Wednesday's Health Winners & Losers

Earnings, both better-than-expected and disappointing, as well as study results, positive and negative, helped keep the health-care sector fairly flat Wednesday.

Sirtris Pharmaceuticals(SIRT Quote) made its debut Wednesday with an initial public offering of 6 million shares at $10 apiece before underwriting discounts and commissions. It offered underwriters a 30-day opportunity to purchase an additional 900,000 shares to cover overallotments. Shares, which are listed on the Nasdaq Global Market, rose $1.02, or 10.3%, to $11.03 in recent trading.

Of those that released earnings, Possis Medical (POSS Quote) was among the losers Wednesday. For the third quarter ended April 30, the company reported net income of $44,000, or break-even on a per-share basis, compared to a net loss of $278,000, or 2 cents a share, in the year-ago period. However, analysts surveyed by Thomson Financial had targeted profit of 5 cents a share. Possis fell $1.25, or 9.3%, to $12.15.

On the other hand, Medtronic(MDT Quote) was among the winners, buoyed by an earnings beat late Tuesday and a subsequent upgrade on Wednesday. The biotech company earned 4 cents a share more than the Thomson Financial consensus target with non-GAAP earnings of 66 cents a share, or $767 million, in the quarter ended April 27. Piper Jaffray upgraded Medtronic to outperform from market perform. The stock was up $2.82, or 5.6%, to $53.64.