• Annals of Laboratory Medicine
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• 제38권6호
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• pp.563-568
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• 2018

Background: Delamanid, bedaquiline, and linezolid have recently been approved for the treatment of multidrug- and extensively drug-resistant (MDR and XDR, respectively) tuberculosis (TB). To use these drugs effectively, drug susceptibility tests, including rapid molecular techniques, are required for accurate diagnosis and treatment. Furthermore, mutation analyses are needed to assess the potential for resistance. We evaluated the minimum inhibitory concentrations (MICs) of these three anti-TB drugs for Korean MDR and XDR clinical strains and mutations in genes related to resistance to these drugs. Methods: MICs were determined for delamanid, bedaquiline, and linezolid using a microdilution method. The PCR products of drug resistance-related genes from 420 clinical Mycobacterium tuberculosis strains were sequenced and aligned to those of M. tuberculosis H37Rv. Results: The overall MICs for delamanid, bedaquiline, and linezolid ranged from ${\leq}0.025$ to >1.6 mg/L, ${\leq}0.0312$ to >4 mg/L, and ${\leq}0.125$ to 1 mg/L, respectively. Numerous mutations were found in drug-susceptible and -resistant strains. We did not detect specific mutations associated with resistance to bedaquiline and linezolid. However, the Gly81Ser and Gly81Asp mutations were associated with resistance to delamanid. Conclusions: We determined the MICs of three anti-TB drugs for Korean MDR and XDR strains and identified various mutations in resistance-related genes. Further studies are needed to determine the genetic mechanisms underlying resistance to these drugs.

• Imaging Science in Dentistry
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• 제53권2호
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• pp.145-151
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• 2023

Purpose: Prior to cone-beam computed tomography (CBCT), orthodontic competence included radiological interpretation. Nevertheless, maxillary impacted canines (MICs), because of their position and adjacent complex anatomy, have been challenging to interpret, particularly with regard to root resorption. Although CBCT cross-sectional reconstructions of MICs yielded clearer insights into its diagnosis and treatment planning, the value of simultaneously using 2 different cross-sectional or multiplanar reconstructions of the CBCT datasets - orthogonal and curved/panoramic multiplanar reconstructions - has hitherto not been considered. Materials and Methods: Both orthogonal and curved/panoramic multiplanar reconstruction series of 5 screenshots were each reconstructed from the 5 cm×5 cm CBCT datasets of 15 separate MICs. Fifteen credentialled and experienced orthodontist volunteers reviewed 2 separate PowerPoints of 15 randomized series each, 1 week apart. Their review considered 6 factors that could affect treatment: the position and level of the MIC, the presence or absence of root resorption, ankylosis, cysts, and dilaceration. Results: All 15 orthodontists were statistically similar regarding overall years of experience and of CBCT use. Although either reconstruction alone allowed the orthodontists to determine whether ankylosis and, to a lesser extent, most of the other features were present or absent in the MIC, reviewing both reconstructions together was necessary to determine whether root resorption was present or absent in the adjacent tooth. Conclusion: Reviewing both orthogonal and curved/panoramic multiplanar reconstructions was necessary to evaluate the presence or absence of root resorption in the teeth adjacent to MICs and that of many other features.

• 대한소아치과학회지
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• 제31권4호
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• pp.605-616
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• 2004

아저해농도(亞沮害濃度)란 세포의 성장을 저해하는 최소 저해 농도(minimum inhibitory concentrations; MIC)이하의 농도를 말하는데, 적용된 화학물질의 동력학에 따라 항균물질은 반드시 이러한 농도로 존재하는 시기를 거치게 되며, 아저해농도의 항균물질은 세포의 성장을 저해하지는 않지만 세균의 대사와 성장에 스트레스로 작용하게 되어 세포의 성질과 독력인자 발현에 영향을 줄 수 있을 것이다. 본 연구는 여러 항균물질의 최소저해농도를 결정하고 아저해농도의 항균물질이 존재 시 세포 성질과 독력 인자에 미치는 영향을 알아보고, 치아우식증의 예방에 대한 화학적 접근법의 효용성을 조사하기 위해 계획되었다. 연구대상 세균으로는 mutans그룹 streptococci 중 두 가지 대표적인 세균종인 S. mutans (S. mutans Ingbritt)와 S. sobrinus (S. sobrinus 6715-7)를 사용하였고 화학물질 8종 (Sanguinaria extract; SG. Chlorhexidine digluconate; CHX, Fluoride; F, Propolis; PP, Hydrogen peroxide HP, Triclosan; TC, Sodium dodecyl sulfate: SDS, Cetylpyridinium chloride; CC) 을 단계 희석하여 배지에 첨가하여 최소저해농도를 구하였으며 아저해농도의 항균물질을 배지에 첨가하여 5% $CO_2$ 존재 하에 $37^{\circ}C$에서 배양하여 이러한 항균물질을 첨가하지 않은 배지에서 배양한 세균과 성장속도, 산생성능, 체표소수성, 수산화인회석에의 부착능, glucan생성능, 세균응집능 등을 비교 관찰하였다. 아저해농도의 항균물질은 세포의 성장과 체표소수성, 타액으로 처리한 수산화인회석에 대한 세균의 부착과 glucan합성에 영향을 주는 것이 관찰되었다. 또한 12시간 배양 후 S. mutans와 S. sobrinus 모두에서 대조군에 비해 통계적으로 유의하게 최종 pH가 높게 나타나 산생성능이 억제되는 것이 관찰되었다 (p<0.05). 세균을 proteinase K로 전처리한 경우 처리하지 않았을 때 보다 세균응집역가가 증가하거나 응집이 관찰되지 않았다. 본 연구의 결과에 따르면, 각각의 항균물질은 아저해농도에서도 알려진 작용기전과 유사하게 세균의 성질에 영향을 주었고 이러한 농도에서도 지속적으로 세균을 억제할 수 있었다. 따라서 이러한 항균물질의 사용은 치아우식증의 효과적 예방법의 하나가 될 수 있다

• 약학회지
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• 제51권5호
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• pp.355-360
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• 2007

The essential oil fraction from the aerial parts of A. annua was analyzed by GC-MS. As the results, caryophyllene oxide (11.7%), caryophyllene (7.54%), camphor (7.32%), 1,8-cineol (4.98%), and borneol (3.99%) were confirmed as the main components of the oil fraction. The effects of this oil and its main components on antibiotic-susceptible and -resistant strains of Salmonella enteritidis and S. typhimurium were assessed. A. annua oil fraction significantly inhibited all strains of the two Salmonella species examined, with minimum inhibiting concentrations (MICs) ranging from 2.0 mg/ml to 8.0 mg/ml. Among the main components of the oil, borneol and camphor showed relatively strong inhibiting activity with MICs between 1.0 mg/ml and 4.0 mg/ml. The MICs of caryophyllene and caryophyllene oxide were higher than 16 mg/ml. The combination effects of the oils with kanamycin were evaluated using a checkerboard microtiter assay. Against S. typhimurium KCCM11862 and CCARM8009 strains, the oil fraction of A. annua, camphor, and 1,8-cineol exhibited significant synergistic with kanamycin with fractional inhibitory concentration (FIC) indices in the range of 0.085 to 0.375. In conclusion, a combination of kanamycin and A. annua oil or its main component, camphor, and cineol, may be useful for reducing the minimum effective dose of antibiotic required for the treatment of resistant S. typhimurium infections.

• 미생물학회지
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• 제38권4호
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• pp.265-265
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• 2002

Iron increased the susceptibilities of clinical isolates Pseudomonas aeruginosa to quinolones. In the presence of iron, increased susceptibilities to ofloxacin were observed in twenty-six out of thirty isolates and with no change in four isolates. In the case of norfloxacin, iran increased susceptibilities of twelve isolates but did not render any change in eighteen isolates. In the case of ciprofloxacin, iron decreased the MICs (Minimal Inhibitory Concentration) of twenty isolates, increased the MIC of one isolate, and did net change the MICs of nine isolates. To find out how iron increased susceptibility to ofloxacin, bacterial cells were grown in Muller Hinton (MH) media and succinate minimal media (SMM) to induce iran acquisition systems and the intracellular ofloxacin concentrations were assayed in the presence of iron. The addition of iron to the media decreased the MICs of cells whether they were grown in MH or SMM. Siderophores, carbonyl cyanide m-chlorophenylhydrazone (an inhibiter of proton motive force), and ouabain (an inhibitor of ATPase) did not decrease the effect of iron. Results suggested that the increase in the intracellular ofloxacin concentration by iron is accomplished not by decreasing the efflux but by increasing the of ofloxacin permeability.

• 한방안이비인후피부과학회지
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• 제17권3호
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• pp.33-37
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• 2004

Objective: The aim of this work is to investigate the antibacterial activity of the Sohporaflavanone G isolated from Sophora flavescens (S. flavescens), as the development of microbial resistance to antibiotics make it essential to constantly look for new and active compounds effective against pathogenic bacteria. Method : Sophoraflavanone G was isolated from the dried roots of Sophora flavescens Aiton (Leguminosae) by bioassay?guided fractionation. We investigated the effect of sophoraflavanone G on oral bacterial at various concentrations after incubation of 24 h in strains in the dose?dependent manner. Results: The structure of active compound, Sophoraflavanone G having a lavandulyl group at C?8, was elucidated on the basis of spectral data especially 1H?NMR and I3C?NMR. The antimicrobial activity showed that Sophoraflavanone G exhibited antimicrobial activilies against all the bacteria tested (MICs, 0.39 - 6.25 ㎍／ml). Sophoraflavanone G showed the strong antimicrobial activity against all the facultative bacteria and microaerophilic bacteria (MICs, 0.78 - 1.56 ㎍／ml) and also Sophoraflavanone G showed the strong antimicrobial activity against obligate anaerobic bacteria (MICs, 0.39 - 6.25 ㎍／ml).

• 한국대기환경학회지
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• 제33권5호
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• pp.480-496
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• 2017

CMAQ (Community Multiscale Air Quality)-HDDM (High-order Direct Decoupled Method) simulations with MICS-Asia 2010 and INTEX-B 2006 emissions inventories were performed to investigate the impact of Chinese $NO_x$ and VOC emissions on 1-hr ozone concentrations over South Korea during May to July in 2014. Chinese $NO_x$ and VOC emissions in MICS-Asia 2010 were 60% higher and 100% lower than those in INTEX-B 2006 during the simulation period. It makes the ratio of Chinese VOC to $NO_x$ emissions in INTEX-B 2006 (Case 1) is 3.2 times higher than that in MICS-Asia 2010 (Case 2). When the observed period mean 1-hr ozone concentration averaged across 106 air monitoring sites in the SMA (Seoul Metropolitan Area) was 37.6 ppb, the modeled values were similar to each other; 37.3 ppb for Case 1, and 40.4 ppb for Case 2. Both cases show that daily maximum 1-hr ZOC (Zero-Out Contribution) of Chinese $NO_x$ and VOC emissions were as high as 55 ppb and 35 ppb for the episode respectively. Correlation coefficients between ZOC of Chinese $NO_x$ and VOC emissions and the SMA daily maximum 1-hr ozone were 0.49~0.69. It indicates that Chinese emissions occasionally affect the SMA daily ozone peaks. On the other hand, Case 2 predicted 7 ppb and 1 ppb higher ZOC of Chinese $NO_x$ and VOC emissions than Case 1, when simulated ozone in the SMA is over 80 ppb. It implies that upwind $NO_x$ emissions would be more important than upwind VOC emissions for the long-range transport of ozone in Northeast Asia.

• 대한한방내과학회지
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• 제19권2호
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• pp.300-316
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• 1998

The various oriental herbal medicines, which have usually been used for treatment of reducing fever, purging intense heat and detoxication, were screened to determine the antibacterial activity and the minimal inhibitory concentration against antibiotics-resistant Staphylococcus aureus. The results obtained were as follows: 1. Among the 23 oriental medicines tested, the water-soluble extract of Coptis japonica showed very excellent antibacterial activity against antibiotics-sensitive and -resistant S. aureus. A little activity was found in the extracts of Scutellaria baicalensis, Eriobotrya japonica and Prunus mume against antibiotics-sensitive S. aureus and in that extracts of P. mume, Schizandra chinensis and S. baicalensis against antibiotics-resistant S. aureus. When C japonica was used, the high antibacterial activity was shown against Bacillus subtilis and other extracts showed a little or no antibacterial activity against B. subtilis and E. coli as a control. 2. The highest antibacterial activities against antibiotics-resistant S. aureus were found in the ethanol-soluble extract of C japonica. Other ethanol-soluble extracts of S, baicalensis, S. chinensis and P. mume showed a little activity against both antibiotics-sensitive and antibiotics-resistant S. aureus. 3. Among the medicinal herbs tested, the water- and ethanol extracts of C. japonica showed very excellent antibacterial activity against the pathogenic S. aureus and both Escherichia coli and Bacillus subtilis used as a control. 4. When the water-soluble extracts of C. japonica and S. baicalensis, minimal inhibitory concentrations (MICs) against antibiotics-sensitive S. aureus were $20mg/m{\ell}\;and\;30mg/m{\ell}$, respectively. The MICs of the ethanol-soluble extracts of C. japonica and P. scabriosaefolia were $7.5mg/m{\ell}\;and\;12mg/m{\ell}$, respectively. 5. For the MICs against antibiotics-resistant S. aureus, the water-soluble extracts of C. japonica and P. mume showed $15mg/m{\ell}\;and\;10mg/m{\ell}$, respectively. The MICs of the ethanol-soluble extracts of C. japonica and P. mume were $13mg/m{\ell}\;and\;20mg/m{\ell}$, respectively. As a result, the highest antibacterial activity was found in both water- and ethanol-soluble extracts of C. japonica against antibiotics-resistant S. aureus. And the water- and ethanol-soluble extracts of S. baicalensis, S. chinensis and P. mume showed comparatively high antibacterial activities against both antibiotics-sensitive and -resistant S. aureus.

• Asian-Australasian Journal of Animal Sciences
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• 제4권3호
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• pp.281-284
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• 1991

Combination effects of sulfamethoxazole (SMX) and trimethoprim (TMP) against nine gram positive bacterial strains and 43 gram negative bacterial strains which included 40 strains of animal intestinal bacteria were studied in vitro. Minimum inhibitory concentrations (MICs) of SMX and TMP alone and 20:1 (SMX : TMP) mixture (ST) were investigated by the method recommended by Ad Hoc Committee of the Japan Society of Chemotherapy for the Evaluation of Sensitivity Testing Methods for Sulfamethoxazole and Trimethoprim. MICs of ST were more potentiated than those of SMX alone in 8 of 9 gram positive strains and 40 of 43 gram negative strains. Especially, 38 strains of 40 intestinal bacteria showed significant susceptibility to ST as compared to SMX. These results suggest a strong synergistic activity of ST mixture against animal intestinal bacteria, The activity was considered to be comparable to those of other current antibiotics.

• 한국환경보건학회지
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• 제27권1호
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• pp.106-111
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• 2001

Recently there were many studies not only to enhance drug delevery effect but to reduce side effect. Drug delivery system efficiency with decreasing side effect of drug dosage. It made possibility to use for a long term. Polymer drug was prepared by acid halide method with polymer in such of polyacylic acid and sulfacetamide. Its chemical properties were identified by means of IR, TGA. The antibacterial activities of polymer drug were studied by MICs and disk susceptivility test. The antibacterial activities by clean zone were increased in order of Staphyloccus aures