Amgen Net Down, Adjusted Earnings Rise  NEW YORK (Reuters) - Amgen Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AMGN.O target=/stocks/quickinfo/fullquote"&gt;AMGN.O&lt;/A&gt;, the world's  biggest biotechnology company, on Wednesday reported a lower  third-quarter net profit as a result of expenses related to the  acquisition of Tularik Inc.