University researchers reported that a protein fragmentrelated to beta-amyloid causes brain damage when injectedinto mice, supporting a causative role for the amyloid plaquesthat are the hallmark of Alzheimer's disease.

As described in the current Proceedings of the NationalAcademy of Sciences, an end portion of the precursor proteinthat includes beta-amyloid was able to induce gross shrinkageof the cortex by four months after transplantation. Theinducing fragment was borne by cells engineered with a genethat directed its synthesis.

The scientists are from the University of California, Irvine, andJohns Hopkins Medical School.

A report in the October issue of the journal also suggested thatamyloid deposits are, in fact, neurotoxic. Researchers at theUniversity of California, San Diego, Medical School and theWhittier Institute, both in La Jolla, Calif., found degenerativedamage after injecting beta-amyloid cores isolated from thebrains of Alzheimer's victims into the brains of rats.

A transgenic mouse developed by Scios Inc. of Mountain View,Calif., bearing DNA coding for the precursor protein of betaamyloid, has been shown to develop preamyloid deposits. --Roberta Friedman, Ph.D.

(c) 1997 American Health Consultants. All rights reserved.