SCREAMER: Boston Scientific Corp. bsx shares dropped 18 percent after the company recalled two different rotational-atherectomy systems because of a product defect. The products are used in a heart-disease treatment that clears the path to an artery without disturbing the vessel wall. Boston Scientific said it's fixing the problem and plans to resume sales. Shares fell 6 7/16 to close at 30 1/16. See Screamers.