• 한국동물위생학회지
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• 제32권3호
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• pp.281-286
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• 2009

Fluoroquinolones in muscle and egg were separated by liquid extraction and determined. The analysis was carried out using following conditions; C18 column ($150{\times}4.6mm$, $5{\mu}m$), mobile phase composed of D.W. (containing 0.4% triethylamine and phosphoric acid) : methanol : acetonitrile (780:100:120, v/v/v), quarternary pump at a flow rate of 0.9ml/min and $20{\mu}l$ of injection volume, fluorescence detector with EX 278nm/Em 456nm. The calibration range of seven fluoroquinolones showed linearity ($r^2{\geq}0.999$) at concentration range of $0.025{\sim}0.8{\mu}g/ml$. The recoveries in fortified muscle and egg represented more than 81.3%. The detection limits for ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, saraloxacin and orbifloxacin were 3.1, 2.5, 3.6, 1.7, 0.9, 2.5 and $2.1{\mu}g/kg$, respectively. We also monitored fluoroquinolones residue in the sample (chicken muscle 182, cattle muscle 140, pig muscle 139, egg 212) using EEC-plate (E. coli ATCC 11303) screening and HPLC confirmation methods. The screening test results, fluoroquinolones, antibacterial substances were all negative.

• BMB Reports
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• 제47권11호
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• pp.625-630
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• 2014

Defensins, which are small cationic molecules produced by organisms as part of their innate immune response, share a common structural scaffold that is stabilized by three disulfide bridges. Coprisin is a 43-amino acid defensin-like peptide from Copris tripartitus. Here, we report the intramolecular disulfide connectivity of cysteine-rich coprisin, and show that it is the same as in other insect defensins. The disulfide bond pairings of coprisin were determined by combining the enzymatic cleavage and mass analysis. We found that the loss of any single disulfide bond in coprisin eliminated all antibacterial, but not antifungal, activity. Circular dichroism (CD) analysis showed that two disulfide bonds, Cys20-Cys39 and Cys24-Cys41, stabilize coprisin's ${\alpha}$-helical region. Moreover, a BLAST search against UniProtKB database revealed that coprisin's ${\alpha}$-helical region is highly homologous to those of other insect defensins.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1393-1400
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• 2009

A bacteriocin-producing strain PI80 was isolated from the gut of Penaeus indicus (Indian white shrimp) and identified as Streptococcus phocae PI80. The bacteriocin was purified from a culture supernatant to homogeneity as confirmed by Tricine SDS-PAGE. Reverse-phase HPLC analysis revealed a single active fraction eluted at 12.94 min, and MALDI-TOF mass spectrometry analysis showed the molecular mass to be 9.244 kDa. This molecular mass does not correspond to previously described streptococcal bacteriocins. The purified bacteriocin was named phocaecin PI80 from its producer strain, as this is the first report of bacteriocin production by Streptococcus phocae. The bacteriocin exhibited a broad spectrum of activity and inhibited important pathogens: Listeria monocytogenes, Vibrio parahaemolyticus, and V. fischeri. The antibacterial substance was also sensitive to proteolytic enzymes: trypsin, protease, pepsin, and chymotrypsin, yet insensitive to catalase, peroxidase, and diastase, confirming that the inhibition was due to a proteinaceous molecule (i.e., the bacteriocin), and not due to hydrogen peroxide or diacetyl. Phocaecin PI80 moderately tolerated heat treatment (up to $70^{\circ}C$ for 10 min) and resisted certain solvents (acetone, ethanol, and butanol). A massive leakage of $K^+$ ions from E. coli $DH5\alpha$, L. monocytogenes, and V. parahaemolyticus was induced by phocaecin PI80, as measured by Inductively Coupled Plasma Optical Emission Spectrometry (ICPOES). Therefore, the results of this study show that phocaecin PI80 may be a useful tool for inhibiting L. monocytogenes in seafood products that do not usually undergo adequate heat treatment, whereas the cells of Streptococcus phocae PI80 could be used to control vibriosis in shrimp farming.

• 대한수의학회지
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• 제52권3호
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• pp.169-176
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• 2012

Probiotics colonize the intestines and exert an antibacterial effect on pathogens. Therefore, probiotics could be used as a preventive agent against lethal infections. To isolate probiotic microorganisms, 116 bacterial strains were isolated from healthy cow's milk and were subjected to Gram-stain, morphology and biochemical analyses, Vitek analysis, and 16S rRNA analysis. One of the strains identified as Bacillus (B.) thuringiensis 87 was found to grow very well at pH 4.0~7.0 and to be resistant to high concentrations of bile salts (0.3~0.9% w/v). B. thuringiensis was susceptible to the antibiotics used in the treatment of bovine mastitis, yet it exhibited an antimicrobial effect against Staphylococcus (S.) aureus 305. Moreover, it protected mice from experimental lethal infections of E. coli O55, Salmonella typhimurium 01D, and S. aureus 305 through a significant induction of interferon-${\gamma}$, even at four-week post-administration of B. thuringiensis. Although oral administration of B. thuringiensis 87 did not provide significant protection against these lethal challenges, these results suggest that B. thuringiensis 87 could be a feasible candidate as a probiotic strain.

• 한국식품조리과학회지
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• 제24권4호
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• pp.494-500
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• 2008

The principal objective of this study was to assess the quality characteristics of Sprouted Brown Rice Dasik(SBRD) manufactured with various addition levels of honey and Yujacheong(Yuja syrup and Yuja sarcocarp) in accordance with the traditional method for the preparation of Korean Dasik(a kind of cookie). The nutritional components, color value, physical tests, volatile compounds, and sensory evaluation of SBRD to which Yujacheong was added were conducted. The results were summarized as follows. In SBRD to which Yujacheong had been added, the moisture contents and crude fat content did not differ significantly among the sample groups, and the contents of crude protein and crude ash increased with increasing additions of Yuja syrup and Yuja sarcocarp. The pH(p<0.001) and sweetness(p<0.001) were significantly higher in sample D1 than in samples D2 and D4. The L color value was highest in D2, the a value was highest in D3, and the b value was highest in sample D2. The texture property analysis showed that the cohesiveness, springiness, gumminess, and chewiness of SBRD to which Yujacheong was added were all significantly higher compared to sample D1. According to the results of our volatile analysis, the D1 and other experimental groups evidenced different flavors and antibacterial compositions. According to the results of our sensory evaluation, the appearance of the D1 sample was superior to the other samples. However, flavor, taste, texture, and overall preference were higher in the samples to which Yuja syrup and Yuja sarcocarp were added. These results indicate that SBRD to which Yujacheong was added, and particularly those to which Yuja syrup was added, is superior to Dasik prepared with honey in terms of flavor and taste, and this method will improve the flavor and preparation time, due to its lower pH.

• The Journal of Advanced Prosthodontics
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• 제6권3호
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• pp.207-214
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• 2014

PURPOSE. This study characterized the synthesis of a modified PMMA (Polymethyl methacrylate) denture acrylic loading platinum nanoparticles (PtN) and assessed its bacterial inhibitory efficacy to produce novel antimicrobial denture base material. MATERIALS AND METHODS. Polymerized PMMA denture acrylic disc ($20mm{\times}2mm$) specimens containing 0 (control), 10, 50, 100 and 200 mg/L of PtN were fabricated respectively. The obtained platinum-PMMA nanocomposite (PtNC) was characterized by TEM (transmission electron microscopy), SEM/EDX (scanning electron microscope/energy dispersive X-ray spectroscopy), thermogravimetric and atomic absorption spectrophotometer analysis. In antimicrobial assay, specimens were placed on the cell culture plate, and $100{\mu}L$ of microbial suspensions of S. mutans (Streptococcus mutans) and S. sobrinus (Streptococcus sobrinus) were inoculated then incubated at $37^{\circ}C$ for 24 hours. The bacterial attachment was tested by FACS (fluorescence-activated cell sorting) analysis after staining with fluorescent probe. RESULTS. PtN were successfully loaded and uniformly immobilized into PMMA denture acrylic with a proper thermal stability and similar surface morphology as compared to control. PtNC expressed significant bacterial anti-adherent effect rather than bactericidal effect above 50 mg/L PtN loaded when compared to pristine PMMA (P=.01) with no or extremely small amounts of Pt ion eluted. CONCLUSION. This is the first report on the synthesis and its antibacterial activity of Pt-PMMA nanocomposite. PMMA denture acrylic loading PtN could be a possible intrinsic antimicrobial denture material with proper mechanical characteristics, meeting those specified for denture bases. For clinical application, future studies including biocompatibility, color stability and warranting the long-term effect were still required.

• 한국연초학회지
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• 제15권2호
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• pp.174-184
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• 1993

This is to investigate the methodology for the simultaneous determination of Wk, mk and TSNA using gas chromatography(GC) in combination with chemiluminescence detector, thermal energy analyzer(TEA) . The simultaneous analysis has been estimated by evaluating tobacco. The TEA was linked to GC equipped with non -polar SPB -5 fused silica capillary column which was introduced into the ceramic pyrolysis tube by the point of 16cm from the end of TEA. Quantification was carried out by internal standardization with WDPA after calibration of retention times and response factors with authentic nitrosoamines. It was demonstrated that WDPA was most preferable as internal standard for the simultaneous analysis. The recoveries of the internal standard were in the range of 83∼96% . Nitrosoamines in this method were detected with determination limit of 0.1ng and was made by a straight line in calibration curve by TEA response. The suitability of nitrosoamines extraction in tobacco leaf was investigated. It was most suitable to extract nitrosoamines from tobacco leaves with 0.01 M NaOH within a period of 8 hours. Thimerosal as an antibacterial agent was added to NaOH solution to prevent artifactual formation. The fractionation and the purification of nitrosoamines form alkaline extracts were conveniently performed using Extrelut multilayer column and dichloromethane. Reproducible and reliable results were obtained for the determination of nitrosamines in a relatively short time compared to previous known method. TSNA contents in burley were about 4 times higher as those in the fluecured tobacco.

• The Journal of Advanced Prosthodontics
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• 제7권2호
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• pp.151-159
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• 2015

PURPOSE. To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS. A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non- quantitatively. RESULTS. All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION. The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.

• 대한화학회지
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• 제40권9호
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• pp.623-629
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• 1996

지의류에 속하는 Umbiliciaria vellea 중 에탄올 분획의 항균활성 물질을 규명하기 위하여 silica겔 컬럼 크로마토그래피 및 재결정법으로 화합물 I과 II를 순수히 분리정제하여 그 구조와 항균활성을 측정하였다. 정제된 화합물I은 Cryptococcus neoformance 등의 균에 대한 항진균활성과, Pseudomonas aeruginosa등의 균에 대한 항세균 활성이 있었다. 이 물질의 녹는점은 129~132$^{\circ}C$였고, 217, 265 및 330 nm의 UV 최대흡광을 보였다. 그리고 EI-mass에서 측정된 분자이온은 m/z 196이었고, 원소분석 결과 분자식은 $C_{10}H_{12}O_4$였으며 IR 및 NMR 스펙트라로부터 이 물질이 ethyl 2,4-dihydroxy-6-methyl benzoate임을 확인하였다. 화합물 II의 녹는점은 58~59$^{\circ}C$였고, 212, 276 및 282 nm의 UV 최대흡광을 보였다. 이 물질의 분자이온은 m/z 124였고, $C_7H_8O_2$의 분자식을 갖는 5-methyl-1,3-benzenediol임을 확인하였다.

• 미생물학회지
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• 제54권3호
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• pp.175-187
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• 2018

점액세균은 포식활동, 자기방어, 세포 간 신호전달 및 아직까지 알려지지 않은 다른 기능을 위해 다양한 이차대사산물을 생산한다. 점액세균에서 분리된 많은 이차대사산물들은 독특한 작용기작을 가지며 항암, 항세균, 항진균 등과 같은 약학적으로 유용한 생리활성을 보인다. 따라서 전 세계적으로 많은 점액세균 균주들이 분리되었고 이들로부터 다양한 생리활성물질들이 탐색되었다. 하지만 16S rRNA 데이터베이스 분석에 의하면 야생에는 지금까지 분리된 종류 이외에도 다양한 점액세균 종류들이 존재할 것으로 추정되며, 유전체 서열 분석에 의하면 각 점액세균들은 기존에 알려진 물질보다 더 많은 물질을 생산할 수 있는 능력이 있는 것으로 나타났다. 본 총설에서는 점액세균 유래 이차대사산물들과 이들의 유전자, 점액세균에서의 기능, 생합성 유전자의 발현을 조절하는 전사조절인자 등에 대한 최근까지의 연구 현황을 살펴보았다.