Trinitrobenzene sulfonic acid로 유도한 대장염에서 대장통과시간 변화 및 장벽내 nitric oxide synthase의 분포

의학과/석사[한글] Nitric oxide (NO)는 대장에서 연동 반사시 미측 윤상근의 이완에 관여하는 물질로서, 정상적인 생리조건에서는 endothelial nitric oxide synthase (eNOS) 및 neuronal NOS (nNOS)에 의해 주로 생성되며, 대장염시에는 다양한 염증세포로부터 합성된 inducible NOS (iNOS)에 의해 생성되는 것으로 알려져 있다. 최근 박 등은 trinitrobenzene sulfonic acid (TNBS) 유도 기니 픽 대장염 모델에서 대장통과 시간은 약제 주입 후 3일째부터 유의하게 지연되지만 염증의 정도와 상관 관계를 보이지 않으며, 무스카린성 수용체를 통한 평활근 세포의 수축 반응에는 이상이 없음을 보고하였다. 본 연구에서는 기니 픽에게 TNBS로 유도한 실험적 대장염 모델에서 대장통과시간의 변화 여부를 관찰하고, TNBS 노출 기간에 따른 nNOS와 iNOS의 장벽내 분포를 조사하여 대장통과시간 변화와 니트레직(nitrergic) 신경분포와의 상관 관계를 알아보고자 하였다. 실험 결과, 대장통과시간은 TNBS 투여군에서 3, 7, 14일 째에 대조군에 비하여 유의하게 지연되는 것을 관찰하였다. nNOS 양성 세포는 대조군에서 점막, 점막하층, 고유근층, 점막하 신경총, 그리고 장근 신경총에서 골고루 관찰되었다. TNBS 주입군에서는 주로 염증이 유발된 점막 및 점막하층에서 nNOS 양성 세포의 감소가 관찰되었으나, 각 군에서 장근 신경총의 nNOS 양성 신경세포의 수는 유의한 차이를 보이지 않았다. iNOS 양성 세포는 대조군에서 주로 점막하 신경총 및 장근 신경총에서 관찰되었다. TNBS 주입군에서는 주로 염증이 유발된 점막 및 점막하층에서 iNOS 양성 세포의 증가가 관찰되었으나 TNBS 노출기간에 따른 변화는 관찰되지 않았으며, 각 군에서 장근 신경총 내 iNOS 양성 세포의 수는 유의한 차이를 보이지 않았다. 결론적으로 TNBS 유도 기니 픽 대장염에서 대장통과시간이 유의하게 지연되었으며, 장근 신경총내 nNOS와 iNOS 양성 세포의 분포변화는 대장통과시간 변화에 주 역할을 하지 않는 것으로 생각된다. [영문]Inflammation-induced alterations in smooth muscle contractility may be due to effects on smooth muscle itself, or its response to neurotransmitters or to effects on enteric nerves. Colonic transit in trinitrobenzene sulfonic acid (TNBS)-induced colitis of guinea pigs is delayed significantly, but it is not related to the muscarinic receptor-mediated contractions. In dextran sulfate sodium-induced colitic rat, the delay in colon-ic transit was caused by decreased activity and production of neuronal nitric oxide synthase (nNOS) in the myenteric plexus in the distal colon. In this study, we investigated the distribution of inducible NOS/(iNOS) and nNOS immunoreactive cells in the myenteric plexus and colonic wall to explain the involvement of NOS in delayed colonic transit in TNBS-induced colitic guinea pig. Colonic transit was delayed significantly at 3, 7 and 14 days after administration of TNBS compared to control. In control, nNOS immunoreactivity was present in the mucosa, submucosa, lamina propria, muscularis mucosa, and in ganglion cells within the myenteric plexus, while after TNBS, reduced nNOS cells were found. However, the number of nNOS immunoreactive ganglion cells in the myenteric plexus was similar to that seen in controls. After administration of TNBS, iNOS immunoreactivity was increased in the mucosa and submucosa compared to that in control, but the number of distribution of iNOS immunoreactive ganglion cells in the myenteric plexus was not changed compared to that in control. In conclusion, it is suggested that in TNBS-induced guinea pig colitis, delayed colonic transit is not associated with the expression of nNOS or iNOS in the myenteric plexus.ope

Correlation between Clinical Symptoms and Radiologic Findings before and after Pneumatic Balloon Dilatation for Achalasia

Background/Aims: We investigated the risk factors for short-term recurrence and analyzed the correlation between subjective clinical symtoms and objective radiological findings in patients with achalasia undergoing pneumatic balloon dilatation. Methods: Twenty patients who were treated by pneumatic balloon dilatation were enrolled. We compared prospectively various indices before and after the treatment as follows: 1) Eckardt symptom score and dysphagia grade, 2) The ratio of the maximal width in mid-esophageal lumen to the minimal width in distal esophagus around lower esophageal sphincter, and 3) the percentage of maximum activity retained in the esophagus at 30 seconds and T½ in esophageal scan two days after the treatment. Results: 1) Clinical indices and radiologic indices significantly improved after pneumatic dilatation. 2) There was no significant correlation between the clinical indices and the radiologic indices before and after the treatment. 3) The difference percentage of clinical indices did not show significant correlation with the difference percentage of the radiologic indices. 4) Compared to the group above 20% in the difference percentage of 30 second residual fraction, the one below 20% had a four-fold risk in short-term recurrence. Conclusions: Clinical symptoms and radiologic indices significantly improve after pneumatic dilatation but have no significant correlation to each other. The group below 20% in the difference percentage of 30 second residual fraction has a high risk of recurrence and may need careful examination and early repeated pneumatic dilationope

A Case of the Main Pancreatic Duct Injury Due to Blunt Abdominal Trauma Cured by Conservative Management Including Octreotide Admonistration

ope

극저주파에 의한 가돌리늄의 세포유전독성 증진효과

Gadolinium (Gd) is widely used for various industrial and medical purposes, particularly in magnetic resonance imaging (MRI) contrast agent. As there has been a large volume of studies about cyto- and geno- toxicity of Gd, it has been utilized as derivatives by chelation with various ligands. Human exposure to Gd and its derivatives is significantly increasing, posing a high risk of accumulation and retention. It is important to investigate the effect of extremely low-frequency electromagnetic fields (ELF-EMF) on the cyto- and geno-toxicity of Gd, since patients are co-exposed to Gd and ELF-EMF generated by MRI scanner. The aim of this study is to investigate the cyto- and geno-toixcity of Gd and the possible enhancing effect of ELF-EMF on the toxicity of Gd in cultured human peripheral blood lymphocytes by performing micronuclei (MN) assay, single cell gel electrophoresis (Comet) assay, trypan blue dye-exclusion assay, apoptosis analysis using flow cytometry and intracellular reactive oxygen species measurement. MN frequencies were 13.0, 14.0, 15.3 and 17.7 per 1000 cells in Gd treatment cells at concentrations of 0, 0.4, 0.8 and 1.2 mM. ELF-EMF exposure (0.8 mT) increased the frequencies of MN induced by Gd treatment alone; 13.3, 17.0, 20.3 and 25.0 per 1000 cells at each Gd concentrations. ELF-EMF exposure also increased cell death, olive tail moment (OTM), apoptosis and ROS level induced by Gd treatment alone. These results suggest that Gd induces DNA damage, apoptotic cell death and ROS generation in human lymphocytes and ELF-EMF can enhance the cyto- and geno-toxicity of Gd.1. Introduction 1 2. Materials & Methods 4 2. 1. Isolation, culturing and stimulation of peripheral blood lymphocytes 5 2. 2. Gd treatment and ELF-EMF exposure condition 5 2. 3. Measurement of cell death 6 2. 4. Cytokinesis-block micronuclei (CBMN) assay 6 2. 5. Single-cell gel electrophoresis (comet) assay 7 2. 6. Detection and quantification of apoptosis 8 2. 7. Measurement of intracellular ROS 9 2. 8. Statistical analysis 10 3. Results 10 3. 1. ELF-EMF enhances Gd-induced cell death in peripheral blood lymphocytes 11 3. 2. ELF-EMF enhances Gd-induced micronuclei in peripheral blood lymphocytes 13 3. 3. ELF-EMF enhances Gd-induced DNA damage in peripheral blood lymphocytes 15 3. 4. ELF-EMF enhances Gd-induced apoptosis in peripheral blood lymphocytes 17 3. 5. ELF-EMF enhances the generation of ROS induced by Gd 19 4. Discussion 23 5. Conclusion 30 6. Reference 31Maste

마그네토스트릭션 효과를 이용한 비접촉 모달 테스팅 기법

Thesis (master`s)--서울대학교 대학원 :기계항공공학부,2001.Maste

대화형 유전 알고리즘을 이용한 이미지 색 양자화

학위논문 (석사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 2. 문병로.Color image quantization is the problem of converting the given image to the image with limited number of colors used, maximizing the similarity. Previous studies measured the similarity as the smaller color difference by pixels, which is hard to evaluate the context of the image. In this thesis, a novel approach of considering the context is shown. Interactive genetic algorithm is applied to reflect the human knowledge in generating the quantized images. The experiment of the system has been done with 12 subjects and four test images, and the result shows that the quantized images generated with the interactive system are evaluated to be more suitable than those with the traditional optimization methods.Abstract i Contents ii List of Figures iv List of Tables v Chapter 1 Introduction 1 Chapter 2 Preliminaries 4 2.1 Color Image Quantization Problem 4 2.2 Genetic Algorithm 5 2.3 Hybrid Genetic Algorithm 8 2.4 Interactive Genetic Algorithm 9 Chapter 3 The Proposed System 11 3.1 Formulation of the Problem 11 3.2 The Framework of the System 11 3.3 The Structure of Chromosomes 14 3.4 Interactive Step and Evolutionary Step 15 3.5 Measurement of Fitness 17 3.6 Local Optimization 17 Chapter 4 Experiment 19 4.1 Experimental Setup 19 4.2 Generated Image 20 4.3 Comparison of Results 21 Chapter 5 Conclusion 24 요약 28Maste

NudH에 의한 대장균 질소인산전달계의 인산화 및 ?S 의 활성 억제

Thesis(doctors) --서울대학교 대학원 :생명과학부, 2009.2.Docto

A study on Structural Condition Assessment of LNG CCS Primary Barriers considering Tension, Compression, Shear and Pressure

학위논문(석사) -- 서울대학교대학원 : 공과대학 조선해양공학과, 2024. 2. 김도균.현재 LNG CCS(Liquefied Natural Gas Cargo Containment System) 분야에서 가장 보편적으로 사용되는 규격 중 하나인 멤브레인 타입 LNG CCS에 대한 연구는 중요하기 때문에 활발히 진행되고 있다. 특히, GTT사의 Mark Ⅲ는 그 점유율이 매우 높다. 본 연구에서는 Mark Ⅲ의 일차 방벽에 대한 구조 상태 평가를 수행하였다. 먼저, 유한요소 해석을 위해 재료 모델을 개발하였다. 일차 방벽을 구성하는 재료인 SUS304L에 대한 상온과 극저온에서의 물성치를 정확하게 반영하기 위해 재료 캘리브레이션을 수행하였다. 이후, 인장, 압축, 전단, 압력 등 총 4가지 하중 상황을 고려하여 시뮬레이션을 수행하였다. 인장 시나리오에서는 인장에 의한 파단을, 압축 시나리오에서는 압축에 의한 좌굴을 실패 지점으로 설정하였다. 이를 통해 인장과 압축에 대한 2차원 상관 곡선을 획득하였다. 전단에 대해서는 압축 시나리오를 고려하여 기존의 2차원 상관 곡선을 3차원으로 확장시켰다. 이후, 정압과 동압에 대한 유한요소 해석을 수행하였으며, 일차 방벽 내에서 가장 큰 변위를 보이는 큰 주름 구조(large corrugation) 부분의 너비를 기준으로 구조 상태 평가를 실시하였다. 본 연구는 Mark Ⅲ 멤브레인 타입 LNG CCS의 안정성 평가 및 새로운 타입의 LNG CCS 설계시 중요한 참고 자료가 될 수 있을 것으로 기대된다. 주요어 : 액화천연가스, 일차 방벽, 극저온, 상관 곡선, 주름 구조 학 번 : 2022-24909Currently, research on membrane type LNG CCS, which is one of the most commonly used specifications in the field of LNG CCS (Liquefied Natural Gas Cargo Containment System), is being actively conducted. In particular, GTT's Mark Ⅲ has received a lot of attention due to its high share, and in this study, the structural condition assessment of the primary barrier of Mark Ⅲ was performed. First, a material model was developed for finite element analysis. Material calibration was performed on SUS304L, the material of the primary barrier, to accurately reflect its properties at room temperature and cryogenic temperature. Simulations were then performed considering four different loading situations: tension, compression, shear, and pressure. In the tension scenario, the failure point was set to fracture under tension, and in the compression scenario, buckling under compression. Two-dimensional correlation curves were obtained for tension and compression. For shear, the existing two-dimensional correlation curves were extended to three dimensions by considering the compression scenario. Finite element analyses were then performed for static and dynamic pressures, and the structural condition was evaluated based on the width of the large corrugation section that exhibited the largest displacement within the primary barrier. This study is expected to provide a new perspective on the stability assessment of Mark Ⅲ membrane type LNG CCS.제 1장 서 론 1 제 1절 연구의 배경 1 제 2절 선행 연구 2 제 3절 연구 흐름도 3 제 2장 Mark-lll 타입 화물창 4 제 1절 Mark Ⅲ 타입 화물창의 특징 4 제 2절 일차 방벽 6 제 3절 일차 방벽이 노출되는 환경 7 제 4절 SUS304L 스테인리스 스틸 8 제 5절 재료 모델 생성 및 캘리브레이션 10 제 3장 일차 방벽의 인장, 압축, 전단 구조 상태 평가 15 제 1절 일차 방벽 모델 15 제 2절 일차 방벽에 가해지는 인장, 압축, 전단 상황 18 제 3절 유한요소해석 19 제 4절 구조 상태 평가 및 상관곡선 24 제 4장 일차 방벽의 내압 구조 상태 평가 29 제 1절 정압 구조 상태 평가 29 제 2절 동압 구조 상태 평가 33 제 5장 결과 및 고찰 37 제 6장 결 론 39 참고문헌 40 Abstract 42석

자기변형을 이용한 유도초음파 및 진동 트랜스듀서의 설계

Thesis(doctoral)--서울대학교 대학원 :기계항공공학부,2006.Docto