• Analytical Science and Technology
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• v.23 no.2
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• pp.119-127
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• 2010

An effective method for the simultaneous analysis of ${\beta}$-lactams from surface water was established. After solid-phase extraction with HLB (Hydrophilic Lipohilic Balance) cartridge at pH 2, seven ${\beta}$-lactams (amoxicillin, ampicillin, penicillin G, cefaclor, cefadroxil, cefatrizine and cephradine) were determined using LC/ESI-MS/MS. In this newly established method, correlation coefficients ($r^2$) of calibration curves for seven ${\beta}$-lactams in blank surface water appeared to be 0.9911~0.9995 in the concentration range of 0.01~1.0 ng/mL. The limits of detection (LODs) and the limits of quantificaiton (LOQs) in spiked surface water were shown to be 0.0003~0.0234 ng/mL and 0.0046~0.0778 ng/mL, respectively. The developed method is believed to serve as a rapid and reliable method for the qualitative and quantitative analysis of residual ${\beta}$-lactam antibiotics from aquatic environment.

• Bioindustry News
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• v.11 no.2
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• pp.11-21
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• 1998

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.120-120
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• 1993

목적: Aminothiazole-oxime type의 세파로스 포린계 항생제가 개발되어 제3, 4세대 항생제로 쓰이고 있거나 개발중에 있다. 본 저자들은 pseudomonas균에도 항균력이 우수하고 $\beta$-Iactamase에도 안전하며 기존에 보고된 화합물 보다 개선된 약물을 찾으려는 시도에서 본 연구를 실시하였다. 방법: Cephem의 C-7위치에 aminothiazole methoximetype를 도입시키고C-3위치에 약리 활성이 기대되는 5-(aryl or hot.)-4-phony고-3-mercapto-4H-1,2,4-triazole 화합물들을 합성하여 도입시켜 gram(＋), gram(－) 및 fungus균에 대하여 항균력을 실험 하였다. 결과: 합성된 복합물들의 항균력 판정은 Pseudomonas균에는 항균력이 대조 물질 보다 떨어졌으나 몇몇균에 대해서는 대조물질과 비슷한 항균력을 나타내었다.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.109-116
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• 2011

Purpose : Pneumococcus is one of the most important causes of invasive infection through the childhood period. In January 2008, the Clinical and Laboratory Standards Institute (CLSI) published revised penicillin breakpoints for Streptococcus pneumoniae and penicillin susceptibility rates of S. pneumoniae increased in Korea. This study was performed to determine the probability of oral amoxicillin for the empirical treatment achieving bactericidal exposure against pneumococcus using pharmacodynamics model. Methods : Twenty-three isolates of pneumococci were subjected to determine minimum inhibitory concentration (MIC) for ${\beta}$-lactams and macrolide. For the ${\beta}$-lactams, exposure of fT >MIC (time that free drug concentrations remain above the MIC) for 50% of the administration interval have determined the probability of target attainment (PTA), and regimens that had a PTA >90% were considered optimal. An analysis was performed by applying MIC of 23 isolates to a 5000-patient Monte Carlo simulation model. Results : Among 23 isolates from healthy children, 7 (30.4%) isolates were MIC ${\leq}$1.0 ${\mu}g$/mL and 19 (82.6%) were MIC ${\leq}$2 ${\mu}g$/mL for amoxicillin. Amoxicillin 40 mg/kg/day achieved PTA >90% at MIC ${\leq}$1.0 ${\mu}g$/mL but PTA decreased to 52% at MIC 2 ${\mu}g$/mL, whereas amoxicillin 90 mg/kg/day can predict 97% of PTA at MIC 2 ${\mu}g$/mL. Overall, oral amoxicillin 90 mg/ kg/day for the empirical treatment against pneumococcus can expect more successful response in Korean children. Conclusion : Considering the resistantce pattern of pneumococci in Korean children, we estimate that oral amoxicillin 90 mg/kg/day will provide a pharmacodynamic advantage for the empirical treatment against pneumococcus. And low dose amoxicillin or macrolide are expected to have higher chance of treatment failure than high dose oral amoxicillin.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.286-288
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• 2018

Moraxella osloensis NP7 was isolated from human skin of a collage male and showed resistance to ${\beta}-lactam$ and aminoglycoside antibiotics. Herein, we report the complete whole-genome sequence and gene annotations of M. osloensis NP7. It possesses single circular chromosome and seven plasmids. Chromosome is 2,389,582 bp in length with the G + C content of 43.9% and encodes 2,065 protein-coding genes. The combined seven plasmids are 654,202 bp in size with the average G + C content of 40.5% and code for a total of 667 protein-coding genes. The chromosome of NP7 strain contains four ribosomal RNA operon copies, one transfer-messenger RNA gene, forty-seven tRNA genes, three riboswitch genes and three CRISPR arrays. Additional CRISPR array is found in the plasmid pNP7-1. The genes conferring resistance to ${\beta}-lactam$ and aminoglycoside antibiotics were predicted to reside in the plasmid pNP7-1.

• YAKHAK HOEJI
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• v.46 no.6
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• pp.387-391
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• 2002

In vitro $\beta$-lactamase inhibitory activity of 6-exomethylene sulbactam compounds (CH-120, 130, 140, 145, 150, 155) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of CH-140 was stronger than sulbactam and clavulanic acid against Type II, III, IV, TEM enzymes and stronger than tazobactam against Type IV enzyme. The inhibitory activity of CH-145 was stronger than sulbactam and clavulanic acid against Type I, II, III, IV, TEM enzymes and stronger than tazobactam against Type III, IV enzymes. The in vitro antimicrobial activity of CH-140 and CH-145 combined with piperacillin and ceftriaxone was compared with the sulbactam and tazobactam against $\beta$-lactamase producing 31 strains. But, synergistic activity of CH-140 and CH-145 was inferior to tazobactam.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.456-460
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• 2003

In vitro $\beta$-lactamase inhibitory activity of 6-exomethylenepenam compounds ( 1, 2, 3, 4 and 5) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of compound 3 was stronger than those of sulbactam and clavulanic acid against Type I and II enzymes and stronger than tazobactam against Type III, IV, TEM enzymes. The inhibitory activity of 5 was stronger than sulbactam and clavulanic acid against Type I and II enzymes and stronger than tazobactam against Type III, and IV enzymes. The in vitro antimicrobial activity of 3, 4 and 5 combined with ampicillin and cefoperazone was compared with the sulbactam against $\beta$-lactamase producing 27 strains. But, synergistic activity of 3 and 5 was inferior to tazobactam.

• YAKHAK HOEJI
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• v.52 no.4
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• pp.306-310
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• 2008

In vitro ${\beta}-lactamase$ inhibitory activity of 6-benzothiazole penicillins (1, 2, 3 and 4) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of exomethylene compounds (3 and 4) was stronger than those of non-exomethylene compounds (1 and 2). The sulfide 3 showed stronger inhibitory activity than sulbactam, clavulanic acid andsimilar to tazobactam against ${\beta}-lactamase$ Type I enzymes. The inhibitory activity of 4 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type III and IV enzymes. The in vitro antimicrobial activity of ampicillin or cefoperazone combined with 3 or 4 was stronger than those of ampicillin or cefoperazone alone against many ${\beta}-lactamase$ producing strains to show that compounds 3 and 4 have some synergistic effect. The synergistic activity of 3 and 4 was comparable to sulbactam in some ${\beta}-lactamase$ producing strains, but it was inferior to tazobactam.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.51-55
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• 2005

In vitro ${\beta}$-lactamase inhibitory activity of 6-triazole exomethylenepenam compounds (1, 2, 3, 4, 5 and 6) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of 3, 4 and 5 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type IV enzymes. And, inhibitory activity of 3 and 4 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type III enzymes. The in vitro antimicrobial activity of 3, 4 and 5 combined with ampicillin was better than those with sulbactam and with cefoperazone was compared with the sulbactam against ${\beta}$-lactamase producing 27 strains. The synergistic activity of (Z)-form compounds (3 and 5) was better than that of (E)-form compound (4) and sulfone compound (5) was better than sulfide compound (3).

• YAKHAK HOEJI
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• v.41 no.4
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• pp.462-472
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• 1997

In this approach, the antimicrobial activities of the compounds were compared with the ${\beta}$-lactam antibiotics against ${\beta}$-lactamase producing strains in vitro. Heteroc yclyl exomethylenepenam derivatives were several numbers of 6-exomethylenepenam sodiums (CH1240, CH1245, CH1250, CH2140, CH2145, CH2150). The inhibitory concentraion assay of six compounds were compared with clavulanic acid, sulbactam, tazobactam. Clavulanic acid, sulbactam and tazobactam are used as inhibitors of a variety of plasmid-mediated beta-lactamases. In vitro ${\beta}$-lactamase inhibitory assay, CH1240 and CH2140 were more active than clavulanic acid, sulbactam and tazobactam against ${\beta}$-lactamases overally. And in vitro comparative antimicrobial susceptibility test of six inhibitors were performed with mixed forms of ampicillin, cefotaxime, amoxicillin, ticarcillin, piperacillin, cefoperazone against ${\beta}$-lactamase producing 31 species strains. Consequently CH2140 and CH1240 among the six compounds enhanced the activity of the ${\beta}$-lactams for 31 ${\beta}$-lactamase producing strains.