Genetic Fragments Could Lead to SARS Treatment

WASHINGTON — Small fragments of genetic material that can silence specific genes are showing promise in battling the deadly severe acute respiratory syndrome.

SARS, first recognized in 2002, killed 774 people worldwide before it was brought under control by quarantine, isolating patients and restricting travel.

Researchers reported Sunday that small fragments of ribonucleic acid, called siRNA or interfering RNA, can reduce an existing infection in monkeys and help prevent new ones. RNA transmits the genetic blueprint for life in cells; siRNA can be tailored to silence specific genes.

All the animals infected in the study developed some SARS symptoms, but there was much less damage to the tiny air sacs in the lungs that exchange oxygen for carbon dioxide in the animals treated with siRNA, and their body temperature increases were smaller. How the treatment deals with SARS is not yet clear.