Updated from 2:40 p.m. EST

Shares of Lifecore Biomedical ( LCBM) were among the best-performing health-related stocks Thursday, rising 30.4% after the company posted second-quarter earnings and sales that were above expectations.

The medical-device maker posted earnings of $2.38 million, or 18 cents a share, on sales of $14.1 million. Analysts polled by Thomson First Call were expecting earnings of 11 cents a share on sales of $13 million. A year ago the company earned $597,000, or 5 cents a share, on sales of $11.6 million. Looking ahead, Lifecore expects third-quarter earnings of 12 cents to 14 cents a share, in line with expectations, on sales of $13.3 million to $13.8 million, which is in line with analysts' expectations of $13.8 million. Shares traded up $3.50 to $15.

Abiomed ( ABMD) fell 12.1% after the company warned that third-quarter results would come in lower than expected. The medical products maker expects to post a loss of 1 cent a share on sales of $9.6 million. Analysts had been expecting earnings of 4 cents a share on sales of $11.3 million. The company attributed the shortfall to slower-than-expected sales force expansion in the U.S. Shares traded down $1.72 to $12.45.

Shares of Arena Pharmceuticals ( ARNA) fell 4.9% after the company said it plans to sell 6 million shares of stock to the public. CIBC World Markets is the underwriting syndicate. The shares are being sold pursuant to an existing and effective shelf registration. The biopharmaceutical company also plans to grant initial purchasers a 30-day option to purchase up to an additional 900,000 shares to cover over-allotments. Shares traded down 32 cents to $6.25.

Other health care movers included Pfizer ( PFE), down 70 cents to $25.33; Aastrom Biosciences ( ASTM), down 18 cents to $2.58; Amgen ( AMGN), down 98 cents to $63.89; Schering-Plough ( SGP), down 76 cents to $20.65; Merck ( MRK), down 43 cents to $30.65; Biopure ( BPUR), down 2 cent to 55 cents; StemCells ( STEM), down 6 cents to $5.31; and Bristol-Myers Squibb ( BMY), down 26 cents to $24.40.