Injections of an enzyme called PAP into an acupuncture point behind the knees of mice relieved pain caused by inflammation for up to six days, Julie Hurt and Mark Zylka of the University of North Carolina at Chapel Hill report online April 23 in Molecular Pain. That’s almost 100 times longer than pain relief from acupuncture, which typically lasts about 1½ hours. Long-lasting pain relief “is truly important, clinically,” says Maiken Nedergaard, a neuroscientist at the University of Rochester in New York. She and colleagues previously demonstrated that inserting and manipulating acupuncture needles causes the body to release a chemical...