The leprosy bacterium grows in humans, armadillos, and the footpads of mice—but not in test tubes. A genetics study of strains of Mycobacterium leprae from patients around the world now shows that a single bacterial clone that has spread but barely mutated over time is responsible for the world's entire leprosy infection. It now looks as if leprosy originated in East Africa, and Europeans and North Africans took it to West Africa. The slave trade took it from there to the Caribbean and South America (Science 2005;308: 1040-2).

Inhibiting gastric acid is critical when managing active peptic ulcer bleeding that doesn't stop spontaneously. A randomized placebo controlled trial comparing treatment with infusing somatostatin and a proton pump inhibitor found that both achieved high intragastric pH values compared with placebo, but that somatostatin was more effective during the first 12 hours of treatment. In this case, somatostatin is thought to work by inhibiting gastrin, in addition to its vasoactive effect of reducing bleeding (Scandinavian Journal of Gastroenterology 2005;40: 515-22).

If someone gave you $10 to complete an automated telephone survey about your sexual behavior, …