• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.359-372
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• 2003

Among objectives of periodontal therapy. the principal one is the morphological and functional reconstruction of lost periodontal supporting tissues. This includes de novo formation of connective tissue attachment and the regrowth of alveolar bone. The use of enamel matrix derivative(EMD) may be a suitable means of regeneration new periodontal attachment in the infrabony defects. Implant used to replace lost tooth but, implantitis occurred after installation. The purpose of this study was to investigate the effects of EMD on differentiation and growth of osteoblast in titanium disc. Twentyfive millimeter diameter and 1mm thick Ti disc which was coated 25, 50, 100, 200${\mu}g$/ml of EMD(Emdogain(R)) used as experimental group, 25, 50, 100, 200ng/d of rhBMP-2 as positive control group, and no coat as negative control group. A human osteosarcoma cell line Saos-2 was cultured in Ti disc and cell proliferation and Alkaline phosphatase (ALP) activity were measured at 1 and 6 days. PCR was performed at 2 and 8 hours. Semi-quantitative RT-PCR for mRNA expressions of various osteoblastic differentiation markers -type I collagen, ALP, osteopontin, and bone sialoprotein - were performed at appropriate concentrations based upon the results of MTT and ALP assay. Cultured cell-disc complexes were prepared for scanning electron microscopy (SEM) at 2 hour. Data were analyzed using Mann-Whitney and repeated- measures 1-way analysis of variance(SPSS software version 10,SPSS. Chicago. IL). After culture, there was more osteoblast in EMD100${\mu}g$/ml than in EMD50, 200${\mu}g$/ml on day 6. There was significant difference in experimental and positive control group compared control group, as times go by(1 and 6 days). Alkaline phosphatase activity was different significantly in EMD100, 200${\mu}g$/ml and BMP100, 200${\mu}g$/ml on day 6. The results of reverse transcriptase-polymerase chain reaction (RT-PCR) showed that expression of mRNA for ALPase, collagen type I, osteopontin. hone sialoprotein and BMP-2 was detected at 2 hour and 8 hour in EMI 200${\mu}g$/ml subgroup and BMP100ng/ml subgroup. The results of this study suggest that application of enamel matrix derivative on osteoblast attached to titanium surface facilitate the expression of bone specific protein and the differentiation and growth of osteoblast.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.263-271
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• 2001

Objective : Glioblastomas, the most common type of primary brain tumors, are highly invasive and cause massive tissue destruction at both the tumor invading edges and in areas that are not in direct contact with glioma cells. As a result, patients with high-grade gliomas are faced with a poor prognosis. Such grim statistics emphasize the need to better understand the mechanisms that underlie glioma invasion, as these may lead to the identification of novel targets in the therapy of high grade gliomas. Protein kinase C(PKC) is a family of serine/threonine kinases and an important signal transduction enzyme that conveys signals generated by ligand-receptor interaction at the cell surface to the nucleus. PKC appears to be critical in regulating many aspects of glioma biology. The purpose of this study was to assess accurately the role of PKC in the invasion regulation of human gliomas based on hypothesis that protein kinase C(PKC) is functional in the process of glial tumor cell invasion. Method : To test this hypothesis, U-87 malignant glioma cell line intracellular PKC levels were up and down regulated and their invasiveness was tested. Intracellular PKC level was characterized using PKC activity assays. Invasion assays including barrier migration and spheroid confrontation were used to study the relationship between PKC concentration and invasiveness. Result : The cell line which were treated by PKC inhibitor tamoxifen and hypericin exhibited decreased PKC activity and decreased invasive abilities dose dependently both in matrigel invasion assay and tumor spheroid fetal rat brain aggregates(FRBA) confrontation assay. However, the cell line that was treated by PKC activator 12-O-tetradecanylphorbol-13acetate(TPA) did not exhibit increases in either PKC activity or invasive ability. Conclusion : These studies suggest that PKC may be a useful molecular target for the chemotherapy of glioblastoma and other malignancies and that a therapeutic approach based on the ability of PKC inhibitors may be helpful in preventing invasion.

• Radiation Oncology Journal
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• v.26 no.3
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• pp.166-172
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• 2008

Purpose: The measurement of radiosensitivity of individuals is useful in radiation therapy. Unfortunately, the measurement of radiation survival using a clonogenic assay, which is the established standard, can be difficult and time consuming. The aim of this study is to compare radiosensitivity results obtained from the MTT and clonogenic assays, and to evaluate whether the MTT assay can be used on clinical specimens. Materials and Methods: HCT-8, LoVo, CT-26, and WiDr were the colon cancer cell lines used for this study. The clonogenic assay was performed to obtain the cell survival curves and surviving fractions at a dose of 2 Gy ($SF_2$) as the standard technique for radiosensitivity. Also, the MTT assay was performed for each of the cell lines (in vitro). To simulate clinical specimens, the cell lines were inoculated into nude mice, removed when the tumors reached 1 cm in diameter, and chopped. Next, the tumors were subjected to the same process involved with the MTT assay in vitro. The inhibition rates (IR) of 10 Gy or 20 Gy of irradiation for in vitro and ex vivo were calculated based on the optical density of the MTT assay, respectively. Results: According to $SF_2$ and the cell survival curve, the HCT-8 and WiDr cell lines were more resistant to radiation than LoVo and CT-26 (p<0.05). The IR was measured by in vitro. The MTT assay IR was 17.3%, 21%, 30% and 56.5% for the WiDr, HCT-8, LoVo and CT-26 cell lines, respectively. In addition, the IR measured ex vivo by the MTT assay was 23.5%, 26%, 38% and 53% in the HCT-8, WiDr, LoVo and CT-26 tumors, respectively. Conclusion: The radiosensitivity measured by the MTT assay was correlated with the measures obtained from the clonogenic assay. This result highlights the possibility that the MTT assay could be used in clinical specimens for individual radiosensitivity assays.

• Archives of Craniofacial Surgery
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• v.11 no.1
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• pp.53-57
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• 2010

Purpose: The radial forearm fasciocutaneous free flap is currently considered as the ideal free flap for reconstruction of mucosal and soft tissue defects of the palate. But the availability of stably attached oral and nasal mucosal lining is needed. In addition to this, for better operation field, operating convenience and esthetics, we planned a prelaminated radial forearm free flap. Methods: A 64-year-old male patient was admitted due to a $4{\times}4.5cm$ full through defect in the middle of the hard palate caused by peripheral T cell lymphoma with actinomycosis. In the first stage, the radial forearm flap was elevated, tailored to fit the hard palate defect, and then it positioned up-side down with split thickness skin graft. Two weeks later, the prelaminated radial forearm free flap was re-elevated and transferred to the palatal defect. One side covered with grafted skin was used to line the nasal cavity, and the other side (the cutaneous portion of the radial forearm flap) was used to line the oral cavity. Results: The prelamination procedure was relatively easy and useful. The skin graft was well taken to the flap. After 2nd stage operation, the flap survived uneventfully. There was no prolapse of the inset flap into the oral cavity and the cutaneous portion of the flap was mucosalized. The procedure was very successful and the patient can enjoy normal rigid diet and speech. Conclusion: The use of prelaminated radial forearm free flap for hard palate reconstruction is an excellent method to restore oral function. Based upon the result of this case, microvascular free flap transfer with prelaminated procedure is a valid alternative to the prosthetic obturator for palatal defect that provides an improved quality of life. It should be considered as an integral component of head and neck cancer therapy and rehabilitation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.948-957
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• 2016

We previously developed an herbal composition (HemoHIM) based on the water extracts of Angelica gigas radix, Cnidium officinale rhizoma, and Paeonia japonica radix to protect and recover hematopoietic and intestinal tissues against radiation injuries. In this study, to develop a composition with improved activities based on enhanced fat-soluble polyphenol contents, we prepared a new herbal composition, MH-30, from the above three herbs by 30% ethanol extraction and hot water extraction. HPLC analysis of the ethanol fractions of MH-30 and HemoHIM revealed that MH-30 had higher contents of many fat-soluble polyphenol compounds than HemoHIM (8.7-fold increase for decursin), whereas contents of water-soluble polyphenol compounds showed little differences between the two compositions. Then, we evaluated MH-30 and HemoHIM for their in vitro antioxidant and immune cell-stimulating activities as well as in vivo protective effects against radiation injuries in hematopoietic and self-renewal tissues. In antioxidant activity assays, MH-30 showed higher hydroxyl radical scavenging activity than HemoHIM (1.4- to 1.9-fold for compositions and 2.3- to 4.5-fold for ethanol fractions). On the other hand, MH-30 and HemoHIM exhibited similar immune cell-stimulating activities as measured by in vitro lymphocyte proliferation. MH-30 increased endogenous spleen colony formation, decreased bone marrow cell apoptosis, and enhanced survival of intestinal crypts in irradiated mice, demonstrating effective protection of MH-30 against radiation-induced injuries in hematopoietic and self-renewal tissues. The 30-day survival rate of lethally irradiated mice, a comprehensive index for radioprotective efficacy, was also elevated by MH-30. Noticeably, MH-30 showed higher protective effects than HemoHIM in all mouse experiments. These results demonstrate that MH-30 can protect hematopoietic and self-renewal tissues against radiation injuries more effectively than HemoHIM. Therefore, MH-30 can be a good candidate to reduce radiation injuries in hematopoietic and self-renewal tissues incurred by radiation accidents or cancer radiation therapy.