Polyurethane의 혈전방지처리가 Staphylococcus epidermidis의 정착에 미치는 영향

김성민,이규백,백경란,오명돈,민병구,최강원 대한감염학회 1996 감염 Vol.28 No.1

목적 : 최근 생체재료로 만든 각종 카테타와 인공관절, 인공심장 등 인공장치의 사용이 점차 증가하고 있으며, 인공장치의 사용을 제한하는 가장 큰 합병증은 생체재료를 중심으로 일어나는 감염과 혈전증이다. 그러므로 인공장치를 장기간 사용하기 위해, 이들 합병증을 예방할 수 있는 생체재료를 개발하는 것이 중요한 과제가 되고 있다. 인공장치는 체내에 들어가서 혈액과 접촉하게 되면, 혈장단백질과 혈소판이 부착하고 활성화되어 혈소판-섬유소 혈전을 만든다. 이렇게 형성된 혈전은 세균의 부착을 촉진하고, 부착한 세균이 인체방어기전이나 항균제의 영향을 받지 않고 증식 할 수 있는 공간이 된다. 또한 정착한 세균은 혈액과 접촉하여, 혈전의 형성을 촉진한다. 즉, 혈전과 세균정착은 서로 영향을 주면서 인공자치의 오랜 사용을 제한하게 된다. 폴리우레탄에 설폰산과 알부민을 표면처리하면 혈전의 형성이 감소하는 효과가 있다는 것은 보고된 바 있으나, 혈전방지를 위해서 표면처리에 사용한 설폰산, 알부민이 세균 정착 및 감염에 미치는 영향에 대해서는 아직 잘 알려져 있지 않다. 이에 저자들은 설폰산, 알부민, 파라벤으로 처리한 폴리우레탄이 세균의 정착에 미치는 영향에 대해 알고자 본 연구를 시행하였다. 방법 : S. epidermidis RP12 부유액(?/mL)에 대조 폴리우레탄과 설폰산과 알부민, paraben으로 각각 처리한 폴리우레탄을 원반모양으로 만들어 담근 다음, 24시간 또는 48시간 동안 배양하였다. 세균 정착의 정도는 세균 집락수 및 SEM 소견으로 판정하였다. 결과 : 24시간 째 및 48시간 째의 세균집락수는 대조 폴리우레탄이 각각 8.3x10⁴/mL, 1.1×?/mL이었고, 파라벤 처리 폴리우레탄이 각각 9.3x10⁴/mL, 2.1x10⁴/mL (p<0.05), 설폰산 처리 폴리우레탄이 각각 1.2×?/mL, 8.2x10⁴/mL,(p<0.05), 알부민 처리 폴리우레탄이 각각 7.3×?/mL, 1,4×?/mL (p<0.05)이었다. 즉, 세균 집락수가 파라벤 처리 폴리우레탄에서는 유의하게 감소하였으나, 설폰산 처리 폴리우레탄에서는 증가하였다. SEM 소견에서는 설폰산 및 알부민 처리 폴리우레탄에서 세균 정착의 감소를 관찰하지는 못하였다. 결론: 본 연구는 in vitro 실험으로, 파라벤으로 처리한 폴리우레탄은 세균의 정착을 감소시키는 효과가 있었으나, 항혈전성 폴리우레탄은 세균 정착을 감소시키지 못하였다. 인체내에서는 세균과 혈소판, 혈장단백질이 복잡하게 반응을 하면서 혈전과 세균 정착이 서로 영향을 주므로, 인체내에서는 항혈전성 폴리우레탄이 혈전 형성을 감소시키고, 2차적으로 세균 정착을 감소시키고 감염을 예방하는 효과가 있을 가능성도 있으므로 이에 대한 연구가 진행되어야 하겠다. Background : Infection and thromboembolism are major complications of prolonged use of prosthetic devices, such as various catheters, prosthetic joints, and artificial hearts, frequently resulting in severe morbidity, or death. Therefore, the prevention of infection and thrombosis is an important subject in developing new biomaterials of prosthetic devices. The first event on insertion of a prosthetic device into the blood is protein adsorption and activation with platelet adhesion, activation and aggregation, leading to the formation of platelet-fibrin thrombi. The thrombi are susceptible to bacterial incorporation and protect the bacteria from the effects of circulating antibodies, phagocytic cells, and antibiotics. Furthermore, adherent bacteria may induce fibrin and platelet adhesion. Sulfonated polyurethane and albumin-immobilized polyurethane were documented to diminish the adhesion and shape-change of platelet on the polymer in comparison with plain polyurethane, in vitro. The objective of this study was to evaluate the effect of these antithrombotic biomaterials on the bacterial colonization. Methods : Plain, sulfonated, albumin-immobilized, and paraben-incorporated polyurethane(PU) films were prepared as a disk form. Staphylococcus epidermidis RP12 was suspended at a concentration of ?/mL and four types of polymeric disks were immersed in the bacterial suspension. After incubation for 24 and 48 hours, the bacterial colonization on the each disk was determined by the colony forming units(CFU) counting method. The colonized disks were examined by scanning EM. Results : The paraben decreased significantly the number of CFU on PU surface to 2.1x10⁴/mL after 48 hours, compared with 1.1×?/mL on plain polymers. The number of CFU on sulfonated or albumin-immobilized PU was 8.2x10⁴/mL, and 1.4×?/mL, respectively. SEM micrographs showed no reduction of colonization on antithrombotic PUs. Conclusion : Antithrombotic treatments of polymers did not decrease the bacterial colonization on polymers, in vitro, that was compared to the decreasing effect of paraben. However, because the thrombi and bacteria interact with each other, the overall effect of the antithrombotic polyurethanes on the bacterial colonization and infection should be studied in vivo.

7개 대학 병원에서 조사한 지역사회 폐렴의 원인균

정문현,김성민,강문원,최희정,정희진,이경원,한성우,송재훈,신형식,김의종,최강원,김민자,박승철,배현주,정윤섭,김준명,백경란,신완식,이규만,김양리 대한감염학회 1997 감염 Vol.29 No.5

목 적 : 폐렴은 많이 발생하면서 사망률이 크게 줄지 않는 질환이며, 이를 적절히 치료하기 위해서는 원인균의 상대적 빈도, 기저 질환에 따른 변화, 항균제 내성률, 사망에 관련된 인자들을 알아야 한다. 원인균의 빈도는 지역마다 차이가 있고 국내에서는 항균제 내성률이 높아 지역사회에서 발생한 폐렴을 치료하기 위한 경험적 항균제 선택에 도움이 되기 위해 서울 소재 6개 대학 병원과 천안의 1개 대학 병원이 참여하여 위의 사항들에 대해 조사를 하였다. 방 법 : 1995년에 내과에 입원했던 16세 이상 환자를 대상으로 했다. 퇴원 진단명이 폐렴 또는 폐결핵인 병록지을 찾았고, 이중에서 병원 감염을 제외하였다. 특이도를 높이기 위해, 이들 중에서 호흡기 증상이 있고 발열이나 저체온이 있으면서 흉부 X-선에서 이상 음영이 있는 환자만을 대상으로 했다. 폐결핵은 위의 기준에 입원 초기에 항균제 치료를 하고 입원 7일 이후에야 항결핵제가 투여된 경우만을 폐렴의 원인균으로 하였다. 혈액 배양에서 양성, 객담에서 항상균이나 M. tuberculosis가 증명된 경우, 혈청학적으로 항체가가 4배 이상 증가된 경우, 조직에서 원인균이 진단된 경우는 확정(definitive) 원인균으로 하였고, 객담에서 배양된 균이 그람 도말과 일치할때, 항결액제에 대한 반응으로 진단한 폐결핵, 단일 항체가 양성이고 이에 대해 항균제를 사용했을 때는 가능(probable) 원인균으로 정의하였다. 다세균 감염균은 각각 다 른 원인균으로 처리하였다. 임상 조사와 함께 임상병리과에서 S. pneumoniae, H. influenzae, M. catarrhalis, mycoplasma, 항상균에 대해 검사 의뢰 건수, 배양 양성수, 항균제 감수성 결과를 조사하였다. 결 과 : 폐렴의 증례 정의에 부합하지 않은 135명과 폐결핵의 정의에 해당하지 않는 230명을 제외하고 남은 246명의 평균 나이는 58.2세이고 남성이 142명(58.2%) 이었고, 71%의 환자에서 기저 질환이 있었다. 진단 방법의 시행 횟수는 혈액 배양 77.6%, 혈청 검사 18.3%, 기관지경 검사는 4.1%였고, 세균의 항원 검사를 한 예는 없었다. 원인균이 밝혀진 예는 77명(31.3%)이었다. 다세균 감염이 4명에서 있었고, 원인균의 상대적 빈도는 결핵 20명(확정 17, 가능 3: 6개 병원 자료), 폐렴구균 18(확정8 가능 10)명과 폐렴구균이 아닌 Streptococcus 3명 (모두 확정), H. influenzae 11명(모두 가능), 그람음성간균 11명(확정 7, 가능 4) (K. pneumoniae 8건), Mycoplasma 5명(확정 1, 가능 4), S. aureus 4명(확정 2, 가능 2), mucormycosis 1명(확정)이었다. 평균 입원 기간은 19일이고, 중환자실 입원률과 인공 호흡기 사용율은 각각 18%와 9.3%였다. 사망률은 13.8%였고 사망까지 평균 기간은 14.6일 이었다. 다변량 분석에서 사망을 예측할 수 있는 인자는 저체온과 빈호흡이었다. 임상병리과에서 배양되었던 모든 폐렴구균의 Penicillin 내성률은 서울 3개 병원에서 82-88%, 천안에서 72%였다. 폐렴 환자의 혈액에서 배양된 7주는 모두 Penicillin에 감수성이 있었다. K. pneumoniae 8주 모두 cefotaxime과 gentamicin에 감수성을 보였다. 결 론 : 후향적 조사이고 병원마다 원인균 진단에 차이가 있지만, 원인이 밝혀진 경우에는 결핵과 폐렴균이 흔하였고, 무균 부위에서 배양된 폐렴구균의 항균제 내성률은 낮았다. 원인이 밝혀지지 않은 경우가 많고, 혈청검사로 진단되는 원인균이 드물며, 분리균주가 적어 항균제 내성 정도를 추정하기 어려워, 이를 밝히기 위한 전향적 조사가 필요하다. Background : Community-acquired pneumonia (CAP) is one of the leading causes of mortality and morbidity, but its management is still challenging. The limitation of diagnostic methods to identify etiologic agents rapidly make it necessary to use empiric antibiotics in almost all patients, and furthermore the discovery of new respiratory pathogens and the emergence of antibiotic-resistant organisms pose difficulties to the selection of an empiric regimen. To clarify the factors necessary for the optimal choice of empirical antibiotics, such as the frequency of etiologic agents, the attributable rates to death and antimicrobial resistance rates in the community, six university hospitals in Seoul and one university hospital in Cheonan were participating in this study. Methods : medical records of adults (>15 years of age) hospitalized for CAP or pulmonary tuberculosis between April 1995 and March 1996, were reviewed. Patients who satisfied all of the following criteria were included in the study: (1) fever or hypothermia; (2) respiratory symptoms; and (3) pulmonary infiltrates on chest roentgenogram. To exclude cases of pulmonary tuberculosis whose roentgenographic features were so typical that it could be easily differentiated from conventional pneumonia, two additional criteria were required for inclusion: antibiotic treatment during the first week of hospital admission and initiation of anti-tuberculosis medications thereafter. Organisms isolated from sterile body sites, acid-fast bacilli or Mycobacterium tuberculosis isolated from sputum, pathogens diagnosed by a 4-fold rising titer of antibodies to “atypical”pathogens, or pathogens revealed by histopathology were defined as definitive cause of pneumonia; isolates from sputum withcompatible Gram stain, pathogens diagnosed by a single diagnostic titer plus use of a specific antimicrobial agent, or tuberculosis diagnosed by clinucal response to anti- tuberculosis medications were considered probable cause of pneumonia. The records of the clinical microbiology were reviewed for isolates of S. pneumoniae, H. influenzae, M. catarrhalis, Mycobacterium or acid-fast bacilli, and Mycoplasma. Then the frequency of these agents, antimicrobial resistance rates of resiratory pathogens from all body sites, and their clinical significance were evaluated. Results: After excluding 365 patients (230 with pulmonary tuberculosis and 135 with CAP) who were screened for inclusion but did not meet the inclusion criteria,246 persons were enrolled in this study. Their mean age was 58.2 years old with slight male predominance (58.2%), and 171(71%) patients had underlying illnesses. Blood cultures were performed on 191 (77.6%) patients and serologic tests on 44(18.3%) patients. The etiologic agents were identified in 31.3%, and the list of individual agents, in decreasing order, was pulmonary tuberculosis (17 definite and 3 probable: data of six hospitals), S. pneumoniae (8 definite and 10 probable), non-pneumococci (3 definite), aerobic gram-negative bacilli (7 definite and 4 probable), Haemophilus spp. (11 probable), mycoplasma (1 definite and 4 probable), polymicrobial infections (2 definite and 2 probable: E. coli and S. agalactiae, M. tuberculosis and S. aureus, S. pneumoniae and H. influenzae and A. baumannii and K. pneumonias), S. aureus (2 definite and 2 probable) , and mucormycosis (1 definite). Among gram-negative bacilli, K. pneumoniae was the most common agent (8isolates). therates of admission to the intensive care unitand of using assisted ventilation were 18% and 9.3%, respectively. The mortality was 13.8% and logistic regression analysis showed that hypothermia and tachypnea were associated with death. Hospital stay averaged 19 days. Susceptible rates of S. pneumoniae isolated from all body sites to penicillin ranged from 8% to 28% but seven isolated from blood of patients with pneumonia were susceptible to penicillin. Also all 8 isolated of k> pneumoniae from patients with pneumonia were susceptible to cefotaxime and gentamicin. Conclusion: In Korea, in addition to S. pneumoniae, M. tuberculosis is an important agent causing community-acquired pneumonia. The low incidence of etiologic diagnosis is probably related to infrequent requesting of test "atypical" pathogens and does not represent the true incidence of infections by "atypical" pathogens, which well be answered by a prospective study. The antimicrobial resistance rates of major respiratory pathogens from sterile body sites are low, however, because of a small number of the isolates this result needs confirmation by a nationwide surveillance of antimicrobial resistance.

Study on fabrication process of anode-supported thin-film solid oxide fuel cells

Sungmin Kang(강성민),Yusung Kim(김유성),Suk Won Cha(차석원),Joongmyeon Bae(배중면) 한국신재생에너지학회 2016 한국신재생에너지학회 학술대회논문집 Vol.2016 No.5

e-Security Framework for Supporting Efficient e-Supply Chain Management in Electronic Commerce Environment

Sungmin Kang,Seng-Phil Hong 한국무역학회 2005 Journal of Korea trade Vol.9 No.1

The business environment today can be described as a digital economy where information flows freely, and where business processes can be improved with the use of information technologies. The Internet has played a key role in transforming and creating new business models for many organizations. And, it has become the infrastructure of choice in electronic commerce because it provides process efficiency, cost reduction, and open standards that can easily be adopted by different organizations. The Internet also can be applied to coordinate supply chain (SC) processes with external organizations by integrating front- and back-end business processes. The success of the Internet didn t come without its share of difficulties and one such difficulty is its security. We address the importance of security framework in managing the information shared among the parties in the SC process. This paper could provide valuable contributions to both academics and industry by addressing how security framework and architecture should be set to deal with security concerns and provide the necessary support for SC process.

The Role of Interpersonal Trust in On-line Learning Communities and Application of Knowledge

Sungmin Kang,Hyunju Suh,Hyogun Kym 한국경영정보학회 2015 Asia Pacific Journal of Information Systems Vol.25 No.4

Distinct layered structure with density modulation in solid phase formed from B2 phase of banana molecules.

Kang, Sungmin,Tokita, Masatoshi,Ogino, Kumiko,Doi, Takayuki,Takahashi, Takashi,Takezoe, Hideo,Watanabe, Junji Published by the American Physical Society through 2006 Physical review. E, Statistical, nonlinear, and so Vol.73 No.1

<P>A unique two-dimensional (2D) long-range structure has been observed in a low-temperature phase X1 for a banana molecule having bromine atom substituted on the central core using synchrotron radiation (SR) x-ray scattering measurements. The X1 phase is formed from the B2 phase with the SmC(A)P(A) structure upon cooling and then shows multiple reflections around the first layer line, which are interpreted as a peculiar frustrated structure with long-range layer modulation order. Furthermore, the observation of a well-defined (100) reflection with a spacing of 171A means that there is the electron density modulation along the layers. By coupling these reflections, a 2D lattice with a=173 A, c=53.4A, and beta=81.1 degrees, is determined where the a axis is parallel to the original layer of the phase. This unique structure with modulation can be interpreted as an undulated layer structure and suggested to be the result from deformation with polarization splay defects periodically occurring along the layer. The angle, beta=81.1 degrees, between a and c axes indicates that the position of splay defects in one layer is staggered from that in the neighboring layer. In other words, the splay defect lines run in a direction tilted by roughly 80 degrees with respect to the a axis.</P>

Quantitative Environmental Impact Analysis and Comparison of 1-kW SOFC Stacks according to Supporting Parts

Sungmin Kang,Eunbi Hwang,Chanwoo Baek,Dong-Hyun Peck,Seog-Young Yoon 한국신재생에너지학회 2023 AFORE Vol.2023 No.11

Combined Fluorescence and Magnetic Resonance Imaging of Primary Macrophage Migration to Sites of Acute Inflammation Using Near-Infrared Fluorescent Magnetic Nanoparticles.

Kang, Sungmin,Lee, Ho Won,Jeon, Young Hyun,Singh, Thoudam Debraj,Choi, Yun Ju,Park, Ji Young,Kim, Jun Sung,Lee, Hyunseung,Hong, Kwan Soo,Lee, Inkyu,Jeong, Shin Young,Lee, Sang-Woo,Ha, Jeoung-Hee,Ahn, Elsevier Science 2015 Molecular imaging and biology Vol.17 No.5

<P>This study aimed to track the migration of primary macrophages labeled with near-infrared (NIR) fluorescent magnetic nanoparticles toward chemically induced acute inflammatory lesions in mice and to visualize the effect of anti-inflammatory drugs on macrophage migration using combined fluorescence and magnetic resonance imaging (FLI/MRI).</P>

The Antecedents of Switching Cost and its Effect on Customer Loyalty in Digital Music Service Industry

Sungmin Kang,Giheon Uhm 한국경영정보학회 2010 Asia Pacific Journal of Information Systems Vol.20 No.2

Isolated Facial Muscle Metastasis From Renal Cell Carcinoma on F-18 FDG PET/CT

Kang, Sungmin,Song, Bong-Il,Lee, Hong Je,Jeong, Shin Young,Seo, Ji-Hyoung,Lee, Sang-Woo,Ahn, Byeong-Cheol,Lee, Jaetae,Lee, Hui-Joong Wolters Kluwer Health, Inc. All rights reserved. 2010 Clinical nuclear medicine Vol.35 No.4

Facial muscle is a very rare site for distant metastasis of renal cell carcinoma (RCC). We present a 71-year-old man with isolated facial muscle metastasis 12 years after right nephrectomy for RCC. Magnetic resonance imaging showed a soft-tissue mass in the masticator space. F-18 fluorodeoxyglucose positron emission tomography/computed tomography showed a large hypermetabolic lesion in the right masticator space without other hypermetabolic lesion in the whole body. Subsequent biopsy and histologic study confirmed metastatic cancer from RCC.