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                                                                   Exhibit 10.49


                             STOCK PLEDGE AGREEMENT
                       (Memphis Clinical Laboratory, Inc.)


DATE:             January 31, 1999

PARTIES:

      Pledgor:          RAINTREE HEALTHCARE CORPORATION,
                        a Delaware corporation
                        15300 North 90th Street
                        Suite 100
                        Scottsdale, AZ 85260

      Secured Party:    David Kremser, Bernice Kremser,
                        Holly Kremser, Michael Kremser,
                        Stanley Kremser and
                        ELK MEADOWS INVESTMENTS, L.L.C.
                        784 Yankee Creek Road
                        Evergreen, CO 80439

RECITALS:

      A. In accordance with the terms of the Debtors' First Amended Joint Plan
of Reorganization dated October 15, 1998 (as amended and supplemented),
confirmed by a final Order of the United States Bankruptcy Court effective
January 20, 1999 (the "Plan"), Pledgor desires to borrow, and Secured Party
desires to lend, the sum of One Million Three Hundred Fifty-Three Thousand Seven
Hundred Four Dollars ($1,353,704) (the "Loan") to Pledgor pursuant to a
promissory note of even date herewith (the "Note"). All documents evidencing and
or securing the Loan may be hereinafter referred to as the "Loan Documents."

      B. Pledgor owns one hundred percent (100%) of the issued and outstanding
capital stock of MEMPHIS CLINICAL LABORATORY, INC., a Tennessee corporation
("MEMPHIS"), consisting of 1,000 shares represented by Certificate(s) No. 10
(the "Shares").

      C. In order to induce Secured Party to make the Loan to Pledgor, Pledgor
desires to grant a security interest in, and, pledge, sign and transfer, all of
Pledgor's right, title and interest in and to the Shares, to Secured Party.

      NOW, THEREFORE, for good and valuable consideration, the receipt of which
is hereby acknowledged, the parties agree as follows:

      1. Pledge. Pledgor hereby grants to Secured Party a security interest in
the Shares together with all rights thereof or arising therefrom, all additions
thereto, dividends, options,
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warrants and payments arising thereunder, all proceeds from the sale or other
disposition thereof, and all substitutions therefor (collectively the
"Collateral"), as security for all of the Pledgor's obligations to Secured Party
under the Note and any and all of the Loan Documents. Upon execution of this
Agreement, Pledgor shall deliver to Secured Party stock power(s) and
assignment(s) separate from certificate for the certificates representing the
Shares endorsed in blank. The books of the issuer of such Shares shall contain a
legend to reflect such pledge of the Shares hereunder.

      2. Covenants and Representations. Pledgor agrees not to knowingly take any
action which would adversely affect the value of the Collateral or which would
encumber, dilute or cloud Pledgor's title or interest therein. Pledgor makes the
following representations, warranties, and covenants:

            (a) Pledgor is and will continue to be the owner of the Collateral,
      free of any liens, security interests or assignments other than the
      security interest created by this Agreement;

            (b) Pledgor shall deliver to Secured Party and Secured Party shall
      retain physical possession of all stock certificates and other instruments
      and documents representing or evidencing any of the Collateral, which
      stock certificates shall be duly endorsed in blank;

            (c) Pledgor will not modify or amend the instruments or documents
      constituting the Collateral, except as required by law, court order, or
      regulation, or make any compromise, adjustment, settlement or termination
      in connection therewith;

            (d) Pledgor will at all times defend the Collateral against any and
      all claims of any person, adverse to the claims of Secured Party upon
      Secured Party's request;

            (e) upon the occurrence of an Event of Default (as defined in
      paragraph 5 hereof and which is continuing) Pledgor will accept no
      payments, distributions or dividends on the Collateral and shall remit to
      Secured Party any payment or distribution received;

            (f) Pledgor has the full power and authority to enter into this
      Agreement, and the persons executing this Agreement on behalf of Pledgor
      have been duly authorized to act on behalf of Pledgor in the execution
      hereof;

            (g) other than Pledgor, there are no parties who assert any type of
      ownership interest whatsoever in the Shares;

            (h) other than this Agreement, there are no agreements which impose
      any conditions or restrictions on the Shares;


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            (i) all of the Shares have been duly authorized, validly issued and
      are fully paid and non-assessable;

            (j) Pledgor, as stockholder, shall not vote for, ratify, accept,
      accede to, or approve any proposed transaction concerning the Collateral
      which would have a material adverse effect on the rights of Secured Party
      hereunder; and

            (k) The Shares represent one hundred percent (100%) of the issued
      and outstanding stock of MEMPHIS, and there are no agreements in effect
      which require or obligate MEMPHIS to issue any additional shares of stock
      of MEMPHIS and there are no outstanding options to purchase any shares of
      stock of MEMPHIS. There will be no agreements in effect which require or
      obligate MEMPHIS to issue any additional shares of stock of MEMPHIS and
      there will be no outstanding options to purchase any shares of stock of
      MEMPHIS.

      3. Delivery of Instruments; Adjustments. Pledgor has delivered to Secured
Party, all stock certificates and all documents evidencing any ownership of the
Collateral or which are necessary or convenient for Secured Party to exercise
any of Secured Party's rights hereunder. If, during the term of this Agreement,
any stock dividends, reclassification, readjustments or other changes are
declared or made in the capital structure of any corporation represented by the
Collateral, or if any subscription or other options are exercisable with respect
to the Collateral, all such new, substitute or additional shares or other
securities, rights or interests issued shall be delivered to and held by Secured
Party subject to this Agreement in the same manner as the Collateral.

      4. Voting. So long as Pledgor is not in default hereunder, any Collateral
may be voted by the Pledgor at all meetings of stockholders, subject to the
restrictions of Paragraph 2(j).

      5. Events of Default. Any one or more of the following will constitute an
event of default ("Event of Default") under this Agreement:

            (a) any event occurs which constitutes an Event of Default under any
      of the Loan Documents;

            (b) if Pledgor fails to pay or perform any of its material
      obligations contained in paragraphs 2, 7 and 8 of this Agreement and which
      failure is not cured upon 30 days written notice by Secured Party to
      Pledgor;

            (c) any covenant, condition, agreement, representation or warranty
      made by Pledgor to Secured Party in this Agreement is materially breached
      or proves untrue in any material respect and is not cured upon 30 days
      written notice by Secured Party to Pledgor.

      6. Remedies on Default. Upon the occurrence and during the continuance of
an Event of Default, Secured Party may exercise any or all of the rights and
remedies provided (a) by this


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Agreement, and/or (b) by any other applicable law. Without limiting the
generality of the foregoing, upon the occurrence and continuance of an Event of
Default, Secured Party may (i) instruct the secretary of MEMPHIS to pay all
dividends to Secured Party, and (ii) sell the Collateral or any part thereof,
without recourse to judicial proceedings, with the right to bid for and buy,
free from any right of redemption, upon ten (10) days' notice (which notice is
agreed to be reasonable notice for the purposes hereof) to the Pledgor, of the
time and place of sale, for cash, upon credit or for future delivery, at Secured
Party's option and in Secured Party's complete discretion:

            (a) at a public sale, including a sale at any broker's board or
      exchange;

            (b) at private sale in any commercially reasonable manner which will
      not require the Collateral, or any part thereof, to be registered in
      accordance with the Securities Act of 1933, as amended, or the rules and
      regulations promulgated thereunder, or any other law or regulation.
      Secured Party is also hereby authorized, but not obligated, to take such
      actions, give such notices, obtain such consents, and do such other things
      as it may deem required or appropriate in the event of sale or disposition
      of any of the Collateral.

      In connection with the sale of any of the Collateral, Secured Party is
authorized, but not obligated, to limit prospective purchasers to the extent
deemed necessary or desirable by Secured Party to render such sale exempt from
the registration requirements of the Securities Act of 1933, as amended, and any
applicable state securities laws, and any sale of the Collateral so made in good
faith by Secured Party shall be deemed to be commercially reasonable. In
connection with any such sale or other disposition in accordance with the
provision hereof, Secured Party shall be authorized to deliver the Stock to or
upon the order of Secured Party.

      7. Taxes. Pledgor shall pay promptly, when due, any and all property
taxes, excise taxes (however called) and other taxes, assessments, duties and
other charges, which, if unpaid, might by law or otherwise become a lien or
charge upon the Collateral (including any and all interest, penalties and
related provisional fees) imposed, levied or assessed against the Collateral, or
upon or measured by the use, ownership, possession or operation thereof, or in
respect to this Agreement or the security interest in the Collateral granted and
conveyed herein.

      8. Pledgor's Failure to Pay Taxes and Other Items. If Pledgor fails to
make any payment or do any act required of it under this Agreement, then Secured
Party shall have the right, but not the obligation, upon three (3) days notice
to Pledgor, and without releasing Pledgor from any obligation under this
Agreement, to make or do the same, and to pay, purchase, contest or compromise
any lien which in Secured Party's judgment places its security interest in the
Collateral or Pledgor's title to the Collateral in jeopardy, and in exercising
any such rights, to expend whatever reasonable amounts of Secured Party in its
sole discretion may deem necessary therefor. Any amounts expended by Secured
Party pursuant to this Section 8 shall be a demand obligation owing by Pledgor,
which shall bear interest at the default rate (as defined in the Loan Documents)
from the date Secured Party expends such amount until repaid.


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      9. Indemnification. Pledgor agrees to indemnify Secured Party from and
against all losses, claims, demands and liabilities of every kind and nature
arising by reason of the assignment and security interest granted and the
Collateral, excluding any of the same arising from the negligence or wilful
misconduct of the Secured Party, and agrees to pay all expenses, including,
without limitation, expert witness fees and attorneys fees, incurred by Secured
Party in the preservation, realization, enforcement or exercise of any of its
rights, powers or remedies hereunder.

      10. Unregistered Securities. Pledgor acknowledges that the Shares
constitute unregistered securities subject to legal restrictions upon the
transfer thereof which will render a public sale of the Shares unavailable. If,
upon an Event of Default, Secured Party exercises its right to sell the shares,
Pledgor waives all rights to public sale and agrees to the private placement of
the Shares to any qualified third-party buyer at a commercially reasonable price
therefor. Pledgor further acknowledges that the legal restrictions upon transfer
of the Shares adversely affect the marketability of the Shares and any
commercially reasonable price for the shares will include a discount from the
proportionate part of the net asset value of the issuer represented by the
Shares to reflect those restrictions upon marketability.

      11. Irrevocable Proxy. Pledgor does hereby irrevocably constitute and
appoint Secured Party and Secured Party's successors and assigns as its proxy,
with full power, in the same manner, to the same extent, and with the same
effect as if they were to do the same:

            (a) to attend any and all meetings of the shareholders of MEMPHIS
      held from the date hereof, and to vote the Collateral at any such meeting
      in such manner as Secured Party shall, in its sole discretion, deem
      appropriate;

            (b) to consent, in the sole discretion of Secured Party, to any and
      all actions by or with respect to Pledgor for which the consent of the
      Pledgor is or may be necessary or appropriate; and

            (c) without limitation, to do all things which Pledgor can or could
      do as a shareholder of MEMPHIS, giving to Secured Party full power and
      substitution and revocation; provided, however, that this proxy shall not
      be exercisable by Secured Party, and Pledgor alone shall have the
      foregoing powers, so long as there is no Event of Default hereunder
      pursuant to which Secured Party has notified Pledgor that Secured Party is
      exercising its rights under this section, and provided further that this
      proxy shall terminate at such time as this Agreement is terminated.
      Pledgor hereby revokes any proxy or proxies heretofore given to any person
      or persons and agrees not to give any other proxy in derogation hereof
      until such time as this Agreement is terminated. Pledgor and Secured Party
      hereby specifically agree that the proxy granted hereunder shall be deemed
      to be valid and irrevocable until this Agreement shall be terminated.

      12. Attorney-in-Fact. Pledgor hereby appoints Secured Party as Pledgor's
Attorney-in-Fact (without imposing any obligations on Secured Party), to perform
all acts which Secured Party


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deems appropriate to perfect and continue the security interest granted
hereunder. The Power of Attorney granted herein is coupled with an interest and
is irrevocable until this Agreement is terminated.

      13. Miscellaneous. This Agreement, the Plan and its related documents, and
all other Loan Documents constitute the entire agreement among the parties
hereto with respect to the subject matter hereof and shall supersede all other
prior agreements, written or oral, with respect thereto.

            (a) This Agreement shall be binding on and inure to the benefit of
      the parties hereto and their respective successors and assigns; provided,
      however, that Pledgor shall not have the right to assign or transfer
      respective rights or obligations under this Agreement except with the
      prior written consent of Secured Party. Secured Party, at any time with
      seven (7) business days prior notice to Pledgor, may sell, assign, grant
      or otherwise transfer, in whole or in part, the indebtedness secured
      hereby and Secured Party's rights, interest and obligations under this
      Agreement or the Collateral with the consent of the Pledgor, which will
      not be unreasonably withheld, and in such event, the transferee shall have
      the same rights, powers and authority with respect to this Agreement and
      the Collateral so transferred as are hereby given to Secured Party;

            (b) This Agreement may be amended modified, renewed or extended but
      only by a written instrument, executed by all of the parties hereto in the
      manner of the execution of this Agreement;

            (c) THIS AGREEMENT SHALL IN ALL RESPECTS BE GOVERNED BY, AND
      CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF ARIZONA, AND, TO
      THE EXTENT THEY PREEMPT SUCH LAWS, THE LAWS OF THE UNITED STATES;

            (d) All parties hereto shall, from time to time, do and perform such
      other and further acts and execute and deliver any and all such other and
      further instruments as may be required or reasonably requested by any
      other party to establish, maintain and protect the respective rights and
      remedies of such other party and to carry out and effect the intents and
      purposes of this Agreement;

            (e) All documents, Agreements, certificates and instruments herein
      required shall be in form and substance satisfactory in all respects to
      Secured Party in its sole discretion and shall be provided at the sole
      cost and expense of Pledgor;

            (f) Pledgor's covenants shall survive the execution hereof and shall
      be performed fully and faithfully by Pledgor at all times until the date
      of repayment of the indebtedness secured hereby.


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            (g) If any term or provision of this Agreement, or the application
      thereof to any circumstance, shall be invalid, illegal or unenforceable to
      any extent, such term or provision shall not invalidate or render
      unenforceable any other term or provision of this Agreement, or the
      application of such term or provision to any other circumstance. To the
      extent permitted by law, the parties hereto hereby waive any provision of
      law that renders any term or provision hereof invalid or unenforceable in
      any respect;

            (h) Time is of the essence of this Agreement; and

            (i) Any notice, demand or any other instruments authorized by this
      Agreement to be served on or given shall be sufficiently served or given
      for all purposes on the earlier of: (a) when personally delivered to any
      officer of the party to whom it is addressed; (b) when sent by certified,
      registered or first class mail, postage prepaid, addressed to each party
      at its address set forth above or at such other address as has been
      furnished in writing by a party to the other in the manner provided in
      this Section; or (c) by overnight courier.

      14. Counterparts. This Agreement may be executed in any number of
counterparts, each of which, when so executed and delivered, shall be deemed to
be an original, but all such counterparts shall together constitute but one and
the same instrument.

      15. Headings. The headings of the sections and paragraphs of this
Agreement have been inserted for convenience of reference only and shall in no
way restrict or otherwise modify any of the terms or provisions hereof.

      16. Construction. All references to the singular shall include the plural
and vice versa and all references to the masculine shall include the neuter or
feminine and vice versa. This Agreement has been reviewed and negotiated by
counsel for each party and no ambiguity in this Agreement shall be construed
against any party based upon its having prepared the same.

      17. Termination. This Agreement and all of its terms and covenants,
representations and warranties shall terminate upon full satisfaction of the
indebtedness hereby secured, and, upon such termination, Secured Party shall
return to Pledgor any of the Collateral held by Secured Party pursuant to this
Agreement, and the original executed copy of this Agreement which contains an
irrevocable proxy.

      18. Acknowledgment. Pledgor acknowledges that Secured Party would not
agree to make the Loan to Pledgor without the execution, delivery and
performance of this Agreement by Pledgor. Pledgor further acknowledges that it
has received good and sufficient consideration for the execution, delivery and
performance of this Agreement.

      19. No Duty to Protect. This is a pledge and assignment of Pledgor's
rights and benefits in the Collateral without an assumption by Secured Party of
any of Pledgor's duties or obligations attendant thereto. Except for physical
safeguarding of the stock certificate(s) included in the


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Collateral delivered to Secured Party, Secured Party shall have no duty to
protect, insure, collect or realize upon the Collateral or any proceeds
therefrom nor shall Secured Party have any obligations to any third party by
virtue of Secured Party's possession of the Collateral.

      IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the date first above written.

      PLEDGOR:                RAINTREE HEALTHCARE CORPORATION,
                              a Delaware corporation

                              By:______________________________________
                              Name:____________________________________
                              Title:___________________________________

      SECURED PARTY:          ELK MEADOWS INVESTMENTS, L.L.C.,
                              a Colorado limited liability company


                              By:______________________________________
                                   David Kremser, Managing Member


                              _________________________________________
                              David Kremser


                              _________________________________________
                              Bernice Kremser by her attorney-in-fact,
                              David Kremser


                              _________________________________________
                              Holly Kremser by her attorney-in-fact,
                              David Kremser


                              _________________________________________
                              Michael Kremser by his attorney-in-fact,
                              David Kremser


                              _________________________________________
                              Stanley Kremser by his attorney-in-fact,
                              David Kremser


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                             IRREVOCABLE STOCK POWER

                              Certificate(s) No(s).

      FOR VALUE RECEIVED, RAINTREE HEALTHCARE CORPORATION, a Delaware
corporation ("Pledgor"), hereby assigns and transfers to David Kremser, Bernice
Kremser, Holly Kremser, Michael Kremser, Stanley Kremser and ELK MEADOWS
INVESTMENTS, L.L.C. (collectively the "Secured Party"), pursuant to the Stock
Pledge Agreement, dated as of January 31, 1999 (the "Stock Pledge Agreement"),
between the Pledgor and Secured Party, 1,000 shares of common stock of MEMPHIS
CLINICAL LABORATORY, INC., a Tennessee corporation (the "Common Shares"), of the
Secured Party, as security for the Loan (as defined in the Pledge Agreement).

      The undersigned does hereby irrevocably constitute and appoint David
Kremser as its attorney-in-fact to transfer the said stock or bond(s), as the
case may be, on the books of MEMPHIS CLINICAL LABORATORY, INC. with full power
of substitution in the premises.

Dated: _______________, 1999



                              RAINTREE HEALTHCARE CORPORATION,
                              a Delaware corporation



                              By:______________________________________
                              Name:____________________________________
                              Title:___________________________________