Study of two bovine bone blocks (sintered and non-sintered) used for bone grafts: physico-chemical characterization and in vitro bioactivity and cellular analysis

High-temperature compression and electron backscatter diffraction (EBSD) techniques were used in a systematic investigation of the dynamic recrystallization (DRX) behavior and texture evolution of the Inconel625 alloy. The true stress–true strain curves and the constitutive equation of Inconel625 were obtained at temperatures ranging from 900 to 1200 °C and strain rates of 10, 1, 0.1, and 0.01 s−1. The adiabatic heating effect was observed during the hot compression process. At a high strain rate, as the temperature increased, the grains initially refined and then grew, and the proportion of high-angle grain boundaries increased. The volume fraction of the dynamic recrystallization increased. Most of the grains were randomly distributed and the proportion of recrystallized texture components first increased and then decreased. Complete dynamic recrystallization occurred at 1100 °C, where the recrystallized volume fraction and the random distribution ratios of grains reached a maximum. This study indicated that the dynamic recrystallization mechanism of the Inconel625 alloy at a high strain rate included continuous dynamic recrystallization with subgrain merging and rotation, and discontinuous dynamic recrystallization with bulging grain boundary induced by twinning. The latter mechanism was less dominan

Biomechanical and histological analysis of titanium (machined and treated surface) versus zirconia implant materials: an in vivo animal study

This article belongs to the Special Issue Clinical Implants and the Biocompatibility of Biodegradable BiomaterialsObjectives: The aim of this study was to perform an in vivo histological comparative evaluation of bone formation around titanium (machined and treated surface) and zirconia implants. For the present study were used 50 commercially pure titanium implants grade IV, being that 25 implants with a machined surface (TiM group), 25 implants with a treated surface (TiT group) and, 25 implants were manufactured in pure zirconia (Zr group). The implants (n = 20 per group) were installed in the tibia of 10 rabbits. The implants distribution was randomized (n = 3 implants per tibia). Five implants of each group were analyzed by scanning electron microscopy and an optical laser profilometer for surface roughness characterization. Six weeks after the implantation, 10 implants for each group were removed in counter-torque for analysis of maximum torque value. The remaining samples were processed, included in historesin and cut to obtain non-decalcified slides for histomorphological analyses and histomorphometric measurement of the percentage of bone-implant contact (BIC%). Comparisons were made between the groups using a 5% level of significance (p < 0.05) to assess statistical differences. The results of removal torque values (mean ± standard deviation) showed for the TiM group 15.9 ± 4.18 N cm, for TiT group 27.9 ± 5.15 N cm and for Zr group 11.5 ± 2.92 N cm, with significant statistical difference between the groups (p < 0.0001). However, the BIC% presented similar values for all groups (35.4 ± 4.54 for TiM group, 37.8 ± 4.84 for TiT group and 34.0 ± 6.82 for Zr group), with no statistical differences (p = 0.2171). Within the limitations of the present study, the findings suggest that the quality of the new bone tissue formed around the titanium implants present a superior density (maturation) in comparison to the zirconia implants

ETP-46321, un inhibidor dual de la fosfoinositida 3-quinasa p110? / ? clase IA modula la activación de los linfocitos T y la artritis inducida por colágeno

Class IA phosphoinositide 3-kinases (PI3Ks) are essential to function of normal and tumor cells, and to modulate immune responses. T lymphocytes express high levels of p110? and p110? class IA PI3K. Whereas the functioning of PI3K p110? in immune and autoimmune reactions is well established, the role of p110? is less well understood. Here, a novel dual p110?/? inhibitor (ETP-46321) and highly specific p110? (A66) or p110? (IC87114) inhibitors have been compared concerning T cell activation in vitro, as well as the effect on responses to protein antigen and collagen-induced arthritis in vivo. In vitro activation of naive CD4+ T lymphocytes by anti-CD3 and anti-CD28 was inhibited more effectively by the p110? inhibitor than by the p110? inhibitor as measured by cytokine secretion (IL-2, IL-10, and IFN-?), T-bet expression and NFAT activation. In activated CD4+ T cells re-stimulated through CD3 and ICOS, IC87114 inhibited Akt and Erk activation, and the secretion of IL-2, IL-4, IL-17A, and IFN-? better than A66. The p110?/? inhibitor ETP-46321, or p110? plus p110? inhibitors also inhibited IL-21 secretion by differentiated CD4+ T follicular (Tfh) or IL-17-producing (Th17) helper cells. In vivo, therapeutic administration of ETP-46321 significantly inhibited responses to protein antigen as well as collagen-induced arthritis, as measured by antigen-specific antibody responses, secretion of IL-10, IL-17A or IFN-?, or clinical symptoms. Hence, p110? as well as p110? Class IA PI3Ks are important to immune regulation; inhibition of both subunits may be an effective therapeutic approach in inflammatory autoimmune diseases like rheumatoid arthritis

ETP-46321, a dual p110\u3b1/\u3b4 class IA phosphoinositide 3-kinase inhibitor modulates T lymphocyte activation and collagen-induced arthritis

Class IA phosphoinositide 3-kinases (PI3Ks) are essential to function of normal and tumor cells, and to modulate immune responses. T lymphocytes express high levels of p110α and p110δ class IA PI3K. Whereas the functioning of PI3K p110δ in immune and autoimmune reactions is well established, the role of p110α is less well understood. Here, a novel dual p110α/δ inhibitor (ETP-46321) and highly specific p110α (A66) or p110δ (IC87114) inhibitors have been compared concerning T cell activation in vitro, as well as the effect on responses to protein antigen and collagen-induced arthritis in vivo. In vitro activation of naive CD4(+) T lymphocytes by anti-CD3 and anti-CD28 was inhibited more effectively by the p110δ inhibitor than by the p110α inhibitor as measured by cytokine secretion (IL-2, IL-10, and IFN-γ), T-bet expression and NFAT activation. In activated CD4(+) T cells re-stimulated through CD3 and ICOS, IC87114 inhibited Akt and Erk activation, and the secretion of IL-2, IL-4, IL-17A, and IFN-γ better than A66. The p110α/δ inhibitor ETP-46321, or p110α plus p110δ inhibitors also inhibited IL-21 secretion by differentiated CD4(+) T follicular (Tfh) or IL-17-producing (Th17) helper cells. In vivo, therapeutic administration of ETP-46321 significantly inhibited responses to protein antigen as well as collagen-induced arthritis, as measured by antigen-specific antibody responses, secretion of IL-10, IL-17A or IFN-γ, or clinical symptoms. Hence, p110α as well as p110δ Class IA PI3Ks are important to immune regulation; inhibition of both subunits may be an effective therapeutic approach in inflammatory autoimmune diseases like rheumatoid arthritis.P.P. is a Tenured Scientist of the Consejo Superior de Investigaciones Científicas (CSIC) at the Centro Nacional de Microbiología, Instituto de Salud Carlos III. GC is recipient of a Miguel Servet fellowship(CPII13/0014). YYA is recipient of a PredoctoralFellowship of the “Junta de Ampliación de Estudios” (JAE) Program (CSIC, Ministerio de Economía y Competitividad, Spain).Supported by Grants PI13/01809 (to JMR), PI13/02153 (to PP)and PI11/00028 (toGC) from “Acción Estratégica en Salud, Plan Estatal I+D+i”, Ministerio de Economía y Competitividad (MINECO), Spain; by Grants CIT-090100-2007-48 (Ministerio de Ciencia y Tecnología) and ADE08/90038 (Ministerio de Sanidad, Igualdad y Servicios Sociales) to JP; and by Associazione Italiana Ricerca sul Cancro grant IG14430(AIRC, Milan) and Fondazione Amici di Jean (Turin) to UD.S