Temporal delimitation of the healing phases via monitoring of fracture callus stiffness in rats

The healing process consists of at least three phases: inflammatory, repair, and remodeling phase. Because callus stiffness correlates with the healing phases, it is suitable for evaluating the fracture healing process. Our aim was to develop a method which allows determination of callus stiffness in vivo, the healing time and the duration of the repair phase. The right femurs of 16 Wistar rats were osteotomized and stabilized with either more rigid or more flexible external fixation. Fixator deformation was measured using strain gauges during gait analysis. The strains were recalculated as the callus stiffness over the time course of healing, and the healing phases were identified based on stiffness thresholds. Our hypothesis was that stabilization with more flexible external fixation prolongs the repair phase, therefore resulting in an extended healing time. Confirming our hypothesis, the duration of the repair phase (rigid: approximately 15 days, flexible: approximately 41 days) and the healing time (rigid: approximately 27 days, flexible: approximately 62 days) were significantly longer for more flexible external fixation. Our method allows the quantitative detection of differences in the healing time and duration of the repair phase without multiple time‐point sacrifices, which reduces the number of animals in experimental studies. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1589–1595, 2014.     

True Strength of Ceramic Fiber Bundles: Experiments and Simulations

A study on the strength of ceramic fiber bundles based on experimental and computational procedures is presented. Tests were performed on single filaments and bundles composed of two fibers with different nominal fiber counts. A method based on fiber rupture signals was developed to estimate the amount of filament rupture during the test. Through this method, the fiber bundle true strength was determined and its variation with the initial fiber count observed. By using different load-sharing models and the single filament data as input parameter, simulations were also developed to verify this behavior. Through different approaches between experiments and simulations, it was noted that the fiber bundle true strength increased with the fiber count. Moreover, a variation of the fibers’ final proportion in the bundles relative to the initial amount was verified in both approaches. Finally, discussions on the influence of different load-sharing models on the results are presented.     

Stimulation of secretory antibody following oral administration of antigen

IgA antibodies produced by plasma cells in secretory tissues associated with mucosal surfaces represent a major host defense against infectious agents. Precursors of these IgA-producing cells originate in gut-associated lymphoid tissue and, to a lesser extent, in bronchial-associated lymphoid tissue and migrate via the blood not only to gut but also to other mucosal tissues, forming a common mucosal immune system. Oral administration of antigen leads to priming of precursor cells in the gut and subsequent occurrence of specific secretory IgA (S-IgA) antibody in saliva, milk, tears, and the respiratory and genital tracts. On the basis of a review of the world literature, it has been concluded that oral live vaccines elicit higher antibody titers in remote-site secretions and in serum than do oral killed vaccines, which usually stimulate only relatively low levels of local secretory antibody. Oral immunization induces S-IgA in children and adults (including the elderly) without detectable adverse effects. Despite a number of remaining questions, oral immunization against extraintestinal infections is a promising area for future clinical studies.     

MANIA—A Pattern Classification Toolbox for Neuroimaging Data

Conventional univariate statistics are common and widespread in neuroimaging research. However, functional and structural MRI data reveal a multivariate nature, since neighboring voxels are highly correlated and different localized brain regions activate interdependently. Multivariate pattern classification techniques are capable of overcoming shortcomings of univariate statistics. A rising interest in such approaches on neuroimaging data leads to an increasing demand of appropriate software and tools in this field. Here, we introduce and release MANIA—Machine learning Application for NeuroImaging Analyses. MANIA is a Matlab based software toolbox enabling easy pattern classification of neuroimaging data and offering a broad assortment of machine learning algorithms and feature selection methods. Between groups classifications are the main scope of this software, for instance the differentiation between patients and controls. A special emphasis was placed on an intuitive and easy to use graphical user interface allowing quick implementation and guidance also for clinically oriented researchers. MANIA is free and open source, published under GPL3 license. This work will give an overview regarding the functionality and the modular software architecture as well as a comparison between other software packages.     

The activation pattern of macrophages in giant cell (temporal) arteritis and primary angiitis of the central nervous system

To determine if the pattern of macrophage activation reflects differences in the pathogenesis and clinical presentation of giant cell arteritis and primary angiitis of the central nervous system, specimens of 10 patients with giant cell arteritis and five with primary angiitis of the central nervous system were immunohistochemically studied and the expression of the macrophage activation markers 27E10, MRP14, MRP8 and 25F9 was determined in the vasculitic infiltrates. Thus, a partly different expression pattern of macrophage activation markers in giant cell arteritis and primary angiitis of the central nervous system was observed. The group comparison revealed that giant cell arteritis cases had significantly higher numbers of acute activated MRP14‐positive macrophages, whereas primary angiitis of the central nervous system is characterized by a tendency toward more MRP8‐positive intermediate/late activated macrophages. Furthermore, in giant cell arteritis comparably fewer CD8‐positive lymphocytes were observed. These observations suggest, that despite their histopathological similarities, giant cell arteritis and primary angiitis of the central nervous system appear to represent either distinct entities within the spectrum of granulomatous vasculitides or different stages of similar disease processes. Their discrete clinical presentation is reflected by different activation patterns of macrophages, which may characterize giant cell arteritis as a more acute process and primary angiitis of the central nervous system as a more advanced inflammatory process.     

Advancing Biomarker Development Through Convergent Engagement: Summary Report of the 2nd International Danube Symposium on Biomarker Development,Molecular Imaging and Applied Diagnostics; March 14–16, 2018; Vienna,Austria

Molecular Imaging and Biology - Here, we report on the outcome of the 2nd International Danube Symposium on advanced biomarker development that was held in Vienna, Austria, in early 2018. During...