Although activated spinal cord glia contribute importantly to neuropathic pain, how nerve injury activates glia remains controversial. It has recently been proposed, on the basis of genetic approaches, that toll-like receptor 4 may be a key receptor for initiating microglial activation following L5 spinal nerve injury. The present studies extend this idea pharmacologically by showing that TLR4 is key for maintaining neuropathic pain following sciatic nerve chronic constriction injury. Established neuropathic pain was reversed by intrathecally delivered TLR4 receptor antagonists derived (...) from lipopolysaccharide. Additionally, -naltrexone, -naloxone, and -naloxone, which we show here to be TLR4 antagonists in vitro on both stably transfected HEK293-TLR4 and microglial cell lines, suppressed neuropathic pain with complete reversal upon chronic infusion. Immunohistochemical analyses of spinal cords following chronic infusion revealed suppression of CCI-induced microglial activation by -naloxone and -naloxone, paralleling reversal of neuropathic pain. Together, these CCI data support the conclusion that neuron-to-glia signaling through TLR4 is important not only for initiating neuropathic pain, as suggested previously, but also for maintaining established neuropathic pain. Furthermore, these studies suggest that the novel TLR4 antagonists -naloxone and -naloxone can each fully reverse established neuropathic pain upon multi-day administration. This finding with -naloxone is of potential clinical relevance. This is because -naloxone is an antagonist that is inactive at the -opioid selective receptors on neurons that produce analgesia. Thus, these data suggest that -opioid antagonists such as -naloxone may be useful clinically to suppress glial activation, yet -opioid agonists suppress pain. (shrink)

This edition of Giraldus Odonis' Logica for the first time gives access to an important and original treatise, which has unduly been neglected since the author's death. It is also important in that it gives evidence of interesting achievements in the field of logic outside the anti-metaphysical circle surrounding Ockham.

In 2011, the Department of Health and Human Services proposed changes to the regulations that govern human subjects protection in federally funded research. The proposed changes involve modifying inclusion standards for minimal-risk research and removing the necessity of review from certain categories of noninvasive research. All studies would instead be required to comply with privacy protections as initiated by the Health Information Portability and Accountability Act . We argue that relying on HIPAA to protect participants from participation-related risks in noninvasive (...) research is insufficient to protect the autonomy and psychological health of potential research participants. Instead, we suggest a streamlined review format for these categories of research. (shrink)