered stainless steel have studied using hardness tester, tensile tester, SEM, TEM, EPMA, EDX. Stainless steel compacts containing Cu (2-10 wt%) were prepared either by electroless Cu-plating method which result in the increased homogenization in alloying powder or by Cu-elemental powder addition method on the stainless steel powder Experimental investigation foucusing on mechanical property was performed for Cu-added samples to study the effects of Cu content, electroless Cu-plating method, and Cu-elemental powder addition method on the surface characteristics of sintered stainless steel in Mo and Cu in sintered stainless steel on the mechanical behaviors. Microstructural characterization revealed that Cu-addition by electroless Cu-plating method resulted in less porous material compared that prepared by Cu-elemental powder addition method. Since Cu is blown to be effective in reducing the precipitation of chromium carbide at sensitization temperature, Cr concentration in electroless Cu-plating method was uniformly distributed in the grain boundary and in the matrix. The sintered density in electroless Cu-plating method increased with reducing porosity as a result of the Cu-uniform distribution due to electroless Cu plating during the sintering process. The amount of Cu added in the sintered stainless steel affected significantly tensile strength which increased with 4 wt% Cu and decreased with more than 7 wt% Cu.

독소루비신과 알로퓨리놀이 화학적 근절제에 미치는 영향

정원균,고한웅,강동희,구상환,박승하 大韓成形外科學會 2004 Archives of Plastic Surgery Vol.31 No.3

조형등대와 건축적 표상에 관한 연구 : 통영 문학기념 조형등대의 디자인 기술을 중심으로

안웅희(Ahn Woong-Hee),송민성(Song Min-Sung),고신채(Ko Sin-Chai),한창수(Han Chang-Soo) 한국항해항만학회 2007 한국항해항만학회 학술대회논문집 Vol.1 No.춘계

등대는 전통적인 기능과 역할에 충실한 항로표지일 뿐만 아니라 사람들의 향수와 해양문화의 기억들이 묻어있는 공간이다. 최근에는 적절한 해양문화공간으로 개발함으로써 해양문화에 대한 인식을 높이고, 지역관광에 공헌을 하고 있는 추세이다. 특히, 해양수산부는 2006년 "희망의 빛 조형등대 설치계획"을 통하여 마산지방해양수산청 소속의 통영시 도남항 동방파제 등대를 건설하였다. 지역과 문화적 특색을 살릴 수 있는 기념등대로 개발하고자 하였으며, 이에 따라 통영의 훌륭한 문화적 성과를 기념대상으로 지정하였다. 이에 현상공모를 통해 한국해양대학교의 안웅희 교수의 작품이 당선되었다. 본 연구는 기존의 등대의 형태에서 벗어난 추상적이면서 기하학적인 형상을 통해 통영 일대의 문화적, 관광적 요소에 미치는 영향을 살펴봄으로써, 향후 등대건축의 방향성을 제시하고, 다양하게 검토되어야 할 논제들을 밝히는 것에 그 목적이 있다. The Lighthouse is not only functioning as a traditional aids to navigate for the vessel, but also space that has memory about marine culture and man's nostalgia. Recently, it contributes to regional tourism and makes a new meaning about marine culture through the development of lighthouse to a proper space of ocean culture. Especially, MOMAF has constructed the sculpture lighthouse in Tongyeong as "the light of hope-sculptural lighthouse project". They hoped to develop the memorial lighthouse that represents characteristic of the region and culture and it became a symbol of the great culture in Tongyeong. Through the competition, prof. Ahn Woong-Hee's design won the project, and constructed. For this situation, we intended to reveal in this study that all the issues which relate to the design for lighthouse in the future through the abstract, geometrical form of lighthouse that deviated the traditional design.

Inactivation of Max-interacting Protein 1 Induces Renal Cilia Disassembly through Reduction in Levels of Intraflagellar Transport 20 in Polycystic Kidney

Ko, Je Yeong,Yoo, Kyung Hyun,Song, Seon Ah,Kim, Do Yeon,Kong, Hyun Kyung,Ahn, Curie,Lee, Han Woong,Kang, Duk-Hee,Oh, Goo Taeg,Park, Jong Hoon American Society for Biochemistry and Molecular Bi 2013 JOURNAL OF BIOLOGICAL CHEMISTRY - Vol.288 No.9

<P>Cilia in ciliated cells consist of protruding structures that sense mechanical and chemical signals from the extracellular environment. Cilia are assembled with variety molecules via a process known as intraflagellar transport (IFT). What controls the length of cilia in ciliated cells is critical to understand ciliary disease such as autosomal dominant polycystic kidney disease, which involves abnormally short cilia. But this control mechanism is not well understood. Previously, multiple tubular cysts have been observed in the kidneys of max-interacting protein 1 (<I>Mxi1</I>)-deficient mice aged 6 months or more. Here, we clarified the relationship between Mxi1 inactivation and cilia disassembly. Cilia phenotypes were observed in kidneys of <I>Mxi1</I>-deficient mice using scanning electron microscopy to elucidate the effect of Mxi1 on renal cilia phenotype, and cilia disassembly was observed in <I>Mxi1</I>-deficient kidney. In addition, genes related to cilia were validated <I>in vitro</I> and <I>in vivo</I> using quantitative PCR, and <I>Ift20</I> was selected as a candidate gene in this study. The length of cilium decreased, and <I>p</I>-ERK level induced by a cilia defect increased in kidneys of <I>Mxi1</I>-deficient mice. Ciliogenesis of <I>Mxi1</I>-deficient mouse embryonic fibroblasts (MEFs) decreased, and this abnormality was restored by <I>Mxi1</I> transfection in <I>Mxi1</I>-deficient MEFs. We confirmed that ciliogenesis and <I>Ift20</I> expression were regulated by Mxi1 <I>in vitro</I>. We also determined that Mxi1 regulates <I>Ift20</I> promoter activity via Ets-1 binding to the <I>Ift20</I> promoter. These results indicate that inactivating Mxi1 induces ciliary defects in polycystic kidney.</P>

HBV : Dynamic Change of HBsAg Titer during Anti-Viral Therapy in Treatment-Na?ve Patients with Chronic Hepatitis B

( Han Wook Chung ),( Yu Jin Ko ),( Sang Wook Lee ),( Hyun Woong Lee ),( Hyung Joon Kim ) 대한간학회 2013 춘·추계 학술대회 (KASL) Vol.2013 No.1

Background/Aims: Quantitative HBsAg (qHBsAg) titers are emerging as useful tools for measuring viral load and predicting predicting virologic response (VR). This study aimed to determine whether serial monitoring of HBsAg levels could predict virologic response to entecavir(ETV) & clevudine(CLV) therapy in treatment-naive patients with CHB Methods: A total of 157 treatment-naive patients with CHB, who visited Chung-Ang University Hospital between January 2007 and December 2008, were enrolled in this study (100 males). 97 patients(69 males, mean age 48) were treated with ETV for average 53 months, and 60 patients (31 males, mean age 43) were treated with CLV for 26months average. HBsAg levels were measured at baseline, week 12, 24, and 48. All patients were assessed for virological response (HBV DNA<140 copies/mL). Serum HBV DNA was quantified using the real time PCR assay (Artus HBV LC PCR Kit, Roche Diagnostics, lower limit of quantification, 140 copies/mL). Results: In 97 ETV-treated patients, the rates of virological response were 56.7% (55/97) at 48months and 60 CLV-treated patients, 30% (18/60) at 24 months, respectively. Mean reduction of baseline HBV DNA was -5.3, and -4.9 log10 copies/mL. In 55 VR patients treated with ETV, 43(78.1%) patients showed early decline of HBsAg titer and 31(56.3%) patients had lower baseline HBsAg levels (< 3.7 log IU/mL). In 18 VR patients treated with CLV, 9(50%) patients showed early decline of HBsAg titer and 11(61.1%) patients had also lower baseline HBsAg levels (< 3.7 log IU/mL) . Conclusions: Early decline of HBsAg was useful for predicting VR, and baseline HBsAg could be indicative as well in CHB patients treated with ETV than patients treated with CLV.

Kasabach-Merritt 증후군 치험 3예

유한욱,강순웅,안효섭,고광욱 大韓血液學會 1982 大韓血液學會誌 Vol.17 No.1

The difference in mRNA expressions of hypothalamic CCK and CCK-A and -B receptors between responder and non-responder rats to high frequency electroacupuncture analgesia

Ko, Eun-Sang,Kim, Sun Kwang,Kim, Jung-Taek,Lee, Giseog,Han, Jae-Bok,Rho, Sam-Woong,Hong, Moo-Chang,Bae, Hyunsu,Min, Byung-Il 경희대학교 동서의학연구소 2006 東西醫學硏究所 論文集 Vol.2006 No.-

The present study was performed to determine whether the expression levels of the hypothalamic cholecystokinin (CCK) and its receptors are associated with the responsiveness to high frequency electroacupuncture (EA) analgesia in rats. EA stimulation (100 Hz, 0.5 mspulse width, 0.2-0.3 mA) was delivered to the Zusanli (ST36) acupoint of male Sprague-Dawley rats for 20 min without anesthetics or holder restraint. The analgesic effect of EA was quantified using a tail flick latency test, and subsequently animals were allocated to responder or non-responder groups. The hypothalamus of rats in each group was dissected and RNA was purified. The mRNA expressions of CCK, and CCK-A and -B receptor were determined by real-time RT-PCR. CCK mRNA levels were not significantly different in the two groups, whereas both CCK-A and -B receptors were significantly more expressed in non-responders. These results suggest that the level of CCK receptor mRNA expression in the hypothalamus, rather than CCK mRNA, has an important relationship with the individual variations to high frequency EA analgesia in rats.

Metabolic characterization of imatinib-resistant BCR-ABL T315I chronic myeloid leukemia cells indicates down-regulation of glycolytic pathway and low ROS production

Ko, Byung Woong,Han, Jeongsu,Heo, Jun Young,Jang, Yunseon,Kim, Soo Jeong,Kim, Jungim,Lee, Min Joung,Ryu, Min Jeong,Song, Ik Chan,Jo, Young Suk,Kweon, Gi Ryang Informa UK (Informa Healthcare) 2016 Leukemia & lymphoma Vol.57 No.9

<P>Long-term imatinib treatment induces drug-resistant chronic myeloid leukemia (CML) cells harboring T315I gate keeper mutation of breakpoint cluster region (BCR)-ABL oncogenic kinase. However, although cell proliferation is coupled with cellular energy status in CML carcinogenesis, the metabolic characteristics of T315I-mutant CML cells have never been investigated. Here, we analyzed cell proliferation activities and metabolic phenotypes, including cell proliferation, oxygen consumption, lactate production, and redox state in the KBM5 (imatinib-sensitive) and KBM5-T315I (imatinib-resistant) CML cell lines. Interestingly, KBM5-T315I cells showed decreased cell proliferation, lactate production, fatty acid synthesis, ROS production, and down regulation of mRNA expression related to ROS scavengers, such as SOD2, catalase, GCLm, and GPx1. Taken together, our data demonstrate that the lower growth ability of KBM5-T315I CML cells might be related to the decreased expression of glycolysis-related genes and ROS levels, and this will be used to identify therapeutic targets for imatinib resistance in CML.</P>

Acceleration of Gastric Tumorigenesis Through MKRN1-Mediated Posttranslational Regulation of p14ARF

Ko, Aram,Shin, Ji-Young,Seo, Jinho,Lee, Kang-Duck,Lee, Eun-Woo,Lee, Min-Sik,Lee, Han-Woong,Choi, Il-Ju,Jeong, Jin Sook,Chun, Kyung-Hee,Song, Jaewhan U.S. Dept. of Health, Education, and Welfare, Publ 2012 Journal of the National Cancer Institute Vol.104 No.21

<P><B>Background</B></P><P>We investigated whether Makorin ring finger protein 1 (MKRN1), an E3 ligase, affects p14ARF-associated cellular senescence and tumorigenesis by posttranslational modification in gastric tumorigenesis.</P><P><B>Methods</B></P><P>A link between MKRN1 and ARF was examined in MKRN1 null mouse embryonic fibroblasts (MEFs) and in human fibroblasts and gastric cancer cells by silencing MKRN1 using small interfering RNA (siRNA) and short hairpin RNA (shRNA). Ubiquitination and proteasomal degradation assays were used to assess p14ARF degradation associated with MKRN1. MKRN1 and p14ARF expression levels were analyzed with immunohistochemistry in malignant and normal tissues from gastric cancer patients and with χ<SUP>2</SUP> tests. The tumor growth of gastric cancer cells stably expressing MKRN1 shRNA, p14ARF shRNA, or both was examined in mouse xenograft models (n = 4–6) and analyzed with unpaired <I>t</I> tests. All statistical tests were two-sided.</P><P><B>Results</B></P><P>MKRN1 knockout MEFs exhibited premature senescence and growth retardation with increased p19ARF protein expression. Similar results were obtained for human fibroblasts or gastric cancer cell lines by MKRN1 knockdown. Biochemical analyses confirmed that MKRN1 targets p14ARF for ubiquitination and subsequent proteasome-dependent degradation. A statistically significant association was shown between MKRN1 overexpression and p14ARF underexpression (<I>P</I> = .016). Xenograft analyses using p53-functional AGS or -dysfunctional SNU601 cells displayed statistically significant tumor growth retardation by silencing MKRN1, which was reversed under depletion of p14ARF (AGS cells, MKRN1 knockdown tumors vs MKRN1 and p14ARF knockdown tumors: 164.6 vs 464.8mm<SUP>3</SUP>, difference = 300.2mm<SUP>3</SUP>, 95% CI = 189.1 to 411.3mm<SUP>3</SUP>, <I>P</I> < .001).</P><P><B>Conclusions</B></P><P>We demonstrated that MKRN1 functions as a novel E3 ligase of p14ARF and that it potentially regulates cellular senescence and tumorigenesis in gastric cancer.</P>