• 대한의생명과학회지
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• 제21권4호
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• pp.165-171
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• 2015

Microbial pathogens are responsible for most of the rapidly-spreading deadly infectious diseases against humans. Thus, there is an urgent need for efficient and rapid detection methods for infectious microorganisms. The detection methods should not only be targeted and specific, but they have to be encompassing of potential changes of the pathogen as it evolves and mutates quickly during an epidemic or pandemic. The existing diagnostics such as the antibody-based ELISA immunoassay and PCR methods are too selective and narrowly focused; they are insufficient to capture newly evolved mutant strains of the pathogen. Here, we introduce a fresh perspective on some new technologies, including aptamers and next generation sequencing for pathogen detection. These technologies are not in their infancy; they are reasonably mature and ready, and they hold great promise for unparalleled applications in pathogen detection.

• IMMUNE NETWORK
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• 제1권2호
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• pp.151-161
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• 2001

Background: Inactivation in p53 tumor suppressor gene through a point mutation and deletion is one of the most frequent genetic changes found in human cancer, with 50% of an incidence. This high rate of mutation mostly suggests that the gene plays a central role in the development of cancer and the mutations detected so far were found in exons 5 to 8. Mutation of p53 locus produced accumulation of abnormal p53 protein, and negative regulation of cell proliferation and transcriptional activation as a suppressor of transformation were lost. In addition, inhibition of its normal cellular function of wild-type by mutant is an important step in tumorigenesis. Method: 4 colon cancer cell lines (SNU C1, C2A, C4, C5) were examined for mutation in exons 5 to 8 of the p53 tumor suppressor gene by PCR-SSCP analysis and expression pattern by western blotting and immunoprecipitation. p53-mediated transactivation ability were examined by CAT assay and base substitution of p53 in SNU C2A cell were detected by DNA sequencing. Results: 1) SNU C2A cell and SNU C5 cell were detected mobility shifts each in exon 5 and exon 7 of p53 gene by the PCR-SSCP method, implicating being of p53 mutation. 2) 3 colon cancer cell lines (SNU C1, SNU C2A, SNU C5) expressed wild type and mutant type p53 protein. 3) In northern blot experiment, SNU C2A and SNU C5 cell expressed high level of p53 mRNA. 4) Results of p53-mediated transactivation in colon cancer cell lines by CAT assay represented only SNU C2A cell has transcriptional activity. 5) DNA sequencing in SNU C2A cell showed missense mutation in codon 179 of one allele, histidine to arginine and wild type p53 in the other allele. Conclusion: Colon cancer cell lines showed correlation with mutation in p53 gene and accumulation of abnormal p53 protein. Colon cancer cell SNU C2A retained p53-mediated transactivation as heterozygous p53 with one mutant allele in 179 codon and the other wild-type allele.

• The Korean journal of internal medicine
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• 제39권2호
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• pp.318-326
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• 2024

Background/Aims: Epidermal growth factor receptor (EGFR) mutation is important in determining the treatment strategy for advanced lung cancer patients with malignant pleural effusion (MPE). Contrary to serum carcinoembryonic antigen (S-CEA) levels, the associations between pleural fluid CEA (PF-CEA) levels and EGFR mutation status as well as between PF-CEA levels and treatment efficacy have rarely been investigated in lung adenocarcinoma patients with MPE. Methods: This retrospective study enrolled lung adenocarcinoma patients with MPE and available PF-CEA levels and EGFR mutation results. The patients were categorized based on PF-CEA levels: < 10 ng/mL, 10-100 ng/mL, 100-500 ng/mL, and ≥ 500 ng/mL. The association between PF-CEA levels and EGFR mutation status as well as their therapeutic impact on overall survival was compared among the four groups. Results: This study included 188 patients. PF-CEA level was found to be an independent predictor of EGFR mutation but not S-CEA level. The EGFR mutation rates were higher as the PF-CEA levels increased, regardless of cytology results or sample types. Among EGFR-mutant lung adenocarcinoma patients receiving EGFR-tyrosine kinase inhibitor (TKI) treatment, those with high PF-CEA levels had significantly better survival outcomes than those with low PF-CEA levels. Conclusion: High PF-CEA levels were associated with high EGFR mutation rate and may lead to a favorable clinical outcome of EGFR-TKI treatment in EGFR-mutant lung adenocarcinoma patients with MPE. These findings highlight the importance of actively investigating EGFR mutation detection in patients with suspected MPE and elevated PF-CEA levels despite negative cytology results.

• 농약과학회지
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• 제15권1호
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• pp.61-67
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• 2011

2010년에 청주, 충주-1, 충주-2, 강진, 예산, 그리고 영주에서 채집한 점박이응애의 bifenazate 약제 저항성을 확인 해 본 결과, 강진과 예산 개체군에서 각각 964.5배, 1130배의 높은 저항성을 나타내었다. 그리고 청주, 충주-1, 충주-2, 그리고 영주개제군에서는 낮은 저항성비를 나타내었다. Bifenazate 약제 저항성 점박이응애의 cytb 점 돌연변이인 G126S를 확인해 본 결과, 생물검정에서 높은 저항성을 보인 강진과 예산 개체군에서 G126S 점 돌연변이를 확인 할 수 있었다. 이와 같이, G126S 점 돌연변이는 bifenazate 약제 저항성을 가지는 점박이응애 선별에 아주 유용한 분자진단 마커로 이용될 수 있다. 두 가지 분자진단 방법인 quantitative sequencing(QS)와 PCR amplification of specific alleles(PASA)는 G126S 점 돌연변이를 잘 탐지하였다. 따라서 이러한 방법들은 야외 계통의 bifenazate 약제 저항성 형질 모니터링과 저항성 관리에 효율적으로 이용될 수 있을 것이다.

• 대한미생물학회지
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• 제35권2호
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• pp.181-190
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• 2000

To investigate resistance to lamivudine (3TC), we examined the incidence of M184V in 20 HIV-1 patients treated with 3TC for $13.1{\pm}9$ months. Fourteen of 20 patients had been exposed to zidovudine (ZDV) or didanosine (ddI) prior to 3TC therapy. Nested PCR targeting to reverse transcriptase (RT) and direct sequencing were performed for peripheral blood mononuclear cells sampled serially. There were resistance mutations to ZDV in at least 9 patients at baseline, although there was no resistance mutation to 3TC. We could detect M184V in 6 (30%) out of 20 patients. The incidence of M184V increased as the duration of therapy prolongs (13% in samples <12 months; 47% in samples ${\ge}12$ months). The frequency of mutation M184V was higher in patients with previous mutation to ZDV than in patients with wild type. Resistance mutation was not detected in 7 patients. This study shows that resistance to 3TC tends to develop rapidly in patients with baseline mutations or two drugs combination therapy than in those treated simultaneously with triple drugs. This report is the first on resistance to 3TC in Korean AIDS patients.

• 대한임상검사과학회지
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• 제39권2호
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• pp.113-121
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• 2007

선천성난청은 비교적 흔한(1/1,000) 유전성질환으로 여러 유전자와 관련이 있으며, 최근에는 connexin 26 단백질내의 GJB2 유전자 돌연변이와의 관련성이 보고되고 있다. 유전질환을 예측하기 위한 유전자선별검사를 임상에 적용하기 위해서는 각 해당 국가별로 정상인에서 유전자돌연변이의 빈도를 구하고, 환자의 결과를 비교하여 활용성을 검토한 후 사용하여야 한다. 본 연구에서는 청력검사(TEOAE)가 정상인 신생아에서 GJB2 유전자 돌연변이 빈도를 구하여 screening test를 위한 한국인의 database를 수립하고자 하였다. 검체로는 437 명의 건강한 신생아의 발꿈치를 천자하여 얻은 혈액을 이용하였고, DNA는 Intron 사의 킷트를 사용하여 추출하였으며, GJB2 PCR을 실시한 후 증폭산물(783 bps)은 2% agarose gel로 전기영동을 실시하였고, DNA 자동염기서열분석기를 이용하여 분석을 실시하였다. 총 437명의 한국인 신생아에서 GJB2 유전자 중 8곳의 돌연변이(35delG, 167delT, 235delC, V27I, V37I, M34T, E114G, I203T)를 분석하였으며, 이 중 5곳에서 돌연변이가 발견되었다. 총 437명 중 301명(68.9%)에서 GJB2 유전자돌연변이가 발견되었는데, 그 중 154명이 단일돌연변이였다. V27I 변이가 271명으로 가장 많이 발견되었으며, 대부분의 V27I 변이는 E114G 변이와 함께 나타났다. E114G 변이는 총 146명, I203T 변이는 17명, V37I 변이는 14명, 235delC 변이는 1명의 순으로 나타났다. 이중돌연변이의 대부분은 V27I/E114G였으며, V27I/I203T는 3명에서 나타났고, 삼중돌연변이 V27I/E114G/I203T는 1명에서 발견되었다. 본 연구결과, PCR을 이용한 자동염기분석검사는 GJB2 유전자의 돌연변이 검출에 매우 유용하며, 본 결과는 향 후 신생아 난청선별검사를 위한 한국인의 database로 활용될 수 있을 것으로 사료된다.

• Tuberculosis and Respiratory Diseases
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• 제50권1호
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• pp.94-105
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• 2001

연구배경 : Pyrazinamide(PZA)는 결핵의 1차 치료 약제이며, 산성 환경 하에서만 작용하기 때문에 in vitro에서 생물학적인 감수성 검사를 하는 것이 어렵다. pncA는 PZase를 생성하는 유전자로 이의 돌연변이가 결핵균의 PZase 활성을 소실시켜 결핵균이 PZA에 대해서 내성을 획득하게 되는 기전으로 추정된다. 본 연구에서는 PZA의 생물학적 감수성, PZase 활성 및 pncA 유전자의 돌연변이 사이의 관계를 검토하고, 아울러 결핵균의 pncA 의 염기서열 결정이 PZA 내성을 예측하는데 이용될 수 있는지를 알아보고자 하였다. 방법 : 폐결핵 환자의 객담에서 분리된 결핵균 28균주를 대상으로 하여, 절대농도법으로 PZA의 감수성을 검사하고, pncA 유전자의 open reading frame 전체 561 bp를 포함하는 710 bp 크기의 유전자를 선택적으로 증폭하였다. PCR 증폭 산물을 직접 염기서열 결정에 이용하였고, GenBank에서 확인한 결핵균 야생주의 pncA 염기서열과 비교하여 돌연변이 여부를 확인하였다. 결과 : PZase 활성이 있는 6균주 모두 pncA의 돌연변이가 없었으나, 1균주(16.7%)는 절대농도법에 의한 감수성 검사에서 위내성으로 나타났다. PZase 활성이 없는 22균주 중 21균주(95.5%)는 pncA의 돌연변이가 확인되었고, 생물학적 감수성 검사에서는 20균주가 PZA 내성, 1균주는 검사 불능, 1균주는 감수성을 보였다. pncA의 돌연변이의 양상(중복 1예 포함)은 promotor 지역과 pncA의 전 open reading frame에 걸쳐서 단일 염기의 치환에 의한 silent mutation 1개, missense mutation 10개, nonsense mutation 1개, 3염기가 삽입된 insertion 1개, 1~3개의 염기가 삽입된 frame shift mutation 4개, 그리고 2~2347개의 염기가 결실된 frame shift mutation 2개였다. 그리고 나머지 3균주는 모두 pncA유전자의 open reading frame 상부의 11번째 염기가 똑같이 adenine에서 guanine으로 치환되어 있었다. 결론 : pncA의 돌연변이는 결핵균의 PZase 활성의 소실에 의한 PZA 내성의 주요 기전이며, 특히 pncA 시작 codon의 상부 11 번째 위치의 염기 치환은 promotor의 돌연변이에 의한 PZA 내성의 주요 부위인 것으로 추정된다. Automatic sequencing에 의한 pncA의 염기서열 결정은 결핵균의 PZA 내성 진단을 위한 빠르고 효과적인 방법으로 이용할 수 있으며, PZA 내성 결핵균의 균주간 연관성을 규명하기 위한 역학 조사의 목적으로 이용할 수 있을 것으로 생각된다.

• BMB Reports
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• 제37권2호
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• pp.246-253
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• 2004

Constitutional RB1 gene mutations were studied in a series of 21 families with unilateral and bilateral retinoblastoma patients. Peripheral blood lymphocytes were analyzed by "exon by exon" PCR-heteroduplex and sequencing. Mutations were identified in 6 (29%) of the patients. One mutation corresponded to an intronic polymorphism in g.174351T > A. The other five mutations resulted C to T exonic transitions, four were CGA sequences (g.65386, g.150037 in two patients, and g.162237), creating stop codons and presumably truncated proteins. The fifth one was new and resulted in alanine to valine substitution (g.73774). Two patients had the same the germline truncated mutation (g.150037C > T), one with a familial bilateral early onset retinoblastoma and one with a sporadic unilateral late onset retinoblastoma. The later type has not been previously described. This finding is discussed in the genotype/phenotype correlation context. Additionally, a single nucleotide change was found in six studied samples, where a C to T homozygous transversion was identified in intron 26 (IVS26 + 28). It is worthy the non concordance of the nucleotide with the published sequence. This analysis proved to be a useful method for the detection of mutations in the RB1 gene, and contributed to the adequate genetic counseling to patients and relatives.

• Journal of Veterinary Science
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• 제21권2호
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• pp.22.1-22.9
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• 2020

Rabid raccoon dogs (Nyctereutes procyonoides koreensis) have been responsible for animal rabies in South Korea since the 1990s. A recombinant rabies vaccine strain, designated as ERAGS, was constructed for use as a bait vaccine. Therefore, new means of differentiating ERAGS from other rabies virus (RABV) strains will be required in biological manufacturing and diagnostic service centers. In this study, we designed two specific primer sets for differentiation between ERAGS and other RABVs based on mutation in the RABV glycoprotein gene. Polymerase chain reaction analysis of the glycoprotein gene revealed two DNA bands of 383 bp and 583 bp in the ERAGS strain but a single DNA band of 383 bp in the field strains. The detection limits of multiplex reverse transcription polymerase chain reaction (RT-PCR) were 80 and 8 FAID₅₀/reaction for the ERAGS and Evelyn-Rokitnicki-Abelseth strains, respectively. No cross-reactions were detected in the non-RABV reference viruses, including canine distemper virus, parvovirus, canine adenovirus type 1 and 2, and parainfluenza virus. The results of multiplex RT-PCR were 100% consistent with those of the fluorescent antibody test. Therefore, one-step multiplex RT-PCR is likely useful for differentiation between RABVs with and those without mutation at position 333 of the RABV glycoprotein gene.

• Smart Structures and Systems
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• 제18권5호
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• pp.983-1004
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• 2016

Nowadays, there are two classes of methods for damage detection in structures consisting of static and dynamic. The dynamic methods are based on studying the changes in structure's dynamic characteristics. The theoretical basis of this method is that damage causes changes in dynamic characteristics of structures. The dynamic methods are divided into two categories: signal based and modal based. The modal based methods utilize the modal properties consisting of natural frequencies, modal damping and mode shapes. As the modal properties are sensitive to changes in the structure, these can be used for detecting the damages. In this study, using dynamic method and modal based approach (natural frequencies and mode shapes), the objective function is formulated. Then, detection of damages of truss structures is addressed by using Simplified Dolphin Echolocation algorithm and solving inverse optimization problem. Many scenarios are used to simulate the damages. To demonstrate the ability of the algorithm, different truss structures with several multiple elements scenarios are tested using a few runs. The influence of the two different levels of noise in the modal data for these scenarios is also considered. The last example of this article is investigated using a different mutation. This mutation obtains the exact answer with fewer loops and population by limited computational effort.