복합유기용제에 노출된 조선소 도장작업자에서 발생한 파킨슨증후군

조민희,류향우,김은아 大韓産業醫學會 2009 대한직업환경의학회지 Vol.21 No.2

배경: 유기용제 노출에 의해 파킨슨증후군이 유발되었다는 사례들은 국외에서 다수 보고되어왔고, 그 기전을 밝히는 연구가 활발히 진행되고 있으나, 아직까지 국내에서는 이에 대한 보고사례가 없었다. 산업안전보건연구원에서 심의된 직업병 사례 중, 복합유기용제에 만성 노출 된 조선소 도장작업자에서 파킨슨증후군이 발생한 사례가 있어 이에 대한 산업의학적 평가 및 고찰을 보고하고자 한다. 사례: 53세 남자근로자가 약 13년간 조선소에서 스프레이 및 웃 도장작업과 선체파워작업을 하다가 특검결과, 중등도 인지기능장애를 보여 유기용제에 의한 만성독성뇌병증을 진단받았다. 작업환경측정 결과 및 과거의 열악한 작업환경을 생각해볼 때 복합유기용제에 의한 과다노출이 상당했을 것으로 추정되었다. 근로자의 과거력 상 특이사항은 없었으며, 지능검사 및 심리검사 결과, 경도의 인지 기능 감퇴와 우울 및 불안소견을 보였고, SPECT 소견에 서는 왼쪽 측두엽 말단부에 경도의 관류 감소 소견을 보였다. MRI에서는 뇌실주위 및 피질하 백색질의 소혈관의 허혈성 변화 외에는 특이소견이 없었다. 신경전도검사상 양측 수근관 증후군 및 신경뇌병증, 말초신경장애 등 으로 진단받아 계속 치료를 받아오던 중 왼쪽 팔다리가 어둔해져오고 운동완만, 경축 등이 있으면서, 왼손의 떨림 현상이 발생하여 파킨슨병 의심 하에 도파민 약물로 치료하였으나 효과가 없었다. 이상의 임상소견과 직업력을 근거로 이 환자는 유기용제에 의한 파킨슨증후군으로 진단받았으며, 양쪽 심부 뇌 자극술을 시행하여 손떨림은 덜해졌으나 운동완만은 호전되지 않았다. 3년 후인 현재, 환자는 왼손 떨림이 오른손으로 진행하는 등 계속적인 악화양상을 보이고 있다. 결론: 이 사례는 환자가 유기용제에 의한 만성독성뇌병증으로 진단된 지 수년 후 파킨슨증후군이 나타난 경우 로, 약 13년간의 유기용제 노출력 및 노출평가를 볼 때 유기용제에 과다노출 되었음을 추정할 수 있었다. 또한, 환자의 임상양상은 파킨슨병에 가까웠으나, 유기용제로 인한 독성뇌병증의 정신 증상이 다른 증상보다 선행하여 나타났고, 중요한 진단기준인 레보도파 약물 치료에는 반응이 없어 파킨슨병과는 차이가 있었다. 망간에 의한 파킨슨증후군의 경우 주로 바닥핵이 손상되어 파킨슨병과 구별되는 임상증상을 보이는 것과 달리, 유기용제의 경우 바닥핵 뿐 아니라 흑색질도 관여된다는 보고와 함께 뇌 백질의 손상도 동반되는 것으로 알려져 파킨슨병과 감별이 어렵다. 따라서 이 환자는 유기용제 독성으로 인한 파킨슨증후군일 가능성이 있는 것으로 판단되었다. 현재 유기용제와 파킨슨증후군의 정확한 발생기전은 알 수 없으나 유기용제 노출 근로자의 신경질환 예방을 위해서는 유기용제에 의한 중추신경독성과 파킨슨증후군의 관련성에대한 활발한 역학적 연구가 필요하다. Background: It is well-known that organic solvents can cause various neurologic toxicities, and in particular, it had been reported that Parkinson's syndrome can be caused by organic solvents. Case report: A 53-year-o1d man who had worked for 13 years as a shipyard spray and brush painter and manifested with moderate cognitive disorder and was diagnosed with chronic toxic encephalopathy. We can assume he had had considerable exposure to organic solvents considering the estimates of the amounts of organic solvents in his work place. He had no specific medical history. The Minnesota Multiphasic Personality Inventory (MMPI) showed mild cognitive deficit, depression, and anxiety. Single Photon Emission Computed Tomography (SPECT) indicated a slightly decreased flow at the edge of the left temporal brain area, while T2 brain Magnetic Resonance Imaging (MRI) showed no specific signs except for ischemic changes in small vessels in the periventricular and subcortical white matter. He was also diagnosed with both carpal tunnel syndrome and peripheral neuropathy through a neuroconductive study. Several years later, he developed progressive bradykinesia and rigidity and, later, resting tremors in the left hand. He was diagnosed with Parkinson's disease and treated with dopaminergic agents, but there was no effect. After that, he was given deep brain stimulation, both. As a result, his tremor is improved, but, the rigidity remained. Three years later, He has continuously received dopaminergic therapy, but, he complains about tremors in both hands and more greatly reduced cognitive function. Conclusion: In this case, we assumed by patient's work history and exposure estimates that he was exposed to excessive levels of organic solvents. The clinical symptoms of this patient were very similar to those from Parkinson's disease, but the psychological symptom appeared earlier than the other Symptoms and there was no response to dopaminergic agents. We conclude that this case is likely Parkinson's syndrome caused by organic solvents.

주물공장 근로자에서 발생한 국한성 석면폐증 1예

김태우,고동희,김민기,유승원,류향우,한정희,정순희 大韓産業醫學會 2009 대한직업환경의학회지 Vol.21 No.2

배경: 주물공장 근로자에서 발생한 석면폐증의 작업 관련성을 평가하고 그 증례를 보고하고자 한다. 증례: 30년간 주물공장에서 근무한 환자로 인후통, 기침, 노란 가래가 있어 검사한 결과 결핵이 의심되어 치료 하였으며, 치료 중 석면폐증으로 진단되었다. 작업 관련성 평가를 위해 실시한 폐 조직의 조직학적 검사에서 1 cm^(2)당 3개의 석면소체가 발견되었고, 투과전자현미경으로 분석한 석면 함유량은 23.26x10^(6) fibers/g이었다. 결론: 작업환경조사, 폐 조직의 석면 분석 등을 통해 작업 관련성이 높다고 판단하였다. Background: Foundry workers are known to be exposed to silica and have an increased risk of Silicosis. There are also reports that state these foundry workers were associated with asbestos-related change in the X-ray results of the lungs. This report discusses a case of localized asbestosis developed in a foundry worker who worked in 12 Korean foundries. Case report: A 49-year-o1d man who worked at molding and melting for 30 years, Presented with sore throat, cough and yellow sputum for 1 month. From physical and clinical examination, Pulmonary tuberculosis was highly suspicious; therefore, he was medicated for 6 months. After tuberculosis medication, the radiological finding was reactivation of tuberculosis, and an asbestos body was detected at a trans-bronchial lung biopsy. During an operation, operators found multiple palpable masses and bullae 10calized in the right upper lobe (RUL) and performed right upper lobectomy and right middle lobe wedge resection. Using hematoxylin-eosin stain and iron stain, we could detect asbestos bodies by light microscopy. We analyzed the asbestos fiber burden in dry lung tissue by transmission electron microscopy with energy dispersive X-ray spectrometer (TEM-EDX). The fiber type was chrysotile and the fiber burden was 23.26 x 10^(6) fiber/g dry lung. Discussion: This case study of a foundry worker with localized asbestosis is uncommon in Korea. We found an occupational relationship between the foundry worker and localized asbestosis through various investigative techniques such as measurements taken at his working environment, clinical, radiological and pathological examination of the foundry worker and mineralogical examination of the asbestos fiber.

회수수에 당류계 안정화제를 처리한 시멘트 모르터의 특성

金虎林,우종완,한민철,류현기,한천구 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

In this paper, fundamental properties of cement mortar using recycled water with stabilizing agent are discussed in order to investigate the applicability of recycled water. Stabilizing agent content, solid contents and open time are varied in this paper. For fresh mortar properties, highest fluidity with 0.15% of stabilizing agent was observed and air content was increased with an increase in stabilizing agent contents. Solid contents and open time of recycled water had nothing to do with fluidity and air content loss. Little difference in setting time was found with the presence of stabilizing agent and without, while it was accelerated with an increase in open time and solid content. For strength properties, the highest strength value was observed at 0.15% of stabilizing agent. An increase in solid contents resulted in an enhancement of strength, while strength decreased with an increase in open time and elapse of age. Drying shrinkage exhibited a reduction with an increase in stabilizing agent contents and open time. From the present paper, the combination of 0.15% of sacharic based stabilizing agent, 3% of solid content and 1day of open time is found to be an optimal condition to perform effectively.

흰쥐에서 음경발기 평가의 척도로서 음경해면체내압측정술 확립

송윤섭,김용준,이광우,김준모,문기혁,박영호,민영기,유형균,김형건 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Purpose: Because studies about the control of penile erection at the entral nervous system was dependent on the animal experiments, establishment of measuring penile erection is important to evaluate the effects changes at the central nervous system on the penile erection. Intracavernous pressure measurement in rats has been introduced as a suitable index for the evaluation of penile erection but this method is invasive and technically difficult. So, we established the intracavernous pressure measurement in rats as the experimental index for penile erection. Materials and Methods: 42 male adult Sprague-Dawley rats (250-300gm) were divided to saline or papaverine treated group. Rats were placed on a heating table to maintain their body temparature and anesthetized with 50mg/kg of pentobarbital sodium by intraperitoneal injection. A cannula was inserted to the left carotid artery to measure systemic blood pressure. Saline (0.05, 0.1ml), papaverine(0.05, 0.1, 0.25, 0.5, 1.0, 2.0mg) were injected intracavernously via 26 guage needle filled with saline or papaverine which connected to pressure transducer and polygraph was inserted into the corpus cavernosum on one side to inject the drug and to measure intracavernous presure. Results: Properly executed insertion and intracavernous administration produced a instantaneous but transient rise in intracavernous pressure that substantially stabilized and maintained at 5.4±0.4mmHg. Intracavernous pressure and duration of penile blood flow following intracavernous injection of papaverine are increased comared to those of saline. Conclusions: Monitoring intracavernous pressure in rats represents a suitable index for the evaluation of penile erection in small laboratory animals.

좌심실 이완기 장애 평가에서 Atrioventricular Plane Displacement의 임상적 중요성

정연손,조구영,이태유,김근숙,최창순,류제헌,최민호,박우정,임종윤,이영 대한순환기학회 2003 Korean Circulation Journal Vol.33 No.12

안지오텐신 변환효소 억제제와 안지오텐신 II 수용체 차단제 투여 후 발생한 급성 신부전과 폐부종으로 전원된 선천성 단일신 환자의 치료 1예

백두현,김경진,홍성철,강석형,송하응,김혜인,김수현,오현정,강혜원,김서우,유민아,류동열,최규복,강덕희 이화여자대학교 의과대학 2010 EMJ (Ewha medical journal) Vol.33 No.1

Blockers of renin-angiotensin system(RAS) including ACE inhibitor or ARB are one of the most frequently prescribed medications for the treatment of hypertension, heart failure and proteinuria. One of the major side effects of these RAS blockers is the deterioration of renal function, mainly due to a reduction of intraglomerular pressure. Therefore, close monitoring of renal function is recommended when RAS blockers are initially prescribed, especially for the patients with impaired renal function. We report a patient who was transferred to our hospital due to the sudden development of oliguria and dyspnea after treatment for hypertension with ACEi and ARB. She was finally diagnosed as RAS blocker-induced acute renal failure with pulmonary edema complicated on congenital solitary kidney. After hemodialysis and conservative treatment, her renal function was recovered with maintenance of normal urine output. Conclusion:This case highlights the necessity of the functional and structural evaluation of kidney to prevent the serious complication such as acute renal failure before the administration of ACEi and/or ARB.

Position-based Routing Algorithm for Improving Reliability of Inter-Vehicle Communication

( Min-woo Ryu ),( Si-ho Cha ),( Jin-gwang Koh ),( Seokjoong Kang ),( Kuk-hyun Cho ) 한국인터넷정보학회 2011 KSII Transactions on Internet and Information Syst Vol.5 No.8

A vehicular ad-hoc network (VANET) consists of vehicles that form a network without any additional infrastructure, thus allowing the vehicles to communicate with each other. VANETs have unique characteristics, including high node mobility and rapidly changing network topology. Because of these characteristics, routing algorithms based on greedy forwarding such as greedy perimeter stateless routing (GPSR) are known to be very suitable for a VANET. However, greedy forwarding just selects the node nearest to the destination node as a relay node within its transmission range. This increases the possibility of a local maximum and link loss because of the high mobility of vehicles and the road characteristics in urban areas. Therefore, this paper proposes a reliability-improving position-based routing (RIPR) algorithm to solve those problems. The RIPR algorithm predicts the positions, velocities, and moving directions of vehicles after receiving beacon messages, and estimates information about road characteristics to select the relay node. Thus, it can reduce the possibility of getting a local maximum and link breakage. Simulation results using ns-2 revealed that the proposed routing protocol performs much better than the existing routing protocols based on greedy forwarding.

Analysis of Effect of the Shape Factor on External Dose Rate in RADTRAN by Comparison With MCNP

Min Woo Kwak,Jae Bin Heo,Hyeung Woo Nam,Gang Woo Ryu,Kwang Pyo Kim 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1

RADTRAN is a code that assesses the radiation risk of radioactive material transportation. RADTRAN assumes that the package is a point source or a line source regardless of package type and corrects the external dose rate using a shape factor which depends on the critical dimension of the package. However, the external dose rate calculated using a shape factor may be different from the actual external dose rate. Therefore, it is necessary to analyze the effect of the shape factor on the external dose rate. In this study, the effect of the shape factor on the external dose rate in RADTRAN was analyzed by comparison with MCNP. This study analyzed change in external dose rate depending on the distance from the package and the critical dimension. The distance from the package was in the range of 1–800 m. The shape of the package was assumed to be cylindrical with a radius of 1 m, and the critical dimensions of the package were assumed to be 2, 4, and 8 m. Attenuation and build-up in the air were not considered to consider only the effect on the shape factor. When simulating the exposure situation using MCNP, the package was assumed to be a volume source, and flux by distance from the package was calculated using F5 tally. The dose rate at 1 m from the package was normalized to 2 mSv·hr?1. As a result of the analysis, the external dose rates of the package were higher in RADTRAN than in MCNP. For the critical dimension of 2, 4, and 8 m, when the distance from package is 1–10 m, the RADTRAN was 1.83, 4.08, and 5.27 times higher on average than MCNP, respectively. And when the distance from the package was 10–100 m and 100–800 m, RADTRAN was 1.10, 2.02, 3.01 times and 1.04, 1.92, 2.43 times higher than MCNP, respectively. It was found that the larger the distance from the package is and the smaller the critical dimension of the package is, the less conservatively RADTRAN assessed. It is because the shape of the package gets closer to the point source as the distance from the package increases, and the shape factor decreases as the critical dimension of the package decreases. The result of this study can be used as the basis for radiation risk assessment when transporting radioactive materials.

Enhanced Photoresponse of Plasmonic Terahertz Wave Detector Based on Silicon Field Effect Transistors with Asymmetric Source and Drain Structures

Ryu, Min Woo,Kim, Sung-Ho,Kim, Kyung Rok The Institute of Electronics and Information Engin 2013 Journal of semiconductor technology and science Vol.13 No.6

We investigate the enhanced effects of asymmetry ratio variations of the source and drain area in silicon (Si) field-effect transistor (FET). Photoresponse according to the variation of asymmetry difference between the width of source and drain are obtained by using the plasmonic terahertz (THz) wave detector simulation based on technology computer-aided design (TCAD) with the quasi-plasma 2DEG model. The simulation results demonstrate the potential of Si FETs with asymmetric source and drain structures as the promising plasmonic THz detectors.

Permutation Predictor Tests in Linear Regression

Ryu, Hye Min,Woo, Min Ah,Lee, Kyungjin,Yoo, Jae Keun The Korean Statistical Society 2013 Communications for statistical applications and me Vol.20 No.2

To determine whether each coefficient is equal to zero or not, usual $t$-tests are a popular choice (among others) in linear regression to practitioners because all statistical packages provide the statistics and their corresponding $p$-values. Under smaller samples (especially with non-normal errors) the tests often fail to correctly detect statistical significance. We propose a permutation approach by adopting a sufficient dimension reduction methodology to overcome this deficit. Numerical studies confirm that the proposed method has potential advantages over the t-tests. In addition, data analysis is also presented.