Mexico's Vitro ( VTO) surged on word that the glass-products maker is working to dig itself out from under a $1.2 billion debt load. The company will refinance some of its obligations with a $750 million debt offering, and it will offer $250 million in 10.75% bonds. Shares were gaining 53 cents, or 9.7%, to $6.

Chelsea Therapeutics International ( CHTP) shares were riding high on news of positive European midphase test results for its Droxidopa treatment. The Charlotte, N.C., biotech said the drug significantly mitigated the drop in orthostatic systolic blood pressure that causes a disorder called neurogenic orthostatic hypotension. Chelsea additionally said patients showed excellent tolerance of the drug. Shares were adding 33 cents, or 9.2%, to $3.91.

Internet technology firm Sykes Enterprises ( SYKE - Get Report) rose after a Robert W. Baird analyst upped the Tampa, Fla., company's rating to outperform from neutral. Shares were up $1.09, or 7.4%, to $15.79.

California Water Service Group ( CWT - Get Report) fell on a downgrade by a Brean Murray analyst to neutral from buy. The water-utility company was dropping $3.20, or 7.2%, to $41.34.