회원작품 - 안녕, 김녕SEA

허동호,Hur, Dongho 대한건축사협회 2022 建築士 Vol.635 No.-

Development and implementation of standardized method for detecting immunogenicity of acellular pertussis vaccines in Korea

박철민,허동호,한승범,최기섭,강규리,김지안,강진한 대한백신학회 2019 Clinical and Experimental Vaccine Research Vol.8 No.1

Purpose: There is no standard method for confirming the immunogenicity of acellular pertussis vaccines. We tried to develop a local standard method for evaluating the immunogenicity of the three-component of acellular pertussis vaccines which was developed by a Korean local company. Materials and Methods: The developed pertussis antigens (pertussis toxin, filamentous hemagglutinin, pertactin) were evaluated by in-house enzyme-linked immunosorbent assay (ELISA) using 189 negative sera, 25 positive sera, and 73 paired sera (pre- and post-Tdap [tetanus, diphtheria, and acellular pertussis] vaccinated sera). ELISA units were calculated by the reference line method, compared with World Health Organization reference sera, and the cutoff value was calculated using negative sera. Results: When compared to National Institute for Biological Standards and Control control antigen (NIBSC) control antigens, the developed pertussis toxin (PT) and filamentous haemagglutinin (FHA) antigens were 203.48 and 61.60 IU/μg, respectively. Each in-house ELISA was established by validating the coefficients of variation % (PT, 11.53%; FHA, 8.60%; pertactin [PRN], 9.86%) obtained from the results of inter- and intra-assay variation. Also, the cut-off values of PT, FHA, and PRN were 11.65, 38.95, and 5.66 EU/mL, respectively. The distributions of antibody levels in paired showed that 93.15% (68/73) in anti-PT IgG, 97.26% (72/73) in anti-FHA IgG, and 100% in anti-PRN IgG were higher than a 100% increase after vaccination. Additionally, the values of 89.04% (65/73) in anti-PT IgG, 97.26% (72/73) in anti-FHA IgG, and 100% in anti-PRN IgG were below each cut-off point. Conclusion: We established an in-house ELISA method using self-developed antigens, and these immunoassays have provided a way to standardize measuring the immunogenicity of newly developed vaccines, through single- and dual-serology.

개선된 교통 신호 제어시스템 설계에 관한 연구

김대성,허광선,권민수,곽동호,원충상 忠州大學校 2010 한국교통대학교 논문집 Vol.45 No.-

There are various ways to operate traffic light system by varying the operational speed of the system. One of the solutions is to vary the length of the clock cycle of the system. It is difficult to vary the length of the signal in systems by varying the period of the clock cycle and nor it is a generalized technology in the current traffic systems. The traffic signal systems of the past used is simply a repetitive traffic signal system which traffic period is consistent, not considering the conditions of traffics. The system that will be introduced in this thesis could substantially improve efficiency of traffic flows by varying the length of traffic signal period with sensors which detect the presence of vehicles on both directions and allows the signal continuously on the direction where there are more waiting vehicles, and even skips the signal where there is no vehicle waiting. In this thesis, it introduces the methodology of detecting the spots that is detected by the sensors of the system and outputs green light in due order in accordance with the priority given to the system. In the meanwhile, the ratio of yellow light and green light is designed to be 1 to 8 in the way that maximizes the efficiency of traffic flows.

β-Lactamase의 역학과 응용

유진홍,허동호,신완식 대한화학요법학회 1993 대한화학요법학회지 Vol.11 No.2

지금까지 β-lactamase의 효소 역학과 이의 응용에 대하여 간략하게 기술하였다. 이는 Michaelis-Menten 이론을 기반으로 효소 역학적으로 접근함으로써 β-lactamase와 항생제간의 관계 및 β-lactamase 억제제의 효과에 대하여 분석하는 또 하나의 시각으로서 의의가 있을 것으로 생각된다.

세균의 분자역학적 형별

유진홍,허동호,신완식 대한감염학회 1994 감염 Vol.26 No.4

Characterization of a Constitutive β-Lactamase from a Pseudomonas aeruginosa

유진홍,허동호,최정현,김양리,신원식,강문원 대한화학요법학회 1996 대한화학요법학회지 Vol.14 No.2

Objective : We analyzed some physicochermical chracteristics of a constitutive β-lactamase from a clinical isolate of a Pseudomonas aeruginosa which resistant to various β-lactams except imipenem and susceptible to aminoglycosides the proportion of its contribution to such resistance profile. Method : 1. Antimicrobial susceptibility test was done by the broth dilution method. 2. In hibition profile was done using EDTA, HgCl₂ and p-chloromercuribenzoate (pCMB). We also measured 50% inhibitory concentration(IC??) using β-lactamase inhibitors, such as clavulanic acid, sulbactam. 3. Kinetics study for substrate profile was performed by spectrophotometric assay using crude extracts and various antimicrobial agents. Relative hydropysis rates were determined. 4. The isoelectric point(pI) was determined by isoelectric focusing. The molecular weight was estimated by SDS-polycrylamide gel electrophoresis. Results : 1. The strain was resistant to ceftriaxone, sulperazon, piperacillin, ceftazidime, and aztreonam, while it was susceptible to gontamicin, tobramycin, amikacin and imipenem. 2. The β-lactamase was not inhibited by EDTA, and pCMB, whereas it was inhibited by HgCI₂. The IC?? of clavulanic acid was over 100μM and that of sulbactam was 22μM. 3. The relative maximal hydrolysis rate was calculated by setting V_(max) for cephaloridine at 100. The enzyme hydrolyzed cephalosporins more rapidly than penicillins. 4. The pI was 9.3 by isoelectric focusing. The molecular weight was estimated to be 40kDa. Conclusion : According to its substrate profile, pI and molecular weight, the β-lactamase from a clinical isolate of P. aeruginosa was a cephalosporinase belonging to group 1 in the Bush-Jacoby-Medeiros classification scheme.

항균제의 약동학/약력학

이동건,허동호,신완식 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

약동학 (pharmacokinetics)이란 약물의 흡수, 분포, 생체 내 변화 및 배설을 연구하는 분야이며 약력학 (pharmacodynamics)은 생체에 대한 약물의 생리학적 및 생화학적 작용과 그 작용기전, 즉 약물이 일으키는 생체의 반응을 주로 연구하는 분야이다. 항균제에서의 약동학은 감염부위에서 시간에 따른 약물의 농도를 다루고 약력학은 항균제의 농도와 항균력과의 관계를 주로 다룬다. 본 종설에서는 약동학, 약력학에 대한 기본적인 개념과 항균제의 항균능력을 평가하는 여러 지표에 대한 해설과 이 지표들을 실제 임상에서 항균제의 효율적인 투여에 어떻게 응용하는지에 대해 기술하고자 한다.

Klebsiella pneumoniae 표준균주에 대한 Ceftriaxone과 Amikacin의 단독 및 병용요법의 Postantibiotic Effect

이동건,허동호,최정현,유진홍,강문원,신완식,Lee, Dong-Gun,Huh, Dong-Ho,Choi, Jung-Hyun,Yoo, Jin-Hong,Kang, Moon-Won,Shin, Wan-Shik 대한임상약리학회 1999 臨床藥理學會誌 Vol.7 No.1

연구배경 및 방법 : PAE는 세균을 항생제에 제한된 시간 동안 노출시키고 항생제를 제거한 후에도 세균의 성장은 계속 억제되는 현상을 말하며 항생제의 효과는 항생제가 제거된 후에도 일정기간동안 유지되는 것으로 항생제 투여횟수, 시기 등을 결정하는데 중요한 요소로 알려져 있다. 그러나, 항생제와 균의 종류, 농도, 실험조건 둥에 따라 PAE가 다르고 그 길이가 측정하는 방법에 따라 많은 차이가 있다. 특히, 그람음성균에 ${\beta}$-lactam 항생제에 노출되었을 때의 PAE는 정도의 차이가 아닌 그 존재의 유무에 대해서조차 논란이 있는 실정이다. 또한, 그람음성균에 ${\beta}$-lactam과 aminoglycoside를 병용할 때 PAE가 상승작용이 있는지에 대해서도 논란이 있다. 저자들은 K. pneumoniae를 대상으로 ceftriaxone과 amikacin을 병용하였을 때 PAE가 있는지 알아보기 위하여 전통적인 집락수 측정법과 BACTEC 혈액배양법을 사용하고 이를 비교하였고 병용시 상승작용이 있는지 알아보았다. 결 과: (1) K. pneumoniae에 대한 ceftriaxone과 amikacin의 상승작용을 disk diffusion 방법, checkerboard 방법, time-kill curve 및 E-test 등을 이용하여 확인한 결과 무작용의 상관관계를 보였다. (2) 1배 MIC $(0.03\;{\mu}/mL)$의 ceftriaxone에서 집락 수 측정법으로 측정한 PAE는 -0.4시간이었으나, 4배 MIC $(4\;{\mu}/mL)$의 amikacin에서는 2.7시간의 PAE를 나타냈다. (3) 다양한 농도의 ciprofloxacin에 2시간 동안 노출시킨후 집락수 (y)와 BACTEC 혈액배양기의 GV (x)는 log y=0.0514x+4의 관계가 있었으며(r=0.88, p<0.0001), 이를 이용해 ceftriaxone의 PAE를 보정한 결과 0시간으로 정정되었다. (4) ceftriaxone과 amikacin을 병용하였을때 집락수 측정법에 의한 PAE는 3.4시간으로 상가작용을 보였다. 결 론: (1) BACTEC 혈액배양법을 이용한 PAE의 측정결과 K. pneumoniae에 대한 ceftriaxone의 PAE는 집락수 측정법에 의해 과소평가 되어있음이 확인되었고 실제적으로는 PAE를 나타내지 않았다. (2) ceftriaxone이 PAE가 없는 이유는 filament를 형성하기 때문이 아니고 본래 PAE가 없는 것으로 추론된다. Introduction & Methods : The postantibiotic effect (PAE) refers to a suppression of bacterial growth that persists after limited exposure of organisms to antimicrobial agents. The major clinical relevance of the PAE pertains to its impact on antimicrobial dose and dosing interval. There is a method-to-method variation in determination of PAE. In case of Gram negative organisms, ${\beta}$-lactams do not demonstrate PAE on the basis of viable count method, a conventional standard. However, as several Gram negative organisms aggregate to form a filament after exposure to ${\beta}$-lactams, the number of colony may not be precisely counted. To overcome this problem, we also used another indicator of assessing PAE-i.e., growth value which represents $CO_2$ generation from colony. In this study, PAE of ceftriaxone alone and in combination with amikacin were determined for the standard strain of K. pneumoniae using viable counting method and BACTEC blood culture system. Results : (1) Using the disk diffusion method, the checkerboard method, the time kill method and the E-test, we could not find synergistic effects with ceftriaxone and amikacin against K. pneumoniae. (2) On the basis of the viable counting method, PAE of ceftriaxone $({\times}1\;MIC,\;0.03\;{\mu}g/mL)$ was negative (-0.4 hours) and that of amikacin $({\times}4\;MIC,\;4\;{\mu}g/mL)$ was 2.7 hours. (3) Following 2-hour exposure to ciprofloxacin at various concentration, the correlation between the cell count (y) and GV (x) measured by BACTEC blood culture system was significantly high (log y=0.0514x+4, r=0.88, p<0.0001). Although recalculating the PAE of ceftriaxone using the above curve, the subsequently corrected PAE value was 0 hour. (4) The ceftriaxone-amikacin combination caused additive effect for PAE against K. pneumoniae compared with the PAE observed after ceftriaxone or amikacin alone measured by the viable counting method. Discussion : (1) Although it is evident that the viable count method underestimated the PAE of ${\beta}$-lactams agianst K. pneumoniae, PAE was absent in spite of correction by BACTEC blood culture system. (2) It may be possible the ceftriaxone does show no PAE against K. pneumoniae naturally not because of filament formation.

Enzyme-linked immunosorbent assay for detecting anti-pertussis toxin antibody in mouse

최기섭,허동호,한승범,안동호,강규리,김지안,최보미,김혜련,강진한 대한백신학회 2019 Clinical and Experimental Vaccine Research Vol.8 No.1

Purpose: Although the DTaP and Tdap vaccines used to prevent pertussis have been used for a long time, there is no standard method for measuring pertussis antigens. Therefore, this preliminary study was conducted to develop an enzyme-linked immunosorbent assay method using an animal model for measuring antibodies against pertussis toxin, the most important pertussis pathogenic antigen, in the sera of vaccinated mice. Materials and Methods: Bordetella pertussis Tohama phase I was cultured for 24-30 hours, and then pertussis toxin was purified from the culture medium by chromatography. Purified pertussis toxin was diluted in phosphate-buffered saline-coating buffer, and 100 µL of diluted pertussis toxin was added to each well and reacted at room temperature for 4 hours. Positive serum was diluted to 1/1,250-1/80,000 and negative serum was diluted to 1/50 to determine the coating concentration with the optimal signal/noise ratio. Optimal test conditions were confirmed from the dilution factors of the secondary antibody and streptavidin horseradish peroxidase (SA-HRP). Results: Optimal conditions were as follows: 4 µg/mL for coating antigen; 1/40,000 for secondary antibody; and 1/1,000 for the SA-HRP dilution factor. Comparison of the sera obtained from mice treated with a developing vaccine and commercial vaccine with National Institute for Biological Standard and Control standard serum under the established conditions showed the following results: 1,300.62, 534.94, and 34.85, respectively. Conclusion: The method developed in this study is suitable for measuring anti-pertussis toxin antibodies and may be applicable for clinical sample analysis or indirect diagnosis of pertussis.

Staphylococcus aureus와 Coagulase-Negative Staphylococcus Species에 대한 Arbekacin의 시험관내 항균력

위성헌,강진한,허동호,이동건,김상일,김양리,최정현,김종현,유진흥,허재균,신완식,강문원 대한감염학회 2001 감염 Vol.33 No.4

Background : Most strains of methicillin-resistant Staphylococcus aureus (MRSA) now exhibit high-level resistance to various antibiotics, such as β -lactam antibiotics, aminoglycosides, macrolides, tetracyclines and quinolones. Recent reports describing the therapeutic failure of vancomycin for MRSA infections have arisen considerable concerns regarding the emergence of MRSA strains, which will require new therapeutic agents. Arbekacin, an aminoglycoside antibiotic, has antibacterial activity against both gram-positive and gram-negative bacteria and is stable in the presence of aminoglycoside inactivating enzymes produced by S. aureus. In this study, we compared the antibacterial activity of arbekacin with those of vancomycin, gentamicin, and amikacin against Staphylococcus aureus (S. aureus) and coagulase-negative staphylococci (CNS). Methods : For a collection of 549 S. aureus and 251 CNS isolates from three Catholic University Hospitals in Korea, minimum inhibitory concentrations (MICs) of arbekacin, vancomycin, amikacin and gentamicin were determined by agar dilution method using Mueller-Hinton agar according to NCCLS (National Committee for Clinical Laboratory Standards, USA)criteria. Results : Among 549 S. aureus isolates, 278 isolates were MRSA and 271 isolates were methicil sensitive S. aureus (MSSA). MIC50 & MIC90 of arbekacin against 549 S. aureus were 0.5 & 1 ㎍/mL, and MIC50 & MIC90 of vancomycin were 1 & 1 ㎍/mL. MIC of arbekacin against 549 S. aureus isolates ranges from 0.03 to 4 ㎍/mL, and MIC of vancomycin against 549 S. aureus ranges from 0.25 to 2 ㎍/mL. MIC90 of amikacin against 549 S. aureus was 32㎍/mL, and that of gentamicin was 128 ㎍/mL. MICs of amikacin and gentamicin were variable, ranging from 0.125 to 256, and otherwise arbekacin and vancomycin revealed relatively narrow range of MICs. MIC90 of arbekacin against 278 MRSA isolates & 271 MSSA were 1 & 0.5 ㎍/mL, and those of vancomycin against MRSA & MSSA were 1 & 1 ㎍/mL. MIC90 of amikacin against 278 MRSA & 271 MSSA isolates were 32 & 4 ㎍/mL, and that of gentamicin against MRSA & MSSA isolates were 128 & 32 ㎍/mL respectively. Among 251 CNS isolates, 122 isolates were MRCNS and 129 were MSCNS. MICSO & MIC90 of arbekacin against 251 CNS isolates were 0.25 & 2 ㎍/mL, and those of vancomycin were 1 & 2 ㎍/mL. MIC of arbekacin against 251 CNS isolates ranges from 0.015 to 32 ㎍/mL, and that of vancomycin isolates ranges from 0.25 to 2 ㎍/mL, MIC90 of arbekacin against 122 MRCNS & 129 MSCNS isolates were 2&0.3 ㎍/ML, and those of vancomycin were 2&s ㎍/ML. MIC90 of amikacin against 251 CNS isolates was 32 ㎍/ML, and that of gentamicin was 128 ㎍/ML for CNS. MIC90 of amikacin against 122 MRCNS & 129 MSCNS isolates were 128 & 8㎍/mL, and those of gentamicin ere 256 & 32 ㎍/mL. Conclusion : Considering above results, arbekacin can be useful agent against most strains of MRSA and MRCMS, which exhibit high-level resistance to amikacin and gentamicin. (Korea J Infect Dis 33:254~260, 2001)