• Tuberculosis and Respiratory Diseases
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• 제42권1호
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• pp.35-41
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• 1995

연구배경: 결핵성 경부임파선염의 진단은 임상소견, 흉부 X-선검사, 튜베르큘린검사의 비관혈적 방법으로 내리기 어려워, 경부 임파절 생검을 필요로 하는 경우가 많다. 저자들은 종합효소연쇄반응(polymerase chain reaction, PCR) 기법을 이용하여 결핵성 경부임파선염을 진단할 수 있는지 알아보고, 가능하다면 그 유용성을 평가해 보고자 본 연구를 시행하였다. 방법: 경부 종물로 내원한 환자의 생검 조직과 세침흡인 검체 29예에서 DNA를 추출하여, 결핵균 DNA인 IS6110의 일부를 복제하기 위한 IS-1,-2를 primer로 사용하여 PCR을 시행하였다. 결과는 임상적 진단 및 병리, 세균학적 진단과 비교하였다. 결과: 평균 107.5mg의 생검조직과 2회 세침흡인 검체에서 추출한 DNA의 양은 각각 평균 $32.46{\pm}17.22mg$과 $220{\pm}140ng$이었고 $OD_{260}/OD_{280}$은 각각 $2.11{\pm}0.23,\;2.76{\pm}0.39$이었으며, 상존유전자인 $\beta$-actin 유전자를 목표로 하는 PCR은 전예에서 양성이었다. 병리학적으로 결핵으로 진단한 8예중 8예 전예에서, 병리소견상 확진되지 않았으나 임상적으로 결핵성 경부임파선염으로 진단한 8예중 5예에서, 병리학적으로 악성 임파절전이나 갑상선낭종으로 진단되어 결핵성 경부임파선염이 배제된 6예중 0예에서, 그리고 임상적으로 결핵성 경부임파선염이 배제된 7예중 2예에서, 결핵균 DNA를 목표로 한 PCR 결과가 양성이었다. 결론: 경부 임파절 조직과 세침흡인 검체의 결핵균 PCR 기법은 결핵성 경부임파선염의 진단에 유용한 방법이라고 생각한다.

• 한국미생물·생명공학회지
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• 제45권4호
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• pp.358-364
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• 2017

Asymmetric PCR preferentially amplifies one DNA strand for use in DNA hybridization studies. Linear-After-The-Exponential-PCR (LATE-PCR) is an advanced asymmetric PCR method which uses innovatively designed primers at different concentrations. This study aimed to optimise LATE-PCR parameters to produce single-stranded DNA of Candida spp. and Aspergillus spp. for detection via probe hybridisation. The internal transcribed spacer (ITS) region was used to design limiting primer and excess primer for LATE-PCR. Primer annealing and melting temperature, difference of melting temperature between limiting and excess primer and concentration of primers were optimized. In order to confirm the presence of single-stranded DNA, the LATE-PCR product was hybridised with digoxigenin labeled complementary oligonucleotide probe specific for each fungal genus and detected using anti-digoxigenin antibody by dot blotting. Important parameters that determine the production of single-stranded DNA in a LATE-PCR reaction are difference of melting temperature between the limiting and excess primer of at least $5^{\circ}C$ and primer concentration ratio of excess primer to limiting primer at 20:1. LATE-PCR products of Candida albicans, Candida parapsilosis, Candida tropicalis and Aspergillus terreus at up to 1:100 dilution and after 1 h hybridization time, successfully hybridised to respective oligonucleotide probes with no cross reactivity observed between each fungal genus probe and non-target products. For Aspergillus fumigatus, LATE-PCR products were detected at 1:10 dilution and after overnight hybridisation. These results indicate high detection sensitivity for single-stranded DNA produced by LATE-PCR. In conclusion, this advancement of PCR may be utilised to detect fungal pathogens which can aid the diagnosis of invasive fungal disease.

• 미생물학회지
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• 제43권3호
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• pp.179-185
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• 2007

본 연구는 polymerase chanin reaction(PCR)기법과 DNA enzyme-linked immunosorbent assay(DNA ELISA) 기법을 이용하여 토양내 식물병원균인 Ralstonia solanacearum를 검출하고자 하였다. 토양 시료로부터 분석에 사용될 R. solanacearum DNA를 추출하기 위하여 몇 가지 방법을 비교 평가한 결과 기존의 DNA 추출 방법에 비하여 Guanidin isothiocyanate와 Chelex-100 resin을 사용하는 방법 이 토양 내에 존재하는 다양한 중류의 반응 저해 물질과 R. solanacearum만의 고유한 PCR반응 저해물질들을 제거하는 데에 효과적이었다. R. solanacearum만을 특이적으로 검출하기 위해 fliC유전자 부위에 특이적인 몇 종의 primer들을 제작하였다. 이들 중 높은 민감도와 특이도를 나타내는 두 set의 primer RsolfliC(forward; 5-GAACGCCAACGGTGCGAACT-3 and reverse; 5-GGCGGCCTTCAGGGAGGTC-3, designed by J. $Sch\ddot{o}nfeld$ et al.)와 RS_247 (forward; 5-GGCGGTCTGTCGGCRG-3 and reverse; 5-CGGTCGCGTTGGCAAC-3, designed by this study)를 선정하여 nested PCR을 수행할 수 있도록 고안하였다. Nested PCR primer에 biotin을 표지하였고 nested PCR산물의 내부 서열과 특이적으로 교잡반응을 할 수 있는 probe를 제작하여 PCR 결과를 DNA-EIA반응으로 확인 분석할 수 있도록 하였다. Primary PCR과 nested PCR의 산물을 전기영동 상에서 확인한 결과, nested PCR이 약 $10^2$정도의 높은 민감도를 나타내었고 DNA-EIA의 경우 $10^2P{\sim}10^3$정도의 민감도를 상승시켜주는 것으로 확인되었다.

• Journal of Microbiology
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• 제44권2호
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• pp.155-161
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• 2006

Comparative analysis of microbial communities in a sequencing batch reactor which performed enhanced biological phosphorus removal (EBPR) was carried out using a cultivation-based technique and 16S rRNA gene clone libraries. A standard PCR protocol and a modified PCR protocol with low PCR cycle was applied to the two clone libraries of the 16S rRNA gene sequences obtained from EBPR sludge, respectively, and the resulting 424 clones were analyzed using restriction fragment length polymorphisms (RFLPs) on 16S rRNA gene inserts. Comparison of two clone libraries showed that the modified PCR protocol decreased the incidence of distinct fragment patterns from about 63 % (137 of 217) in the standard PCR method to about 34 % (70 of 207) under the modified protocol, suggesting that just a low level of PCR cycling (5 cycles after 15 cycles) can significantly reduce the formation of chimeric DNA in the final PCR products. Phylogenetic analysis of 81 groups with distinct RFLP patterns that were obtained using the modified PCR method revealed that the clones were affiliated with at least 11 phyla or classes of the domain Bacteria. However, the analyses of 327 colonies, which were grouped into just 41 distinct types by RFLP analysis, showed that they could be classified into five major bacterial lineages: ${\alpha},\;{\beta},\;{\gamma}-$ Proteobacteria, Actinobacteria, and the phylum Bacteroidetes, which indicated that the microbial community yielded from the cultivation-based method was still much simpler than that yielded from the PCR-based molecular method. In this study, the discrepancy observed between the communities obtained from PCR-based and cultivation-based methods seems to result from low culturabilities of bacteria or PCR bias even though modified culture and PCR methods were used. Therefore, continuous development of PCR protocol and cultivation techniques is needed to reduce this discrepancy.

• 한국식품위생안전성학회지
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• 제38권5호
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• pp.347-355
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• 2023

본 연구에서는 시가독소 생성 대장균(STEC)을 검출하기 위해 식품공전의 polymerase chain reaction (PCR)검사법과 loop-mediated isothermal amplification (LAMP)를 비교하였다. PCR 및 LAMP의 검출 한계(LOD) 및 정량화 한계(LOQ), 민감도, 특이성 및 효율성을 평가하기 위해 다양한 식품에 STEC를 접종하였다. LOD는 PCR의 경우 10⁴ CFU/mL 이하, LAMP의 경우 10³ CFU/mL 이하로 측정되었다. LOQ 값은 PCR과 LAMP 간에 차이가 없었다. 그러나 4가지 식품군에서 민감도는 양념육이 최대 11.1%, 간소고기가 최소 8.1% 차이가 났다. LAMP는 네 가지 음식 유형 모두에 대해 높은 민감도와 100% 특이도를 보였다. 따라서 LAMP는 식품 유형에 따라 검출률이 비슷하고 특이도와 민감도가 식품공전 PCR보다 우수하기 때문에 STEC에 대한 신뢰할 수 있는 분자 검출 방법이다.

• The Plant Pathology Journal
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• 제30권2호
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• pp.178-182
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• 2014

Among imported plants, seeds are the items that have many latent pathogens and are difficult to inspect. Also, they are the import and export items whose market is expected to expand. The biggest problem with seeds is viruses. Prune dwarf virus (PDV) is the virus that is commonly inspected in Prunus cerasifera, P. persica, P. armeniaca, P. mandshurica, P. cerasus, P. avium or P. serotina seeds. In this study, two RT-PCR primer sets, which can promptly and specifically diagnose plant quarantine seed-transmitted PDV, were developed; and nested PCR primers, where products amplify 739 and 673 nucleotides (nt), and an nested PCR-product, 305 nt, can be obtained as these products are amplified again, were developed. Also, a modified-positive control plasmid was developed, where the restriction enzyme XhoI, which can identify the contamination of samples from the control, was inserted. The method developed in this study has detected PDV in 18 cases since 2007, and is expected to continuously contribute to the plant quarantine in Korea.

• Nuclear Engineering and Technology
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• 제45권5호
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• pp.573-580
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• 2013

The combined effects of reactivity coefficients, along with other core nuclear characteristics, determine reactor core behavior in normal operation and accident conditions. The Power Coefficient of Reactivity (PCR) is an aggregate indicator representing the change in reactor core reactivity per unit change in reactor power. It is an integral quantity which captures the contributions of the fuel temperature, coolant void, and coolant temperature reactivity feedbacks. All nuclear reactor designs provide a balance between their inherent nuclear characteristics and the engineered reactivity control features, to ensure that changes in reactivity under all operating conditions are maintained within a safe range. The $CANDU^{(R)}$ reactor design takes advantage of its inherent nuclear characteristics, namely a small magnitude of reactivity coefficients, minimal excess reactivity, and very long prompt neutron lifetime, to mitigate the demand on the engineered systems for controlling reactivity and responding to accidents. In particular, CANDU reactors have always taken advantage of the small value of the PCR associated with their design characteristics, such that the overall design and safety characteristics of the reactor are not sensitive to the value of the PCR. For other reactor design concepts a PCR which is both large and negative is an important aspect in the design of their engineered systems for controlling reactivity. It will be demonstrated that during Loss of Regulation Control (LORC) and Large Break Loss of Coolant Accident (LBLOCA) events, the impact of variations in power coefficient, including a hypothesized larger than estimated PCR, has no safety-significance for CANDU reactor design. Since the CANDU 6 PCR is small, variations in the range of values for PCR on the performance or safety of the reactor are not significant.

• Tuberculosis and Respiratory Diseases
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• 제69권4호
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• pp.250-255
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• 2010

Background: The purpose of this study was to evaluate recently developed real-time polymerase chain reaction (PCR) assay kit to detect Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM) in respiratory specimens. Methods: We assessed the positive rate of the real-time PCR assay to detect MTB and NTM in 87 culture-positive specimens (37 sputum, 50 bronchial washing), which were performed real-time PCR by using $Real-Q_{TM}$ MTB&NTM Kit from January 2009 to June 2009, at Gyeongsang University Hospital. To compare the efficacy with the TB-PCR assay, we evaluated 63 culture-positive specimens (19 sputum, 44 bronchial washing) for MTB or NTM, which were performed TB-PCR by using ABSOLUTETM MTB II PCR Kit from March 2008 to August 2008. Results: Among 87 specimens tested using real-time PCR, MTB and NTM were cultured in 58 and 29, respectively. The positive rate of real-time PCR assay to detect MTB was 71% (22/31) and 92.6% (25/27) in AFB stain-negative and stain-positive specimens. For NTM, the positive rate of real-time PCR was 11.1% (2/18) and 72.7% (8/11) in AFB stain-negative and stain-positive specimens. Among 63 specimens performed using TB-PCR, MTB and NTM were cultured in 46 and 17, respectively. The positive rate of TB-PCR was 61.7% (21/34) and 100% (12/12) in AFB stain-negative and stain-positive specimens. TB-PCR was negative in all NTM-cultured 17 specimens. Conclusion: TB/NTM real-time PCR assay is useful to differentiate MTB and NTM in AFB stain-positive respiratory specimens and it is as effective in detecting MTB with TB-PCR.

• 대한바이러스학회지
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• 제30권3호
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• pp.171-178
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• 2000

Herpes simplex virus, Varicella zoster virus and Human herpes virus-6 caused central nervous system infections and latent infections but there is no data of the 3 viruses being tested from the same cerebrospinal fluid samples with aseptic meningitis or encephalitis in adults patients. These viruses produced similar neurologic symptoms but difficulties existed in differentiating of etiologic agents and therefore the viruses needed to be detected in the early state. Herpes simplex virus encephalitis (HSVE) in adults, if not treated promptly was fatal. If treated with antiviral drugs in the early phase of encephalitis, neurologic sequales decreased by 65%. Recently, a PCR method for detection of HSVE with CSF was developed. VZV primary and secondary infections caused neurologic symptoms of encephalitis or meningitis. The second frequency of adult encephalitis that caused VZV were reported. HHV-6 caused CNS latent infection that was studied with normal adults brains. But there is no data of HSV, VZV and HHV-6 for aseptic meningitis and encephalitis of Korean adults through etiologic study. We cultured CSFs on HEp-2 cells and simultaneously tested for HSV PCR, VZV nested PCR and HHV-6 PCR with 8 specific primers. The PCR results of CSF from meningitis Korean adults were 13/19 (68.4%) for HSV, 10/19 (52.6%) for VZV and 12/19 (63.2%) for HHV-67/19 (36.8%) cases were triple infected HSV PCR, VZV PCR and HHV-6 PCR positive; 3/19 (15.8%) cases were dual infected HSV PCR and HHV-6 PCR positive; 1119 (0.5%) cases was VZV PCR positive. Strong viral DNA amplification of CSF means a causative virus may be present in aseptic meningitis or encephalitis patients and may cause clinical neurologic symptoms. HSV and HHV-6 viruses detection rate were higher than VZV by PCR with CSFs.

• 대한수의학회지
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• 제40권1호
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• pp.56-62
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• 2000

Pasteurella multocida is kind of commensal bacteria in the upper respiratory tract of pigs. It is classified toxigenic and nontoxigenic strains based on the production of dermonecrotic toxin. Toxigenic strain is most associated with atrophic rhinitis which brings great economical loss in swine industry. However, toxigenic and nontoxigenic strains do not differ by diagnostic biochemical reaction or morphology. One of recently developed techniques, PCR detects the toxigenic P multocida. Amplification of an 846-nucleotide fragment of toxA gene was developed. The fragment amplified by PCR was detected in P multocida type D not type A. The PCR amplification was as sensitive as it could detect 1 pg of P multocida DNA. We compared the result of the PCR with the enzyme linked immunosorbent assay (ELISA) in a test for 40 swine nasal swabs. All of these isolates were toxin negative based on the ELISA while 2 isolates were detected in the PCR technique. in addition to accuracy, as required for rapid detection from contaminated nasal swabs, toxigenic P multocida was recovered efficiently from contaminated culture without inhibition of the PCR. The results show that the PCR detection of toxigenic P multocida directly form nasal swabs are feasible.