• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3267-3274
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• 2014

In order to investigate the effects of the double replacement of $\small{L}$-Pro, $\small{D}$-Pro, $\small{D}$-Leu or Nleu (the peptoid residue for Leu) in the hydrophobic face (positions 9 and 13) of amphipathic ${\alpha}$-helical non-cell-selective antimicrobial peptide $L_8K_9W_1$ on the structure, cell selectivity and mechanism of action, we synthesized a series of $L_8K_9W_1$ analogs with double replacement of $\small{L}$-Pro, $\small{D}$-Pro, $\small{D}$-Leu or Nleu in the hydrophobic face of $L_8K_9W_1$. In this study, we have confirmed that the double replacement of $\small{L}$-Pro, $\small{D}$-Pro, or Nleu in the hydrophobic face of $L_8K_9W_1$ let to a great increase in the selectivity toward bacterial cells and a complete destruction of ${\alpha}$-helical structure. Interestingly, $L_8K_9W_1$-$\small{L}$-Pro, $L_8K_9W_1$-$\small{D}$-Pro and $L_8K_9W_1$-Nleu preferentially interacted with negatively charged phospholipids, but unlike $L_8K_9W_1$ and $L_8K_9W_1$-$\small{D}$-Leu, they did not disrupt the integrity of lipid bilayers and depolarize the bacterial cytoplasmic membrane. These results suggested that the mode of action of $L_8K_9W_1$-$\small{L}$-Pro, $L_8K_9W_1$-$\small{D}$-Pro and $L_8K_9W_1$-Nleu involves the intracellular target other than the bacterial membrane. In particular, $L_8K_9W_1$-$\small{L}$-Pro, $L_8K_9W_1$-$\small{D}$-Pro and $L_8K_9W_1$-Nleu had powerful antimicrobial activity (MIC range, 1 to $4{\mu}M$) against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Pseudomonas aeruginosa (MDRPA). Taken together, our results suggested that $L_8K_9W_1$-$\small{L}$-Pro, $L_8K_9W_1$-$\small{D}$-Pro and $L_8K_9W_1$-Nleu with great cell selectivity may be promising candidates for novel therapeutic agents, complementing conventional antibiotic therapies to combat pathogenic microorganisms.

• Journal of Periodontal and Implant Science
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• 제37권1호
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• pp.115-124
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• 2007

Silica is known as a promising osteoconductive material, and polycaprolactone is a bioactive and degradable material. The purpose of this study was to monitor the differentiation of MC3T3-E1 cells cultured on the layer-built silica/poly caprolactone non-woven fabric produced by electrospinning. Non-woven fabric (silica, polycaprolactone, PSP, SPS) was made by electrospinning and they were inserted in the 48 well cell culture plate. MC3T3-E1 cells were prepared by subculture. Cells were seeded to each well $1{\times}10^5$ concentration per well. Dulbecco's modified eagle medium with 10% FBS and 1% antibiotic-antimycotic solution was used. Confocal laser scanning microscope was taken 4 hours after incubation (95% air. 5% $CO_2$, $37^{\circ}C$). Cell proliferation was monitored by spectrophotometer on 1, 7, 14 days, and the morphology of the growing cells was observed by field emission scanning electron microscope. To monitor the differentiation of osteoblasts on the materials, MC3T3-E1 cells were incubated in 48 well culture plate after seeding with the density of $1{\times}10^5$ concentration. Then ELISA kit & EIA kit were used on to assess osteocalcin and osteopontin expression respectively. The other conditions were the same as above. MC3T3-E1 cells were proliferated well on all of the materials. There were no statistical differences among them. The osteopontin expression of silica, PSP, SPS was significantly higher than other groups on day 3 (p/0,05), but after that time, there were no statistically signigicant differences. The osteocalcin expression was significantly higher in silica and PSP than other groups on day 14. These findings show that PSP was as good as silica on the effect of osteoblast differentiation. The PSP non-woven fabric may have the possibility as bone graft materials.

• 생명과학회지
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• 제25권11호
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• pp.1319-1323
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• 2015

매년 어류 양식의 생산량은 증대되고 있으며, 생산량 증가를 위한 고밀도 사육은 수질 악화 및 어류들의 스트레스를 증가시켜 질병들이 잦아지게 된다. 이로 인한 경제적 피해는 어류 양식 어민들에게 있어 막대한 피해를 입게 되며, 이를 예방하기 위해 화학 요법인 항생제를 투여하게 된다. 본 연구에서는 항생제 대체 물질 및 안전 요법으로 알려진 프로바이오틱스를 분리하기 위해, 한국전통식품인 고추 장아찌와 갈치 젓갈에서 다양한 세균을 분리하였다. 분리 된 균주들은 16S rDNA 염기서열을 분석 및 동정하고, 상층액 및 균체로 나뉘어 항균 활성을 측정하였다. 고추 장아찌에서 분리된 4종과 갈치 젓갈에서 분리된 7종은 상층액 보다 균체에서 항균 활성이 높게 나타나는 것을 확인할 수 있었다. 그 중 JKM-2는 43 mm(S. iniae), 40 mm(S. parauberis), 35 mm(S. mutans), 26.5 mm(V. vuinificus)로 가장 높은 항균 활성을 나타냈다. 본 균주의 염기서열 분석 결과, Bacillus subtilis 97.71%, Bacillus tequilensis 97.71%, Brevibacterium halotolerans 97.71%, Bacilus subtils 97.63%, Bacillus subtlis 97.63%, Bacillus mojavensis 97.54%, Bacillus vallismortis 97.46%, Bacillus nanillea 97.45%, Bacillu smethylotrophicus 97.37%, Bacillu ssiamensis 97.37%로 분석되었다. 추후 JKM-3의 신종 균주 확인과 균체 물질 규명 및 분석을 통하여 충분한 안정성을 확보하고 양식 산업에 적용시켜 항생제 대체 물질로서의 이용가치를 확인하고자 한다.

• 생명과학회지
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• 제19권10호
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• pp.1438-1443
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• 2009

이 연구는 신장섬유아 세포를 이용하여 LPS에 의해 유도된 신장섬유화 표적유전자인 plasminogen activator inhibitor (PAI-1) 발현과 Ascofuranone (AF)에 의한 신장섬유화 저해효과를 연구하였다. 이 연구를 통해 LPS가 PAI-1의 발현을 농도 및 시간 의존적으로 증가시켜 LPS가 신장섬유화 유도물질임을 확인 할 수 있었다. 또한 LPS로 유도된 PAI-1 mRNA 및 단백질 발현 레벨이 AF에 의해 저해되었으며, 신장섬유화의 또 다른 대표유전자인 fibronectin의 단백질 발현도 AF에 의해 억제되어 AF가 신장섬유화를 저해하는 사실을 확인할 수 있었다. 그리고 AF에 대한 PAI-1 프로모터 활성을 조사하기 위하여 p800-PAI-1-luc을 신장섬유아 세포에 형질전환 시킨 결과, AF가 PAI-1의 전사 활성 조절을 통해 발현을 억제한다는 것을 확인하였다. ERK-1/2의 상위에 존재하는 MEK inhibitor를 처리하여 PAI-1의 발현을 확인한 결과에서도 AF를 처리한 경우와 동일하게 PAI-1 발현이 저해되어 LPS로 유도된 PAI-1의 발현이 ERK-1/2에 의해 조절됨을 알 수 있었다. 또한 LPS로 유도된 ERK-1/2의 인산화가 AF 농도의존적으로 저해된 결과는, AF가 ERK-1/2의 활성저해를 통하여 PAI-1 발현을 조절한다는 사실을 확인 할 수 있었다. 따라서 이러한 연구결과 AF가 신장섬유화를 저해하는 유력한 후보물질로서의 가능성을 제시하였다.

• 식물병연구
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• 제24권1호
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• pp.41-51
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• 2018

국내 과수 화상병은 2015년 사과 및 배에서 발생하여 큰 피해를 주고 있으나, 이에 대한 적절한 방제제는 등록되어 있지 않다. 다만 농촌진흥청은 무름병과 세균점무늬병 등 다른 식물세균병해에 등록되어 있는 살세균제들을 직권등록 시켜놓은 상태이다. 그러나 직권등록이란, 약효는 보증하지 않으면서 약해만을 보증하는 제도로, 국내에서 과수 화상병이 지속적으로 발생되고 있는 상황에서는 적절한 방제제를 선발하는 것이 요구되어지기에 본 연구를 수행하였다. 직권등록 국내 과수 화상병 방제제 중, 각각 4종의 농용항생제와 구리 합성 화학물 그리고 생물학적 방제제 2종에 대한 기내 검정법을 통하여 국내 과수 화상병원세균 억제 및 병징확산 억제효과를 검증하였다. Kasugamycin, Oxytetracycline 및 streptomycin의 항생제는 효과가 우수하였으며, oxolinic acid는 꽃에서의 억제효과는 우수하였지만 신초 및 미성숙과 기내검정에서는 다소 효과가 감소하였다. 4종의 구리 합성 화학물은 항생제만큼의 억제효과는 나타내지 않았지만, 사용가능한 수준으로 조사되었다. 또한 2종의 생물적 방제제는 처리시기 등을고려할 경우, 친환경 재배지에서는 사용 가능할 것으로 판단되었다. 한편 국내 과수 화상병원세균은 선발 방제제 중 항생제 저항성 유전자들을 가지고 있지 않고,화분매개충에 대한 영향도 없는 것으로 조사되었다.

• 한국가금학회지
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• 제34권2호
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• pp.137-141
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• 2007

본 연구는 Saccharomyces exguus의 첨가 급여가 육계 생산성 및 분내 유해가스 발생에 미치는 영향을 구명하기 위하여 수행되었다. 1일령 육계 수평아리(Ross strain) 270수를 공시하여 3처리 3반복 반복당 30수씩 완전 임의배치하였다. 처리구는 대조구인 항생제 첨가구 및 효모 0.5와 1.0% 처리구를 두었다. 본 실험에서 5주 종료 체중 및 증체율이 효모의 첨가 수준에 따라 유의하게 증가하였으며(P<0.05), 사료 요구율은 효모 첨가시 개선되는 경향이 보였으나, 유의성은 인정되지 않았다. 맹장 내 E. coli, Salmonella, Lactobacillus 수는 대조구인 항생제 첨가구와 비교하여 차이가 없었다. 암모니아 가스의 발생량은 대조구에 비해 유의하게 감소하였다(P<0.05). 계분 내 저급 지방산 및 휘발성 유기 화합물은 변화가 없었다. 본 연구 결과 육계에 Saccharomyces exguus급여는 생산성을 향상시키고 계분 내 암모니아 가스 발생량을 감소시켜 항생제 대체 및 환경 개선제로 이용 가능함을 시사하였다.

• Tuberculosis and Respiratory Diseases
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• 제41권2호
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• pp.120-126
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• 1994

연구배경 : 내과적 치료에 반응이 없는 폐농양 환자와 감염성 낭포환자에서 대체 치료방법은 폐농양 환자에서는 페엽절제술과 같은 수술이나 감염성 낭포환자에서는 계속적 항생제 투여였는데, 저자들은 이와같은 경우 직경이 작은 카테타로 국소마취하에 경피적 배농술을 시행하여 그 치료효과와 부작용을 알아 보고자 본 연구를 시행하였다. 방법 : 1주 이상의 항생제를 포함한 내과적 치료에 반응이 없고, 공동의 직경이 6cm 이상인 만성적 기저질환을 가지는 폐농양 환자 9에와 감염성 낭포환자 3예에서 흉부 단순촬영과 흉부 전산화 단층촬영 후 투시하에 seldinger 방법을 사용하여 8.3~12.3 Fr의 카테타를 삽입 후 배농시키면서 임상경과를 관찰하였다. 결과 : 카테타 삽입 후 농흉이 발생한, 폐암과 동반된 1예를 제외한 8예의 폐농양과 3예의 감염성 낭포에서 경피적 배농술 후 임상적 호전을 보였다. 배농 후 평균 1.9일 내 해열되었고, 평균 배농기간은 9.9일이였다. 7예에서 퇴원 후 1~7개월간 외래 관찰되었으며, 재발 등의 문제는 없었다. 결론 : 내과적 치료에 반응이 없는 거대 폐암 환자에게 경피적 배농술은 효과적이고 안전한 방법이므로, 수술보다 우선적으로 고려되어야 하겠다. 그러나 감염성 낭포환자에 대한 경피적 배농술은 본 연구의 결과만으로 내과적 치료보다 더 안전하고 효과적이라고 할 수 없으므로 더 많은 연구가 있어야 하겠다.

• 농촌의학ㆍ지역보건
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• 제18권2호
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• pp.105-119
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• 1993

The purpose of this study was to evaluate the program for the control of acute respiratory infections(ARI) in children in a Korean rural area(Yonchon county). Evaluating the program, we focused on the pattern of prescription and appropriateness of antibiotics prescribed by the health personnel who had participated in the ARI Control Program. It was implemented at the primary health care setting in rural area, such as district hospital, health subcenters, and health posts. During six-months programme monitoring period, medical records were reviewed and collected data were analysed by the pediatrician, research coordinator of this study. The baseline data were collected from medical records of the same period(six months) of one year before the implementation of the ARI programme. The study results were as follow : 1. Common cold was the most prevalent disease(78.7%. 594 cases) among the all ARI cases (755 cases). The less frequent cases were bronchitis(11.9%), acute pharyngitis(5.2%), and pneumonia(1.8%). 2. Significant reduction in the use of antibiotics was observed after the programme implementation. Ninety three(15.7%) of 594 common cold cases were received antibiotics compared with 282(35.2%) of 802 in the baseline period. In the cases of bronchitis and acute pharyngitis, the reduction rates were 15.1% and 23.2% respectively compared to the baseline period. 3. Mean duration of antibiotics prescription was 1.81-1.75 days, similar to the baseline data. 4. The appropriateness rate of antibiotics prescriptions were 84.3%(common cold), 35.6% (bronchitis) and 28.2%(acute pharyngitis). In the case of pneumonia, the antibiotics prescription was compatible to the criteria developed. 5. Pediatrician prescribed antibiotics more appropriately for all cases than general practitioners in health sub-center, and nurse practitioners in health posts. 6. Antibiotics therapy was shown to be of no effect in the treatment of the all ARI cases. At the 5 and 10 days check-up of common cold cases after visits, proportion of improved patients were 58.3% in the antibiotics-used group and 51.4% in the control group. In the other cases of ARI, the patterns of response were similar to common cold. None of the differences in outcome between the antibiotics-used and control group was statistically significant. This ARI programme may have substantial a substantial impact on antibiotics use at the public health institutions(district hospital, health subcenters, health posts) which are of major domain for primary health care in Korean rural areas.

• Asian-Australasian Journal of Animal Sciences
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• 제25권3호
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• pp.382-392
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• 2012

This study evaluated the effects of dietary anticoccidial drugs plus antibiotic growth promoters (AGPs) on parameters of immunity in commercial broiler chickens. Day-old chicks were raised on used litter from a farm with endemic gangrenous dermatitis to simulate natural pathogen exposure and provided with diets containing decoquinate (DECX) or monensin (COBN) as anticoccidials plus bacitracin methylene disalicylate and roxarsone as AGPs. As a negative control, the chickens were fed with a non-supplemented diet. Immune parameters examined were concanavalin A (ConA)-stimulated spleen cell proliferation, intestine intraepithelial lymphocyte (IEL) and spleen cell subpopulations, and cytokine/chemokine mRNA levels in IELs and spleen cells. ConA-induced proliferation was decreased at 14 d post-hatch in DECX-treated chickens, and increased at 25 and 43 d in COBN-treated animals, compared with untreated controls. In DECX-treated birds, increased percentages of $MHC2^+$ and $CD4^+$ IELS were detected at 14 d, but decreased percentages of these cells were seen at 43 d, compared with untreated controls, while increased $TCR2^+$ IELs were evident at the latter time. Dietary COBN was associated with decreased fractions of $MHC2^+$ and $CD4^+$ IELs and reduced percentages of $MHC2^+$, $BU1^+$, and $TCR1^+$ spleen cells compared with controls. The levels of transcripts for interleukin-4 (IL-4), IL-6, IL-17F, IL-13, CXCLi2, interferon-${\gamma}$ (IFN-${\gamma}$), and transforming growth factor${\beta}$4 were elevated in IELs, and those for IL-13, IL-17D, CXCLi2, and IFN-${\gamma}$ were increased in spleen cells, of DECX- and/or COBN-treated chickens compared with untreated controls. By contrast, IL-2 and IL-12 mRNAs in IELs, and IL-4, IL-12, and IL-17F transcripts in spleen cells, were decreased in DECX- and/or COBN-treated chickens compared with controls. These results suggest that DECX or COBN, in combination with bacitracin and roxarsone, modulate the development of the chicken post-hatch immune system.

• Asian-Australasian Journal of Animal Sciences
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• 제21권11호
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• pp.1651-1658
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• 2008

This study was conducted to determine the effects of dietary supplementation of either 100 mg/kg chito-oligosaccharide (COS) or chlortetracycline (CTC) with corn-soybean-fish meal on immunity in broiler chickens. A total of 147 one-day old male broiler chicks were randomly allocated to 3 treatments with 7 replicate pens per treatment and 7 birds per pen. The experimental diets consisted of a control diet based on corn, soybean and fish meal without COS and any antibiotic supplement and similar diets supplemented with either CTC (80 mg/kg from d 1 to 21 and 50 mg/kg from d 22 to 42) or COS (100 mg/kg from d 1 to 42). During the entire experimental period, all birds had ad libitum access to diets and water. The main immune organ indices, T-lymphocyte proliferation, serum cytokine concentrations, serum NO level and serum iNOS activity were measured on d 21 and d 42. On d 21, broilers fed 100 mg/kg COS had improved (p<0.01) indices of spleen, thymus, and bursa of Fabricius compared with the control and CTC birds. Birds receiving 100 mg/kg COS had higher (p<0.05) serum concentrations of $IL-1{\beta}$, IL-6, IgM, NO and iNOS than birds on the control treatment. Serum $Ca^{2+}$ level of birds fed 100 mg/kg COS tended to be higher (p = 0.049) than in birds fed CTC. On d 42, the birds fed 100 mg/kg COS had higher (p<0.05) concentrations of TNF-${\alpha}$ and IgM in serum than birds in both the CTC and control treatments. Birds fed 100 mg/kg COS had a higher concentration of IFN-$\gamma$ than the control group. In conclusion, dietary supplementation of COS appeared to improve the immunity of broilers by promoting the weight of the main immune organs, increasing IgM secretion, stimulating microphages to release $TNF-{\alpha}$, $IL-1{\beta}$, IL-6 and IFN-$\gamma$, and activating iNOS to induce NO.