• Title/Summary/Keyword: Adhesion:models, experiment

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A Experimental Study for the Effect of Sodium Carboxymethyl Cellulose on Prevention of Percardial Adhesion (Sodium Carboxymethyl Cellulose의 심막유착 방지효과에 관한 실험적 연구)

  • 이석열;전철우;이만복;이길노;고은석;엄영익
    • Journal of Chest Surgery
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    • v.33 no.7
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    • pp.541-546
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    • 2000
  • Background; Pericardial adhesion poses a major problem during re-operative cardiac surgery. The purpose of this study was to determine the effect of sodium carboxymethol cellulose on experimental pericardial adhesions. Material and Method; Twenty-four rabbits were divided into 2 groups of 12 rabbits each and pericardial mesothelial injury was induced by abrasion. Group A included rabbits receiving intrapericardial injection of Ringer's solution, and Group B included rabbits receiving intrapericardial injection of 3% sodium carboxymethoyl cellulose solution. Three weeks after the surgery, the incidence of adhesions in Group A was compared with that in Group B. Result; Pericardial adhesions were evaluated by tenacity and type scores. Tenacity scores of 3 or greater were considered clinically significant adhesion. Pericardial adhesion was found in 100% of rabbits in group A. However 25% of the rabbits in Group B had pericardial adhesions(p<0.0001). Type scores were also considered clinically significant between 2 groups. Conclusion; Our findings demonstrated that intrapericardial injection of 3% sodium carboxymethyl cellulose solution reduced the incidence of pericardial adhesions in an animal models.

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Inhibition of Contact Dermatitis in Animal Models and Suppression of Proinflammatory Gene Expression by Topically Applied Flavonoid, Wogonin

  • Lim, Hyun;Park, Haeil;Kim, Hyun-Pyo
    • Archives of Pharmacal Research
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    • v.27 no.4
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    • pp.442-448
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    • 2004
  • Wogonin (5,7-dihydroxy-8-methoxyflavone) is a down-regulator of cyclooxygenase-2 and inducible nitric oxide synthase expression, contributing to anti-inflammatory activity in vivo. For further characterization of modulatory activity on ploinflammatory gene expression in vivo, the effect of wogonin was examined in this experiment using animal models of skin inflammation. By topical application, wogonin inhibited an edematic response as well as ploinflammatory gene expression against contact dermatitis In mice. Wogonin inhibited ear edema ($19.4-22.6\%$) at doses of $50-200\;{\mu}g$/ear and down-regulated interleukin-$1{\beta}$ induction ($23.1\%$) at $200{\mu}g$/ear in phenol-induced simple irritation. Wogonin ($2{\times}50-2{\times}200{\mu}g$/ear) also inhibited edematic response ($51.2-43.9\%$) and down-regulated ploinflammatory gene expression of cyclooxygenase-2, interleukin-$1{\beta}$, interferon-$\gamma$, intercellular adhesion molecule-1 and inducible nitric oxide synthase with some different sensitivity against picryl chloride-induced delayed hypersensitivity reaction. All these results clearly demonstrate that wogonin is a down-regulator of ploinflammatory gene expression in animal models of skin inflammation. Therefore, wogonin may have potential for a new anti-inflammatory agent against skin inflammation.

GINGIVAL MARGIAL LEAKAGE AND BONDING PATTERN OF THE COMPOSITE RESIN INLAY ACCORDING TO VARIOUS THICKNESS OF DIE SPACER (Die spacer의 두께에 따른 복합레진 inlay의 치은 변연부 미세누출 및 접착양태에 관한 연구)

  • Park, Tae-Il;Shin, Dong-Hoon;Hong, Chan-Ui
    • Restorative Dentistry and Endodontics
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    • v.20 no.1
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    • pp.152-163
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    • 1995
  • This experiment was performed to observe the adhesion pattern and microleakage in the gingival margin according to variation in the resin cement thickness which results from thickness of Die spacer. which is considered to effect the adaptability of the composite resin inlays. Clearfil CR inlays were fabricated on stone models with CR Sep applicated once and Nice fit twice, 4 times, and 6 times each. After 2nd curing within the CRC-100 oven, CR inlays were cemented with CR inlay cement. Dye(2% methylene blue) penetration and adhesion pattern were evaluated after sectioning of gingival margin into :3 pieces. The results were as follows ; 1. The thickness of resin cement showed unevenchanging pattern with that of die spacer, namely, it was increased until 4 times' application of Nice-Fit but was decreased with 6 times' application of that. 2. The degree of dye penetration wasn't affected by cement thickness within a limited value. 3. Most of dye penetration was shown through the interface between cement and enamel rather than the interface between cement and CR inlay. This shows that the affinity of resin cement for CR inlay was superior to the adhesive strength with tooth structure. 4. No gap was found at the interface between enamel and cement but some showed separation between dentin and cement. It is concidered that the contraction force of cement was less than the bond strength with the enamel. 5. Lots of voids were found in the CR inlay and resin cement. There was a pooling tendency of bonding agent and cement in the axiogingival line angle portion. 6. In some specimens, cracks were shown in enamel margin. From this it could be considered that cavity preparation and surface treatment weakened the tooth structure.

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Atomic Force Microscopy Study on Correlation between Electrical Transport and Nanomechanical properties of Graphene Layer

  • Kwon, Sang-Ku;Choi, Sung-Hyun;Chung, H.J.;Seo, S.;Park, Jeong-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.85-85
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    • 2010
  • Graphene, the building block of graphite, is one of the most promising materials due to their fascinating electronic transport properties. The pseudo-two-dimensional sp2 bonding in graphene layers yields one of the most effective solid lubricants. In this poster, we present the correlation between electrical and nanomechanical properties of graphene layer grown on Cu/Ni substrate with CVD (Chemical Vapor Deposition) method. The electrical (current and conductance) and nanomechanical (adhesion and friction) properties have been investigated by the combined apparatus of friction force microscopy/conductive probe atomic force microscopy (AFM). The experiment was carried out in a RHK AFM operating in ultrahigh vacuum using cantilevers with a conductive TiN coating. The current was measured as a function of the applied load between the AFM tip and the graphene layer. The contact area has been obtained with the continuum mechanical models. We will discuss the influence of mechanical deformation on the electrical transport mechanism on graphene layers.

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The Ability of Anti-tumor Necrosis Factor Alpha(TNF-${\alpha}$) Antibodies Produced in Sheep Colostrums

  • Yun, Sung-Seob
    • 한국유가공학회:학술대회논문집
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    • 2007.09a
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    • pp.49-58
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    • 2007
  • Inflammatory process leads to the well-known mucosal damage and therefore a further disturbance of the epithelial barrier function, resulting abnormal intestinal wall function, even further accelerating the inflammatory process[1]. Despite of the records, etiology and pathogenesis of IBD remain rather unclear. There are many studies over the past couple of years have led to great advanced in understanding the inflammatory bowel disease(IBD) and their underlying pathophysiologic mechanisms. From the current understanding, it is likely that chronic inflammation in IBD is due to aggressive cellular immune responses including increased serum concentrations of different cytokines. Therefore, targeted molecules can be specifically eliminated in their expression directly on the transcriptional level. Interesting therapeutic trials are expected against adhesion molecules and pro-inflammatory cytokines such as TNF-${\alpha}$. The future development of immune therapies in IBD therefore holds great promises for better treatment modalities of IBD but will also open important new insights into a further understanding of inflammation pathophysiology. Treatment of cytokine inhibitors such as Immunex(Enbrel) and J&J/Centocor(Remicade) which are mouse-derived monoclonal antibodies have been shown in several studies to modulate the symptoms of patients, however, theses TNF inhibitors also have an adverse effect immune-related problems and also are costly and must be administered by injection. Because of the eventual development of unwanted side effects, these two products are used in only a select patient population. The present study was performed to elucidate the ability of TNF-${\alpha}$ antibodies produced in sheep colostrums to neutralize TNF-${\alpha}$ action in a cell-based bioassay and in a small animal model of intestinal inflammation. In vitro study, inhibitory effect of anti-TNF-${\alpha}$ antibody from the sheep was determined by cell bioassay. The antibody from the sheep at 1 in 10,000 dilution was able to completely inhibit TNF-${\alpha}$ activity in the cell bioassay. The antibodies from the same sheep, but different milkings, exhibited some variability in inhibition of TNF-${\alpha}$ activity, but were all greater than the control sample. In vivo study, the degree of inflammation was severe to experiment, despite of the initial pilot trial, main trial 1 was unable to figure out of any effect of antibody to reduce the impact of PAF and LPS. Main rat trial 2 resulted no significant symptoms like characteristic acute diarrhea and weight loss of colitis. This study suggested that colostrums from sheep immunized against TNF-${\alpha}$ significantly inhibited TNF-${\alpha}$ bioactivity in the cell based assay. And the higher than anticipated variability in the two animal models precluded assessment of the ability of antibody to prevent TNF-${\alpha}$ induced intestinal damage in the intact animal. Further study will require to find out an alternative animal model, which is more acceptable to test anti-TNF-${\alpha}$ IgA therapy for reducing the impact of inflammation on gut dysfunction. And subsequent pre-clinical and clinical testing also need generation of more antibody as current supplies are low.

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