Updated from 2:14 p.m. EDT

Shares of Regeneration Technologies ( RTIX - Get Report) were among the worst-performing health-related stocks Tuesday, falling 30.9% after the company posted first-quarter results that missed expectations by a wide margin.

The company, which processes allograft tissue into shaped implants for use in orthopedic, cardiovascular and other surgeries, posted a loss of $1.3 million, or 5 cents a share, on sales of $15 million. Analysts polled by Thomson First Call were expecting a profit of 7 cents a share on sales of $25.3 million. A year ago the company earned $1.4 million, or 5 cents a share, on sales of $23.6 million. First-quarter results were plagued by order delays, which the company attributed to its review of strategic alternatives. The review, the company said, created uncertainty. Regarding the company's review of strategic alternatives, Regeneration has decided that it is best served by remaining an independent company. "We have worked with great diligence to reach this conclusion," the company said. Shares traded down $2.78 to $6.22.

WellCare Health Plans ( WCG - Get Report) rose 5.3% after the health care provider posted first-quarter results that were better than expected. The company earned $10.6 million, or 27 cents a share, on sales of $418.9 million. Analysts were expecting earnings of 25 cents a share on sales of $406.9 million. Looking ahead, WellCare forecast second-quarter earnings of 32 cents to 34 cents a share, in line with estimates, on sales of $430 million to $435 million. Analysts are expecting earnings of 33 cents a share on sales of $419.1 million. WellCare now expects 2005 earnings of $60 million to $62 million, or $1.50 to $1.55 a share, on sales of $1.72 billion to $1.75 billion. Previously, the company forecast earnings of $57 million to $60 million. Analysts are expecting earnings of $1.51 a share on sales of $1.72 billion. Shares traded up $1.68 to $33.40.

Shares of Dendreon ( DNDN) rose 6.6% after the biotech company posted a first-quarter loss that was narrower than expected. The company reported a loss of $19.5 million, or 33 cents a share, on sales of $57,000. Analysts were expecting a loss of 39 cents a share on sales of $320,000. A year ago the company reported a loss of $14.9 million, or 28 cents a share, on sales of $4.7 million. Last year's first quarter included significant revenue that was associated with the company's license agreement with Nuvelo. Shares traded up 37 cents to $5.94.

Diagnostic Products ( DP) fell 12.7% after the company posted first-quarter results that fell well below expectations. The maker of automated lab instrumentation products posted earnings of $16.1 million, or 54 cents a share, on sales of $112.9 million. Analysts were expecting earnings of 61 cents a share on sales of $119.3 million. A year ago the company earned $15.5 million, or 52 cents a share, on sales of $106.1 million. In the latest quarter, international sales increased 5% to $80.6 million while domestic sales, which fell below the company's expectations, increased 10% to $32.2 million. Shares traded down $6.45 to $44.50.

Shares of PDI ( PDII) fell 8% after the provider of sales and marketing services to the biopharmaceutical industry posted first-quarter earnings that fell below expectations. The company reported a loss of $62,000 -- break-even on a per-share basis -- on sales of $82 million. Results included litigation charges and severance expenses that amounted to about 13 cents a share. Analysts were expecting earnings of 24 cents a share. A year ago the company earned $6 million, or 40 cents a share, on sales of $92.6 million. The decrease in year-over-year sales was mainly attributed to a $13 million reduction in sales to AstraZeneca ( AZN), which cut the number of sales representatives under contract near the end of 2004. Shares traded down $1.01 to $11.69.

Other health care volume movers included Elan ( ELN), up 60 cents to $6.90; Vertex Pharmaceuticals ( VRTX - Get Report), up $2.21 to $13.40; Pfizer ( PFE), down 31 cents to $27.66; Amgen ( AMGN), up 70 cents to $61.03; Johnson & Johnson ( JNJ), down 44 cents to $67.73; Merck ( MRK), down 32 cents to $33.88; Schering-Plough ( SGP), down 19 cents to $20.31; and Genentech ( DNA), up 98 cents to $74.30.