The Retention Effect of Resin-Based Desensitizing Agents on Hypersensitivity-A Randomized Controlled Trial

Recently, the development of dental materials has increased the availability of various hyperesthesia desensitizers. However, there are no studies on the duration of retreatment in terms of adherence rates. Thus, the adhesion rates of resin-based desensitizers were investigated. We used a conventional desensitizer and a recently developed desensitizer containing calcium salt of 4-methacryloxyethyl trimellitic acid (C-MET) and 10-methacryloyloxydecyl dihydrogen calcium phosphate (MDCP). These colored agents were applied to the surfaces of premolars and molars, and the area was measured from weekly oral photographs. Areas were statistically analyzed and mean values were calculated using 95% confidence intervals. A p-value of <0.05 was considered statistically significant. These rates were significantly higher on the buccal side of the maxilla and lower on the lingual side of the maxilla. In addition, the desensitizer containing C-MET and MDCP displayed significantly higher adhesion rates. It is suggested that this will require monthly follow-ups and reevaluation because both agents cause less than 10% adherence and there is almost no sealing effect after 4 weeks. In addition, the significantly higher adhesion rate of the desensitizer containing C-MET and MDCP indicated that the novel monomer contributed to the improvement in the adhesion ability.

Connexin 43-Mediated Gap Junction Communication Regulates Ameloblast Differentiation via ERK1/2 Phosphorylation

Connexin 43 (Cx43) is an integral membrane protein that forms gap junction channels. These channels mediate intercellular transport and intracellular signaling to regulate organogenesis. The human disease oculodentodigital dysplasia (ODDD) is caused by mutations in Cx43 and is characterized by skeletal, ocular, and dental abnormalities including amelogenesis imperfecta. To clarify the role of Cx43 in amelogenesis, we examined the expression and function of Cx43 in tooth development. Single-cell RNA-seq analysis and immunostaining showed that Cx43 is highly expressed in pre-secretory ameloblasts, differentiated ameloblasts, and odontoblasts. Further, we investigated the pathogenic mechanisms of ODDD by analyzing Cx43-null mice. These mice developed abnormal teeth with multiple dental epithelium layers. The expression of enamel matrix proteins such as ameloblastin (Ambn), which is critical for enamel formation, was significantly reduced in Cx43-null mice. TGF-β1 induces Ambn transcription in dental epithelial cells. The induction of Ambn expression by TGF-β1 depends on the density of the cultured cells. Cell culture at low densities reduces cell–cell contact and reduces the effect of TGF-β1 on Ambn induction. When cell density was high, Ambn expression by TGF-β1 was enhanced. This induction was inhibited by the gap junction inhibitors, oleamide, and 18α-grycyrrhizic acid and was also inhibited in cells expressing Cx43 mutations (R76S and R202H). TGF-β1-mediated phosphorylation and nuclear translocation of ERK1/2, but not Smad2/3, were suppressed by gap junction inhibitors. Cx43 gap junction activity is required for TGF-β1-mediated Runx2 phosphorylation through ERK1/2, which forms complexes with Smad2/3. In addition to its gap junction activity, Cx43 may also function as a Ca²⁺ channel that regulates slow Ca²⁺ influx and ERK1/2 phosphorylation. TGF-β1 transiently increases intracellular calcium levels, and the increase in intracellular calcium over a short period was not related to the expression level of Cx43. However, long-term intracellular calcium elevation was enhanced in cells overexpressing Cx43. Our results suggest that Cx43 regulates intercellular communication through gap junction activity by modulating TGF-β1-mediated ERK signaling and enamel formation.

G protein-coupled receptor Gpr115 (Adgrf4) is required for enamel mineralization mediated by ameloblasts

Dental enamel, the hardest tissue in the human body, is derived from dental epithelial cell ameloblast-secreted enamel matrices. Enamel mineralization occurs in a strictly synchronized manner along with ameloblast maturation in association with ion transport and pH balance, and any disruption of these processes results in enamel hypomineralization. G protein-coupled receptors (GPCRs) function as transducers of external signals by activating associated G proteins and regulate cellular physiology. Tissue-specific GPCRs play important roles in organ development, although their activities in tooth development remain poorly understood. The present results show that the adhesion GPCR Gpr115 (Adgrf4) is highly and preferentially expressed in mature ameloblasts and plays a crucial role during enamel mineralization. To investigate the in vivo function of Gpr115, knockout (Gpr115-KO) mice were created and found to develop hypomineralized enamel, with a larger acidic area because of the dysregulation of ion composition. Transcriptomic analysis also revealed that deletion of Gpr115 disrupted pH homeostasis and ion transport processes in enamel formation. In addition, in vitro analyses using the dental epithelial cell line cervical loop-derived dental epithelial (CLDE) cell demonstrated that Gpr115 is indispensable for the expression of carbonic anhydrase 6 (Car6), which has a critical role in enamel mineralization. Furthermore, an acidic condition induced Car6 expression under the regulation of Gpr115 in CLDE cells. Thus, we concluded that Gpr115 plays an important role in enamel mineralization via regulation of Car6 expression in ameloblasts. The present findings indicate a novel function of Gpr115 in ectodermal organ development and clarify the molecular mechanism of enamel formation.

Connexin 43 Is Necessary for Salivary Gland Branching Morphogenesis and FGF10-induced ERK1/2 Phosphorylation

Cell-cell interaction via the gap junction regulates cell growth and differentiation, leading to formation of organs of appropriate size and quality. To determine the role of connexin43 in salivary gland development, we analyzed its expression in developing submandibular glands (SMGs). Connexin43 (Cx43) was found to be expressed in salivary gland epithelium. In ex vivo organ cultures of SMGs, addition of the gap junctional inhibitors 18α-glycyrrhetinic acid (18α-GA) and oleamide inhibited SMG branching morphogenesis, suggesting that gap junctional communication contributes to salivary gland development. In Cx43(-/-) salivary glands, submandibular and sublingual gland size was reduced as compared with those from heterozygotes. The expression of Pdgfa, Pdgfb, Fgf7, and Fgf10, which induced branching of SMGs in Cx43(-/-) samples, were not changed as compared with those from heterozygotes. Furthermore, the blocking peptide for the hemichannel and gap junction channel showed inhibition of terminal bud branching. FGF10 induced branching morphogenesis, while it did not rescue the Cx43(-/-) phenotype, thus Cx43 may regulate FGF10 signaling during salivary gland development. FGF10 is expressed in salivary gland mesenchyme and regulates epithelial proliferation, and was shown to induce ERK1/2 phosphorylation in salivary epithelial cells, while ERK1/2 phosphorylation in HSY cells was dramatically inhibited by 18α-GA, a Cx43 peptide or siRNA. On the other hand, PDGF-AA and PDGF-BB separately induced ERK1/2 phosphorylation in primary cultured salivary mesenchymal cells regardless of the presence of 18α-GA. Together, our results suggest that Cx43 regulates FGF10-induced ERK1/2 phosphorylation in salivary epithelium but not in mesenchyme during the process of SMG branching morphogenesis.

The time-resolved and extreme conditions XAS (TEXAS) facility at the European Synchrotron Radiation Facility: the general-purpose EXAFS bending-magnet beamline BM23

BM23 is the general-purpose EXAFS bending-magnet beamline at the ESRF, replacing the former BM29 beamline in the framework of the ESRF upgrade. Its mission is to serve the whole XAS user community by providing access to a basic service in addition to the many specialized instruments available at the ESRF. BM23 offers high signal-to-noise ratio EXAFS in a large energy range (5-75 keV), continuous energy scanning for quick-EXAFS on the second timescale and a micro-XAS station delivering a spot size of 4 µm × 4 µm FWHM. It is a user-friendly facility featuring a high degree of automation, online EXAFS data reduction and a flexible sample environment.

Increased circulating Th17 frequencies and serum IL-22 levels in patients with acute generalized exanthematous pustulosis

BACKGROUND/OBJECTIVE

Acute generalized exanthematous pustulosis (AGEP) is a diffuse pustular disorder that usually begins in intertriginous folds with widespread erythema. The causes in the majority of the cases are drugs. T cells and interleukin (IL)-8 play roles in the development of AGEP, but the mechanism remains to be elucidated. We investigated the involvement of Th17 cells and their cytokine IL-22 in the pathogenesis.

METHODS

Three patients with AGEP were enrolled in this study. The percentages of IL-17(+) Th17 cells, interferon γ(+) T cells and IL-4(+) T cells were measured in the patients' peripheral blood lymphocytes by intracellular cytokine staining and flow cytometry. The concentration of IL-22 in the sera was measured by enzyme-linked immunosorbent assay.

RESULTS

The percentages of Th17 cells were markedly higher in all three patients than healthy control individuals. The frequencies of interferon γ(+) T cells were slightly high in the patients compared with the control, and there was no definite tendency in IL-4(+) T-cell frequencies. The concentration of IL-22 was remarkably high in all patients when compared with normal subjects with levels under detection.

CONCLUSION

Th17 cells and their produced cytokine IL-22 were elevated in the peripheral blood of patients with AGEP. As IL-17 and IL-22 cooperatively stimulate keratinocytes to produce IL-8, IL-8 may contribute to the accumulation of neutrophils in the lesional epidermis of AGEP.

Inhibition of T helper 2 chemokine production by narrowband ultraviolet B in cultured keratinocytes

BACKGROUND

Narrowband ultraviolet B (NB-UVB) has recently been used for the treatment of various skin disorders. Its effects on the production of cytokines and chemokines by keratinocytes are unknown.

OBJECTIVES

To investigate the effect of NB-UVB on production of chemokines and proinflammatory cytokines by keratinocytes in comparison with broadband (BB)-UVB.

METHODS

Normal human epidermal keratinocytes (or the human keratinocyte cell line HaCaT in some experiments) at semiconfluency were irradiated with NB-UVB at 10, 100, 500 or 1000 mJ cm(-2) or BB-UVB at 10 or 100 mJ cm(-2). The cultures were maintained in the presence or absence of interferon (IFN)-gamma at 200 U mL(-1). The 72-h culture supernatants were analysed by enzyme-linked immunosorbent assay to quantify T helper (Th)1 chemokines (IFN-inducible protein 10 and monokine induced by IFN-gamma), Th2 chemokines [macrophage-derived chemokine (MDC) and thymus and activation-regulated chemokine (TARC)] and proinflammatory cytokines [interleukin (IL)-1alpha and tumour necrosis factor (TNF)-alpha]. The expression of mRNA for these molecules was simultaneously assessed by reverse transcriptase-polymerase chain reaction. The culture supernatants were also tested for their chemotactic activity for Th1 and Th2 cells. The two UVB sources were compared on the basis of their minimal erythemal doses and clinically used doses.

RESULTS

Although both NB-UVB and BB-UVB increased the production of IL-1alpha and TNF-alpha, the augmentative effect of NB-UVB was less than that of BB-UVB. Both wavelength ranges of UVB enhanced or had no effect on Th1 chemokine production, but suppressed the production of Th2 chemokines MDC and TARC. This was confirmed by chemotactic assay, which showed decreased chemotactic activity for Th2 cells by the culture supernatants from NB-UVB-irradiated keratinocytes.

CONCLUSIONS

NB-UVB reduces the production of Th2 chemokines without excess production of proinflammatory cytokines, suggesting its therapeutic effectiveness on Th2-mediated skin disorders as well as its relative safety in clinical usage.

Evidence for polyclonal infection of Epstein-Barr virus in a patient with primary cutaneous anaplastic large cell lymphoma

We report a case of CD30 + primary cutaneous anaplastic large cell lymphoma. The lymphoma cells were shown to express the Epstein-Barr virus (EBV)-encoded small RNAs by in situ hybridization and to have EBV genomes by PCR, whereas no monoclonal band was detected by Southern blot analysis using the EBV terminal repeat probe. These data suggested polyclonal infection by EBV, which provides evidence that EBV plays little part in the pathogenesis of this tumour even in the infected cases.

[Successful treatment of refractory idiopathic thrombocytopenic purpura by eradication of Helicobacter pylori]

A 53-year-old woman was diagnosed as having idiopathic thrombocytopenic purpura (ITP) in 1990, and treated with prednisolone and splenectomy, which did not result in remission. In November 2000, gastrointestinal endoscopy showed superficial gastritis, and Helicobacter pylori infection was revealed by the rapid urease test and histologic examination. After eradication of Helicobacter pylori by amoxicillin, clarithromycin and lansoprazole, the patient's platelet count was increased from 24 x 10(9)/l to 134 x 10(9)/l and platelet-associated IgG (PAIgG) was decreased from 695 ng/10(7) cells to 33 ng/10(7) cells. This case suggests that eradication of Helicobacter pylori may be useful for treating some patients with refractory ITP.

Cloning and characterization of FGF23 as a causative factor of tumor-induced osteomalacia

Tumor-induced osteomalacia (TIO) is one of the paraneoplastic diseases characterized by hypophosphatemia caused by renal phosphate wasting. Because removal of responsible tumors normalizes phosphate metabolism, an unidentified humoral phosphaturic factor is believed to be responsible for this syndrome. To identify the causative factor of TIO, we obtained cDNA clones that were abundantly expressed only in a tumor causing TIO and constructed tumor-specific cDNA contigs. Based on the sequence of one major contig, we cloned 2,270-bp cDNA, which turned out to encode fibroblast growth factor 23 (FGF23). Administration of recombinant FGF23 decreased serum phosphate in mice within 12 h. When Chinese hamster ovary cells stably expressing FGF23 were s.c. implanted into nude mice, hypophosphatemia with increased renal phosphate clearance was observed. In addition, a high level of serum alkaline phosphatase, low 1,25-dihydroxyvitamin D, deformity of bone, and impairment of body weight gain became evident. Histological examination showed marked increase of osteoid and widening of growth plate. Thus, continuous production of FGF23 reproduced clinical, biochemical, and histological features of TIO in vivo. Analyses for recombinant FGF23 products produced by Chinese hamster ovary cells indicated proteolytic cleavage of FGF23 at the RXXR motif. Recent genetic study indicates that missense mutations in this RXXR motif of FGF23 are responsible for autosomal dominant hypophosphatemic rickets, another hypophosphatemic disease with similar features to TIO. We conclude that overproduction of FGF23 causes TIO, whereas mutations in the FGF23 gene result in autosomal dominant hypophosphatemic rickets possibly by preventing proteolytic cleavage and enhancing biological activity of FGF23.

[Multiple myeloma with massive ascites fluid--immunophenotypic analysis of myeloma cell and its IL-6-dependent growth]

A 75-year-old female was diagnosed as having multiple myeloma (IgG.lambda type. Stage IIA) with plasmacytoma of the head and back in October, 1989. She obtained partial remission by MCNU and MP therapy, but relapsed with massive ascites in January, 1991. VAD therapy was not effective and she died of multiple organ failure on February 23. Her ascites contained a large number of myeloma cells, and the phenotypic analysis and the response to interleukin-6 (IL-6) of these myeloma cells were examined. The myeloma cells were positive for CD33, CD45, CD45RA, CD63, CD71, plasma cell associated antigens such as CD38, PCA-1, BL3, and various kinds of adhesion molecules: CD11a/CD18 (LFA-1), CD29 (VLA-beta 1), CD44 (H-CAM), CD49d (VLA-4), CD54 (ICAM-1), CD56 (N-CAM), CD58 (LFA-3). IL-6 level in the ascites was increased at 91.0pg/ml. The myeloma cells showed an IL-6 dependent growth, which was inhibited by anti-IL-6 antibody (Ab) and anti-IL-6 receptor Ab in vitro. Myeloma cells appearing in ascites have rarely been reported. Our case suggested that IL-6 was a potent growth factor of myeloma cells through an autocrine mechanism in the ascites, and resulted in an aggressive myeloma.