• Journal of the Korean Society of Radiology
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• v.82 no.2
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• pp.417-422
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• 2021

Neurofibromatosis type 1 (NF1) is a rare neuroectodermal disease that is associated with an increased risk of malignancy. Here, we report a rare case of bilateral breast cancer in a 49-year-old woman with NF1 that presented as a microlobulated oval hypoechoic mass and a complex cystic solid mass on sonography. She underwent bilateral mastectomy. The masses were diagnosed as invasive ductal carcinoma, ductal carcinoma in situ, and a malignant peripheral nerve sheath tumor. We describe the imaging findings, including ultrasonography, CT, and ¹⁸F-fluorodeoxyglucose PET.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.406-414
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• 2005

The genetic instability of cancer cells may be related to inappropriately activated DNA repair pathways. In present study, the modulated expression of DNA-dependent protein kinase (DNA-PK), a major DNA repair protein, in human cancer metastatic cells was tested. The expressions of Ku70/80, regulatory subunit of DNA-PK, and the Ku DNA-binding activity in various highly metastatic cell lines were higher than those in each parental cell line. Also, the expression of DNA-PKcs, catalytic subunit of DNA-PK, and the kinase activity of the whole DNA-PK complex in highly metastatic cells were significantly increased as compared to those of parental cells, suggesting that the enhanced DNA repair capacity of metastatic cells could be associated with aberrant use of DNA repair, which may mediate tumor progression and metastatic potential. Increased EGFR (epidermal growth factor receptor) signaling has been associated with tumor invasion and metastasis, and the linkage between EGFR-mediated signaling and DNA-PK has been suggested. This study showed that PKI166, the new EGFR tyrosine kinase inhibitor, modulated the expressions of Ku70/80 and DNA-PKcs and also revealed the chemosensitization effect of PKI166 against metastatic cells may be in part due to inhibition of Ku70/80. These results suggest that interference in EGFR signaling by EGFR inhibitor resulted in the impairment of DNA repair activity, and thus DNA-PK could be possible molecular targets for therapy against metastatic cancer cells.

• The Korean Journal of Applied Statistics
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• v.29 no.6
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• pp.1117-1128
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• 2016

In genetic association studies with high-dimensional genomic data, regularization procedures based on penalized likelihood are often applied to identify genes or genetic regions associated with diseases or traits. A network-based regularization procedure can utilize biological network information (such as genetic pathways and signaling pathways in genetic association studies) with an outstanding selection performance over other regularization procedures such as lasso and elastic-net. However, network-based regularization has a limitation because cannot be applied to high-dimension genomic data with a group structure. In this article, we propose to combine data dimension reduction techniques such as principal component analysis and a partial least square into network-based regularization for the analysis of high-dimensional genomic data with a group structure. The selection performance of the proposed method was evaluated by extensive simulation studies. The proposed method was also applied to real DNA methylation data generated from Illumina Innium HumanMethylation27K BeadChip, where methylation beta values of around 20,000 CpG sites over 12,770 genes were compared between 123 ovarian cancer patients and 152 healthy controls. This analysis was also able to indicate a few cancer-related genes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.509-517
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• 2008

DNA damage accumulates in cells as a result of exposure to exogenous agents such as benzopyrene, cigarette smoke, ultraviolet light, X-ray, and endogenous chemicals including reactive oxygen species produced from normal metabolic byproducts. DNA damage can also occur during aberrant DNA processing reactions such as DNA replication, recombination, and repair. The major of DNA damage affects the primary structure of the double helix; that is, the bases are chemically modified. These modification can disrupt the molecules'regular helical structure by introducing non-native chemical bonds or bulky adducts that do not fit in the standard double helix. DNA repair genes and proteins scan the global genome to detect and remove DNA damage and damage to single nucleotides. Direct reversal of DNA damage, base excision repair, double strand break. DNA repair are known relevant DNA repair mechanisms. Four different mechanisms are distinguished within excision repair: direct reversal, base excision repair, nucleotide excision repair, and mismatch repair. Genetic variation in DNA repair genes can modulate DNA repair capacity and alter cancer risk. The instability of a cell to properly regulate its proliferation in the presence of DNA damage increase risk of gene mutation and carcinogenesis. This article aimed to review mechanism of excision repair and to understand the relationship between genetic variation of excision repair genes and head and neck cancer.

• Radiation Oncology Journal
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• v.4 no.2
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• pp.129-133
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• 1986

To know the three questions about multiple primary cancers: 1) what are the characteristics of persons having multiple parimary cancer? 2) Does the presence of a single primary concer after the susceptability to multiple primary cancers? 3) Does the location of one multiple primary cancer influence the site of others?, we analysed 121 cases of multiple primary malignant neoplasms registered in Seoul National University Hospital during 8 years from July 1978 to August 1986. Of 121 cases, double primary malignant neoplasms were 119 cases and triples were 2 cases. The incidence of multiple primary malignant neoplasms was $0.7\%$. The metachronous tumor (>6 months) was found in 70 cases and the median time between the first and the second was 32 months. The most commonly associated tumors were stomach and primary liver carcinoma. Cervix and Lung cancer, Stomach and Rectal cancer, Stomach and Esophagus cancer were also commonly associated.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.99-108
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• 2022

Avian leukosis virus (ALV) is a highly contagious retrovirus that causes tumors and has resulted in great economic loss worldwide owing to its high transmission rate. Various ALV viral subgroups exist, with infections occurring via specific host receptors. The susceptibility or resistance of avian species to the ALV-A and K subgroups is determined by the host receptor, the tumor virus locus A (tva) gene, while that to ALV-B depends on another host receptor, the tumor virus locus B (tvb) gene. The resistance alleles of tva and tvb have primarily been identified in China, but none have beendetected in Korea. We analyzed the frequencies of tva and tvb genotypes in White Leghorn (WL), Korean Ogye (KO), and Korean native chicken (KNC) breeds, and assessed the resistance to ALV subgroups. In WL, both tva and tvb had various genotypes, including susceptibility and resistance alleles, whereas in KO, tva and tvb resistance alleles were dominant. In KNC, tva susceptibility and resistance alleles were mixed, whereas tvb resistance alleles were dominant. In addition, we showed that there were differences in the splicing pattern of tva transcripts and the expression level of tvb transcripts within breeds. Finally, we confirmed that ALV resistance depended on KO and KNC genotypes by in vitro infection of chicken embryonic fibroblasts with ALV. These results highlight that some KO and KNC individuals are naturally resistant to ALV subgroups A, B, and K, and will facilitate the preservation of economically superior traits through selective breeding.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.85-85
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• 1993

The clinical staging system for laryngeal cancers is not sufficient for prognosticator due to different biologic characteristics and their microenvironment according to primary sites. For determining the prognosticators, the authors peformed immunohistochemical staining to EGFR, p53 protein, and pRB in 40 cases of surgically treated squamous cell carcinomas of larynx in our institute during the past 5 years. The results are as followings; 1. The positive expression rate of p53 protein and negative expression rate of pRB showed correlations with clinical parameters. 2. The three-year survival rate for p53 protein positive cases was worse than the p53 protein negative cases. 3. Expression rate of EGFR was not correlated with the clinical parameters. As a conclusion, expression rates of p53 protein and pRB not only reflect well the biologic behavior of laryngeal cancer, but correlate closely with the tumor factors. Therefore they may be useful as the prognosticator to predict the malignant potency of laryngeal squamous cell carcinomas.

• Journal of the Korea Society for Simulation
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• v.20 no.2
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• pp.77-85
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• 2011

It is believed that the anomalies or diseases of human organs are identified by the analysis of the patterns. This paper proposes a new classification technique for the identification of cancer disease using the proteome patterns obtained from two-dimensional polyacrylamide gel electrophoresis(2-D PAGE). In the new classification method, three different classification methods such as support vector machine(SVM), multi-layer perceptron(MLP) and k-nearest neighbor(k-NN) are extended by multi-boosting method in an array of subclassifiers and the results of each subclassifier are merged by ensemble method. Genetic algorithm was applied to obtain optimal feature set in each subclassifier. We applied our method to empirical data set from cancer research and the method showed the better accuracy and more stable performance than single classifier.

• Korean Journal of Human Ecology
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• v.22 no.1
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• pp.181-188
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• 2013

노인에게서 두드러지게 나타나고 있는 저근육형 비만은 근육감소를 동반한 체지방의 증가로 신체상의 뚜렷한 체성분의 변화를 야기 시킨다. 이때 골감소증을 동반하여 신체기능의 감소 및 골절장애 그리고 대사성 관련 질환의 위험도가 올라가는 것으로 보고되고 있다. 노화로 인한 체성분의 변화는 단순한 저근육형일 경우와 비만일 때 보다 급격히 증가된 복부내장 지방조직에서 분비되는 염증성 사이토카인, C-반응성 단백질(CRP), 인터루킨(IL)-6, IL-8 및 종양 괴사 인자(TNF-${\alpha}$)들이 단백질 대사를 저해하여 근육량의 감소를 더욱 촉진시키며, 염증관련 대사질환의 유병률에 중요한 요인이다. 본 연구에서는 DNA 메틸화가 당뇨병, 심혈관질환, 암과 같은 만성염증성 질환에 관계하고 있다는 최근 연구 결과를 기초로 하여 항염증 영양소와 생리활성을 갖는 식품인자들의 충분한 섭취가 염증조절에 중요하게 기여할 것으로 생각되며, 또한 염증성 질환의 주요 표식자인 DNA 메틸화와 히스톤 변형을 유발하는 효소의 활성 또는 비 암호화된 RNA의 발현을 조절함으로써 근육량 증가와 체지방 감소에 중요한 역할을 하는 것을 살펴보았다. 따라서 최근 새롭게 인식되는 후생유전학적 연구의 중심에 있는 항염증 영양소의 효과와 체성분 변화와의 긍정적 관계를 중심으로 저근육형 비만의 예방 및 인구고령화에 건강한 노화를 위한 효과적인 방법을 제시하였다.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1591-1595
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• 2002

Familial adenomatous polyposis(FAP) is an autosomal dominant disease characterized by numerous adenomas in the colorectum. Patients with FAP are always at risk of malignant transformation, so that colectomy is unavoidable. NSAID, such as sulindac, and selective COX-2 inhibitor, such as celecoxib, have shown a positive effect on FAP by causing polyp regression in some patients. We report a case of FAP in a 9-year-old female whose polyposis regressed markedly after six months-treatment with celecoxib.