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                                                                    EXHIBIT 4.12


THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933, AS AMENDED, NOR UNDER ANY STATE SECURITIES LAWS AND NEITHER THE
SECURITIES NOR ANY INTEREST THEREIN MAY BE TRANSFERRED, PLEDGED OR OTHERWISE
DISPOSED OF IN THE ABSENCE OF SUCH REGISTRATION OR AN EXEMPTION THEREFROM UNDER
SAID ACT OR SUCH LAWS AND THE RULES AND REGULATIONS THEREUNDER

                      WARRANT TO PURCHASE SHARES OF COMMON
                     STOCK OF AMPERSAND MEDICAL CORPORATION

WARRANT NO.  1 - P.S.A                                     DATED: MAY 23, 2000

         This certifies that Prospektiva, SA, Via Funicolare 2, 6900 Lugano,
Switzerland (the "HOLDER") for value received, is entitled, subject to the terms
set forth below to purchase from AMPERSAND MEDICAL CORPORATION, a Delaware
corporation (the "COMPANY"), forty-eight thousand three hundred and thirty-three
(48,333) fully paid and nonassessable shares (the "WARRANT SHARES") of the
Company's Common Stock, par value $0.001 per share (the "STOCK") at a price of
one dollar and fifty cents ($1.50) per share (the "STOCK PURCHASE PRICE") at any
time but not earlier than the Commencement Date (as defined below) or later than
5:00 pm (New York Time) on the Expiration Date (as defined below), upon
surrender to the Company at its principal office at 414 N. Orleans St.. Suite
510, Chicago, Illinois 60610, Attention: President (or at such other location as
the Company may advise Holder in writing) of this Warrant properly endorsed with
the form of Exercise Notice attached hereto duly completed and signed upon
payment in cash or cashier's check of the aggregate Stock Purchase Price for the
number of shares for which this Warrant is being exercised determined in
accordance with the provisions hereof. The Stock Purchase Price and the number
of Warrant Shares purchasable hereunder are subject to adjustment as provided in
Section 3 of this Warrant. This Warrant and all rights hereunder to the extent
not exercised in the manner set forth herein shall terminate and become null and
void on the Expiration Date (as defined below). "COMMENCEMENT DATE" shall mean
the date of this Warrant. Expiration date shall mean the third anniversary of
the Commencement Date.

         This Warrant is subject to the following terms and conditions:

         1. EXERCISE; ISSUANCE OF CERTIFICATES PAYMENT FOR WARRANT SHARES

            (a) This Warrant is exercisable by payment of the Stock Purchase
Price by cash payment, certified check or wire transfer, in the manner set forth
above at the option of Holder at any time but not earlier than the Commencement
Date or later than 5:00 p.m. (New York Time) on the Expiration Date for all or a
portion of the shares of Stock subject to this Warrant. The Company agrees that
the Warrant Shares purchased under this Warrant shall be and are deemed to be
issued to Holder as the record owner of such shares as of the close of business
on the date on which this Warrant shall have been surrendered and payment made
for such shares (unless the Conversion Right is exercised). Subject to the
provisions of Section 2, certificates for the Warrant Shares so purchased shall
be delivered to holder by the Company's transfer agent at the Company's

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expense within a reasonable time after the rights represented by this Warrant
have been exercised. The stock certificate(s) so delivered shall be in such
denominations of Stock requested by Holder and shall be registered in the name
of the Holder or such other name as shall be designated by the Holder, subject
to the limitations contained in Section 2. If, upon exercise of this Warrant,
fewer than all of the shares of Stock evidenced by this Warrant are purchased
prior to the Expiration Date of this Warrant, one or more new warrants
substantially in the form of, and on the terms of, this Warrant will be issued
for the remaining number of shares of Stock not purchased upon exercise of this
Warrant.

            (b) In lieu of the payment of the Stock Purchase Price, the Holder
may require the Company to convert this Warrant into shares of Stock (the
"CONVERSION RIGHT") as provided for in this SECTION 1(b). Upon exercise of the
Conversion Right, the Company shall deliver to the Holder (without payment by
the Holder of any of the Stock Purchase Price) that number of shares of Stock
equal to the quotient obtained by dividing (x) the value of the Warrant at the
time the Conversion Right is exercised (determined by subtracting the aggregate
Stock Purchase Price in effect immediately prior to the exercise of the
Conversion Right from the aggregate Market Value (as defined in SECTION 1(d)
below), for the Warrant Shares immediately prior to the exercise of the
Conversion Right) by (y) the Market Value.

            (c) The Conversion Right may be exercised by the Holder by
delivering the Warrant Certificate with a duly executed Exercise Notice in the
form attached hereto with the conversion section completed to the Company.

            (d) For the sole purpose of determining the number of Warrant Shares
which shall be delivered to the Holder by the Company pursuant to the Conversion
Right as set forth in SECTION 1(b) above, "Market Value") shall mean the average
daily closing price of a share of the Stock as listed on the exchange or
quotation system of which the Stock may then be listed for the ten (10)
consecutive days of trading ending on the third business day immediately
preceding the date of exercise of such Conversion Right, or in the event the
Stock is not then publicly traded, the Market Value shall be determined in good
faith by the Company and the Holder.

         2. SHARES TO BE FULLY PAID; RESERVATION OF SHARES. The Company
covenants and agrees that the Warrant Shares will, upon issuance, be duly
authorized, validly issued, fully paid and nonassessable and free from all
preemptive rights of any stockholder and free of all taxes (other than income
taxes, which may be applicable to Holder, liens and charges with respect to the
issue thereof. The Company covenants that it will reserve and keep available a
sufficient number of shares of its authorized but unissued Stock for such
exercise. The Company will take all such reasonable action as may be necessary
to assure that such shares of Stock may be issued as provided herein without
violation of any applicable law or regulation, or of any requirements of any
domestic securities exchange or automated quotation system upon which the Stock
may be listed.

         3. ADJUSTMENT OF STOCK PURCHASE PRICE PAID NUMBER OF SHARES. The Stock
Purchase Price and the number of shares purchasable upon the exercise of this
Warrant shall be subject to adjustment from time to time upon the occurrence of
certain events described in this

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SECTION 3.

         3.1 SUBDIVISION OR CONTINUATION OF STOCK AND STOCK DIVIDEND. In case
the Company shall at any time subdivide its outstanding shares of Stock into a
greater number of shares or declare a dividend upon its Stock payable solely in
shares of Stock, the Stock Purchase Price in effect immediately prior to such
subdivision or declaration shall be proportionately reduced, and the number of
shares issuable upon exercise of the Warrant shall be proportionately increased.
Conversely, in case the outstanding shares of Stock of the Company shall be
combined into a smaller number of shares the Stock Purchase Price in effect
immediately prior to such combination shall he proportionately increased and the
number of shares issuable upon exercise of the Warrant shall be proportionately
reduced.

         3.2 NOTICE OF ADJUSTMENT. Promptly after adjustment of the Stock
Purchase Price or any increase or decrease in the number of shares purchasable
upon the exercise of this Warrant, the Company shall give written notice
thereof: by first class mail, postage prepaid, addressed to the Holder at the
address of the Holder as shown on the books of the Company (the notice shall be
signed by an authorized officer of the Company and shall state the effective
date of the adjustment and the Stock Purchase Price resulting from such
adjustment and the increase or decrease, if any, in the number of shares
purchasable at such price upon the exercise of this Warrant, setting forth in
reasonable detail the method of calculation and the facts upon which such
calculation is based.

         3.3 CHANGES IN STOCK. In case at any time prior to the Expiration Date,
the Company shall be a party to any transaction (including, without limitation,
a merger, consolidation, sale of all or substantially all of the Company's
assets or recapitalization of the Stock) in which the previously outstanding
Stock shall be changed into or exchanged for different securities of the Company
or common stock or other securities of another corporation or interests in a
noncorporate entity or other property (including cash) or the Company shall make
a distribution on its shares, other than regular cash dividends on its
outstanding stock, or any combination of any of the foregoing (each such
transaction being herein called the "TRANSACTION" and the date of consummation
of the Transaction being herein called the "CONSUMMATION DATE"), then, as a
condition of the consummation of the Transaction, lawful and adequate provisions
shall be made so that each Holder, upon the exercise hereof at any time on or
after the Consummation Date, shall be entitled to receive, and this Warrant
shall thereafter represent the right to receive, in lieu of the Stock issuable
upon such exercise prior to the Consummation Date, the highest amount of
securities or other property to which the Holder would actually have been
entitled as a stockholder upon the consummation of the Transaction if the Holder
had exercised such Warrant immediately prior thereto. The provisions of this
SECTION 3.3 shall similarly apply to successive Transactions.

         4.  INVESTMENT REPRESENTATIONS.

         By receipt of this Warrant, and by its execution the Holder represents
to the Company the following:

             (a) the Holder understands that this Warrant and any Stock
purchased upon its exercise are securities, the issuance of which requires
compliance with Federal and state

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securities laws, and

             (b) the Holder is aware of the Company's business affairs and
financial condition and has acquired sufficient information about the Company to
reach an informed and knowledgeable decision to acquire this Warrant; and

             (c) the Holder is acquiring this Warrant for investment for the
Holder's own account only and not with a view to, or for resale in connection
with, any "distribution" thereof within the meaning of the Securities Act of
1933, as amended (the "ACT"), and

             (d) the Holder acknowledges and understands that the securities
constitute "restricted securities" under the Act and must be held indefinitely
unless they are subsequently registered under the Act or an exemption from such
registration is available.

         5. ISSUE TAX. The issuance of certificates for shares of Stock upon the
exercise of the Warrant shall be made without charge to the holder of the
Warrant for any issue tax in respect thereof; provided, however, that the
Company shall not be required to pay any tax which may he payable in respect of
any transfer involved in the issuance and delivery of any certificate in a name
other than that of the then holder of the Warrant being exercised.

         6. NO VOTING OR DIVIDEND RIGHTS; LIMITATION OF LIABILITY. Nothing
contained in this Warrant shall be construed as conferring upon the Holder
hereof the right to vote or to consent or to receive notice as a stockholder in
respect of meetings of stockholders for the election of directors of the Company
or any other matters or any rights whatsoever as a stockholder of the Company in
addition if the Holder of the Warrant does not exercise this Warrant or convert
this Warrant pursuant to SECTION 1(b) above prior to the occurrence of an event
described above, except as provided in SECTION 3.1 AND 3.5, the Holder shall not
be entitled to receive the benefits accruing to existing holders of the Stock
pursuant to such event. No dividends or interest shall be payable or accrued in
respect of this Warrant or the interest represented hereby or the shares
purchasable hereunder until, and only to the extent that, this Warrant shall
have been exercised. No provisions hereof in the absence of affirmative action
by the Holder to purchase shares of Stock, and no mere enumeration herein of the
rights or privileges of the Holder hereof shall give rise to any liability of
the Holder for the Stock Purchase Price or as a stockholder of the Company
whether such liability is asserted by the Company or by its creditors.

         7.  RESTRICTIONS ON TRANSFERABILITY OF SECURITIES; COMPLIANCE WITH
SECURITIES ACT; REGISTRATION RIGHTS.

         7.1 RESTRICTIONS ON TRANSFERABILITY. This Warrant and the Warrant
Shares shall not be transferable in the absence of the effectiveness of a
registration statement with respect to such securities under the Act, or an
exemption therefrom. This Warrant and the Warrant Shares may be transferred in
any manner in compliance with applicable law.

         7.2 RESTRICTIVE LEGEND. In the absence of the effectiveness of
registration under the Act or an exemption therefrom as contemplated by SECTION
7.1, each certificate representing the

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Warrant Shares or any other securities issued in respect to the Warrant Shares
upon any stock split, stock dividend, recapitalization, merger, consolidation or
similar event, shall be stamped or otherwise imprinted with a legend
substantially IN the following form (in addition to any legend required under
applicable state securities laws):

         THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
         SECURITIES ACT OF 1933, AS AMENDED ("ACT"), NOR UNDER ANY STATE
         SECURITIES LAWS AND NEITHER THE SECURITIES NOR ANY INTEREST THEREIN MAY
         BE TRANSFERRED, PLEDGED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF
         REGISTRATION OR AN EXEMPTION THEREFROM UNDER SAID ACT OR SUCH LAWS AND
         THE RULES AND REGULATIONS THEREUNDER.

         7.3 REGISTRATION RIGHTS. Should a Holder exercise his rights, in whole
or in part, to purchase Warrant Shares, and provided that more than one year has
elapsed from the date of issuance of this Warrant then the Company shall honor a
request to register such Warrant Shares pursuant to a filing under the Act, to
the extent requisite to permit the sale by such holder of such Warrant Shares.
The Company shall make such filing in timely fashion, but in no case more than
30 days from the time of such request. Any expenses relating to such filing
shall be paid by the Company. Should the Company fail to make such filing within
a 30 day period from the time of such request, the Company shall be obligated to
purchase such Warrant Shares for a cash payment per Warrant Share equal to the
difference between the Exercise Price and average closing price of the Common
Stock during the 30 calendar days immediately following Holder's request to
register the Warrant Shares.

          8. MODIFICATION AND WAIVER. Warrant and any provision hereof may be
changed, waived, discharged or terminated only by an instrument in writing
signed by the party against which enforcement of the same is sought.

         9. NOTICES. Any notice, request or other document required or permitted
to be given or delivered to the holder hereof or the Company shall be delivered
or shall be sent by certified or registered mail postage prepaid, to each the
Holder at its address as shown on the books of the Company or to the Company at
the address indicated therefore in the first paragraph of this Warrant.

         10. DESCRIPTIVE HEADINGS AND GOVERNING LAW. The descriptive headings of
the several sections and paragraphs of this Warrant are inserted for convenience
only and do not constitute a part of this Warrant. This Warrant shall be
construed and enforced in accordance with, and the rights of the parties shall
be governed by the laws of the State of Illinois without reference to the
principles of conflicts of laws.

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         11. LOST WARRANTS OF STOCK CERTIFICATES. The Company represents and
warrants to the Holder that upon receipt of evidence reasonably satisfactory to
the Company of the loss, theft, destruction or mutilation of any Warrant or
stock certificate representing the Warrant Shares and in the case of any such
loss, theft, destruction or mutilation, upon receipt of an indemnity and, if
requested, bond reasonably satisfactory to the Company, or in the case of any
such mutilation, upon surrender and cancellation of such Warrant or stock
certificate, the Company at its expense will make and deliver a new Warrant or
stock certificate, of like tenor, in lieu of the lost, stolen, destroyed or
mutilated Warrant or stock certificate.

         12. FRACTIONAL SHARES. No fractional shares shall be issued upon
exercise of this Warrant. The Company shall, in lieu of issuing any fractional
share pay the holder entitled to such fraction a sum in cash equal to the fair
market value of any such fractional interest as it shall appear on the public
market, or if there is no public market for such shares, then as shall be
reasonably determined by the Company.

                                  * * * * * * *

         IN WITNESS WHEREOF, the Company has caused this Warrant to be executed
by its officer, thereunto duly authorized as of the date first written above.

                                 AMPERSAND MEDICAL CORPORATION

                                 By: ________________________________________
                                     Name:
                                     Title:


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                             FORM OF EXERCISE NOTICE

                           (To be signed and delivered
                            upon exercise of Warrant)


AMPERSAND MEDICAL CORPORATION
414 N Orleans St., Suite 510
Chicago, Illinois 60610



         The undersigned, the holder of the within Warrant (Warrant Certificate
Number 1 - P.S.A.), hereby irrevocably elects to exercise the purchase right
represented by such Warrant for, and to purchase thereunder, ______________
shares of Common Stock, par value $0.001 per share (the "STOCK"), of AMPERSAND
MEDICAL CORPORATION (the "COMPANY"), and subject to the following paragraph,
herewith makes payment of ______________ Dollars ($______) therefor and requests
that the certificates for such shares be issued in the name of, and delivered
to, ___________________________whose address is _______________________________.

         The undersigned does/does not (circle one) request the exercise of the
within Warrant pursuant to the "Conversion Right" set forth in SECTION 1(b) of
the Warrant.



DATED:___________________


                           ____________________________________________________

                           (Signature must conform in all respects to name
                           of holder as specified on the face of the
                           Warrant)

                           ____________________________________________________

                           ____________________________________________________

                           (Address)


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