• Restorative Dentistry and Endodontics
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• v.48 no.2
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• pp.18.1-18.10
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• 2023

Objectives: This study aimed to determine whether collagen triple helix repeat containing-1 (CTHRC1), which is involved in vascular remodeling and bone formation, can stimulate odontogenic differentiation and angiogenesis when administered to human dental pulp stem cells (hDPSCs). Materials and Methods: The viability of hDPSCs upon exposure to CTHRC1 was assessed with the WST-1 assay. CTHRC1 doses of 5, 10, and 20 ㎍/mL were administered to hDPSCs. Reverse-transcription polymerase reaction was used to detect dentin sialophosphoprotein, dentin matrix protein 1, vascular endothelial growth factor, and fibroblast growth factor 2. The formation of mineralization nodules was evaluated using Alizarin red. A scratch wound assay was conducted to evaluate the effect of CTHRC1 on cell migration. Data were analyzed using 1-way analysis of variance followed by the Tukey post hoc test. The threshold for statistical significance was set at p < 0.05. Results: CTHRC1 doses of 5, 10, and 20 ㎍/mL had no significant effect on the viability of hDPSCs. Mineralized nodules were formed and odontogenic markers were upregulated, indicating that CTHRC1 promoted odontogenic differentiation. Scratch wound assays demonstrated that CTHRC1 significantly enhanced the migration of hDPSCs. Conclusions: CTHRC1 promoted odontogenic differentiation and mineralization in hDPSCs.

• International Journal of Oral Biology
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• v.31 no.3
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• pp.73-79
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• 2006

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 (${\beta}-GP$) 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 ${\beta}-GP$. 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.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.2
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• pp.17-23
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• 2015

Natural cellulose hydrogel membrane cannot be directly used for cell encapsulation because it has many large pores on the surface that immune biomolecules are able to penetrate into easily. For the reason, alginate was used for the control of pore size of the cellulose hydrogel membrane. The surface morphology of cellulose/alginate nanocomposite confirmed the successful control of the porosity of the membrane. The permeability of the cellulose/alginate nanocomposite was decreased but mechanical properties were increased compared with the bacterial cellulose membrane. The cellulose/alginate nanocomposite could be used for the functional membrane as a promising biomedical material in the future.

• International Journal of Oral Biology
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• v.32 no.2
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• pp.45-49
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• 2007

In this study, the cytotoxicity of commonly used local anesthetics was evaluated on odontoblasts which are essential for pulpal homeostasis in vitro. Local anesthetics, such as articaine, bupivacaine, levobupivacaine, lidocaine, mepivacaine, prilocaine, and procaine, were tested on the odontoblast cell line, MDPC-23. The concentration-and time-dependent cytotoxic effects of local anesthetics on odontoblasts were measured by MTT assay. Among local anesthetics treated for 18 h, only bupivacaine significantly showed cell death in a concentration-($LC_{50}=1.2mM$) and time-dependent manner. To confirm cell death induced by bupivacaine, the observation of cell morphology and FACS using Annexin V and propidium iodide (PI) staining were performed. As a result of Annexin V and PI staining, as well as the morphological change, only bupivacaine induced apoptotic cell death on odontoblasts when compared with levobupivacaine and lidocaine. These results suggest that bupivacaine might affect normal pulpal integrity even after uneventful local anesthesia.

• Journal of the korean academy of Pediatric Dentistry
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• v.10 no.1
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• pp.67-76
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• 1983

The state of pulp and dental hard tissue during the process of resorption and shedding of 104 non-carious primary teeth was assessed by histomorphologic study. The teeth were extracted from the Korean school children aged 5 to 15 and classified into preshedding, shedding, delayed shedding groups according to the age of the child at the time of extraction, The results were as follows: 1. The inflammatory cell infiltration in primary pulp tissues occurred in 61.5% of observed teeth and were increased in the order of preshedding, shedding and delayed shedding stages. 2. The odontoclasts were appeared in 43.3% of observed teeth and were increased in the order of preshedding, shedding and delayed shedding stages. 3. The polymorphonuclear leukocytes and odontoclasts couldn't be observed in the exfoliated primary pulp tissues before the process of resorption has involved the root surface about 1.8mm subjacent to the cemento-enamel junction. 4. The intact root surface was the longest and largest in the preshedding stage. 5. The resorption process of primary teeth roots occurred mainly in the stage of preshedding and shedding stages. 6. There was a tendency of repair of resorbing root surfaces in the delayed shedding stage.

• Journal of the Korean Wood Science and Technology
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• v.28 no.4
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• pp.10-16
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• 2000

Two wood decay ascomycetes fungi identified as Hypoxylon mammatum and H. truncatum were isolated from backyard of Korea Research Institute of Chemical Technology (KRICT) in Korea. Hypoxylon truncatum is newly recorded as a wood degrader in Korea. Unusual germination mechanisms of ascospores in H. mammatum and H. truncatum are described and illustrated. The differences between two species were noticed on the process of germ tube formation. In the process of germ tube formation, the fast movement to pigmented ascospores activated from their perispores was termed as spore eclosion that was only found in H. mammatum. This sophisticated recognition mechanism indicated the existence of specific eclosion and germ tube formation due to the composition of cell wall layers and their preferable host derive, based on examined two species under a genus. The observation on present study postulates different composition of wall layers of ascospore and different nutrient composition for germination.

• Restorative Dentistry and Endodontics
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• v.28 no.5
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• pp.419-424
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• 2003

이 연구의 목적은 원래의 치수조직과 유사한 조직을 재생하기 위한 pulp tissue engineering의 한 방법으로 건전한 조직으로부터 배양된 치수세포와 쥐의 조섬유세포(NIH 3T3 cell)를 Rat tail type I collagen solution에서 3차원적으로 관찰하기 위한 것으로, 콜라젠 젤의 수축량과 세포의 증식 량을 비교하였으며, 또한 마모된 사람치아의 표면과 배양용기에서 두 세포의 증식 량을 비교하여 다음과 같은 결과를 얻었다. 1. 콜라젠 젤에 NIH 3T3 세포를 배양한 경우 그 수축량은 최소였으나, 치수세포를 배양한 경우 그 수축량은 현저하였다. 2. 서로 다른 수의 치수세포를 콜라젠 젤에서 배양시킨 경우 세포 수가 많을수록 수축량이 증가하였으며, 세포가 없는 콜라젠 젤은 수축하지 않았다. 3. 치수세포를 콜라젠 젤에서 18일간 배양시킨 후 세포의 증식은 거의 없는 반면, NIH 3T3 세포는 계속 증식하였다. 4. 마모된 사람 치아 표면과 배양 용기에서 치수세포와 NIH 3T3세포를 배양한 경우 NIH 3T3세포가 치수세포에 비해 빠르게 증식 하였으며 , 특히 사람 치아의 표면에서 NIH 3T3세포가 현저히 빠른 증식을 보였다. 이상의 결과는 치수세포를 type I collagen gel에서 3차원 적으로 배양 후 치수조직의 재생을 유도하는 pulp tissue engineering에 관한 연구에 발판이 될 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
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• v.47 no.5
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• pp.617-632
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• 2019

This study aimed to investigate the anatomical structure and fiber quality of four lesser-used wood species namely Benuang (O. sumatrana), Duabanga (D. moluccana), Pisang Merah (H. hellwigii), and Terap (A. odoratissimus). This study evaluated its suitability for raw material in pulp and paper manufacturing. The anatomical structure was observed macro- and microscopically. Macroscopic structures were observed directly to the wood samples, while microscopic characteristics were observed through microtome specimens. Fiber dimension was measured through macerated specimens and fiber quality was analyzed following the Rachman and Siagian's method. Results showed that these four timber species have similarity in the indistinct growth ring, diffuse porous in a radial pattern, rounded solitary vessel outline, 1 to 3 cells of ray width, deposits within the rays, fiber length, and cell wall thickness. Differences were found on vessel diameter, vessel grouping, vessel frequency, tyloses existence, type of axial parenchyma, and ray height. Based on fiber length and its derived values, the wood fibers of all species studied are suitable for pulp and paper manufacturing. They belong to the II quality class. The produced pulp and paper would have good quality, especially in tensile, folding, and tear strength. To promote their utilization, silviculture aspect of these four species has to be well understood.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.7-17
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• 1982

The purpose of this study was to investigate the fine structural modifications of fibroblasts in the coronal region of inflamed human pulps from carious teeth. Six untreated human teeth with large carious lesions and two normal teeth as control were selected from male and female patients between the ages of 20 and 39. The teeth were divided into 4 groups by light microscopic findings: the normal control group, the chronic inflammatory cell-appeared group, the acute and chronic inflammatory cell-appeared group, and the total necrosis group. All tissues were fixed in 2.5% glutaraldehyde in 0.1M sodium cacodylate buffer at pH 7.4 and 1% osmic acid in same buffer. They were embedded in Epon 812. The ultrathin sections were stained conventionally and examined with a AEI Corynth 500 electron microscope. The results were as follows; 1. The fibroblasts of the normal pulps were almost in a quiescent state. 2. The active and the quiescent fibroblasts were found in the pulps of the chronic inflammatory cell-appeared group. Lymphocytes and plasma cells were also seen scattered among these fibroblasts. 3. In the pulps of the acute and chronic inflammatory cell-appeared group, active, degenerative and necrotic fibroblasts were found in the PMN appeared area. And all the fibroblasts in the fibrosis area were active. In the area of chronic inflammatory cellular infiltration, almost all the fibroblasts were active, but seldom were quiescent fibroblasts observed. Some fibroblasts in the pulps of two teeth had large vacuoles that contained banded collagen fibrils. The phagosomes had small beaded vesicles or large lysosome-like varicosity. In two of the teeth, microorganisms were present and two morphological shapes were identified, a rod and a coccus. 4. Vacuolar, vesicular, lamellar, fibrous and myelin structures were observed in the pulp of the total necrosis group, and cocci were also seen.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.4
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• pp.144-150
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• 2015

Stems of Pinus thunbergii Parl. grown with high salinity were analyzed for chemical characteristics. Stem of 2 years was rich in soluble compounds and stem of 3 years reduced the amount of the soluble compound. But, the lignin content have not seen a large change. Also, Klason lignins of stem of 2 and 3 years has not changed in nitrogen and hydrogen content. In Klason process, it was significantly increased the carbon concentration due to the hydrolysis of the carbohydrate. In addition, the accumulation of xylan from Pinus thunbergii Parl. with salinity treatment were increased noticeably. Finally, functional group of Pinus thunbergii Parl. with salinity treatment were not changed.