EXHIBIT 3.25

                             VIVENTIA BIOTECH INC.

                             DEMAND PROMISSORY NOTE

Date: April 28, 2005

         FOR VALUED RECEIVED the undersigned hereby unconditionally promises to
pay on demand to the order of Clairmark Investments Ltd., in lawful money of
Canada, the amount of ONE MILLION FIVE HUNDRED THOUSAND ($1,500,000) and
interest thereon. Interest shall accrue on a basis which is equal four and
one-half percent (4.5%) per annum, calculated on the basis of a 365-day year and
actual days elapse, and compounded annually.

         This note may be prepaid in full or in part at any time without
penalty.

         Payments of principal and interest hereunder must be made at such
other location as may be notified by Leslie Dan to the undersigned.

         The undersigned waives presentment for payment, notice of non-payment,
protest and notice of protest of this promissory note and diligence in
collection or bringing suit.

         This promissory note shall be governed by and construed in accordance
with the laws of the Province of Ontario.


                                VIVENTIA BIOTECH INC.


                                by:             /s/ Michael Byrne
                                    --------------------------------------------
                                    Name:  Michael Byrne
                                    Title: Chief Financial Officer and Secretary