• International Journal of Oral Biology
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• 제36권1호
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• pp.31-35
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• 2011

Teeth develop via a reciprocal induction between the ectomesenchyme originating from the neural crest and the ectodermal epithelium. During complete formation of the tooth morphology and structure, many cells proliferate, differentiate, and can be replaced with other structures. Apoptosis is a type of genetically-controlled cell death and a biological process arising at the cellular level during development. To determine if apoptosis is an effective mechanism for eliminating cells during tooth development, this process was examined in the rat mandible including the developing molar teeth using the transferase-mediated dUTP-biotin nick labeling (TUNEL) method. The tooth germ of the mandibular first molar in the postnatal rat showed a variety of morphological appearances from the bell stage to the crown stage. Strong TUNEL-positive reactivity was observed in the ameloblasts and cells of the stellate reticulum. Odontoblasts near the prospective cusp area also showed a TUNEL positive reaction and several cells in the dental papilla, which are the forming pulp, were also stained intensively in this assay. Our results thus show that apoptosis may take place not only in epithelial-derived dental organs but also in the mesenchyme-derived dental papilla. Hence, apoptosis may be an essential biological process in tooth development.

• Toxicological Research
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• 제16권3호
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• pp.201-209
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• 2000

In association with the international validation program to establish a rodent uterotrophic assay, we conducted preliminary uterotrophic assay proposed by GECD using immature female rats. In the present study, oral and subcutaneous routes were chosen to compare the effects of estrogenic com-pounds in the two dosing regimens. The reference compound ethinyl estradiol (EE) and the antagonist ZM189154(ZM) were administered by gavage or subcutaneously (s.c.) to immature female SD rats from 20 to 22 days of age. For each study, sixty-six female rats were randomly assigned to eleven groups: Untreated control, EE 0,0.01, 0.03, 0.1, 0.3, 1.0,3.0 and 10.0 $\mu\textrm{g}$/kg, EE 3.0 $\mu\textrm{g}$/kg(gavage)/0.3 $\mu\textrm{g}$/kg(s.c) & ZM 0.1 mg/kg, and EE 3.0 $\mu\textrm{g}$/kg(gavage)/0.3 $\mu\textrm{g}$/kg (s.c) & ZM 1.0 mg/kg. There were no treatment-related changes in clinical signs, body weights, food consumption, and necropsy findings in any groups of two studies. The wet and blotted uterus weights increased dose-dependently. Histopathological examination revealed that diameter of uterine duct, height of uterine luminal epithelium. and height oj vaginal epithelium increased dose-dependently. The proliferating cell nuclear antigen (PCNA) immunoreactive cells were increased in number dose-dependently. The estrogenic effects observed in the present studies occurred at $\geq$ 0.3 $\mu\textrm{g}$/kg of oral dose and $\geq$ 0.1 $\mu\textrm{g}$/kg of s.c. dose. An antagonistic effect of ZM against EE was found in both uterus weight and histopathological parameters. From the results obtained, it can be concluded that dose-dependence of the uterotrophic assay using EE and ZM was well demonstrated by gavage and subcutaneous administration and that the estrogenic effects of EE by s.c. dose were higher than those by gavage administration. In addition, blotted uterus weight was more sensitive than wet uterus weight and vaginal epithelial height was found to be the most sensitive parameter among the parameters examined.

• International Journal of Oral Biology
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• 제41권1호
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• pp.25-32
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• 2016

The tongue has 4 kinds of papillae, which are filiform, fungiform (FU), foliate (FO) and circumvallate papilla (CV). Tongue papillae except filiform papilla include taste buds. The papillae differ in taste sensitivities, likely due to differential expression of taste receptors. In this study, we evaluated differences in the expression levels of taste receptors in FU, FO and CV. Male DBA2 mice, 42-60 days old, were used in the study. Messenger RNAs were extracted from the murine epithelial tissues including FU, FO and CV. Cloned DNAs were synthesized by reverse transcription. Quantitative PCRs (qPCRs) were performed to determine mRNA expression levels of taste receptors. Results of qPCR revealed that the relative expression levels and patterns were different among FU, FO and CV. All three type 1 taste receptors were expressed FU, FO and CV at varying relative expression levels. All 35 kinds of type 2 taste receptors showed higher expression in FO and CV than in FU. Tas2r108 and Tas2r137 showed the two highest expression levels in all tested papillae. The differential expression levels and patterns of taste receptors among the three papillae could contribute to the different physiological sensitivities by tongue areas. Additional studies such as in situ hybridization or taste receptor cell activity recording is necessary to elucidate the functional relationship between expression levels of taste receptors and taste sensitivity.

• 한국임상수의학회지
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• 제30권5호
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• pp.339-345
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• 2013

MAPKs는 다양한 세포자극에 반응하는 중요한 세포신호전달경로이며, 특히 세포의 생존과 사멸과정에 관여한다고 알려져 있다. 그러나 위궤양의 진행에 있어 MAPKs의 세포특이적 활성에 관한 연구결과들에 대해서는 잘 알려져 있지 않다. 본 연구에서는 이부프로펜에 의해 유도된 위궤양의 진행에 있어 활성화된 MAPKs가 다양한 세포들에 어떻게 분포하는지를 실험하였다. 위궤양 유발은 200 mg/kg 이부프로펜을 하루에 8시간간격으로 3번 투여하였다. 동물부검은 이부프로펜을 투여한 후 24, 48, 72시간에 실시하였고, 위조직은 면역조직화학 및 웨스턴블랏에 사용되었다. 활성화된 p-ERK는 정상 랫드 위점막상피의 위상피증식층에서만 주로 발현되었으나, 이부프로펜을 투여한 후 24시간째에는 위기저부의 벽세포들에서 강하게 발현되었다. 이부프로펜을 투여 후 48시간 경과한 군에 있어서는 위궤양에 인접한 위점막상피 또는 위궤양 기저부의 결합조직에 나타난 신생혈관, 염증세포 및 육아조직에서 p-ERK가 강하게 발현되었다. 반면에 p-JNK는 초기 위점막손상을 나타내는 위표면점막상피와 샘위의 점막상피세포의 핵에서 주로 발현되었다. 점차적으로 p-JNK는 위궤양 기저부의 결합조직내에 침윤된 염증세포, 섬유모세포에서 특히 강하게 염색되었다. P-p38 양성세포는 위점막의 결합조직내에서 분산되어 관찰되었으며, 특히 위궤양 기저부의 결합조직내로 침윤된 대식 세포에 강한 염색성을 나타내었다. 이상의 연구결과는 각각의 MAPK들이 위궤양진행에 있어 특정세포들의 활성화에 관여하는 것으로 보여진다.

• Journal of Microbiology and Biotechnology
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• 제30권4호
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• pp.515-525
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• 2020

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.145-158
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• 1993

The oral microbiota such as P. gingivalis, P. intermedia and A. actinomycetemcomitans play a primary role in the initiation and progression of the periodontal disease. The purpose of this study was to evaluate the antimicrobial effects and inhibitory effects of honokiol and magnolol on the bacterial collagenase activity, cytotoxicity and cytokine production of periodontopathic microorganisms. The antimicrobial activities of honokiol and magnolol was evaluted with minimum inhibition concentration. Honokiol was more active than magnolol, but less than chlorhexidine on antimicrobial activity. The inhibitory effects of magnolol and honokiol on the collagenolytic activity and cytotoxicity were evaluated using a Collagenokit CLN-100 and rapid colorimetric assay (MTT method) for cellular growth and survival of gingival fibroblast and periodontalligament cell and $[^3H]-thymidine$ incorporation for the gingival epithelial cell. The inhibitory effects on the collagenolytic activity was the highest in chlorhexidine, and the lowest in magnolol. Magnolol had the lowest cytotoxic effect and chlorhexidine had the highest. The inhibitory effects on cytokine production was evaluated using $interleukin-1{\beta}$ ELISA kit (Cistron Biotech.), IL-6, $TNF-{\alpha}$ ELISA kit (Genzyme) and inhibitory effects were higher than bacterial LPS and there is no difference among the honokiol, magnolol and chlorhexidine. From these results, the antimicrobial and antienzymatic activities of honokiol and magnolol were seemed to inhibit bacterial growth and enzyme activities with lesser cytotoxic activities. Therefore, it was suggested that honokiol and magnolol are very effective antimicrobial agents on periodontal pathogens.

• 한방안이비인후피부과학회지
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• 제32권2호
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• pp.94-106
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• 2019

Objectives : This study was conducted to investigate the effects of Gwakhyangjeonggi-san(GJS) on atopic dermatitis(AD) induced by 2,4-dinitrochlorobenzene(DNCB) in mice. Methods : The mice(Balb/c mice) were divided into three groups; normal Balb/c mice with oil treatment(Sham group), DNCB-induced AD mice(AD group), and GJS treated AD mice(GJS group). GJS group were orally administered GJS daily for 2 weeks. We observed changes of clinical skin severity score, the expression of thymic stromal lymphopoietin(TSLP), interleukin(IL)-4 and tumor necrosis factor(TNF)-${\alpha}$ in skin and mast cell infiltration. Also, serum immunoglobulinE(IgE), IL-4, $TNF-{\alpha}$ and IL-6 were evaluated. Results : The clinical skin severity score of GJS group was decreased compared to AD group. In hematoxylin and eosin staining results, GJS group showed a significant reduction of epithelial skin thickness. In addition, expression of TSLP and mast cell infiltration in skin were also reduced by GJS treatment compared to those of AD group. Thus, we evaluated expression of IL-4, Th2-dependent cytokine, and $TNF-{\alpha}$, pro-inflammatory cytokine in skin. GJS significantly reduced both IL-4 and $TNF-{\alpha}$ compared to AD mice. Moreover, levels of IgE, IL-4, $TNF-{\alpha}$ and IL-6 in plasma also significantly decreased by oral GJS treatment. Conclusion : The present study suggests that GJS can significantly reduced symptoms of AD, therefore it can be a promising candidate for anti-atopic dermatitis treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권3호
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• pp.226-237
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• 2005

Purpose : Extensive defect of oral and maxillofacial area is usually reconstructed with composite flap including skin paddle. However, if the defects are lined with only skin components, the mucosa's role in mastication and texture are not restored. Furthermore, stiffness and hair-growing prevent denture rehabilitation and good oral hygiene. This study was performed to overcome the disadvantages of composite soft tissue flaps including the skin and to make a model for myo-mucosal flaps. Materials and methods : Buccal mucosa sized $0.5\times1.0\;cm^2$ from New Zealand rabbit (around 1.5kg) was harvested and cultivated by the modification of Rheinwald and Green's keratinocyte culture method. Cultured mucosa was grafted on the fascia of latismus dorsi as form of mucosal sheet. After 7, 10, 14 days, the myomucosal flap was excised and evaluated under light microscope with H & E and immunohistochemical staining. As control group, harvested buccal mucosa from rabbit was transplanted to gracilis muscle(n=6). Results : From 7 days after prelamination, the basal layer of the grafted mucosa resembled that of normal mucosa. As control group, transplanted mucosa had original shape but there's slight inflammatory reaction. Prelaminated mucosa has 19.8$\pm$4.59 cell layers and some samples have more than 20 layers. The expression rate of PCNA was relatively strong (42.9%$\pm$14.1) at the basal layer of grafted mucosa and the laminin was found at the basal layer. On the contrary, prelaminated mucosa at 10 days showed moderate expression rate of PCNA(32.4%$\pm$4.62). We found the mucosal layer was somehow disappeared and there is strong inflammatory reaction. After 14 days prelamination, the grafted oral keratinocytes were almost disappeared and expression of PCNA was not observed. Conclusion : We can make 75 fold large mucosal($3850mm^2$) sheet from small samples of mucosa $(50mm^2)$. Epithelial sheet that grafted on the fascia of muscle underwent differentiation and proliferation. But after 10, 14 days, there was strong inflammatory reaction and the grafted mucosa was destroyed from surface layer. In rabbit model, transfer of fascio-mucosal flap should be done from 7 to 10 days after prelamination.

• Restorative Dentistry and Endodontics
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• 제31권6호
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• pp.437-444
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• 2006

본 연구에서는 법랑모세포 분화와 법랑질 형성에 연관이 있는 OD314 일명 Apin protein의 기능을 밝힐 목적으로, in-situ hybridization에 의한 OD314 mRNA 발현과 법랑모세포 세포주에서 OD314와 enamel matrix protein의 발현, 그리고 OD314 유전자를 과발현/억제시킬 수 있는 construct를 제작한 후 법랑질 형성 중에 OD314의 기능을 알아보고자 RT-PCR를 시행하여 다음과 같은 결과를 얻었다. 1. OD314 mRNA는 발생중인 상아모세포보다 법랑모세포에서 강하게 발현되었다. 2. Tuftelin은 석회화 결정이 형성되는 14일까지 발현이 지속되고, 그 이후부터 점차 감소하였다. Amelogenin과 enamelin은 7일부터 그 발현이 점점 감소하였다. 3. U6-OD314 siRNA construct를 이용하여 transfection한 법랑모세포 세포주는 OD314와 tuftelin, MMP20 mRNA 발현이 감소하였으며, CMV-OD3l4를 transfection하여 OD314의 과발현을 유도한 경우에는 OD3l4와 MMP20 mRNA의 발현이 뚜렷이 증대되었다. 이 결과는 OD314가 법랑모세포의 분화와 법랑질의 형성 그리고 석회화 과정에 중요한 역할을 하는 새로운 인자임을 시사한다.

• 한국임상수의학회지
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• 제30권3호
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• pp.214-217
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• 2013

3세령의 암컷 고슴도치(Atelerix albiventris)가 심하게 종대된 하악 병변의 평가를 위해 내원하였다. 세포학적 검사를 위해 세침흡인을 실시하였으며, 도말표본을 제작 후 로마노프스키식 염색으로 염색하였다. 세포학적 검사에서 원형을 포함한 다양한 모양의 편평상피세포가 주로 관찰되었으며, 일부 세포는 유사 방추 모양 또는 매우 길쭉한 모양을 띄고 있었다. 세포학적 소견은 편평상피암종이었으며, 조직검사를 위해 수술적으로 제거하였다. 조직병리상 악성 편평상피암종세포들이 중등도의 콜라겐과 방추형 섬유모세포로 이루어진 간질에 둘러싸여 있었으며, 인접한 골격근과 골조직으로의 침습이 관찰되었다. 종양세포는 중등도의 세포 대소부동과 핵 대소부동을 보였으며, 중등도 이상의 각화상태를 보였다. 종양의 중심부에서는 극세포해리가 있었으며 림프형질세포 및 호중구성 염증소견이 동반되었다. 유사 분열상은 고배율에서 2-3개가 관찰되었다. 이와 같은 소견에 기초해서 편평상피암종으로 진단하였으며, 보호자는 종괴의 수술적 제거 후 더이상의 치료를 원치 않아 바로 퇴원하였다. 환자는 추가 처치 없이 3개월 생존 후 폐사하였다.