Anyone who reads gothic fiction will tell you that vampires are bad news. People who read modern medical journals, however, might disagree--in fact, they think vampires just might help save lives.
The kind of vampire I'm talking about is Desmodus rotundus, commonly known as the "vampire bat." Yep, these little creatures are real; and even though they almost never turn into suave Romanian counts to drool over, they do drool a lot themselves. That's because their saliva is an essential part of their dining habits.
When a vampire bat latches onto, say, a steer, it needs to keep the blood flowing from the puncture made by its teeth. That's achieved by a natural anti-coagulant in the vampire bat's saliva. Despite what you see in the movies, vampire bats almost never drink human blood. But people do suffer from other blood problems--a leading one being stroke.
Stroke is caused by a clotting in the blood which stops the flow and can starve areas of the brain of oxygen. Doctors have generally broken up clots with a compound called tPA. TPA works okay, but it has dangerous side effects, and can even hurt brain cells.
A better idea? Bring in the bats, says researcher Robert Medcalf, a biochemist from Australia. Vampire bat spit contains a different compound, DSPA, which does the good things tPA does with far fewer side-effects. DSPA is now being tried on patients who have suffered a stroke; the data should be in within a year. If it works, doctors might have found an unlikely friend--the vampire bat.