Word: tumorous
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Another pesticide frontrunner, ethylene dibromide, was years ago shown to cause some chromosome damage, to induce tumor formation, and to cause reproductive problems in several species. The EPA has only begun to look at the pesticide's safety, even though EDB is used on peaches, grapes, beans, peas and other fruits, as well as soybeans and cotton...
Another approach would be to find a substance that breaks down the cocoon from the outside, allowing the immune cells to get at the tumor. A third tactic that Dvorak and his colleagues are planning to explore is the production of antibodies against the tumor's own chemicals...
...discovery by Pathologists Harold and Ann Dvorak, along with W. Hallowell Churchill of Boston's Peter Bent Brigham Hospital, results from three years of work with guinea pigs. It is based on two vital clues provided by earlier investigators: first, some tumors have nearby deposits of fibrin, the substance of blood clots, which prevents further bleeding after injury; second, tumors are often associated with slight, local hemorrhaging. Using sophisticated microscopy techniques, the Boston researchers began looking at the point where the tumor meets healthy tissue. Explains Harold Dvorak: "That would have to be the battlefield on which they fought...
What the team found was that early in their development, tumors secrete three powerful chemicals that promote formation of a protective shield of fibrin gel around them. One substance encourages nearby blood vessels to leak plasma; another turns fibrinogen, a plasma constitutent, into fibrin; the third diverts immune cells away from the growing shield. Dvorak speculates that the tumor's chemical weaponry is so sophisticated that the fibrin itself encourages growth of blood vessels in the vicinity of the tumor, providing the malignant cells with a nourishing blood supply. As it enlarges, the tumor appears to secrete a fourth...
...this biochemical wizardry, the tumor has in effect duped the body into regarding it as a wound to be healed rather than as a lethal intruder. Says Dvorak: "The tumor is a sophisticated and subtle parasite that uses the host's own defense mechanism against the host...