• 한국식품위생안전성학회지
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• 제33권3호
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• pp.207-213
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• 2018

본 연구는 까마귀쪽나무열매추출물(LJF-HE)의 유전독성을 평가하고자 하였다. 유전독성연구는 OECD와 MFDS(Korea Ministry of Food and Drug Safety) 지침에 따라 복귀돌연변이시험, 염색체이상시험, 마우스 골수세포를 이용한 소핵시험을 실시하였다. 세균을 이용한 복귀돌연변이시험은 까마귀쪽나무열매추출물(LJF-HE) 처리군에서 S9 mix 존재유무에 상관없이 복귀돌연변이 콜로니 수는 음성 대조군과 비교하였을 때 증가 양상을 나타내지 않은 반면에 양성 대조물질에서 유발된 복귀돌연변이 콜로니 수는 대사활성계 미적용(S9-) 및 적용(S9+)의 모든 시험 균주에 대하여 음성(용매)대조 값의 2배를 넘어 증가한 것으로 나타났다. 염색체 이상 시험에서 까마귀쪽나무열매추출물(LJF-HE) 처리군에서 모든 세포주의 처리시간 및 S9 mix 존재유무에 상관없이 5%미만의 비정상적인 염색체이상을 나타내었으나, 음성대조군에 비해 유의적인 변화는 없었다. 소핵시험은 까마귀쪽나무열매추출물(LJF-HE) 처리군에서 음성 대조군과 비교하여 소핵을 가진 다염성 적혈구의 증가는 볼 수 없었으며 통계학적인 유의성도 나타나지 않았다. 상기의 결과를 종합하면 까마귀쪽나무열매추출물(LJF-HE)은 유전독성을 유발하지 않는 것으로 판단되어진다.

• 한방재활의학과학회지
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• 제25권2호
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• pp.1-13
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• 2015

Objectives Methicillin-Resistant Staphylococcus aureus (MRSA) is a human pathogen and a major cause of hospital-acquired infections. New antibacterial agents that have not been compromised by bacterial resistance are needed to treat MRSA-related infections. In this study, we investigated the antimicrobial activity ofethanol extract of Haedokgeumhwa-san (HGH) which prescription is composed of korean medicine against MRSA. Methods The antibacterial activity of HGH extract was evaluated against MRSA strains by using the Disc diffusion method, broth microdilution method (minimal inhibitory concentration; MIC), checkerboard dilution test, and time-kill test; its mechanism of action was investigated by bacteriolysis, detergent or ATPase inhibitors. The checkerboard dilution test was used to examined synergistic effect of ampicillin, oxacillin, ciprofloxacin, vancomycin, gentamicin and norfloxacin in combination with HGH ethanol extract. A time-kill assay was performed a survival curve which was obtained by plotting viable colony counts depending on time on bacterial growth. Results The minimum inhibitory concentration (MIC) of ethanol extract (HGH) ranged from 1,000 to $2,000{\mu}g/mL$ against all the tested bacterial strains, respectively. We are able to confirm that HGH extract has potentially strong antibacterial activity. In the checkerboard dilution test, fractional inhibitory concentration index of HGH in combination with antibiotics indicated synergy or partial synergism against S. aureus. A time-kill study showed that the growth of the tested bacteria was considerably inhibited after 8 hr of treatment with the combination of HGH with selected antibiotics. For measurement of cell membrane permeability, HGH $250{\sim}1,000{\mu}g/mL$ along with concentration of Triton X-100 (TX) and Tris-(hydroxymethyl) aminomethane (Tris) were used. In the other hand, N,N-dicyclohexylcarbodimide (DCCD) and Sodium azide ($NaN_3$) was used as an inhibitor of ATPase. TX, Tris, DCCD and $NaN_3$ cooperation against S. aureus showed synergistic action. Accordingly, antimicrobial activity of HGH was affected by cell membrane and inhibitor of ATPase. Conclusions These results suggest that Haedokgeumhwa-san extract has antibacterial activity, and that HGH extract offers a potential as a natural antibiotic against MRSA.

• 약학회지
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• 제40권5호
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• pp.608-615
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• 1996

6-[(N-3,4-Difluorophenyl)amino]-7-chloro-5,8-quinolinedione(RCK4) was tested for antifungal activities, against systemic infections with Candida albicans in normal mice. The therapeutic potential of RCK4 had been assessed in comparison with ketoconazole and fluconazole. RCK4 had $ED_{50},\;0.30{\pm}0.14$ but ketoconazole and fluconazole had $ED_{50},\;8.00{\pm}0.73,\;10.00{\pm} 0.43mg/kg$ respectively. Intraperitoneally administered RCK3 at the $ED_{50}$ for 7 days and 14 days reduced Candida albicans colony count in the kidneys and liver as well as ketoconazole and fluconazole at these $ED_{50}$. And administered RCK4 at the $ED_{50}$ for 14 days improved survival rates as well as ketoconazole. Acute oral toxicity studies of RCK4 were carried out in ICR mice of both sexes. These acute oral toxicities of RCK4 were low and $LD_{50}$ values were over 2,850mg/kg in ICR mice. The genotoxicities of RCK4 had been evaluated. RCK4 was negative in Ames test with Salmonella typhimurium and chromosomal aberration test in CHL cells. The clastogenicity was tested on the RCK4 with in vivo mouse micronucleus assay. RCK4 did not show any clastogenic effect in mouse peripheral blood and was negative in mouse micronucleus assay. These results indicate that RCK4 has no genotoxic potential under these experimental conditions.

• 대한소아치과학회지
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• 제31권4호
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• pp.671-679
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• 2004

레이저와 플라스마 광, 할로겐 광 중합기를 이용하여 각 개인의 우식 활성토를 측정할 수 있는지를 규명하기 위해 7-8세 아동 45명을 대상으로 치아의 순면과 협면에 각 광원을 조사하고 특수 필터를 사용하여 초기 치아우식증으로 판별된 치아의 개수를 측정하여 기존의 우식활성도 측정방법인 dDfFtT rate와 mutans streptococci 측정법, Lactobacilli 측정법과 비교, 평가하고 그 특이도, 민감도, 예측력을 평가하였다. 1. 아르곤 레이저, 플라스마 광, 할로겐 광 조사시 육안검사시 보다 유의하게 많은 초기우식 병소가 관찰되었다(p<0.05). 2. 아르곤 레이저, 플라스마 광, 할로겐 광을 이용한 우식활성도 측정법은 dDfFtT rate와 양의 상관관계 (${\gamma}=0.42,\;0.41,\;0.39$)를 보였다(p<0.01). 3. 기존의 우식활성도 측정방법을 기준으로 하여 평가한 결과 특이도와 민감도, 예측력은 모두 레이저가 가장 높았으며 플라스마 광, 할로겐 광 순으로 나타났다. 이상의 결과를 종합하여 볼 때 아르곤 레이저와 플라스마 광, 할로겐 광을 이용한 형광법은 모두 양호한 진단학적 지표를 보여줌으로써 향후 광학적 우식활성검사법으로 활용 가능성이 높을 것으로 사료된다.

• Animal Bioscience
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• 제35권2호
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• pp.281-289
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• 2022

Objective: The aim of this study was to characterize the exopolysaccharides (EPS)-producing lactic acid bacteria from Taiwanese ropy fermented milk (TRFM) for developing a clean label low-fat fermented milk. Methods: Potential isolates from TRFM were selected based on the Gram staining test and observation of turbid suspension in the culture broth. Random amplified polymorphic DNA-polymerase chain reaction, 16S rRNA gene sequencing, and API CHL 50 test were used for strain identification. After evaluation of EPS concentration, target strains were introduced to low-fat milk fermentation for 24 h. Fermentation characters were checked: pH value, acidity, viable count, syneresis, and viscosity. Sensory evaluation of fermented products was carried out by 30 volunteers, while the storage test was performed for 21 days at 4℃. Results: Two EPS-producing strains (APL15 and APL16) were isolated from TRFM and identified as Lactococcus (Lc.) lactis subsp. cremoris. Their EPS concentrations in glucose and lactose media were higher than other published strains of Lc. lactis subsp. cremoris. Low-fat fermented milk separately prepared with APL15 and APL16 reached pH 4.3 and acidity 0.8% with a viable count of 9 log colony-forming units/mL. The physical properties of both products were superior to the control yogurt, showing significant improvements in syneresis and viscosity (p<0.05). Our low-fat products had appropriate sensory scores in appearance and texture according to sensory evaluation. Although decreasing viable cells of strains during the 21-day storage test, low-fat fermented milk made by APL15 exhibited stable physicochemical properties, including pH value, acidity, syneresis and sufficient viable cells throughout the storage period. Conclusion: This study demonstrated that Lc. lactis subsp. cremoris APL15 isolated from TRFM had good fermentation abilities to produce low-fat fermented milk. These data indicate that EPS-producing lactic acid bacteria have great potential to act as natural food stabilizers for low-fat fermented milk.

• 한국식품위생안전성학회지
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• 제28권3호
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• pp.234-240
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• 2013

본 연구는 E. coli와 S. typhimurium을 대상으로 orthophenylphenol 20%를 함유한 훈증소독제, Fumagari OPP$^{(R)}$의 살균효과를 평가하기 위해 수행되었다. 예비 시험에서, E. coli와 S. typhimurium의 현탁액 균수는 모두 $4.0{\times}10^8CFU/mL$이었으며, 모든 훈증소독제에 노출시킨 담체의 균수는 모두 평판배지법과 여과법으로 배양한 시험균주 현탁액의 균수의 50%보다 많았다. 또한, 대조 담체로부터 회복된 E. coli와 S. typhimurium 균수는 모두 $3.4{\times}10^6CFU/mL$이었다. 훈증소독제의 살균효과 시험에서는, 훈증소독제를 처리한 담체의 E. coli와 S. typhimurium의 감소 균수는 각각 5.64와 5.26 logCFU/mL로 나타났다. 이상의 결과로부터, 훈증소독제, Fumagari OPP$^{(R)}$은 E. coli와 S. typhimurium에 대해 효과적인 살균력을 갖는 것으로 확인되었으며, 병원성 세균에 오염된 식품재료 및 주방용품의 소독에 적용할 수 있을 것으로 사료된다.

• 대한미생물학회지
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• 제22권1호
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• pp.35-53
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• 1987

Multiply resistant Shigella strains isolated in Taegu area were subjected for the characterization of R plasmids. All strains isolated in 1984 and 1985 were susceptible to gentamicin, amikacin, and cephalothin, and most strains were susceptible to kanamycin (Km) and rifampin by agar dilution antimicrobial susceptibility test. The resistance frequency of S. flexneri against ampicillin (Ap) was higher than that of S. sonnei. The strains resistant to sulfisomidine (Su) and trimethoprim (Tp) were found at higher frequency in S. sonnei than in S. flexneri. The most prevalent resistance pattern of S. flexneri was chloramphenicol (Cm) tetracycline (Tc) streptomycin (Sm) Ap, followed by the pattern of CmTcSmSuApTp, CmTcSmSuApTp nalidixic acid, and CmTcSmSuAp in the decreasing order. The antibiogram of CmTcSmSuTp was found to be the most frequent pattern in S. sonnei. The ratio of conjugal transfer of S. flexneri was 47% and 75% of S. sonnei. The average number of plasmid harboring in Shigella was 4 and the size of plasmid ranged 1.3 to 134 megadalton (Mdal). Most S. flexneri carried plasmids of 2 to 3 Mdal and S. sonnei carried those of 3 to 4 Mdal size. The sizes of conjugative plasmids ranged 40-90 Mdal. The incompatibility group (Inc) F II plasmids (54-59 Mdal) were most frequent and rare Inc B plasmids (60 Mdal) of isolates in 1979 and 1980 and Inc FI (87 Mdal) of 1983 isolates were able to be classified by the colony test with standard reference plasmids. The R plasmids of known Inc group were tested for the restriction endonuclease analysis. The pattern of plasmids digested by EcoRl were apparently different by the Inc group but there was no significant difference between species or by the resistance patterns. Nonconjugative plasmids and their phenotypes were identified by transformation test. The transformants were resistant to less than two drugs. Colicin producing transformants carried the Col plasmid of 3.7 or 3.9 Mdal size. $Ap^r$ plasmids derived from S. sonnei were found to be mobilized by transfer factor RT641 to E. coli #CS100. $Ap^r$ plasm ids of same size shared by S. flexneri, S. sonnei, and E. coli were digested with Pstl. All of them showed two restriction fragments of 2.8 kilobase(kb) and 0.7kb. Other plasmids ($Sm^r\;Su^r$) derived from S. flexneri, S. boydii, and S. sonnei were digested with Pstl and they showed same restriction fragment patterns of 3.1kb and 2.9kb. The plasmid profiles of three strains of S. sonnei producing colicin and showing same resistance pattern of CmTcSmSuApTpKm appeared to be similar. Restriction patterns by EcoRl and the behavior of plasmids in conjugation or transformation process were also similar between those plasmids. The restriction patterns were significantly different between the plasmids of Inc FI group and those of unclassified Inc group.

• 대한임상검사과학회지
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• 제38권3호
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• pp.166-172
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• 2006

Metallo-${\beta}$-lactamase (MBL) can hydrolyze all ${\beta}$-lactams except monobactams and frequently coexists with various antibiotic resistance genes such as aminoglycoside resistance, sulfonamide resistance gene, etc. Therefore, the effective antibiotics against infections by these bacteria are markedly limited or can't even be found. We tried to search in-vitro antimicrobial combinations with synergistic effects for a VIM-2 type MBL producing Pseudomonas aeruginosa, isolated from clinical specimen. On the selection of antibiotic combinations with synergistic effects, we performed a one disk synergy test, modified Pestel's method, in agar without aztreonam (AZT). The bacteriostatic synergistic effects of this tests were scored as $S_1$ (by susceptibility pattern in agar without antibiotics), $S_2$ (by the change of susceptibility in agar with or without antibiotics) and $S_3$ ($S_1$ + $S_2$) and was classified into weak (1 point), moderate (2 points) and strong (3 points) by $S_3$ score. Subsequently, we carried out the time-killing curve for the antibiotic combinations with the strong synergistic bacteriostatic effect. One VIM-2 type MBL producing P. aeruginosa confirmed by the PCR showed all resistance against all ${\beta}$-lactams except AZT, aminoglycoside and ciprofloxacin. In the one disk synergy test, this isolate showed a strong bacteriostatic synergistic effect for the antibiotic combination of AZT and piperacillin-tazobactam (PIP-TZP) or AZT and amikacin (AN). On the time-killing curve after six hours of incubation, the colony forming units (CFUs/mL) of this bacteria in the medium broth with both combination antibiotics were decreased to 1/18.7, 1/17.1 of the least CFUs of each single antibiotics. The triple antibiotic combination therapy including AZT, PIP-TZP and AN was shown to be significantly synergistic after 8 hrs of exposure. In a VIM-2 MBL producing P. aeruginosa with susceptibility for AZT, the triple antibiotic combination therapy including AZT, PIP-TZP and AN may be considered as an alternative antibiotics modality against the infection by some MBL type. But the antimicrobial combination therapy for many more MBL producing isolates is essential to know as soon as possible for the selection of effective treatment against the infection by this bacteria.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.490-494
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• 2004

An efficacy test of PRP (polyribosylribitol phosphate)-TT (Tetanus toxoid) conjugate vaccines was carried out using BALB/c mice as an animal model by inoculating Haemophilus in­fluenzae type b (Hib) with a virulence enhancement factor (VEF). Three administrations of the conjugate vaccines at 2-week intervals elicited a significantly high level of PRP antibodies (P>0.0001). The protective activity of the PRP immunization was challenged with either Hib with iron dextran (Hib/) or with a combination of mucin and hemoglobin (Hibmh) as a VEF. The me­dium lethal dose $(LD_{50})$ for Hibmh and Hibiwas measured as 10 CFU (Colony Forming Unit) and $2.5{\times}10^{8}$ CFU respectively. Each immunized animal was challenged with five or ten times the $LD_{50}$ level of bacteria with a VEF. A significant difference in mortality between the immunized and control mice (P> 0.01) was observed with the Hibmh challenge inoculation but not with the Hibi challenge inoculation. These results show that a combination of mucin and hemoglobin was able to enhance the virulence of Hib in BALB/c mice to cause a lethal infection, thus suggesting that BALB/c mice introduced to this method can be an effective model animal for testing the protective efficacy of H. influenzae conjugate vaccines.

• Restorative Dentistry and Endodontics
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• 제38권1호
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• pp.36-42
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• 2013

Objectives: This study evaluated the antibacterial effect and mechanical properties of composite resins ($L_{CR}$, $M_{CR}$, $H_{CR}$) incorporating chitosan with three different molecular weights (L, Low; M, Medium; H, High). Materials and Methods: Streptococcus (S). mutans 100 mL and each chitosan powder were inoculated in sterilized 10 mL Brain-Heart Infusion (BHI) solution, and was centrifuged for 12 hr. Absorbance of the supernatent was measured at $OD_{660}$ to estimate the antibacterial activities of chitosan. After S. mutans was inoculated in the disc shaped chitosan-containing composite resins, the disc was cleansed with BHI and diluted with serial dilution method. S. mutans was spread on Mitis-salivarius bacitracin agar. After then, colony forming unit (CFU) was measured to verify the inhibitory effect on S. mutans biofilm. To ascertain the effect on the mechanical properties of composite resin, 3-point bending and Vickers hardness tests were done after 1 and 3 wk water storage, respectively. Using 2-way analysis of variance (ANOVA) and Scheffe test, statistical analysis was done with 95% significance level. Results: All chitosan powder showed inhibition effect against S. mutans. CFU number in chitosan-containing composite resins was smaller than that of control resin without chitosan. The chitosan containing composite resins did not show any significant difference in flexural strength and Vickers hardness in comparison with the control resin. However, the composite resin, $M_{CR}$ showed a slightly decreased flexural strength and the maximum load than those of control and the other composite resins $H_{CR}$ and $L_{CR}$. Conclusions: $L_{CR}$ and $H_{CR}$ would be recommended as a feasible antibacterial restorative due to its antibacterial nature and mechanical properties.