A protein-free extract prepared from glands in the brains of beef cattle shows great promise in the treatment of chronic schizophrenics and other mental patients, a Harvard Medical School researcher reported yesterday.

Dr. Mark D. Altschule, assistant clinical professor of Medicine, wrote in the New England Journal of Medicine that injection of the pineal gland extract has brought a constant improvement in the behavior pattern of patients and in their blood chemistry.

Dr. Altschule, who is also director of internal medicine and research in clinical physiology at McLean Hospital in Waverly, emphasized the great promise of the treatment. He stated that behavioral improvement was maintained during and after the treatments.

Dr. Altschule warned against premature enthusiasm for the cure, saying that broader clinical and laboratory studies remain to be done.