TH9 cells are required for tissue mast cell accumulation during allergic inflammation

BACKGROUND: IL-9 is important for the growth and survival of mast cells. IL-9 is produced by T cells, natural killer T cells, mast cells, eosinophils, and innate lymphoid cells, although the cells required for mast cell accumulation during allergic inflammation remain undefined. OBJECTIVE: We sought to elucidate the role of TH9 cells in promoting mast cell accumulation in models of allergic lung inflammation. METHODS: Adoptive transfer of ovalbumin-specific TH2 and TH9 cells was used to assess the ability of each subset to mediate mast cell accumulation in tissues. Mast cell accumulation was assessed in wild-type mice and mice with PU.1-deficient T cells subjected to acute and chronic models of allergic inflammation. RESULTS: Adoptive transfer experiments demonstrated that recipients of TH9 cells had significantly higher mast cell accumulation and expression of mast cell proteases compared with control or TH2 recipients. Mast cell accumulation was dependent on IL-9, but not IL-13, a cytokine required for many aspects of allergic inflammation. In models of acute and chronic allergic inflammation, decreased IL-9 levels in mice with PU.1-deficient T cells corresponded to diminished tissue mast cell numbers and expression of mast cell proteases. Mice with PU.1-deficient T cells have defects in IL-9 production from CD4(+) T cells, but not natural killer T cells or innate lymphoid cells, suggesting a TH cell-dependent phenotype. Rag1(-/-) mice subjected to a chronic model of allergic inflammation displayed reduced mast cell infiltration comparable with accumulation in mice with PU.1-deficient T cells, emphasizing the importance of IL-9 produced by T cells in mast cell recruitment. CONCLUSION: TH9 cells are a major source of IL-9 in models of allergic inflammation and play an important role in mast cell accumulation and activation

Effect of Canal Length and Curvature on Working Length Alteration with WaveOne Reciprocating Files

The article “Effect of Canal Length and Curvature on Working Length Alteration with WaveOne Reciprocating Files” by Elio Berutti, Giorgio Chiandussi, Davide Salvatore Paolino, Nicola Scotti, Giuseppe Cantatore, Arnaldo Castellucci and Damiano Pasqualini (J Endod 37[12]:1687–90; 2011] should have included this statement in the author information section: “Giuseppe Cantatore, Arnaldo Castellucci, and Elio Berutti declare that they have financial involvement (patent licensing arrangements) with Dentsply Maillefer with direct financial interest in the materials discussed in this article.” In addition, Dentsply provided some of the instruments used in this study." The authors regret this omission

Computed micro-tomographic evaluation of glide pathwith nickel-titanium rotary pathFile in maxillary firstmolars curved canals

Introduction: X-ray computed micro-tomography scanning allows high-resolution 3-dimensional imaging of small objects. In this study, micro-CT scanning was used to compare the ability of manual and mechanical glide path to maintain the original root canal anatomy. Methods: Eight extracted upper first permanent molars were scanned at the TOMOLAB station at ELETTRA Synchrotron Light Laboratory in Trieste, Italy, with a microfocus cone-beam geometry system. A total of 2,400 projections on 360 degrees have been acquired at 100 kV and 80 mu A, with a focal spot size of 8 mu m. Buccal root canals of each specimen (n = 16) were randomly assigned to Path File (P) or stainless-steel K-file (K) to perform glide path at the full working length. Specimens were then microscanned at the apical level (A) and at the point of the maximum curvature level (C) for post-treatment analyses. Curvatures of root canals were classified as moderate (<= 35 degrees) or severe (>= 40 degrees). The ratio of diameter ratios (RDRs) and the ratio of cross-sectional areas (RAs) were assessed. For each level of analysis (A and C), 2 balanced 2-way factorial analyses of variance (P < .05) were performed to evaluate the significance of the instrument factor and of canal curvature factor as well as the interactions of the factors both with RDRs and RAs. Results: Specimens in the K group had a mean curvature of 35.4 degrees +/- 11.5 degrees; those in the P group had a curvature of 38 degrees +/- 9.9 degrees. The instrument factor (P and K) was extremely significant (P < .001) for both the RDR and RA parameters, regardless of the point of analysis. Conclusions: Micro-CT scanning confirmed that NiTi rotary Path File instruments preserve the original canal anatomy and cause less canal aberrations. (J Endod 2012;38:389-393

TH9 cells are required for tissue mast cell accumulation during allergic inflammation

BACKGROUND: IL-9 is important for the growth and survival of mast cells. IL-9 is produced by T cells, natural killer T cells, mast cells, eosinophils, and innate lymphoid cells, although the cells required for mast cell accumulation during allergic inflammation remain undefined. OBJECTIVE: We sought to elucidate the role of TH9 cells in promoting mast cell accumulation in models of allergic lung inflammation. METHODS: Adoptive transfer of ovalbumin-specific TH2 and TH9 cells was used to assess the ability of each subset to mediate mast cell accumulation in tissues. Mast cell accumulation was assessed in wild-type mice and mice with PU.1-deficient T cells subjected to acute and chronic models of allergic inflammation. RESULTS: Adoptive transfer experiments demonstrated that recipients of TH9 cells had significantly higher mast cell accumulation and expression of mast cell proteases compared with control or TH2 recipients. Mast cell accumulation was dependent on IL-9, but not IL-13, a cytokine required for many aspects of allergic inflammation. In models of acute and chronic allergic inflammation, decreased IL-9 levels in mice with PU.1-deficient T cells corresponded to diminished tissue mast cell numbers and expression of mast cell proteases. Mice with PU.1-deficient T cells have defects in IL-9 production from CD4(+) T cells, but not natural killer T cells or innate lymphoid cells, suggesting a TH cell-dependent phenotype. Rag1(-/-) mice subjected to a chronic model of allergic inflammation displayed reduced mast cell infiltration comparable with accumulation in mice with PU.1-deficient T cells, emphasizing the importance of IL-9 produced by T cells in mast cell recruitment. CONCLUSION: TH9 cells are a major source of IL-9 in models of allergic inflammation and play an important role in mast cell accumulation and activation