Updated from 3:21 p.m. EDT

Shares of

LifeCell

( LIFC) were among the best-performing health-related stocks Tuesday, rising 19.9% after the company posted first-quarter earnings that topped expectations and raised 2005 earnings and sales targets.

The company, which develops products made from human tissue for use in surgical procedures, posted earnings of $2.1 million, or 7 cents a share, on sales of $19.9 million. Analysts surveyed by Thomson First Call were expecting earnings of 4 cents a share on sales of $17.6 million. A year ago the company earned $883,000, or 3 cents a share, on sales of $13.8 million. Sales gains were fueled by strength in the company's AlloDerm product, which increased 62% to $14.9 million. Looking ahead, LifeCell now expects 2005 earnings of 27 cents to 31 cents a share on sales of $84.5 million to $91.5 million. Previously, the company forecast earnings of 22 cents to 24 cents a share on sales of $73 million to $77 million. Analysts had been expecting earnings of 23 cents a share on sales of $77.1 million. Shares traded up $1.85 to $11.15.

Medco

(MHS)

fell 9.1% after the company posted mixed first-quarter results. Excluding items, the pharmacy benefit manager posted earnings of 57 cents a share, beating estimates by a penny, but sales of $8.74 billion were short of the $8.87 billion that analysts were expecting. A year ago the company earned 53 cents a share on sales of $8.91 billion. Looking ahead, Medco backed its 2005 earnings guidance of $2.33 to $2.42 a share. Analysts are expecting earnings of $2.39 a share. Shares traded down $4.92 to $49.

Shares of

NBTY

( NTY) fell 6.3% after the nutritional supplements company posted second-quarter earnings that missed expectations by a wide margin. The company earned $20.9 million, or 30 cents a share, on sales of $442.7 million. Analysts were expecting earnings of 50 cents a share on sales of $443 million. A year ago the company earned $41.3 million, or 60 cents a share, on sales of $439.6 million. Second-quarter results were hurt by an increase in raw material costs -- which were not passed on to customers -- and by a 79% jump in advertising costs. Shares traded down $1.45 to $21.52.

Applera Biosystems

(ABI)

rose 1.8% after the company posted third-quarter earnings that topped expectations. The maker of gene sequencing equipment posted adjusted earnings of $55.4 million, or 28 cents a share, on sales of $454.8 million. Analysts were expecting earnings of 25 cents a share on sales of $455.2 million. The company's latest results included a 2-cent gain from favorable currency translation. Notwithstanding the company's latest results, Applera said that it remains cautious because of a constrained funding environment. Shares traded up 35 cents to $20.19.

Despite posting first-quarter earnings that were better than expected, shares of

VISX

(EYE) - Get Report

fell Tuesday. Excluding items, the maker of laser vision correction systems posted earnings of $15.3 million, or 29 cents a share, on sales of $51.3 million. Analysts were expecting earnings of 27 cents a share on sales of $49.8 million. A year ago the company posted earnings of $11.8 million, or 23 cents a share, on sales of $43.8 million. Shares traded down 64 cents to $24.86.

Other health-care volume movers included

Pfizer

(PFE) - Get Report

, down 12 cents to $26.91;

Genentech

( DNA), up $3.12 to $72.55;

Amgen

(AMGN) - Get Report

, down 83 cents to $57.20;

Elan

(ELN)

, up 14 cents to $4.20;

Merck

(MRK) - Get Report

, down 32 cents to $33.60;

Johnson & Johnson

(JNJ) - Get Report

, down 52 cents to $68.02; and

Schering-Plough

( SGP), down 11 cents to $20.59.