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FimH is the adhesin of type I fimbriae expressed on Escherichia coli that can mediate specific adherence to host cells. High binding mutations in FimH are related to the adaptive evolution of bacteria. However, additional roles that these allelic variations may play remain elusive. To investigate novel biological functions of the mutations in FimH, we introduced four different variants of FimH by incorporating single amino acid substitutions at specific sites, namely A25P, G73R, A106, and T158P, respectively. In this study, adjuvant potential of FimH variants was evaluated by investigating their ability to trigger innate immune response to DC2.4 and adaptive immunity to improve immunological characteristics. The data revealed that purified A106 and T158P up-regulated the expression of co-stimulatory molecules critically involved in DC2.4 activation by interaction with TLR4, whereas A25P and G73R did not induce the phenotypic maturation of DC2.4. Besides, the culture of DC2.4 with A106 and T158P enhanced the release of cytokines and protein phagocytosis. When formulated with PAc, T158P elicited more robust PAc-specific IgG and IgA antibody responses compared to PBS, PAc and PAc+K12 groups and inhibited bacteria colonization. Collectively, the results confirmed that the T158P mutation located around the inter-domain interface of the protein induced a specific enhancement effect on adjuvant characteristics.

Objective To investigate whether intragastric administration of 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ) could inhibit the bone resorption and inflammation in a mouse calvarial model infected by Porphyromonas gingivalis ( P. gingivalis ). Design Live P. gingivalis ATCC 33277 was injected once daily for 6 days into the subcutaneous tissue overlying the calvaria in mice. At the same time, 1,25(OH) 2 D 3 (50 μg/kg per day) was administered by gavage for 9 days, starting 3 d before the infection. Mice were killed under ether anesthesia 8 h after the last injection of P. gingivalis . Micro-computed tomography scanning was used to evaluate calvarial bone loss. Tartrate-resistant acid phosphatase was used to detect osteoclast activity. Real-time PCR was used to assess the mRNA expressions of OPG, RANKL, c-Fos, NFATc1, CTSK and TRAP in calvarial bone and IL-6, IL-10, IL-1β, IL-12p40 and TNF-α in soft tissue. The levels of serum IL-6, IL-10 were determined by ELISA. Results 1,25(OH) 2 D 3 treatment apparently attenuated bone resorption in P. gingivalis -induced mouse calvarial model and markedly reduced the number of osteoclasts. The expression levels of RANKL and osteoclast-related genes such as c-Fos, NFATc1, CTSK and TRAP were also decreased by 1,25(OH) 2 D 3 . Besides, 1,25(OH) 2 D 3 inhibited the expression of pro-inflammatory cytokines IL-6, IL-12p40 and TNF-α and enormously elevated the expression of anti-inflammatory cytokine IL-10. Conclusion 1,25(OH) 2 D 3 may decrease bone resorption in vivo via suppressing the expression of osteoclast-related genes and its anti-inflammatory properties.

The aim of this article was to present a right maxillary second molar with an unusual root canal morphology of 4 roots and 5 canals as confirmed by cone-beam computed tomographic (CBCT) imaging. The tooth had a C-shaped mesiobuccal root (CBCT imaging revealed that the root was closer to the palate than the buccal side) with 2 canals, 2 fused distobuccal roots with 2 separate canals, and 1 normal bulky palatal root with 1 canal. After thoroughly examining the rare anatomy, root canal treatment was applied on the tooth. This article shows the complexity of maxillary second molar variation and shows the significance of CBCT imaging in the confirmation of the 3-dimensional anatomy of teeth and endodontic treatment.

Toll-like receptors (TLR) and the receptor for interleukin-1 (IL-1R) signaling play an important role in bacteria-mediated bone loss diseases including periodontitis, rheumatoid arthritis, and osteomyelitis. Recent studies have shown that TLR ligands inhibit the receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation from un-committed osteoclast precursors, whereas IL-1 potentiates RANKL-induced osteoclast formation. However, IL-1R and TLR belong to the same IL-1R/TLR superfamily, and activate similar intracellular signaling pathways. Here, we investigate the molecular mechanisms underlying the distinct effects of IL-1 and Porphyromonas gingivalis lipopolysaccharide (LPS-PG) on RANKL-induced osteoclast formation. Our results show that LPS-PG and IL-1 differentially regulate RANKL-induced activation of osteoclast genes encoding Car2, Ctsk, MMP9, and TRAP, as well as expression of NFATc1, a master transcription factor of osteoclastogenesis. Regulation of osteoclast genes and NFATc1 by LPS-PG and IL-1 is dependent on MyD88, an important signaling adaptor for both TLR and IL-1R family members. Furthermore, LPS-PG and IL-1 differentially regulate RANKL-costimulatory receptor OSCAR (osteoclast-associated receptor) expression and Ca(2+) oscillations induced by RANKL. Moreover, LPS-PG completely abrogates RANKL-induced gene expression of B lymphocyte-induced maturation protein-1 (Blimp1), a global transcriptional repressor of anti-osteoclastogenic genes encoding Bcl6, IRF8, and MafB. However, IL-1 enhances RANKL-induced blimp1 gene expression but suppresses the gene expression of bcl6, irf8, and mafb. Our study reveals the involvement of multiple signaling molecules in the differential regulation of RANKL-induced osteoclastogenesis by TLR2 and IL-1 signaling. Understanding the signaling cross-talk among TLR, IL-1R, and RANK is critical for identifying therapeutic strategies to control bacteria-mediated bone loss.

The properties of continuous wave (CW) and Q-switching on the diode-pumped Nd,Y:CaF2 disordered crystal were demonstrated around 1 μm in this paper. Using the different cavity lengths, we measured the output properties of CW of Nd,Y:CaF2 disordered crystal. Then based on Cr4+:YAG as the saturable absorber, the Q-switched pulse characteristics of this novel disordered crystal were researched for the first time. The maximum average output power of 120 mW and the shortest pulse width of 132 ns were obtained at the pulse repetition rate of 6.2 kHz.

Oral squamous cell carcinoma (OSCC) is a common human malignant tumor with high mortality. So far, the molecular pathogenesis of OSCC remains largely unclear. Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is an important multi-function splicing factor and closely related to tumorigenesis. hnRNP A1 is overexpressed in various tumors, and promotes aerobic glycolysis and elongation of telomere, but the function of hnRNP A1 in cell cycle and proliferation remains unclear. We found that hnRNP A1 was overexpressed in OSCC tissues, and was required for the growth of OSCC cells. Moreover, hnRNP A1 was highly expressed in the G2/M cell cycle phase. Knockdown of hnRNP A1 induced G2/M arrest. DNA microarray assay result showed that hnRNP A1 regulated the expression of a number of target genes associated with G2/M phase. Moreover, hnRNP A1 controlled the alternative splicing of CDK2 exon 5. These findings suggested that hnRNP A1 plays key roles in the regulation of cell cycle progression and pathogenesis of OSCC.

The purpose of this study was to determine the relationships among early childhood caries (ECC), root caries (RC), the quantity of Streptococcus mutans in saliva, and the concentrations of total and specific secretory IgA (sIgA). Saliva samples were collected from 70 children, 3-4 yr of age, with and without ECC, and from 43 adults, ≥60 yr of age, with and without RC. The decayed, missing, and filled teeth (dmft) and decayed, missing, and filled surfaces (dmfs) scores of each child, and the root decayed and filled teeth (RDFT) and root decayed and filled surfaces (RDFS) scores of each elderly subject, were determined. The S. mutans levels, total sIgA, and specific sIgA against two virulence antigens of S. mutans in saliva were analysed using quantitative real-time PCR (qPCR) and ELISAs. The quantity of S. mutans was significantly higher in caries-positive subjects within the two populations than in the caries-free subjects; and a positive correlation was found between the quantity of S. mutans and the dmft, dmfs, RDFT, and RDFS scores. In addition, the salivary total sIgA was significantly higher in children with severe early childhood caries (SECC) and in the elderly subjects with RC. Moreover, although the S. mutans level was significantly higher, the concentrations of specific sIgA against S. mutans antigens were significantly lower in samples from elderly subjects than in samples from children. These results support the concept that S. mutans is positively associated with ECC and RC. Furthermore, the levels of S. mutans-specific antibodies in saliva are too low to prevent infection with cariogenic bacteria and to inhibit development of ECC and RC.

Introduction Dental papilla cells (DPCs) are precursors of odontoblasts and have the potential to differentiate into odontoblasts. Osteoblasts and odontoblasts have many common characteristics. Osterix (Osx) is essential for osteoblast differentiation. However, no information is available for the effects of Osx on the odontoblastic differentiation of DPCs. The purpose of this study was to investigate the effects of Osx on the proliferation and odontoblastic differentiation of DPCs. Methods An immortalized human dental papilla cell (hDPC) line was used. Osx was stably overexpressed or knocked down in hDPCs with infection of lentiviral particles to determine its biological effects on hDPCs. The proliferation of cells was measured by the 5-ethynyl-2′-deoxyuridine incorporation assay and direct cell counting. Expressions of dentin sialophosphoprotein, nestin, dentin matrix protein 1, and alkaline phosphatase were detected by real-time polymerase chain reaction to determine the odontoblastic differentiation of cells. The mineralization ability of cells was evaluated by von Kossa staining and alkaline phosphatase activity assay. Results Overexpression of Osx retarded the proliferation of hDPCs, whereas knockdown of Osx increased the cell proliferation. Overexpression of Osx promoted the odontoblastic differentiation of hDPCs by up-regulating odontoblastic differentiation genes and increased the mineralization ability of hDPCs. Knockdown of Osx down-regulated odontoblastic differentiation genes and decreased the mineralization ability of hDPCs. Conclusions Osx might function as a potential regulator for the proliferation and odontoblastic differentiation of hDPCs.

Dlx3 is essential for osteoblast differentiation and bone formation, and its expression is regulated by bone morphogenetic protein-2 (BMP-2). However, the intimate mechanism of BMP-2 regulation of Dlx3 transcription in osteoblasts is still unknown. Considering the important roles of Smad5 and p38 in osteoblast differentiation, we hypothesized that Smad5 and p38 mediated BMP-2-induced Dlx3 transcription in osteoblasts. We found activation of Smad5 and p38 increased the expression of Dlx3, whereas knocking down Smad5 or inactivation of p38 inhibited BMP-2-induced Dlx3 expression. Both Smad5 and p38 were able to activate Dlx3 promoter activity and p38/Smad5 response elements were located from −698 to −368 in Dlx3 promoter. Two Smad5 binding sites (SBEI and SBEII, TGTCT box) were identified in this region by EMSA and ChIP assay. Deletions and mutagenesis study of the Dlx3 promoter region indicated that the TGTCT boxes are crucial for p38/Smad5-induced Dlx3 promoter activity. At last, we found a cross-talk between p38 and Smad5, and that activation of p38 is necessary for BMP-2-induced Smad5 phosphorylation and nuclear translocation. Overall, we provide a novel insight that BMP-2-induced Dlx3 expression is regulated by p38/Smad5 signaling pathway in osteoblasts. J. Cell. Physiol. 229: 943–954, 2014. © 2013 Wiley Periodicals, Inc.

This study examined the adhesive strength of two self-adhesive methacrylate resin-based sealers (MetaSEAL and RealSeal SE) to root dentin and compared them with RealSeal and AH Plus in properties. A total of 48 extracted human single-rooted teeth were used to prepare the 0.9-mm thick longitudinal tooth slice (each per tooth). Standardized simulated canal spaces of uniform dimensions were prepared in the middle of radicular dentin. After treated with 5.25% sodium hypochlorite (NaOCl) and 17% EDTA, tooth slices were allocated randomly to four groups (n=12) in terms of different sealers used: MetaSEAL, RealSeal SE, RealSeal, and AH plus groups. The simulated canal spaces were obturated with different sealers in each group. There were 10 slabs with 20 simulated canal spaces (n=20) used in each group for push-out testing. The failure modes and the ultrastructures of fractured sealer-dentin interfaces were examined. The remaining 2 slabs in each group underwent partial demineralization for observation of the ultrastructure of resin tags. The results showed that the push-out bond strength was 12.01±4.66 MPa in MetaSEAL group, significantly higher than that in the other three groups (P0.05). Moreover, no statistically significant differences were noted in the push-out bond strength between RealSeal SE (5.43±3.68 MPa) and AH Plus (7.34±2.83 MPa) groups and between RealSeal SE and RealSeal (2.93±1.76 MPa) groups (P0.05). Mixed failures were predominant in the fractured sealer-dentin interfaces in MetaSEAL and AH Plus groups, while adhesive failures were frequently seen in RealSeal SE and RealSeal groups. In conclusion, after complete removal of the smear layer, MetaSEAL showed superior bond ability to root dentin. The RealSeal SE is applicable in clinical practice, with its adhesive strength similar to that of AH Plus. The self-adhesive methacrylate resin-based sealer holds promise for use in endodontic treatment.

The aim of this study was to test the hypothesis that the conventional restorative treatment (CRT) and the atraumatic restorative treatment (ART) protocols, in comparison with the ultra-conservative treatment (UCT) protocol, would increase the quality of life of children over a period of 1 year. Cavitated primary molars of 302 children 6–7 years of age were treated according to the CRT, ART and UCT protocols at the school compound. Children’s parents completed the Brazilian version of the Early Childhood Oral Health Impact Scale (B-ECOHIS) at baseline and one year later. Paired t-test, Chi-square test and anova were applied in analysing the data. Questionnaires from 277 and 160 children were collected at baseline and after 1 year, respectively. A statistically significant difference in B-ECOHIS scores over the 1-year period was found for domains ‘child symptoms’ (P = 0.03) and ‘child psychology’ (P = 0.02). Treatment protocols did not statistically significantly influence the changes in B-ECOHIS scores over the 1-year period (P = 0.78). It can be concluded that the UCT protocol was as good as the two restorative protocols. All treatment protocols were effective in reducing children’s experience of pain, their sleeping problems and their irritability and/or frustration levels over the 1-year period.

We previously demonstrated that an anti-caries DNA vaccine intranasally administered with recombinant flagellin protein as a mucosal adjuvant enhanced salivary IgA response and conferred better protection against caries. However, the relatively weak immunogenicity of DNA vaccines and the necessity for a large quantity of antigens remain significant challenges. Here, we fused the flagellin derived from E. coli (KF) and target antigen PAc containing the A-P fragment of PAc from S. mutans (rPAc) to produce a single recombinant protein (KF-rPAc). The abilities of KF-rPAc to induce rPAc-specific mucosal and systemic responses and protective efficiency against caries following intranasal immunization were compared with those of rPAc alone or a mixture of rPAc and KF (KF + rPAc) in rats. Results showed that KF-rPAc promoted significantly higher rPAc-specific antibodies in serum as well as in saliva than did an equivalent dose of rPAc alone or a mixture of KF + rPAc. Intranasal immunization of 8.5 µg KF-rPAc could achieve 64.2% reduction of dental caries in rats. In conclusion, our study demonstrated that flagellin and PAc fusion strategy is promising for anti-caries vaccine development, and KF-rPAc could be used as an anti-caries mucosal vaccine.

Background: The aim of this study was to validate the micro-CT and related software against the section method using the stereomicroscope for marginal leakage assessment along the sealant-enamel interface. Methods: Pits and fissures of the occlusal surface of 10 teeth were sealed with a resin-fissure sealant material without acid etching, thermocycled for 5000 cycles, immersed in 50% silver nitrate for three hours and scanned using micro-CT. Teeth were embedded in epoxy resin and cut in three sections. The middle section was subjected to micro-CT and stereomicroscopy. Images were taken from the left and right sides of the sealant-enamel interface at both the left and the right site of the section. Two experienced evaluators assessed marginal leakage. Results: Both assessment instruments observed no leakage in 37 out of the 40 images evaluated. Leakage at the sealant-enamel interface was observed in three stereomicroscopy images only. A fracture line in the sealant was seen on eight stereomicroscopy images and observed in only two micro-CT images. Conclusions: The quality of the micro-CT and related software used in the present study does not qualify it to replace the section method as the gold standard for marginal leakage assessment at the sealant-enamel interface of permanent teeth.

In this study, porous chitosan/collagen scaffolds were prepared through a freeze-drying process, and loaded with the plasmid vector encoding human bone morphogenetic protein-7 (BMP-7) gene. To investigate the feasibility and efficacy of this gene-activated scaffold on dental tissue engineering, human dental pulp stem cells (DPSCs) were seeded in this scaffold for in vitro and in vivo study. In vitro results indicated that cells can be transfected successfully by loaded plasmid and secrete BMP-7 until day 24. Evaluation of DNA content, ALP activity, calcium content, SEM, and real-time PCR revealed that cells on gene-activated scaffold showed better proliferation properties and odontoblastic differentiation behaviors than cells on pure scaffolds. Then, these cell-scaffold complexes were implanted subcutaneously and retrieved after 4 weeks for histology evaluation. In vivo results that gene-activated scaffold group could still trace the existence of tranfected cells at week 4 and showed the upregulated expression of DSPP compared to pure scaffold groups. On the basis of our results, chitosan/collagen-loaded BMP-7 DNA appears to be an effective substrate candidate for gene delivery and indeed enhanced DPSCs differentiation toward an odontoblast-like phenotype in vitro and in vivo. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.

Item does not contain fulltext OBJECTIVES: The aim of the present study was to investigate the caries-preventive effect of sealants produced with a high-viscosity glass-ionomer with an elevated powder-liquid ratio (ART), of having energy added to this glass-ionomer, and that of glass-carbomer, in comparison to that of resin composite sealants. METHODS: The randomized controlled trial covered 407 children, with a mean age of 8 years. At a school compound three dentists placed sealants in pits and fissures of high caries-risk children. Evaluation by two independent evaluators was conducted after 0.5, 1 and 2 years. The Kaplan-Meier survival method, ANOVA and t-test were used in analyzing the data. RESULTS: 1352 first permanent molars were sealed. 6.6% of children and 6.8% of sealants dropped out within 2 years. 27 re-exposed pits and fissures, 20 in occlusal and 7 in smooth surfaces, in 25 children, developed a dentin carious lesion. The cumulative survival of dentin carious lesion-free pits and fissures in the glass-carbomer sealant group was statistically significantly lower (97.4%) than those in the high-viscosity glass-ionomer with energy supplied (99%) and the resin-composite (98.9%) sealant groups. There was no statistically significant difference in the cumulative survival of dentin carious lesion-free pits and fissures, between the high-viscosity glass-ionomer with (99%) and without (98.3%) energy supplied sealant groups, after 2 years. SIGNIFICANCE: The survival of dentin carious lesion-free pits and fissures was high in all sealant types. More dentin carious lesions were observed in the glass-carbomer sealant group. 01 mei 2012

Directing antigens to antigen presenting cells (APCs) has been demonstrated to be an efficient strategy to enhance immune responses induced by DNA vaccination. Fusion of antigens to cytotoxic T-Lymphocyte antigen 4 (CTLA4), a ligand of B7 molecules on the surfaces of APCs with strong binding affinity, enhanced the immunogenicities of antigens in various degrees. To investigate the relationship between antigen size and the immunogenicity of CTLA4 fusion DNA vaccine, we constructed CTLA4 targeted fusion anti-caries DNA vaccines containing different size of antigens. In vivo and in vitro experiments showed that CTLA4 fusion with smaller antigen induced stronger humoral immune responses and had higher affinity to B7-expressed cells than fusion with larger antigen. In conclusion, antigen size is one of the important factors regulating the potency of humoral immune response induced by CTLA4 targeted DNA vaccines.

J Oral Pathol Med (2011) 40: 643–650 Background: Beta-catenin is one of the key components of Wnt signaling pathway. Increased level of this protein has been proved to be associated with enhanced cellular proliferation and the development of many kinds of cancers. But its role in the carcinogenesis in human tongue squamous cell carcinoma, one of the most common carcinomas of the human oral cavity, remains poorly characterized. Methods: In this study, we used lentivirus-mediated RNA interference (RNAi) targeted against beta-catenin to determine the effects of decreasing the high constitutive level of this protein in human tongue carcinoma cell line Tca8113. Results: Our studies demonstrated that RNAi directly against beta-catenin markedly decreased beta-catenin gene expression and inhibited cellular proliferation as reflected in the reduced growth of tongue cancer cells both in vitro and in nude mice. Conclusions: RNA interference (RNAi) targeting against beta-catenin can induce cell growth suppression of tongue cancer and may have the potential as a therapeutic modality to treat human tongue cancer.

With a reflective single-walled carbon nanotube as the saturable absorber, a laser diode-pumped passively mode-locked Nd:YVO4 laser at 1064 nm was realized for the first time. The pulse duration of 12 Ps was produced with a repetition rate of 83.7 MHz. The peak power and the single pulse energy of the mode-locking laser were 1.28 kW and 15.4 nJ, respectively. (C) 2014 Elsevier GmbH. All rights reserved.

Although Porphyromonas gingivalis lipopolysaccharide (P-LPS) is known to inhibit osteoblast differentiation, the exact molecular mechanisms underlying this phenomenon remain unclear. Here, we investigated the role of Notch signaling in the osteoblastic differentiation of both MC3T3E-1 cells and primary mouse bone marrow stromal cells (BMSCs). P-LPS stimulation activated the Notch1 signaling cascade and increased expression of the Notch target genes HES1 and HEY1. P-LPS can also act as an inhibitor because it is capable of suppressing Wnt/beta-catenin signaling in preosteoblasts by decreasing both glycogen synthase kinase-3 beta (GSK-3 beta) phosphorylation and the expression of nuclear p-catenin. These effects were rescued, however, by inhibiting Notch1 signaling. Furthermore, P-LPS treatment inhibited osteoblast differentiation in preosteoblasts as demonstrated by reductions in alkaline phosphatase activity, osteoblast gene expression, and mineralization, all of which were rescued by suppression of Notch1 signaling. Moreover, inhibition of GSK-3 beta, HES1, or HEY1 partially reversed the P-LPS-induced inhibition of osteoblast differentiation. Together, these findings suggest that P-LPS inhibits osteoblast differentiation by promoting the expression of Notch target genes and suppressing canonical Wnt/beta-catenin signaling. J. Cell. Physiol. 225: 106-114, 2010. (C) 2010 Wiley-Liss, Inc.

Background The cytotoxic T lymphocyte antigen 4 (CTLA4) represents an attractive ligand for use in the targeting of antigens to dendritic cells (DCs). Studies have shown that CTLA4 targeted DNA vaccines induced accelerated and increased antibody responses compared to nontargeted vaccines. However, little is known about the molecular events on DCs after transfection with targeted DNA vaccines. Methods Here we constructed a green fluorescent protein (GFP)-labeled targeted anti-caries plasmid pMGJGLU/GFP and a GFP-labeled nontargeted anti-caries plasmid pCDGLU/GFP, compared the antibody responses they induced in mice, and investigated the gene expression profiles of DCs transfected with pMGJGLU/GFP and pCDGLU/GFP by gene array analysis. Results The data obtained showed that pMGJGLU/GFP induced accelerated and increased serum antibody responses in mice compared to pCDGLU/GFP. Overall, the expression levels of 28 genes were up-regulated in pMGJGLU/GFP transfected DCs compared to pCDGLU/GFP transfected DCs by gene array analysis. Real-time reverse transcriptase-polymerase chain reaction analysis on pMGJGLU/GFP transfected DCs and pCDGLU/GFP transfected DCs confirmed the up-regulation of the mRNA expression levels of seven selected genes. Notably, we identified the specific up-regulation of mRNA expression levels of cytokines Ccl17, Ccl19, and antigen presentation receptor Cd209a of pMGJGLU/GFP transfected DCs, suggesting a more rapid migration of DCs to lymph nodes and a T helper 2 biased immune response. Conclusions In the present study, we confirmed our previous reports that CTLA4 targeted DNA vaccines could induce increased antibody responses compared to nontargeted vaccines. Ccl17, Ccl19 and Cd209a may play an important role in the enhanced immune responses. Copyright © 2009 John Wiley & Sons, Ltd.

Previously, in vitro differentiation of odontoblasts was shown for dental pulp stem cells (DPSCs) transfected with bone morphogenetic protein-2 ( Bmp2). For this study, we hypothesized that such cells also show potential for mineralized tissue formation in vivo. DPSCs were transfected with Bmp2 and seeded onto a ceramic scaffold. These complexes were cultured in medium without dexamethasone, and thereafter placed subcutaneously in nude mice for 1, 4, and 12 weeks. Samples were evaluated by histology and real-time PCR for osteocalcin, bone sialoprotein, dentin sialophosphoprotein, and dentin matrix protein 1. Results indicated that only the transfected DPSCs showed obvious mineralized tissue generation, and 12 weeks of implantation gave the highest percentage of mineralized tissue formation (33 ± 7.3% of implant pore area). Real-time PCR confirmed these results. In conclusion, Bmp2-transfected DPSCs effectively show mineralized tissue formation upon ectopic implantation.

Our previously prophylactic studies have proved that the anti-caries DNA vaccine pGJA-P/VAX could generate effective immune response by intramuscular (i.m.) and intranasal (i.n.) administration in rats without caries. In the present, we determine whether it also could produce efficacy in rats with caries. By immunized with pGJA-P/VAX, rats were elicited both significantly higher anti-Streptococcus mutans serum IgG and salivary SIgA responses, compared to those with pVAX1. Correspondingly, rats immunized with pGJA-P/VAX via i.n. displayed significantly fewer enamel, dentinal lesions compared to those with pVAX1 via i.n. However, there was no significant difference in dental caries lesions between pGJA-P/VAX (i.m.) and pVAX1 (i.m.). These findings suggest that DNA vaccination via i.n., with bupivacaine delivery system, could be a promising alternatives for slowing down caries development in rat models.

Introduction The general secretory (Sec) pathway is the main pathway for protein transport. Sortase A has been shown to anchor surface protein containing an LPXTG motif to the cell wall. In order to know the distribution pattern of the Sec translocons and sortase A in Streptococcus mutans , we explored the subcellular localisation of SecA and sortase A. Methods The anti-SecA antibody and anti-sortase A antibody were examined on Western blots to evaluate specificities. An indirect post-embedding immunogold method was used to determine the subcellular localisation of the Sec pathway and sortase A enzyme in S. mutans membrane. Results Immunoblotting experiments showed that the anti-SecA antibody and anti-sortase A antibody specifically recognised a single band of about 95 kDa and 27 kDa, respectively in the S. mutans GS-5 cell lysates. Immunogold electron micrographs showed that small and large gold particles clustered together at a distinct microdomain. Conclusions These data showed for the first time that Sec translocase and sortase A colocalised to a single locus in the cytoplasmic membrane of S. mutans GS-5.

Temperature-responsive polymers are attractive candidates for applications related to injectable delivery of biologically active therapeutics. In this study, a novel approach to provide thermally sensitive neutral solutions based on chitosan/carboxymethyl cellulose (Ch/CMC) combinations is described. The potential of thermosensitive Ch/CMC as a biomaterial is evaluated for the culture of chondrocytes, with the goal of using the Ch/CMC polymer as an injectable matrix/cell therapeutic. These formulations possess a physiological pH and can be held as liquid below room temperature for encapsulating living cells. At body temperature they form monolithic gels, thus injected in vivo, the liquid formulations turn into gel implants in situ. The sols/gels have been thoroughly characterized for rheology and morphology analysis. The use of Ch/CMC aqueous solutions as gelling systems is a new discovery of a new family of thermosetting gels highly compatible with biological compounds.

Background:Porphyromonas gingivalis, a major periodontopathic bacterium, is necessary for periodontitis to take place. The lipopolysaccharide (LPS) of P. gingivalis stimulates cytokine secretion in immune cells, and thereby initiates the inflammation related to periodontitis. Macrophages are the important ones of the immune cells that are prominent at inflammatory periodontal sites. Curcumin, a major curcumanoid found in the spice turmeric, exhibits anti-inflammatory properties. The aim of this study was to investigate the anti-inflammatory effect and the mechanism of action of curcumin in macrophages stimulated by P. gingivalis LPS. Methods: RAW264.7 cells pre-treated with various concentrations of curcumin were stimulated by P. gingivalis LPS. TNF-α and IL-1β expressions were separately detected by RT-PCR and ELISA. Next, activation of NF-ĸB-dependent transcription was examined by luciferase assay. Results: Curcumin dose-dependently inhibited TNF-α and IL-1β gene expression and protein synthesis in RAW264.7 cells stimulated with P. gingivalis LPS. P. gingivalis LPS activated NF-ĸB-dependent transcription in RAW264.7 cells, which were down-regulated by pre-treatment with curcumin as well. Conclusion: Our data suggest that curcumin can inhibit P. gingivalis LPS-induced cytokine expression, and that this could be due to the inhibition of the NF-ĸB pathway.

Contains fulltext : 53134.pdf (Publisher’s version ) (Closed access) OBJECTIVES: Hereditary gingival fibromatosis (HGF) is characterized by excess accumulation of interstitial collagen. However, until now, there has been controversy about the mechanism of collagen accumulation in HGF gingivae. The present study aimed to clarify the pathogenic mechanisms potentially involved. DESIGN: Gingival fibroblasts from three Chinese HGF patients and three healthy subjects were cultured. Cell proliferation was assessed by MTT assay. The mRNA levels of type I collagen, MMP-1, MMP-3, TIMP-1, prolyl 4-hydroxylase (P4H)alpha(I), alpha(II), alpha(III) and P4Hbeta were analyzed in gingival fibroblasts by RT-PCR. The protein production of type I collagen and P4H was examined respectively by ELISA and Western blot. RESULTS: In culture, HGF gingival fibroblasts showed similar growth characteristics to fibroblasts isolated from control gingivae. The mRNA and protein levels of type I collagen and P4Halpha in HGF fibroblasts were higher than those in controls. There were no detected differences in mRNA expression levels of MMP-1, MMP-3, TIMP-1, P4Halpha(II), alpha(III) and P4Hbeta between HGF and control fibroblasts. CONCLUSIONS: These data suggest that increased collagen post-translational modification by P4H may be one mechanism by which increased collagen accumulation occurs in some forms of HGF.

Novel polyelectrolyte complex (PEC) chitosan/carboxymethyl cellulose (CMC) scaffolds are prepared using a freeze-dry process. The microstructure is characterized by SEM and the average pore diameters and internal porosities are calculated. The morphology and distribution of pulp cells on these three-dimensional scaffolds are investigated by SEM and confocal laser scanning microscopy (CLSM). The expression of osteonectin (ON) and dentin sialophosphoprotein (DSPP) is detected by reverse transcription polymerase chain reaction (RT-PCR). The scaffolds are then implanted subcutaneously into BALB/c mice. The addition of CMC to chitosan decreases the pore diameter and increases internal porosity. The pulp cells co-cultured in these PEC scaffolds show improved adhesion, spreading, cell capacity, and three-dimensional configurations compared to pure chitosan scaffolds. Based on the data obtained, the chitosan/CMC complex provides an improved scaffold material for pulp tissue engineering.

Most manifestations of candidiasis are associated with biofilm formation occurring on the surfaces of host tissues and medical devices. Candida albicans is the most frequently isolated causative pathogen of candidiasis, and the biofilms display significantly increased levels of resistance to the conventional antifungal agents. Eugenol, the major phenolic component of clove essential oil, possesses potent antifungal activity. The aim of this study was to investigate the effects of eugenol on preformed biofilms, adherent cells, subsequent biofilm formation and cell morphogenesis of C. albicans. Eugenol displayed in vitro activity against C. albicans cells within biofilms, when MIC(50) for sessile cells was 500 mg/L. C. albicans adherent cell populations (after 0, 1, 2 and 4 h of adherence) were treated with various concentrations of eugenol (0, 20, 200 and 2,000 mg/L). The extent of subsequent biofilm formation were then assessed with the tetrazolium salt reduction assay. Effect of eugenol on morphogenesis of C. albicans cells was observed by scanning electron microscopy (SEM). The results indicated that the effect of eugenol on adherent cells and subsequent biofilm formation was dependent on the initial adherence time and the concentration of this compound, and that eugenol can inhibit filamentous growth of C. albicans cells. In addition, using human erythrocytes, eugenol showed low hemolytic activity. These results indicated that eugenol displayed potent activity against C. albicans biofilms in vitro with low cytotoxicity and therefore has potential therapeutic implication for biofilm-associated candidal infections.

The aim of this article is to describe the innovations in the School of Stomatology at Wuhan University (WHUSS) that are likely to shape the future of dental education in the People's Republic of China. There are forty dental schools in China; the five most well known are located in Beijing, Chengdu, Shanghai, Xi'an, and Wuhan. Although patient-centered, comprehensive care has been recommended as the future of dental education, traditional dental education in China still faces many challenges to accomplish this goal. WHUSS, one of the more progressive dental schools in China, has implemented several educational innovations to traditional dental education by restructuring the curriculum through the introduction of problem-based learning (PBL) and other strategies in clinical training. Although implementation of educational innovations is still at an early stage throughout China, it is reasonable to speculate that many schools will develop similar strategies as those developed at Wuhan to improve dental education during the next several years. However, additional research is necessary to evaluate the efficacy of such educational strategies and to determine the appropriate implementation of a contemporary dental curriculum and pedagogic methodology. The curriculum modifications that have been achieved to date as well as the existing challenges are discussed to provide the reader with an understanding of contemporary dental education in China.

Contains fulltext : 53242.pdf (Publisher’s version ) (Closed access) OBJECTIVES: This study aimed to determine whether salivary mutans streptococci (MS) counts in Chinese children had any value in the prediction of new caries in the permanent dentition in the age interval of 6.5-8.5 years. METHODS: Four hundred and thirty-three 6-7-year-old children participated in this 2-year longitudinal study. Salivary MS counts were obtained at baseline with the spatula method. Dentin and enamel caries was recorded at baseline and at the follow-up, 2 years later. Spearman's correlation coefficients were computed. Past caries experience variables at baseline were entered into a multiple regression model with caries increment of the permanent dentition as dependent variable. MS counts were subsequently entered into the model to assess the additional caries predictive value. RESULTS: Spearman's correlation coefficient for MS counts and caries experience of the primary dentition at baseline was 0.48 and for MS counts and caries increment in the permanent dentition 0.12. In the multiple regression model caries increment of the permanent dentition had an adjusted R2 of 0.17 when the past caries experience variables were entered. Adding MS counts in the regression model did not change the R2 value. CONCLUSIONS: Salivary MS counts did not add any caries predictive value when past caries experience variables were used as caries predictors in this Chinese child population.

Contains fulltext : 52440.pdf (Publisher’s version ) (Closed access) The presence of heterogeneous cell populations in dental pulp may count for the considerable variation in the outcome of in vitro and in vivo experiments. Here, we intended to determine whether a minor cell sub-population of high proliferation and odontogenic potential existed among a larger compartment of perhaps more committed progenitors. In this study, the STRO-1 antigen, defining a mesenchymal stem cell or progenitor subpopulation, was used for separating rat dental pulp cells with fluorescence-activated cell sorting (FACS). Subsequently, the STRO-1 positive cells were tested for their ability to differentiate towards an odontoblast-like phenotype. Three cell populations (STRO-1 positive, STRO-1 negative, and non-sorted cells) were cultured in odontogenic medium containing dexamethasone and beta-glycerophosphate. Cultures were analyzed by light- and scanning electron microscopy (SEM), and assessed for proliferation, ALP activity, and calcium content. Results showed that the STRO-1 positive cell population was able to differentiate into the odontoblast phenotype, similar to the non-sorted population. The negative cells however showed a fibroblast-like phenotype. SEM and real-time PCR confirmed such results. In conclusion, the STRO-1 selection proved applicable for rat-derived material, to obtain a cell population which is more homogeneous. This positive cell fraction was capable of differentiating into the odontogenic pathway, whereas the negative fraction was not. However, the effect was not always advantageous, when compared to non-sorted cells.

Contains fulltext : 53235.pdf (Publisher’s version ) (Open Access) Dental pulp stem cells harbor great potential for tissue-engineering purposes. However, previous studies have shown variable results, and some have reported only limited osteogenic and odontogenic potential.Because bone morphogenetic proteins (BMPs) are well-established agents to induce bone and dentin formation,in this study STRO-1-selected rat dental pulp-derived stem cells were transfected with the adenoviral mediated human BMP-2 gene. Subsequently, the cells were evaluated for their odontogenic differentiation ability in medium not containing dexamethasone or other stimuli. Cultures were investigated using light microscopy and scanning electron microscopy (SEM) and evaluated for cell proliferation, alkaline phosphatase(ALP) activity, and calcium content. Real-time polymerase chain reaction (PCR) was performed for gene expression of Alp, osteocalcin, collagen type I, bone sialoprotein, dentin sialophosphoprotein, and dentin matrix acidic phosphoprotein 1. Finally, an oligo-microarray was used to profile the expression of odontogenesis-related genes. Results of ALP activity, calcium content, and real-time PCR showed that only BMP2-transfected cells had the ability to differentiate into the odontoblast phenotype and to produce a calcified extracellular matrix. SEM and oligo-microarray confirmed these results. In contrast, the non-transfected cells represented a less differentiated cell phenotype. Based on our results, we concluded that the adenovirus can transfect STRO-1 selected cells with high efficacy. After BMP2 gene transfection, these cells had the ability to differentiate into odontoblast phenotype, even without the addition of odontogenic supplements to the medium.

The HDAC inhibitor Trichostatin A (TSA) exhibits antiturnour activity in various tumour cells. However, little is known about the effect of TSA on growth of human tongue carcinoma cells. In this study, we observed that TSA concentration-dependently inhibited growth of human tongue carcinoma Tca8113 cells by inducing G2/M arrest, apoptosis, up-regulation of the pro-apoptotic protein Bax and down-regulation of the anti-apoptotic proteins Bcl-2 and Bcl-XL which are regulated by the transcription factor nuclear factor (NF)-kappa B. Coincident with this observation, TSA induced a concentration-dependent reduction of constitutive and tumour necrosis factor (TNF)-alpha-induced NF-kappa B activation in Tca8113 cells. This induction was correlated with decreased phosphorylation and increased expression of inhibitors of NF-kappa B (I kappa B)alpha induced by TSA. Overall, our results indicate inhibition of NF-kappa B activation contributes, at least partially, to the antiturnour activity of TSA in human tongue carcinoma cells. (c) 2006 Elsevier Ltd. All rights reserved.

A 27-year-old patient with an anomalous mandibular molar was referred for endodontic therapy. Clinical and radiographic examination revealed the connation of a second mandibular molar with a third molar. Challenging endodontic therapy was performed in the unusual connated molars. A 2-year recall showed good treatment result.

Dental caries has been an intractable disease in spite of intense dental research. Glucosyltransferase (GTF) enzyme plays the most important role in the development of dental caries. In our previous studies, magnolol, a compound from Magnolia officinalis Rehder et Wilson (Magnoliaceae), was shown to possess a strong anti-GTF activity. The purpose of the present study was to examine the effect of magnolol on the functional domains of GTF for the purpose of defining its anti-GTF activity mechanism. GTF-I which was prepared from Streptococcus milleri transformant KSB8 cells expressing the gtfB gene was used. The results demonstrated magnolol reduced total glucan synthesis, depending on the magnolol concentration. There were no significant differences in Michaelis constant (K(m)) values between the presence and absence of magnolol as determined by Lineweaver-Burk plot, and maximum velocity (V(m)) in the presence of magnolol was lower than that in its absence. Magnolol significantly inhibited both sucrose hydrolysis and glucosyl transfer to glucan by GTF-I. Free glucose in the presence of magnolol was reduced by 33-48% as compared to in its absence, while the quantity of glucan was reduced by 75-82%. These findings suggested that magnolol inhibited both two sequential reaction phases of GTF non-competitively by operating on the glucan-binding domain, but not on the catalytic domain. Magnolol could be a valuable resource for the exploration of novel bioactive compounds in natural products.

Aim To evaluate the accuracy of three different electronic apex locators (EALs) using glass tubules. Methodology Forty-eight glass tubules with different diameters and an agar model were used to mimic root canals. A size 15 stainless steel K-file was used as the measuring electrode. The Root ZX, Propex and Neosono Ultima EZ were used to measure the tubule length with tubules dry, or filled with 0.9% NaCl, 3% H2O2, 2.5% NaOCl or 17% EDTA. The distance between the real length (RL) and measured length (ML) of the tubules was recorded. The range of RL ± 0.5 mm and RL ± 1 mm was used to evaluate the accuracy of the EALs. Results were subject to correlation analysis and Friedman's test. Results In dry tubules, the accuracy of Root ZX was 75–91.7% for RL ± 0.5 mm and 100% for RL ± 1 mm, whilst the measurements of the other two EALs were all within the RL ± 0.5 mm. No influence from the increase in tubule diameter on the accuracy of all three EALs was observed in dry tubules. In tubules filled with electrolyte, the accuracy of the Root ZX decreased as tubule diameter increased (Rd > 0, P