Author of three solid medical guides (Aging Myths, Examine Your Doctor, Is Surgery Necessary?), Kra now does an Oliver Sacks--but not half as well as the original--with this thin collection of 12 medical mystery tales. Kra's a cardiologist, and his stories emphasize bizarre physical dysfunction--and thus prove far less intellectually challenging than the psychospiritual-oriented cases of Sacks, a neurologist. Moreover, the two kickoff tales here recount cases in which Kra had no personal involvement and that hinge on gross physical impairments: dull Ripley's stuff related without insight or wit (the title tale describes a Don Juan whose sudden impotence is due to arterial block; "Dead Mackerel" tells of a woman who, due to an excess protein in her body, smells of dead fish). More appealing is "The Kosher Connection," the first story in which Kra figures and one of the more satisfying cases here--i.e., one which details a train of deduction leading to a logical solution. Here, an Orthodox Jewish woman (who would never eat pork) exhibits symptoms of trichinosis. Why? Because, as Kra deduces, her allegedly kosher butcher cut her carp for gelfilte fish on the same block on which he'd cut tainted pork. Equally satisfying is the tale of "The Mad Hatter," wherein Kra traces a dentist's mental and physical collapse to overexposure to mercury used for cavity fillings. And also memorable, more for the emotion evinced in the retelling than for any medical novelty, are two tales bathed in romance--"Leysin," the story of how Kra as a young M.D. fell in love with a TB patient; and "The Marquise of Toulouse," in which Kra suspects, then exonerates, that glamorous woman of poisoning her husband. Definitely not Oliver Sacks. Pretty close to Ben Casey reruns, though.