Lipopolysaccharide-mediated ATP signaling regulates interleukin-6 mRNA expression via the P2-purinoceptor in human dental pulp cells

Dental pulp cells play a crucial role in maintaining the balance of the pulp tissue. They actively respond to bacterial inflammation by producing proinflammatory cytokines, particularly interleukin-6 (IL-6). While many cell types release adenosine triphosphate (ATP) in response to various stimuli, the mechanisms and significance of ATP release in dental pulp cells under inflammatory conditions are not well understood. This study aimed to investigate ATP release and its relationship with IL-6 during the inflammatory response in immortalized human dental pulp stem cells (hDPSC-K4DT) following lipopolysaccharide (LPS) stimulation. We found that hDPSC-K4DT cells released ATP extracellularly when exposed to LPS concentrations above 10 μg/mL. ATP release was exclusively attenuated by N-ethylmaleimide, whereas other inhibitors, including clodronic acid (a vesicular nucleotide transporter inhibitor), probenecid (a selective pannexin-1 channel inhibitor), meclofenamic acid (a selective connexin 43 inhibitor), suramin (a nonspecific P2 receptor inhibitor), and KN-62 (a specific P2X7 antagonist), did not exhibit any effect. Additionally, LPS increased IL-6 mRNA expression, which was mitigated by the ATPase apyrase enzyme, N-ethylmaleimide, and suramin, but not by KN-62. Moreover, exogenous ATP induced IL-6 mRNA expression, whereas ATPase apyrase, N-ethylmaleimide, and suramin, but not KN-62, diminished ATP-induced IL-6 mRNA expression. Overall, our findings suggest that LPS-induced ATP release stimulates the IL-6 pathway through P2-purinoceptor, indicating that ATP may function as an anti-inflammatory signal, contributing to the maintenance of dental pulp homeostasis.

Bioactive gelatin-sheets as novel biopapers to support prevascularization organized by laser-assisted bioprinting for bone tissue engineering

Despite significant advances in the management of patients with oral cancer, maxillofacial reconstruction after ablative surgery remains a clinical challenge. In bone tissue engineering, biofabrication strategies have been proposed as promising alternatives to solve issues associated with current therapies and to produce bone substitutes that mimic both the structure and function of native bone. Among them, laser-assisted bioprinting (LAB) has emerged as a relevant biofabrication method to print living cells and biomaterials with micrometric resolution onto a receiving substrate, also called 'biopaper'. Recent studies have demonstrated the benefits of prevascularization using LAB to promote vascularization and bone regeneration, but mechanical and biological optimization of the biopaper are needed. The aim of this study was to apply gelatin-sheet fabrication process to the development of a novel biopaper able to support prevascularization organized by LAB for bone tissue engineering applications. Gelatin-based sheets incorporating bioactive glasses (BGs) were produced using various freezing methods and crosslinking (CL) parameters. The different formulations were characterized in terms of microstructural, physical, mechanical, and biological properties in monoculture and coculture. Based on multi-criteria analysis, a rank scoring method was used to identify the most relevant formulations. The selected biopaper underwent additional characterization regarding its ability to support mineralization and vasculogenesis, its bioactivity potential andin vivodegradability. The biopaper 'Gel5wt% BG1wt%-slow freezing-CL160 °C 24 h' was selected as the best candidate, due to its suitable properties including high porosity (91.69 ± 1.55%), swelling ratio (91.61 ± 0.60%), Young modulus (3.97 × 104± 0.97 × 104Pa) but also its great cytocompatibility, osteogenesis and bioactivity properties. The preorganization of human umbilical vein endothelial cell using LAB onto this new biopaper led to the formation of microvascular networks. This biopaper was also shown to be compatible with 3D-molding and 3D-stacking strategies. This work allowed the development of a novel biopaper adapted to LAB with great potential for vascularized bone biofabrication.

New Implications of Metabolites and Free Fatty Acids in Quality Control of Crossbred Wagyu Beef during Wet Aging Cold Storage

Efficient cold-chain delivery is essential for maintaining a sustainable global food supply. This study used metabolomic analysis to examine meat quality changes during the "wet aging" of crossbred Wagyu beef during cold storage. The longissimus thoracic (Loin) and adductor muscles (Round) of hybrid Wagyu beef, a cross between the Japanese Black and Holstein-Friesian breeds, were packaged in vacuum film and refrigerated for up to 40 days. Sensory evaluation indicated an increase in the umami and kokumi taste owing to wet aging. Comprehensive analysis using gas chromatography-mass spectrometry identified metabolite changes during wet aging. In the Loin, 94 metabolites increased, and 24 decreased; in the Round, 91 increased and 18 decreased. Metabolites contributing to the umami taste of the meat showed different profiles during wet aging. Glutamic acid increased in a cold storage-dependent manner, whereas creatinine and inosinic acid degraded rapidly even during cold storage. In terms of lipids, wet aging led to an increase in free fatty acids. In particular, linoleic acid, a polyunsaturated fatty acid, increased significantly among the free fatty acids. These results provide new insight into the effects of wet aging on Wagyu-type beef, emphasizing the role of free amino acids, organic acids, and free fatty acids generated during cold storage.

Effect of Bioactive Glasses and Basic Fibroblast Growth Factor on Dental Pulp Cells

Ideal regeneration of hard tissue and dental pulp has been reported with the use of a combination of bioactive glass and basic fibroblast growth factor (bFGF). However, no previous study has investigated the molecular mechanisms underlying the processes induced by this combination in dental pulp cells. This study aimed to examine the cellular phenotype and transcriptional changes induced by the combination of bioactive glass solution (BG) and bFGF in dental pulp cells using phase-contrast microscopy, a cell counting kit-8 assay, alkaline phosphatase staining, and RNA sequence analysis. bFGF induced elongation of the cell process and increased the number of cells. Whereas BG did not increase ALP activity, it induced extracellular matrix-related genes in the dental pulp. In addition, the combination of BG and bFGF induces gliogenesis-related genes in the nervous system. This is to say, bFGF increased the viability of dental pulp cells, bioactive glass induced odontogenesis, and a dual stimulation with bioactive glass and bFGF induced the wound healing of the nerve system in the dental pulp. Taken together, bioactive glass and bFGF may be useful for the regeneration of the dentin-pulp complex.

The Pitfall of VA ECMO management in the Impella era

Introduction

VA ECMO is effective in cardiogenic shock, but complications of cardiogenic pulmonary edema due to increased afterload are problematic. The advent of percutaneous left ventricular assist devices (Impella) has enabled effective reduction of left ventricular intraventricular pressure and has avoided these complications, but differential hypoxia can still occur during VA ECMO + Impella (Ecpella) management, requiring conversion to V-AV ECMO. Cases may be experienced.

Purpose

Elucidate the frequency of differential hypoxia and its pathogenesis, which requires the transition from VA ECMO to V-AV ECMO.

Methods

We retrospectively reviewed 52 consecutive patients who underwent E-CPR from January 2017 through November 2021 in our institute. 8 patients who received ECMO alone were excluded, and 44 patients were recruited. 22 patients underwent VA ECMO with IABP (VA ECMO + IABP group) and 22 patients underwent VA ECMO with Impella (VA ECMO + Impella group). The 30-day survival rate and the rate of transition VA ECMO to VA-V ECMO, The date just before VA ECMO to V-AV ECMO were assessed.

Results

The 30-day all-cause mortality was no significant difference between the two groups. 2 patients (9%) in the VA ECMO + IABP group and 8 patients (36%) in the VA ECMO + Impella group were transferred to V-AV ECMO (P=0.025). At the time of addition of V-AV ECMO, SaO2 (right radial artery) was 87±7.1% and 91.3±1.9% (p=0.112) in the VA ECMO + IABP and VA ECMO + Impella groups, respectively, and the P/F ratio was 86±37.1 and 95±24.6 (p=0.685). Mean pulmonary artery wedge pressure was 23±1.4 mmHg in the VA ECMO + IABP group and 16.3±3 mmHg in the VA ECMO + Impella group (p=0.0193), significantly lower in the Impella group.

Conclusion

The Impella group was more likely to have hypoxia due to factors other than cardiogenic pulmonary edema. In cases of cardiopulmonary arrest requiring V-AV ECMO management, differential hypoxia due to causes other than cardiogenic pulmonary edema may become apparent earlier in the Impella group, suggesting that careful management, including the addition of V-AV ECMO, is required.

Funding Acknowledgement

Type of funding sources: None.

Evaluation of New Hollow Sleeve Composites for Direct Post-Core Construction

The preset shape and diameter of a prefabricated FRC post rarely follows the anatomy of the root canal. To solve this problem, a new hollow sleeve composite (HSC) system for post-core construction was developed and characterized. A woven fiber was impregnated with two types of resins: Bis-GMA or PMMA, and rolled into cylinders with outer diameter of 2 mm and two different inner diameters, namely 1.2 or 1.5 mm. The commercial i-TFC system was used as a control. Dual-cure resin composite was injected into these sleeves. Additionally, conventional solid fiber post was used as the inner part of the sleeve. The three-point bending test was used to measure the mechanical properties of the specimens and the fracture surface was examined using an electron microscope (SEM). The HSC (1.5 mm, Bis-GMA) revealed a statistically similar flexural modulus but higher flexural strength (437 MPa) compared to i-TFC (239 MPa; ANOVA, p < 0.05). When a fiber post was added inside, all values had a tendency to increase. After hydrothermal accelerated aging, the majority of specimens showed a significant (p < 0.05) decrease in flexural strength and modulus. SEM fracture analysis confirmed that the delamination occurred at the interface between the outer and inner materials. The HSC system provided flexibility but still high mechanical values compared to the commercial system. Thus, this system might offer an alternative practical option for direct post-core construction.

Odontoblast differentiation is regulated by an interplay between primary cilia and the canonical Wnt pathway

Primary cilium is a protruding cellular organelle that has various physiological functions, especially in sensory reception. While an avalanche of reports on primary cilia have been published, the function of primary cilia in dental cells remains to be investigated. In this study, we focused on the function of primary cilia in dentin-producing odontoblasts. Odontoblasts, like most other cell types, possess primary cilia, which disappear upon the knockdown of intraflagellar transport protein 88. In cilia-depleted cells, the expression of dentin sialoprotein, an odontoblastic marker, was elevated, while the deposition of minerals was slowed. This was recapitulated by the activation of canonical Wnt pathway, also decreased the ratio of ciliated cells. In dental pulp cells, as they differentiated into odontoblasts, the ratio of ciliated cells was increased, whereas the canonical Wnt signaling activity was repressed. Our results collectively underscore the roles of primary cilia in regulating odontoblastic differentiation through canonical Wnt signaling. This study implies the existence of a feedback loop between primary cilia and the canonical Wnt pathway.

Physicochemical Properties, Cytocompatibility, and Biocompatibility of a Bioactive Glass Based Retrograde Filling Material

The ideal retrograde filling material that is easy to handle, has good physicochemical properties, and is biocompatible has not yet been developed. The current study reports the development of a novel bioactive glass based powder for use as a retrograde filling material that is capable of altering the consistency and hardening rate of mixtures when mixed with existing bioactive glass based cement. Furthermore, its physicochemical properties, in vitro effects on human cementoblast-like cells, and in vivo effects on inflammatory responses were evaluated. The surface of the hardened cement showed the formation of hydroxyapatite-like precipitates and calcium and silicate ions were eluted from the cement when the pH level was stabilized at 10.5. Additionally, the cement was found to be insoluble and exhibited favorable handling properties. No adverse effects on viability, proliferation, and expression of differentiated markers were observed in the in vitro experiment, and the cement was capable of inducing calcium deposition in the cells. Moreover, the cement demonstrated a lower number of infiltrated inflammatory cells compared to the other materials used in the in vivo mouse subcutaneous implantation experiment. These findings suggest that the retrograde filling material composed of bioactive glass and the novel bioactive glass based powder exhibits favorable physicochemical properties, cytocompatibility, and biocompatibility.

Effects of Both Fiber Post/Core Resin Construction System and Root Canal Sealer on the Material Interface in Deep Areas of Root Canal

This study aimed to examine the resin polymerization of a fiber post/core resin construction system and the interface between resin and root canal sealers, which are important for root canal sealing. We used the i-TFC Luminus fiber post and i-TFC Luminus LC flow (i-TFC-L), the GC fiber post and Unifil Core EM (GCF), and the FiberKor post and Build-It FR (FKP) as core construction systems, and Nishika Canal Sealer BG (CS-BG), Metaseal Soft (META), and Nishika Canal Sealer EN (CS-EN) as sealers. The light transmission of fiber posts (n = 5), the polymerization of core resin (n = 5), and the adhesion between the sealer and core resin (n = 10) were evaluated. The i-TFC Luminus fiber post light transmission was significantly higher than that of other posts. Without shielding, i-TFC-L showed a significantly greater amount of polymerized resin than the other systems. With shielding, although i-TFC-L showed a significantly greater amount of polymerized resin immediately after light irradiation, polymerized resin was significantly greater in GCF and FKP after 10 min. All systems adhered to CS-BG and META but not to CS-EN. These results indicate that resin polymerization in the cavity differs among fiber post/core resin construction systems and that the adhesion of the resin and sealer depends on the property of the sealer.

A novel inhibitor of NF-κB-inducing kinase prevents bone loss by inhibiting osteoclastic bone resorption in ovariectomized mice

Musculoskeletal diseases and disorders, including osteoporosis and rheumatoid arthritis are diseases that threaten a healthy life expectancy, and in order to extend the healthy life expectancy of elderly people, it is important to prevent bone and joint diseases and disorders. We previously reported that alymphoplasia (aly/aly) mice, which have a loss-of-function mutation in the Nik gene involved in the processing of p100 to p52 in the alternative NF-κB pathway, show mild osteopetrosis with a decrease in the osteoclast number, suggesting that the alternative NF-κB pathway is a potential drug target for ameliorating bone diseases. Recently, the novel NF-κB-inducing kinase (NIK)-specific inhibitor compound 33 (Cpd33) was developed, and we examined its effect on osteoclastic bone resorption in vitro and in vivo. Cpd33 inhibited the receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis accompanied by a decrease in the expression of nfatc1, dc-stamp, and cathepsin K, markers of osteoclast differentiation, without affecting the cell viability, in a dose-dependent manner. Cdp33 specifically suppressed the RANKL-induced processing of p100 to p52 but not the phosphorylation of p65 or the degradation or resynthesis of IκBα in osteoclast precursors. Cpd33 also suppressed the bone-resorbing activity in mature osteoclasts. Furthermore, Cdp33 treatment prevented bone loss by suppressing the osteoclast formation without affecting the osteoblastic bone formation in ovariectomized mice. Taken together, NIK inhibitors may be a new option for patients with a reduced response to conventional pharmacotherapy or who have serious side effects.

A small nuclear acidic protein (MTI-II, Zn2+-binding protein, parathymosin) attenuates TNF-α inhibition of BMP-induced osteogenesis by enhancing accessibility of the Smad4-NF-κB p65 complex to Smad binding element

Pro-inflammatory cytokines prevent bone regeneration in vivo and activation of nuclear factor-κB (NF-κB) signaling has been proposed to lead to suppression of bone morphogenetic protein (BMP)-induced osteogenesis via direct binding of p65 to Smad4 in vitro. Application of a small nuclear acidic protein (MTI-II) and its delivered peptide, MPAID (MTI-II peptide anti-inflammatory drug) has been described to elicit therapeutic potential via strong anti-inflammatory action following the physical association of MTI-II and MPAID with p65. However, it is unclear whether MTI-II attenuates tumor necrosis factor (TNF)-α inhibition of BMP-induced osteogenesis. Herein, we found that TNF-α-mediated suppression of responses associated with BMP4-induced osteogenesis, including expression of the osteocalcin encoding gene Ocn, Smad binding element (SBE)-dependent luciferase activity, alkaline phosphatase activity, and alizarin red S staining were largely restored by MTI-II and MPAID in MC3T3-E1 cells. Mechanistically, MTI-II and MPAID did not inhibit nuclear translocation of p65 or disassociate Smad4 from p65. Further, results from chromatin immunoprecipitation (ChIP) analyses revealed that Smad4 enrichment in cells over-expressing MTI-II and treated with TNF-α was equivalent to that in cells without TNF-α treatment. Alternatively, Smad4 enrichment was considerably decreased following TNF-α treatment in control cells. Moreover, p65 enrichment in the Id-1 promoter SBE was detected only when cells over-expressing MTI-II were stimulated with TNF-α. Overall, our study concludes that MTI-II restored TNF-α-inhibited suppression of BMP-Smad-induced osteogenic differentiation by enhancing accessibility of the Smad4-p65 complex to the SBE rather than by liberating Smad4 from p65.

Concordance study between regular face-to-face dental diagnosis and dental telediagnosis using fluorescence

Background

Teledentistry consultations are an effective way to increase access to care. Whether it be for a screening, referral or even an adapted treatment plan for a certain number of patients whose access to care is complicated, demonstrating the reliability of remote consultations is essential in allowing the technique to become generalised.

Aim

This study aimed to determine if teledentistry consultations using fluorescence are of the same quality as regular consultations in the diagnosis of caries.

Methods

Patients were seen in consultation in the dental care centre at the Montpellier University Hospital (France) and in the centre at Kyushu Dental University Hospital (Japan). The protocol was broken down into three parts: the regular consultation, the recording of videos with the Soprocare camera and the remote consultation. The regular consultation and the remote consultation were blinded and carried out by two different dentists. The recording of videos was carried out by a third dentist. The carious diagnosis was based on the International Caries Detection and Assessment System: a clinical rating system for the detection and assessment of caries.

Results

One hundred and ninety-five patients met the predefined inclusion criteria. Most patients had at least one surface at stage 3 or higher (73%) with a higher proportion amongst French patients (81% compared to 66%). However, they had good dental hygiene, given that dental hygiene was only deemed unsatisfactory for 10.8% (19% for French patients and 2% for Japanese patients). The odontogram (presence/absence of each tooth) seemed to be correctly identified during the remote consultation (reinterpretation). Out of the 195 patients, 168 (86.2%) were identified without error.

Conclusions

Teledentistry consultations can represent acceptable diagnostic performance with regard to the detection of dental caries. The Soprocare camera enables an early diagnosis of carious lesions with optimal efficiency. Several areas still need to be improved, however, so that the use of the camera during remote consultations is as coherent and effective as possible, especially with regard to the organisational aspects of remote consultations.

Bioactive Glass-Based Endodontic Sealer as a Promising Root Canal Filling Material without Semisolid Core Materials

Endodontic treatment for a tooth with damaged dental pulp aims to both prevent and cure apical periodontitis. If the tooth is re-infected as a result of a poorly obturated root canal, periapical periodontitis may set-in due to invading bacteria. To both avoid any re-infection and improve the success rate of endodontic retreatment, a treated root canal should be three-dimensionally obturated with a biocompatible filling material. Recently, bioactive glass, one of the bioceramics, is focused on the research area of biocompatible biomaterials for endodontics. Root canal sealers derived from bioactive glass-based have been developed and applied in clinical endodontic treatments. However, at present, there is little evidence about the patient outcomes, sealing mechanism, sealing ability, and removability of the sealers. Herein, we have developed a bioactive glass-based root canal sealer and provided evidence concerning its physicochemical properties, biocompatibility, sealing ability, and removability. We also review the classification of bioceramics and characteristics of bioactive glass. Additionally, we describe the application of bioactive glass to facilitate the development of a new root canal sealer. Furthermore, this review shows the potential application of bioactive glass-based cement as a root canal filling material in the absence of semisolid core material.

Adhesive bonding of alumina air-abraded Ag-Pd-Cu-Au alloy with 10-methacryloyloxydecyl dihydrogen phosphate

The aim of this paper is to study changes in the Ag-Pd-Cu-Au alloy surfaces by alumina air-abrasion process and effect of those changes on the adhesive bonding characteristic. Surface roughness, surface composition and chemical state of the alumina air-abraded alloys were analyzed by a confocal laser scanning microscope, an energy dispersive X-ray spectroscopy and an X-ray photoelectron spectroscopy. The results showed that the alumina air-abrasion changed the alloy surface by mechanical roughening, alumina remain and copper oxidation. Effect of the changes in the alloy surface on the adhesive bonding characteristic was examined by using a methyl methacrylate/tri-n-butylborane derivative (MMA/TBB) resin cement with the 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer. The shear bond strength test results indicated that the surface oxidation by the abrasion is the main contributor that improved the adhesive bonding rather than other effects such as mechanical roughening or alumina remain.

Expression and function of dopamine in odontoblasts

Dopamine (DA) is produced from tyrosine by tyrosine hydroxylase (TH). A recent study has reported that DA promotes the mineralization of murine preosteoblasts. However, the role of DA in odontoblasts has not been examined. Therefore, in this investigation, we researched the expression of TH and DA in odontoblasts and the effects of DA on the differentiation of preodontoblasts (KN-3 cells). Immunostaining showed that TH and DA were intensely expressed in odontoblasts and preodontoblasts of rat incisors and molars. KN-3 cells expressed D1-like and D2-like receptors for DA. Furthermore, DA promoted odontoblastic differentiation of KN-3 cells, whereas an antagonist of D1-like receptors and a PKA signaling blocker, inhibited such differentiation. However, antagonists of D2-like receptors promoted differentiation. These results suggested that DA in preodontoblasts and odontoblasts might promote odontoblastic differentiation through D1-like receptors, but not D2-like receptors, and PKA signaling in an autocrine or paracrine manner and plays roles in dentinogenesis.

Chemical alteration of Ag-Pd-Cu-Au alloy surface by alumina air-abrasion and its effect on bonding to resin cement

The goal of this study was to investigate the chemical alteration of a dental alloy surface by alumina air-abrasion and its effect on bonding to resin cement. Alumina air-abrasion was carried out on an Ag-Pd-Cu-Au alloy. The surface morphology and chemical state of the abraded alloy were characterized. The effect of the air-abrasion on the shear bond strength between the alloy and a methyl methacrylate/tri-n-butyl borane (MMA/TBB) resin cement with some primers was evaluated. The surface characterization revealed that the alumina air-abrasion mechanically roughened and chemically altered the surface. The chemical alterations had two effects: (1) abraded alumina particles remained on the alloy surface and (2) copper ions were oxidized in the alloy surface. As the result, the shear bond strength test indicated that 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer worked with the abraded alloy surface, whereas it did not work with the non-abraded alloy surface.

Preparation of gelatin hydrogel sponges incorporating bioactive glasses capable for the controlled release of fibroblast growth factor-2

Gelatin hydrogel sponges incorporating bioactive glasses (Gel-BG) were fabricated. We evaluated the characteristics of Gel-BG as scaffolds from the perspective of their mechanical properties and the formation of hydroxyapatite by the incorporation of bioactive glasses (BG). In addition, the Gel-BG degradation and the profile of fibroblast growth factor-2 (FGF-2) release from the Gel-BG were examined. Every Gel-BG showed an interconnected pore structure with the pore size range of 180-200 µm. The compression modulus of sponges incorporating BG increased. The time profiles of degradation for the 72-h crosslinked gelatin hydrogel sponges incorporating 10 wt% BG (Gel-BG(10)) and 50 wt% BG (Gel-BG(50)) were analogous to that of the 24-h crosslinked gelatin hydrogel sponge without BG (Gel-BG(0)). In measuring the release of FGF-2 from Gel-BG, the Gel-BG(10) and Gel-BG(50) showed almost analogous 100% cumulative release within 28 days in vivo. Additionally, a bioactivity evaluation showed that the presence of gelatin does not affect the in vitro bioactivity of Gel-BG. These sponges showed mechanical and chemical functionality as scaffolds, featuring both the controlled release of FGF-2 and the induction of hydroxyapatite crystallization.

In Vitro Evaluation of a Novel Root Canal Endoscope for Visualizing the Apex of Curved Root Canal Models and an Extracted Tooth

INTRODUCTION

In straight root canals, intraradicular structures around the root canal orifice and apical foramen can be visualized with a dental operating microscope and commercially available root canal endoscopes. However, the root apex area, including the apical foramen, in a curved root canal cannot be visualized using these devices. In the present study, the potential of a newly developed root canal endoscope implementing an image fiber was examined in 3 types of root canal models and extracted teeth.

METHODS

A straight and 2 curved (10° and 30°) resin block models were prepared. A resolution chart was set at the outer surface of the apical foramen in each model. Using the microscope and the endoscope, the resolution chart was observed, and the captured images were analyzed quantitatively. Additionally, fracture lines in 20 extracted teeth were observed with both devices.

RESULTS

With the dental operating microscope, a resolution chart line was clearly observed in the straight canal model with 18.0 line pairs/mm resolution and an observing capability of 0.16 at 40 × magnification but not in the curved root canal models. With the root canal endoscope, resolution charts in all types of root canal models were visualized, and the resolution and observing capability were 16.0 line pairs/mm and 0.053, respectively. Fracture lines and the apical foramen of the extracted teeth were observed more clearly with the endoscope than the microscope.

CONCLUSIONS

The newly developed root canal endoscope using an image fiber is useful for accurate visualization of the apex area of curved root canals.

Current and future options for dental pulp therapy

Dental pulp is a connective tissue and has functions that include initiative, formative, protective, nutritive, and reparative activities. However, it has relatively low compliance, because it is enclosed in hard tissue. Its low compliance against damage, such as dental caries, results in the frequent removal of dental pulp during endodontic therapy. Loss of dental pulp frequently leads to fragility of the tooth, and eventually, a deterioration in the patient’s quality of life. With the development of biomaterials such as bioceramics and advances in pulp biology such as the identification of dental pulp stem cells, novel ideas for the preservation of dental pulp, the regenerative therapy of dental pulp, and new biomaterials for direct pulp capping have now been proposed. Therapies for dental pulp are classified into three categories; direct pulp capping, vital pulp amputation, and treatment for non-vital teeth. In this review, we discuss current and future treatment options in these therapies.

Endoscopic System Based on Intraoral Camera and Image Processing

OBJECTIVE

In dentistry, dentists perform many treatments with a few visually magnified information. About deep area of root canals, it commonly relies on exploration carried out with the fingers of the dentist, because the root canal entrance is very small to be observed. In clinical practice, the intraoral camera and endoscopic systems are separate devices, and there are no sensors to capture both pictures of the whole tooth and those inside the root canal. Objective of this research is to combine the intraoral camera and endoscopic system facilitating to use clinical practice.

METHODS

We propose an endoscopic system based on the thin image fiber, SOPROLIFE intraoral camera as an image sensor, and a new adaptor to connect the two parts. We observed resolution charts with 50, 25, 10, and 5 line pairs (LP)/mm patterns. The acquired images are processed to both remove fixed-pattern noise using robust principal component analysis and enhance contrast.

RESULTS

The acquired images containing all LP/mm patterns were clear and showed higher contrast after processing. Visibility of the processed images is 1.7, 1.6, 2.2, and 1.9 times higher than that of the raw images for 50, 25, 10, and 5 LP/mm patterns, respectively.

CONCLUSION

Our fabricated endoscopic system based on the SOPROLIFE intraoral camera could observe 50, 25, 10, and 5 LP/mm patterns. After image processing, the noise was reduced, and high-contrast images were obtained.

SIGNIFICANCE

This system can be considered as a further step toward facilitating noninvasive and contactless systems in clinical practice.

A peptide that blocks the interaction of NF-κB p65 subunit with Smad4 enhances BMP2-induced osteogenesis

Bone morphogenetic protein (BMP) potentiates bone formation through the Smad signaling pathway in vitro and in vivo. The transcription factor nuclear factor κB (NF-κB) suppresses BMP-induced osteoblast differentiation. Recently, we identified that the transactivation (TA) 2 domain of p65, a main subunit of NF-κB, interacts with the mad homology (MH) 1 domain of Smad4 to inhibit BMP signaling. Therefore, we further attempted to identify the interacting regions of these two molecules at the amino acid level. We identified a region that we term the Smad4-binding domain (SBD), an amino-terminal region of TA2 that associates with the MH1 domain of Smad4. Cell-permeable SBD peptide blocked the association of p65 with Smad4 and enhanced BMP2-induced osteoblast differentiation and mineralization without affecting the phosphorylation of Smad1/5 or the activation of NF-κB signaling. SBD peptide enhanced the binding of the BMP2-inudced phosphorylated Smad1/5 on the promoter region of inhibitor of DNA binding 1 (Id-1) compared with control peptide. Although SBD peptide did not affect BMP2-induced chondrogenesis during ectopic bone formation, the peptide enhanced BMP2-induced ectopic bone formation in subcortical bone. Thus, the SBD peptide is useful for enabling BMP2-induced bone regeneration without inhibiting NF-κB activity.

In vitro and in vivo effects of a novel bioactive glass-based cement used as a direct pulp capping agent

Direct pulp capping is an important procedure for preserving pulp viability. The pulp capping agent must possess several properties, including usability, biocompatibility, and the ability to induce reparative dentin formation. In this study, a novel bioactive glass-based cement was examined to determine whether the cement has the necessary properties to act as a direct pulp capping agent. Physicochemical properties of the bioactive glass-based cement and in vitro effects of the cement on odontoblast-like cells, as well as in vivo effects on the exposed dental pulp, were analyzed. The cement immersed in water stabilized at pH10, and hydroxyapatite-like precipitation was induced on the surface of the cement in simulate body fluid. There were no cytotoxic effects on the viability, alkaline phosphatase activity, or calcium deposition ability of odontoblast-like cells. In the in vivo rat study of an exposed dental pulp model, the cement induced a sufficient level of reparative dentin formation by odontoblast-like cells expressing odontoblastic markers at the exposed area of the dental pulp. These results suggest that the newly developed bioactive glass-based cement provides favorable biocompatibility with the dental pulp and may be useful as a direct pulp capping agent. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 161-168, 2019.

Celecoxib inhibits osteoblast differentiation independent of cyclooxygenase activity

Non-steroidal anti-inflammatory drugs (NSAIDs) exert their effects primarily by inhibiting the activity of cyclooxygenase (COX), thus suppressing prostaglandin synthesis. Some NSAIDs are known to perform functions other than pain control, such as suppressing tumour cell growth, independent of their COX-inhibiting activity. To identify NSAIDs with COX-independent activity, we examined various NSAIDs for their ability to inhibit osteoblastic differentiation using the mouse pre-osteoblast cell line MC3T3-E1. Only celecoxib and valdecoxib strongly inhibited osteoblastic differentiation, and this effect was not correlated with COX-inhibiting activity. Moreover, 2,5-dimethyl (DM)-celecoxib, a celecoxib analogue that does not inhibit COX activity, also inhibited osteoblastic differentiation. Celecoxib and DM-celecoxib inhibited osteoblastic differentiation induced by bone morphogenetic protein (BMP)-2 in C2C12 mouse myoblast cell line. Although celecoxib suppresses the growth of some tumour cells, the viability and proliferation of MC3T3-E1 cells were not affected by celecoxib or DM-celecoxib. Instead, celecoxib and DM-celecoxib suppressed BMP-2-induced phosphorylation of Smad1/5, a major downstream target of BMP receptor. Although it is well known that COX plays important roles in osteoblastic differentiation, these results suggest that some NSAIDs, such as celecoxib, have targets other than COX and regulate phospho-dependent intracellular signalling, thereby modifying bone remodelling.

Ameloblastin Upregulates Inflammatory Response Through Induction of IL-1β in Human Macrophages

Ameloblastin (AMBN) is an enamel matrix protein that has various biological functions such as healing dental pulp and repairing bone fractures. In the present study, we clarified the effect of AMBN on the expression of an inflammatory cytokine, interleukin-1β (IL-1β) in lipopolysaccharide (LPS)-treated human macrophages. Real-time RT-PCR analysis showed that LPS treatment upregulated expression of the IL-1β gene in U937 cells. Interestingly, AMBN significantly enhanced IL-1β gene expression in LPS-treated U937 cells as well as the secretion of mature IL-1β into culture supernatants by these cells. AMBN also activated caspase-1 p10 expression in LPS-treated U937 cells. Pretreatment with a caspase-1 inhibitor, Z-YVAD-FMK, downregulated the mature IL-1β expression enhanced by AMBN treatment in LPS-treated U937 cells. A co-immunoprecipitation assay showed that treatment with LPS and AMBN upregulated toll-like receptor 4 (TLR4) and myeloid differentiation primary response gene 88 (MyD88) interactions, but there was no significant difference compared with LPS treatment alone in U937 cells. In contrast, western blot analysis revealed that AMBN remarkably prolonged the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), a member of the mitogen-activated protein kinase (MAPK) family. An ERK1/2-selective inhibitor, U0126, suppressed expression of the IL-1β gene as well as its protein expression in U937 cells treated with LPS and AMBN. Taken together, these results indicate that AMBN enhances IL-1β production in LPS-treated U937 cells through ERK1/2 phosphorylation and caspase-1 activation, suggesting that AMBN upregulates the inflammatory response in human macrophages and plays an important role in innate immunity. J. Cell. Biochem. 118: 3308-3317, 2017. © 2017 Wiley Periodicals, Inc.

A Small Nuclear Acidic Protein (MTI-II, Zn2+ Binding Protein, Parathymosin) That Inhibits Transcriptional Activity of NF-κB and Its Potential Application to Antiinflammatory Drugs

Nuclear factor-κB (NF-κB) is the most potent proinflammatory transactivator, and an inhibitor of NF-κB is a good antiinflammatory drug. Glucocorticoids (GCs) are the strongest and the most frequently used antiinflammatory drugs. GC-bound glucocorticoid receptor (GR) inhibits the transcriptional activity of NF-κB and thereby suppresses a broad range of inflammatory processes. Concurrently, in whole body outside the inflammation area, the GR exerts a lot of hormone action, which results in severe side effects. There is a long-awaited need for a new NF-κB inhibitor. Previously we found a small nuclear acidic protein (named MTI-II, also known as Zn²⁺-binding protein or parathymosin), which worked as a coactivator of GR. Here we showed that overexpression of MTI-II inhibited a transcriptional activity of NF-κB independently of GCs and the GR. Vise versa, RNA interference suppression of inherent MTI-II enhanced the transcriptional activity of NF-κB. An immunoprecipitation analysis showed that MTI-II precipitated NF-κB after the stimulation of TNFα. Deletion mutants of MTI-II showed that central acidic region is essential for the inhibition of the transcriptional activity of NF-κB. These results suggest that MTI-II would be an inherent inhibitor that interacts with NF-κB. Next, we constructed MTI-II-based antiinflammatory drugs (three fusion proteins of MTI-II with a protein transduction domain and a fusion peptide of the central acidic region with protein transduction domain). These drugs had significant antiinflammatory effects on acute inflammation models and on animal models of human chronic inflammation diseases without an increase of the blood glucose level and repeated-dose toxicity. The MTI-II-based antiinflammatory drug will be a good alternative of GCs.

Re-oxygenation Improves Hypoxia-induced Pulp Cell Arrest

Dental pulp cells can be exposed to hypoxia during severe inflammation or restorative procedures, though their response to hypoxia is not well-understood. We hypothesized that hypoxia has effects on the growth of pulp cells in vitro. When the cells were exposed to hypoxia for 48 hr, cell growth was suppressed, and cell death was detected by Hoechst staining. Western blot analysis revealed that phosphorylation of retinoblastoma protein was inhibited in cells exposed to hypoxia. Analyses of the molecules involved in retinoblastoma protein phosphorylation revealed that hypoxia suppressed cyclin D2 and activated p21CIP1/WAF1. Further, hypoxia-exposed pulp cells showed improvement of cell viability, cell-cycle progression, and expression of cyclin D2 with re-oxygenation. These findings indicate that hypoxia-induced cell cycle arrest in pulp cells is reversible, while cyclin D2 may play an essential role in the improvement of cell proliferation with re-oxygenation.

Two-year clinical comparison of a flowable-type nano-hybrid composite and a paste-type composite in posterior restoration

AIM

The purpose of the present study was to compare the clinical efficacy between a flowable-type nano-hybrid composite and a paste-type composite for posterior restoration.

METHODS

Of 62 posterior teeth in 33 patients (mean age: 34.1 years), 31 were filled with a paste-type composite (Heliomolar [HM] group), and another 31 with a flowable nano-hybrid composite (MI FIL [MI] group). Clinical efficacy was evaluated at 2 years after the restoration.

RESULTS

There were no differences for retention, surface texture deterioration, anatomical form change, deterioration of marginal adaptation, and secondary caries, while a statistical difference was found for marginal discoloration, which was significantly greater in the HM group (P < 0.05). Furthermore, color matching in the MI group was superior to that in the HM group immediately after the restoration throughout the study period.

CONCLUSIONS

The present 2-year clinical evaluation of different composites showed that the flowable nano-hybrid composite could be an effective esthetic material for posterior restoration.

Effects of 4-META/MMA-TBB Resin at Different Curing Stages on Osteoblasts and Gingival Epithelial Cells

PURPOSE

To assess the effects of different curing stages of 4-META/MMA-TBB resin on osteoblasts and gingival keratinocytes.

MATERIALS AND METHODS

The MC3T3-E1 murine pre-osteoblastic cell line and GE-1 murine gingival epithelial cell line were cultured with mixtures of Super-Bond C&B at different curing stages, and the cell viability was assessed. The alkaline phosphatase (ALP) activity of the MC3T3-E1 cells was also assessed.

RESULTS

The majority of the MC3T3-E1 cells died and showed no ALP activity when cultured with 4-META/MMA-TBB resin during the initial curing phase (1 min of curing). A later curing phase of the 4-META/MMA-TBB resin (7 min of curing) showed cytotoxicity at day 1, but the toxic effect was temporary and the proliferative capacity and ALP activity in the cells were similar to control cells at day 7. Completely cured 4-META/MMA-TBB resin (after 1 or 12 h of curing) did not affect the cell viability or ALP activity of the MC3T3-E1 cells. In contrast, 4-META/MMA-TBB resin showed no effect on the GE-1 cells at any stage of curing.

CONCLUSION

Although 4-META/MMA-TBB resin during the initial curing phase shows toxic effects on MC3T3-E1 cells, that cytotoxicity is minimal at later curing phases. In contrast, neither the uncured nor cured resins affected the GE-1 cells.

Expression of Vesicular Nucleotide Transporter in Rat Odontoblasts

Several theories have been proposed regarding pain transmission mechanisms in tooth. However, the exact signaling mechanism from odontoblasts to pulp nerves remains to be clarified. Recently, ATP-associated pain transmission has been reported, but it is unclear whether ATP is involved in tooth pain transmission. In the present study, we focused on the vesicular nucleotide transporter (VNUT), a transporter of ATP into vesicles, and examined whether VNUT was involved in ATP release from odontoblasts. We examined the expression of VNUT in rat pulp by RT-PCR and immunostaining. ATP release from cultured odontoblast-like cells with heat stimulation was evaluated using ATP luciferase methods. VNUT was expressed in pulp tissue, and the distribution of VNUT-immunopositive vesicles was confirmed in odontoblasts. In odontoblasts, some VNUT-immunopositive vesicles were colocalized with membrane fusion proteins. Additionally P2X3, an ATP receptor, immunopositive axons were distributed between odontoblasts. The ATP release by thermal stimulation from odontoblast-like cells was inhibited by the addition of siRNA for VNUT. These findings suggest that cytosolic ATP is transported by VNUT and that the ATP in the vesicles is then released from odontoblasts to ATP receptors on axons. ATP vesicle transport in odontoblasts seems to be a key mechanism for signal transduction from odontoblasts to axons in the pulp.

Inhibition of BMP2-induced bone formation by the p65 subunit of NF-κB via an interaction with Smad4

Bone morphogenic proteins (BMPs) stimulate bone formation in vivo and osteoblast differentiation in vitro via a Smad signaling pathway. Recent findings revealed that the activation of nuclear factor-κB (NF-κB) inhibits BMP-induced osteoblast differentiation. Here, we show that NF-κB inhibits BMP signaling by directly targeting the Smad pathway. A selective inhibitor of the classic NF-κB pathway, BAY11-770682, enhanced BMP2-induced ectopic bone formation in vivo. In mouse embryonic fibroblasts (MEFs) prepared from mice deficient in p65, the main subunit of NF-κB, BMP2, induced osteoblastic differentiation via the Smad complex to a greater extent than that in wild-type MEFs. In p65(-/-) MEFs, the BMP2-activated Smad complex bound much more stably to the target element than that in wild-type MEFs without affecting the phosphorylation levels of Smad1/5/8. Overexpression of p65 inhibited BMP2 activity by decreasing the DNA binding of the Smad complex. The C-terminal region, including the TA2 domain, of p65 was essential for inhibiting the BMP-Smad pathway. The C-terminal TA2 domain of p65 associated with the MH1 domain of Smad4 but not Smad1. Taken together, our results suggest that p65 inhibits BMP signaling by blocking the DNA binding of the Smad complex via an interaction with Smad4. Our study also suggests that targeting the association between p65 and Smad4 may help to promote bone regeneration in the treatment of bone diseases.

Inhibitory effects of ameloblastin on epithelial cell proliferation

OBJECTIVE

Ameloblastin is an enamel matrix protein expressed in several tissues. Many potential mechanisms have been identified by which ameloblastin functions as an extracellular matrix protein. However, the biological effects of ameloblastin on gingival epithelial cells remain unclear. In the present study, we established a novel system to purify recombinant human ameloblastin and clarified its biological functions in epithelial cells in vitro.

DESIGN

Recombinant human ameloblastin was isolated from COS-7 cells overexpressing HaloTag-fused human ameloblastin by the HaloTag system and then purified further by reverse-phase high-performance liquid chromatography. SCC-25 cells, derived from human oral squamous cell carcinoma, were treated with recombinant ameloblastin and then cell survival was assessed by a WST-1 assay. Cell cycle analysis was performed by flow cytometry.

RESULTS

The novel purification system allowed effective recovery of the recombinant ameloblastin proteins at a high purity. Recombinant ameloblastin protein was found to suppress the proliferation of SCC-25 cells. Flow cytometric analysis showed that ameloblastin treatment induced cell cycle arrest G1 phase.

CONCLUSIONS

We developed a procedure for production of highly purified recombinant human ameloblastin. Biological analyses suggest that ameloblastin induces cell cycle arrest in epithelial cells and regulates the progression of periodontitis.

Continuous fever-range heat stress induces thermotolerance in odontoblast-lineage cells

OBJECTIVE

Heat shock during restorative procedures can trigger damage to the pulpodentin complex. While severe heat shock has toxic effects, fever-range heat stress exerts beneficial effects on several cells and tissues. In this study, we examined whether continuous fever-range heat stress (CFHS) has beneficial effects on thermotolerance in the rat clonal dental pulp cell line with odontoblastic properties, KN-3.

METHODS

KN-3 cells were cultured at 41°C for various periods, and the expression level of several proteins was assessed by Western blot analysis. After pre-heat-treatment at 41°C for various periods, KN-3 cells were exposed to lethal severe heat shock (LSHS) at 49°C for 10min, and cell viability was examined using the MTS assay. Additionally, the expression level of odontoblast differentiation makers in surviving cells was examined by Western blot analysis.

RESULTS

CFHS increased the expression levels of several heat shock proteins (HSPs) in KN-3 cells, and induced transient cell cycle arrest. KN-3 cells, not pre-heated or exposed to CFHS for 1 or 3h, died after exposure to LSHS. In contrast, KN-3 cells exposed to CFHS for 12h were transiently lower on day 1, but increased on day 3 after LSHS. The surviving cells expressed odontoblast differentiation markers, dentine sialoprotein and dentine matrix protein-1. These results suggest that CFHS for 12h improves tolerance to LSHS by inducing HSPs expression and cell cycle arrest in KN-3 cells.

CONCLUSIONS

The appropriate pretreatment with continuous fever-range heat stress can provide protection against lethal heat shock in KN-3 cells.

Variety and complexity of fluorine-18-labelled fluoro-2-deoxy-D-glucose accumulations in the oral cavity of patients with oral cancers

OBJECTIVES

To elucidate the points that require attention when interpreting fluorine-18-labelled fluoro-2-deoxy-d-glucose ((18)F-FDG)/positron emission tomography (PET) images by demonstration of (18)F-FDG accumulation in various areas of the oral cavity other than primary lesions in patients with oral cancers.

METHODS

(18)F-FDG accumulations with a maximal standardized uptake value of over 2.5 in various areas of the oral cavity other than primary lesions were identified in 82 patients with oral cancers.

RESULTS

(18)F-FDG/PET-positive areas, excluding primary tumours, included the front intrinsic muscles of the tongue (89.0%), upper and lower marginal parts of the orbicularis oris muscle (64.6%), sublingual glands, palatine tonsil, pharyngeal tonsil, and lingual tonsil. In addition, some areas in the jaws also showed accumulation.

CONCLUSIONS

In patients with oral cancers, areas of (18)F-FDG accumulation in the oral cavity should be precisely identified and appropriately diagnosed, because accumulations can be seen in areas other than the primary tumour.

Sesamin suppresses activation of microglia and p44/42 MAPK pathway, which confers neuroprotection in rat intracerebral hemorrhage

Thrombin plays important roles in the pathology of intracerebral hemorrhage (ICH). The recruitment of activated microglia, accompanied by thrombin-induced phosphorylation of the mitogen-activated protein kinase (MAPK) family, contributes to ICH-associated neuron loss. Here we investigated the possibility that sesamin, a lignan of sesame seed oil, is a natural candidate as an inhibitor of microglial activation and MAPK pathways under ICH insults. Sesamin (30-100 μM) suppressed thrombin-induced nitric oxide (NO) production by primary-cultured rat microglia via inhibition of inducible NO synthase (iNOS) protein expression, independently of the antioxidative effect. Sesamin selectively inhibited p44/42 MAPK phosphorylation in the MAPK family (p38 and p44/42) involved in iNOS protein expression in primary-cultured rat microglia. An in vivo rat ICH model was prepared by intrastriatal injection of 0.20U collagenase type IV unilaterally. ICH evoked the phosphorylation of p44/42 MAPK, microglial proliferation with morphological change into the activated ameboid form, and neuron loss. The phosphorylation of p44/42 MAPK was inhibited by intracerebroventricular administration of 30-nmol sesamin. Sesamin prevented ICH-induced increase of microglial cells in the perihematomal area. Notably, ramified microglia, the resting morphology, were observed in brain sections of the animals administrated sesamin. Sesamin furthermore achieved neuroprotection in the perihematomal area but not in the hematomal center. These results suggest that sesamin is a promising natural product as a novel therapeutic strategy based on the regulation of microglial activities accompanied by the activated p44/42 MAPK pathway in ICH.

Reflection of ¹⁸F-FDG accumulation in the evaluation of the extent of periapical or periodontal inflammation

OBJECTIVES

To elucidate whether fluorine-18-labeled ((18)F) fluoro-2-deoxy-d-glucose (FDG) accumulation can reflect the extent of periodontal inflammation, periapical inflammation, or dental caries.

STUDY DESIGN

(18)F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) were retrospectively compared with the size of the bone resorption areas caused by periodontal inflammation, periapical inflammation, or dental caries on panoramic radiographs, CT, and magnetic resonance imaging (MRI) in 44 subjects.

RESULTS

A significant correlation was found between the size of the bone resorption area caused by periodontal (r = 0.595, P < .01) or periapical (r = 0.560, P < .01) inflammation and the highest standardized uptake value (SUVmax) of (18)F-FDG accumulation. A significant correlation was found between the periodontal (r = 0.622, P < .01) or periapical (r = 0.394, P < .01) inflammatory findings on MRI and the SUVmax of (18)F-FDG accumulation. The SUVmax of (18)F-FDG around most teeth with caries was under 1.5.

CONCLUSIONS

(18)F-FDG accumulation reflects the extent of dental inflammation, not dental caries.

Apoptosis and survivability of human dental pulp cells under exposure to Bis-GMA

Objective

In the present study, we examined whether 2, 2-bis [4-(2-hydroxy-3methacryloxypropoxy) phenyl] propane (Bis-GMA) has effects on LSC2 cells, human dental pulp cell line.

Material and Methods

The viability, cell cycle, and morphology of LSC2 cells were analyzed after exposure to several different concentrations of Bis-GMA. The recovery of viability of Bis-GMA exposed cells was also analyzed in the condition without Bis-GMA. Further, penetration of Bis-GMA to dentin disc was examined using isocratic high-performance liquid chromatography.

Results

There was a concentration-dependent decrease in cell proliferation and an increase in cell number in the sub-G1 population after exposure to Bis-GMA. Furthermore, the cells showed typical characteristics of apoptotic cells after the exposure to high concentration of Bis-GMA. In contrast, cells exposed to lower concentrations of Bis-GMA recovered their viability after being cultured without Bis-GMA. We also found that Bis-GMA is capable of penetrating 1-mm-thick dentin discs, though the penetrated concentration was lower than that showing cytotoxicity.

Conclusion

These results suggest that Bis-GMA has cytotoxic effects, though dental pulp exposed to lower concentrations is able to recover their viability when Bis-GMA is removed.

How effective is video consultation in clinical oncology? A systematic review

BACKGROUND

Video-consultation (VC) is a specialized type of telemedicine that uses technology to provide real-time visual and audio patient assessment at a distance. In the present review, we set out to evaluate whether vc is feasible for the assessment, monitoring, and management of oncology patients.

METHODS

A search strategy designed to capture studies that addressed the use of telemedicine to deliver cancer care identified relevant articles in the medline (1966 to September 2008) and PubMed (to 2008) databases. Articles were included if they described studies incorporating video-conferencing between patient and provider for assessment or monitoring,physicians or nurses as the care providers,cancer patients,consultation in real-time, and reporting of 1 or more outcomes.

RESULTS

Of the more than three hundred articles retrieved, nineteen articles describing 15 unique patient populations involving 709 patients were inclusded in the analysis. No randomized trials were located. Eight studies included a control group; seven involved a case series. The most commonly reported outcomes were patient satisfaction (ten studies), cost to perform consultation (six studies), patient preference for vc compared with in-person consultation (five studies), provider satisfaction (four studies), and provider convenience (four studies). Of these outcomes, satisfaction on the part of patients and physicians has been positive overall, total costs were comparable to or less than those for in-person consultations, and patients valued having vc as an option for consultation. Outcomes evaluating the effect on clinical care were infrequently reported.

CONCLUSIONS

While there is evidence to suggest that vc is both feasible and effective for use in the clinical care of oncology patients, studies are generally small and methodologically weak, with limited power of inference.

Bactericidal Effects of Diode Laser Irradiation on Enterococcus faecalis Using Periapical Lesion Defect Model

Objective. Photodynamic therapy has been expanded for use in endodontic treatment. The aim of this study was to investigate the antimicrobial effects of diode laser irradiation on endodontic pathogens in periapical lesions using an in vitro apical lesion model. Study Design. Enterococcus faecalis in 0.5% semisolid agar with a photosensitizer was injected into apical lesion area of in vitro apical lesion model. The direct effects of irradiation with a diode laser as well as heat produced by irradiation on the viability of microorganisms in the lesions were analyzed. Results. The viability of E. faecalis was significantly reduced by the combination of a photosensitizer and laser irradiation. The temperature caused by irradiation rose, however, there were no cytotoxic effects of heat on the viability of E. faecalis. Conclusion. Our results suggest that utilization of a diode laser in combination with a photosensitizer may be useful for clinical treatment of periapical lesions.

Effects of hyaluronic acid sponge as a scaffold on odontoblastic cell line and amputated dental pulp

It is important to develop a suitable three-dimensional scaffold for the regeneration therapy of dental pulp. In the present study, the effects of hyaluronic acid (HA) sponge on responses of the odontoblastic cell line (KN-3 cells) in vitro, as well as responses of amputated dental pulp of rat molar in vivo, were examined. In vitro, KN-3 cells adhered to the stable structure of HA sponge and that of collagen sponge. In vivo, dental pulp proliferation and vessel invasion were observed in both sponges implanted at dentin defect area above amputated dental pulp, and the cell-rich reorganizing tissue was observed in the dentin defect when HA sponge was implanted as compared with collagen sponge. Expression levels of IL-6 and TNF-alpha in KN-3 cells seeded in HA sponge were nearly the same with those in the cells seeded in collagen sponge, while the numbers (0.67 x 10(3) at 1 week and 0.7 x 10(3) at 3 weeks) of granulated leukocytes that invaded into HA sponge from amputated dental pulp was significantly lower than those (1.22 x 10(3) at 1 week and 1.1 x 10(3) at 3 weeks) of collagen sponge (p < 0.01 at 1 week and p < 0.05 at 3 weeks). These results suggest that HA sponge has an appropriate structure, biocompatibility, and biodegradation for use as a scaffold for dental pulp regeneration.

Mechanisms involved in suppression of NGF-induced neuronal differentiation of PC12 cells by hyaluronic acid

In the present study, we found that hyaluronic acid (HA) suppressed the neuronal differentiation mediated by nerve growth factor (NGF). In addition, we examined the mechanism by which HA inhibits the NGF-induced neurite outgrowth of PC12 cells. We elucidated the direct interaction between NGF and HA, and found that HA did not bind to NGF directly using a quartz-crystal microbalance. Western blot analysis revealed that HA suppressed NGF-induced phosphorylation of p38 MAPK, ERKs, and transcriptional factor CREB in PC12 cells. Furthermore, HA inhibited the luciferase activity of pCRE-Luc transfected PC12 cells in the presence of NGF. We confirmed that the p38 MAPK inhibitor SB203580 and ERK inhibitor U0126 suppressed NGF-induced neurite outgrowth of PC12 cells, and found that the inhibitory effects of HA on phosphorylation of ERKs, but not of p38 MAPK, were restored by the anti-RHAMM antibody. The number of PC12 cells with neurites increased remarkably when pre-cultured with the anti-RHAMM antibody, then treated with NGF and HA. Our findings indicate that HA inhibits NGF-induced neuronal differentiation of PC12 cells partially by inhibiting ERK phosphorylation through RHAMM, and suggest that the binding of HA to RHAMM modifies the signaling pathways in PC12 cells treated with NGF.