0000000000054795

AUTHOR

Johannes Roth

Keratinocytes Determine Th1 Immunity during Early Experimental Leishmaniasis

Experimental leishmaniasis is an excellent model system for analyzing Th1/Th2 differentiation. Resistance to Leishmania (L.) major depends on the development of a L. major specific Th1 response, while Th2 differentiation results in susceptibility. There is growing evidence that the microenvironment of the early affected tissue delivers the initial triggers for Th-cell differentiation. To analyze this we studied differential gene expression in infected skin of resistant and susceptible mice 16h after parasite inoculation. Employing microarray technology, bioinformatics, laser-microdissection and in-situ-hybridization we found that the epidermis was the major source of immunomodulatory mediat…

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Proceedings Of The 23Rd Paediatric Rheumatology European Society Congress: Part Two

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Molecular dynamics studies of 3D quasicrystals

Abstract The thermodynamic behaviour of monatomic and diatomic models of three-dimensional icosahedral quasicrystals has been studied in NVT and NPT ensembles using molecular dynamics simulations with atoms interacting via Lennard-Jones potentials. We also report on a microcanonical MD simulation of decagonal Al 65 Cu 20 Co 15 quasicrystals where an experimentally determined binary model has been used. To obtain stability in this latter case it is necessary to endow the atoms with effective pair potentials. No transitions to crystalline or amorphous phases were found for diatomic models. Monatomic models, however, display a certain stability only in the low-temperature region. In the range …

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Impact of carbon ion irradiation on epidermal growth factor receptor signaling and glioma cell migration in comparison to conventional photon irradiation

PURPOSE: Radiotherapy of malignant gliomas may be limited by an interference of radiation with the migratory potential of tumor cells. Therefore, the influence of conventional photon and modern carbon ion ((12)C) irradiation on glioblastoma cell migration and on epidermal growth factor receptor-related (EGFR) signaling was investigated in vitro. MATERIALS AND METHods: EGFR overexpressing glioblastoma cell lines U87 EGFR++ and LN229 EGFR++ were irradiated with 0, 2 or 6 Gy photons or (12)C heavy ions. Migration was analyzed 24 h after treatment in a standardized Boyden Chamber assay. At different time points EGFR, protein kinase B (PKB/AKT) and extracellular signal-related kinases (ERK1/2) w…

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Proceedings of the 23rd Paediatric Rheumatology European Society Congress: part one

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Intrinsic stability of quasicrystals under the generation of Frenkel pairs

Under irradiation metastable quasicrystals undergo a phase transition to an amorphous state. This transition can be reversed by annealing. As in normal crystalline materials the phase transition is considered to be triggered by generation and recombination of vacancies and interstitial atoms (Frenkel pairs). We have classified the possible Frenkel defects in a metastable monatomic quasicrystal with respect to geometric and energetic properties. With numerical simulation we have studied the behaviour of the quasicrystal under a load of Frenkel defects for various defect concentrations. We find three ranges of behaviour: up to 5% defects per atom the structure remains icosahedral, in a middle…

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Nucleation of quasicrystals by rapid cooling of a binary melt: A molecular-dynamics study.

A binary Lennard-Jones fluid was cooled in an NPT ensemble by molecular-dynamics simulations. Depending on the cooling rate, we find a sharp transition from the melt either into a disordered structure or into a phase of icosahedral long-range order. We also observed a decagonal phase.

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Allergen-Specific Low Zone Tolerance Is Independent of MRP8/14-, TLR4-, TLR7-, and TLR9-Mediated Immune Processes.

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LFA-1 Contributes to Signal I of T-Cell Activation and to the Production of Th1 Cytokines

The beta(2) integrins are important for both transendothelial migration of leukocytes and T-cell activation during antigen presentation. In T cells, triggering of leukocyte functional antigen-1 (LFA-1) is required for full activation and T-helper (Th)1/Th2 differentiation. We used CD18-deficient (CD18(-/-)) mice to examine the role of LFA-1 in the activation of T cells. Compared with wild-type controls, CD18(-/-) T cells proliferated normally when stimulated with antibodies against CD3 and CD28, but secreted significantly less IFN-gamma and IL-2 than their wild-type counterparts. However, when T cells were stimulated with dendritic cells (DCs) that provide additional LFA-1 ligation, the pro…

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