** " Throwing a molecular monkey wrench into the works** When a virus enters a human cell, its outer shell opens, like the trapdoor in a Trojan horse. Inside are genes that turn the human cell into a virus-making machine. Scientists hope to block the trapdoor of a major cold-causing virus by filling a tiny cavity in its shell. A team led by Carol Post, a computational biologist at Purdue University, has shown that antiviral drugs called WIN compounds can wriggle into a virus's protein shell and gum up the works. In human tests, one such compound, Pleconaril, speeded patients' recovery--but only by a day. Drugmaker Schering-Plough is making a nasal-spray version that could be on shelves by next year.