Washington, Aug 12 - A 65-year-old woman, who has routine hip surgery, develops memory loss six months later and is diagnosed with Alzheimer's. Just a coincidence? Researchers at the University of South Florida (USF) and Vanderbilt University don't think so.

They suspect that the culprit precipitating Alzheimer's disease in the elderly women may be a routine administration of high concentrations of oxygen for several hours during, or following surgery - a hypothesis borne out in a recent animal model study.

Gary Arendash, neuroscientist at the USF Alzheimer's Disease Research Centre and L. Jackson Roberts at Vanderbilt University used genetically altered mice to develop abnormal levels of the protein beta amyloid, which deposits in the brain as plaques and eventually leads to Alzheimer-like memory loss as the mice age.