• 미생물학회지
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• 제55권1호
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• pp.64-66
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• 2019

Cutibacterium acnes는 사람의 피부, 결막, 장관, 외이도 및 구강의 정상 세균 총의 하나이다. 이 세균 종은 여드름, 심내막염 감염, 유육종증, 뇌 농양, 치주염 및 골수염과 관련된 기회감 염성병원균으로 확인되었다. C. acnes KCOM 1315 (= ChDC KB81)는 사람 악골골수염 병소로부터 분리되었다. 여기에서 C. acnes KCOM 1315 균주 완전 유전체 염기서열을 해독하여 보고한다.

• 미생물학회지
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• 제55권2호
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• pp.154-156
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• 2019

Eikenella corrodens는 그람 음성, 통성 혐기성이며 막대 모양의 세균이다. 이 세균 종은 사람의 심내막염, 간농양 및 두개 내 세균감염 등과 같은 전신질환과 연관이 있을 뿐만 아니라 점막의 정상 세균총에 속한다. E. corrodens KCOM 3110 (= JS217) 균주가 사람 치주질환 병소의 치은연하치면세균막에서 분리되었다. 여기에서 E. corrodens KCOM 3110 균주의 유전체 염기서열을 완전 해독하여 보고한다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2009년도 International Meeting of the Microbiological Society of Korea
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• pp.72-73
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• 2009

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권4호
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• pp.337-344
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• 2000

본 연구에서는 MSI와 구강암과의 상관관계를 규명하기 위하여 17례의 구강암에 대하여 12종류의 marker를 이용하여 MSI 빈도를 조사하였으며, 동시에 p53단백의 과발현과 유전자 돌연변이 양상에 대해서도 알아보았다. 그 결과 4종류 이상의 marker에 대해서 MSI가 나타나는 widespread MSI의 경우 임상병리학적으로 뚜렷한 특징이 없었다. 또한 흡연과 MSI 빈도간에도 연관성이 없었으나 흡연은 p53 유전자의 돌연변이를 증가시켜 암화과정을 촉진하는 작용을 하는 것으로 나타났다.

• Journal of Periodontal and Implant Science
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• 제44권6호
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• pp.266-273
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• 2014

Purpose: We previously reported that human serum significantly reduces the invasion of various oral bacterial species into gingival epithelial cells in vitro. The aims of the present study were to characterize the serum component(s) responsible for the inhibition of bacterial invasion of epithelial cells and to examine their effect on periodontitis induced in mice. Methods: Immortalized human gingival epithelial (HOK-16B) cells were infected with various 5- (and 6-) carboxy-fluorescein diacetate succinimidyl ester-labeled oral bacteria, including Fusobacterium nucleatum, Provetella intermedia, Porphyromonas gingivalis, and Treponiema denticola, in the absence or presence of three major serum components (human serum albumin [HSA], pooled human IgG [phIgG] and ${\alpha}1$-antitrypsin). Bacterial adhesion and invasion were determined by flow cytometry. The levels of intracellular reactive oxygen species (ROS) and activation of small GTPases were examined. Experimental periodontitis was induced by oral inoculation of P. gingivalis and T. denticola in Balb/c mice. Results: HSA and phIgG, but not ${\alpha}1$-antitrypsin, efficiently inhibited the invasion of various oral bacterial species into HOK-16B cells. HSA but not phIgG decreased the adhesion of F. nucleatum onto host cells and the levels of intracellular ROS in HOK-16B cells. N-acetyl-cysteine (NAC), a ROS scavenger, decreased both the levels of intracellular ROS and invasion of F. nucleatum into HOK-16B cells, confirming the role of ROS in bacterial invasion. Infection with F. nucleatum activated Rac1, a regulator of actin cytoskeleton dynamics. Not only HSA and NAC but also phIgG decreased the F. nucleatum-induced activation of Rac1. Furthermore, both HSA plus phIgG and NAC significantly reduced the alveolar bone loss in the experimental periodontitis induced by P. gingivalis and T. denticola in mice. Conclusions: NAC and the serum components HSA and phIgG, which inhibit bacterial invasion of oral epithelial cells in vitro, can successfully prevent experimental periodontitis.

• BMB Reports
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• 제57권5호
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• pp.232-237
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• 2024

This study investigated how adipose tissue-derived mesenchymal stem cells (AT-MSCs) respond to chondrogenic induction using droplet-based single-cell RNA sequencing (scRNA-seq). We analyzed 37,219 high-quality transcripts from control cells and cells induced for 1 week (1W) and 2 weeks (2W). Four distinct cell clusters (0-3), undetectable by bulk analysis, exhibited varying proportions. Cluster 1 dominated in control and 1W cells, whereas clusters (3, 2, and 0) exclusively dominated in control, 1W, and 2W cells, respectively. Furthermore, heterogeneous chondrogenic markers expression within clusters emerged. Gene ontology (GO) enrichment analysis of differentially expressed genes unveiled cluster-specific variations in key biological processes (BP): (1) Cluster 1 exhibited up-regulation of GO-BP terms related to ribosome biogenesis and translational control, crucial for maintaining stem cell properties and homeostasis; (2) Additionally, cluster 1 showed up-regulation of GO-BP terms associated with mitochondrial oxidative metabolism; (3) Cluster 3 displayed up-regulation of GO-BP terms related to cell proliferation; (4) Clusters 0 and 2 demonstrated similar up-regulation of GO-BP terms linked to collagen fibril organization and supramolecular fiber organization. However, only cluster 0 showed a significant decrease in GO-BP terms related to ribosome production, implying a potential correlation between ribosome regulation and the differentiation stages of AT-MSCs. Overall, our findings highlight heterogeneous cell clusters with varying balances between proliferation and differentiation before, and after, chondrogenic stimulation. This provides enhanced insights into the single-cell dynamics of AT-MSCs during chondrogenic differentiation.

• Imaging Science in Dentistry
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• 제43권2호
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• pp.111-115
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• 2013

Adenomatoid odontogenic tumor (AOT) usually presents as a unilocular, pericoronal radiolucency in the maxillary anterior region in adolescent females. Very few conditions occur in such a narrow age range and at such a restrictive site. Rarely, these tumors present with varied clinical features. A case of AOT of the mandible is reported with unusual features such as large size, multilocular appearance, and aggressive behavior. The role of radiology in diagnosis of atypical AOT is extremely important. The unique radiological manifestations of the lesion helped in the diagnosis, and it was managed conservatively with no evidence of recurrence.

• International Journal of Oral Biology
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• 제44권4호
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• pp.191-194
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• 2019

The purpose of this study was to investigate the antimicrobial effects of Australia propolis against cariogenic and periodontopathic bacteria. Antimicrobial activity was determined by evaluating the minimal bactericidal concentration (MBC). Cell cytotoxicity of propolis extract on normal human gingival fibroblast (HGF-1) cells was observed using the methylthiazolyldiphenyl-tetrazolium bromide assay. The data indicated that, with the exception of Aggregatibacter actinomycetemcomitans (KCOM 1306), the MBC values of the propolis strains were 0.25-1% without HGF-1 cell cytotoxicity. These results suggest that propolis can be used to develop oral hygiene products for the prevention of oral infectious disease.

• International Journal of Oral Biology
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• 제40권1호
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• pp.35-39
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• 2015

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of bacteria. It has been reported that sub-MIC of antibiotics may result in morphological alterations, along with the biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of Aggregatibacter actinomycetemcomitans, after the treatment with sub-MIC metronidazole and penicillin. The bacterial morphology was observed with scanning electron microscope, after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans was increased after the incubation with sub-MIC metronidazole and penicillin. Sub-MIC metronidazole and penicillin inhibited bacterial division and induced long filaments. Our study showed that metronidazole and penicillin can induce the morphological changes in A. actinomycetemcomitans.

• International Journal of Oral Biology
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• 제35권4호
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• pp.197-202
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• 2010

Most oral microorganisms exist as biofilms which initiate formation via the attachment of an early colonizer to host proteins on the tooth surface. Fusobacterium nucleatum act as a bridge between early and late colonizers. Dental biofilms eventually comprise dental pathogens such as Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia. To evaluate the effects of mutual interactions between oral bacteria on the growth of biofilms, periodontopathogens were co-cultured with a $0.4\;{\mu}m$ barrier. Streptococcus gordonii inhibited the growth of F. nucleatum and periodontopathogens. However, F. nucleatum, P. gingivalis and T. denticola activated the growth of other bacteria. A co-culture system of early and late colonizers could be a useful tool to further understand bacterial interactions during the development of dental biofilm.