Updated from 2:01 p.m. EDT

Health stocks dominated small-cap movers Tuesday, and leading the way was Adolor ( ADLR), plummeting more than 58% after a late-phase study of alvimopan, a gastrointestinal treatment, induced higher (but statistically insignificant) rates of adverse cardiovascular events and cases of skin lesions than a placebo. Adolor's partner, GlaxoSmithKline ( GSK), halted other studies involving the compound. Adolor shares closed down $5.12 to $3.60. GlaxoSmithKline shares gave up 17 cents to $55.95.

Advancis Pharmaceutical ( AVNC), based in Maryland, plans to sell around 10.2 million of its shares, along with five-year warrants to buy some 7.6 million more for $2.27 apiece, at $2.36 per unit (each consisting of one share and a warrant for 0.75 shares). Gross proceeds should total about $24 million. Shares slid 9 cents, or 3.6%, to $2.41.

Meanwhile, shares of both Synergetics USA ( SURG) and Iridex ( IRIX) were leaping after the medical-equipment makers settled all of Iridex's patent-infringement claims regarding its laser-probe technology. Synergetics is required to pay Iridex $2.5 million on April 16, as well as $800,000 annually until 2012. But under a new agreement, Synergetics is also now allowed to make "various laser disposables" for a potential of more than $3 million in revenue over the next five years. Its shares soared 87 cents, or 21.1%, to $4.99. Iridex stock climbed 43 cents, or 6.5%, to $7.05.

TLCVision ( TLCV) got a lift after the St. Louis-based eye care services company said it will buy back up to $125 million of its shares for $5.75 to $6.25 apiece -- up to 20 million shares in total. Shares closed up 51 cents, or 9.5%, to $5.90.

Amarin ( AMRN) was higher after the drugmaker hired former Pfizer head of worldwide development, Declan Doogan, as its president of research and development. Shares of the U.K.-based company were up 40 cents, or 15.4%, to $3.

Elsewhere, ManTech International ( MANT), which makes software for national security programs, agreed to buy defense technology firm SRS Technologies for an undisclosed amount. The transaction should close within the current quarter, and it will likely be accretive to per-share earnings in late 2007. Shares of the Fairfax, Va., company rose 48 cents, or 1.5%, to $33.37.

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