Health Behavior Change Support Systems as a research discipline; a viewpoint

As research on Health Behavior Change Support Systems (HBCSS) proliferates, meaningful management of the different findings is becoming a challenge. We argue that for the field to evolve, it is important to establish the study of HBCSSs as an independent research area, which means that instead of only applying theories from related disciplines to HBCSSs, we need to significantly extend and adapt these theories, or develop new theories, to explain the phenomena that are encountered. Current research in HBCSSs is carried out in different disciplines, with a different approach in each of these disciplines. However, both the CeHRes roadmap and the Persuasive System Design Model show that HBCSSs are complex and the development and evaluation of these systems need to deal with this complexity to be successful. Therefore, an integrative approach is needed to study the combination of content, system, and context. Although research into the separate areas has yielded important findings that are discussed in this paper, we argue that an integrated approach of HBCSSs is useful. We discuss two examples to show how a truly integrative approach can be utilized to enhance the field involving tailoring, personalization, and support. In conclusion we present three practical and relatively easy–to-implement recommendations for researchers who want to contribute to this discipline: Avoid the black box, be specific about the terms used, and look past the borders of one’s own discipline

Effects of phospholipase A2 and its products on structural stability of human LDL: relevance to formation of LDL-derived lipid droplets[S]

Hydrolysis and oxidation of LDL stimulate LDL entrapment in the arterial wall and promote inflammation and atherosclerosis via various mechanisms including lipoprotein fusion and lipid droplet formation. To determine the effects of FFA on these transitions, we hydrolyzed LDL by phospholipase A2 (PLA2), removed FFA by albumin, and analyzed structural stability of the modified lipoproteins. Earlier, we showed that heating induces LDL remodeling, rupture, and coalescence into lipid droplets resembling those found in atherosclerotic lesions. Here, we report how FFA affect these transitions. Circular dichroism showed that mild LDL lipolysis induces partial β-sheet unfolding in apolipoprotein B. Electron microscopy, turbidity, and differential scanning calorimetry showed that mild lipolysis promotes LDL coalescence into lipid droplets. FFA removal by albumin restores LDL stability but not the protein conformation. Consequently, FFA enhance LDL coalescence into lipid droplets. Similar effects of FFA were observed in minimally oxidized LDL, in LDL enriched with exogenous FFA, and in HDL and VLDL. Our results imply that FFA promote lipoprotein coalescence into lipid droplets and explain why LDL oxidation enhances such coalescence in vivo but hampers it in vitro. Such lipid droplet formation potentially contributes to the pro-atherogenic effects of FFA