Investigation of the possibility of improving spatial resolution in SPECT with the combination of LaBr3:Ce-based detector and 3D-OSEM reconstruction algorithms

This study investigates the potential of improving spatial resolution in SPECT imaging using a combination of LaBr(3):Ce detectors and 3D-OSEM image reconstruction algorithms. Potential spatial resolution improvement was assessed intrinsically and extrinsically using GATE Monte Carlo simulation. Significantly improved MTF of LaBr(3):Ce detectors suggests better resolution performance at all spatial frequencies. In comparison to conventional Nal(Tl) scintillators, a combination of the LaBr(3):Ce crystal and 3D-OSEM incorporating resolution recovery could significantly improve the extrinsic spatial resolution of SPECT images. (C) 2010 Elsevier B.V. All rights reserved

Large deletions and point mutations involving the dedicator of cytokinesis 8 (DOCK8) in the autosomal-recessive form of hyper-IgE syndrome

International audienceBackground: The genetic etiologies of the hyper-IgE syndromes are diverse. Approximately 60% to 70% of patients with hyper-IgE syndrome have dominant mutations in STAT3, and a single patient was reported to have a homozygous TYK2 mutation. In the remaining patients with hyper-IgE syndrome, the genetic etiology has not yet been identified. Objectives: We aimed to identify a gene that is mutated or deleted in autosomal recessive hyper-IgE syndrome. Methods: We performed genome-wide single nucleotide polymorphism analysis for 9 patients with autosomal-recessive hyper-IgE syndrome to locate copy number variations and homozygous haplotypes. Homozygosity mapping was performed with 12 patients from 7 additional families. The candidate gene was analyzed by genomic and cDNA sequencing to identify causative alleles in a total of 27 patients with autosomal-recessive hyper-IgE syndrome. Results: Subtelomeric biallelic microdeletions were identified in 5 patients at the terminus of chromosome 9p. In all 5 patients, the deleted interval involved dedicator of cytokinesis 8 (DOCK8), encoding a protein implicated in the regulation of the actin cytoskeleton. Sequencing of patients without large deletions revealed 16 patients from 9 unrelated families with distinct homozygous mutations in DOCK8 causing premature termination, frameshift, splice site disruption, and single exon deletions and microdeletions. DOCK8 deficiency was associated with impaired activation of CD4(+) and CD8(+)T cells. Conclusion: Autosomal-recessive mutations in DOCK8 are responsible for many, although not all, cases of wautosomal-recessive hyper-IgE syndrome. DOCK8 disruption is associated with a phenotype of severe cellular immunodeficiency characterized by susceptibility to viral infections, atopic eczema, defective T-cell activation and T(H)17 cell differentiation, and impaired eosinophil homeostasis and dysregulation of IgE. (J Allergy Clin Immunol 2009;124:1289-302.

Structure and properties of polydiacetylene-containing peptide amphiphile fibres

Contains fulltext : 83167.pdf (publisher's version ) (Open Access)Radboud Universiteit Nijmegen, 10 februari 2011Promotor : Hest, J.C.M. van Co-promotor : Lowik, D.W.P.M.184 p