• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6757-6760
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• 2013

Gastric cancer is one of the most frequently occurring malignancies in the world. Development of multiple drug resistance (MDR) to chemotherapy is known as the major cause of treatment failure for gastric cancer. Multiple drug resistance 1/P-glycoprotein (MDR1/p-gp) contributes to drug resistance via ATP-dependent drug efflux pumps and is overexpressed in many solid tumors including gastric cancer. To investigate the role of MDR1 knockdown on drug resistance reversal, we knocked down MDR1 expression using shRNA in drug resistant gastric cancer cells and examined the consequences with regard to adriamycin (ADR) accumulation and drug-sensitivity. Two shRNAs efficiently inhibited mRNA and protein expression of MDR1 in SGC7901-MDR1 cells. MDR1 knockdown obviously decreased the ADR accumulation in cells and increased the sensitivity to ADR treatment. Together, our results revealed a crucial role of MDR1 in drug resistance and confirmed that MDR1 knockdown could reverse this phenotype in gastric cancer cells.

• 한국수산과학회지
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• 제47권5호
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• pp.508-515
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• 2014

The contamination status of Vibrio parahaemolyticus in commercially valuable shellfish from the south and west coasts of Korea and the antimicrobial resistance patterns of isolated V. parahaemolyticus were investigated from July through October, 2011. The range of V. parahaemolyticus concentrations in oysters Crassostrea gigas and short neck clams Venerupis philippinarum was <30~290 MPN/100 g and <30~46,000 MPN/100 g, respectively, and greater than 10,000 MPN/100 g of V. parahaemolyticus was detected from 7 of 40 short neck clams. During the survey period, 436 strains of V. parahaemolyticus were isolated (129 from oysters and 307 from short-neck clams) and the antimicrobial resistance patterns of all of the isolates were examined. Antimicrobial resistance against at least one antibiotic was seen in 79.8% of the oyster isolates (103 strains) and 63.8% of the short neck clam isolates (196 strains). The antimicrobial resistance patterns were relatively simple because the antimicrobial resistance of the isolates was simply due to resistance to ampicillin. Only one oyster isolate and three short neck clam isolates showed multiple antibiotic resistance, i.e., resistance against more than four antibiotics.

• 대한의생명과학회지
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• 제5권1호
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• pp.17-26
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• 1999

Mar (multiple-antibiotic-resistance) 대장균의 marRAB 돌연변이가 그람음성 세균들 사이로 전파 될수 있는지를 알아보기 위해서, 염색체 위의 marRAB 돌연변이를 $\lambda$placMu9 (Km$^{r}$)를 이용하여 대장균의 다른 균주내의 pUC19 (Lac$^{+}$, Ap$^{r}$)의 클로닝 사이트, S. typhimurium 및 P. aeruginosa의 염색체 위로 각각 전달시킨 후, Mar phenotype, Km$^{r}$, Lac$^{-}$, 혹은 Ap$^{r}$ 균주를 선택한 다음, salicylate (SAL)의 유도 (induction) 유무에 따른 항생제 내성검사를 실시하였다. pUC19의 보유 유무에 관계없이 대조군인 야생형 대장균 JM109, NM522에 비해서, pUC19::marRAB 돌연변이를 가진 JM109 혹은 NM522의 대부분 균주들은 항생제 내성 수준들이 훨씬 더 높았으며, Mar표현형의 유도도 SAL에 의해서 훨씬 더 높게 나타났다. 하지만 일부 소수의 항생제에 대해서는 예외적으로 내성 수준이 더 낮게 나타났는데, 야생형 JM109 균주에서는 chloramphenicol (Cm)과 tetracycline (Tc)이 , pUC19::marRAB 돌연변이를 가진 NM522 균주 에서는 Tc와 ciprofloxacin (Cp)에 대한 내성 수준이 각각 더 낮게 나타났다. S. typhimurium 및 P. aeruginosa에 대한 같은 실험의 결과도 야생형 대장균의 경우와 거의 대부분 일치하였다. 형질전환 (transformation)과 형질도입 (transduction)의 방법을 주로 사용한 이 실험의 결과는, marRAB 돌연변이가 그람음성 세균들 사이로 전파될 수 있음을 간접적으로 암시한다.

• 대한미생물학회지
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• 제5권1호
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• pp.1-8
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• 1970

This report is to observe the rate of multiple resistance to various antibiotics among staphylococcus aureus and E. coli which were isolated with high frequency at our department during 1969. 1. One hundred fifty two strains(20.6%) resistant to four antibiotics multiple resistant was the highest incidence among 739 strains of Staphylococcus aureus. 2. Regarding the multiple antibiotic resistant of Staphylococcus aureus, 75strains(10.1%) to SA. PC. TC the three antibiotics resistant, have been observed, with the highest incidence, and next to this, 69 strains(9.3%) to SA. PC. SM. TC the four autibiotics resistant, and 68 strains(9.2%) to SA. PC. SM. CM. TC. SM. the six antibiotics resistant, have been observed in descending order. 3. The case of one hundred twenty seven strains(28.0%) of the six antibiotic multiple resistant among 454 strains of Escherchia coli was the highest incidence. 4. Concerning the multiple antibiotic resistant of Escherichia coli, 70 strains(l5.4%) to SA. SM. CM. TC. EM. FD. the six antibiotics resistant, have been observed, with the highest incidence, and next to this, 59 strains(l3.0%) to SA. SM. CM. TC. EM. FD. AC the seven antibiotics resistant, and 42 strains(9.3%) to SA. SM. CM. TC. EM. FD. KM. AC the eight antibiotics resistant have been observed in descending order.

• 대한환경공학회지
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• 제33권11호
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• pp.827-833
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• 2011

본 연구에서는 안산천을 대상으로 하천의 비점오염원 추적조사를 하였다. 사용된 Multiple Antibiotic Resistance Analysis (MARA) 기법은 사람과 각각의 동물의 장을 통해 배출되는 분변성 미생물들이 항생제에 대한 저항 정도가 다름을 이용하여 기지의 미생물에 대해 데이터베이스를 구축하고 미지 시료에 대해 통계적 분석을 통해 오염원을 찾아내는 방법이다. 안산천 유역을 크게 상류(축산농가지역), 중류(구시가지), 그리고 하류(신시가지) 지역으로 나누어 하천 유역의 환경적인 영향을 알아보고자 하였다. 통계 분석 결과, 가축, 애완 동물, 사람으로 구분한 3-Way 방법의 경우 45.8%가 가축으로 분류되어 상류 지역은 축산 농가 지역의 특성상 동물에 의한 영향이 큰 것으로 판단할 수 있었다. 중류는 구시가지 지역으로써 인간의 영향이 60% 이상으로 나타났으며, 하류 지역 역시 신시가지 지역으로 인간의 영향이 80% 이상으로 나타났다. 실제 현장 조사를 근거로 예상할 수 있었던 비점오염원과 MARA를 통한 분석 결과가 매우 일치하는 모습을 통해 비점오염원 추적을 위한 MARA기법의 유용성을 판단할 수 있었으며, 각 지역의 특성에 맞는 데이터 베이스 구축을 통해 효과적인 비점오염원의 추적이 가능할 것으로 기대된다.

• 한국가금학회지
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• 제42권1호
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• pp.27-32
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• 2015

In this study, we used two breeds of chicken to identify genomic regions corresponding to necrotic enteritis (NE) resistance. We scanned the genomes of a resistant and susceptible line of Fayoumi and White Leghorn chickens (20 birds/line) using a chicken 60 K Illumina SNP panel. A total of 235 loci with divergently fixed alleles were identified across the genome in both breeds; particularly, several clusters of multiple loci with fixed alleles were found in five narrow regions. Moreover, consensus 15-SNP haplotypes that were shared by the resistant lines of both breeds were identified on chromosomes 3, 7 and 9. Genes responsible for NE resistance were identified in chicken lines selected for resistance and susceptibility. Annotation of the regions spanning clustered divergently fixed regions revealed a set of interesting candidate genes such as phosphoinositide-3-kinase, regulatory subunit 5, p101 (PIK3R5) and inositol 1,4,5-trisphosphate receptor 1 (ITPR1), which participate in immune response. Consensus haplotypes were found in regions containing possibly relevant genes, such as myostatin and myosin, which play important roles in muscle development. Thus, genome scans of divergent selection in multiple chicken lines and breeds can be used to identify genomic regions associated with NE resistance.

• 대한수의학회지
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• 제41권4호
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• pp.511-521
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• 2001

Microorganisms were isolated and identified from bovine 296 quarters which showed positive reaction by California Mastitis Test (CMT) in 40 farms of Jeju from September 1999 to June 2000. The organisms associated with the mastitis of bovine were 11 different bacterial species in this study. Which of them, Staphylococcus aureus was the most predominant species as 152 (51.4%) isolates. Other identified species included 49 (16.5%) coliform, 47 (15.8%) Streptococcus dysgalactiae, 15 (5.1%) Bacillus spp., 8 (2.7%) Staphylococcus epidermidis, 6 (2.1%) Streptococcus agalactiae, 5 (1.7%) Enterococcus faecalis, 5 (1.7%) Corynebacterium spp., 3 (1.0%) Streptococcus uberis, 1 (0.3%) Pseudomonas aeruginosa and 1 (0.3%) Pasteurella haemolytica. Almost of all the islolated beacterial species showed high sensitivity against kanamycin (98.6%), cephalothin (98.0%), streptomycin (94.9%), gentamicin (94.6%), ampicillin (92.2%) and polymyxin B (90.2%). On the contrary, they showed resistance against penicillin (47.0%), tetracycline (37.2%), cefazolin (26.0%), bacitracin (22.6%) and erythromycin (19.9%). Eighty-one isolates were not resistant to any antibiotics and 215 drug resistant isolates showed 89 different drug resistance patterns from single to nine multiple antibiotics resistance patterns.

• 한국식품위생안전성학회지
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• 제22권2호
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• pp.116-119
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• 2007

돼지로부터 분리한 eae+Escherichia coli 67주에 대한 항생제 감수성 시험 결과, Ne에 41.8%, Li에 74.6%, DFX에 73.1%, ENR에 64.2%, Cef에 98.5%의 감수성을 나타내었다. 총 8종의 항생제에 대한 E. coli의 내성패턴을 분석하였을 때 12가지 내성 패턴을 나타내었으며, 그 중 4 제, 3 제 및 6제에 각각 26주(39%), 16 주(24%), 10주(14.9%)로 높았으며, 7종 항생제에 대해 내성을 나타내는 균주도 6주(8.9%)가 확인되었다. 본 실험에 의하면 최근에 사용되기 시작한 항생제의 경우 항생제 내성의 출현이 활발하지 않았으며, 지속적으로 노출된 항생제에 대해서는 감수성이 현저히 낮은 것으로 나타났다. Penicillin, Tetracycline, Neomycin은 본 실험에서 100%의 내성을 나타내며 돈육에서 분리되는 대장균간에 내성 전이가 활발한 것으로 추정되었다.

• 한국식물병리학회지
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• 제14권6호
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• pp.682-688
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• 1998

Fungicide resistance of 48 isolates of Botrytis cinerea collected from citrus in Cheju was investigated and genetic diversity was analyzed with random amplified polymorphic DNA(RAPD). High levels of resistance to benzimidazole fungicides benomyl and thiophanate-methyl and N-phenylcarbamate fungicide diethofencarb were observed. Negative cross resistance was clear between benzimidazole and N-phenylcarbamate fungicides, and multiple resistance to the fungicides was also observed. There was cross resistance among the dicarboximide fungicides procymidione, vinclozolin and iprodione as it was observed between the benzimidazole fungicides benomyl and thiophanate-methyl. The lowest levels of resistance were to the dicarboximide fungicides, but no sensitive isolate to polyoxin B was observed. The isolates showed genetically diverse RAPD profiles according to the geographic origin collected, but there was no significant correaltion between RAPD profiles of genomic DNA and the levels of fungicide resistance of the isolates. The isolates showed genetically diverse RAPD profiles, indicating that genetic differentiation had already occurred in the populations of B. cinerea distributed in Cheju.

• 전기학회논문지
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• 제65권9호
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• pp.1564-1570
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• 2016

This study proposes a newly modified form of existing ground electrodes in order to secure trust of grounding system for large current caused by a stroke of lightning. Proposed planar earth structure has a several needle electrodes around a circular rod and 4 plane electrodes in all directions. The plane electrodes are fused with the insulator on the linear rod, so that they're electrically isolated. The concept is to increase the discharge amount of earth structure using multiple discharge paths like needle and plane electrodes. To check the discharge efficiency of the suggested scheme, the discharge currents are compared with typically used two kinds of ground rods. To ensure accuracy in the measurement of the discharge current, the same material was used for the comparison model. Also, the ground resistance are simulated by CDEGS commercial software and the results are compared with measured data. Based on this kind of experimental study, the suggested ground rod can be used when designing a ground system or when constructing a ground system at the site.