• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.86-86
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• 1993

혈관근의 수축 또는 이완 반응에서 $Na^{＋}$/Ca$^{2＋}$ exchange계의 역할을 알아보고자 먼저 가토와 흰쥐 흉부 대동맥에서 수축과 이완 반응을 검색하고 이때의 혈관 이완 반응을 증개하는 cAMP와 cGMP농도를 측정하였다. 내피세포가 존재한 표본에서 acetylcholine은 norepinephrine 수축 반응을 이완시켰고 이완 반응은 methylene blue로 소실되었으며 isoproterenol과 nitroprusside는 내피 존재와 제거 양표본에서 이완 반응을 일으켰으며 이때 isoproterenol은 CAMP농도를, nitroprusside는 cGMP농도를 증가시켰다.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.151-157
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• 1999

Background: Increasing evidences from experimental studies indicate that apoptosis may be inversely related to angiogenesis in tumor progression. Material and Method: To explore how apoptosis correlates with tumor angiogenesis, we measured the apoptotic index(AI) using the terminal deoxynucleotidyl transferase method(Apop Tag In Situ Apoptosis Detection Kit, ONCOR) and the intratumoral microvessel density using the anti-CD31 monoclonal antibody in non-small cell lung cancer. Result: Statistical analysis revealed an inverse correlation between AIs and intratumoral microvessel densities in squamous cell lung carcinoma(Spearman rank correlation coefficient r=- 0.229, p=0.047). Conclusion: The results of this study demonstrated that the amount of apoptosis in squamous cell lung carcinoma may be influenced by the extent of neovascularization. This suggests that tumor angiogenesis may contribute to a reduction of apoptosis in tumor cells.

• Proceedings of the KTCVS Conference
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• 1996.10a
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• pp.61-61
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• 1996

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.624-627
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• 2008

본 연구에서는 유비쿼터스 헬스케어를 위하여 비침습적으로 측정기 가능하고, 많은 건강정보를 포함하고 있는 심전도(electrocardiogram, ECG)와 광전용적맥파(photo plethysmograph, PPG)를 측정하고자 하였다. 이를 위하여 배터리로 구동 가능한 초소형의 심전도 및 맥파측정 시스템의 구현을 위하여 각각의 신호를 검출 및 신호처리하기 위한 회로를 구현하였다. 그리고 계측된 심전도 및 맥파신호의 무선전송을 위하여 초저전력 무선센서네트워크 기술을 적용한 무선 생체신호 전송시스템을 구현하였다. 계측된 심전도의 R파 정점과 인체의 말초부위에서 측정한 맥파의 기준점 사이의 시간인 맥파전달시간(pulse transit time, PTT)을 분석하여 심장에서 말초부위까지 혈관의 물리적 특성을 평가함으로써 동맥경화와 같은 혈관질환의 사전모니터 링이 가능한 시스템을 구현하고자 하였다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.6
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• pp.61-66
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• 2004

To make a guide line of property control of angiography equipments, we made standard evaluation sheet forms of facility and management of angiography suite, physical properties of angiography equipments, and image quality of film and then surveyed them at 29 hospital nationwide. Survey and development of standard evaluation sheet form of physical properties of angiography equipments. By using resolution & radiation dose, physical properties of angiography equipments of 49 in number nationwide were evaluated. Most of them (91%) had good performance.

• Journal of KIISE:Software and Applications
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• v.36 no.12
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• pp.967-976
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• 2009

In this paper, we propose an automatic lower extremity vessel extraction based on rigid registration and bone elimination techniques in CT and CT angiography images. First, automatic partitioning of the lower extremity based on the anatomy is proposed to consider the local movement of the bone. Second, rigid registration based on distance map is performed to estimate the movement of the bone between CT and CT angiography images. Third, bone elimination and vessel masking techniques are proposed to remove bones in CT angiography image and to prevent the vessel near to bone from eroding. Fourth, post-processing based on vessel tracking is proposed to reduce the effect of misalignment and noises like a cartilage. For the evaluation of our method, we performed the visual inspection, accuracy measures and processing time. For visual inspection, the results of applying general subtraction, registered subtraction and proposed method are compared using volume rendering and maximum intensity projection. For accuracy evaluation, intensity distributions of CT angiography image, subtraction based method and proposed method are analyzed. Experimental result shows that bones are accurately eliminated and vessels are robustly extracted without the loss of other structure. The total processing time of thirteen patient datasets was 40 seconds on average.

• Journal of Biomedical Engineering Research
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• v.22 no.2
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• pp.133-138
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• 2001

동맥계에서 맥파의 전달속도는 혈관의 긴장도에 따라 결정된다. 동맥혈관의 긴장도는 혈압에 의존적이며 순간적인 혈압의 증가에 따른 혈관긴장도의 변화는 순환기계의 질병을 야기할 수 있다. 본 연구에서는 말초맥파를 이용한 동맥 긴장도 평가 방법의 유용성을 밝히기 위하여 말초맥파 도달시간을 체위에 따라 측정하고, 체위 변화에 따른 정수압 변화와 말초맥파도달시간의 관계를 관찰하였다. 말초맥파도달시간의 측정은 심전도의 QRS파 피크로부터 말초에서 나타나는 광전용적맥파의 최대기울기점까지 시간을 측정하였다. 생체 신호를 아날로그-디지털 변환하여 PC에서 매번 심장주기마다 맥파도달시간을 분석하였으며 결과는 스플라인 보간법을 사용하여 그래프로 결과를 제시하였다. 소프트웨어는 C＋＋을 사용하여 windows 환경에서 운용하였다. 앙아위에서 말초맥파도달시간은 233.38$\pm$1.84 ms이었으며 서있는 자세에서는 226.77$\pm$2.16 ms로 유의하게 감소하였다. 앙아위의 자세에서 손을 수직으로 들어올림에 따라 말초맥파도달시간은 각도에 비례하여 증가하는 특성을 보였다. 이러한 실험결과는 말초맥파도달시간이 동맥계의 일시적인 압력 변화에 매우 민감하게 반응하는 것을 제시하였으며, 고혈압 및 동맥경화가 있는 환자에서 예후를 판단하는 방법으로 유용하게 사용될 것이라 사료된다.

• Tuberculosis and Respiratory Diseases
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• v.41 no.4
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• pp.319-327
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• 1994

Background: The pathogenetic mechanism of adult respiratory distress syndrome(ARDS) is not clearly defined yet, but it is well known that increased pulmonary capillary permeabilty is characteristic feature of ARDS. The increased alveolar-capillary permeability is usually preceded by damage of pulmonary artery endothelial cells. The released enzymes and oxygen free radicals from the activated neutrophils seem to play a predominant role in endothelial cell cytotoxicity. The activated neutrophils, however, probably are not the sole contributing factor in this type of damage because many cases of ARDS have been reported in severe neutropenia. Bacterial endotoxin perse and/or oxygen free radicals released from endothelial cells are suggested to be possible factors that contribute to the development of ARDS. The purpose of this study is to investigate the direct cytotoxicity of endotoxin and the role of oxygen free radicals released from the endothelial cells in endotoxin-induced endothelial cell cytotoxicity. Methods: First, to investigate whether endotoxin is cytotoxic to HUVE by itself, various doses of endotoxin were added to culture medium and cytotoxicity was measured. Second, to evaluate the possible role of oxygen free radical in endotoxin-induced HUVE cytotoxicity, various antioxidants were added on the endotoxin-induced HUVE cytotoxicity and cytotoxicity was measured. Third, to verify the release of oxygen free radicals from HUVE, the concentrations of hydrogen peroxide in the endotoxin-treated culture supernatant were measured. Finally, to observe the cytotoxic effect of hydrogen peroxide, HUVE cytotoxicity in the presence of various doses of hydrogen peroxide was measured. The fourth generations of subcultured HUVE from primary culture were used. The cell cytotoxicity was quantified by the chromium-51 release assay. Results: 1) Endotoxin alone showed HUVE cytotoxicity in a dose-dependent fashion. 2) Endotoxin-induced HUVE cytotoxicity was significantly attenuated by the pretreatment of catalase and DMTU. 3) Hydrogen peroxide was released from HUVE after endotoxin treatment in a dose-dependent fashion. 4) Exogenous hydrogen peroxide also showed HUVE cytotoxicity in a dose-dependent fashion. Conclusion: These results suggest that endotoxin alone can directly injure HUVE, and, oxygen-free radicals released from HUVE in response to endotoxin may also participate in the endotoxin-induced HUVE cytotoxicity.

• Journal of Korean Academy of Nursing
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• v.28 no.1
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• pp.143-147
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• 1998

당뇨병환자의 자가혈당조절에 있어서의 기준이 되는 혈당측정에 있어서 하나의 지침을 제공하기 위해 본 연구는 말초혈관과 상완정맥에서의 혈액을 채취하여 이들 검사물들의 혈당치를 직접적으로 비교했다. 30명의 건강한 한국인 성인 남자(연령 : 평균=30세)로부터, 공복시의 혈액을 세가지의 서로 다른 방법들(우선 손가락 끝에 말초혈관을 울혈이 되도록 한 뒤에, 이후 같은 편의 팔의 상완정맥에서, 마지막으로 다시 처음 검채를 시행했던 바로 그 말초의 천자부위에서 혈액을 짜내는 방법으로.)로 각각의 대상에서 검채하였다. 검사물들의 혈당치는 간편측정용 혈당측정기(Glucocard, KDK Corp., Japan. 1995)로 측정한 결과 상완정맥에서 채취한 혈액의 혈당치(107.58$\pm$21.03mg/dl)가 말초에서 채취한 혈액(울혈 후 : 100.21$\pm$24.03mg/dl, .짜낸 경우 : 97.84$\pm$22.45mg/dl)들 보다 높았다(T=2.86. p=.0081 : T=3.084. p=.0055). 그러나 이 결과는 기타의 연구들에서의 결과와는 일치하지 않았다. 이러한 불일치는 자가혈당측정기가 인슐린 의존형 당뇨환자는 물론이고 비의존성 당뇨환자들의 자가관리에 결정적인 지침이 된다는 점을 고려할 때, 좀 더 통제된 상황에서 더욱 많은 사람을 대상으로 한 임상시험을 통해 자가 혈당측정치에 있어서 기계요인에 대한분석이 이루워질 필요를 시사하고 있다. 또한 동일한 부위에서 서로 다른 방법들(혈관을 울혈을 시킨 천자하여 얻은 경우와 천자 후 그 부위를 짜서 검사물을 얻는 방법)에 의해서 얻어진 혈액의 헐당치 측정 결과 간에 차이가 없는 것으로 나타나서(t=0.72, p=.4791), 일반적으로 혈당치의 측정 시 검채한 양이 부족할 때, 새로이 천자하여 검사를 시행하는 것을 원칙으로 인식하고 있으나 본 연구결과를 볼 때, 이러한 채혈의 방식에 의한 차이는 환자의 안녕의 차원에서 고려하여 필요하다면 간과될 수도 있음을 의미하고 있다.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.342-348
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• 2004

It is very important for hemodialysis in patients with end stage renal disease to obtain vascular access that resists repeated punctures and maintains adequate blood flow. This study was designed to indentify factors that may influence early patency rate of autogenous arteriovenous fistula. Material and Method: 49 cases in 47 patients who underwent radiocephalic fistula formation in our hospital from June 2002 through May 2003 were reviewed and analyzed. Result: The early patency rate was 79.6%. Age, sex, hypertension, and diabetes mellitus were not significant factors for patency. Body mass index and duration of hypertension and diabetes did not influence the early results either. Cephalic vein diameter measured preoperatively and blood flow at radio-cephalic fistula were significantly positive correlative factors. Groups with the vein diameter less than 2.7mm, or with the blood flow less than 100 mL/min had significantly lower early patency rate than the other groups. Conclusion: To improve early patency rate of radiocephalic fistula, large sized cephalic vein should be selected and if the intraoperative flow at radiocephalic fistula is less than 100 mL/min, another arteriovenous fistula formation should be considered.