Cellular Islet Autoimmunity Associates with Clinical Outcome of Islet Cell Transplantation

Islet cell transplantation can cure type 1 diabetes (T1D), but only a minority of recipients remains insulin-independent in the following years. We tested the hypothesis that allograft rejection and recurrent autoimmunity contribute to this progressive loss of islet allograft function.Twenty-one T1D patients received cultured islet cell grafts prepared from multiple donors and transplanted under anti-thymocyte globulin (ATG) induction and tacrolimus plus mycophenolate mofetil (MMF) maintenance immunosuppression. Immunity against auto- and alloantigens was measured before and during one year after transplantation. Cellular auto- and alloreactivity was assessed by lymphocyte stimulation tests against autoantigens and cytotoxic T lymphocyte precursor assays, respectively. Humoral reactivity was measured by auto- and alloantibodies. Clinical outcome parameters--including time until insulin independence, insulin independence at one year, and C-peptide levels over one year--remained blinded until their correlation with immunological parameters. All patients showed significant improvement of metabolic control and 13 out of 21 became insulin-independent. Multivariate analyses showed that presence of cellular autoimmunity before and after transplantation is associated with delayed insulin-independence (p = 0.001 and p = 0.01, respectively) and lower circulating C-peptide levels during the first year after transplantation (p = 0.002 and p = 0.02, respectively). Seven out of eight patients without pre-existent T-cell autoreactivity became insulin-independent, versus none of the four patients reactive to both islet autoantigens GAD and IA-2 before transplantation. Autoantibody levels and cellular alloreactivity had no significant association with outcome.In this cohort study, cellular islet-specific autoimmunity associates with clinical outcome of islet cell transplantation under ATG-tacrolimus-MMF immunosuppression. Tailored immunotherapy targeting cellular islet autoreactivity may be required. Monitoring cellular immune reactivity can be useful to identify factors influencing graft survival and to assess efficacy of immunosuppression.Clinicaltrials.gov NCT00623610

Thermal-Chemical Characteristics of Al-Cu Alloy Nanoparticles

This work investigated the oxidation, ignition, and thermal reactivity of alloy nanoparticles of aluminum and copper (nAlCu) using simultaneous thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) method. The microstructure of the particles was characterized with a scanning electron microscope (SEM) and transmission electron microscope (TEM), and the elemental composition of the particles before and after the oxidation was investigated with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The particles were heated from room temperature to 1200 °C under different heating rates from 2 to 30 K/min in the presence of air. The complete oxidation process of the nAlCu was characterized by two exothermic and two endothermic reactions, and the reaction paths up to 1200 °C were proposed. An early ignition of nAlCu, in the temperature around 565 °C, was found at heating rates ≥ 8 K/min. The eutectic melting temperature of nAlCu was identified at ∼546 °C, which played a critical role in the early ignition. The comparison of the reactivity with that of pure Al nanoparticles showed that the nAlCu was more reactive through alloying

Fabrication of ordered macroporous structures based on hetero-coagulation process using nanoparticle as building blocks

A simple method based on hetero-coagulation process for the preparation of well-defined ordered macroporous inorganic materials from nanoparticles and spherical polymer templates is reported

Crystalline-oriented TiO2 fabricated by the electrophoretic deposition in a strong magnetic field

Electrophoretic deposition of titania (anatase) suspension was conducted in a strong magnetic field of 10 T. The direction of the electric field E relative to the magnetic field B was altered (phi(B-E) = 0, 30, 60 and 90degrees) to control the dominant crystal faces of the deposit surfaces. The crystalline orientation was investigated by the X-ray diffraction for the titania films of as-deposited, sintered at 650, 750 and 1200 degreesC as a function of the angle between the directions of B and E (phi(B-E)). It was found that changing the angle phi(B-E) during the EPD could control the crystalline orientation of the titania films. (C) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Crystalline-oriented TiO2 fabricated by the electrophoretic deposition in a strong magnetic field

Electrophoretic deposition of titania (anatase) suspension was conducted in a strong magnetic field of 10 T. The direction of the electric field E relative to the magnetic field B was altered (phi(B-E) = 0, 30, 60 and 90degrees) to control the dominant crystal faces of the deposit surfaces. The crystalline orientation was investigated by the X-ray diffraction for the titania films of as-deposited, sintered at 650, 750 and 1200 degreesC as a function of the angle between the directions of B and E (phi(B-E)). It was found that changing the angle phi(B-E) during the EPD could control the crystalline orientation of the titania films. (C) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved