8 results on '"Pil Seung Kwon"'
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2. Inactivation of Candida albicans Biofilm by Radachlorin-Mediated Photodynamic Therapy
- Author
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Pil Seung Kwon
- Subjects
biology ,Chemistry ,medicine.medical_treatment ,Biofilm ,medicine ,Radachlorin ,Photodynamic therapy ,Candida albicans ,biology.organism_classification ,Microbiology - Published
- 2015
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3. Functional analysis of seaR protein identified from Saccharopolyspora erythraea
- Author
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Hyeong Seon Lee, Jae Ki Ryu, and Pil-Seung Kwon
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Genetics ,biology ,Tetracycline ,Streptomyces coelicolor ,Wild type ,Phenotype microarray ,Promoter ,biology.organism_classification ,Microbiology ,medicine ,Saccharopolyspora erythraea ,Secondary metabolism ,Gene ,medicine.drug - Abstract
Secondary metabolism in actinomycetes has been known to be controlled by a small molecule, -butyrolactone autoregulator, the binding of which to each corresponding receptor leads to the regulation of the transcriptional expression of the secondary metabolites. We expected that expression of an autoregulator receptor or a pleiotropic regulator in a non-host was to be gained insight of effective production of new metabolic materials. In order to study the function of the receptor protein (seaR), which is isolated from Saccharopolyspora erythraea, we introduced the seaR gene to Streptomyces coelicolor A3(2) as host strains. An effective transformation procedure for S. coelicolor A3(2) was established based on transconjugation by Escherichia coli ET12567/pUZ8002 with a -derived integration vector, pSET152, which contained int, oriT, attP and (erythromycin promotor). Therefore, the pEV615 was introduced into S. coelicolor A3(2) by conjugation and integrated at the attB locus in the chromosome of the recipients by the integrase (int) function. Exconjugant of S. coelicolor A3(2) containing the seaR gene was confirmed by PCR and transcriptional expression of the seaR gene in the transformant was analyzed by RT-PCR. In case of S. coelicolor A3(2), a phenotype microarray was used to analyze the phenotype of transformant compared with wild type by seaR expression. After that, in order to confirm the accuracy of the results obtained from the phenotype microarray, an antimicrobial susceptibility test was carried out. This test indicated that sensitivity of the transformant was higher than wild type in tetracycline case. These results indicated that some biosynthesis genes or resistance genes for tetracycline biosynthesis in transformant might be repressed by seaR expression. Therefore, subsequent experiments, analysis of transcriptional pattern of genes for tetracycline production or resistance, are needed to confirm whether biosynthesis genes or resistance genes for tetracycline are repressed or not.
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- 2015
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4. Antimicrobial Effects of Photodynamic Therapy Using Blue Light Emitting Diode with Photofrin and Radachlorine against Propionibacterium acnes
- Author
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Pil Seung Kwon
- Subjects
Colony-forming unit ,medicine.diagnostic_test ,biology ,Chemistry ,medicine.medical_treatment ,Photodynamic therapy ,Antimicrobial ,biology.organism_classification ,Molecular biology ,Flow cytometry ,Agar plate ,Propionibacterium acnes ,medicine ,Irradiation ,Antibacterial activity - Abstract
Photodynamic therapy (PDT) apply photosensitizers and light. The purpose of this study was to evaluate the in vitro efficacy of PDT using blue LED (light emitting diode) with photofrin and radachlorin for Propionibacterium acnes. The colony forming units method was used to assess the antibacterial activity. Suspension (1 mL) containing P. acnes at 1×105 CFU/mL were prepared and then 2 fold serial diluted to 12.5 g/mL from 50 g/mL concentration of photofrin and radachlorin. After 60 minutes incubation, light was irradiated for 10 to 30 minutes using the following light source of wavelength 460 nm, each energy density 36, 72 and 108 J/cm2. Bacterial growth was evaluated after 72 hours incubation in a Phenylethanol Blood Agar (PEBA) culture. In addition, flow cytometric analysis were performed to measure the live cell after PDT. Also transmission electron microscopy (TEM) was employed to evaluate the effect of pathogens by PDT. The PDT Group was perfectly killed to all kind of photosensitizers dose of 12.5 g/mL with irradiation of 10 minutes. Also other Groups were killed to all kind of photosensitizers dose of 6.25 g/mL with irradiation time of 20 and 30 minutes. The flow cytometry showed a lower number of viable bacteria in the PDT group compared to the control group. The images of the TEM results were showed in cytoplasmic membrane damage and partially deformed to cell morphologies. These results suggest that radachlorin and photofrin combine blue LED PDT can be effectively treated when was proved treatment for acnes therapy.
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- 2015
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5. Factors Analysis Affecting Lateral Canal Benign Paroxysmal Positional Vertigo
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Chul Seung Kim, Choong Won Seo, Pil Seung Kwon, Eun Pyo Lee, and Hee Young Choi
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medicine.medical_specialty ,Benign paroxysmal positional vertigo ,Benign paroxysmal vertigo ,biology ,Cerebral infarction ,business.industry ,medicine.disease ,biology.organism_classification ,Lateral canal ,Surgery ,Vertigo ,otorhinolaryngologic diseases ,medicine ,Head position ,In patient ,Statistical analysis ,sense organs ,business - Abstract
Lateral canal benign paroxysmal vertigo (BPPV) causing dizziness is a common cause is not found while continuing to appeal for vertigo is a typical disease. It is characterized by acute stand up, brief and rotatory vertigo attacks provoked by change in head position. Treatment requires only one treatment visit in most patients. However, there are significant numbers of patients who require multiple treatment visits for relief. The purpose of this study benign paroxysmal positional vertigo treatment of type affect is to analyze the cause. Dizziness and vertigo patient`s in patients admitted to the dizziness center of lateral canal benign paroxysmal positional vertigo were classified. In patients with lateral canal benign paroxysmal positional vertigo and accompanying lateral 15 treatment affects disease were investigated. March 2008 to November 2010 lateral canal benign paroxysmal positional vertigo 166 people cure rate of patients was investigated. First time the success rate of 74.1%, twice times the success rate of 12.0%, three times the success rate of 9.6%, more than three times the success rate was 4.2%. Affecting factor treatment of benign paroxysmal positional vertigo in post-traumatic, medicine disease, headache, cerebral infarction, small vessel disease, vestibulopathy, (p<0.05). Statistical analysis using SPSS (version 12K) in coefficient measure through descriptive statistical of cross table.
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- 2015
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6. Photodynamic effect of Photofrin and Radachlorin against Staphylococcus aureus and Staphylococcus epidermidis
- Author
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Pil-Seung Kwon, Jae-Gi Ryu, and Choong-Won Seo
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biology ,Staphylococcus epidermidis ,Chemistry ,Staphylococcus aureus ,medicine ,Radachlorin ,biology.organism_classification ,medicine.disease_cause ,Microbiology - Published
- 2014
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7. In vitro and in vivo photodynamic therapy of otitis media in gerbils
- Author
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Myung Whan Suh, Jae Yun Jung, Jin Chul Ahn, Ruifeng Ge, Chung Ku Rhee, and Pil Seung Kwon
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Hematoporphyrin ,Pathology ,medicine.medical_specialty ,biology ,business.industry ,medicine.medical_treatment ,Photodynamic therapy ,medicine.disease_cause ,biology.organism_classification ,Bacterial cell structure ,Haemophilus influenzae ,Microbiology ,Moraxella catarrhalis ,chemistry.chemical_compound ,Otitis ,Otorhinolaryngology ,chemistry ,In vivo ,Streptococcus pneumoniae ,medicine ,medicine.symptom ,business - Abstract
Objectives/Hypothesis: The aim of this study was to evaluate the antibacterial effects of photodynamic therapy (PDT) on common bacteria causing otitis media with effusion (OME). Methods: An in vitro study was carried out using a hematoporphyrin derivative sensitizer (Photogem; Lemonosov Institute of Fine Chemical, Moscow, Russia) and a 632-nm diode laser on Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae. The presence of colony-forming units of the bacteria was examined, the microscopic structures of the bacteria were examined by transmission electron microscopy (TEM), and flow cytometry of the bacteria was performed. An in vivo PDT study was performed using gerbils. S. pneumoniae or H. influenzae were injected into bullae. The Photogem was injected into the bullae 2 days later when OME developed, and transcanal irradiation with the 632-nm diode laser (90 J) was performed. Middle ear and bulla were washed with Dulbecco's phosphate buffered saline (DPBS) and the washed DPBS was cultured. The presence of bacterial colonies was examined. Results: The PDT was effective in killing all three kinds of bacteria. TEM showed damaged bacterial cell membranes and cytoplasmic structures, and the flow cytometry showed a lower number of viable bacteria in the PDT group compared to the control group. PDT was effective in killing S. pneumoniae in 87% of the infected bullae with OME, whereas it was effective in eradicating H. influenzae in 50% of the infected bullae with OME. Conclusions: The results of these studies demonstrated that PDT may be effective to treat otitis media. PDT may have clinical implications in the treatment of otitis media that is resistant to antibiotic therapy. Laryngoscope, 2009
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- 2009
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8. [Detection of rifampin resistant mycobacterium tuberculosis complex using denaturing HPLC]
- Author
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Su Min Park, Jong-Wan Kim, Min Ho Cho, Youn Hyoung Nam, Young Chang Ahn, Pil Seung Kwon, Won Cheoul Jang, and Sang-Hyun Lee
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DNA, Bacterial ,Tuberculosis ,medicine.drug_class ,Clinical Biochemistry ,Antibiotics ,Drug resistance ,Gene mutation ,Microbiology ,Drug Resistance, Bacterial ,medicine ,Humans ,Antibiotics, Antitubercular ,Chromatography, High Pressure Liquid ,biology ,Biochemistry (medical) ,General Medicine ,Mycobacterium tuberculosis ,Amplicon ,bacterial infections and mycoses ,rpoB ,medicine.disease ,biology.organism_classification ,Bacterial Typing Techniques ,Mycobacterium tuberculosis complex ,Mutation ,Restriction fragment length polymorphism ,Rifampin - Abstract
Background Tuberculosis (TB) remains an important cause of morbidity and mortality throughout the world. The surge of TB has been accompanied by an increase in multi-drug-resistant tuberculosis (MDR-TB). In this study, we developed a denaturing HPLC (DHPLC) method for detecting rpoB gene mutation as a rifampin resistance based on sequence. Methods In this study, we used 99 mycobacterial isolates grown in Ogawa media. At first, we used a PCR method that can amplify the 235 bp and 136 bp rpoB DNAs of Mycobacterium tuberculosis complex (MTB) and Non-tuberculous mycobacteria (NTM). And then, PCR-restriction fragment length polymorphism (RFLP) of rpoB DNA (342 bp), which comprises the Rif(T) region, was used for the differential identification of Mycobacteria. Finally, we detected these amplicons by DHPLC, compared to PCR-RFLP results, and performed sequencing. Results Among 99 mycobacterial isolates, 80 (81%) were MTB and 19 (19%) were NTM. NTM were identified to 7 different species by DHPLC and PCR-RFLP. rpoB mutation was detected in 9 (11%) of the MTB specimens. These results were confirmed by using sequencing. Conclusions DHPLC provided a rapid, simple, and automatable performance for detection of rifampin resistant Mycobacterium tuberculosis complex and would be helpful as a supplemental method in high-throughput clinical laboratories.
- Published
- 2008
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