Before the Bell: Atherogenics Up 82 Pct.  NEW YORK (Reuters) -  Shares of AtheroGenics Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AGIX.O target=/stocks/quickinfo/fullquote"&gt;AGIX.O&lt;/A&gt;  soared 82 percent before the bell on Tuesday, a day after the  pharmaceutical company announced positive interim results from  a study on an anti-inflammatory agent.