Methamphetamine Increases LPS-Mediated Expression of IL-8, TNF-α and IL-1β in Human Macrophages through Common Signaling Pathways

The use of methamphetamine (MA) has increased in recent years, and is a major health concern throughout the world. The use of MA has been associated with an increased risk of acquiring HIV-1, along with an increased probability of the acquisition of various sexually transmitted infections. In order to determine the potential effects of MA exposure in the context of an infectious agent, U937 macrophages were exposed to various combinations of MA and bacterial lipopolysaccharide (LPS). Treatment with MA alone caused significant increases in the levels of TNF-α, while treatment with both MA and LPS resulted in significant increases in TNF-α, IL-1β and the chemokine IL-8. The increases in cytokine or chemokine levels seen when cells were treated with both LPS and MA were generally greater than those increases observed when cells were treated with only LPS. Treatment with chemical inhibitors demonstrated that the signal transduction pathways including NF-kB, MAPK, and PI3-Akt were involved in mediating the increased inflammatory response. As discussed in the paper, these pathways appear to be utilized by both MA and LPS, in the induction of these inflammatory mediators. Since these pathways are involved in the induction of inflammation in response to other pathogens, this suggests that MA-exacerbated inflammation may be a common feature of infectious disease in MA abusers

Beyond internet addiction. A new framework to understand risks and benefits of being online

This paper introduces a research whose purpose is to investigate the relationships between online and offline lives. Starting by the concept of functional organ (Leont'ev, 1972) and inverse instrumentality (Ekbia & Nardi, 2012), the goal of this study is trying to define a model able to predict why some people have their life empowered by the web and while others get trapped in the problematic use. The model, designed after a deep analysis of existing literature, takes into account online behaviors, self-control traits, life satisfaction and online and offline social activity; in order to understand when intense use of the internet can become empowering or problematic

Phosphorylation of STEF/Tiam2 by protein kinase A is critical for Rac1 activation and neurite outgrowth in dibutyryl cAMP–treated PC12D cells

Although cAMP-induced neuritogenesis was described in 1975, the signaling pathways from cAMP to cytoskeletal regulation remain elusive. Here we report that the protein kinase A (PKA)-Sif-and Tiam1-like exchange factor (STEF)-Rac1 pathway plays a central role in cytoskeletal regulation during neurite outgrowth in PC12D cells. This result could be extrapolated to axon guidance depending on cAMP signals