가상 병원과 의료양상 정보

정현철 광주보건대학 1999 論文集 Vol.24 No.-

To extend quality medical care to a greater number of indivisuals, a more efficient strategy was needed to distribute information to primary care physicians. Therefore, a concept called virtual hospital was developed. Also, to process standard medical images DICOM offered the promise of exchangeability of medical images from different manufacturers and across heterogeneous systems. Medical professors needed a convenient way of providing feedback and monitoring students' progress. Networked Virtual Reality Medical Tutor (NVRMT) enabled the shared viewing and manipulation of 3-dimensional computer models. For the purpose of providing the basic concept of some medical informatics with someone concerned with it, this paper reviewed the concept of virtual hospital, DICOM standard for medical images, NVRMT visualizing the locations and functions of organs of human anatomy and physiology in 3-dimensional virtual reality.

제어 시스템 설계를 위한 IEC 1131-3 기반의 제어 로직 생성기의 개발

정구,심주현,이제필,이철수 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

This paper describes the methodology of an IEC 1131-3-based control logic generator for the control system design and converting algorithm between programmable languages. The proposed control logic generator is generated based on the software model and common element with data type, variables, POUs(program organization unit) and execution control unit commonly used within programmable languages of IEC 1131-3 Standard. The generation method of object file was proposed on five programmable language based on IEC1131-3. The generation method of object file is represented as following; 1) the generation method using conversion algorithm from LD to IL with FBD(function block diagram), 2) the generation method using C code generation algorithm from SFC using the SFC execution sequence with FBD and ST(structured text). The proposed control logic generator was implemented by Visual C++ and MFC on MS-windows NT 4.0

웨이블릿과 의료 영상 처리

정현철 광주보건대학 2001 論文集 Vol.26 No.-

Modern medicine is a field that has been revolutionized by the emergence of computer and imaging technology. It is increasingly difficult, however, to manage the ever growing enormous amount of medical imaging information available in digital formats. Numerous techniques has been developed to make to imaging information more easily accessible and to perform analysis automatically. Among these techniques, wavelet transforms have proven prominently useful not only for biomedical imaging but also for signal and image processing in general. Wavelet transforms decompose a signal into frequency bands, the width of which are determined by a dyadic scheme. This particular way of dividing frequency bands matches the statistical properties of most images very well. During the past decade, there has been active research in applying wavelets to various aspects of imaging informatics, including compression, enhancements, analysis, classification, and retrieval. This review represents a survey of the most significant practical and theoretical advances in the field of wavelet-based imaging informatics.

갈륨액체금속 이온원과 인듐액체금속 이온원의 빔 특성에 대한 연구

현정우,임연찬,정강원,정원희,박철우,이종향,강승언 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

본 연구에서는 인듐 액체금속이온원을 제작하여 빔 특성에 대해 연구를 하였으며, 기존에 연구를 하였던 갈륨 액체금속이온원의 빔특성과 비교 분석 하였다. 빔특성 분석을 위해 빔 안정도, 전류-전압특성곡선, 에너지 퍼짐을 측정하였다. 액체금속이온원에 사용되는 액체금속 저장소 및 바늘전극(tip)은 500μm의 직경을 갖는 텅스텐을 사용하였으며, 국내에서 제작된 제품을 사용하였다. 액체금속 저장소의 구조는 이전에 구상하여 연구가 이루어진 6개의 pre-etching된 텅스텐와이어(wire)가 묶여진 형태를 사용하였다.

바이오컴퓨팅 환경에서 인공망막의 개발 동향

정현철 광주보건대학 2004 論文集 Vol.29 No.-

We survey some papers for the research trend of artificial retinas in biocomputing environments. A digital retina is an array processor with integrated optical input and external control. As so, it is a specialized computing unit in the same way as a floating point unit in a microprocessor. To keep with the analogy between biological and artificial vision, let us call "cortex" the set of resources that must be associated to an artificial retina to turn it into a vision system able to observe and understand scenes up to action-oriented decision making. Functionally speaking, there is a master-slave relationship between cortex and retina : the cortex controls the digital retina in order to make it produce image descriptors useful for decision making. Computationally speaking, the cortex+retina association is a hybrid parallel system where the digital retina supports low to middle level vision - as long as data feature a bidimensional structure - while the cortex is in charge of middle to high level vision, the part of vision which is closer to artificial intelligence than signal processing, and where data structures are no longer images but rather scalar values, lists, vectors, graphs, etc. The cortex is typically implemented using a standard microprocessor with enhanced I/O. The point of using a digital retina in a vision system is that the volume of data manipulated is much larger at low than high level. To a lesser extent, this is also true about the computational load. Then a vision system incorporating a digital retina is expected to largely inherit from the retina high performances in terms of volume, weight, speed and power consumption. From the architect viewpoint, the cortex+retina association is fairly insensitive to the memory/computing fracture mentioned earlier, at the retina level as well as at the system level.

동종 골수이식 후 만성 이식편대숙주질환과 동반되어 신증후군으로 발현된 IgA 신병증 1예

정철권,김현수,박준성,정성현,조도연,최진혁,남동기,임호영,김명성,신규태,임현이,김효철 대한조혈모세포이식학회 1999 대한조혈모세포이식학회지 Vol.4 No.2

동종 골수이식 후 발생하는 신기능부전은 원인이 다양하여 감별에 어려움이 있다. 만성 GVHD는 흉선의 기능저하에 따른 면역관용의 실패로 발생되는 자가면역현상에 의해 발생되는 것으로 알려져 있으며 드물게 신장을 침범하여 신증후군을 일으키기도 한다. CaA의 용량을 줄이거나 투약중지 후 발생한 만성 GVHD에 동반된 신증후군의 경우 조기에 신조직검사를 시행하여 감별진단하고 CsA의 용량을 증량하거나 재투약하여 좋은 치료 결과를 보일 것으로 기대된다. 저자들은 문헌고찰을 통해 동종 골수이식 후 발생된 신증후군이 유사한 임상양상을 보이며 발생기전에 만성 GVHD와 자가면역현상이 연관되어 있음을 확인하였으며 동종 골수이식 후 신증후군의 임상양상을 보이는 환자에서 병리조직학적으로 lgA 신병증을 진단하고 이러한 lgA 신병증이 발생기전에 만성 GVHD와 자가 면역현상이 연관되어 있을 가능성을 최초로 확인하였으며 CsA를 이용하여 성공적으로 치료한 경험을 하였기에 보고하는 바이다. Renal insufficiency is occasionally encountered in allogeneic bone marrow transplantation and its cause is difficult to ascertain. Chronic graft-versus-host disease (GVHD) related to thymic dysfunction is immune-mediated and involves autoreactivity of T-lymphocytes derived from donor marrow to recipient's major histocompatibility complex(MHC) minor antigens. The clinical mainifestations of chronic GVHD are similar to those of autoimmune disease but kidney involvement is rare. Few cases of nephrotic syndrome with membranous nephropathy or minimal change nephrotic syndrome have been reported to be associated with chronic GVHD in allogeneic bone marrow transplant recipient especially after cyclosporine A(CsA) withdrawal, and these cases have responded well to CsA. Therefore, it is prudent to differentiate the cause of post-transplant renal insufficiency using renal biopsy and to start CsA in a case of nephrotic syndrome associated with chronic GVHD as early as possible. We report a case who had a massive proteinuria during the post-allogeneic marrow transplantation period. The cause of nephrotic syndrome was diagnosed as IgA nephropathy by renal biopsy. The patient was successfully treated with reintroduction of CsA.

한국인 알코올의존환자에서의 제1형 부신피질자극 호르몬 분비 촉진 호르몬수용체의 유전자 다형성에 관한 연구

김철민,김성곤,김지훈,김현경,김미경,유정현,민은정 대한생물치료정신의학회 2011 생물치료정신의학 Vol.17 No.2

스트레스 반응에 중요한 역할을 하고 있는 CRHR1 유전자 SNP와 알코올 의존과의 연관성에 관한 선행 연구들이 있다. 이에 본 연구는 백인을 대상으로 조사했던 기존연구와는 달리 한국인 남녀를 대상으로 하여 알코올 의존군과 정상 대조군의 CRHR1 유전자형 빈도 및 대립유전자형 빈도를 비교하였다. 본 연구의 연구대상자들은 알코올 의존군 268명(남자 218명, 여자 50명)과 정상 대조군 137명(남자 78명, 여자 59명)이었다. CRHR1 유전자 SNP를 SNP database와 선행연구를 근거로 선정한 후, 연구 대상자들의 이러한 SNP 유전자형을 PCRRFLP방법으로 조사하였다. 그 결과, 한국인의 CRHR1 유전자 SNPs로 7개(rs242938, rs404623, rs28364027, rs16940686, rs937, rs878886, rs878887)가 분석되었다. 이중 rs28364027의 A 대립 유전자의 빈도는 남녀 각각에서 알코올 의존군이 대조군보다 유의하게 높았다. 그리고 rs28364027의 AA 유전자형 및 A 대립 유전자와 rs878886의 CC유전자형 및 C 대립유전자의 빈도는 알코올 의존군내에서 여성이 남성보다 유의하게 높았다. 이러한 결과를 종합해 보면 CRHR1 유전자 SNP가 알코올 의존의 유전적 원인의 중요한 요인일 가능성을 제시하고 있다. 또 이러한 CRHR1 유전자 SNP가 알코올 의존의 유전적 원인에서 남녀간 차이를 설명할 수 있을 가능성도 시사하고 있다. Objectives:There were several preceding studies investigating the association between alcohol dependence and corticotropine releasing hormone receptor1(CRHR1) gene SNPs that play an important role in response to stress. The frequencies of CRHR1 genotypes and alleles were compared between alcohol-dependent patients and normal control subjects. Methods:The subjects were 268 alcohol-dependent patients(218 males, 50 females) and 137 normal controls(78 male, 59 female). CRHR1 gene SNPs were investigated according to the SNP database and the results from previous studies, and their genotypes were analyzed by polymerase chain reaction(PCR) and restriction fragment length polymorphism(RFLP). Results:Seven CRHR1 gene SNPs(rs242938, rs404623, rs28364027, rs16940686, rs937, rs878886, rs878887) were found in Korean subjects. The frequency of rs28364027 A allele was significantly higher in alcohol-dependent patients than normal controls in both genders. In alcohol-dependent patients, the frequencies of AA genotype and A allele of rs28364027, and of CC genotype and C allele of rs878886 were higher in female than male. Conclusion:These results suggest that CRHR1 gene SNP is one of the important genetic factors in the etiology of alcohol dependence. And also it is supposed that the different frequency of SNP genotype could explain stress-related gender difference in the genetic etiology of alcohol dependence.

생명의료정보 처리를 위한 데이터베이스 전환

정현철 광주보건대학 2003 論文集 Vol.28 No.-

We survey some papers for UCLA(Leec@mbi.ucla.edu, et al) to accomplish on bioinformatics. They wish to propose a database architecture combining a general view of bioinformatics data as a graph of nodes(data objects) and edges(data relationships), with the efficiency and robustness of data management and query provided by indexing and generic programming techniques. Here, they invert the role of the index, and make it a first-class citizen in the query language. It is possible to do this in a structured way, allowing users to mention indexes explicitly without yielding to a procedural query model, by converting functional relations into indexes(explicit functions). In the limit, the database becomes a graph, in which the edges are these indexes. Function composition can be specified either explicitly or implicitly as path queries. The net effect of the inversion is to convert the database into a hyperdatabase: a database of databases, connected by indexes or functions. The inversion approach was motivated by their work in biological databases, for which hyperdatabases are a good model. The need for a good model has slowed progress in bioinformatics.

사회적 음주자에서 매운 맛 선호도가 급성 음주 반응에 대한 Naltrexone 효과에 미치는 영향

정희정,김성곤,김종현,박숙현,강철중 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.6

Capsaicin과 알코올이 각각 중추신경 아편계 활성도를 증가시킨다는 선행 연구들이 있다. 이에 본 연구는 매운맛 선호도에 따라 급성 음주 반응에 차이가 있는지와 급성 음주 반응에 naltrexone이 미치는 영향에 차이가 있는지를 조사하고자 하였다. 12명의 의과대학 남학생을 대상으로 두 군으로 나눈 후 cross-over design을 사용하여, 한 군(6명)은 naltrexone 25 mg을 실험 1일째에, 50 mg을 실험 2일러에 주었고, 다른 군(6명)은 naltrexone 25 mg을 실험 8일째에, 50mg을 실험 9일째에 주었다. 실험 2일째와 9일째에 각대상자의 Biphasic Alcohol Effects Scale (BAES)로 측정한 급성 음주 반응과 음주갈망, 혈중알코을 농도 등을 음주 전, 음주(0.6 ml/kg) 후 15분, 30분, 60분에 측정하였다. 통계 분석 시 Food Preference Scale 점수에 따라 모든 대상자를 매운 맛을 선호하는 군(strong preference for hot food, SP)과 매운 맛을 덜 선호하는 군(lesser preference for hot food, LP)의 두 군으로 다시 나누어 분석하였다. 결과는 다음과 같다. 1) Naltrexone을 투여 여부에 관계없이 알코올의 급성 흥분 효과는 매운 맛 선호도에 따른 차이가 없었다. 그리고 LP에서도 naltrexone의 투여 여부에 따른 알코올의 급성 흥분 효과의 차이가 없었다. 그러나 SP에서는 알코올의 급성 흥분 효과가 naltrexone 투여 시 유의하게 억제되었다. 2) 알코올의 급성 진정 효과, 음주 갈망 및 혈중 알코올 농도는 매운 맛 선호도 혹은 naltrexone 투여 여부에 따른 차이가 없었다. 본 연구에서 매운맛을 선호하는 경우 알코올의 급성 흥분효과가 naltrexone에 의해 억제되었다. 이것으로 naltrexone이 매운맛을 선호하는 군에서 알코을 의존 재발 예방 효과가 더 클 가능성을 제시한다. Objectives : Both capsaicin, a pungent substance of hot food, and alcohol, are known to affect central opioid activity. The purpose ofthis study was to investigate the difference in the subjective acute responses to alcohol and the effect of naltrexone on them among those who prefer hot food to varying degrees. Methods : Twelve male medical students were divided into two groups using a cross-over design. One group was given naltrexone on only the first (25 mg) and the second day (50 mg), and the other group was given naltrexone on only the eighth (25 mg) and the ninth day (50 mg). On the second and the ninth day, the acute effect of alcohol was assessed in all subjects, using the Biphasic Alcohol Effects Scale (BAES) just before drinking and at 15 minutes, 30 minutes and 60 minutes after drinking (0.6 ml/kg). Alcohol craving was also measured, using Visual Analogue Scale for craving (VAS-C) and blood alcohol concentration (BAC), at the same interval. For statistical analysis, subjects of both group were re-divided into two group, those with a strong preference and those with a less preference (LP) for hot (spicy) food (SP), using the Food Preference Scale. Results : 1) Repeated measures of ANOVA (2 preference groupsX4 time blocks) on the stimulative subscale of BAES yielded no significant group by block interaction of naltrexone administration. Repeated measures of ANOVA (2 drug groupsX4 time blocks) on the stimulative subscale of BAES revealed a significant group by block interaction in SP (p=0.028), but not in LP. The paired t-test revealed that significant suppression of the stimulative subscale of BAES was observed at 15 minutes and 30 minutes after drinking when naltrexone condition was compared with no-medication condition in SP(p=0.014 ; p=0.007). 2) For the sedative subscale ofBAES, VAS-C and BAC, repeated measures of ANOVA yielded nosignificant group by block interaction by either hot food preference or naltrexone administration. Conclusion : For those who prefer hot food, the effect of stimulative acute alcohol was suppressed by naltrexone. This result strongly suggests that naltrexone could prevent relapse more effectively in those who prefer hot food.

한국형 우울장애 약물치료 알고리듬 2006 (Ⅰ)

서정석,민경준,김원,석정호,박원명,송해철,이상열,전덕인,전현태,홍진표,한국형 우울장애 약물치료 알고리듬 2006 연구그룹 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.5

Objectives : Since the publication of Korean Medication Algorithm Project for Major depressive Disorder (KMAP-MD) in 2002, there has been a substantial need for a revision due to rapid progress in the pharmacological management for depressive disorder. We revised KMAP-MD to Korean Medication Algorithm Project for Depressive Disorder (KMAP-DD) in 2006. This paper is one of the following 4 papers consisting of Korean pharmacological algorithm for depressive disorder. Methods : The questionnaire consisted of 4 parts ; initial treatment of 1) non-psychotic depressive disorder, 2) psychotic depressive disorder, 3) treatment strategy for clinical subtypes and drug choice considering adverse effects, and 4) treatment for depressive disorder in women. It was composed of 22 questions, and each question had 54 sub-items. The questionnaire was completed by the review committee consisting of 101 experienced Korean psychiatrists. We classified the expert opinion to 3 categories (the first-line, the second-line, or the third-line). Results : For non-psychotic major depression, regardless ofthe severity of an episode, the antidepressant (AD) monotherapy was the optimal first-line treatment. SSRI, venlafaxine, and mirtazapine were the 1st-line AD. In case of a partial or no response to initial strategy, adding another AD was recommended. For psychotic major depression, combination of an AD and an atypical antipsychotic (AAP) was the treatment of choice. Among AAPs, quetiapine, rispendone, olanzapine were preferred. For non-responder to initial strategy, the next step was adding or changing AD before changing AAP. For women with premenstrual dysphoric syndrome or postpartum depression without psychotic features, AD monotherapty was a preferred strategy while for psychotic postpartum depression, combination of AD and AAP was recommended. Experts recommended various ADs according to adverse effect. Conclusion : These results suggest that the medication strategies for depressive disorder are rapidly changing and reflect the recent studies and clinical experiences.