• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.52-58
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• 2008

The object of this study is to investigate the effects of intermittent cyclic stretching on the smooth muscle cells (SMCs) seeded onto aligned multi-layered fibrous scaffold. To make multi-layered fibrous scaffold, polyurethane (PU) and poly(ethylene oxide) (PEO) were electrospun alternatively, then were immersed into distilled water to extract PEO. Various types of scaffolds were fabricated depending on fiber directions, i.e., aligned or randomly oriented. The direction of stretching was either parallel or vertical to the fiber direction for the aligned scaffolds. The stretching was also applied to the randomly aligned scaffolds. The duration of stretching was 2 min with 15 min resting period. During the stretching, the maximum and minimum strain was adjusted to be 10 and 7%, respectively with the frequency of 1 Hz. The bioactivities of cells on the scaffolds were assessed by quantifying DNA, collagen, and glycosaminoglycan (GAG) levels. And the cell morphology was observed by staining F-actin. SMCs under parallel stretching to the fiber direction responded more positively than those in other conditions. From the results, we could explain the morphological effect of a substrate on cellular activities. In addition the synergistic effects of substrate and mechanical stimuli effects were confirmed.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.151-157
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• 1999

Purpose : By sequencing the Erpressed Sequence Tags of human 걸ermal papilla CDNA library, we identified a clone named K872 of which the expression decreased during differentiation of HL6O cell line. Materials and Methods : K872 plasmid DNA was isolated according to QIA plasmid extraction kit (Qiagen GmbH, Germany). The nucleotide sequencing was performed by Sanger's method with K872 plasmid DNA. The most updated GenBank EMBL necleic acid banks were searched through the internet by using BLAST (Basic Local Alignment Search Tools) program. Nothern bots were performed using RNA isolated from various human tissues and cancer cell lines. The gene expression of the fusion protein was achieved by His-Patch Thiofusicn expression system and the protein product was identified on SDS-PAGE. Results : K872 clone is 1006 nucleotides long, and has a coding region of 675 nucleotides and a 3' non-coding region of 280 nucleotides. The presumed open reading frame starting at the 5' terminus of K872 encodes 226 amino acids, including the initiation methionine residue. The amino acid sequence deduced from the open reading frame of K872 shares $70\%$, identity with that of rat glutathione 5-transferase kappa 1 (rGSTKl). The transcripts were expressed in a variety of human tissues and cancer cells. The levels of transcript were relatively high in those tissues such as heart, skeletal muscle, and peripheral blood leukocyte. It is noteworthy that K872 was found to be abundantly expressed in coloreetal cancer and melanoma cell lines. Conclusion : Homology search result suggests that K872 clone is the human homolog of the rGSTK1 which is known to be involved in the resistance of cytotoxic therapy. We propose that meticulous functional analysis should be followed to confirm that.

• Archives of Plastic Surgery
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• v.34 no.6
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• pp.671-678
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• 2007

Purpose: Venous malformation(VM) which often causes pain and discomfort is the most common type of vascular malformations. Although it is presented with disfigured appearance and associated soft tissue or skeletal hypertrophy, the molecular bases of VMs are poorly understood. Differentially expressed genes(DEGs) of VMs were investigated to illuminate the molecular mechanism of the disease entity. Methods: Gene expressions of VM patients' subcutaneous tissue were studied in comparison with normal persons' by $GeneFishing^{TM}$ technique using the annealing control primers (ACPs) to identify DEGs. Candidate genes were sequenced and screened by basic local alignment search tool (BLAST) afterwards. Results: Among seventy DEGs identified, forty DEGs which had shown significantly different expression pattern were sequenced. Twenty eight out of 40 were up-regulated while 12 were down-regulated. BLAST searches revealed that 37 were known genes and 3 were unknown genes. Many genes were involved in the differentiation and remodeling of smooth muscle cells, opposed to the previous hypothesis that a lot of angiogenetic genes would be involved. Furthermore, several transcription factors and related genes, as well as cell signaling and metabolism regulators, were up regulated. Conclusion: It suggests that analysis of DEGs in VMs provide basic knowledge about its pathophysiology. and new therapeutic approaches.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1661-1669
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• 2007

Gamma-aminobutyric acid (GABA) is a non-protein amino acid. It is well known for its role as an inhibitory neurotransmitter of developing and operating nervous systems in brains. In this study, a novel function of GABA in the healing process of cutaneous wounds was presented regarding anti-inflammation and fibroblast cell proliferation. The cell proliferation activity of GABA was verified through an MTT assay using murine fibroblast NIH3T3 cells. It was observed that GABA significantly inhibited the mRNA expression of iNOS, IL-$1{\beta}$, and TNF-${\alpha}$ in LPS-stimulated RAW 264.7 cells. To evaluate in vivo activity of GABA in wound healing, excisional open wounds were made on the dorsal sides of Sprague-Dawley rats under anesthesia, and the healing of the wounds was apparently assessed. The molecular aspects of the healing process were also investigated by hematoxylineosin staining of the healed skin, displaying the degrees of re-epithelialization and linear alignment of the granulation tissue, and immunostaining and RT-PCR analyses of fibroblast growth factor and platelet-derived growth factor, implying extracellular matrix synthesis and remodeling of the skin. The GABA treatment was effective to accelerate the healing process by suppressing inflammation and stimulating re-epithelialization, compared with the epidermal growth factor treatment. The healing effect of GABA was remarkable at the early stage of wound healing, which resulted in significant reduction of the whole healing period.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.622-629
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• 2018

Expansins are cell wall proteins that mediate cell wall loosening and promote specific tissue and organ morphogenesis in plants and in some microorganisms. Unlike plant expansins, the biological functions of fungal expansin-like proteins have rarely been discussed. In the present study, an expansin-like protein-encoding fvexpl1 gene, was identified from Flammulina velutipes by using local BLAST. It consisted of five exons with a total length of 822 bp. The deduced protein FVEXPL1 contained 274 amino acids with a predicted molecular mass and isoelectric point of 28,589 Da and pH 4.93, respectively. The first 19 amino acids from the N terminal are the signal peptide. Phylogenetic analysis and multiple protein alignment indicated FVEXPL1 was an expansin-like protein. The expression level of fvexpl1 gene in the stipe was significantly higher than that in the mycelia, primordia, and cap. However, the expression level of fvexpl1 gene was significantly higher in the fast elongation region of the stipe as compared with the slow elongation region. Expression analysis indicated that fvexpl1 gene might have an auxiliary role in the stipe morphogenesis of F. velutipes.

• ETRI Journal
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• v.38 no.2
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• pp.265-271
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• 2016

We analyzed the interface characteristics of Zn-based thin-film buffer layers formed by a sulfur thermal cracker on a $Cu(In,Ga)Se_2$ (CIGS) light-absorber layer. The analyzed Zn-based thin-film buffer layers are processed by a proposed method comprising two processes - Zn-sputtering and cracker-sulfurization. The processed buffer layers are then suitable to be used in the fabrication of highly efficient CIGS solar cells. Among the various Zn-based film thicknesses, an 8 nm-thick Zn-based film shows the highest power conversion efficiency for a solar cell. The band alignment of the buffer/CIGS was investigated by measuring the band-gap energies and valence band levels across the depth direction. The conduction band difference between the near surface and interface in the buffer layer enables an efficient electron transport across the junction. We found the origin of the energy band structure by observing the chemical states. The fabricated buffer/CIGS layers have a structurally and chemically distinct interface with little elemental inter-diffusion.

• Korean Journal of Microbiology
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• v.37 no.1
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• pp.49-55
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• 2001

Bacillus anthracis is a gram-positive spore-forming bacterium that causes the disease anthrax. The anthrax toxin contains three components, including the protective antigen (PA), which binds to eucaryotic cell surface receptors and mediates the transport of toxins into the cell. In this study, the entire 2,294-nucleotide protective antigen gene (pag) was sequenced from 4 of B. anthracis strains to identify potential variation in the toxin and to further our understanding of B. anthracis evolution in Korea. Sequence alignment of the entire PA gene from 30 strains representative of the four B. anthracis diversity groups revealed mutations. The mutation of B. anthracis BAK are located adjacent to a highly antigenic region crossing the junction between PA domains 3 and 4 shown to be critical to LF binding. The different mutational combinations observed in this study give rise to 11 PA genotypes and 4PA phenotypes. Three-dimensional analysis of all the amino acid changes (Ala to Val) observed in BAK indicated that these changes are not only close sequentially but also very close in three-dimensional space to the antigenic region importan tfor LF binding. Phylogenetic (cladistic) analysis of the pag corresponded with previous strain grouping based on chromosomal variation, suggesting that plasmid evolution in B. anthracis has occurred with little or no horizontal transfer between the different strains.

• Journal of Biomedical Engineering Research
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• v.40 no.5
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• pp.143-150
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• 2019

To evaluate the toxicity of ophthalmic drug, the Draize test and Bovine Corneal Opacity and Permeability (BCOP) test commonly used. In Draize test, experimental animals were under stress and pain due to long-term exposure of drug. In addition, regarding physiological functions, animal model is not perfectly reflected a human eye condition. Although some models such as $EpiOcular^{TM}$, HCE model, LabCyte Cornea-Model, and MCTT $HCE^{TM}$ were already presented advanced cornea ex-vivo model to replace animal test. In this sense, cornea tissue structure mimicked ex-vivo toxicity model was fabricated in this study. The corneal epithelial cells (CECs) and keratocytes (CKs) isolated from rabbit eyeball were seeded on non-patterned silk film (n-pSF) and patterned silk film (pSF) at $32,500cells/cm^2$ and $6,500cells/cm^2$. Sequentially, n-pSF and pSF were stacked to mimic a multi-layered stroma structure. The thickness of films was about $15.63{\mu}m$ and the distance of patterns was about $3{\mu}m$. H&E stain was performed to confirm the cell proliferation on silk film. F-actin of CKs was also stained with Phalloidin to observe the cytoskeletal alignment along with patterns of the pSF. In the results, CECs and CKs were shown the good cell attachment on the n-pSF and pSFs. Proliferated cells expressed the specific phenotype of cornea epithelium and stroma. In conclusion, we successfully established the ex-vivo cornea toxicity model to replace the eye irritation tests. In further study, we will set up the human ex-vivo cornea toxicity model and then will evaluate the drug screening efficacy.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.73-80
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• 2009

G protein-coupled receptors(GPCRs) family is a cell membrane protein, and plays an important role in a signaling mechanism which transmits external signals through cell membranes into cells. But, GPCRs each are known to have various complex control mechanisms and very unique signaling mechanisms. Structural features, and family and subfamily of GPCRs are well known by function. and accordingly, the most fundamental work in studies identifying the previous GPCRs is to classify the GPCRs with given protein sequences. Studies for classifying previously identified GPCRs more easily with mathematical models have been mainly going on. In this paper Considering that functions of proteins are determined by their stereoscopic structures, the present paper proposes a method to compare secondary structures of two GPCRs having different amino acid sequences, and then detect an unknown GPCRs assumed to have a same function in databases of previously identified GPCRs.

• Genomics & Informatics
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• v.4 no.1
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• pp.33-39
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• 2006

Alternative splicing (AS) is an important mechanism of producing transcriptome diversity and microarray techniques are being used increasingly to monitor the splice variants. There exist three types of microarrays interrogating AS events-junction, exon, and tiling arrays. Junction probes have the advantage of monitoring the splice site directly. Johnson et al., performed a genome-wide survey of human alternative pre-mRNA splicing with exon junction microarrays (Science 302:2141-2144, 2003), which monitored splicing at every known exon-exon junctions for more than 10,000 multi-exon human genes in 52 tissues and cell lines. Here, we describe an algorithm to deduce the relative concentration of isoforms from the junction array data. Non-negative Matrix Factorization (NMF) is applied to obtain the transcript structure inferred from the expression data. Then we choose the transcript models consistent with the ECgene model of alternative splicing which is based on mRNA and EST alignment. The probe-transcript matrix is constructed using the NMF-consistent ECgene transcripts, and the isoform abundance is deduced from the non-negative least squares (NNLS) fitting of experimental data. Our method can be easily extended to other types of microarrays with exon or junction probes.