Neutral lipid storage disease comprises a heterogeneous group of inherited disorders characterized by severe accumulation of cytoplasmic triglyceride droplets in several tissues and neutrophils. A novel type of autosomal recessive lipid myopathy due to PNPLA2 mutations was recently described with associated cardiac disease, myopathy and frequent infections, but without ichthyosis. Here we describe the clinical and biochemical characteristics of a long surviving patient and report on four carrier family members with diverse clinical involvement. Interestingly, heterozygous patients show neutral lipid storage in muscle and in the keratocytes of the skin, Jordans' bodies, mild myopathy and frequent infections. Biochemical analysis of fibroblasts obtained from patients revealed increased triglyceride storage and reduced lipid droplet-associated triglyceride hydrolase activity. Together, our data implicate that the wild-type allele cannot fully compensate for the mutated dysfunctional allele of PNPLA2 leading to triglyceride accumulation in muscle and mild myopathy in PNPLA2 mutation carriers. The presence of neutral lipid droplets in the skin in PNPLA2 mutation carriers strengthens the link between NLSD and other neutral lipid storage diseases with ichthyosis.

As hypertext learning environments (HLE) are widely used in education, it is important to study and know the effects and consequences of its use. HLEs are non-linear which means that students have to develop ways of navigating through them. Thus, developing interfaces that facilitate and even guide navigation is important for learning. Research showed that successful learning in HLEs depends on both learner characteristics and HLE features. This study investigated an HLE navigation feature (navigational support with either a tag-cloud or conventional hierarchical menu), task complexity (fact-finding vs. information-gathering task) and a user characteristic (gender). Results show that neither navigational support nor gender is associated with differences in task performance. However, there are differences in information processing. Participants using a tag clouds looked longer at the navigational support and shorter at the overview pages. Combined with fewer revisits of webpages in the tag cloud condition, this indicates a more focused selection of pages. The deeper processing of information needed for the information-gathering task was reflected in fewer visits to, but longer viewing times of pages. As no differences in task performance were found, tag clouds seem to be as effective for performance as more traditional navigation structures for navigational support.

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