Key network approach reveals new insight into Alzheimer's disease.

Alzheimer's disease (AD) is a severe neurodegenerative disorder without curative treatment. Extensive data on pathological molecular processes have been accumulated over the last years. These data combined allows a systems biology approach to identify key regulatory elements of AD and to establish a model descriptive of the disease process which can be used for the development of therapeutic agents. In this study, the authors propose a closed network that uses a set of nodes (amyloid beta, tau, beta-secretase, glutamate, cyclin-dependent kinase 5, phosphoinositide 3-kinase and hypoxia-induced factor 1 alpha) as key elements of importance to the pathogenesis of AD. The proposed network, in total 39 nodes, is able to become a novel tool capable of providing new insights into AD, such as feedback loops. Further, it highlights interconnections between pathways and identifies their combination for therapy of AD.

Nanosilver: application and novel aspects of toxicology.

Nanomaterials are a challenge to toxicology. The high diversity of novel materials and products will require extensive expertize for evaluation and regulatory efforts. Nanomaterials are of substantial scientific and economic potential. Here, we will focus on nanosilver, a material not only with medical applications, but a rapidly increasing use in surprisingly many products. Consequently, toxicological evaluation has to cover an increasing range of complex topics. The toxicology of nanosilver is advancing rapidly; regulatory efforts by Federal Drug Agency and European Environment Protection Agencies are substantial. Current toxicological data, ranging from in vitro studies with cell lines to rodent experiments and ecological evaluation, are numerous, and many groups are providing continuously new data. However, standard classification based on nanosize only is neglecting nanoshape, which adds another level of complexity to the analysis of biological effects. A surprising neglect in nanosilver toxicology so far is the analysis of effects of nanosilver on amyloidosis. Amyloid diseases are widespread in humans and a severe health hazard. The known potential of silver to stimulate amyloidosis in rodents will require a timely and balanced evaluation of nanosilvers.