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This study was designed to determine whether the ethanol extract of Artemisia princeps could inhibit the cariogenic activity of Streptococcus mutans. The increase in acid production and bi...

The emergence of antibiotic-resistant bacteria has caused difficulty in treating infectious diseases. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most commonly recognized antibiotic-resistant bacteria. Novel antibiotics are urgently required to treat these bacteria. Raw materials derived from natural sources can be used for the development of novel antibiotics, such as Chamaecyparis obtusa (C. obtusa), which has been traditionally used in treating asthmatic disease. In this study, the antibacterial activity of the essential oil (EO) extracted from C. obtusa leaves against MRSA was investigated. MRSA growth and acid production from glucose metabolism were inhibited at concentrations greater than 0.1 mg/mL C. obtusa EO. MRSA biofilm formation was observed using scanning electron microscopy and safranin staining. C. obtusa EO inhibited MRSA biofilm formation at concentrations greater than 0.1 mg/mL. Using real-time polymerase chain reaction, mRNA expression of virulence factor genes, sea, agrA, and sarA, was observed. agrA expression was inhibited with C. obtusa EO concentrations greater than 0.2 mg/mL, whereas inhibition of sea and sarA expression was also observed at a concentration of 0.3 mg/mL. C. obtusa EO was analyzed by gas chromatography (GC) and GC coupled for mass spectrometry, which identified 59 constituents, accounting to 98.99% of the total EO. These findings suggest that C. obtusa EO has antibacterial effects against MRSA, which might be associated with the major components of C. obtusa EO, such as sabinene (19.06%), α-terpinyl acetate (16.99%), bornyl acetate (10.48%), limonene (8.54%), elemol (7.47%), myrcene (5.86%), γ-terpinene (4.04%), and hibaene (3.01%).

In this study, we used ethanol extract ofA. princepsand investigated its antibacterial effects against MRSA. Ethanol extract ofA. princepssignificantly inhibited MRSA growth and organic acid production during glucose metabolism at concentrations greater than 1 mg/mL (P A. princepsextract was found to inhibit MRSA biofilm formation at concentrations higher than 2 mg/mL significantly (P A. princepswere observed using confocal laser microscopy, which showed thatA. princepswas bactericidal in a dose-dependent manner. Using real-time PCR, expression ofmecA, an antibiotic-resistance gene of MRSA, was observed, along with that ofsea, agrA, andsarA.A. princepssignificantly inhibitedmecA, sea, agrA, andsarA, mRNA expression at the concentrations greater than 1 mg/mL (P A. princepsshowed a relatively high content of organic acids and glycosides. The results of this study suggest that the ethanol extract ofA. princepsmay inhibit proliferation, acid production, biofilm formation, and virulence gene expressions of MRSA, which may be related to organic acids and glycosides, the major components in the extract.

Staphylococcus species are one of prevalent pathogens found in hospitals. Microbes that are a primary cause of nosocomial infection were isolated from a dental and medical environment it may assist the reader to explain what this is and how it differs from the ‘dental health care providers and ward health care providers’. To investigate the distribution of staphylococcus species in this environment, we used vitek II to measure drug sensitivity, and further performed biochemical testing. The isolation rate of staphylococcus species from the dental and medical environment was 100% but from dental health care providers and ward health care providers were 44.4% and 33.3%, respectively. In the analyses, staphylococcus species showed resistance to diffusion of cefoxitin and oxacillin discs. These staphylococci may be sufficiently positive for the mecA gene. Our results suggest that staphylococci might be an important cause of nosocomial infection in the dental clinic.

In this study, root bark ofUlmus pumila(U. pumila) was extracted with ethanol, and then the antimicrobial effects were tested on clinically isolated 12 MRSA strains and 1 standard MRSA strain.U. pumilashowed antibacterial activities against all MRSA strains. Minimum inhibitory concentration (MIC) ofU. pumilaroot bark against all MRSA strains revealed a range from 125 to 250 μg/mL. These results may provide the scientific basis on whichU. pumilaroot bark has traditionally been used against infectious diseases in Korea. In real-time PCR analysis, the sub-MIC (64–125 μg/mL) concentrations ofU. pumilaroot bark extract showed the inhibition of the genetic expressions of virulence factors such asmecA,sea,agrA, andsarAin standard MRSA. Phytochemical analyses ofU. pumilaroot bark showed relatively strong presence of phenolics, steroids, and terpenoids. These results suggest that the ethanol extract ofU. pumilaroot bark may have antibacterial activity against MRSA, which may be related to the phytochemicals such as phenolics, steroids, and terpenoids. Further studies are needed to determine the active constituents ofU. pumilaroot bark responsible for such biomolecular activities.

Effect of metal compounds on the thermal degradation behaviors of poly(3-hydroxybutyric acid) (P(3HB)), poly(4-hydroxybutyric acid) (P(4HB)), and poly(ɛ-caprolactone) (PCL) was investigated by means of thermogravimetric and pyrolysis-gas chromatograph mass spectrometric analyses. Na and Ca compounds accelerated a random chain scission of P(3HB) molecules resulting in a decrease of thermal degradation temperature, whereas the contribution of Zn, Sn, Al compounds to the thermal degradation of P(3HB) was very small. In contrast to P(3HB), Zn, Sn and Al compounds induced the thermal degradation of PCL at lower temperature range by catalyzing the selective unzipping depolymerization from ω-hydroxyl chain end. Transesterification reaction of PCL molecules could be facilitated by the presence of Ca compound, while the gravimetric change was detected at almost identical temperature region regardless of the content of Ca compound. According to the lactonizing characteristic of monomer unit, the thermal degradation of P(4HB) progressed by the cyclic rupture via unzipping reaction from the ω-hydroxyl chain end or/and random intramolecular transesterification at the main chain with a release of γ-butyrolactone as volatile product. Each of metal compounds used in this study was effective to catalyze the cyclic rupture of P(4HB) molecules, and the degradation rate was accelerated by the presence of metal compounds.

Infectious diseases have represented a threat to human lives since the beginning of human existence. Many infectious diseases have been conquered through the discovery of antibiotics and antiviral agents. However, the antibiotic-resistant strains and mutant microorganisms that are now emerging are more powerful than the existing ones. In addition, some existing microorganisms have developed resistance to antibiotics, leading to infections that are more difficult to treat. Moreover, microbial biofilms cannot be treated by antibiotics and can cause chronic infections. Infectious diseases continue to pose a threat to humans, and continued efforts are needed to develop effective treatments.

Objective: To explore and describe international oral health attitudes/behaviours among final year dental students. Methods: Validated translated versions of the Hiroshima University—Dental Behavioural Inventory (HU—DBI) questionnaire were administered to 1,096 final-year dental students in 17 countries. Hierarchical cluster analysis was conducted within the data to detect patterns and groupings. Results: The overall response rate was 72%. The cluster analysis identified two main groups among the countries. Group 1 consisted of twelve countries: one Oceanic (Australia), one Middle-Eastern (Israel), seven European (Northern Ireland, England, Finland, Greece, Germany, Italy, and France) and three Asian (Korea, Thailand and Malaysia) countries. Group 2 consisted of five countries: one South American (Brazil), one European (Belgium) and three Asian (China, Indonesia and Japan) countries. The percentages of ‘agree’ responses in three HU—DBI questionnaire items were significantly higher in Group 2 than in Group 1. They include: “I worry about the colour of my teeth.”; “I have noticed some white sticky deposits on my teeth.”; and “I am bothered by the colour of my gums.” Conclusion: Grouping the countries into international clusters yielded useful information for dentistry and dental education.

Thermal degradation behavior of poly(4-hydroxybutyric acid) (P(4HB)) was investigated by thermogravimetric and pyrolysis–gas chromatography mass spectrometric analyses under both isothermal and non-isothermal conditions. Based on the thermogravimetric analysis, it was found that two distinct processes occurred at temperatures below and above 350 °C during the non-isothermal degradation of P(4HB) samples depending on both the molecular weight and the heating rate. From 1 H NMR analysis of the residual P(4HB) molecules after isothermal degradations at different temperatures, it was confirmed that the ω-hydroxyl chain-end was remained unchanged in the residual P(4HB) molecules at temperatures below 300 °C, while the ω-chain-end of P(4HB) molecules was converted to 3-butenoyl units at temperatures above 300 °C. In contrast, the majority of the volatile products evolved during thermal degradation of P(4HB) was γ-butyrolactone regardless of the degradation temperature. From these results, it is concluded that during the thermal degradation of P(4HB), the selective formation of γ-butyrolactone via unzipping reaction from the ω-hydroxyl chain-end predominantly occurs at temperatures below 300 °C. At temperatures above 300 °C, both the cis -elimination reaction of 4HB unit and the formation of cyclic macromolecules of P(4HB) via intramolecular transesterification take place in addition to unzipping reaction from the ω-hydroxyl chain-end. Finally, the primary reaction of thermal degradation of P(4HB) at temperatures above 350 °C progresses by the cyclic rupture via intramolecular transesterification of P(4HB) molecules with a release of γ-butyrolactone as volatile product. Moreover, we carried out the thermal degradation tests for copolymer of 93 mol% of 4HB with 7 mol% of 3-hydroxybutyric acid (3HB) to examine the effect of 3HB units on thermal stability of P(4HB).

Thermal degradation behaviours of poly(3-hydroxybutyric acid) (P(3HB); bacterial poly[( R )-3-hydroxybutyric acid] and synthetic poly[( R , S )-3-hydroxybutyric acid] samples, were examined under both isothermal and non-isothermal conditions. The inverse of number-average degree of polymerisation for all P(3HB) samples decreased linearly with degradation time during the initial stage of isothermal degradation at a temperature ranging from 170–190 °C. In addition, crotonyl unit was detected in the residual polymer samples as main ω-chain-end. These results indicate that the dominant thermal degradation reaction for P(3HB) is a random chain scission via cis -elimination reaction of P(3HB) molecules. It was found that the presence of either Ca or Mg ions enhances the depolymerisation of P(3HB) molecules, while that Zn ions hardly catalyse the reaction. As a result, a shift of thermogravimetric curves toward the lower temperature regions was observed for the P(3HB) samples containing high amounts of Ca and Mg compounds.

We have previously reported that extract of radish roots exhibits an increase in gastrointestinal motility through the activation of muscarinic acetylcholine (ACh) receptors. Based on the stimulatory activity-guided fractionation on rat ileal segments, this study isolated methylisogermabullone (MIGB, C23H31O5NS, MW 433) from methanol extracts of radish roots. MIGB caused a significant increase of the isolated rat ileal contraction in a concentration-dependent manner (23–693 μm), and the pattern of MIGB-induced ileal contraction was different in the time course to that produced by ACh. The EC50 value of MIGB, to produce 50% maximum ileal contraction, was estimated to be 45.5 μm. MIGB (230 μm)-induced ileal contractions were enhanced by pretreatment of segments with ACh (0.1 μm). Ileal contractions produced by MIGB (230 μm) or ACh (0.1 μm) at submaximal concentration were partially inhibited by pretreatment of hexamethonium (0.1 mm), a ganglionic blocker, whereas they were almost completely abolished by atropine (10 μm). Oral administration of MIGB to mice stimulated the small intestinal transit of charcoal in a dose-dependent manner (10–100 mg kg−1), and MIGB (100 mg kg−1)-induced stimulation of small intestinal transit was significantly attenuated by co-administration of atropine (50 mg kg−1). Taken together, these results demonstrate that MIGB isolated from radish roots stimulates the small bowel motility through the activation of ACh receptors. These findings suggest that MIGB may become a potential regulatory agent for therapeutic intervention in dysfunction of gastrointestinal motility.

Methicillin-resistant Staphylococcus aureus (MRSA) has been emerging worldwide as one of the most important hospital and community pathogens. Therefore, new agents are needed to treat MRSA associated infections. The present study investigated the antimicrobial activity of ethyl acetate, methanol and water extracts of Curcuma longa L. (C. longa) against MRSA. The ethyl acetate extract of C. longa demonstrated a higher antibacterial activity than the methanol extract or water extract. Since the ethyl acetate extract was more active than the other extracts, the study examined whether the ethyl acetate extract could restore the antibacterial activity of beta-lactams and alter the MRSA invasion of human mucosal fibroblasts (HMFs). In the checkerboard test, the ethyl acetate extract of C. longa markedly lowered the MICs of ampicillin and oxacillin against MRSA. In the bacterial invasion assay, MRSA intracellular invasion was significantly decreased in the presence of 0.125-2 mg/mL of C. longa extract compared with the control group. These results suggest that the ethyl acetate extract of C. longa may have antibacterial activity and the potential to restore the effectiveness of beta-lactams against MRSA, and inhibit the MRSA invasion of HMFs.

Thermal degradation processes of end-capped poly(L-lactide)s (PLLAs) were investigated by means of several thermoanalytical techniques under both isothermal and nonisothermal conditions. Based on the thermogravimetric analysis, it was found that two distinct processes at temperatures below and above 330 degrees C were existed in the nonisothermal degradation for PLLA samples depending on the amounts of residual zinc compounds from synthesis process. Isothermal degradation experiments at different temperature regions showed that the sample weight of PLLA decreased linearly with time in both cases, whereas the changes in molecular weight revealed different tendency for the temperature. On the basis of characterization of the residual PLLA molecules after isothermal degradation at 330 degrees C, it was confirmed that the omega chain end of the residual molecules was an acrylic ester unit. Majority of volatile products during thermal degradation of PLLA was the lactide regardless of the degradation temperature. From these results, it is concluded that, during the thermal degradation of PLLA samples in the presence of large amounts of residual zinc compounds, the zinc compounds catalyze both the intermolecular transesterification generating PLLA with low molecular weights and the selective unzipping depolymerization of PLLA with low molecular weights at temperatures below 330 degrees C. In contrast, the primary reaction of thermal degradation for PLLA in the absence of residual zinc compounds above 330 degrees C is a competition between the random chain scission via a cis-elimination reaction and the cyclic rupture via intramolecular transesterification of PLLA molecules. In addition, it was evidenced that the racemization of lactic acid units in the main chain of PLLA molecules occurred at temperatures above 330 degrees C.

In the present study, we investigated antimicrobial activity of Caesalpinia sappan against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and effect of Caesalpinia sappan extract on the invasion of MRSA to human mucosal fibroblasts (HMFs). Chloroform, n-butanol, methanol, and aqueous extracts of the Caesalpinia sappan showed antimicrobial activity against standard methicillin-sensitive Staphylococcus aureus (MSSA) as well as MRSA. Methanol extract of Caesalpinia sappan demonstrated a higher inhibitory activity than n-butanol, chloroform, and aqueous extracts. In the checkerboard dilution method, methanol extract of Caesalpinia sappan markedly lowered the minimal inhibitory concentrations (MICs) of ampicillin and oxacillin against MRSA. To determine whether methanol extract of Caesalpinia sappan inhibits the MRSA invasion to HMFs, the cells were treated with various sub-MIC concentrations of methanol extract and bacterial invasion was assayed. MRSA invasion was notably decreased in the presence of 20-80 microg/ml of Caesalpinia sappan extract compared to the control group. The effect of Caesalpinia sappan extract on MRSA invasion appeared dose-dependent. These results suggest that methanol extract of Caesalpinia sappan may have antimicrobial activity and the potential to restore the effectiveness of beta-lactam antibiotics against MRSA, and inhibit the MRSA invasion to HMFs.

The essential oil of Chrysanthemum boreale Makino was analyzed by means of GC and GC-MS. Eighty-seven constituents were identified, representing 94.13 % of the total oil and the major components were camphor, alpha-thujone, cis-chrysanthenol, 1,8-cineole, alpha-pinene, and beta-caryophyllene. Furthermore, the essential oil exhibited antibacterial activity (MIC, more than 800 microg/mL versus 0.125 microg/mL for ampicillin) after it was tested against 6 Gram(+) bacteria and 8 Gram(-) bacteria.

Objective: To compare cross-national differences of dental health behaviour among dental hygiene students. Design: Cross-cultural differences. Setting: United States (USA) and Korea. Subjects and methods: One hundred and twenty-six dental hygiene students in USA and 246 in Korea were surveyed using the Hiroshima University-Dental Behavioural Inventory (HU-DBI) (in English and Korean versions respectively). Results: There were considerable differences in oral health behaviour between USA and Korean dental hygiene students. Of great significance were findings that while only a small proportion of the USA students (1%) reported gum bleeding when they brushed their teeth, 37% of the Korean students did so (P

Following the coincidental discovery that beta-actin isolated from renal epithelial cells was precipitated by staphylococcal protein A (SPA), the possibility that SPA and cytoskeletal actin filaments may be involved in Staphylococcus aureus infection of epithelial cells was considered. Therefore, to clarify the potential role of SPA and actin filaments in S. aureus infection, the invasion efficiency of S. aureus was determined quantitatively by measuring the number of cfu of viable organisms recovered from cultured KB cells. S. aureus invasion was found to be time dependent (0-60 min) and increased linearly when increasing numbers of bacteria were added (10(4)-10(6) cfu/ml). However, significant variation in the level of invasion was noted in protein A-deficient S. aureus Wood 46. Cytochalasin B inhibited the invasion efficiency of S. aureus in a dose-dependent manner. The present study suggests that interaction of staphylococcal protein A and cytoskeletal actin filaments is involved in the S. aureus invasion of cultured KB cells, and this process may contribute, in part, to the intracellular movement, cell-to-cell spread and dissemination of S. aureus within human oral epithelial cells in vivo.

Methanol extract and its fractions (CHCl3, n-BuOH and H2O) of the fruit body of Phellinus linteus mushroom were investigated for antibacterial activity against methicillin-resistant Staphylococcus aureus. The n-BuOH fraction showed a good antibacterial activity (MIC, 63-125 microg/ml) against all tested strains.

In recent years, international relationships in dentistry have grown stronger through journals, books, academies, seminars, researcher exchanges and so forth. Korea and Japan are neighbours in East Asia. However, no comparison of the dental education systems of the two countries has been published. Therefore, the authors have provided the present comparison to promote mutual understanding and to familiarise dentists around the world with dental education in these two countries. The number of dentists, life expectancy at birth, and number of decayed, missing, and filled teeth (DMFT) at age 12 years in Korea and Japan are summarised.

This study aimed to compare the dental curriculum of the traditional six-year system with that of the new four-year (graduate-entry) system in South Korea. There are 11 dental schools in South Korea: six are public and five are private. Eight offer the new four-year program and the other three offer the traditional six-year program. Descriptive analyses were conducted using bibliographic data and local information along with statistical analyses such as chi-square tests. In the six-year programs, clinical dentistry subjects were taught almost equally in practical and didactic courses, while the basic science courses were taught more often as practical courses (P < 0.0001). In the four-year programs, both the basic science and clinical dentistry subjects were taught didactically more often; while more dentistry subjects were taught than basic sciences (P = 0.004). The four-year program model in South Korea is more focused on dentistry than on basic science, while both basic and clinical dentistry subjects were equally taught in the six-year program.

Mobile genetic segments, or transposons, are also referred to as "jumping genes" as they can shift from one position in the genome to another, thus inducing a chromosomal mutation. According to the target site-specificity of the transposon during a transposition event, the result is either the insertion of a gene of interest at a specific chromosomal site, or the creation of knockout mutants. The former situation includes the integration of conjugative transposons via site-specific recombination, several transposons preferring a target site of a conserved ATrich sequence, and Tn7 being site-specifically inserted at attTn7, the downstream of the essential glmS gene. The latter situation is exploited for random mutagenesis in many prokaryotes, including IS (insertion sequence) elements, mariner, Mu, Tn3 derivatives (Tn4430 and Tn917), Tn5, modified Tn7, Tn10, Tn552, and Ty1, enabling a variety of genetic manipulations. Randomly inserted transposons have been previously employed for a variety of applications such as fmgenetic footprinting, gene transcriptional and translational fusion, signature-tagged mutagenesis(STM),DNA or cDNA sequencing, transposon site hybridization(TraSH), and scanning linker mutagenesis(SLM). Therefore, transposon-mediated genetic engineering is a baluable discipiline for the study of bacterial physiology and pathogenesis in living hosts.

현대사회가 발전하면서 구강건강 문제가 중요하게 대두되고 있 다 치아우식증은 치면세균막내 세균의 당 대사를 통해 생성되는 산 . 에 의해 치질이 탈회되는 과정으로 이루어지는 세균성 치아경조직 질환이다1) 이를 방치하게 되면 치수염을 일으켜 심한 통증을 느끼 . 게 되고 이로 인해서 치아를 상실할 수도 있다 치아우식증을 유발 , . 하는데 관련된 요인으로는 크게 미생물요인2) 숙주요인 및 식이요인 , 3) 등이 있는데 이 중에서 미생물요인은 치아우식증의 원인균들과 , 관련된 중요한 인자이다 치아우식증에 관련된 여러 세균 중에서 그 . 람양성 세균인 Streptococcus mutans는 외부로부터 섭취한 음식 물에 포함되어 있는 설탕 이나 포도당 등을 분해하여 치아 (sucrose) 우식증을 유발하는 중요한 원인로 지적되어왔다4) 또한 . , S. mutans 가 생산하는 는 자당을 기질로 하여 점착성의 비수용성 글 GTFase Galla Chinensis Streptococcus mutans

In a continuing search for compounds with antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), a chloroform extract of roots of Aralia continentalis was found to contain continentalic acid (CA, C20H30O2), a diterpenic acid. This compound exhibited potent activity against standard methicillin-susceptible Staphylococcus aureus (MSSA) as well as clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). It was determined that continentalic acid had minimum inhibitory concentrations (MICs) of approximately 8–16 µg/mL against S. aureus, including the MSSA and MRSA standard strains. Therefore, the results obtained in this study suggest that continentalic acid might have potential as an adjunct in the treatment of antibiotic-resistant bacteria. Copyright © 2006 John Wiley & Sons, Ltd.

Methicillin-resistant Staphylococcus aureus (MRSA) bacteria have been responsible for substantial morbidity and mortality in hospitals because they usually have multidrug resistance. Some natural products are candidates as new antibiotic substances. In the present study, we investigated the antimicrobial activity of berberine, the main antibacterial substance of Coptidis rhizoma (Coptis chinensis Franch) and Phellodendri cortex (Phellodendron amurense Ruprecht), against clinical isolates of MRSA, and the effects of berberine on the adhesion to MRSA and intracellular invasion into human gingival fibroblasts (HGFs). Berberine showed antimicrobial activity against all tested strains of MRSA. Minimum inhibition concentrations (MICs) of berberine against MRSA ranged from 32 to 128 microg/mL. Ninety percent inhibition of MRSA was obtained with 64 microg/mL or less of berberine. In the checkerboard dilution test, berberine markedly lowered the MICs of ampicillin and oxacillin against MRSA. An additive effect was found between berberine and ampicillin, and a synergistic effect was found between berberine and oxacillin against MRSA. In the presence of 1-50 microg/mL berberine, MRSA adhesion and intracellular invasion were notably decreased compared with the vehicle-treated control group. These results suggest that berberine may have antimicrobial activity and the potential to restore the effectiveness of beta-lactam antibiotics against MRSA, and inhibit the MRSA adhesion and intracellular invasion in HGFs.

Objective: To identify similarities and differences in oral health attitudes, behaviour and values among freshman dental students. Design: Cross-cultural survey of dental students. Setting: 18 cultural areas. Participants and Methods: 904 first-year dental students completed the Hiroshima University-Dental Behavioural Inventory (HU-DBI) translated into their own languages. Individual areas were clustered by similarity in responses to the questions. Results: The first group displayed an Occidental-culture orientation' with the exception of Brazil (Cluster 1 comprised: Australia, United Kingdom, Ireland, Belgium and Brazil, Cluster 2: Germany, Italy, Finland and France). The second group displayed an 'oriental-cultural orientation' with the exception of Greece and Israel (Cluster 3 comprised: China and Indonesia, and Cluster 4: Japan, Korea, Israel, Hong Kong, Malaysia, Thailand and Greece). Australia and United Kingdom were the countries that were most alike. Ireland was the 'neighbour' to these countries. Greece and Malaysia had similar patterns of oral health behaviour although geographic conditions are very different. Although it was considered that in Hong Kong, occidental nations have affected the development of education, it remained in the oriental-culture group. Comparison with the data from the occidentals indicates that a higher percentage of the orientals put off going to the dentist until they have toothache (p

Based on an inhibitory activity-guided fractionation for the high glucose-induced proliferation of glomerular mesangial cells (GMCs), chloroform extracts of the roots of Phytolacca americana were found to contain alpha-spinasterol (C (29)H (48)O), a delta (7)-sterol. This phytosterol proved to be a potent inhibitor (IC (50) = 3.9 x 10 (-12) g/mL, 9.5 pmol/L) of glomerular mesangial cell proliferation caused by high-ambient glucose (5.6 mM vs. 25 mM), and its inhibitory potency was about 1,000 times higher than that of simvastatin, an HMG-CoA reductase inhibitor used as a positive control. alpha-Spinasterol also significantly reduced the increases of serum triglycerides, renal weight and urinary protein excretion in streptozotocin-induced diabetic mice, and these were comparable to the results observed in insulin-treated diabetic mice. Therefore, the results obtained in this study suggest that alpha-spinasterol has a significant therapeutic potential to modulate the development and/or progression of diabetic nephropathy.

This study describes a potential of Phytolaccaceae (Phytolacca americana var.) as an inhibitor of high glucose-stimulated production of extracellular matrix (ECM) proteins and TGF-beta in cultured glomerular mesangial cells (GMCs). Raising the ambient glucose concentration for 24 hrs caused a dose-dependent increase in [3H]thymidine incorporation of GMCs, and the maximal response was achieved at 20 mM. Phytolaccaceae extracts (2.5-20 microg/ml) inhibited the high glucose-induced [3H]thymidine incorporation in a dose-dependent manner, and the concentrations tested here did not affect to the cell viability. Exposure of the GMCs to 20 mM glucose caused both ECM (collagen and fibronectin) accumulation and TGF-beta secretion, and these changes were significantly diminished by treatment of GMCs with Phytolaccaceae (10 microg/ml). Taken together, these results indicate that Phytolaccaceae inhibits the high glucose-induced GMCs proliferation partially through suppressing accumulation of ECM components and TGF-beta production, suggesting that Phytolaccaceae may be a promising agent for treating the development and progression of diabetic glomerulopathy.

The chemical composition of the essential oil from Artemisia iwayomogi Kitamura was analyzed by means of GC and GC-MS. Eighty-five constituents were identified representing 96.23 % of the total oil. Camphor (19.31 %), 1,8-cineole (19.25 %), borneol (18.96 %), camphene (4.64 %), and beta-caryophyllene (3.46 %) were found to be the major components. Furthermore, the oil exhibited antibacterial activity against six Gram-(+) and six Gram-(-) bacteria in tests using the broth dilution method.

The inhibitory effects of tanshinone IIA, a diterpene isolated from Salvia miltiorrhiza root, on the production of nitric oxide (NO), interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), and the expression of inducible nitric oxide synthase (iNOS) were investigated in activated RAW 264.7 cells. This compound markedly inhibited the production of NO, IL-1beta and TNF-alpha, and suppressed the expression of iNOS in a dose-dependent manner. These results suggest that the traditional use of S. miltiorrhiza as an anti-inflammatory herbal medicine may be explained, in part, by the inhibition of NO, IL-1beta, IL-6 and TNF-alpha production, and expression of iNOS.

The purpose of this study was to examine oral health attitudes/behavior and gingival self-care levels of Korean dental hygiene students (n=271). A questionnaire known as HU-DBI (Korean version) was administered to each class. Higher scores of the HU-DBI indicate better oral health attitudes/behavior. The student's gingival self-care level was scored as excellent (+2), good (+1), questionable (0), poor (-1), or very poor (-2) according to the criteria of the Oral Rating Index (ORI) for youth. The mean score of the HU-DBI was 6.40, and that of the ORI was +0.12. Most samples scored 0 or +1. The mean HU-DBI scores of year-2 and year-3 students (7.06, and 7.61 respectively) were significantly greater than that of year-1 students (5.23) (P< 0.001). Twenty-three percent of the students reported a belief that they may eventually require false teeth. Half stated that they put off going to the dentist until they had toothache. Year-1 students were more likely to have this attitude compared to year-3 students. HU-DBI scores were significantly associated with ORI scores (r = 0.315; P< 0.001). The differences in the HU-DBI and ORI scores across the level of education were highly significant. (J. Oral Sci. 43, 49-53, 2001)

Objective. The purpose of this study was to investigate the pathogenicity of Staphylococcus lugdunensis in acute oral infection. Study Design. S lugdunensis was isolated from patients with acute oral infections and from healthy control subjects. Antibiotic susceptibility, in vitro cellular toxicity, in vivo virulence, and hemolytic activity testing and dot blot analysis were performed. The statistical significance of in vitro cellular toxicity was determined by means of analysis of variance. Results. Isolated from the infected patients, S lugdunensis showed resistance to penicillin, ampicillin, methicillin, cephalothin, and clindamycin, exhibited virulence in vivo, and showed δ-like hemolysin activity. Four of the 6 strains of S lugdunensis gave synergistic hemolysis. In dot blot analysis, S lugdunensis showed a positive reaction to the probe of the δ-hemolysin gene in S aureus . Conclusions. The results suggest that S lugdunensis may be a potential pathogen in acute oral infection. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;87:297-302)

Staphylococcus aureus (S. aureus) is one of the most common bacterial pathogens, causing approximately 80% of all cases of osteomyelitis with a broad host range in coagulase-positive staphylococci and is one of the leading causes of infections in oral and maxillofacial regions1, 2. Moreover, the rapidly increasing frequency of antibiotic-resistant bacteria has caused considerable alarm within the dental and medical community3, 4. Infections associated with this organism are extremely common and often life threatening; therefore, there is serious potential for S. aureus to cause increased morbidity and mortality in oral and maxillofacial regions3-6. To cause the infection, the bacteria do the followings: adhere and enter the host, multiply on or in the host tissues, resist host defences, and damage the host. All four processes must be accomplished in order to produce an infectious disease, and each is complex, involving several determinants. Bacterial attachment and penetration into underlying tissues play an important role in the initiation of infection. Some bacteria may penetrate tissue surfaces by producing lytic substances that break down the tissue surface, easing penetration to the deeper tissues, and other bacteria can penetrate through epithelial cells. It is likely that a variety of mechanisms are used by different organisms to penetrate the various tissue surfaces that they use as their portal of entry7. However lately, many authors have demonstrated the capability of the bacteria to attach on and invade the internal space of non-phagocytic eukaryotes8-13. On the other hand, it has been suggested that the continuous process of actin filament elongation provides the driving force for bacterial propulsion in infected cells or cytoplasmic extracts14-16. Several unrelated intracellular bacterial pathogens, including Listeria monocytogenes (L. monocytogenes), Shigella flexneri, Rickettsiae and Vaccinia virus, are known to share the ability to use actin polymerization as a driving force for intracellular movement, cell-to-cell spread and dissemination within infected tissues. While S. aureus has not traditionally been considered to be an intracellular pathogen, previous studies have revealed that S. aureus may be actively internalized by phagocytosis and are capable of intracellular survival in epithelial and endothelial cells17, 18. It has also been suggested that S. aureus interact with or binds to the cell surface of bovine

Some therapeutic agents and medicines such as phenytoin(PHT), nifedipine and cyclosporine may lead to adverse effects causing pathologic changes in tissue, especially on the gingivae1-8). The common histological finding is a marked gingival hyperplasia, with proliferation of gingival fibroblasts and an increase of collagen fibers in connective tissue. PHT-induced human gingival overgrowth may be genetically programmed for increased synthesis of collagen9). PHT-induced gingival overgrowth was preceded by the inflammation of gingivae10-11). Previous studies reported that PHT, nifedipine and cyclosporine increased the cell activity of human gingival fibroblasts12-17). Some differentiation factors such as glycyrrhetinic acid(GA), retinoic acid, ursolic acid and oleanolic acid inhibited18-25). Previous studies reported that GA inhibited intercellular communication between human fibroblasts26-27). Glycyrrhizin(GL), a major component of licorice (Glycyrrhiza glabra L.), is ingested orally as a sweetener or as an ingredient in oriental medicine. GL has a steroid-like action and anti-viral activity (Pompei et al., 1979). Indeed, use of GL to treat chronic viral hepatitis has shown that it can reduce hepatocellular injury by immunopathologic mechanisms and hepatotoxins, possibly through its ability to inhibit phospholipase A2 activity preventing liver lysosome labilization29-30). GL is metabolized to GA, and then 3-epi-18-GA via 3-keto-18-GA by human intestinal flora31). GA shows pronounced antiinflammatory activity and anti-estrogenic action via alteration of cortisol metabolism32-35). GA inhibits the growth and stimulates melanogenesis in cultured melanoma cells36). There are many reports about the use of differentiation factors for the resolution of uncontrolled growth such as in tumors, but there are few report about its use in the dental field including gingival hyperplasia. The purpose of this study was to investigate the 대한치주과학회지 : Vol. 28, No. 3, 1998

China is geographically located in the east of Asia and its population exceeds 1.3 billion. An understanding of dental education in China is thus of interest. However, as there is little published information on this topic, this paper provides information about China regarding its dental history, dental school system including curriculum and dental licensure. High school graduates take a nationwide entrance examination to apply for dental school, of which there are more than 50 in China. A five year dental education leads to the BDS degree. Dental school graduates must then pass the nationwide licensure examination to practise dentistry. Currently, there are not adequate numbers of dentists to provide the necessary oral health care for people living outside metropolitan areas.