Johnson & Johnson, the world's largest maker of medical devices, indicated its 1999 profit will be less than the $3 a share it estimated earlier, analysts said, sending its stock down as much as 4.1%. Shares of J&J, which also makes Tylenol and a line of baby-care products, fell $2.44 to close at $82.81 on the New York Stock Exchange. The New Brunswick, N.J.-based company said it guided analysts to lower estimates by 5 cents a share, or about 1.7%, to account for expenses stemming from its $3.5-billion purchase of orthopedics maker DePuy Inc. Revenue was hurt this year as J&J lost a near monopoly on U.S. sales of coronary stents, which are used to prop open once-clogged arteries. J&J Chief Executive Ralph Larsen has said the company is using cost controls to grow quarterly profit as it tries to develop products to replace the stent. The company has suffered several setbacks on new products. In the latest, the Food and Drug Administration this week rejected a diabetes drug that J&J was working on with Ergo Science Corp.