• Journal of the Korean Society of Visualization
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• v.14 no.1
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• pp.57-61
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• 2016

We report a finding of fast(exceeding 2,000 K/s) heating of polydimethylsiloxane(PDMS), one of the most commonly-used microchannel materials, under cyclic loadings at high(~MHz) frequencies. A microheater was created based on the finding. The heating mechanism utilized vibration damping of sound waves, which were generated and precisely manipulated using a conventional surface acoustic wave(SAW) microfluidic system, in PDMS. The penetration depths were measured to range from $210{\mu}m$ to $1290{\mu}m$, enough to cover most microchannel heights in microfluidic systems. The energy conversion efficiency was SAW frequency-dependent and measured to be the highest at around 30 MHz. Independent actuation of each interdigital transducer(IDT) enabled independent manipulation of SAWs, permitting spatiotemporal control of temperature on the microchip. All the advantages of this microheater facilitated a two-step continuous flow polymerase chain reaction(CFPCR) to achieve the billion-fold amplification of a 134 bp DNA amplicon in less than 3 min. In addition, a technique was developed for establishing dynamic free-form temperature gradients(TGs) in PDMS as well as in gases in contact with the PDMS.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.3
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• pp.233-240
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• 2003

연구목적: 본 연구에서는 정상 환자와 습관성 유산 질환 환자에서 유래된 융모막 조직 내에서의 면역억제유전자들의 발현 양상에 대해 알아보고자 하였다. 연구재료 및 방법: 임신 6주와 8주의 습관성 유산 질환 환자와 정상 환자로부터 융모막 조직을 채취하였다 (Normal N=6; RSA N=6). 면역조직화학적 분석을 통해서 조직을 관찰하고 세포가 살아있음을 확인한 후에, 역전사 중합효소연쇄반응을 통해서 면역억제유전자인 placenta protein 14 (PP14), indoleamine 2, 3-dioxygenase (IDO) 그리고 mucin1 (MUC1) 유전자의 발현 정도를 비교하였다. GAPDH 발현에 기준한 면역억제유전자 발현을 정량 분석하여 Student's t-test를 시행하였고, p<0.05를 유의성이 있는 것으로 판정하였다. 결 과: 습관성 유산 질환 환자의 경우, 임신 6주와 8주의 융모막 조직에서의 면역억제유전자 (PP14, IDO, MUC1) 발현이 현저하게 낮은 양상을 보이고 있었다. 습관성 유산과 면역억제유전자의 발현이 통계학적으로 유의성 있는 연관성을 가지고 있다는 것이 확인되었다. 결 론: 면역억제유전자 (PP14, IDO, MUC1)의 발현이 습관성 유산 질환 환자에서 특이적으로 낮게 나타나는 것으로 보아 습관성 유산 질환의 진단과 치료 연구 방안에 이 유전자들의 발현이 이용될 수 있을 것으로 사료된다.

• Journal of Oral Medicine and Pain
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• v.33 no.3
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• pp.241-246
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• 2008

Lichen planus is a common, chronic inflammatory disease of the skin and mucous membrane for which no precise causes have been confirmed. But it is often connected with infections. Helicobacter pylori(H. pylori) among various bacteria has been associated with the cause of gastritis, peptic ulcer and gastric cancer. Considering the similarities of histological features between gastric ulcer and oral ulcers, it is resonable to assume that H. pylori might also be involved in the development oral mucosal ulceration. So we employed this study to investigate the possible involvement of H. pylori in the aetiology of erosive oral lichen planus. We analyzed detection rate of H. pylori in saliva of patients with erosive oral lichen planus by nested PCR. As a result, it revealed a significant difference statistically by showing positivity in 16 to 21(76.2%) saliva samples of patients group and in 11 of 44(25%) saliva samples of control group(P>0.001). We were able to suppose that H. pylori in saliva can be related to cause of erosive oral lichen planus.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.2
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• pp.201-206
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• 1994

Down syndrome is one of the major chromosomal anomalies in Korea. To decrease incidence of Down syndrome, antenatal diagnosis is essential. At present, antenatal diagnosis of Down syndrome is done by karyotyping from chorionic villus sampling, amniocentesis, and cordocentsis. All these methods have some problems such as a risk of abortion, a long waiting time, difficulties in sampling, and so on. The aim of study was to confirm that PCR(Polymerase Chain Reaction) using D21S11 primer could be a diagnostic tool for Down syndrome. PCR using D21S11 primers with $^{32}P$ labeling at 5' end was done in 21 cases of DNA from 21 Trisomy and 20 cases of DNA from normal karyotype. PCR product was running for 10 hours on the 6% polyacrylamide gel under 1,000 V or for 8 hours under 1,500 V. After X-ray film exposure, it was read by densitometry. Normal group showed 1: 1 band or single band. 21 Trisomy group showed 1.3-2: 1 band or 2.3 times of density compared to normal single band or 3 bands. This method gave the result within 24 hours. It can be an useful diagnostic tool to detect 21 Trisomy antenatally, especially in late pregnancy, and in preimplantation diagnosis.

• Journal of Yeungnam Medical Science
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• v.15 no.2
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• pp.237-245
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• 1998

만성 B형 간염 환자에서 Interferon (IFN) 치료 후 혈청 HBeAg 소실 및 anti-HBe의 양전율을 높이고 효율적인 치료의 근거를 알기 위하여 치료 전 간기능검사상 갑자기 상승한 혈청 ALT치를 나타낸 환자군과 그렇지 않은 대조군을 대상으로 하여 IFN을 투여한 군과 IFN 치료없이 정상 HBeAg의 자연 소실을 보인 환자군을 임상적으로 장기간 관찰하고 조사하였다. ALT치가 정상 상한치의 4배 이상 높이 증가되어 3개월 이상 왕복을 보인 40명의 환자(A군)와 ALT치가 정상 상한치의 3배 이하로 증가된 10명(B군)에게 ${\alpha}$-IFN 2b를 매일 300만 단위 피하주사로 3~12개월 주사하였다. 대조군으로는 ALT치가 A군처럼 장승한 45명 (C군)이었으며, IFN 치료없이 평균 2.9년을 관찰하였다. HBeAg/anti-HBe 혈청 양전율은 A군 68%, B군 20%, C군 13%이었으며 IFN 치료 중단 후 1년까지의 HBeAg 재양성율은 A군에서 29%였고 HBeAg이 소실된 A와 B군의 38명중에서 6명에서 HBV DNA가 양성이었다. 6명중 4명은 HBeAg/anti-HBe 양전을 보였으나 HBV DNA 양성이었고 나머지 2명은 HBeAg, anti-HBe 및 HBV DNA (hybridization) 모두 음성이었으나 중합효소연쇄반응검사상 HBV DNA 양성이었다. 이상의 결과를 보면 비록 IFN 치료 후에 HBeAg이 소실되었다가 다시 양성화되더라도 IFN은 단기간내에 혈중 HBeAg이나 DNA가 자연적으로 감소가 될 환자나 그렇지 않은 환자에게도 HBV의 비증식화를 유발하여 도움이 될 것으로 사료된다. 그러나 IFN 투여 후에도 혈중 HBeAg과 DNA 소실에 전혀 도움이 되지 않을 환자 및 HBV 증식 억제효과가 기대되는 HBV 간질환 환자의 조건, IFN 투여량, 기간 등에 대한 계획적이고 체계적인 연구로 더 나은 치료효과를 기대할 수 있으리라 생각된다.

• Journal of Korean society of Dental Hygiene
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• v.17 no.1
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• pp.13-25
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• 2017

Objectives: The purpose of this study was to compare colony forming unit (CFU) method and multiplex real-time polymerase chain reaction (MRT-PCR) method for accurate quantitative analysis of bacteria. Methods: We compared the CFU method and the MRT-PCR method, which are still used in Korea, for Prevotella intermedius (P. intermedius), a periodontal disease pathogen selected by MRT-PCR, and Streptococcus mutans (S. mutans), a dental caries causative organism. The subjects of this study were 30 patients who visited the C dental hospital. Results: Total microorganisms in MRT-PCR method were significantly higher in both types of bacteria (p<0.05), since DNA of dead bacteria was also analyzed. This was because the periodontal dise(-) anaerobes, and even dead bacteria contain large amounts of toxic substances called LPS in the extracellular membrane, and fimbriae and pili, which are motility structures, still remain as a strong toxic substance in periodontal tissue. Conclusions: Therefore, in terms of the total amount of bacteria found, the MRT-PCR method will be a useful technique for searching all the bacteria in the oral cavity including live bacteria, as well as sterilization.

• Research in Plant Disease
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• v.8 no.4
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• pp.207-214
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• 2002

Tobacco rattle virus(TRV) was detected from Gladiolus hybridus, Crocus spp. and Narcissus spp. leaves show-ing notched or stripe on the leaf and malformation symptoms collected from Daegu and Kyungbuk province by electron microscopy (EM), immunosorbent electron microscopy (ISEM) and host range study. Direct negative staining method by EM showed rigid rod long particles 170~200$\times$22 nm and rigid rod short particles 40~114$\times$22 m. TRV-K isolated from G. hybridus propagated with Nicotiana tabacum. TRV coat protein(CP) gene was amplified using specific oligonucleotide primer by RT-PCR. Sequence analysis of amplified CP gene showed 99.5％ nucleotide similarity to TRV-ORY.

• The Journal of Korean Society of Virology
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• v.30 no.3
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• pp.179-187
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• 2000

The etiology of rheumatic arthritis (RA) is associated with a number of genetic and environmental factors, but is not definitively elucidated. Recently, more attention has been paid to the possibility of microbial etiology in the pathogenesis of RA, because many different infectious agents have been reported to precede the onset or exacerbation of RA. Adenovirus (ADV) may be one cause of persistent or recurrent inflammatory arthritis. Varicella zoster virus (VZV) arthritis is detected frequently in RA patients treated with low dose methotrexate. The demonstration of simultaneous presence of both viral agents of specific viral nucleic acid in synovial fluids from synovitis patients would provide more direct evidence for arthritis etiological relationship, but there are no confirmed results. Therefore, we studied the ability of adenovirus and VZV to establish coinfection and persistent infection in synovial fluid from synovitis patients. The presence of viral agents in the synovial fluid demonstrated by isolation of cell culture, enzyme immunoassay and nested-PCR. The synovial fluids were also investgated for the presence of viral nucleic acid by nested-PCR using specific primer. ADV produced 220 bp and VZV produced 447 bp by each nested-PCR with specific primers. We detected 4/6 cases (66.7%) with persistent infection of ADV and 5/6 cases (83.3%) of VZV with 13 synovial fluids (between 7 to 52 day intervals) from synovitis patients by monoclonal ErA and nested-PCR. 21/28 cases (75%) with coinfection of adenovirus and VZV with synovial fluids from synovitis patients by nested-PCR. ADV and VZV coinfection and persistent infection of synovial fluids may provide a chronic antigenic stimuli to the immune system therefore provoking a continuing inflammatory response and caused the possibility of synovitis and arthritis.

• Animal Systematics, Evolution and Diversity
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• no.nspc3
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• pp.139-146
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• 1992

The primary sequence of the 18S rRNA gene of a crustacean Pugettia quadridens (Decapoda: Pleocyemata: Brachyura) was determined by the PCR cloning and Taq sequencing. The 18S rRNA gene of this species in 1837 bases long, and 46 bases shorter than that of another crustacean decapod Oedignathus inermis. The similarity between two species is 90.8% when the insertion and/or deletion sites were excluded. Within the molecule, the most conservative (identical) region locates at the position of 1137-1206 and it is 70 bases long. The most long consecutive nucleotide differences occur at the position between 46-55 and the second most between 399-407. The sequence variation in the primary structure of 18S rRNA gene are not evenly distributed throughout the molecule.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.118-125
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• 1999

Porcine Proliferative Enteropathy(PPE) is an infectious enteric disease and a major cause of economic loss in swine industry due to weight loss, poor growth and sudden death in growing and finishing pigs at 6 to 20 weeks of age. PPE has been diagnosed by clinical signs, syndrom and lesions in the intestine in Korea. However, the diagnostic method had several problems in the detection of infected or carrier pigs. Therefore, in this study, we established the polymerase chain reaction(PCR) which was a fast, specific and sensitive method for identification of Lawsonia intracellularis (L intracellularis). We designed and synthesized primer on the 16S rDNA and p78 gene encoding L intracellularis. Specificity of the method was confirmed by comparison of the PCR results using other enteric bacteria and the study has shown that PCR method was sensitive to detect 1ng of genomic DNA as a template. Identity of the PCR products was confirmed by comparison of pattern of restriction endonuclease analysis with restriction enzyme Hae III and Pst I. Also, the PCR method was applicable to the naturally affected pigs with PPE. Based on the results from this study, the PCR method could be used as a fast and specific diagnostic tool for PPE.