Role of TNFα in pulmonary pathophysiology

Tumor necrosis factor alpha (TNFα) is the most widely studied pleiotropic cytokine of the TNF superfamily. In pathophysiological conditions, generation of TNFα at high levels leads to the development of inflammatory responses that are hallmarks of many diseases. Of the various pulmonary diseases, TNFα is implicated in asthma, chronic bronchitis (CB), chronic obstructive pulmonary disease (COPD), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In addition to its underlying role in the inflammatory events, there is increasing evidence for involvement of TNFα in the cytotoxicity. Thus, pharmacological agents that can either suppress the production of TNFα or block its biological actions may have potential therapeutic value against a wide variety of diseases. Despite some immunological side effects, anti-TNFα therapeutic strategies represent an important breakthrough in the treatment of inflammatory diseases and may have a role in pulmonary diseases characterized by inflammation and cell death

Fair sharing of mac under tcp in wireless ad hoc networks

In this study we investigate the performance of TCP and MAC layer in a wireless multi-hop network. Using simulation, we provide new insights into the interactions between TCP and various MAC layer protocols, including CSMA, FAMA and 802.11. These MAC protocols were chosen because they provide an evolution of wireless medium access schemes, starting with carrier sensing (CSMA), then evolving to the utilization of RTS/CTS control frames (FAMA) and finally progressing to collision avoidance and acknowledgements (802.11). We examine these interactions in various network topologies and in a mobile environment where node movements are unpredictable. In particular, we address the issue of fair sharing of MAC with multiple TCP flows. 1