Detection of Hepatic VX2 Tumors in Rabbits:Comparison of Conventional US and Phase-Inversion Harmonic US During the Liver-Specific Late Phase of Contrast Enhancement

JeongMinLee,JiHyunYouk,YoungHwanLee,YoungKonKim,ChongSooKim,ChunAiLi 대한영상의학회 2003 Korean Journal of Radiology Vol.4 No.2

Objective: To compare phase-inversion sonography during the liver-specific phase of contrast enhancement using a microbubble contrast agent with conventional B-mode sonography for the detection of VX2 liver tumors. Materials and Methods: Twenty-three rabbits, 18 of which had VX2 liver tumor implants, received a bolus injection of 0.6 g of Levovist (200 mg/ml). During the liver-specific phase of this agent, they were evaluated using both conventional sonography and contrast-enhanced phase-inversion harmonic imaging (CEPIHI). Following sacrifice of the animals, pathologic analysis was performed and the reference standard thus obtained. The conspicuity, size and number of the tumors before and after contrast administration, as determined by a sonographer, were compared between the two modes and with the pathologic findings. Results: CE-PIHI demonstrated marked hepatic parenchymal enhancement in all rabbits. For VX2 tumors detected at both conventional US and CE- PIHI, conspicuity was improved by contrast-enhanced PIHI. On examination of gross specimens, 52 VX2 tumors were identified. Conventional US correctly detected 18 of the 52 (34.6%), while PIHI detected 35 (67.3%) (p < 0.05). In particular, conventional US detected only three (8.3%) of the 36 tumors less than 10 mm in diameter, but CE-PIHI detected 19 such tumors (52.8%) (p < 0.05) . Conclusion: Compared to conventional sonography, PIHI performed during the liver-specific phase after intravenous injection of Levovist is markedly better at detecting VX2 liver tumors.

Production and Expression of Gro-α and RANTES by Peripheral Blood Mononuclear Cells Isolated from Patients with Kawasaki Disease and Measles

HeeSunKim,WonDukKim,YoungHwanLee 대한의학회 2003 Journal of Korean medical science Vol.18 No.3

Percutaneous Radiofrequency Thermal Ablation with Hypertonic Saline Injection: In Vivo Study in a Rabbit Liver Model

JeongMinLee,YoungKonKim,YoungHwanLee,SangWonKim,ChunAiLi,ChongSooKim 대한영상의학회 2003 Korean Journal of Radiology Vol.4 No.1

Curved Planar Reconstruction of MR Images in Focal Cortical Dysplasia of the Brain

GyungHoChung,SangYongLee,ChongSooKim,YoungKonKim,YoungHwanLee,SuHyunJeong 대한영상의학회 2002 대한영상의학회지 Vol.46 No.5

Purpose: To describe curved planar reconstruction imaging (CPRI) and determine its usefulness in the evaluation of focal cortical dysplasia of the brain. Materials and Methods: In 17 cases of focal cortical dysplasia [cortical dysplasia (n=9), schizencephaly (n=5), and heterotopia (n=3)], CPR images were created using a multiplanar reconstruction program and imaging data obtained during T1 magnetizationprepared rapid acquisition gradient-echo MR imaging. We assessed the precise configuration of abnormalities and their relation to adjacent gyri and sulci. Results: CPRI showed the brain cortex as a 2D panoramic image, demonstrating the precise configurations and locations of dysplasia-associated abnormalities and their relation to adjacent gyri and sulci, and the precise shape of the gray-white matter interface. Conclusion: CPRI can provide important radiological information about the extension and configuration of focal cortical dysplasia, and its relation to neighboring cortical structures. We believe that CPRI should form an essential part of the routine investigation of suspected cases of focal cortical dysplasia. 목적: 3차원 MR영상법으로 촬영된 MR데이터를 사용하여 곡면재구성영상을 얻어 국소적 뇌피질 이형성증을 평가하는데 유용성을 알아 보았다. 대상과 방법: 국소적 뇌피질 이형성증 17명을 대상으로 하였고 뇌피질 이형성증(cortical dysplasia, n=9), 분열뇌증(schizencephaly, n=5), 이소성 회질증(gray matter heterotopias, n=3)이었다. 곡면재구성영상은 자화준비고속경사 에코획득을 이용하여 얻은 영상에서 곡면재구성프로그램을 이용하여 만들었다. 곡면재구성영상에서 병변의 범위, 모양, 주위 정상 대뇌이랑, 고랑과의 관련성을 분석하였다. 결과: 곡면재구성영상은 뇌표면을 파노라믹 모양의 2차원으로 벌려 놓은 모양이었다. 17예의 국소적 뇌피질 이형성증 환자에서 곡면재구성영상은 이형성된 뇌피질의 위치와 모양, 그리고 주위의 정상 대뇌 이랑과 고랑과의 관계를 잘 보여 주었다. 결론: 곡면재구성영상은 국소적 뇌피질 이형성증 환자에서 병변의 위치와 범위 그리고 주위 구조물사이의 중요한 방사선과적 그리고 해부학적 정보를 제공했다. 국소적 뇌피질 이형성증이 의심될 때 곡면재구성영상은 일반적인 영상방법과 함께 포함되어야 할 검사법이다.

Focal Hepatic Lesions: Contrast-Enhancement Patterns at Pulse-Inversion Harmonic US using a Microbubble Contrast Agent

Eun-AKim,Kwon-HaYoon,YoungHwanLee,HyeWonKim,SeonKwanJuhng,JongJinWon 대한영상의학회 2003 Korean Journal of Radiology Vol.4 No.4

Objective: To analyze the contrast-enhancement patterns obtained at pulseinversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect. Materials and Methods: We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HCC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns. Results: Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral nodular enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively. Conclusion: Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

E - commerce Architecture Evaluation Through Stress Test

Young Hwan Lee,Jong Soon Park 한국경영정보학회 2001 한국경영정보학회 학술대회논문집 Vol.2001 No.-

Production of Plasma Leptin and Expression of Interferon-γ Inducible Protein-10 (IP-10), Monokine Induced by Interferon-γ (Mig) and Interleukin-8 (IL-8) mRNA in Kawasaki Disease

Young-Hwan Lee,Won-Duk Kim,Hee-Sun Kim 대한면역학회 2002 Immune Network Vol.2 No.4

Optical Effect due to Thickness Variation of Electron Injection Layer in Organic Light-emitting Diodes

Young-Hwan Lee,Kang-Won Lee,Keon-Young Yi,Jin-Woong Hong,Tae Wan Kim 한국전기전자재료학회 2008 Transactions on Electrical and Electronic Material Vol.9 No.1

Organic light-emitting diodes (OLEDs) are attractive because of possible application in display with low-operating voltage, low-power consumption, self-emission and capability of multicolor emission by the selection of emissive materials. To investigated the optical effects, we studied the electrical and optical characteristics due to thickness variation of electron injection materials LiF on organic light-emitting diodes in the ITO (indium-tin-oxide)/N,N'-diphenyl-N,N'-bis(3-methyphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/tris(8-hydroxyquinoline) aluminum (Alq₃)/LiF layer/Al device. We maintained the thicknesses of TPD and Alq₃ layers at 40 nm and 60 nm, respectively. The deposition rates of TPD and Alq3 were in the 1.5 Å/s under a base pressure of 5x10-6 Torr. It was found that luminance and luminous efficiency of the device with 0.7 nm LiF layer improve 25 times and 7 times than the device without the LiF layer, respectively.

Political Economy of Excise Tax Policy in a Probabilistic Voting Framework

Young-Hwan Lee,이성규 한국세무학회 2007 세무학 연구 Vol.24 No.2

조세구조는 정치적(政治的) 과정의 부산물이다. 그럼에도 불구하고 조세정책에 대한 경제적(經濟的) 분석은 조세구조가 고안(考案)되는’정치적 환경’을 거의 고려하지 않고 있는 실정이다. 정치적 환경을 고려하지 않은 조세정책의 분석은 결코 완전한 분석이라고 할 수 없다. 현실세계에서의 실제 조세 시스템의 본질적인 특성은 ‘확률적 투표 모형에서의 합리적 행위의 결과’라고 이해될 수 있다. 확률적 투표 모형이란 민주주의 국가에서 정치인이나 정당들이 기대투표나 지지를 극대화하기 위하여 서로 경쟁하는 과정을 의미한다. 상품세(商品稅)의 정치적 결정을 분석하기 위하여 우리는 확률적 투표 모형 또는 투표 극대화 모형을 사용한다. 상품세 결정 요인으로 기존의 경제적 요인과 국제적 요인 그리고 정치적 요인을 결합하여 분석하고 자 한다. 특히 외부성과 국경세 문제 그리고 정치적 요인을 포함하여 분석한다. 정치적 요인으로 상품세의 비가시성(非可視性, invisibility)을 모형에 명시적으로 포함시키고자 한다. 정치인이나 정당들이 재선(再選) 가능성을 극대화하기 위하여 상품세 결정으로부터 발생하는 정치적 이득과 손실을 동시에 고려해야만 한다. 즉 공공서비스의 확대로부터 생기는 ‘정치적 이득’과 상품세 세율 인상으로부터 발생하는 ‘정치적 비용’을 균형적으로 헤아려야 한다.본 논문의 목적은 두 가지이다. 첫째, 확률적 투표 모형을 이용하여 정당들이 결정하는 균형 조세정책의 특성(特性)을 분석하는 데 있다. 정당이나 정치인들은 집권을 유지하기 위한 노력의 일환으로 기대득표나 기대지지를 극대화하기 위하여 상품세를 어떻게 결정하는 가를 분석하는 데 그 초점이 맞추어져 있다. 둘째, 기존의 확률적 투표 모형을 확장하고 자 한다. 기존의 모형에 조세환상(租稅幻像)을 포함하여 이것이 정치적 비용(득표손실)에 미치는 효과를 분석하고 자 한다.<주제어> 상품세, 확률적 투표, 정치적 비용, 정치적 최적 조세, 조세환상

Translocator protein (TSPO): the new story of the old protein in neuroinflammation

( Younghwan Lee ),( Youngjin Park ),( Hyeri Nam ),( Ji-won Lee ),( Seong-woon Yu ) 생화학분자생물학회(구 한국생화학분자생물학회) 2020 BMB Reports Vol.53 No.1

Translocator protein (TSPO), also known as peripheral benzodiazepine receptor, is a transmembrane protein located on the outer mitochondria membrane (OMM) and mainly expressed in glial cells in the brain. Because of the close correlation of its expression level with neuropathology and therapeutic efficacies of several TSPO binding ligands under many neurological conditions, TSPO has been regarded as both biomarker and therapeutic target, and the biological functions of TSPO have been a major research focus. However, recent genetic studies with animal and cellular models revealed unexpected results contrary to the anticipated biological importance of TSPO and cast doubt on the action modes of the TSPO-binding drugs. In this review, we summarize recent controversial findings on the discrepancy between pharmacological and genetic studies of TSPO and suggest some future direction to understand this old and mysterious protein. [BMB Reports 2020; 53(1): 20-27]