WellPoint Health Profit Up on Premiums  CHICAGO (Reuters) - WellPoint Health Networks Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=WLP.N target=/stocks/quickinfo/fullquote"&gt;WLP.N&lt;/A&gt;,  one of the biggest U.S. health insurers, on Monday posted a  steep rise in quarterly profit as it kept health premiums above  rising medical costs.