• Optical Science and Technology
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• v.17 no.3
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• pp.5-8
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• 2013

• Korean Journal of Optics and Photonics
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• v.30 no.2
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• pp.59-66
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• 2019

We report highly sensitive detection of myocardial infarction biomarkers, such as myoglobin and cTnI, within several hundred seconds using a rotating-analyzer ellipsometer and a biosensor with biochips fabricated on a $SiO_2$-coated tilted silicon substrate. We choose the running buffer to be pure phosphate-buffered saline (PBS) or 10% mixed human serum. When we choose the running buffer to be pure PBS, we obtain diagnostic densities of pure myocardial infarction biomarkers of up to 1 ng/ml and 5 pg/ml respectively. Meanwhile, when we use PBS with 10% human serum, the measured densities of myoglobin and cTnI were up to 1 ng/mL and 1 pg/mL respectively. The measured diagnostic densities are less than 1/15 and 1/80 (in cases of myoglobin and cTnI respectively) of those referenced by the World Health Organization.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.4
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• pp.299-308
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• 2007

Purpose: The aim of this study was to develop a bioinformatics software and to test it in serum samples of papillary thyroid cancer using mass spectrometry (SELDI-TOF-MS). Materials and Methods: Development of 'Protein analysis' software performing decision tree analysis was done by customizing C4.5. Sixty-one serum samples from 27 papillary thyroid cancer, 17 autoimmune thyroiditis, 17 controls were applied to 2 types of protein chips, CM10 (weak cation exchange) and IMAC3 (metal binding - Cu). Mass spectrometry was performed to reveal the protein expression profiles. Decision trees were generated using 'Protein analysis' software, and automatically detected biomarker candidates. Validation analysis was performed for CM10 chip by random sampling. Results: Decision tree software, which can perform training and validation from profiling data, was developed. For CM10 and IMAC3 chips, 23 of 113 and 8 of 41 protein peaks were significantly different among 3 groups (p<0.05), respectively. Decision tree correctly classified 3 groups with an error rate of 3.3% for CM10 and 2.0% for IMAC3, and 4 and 7 biomarker candidates were detected respectively. In 2 group comparisons, all cancer samples were correctly discriminated from non-cancer samples (error rate = 0%) for CM10 by single node and for IMAC3 by multiple nodes. Validation results from 5 test sets revealed SELDI-TOF-MS and decision tree correctly differentiated cancers from non-cancers (54/55, 98%), while predictability was moderate in 3 group classification (36/55, 65%). Conclusion: Our in-house software was able to successfully build decision trees and detect biomarker candidates, therefore it could be useful for biomarker discovery and clinical follow up of papillary thyroid cancer.

• Journal of Korean geriatric psychiatry
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• v.16 no.1
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• pp.17-23
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• 2012

The diagnosis of Alzheimer's disease (AD) is still obscure even to specialists. To improve the diagnostic accuracy, to find at-risk people as early as possible, to predict the efficacy or adverse reactions of pharmacotherapy on an individual basis, to attain more reliable results of clinical trials by recruiting better defined participants, to prove the disease-modifying ability of new candidate drugs, to establish prognosis-based therapeutic plans, and to do more, is now increasing the need for biomarkers for AD. Among AD-related biochemical markers, cerebrospinal beta-amyloid and tau have been paid the most attention since they are materials directly interfacing the brain interstitium and can be obtained through the lumbar puncture. Level of beta-amyloid is reduced whereas tau is increased in cerebrospinal fluid of AD patients relative to cognitively normal elderly people. Remarkably, such information has been found to help predict AD conversion of mild cognitive impairment. Despite inconsistent findings from previous studies, plasma beta-amyloid is thought to be increased before the disease onset, but show decreasing change as the disease progress. Regarding other peripheral biochemical markers, omics tools are being widely used not only to find useful biomarkers but also to generate novel hypotheses for AD pathogenesis and to lead new personalized future medicine.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.114-117
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• 2016

In vivo labeling of bone with fluorochromes is a widely used method for assessment of bone formation and remodeling processes. In particular, calcein is used as a marker for identification of bone growth, which is indicated by a green color. Calcein green is a calcium chelator that adheres to regions of mineralizing bone thereby allowing localization of new bone. Bone formation and remodeling in vivo can be assessed by calcium-binding calcein labeling. In this study, changes in the femoral bone of a normal mouse model at both 4 and 8 weeks were evaluated using calcein labeling. Intense deposition of calcium in the bone was observed after application for 8 weeks. A mouse model is suitable for application in in vivo experiments using genetically modified mice, such as knock-out mice, however data regarding femoral cross sectional bone in young mice are limited. The current study confirmed calcein as a useful marker for identification of bone growth, which was indicated by a green color on photomicrographs. This methodological process may provide basic information for interpreting bone formation and regeneration to pharmacologic or genetic manipulation in mice.

• Journal of Sensor Science and Technology
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• v.30 no.5
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• pp.314-319
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• 2021

In this study, biomarkers were analyzed and segmented using tunable infrared gas sensors after performing the principal component analysis. The free spectral range of the device under test (DUT) was around 30 nm and DUT-5580 yielded the highest output voltage property among the others. The biomarkers (isoprophyl alcohol, ethanol, methanol, and acetone solutions) were sequentially mixed with deionized water and their mists were carried into the gas chamber using high-purity nitrogen gas. A total of 17 different mixed gases were tested with three tunable infrared gas sensors, namely DUT-3144, DUT-5580, and DUT-8010. DUT-8010 resolved the infrared absorption spectra of whole mixed gases. Based on the principal component analysis with each DUT and their combinations, each mixed gas and the trends in increasing gas concentration could be well analyzed when the contributions of the eigenvalues of the first and second were higher than 70% and 10%, respectively, and their sum was greater than 90%.

• Journal of Sensor Science and Technology
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• v.28 no.3
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• pp.171-176
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• 2019

The biomarkers related to the colorectal cancers and diseases were surveyed and summarized, and an optical electronic nose was researched and developed for their analysis. The prototyped sensor revealed that it could discriminate two gases: ethanol 2000 ppm and $CO_2$ 500 ppm. Furthermore, the sensor demonstrated the potential capability of estimation of $CO_2$ concentration with 95% confidence level. Based on the above experimental results, the developed optical electronic nose was tested with the mixtures of gases (Isopropyl Alcohol, Acetone, Methanol, and Toluene) and the biomarkers were successfully segregated using principal component analysis.

• Radiation Oncology Journal
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• v.26 no.1
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• pp.45-55
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• 2008

Purpose: This study evaluates the association of estrogen receptor(ER), progesterone receptor(PR), Her-2, COX-2, and survivin with the clinicopathological features and outcomes in young Korean women with breast cancer using recently developed tissue microarray(TMA) technology. Materials and Methods: A cohort of 212 young patients with breast cancer diagnosed at the age of 45 years or younger from March 1994 to August 2005, were enrolled in this study. The age range of patients was $23{\sim}45$ years(median age, 39 years). The minimum and median follow-up periods were 24 months and 60 months, respectively. Serial sections of primary tumors were processed by the use of a TMA for immunohistochemical staining for five biomarkers. The correlation of these five biomarkers and the clinicopathological features and outcomes were analyzed by statistical methods. Results: The majority of the patients were stage T1(90 patients) or T2(101 patients), and 105 patients(49.5%) had an axillary node metastasis. The 5-year overall and relapse free survival rates for all of the patients were 90.4% and 82.3%, respectively, and 36 patients had a locoregional or distant metastasis as a first event. Positive expression of ER, PR, Her-2, COX-2, and survivin was determined in 38.2%, 45.3%, 25.9%, 41.5%, and 43.4%, of the tumor samples, respectively. Tumor stage, nodal status, age, as well as expression of ER, PR, and HER-2 status were significantly associated with the disease free survival rate. Tumor stage, nodal status, as well as expression of ER, PR, and HER-2 were significantly related with the overall survival rate. Expression of COX-2 and survivin were not single independent prognostic factors for the disease free and overall survival rate although co-expression of HER-2 and COX-2 had a tendency as a poor prognostic factor. By multivariate analysis, only T stage and lymph node status were significant prognostic factors, and ER status was a marginally significant prognostic factor(p=0.075). Conclusion: Expression of ER, PR and HER-2 were significant prognostic factors for the relapse free and overall survival rate. Expression of COX-2 and survivin were not prognostic factors for young women with breast cancer.

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.375-382
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• 2019

Abnormalities of trophoblast due to early inflammation in pregnancy increase the expression of CRP and affect maternal-fetal interactions, leading to preterm birth and preeclampsia. However, biomarkers related to the regulation of CRP expression have not been found. In this study, miRNA associated with increased expression of CRP was identified and their expression was analyzed to reveal biomarkers involved in the regulation mechanism of trophoblast inflammation through miRNAs. miRNAs that were predicted to regulate CRP gene expression in miRNA databases (mirna, TargetScan, MicroCosm) were screened and HTR-8/SVneo cell lines were treated with LPS (20 ng/mL) to induce inflammatory responses in vitro, with selected miR-7, miR-150, miR-186 and miR-424. The expression was analyzed by qRT-PCR. As a result, expression of CRP was significantly increased in LPS-treated trophoblast (p<0.001) and miR-150 and miR-424 expression were significantly decreased (p<0.001). Thus, miR-150 and miR-424 are involved in the regulation of CRP expression in inflammatory-induced trophoblast and may be useful for the prenatal diagnosis of inflammatory obstetric diseases.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.42.1-42.1
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• 2010

Poly-carprolactone (PCL)은 생분해성 고분자로 장기간의 임상실험 결과 생체에 독성이 없으며 생체친화성이 우수한 소재로 확인되어 PLGA, PLLA 등과 더불어 조직공학 분야에서 널리 사용되고 있는 생체재료이다. 그러나 PCL은 5개의 비극성 methylene group과 1개의 극성 ester group이 반복되는 지방족의 polyester로 구조상 탄소수가 많아 소수성을 띄는 단점을 가지고 있다. 이러한 표면이 소수성인 재료의 경우, 초기 단백질 흡착능이 떨어져 세포의 부착이 느린 속도로 일어나므로 세포 분화 및 조직 재생이 더디게 일어난다. 본 연구에서는 소수성의 PCL 표면의 단백질 흡착능을 증가시키기 위해 기능성 amine group을 부착하였으며, 또한 골재생을 촉진시킬 수 있는 세포외 기질인 collagen과 osteopontin을 부착함으로써 고기능성 PCL membrane을 제조하였다. 제조된 PCL membrane은 골재생용 조직공학에의 응용을 위해 지방유래 줄기세포를 이용하여 부착능 및 골세포로의 분화능을 확인하였다. 표면 성질의 변화에 의한 세포의 부착능의 변화를 confocal microscopy을 이용하여 부착에 관여하는 단백질의 발현을 확인하였으며, collagen과 osteopontin에 의한 골세포로의 분화능을 확인하기 위해 real time PCR을 통해 골세포의 분화 표지 유전자의 발현을 비교 분석하였다.