• Journal of Oral Medicine and Pain
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• 제24권3호
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• pp.235-244
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• 1999

The present study was performed to investigate the binding between salivary proteins(low-molecular-weight mucin;MG2, amylase, proline-rich proteins;PRPs) and oral pathogens(Streptococcus gordonii, Actinomyces viscosus, Staphylococcus aureus) by using solid-phase assay. In the case of transferring proteins to Immobilon-P, S. gordonii binds to MG2. A. viscosus binds to MG2, amylase, and PRPs, and S. aureus binds to MG2 and amylase. On nitrocellulose membrane, S, gordonii and A. viscosus bind to MG2, amylase, and PRPs. S. aureus binds to MG2 and PRPs. However, rabbit anti-A. viscosus antisera and rabbit anti-S. aureus antisera showed cross reactivity to PRPs adsorbed to only nitrocellulose membrane in negative control experiments, which were done without bacterial overlay. The results were different according to the membrane used as solid-phase, which reflected the assay-sensitive nature of binding experiment. PRPs and amylase are known to be components of tooth enamel pellicle. In addition, there was experimental evidence that PRPs and MG2 may covalently bind to oral mucosal epithelium. Considering above facts, the results of the present study can provide information on the interactions between salivary proteins and oral bacteria on tooth and oral mucosal surfaces.

• International Journal of Oral Biology
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• 제39권3호
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• pp.137-143
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• 2014

Dental professionals are repeatedly exposed to many microorganisms present in both blood and saliva. Thus, dental professionals are at a greater risk of acquiring and spreading infections, and the implementation of infections control guidelines is necessary. Cellular phones have become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. Nevertheless, studies about rate and levels of bacterial contamination of cellular phones have been extremely limited with regards to dental personnel. The purpose of this study was to identify bacterial flora on the cellular phones of dentists by a molecular biological method using the 16S rRNA cloning and sequencing method. We acquired total 200 clones from dentists' cell phones and identified the bacterial species. Pseudomonas (34.6%), Lactobacillus (18.5%), Azomonas (11.5%), and Janthinobacterium (6%) were the dominant genera on dentists' cell phones. The oral bacteria identified were Anaerococcus lactolyticus, Gibbsiella dentisursi, Lactobacills leiae, Streptococcus mitis, Streptococcus oligofermentans, and Streptococcus sanguinis. Pathogenic bacteria and opportunistic pathogens such as Carnobacterium funditum, Raoultella planticola, Shigella flexneri, Lactobacillus iners, Staphylococcus aureus, and Staphylococcus epidermidis were also identified.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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• pp.291-297
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• 2015

An oral environment is constantly exposed to environmental factors and microorganisms. The periodontal ligament (PDL) fibroblasts within this environment are subject to bacterial infection and allergic reaction. However, how these condition affect PDL fibroblasts has yet to be elucidated. PDL fibroblasts were isolated from healthy donors. We examined using reverse transcription-polymerase chain reaction and measuring the intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$). This study investigated the receptors activated by exogenous bacterial pathogens (Lipopolysaccharide and peptidoglycan) and allergens (German cockroach extract and house dust mite) as well as these pathogenic mediators-induced effects on the intracellular $Ca^{2+}$ signaling in human PDL fibroblasts. Moreover, we evaluated the expression of pro-inflammatory cytokines (interleukin (IL)-$1{\beta}$, IL-6, and IL-8) and bone remodeling mediators (receptor activator of NF-${\kappa}B$ ligand and osteoprotegerin) and intracellular $Ca^{2+}$-involved effect. Bacterial pathogens and allergic mediators induced increased expression of pro-inflammatory cytokines, and these results are dependent on intracellular $Ca^{2+}$. However, bacterial pathogens and allergic mediators did not lead to increased expression of bone remodeling mediators, except lipopolysaccharide-induced effect on receptor activator of NF-${\kappa}B$ ligand expression. These experiments provide evidence that a pathogens and allergens-induced increase in $[Ca^{2+}]_i$ affects the inflammatory response in human PDL fibroblasts.

• Restorative Dentistry and Endodontics
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• 제28권2호
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• pp.178-183
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• 2003

The purpose of this study was to investigate the frequency of 7 putative pathogens in endodontic infections. The specimens were collected from infected pulpal tissue of patients who were referred for root canal treatment to the department of conservative dentistry, Chosun University Samples were collected aseptically using a barbed broach and a paper point. The cut barbed broaches and paper points were transferred to an eppendorf tube containing 500 ml of 1 X PBS. DNAs were extracted from the samples by direct DNA extraction method using lysis buffer (0.5% EDTA, 1% Triton X-100). Identification of 7 putative pathogens was performed by PCR based on 16S rDNA. The target species were as follows : Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Bacteroides forsythus, Actinobacillus actinomycetemcomitans, and Treponema denticola. Our data revealed that the prevalence of P. endodontalis was found in 88.6% (39/54), P. ginivalis 52.3% (23/44), P. nigrescens 18.2% (8/44), P intermedia 15.9% (7/44) B. forsythus 18.2% (8/44), A. actinomycetemcomitans 3.3% (1/44), T. denticola 25% (l1/44) of the samples. The high prevalence of P. endodontalis and P. ginivalis suggests that they may play an important role in the etiology of endodontic infections.

• International Journal of Oral Biology
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• 제39권4호
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• pp.169-176
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• 2014

A positional scanning synthetic peptide combinatorial library (PS-SCL) was screened in order to identify antimicrobial peptides against the cariogenic oral bacteria, Streptococcus mutans. Activity against Streptococcus gordonii and Aggregatibacter actinomycetemcomitans was also examined. The library was comprised of six sub-libraries with the format $O_{(1-6)}XXXXX-NH_2$, where O represents one of 19 amino acids (excluding cysteine) and X represents equimolar mixture of these. Each sub-library was tested for antimicrobial activity against S. mutans and evaluated for antimicrobial activity against S. gordonii and A. actinomycetemcomitans. The effect of peptides was observed using transmission electron microscopy (TEM). Two semi-mixture peptides, RXXXXN-$NH_2$ (pep-1) and WXXXXN-$NH_2$ (pep-2), and one positioned peptide, RRRWRN-$NH_2$ (pep-3), were identified. Pep-1 and pep-2 showed significant antimicrobial activity against Gram positive bacteria (S. mutans and S. gordonii), but not against Gram negative bacteria (A. actinomycetemcomitans). However, pep-3 showed very low antimicrobial activity against all three bacteria. Pep-3 did not form an amphiphilic ${\alpha}$-helix, which is a required structure for most antimicrobial peptides. Pep-1 and pep-2 were able to disrupt the membrane of S. mutans. Small libraries of biochemically-constrained peptides can be used to generate antimicrobial peptides against S. mutans and other oral microbes. Peptides derived from such libraries may be candidate antimicrobial agents for the treatment of oral microorganisms.

• International Journal of Oral Biology
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• 제43권4호
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• pp.217-222
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• 2018

Phagocytosis is a fundamental process in which phagocytes capture and ingest foreign particles including pathogenic bacteria. Several oral pathogens have anti-phagocytic strategies, which allow them to escape from and survive in phagocytes. Impaired bacteria phagocytosis increases inflammation and contributes to inflammatory diseases. The purpose of this study is to investigate the influences of various agents on oral pathogenic phagocytosis. To determine phagocytosis, Streptococcus mutans, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were stained with 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFSE), and was measured using flowcytometery and confocal microscopy. The influencing factors on phagocytosis were evaluated through the pretreatment of ROS inhibitor (N-acetyl-L-cysteine (NAC)), lysozyme, potassium chloride (KCI) and adenosine triphosphate (ATP) in THP-1 cells. Expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA). The phagocytosis of various bacteria increased in a MOI-dependent manner. Among the tested bacteria, phagocytosis of P. gingivalis showed the highest fluorescent intensity at same infection time. Among the tested inhibitors, the NAC treatment significantly inhibited phagocytosis in all tested bacteria. In addition, NAC treatment indicated a similar pattern under the confocal microscopy. Moreover, NAC treatment significantly increased the bacteria-induced secretion of $IL-1{\beta}$ among the tested inhibitors. Taken together, we conclude that the phagocytosis occurs differently depending on each bacterium. Down-regulation by ROS production inhibited phagocytosis and lead increased of oral pathogens-associated inflammation.

• 대한간호학회지
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• 제47권4호
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• pp.540-550
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• 2017

Purpose: The aim of this study was to identify the effect of Dongchimi juice containing kimchi Lactobacillus as an oral hygiene agent and to compare it with that of chlorhexidine solution (0.12% dilution). Methods: This study employed a pretest-posttest experimental design in which a single group of patients was exposed to two different treatments over a period of time. The study included 32 patients hospitalized at a longterm care hospital in Korea. Data were collected between August 12, 2016 and September 28, 2016. The patients first used chlorhexidine solution as an oral care agent for 1 week. After an interval of 2 weeks, they used Dongchimi juice for 1 week. Each agent was applied 2 times a day depending on the protocol. The oral status of the patients was measured using Beck's Oral Exam Guide (OEG) scores. The number of pathogens in the oral cavity was counted by culture, and the patients' subjective satisfaction score for each oral agent was measured using a visual analogue scale. T-test and Mann-Whitney test were performed to identify significant differences between Dongchimi juice and chlorhexidine solution by using PASW Statistics for Windows, Version 18.0 (SPSS Inc., Chicago, IL, USA). Results: The OEG score was not statistically different with the use of chlorhexidine solution and Dongchimi juice. However, decreasing number of pathogens and the subjective satisfaction score were higher with Dongchimi juice than with the chlorhexidine solution. Conclusion: These findings support the use of Dongchimi juice containing kimchi Lactobacillus as an oral hygiene agent for Korean patients.

• Journal of Periodontal and Implant Science
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• 제43권2호
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• pp.72-78
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• 2013

Purpose: The purpose of this study was to compare the phototoxic effects of blue light exposure on periodontal pathogens in both planktonic and biofilm cultures. Methods: Strains of Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis, in planktonic or biofilm states, were exposed to visible light at wavelengths of 400.520 nm. A quartz-tungsten-halogen lamp at a power density of $500mW/cm^2$ was used for the light source. Each sample was exposed to 15, 30, 60, 90, or 120 seconds of each bacterial strain in the planktonic or biofilm state. Confocal scanning laser microscopy (CSLM) was used to observe the distribution of live/dead bacterial cells in biofilms. After light exposure, the bacterial killing rates were calculated from colony forming unit (CFU) counts. Results: CLSM images that were obtained from biofilms showed a mixture of dead and live bacterial cells extending to a depth of $30-45{\mu}m$. Obvious differences in the live-to-dead bacterial cell ratio were found in P. gingivalis biofilm according to light exposure time. In the planktonic state, almost all bacteria were killed with 60 seconds of light exposure to F. nucleatum (99.1%) and with 15 seconds to P. gingivalis (100%). In the biofilm state, however, only the CFU of P. gingivalis demonstrated a decreasing tendency with increasing light exposure time, and there was a lower efficacy of phototoxicity to P. gingivalis as biofilm than in the planktonic state. Conclusions: Blue light exposure using a dental halogen curing unit is effective in reducing periodontal pathogens in the planktonic state. It is recommended that an adjunctive exogenous photosensitizer be used and that pathogens be exposed to visible light for clinical antimicrobial periodontal therapy.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제17권3호
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• pp.140-146
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• 2014

Purpose: The etiology of acute gastroenteritis (AGE) has changed since the introduction of the rotavirus vaccination. The aim of this study was to clarify which common pathogens, both bacterial and viral, are currently causing AGE in infants. Methods: Infants with acute diarrhea were enrolled. We tested for 10 bacterial pathogens and five viral pathogens in stool specimens collected from infants with AGE. The clinical symptoms such as vomiting, mucoid or bloody diarrhea, dehydration, irritability, and poor oral intake were recorded, and laboratory data such as white blood cell count and C-reactive protein were collected. The clinical and laboratory data for the cases with bacterial pathogens and the cases with viral pathogens were compared. Results: Of 41 total infants, 21 (51.2%) were positive for at least one pathogen. Seventeen cases (41.5%) were positive for bacterial pathogens and seven cases (17.1%) were positive for viral pathogens. Staphylococcus aureus (13 cases, 31.7%) and Clostridium perfringens (four cases, 9.8%) were common bacterial pathogens. Norovirus (five cases, 12.2%) was the most common viral pathogen. Fever and respiratory symptoms were common in the isolated viral infection group (p=0.023 and 0.044, respectively), whereas other clinical and laboratory data were indistinguishable between the groups. Conclusion: In our study, S. aureus (41.5%) and norovirus (12.2%) were the most common bacterial and viral pathogens, respectively, among infants with AGE.

• 생명과학회지
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• 제22권8호
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• pp.1071-1076
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• 2012

사방오리나무의 분획물과 분리화합물인 gallic acid의 항우식 작용과 항구취 활성을 조사하기 위해 구강병원균에 대한 항균활성, 부착능 그리고 산 생성을 조사하였다. 그리고 휘발성 황화합물의 측정은 oral chroma를 이용하여 구취억제 효과를 측정하였다. DCM 분획물은 넓은 항균스펙트럼을 가졌으며, EA 분획물은 Streptococcus mutans와 Porphyromons gingivalis에 대해 상대적으로 높은 항균활성을 가진 것으로 나타났다. 게다가 GA와 DCM 분획물은 각각 S. mutans와 S. salivarius에 대해 산 생성과 부착을 효과적으로 억제하였다. 사방오리나무의 2% MeOH 추출물은 구취유발 화합물인 황화수소, 메틸머캅탄, 황화디메틸을 억제하는 효과가 뛰어났으며(p<0.05), 2% GA 또한 황화수소를 억제시키는 효과가 있음이 확인되었다(p<0.05). 본 연구의 결과, 사방오리나무의 활성 분획물과 GA는 항균효능, 산생성 억제능, 부착 억제능 및 구취 억제효능을 가짐으로써 구강병원균에 대한 천연항균제제로써의 사용 가능성이 충분히 있는 것으로 판단된다.