Sue Hartigan <[EMAIL PROTECTED]> writes: Researchers Find How Anthrax Kills > WASHINGTON (AP) -- Researchers are moving closer to > finding drugs to disarm anthrax and make the deadly > bacteria useless as a weapon. > > In a study published today in the journal Science, > researchers report they have discovered how anthrax > toxin destroys cells and rapidly causes death. This > puts science closer to finding an antitoxin, or > inhibitor drug, that would block the deadly work of the > bacteria, said Dr. George F. Vande Woude of the > National Cancer Institute. > > ``An inhibitor drug would make anthrax as a weapon as > useful as a water pistol,'' said Vande Woude, a > co-author of the study in Science. > > Experts consider anthrax-based biological weapons to be > major threats to military personnel and civilians. > Bioterrorism weapons using anthrax or other bacteria > are easier to make and distribute than nuclear weapons, > and anthrax bombs are a major concern of U.N. weapons > inspectors working in Iraq. > > Attorney General Janet Reno and FBI Director Louis J. > Freeh warned Congress last week that U.S. civilian > targets are vulnerable to biological terrorism. Some in > Congress have said classified studies suggest such an > attack on American civilians could occur within a > decade. > > The military is inoculating all of its troops against > anthrax, using a vaccine that would prevent infection > from the disease. However, the vaccine is not 100 > percent effective and most civilians do not receive > these shots. > > Anthrax is a rapid and highly effective killer. When it > infects, the bacteria produces a toxin, or poison, that > attacks cells. > > ``The only treatment now for anthrax is to give > massive, massive amounts of antibiotics,'' said > Nicholas S. Duesbery of the cancer institute. ``You > have to give it almost immediately after exposure. If > you give it 24 hours later, it is too late. Your > patient is dead.'' > > Anthrax toxin consists of three proteins, and early > research showed that one of the proteins, called lethal > factor, or LF, was the major cause of cell death. But > what science didn't know until now is how LF killed the > cells. > > Vande Woude, Duesbery and their colleagues found that > LF disrupts a signaling system in cells called the > MAP-Kinase-Kinase (MAP-K-K) pathway. When this system > is blocked, said Duesbery, a cell ``is cut off from the > world.'' Its metabolism shuts down and it can no longer > divide. The toxin also causes the massive release of an > inflammation protein and destruction of immune system > cells called macrophages. > > The result, said Duesbery, is rapid shock and death. In > laboratory experiments, he said, ``rats are quite dead > within just 40 minutes'' when injected with anthrax > toxin. > > Now that researchers know the MAP-K-K target of lethal > factor, said Duesbery, ``This gives us the first clues > of what we need to develop an antitoxin. We can look at > the protein structure of the target and come up with (a > protein molecule) that will block lethal factor from > chopping up its target.'' > > Col. Arthur M. Friedlander, an Army anthrax researcher, > said the discovery is significant in understanding how > anthrax kills, but he cautioned that it may take more > than a single antitoxin to disarm the disease. > > ``It is not just that toxin that kills in this > disease,'' he said. ``But this offers a new approach > that may lead to other inhibitors that would work.'' > > Ironically, the anthrax cell target was found while NCI > researchers were searching for a way to block the > spread of cancer. Vande Woude said the cell-signaling > system that the anthrax toxin turns off is permanently > turned on in some cancers. The goal now is to use > lessons learned from the anthrax research to find a way > to selectively shut down the cell signals that promote > cancer, he said. -- Two rules in life: 1. Don't tell people everything you know. 2. Subscribe/Unsubscribe, email: [EMAIL PROTECTED] In the body of the message enter: subscribe/unsubscribe law-issues
