Functional Analysis of Ficolin-3 Mediated Complement Activation

The recognition molecules of the lectin complement pathway are mannose-binding lectin and Ficolin -1, -2 and -3. Recently deficiency of Ficolin-3 was found to be associated with life threatening infections. Thus, we aimed to develop a functional method based on the ELISA platform for evaluating Ficolin-3 mediated complement activation that could be applicable for research and clinical use. Bovine serum albumin (BSA) was acetylated (acBSA) and chosen as a solid phase ligand for Ficolins in microtiter wells. Binding of Ficolins on acBSA was evaluated, as was functional complement activation assessed by C4, C3 and terminal complement complex (TCC) deposition. Serum Ficolin-3 bound to acBSA in a calcium dependent manner, while only minimal binding of Ficolin-2 and no binding of Ficolin-1 were observed. No binding to normal BSA was seen for any of the Ficolins. Serum C4, C3 and TCC deposition on acBSA were dependent only on Ficolin-3 in appropriate serum dilutions. Deposition of down stream complement components correlated highly significantly with the serum concentration of Ficolin-3 but not with Ficolin-2 in healthy donors. To make the assay robust for clinical use a chemical compound was applied to the samples that inhibited interference from the classical pathway due to the presence of anti-BSA antibodies in some sera. We describe a novel functional method for measuring complement activation mediated by Ficolin-3 in human serum up to the formation of TCC. The assay provides the possibility to diagnose functional and genetic defects of Ficolin-3 and down stream components in the lectin complement pathway

Two new methods for estimating structural equation models: An illustration and a comparison with two established methods

The application of structural equation models (SEMs) is common in marketing and the behavioral sciences. Accordingly, the exploration of more effective methods to estimate SEMs is also a popular area of research. Croon (2002) and Skrondal and Laake (2001) have each proposed a new method for estimating SEMs, but since these proposals nearly a decade ago, these methods have been mostly overlooked by applied researchers. We suggest that reasons for this oversight may include not only a lack of guidance in implementing these new methods but also the absence of a formal comparison to review these new methods relative to the more familiar maximum likelihood structural equation modeling (MLSEM) and partial least squares (PLS). In this paper, our goal was to make the Croon and Skrondal-Laake (SL) methods more accessible to applied researchers. We first provide a step-by-step illustration of how to implement the Croon and SL methods. We also present the first comprehensive evaluation of the new methods relative to MLSEM and PLS. From this evaluation, we can better appreciate the circumstances under which these new methods are preferable to MLSEM and PLS. Thus, we intend to help readers understand how and when to apply these new methods

The ivory tower and the street: How researchers defined country image over four decades and what consumers think it means

This study's purpose is to provide a comprehensive and systematic analysis on the diversity and nature of country image (CI) definitions in academic research. We used both qualitative content analysis and quantitative social network analysis to systematically analyse CI definitions. The study identified the key concepts that have been central to defining CI and the processes of CI formation. We also examined how the definitions have evolved over four decades. We found an increasing diversity in the academic definitions of CI. We identified several trends in the academic definitions to suggest that the conceptualization of CI has become broader and is no longer confined to the context of consumption. We also compared definitions from academia to those from the general population. With a few exceptions, academia and the general population did not agree on the popular concepts and mechanisms in CI definition

Role of the complement-lectin pathway in anapylactoid reaction induced with lipopolysaccharide in mice.: Eur.J.Immunol.

NRC publication: Ye

L-ficolin in children with recurrent respiratory infections

The lectin pathway of complement activation is used by a collectin, mannan-binding lectin (MBL), and two ficolins, L-ficolin and H-ficolin, to opsonize microorganisms for phagocytosis. We published evidence recently that MBL insufficiency is associated with recurrent respiratory infections in childhood. We have now measured serum L-ficolin in 313 respiratory infection patients and 74 healthy control children. L-ficolin concentrations below the lower limit of the control group were found in 6% of the patients (P < 0·02) and were associated most strongly with children having co-existing atopic disorders (11%; P = 0·002). We suggest that L-ficolin may have a role in protection from microorganisms complicating allergic disease