So effective was the treatment in eight dogs severely affected by osteroarthritis, cancer-related pain, or both, all eventually became more active and later walked with slight or no limps. Just as importantly, none showed any adverse side effects from the treatment, their temperaments were improved, and their need for other pain-controlling medications was eliminated or greatly reduced.
The authors also reported selectively deleting the nerve cells, called C-fiber neurons, from among various human neurons cultured together in the laboratory, an indication the strategy might work in people. C-fibers convey to the central nervous system sensations of noxious heat and certain inflammatory signals. "Some have referred to the technique as using a 'molecular scalpel,'" said Dr. Michael J. Iadarola, a scientist at the NIH's National Institute of Dental and Craniofacial Research (NIDCR) and a senior author on the paper. "The technique selectively deletes certain neurons but leaves others untouched. As a result, the nervous system functions normally, it's just a certain spectrum of pain responsiveness that has been deleted."
Currently, doctors have no way of selectively eliminating nerve cells involved in chronic pain. Opioid-based analgesics, the mainstay of current treatments for moderate to severe chronic pain, cannot provide universal relief, and other treatments are nonselective and/or can cause serious side effects.
Iadarola said this month's paper stems from using the old drug resiniferatoxin, or RTX, in a new way. First isolated in the 1970s, RTX is often used as a laboratory tool b
Contact: Bob Kuska
NIH/National Institute of Dental and Craniofacial Research