• 대한수의학회지
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• 제36권3호
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• pp.541-550
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• 1996

Tetracycline antibiotics have been widely used not only therapeutics but feed additives. There are many methods for the isolation and determination of tetracycline antibiotics in animal muscle tissue. But those methods take much time and labor, so it is difficult to analyse many samples simultaneously. A rapid isolation method and liquid chromatographic determination of tetracycline antibiotics in animal muscle tissue (bovine, porcine, chicken) is presented. Blank control and tetracyclines fortified samples (0.5g) were blended with $C_{18}$ containing 0.05g each of oxalic acid and disodium ethylenediaminetetraacetate. After homogenize, homogenate was transferred to glass column made from 10ml glass syringe and compressed to 4~4.5ml volume. A column made from the $C_{18}$/meat matrix was washed with hexane (8ml) and dichloromethane (8ml, if needed), following which the tetracyclines were eluted,vith methanol or 0.01M methanolic oxalic acid (8ml). The eluates containing tetracyclines analytes were free from interfering compounds when analysed by HPLC with UV detection (photodiode array at 360nm). Standard curve for each tetracycline showed a linear response at the range of $0.05{\sim}1.0{\mu}g/ml$ and tetracycline antibiotics were eluted within 4ml of eluted volume. All tetracycline antibiotics except tetracycline were stable during the concentration process at $40^{\circ}C$ and time required for concentration was 3~4 hours. Fortified samples containing oxalic aicd and EDTA represented more good recoveries than those of not-contained sample. Recoveries were 91.8~110.1% (oxytetracycline; OTC), 57.7~79.5% (tetracycline; TC), 78.1~88.6% (chlortetracyclines; CTC) and 88.4~100.6% (doxycycline; DC) in pork tissue, 101.1~126.8% (OTC), 66.4~75.4% (TC), 79.2~88.1% (CTC) and 69.3~86.7% (DC) in beef tissue, and 90.8~95.6% (OTC), 66.2~84.4% (TC), 75.7~77.2% (CTC) and 55.6~80.7% (DC) in chicken muscle tissue. The detection limits validated in muscle tissue by this method were $0.05{\mu}g/g$ for OTC and TC, and $0.1{\mu}g/g$ for CTC and DC.

• 한국산학기술학회논문지
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• 제4권4호
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• pp.334-340
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• 2003

본 연구는 지황, 천궁, 감초, 오미자, 차전자, 산약, 둥글레, 당귀 그리고 황백 등을 배합한 복합생약제제의 비육돈 사료내 첨가가 성장율과 도체특성에 미치는 영향을 조사하기 위해 실시하였다. 시험 1은 개시시 체중 81.58±3.20㎏의 3원교잡종［(Duroc×Yorkshire)×Landrace］비육돈 80두를 공시하여 45일간 사양시험을 실시하였다. 시험설계는 옥수수-대두박 위주의 사료인 1) NC(negative control; antibiotics-free diet), 2) PC(positive control; NC diet added 0.1％ of chlortetracycline), 3) NCM(NC diet added 0.1％ of herbal plant mixture) 그리고 4) PCM(PC diet added 0.1％ of herbal plant mixture)의 4개의 처리구로 하여 처리당 5반복, 반복당 4두씩 완전임의 배치하였다. 시험 1에서는 사양기간동안 일당증체량에서는 대조구에 비해 생약제 첨가구인 HPM과 PHMP 처리구가 높았으며(P<0.08), 무항생제 처리구(NC)에 생약제를 첨가하므로서 체중의 증가 효과를 보였다. (P<0.01). 사료섭취량과 사료효율에 있어서는 PC처리구와 NCM처리구에서 증가를 보였으나 처리구간의 유의적인 차이는 없었다. Total protein에서는 항생제가 없는 대조구에 생약제를 첨가하므로서 증가 효과가 있었다(P<0.04). 시험 2는 개시시 체중 77.36±2.0l㎏의 3원교잡종［(Duroc×Yorkshire)×Landrace］ 비육돈 100두를 공시하여 28일간 사양시험을 실시하였다. 시험설계는 옥수수-대두박 위주의 사료인 1) NC(negative control; antibiotics-free diet), 2) PC(positive control; NC diet added 0.1％ of chlortetracycline), 3) PM0.1(NC diet added 0.1% of herbal plant mixture) 그리고 4) PM 0.2(NC diet added 0.2％ of herbal plant mixture)의 4개의 처리구로 하여 처리당 5반복, 반복당 5두씩 완전임의 배치하였다. 시험 2에서는 사양기간동안 PM0.1 처리구가 다른 처리구들보다 증체량이 증가 되었으나 유의적인 차이는 보이지 않았다. 도체중에서는 대조구가 다른 처리구와 비교하여 높게 평가되었다(P<0.06). 등지방 두께에서는 PC처리구가 다른 처리구보다 높았지만 유의적인 차이는 보이지 않았다. 하지만 도체 등급에서는 생약제를 첨가한 처리구가 대조구 보다 A등급율이 높게 나타났다(P<0.04). 이상의 결과로 종합하여 볼 때 비육돈 사료내 생약제의 첨가는 성장율이나 혈액 내 면역글로불린에 좋은 영향을 미치는 것으로 보인다.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.251-257
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• 2000

Chitin synthases are identified as key enzymes of chitin biosynthesis in most of the fungi. Among them, chitin synthase II has been reported to be and essential enzyme in chitin biosynthesis, and exists as a membrane-bound form. To search and screen new antifungal agents from natural resources to inhibit chitin synthase II, the assay conditions were established using the enzyme isolated from Saccharomyces cerevisiae ECY38-38A(pAS6) that overproduces only chitin synthase II. This enzyme was activated only by partial proteolysis with trypsin. Its actibity reached the maximum at $80{\;}\mu\textrm{g}/ml$ of trypsin and was strongly stimulated by 2.0 mM $Co^{2+}$, 1.0 nM UDP-[$^{14}C$]-GicNAc, and 32 mM free-GlcNAc. Under these assay conditions, the highest chitin synthase II activity was observed by incubation at $30^{\circ}C$ for 90 min. However, and extremely narrow range of organic solvents up to as much as 25% of DMSO and 25% of MeOH was useful for determining optimal assay conditions. After a search or potent inhibitors of chitin synthase II from natural resources, prodigiosin was isolated from Serratia marcescens and purified by solvent extration and silica gel column chromatographies. The structure of prodigiosin was determined by UV, IR, Mass spectral, and NMR spectral analyses. Its molecular weight and formula were found to be 323 and $C_{20}H_{25}N_{3}O$, respectively. Prodigiosin ingibited chitin synthase II by 50% at the concentration of $115{\;}\mu\textrm{g}/ml$.

• 한국환경성돌연변이발암원학회지
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• 제25권4호
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• pp.157-160
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• 2005

Biofilm 내부의 항생제 내성 박테리아의 성장형태는 만성감염과 질병을 발생한다. 인위적 형성한 biofilm의 체외실험 모델 시스템 통한 항생제 침투 실험을 수행하였다. 항생제 내성 균주 (E. coli, S. aureus)는 항생제 내성균주 은행으로부터 획득하였다 Ca-alginate bead를 인위적 biofilm으로 사용하였고, 세포 생존률을 향상시키기 위해 공기 압축을 이용한 세포 포획 실험도 측정되었다. biofilm의 항생제 감수성은 항생제의 농도 따라 최저 저해 농도 (MIC)를 이용하여 측정되었다. bead생성에 따른 안정성은 bead를 형성하지 않은 세포와 비교하여 감소하였다. 항생제에 민감한 E. coli의 경우 시간이 지남에 따라 균체수도 감소하였으나, 항생제 내성 E. coli는 일정한 균체수를 유지하였다. bead형성 후 항생제 투여 효과는 항생제 내성이 있고, 낮은 농도의 항생제를 처리할수록 더 높은 생존률을 보였다.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.46-55
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• 2022

Clostridioides difficile infection (CDI) is a significant cause of hospital-acquired and antibiotic-mediated intestinal diseases and is a growing global public health concern. Overuse of antibiotics and their effect on normal intestinal flora has increased the incidence and severity of infections. Thus, the development of new, effective, and safe treatment options is a high priority. Here, we report a new probiotic strain, Bacillus amyloliquefaciens (BA PMC-80), and its in vitro/in vivo anti-C. difficile effect as a prospective novel candidate for replacing conventional antibiotics. BA PMC-80 showed a significant anti-C. difficile effect in coculture assay, and its cell-free supernatant (CFS) also exhibited a considerable anti-C. difficile effect with an 89.06 ㎍/ml 50% minimal inhibitory concentration (MIC) in broth microdilution assay. The CFS was stable and equally functional under different pHs, heat, and proteinase treatments. It also exhibited a high sensitivity against current antibiotics and no toxicity in subchronic toxicity testing in hamsters. Finally, BA PMC-80 showed a moderate effect in a hamster CDI model with reduced infection severity and delayed death. However, further studies are required to optimize the treatment condition of the hamster CDI model for better efficacy and identify the antimicrobial compound produced by BA PMC-80.

• Journal of Plant Biotechnology
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• 제7권4호
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• pp.241-246
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• 2005

Factors affecting regeneration of different Rubus varieties (blackberry, raspberry and their hybrid) were examined and a reliable regeneration system was established. Media for stock plant maintenance were tested; different explants and media were investigated to find the best circumstances for the regeneration. The effect of the commonly used antibiotics was studied to determine the most suitable one for selection of the transformants. We found that both MS and LS media supplemented by $20\;gL^{-1}$ sucrose are suitable for the stock plant maintenance. The optimal hormone content for the stock plants is $0.125\;mgL^{-1}$ 6-benzylaminopurine (BAP) with $0.01\;mgL^{-1}$ indole-3- butyric acid (IBA). The highest regeneration rate was observed on medium containing MS salts with B5 vitamins complemented with glucose, sucrose, maltose, $10\;gL^{-1}$ each, supplemented with benzylaminopurine riboside (BAR) ($2\;mgL^{-1}$) and indole-3-acetic acid (IAA) ($0.1\;mgL^{-1}$). The regenerated shoots appeared directly from the cut edges, without callus phase. Hygromycin and geneticin proved to be good selection agents for the Rubus explants, but due to their severe effect on the tissues we propose to use marker-free constructions for the transformation.

• Journal of Korean Neurosurgical Society
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• 제29권10호
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• pp.1328-1332
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• 2000

We present a modified method for the treatment of brain abscess. The double lumen extraventricular drainage (EVD) catheter which was developed for the intracerebral hematoma management, was applied for the treatment of brain abscess drainage. We placed the double lumen EVD catheter into the abscess cavity by free-hand technique and irrigated the abscess cavity continuously with antibiotics solution for 7 days. Simultaneous intravenous antibiotics was administered for 4 weeks. The continuous irrigation with double lumen catheter was found to be safe and effective treatment modality in the brain abscess.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.1030-1036
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• 2018

Bacillus strains produce various types of antibiotics, and random mutagenesis has traditionally been used to overproduce these natural metabolites. However, this method leads to the accumulation of unwanted mutations in the genome. Here, we rationally designed a single nucleotide substitution in the degU gene to generate a B. subtilis strain displaying increased plipastatin production in a foreign DNA-free manner. The mutant strain (BS1028u) showed improved antifungal activity against Pythium ultimum. Notably, pps operon deletion in BS1028u resulted in complete loss of antifungal activity, suggesting that the antifungal activity strongly depends on the expression of the pps operon. Quantitative real-time PCR and lacZ assays showed that the point mutation resulted in 2-fold increased pps operon expression, which caused the increase in antifungal activity. Likewise, commercial Bacillus strains can be improved to display higher antifungal activity by rationally designed simple modifications of their genome, rendering them more efficient biocontrol agents.

• Reproductive and Developmental Biology
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• 제38권3호
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• pp.129-136
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• 2014

본 시험은 무항생제 사육방식이 한우육내 코티졸과 지방산 함량에 미치는 영향을 구명하고자 실시하였다. 무항생제 및 관행 축산으로 생산된 한우육 1등급 등심(M. longissimus)부위를 3가지의 브랜드별로 각각 3회씩 구매하여 시료로 공시하였고, 분석한 결과는 다음과 같다. 한우육 등심내 코티졸 함량은 무항생제 처리구에서 관행사육 처리구 대비 유의적(p=0.0176)으로 낮게 나타났으며, 포화지방산 및 불포화지방산 함량에서는 유의적(p>0.05)인 차이를 나타내지는 않았으나, 관행사육 처리구에서는 포화지방산이, 무항생제 처리구에서는 불포화지방산이 각각 높은 경향으로 분석되었다. 또한, 불포화지방산 중 n-3과 n-9 지방산을 제외한 n-6 지방산(linoleic acid, ${\gamma}$-linolenic acid)에서 유의적(p<0.01)인 차이를 보였다. 또한, 한우육내 코티졸 농도와 n-6 지방산 농도간의 상관관계를 분석한 결과, 특히 linoleic acid와 유의적(p=0.0140)으로 부(-)의 상관관계가 성립되었다. 결과적으로, 무항생제 인증으로 사육된 한우육은 관행적으로 사육된 한우육에서 보다 상대적으로 코티졸 함량이 낮았으며, 건강에 유익한 불포화지방산 함량이 다소 높은 경향으로 분석됨으로써 육질을 향상시키는 것으로 나타났다.

• Archives of Reconstructive Microsurgery
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• 제20권2호
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• pp.89-95
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• 2011

Purpose: The purpose of this study was to evaluate the clinical results of anterolateral thigh free flap on soft tissue defect following wide excision in malignant soft tissue tumor of lower extremities. Methods: Between February 2005 to April 2010, we followed up 19 cases who were undergoing anterolateral thigh free flap because of soft tissue defect following wide excision of malignant soft tissue tumor in lower extremity, including 9 cases were heel, 5 cases in foot, 3 cases in ankle, 2 cases in knee and leg. We observed that of implanted area's color, peripheral circulation at 3, 5, 7 days after operation and evaluated operating time, amount of hemorrhage, implanted skin necrosis, additional operations, complications. And we also evaluated the oncologic results, including local recurrence, metastasis, and morbidity. Results: Average operation time of wide excision and anterolateral thigh free flap was 7 hour 28 minutes. 18(94.7%) of total 19 cases showed successful engraftment, on the other hand, failure of engraftment due to complete necrosis of flap in 1 case. In 18 cases with successful engraftment, reoperation was performed in 4 cases. Among them, removal of hematoma and engraftment of flap after bleeding control was performed in 3 cases, because of insufficient circulation due to the hematoma. In the remaining 1 case, graft necrosis due to flap infection was checked, and grafted after combination of wound debridement and conservative treatment such as antibiotics therapy, also skin graft was performed at debrided skin defect area. Skin color change was mainly due to congestion with hematoma, flap was not observed global congestion or necrosis except 4 cases which shows partial necrosis on margin that treated with conservative therapy. Conclusions: Anterolateral thigh free flap could be recommended for reconstruction of soft tissue defect following wide excision of malignant soft tissue tumor in lower extremity.