• Applied Microscopy
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• v.36 no.2
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• pp.93-99
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• 2006

Gemifloxacin is a synthetic fluoroquinolone antimicrobial agent that exhibits potent activity against most Gram-negative and Gram-positive organisms, and has a comparatively low chondrotoxic potential in immature animals. This study examined the effects of gemifloxacin on the Achilles tendons in immature Sprague-Dawley rats treated by oral intubation once daily for 5 consecutive days from postnatal week 4 onward at doses of 0 (vehicle), and 600mg/kg body weight Ofloxacin was used for comparison. The Achilles tendon sperimens were examined by electron microscopy. In comparison with the vehicle-treated controls, there were ultrastructural changes in all samples from the gemifloxacin- and ofloxacin-treated rats. Degenerative changes were observed in the tenocytes, and the cells that detached from the extracellular matrix were recognizable. The degree of degenerative changes and the number of degenerated cells in the Achilles tendon were significantly higher in the treated group than in the control group. Moreover, among the quinolone treated groups, these findings were more significant in the ofloxacin treated group, and less significant in the gemifloxacin treated group. It is unclear what these findings mean with respect to the possible risk ill juvenile patients treated with gemifloxacin or other quinolones. However, these results show that gemifloxacin causes fewer changes in the connective tissue structures.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.69-87
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• 2003

Background : LB20304(gemifloxacin) is a new fluoroquinolone antibacterial agent with excellent activity against both Gram-negative and Gram-positive organisms. In vitro studies using clinical isolates have shown gemifloxacin to be highly active against penicillin-resistant strains of S. pneumoniae and in contrast to other reference quinolones, gemifloxacin retained good activity against clinical isolates of S. pneumoniae that were resistant to other members of the quinolone class. Therefore, gemifloxacin is thought to be effective in treating acute bacterial exacerbation of chronic bronchitis(AECB). The objective of this study was to evaluate the efficacy and safety of oral gemifloxacin at doses of 160mg or 320mg once daily for 7 days for the treatment of AECB in Korean adult population. Methods : This was a randomized, multicenter, double-blind, parallel group Phase II study to assess the clinical and antibacterial efficacy and safety of oral gemifloxacin for the treatment of AECB. Treatment Group A (67 patients) took oral gemifloxacin 160mg once daily for seven days and treatment Group B (70 patients) took oral gemifloxacin 320mg once daily for seven days. Results : The demographic profiles of the two treatment groups were similar. The clinical response at follow-up was 84.2% in the gemifloxacin 160-mg group, and 88.7% in the gemifloxacin-320 mg group, showing no statistically significant difference between two treatment groups(p=0.49). The clinical response at the end of therapy was 96.5% in the 160-mg group, and 96.4% in the 320-mg group. The bacteriological response at the end of therapy and follow-up were 81.8% and 78.9%, respectively, in the 160-mg group, and 86.4% and 84.2%, respectively, in the 320-mg group, showing no statistically significant difference between two treatment groups(p=0.68 and 0.68, respectively). S. pneumoniae(12 isolates) and H. influenzae(10 isolates) were the most prevalent pathogens. The MICs were lower for gemifloxacin than other quinolones against these key pathogens, and for S. pneumoniae, the MICs for gemifloxacin were considerably lower(${\leq}0.03$ ug/mL) than those for other quinolones, beta-lactams and macrolides. In the period on-therapy plus 30 days post-therapy, a total of 18 patients(26.9%) in the gemifloxacin 160mg group and 22 patients(31.4%) in the 320mg group reported at least one adverse event(AE). The most frequently reported AE was abdominal pain(3/67 patients, 4.5%) in the gemifloxacin 160mg group and increased level of hepatic enzyme(5/70 patients, 7.1%) in the 320mg group. The overall AE profiles for the two treatment groups were similar. Two out of 67 patients(3.0%) in the gemifloxacin 160mg group and 1/70 patients(1.4%) in the 320mg group reported at least one serious AE, however, none of which was considered by the investigator to be of suspected or probable relationship to study medication. Conclusion : The results of this study showed that gemifloxacin at doses of 160mg or 320mg once daily for 7 days in the treatment of acute exacerbations of chronic bronchitis(AECB) in adult Koreans was a very effective and safe treatment both clinically and bacteriologically.

• Advances in nano research
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• v.10 no.5
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• pp.461-470
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• 2021

Infection is one of the major mortality causes throughout the globe. Nuclear medicine plays an important role in diagnosis of deep infections such as osteomyelitis, arthritis infection, heart valve and heart prosthesis infections. Techniques such as labeled leukocytes are sensitive and selective for tracking the inflammations but they are not suitable for differentiating infection from inflammation. Anionic linear-globular dendrimer-G₂ was synthesized then conjugation to gemifloxacin antibiotic. The structures were identified by FT-IR, ¹H-NMR, C-NMR, LC-MS and DLS. The toxicity of gemifloxacin and dendrimer-gemifloxacin complex was compared by MTT test. Dendrimer-G₂-gemifloxacin was labeled by Technetium-99m and its in-vitro stability and radiochemical purity were investigated. In-vivo biodistribution and SPECT imaging were studied in a rabbit model. Identify and verify the structure of the each object was confirmed by FT-IR, ¹H-NMR, C-NMR and LC-MS, also, the size and charge of this compound were 128 nm and -3/68 mv respectively. MTT test showed less toxicity of the dendrimer-G₂-gemifloxacin than free gemifluxacin (P < 0.001). Radiochemical yield was > %98. Human serum stability was 84% up to 24 h. Biodistribution study at 50 min, 24 and 48 h showed that the complex is significantly absorbed by the intestine and accumulation in the lungs and affects them, finally excreted through the kidneys, biodistribution results are consistent with results from full image means of SPECT/CT technique.

• Journal of the Korean Chemical Society
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• v.46 no.5
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• pp.412-429
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• 2002

Chiral separation of gemifloxacin, an quinolone antibacterial agent, using (+)-(18-crown-6)-tetracar-boxylic acid $(18C6H_4)$ as a chiral selector was performed by capillary electrophoresis (CE). Direct analysis of quinolone antibacterial agent in body fluid is beneficial in terms of fast analysis time, multicomponent analysis. However, high con-centration of sodium ion in body fluid can prevent gemifloxacin from interacting with $18C6H_4$ since sodium ion has high affinity with $18C6H_4$ due to the strong charge interaction. Ethylenediaminetetraacetic acid (EDTA), as a chelating ligand, was added in the running buffer in order to reduce the interaction between sodium ion and the chiral selector. Increased separation efficiency and reduced migration time were observed while sodium ion exists in the sample solution at the concentration up to 150 mM.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.217.2-218
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• 2001

• 대한임상약리학회:학술대회논문집
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• 2006.11a
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• pp.35-36
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• 2006

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.64-65
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• 2000

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.70.2-71
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• 2003

Quinolone resistance in Streptococcus pneumoniae is related to mutations in the DNA gyrase and topoisomerase IV genes. DW-286a displayed potent activity against S. pneumoniae C9211 (MIC, 0.015 ${\mu}$g/ml) compared with gemifloxacin (MIC, 0.06 ${\mu}$g/ml). This study was performed to analyze the ability of DW-286a to cause resistance development in S. pneumoniae and to establish whether DNA gyrase or topoisomerase IV is primary target. DW-286a resistant mutants of S. pneumoniae C9211 were generated by stepwise selection at increasing drug concentration. (omitted)

• YAKHAK HOEJI
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• v.55 no.1
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• pp.11-15
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• 2011

Zabofloxacin is a novel broad spectrum fluoroquinolone with excellent anti-pneumococcal activity. We investigated the in vitro activity of zabofloxacin against clinical isolates of gram-positive bacteria and the in vivo activity against systemic infection in mice. Zabofloxacin was very active against gram-positive bacteria except QRSA (Quinolone-resistant S. aureus) and VRE(Vancomycin-resistant Enterococci). Especially, zabofloxacin was extremely potent against clinical isolates of Streptococci. Zabofloxacin was as active as gemifloxacin against systemic infection in mice. In view of its improved antibacterial activities against gram-positive bacteria and good pharmacokinetic profiles in animals, the clinical usefulness of zabofloxacin should be established by further studies.

• YAKHAK HOEJI
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• v.56 no.5
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• pp.304-308
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• 2012

In vitro antibacterial activity of DW286 was tested against recently collected clinical isolates of Gram-positive strains by the two fold agar dilution method. In vivo activity of DW286 was also determined against systemic infections in mice caused by Staphylococcus aureus. DW286 showed 16~64-fold more potent in vitro activities than ciprofloxacin against Gram-positive bacteria. Against systemic infection model caused by two S. aureus strains, one being methicillin-susceptible and the other methicillin-resistant, DW286 ($ED_{50}s$, 0.16 mg/kg and 4.36 mg/kg, respectively) was more potent than gemifloxacin (1.37 mg/kg, 26.58 mg/kg, respectively).