WASHINGTON (AP) _ Flooding the body with laboratory-engineered white blood cells shriveled melanoma tumors in a small group of seriously ill patients, leaving some virtually free of the disease, according to researchers at the National Institutes of Health. A team led by Dr. Steven A. Rosenberg of the National Cancer Institute used amplified lymphocytes _ the body's white blood cells _ to attack melanoma tumors in 13 patients. Ten of those patients are still alive, four are ``virtually cancer free'' and two others have experienced ``substantial'' shrinkage of their tumors, Rosenberg said. Rosenberg, who has spent years developing ways to...