포도상구균의 약제 내성 및 β-lactamase의 생산에 관하여

양재윤,박상욱,이용진,조규봉,이연태 단국대학교 신소재기술연구소 1994 신소재 Vol.4 No.-

항균제의 오남용으로 내성균의 출혈빈도가 매우 높아져 임상가에서는 환자치료에 어려움이 적지 않다. 특히 많은 균종중에서 병원감염의 문제가 되고 있고 포도상구균에 대한 내성빈도는 환자치료에 중요하다고 판단된다. 따라서, 1992년 12월부터 1993년 2월 사이에 서울대 병원에 내원(來院)한 환자로부터 총 108주의 포도상구균을 분양 받아 항균제 내성검사를 실시하였고 황색포도상구균의 경우는 β-lactamase 생산유무 확인 및 methicillin에 대한 MIC 농도를 비교하였으며, methicillin에 대하여 각기 다른 MIC농도를 갖는 균종에 대한 substrate 분해능 검사를 실시하여 다음과 같은 결론을 얻었다 (1). 항균제 내성검사를 실시한 108주의 포도상구균은 penicillin에 가장 높은 내성을 나타냈다. 황색포도상 구균의 경우는 97%, 표피포도상 구균의 경우 100%, coagulase 음성포도상구균의 경우 95.7%로 나타났다 (2). vancomycin의 경우는 전 균주가 감수성을 나타냈다 (3). methicillin에 대한 내성율은 41.4%로 나타났다. 이 내성균주들은 10가지 검사 항생제중 최고 9가지에 대한 항균제 내성을 나타내어 다약제 내성임을 알 수 있었다 (4). β-lactamase 생산 실험에서는 58균주의 황색포도상 구균중 53주가 양성을 나타내어 91.4%의 결과를 얻었다. β-lactamase 생산균주와 methicillin에 대한 내성균주가 반드시 일치하지는 않았다 (5). Spectrophotometric assay에서는 내성이 높은 균주와 낮은 균주간에 β-lactamase에 의한 substrate 분해능이 서로 유사하게 나와 황색포도상 구균의 methicililin에 대한 내성 획득은 β-lactamase 뿐만이 아닌 penicillin binding protein(PBP)의 구조적 변화로 인한 내성획득도 시사함을 알 수 있다. One hundred and eight Staphylococcus aureus strains were isolated from patients of Seoul National University Hospital from December 1992 to Feburary 1993. All strains were tested for their sensitivities against antibiotics. β-lactamse producing test was also performed in order to know the relationship between the methicillin resistance and β-lactamase production. Its activity was determined by direct spectrophotometric method. Initial velocities of hydrolysis of the antibiotics were monitored at wavelength 323 nm which corresponded to maximal change in absorbance between the unhydrolyzed substrate and the hydrolyzed product. The results are summarized as follows: 1. In antibiotics sensitivity test of 108 isolated strains of Staphylococcus, they showed hightest resistance to penicillin but all of tested strains were susceptible to vancomycin. 2. 41.4% of them showed resistance to methicillin. 3. All methicillin resistant strains were found to be multi-drug resistant, from 3 to 9 antibiotics. 4. 91.4%(53 out of 58) produced β-lactamase, β-lactamase producing strains did not always coincide with the methicillin resistant strains. 5. β-lactamase activities were similar among staphylococus strains, irrespective of their methicillin resistance.

VP-16으로 성공적으로 치료된 위 Kaposi 육종 1예

양웅석,송근암,조몽,이재승,송철수,김형욱,김영민,이수봉,김태오,이성훈 대한소화기내시경학회 1999 Clinical Endoscopy Vol.19 No.4

The skin is an uncommon site of distant metastasis from any internal malignancy, and the incidence of metastatic skin lesions as the first symptom of disease is only 0.8% in patients with all systemic malignancies. Furthermore, cutaneous metastasis from adenocarcinoma of the stomach has been found to be extremely rare. A 35-year-old female patient was admitted due to multiple cutaneous nodules in her chest, abdomen, and back. A gastroendoscopic examination and biopsy was made according to the results of skin pathologic findings. Stomach and skin biopsy results revealed a signet ring cell type of adenocarcinoma. A case of gastric adenocarcinoma in which metastatic skin nodules appeared as the first sign of disease, is here in reported with a review of related literature.

Global-MAHN에서 라우팅 오버헤드 개선에 대한 연구

張良根,金玄旭,李光培,吳世德,裵振勝,金在浩 明知大學校 産業技術硏究所 2007 産業技術硏究所論文集 Vol.26 No.-

In this Paper, we studied the mechanism that increases the network reliability and decreases network load in GMAHN environment based on the AODV routing protocol. This proposed algorithm is the research on the algorithm, minimizing network overhead by preventing unnecessary network overhead previously and adapting Local repair mechanism to efficient data transmission when route error happens in network, in GMAHN environment. To evaluate the proposed algorithm's performance, we analyzed the proposed algorithm and adapting in various experiment environment according to 5 experiment viewpoint such as node movement, gateway network zone, mobile node number, flow number. After evaluating the experiment, we confirmed better network improvement altogether through following result such as total average data reception rate's increase, average data transmission time's decrease, network overhead's decrease than existing GMAHN algorithm.

원추형 회전체-자기베어링의 능동 진동 제어

석창욱,양승준,곽병철,이재응 중앙대학교 기술과학연구소 2000 기술과학연구소 논문집 Vol.30 No.-

기존 접촉식 베어링과 비교할 때 능동 자기 베어링(AMB)는 많은 장점을 가진다. 자기 베어링 시스템은 주축을 자기력을 이용하여 부상시켜 기계적인 마찰이 없는 상태에서 회전시키기 때문에 윤활을 하지않고도 작동시킬 수 있다. 따라서 이 베어링은 우주에서의 진공상태와 같은 극한상황에서도 사용할 수 있다. 특히 원추형 자기 베어링은 4조의 전자석으로 구성되어 래디얼 타입 자기 베어링보다 소형, 경량화할 수 있는 장점을 가진다. 본 논문에서는 먼저 원추형 자기베어링에 대한 운동방정식을 유도하고, 이 시스템의 진동 제어를 위해 비연성인 디지털 PD, PID 제어기를 설계하였다. 컴퓨터 모의실험을 통해 제어기의 성능을 평가하여 만족할 만한 성능을 얻었다. There are many advantages of the Active Magnetic Bearing(AMB) system, compared with conventional contacting bearing systems. Since the spindle in the AMB system is levitated by electro-magnetic forces and rotates without mechanical friction, it can run without lubrication. So, it can run in the extreme circumstances, e.g. a vacuum condition in the space. Particularly, the cone-type AMB system consists of only 4 couples of magnet, it can be smaller and lighter than radial-type AMB system. In this thesis, the equations of motion of the cone-type AMB system is derived first, and the digital PD and PID controllers are designed for the vibration control of the system. The controllers are designed based on the decoupled equations of motion, and the performance of the controllers are evaluated through the computer simulations. The results of the simulation show good performance of the controllers.

발열을 동반한 호중구감소증에서 Cefepime 단독투여와 Ceftazidime 및 Tobramycin 병합투여의 효능비교

정현욱,채제욱,강미라,양정채,문치숙,기현균,장현하,오원섭,김기현,백경란,이남용,송재훈 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내에서 발열을 동반한 호중구감소증이 있는 악성 종양환자에게 경험적 항생제로 베타락탐계 항생제와 아미노배당체의 병합요법의 사용이 일반적이다. Cefepime은 광범위 항균 작용을 가지고 있어, 그람 음성균 뿐만 아니라 그람 양성균에 대해서도 우수한 효과를 나타낸다. 재료 및 방법: 발열을 동반한 호중구감소증이 있는 악성 종양환자를 대상으로 무작위, 공개, 비교 연구를 시행하였다. 대상 환자를 무작위로 cefepime 단독요법군과 ceftazidime 및 tobramycin 병합요법군으로 나누어 투여하고 각각의 임상적 효능과 안전성을 비교하였다. 구강및 인후 점막염이 있는 환자에서 분리된 녹색 연쇄알 구균에 대한 항생제 내성 정도를 조사하였다. 결과 : 대상환자 89명 중 CA 투여군이 48예(53.9%), CT 투여군이 41예(46.1%)이었다. 발열의 유형별로 MDI는 18예(20.2%), CDI는 9예(10.1%), UF는 62예(69.7%)로 두 군 간에 차이가 없었다. CA 투여군과 CT 투여군의 임상적 호전률은 시험약 투여 후 2-4일째 각각 91.7%, 85.4% (P=0.31), 치료 종료 시 각각 91.7%, 100% (P=0.15)로 두 군간에 유의한 차이가 없었다. 치료 종료 시 CA 투여군과 CT 투여군의 세균학적 소실률은 모두 100%로 두 군간의 유의한 차이가 없었다(P=0.78). 점막염이 있는 환자로부터 녹색 연쇄알 구균이 분리된 경우는 25예(28.1%)이었으며, 분리된 녹색 연쇄알 구균은 penicillin, ceftriaxone, cefepime, vancomycin에 모두 감수성을 보였다. 약제 관련 이상 반응의 발생 빈도도 두 군간에 유의한 차이가 없었다. 결론 : 발열을 동반한 호중구감소증이 있는 악성 종양환자의 경험적 항생제로서 cefepime 단독요법은 ceftazidime 및 아미노배당체의 병합요법만큼 효과적이고 안전하였다. Background : Broad-spectrum antibiotic therapy has been recommended as an empirical regimen in cancer patients with febrile neutropenia. Cefepime is a fourth generation cephalosporin with good activity against both gram-positive cocci and gram-negative bacilli. Materials and Methods : To compare the efficacy and safety of cefepime alone with ceftazidime plus tobramycin as empirical regimen for adult cancer patients with febrile neutropenia, a randomized, open label, comparative trial was performed. If the patient showed clinical improvent 72 hours, antibiotic could be changed to oral ciprofloxacin. Clinical and microbiological responses were determined at 72 hours and at the end of therapy. To investigate the antimicrobial resistance of viridans streptococci, swab cultures were obtained from throat in all enrolled patients and antimicrobial susceptibility tests were performed by using microdilution method according to the NCCLS. Results : A total of 89 patients were enrolled. Forty-eight patients received cefepime alone (CA), and 41 patients received ceftazidime plus tobramycin (CT). Demographic and baseline clinical characteristics were similar in both groups (P>0.05). The initial clinical success rate at day 2-4 in group CA (91.7%) was similar with that in CT group (85.4%) (P=0.31). At the end of therapy, the final clinical success rate in CA group (91.7%) was similar to that in CT group (100%) (P=0.15). In 18 patients, with microbiologically defined infections, the eradication rate was 100% in both groups. Adverse events including liver dysfunction (21.3%) and renal dysfunction (2.2%), were similar in both groups (P=0.87). Viridans streptococci were isolated from the throat cultures in 25 cases, and all of these strains were susceptible to penicillin (MIC_(90) 0.12 ㎍/mL), cefepime (1 ㎍/mL), and vancomycin (0.12 ㎍/mL). Conclusion : Efficacy and safety of cefepime monotherapy was comparable to the combination of ceftazidime and tobramycin. It could be used as an alternative empirical regimen for treating cancer patients with febrile neutropenia.

내시경적 점막절제술로 치험한 식도 과립상 세포종 1례

강혁주,김성욱,최석진,이중현,장재식,서영범,윤병구,박건욱,김성자,김용섭,강승완,이구,양창헌,이창우,김욱년,이광헌,서정일 동국대학교 의학연구소 2000 東國醫學 Vol.7 No.-

과립상 세포종은 Schwann 세포 기원으로 생각되며 인체에 비교적 드물게 발생한다. 과립상 세포종은 전신 어느 곳에서나 발견될 수 있으나 주로 혀, 구강, 피부 혹은 유방 등에서 호발하며 드물게 위장관에서 발견된다. 위장관에서는 식도에서 가장 호발하며 다음으로 위, 대장 순이다. 과립상 세포종은 대부분, 특히 위장관에서는 양성이며 소수의 악성 병변이 보고되었다. 이러한 이유와 함께 수술 전의 진단이 어렵기 때문에 과립상 세포종에 대한 근본적인 치료는 현재까지 외과적 절제술이다. 최근에 시도되는 치료방법들로는 내시경적 레이저 치료, 용종절제술, 내시경적 점막 절제술 등이 있다. 저자들은 상부 소화관 내시경검사를 시행하여 식도 과립상 세포종을 진단하고 내시경적 점막 절제술을 시행하여 합병증 없이 퇴원하여 현재 재발없이 경과 관찰중인 1례를 경험하였기에 보고하는 바이다. Granular cell tumors, which occur infrequently, are probably of Schwann cell origin. They can occur almost anywhere in the body but usually affect the tongue, oral cavity, skin, or breasts and are rarely found in the gastrointestinal tracts. The esophagus is the most frequent gastrointestinal site, followed by the stomach and the colon. Granular cell tumors are generally benign, especially in the gastrointestinal tract, some malignant lesions have been reported. For this reason, and also because preoperative diagnosis is difficult, the standard treatment for granular cell tumor has until now been surgical excision. In recent years, other therapeutic methods is endoscopic laser therapy (ELT), polypectiomy, endoscopic mucosal resection (EMR). We report a case of esophageal granular cell tumor which was diagnosed by an endoscopy and managed using an endoscopic mucosal resection without complication.

Sound Analysis in an In Vitro Endotracheal Tube Model

( Young Sik Park ),( Young Wook Kee ),( Kwang Suk Park ),( Jin Woo Lee ),( Sang Min Lee ),( Jae Joon Yim ),( Chul Gyu Yoo ),( Young Whan Kim ),( Sung Koo Han ),( Seok Chul Yang1 ) 대한내과학회 2011 The Korean Journal of Internal Medicine Vol.26 No.4

Background/Aims: Complete endotracheal tube obstruction is a medical emergency, and partial occlusion causes increased breathing rates and failure to wean off mechanical ventilation. Partial occlusion may be underestimated due to the lack of proper detection methods. We tested whether the sound of an endotracheal tube could be used to detect an endotracheal tube obstruction using an in vitro model. Methods: An endotracheal tube was connected to a ventilator on one end and a test lung on the other. Sounds were recorded with a microphone located inside the endotracheal tube via a connector. During mechanical ventilation, we changed the endotracheal tube internal diameter from 5.0 to 8.0 mm and different grades of obstruction at different sites were used along the tube. Sound energy was compared among the different conditions. Results: The energy of endotracheal tube sounds was positively correlated with the internal diameter and negatively correlated with the degree of obstruction. The rate of decline in energy differed with obstruction location. When the obstruction was more distal, the rate of decline in endotracheal sound energy was more rapid. Conclusions: Changes in the sound of an endotracheal tube can be used to detect an obstruction. Further studies are needed for clinical application.

고빌리루빈혈증을 동반한 자가면역성 간염 1례

서영범,김성욱,장재식,강혁주,이중현,윤병구,김욱년,이광헌,이구,유석동,양창헌,이정호,이영현,이창우,서정일 동국대학교 의학연구소 2000 東國醫學 Vol.7 No.-

자가면역성 간염은 대개 만성 경과를 가지며, 혈중 자가면역항체와 혈청 글로불린치의 상승, 그리고 조직학적으로 괴사 염증성 변화를 특징으로 하는 질환으로 아직 정확한 병인이 밝혀져 있지 않은 상태이다. 발병연령은 대개 젊은 영자(15-25세)에서 호발한다. 이 질환은 급성 간염의 임상경과를 보일 수 있으나, 심한 급성 간염이나 전격성 간염으로도 나타날 수 있는데, 이 경우 아주 나쁜 예후를 보인다고 한다. 치료는 자가면역성 간염 임상 경과의 다양성이나 병인, 병리기전의 불확실성에도 불구하고 대개 steroid 치료에 반응하는 것으로 알려져 있으며 대개 80%의 관해율을 나타내며 궁극적으로 간경변으로의 진행을 막을 수 있는 것으로 보인다. 저자들은 58세 남자에서 발생한 급성의 경과를 가지고 심한 황달을 동반한 자가면역성 간염을 경험하였기에 문헌고찰과 함께 보고하는 바이다. Autoimmune hepatitis (AIH) is a chronic necroinflammatory liver disorder of unknown cause associated with circulating autoantibodies and a high serum globulin level. The age of onset of AIH show a peak between the age of 15 and 25 years. AIH can develop and be manifested as acute hepatitis, but severe form of acute hepatitis or fulminant hepatic failure has a poor prognosis. Although AIH is likely to progress from chronic active hepatitis to cirrhosis, steroid therapy can control the disease activity, prolong survival, improve the quality of life , and defer liver transplantation. In the present report we describe a 58-year-old man who admitted because of progressive jaundice and fatigue. He was diagnosed with AIH from laboratory test result showing positivity for antinuclear antibodies, anti-smooth muscle antibodies, and negativity for hepatitis viral markers and from liver biopsy. Steroid therapy, oral administration of prednisolone, was effective in improving the liver function test. Following liver biopsy 6 months after onset shows markedly improved necroinflammatory activity.

흉골골절이 의심되는 외상환자에서 초음파의 진단적 효용성

염석란,김재광,이근,박철완,양혁준,현성열,임용수,진욱 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Purpose: This study compared the value of ultrasonography(US) in the diagnosis of sternal fractures with those of conventional radiography and bone scan. Material and Method: From March 2000 to March 2001, in Gil Medical Center, Gachon Medical College, 44 patients(22 women and 22 men, mean age 46 years, range 5∼81 years) complained of tenderness in the sternal area. The cases histories of these patients with clinically suspected sternal fracture due to blunt trauma were prospectively studied. At the time of admission, conventional radiography(sternal view) was done. At one day after admission, sternal ultrasonography was obtained, and after 4∼5 days, a bone scan was done. Sternal ultrasonographic findings, conventional radiographic findings, and bone-scan findings were compared. In addition, a 12-lead ECG was done. When it was necessary, cardiac enzyme was checked and echocardiography was performed. Result: In 21 of 44 patients(48%), a sternal fracture was found by sternal US. Only 9 of 21 patients (43%) were diagnosed as having a sternal fracture by using conventional radiography. 23 of 44 patients (52%) have negative findings on sternal US; they also had negative findings on conventional radiography. Except for 7 unchecked patients, 13 of 21 patients(62%) were diagnosed as having a sternal fracture by bone scan, and among the 23 patients who had negative findings on sternal US, the 19 patients checked with a bone scan also had negative findings. Conclusion: Sternal US can find sternal fractures that are difficult to find on conventional radiography. Compared with bone scan, sternal US takes a shorter time and sternal US is not difficult. Additionally, combined lesions with sternal fractures(peristernal hematoma, soft tissue swelling) and costar cartilage fractures are diagnosed more easily when using sternal US.

GMAHN 환경에서의 TCP 프로토콜 성능 분석

吳世德,金玄旭,李光培,張良根,裵振勝,金在浩 明知大學校 産業技術硏究所 2007 産業技術硏究所論文集 Vol.26 No.-

Recently, GMAHN that provides interface between MANET and Wired Network has been focused in Mobile Communication. It is necessary that The technology provide reliable data transmission technology between mobile node and wired network in MANET environment that varing by the node movement. In this paper, using the TCP protocol(Tahoe, Reno, Vegas, SACK)that increases reliability between source and destination, we applied the TCP protocol mechanism to various environment, and compared result, and also proposed the efficient TCP mechanism by comparing each mechanism.