• Title/Summary/Keyword: adhesion model

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PIV Measurement of Pulsatile Flows in 3D Curved Tubes Using Refractive Index Matching Method (3차원 곡관에서의 굴절률 일치법을 이용한 맥동 유동의 PIV 측정)

  • Hong, Hyeon Ji;Ji, Ho Seong;Kim, Kyung Chun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.8
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    • pp.511-517
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    • 2016
  • Three-dimensional models of stenosis blood vessels were prepared using a 3D printer. The models included a straight pipe with axisymmetric stenosis and a pipe that was bent $10^{\circ}$ from the center of stenosis. A refractive index matching method was utilized to measure accurate velocity fields inside the 3D tubes. Three different pulsatile flows were generated and controlled by changing the rotational speed frequency of the peristaltic pump. Unsteady velocity fields were measured by a time-resolved particle image velocimetry method. Periodic shedding of vortices occurred and moves depended on the maximum velocity region. The sizes and the positions of the vortices and symmetry are influenced by mean Reynolds number and tube geometry. In the case of the bent pipe, a recirculation zone observed at the post-stenosis could explain the possibility of blood clot formation and blood clot adhesion in view of hemodynamics.

Analysis of Disease Progression-Associated Gene Expression Profile in Fibrillin-1 Mutant Mice: New Insight into Molecular Pathogenesis of Marfan Syndrome

  • Kim, Koung Li;Choi, Chanmi;Suh, Wonhee
    • Biomolecules & Therapeutics
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    • v.22 no.2
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    • pp.143-148
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    • 2014
  • Marfan syndrome (MFS) is a dominantly inherited connective tissue disorder caused by mutations in the gene encoding fibrillin-1 (FBN1) and is characterized by aortic dilatation and dissection, which is the primary cause of death in untreated MFS patients. However, disease progression-associated changes in gene expression in the aortic lesions of MFS patients remained unknown. Using a mouse model of MFS, FBN1 hypomorphic mouse (mgR/mgR), we characterized the aortic gene expression profiles during the progression of the MFS. Homozygous mgR mice exhibited MFS-like phenotypic features, such as fragmentation of elastic fibers throughout the vessel wall and were graded into mgR1-4 based on the pathological severity in aortic walls. Comparative gene expression profiling of WT and four mgR mice using microarrays revealed that the changes in the transcriptome were a direct reflection of the severity of aortic pathological features. Gene ontology analysis showed that genes related to oxidation/reduction, myofibril assembly, cytoskeleton organization, and cell adhesion were differentially expressed in the mgR mice. Further analysis of differentially expressed genes identified several candidate genes whose known roles were suggestive of their involvement in the progressive destruction of aorta during MFS. This study is the first genome-wide analysis of the aortic gene expression profiles associated with the progression of MFS. Our findings provide valuable information regarding the molecular pathogenesis during MFS progression and contribute to the development of new biomarkers as well as improved therapeutic strategies.

Identification of Endothelial Specific Region in the Intracellular Adhesion Molecule-2 (ICAM2) Promoter of Miniature Pig

  • Jang, Hoon;Jang, Won-Gu;Kim, Dong Un;Kim, Eun-Jung;Hwang, Sung Soo;Oh, Keon Bong;Lee, Jeong-Woong
    • Reproductive and Developmental Biology
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    • v.36 no.3
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    • pp.207-212
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    • 2012
  • The shortage of human organs for transplantation has induced the research on the possibility of using animal as porcine. However, pig to human transplantation as known as xeno-transplantation has major problem as immunorejection. Recently, the solutions of pig to human xenotransplantation are commonly mentioned as having a genetically modification which include alpha 1, 3 galatosyl transferase knockout (GTKO) and immune-suppressing gene transgenic model. Unfortunately, the expression level of transgenic gene is very low activity. Therefore, development of gene overexpression system is the most urgent issue. Also, the tissue specific overexpression system is very important. Because most blood vessels are endothelial cells, establishment of the endothelial-specific promoter is attractive candidates for the introduction of suppressing immunorejection. In this study, we focus the ICAM2 promoter which has endothelial-specific regulatory region. To detect the regulatory region of ICAM2 promoter, we cloned 3.7 kb size mini-pig ICAM2 promoter. We conduct serial deletion of 5' flanking region of mini-pig ICAM2 promoter then selected promoter size as 1 kb, 1.5 kb, 2 kb, 2.5 kb, and 3 kb. To analyze promoter activity, luciferase assay system was conducted among these vectors and compare endothelial activity with epithelial cells. The reporter gene assay revealed that ICAM2 promoter has critical activity in endothelial cells (CPAE) and 1 kb size of ICAM2 promoter activity was significantly increased. Taken together, our studies suggest that mini-pig ICMA2 promoter is endothelial cell specific overexpression promoter and among above all size of promoters, 1 kb size promoter is optimal candidate to overcome the vascular immunorejection in pig to human xenotransplantation.

Gene Microarray Assessment of Multiple Genes and Signal Pathways Involved in Androgen-dependent Prostate Cancer Becoming Androgen Independent

  • Liu, Jun-Bao;Dai, Chun-Mei;Su, Xiao-Yun;Cao, Lu;Qin, Rui;Kong, Qing-Bo
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9791-9795
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    • 2014
  • To study the gene expression change and possible signal pathway during androgen-dependent prostate cancer (ADPC) becoming androgen-independent prostate cancer (AIPC), an LNCaP cell model of AIPC was established using flutamide in combination with androgen-free environment inducement, and differential expression genes were screened by microarray. Then the biological process, molecular function and KEGG pathway of differential expression genes are analyzed by Molecule Annotation System (MAS). By comparison of 12,207 expression genes, 347 expression genes were acquired, of which 156 were up-ragulated and 191 down-regulated. After analyzing the biological process and molecule function of differential expression genes, these genes are found to play crucial roles in cell proliferation, differntiation, cell cycle control, protein metabolism and modification and other biological process, serve as signal molecules, enzymes, peptide hormones, cytokines, cytoskeletal proteins and adhesion molecules. The analysis of KEGG show that the relevant genes of AIPC transformation participate in glutathione metabolism, cell cycle, P53 signal pathway, cytochrome P450 metabolism, Hedgehog signal pathway, MAPK signal pathway, adipocytokines signal pathway, PPAR signal pathway, TGF-${\beta}$ signal pathway and JAK-STAT signal pathway. In conclusion, during the process of ADPC becoming AIPC, it is not only one specific gene or pathway, but multiple genes and pathways that change. The findings above lay the foundation for study of AIPC mechanism and development of AIPC targeting drugs.

Evaluation of Physical Properties as Magnesium Stearate Blendedin Hydrophilic Matrix Tablets

  • Choi, Du-Hyung;Jung, Youn-Jung;Wang, Hun-Sik;Yoon, Jeong-Hyun;Jeong, Seong-Hoon
    • Journal of Pharmaceutical Investigation
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    • v.41 no.2
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    • pp.83-90
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    • 2011
  • Main objectives of this study were to investigate the effects of a lubricant, magnesium stearate, as blended in a hydrophilic matrix tablet and to identify significant factors using a tablet ejection force and a swelling property. The characteristics of tablet ejection were evaluated with three different compression forces (30, 40, and 60 MPa) and two controlled factors, amount of magnesium stearate and its mixing time. A hydrophilic model drug (terazosin HCl dihydrate) was regarded as a default factor. Tablet swelling was also evaluated. The optimal amount of PEG compared to PEO was set to be 88.50% w/w. As the amount of magnesium stearate was varied from 0.79% to 2.20% w/w, the amount of PEO and PEG was adjusted to meet the tablet's total weight while maintaining the ratio between the two excipients constant. As the mixing time of magnesium stearate was increased, the tablet ejection force and the swelling property were decreased. As the amount of magnesium stearate was increased, the tablet ejection force and the swelling property were decreased since the increased mixing time and the amount of magnesium stearate induced hydrophobic properties of the matrix tablet more effectively. The ejection force of the tablet increased as a result of increase in the compression force, which means that the breaking of tablet/die-wall adhesion energy was also increased when the compression energy was increased. The results gavea valuable guide how to choose suitable amount of the lubricant with processing conditions for the development of hydrophilic matrix formulations.

COMPARISON OF THE BIOMECHANICAL AND BIOSYNTHETIC BEHAVIOR OF NORMAL HUMAN FIBROBLASTS AND FIBROBLASTS ISSUE FROM A FOREHEAD WRINKLE

  • Jouandeaud, M.;Viennet, C.;Chadebec, P.;Bordes, S.;Closs, B.;Humbert, P.
    • Proceedings of the SCSK Conference
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    • 2003.09a
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    • pp.192-202
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    • 2003
  • The wrinkles correspond to the most obvious expression of skin ageing and are manifested by changes on the organization and dermal structure. In the extracellular matrix, decreased quantities of collagens and glycosaminoglycans as well as a deterioration of the fibrillary network is noted, result in a reduction of dermal thickness. In addition, the activity of the collagenases increases in contrast to the synthesis of collagen fibers. Nor are cells spared during the aging process. We thus studied and compared the contractile capacity as well as the synthesis capacity of normal human fibroblasts and human fibroblasts obtained from biopsies of forehead wrinkles. The capacity of the fibroblasts to be adhered to the collagen network and to maintain a three-dimensional structure of dermis was studied on a model of equivalent dermis. The metabolic activity was studied by evaluating the capacities of synthesis of collagen I, main component of dermis. Human fibroblasts resulting from the forehead wrinkle contract less the gel of collagen than the normal human fibroblasts and present an activity of biosynthesis of collagen I less important than normal human fibroblasts. These results show that fibroblasts with aging present a deceleration of their metabolic activity and lose their capacity of adhesion to collagen fibers thus limiting the possibility of organizing the dermal tissue. We investigated the potential of an active ingredient able to compensate for the reduction of the metabolic activity and to restore the contractile capacity of fibroblasts obtained from forehead wrinkles. This effect was compared with a reference molecule: the vitamin C.

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The Effect of Ramulus Cinnamomum Aqua - acupuncture on The Cellular Immune Responses to LPS Induced Arthritis in Mice (계지약침자극(桂枝藥鍼刺戟)이 mouse의 LPS유발(誘發) 관절염(關節炎) 중 세포성면역반응(細胞性免疫反應)에 미치는 영향(影響))

  • Cho, Yoo-Haeng;Kim, Kap-Sung;Lee, Seung-Deok
    • Journal of Acupuncture Research
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    • v.18 no.1
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    • pp.100-112
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    • 2001
  • Objective : The purpose of this study is to investigate the immunological effect of Ramulus Cinnamomum aqua-acupuncture on the cellular immune response in mice with LPS induced arthritis. Methods : All the BALB/C mice used in this study were bred and maintaned in our pathogen-free mouse colony and were 6wk of age at the start of the experiment. The experimental model of arthritis was induced by injeciton of 300${\mu}g$/kg LPS in mice knee joint. Ramulus Cinnamomum aqua-acupuncture was injected into Yangnungchon(Gb34) of mice 2daily for 14days. Immunohistochemical analysis was carried out to assess CD4+, CD8+, CD11b, IL-$1{\beta}$, IL-2R and CD106 expression in common iliac lymph nodes and synovial menbrane after stimulation with Ramulus Cinnamomum. Electron microscopy was carried out to assess change of synovial membrane. Ramulus Cinnamomum aqua-acupuncture stimulation group was compared to control group and non stimutated with aqua-acupuncture. Resutts : At day 14 post arthritis onset, Immunohistological studies using monoclonal antibodies showed that Ramulus Cinnamomum aqua-acupuncture goup had decreased expression of CD4+, CD8+, CD11b, IL-$1{\beta}$, IL-2R and CD106 at common illiac lymph nodes and synovial membrane compared with control group. Conclusions : Ramulus Cinnamomum aqua-acupuncture stimulation inhibited the development of cellular immunity to LPS-induced arthritis in mice. Thus, aqua-acupuncture stimulation may have preventive effects on autoimmune inflammatory joint diseases. The effects of AA on immune function and disease activity in patients with RA warrant further investigation.

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Anti-metastasis Activity of Black Rice Anthocyanins Against Breast Cancer: Analyses Using an ErbB2 Positive Breast Cancer Cell Line and Tumoral Xenograft Model

  • Luo, Li-Ping;Han, Bin;Yu, Xiao-Ping;Chen, Xiang-Yan;Zhou, Jie;Chen, Wei;Zhu, Yan-Feng;Peng, Xiao-Li;Zou, Qiang;Li, Sui-Yan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6219-6225
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    • 2014
  • Background: Increasing evidence from animal, epidemiological and clinical investigations suggest that dietary anthocyanins have potential to prevent chronic diseases, including cancers. It is also noteworthy that human epidermal growth factor receptor 2 (ErbB2) protein overexpression or ErbB2 gene amplification has been included as an indicator for metastasis and higher risk of recurrence for breast cancer. Materials and Methods: The present experiments investigated the anti-metastasis effects of black rice anthocyanins (BRACs) on ErbB2 positive breast cancer cells in vivo and in vitro. Results: Oral administration of BRACs (150 mg/kg/day) reduced transplanted tumor growth, inhibited pulmonary metastasis, and decreased lung tumor nodules in BALB/c nude mice bearing ErbB2 positive breast cancer cell MDA-MB-453 xenografts. The capacity for migration, adhesion, motility and invasion was also inhibited by BRACs in MDA-MB-453 cells in a concentration dependent manner, accompanied by decreased activity of a transfer promoting factor, urokinase-type plasminogen activator (u-PA). Conclusions: Together, our results indicated that BRACs possess anti-metastasis potential against ErbB2 positive human breast cancer cells in vivo and in vitro through inhibition of metastasis promoting molecules.

Effects of Poly-N-acetyl Glucosamine(pGlcNAc) Patch on Wound Healing in db/db Mouse (Poly-N-acetyl-glucosamine이 당뇨병 쥐에서 창상치료에 미치는 영향)

  • Yang, Ho Jik;Yoon, Chi Sun
    • Archives of Plastic Surgery
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    • v.35 no.2
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    • pp.121-126
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    • 2008
  • Purpose: Poly-N-acetyl glucosamine(PGlcNAc) nanofiber-based materials, produced by a marine microalga, have been characterized as effective hemostatic and angiogenic agents. The similarity between PGlcNAc patch and the natural extracellular matrix allows it to support new healthy tissue growth in an injured area and to encourage fluid absorption. In this study, we hypothesized that a poly-N-acetyl glucosamine fiber patch(PGlcNAc patch) may enhance wound healing in the db/db mouse. Methods: PGlcNAc patches were applied on one square centimeter, full-thickness, skin wounds in the db/db mouse model. Wounds(n=15 per group) were dressed with a PGlcNAc nanofiber patch for 1 hour(1 h), 24 hours(24 h) or left untreated(NT). After the application time, patches were removed and wounds were allowed to heal spontaneously. The rate of wound closure was evaluated by digital analysis of unclosed wound area in course of time. At day 10, wounds(n=7 per group) were harvested and quantified with immunohistochemical markers of proliferation(Ki-67) and vascularization (platelet endothelial cell adhesion molecule, PECAM-1). Results: Wounds dressed with PGlcNAc patches for 1 hour closed faster than control wounds, reaching 90% closure in 16.6 days, nine days faster than untreated wounds. Granulation tissue showed higher levels of proliferation and vascularization following 1 h treatment than the 24 h and NT groups. In addition to its hemostatic properties, the PGlcNAc material also appears to accelerate wound closure in healing-impaired genetically diabetic mice. Conclusion: This material, with its combination of hemostatic and wound healing properties, has the potential to be effective agent for the treatment of complicated wounds.

A Suggestion of Formulae to Calculate Sectional Tractive Force on the Slope of Cohesive River Bank and its Application (점착성 제방사면의 구간별 소류력 산정식 제안 및 적용)

  • Han, Man-Shin;Choi, Gye-Woon
    • Journal of Korea Water Resources Association
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    • v.45 no.6
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    • pp.583-596
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    • 2012
  • The revetment is a installed structure on the slope of river bank to protect against flowing. Through the design standards of domestic and overseas, the maximum tractive force is calculated and applied to the average concept on the slope of river bank. In the case of calculating the method of permissible tractive force on the slope of river bank, there is a need to consider soil sliding. In this study, suggested the tractive force formulae by section of adhesion that have 0 < ${\Phi}$ < $90^{\circ}$ slope of river bank and installed an open channel of length of 20 m and 2 m wide for calculating permissible tractive force and hydraulic model experimented with changing discharge. According to the results, the calculated permissible tractive force of section on the slope is the largest due to the significant effects of surface roughness of different revetment materials. In addition, the permissible tractive force increased in the presence of vegetation but has no the effect by vegetation density.