Updated from 2:43 p.m.

Shares of

Connetics

(CNCT)

were among the worst-performing health-related stocks Wednesday, falling 19.1% after the company posted mixed first-quarter results and warned that second-quarter earnings would be well below expectations.

The specialty pharmaceutical company earned $1 million, or 3 cents a share, on sales of $42.4 million. Analysts polled by Thomson First Call were expecting earnings of 2 cents a share on sales of $43.2 million. A year ago, the company earned $1.9 million, or 5 cents a share, on sales of $25 million. Looking ahead, Connetics forecast second-quarter earnings of 6 cents to 8 cents a share on sales of $45 million to $47 million. Analysts had been expecting earnings of 18 cents a share on sales of $45.3 million. Shares traded down $5.27 to $22.30.

LCA-Vision

(LCAV)

rose 15.9% after the company posted first-quarter results that were better than expected. The laser vision correction services company earned $9.3 million, or 44 cents a share, on sales of $50.2 million. Analysts were expecting earnings of 31 cents a share on sales of $47.4 million. Excluding a tax benefit, the company earned 20 cents a share on sales of $31.7 million a year ago. As a result of the strong first-quarter numbers, LCA-Vision now expects 2005 earnings of $1.15 to $1.20 a share, up from previous guidance of $1 to $1.05 a share. Analysts had been expecting earnings of $1.09 a share. Shares traded up $5.42 to $39.42.

Shares of

Thoratec

(THOR) - Get Report

vaulted 15.6% after the company delivered first-quarter earnings and sales that were better than expected. The medical device maker posted pro forma earnings of $5.1 million, or 10 cents a share, on sales of $50.5 million. Analysts were expecting earnings of 7 cents a share. A year ago, the company earned $3.2 million, or 6 cents a share, on sales of $42.8 million. Thoratec's most recent results were led by strong sales gains in its cardiovascular division, which notched a 21% jump in sales, and its ITC division, where sales grew by 13%. Looking ahead, Thoratec said that, based on first-quarter results, it believes it could post 2005 earnings that are at the higher end of its guidance, which calls for year-over-year pro forma earnings growth of 35% to 40%. Sales, meanwhile, are expected to grow by about 10%, it said. Shares traded up $1.79 to $13.24.

Hologic

(HOLX) - Get Report

rose 12.6% after the company posted second-quarter earnings and sales that topped forecasts. The maker of digital imaging systems earned $6 million, or 27 cents a share, on sales of $69.2 million. Analysts were expecting earnings of 24 cents a share on sales of $66.5 million. A year ago, the company earned $2.6 million, or 12 cents a share, on sales of $55.6 million. During the quarter, Hologic recognized revenue on 54 Selenia full-field digital mammography systems. At the end of the quarter, backlog orders for the company's Selenia system stood at 131, up from 104 systems at the end of the year. Shares traded up $3.93 to $35.01.

Shares of

Pharmion

( PHRM) fell 11.5% after the company posted a first-quarter sales shortfall. The company earned $4.3 million, or 13 cents a share, on sales of $51.7 million. Earnings easily beat the 8 cents a share that analysts were expecting but investors keyed on sales that fell short of the $54.3 million that analysts had expected. A year ago, the company posted a loss of $9.8 million, or 40 cents a share, on sales of $15.7 million. "While we are pleased with our increased profitability this quarter," the company said, "we remain focused on growing sales, particularly for Vidaza in the U.S."

The company hopes that a second wave of Vidaza marketing initiatives will lead to increased awareness and positively affect its sales. Looking ahead, Pharmion said that it continues to expect 2005 earnings of 33 cents to 48 cents a share on sales of $229 million to $245 million. Analysts are expecting earnings of 41 cents a share on sales of $243.2 million. Shares traded down $2.99 to $23.06.

Other health-care volume movers included

Pfizer

(PFE) - Get Report

, up 1 cent to $26.92;

Gilead Sciences

(GILD) - Get Report

, down $2.42 to $36.88;

Elan

(ELN)

, up 5 cents to $4.25;

Merck

(MRK) - Get Report

, down 11 cents to $33.49;

Amgen

(AMGN) - Get Report

, up 71 cents to $57.91;

Genentech

( DNA), down 66 cents to $71.89;

Johnson & Johnson

(JNJ) - Get Report

, up 31 cents to $68.33; and

Schering-Plough

( SGP), down 4 cents to $20.55.