Wednesday, November 9, 2005
Pain has a couple of very interesting piece amidst the murine model papers I've never been able to appreciate. First, an editorial about current research that buprenorphine not only has analgesic effects but also anti-hyperalgesic effects (as in opioid-induced hyperalgesia), via kappa-opioid receptor antagonism. The editorial of course refers to an actual article in Pain, but for the average reader (like me) I'd suggest sticking with the editorial. "Today, opioids cannot only be considered for their potency to reduce nociceptive symptoms but also for their ability to oppose active processes leading to pain hypersensitivity. This might be a new and beneficial approach for preemptive analgesia and improving the treatment of some forms of chronic pain dominated by central sensitization."
And then, the article which explains several life-long habits of mine: chewing gum relieves pain. I'm not going to bother to critique this one--it's actually really interesting with a lengthy discussion about serotonin in nociception, speculation about the the necessity of rhythmic chewing to achieve the nociception, and a brief review of the chewing & analgesia literature. I do want to highlight my appreciation of the authors' quietly funny prose however:
"The NFR recording and stimulating electrodes were attached to the subject. All recording and stimulation electrode sites were cleaned and gently abraded. The reflex was induced by transcutaneous electrical stimulation of the sural nerve at the right ankle while the subject reclined in a comfortable armchair with the lower legs bent to an angle of less than 150 degrees so as to achieve a state of muscular relaxation."
A subject was asked to chew gum voluntarily and rhythmically for 20 min at a comfortable speed (task experiment). To ensure the intensity and rhythm of mastication, we monitored EMG of masseter muscle throughout gum chewing. The composition of gum (Xylish sugarless, Meiji Co., Tokyo, Japan) was gumbase, maltitol, xylitol and so on. The flavor was mint. The quantity of gum was up to the subject. The mean quantity was 4.3±1.4 g."
Finally, there's a review on neuropathic pain from the non-surgical treatment of breast cancer (chemo and radiation therapy).