• YAKHAK HOEJI
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• v.39 no.3
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• pp.223-230
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• 1995

The phannacokinetics and tissue distribution of DWQ-013, a new quinolone, were examined in rats and mice following a single intravenous and oral administration. DWQ-013 in plasma and urine was determined by both HPLC and microbiological assay. The plasma concentration of the drug declined biexponentially. The terminal half life of the drug was 11.11$\pm$0.14 hour after intravenous dosing. The volume of distribution at terminal elimination phase(Vd$_\beta$) and total clearance of the drug were 1.29$\pm$0.15 l/kg and 0.78$\pm$0.09 l/h/kg. The bioavailability of DWQ-013 after oral administration was 56.0% (HPLC) and 77.2%(bioassay), respectively. Twelve-hour urinary recovery of drug was measured by HPLC and bioassay to 0.035$\pm$0009% and 4.71$\pm$066% after oral dosing, to 0.055$\pm$0.014% and 7.65$\pm$1.53% after intravenous dosing, which may indicate the presence of biologically active metabolites. Binding of the drug to plasma proteins ranged from 97%~99% at various concentrations. The drug was highly distributed in order of liver, kidney and lung after 1.5 hours in mice.

• YAKHAK HOEJI
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• v.38 no.5
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• pp.586-594
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• 1994

The general pharmacological effects of DWQ-013, a new synthetic quinolone antibacterial agent, were examined on the central nervous system in experimentral animals and the following results were obtained. Drug interaction of DWQ-013 with theophylline, fenbufen and nonsteroidal antiinflammatory drugs was also examined. DWQ-013 decreased touch escape effect on the general behavior and decreased body temperature at a concentration of 1000 mg/kg in mice. But DWQ 013 had no effect on the locomotor activity, rotarod perfomance and traction test in mice. Furthermore, DWQ-013 increased pentobarbital-induced sleeping time and affected the onset time in acetic acid-induced writhing test in mice. DWQ-013 reduced onset time and death time on strychnine-induced convulsions and death time on pentylenetetrazole-induced convulsions at a concentration of 1000 mg/kg in mice. But, the drug had no effect on the electroshock. DWQ-013 did not interact with fenbufen and any other NSAIDs but it did interact with theophylline. From these results, it could be suggested that DWQ-013 had less pharmacological effect than other quinolones on the central nervous system.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.321-330
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• 1997

Enrofloxacin is one of the second-generation quinolones which have been widely used to treat bacterial infections in various species including chicken, pig, horse and cattle. The objective of the present study was to describe the serum bactericidal activity(SBA) of enrofloxacin, its pharmacokinetic behaviors after intramuscular or intravenous administration to Korean native goats in the dose rate of 5mg/kg b.w. The results obtained through this study were as follows : 1. Sera collected from both sexes of Korean native goats administered 5mg/kg i.v. or i.m. showed potent antibacterial activities up to the 12 hours by way of the serum bactericidal activity. 2. Concentrations of enrofloxacin in the biological samples were measured by high-performance liquid chromatography(HPLC) so as to study pharmacokinetic characteristics. For detection of enrofloxacin, 10% TCA was optimal for protein precipitation and the mobile phase was 0.01M citric acid/methanol/acetonitrile(7/2/1, pH 3.5) with solid phase being the $C_{18}$ reversephase column and detection wavelength being 278nm. The limit of detection of enrofloxacin on HPLC was $0.05{\mu}g/ml$. 3. Pharmacokinetic profile of enrofloxacin administered 5mg/kg i.v. in Korean native goats was best described by two-compartment open model and that administered i.m. the same rate by one-compartment model. There were no sex differences in pharmacokineticl parameters. In conclusion, enrofloxacin showed potent in vivo antibacterial activity and excellent pharmacokinetic properties in Korean native goats, hence it may be used as a potential antibacterial in the veterinary clinical settings.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1740-1745
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• 2004

In order to evaluate the in vitro synergic effect of Eunkyo-san, with quinolone antibiotics, rufloxacin (RUFX), the minimal inhibitory concentration (MIC), MIC50 and MIC90 of single use of quinolones and concomitant treatment with Eunkyo-san against 9 strains of aerobic gram positive bacteria. The obtained results were as follows : In the case of aerobic gram positive bacteria, the MIC, MIC50 and MIC90 against Staphylococcus aureus, Staphylococcus aureus smith, Staphylococcus epidermidis, Staphylococcus pyogens, Streptococcus pneumoniae Type Ⅰ, Type Ⅱ and Type Ⅲ was significantly decreased in concomitant treated groups with Eunkyo-san compared to those of single treated groups of RUFX, respectively. However, no significant changes were demonstrated against Bacillus subtilis and Enterococcus faecalis. In conclusion, the in vitro antibacterial activity of RUFX were increased against some strains of aerobic gram positive strains, especially, pneumococcus such as Staphylococcus and Streptococcus by concomitant use of Eunkyo-san.

• Biomolecules & Therapeutics
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• v.5 no.2
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• pp.187-193
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• 1997

The in vivo and in vivo antibacterial activity of DW-116, a newly synthesized fluoroquinolone, were compared with those of other quinolones. DW-116 exhibited more potent antibacterial activity than rufloxacin and lower activity than ofloxacin and ciprofloxacin in in vivo assay But, DW-116 particularly showed strong activity against the family of staphylococci including methicillin-sensitive staphylococcus and its activity was more active than that of ciprofloxacin. The time-kill curve studies showed rapid bactericidal activity for DW-116. The post-antibiotic effect of DW-116 was observed between 0.66 and 5 hours. The therapeutic efficacy of DW-116 against respiratory infection with P. aeruginosa was as strong as that of ciprofloxacin and its effect against urinary tract in(traction with E. coli was more effective than rufloxacin. The excellent therapeutic efficacy of DW-116 against these local infections is due to its good pharmacokinetic profiles.

• Korean Journal of Clinical Pharmacy
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• v.20 no.2
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• pp.145-150
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• 2010

In order to investigate the antibiotic prescription pattern for upper respiratory infections (URI), the prescription sheets for outpatients from July 2008 to June 2009 were collected from 7 community pharmacies in Ulsan City, and the prescription pattern of Pediatric and ENT physicians was analyzed. The antibiotic prescription rates of Pediatric and ENT physicians were 63.8% and 61.7%, respectively. It was also observed that the oral antibiotic prescription was 95.6% in Pediatrics and 97.6% in ENT. The most favorable antibiotics by Pediatric physicians were penicillins (21.5%) penicillin-clavulanate (36.4%) and cephalosporins (16.5%), macrolides (11.6%), quinolones (3.5%), and nifuroxazide (3.5%). In case of ENT, the commonly prescribed antibiotics were also penicillin-clavulanate (47.6%), cephalosporins (31.6%), macrolides (11.9%) and sulfonamide (1.3%). The antibiotic combination rate was 7.6% in Peditrics and 1.9% in ENT, among antibiotic prescriptions. The combination of more than two oral antibiotics was examined as 66.8% in Pediatrics and 44.2% in ENT. The common oral antibiotic combination in Pediatrics was prescriptions of two ${\beta}$-lactam antibiotics (54.3%). Among them 83% was the combination of amoxicillin-clavulanate (7:1) and amoxicillin, which could be judged as antibiotic overuse. The next highly prescribed oral antibiotic combination was ${\beta}$-lactam/macrolide antibiotic combination probably for URI (11.3%) and ${\beta}$-lactam/nifuroxazide combination (10.0%) presumably for acute diarrhea. Comparatively the oral antibiotic combination prescribed by ENT physicians was negligible except one physician. In conclusion, the antibiotic over-prescription rate by antibiotic combination was much higher in Pediatrics than ENT, even though both clinical departments showed nealy the similar antibiotic prescription rates.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.247-254
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• 2014

To investigate the acquisition of quinolone resistance, we examined mutations in the quinolone resistance-determining region (QRDR) of type II topoisomerase genes in ciprofloxacin (CIP)-resistant clinical isolates and in vitro mutants of Streptococcus parauberis. The CIP-resistant clinical isolates had one base change responsible for a Ser-79${\rightarrow}$Thr in the QRDR of parC. However, the CIP-resistant in vitro mutants had an altered QRDR of parC (Ser-79${\rightarrow}$Ile) that differed from that of the isolates. None of the CIP-resistant S. parauberis clinical isolates or in vitro mutants exhibited amino acid changes in gyrA or gyrB. However, even though involvement in the increased resistance was not clear, an Arg-449${\rightarrow}$Ser mutation outside of the QRDR of parE was detected in CIP-resistant mutant 2P1. These results suggest that the topoisomerase IV gene, parC (and possibly parE, as well), is the primary ciprofloxacin target in S. parauberis. Additionally we established a high-resolution melting (HRM) assay capable of detecting the dominant mutation in four type II topoisomerase genes conferring ciprofloxacin resistance. These rapid and reliable assays may provide a convenient method of surveillance for genetic mutations conferring antibiotic resistance.

• Journal of Microbiology
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• v.43 no.2
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• pp.133-143
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• 2005

Shigellosis is a global human health problem. Four species of Shigella i.e. S. dysenteriae, S. flexneri, S. boydii and S. sonnei are able to cause the disease. These species are subdivided into serotypes on the basis of O-specific polysaccharide of the LPS. Shigella dysenteriae type 1 produces severe disease and may be associated with life-threatening complications. The symptoms of shigellosis include diarrhoea and/or dysentery with frequent mucoid bloody stools, abdominal cramps and tenesmus. Shigella spp. cause dysentery by invading the colonic mucosa. Shigella bacteria multiply within colonic epithelial cells, cause cell death and spread laterally to infect and kill adjacent epithelial cells, causing mucosal ulceration, inflammation and bleeding. Transmission usually occurs via contaminated food and water or through person-to-person contact. Laboratory diagnosis is made by culturing the stool samples using selective/differential agar media. Shigella spp. are highly fragile organism and considerable care must be exercised in collecting faecal specimens, transporting them to the laboratories and in using appropriate media for isolation. Antimicrobial agents are the mainstay of therapy of all cases of shigellosis. Due to the global emergence of drug resistance, the choice of antimicrobial agents for treating shigellosis is limited. Although single dose of norfloxacin and ciprofloxacin has been shown to be effective, they are currently less effective against S. dysenteriae type 1 infection. Newer quinolones, cephalosporin derivatives, and azithromycin are the drug of choice. However, fluoroquinolone-resistant S. dysenteriae type 1 infection have been reported. Currently, no vaccines against Shigella infection exist. Both live and subunit parenteral vaccine candidates are under development. Because immunity to Shigella is serotype-specific, the priority is to develop vaccine against S. dysenteriae type 1 and S. flexneri type 2a. Shigella species are important pathogens responsible for diarrhoeal diseases and dysentery occurring all over the world. The morbidity and mortality due to shigellosis are especially high among children in developing countries. A recent review of literature (KotIoff et al.,1999) concluded that, of the estimated 165 million cases of Shigella diarrhoea that occur annually, $99\%$ occur in developing countries, and in developing countries $69\%$ of episodes occur in children under five years of age. Moreover, of the ca.1.1 million deaths attributed to Shigella infections in developing countries, $60\%$ of deaths occur in the under-five age group. Travellers from developed to developing regions and soldiers serving under field conditions are also at an increased risk to develop shigellosis.

• Clinical and Experimental Pediatrics
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• v.60 no.6
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• pp.167-174
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• 2017

Mycoplasma pneumoniae pneumonia (MPP) is one of the most common forms of community-acquired pneumonia in children and adolescents. Outbreaks of MPP occur in 3- to 7-year cycles worldwide; recent epidemics in Korea occurred in 2006-2007, 2011, and 2015-2016. Although MPP is known to be a mild, self-limiting disease with a good response to macrolides, it can also progress into a severe and fulminant disease. Notably, since 2000, the prevalence of macrolide-resistant MPP has rapidly increased, especially in Asian countries, recently reaching up to 80%-90%. Macrolide-resistant Mycoplasma pneumoniae (MRMP) harbors a point mutation in domain V of 23S rRNA with substitutions mainly detected at positions 2063 and 2064 of the sequence. The excessive use of macrolides may contribute to these mutations. MRMP can lead to clinically refractory pneumonia, showing no clinical or radiological response to macrolides, and can progress to severe and complicated pneumonia. Refractory MPP is characterized by an excessive immune response against the pathogen as well as direct injury caused by an increasing bacterial load. A change of antibiotics is recommended to reduce the bacterial load. Tetracyclines or quinolones can be alternatives for treating MRMP. Otherwise, corticosteroid or intravenous immunoglobulin can be added to the treatment regimen as immunomodulators to downregulate an excessive host immune reaction and alleviate immune-mediated pulmonary injury. However, the exact starting time point, dose, or duration of immunomodulators has not been established. This review focuses on the mechanism of resistance acquisition and treatment options for MRMP pneumonia.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.125-125
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• 1995

Quinolone계 항균제인 rufloxacin의 전임상시험의 일환으로 항원성 유발여부를 평가하기 여부를 평가하기 위하여 아나필락시스 쇼크 반응시험, 수동 피부 아나필락시스 반응시험 및 간접 적혈구 응집 반응시험을 실시하여 다음과 같은 결과를 얻었다. 1. 기니픽을 이용한 아나필락시스 쇼크 반응시험에서 rufloxacin의 저용량투여군(1mg/body, 추정임상용량), 고용량투여군(5mg/body), 고용량혼합투여군(5mg/body mixed with Freunds' complete or incomplete adjuvant) 및 단백결합혼합투여군(rufloxacin-BSA, 1mg/body)에 있어서 아나필락시스 쇼크 반응이 관찰되지 않았다. 2. 마우스-랫드를 이용한 수동 피부 아나필락시스 반응시험에서 저용량투여군, 고용량투여군, 오용량혼합투여군 및 bovine serum albumin(BSA)과 결합시킨 단백결합혼합투여군 모두에서 음성의 반응을 나타내었다. 3. 간접 적혈구 응집 반응시험 결과 저용량투여군, 고용량투여군, 고용량혼합투여군 및 단백결합혼합투여군에서는 각군당 1-4마리에서 16-32배에서 양성반응을 나타내었다. 그러나 음성대조군에서도 10마리 중 4마리에서 16-32배에서 양성반응을 나타낸 것으로 미루어 약물투여군에서의 미약란 양성반응이 약물특이적 반응은 아닌 것으로 사료된다. 이상의 실험결과로 미루어 rufloxacin은 항체 생성능은 가지지 않는 것으로 사료된다. 이상의 실험결과를 종합하여 볼 때 ndloxacin은 전반적인 항원성 potential은 없는 것으로 사료되며 또한 생체내에서 체내 단백과 결합하여 hapten으로 작용할 가능성은 없는 것으로 사료된다.