Tissue stem cells are used for the regenerative medicine. In previous study we observed hard tissue formation of human dental pulp-derived cells using alginate scaffold. In this study, we explore the ability to differentiate of the 13th passage cells with glycerol 2-phosphate disodium salt hydrate (β-GP) which accelerate calcification. Reverse transcriptase Polymerase Chain Reaction (RT-PCR), transplants using alginate scaffold and histological examination were performed. We observed the expression of DSPP mRNA on day 10 cultured cells with β-GP. In conclusion, the 13th passage cells still have an ability to differentiate into odontoblast-like cells and alginate supports the differentiation of cultured cells in the transplants.

  In this paper, we described the existing methodology of product safety analysis and proposed a Petri-nets based method to analyze product safety systematically. The proposed method can be used to find the defects of hardware/software and the error of hu

System L amino acid transporter is a major route for providing living cells with neutral amino acids including several essential amino acids. To elucidate the expression pattern of L-type amino acid transporter 1 (LAT1) in the bone formation process, the expressions of LAT1 and its subunit 4F2 heavy chain (4F2hc) were investigated in the healing process after the implantation of bone graft materials in the calvarial osseous defected rats. Circular calvarial defects (1 cm in diameter) were made midparietally. The rats were divided into 4 groups of 1 control group and 3 experimental groups. In the control group, the defect was only covered with soft tissue flap. In the experimental groups, they were filled with human particulate dentin (particulate dentin group), with plaster of Paris (plaster of Paris group) and with the mixture of human particulate dentin and plaster of Paris with ratio of 2 : 1 by weight (mixture group). The rats were sacrificed at the 1, 2, 4 and 8 weeks after operation and the RT-PCR analysis and immunohistochemical analysis were performed. In the RT-PCR analysis, the mRNAs of LAT1 and 4F2hc were strongly detected in all 4 groups. In the immunohistochemical analysis, at 1 week after operation, the LAT1 protein and its subunit 4F2hc protein were mainly expressed in the osteoblasts, osteocytes and interstitial tissues of the around the defect and inner part of newly forming bone in all 4 groups. The expressions of LAT1 and 4F2hc proteins were decreased at 2 and 4 weeks after operation. The LAT1 and 4F2hc proteins were scarcely expressed at 8 weeks after operation in all 4 groups. These results suggest that the LAT1 and its subunit 4F2hc highly expressed at the early stage of new bone formation and may have an important role in providing cells with neutral amino acids including several essential amino acids at that stage.

It is well known that the imbalance between epithelial cell growth and inhibitor factors may cause human epithelial cancer. Over-expression of the epidermal growth factor receptor(EGFR) has been implicated in the development of oral squamous cell carcinoma. ZD1839 inhibits selectively the EGFR tyrosine kinase activity and is clinically used for cancer patients. However the mechanisms by which it exerts its anti-tumor activity remains unclear. This study attempted to determine the mechanisms underlying the effects of ZD1839 on the cellular level and to characterize the effects of ZD1839 with regard to human oral squamous cell carcinoma(OSCC) cell growth. The YD-10B and YD-38 cell lines established from OSCC in the department of Oral Pathology, Yonsei University College of Dentistry and ZD1839(Iressa) were used for this study. The inhibition of cell proliferation induced by ZD1839 was reversible and the lowest dose of ZD1839 that produced statistically significant growth inhibition in YD cell lines were 0.1 μM. The delay in cell cycle progression was induced by 0.1 μM of ZD1839 treatment after 24 hr. This reduction in cell proliferation and cell cycle delay were associated with up-regulation of the cyclin dependent kinase inhibitor(CDKI), P21CIP1/WAF1 and P27KIP1. Reduced expression of cyclin D1 was also observed after treatment with ZD 1839 to YD-38 cells but not to YD-38. The present results suggest that the antiproliferative effects of ZD1839, in vitro was associated with degradation of cyclin D1, which may be used as a possible indicator of a high cell sensitivity to ZD1839.

Development of placenta is a complex process that is critical for the pregnancy and controlled by many factors including cytokines, hormones, growth factors and apoptotic molecules. Recently, it has been shown that progranulin (PGRN) functions in growth of embryo and trophectoderm as well as cell migration. To initiate understanding the role of PGRN in human placental development, we investigated the expression of PGRN mRNA and protein in early and late gestation human placentas, term cytotrophoblast cells and two choriocarcinoma cell lines, JEG-3 and Jar. Reverse transcriptase polymerase chain reaction identified mRNAs derived from the PGRN gene in all samples. Immunoblot analysis showed that PGRN proteins are present in early and late gestation human placentas with decreasing levels over gestation and that PGRN proteins are present in normal and transformed trophoblast cells. Immunohistochemical analysis using paraformaldehyde-fixed tissue sections taken from early and late stages of pregnancy showed that PGRN proteins are present in cytotrophoblast cells, syncytiotrophoblast and extravillous cytotrophoblast cells and that expression pattern of PGRN differed according to the stage of cell differentiation. The results of this study are consistent with the hypothesis that PGRN proteins have critical roles in placental development and suggest that PGRN may function in trophoblast cell growth and differentiation.

This study was conducted to examine the effect of IRES controlled reporter gene on screening and production of recombinant human erythropoietin (EPO) proteins from cultured CHO cells. The cDNA was cloned for EPO from human liver cDNA. Using site-directed mutagenesis, we generated recombinant human EPO (rhEPO) with two additional N-glycosylations (Novel erythropoiesis-stimulating protein: NESP). Wild type hEPO and NESP were cloned into expression vectors with GFP reporter gene under regulatory control of CMV promoter and IRES so that the vectors could express both rhEPO and GFP. The expression vectors were transfected to cultured CHO-K1 cells. Under microscopy, expression of GFP was visible. Using supernatant of the culture, ELISA assay, immunocytochemistry and in vitro assay using EPO dependant cell line were performed to estimate biological activity to compare the production characteristics (secretion levels, etc.) between rhEPO and NESP. The activity of NESP protein, obtained by mutagenesis, was described and compared with its rhEPO counterpart produced under same conditions. Although NESP had less secretion level in CHO cell line, the biological activity of NESP was greater than that of rhEPO. These results are consistent with previous researches. We also demonstrated that rhEPO and GFP proteins expressed simultaneously from transfected CHO cell line. Therefore we conclude that use of GFP reporter gene under IRES control could be used to screen and produce rhEPO in cultured CHO cells.

The purpose of this study was to investigate how comparative menu price, human service, amenity, and menu quality affected menu value, and how menu value influenced revisit intention. The model was tested in a family restaurant setting using a sample of customers visiting and enjoying menu in Daegu metropolitan city. Empirical results confirmed that not only do human service, amenity and menu quality increase menu value but that comparative menu price reduces menu value. Menu value was also found to be a significant antecedent of revisit intention. The results obtained have major implications for family restaurant marketers as well as for future research. First, family restaurant marketers should pay attention to menu pricing, as menu price decreased menu value. Second, family restaurant marketers should try to increase menu value through training of human service. Third, family restaurant marketers should try to add menu value by way of recruiting high-skilled cook. Fourth, family restaurant marketers should make efforts to attract customers through interior design.

This experiment was performed to study the biocompatibility of xenograft materials (ABBM. coralline HA). Both autogenous bone grafts and allogenic banked bone were frequently and successfully used to promote regeneration of parts of skeleton. The use of these types of grafts were limited by the cost of donor site operation for autogenous boneor by fear of the risk of infection of allogenic materials. Another type of graft is xenograft which include ABBM and coralline HA. For investigating the biocompatibility, generally many investigators used cancer cell lines or animal cell lines. But cancer cell lines and animal cell lines had functioned different metabolism from normal human cell. So the experiment used normal human osteoblast for compare the biocompatibility of ABBM with coralline HA which were fixed in 24 well base contained culture medium. After 1st, 3rd, 7th, 14th, 28th days, the culture medium were taken out and checked the concentrations ofcalcium( Ca), inorganic phosphate(IP) and alkaline phosphatase(ALP). In another method, histologic samples were investigated after 8weeks of xenograft materials implantated on rabbit's tibia, the bone was cut and made undecalcified ground samples and checked with fluorecent microscope, polarizing microscope, reflection electron microscope and electron probe microanalysis. The statistical results of concentrations (Ca, IP, ALP) of materials in the culture medium have decreasedby day's, which meant that xenograft materials were effective for bone remodelling. The concentrations in the culture medium of ABBM were lower than that of coralline HA, that meant that biocompatibility of ABBM were superior than that of coralline HA. Histologic samples showed that ABBM had better bone remodelling effect than coralline HA. ABBM showed good alizarin red marking lines, more deposition of Ca, IP, and dense color of bone around newly formed osteon and bone trabeculae. it was concluded that ABBM was more biocompatible than corallineHA in vivo and in vitro test

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotion of wound healing have been well known, there are few reports about molecular mechanisms associated with wound healing by LED irradiation. The purpose of the present study was to investigate the expression pattern of various extracellular matrix(ECM) molecules in relation to wound healing after LED irradiation on primary human gingival fibroblasts(hGFs) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635 nm, and manufactured that energy density was 5 mW/cm2 on sample surfaces. The hGFs were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 24 and 48 hour after irradiation. To investigate the molecular mechanisms associated with wound healing, we examined the mRNA expression of 6 types of collagens, 7 types of matrix metalloproteinases(MMPs) and 4 types of tissue inhibition of metalloproteinases(TIMPs) after LED irradiation by RT-PCR. The mRNA expression of collagen 4, MMP-3, 9, and 16, and TIMP-3 was influenced by LED irradiation. Generally, the collagen expression of the irradiation group was slightly increased, particularly collagen 4 was significantly increased at 0 hour. The expression of MMP-3 was increased at 0 and 24 hours and MMP-16 was increased at 24 hours, respectively. The expression of MMP-9 was decreased at 0 hour and increased at 24 and 48 hours. The mRNA expression of TIMP-3 was significantly decreased at 24 and 48 hours after irradiation. These results suggest that the altered expression of ECM molecules after LED irradiation may contribute to the accelerated wound healing.

Pro-inflammatory cytokines are important mediators of cutaneous cellular activities during many oral mucosal diseases. IHOK culture model transfected by E6/E7 genes provide further evidence for the role of HPV in tumorogenesis. It is interesting to investigate cytokine expression of immortalized human oral keratinocyte(IHOK). The purpose of this study were to analysis cytokine mRNA expression levels of NHOK and IHOK by RT-PCR. IHOK showed about 5 fold increases of IL-6 compared with NHOK, while TNF-α was the lowest. It suggested that immortalization of NHOK with E6/E7 could result in elevated expression of IL-6, and IHOK be in the intermediate stage of oral carcinogenesis.

본 논문에서는 세계적으로 널리 사용되어지고 있는 초고층 건축물의 진동사용성 평가기준이 검토되었다. 초고층 건축물의 진동에 대한 사용성 평가기준은 바람에 의한 초고층 건축물의 가속도 응답의 크기로 나타내는 것이 일반적이다. 건축물의 가속도의 응답의 크기를 산정함에 있어서 두 가지의 서로 다 른 척도, 즉 최대가속도 또는 RMS가속도를 각 기준에서 채택하고 있는데 이에 대한 상이점을 토의하고 각 국의 진동사용성 평가기준을 고찰함으로써 우리나라에는 어떤 진동사용성 평가기준이 적합한가에 대한 논의를 시작하고자 하였다. 그리고 건축물의 각기 다른 응답을 조사하여 최대가속도와 RMS가속도와 관계를 면밀히 검토하고 각각에 대해 기술적인 논거를 기술하였다.

Since ancient Eygypt, various dental materials were used for lost teeth including gold. The key point of this materials were nontoxic to human body. Since early of 1990's, dental implant was done for recovery of maxillofacial defects. From middle of 1970's, osseointergation concept of implant was introduced and performed in dental field. Biocompatibility of titanium showed good effect for osseointergration but had some problems (Galvance current and toxic corrosion) with suprastructures such as gold crowns. This study was performed to make safe dental implants which have reduced Galvanic currents and corrosion. 3 kind of dental casting gold alloys (different Gold contents, 1㎝×1㎝×0.1㎝ plates.) were used as experimental group, while Titanium were used as control group. Normal human osteoblasts(NHOsts)were cultured during 1-4weeks for histologic study. For analysing the calcium(Ca), Phosphorus(P) and alkaline phosphatase(ALP), NHosts were cultred during 2-23days. After experiments, histologic finding were observed by LSM and SEM. Ca, P, ALP concentration by automatic biochemical analyzer were analyzed by ANOVA test and linear regression method. The results were as follows. Biocompatibility of dental casting gold alloys were similar to titianium alloys histolgically. Biochemical analysis of dental casting gold alloys had no significant difference to titianium alloy except AIGIS-Fine. We could conclude that biocompatibility of dental casting gold alloys with high contents of gold were superior to that of low contents and alloys with high contents of gold had no significant difference from titanium on NHost culture. Gold dental implant might be better than titanium implant due to similar biocompatibility and no galvanic currency.