Shares of Intuitive Surgical ( ISRG) were among the best-performing health-related stocks Wednesday, rising 27% after the surgical robotics company posted results that blew away third-quarter forecasts.

The company earned $20.7 million, or 55 cents a share, on sales of $60.9 million. Analysts polled by Thomson First Call expected earnings of 29 cents a share and sales of $50 million. A year earlier, the company earned $6.1 million, or 17 cents a share, on sales of $35.5 million. During the most recent period, the company sold 30 of its da Vinci surgical systems, up from 18 a year ago. System revenue surged to $33.6 million from $19 million last year. Shares were recently trading up $19.47 to $91.46.

Kensey Nash ( KNSY) fell 11% after the medical device company posted first-quarter results that disappointed Wall Street and forecast a weak second quarter. The company reported a loss of $182,752, or 2 cents a share, on total revenue of $12.7 million. On a pro forma basis, which excludes a depreciation charge and other one-time items, the company reported earnings of $1.2 million, or 10 cents a share. Analysts projected earnings of 19 cents a share and total revenue of $15.5 million. A year earlier, the company earned $3.2 million, or 26 cents a share, on sales of $15.1 million.

Looking ahead, Kensey Nash forecast second-quarter pro forma earnings of 11 cents to 13 cents a share, below analysts' mean estimate of 25 cents. The company sees total sales of $13.3 million to $14.1 million, short of Wall Street's expectation of $16.6 million. Shares traded down $2.96 to $24.24.

Tanox ( TNOX) rose 12% after the company said its HIV inhibitor performed well in a Phase II trial. The study showed that TNX-355, in combination with an optimized background therapy, demonstrated a statistically significant reduction in viral load when compared to a placebo. "TNX-355 has the potential to provide considerable advantages over the current standard-of-care for HIV patients," the company said, "and we look forward to working with the FDA on next steps toward bring this therapy to a growing number of patients who have limited treatment alternatives." The company, which is still conducting Phase II testing, said it hopes to begin a Phase III study of the drug during 2006. Shares were up $1.50 to $13.99.

Shares of Biosite ( BSTE) fell 17% after the maker of medical tests posted third-quarter sales that fell below expectations and narrowed its 2005 guidance. For the third quarter, the company earned $12.6 million, or 68 cents a share, on sales of $69.7 million. Analysts predicted earnings of 68 cents a share and sales of $72 million. In the year-ago period, the company earned $10.4 million, or 60 cents a share, on sales of $61.2 million.

Biosite now expects 2005 earnings growth of 18% to 20%, compared to its previous estimate of 15% to 21%. Analysts are expecting earnings of $2.90 a share, or earnings growth of 20%. Biosite said sales, meanwhile, are now expected to grow by 17% to 19%, narrowed from its previous forecast of 16% to 20%. Wall Street targets sales of $292 million, or sales growth of 19%. Shares fell $11.41 to $55.75.

LifeCell ( LIFC) dropped 10% after the company lowered its 2005 earnings guidance. The company, which develops products made from human tissue for use in surgical procedures, reported third-quarter earnings of $2.5 million, or 7 cents a share, on sales of $24.5 million. Results were hurt by a pretax charge related to the write-off of $1.4 million in inventory and by a $469,000 reserve for product returns related to a recall. Analysts expected earnings of 10 cents a share, with sales of $24.4 million. A year ago, the company earned $1.1 million, or 3 cents a share, on sales of $15.6 million.

For the full year, LifeCell now expects earnings of $11.7 million to $12.3 million, or 35 cents to 36 cents a share. Previously, the company projected it would earn $12.1 million to $13.3 million, or 37 cents to 40 cents a share. The company narrowed its sales projection to $92 million to $94 million from $90 million to $94 million. Analysts had forecast earnings of 39 cents a share and sales of $93.1 million. Shares were trading down $1.92 to $17.03.

Other health care volume movers included Pfizer ( PFE), down 11 cents to $21.09; Novavax ( NVAX), down 18 cents to $5.35; Amgen ( AMGN), down 3 cents to $75.96; Johnson & Johnson ( JNJ), down 59 cents to $62.99; Merck ( MRK), up 18 cents to $27.20; Bristol-Myers Squibb ( BMY), up 12 cents to $21.77; BioCryst Pharmaceuticals ( BCRX), up 37 cents to $15.67; and Genentech ( DNA), up $1.61 to $89.98.

More from Stocks

Why The FANG Stocks' Dominance May Not Be So Bad For The Market

Why The FANG Stocks' Dominance May Not Be So Bad For The Market

Danica Patrick's Final Race at 2018 Indianapolis 500: What She Thinks About Cars

Danica Patrick's Final Race at 2018 Indianapolis 500: What She Thinks About Cars

At End of May, Investors Signalling They May Stay Away

At End of May, Investors Signalling They May Stay Away

Inside Carnival's Mind Blowing New Horizon Cruise Ship (Video)

Inside Carnival's Mind Blowing New Horizon Cruise Ship (Video)

Neel Kashkari: The Heart of Our Financial System Is More Radioactive Than Ever

Neel Kashkari: The Heart of Our Financial System Is More Radioactive Than Ever