• 대한치주과학회:학술대회논문집
• /
• 2001.12a
• /
• pp.108-108
• /
• 2001

• Proceedings of the Ginseng society Conference
• /
• 2004.05a
• /
• pp.64-64
• /
• 2004

• Journal of Life Science
• /
• v.31 no.3
• /
• pp.330-337
• /
• 2021

This study was conducted to investigate the potential of Stewartia koreana as oral healthcare materials. The antibacterial activity of ethanol extracts from leaves and branches of S. koreana against oral bacteria was confirmed. The leaf and branch extracts (1 mg/disc) showed antibacterial activity against P. gingivalis only among several tested oral bacteria. The leaf extracts showed higher antibacterial activity, with values similar to those of chlorhexidine, which was used as a positive control. The MIC of the leaf extract against P. gingivalis was 0.4 mg/ml and showed bacteriostatic action. The inhibitory effects of the extract on biofilm formation and on gene expression related to biofilm formation by P. gingivalis were determined by biofilm biomass staining, scanning electron microscopy (SEM), and qRT-PCR analysis. The biofilm production rate and cell growth of P. gingivalis in the cultures treated with 0.2-2.0 mg/ml of S. koreana leaf extracts were significantly decreased in a concentration-dependent manner. The inhibitory effect on the formation of P. gingivalis biofilms at concentrations of 1 mg/ml was confirmed by SEM. The qRT-PCR analysis showed concentration-dependent suppression of the fimA and fimB gene expression associated with fimbriae formation in the cultures treated with 0.2-2.0 mg/ml S. koreana leaf extract. These results support the conclusion that S. koreana leaf extracts can be used as oral healthcare materials derived from natural materials, as demonstrated by the antibacterial action and inhibition of biofilm formation of P. gingivalis.

• Restorative Dentistry and Endodontics
• /
• v.20 no.2
• /
• pp.645-654
• /
• 1995

Porphyromonas endodontalis is a black-pigmented anaerobic Gram negative rod which is associated with endodontal infections. It has been isolated from infected dental root canals and submucous abscesses of endodontal origin. DNA probe is an available alternative, offering the direct detection of a specific microorganism. Nucleic-acid probes can be off different types: whole different: whole-genomic, cloned or oligonucleotide probes. Wholegenomic probes are the most sensitive because the entire genome is used for possible hybridization sites. However, as genetically similar species of bacteria are likely to be present in specimences, cross-reactions need to be considered. Cloned probes are isolated sequences of DNA that do not show cross-reactivity and are produced in quantity by cloning in a plasmid vector. Cloned probes can approach the sensitivity found with whole-genomic probes while avoiding known cross-reacting species. Porphyromonas endodontalis ATCC 35406 (serotype $O_1K_1$) was selected in this experiment to develop specific cloned DNA probes. EcoR I-digested genomic DNA fragments of P. endodontalis ATCC 35406 were cloned into pUC18 plasmid vector. From the E. coli transformed with the recombinant plasmid 4 clones were selected to be tested as specific DNA probes. Restriction-digested whole-genomic DNAs prepared from P. gingivalis 38(serotype a), W50(serotype b), A7A1-28(serotype C), P. intermedia 9336(serotype b), G8-9K-3(serotype C), P. endodontalis ATCC 35406(serotype $O_1K_1$), A. a Y4(serotype b), 75(serotype a), 67(serotype c), were each seperated on agarose gel electrophoresis, blotted on nylon membranes, and were hybridized with digoxigenin-dUTP labeled probe. The results were as follows: 1. Three clones of 1.6kb(probe e), 1.6kb(probe f), and 0.9kb(probe h) in size, were obtained. These clones were identified to be a part of the genomic DNA of P. endodontalis ATCC 35406 judging from their specific hybridization to the genomic DNA fragments of their own size on Southern blot. 2. The clones of 4.9kb(probe i) was identified to be a part of the genomic DNA of P. endodontalis ATCC 35406. but not to specific for itself. It was hybridized to P. gingivalis A7A1-28, P. intermedia G89K-3.

• Journal of Oral Medicine and Pain
• /
• v.32 no.2
• /
• pp.137-150
• /
• 2007

Trees emit phytoncide into atmosphere to protect them from predation. Phytoncide from different trees has its own unique fragrance that is referred to as forest bath. Phytoncide, which is essential oil of trees, has microbicidal, insecticidal, acaricidal, and deodorizing effect. The present study was performed to examine the effect of phytoncide on Porphyromonas gingivalis, which is one of the most important causative agents of periodontitis and halitosis. P. gingivalis 2561 was incubated with or without phytoncide extracted from Hinoki (Chamaecyparis obtusa Sieb. et Zucc.; Japanese cypress) and then changes were observed in its cell viability, antibiotic sensitivity, morphology, and biochemical/molecular biological pattern. The results were as follows: 1. The phytoncide appeared to have a strong antibacterial effect on P. gingivalis. MIC of phytoncide for the bacterium was determined to be 0.008%. The antibacterial effect was attributed to bactericidal activity against P. gingivalis. It almost completely suppressed the bacterial cell viability (>99.9%) at the concentration of 0.01%, which is the MBC for the bacterium. 2. The phytoncide failed to enhance the bacterial susceptibility to ampicillin, cefotaxime, penicillin, and tetracycline but did increase the susceptibility to amoxicillin. 3. Numbers of electron dense granules, ghost cell, and vesicles increased with increasing concentration of the phytoncide, 4. RT-PCR analysis revealed that expression of superoxide dismutase was increased in the bacterium incubated with the phytoncide. 5. No distinct difference in protein profile between the bacterium incubated with or without the phytoncide was observed as determined by SDS-PAGE and immunoblot. Overall results suggest that the phytoncide is a strong antibacterial agent that has a bactericidal action against P. gingivalis. The phytoncide does not seem to affect much the profile of the major outer membrane proteins but interferes with antioxidant activity of the bacterium. Along with this, yet unknown mechanism may cause changes in cell morphology and eventually cell death.

• Journal of Periodontal and Implant Science
• /
• v.29 no.1
• /
• pp.251-264
• /
• 1999

본 연구는 조기발병형 치주염의 서로 다른 4가지 표현형에 있어서 Porphyromonas gingivalis(Pg) 381과 Actinobacillus actinomycetemcomitans(Aa) Y4에 대한 상승된 IgG subclass의 양상을 평가하기 위해 시행하였다. Subform I(distinctive localized juvenile periodontitis pattern)에서 3명 subform II(post juvenile periodontitis pattern)에서 19명, subform III (localized but rapidly progressing pattern)에서 15명, subform IV(distinctive rapidly progressing periodontitis pattern)에서 15명의 환자를 조사하여 Pg에 대한 그들의 total IgG level과 각각의 IgG subclass level 및 Aa에 대한 IgG level을 검사했다. Pg에 대한 total IgG level은 subform II와 IV보다 subform I과 III에서 훨씬 높게 나타났다. IgG3 level이 subform I과 IV사이에서 현저한 차이가 있다는 점을 제외하고는, 다른 IgG subclass level에서 subform 사이에 아무런 차이가 없었다. Pg에 대한 IgG subclass는 single class 혹은 다양한 group에서 상승되어 나타났으며, IgG1+2+4가 가장 흔하게 발견되었고, 다음으로 IgG4 단독, IgG2 단독, IgG2+4, IgG2+3+4의 순으로 발견되었다. IgG2와 IgG4가 빈번히 상승되어 발견되었는데, 특히 severe form(subform III & IV)에서 그러했다. 뿐만 아니라, IgG level은 subform II, III, IV와 일치하여 점차적으로 증가하였고, 반면에 IgG1/IgG4 ratio는 그와 일치하여 감소되었다. 이러한 ratio의 감소는 단백질성의 오래된 항원의 과부하로 인해 immunoglobulin gene의 전환을 가능하게 한다는 것을 나타내고 있다. Aa에 대한 IgG2 level은 다른 유형보다 subform I에서 상당히 높았다. Pg에 대한 IgG2 levels이 subform I의 국소 부위에서 발생하는 disease activity와 밀접한 관련이 있으며, Aa의 경우에는 이러한 관련성이 나타나지 않았다. Pg에 대한 IgG2 level은 18-25세에서 훨씬 높은 동시에 26-35세에서는 감소했으며 결국 30대 후반에서는 더 높은 수치로 되돌아갔다. 이러한 결과는 Pg에 대한 IgG2 및 IgG responsiveness (single 혹은 combined)가 EOP의 severe form의 발달에 중요하게 작용하며 IgG2 levels은 IgG1/IgG4 ratio와 더불어 EOP의 localized type이 generalized type으로 계속 진행하는 것을 조절하는 역할을 하는 것으로 보인다는 것을 강하게 시사하였다.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.3
• /
• pp.393-398
• /
• 2015

Aptamers are composed of single-stranded oilgonucleotides that can selectively bind desired molecules. It has been reported that RNA or DNA could act as not only a genetic messenger but also a catalyst in metabolic pathways. RNA aptamers (average sizes 40-50 bp) are smaller than antibodies and have strong binding capacities to target molecules, similar to antigenantibody interactions. Once an aptamer was selected, it can be readily produced in large quantities at low cost. The objectives of this study are to screen and develop aptamers specific to oral pathogens such as Porphyromonas gingivalis, Treponema denticola, and Streptococcus mutans. The bacterial cell pellet was fixed with formaldehyde as a target molecule for the screening of aptamers. The SELEX method was used for the screening of aptamers and a modified western blot analysis was used to verify their specificities. Through SELEX, 40 kinds of aptamers were selected and the specificity of the aptamers to the bacterial cells was confirmed by modified western blot analysis. Through the SELEX method, 40 aptamers that specifically bind to oral pathogens were screened and isolated. The aptamers showed possibility as effective candidates for the detection agents of oral infections.

• International Journal of Oral Biology
• /
• v.45 no.2
• /
• pp.42-50
• /
• 2020

Lysophosphatidic acid (LPA) is a lipid messenger mediated by G protein-coupled receptors (LPAR1-6). It is involved in the pathogenesis of certain chronic inflammatory and autoimmune diseases. In addition, it controls the self-renewal and differentiation of stem cells. Recent research has demonstrated the close relationship between periodontitis and various diseases in the human body. However, the precise role of LPA in the development of periodontitis has not been studied. We identified that LPAR1 was highly expressed in human periodontal ligament stem cells (PDLSCs). In periodontitis-mimicking conditions with Porphyromonas gingivalis-derived lipopolysaccharide (Pg-LPS) treatment, PDLSCs exhibited a considerable reduction in the cellular viability and osteogenic differentiation potential, in addition to an increase in the inflammatory responses including tumor necrosis factor-α and interleukin-1β expression and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. Of the various LPAR antagonists, pre-treatment with AM095, an LPAR1 inhibitor, showed a positive effect on the restoration of cellular viability and osteogenic differentiation, accompanied by a decrease in NF-κB signaling, and action against Pg-LPS. These findings suggest that the modulation of LPAR1 activity will assist in checking the progression of periodontitis and in its treatment.

• Journal of Periodontal and Implant Science
• /
• v.25 no.3
• /
• pp.568-586
• /
• 1995

542 periodontal patients having early-onset periodontitis(EOP) have been reclassified into a more homogeneous phenotypic subsets by newly revised radiographic criteria. Representative patients of each EOP subform have been examined of serum IgG subclass antibodies against periodontopathic bacteria, Porphyromonas gingivalis(Pg) 381 and of genetic markers for IgG allotypes to clarify the relationship between these parameters and phenotype expression of each subform. The early onset periodontitis could be reclassified by the radiographic parameters combining the mean interproximal alveolar bone loss(BL) and the radiographic ratio(between 1st molars and the adjacent teeth: Ratio) with statistical significance(p<0.001 by MANOVA). Moreover these EOP subforms could clearly be delineated from adult periodontitis. Of subform I and II(localized type EOP) patients with minimal mean bone loss(BL<5.0), patients demonstrating disease activities in localized areas(Ratio.>1.5) showed the elevated responses in all the IgG subclasses against Pg compared with those of patients without disease activity(Ratio <1.5). There were gradual increase in the IgG2 and IgG4 titers against Pg as the disease developed into the generalized forms suggesting the possible role of these antibodies in modulating the phenotype expression. The genetic marker study for IgG allotype revealed that mean IgG2 and IgG4 subclass titers were significantly higher(p<0.01, p<0.05, respectively) in patients who were positive for G2m(n). This indicated that IgG subclass responsiveness against the bacterial antigens are under the immnuogenetic control. The observed frequencies of G2m(n) were significantly higher (p<0.05) in subfrom IV patients who had the characteristic features of classical rapidly progressing periodontitis indicating the possible genetic predisposition in these patients.

• Journal of Periodontal and Implant Science
• /
• v.25 no.3
• /
• pp.648-658
• /
• 1995

The present study has been performed to evaluate the clinical, microbiological, biochemical and immunological parameters associated with the periodontal disease activity in adolescent periodontitis. 21 young adolescents with evidences of periodontal attachment loss participated in the study for upto 3 years of examination. Probing pocket depths and attachment levels of whole dentitions were annually recorded and 4 deepest pockets, with initial probing depth ${\geq}$ 4mm, were selected as the representative experimental sites of a patient. Sites experiencing attachment loss ${\geq}$ 1mm during the 3-year experimental period were designated as the active sites and these sites were examined for the microbiological and biochemical profiles at the time when attachment loss occurred. Microbiological assay included cultural studies and PerioScan for monitoring BANA(+) organisms(e.g. Porphyromonas gingivalis, Treponema denticola, Bacteriodes forsythus). Biochemical assay has been performed for monitoring GCF levels of neutral protease. Serum IgG and IgG2 titers against Porphyromonas gingivalis 381 were determined of a patients at the beginning and the end of the study, respectively for patient-based analysis. The results indicated that the parameters consisting of microbiological cultures and GCF neutral protease exhibited low association with the periodontal disease activity in adolescents. However, the specificity for microbiological culture of the selected periodontopathic organisms(Aa,Pg,Pi) were considerably high. Moreover, the clinical pameters such as bleeding on probing and presence of plaque as well as IgG levels against Pg at the baseline exminations were closely associated with the subsequent evidences of attachment loss during the whole experimental period(3-year).