• Journal of Periodontal and Implant Science
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• 제26권2호
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• pp.414-428
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• 1996

The use of basic fibroblast growth factor which function as potent biologic mediators regulating numerous activities of wound healing has been suggested for the promotion of periodontal regeneration. The mitogenic effects of basic fibroblast growth factor on human periodontal ligament cells and human gingival fibroblasts were evaluated by determining the incorporation of 5-Bromo-2'deoxy-uridine into DNA of the cells in a dose -dependent manner. The cells which were prepared were the primary cultured gingival fibroblasts and periodontal ligament cells from human the fourth or sixth subpassages were used in the experiments. The cells which were seeded DMEM contain 10% FBS. The added concentrations of basic fibroblast growth factor were 0.1, 1, 10, 50, $l00{\eta}g/ml$ and basic fibroblast growth factor were added to the quiescent cells for 24 hours, 48 hours and 72 hours. They were labeled with $10{\mu}l/200{\mu}l$ 5Bromo-2'-deoxy-uridine for the last 6 hours of each culture. The results of the five determinants were presented as mean and S.D.. The results were as follows. : The DNA synthetic activity of human gingival fibroblasts was increased dose dependently by basic fibroblast growth factor at 24 hours, 48 hours and 72 hours. The similar mitogenic effects were at the 24 and 48 hours of basic fibroblast growth factor, but the DNA synthetic activity of human gingival fibroblasts generally decreased at 72 hours. The DNA synthetic activity of human periodontal ligament cells was increased dose dependently to $50{\eta}g/ml$ by basic fibroblast growth factor at 24, 48 and 72 hours, but the DNA synthetic activity decreased at $l00{\eta}g/ml$ of each hour. Generally the maximum mitogenic effects were at the 48 hours application of basic fibroblast growth factor. The DNA synthetic activity of human periodontal ligament cells generally decreased lower at 72 hours than at 24, 48 hours the application of basic fibroblast growth factor. In the comparison of DNA synthetic activity between human gingival fibroblasts and human periodontal ligament cells, human periodontal ligament cells had slightly higher proliferation activity than human gingival fibroblasts for a longer time at the high dosage of the basic fibroblast growth factor.In conclusion, basic fibroblast growth factor have important roles in the stimulation of DNA synthesis in human periodontal ligament cells and human gingival fibroblasts, and thus may be useful for clinical applications in periodontal regenerative procedures.

• Molecules and Cells
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• 제21권3호
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• pp.343-355
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• 2006

Stem cells are unique cell populations with the ability to undergo both self-renewal and differentiation, although a wide variety of adult stem cells as well as embryonic stem cells have been identified and stem cell plasticity has recently been reported. To identify genes implicated in the control of the stem cell state as well as the characteristics of each stem cell line, we analyzed the expression profiles of genes in human embryonic, hematopoietic ($CD34^+$ and $CD133^+$), and mesenchymal stem cells using cDNA microarrays, and identified genes that were differentially expressed in specific stem cell populations. In particular we were able to identify potential hESC signature-like genes that encode transcription factors (TFAP2C and MYCN), an RNA binding protein (IMP-3), and a functionally uncharacterized protein (MAGEA4). The overlapping sets of 22 up-regulated and 141 down-regulated genes identified in this study of three human stem cell types may also provide insight into the developmental mechanisms common to all human stem cells. Furthermore, our comprehensive analyses of gene expression profiles in various adult stem cells may help to identify the genetic pathways involved in self-renewal as well as in multi-lineage specific differentiation.

• 대한미생물학회지
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• 제21권4호
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• pp.407-415
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• 1986

This study investigated whether a correlation exists between environmental physical and biochemical factors and adherence of Candida albicans to human buccal epithelial cells by using normal and UV-irradiated strains. The results were as follows: 1. The percentage of germ tube forming activities of normal Candida albicans was 91.5% and UV-irradiated Candida albicans was 15.0%. The $LD_{50}$ of normal strains in mice were $1.0{\times}10\;cells/ml$, but could not be observed in the UV-irradiated strains even with $1.0{\times}10\;cells/ml$. It demonstrated that the virulence is decreased in the UV-irradiated strain. 2. The adherence of normal Candida albicans to human buccal epithelial cells($166{\pm}29{\sim}207{\pm}17\;cells$/100 epithelial cells) was significantly greater than UV-irradiated Candida albicans($99{\pm}21{\sim}131{\pm}25\;cells$/100 epithelial cells). 3. Candida albicans cultured at $37^{\circ}C$ adhered to buccal epithelial cells($166{\pm}16{\sim}207{\pm}17\;cells$/100 epithelial cells) in greater numbers than cultured at $25^{\circ}C$($80{\pm}15{\sim}143{\pm}22\;cells$/100 epithelial cells). 4. On comparison of the adherence of viable and nonviable(heat-killed) Candida albicans to human buccal epithelial cells, the nonviable Candida albicans demonstrated poorer adherence than viable Candida albicans. 5. Adherence in vitro of Candida albicans to human epithelial cells appeared to be effected by the pH. The adherence ability was maximum increased at pH 7.0($187{\pm}22\;cells$/100 epithelial cells) other than experimental pH. 6. The adherence was proportional to the incubation time and the Candida cell concentration in the suspension. 7. A strong correlation was shown between germ tube forming activity and increased adherence of Candida albicans to human epithelial cells, indicating that germ tube forming activity were responsible for candidal virulence.

• 한국환경성돌연변이발암원학회지
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• 제21권1호
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• pp.34-43
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• 2001

Di-2-ethylhexyl phthalate (DEHP) is the most commonly used phthalate ester in polyvinyl chloride formulations including food packing and storage of human blood. DEHP is a well known as non-genotoxic carcinogen and endocrine disrupting chemical (EDC). DEHP have shown all negative results in ICH-guildeline recommended standard genotoxicity test battery. In this study, to assess the clastogenic and DNA damaging effect in human-derived tissue specific cells, DEHP was treated in human derived MCE-7 cells, HepG2 cells, LNCap cells, BeWo cells, MCE-10A cells, and female peripheral blood cells using micronucleus assay and in human breast carcinoma MCF-7 cells up to $1.28$\times$10^{-2}$ M using Comet assay. The in vitro micronucleus assay is a mutagenicity test system for the detection of chemicals which induce the formation of small membrane bound DNA fragment i.e. micronuclei in the cytoplasm of interphase cells, originated from clastogenic and/or aneugenic mechanism. The single cell gel electrophoresis assay (Comet assay) is used to detect DNA strand-breaks and alkaline labile site. In our results, DEHP increased significantly and/or dose-depentently and time-dependently micronucleus frequency at the 6 and 24 hr without metabolic activation system only in MCE-7 cells. DEHP treated with 2 hrs in MCF-7 cells using Comet assay induced DNA damage dose-depentantly.

• Preventive Nutrition and Food Science
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• 제2권2호
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• pp.167-173
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• 1997

The inhibitory effects of kale juice on the growh and DNA incorporation of human cancer cells, using HT-29 colon cancer cells, MG-63 osteosarcoma cells, AGS gastric adenocarcinoma cells and K-562 leukemia cells, were studied. The growth of human cancer cells were inhibited in the presence of kale juice (10, 20 nd 40$\mu$l/ml) and the effects were the juice concentration- and incubation time-dependent up to 6 days. When 20$\mu$l/ml of kale juice was added to the media of HT-29, MG-63, AGS and K-562 cancer cells, the cell growth after 6 or 4 days of incubation was retarded by 83~95% of control group. Morphological changes of HT-29 colon cancer cells wre studied under inverted microscope. As the concentration of kale juice increased up to 20$\mu$l/ml, degree of cell aggregation was decreased. Moreover, the DNA incorporation o AGS gastric adenocarcinoma cells and MG-63 osteosarcoma cells which were labeled with [$^3$H] thymidine was significantly reduced after 2 days of incubation at 37$^{\circ}C$ with kale juice. Therefore, we concluded that kale juice strongly decreased the growth of various human cancer cells.

• Molecules and Cells
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• 제39권3호
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• pp.186-194
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• 2016

Epidemiological evidence suggests that bone is especially sensitive to oxidative stress, causing bone loss in the elderly. Previous studies indicated that human amnion-derived mesenchymal stem cells (HAMSCs), obtained from human amniotic membranes, exerted osteoprotective effects in vivo. However, the potential of HAMSCs as seed cells against oxidative stress-mediated dysfunction is unknown. In this study, we systemically investigated their antioxidative and osteogenic effects in vitro. Here, we demonstrated that HAMSCs significantly promoted the proliferation and osteoblastic differentiation of $H_2O_2$-induced human bone marrow mesenchymal stem cells (HBMSCs), and down-regulated the reactive oxygen species (ROS) level. Further, our results suggest that activation of the ERK1/2 MAPK signal transduction pathway is essential for both HAMSCs-mediated osteogenic and protective effects against oxidative stress-induced dysfunction in HBMSCs. U0126, a highly selective inhibitor of extracellular ERK1/2 MAPK signaling, significantly suppressed the antioxidative and osteogenic effects in HAMSCs. In conclusion, by modulating HBMSCs, HAMSCs show a strong potential in treating oxidative stress- mediated bone deficiency.

• Toxicological Research
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• 제12권2호
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• pp.271-275
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• 1996

Carcinogenic potential of HPV-16 DNA and NNK in a human keratinocyte cell line was assessed to study effects of viral-chemical interaction. Human cells were transfected with HPV-16 DNA and 6 clonal cell lines were subsequently obtained. Clonal line-3 and 6 at passage 7 showed characteristics of tumor cells such as increases of saturation density, soft-agar colony formation, cell aggregation and foci appearance. Among cells treated with 1$\mu M$, 10$\mu M$, 100$\mu M$ or 1 mM of NNK for 4 weeks, 100$\mu M$ treatment showed most tumorigenic characteristics at passage 7. These results indicate that either HPV-16 or NNK alone is tumorigenic in this in human in vitro model. When cells transfected with HPV-16 were subsequently exposed by 100 uM NNK for 4 weeks, all the clonal cells except clone-1 showed higher levels of tumor cell characteristics than HPV-16 DNA or NNK exposure alone. Clonal line-6, the most tumorigenic cells, showed higher transcriptional level of fibronectin and lower level of TGF-$\beta_1$, as compared to control cells, suggesting that alteration of growth factor or extracellular matrix may play a role in carcinogenesis process induced by HPV-16 and NNK. Taken together, the present study indicates that viral-chemical interactions between HPV-16 DNA and NNK enhance carcinogenic potentials of human cells and implies that smoking among people infected with human papillomavirus may pose an additional risk of causing cancer.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.455-463
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• 2007

The present study was designed to evaluate effects of the commonly used NSAIDs(acetaminophen, aspirin, and ibuprofen) on human periodontal ligament cells. Human periodontal ligament cells were grown from a cell line provided by Kyungpook National University. Effects of NSAIDs on the proliferation of human periodontal ligament cells were assessed using MTT assays. And then $PGE_2$ concentrations were determined by ELISA and the changes of cellular configuration were found by electron micrograph. The results were as follows; 1. The MTT assay demonstrated that the commonly used NSAIDs(acetaminophen, aspirin, and ibuprofen) had not significant cytotoxic effect on human periodontal ligament cells. 2. NSAIDs inhibited the $PGE_2$ synthesis of human periodontal ligament cells compared with the control group. These inhibitory effects had no significant differences with NSAID type and concentration. 3. Electron micrographs of human periodontal ligament cells treated with NSAIDs showed more narrow and irregular shape.

• 약학회지
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• 제54권2호
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• pp.112-121
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• 2010

The cytotoxic activity of 33,4,5-trihydroxybenzoic acid methylester and related compounds on the growth of normal cell lines, human skin melanoma cells and human oral epithelioid cell line were evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and 2,3-bis-[2-methoxy-4-nitro-5-sulfo-phenyl]-2-H-tetrazolium-5-caboxanilide (XTT) methods. 3,4,5-Trihydroxybenzoic acid methylester decreased the cell viability of human skin melanoma cells and human oral epithelioid cells shown by the MTT method and the cell adhesion activity of human skin melanoma cells and human oral epithelioid cells shown by the XTT method. In light microscopy, 100 ${\mu}M$ 3,4,5-trihydroxybenzoic acid methylester showed the highest cytotoxic activity. These results suggest that 3,4,5-trihydroxybenzoic acid methylester has a potential anticancer activity.

• Molecules and Cells
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• 제41권7호
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• pp.613-621
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• 2018

The capacity of differentiation of human pluripotent stem cells (hPSCs), which include both embryonic stem cells and induced pluripotent stem cells, into cardiomyocytes (CMs) in vitro provides an unlimited resource for human CMs for a wide range of applications such as cell based cardiac repair, cardiac drug toxicology screening, and human cardiac disease modeling. However, their applicability is significantly limited by immature phenotypes. It has been well known that currently available CMs derived from hPSCs (hPSC-CMs) represent immature embryonic or fetal stage CMs and are functionally and structurally different from mature human CMs. To overcome this critical issue, several new approaches aiming to generate more mature hPSC-CMs have been developed. This review describes recent approaches to generate more mature hPSC-CMs including their scientific principles, advantages, and limitations.