• International Journal of Oral Biology
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• v.39 no.4
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• pp.201-206
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• 2014

This study investigated the antimicrobial activity of methanol extract of mulberry leaf against 16 strains of mutans streptococci and four species of periodontopathogens: Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans. The antimicrobial activities of the crude extracts or silica gel chromatography fractions of methanol-extracted mulberry leaf were evaluated by determining minimal inhibitory concentrations using an established microdilution method. The cytotoxicity of the extracts of mulberry leaf on KB cells was tested by the methyl thiazolyl tetrazolium assay. Chromatography fraction 12 displayed the most potent antimicrobial activity against all 16 strains of mutans streptococci, P. gingivalis, and P. intermedia. No KB cell cytotoxicity was evident up to $128{\mu}g/ml$ of fraction 12. The methanol extract had no antimicrobial activity against F. nucleatum and A. actinomycetemcomitans. These results suggest chromatography fraction 12 methanol extract of mulberry leaf could be useful in the development of oral hygiene products, such as dentifrice and oral hygiene solution, for the prevention of dental caries.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.227-231
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• 2007

Many of antimicrobial components used in the mouthwash have disadvantages such as coloring of periodontal tissue and homing sensation. To find the more biocompatible antimicrobial agent, we have screened the 2,125 kinds of natural plant extracts obtained from by the Plant Extract Bank (Daejeon, Korea). The antimicrobial activity was determined by spectrophotometric growth inhibition assay for the major dental pathogens. For the Porphyromonas gingivalis, 19 plant extracts had an antimicrobial activity, 17 plant extracts for the Prevotella intermedia, 45 plant extracts for the Haemophilus actinomycetemcomitans and 85 plant extracts for the Streptococcus mutans. Among these effective extracts, 8 kind of natural plant extracts had an antimicrobial activity for more than 3 species of dental pathogens. In our experiment, Cudrania tricuspidata, Morus bombycis and Mallotus japonicas have antibacterial effects on the all kinds of major dental pathogens. Therefore these plant extracts have a possibility to be a candidate for major antibacterial components in dental products.

• Restorative Dentistry and Endodontics
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• v.24 no.3
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• pp.447-452
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• 1999

The role of bacteria in root canals and periapical infections is well known and established. In these bacteria, black-pigmented bacteria(BPH) play important role in endodontic infection. BPB are Gram negative anaerobic rods which are closely related 50 clinical symptoms such as pain, percussion, tenderness, foul odor, etc. In America and Europe, many studies on BPB have been done and are continued. But, relatively few studies have been done in Korea, especially its prevalence in Korean population is not yet studied. The purpose of this study is to establish prevalence of BPB in infected root canals and periapical abscesses in Korean people. Microbial samples were collected from the root canals of 34 intact tooth with periapical rarefactions of endodontic origin and 3 periapical abscesses. All samples were incubated in an anaerobic chamber(Coy, Model No. 77. Ann Arbor, Michigan, USA.). Identification of In microorganism was based on its growth in the anaerobic chamber, colonial pigmentation, colonial morphology, Gram stain, and Rapid ID32A(BioMericux SA/69280 Marcy-l'Etoile/France) results. In addition, the polyme ase chain reaction using specific primers for 16S rRNA genes were used differentiate Prevotella nigrescens for Prevotella intermedia. The results were as follows : 1. In this study, thirteen (35%) of thirty seven samples were positive for the growth of BPB. In thirteen samples, sixteen strains of BPR were found. 2. The most frequently identified BPB in root canals and abscesses in Korean were P. nigrescens 5/37(14%) and P. intermedia 5/37(14%). Porphyromonas gingivalis 3/37(8%), Porphyromonas endodontalis 2/37(5%) and Prevotella loecheii 1/37(3%) were also found. 3. In this study, no significant differences were found between the prevalence of BPB in Korean and that of American and European.

• Restorative Dentistry and Endodontics
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• v.28 no.2
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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.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.401-411
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• 2005

The aim of this study was to determine the minimal inhibitory concentration(MIC) of cefixime, which is a 3rd generation of cefalosporin, against 6 species of putative periodontopathogens; Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Prevotella nigrescens, Tannerella forsythia and Porphyromonas gingivalis. The efficacy of cefixime was examined by comparing it with that of several antibiotics(amoxicillin, $Augmentin^{(R)}$ ciprofloxacin, metronidazole, and tetracycline), which were used as the control. The MIC was measured using a microdilution method. The MIC of cefixime against the putative periodotopathogens, as a single use regimen, was relatively lower than that of the other antibiotics. The MIC of cefixime/metronidazole against P. intermedia ChDC KB14, P. nigrescens ChDC KB50, F. nucleatum ChDC PV-F37, F. nucleatum ChDC F130, and F. nucleatum ChDC F175, as a simultaneous regimen, was lower than that of the other antibiotics. The concentration of cefixime in the crevicular fluid of volunteers who received 250mg every 12 hours for 3 days was $9{\mu}g/ml$ after 9 hours. In conclusion, cefixime showed good antimicrobial activity in a single treatment or as a combined therapy with amoxicillin, $Augmentin^{(R)}$ or metronidazole against 6 periodontopathogens.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.2
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• pp.145-158
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• 1997

Method for synchronizing multimedia data is needed to support continuous transmission of multimedia data through a network in a bounded time and it also required for supporting continuous presentation of multimedia data with the required norminal playout rate in distributed network environments. This paper describes a new synchronization method for supporting delay-sensitive multimedia Presentation without degration of Quality of services of multimedia application. It mainly aims to support both intermedia and intermedia synchronization by absorbing network variations which may cause skew or jitter. In order to remove asynchonization problems, we make use of logical time system, dynamic buffer control method, and adjusting synchronization intervals based on the quality of services of a multimedia. It might be more suitable for working on distribute[1 multimedia systems where the network delay variation is changed from time to time and no global clock is supported. And it also can effectively reduce the amount of buffer requirements needed for transfering multimedia data between source and destination system by adjusting synchronization intervals with acceptable packet delay limits and packet loss rates.

• Journal of Veterinary Science
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• v.22 no.5
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• pp.64.1-64.12
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• 2021

Background: Pituitary pars intermedia dysfunction (PPID), a neurodegenerative disease leading to reduced dopamine production, is a common disease in aged horses. The treatment is based on administration of the dopamine agonist pergolide. This drug has been related to valvular fibrosis in humans, but the cardiovascular effect of this drug has not yet been investigated in horses. Objectives: To determine whether pergolide induces valvular disease in horses or affects the cardiac function. Methods: Standard, tissue Doppler (TDE) and two-dimensional speckle tracking (STE) echocardiography were performed in horses with diagnosed PPID based on adrenocorticotropic hormone dosage. Measurements taken in horses treated with pergolide were compared with those from untreated horses with nonparametric t-tests. Furthermore, measurements from follow-up examinations performed at least three months after the initial exam were compared with a Wilcoxon signed rank test for repeated measurements in each group. Results: Twenty-three horses were included. None of the 12 horses under treatment developed valvular regurgitation. Furthermore, no differences in the measurements of the left ventricular systolic or diastolic function could be seen between the group of horses with treatment and those without treatment. Measurements taken in the follow-up exam did not differ compared to those taken in the initial exam in both groups. Conclusions: No changes of the left ventricular function assessed by TDE and STE could be shown in a small population of horses with confirmed PPID. Treatment with pergolide did not affect the ventricular function nor induce valvular disease.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.25-32
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• 2019

Objectives : Ephedra regeliana, although similar to the other E. sinica, E. intermedia, and E. equisetina, is not authorized by The Korean Pharmacopoeia and yet has also been imported under the name of 'Ma-Hwang'. The aim of this study was to perform a comparative anatomical evaluation of Ephedrae Sinicae Herba (ESH), Ephedrae Intermedicae Herba (EIH), Ephedrae Equisetinae Herba (EEH) and Ephedrae Regelianae Herba (ERH). Methods : Permanent paraffin-embedded specimens were produced using the paraffin-tertiary butyl alcohol (TBA) method, to visualize their anatomical features via light microscopy. Results : ESH and ERH transverse sections were in the shape of a long ellipse, while those of EIH and EEH were in the shape of a circle. These anatomical characteristics substantiated the results of external morphological examination. The sections revealed that each of the four samples showed significantly different cortexes. The cortex of ESH was wider than two thirds of the section, unlike that of the other samples which was relatively narrow. The xylems of ERH, EIH, and EEH demonstrated interconnectivity with other adjacent xylems, contrary to those in ESH. Therefore, the characteristic development of the xylems over time was used to distinguish ERH from the other. Furthermore, parenchymal morphology in the central cylinder was also a good criterion to differentiate between EIH and EEH, since EIH demonstrated parenchymal cells that were shaped like a rounded-triangle, whereas EEH parenchymal cells were chrysanthemum-shaped. Conclusions : The identification-keys established in this study would facilitate the accurate identification of microscopic features of the four varieties of 'Ma-Hwang'.

• Journal of Oral Medicine and Pain
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• v.47 no.1
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• pp.10-26
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• 2022

Purpose: The purpose of this study was to investigate whether various saliva collection methods affect the observed salivary microbiome and whether microbiomes of stimulated and unstimulated saliva and plaque differ in richness and diversity. Methods: Seven sampling methods for unstimulated saliva, stimulated saliva, and plaque samples were applied to six orally and systemically healthy participants. Bacterial 16S ribosomal RNA genes of 10 major oral bacterial species, namely, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Prevotella nigrescens, Streptococcus mitis, Streptococcus sobrinus, and Lactobacillus casei, were analyzed by real-time polymerase chain reaction. We comprehensively examined the dependence of the amount of bacterial ribosomal DNA (rDNA), bacterial-community composition, and relative abundance of each species on sample collection methods. Results: There were significant differences in the bacterial rDNA copy number depending on the collection method in three species: F. nucleatum, P. nigrescens, and S. mitis. The species with the highest richness was S. mitis, with the range from 89.31% to 100.00%, followed by F. nucleatum, P. nigrescens, T. denticola, T. forsythia, and P. intermedia, and the sum of the proportions of the remaining five species was less than 1%. The species with the lowest observed richness was P. gingivalis (<0.1%). The Shannon diversity index was the highest in unstimulated saliva collected with a funnel (4.449). The Shannon diversity index was higher in plaque samples (3.623) than in unstimulated (3.171) and stimulated (3.129) saliva and in mouthwash saliva samples (2.061). Conclusions: The oral microbial profile of saliva samples can be affected by sample collection methods, and saliva differs from plaque in the microbiome. An easy and rapid technique for saliva collection is desirable; however, observed microbial-community composition may more accurately reflect the actual microbiome when unstimulated saliva is assayed.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.344-351
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• 2016

A marine bacterium, designated as strain 50C-3, was isolated from a seawater sample collected from the East Sea of South Korea. The strain is a Gram-negative, aerobic, yellow colored polar-flagellated bacterium that grows at $20-50^{\circ}C$ and pH 5.5-8.5. Optimal growth occurred at $40-50^{\circ}C$, at pH 6.5-7.5, and in the presence of 2% (w/v) NaCl. Based on 16S rRNA gene sequence similarity, the isolate was considered to represent a member of the genus Ruegeria. The result of this analysis showed that strain 50C-3 shared 99.4% and 96.98% sequence similarity with Ruegeria intermedia CC-GIMAT-$2^T$ and Ruegeria lacuscaerulensis ITI-$1157^T$, respectively. Furthermore, strain 50C-3 showed clear differences from related strains in terms of several characteristics such as motility, carbon utilization, enzyme production, etc. The DNA G+C content was 66.7 mol%. Chemotaxonomic analysis indicated ubiquinone-10 (Q-10) as the predominant respiratory quinone. Based on phenotypic, chemotaxonomic, and phylogenetic characteristics, the isolate represents a novel variant of the Ruegeria intermedia CC-GIMAT-$2^T$, for which we named Ruegeria sp. 50C-3 (KCTC23890=DSM25519). Strain 50C-3 did not produce cellulase and agarase, but produced alkaline phosphatase, ${\alpha}$-galactosidase, and ${\beta}$-galactosidase. The three enzymes showed stable activities even at $50^{\circ}C$ and thus regarded as thermostable enzymes. Especially, the ${\beta}$-galactosidase activity enhanced by 1.9 times at $50^{\circ}C$ than that at $37^{\circ}C$, which may be very useful for industrial application.