• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.71-76
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• 2006

Comparative genomic hybridization (CGH) is a technique for studying chromosomal changes in cancer. As cancerous cells multiply, they can undergo dramatic chromosomal changes, including chromosome loss, duplication, and the translocation of DNA from one chromosome to another. Chromosome aberrations have previously been detected using optical imaging of whole chromosomes, a technique with limited sensitivity, resolution, quantification, and throughput. Efforts in recent years to use microarrays to overcome these limitations have been hampered by inadequate sensitivity, specificity and flexibility of the microarray systems. The oligonucleotide CGH microarray system overcomes several scientific hurdles that have impeded comparative genomic studies of cancer. This new system can reliably detect single copy deletions in chromosomes. The system includes a whole human genome microarray, reagents for sample preparation, an optimized microarray processing protocol, and software for data analysis and visualization. In this study, we determined the sensitivity, accuracy and reproducibility of the new system. Using this assay, we find that the performance of the complete system was maintained over a range of input genomic DNA from 5 ug down to 0.15 ug.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.112-118
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• 2005

In this paper, we propose a new nonlinear matching measure for automatic analysis of the on-off type DNA microarray images in which the hybridized spots are detected by the template matching method. The proposed measure is obtained by binary-thresholding over the whole template region and taking the number of white pixels inside the spotted area. This measure is compared with the normalized covariance in terms of the classification ability of the successfulness of the locating markers. The proposed measure is evaluated for the scanned images of HPV DNA microarrays where the marker locating is a critical issue because of the small number of spots. The targeting spots of HPV DNA chips are designed for genotyping 22 types of the human papilloma virus(HPV). The proposed measure is proven to give more discriminative response reducing the miss cases of the successful marker locating.

• Genomics & Informatics
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• v.2 no.2
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• pp.92-98
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• 2004

A cDNA microarray experiment is one of the most useful high-throughput experiments in medical informatics for monitoring gene expression levels. Statistical analysis with a cDNA microarray medical data requires a normalization procedure to reduce the systematic errors that are impossible to control by the experimental conditions. Despite the variety of normalization methods, this. paper suggests a more general and synthetic normalization algorithm with a control gene set based on previous studies of normalization. Iterative normalization method was used to select and include a new control gene set among the whole genes iteratively at every step of the normalization calculation initiated with the housekeeping genes. The objective of this iterative normalization was to maintain the pattern of the original data and to keep the gene expression levels stable. Spatial plots, M&A (ratio and average values of the intensity) plots and box plots showed a convergence to zero of the mean across all genes graphically after applying our iterative normalization. The practicability of the algorithm was demonstrated by applying our method to the data for the human photo aging study.

• Korean Journal of Biological Psychiatry
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• v.8 no.2
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• pp.203-207
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• 2001

The genome sequencing project has generated and will continue to generate enormous amounts of sequence data including 5 eukaryotic and about 60 prokaryotic genomes. Given this ever-increasing amounts of sequence information, new strategies are necessary to efficiently pursue the next phase of the genome project-the elucidation of gene expression patterns and gene product function on a whole genome scale. In order to assign functional information to the genome sequence, DNA chip(or gene microarray) technology was developed to efficiently identify the differential expression pattern of independent biological samples. DNA chip provides a new tool for genome expression analysis that may revolutionize many aspects of biotechnology including new drug discovery and disease diagnostics.

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.35-47
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• 2006

2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin (TCDD) are well known as the most toxic environmental compound in these days. Many researches are reported that dioxin produces multiple toxic effects, such as endocrine toxicity, reproductive toxicity, immunotoxicity and cancer. In this study, we carried to discover novel evidence for previously unknown gene expression patterns in human exposed to dioxin by using radioactive cDNA microarray. 548 workers who were divided into experimental and control groups according to their urinary Naphthol levels were enrolled in our study. Blood mRNA in human was isolated, and the gene expression profiles were analyzed by cDNA microarray. Gene expression analysis identified 52 genes which exhibited a significant change. In our study, most notably, genes involved in cell cycle, cell proliferation, signal transduction and apoptosis in human exposed to dioxin, such as CCND3, TSHR, and EFRN5, were up-regulated. In the current study, we observed gene expression of people that are exposed to dioxin using radioactive cDNA microarray. Through these results, we suggest when objects are exposed to toxic compounds, such as dioxin, the radioactive cDNA microarray may be using in sensitively detecting of cancerous change.

• Journal of Acupuncture Research
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• v.20 no.3
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• pp.34-44
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• 2003

Objective : Bone homeostasis is maintained by balance of bone formation and resorption. Therefore, bone related diseases arose by disturbance of this balance between osteoblast and osteoclast activities. To develop a successful screening system the therapeutic components based on oriental medicine is essential to set up systematic approach for that purpose. The purpose of this study is to the know the gene expression using cDNA microarray assay. Methods : Cervi Pantotricuhum Cornu Herbal-acupuncture extract was prepared by boiling. human osteosarcoma cells(HOS) were treated with Cervi Pantotricuhum Cornu Herbal-acupuncture solution. Then mRNA was extracted and cDNA microarray assay was performed. Results : Human osteosarcoma cells(HOS) treated with Cervi Pantotricuhum Cornu Herbal-acupuncture solution($500{\mu}g/m{\ell}$) showed that thioredoxin, TAFII31 and two novel genes were increased. However many genes decreased their expression by Cervi Pantotricuhum Cornu Herbal-acupuncture. Conclusions : This type of approach will give a good chance to explore the favorable effects of Cervi Pantotricuhum Cornu Herbal-acupuncture. Further study is needed for investigating the effect of Cervi Pantotricuhum Cornu Herbal-acupuncture.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.04a
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• pp.47-48
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• 2003

The development of cDNA microarray has permitted the analysis of thousands of genes simultaneously. cDNA microarray has been used to analyze gene expression profiles during developmental stage in both single and multicellular organisms. Two significant factors contributing to the limitation of the development of cDNA microarray in the Bombyx mori are the shortage of accessible repositories of cDNA clones and ESTs and the relative scarcity of facilities to produce microarrays and analyze the data generated. (omitted)

• Genomics & Informatics
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• v.2 no.1
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• pp.30-35
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• 2004

To investigate the XIST gene expression and its effect in a Klinefelter's patient, we used Klinefelter's syndrome (XXY) patient with azoospermia and also used a normal male (XY) and a normal female (XX) as the control, We were performed cytogenetic analysis, Y chromosomal microdeletion assay (Yq), semi-quantitative RT-PCR, and the Northern blot for Klinefelter's syndrome (KS) patient, a female and a male control, We extracted total RNA from the KS patient, and from the normal cells of the female and male control subjects using the RNA prep kit (Qiagen), cDNA microarray contained 218 human X chromosome-specific genes was fabricated. Each total RNA was reverse transcribed to the first strand cDNA and was labeled with Cy-3 and Cy-5 fluorescein, The microarray was scanned by ScanArray 4000XL system. XIST transcripts were detected from the Klinefelters patient and the female by RT-PCR and Northern blot analysis, but not from the normal male, In the cDNA microarray experiment, we found 24 genes and 14 genes are highly expressed in KS more than the normal male and females, respectively. We concluded that highly expressed genes in KS may be a resulted of the abnormal X inactivation mechanism.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.945-951
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• 2007

DNA-DNA hybridization has been established as an important technology in bacterial species taxonomy and phylogenetic analysis. In this study, we analyzed how the efficiency with which the genomic DNA from one species hybridizes to the genomic DNA of another species (DNA-DNA hybridization) in microarray analysis relates to the similarity between two genomes. We found that the predicted DNA-DNA hybridization based on genome sequence similarity correlated well with the experimentally determined microarray hybridization. Between closely related strains, significant numbers of highly divergent genes (>55% identity) and/or the accumulation of mismatches between conserved genes lowered the DNA-DNA hybridization signal, and this reduced the hybridization signals to below 70% for even bacterial strains with over 97% 16S rRNA gene identity. In addition, our results also suggest that a DNA-DNA hybridization signal intensity of over 40% indicates that two genomes at least shared 30% conserved genes (>60% gene identity). This study may expand our knowledge of DNA-DNA hybridization based on genomic sequence similarity comparison and further provide insights for bacterial phylogeny analyses.

• Journal of KIISE:Software and Applications
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• v.29 no.11
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• pp.775-784
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• 2002

Microarray data, obtained from DNA chip technologies, is the measurement of the expression level of thousands of genes in cells or tissues. It is used for gene function prediction or cancer diagnosis based on gene expression patterns. Among diverse methods for data analysis, the Bayesian network represents the relationships among data attributes in the form of a graph structure. This property enables us to discover various relations among genes and the characteristics of the tissue (e.g., the cancer type) through microarray data analysis. However, most of the present microarray data sets are so sparse that it is difficult to apply general analysis methods, including Bayesian networks, directly. In this paper, we harness an efficient structural learning algorithm and data dimensionality reduction in order to analyze microarray data using Bayesian networks. The proposed method was applied to the analysis of real microarray data, i.e., the NC160 data set. And its usefulness was evaluated based on the accuracy of the teamed Bayesian networks on representing the known biological facts.