(in thousands) 1998 1997 1996
Cash Flows From Operating Activities:
  Net income (loss)   $ (29,698 )   $ (11,437 )   $ 5,073
  Adjustments to reconcile net income (loss) to net cash provided by
    (used in) operating activities:
    Depreciation and amortization 3,575 2,735 1,102
    Noncash compensation expense 558 1,236 1,309
    Gain on sale of assets 26
  Changes in assets and liabilities:
    Accounts receivable, other current assets, and other assets (1,339 ) (135 ) (94 )
    Inventory 51 191 (1,533 )
    Accounts payable and other current liabilities 908 3,306 2,110
      Net cash provided by (used in) operating activities (25,919 ) (4,104 ) 7,967
Cash Flows From Investing Activities:
  Investment in purchases of property and equipment, net (5,104 ) (6,433 ) (9,101 )
  Sale and maturities of marketable securities 100,130 100,457 47,010
  Purchases of marketable securities (84,222 ) (174,453 ) (92,633 )
      Net cash provided by (used in) investing activities 10,804 (80,429 ) (54,724 )
Cash Flows From Financing Activities:
  Net proceeds from issuances of common stock 1,296 93,063 50,584
  Purchase of treasury stock (521 ) (878 )
  Proceeds from bond and term loan issuances 1,843 7,867
  Equity proceeds from Gell Pharmaceuticals Inc.
    relating to the put option 1,076
  Payment of notes receivable on common stock 69
  Principal payments on bond and term loan payable (2,160 ) (1,144 ) (470 )
      Net cash provided by (used in) financing activities (1,385 ) 92,953 59,057
Net increase (decrease) in cash and cash equivalents (16,500 ) 8,420 12,300
Cash and cash equivalents at the beginning of period 24,980 16,560 4,260
Cash and cash equivalents at the end of period $ 8,480 $ 24,980 $ 16,560

Supplemental disclosures of cash flow information:
  Net interest paid $ 784 $ 828 $ 470

See accompanying notes to consolidated financial statements.