• Restorative Dentistry and Endodontics
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• 제43권3호
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• pp.30.1-30.12
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• 2018

Objectives: To evaluate sealing ability of root canals obturated with bioceramic-impregnated gutta percha cone (BCC) or gutta percha (GP), with bioceramic sealer (BCS) or AH Plus (AH; Dentsply-Maillefer), in roundly-prepared canals using matched single-cone technique, based on bacterial leakage test, and to analyze obturation quality using micro-computed tomography (CT) analysis. Materials and Methods: Ninety-two distobuccal roots of maxillary molars were prepared using nickel-titanium files to apical size 40/0.06. The roots were divided into 4 groups (n = 20) that were obturated with a master cone and sealer: GP/AH, BCC/AH, GP/BCS, and BCC/BCS. Bacterial leakage model using Enterococcus faecalis was used to evaluate sealing ability for 60-day period. Obturated samples from each group (n = 4) were analyzed using micro-CT. Results: All groups showed bacterial leakage at 20%-45% of samples with mean leakage times of 42-52 days. There were no significant differences in bacterial leakage among the groups. Micro-CT showed minimal gaps and voids in all groups at less than 1%. Conclusions: In roundly-prepared canals, the single cone obturation with BCC/BCS was comparable to GP/AH for bacterial leakage at 60 days.

• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.92-102
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• 2019

Objective: To investigate changes in rumen fermentation characteristics and bacterial community by a sudden change to a high concentrate diet (HC) in Korean domestic ruminants. Methods: Major Korean domestic ruminants (each of four Hanwoo cows; $545.5{\pm}33.6kg$, Holstein cows; $516.3{\pm}42.7kg$, and Korean native goats; $19.1{\pm}1.4kg$) were used in this experiment. They were housed individually and were fed ad libitum with a same TMR (800 g/kg timothy hay and 200 g/kg concentrate mix) twice daily. After two-week feeding, only the concentrate mix was offered for one week in order to induce rapid rumen acidosis. The rumen fluid was collected from each animals twice (on week 2 and week 3) at 2 h after morning feeding using an oral stomach tube. Each collected rumen fluid was analyzed for pH, volatile fatty acid (VFA), and $NH_3-N$. In addition, differences in microbial community among ruminant species and between normal and an acidosis condition were assessed using two culture-independent 16S polymerase chain reaction (PCR)-based techniques (terminal restriction fragment length polymorphism and quantitative real-time PCR). Results: The HC decreased ruminal pH and altered relative concentrations of ruminal VFA (p<0.01). Total VFA concentration increased in Holstein cows only (p<0.01). Terminal restriction fragment length polymorphism and real-time quantitative PCR analysis using culture-independent 16S PCR-based techniques, revealed rumen bacterial diversity differed by species but not by HC (p<0.01); bacterial diversity was higher in Korean native goats than that in Holstein cows. HC changed the relative populations of rumen bacterial species. Specifically, the abundance of Fibrobacter succinogenes was decreased while Lactobacillus spp. and Megasphaera elsdenii were increased (p<0.01). Conclusion: The HC altered the relative populations, but not diversity, of the ruminal bacterial community, which differed by ruminant species.

• 대한소아치과학회지
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• 제31권3호
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• pp.439-447
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• 2004

한국인 소아의 치면세균막에 존재하는 mutans streptococci종 및 생물형의 발현빈도와 치아우식경험지수와 상관관계를 알아보기 위하여, 조선대학교 치과병원에 내원한 12세 미만 113명의 소아 환자의 치아우식경험지수를 구하고, 이들의 상하 악 유전치 및 유구치의 협면 및 설면의 치면세균막 샘플을 채취하여 mutans streptococci를 mitis-salivarius bacitracin 배지에서 선택적으로 분리하였다. 이들의 biotype을 알아보기 위해 생화학적 검사를 실하였고, 이들의 종 수준에서의 동정을 위해 dextranase 유전자를 표적으로 하는 중합효소연쇄반응을 시행하여 하였다. 113명의 환자 중에서 40명의 치면세균막에서 40 균주의 mutans streptococci이 검출되었다. 이들 중 생물형 제 I 형(45%)이 가장 많이 검출되었으며, 그 다음으로 제 IV 형(32.5%), 제 II 형(15%), 제 V 형(5%) 제 III 형(2.5%) 순으로 검출되었다. 또한, 종 수준에서의 발현빈도를 알아본 결과 S. mutaus가 69%, S. sobrinus는 31%였다. Mutans streptococci 종 또는 생물형에 따른 환자의 치아우식경험지수간의 차이는 없는 것으로 조사되었다(p>0.05). 이상의 결과를 종합할 때, 한국인의 소아의 구강 내에 존재하는 mutans streptococci중 생물형 제 I 형인 S. mutans가 가장 높은 빈도로 존재하며, 치아우식증이 세균학적 요소만이 아닌 기타 여러 원인요소에 의해 발병되는 다른 여러 연구 결과와 일치함을 알 수 있었다.

• International Journal of Oral Biology
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• 제30권4호
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• pp.125-130
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• 2005

Thrombin-induced platelet microbicidal proteins (tPMP) are antibacterial proteins released when platelets are stimulated by thrombin. It has been reported that tPMP has antibacterial activity against various bacterial species including causative agents of infective endocarditis. Most of the oral streptococci have resistance to the killing by tPMP and this fact may play an important role as a virulence factor in infective endocarditis. However, the susceptibility and resistance mechanism of oral streptococci for tPMP have not been revealed yet. In this study, the killing mechanism of tPMP for oral streptococci has been investigated. Streptococcus rattus BHT, a susceptible strain, and Streptococcus gordonii DL1, a resistant strain, have been used in this study. tPMP was isolated from platelet after stimulation with thrombin. Cell membrane depolarization was examined with 3,3'-dipropylthiodicarbocyanine iodide ($DiSC_3$), membrane potential-sensitive cyanine dye, by fluorescence spectrophotometry. The permeabilization of cell membrane by tPMP was investigated with propidium iodide (PI) by flow cytometry. tPMP susceptible S. rattus BHT showed the increase of the $DiSC_3$ fluorescence level meaning depolarization of cell membrane and increase of the uptake of PI which means permeabilization of cell membrane. However, tPMP resistant S. gordonii DLI did not show depolarization and permeabilization. These results indicate that the increasing depolarization and permeabilization of oral streptococcal cell membrane are associated with the bactericidal activity of tPMP.

• 대한소아치과학회지
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• 제27권1호
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• pp.90-97
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• 2000

치태의 형성은 이온, 효소, 영양물질, 화학물질 등과 같은 구강내 존재하는 다양한 물질들과 이들의 변화에 영향을 받는다. 본 연구에서는 치태형성에 중요한 역할을 하는 구강내 연쇄상구균인 Streptococcus sobrinus를 공시균으로, 비수용성 글루캔의 합성과 세균 증식 에 미치는 여러 인자들의 영향을 관찰하여 다음과 같은 결과를 얻었다. Streptococcus sobrinus 배양 배지의 pH가 7.0일 때 비수용성 글루캔이 가장 많이 합성 되었고, pH 5.5와 pH 8.5에서는 그 합성이 감소하였다. 세균 증식도 pH 7.0에서 가장 활발하였다. 2. 효모 추출물은 2.5%일 때 비수용성 글루캔의 합성과 세균증식이 모두 활발하였다. 자당의 경우 농도가 증가할수록 비수용성 글루캔의 합성은 감소하여 1.25%보다 20%에서 합성이 10배 정도 감소하였으나, 세균의 증식은 20배 정도 증가하였다. 3. 배지의 calcium chloride 농도가 1.0mM, potassium chloride 농도가 40mM, magnesium chloride 농도가 0.1mM 이었을때 비수용성 글루캔의 합성이 가장 활발했으나, 세균의 증식에는 큰 영향을 미치지 않았다. 4. Sodium bicarbonate 10mM에서 비수용성 글루캔 합성과 세균의 증식 이 모두 활발하였으며 100mM 이상에서는 모두 억제되었다. Tris 10mM에서 비수용성 글루캔 합성과 세균의 증식이 모두 억제되었으며 100mM 이상에서는 모두 증가되었다. 5. Sodium phosphate와 potassium phosphate는 10mM 이상에서 비수용성 글루캔 합성과 세균증식이 모두 억제되었다.

• 기본간호학회지
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• 제13권3호
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• pp.351-358
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• 2006

Purpose: The purpose of this study was to compare the effects of oral hygiene with 0.1% chlorhexidine or with normal saline on the incidence of pathogens in the oral cavity of patients in Intensive Care Units (ICU). Method: A quasi experimental design with non-equivalent control group and non-synchronized design was used. For the study 46 patients were recruited from a university hospital (24 for the experimental group, 22 for the control group). patients in the experimental group received mouth care with 0.1% chlorhexidine gluconate and those in the control group received mouth care with normal saline twice a day for 7 days in a row. Oral samples were taken for bacterial cultures on admission day, the 4th day and the 7th day for both groups. Results: The incidence of oral pathogens decreased in the experimental group, and increased in the control group. There was no significant difference in the incidence of oral pathogens between the two groups. However oral hygiene using 0.1% chlorhexidine gluconate decreased the incidence of oral pathogens significantly for patients who already had pathogenic bacteria in their mouths on the admission day. Conclusion: The results suggest that mouth care with 0.1% chlorhexidine is effective for decreasing the incidence of oral infection for ICU patients who have oral infections.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권4호
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• pp.175-181
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• 2013

Objectives: This retrospective study was performed to evaluate the clinical impact of diabetes mellitus on the prognosis in secondary space infection. Materials and Methods: Medical records, radiographic images, computed tomography, and microbial studies of 51 patients (25 diabetic patients and 26 non-diabetic patients) were reviewed. Patients were diagnosed as secondary fascial space infections with odontogenic origin and underwent treatment at Chonnam National University Hospital, in Department of Oral and Maxillofacial Surgery, from January 2007 to February 2009. Results: Compared to patients without diabetes, patients with diabetes were presented with the following characteristics: older age (diabetic patients: 62.9 years, non-diabetic patients, 47.8 years), more spaces involved (diabetic patients, 60%; non-diabetic patients, 27.3%), more intense treatment, longer hospitalization (diabetic patients, 28.9 days; non-diabetic patients, 15.4 days), higher white blood cell and C-reactive protein values, higher incidence of complication (diabetic patients, 40%; non-diabetic patients, 7.7%), and distinctive main causative microorganisms. Conclusion: These results suggest that the prognosis of diabetic patients is poorer than that of non-diabetic patients in secondary space infections since they had greater incidence rates of involved spaces, abnormal hematologic findings, more complications, and additional procedures, such as tracheostomy.

• 미생물학회지
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• 제23권1호
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• pp.43-48
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• 1985

철저한 혐기적 방법으로 배양분리한 결과 편성 혐기성세균의 분리율이 높아졌고, 검체당 평균 3.3주가 분리되었다. 혈액배지인 NATB배지와 BA배지에서 비혈액배지인 NAT배지와 GAM배지에서 보다 세균 분리효과가 우수했다. NATB배지에는 혐기성 그람 양성 구균에 좋은 분리효과를 나타내었고, 그람 음성 간균은 15주 분리되었다. 이 중 Bacteroides가 12주로서 가장 많이 존재하는 균종이었다.

• 한방안이비인후피부과학회지
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• 제17권3호
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• pp.33-37
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• 2004

Objective: The aim of this work is to investigate the antibacterial activity of the Sohporaflavanone G isolated from Sophora flavescens (S. flavescens), as the development of microbial resistance to antibiotics make it essential to constantly look for new and active compounds effective against pathogenic bacteria. Method : Sophoraflavanone G was isolated from the dried roots of Sophora flavescens Aiton (Leguminosae) by bioassay?guided fractionation. We investigated the effect of sophoraflavanone G on oral bacterial at various concentrations after incubation of 24 h in strains in the dose?dependent manner. Results: The structure of active compound, Sophoraflavanone G having a lavandulyl group at C?8, was elucidated on the basis of spectral data especially 1H?NMR and I3C?NMR. The antimicrobial activity showed that Sophoraflavanone G exhibited antimicrobial activilies against all the bacteria tested (MICs, 0.39 - 6.25 ㎍／ml). Sophoraflavanone G showed the strong antimicrobial activity against all the facultative bacteria and microaerophilic bacteria (MICs, 0.78 - 1.56 ㎍／ml) and also Sophoraflavanone G showed the strong antimicrobial activity against obligate anaerobic bacteria (MICs, 0.39 - 6.25 ㎍／ml).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권4호
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• pp.322-328
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• 2005

Oral and maxillofacial infections are most commonly odontogenic in origin. The present study was implemented for patients with oral and maxillofacial infections in order to determine what differences were present in cultured bacteria, depending upon the different types of infection. For the present study, the epidemiological characteristics, the state of infection, and the results of the pus culture and antibiotic susceptibility tests were analyzed for the 159 cases where pus culture tests were performed. The patients were treated at the Oral and Maxillofacial Surgical Department of Chonnam National University Hospital during an 18-months period from March 2003 to August 2004. Among the total 159 pus culture specimens, bacteria were cultured in 111 cases (69.8%). In the 111 pus culture specimens, Streptococcus species, Neisseria species, and Staphylococcus species were cultured from 69 cases (51.1%), 21 cases (15.6%), and 15 cases (11.1%), respectively and were determined to be bacterial strains the predominant bacteria responsible for oral and maxillofacial infectious diseases. Twenty four cases (15.1%) among the 159 specimens showed mixed infections. The mostly isolated bacteria from each of the space abscess, dentoalveolar abscess, inflammatory cyst, and pericoronitis cases were the Viridans streptococci. There was little relevance between the type of infection and the type of cultured bacteria. Antibiotic susceptibility tests showed a high level of susceptibility to teicoplanin(100%), vancomycin(100%), chloramphenicol(96.4%), ofloxacin(88.3%), imipenem(83.3%), erythromycin(82.5%) and a low susceptibility to cefazolin(40.0%), oxacillin(44.7%), ampicillin(49.4%), penicillin(51.1%). These results indicate that there was no significant difference among the cultured bacteria depending on the type of infections and their susceptibility to cephalosporin and penicillin G was low.