• Restorative Dentistry and Endodontics
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• 제31권3호
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• pp.203-214
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• 2006

치수는 상아질로 둘러싸인 간엽조직으로 다양한 세포와 기저 물질들로 구성되어 있으며 혈관과 신경조직이 분포되어 있다. 치수의 염증은 조직의 분해를 야기하며 이는 Matrix Metalloproteinase에 의해 세포 외 기질의 분해가 촉진되어 병적인 과정을 거치게 된다. 이에 Lipopolysaccharide에 의한 MMP와 inflammatory cytokine의 유도와 peroxisome proliferator-activated receptors (PPAR)에 의한 염증매개 물질의 조절에 대해 알아보고자 하였다. 사람의 치수세포를 다양한 LPS농도에 노출시킨 후 24시간째 MMP-2, MMP-9의 변화를 보고 LPS에 의해 자극된 치수세포에서 ICAM-1, VCAM-1, $IL-1{\beta},\;TNF-{\alpha}$의 분비가 증가됨을 알 수 있었다. 또한 Adenovirus $PPAR{\gamma}\;(Ad/PPAR{\gamma})$와 $PPAR{\gamma}$ agonist인 rosiglitazone를 LPS로 자극된 치수세포에 처리하였을 때 48시간째 MMPs와 Adhesion molecules, cytokines의 감소를 확인하였다. 이로써 사람의 치수세포에서 $PPAR{\gamma}$가 가지는 항 염증효과에 대해 지속적 인 연구가 필요할 것으로 사료된다.

• 펄프종이기술
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• 제41권2호
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• pp.47-54
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• 2009

Anatomical characteristics of kenaf were investigated in transverse, radial and tangential direction by optical and scanning electron micrograph. Kenaf was made up of bast fibers, wood fibers, vessels and parenchyma cells. Bast fibers were long slender cells with different types of pits. The shape of wood fibers were in various ways and pointed at the ends. The pits were observed on the surface of bast fibers. Kenafs were diffuse and radial porous. and composed of solitary pores and two or three radial pore multiples. Various types of vessels were observed. The pits showed alternate pitting and larger diameter than other cells. Parenchyma cells were rectangular or square with different shapes of pith parenchyma cells compared to conventional types of parenchyma cells in wood. The number of pith on the surfaces were small.

• 구강회복응용과학지
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• 제25권2호
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• pp.191-200
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• 2009

줄기세포는 미분화 상태의 세포로 지속적인 자가 분열능과 특정 세포로 분화 할 수 있는 분화능을 지니고 있으며 이러한 특성으로 말미암아 난치병의 새로운 장을 열 것이라는 기대감을 얻고 있다. 즉, 세포이식 후 특정 세포로 분화 유도를 시켜 기존의 치료 방법으로는 치료가 되지 않았던 많은 의학적 난제들을 풀 수 있는 열쇠인 것이다. 치아는 평생에 걸쳐 발거되는 조직으로 치아줄기세포는 얻기가 비교적 쉬워서 다른 성체줄기세포들보다 더 높이 평가되고 있다. 과잉치는 전 세계 다양한 인종에서 발견되는 중요한 임상적 질환이다. 과잉치의 유병율은 관련 연구 보고서마다 다양하나 소아치과 의사들의 경우 임상에서 자주 과잉치를 발거하고 있다. 그러나, 현재까지 진행된 줄기세포 관련 연구들을 살펴보면 과잉치의 줄기세포에 관한 보고는 없으며, 이는 줄기세포로 이용 가능한 중요한 자원을 파기하고 있는 것은 아닌지 의문이 생긴다. 그러므로 본 연구는 과잉치에 포함된 세포가 줄기세포의 특징을 가지고 있는지를 밝혀내기 위해 진행되었다.

• International Journal of Oral Biology
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• 제47권4호
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• pp.55-62
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• 2022

Bioactive flavonoids have been shown to improve the biological activity of stem cells derived from different sources in tissue regeneration. The goal of this study was to see how naringin, a natural flavonoid discovered in citrus fruits, affected the biological properties of human dental pulp stem cells (HDPSCs). In this study, we found that naringin increases the migratory ability of HDPSCs. Naringin increased matrix metalloproteinase-2 (MMP-2) and C-X-C chemokine receptor type 4 (CXCR4) mRNA and protein expression in HDPSCs. ARP100, a selective MMP-2 inhibitor, and AMD3100, a CXCR4 antagonist, both inhibited the naringin-induced migration of HDPSCs. Furthermore, naringin increased osteogenic differentiation of HDPSCs and the expression of the osteogenic-related marker, alkaline phosphatase in HDPSCs. Taken together, our findings suggest that naringin may be beneficial on dental tissue or bone regeneration by increasing the biological activities of HDPSCs.

• Restorative Dentistry and Endodontics
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• 제48권4호
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• pp.39.1-39.23
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• 2023

Objectives: This study aimed to investigate the effectiveness of different topical/systemic agents in reducing the damage caused by bleaching gel to pulp tissue or cells. Materials and Methods: Electronic searches were performed in July 2023. In vivo and in vitro studies evaluating the effects of different topical or systemic agents on pulp inflammation or cytotoxicity after exposure to bleaching agents were included. The risk of bias was assessed. Results: Out of 1,112 articles, 27 were included. Nine animal studies evaluated remineralizing/anti-inflammatories agents in rat molars subjected to bleaching with 35%-38% hydrogen peroxide (HP). Five of these studies demonstrated a significant reduction in inflammation caused by HP when combined with bioglass or MI Paste Plus (GC America), or following KF-desensitizing or Otosporin treatment (n = 3). However, orally administered drugs did not reduce pulp inflammation (n = 4). Cytotoxicity (n = 17) was primarily assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on human dental pulp cells and mouse dental papilla Cell-23 cells. Certain substances, including sodium ascorbate, butein, manganese chloride, and peroxidase, were found to reduce cytotoxicity, particularly when applied prior to bleaching. The risk of bias was high in animal studies and low in laboratory studies. Conclusions: Few in vivo studies have evaluated agents to reduce the damage caused by bleaching gel to pulp tissue. Within the limitations of these studies, it was found that topical agents were effective in reducing pulp inflammation in animals and cytotoxicity. Further analyses with human pulp are required to substantiate these findings.

• 대한소아치과학회지
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• 제43권4호
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• pp.419-426
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• 2016

본 연구는 상악 매복 과잉치를 가지고 전신질환 및 의과 병력이 없는 만 5 - 9세 사이의 남녀 20명으로부터 서면동의를 얻고 상악 전치부에 매복된 과잉치를 발치하고 치수세포를 채취하였다. 채취 후 세포의 1차 배양 동안 오염된 3명(남자 2명, 여자 1명)을 제외하고 총 17명(남자 10명, 여자 7명)을 대상으로 하였다. 이번 연구에서 과잉치 치수조직으로부터 유래한 세포의 계대 배양에 소요된 평균 시간은 $2.91{\pm}0.29$일이었다. 최초 치수조직으로부터 세포를 얻은 후 80% confluency를 얻는데 소요되는 시간이 $4.53{\pm}0.94$일로 가장 많이 걸렸고, 이후 계대부터는 $2.73{\pm}0.32$일이 소요되었다. 남자의 비율은 58.82%, 여자의 비율은 41.18%이었다. 여자의 평균 소요시간은 $2.81{\pm}0.27$일 이었으며, 남자는 $2.98{\pm}0.29$이었다. 과잉치가 역위된 비율은 82.35%, 정위 비율은 17.65%였다. 평균 계대 소요 배양 시간은 역위가 $2.94{\pm}0.30$일, 정위는 $2.80{\pm}0.20$일이었다. 원뿔형(Conical type)은 76.47%였고, 그 외 형태는 23.53%였다. 원뿔형의 평균 소요시간은 $2.92{\pm}0.31$이었고, 그 외 형태의 소요 시간은 $2.88{\pm}0.22$이었다. 매복 방향과 형태에 따른 계대 배향 시간은 통계적으로 유의한 차이를 보이지 않았다. 향후 초기 계대와 후기 계대에서 얻어진 세포의 줄기세포로써의 능력을 평가하는 후속 연구들이 필요하며, 3일 이내의 계대 배양 시간이 소요된 점을 고려할 때, 연구의 효율성과 빠른 배양시간 등은 과잉치 유래세포가 치아유래 줄기세포의 연구에 활용가능성이 충분하리라 판단되었다.

• 대한치과의사협회지
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• 제16권3호통권106호
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• pp.193-195
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• 1978

The author observed the effect of x-ray irradiation on the tooth germ development of the rat fetuses. The lower right abdomen of the pregnant rats were exposed to x-ray irradiation (400 rads) on 9½th day of qestation. At 18½th day of qestation, the fetuses were removed from their mothers and histological sections of molar region were prepared. The results were as folows: 1. In the experimental fetuses, no significant changes appeared in the histological aspects of the enamel pulp, except the poor development of the innerenamel epithelium in the cusp region. 2. Pulp cells of cusp region in the irradiated fetuses were not differentiated to odontoblasts, The arrangement and population of pulp cells showed marked regional differences in the dental papilla. 3. Developmental features of dental follicle of irradiated fetuses were similar with controls.

• 미생물학회지
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• 제14권1호
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• pp.1-7
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• 1976

Effect of some nutrients on the growth of 3 yeast strains in the pulp mill waste liquor was determined during an attempt to lower the BOD content of the waste liquor and to produce the fodder yeast. The strains applied were Debaryomyces castelli Capriotti, D.phoffi Capriotti, and Cryptococcus luteolus (Saito)Skinner. The necessity of the addition of 0.2% ${NH_4}2SO_4$ 0.5% yeast extract, 0.2% $NH_2SO_4$, and 0.1% $MgSO_4$.$7H_2$O for the best growth of all three strains in the waste liquor was ascertained as a result. After 3-day treatment of the yeast cells on the waste liquor, the BOD content was lowered by about 60-70%. Harvested yeast cells contained ca. 75% water with 1.5-3% lipid, 40-46% protein, 50% carbohydrate and 3-5% ash on the dry weight basis, indicating the possibility of being utilized as the fodder yeast.

• International Journal of Oral Biology
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• 제42권3호
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• pp.91-97
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• 2017

Although anti-aging activities of melatonin, a hormone secreted by the pineal gland, have been reported in senescence-accelerated mouse models and several types of cells, its impact and mechanism on the senescence of human dental pulp cells (HDPCs) remains unknown. In this study, we examined the impact of melatonin on cellular premature senescence of HDPCs. Here, we found that melatonin markedly inhibited senescent characteristics of HDPCs after exposure to hydrogen peroxide ($H_2O_2$), including the increase in senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal)-positive HDPCs and the upregulation of p21 protein, an indicator for senescence. In addition, as melatonin attenuated $H_2O_2$-stimulated phosphorylation of c-Jun N-terminal kinase (JNK), while selective inhibition of JNK activity with SP600125 significantly attenuated $H_2O_2$-induced increase in SA-beta-gal activity. Results reveal that melatonin antagonizes premature senescence of HDPCs via JNK pathway. Thus, melatonin may have therapeutic potential to prevent stress-induced premature senescence, possibly correlated with development of dental pulp diseases, and to maintain oral health across the life span.

• Biomaterials and Biomechanics in Bioengineering
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• 제3권2호
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• pp.105-114
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• 2016

The purpose of this study is to evaluate the effects of cryopreservation on dental pulp-derived stem cells (DPSC) viability over a period of three years. Dental pulp-derived stem cells were isolated and cultured from thirty-one healthy teeth. DPSC isolates were assessed for doubling-time and baseline viability prior to cryopreservation and were assessed again at three time points; one week (T1), 18 months (T2), and 36 months (T3). DPSC can be grouped based on their observed doubling times; slow (sDT), intermediate (iDT), and rapid (rDT). Viability results demonstrated all three types of DPSC isolates (sDT, iDT and rDT) exhibit time-dependent reductions in viability following cryopreservation, with the greatest reduction observed among sDT-DPSCs and the smallest observed among the rDT-DPSC isolates. Cryopreserved DPSCs demonstrate time-dependent reductions in cellular viability. Although reductions in viability were smallest at the initial time point (T1) and greatest at the final time point (T3), these changes were markedly different among DPSC isolates with similar doubling times (DTs). Furthermore, the analysis of various DPSC biomarkers - including both intracellular and cell surface markers, revealed differential mRNA expression. More specifically, the relative high expression of Sox-2 was only found only among the rDT isolates, which was associated with the smallest reduction in viability over time. The expression of Oct4 and NANOG were also higher among rDT isolates, however, expression was comparatively lower among the sDT isolates that had the highest reduction in cellular viability over the course of this study. These data may suggest that some biomarkers, including Sox-2, Oct4 and NANOG may have some potential for use as biomarkers that may be associated with either higher or lower cellular viability over long-term storage applications although more research will be needed to confirm these findings.