Biotechnology companies shares mixed at the close of trading

Shares of some top biotechnology companies were mixed at the close of trading:

Amgen Inc. rose $2.39 or 1.5 percent, to $165.97.

Biogen Idec rose $3.48 or .8 percent, to $422.92.

Celgene Corp. rose $1.28 or 1.1 percent, to $114.75.

Gilead Sciences Inc. fell $.73 or .7 percent, to $100.66.