NEW YORK (AP) — Shares of some top biotechnology companies are mixed at 10 a.m.: Amgen fell $.15 or .3 percent, to $57.61. Biogen Idec rose $.92 or 1.6 percent, to $58.76. Celgene rose $.15 or .2 percent, to $61.91. Gilead Sciences rose $.16 or .3 percent, to $47.60.