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                                                                   Exhibit 10.68

                                 PROMISSORY NOTE

$40,000,000.00                                                December 23, 2005

     FOR VALUE RECEIVED, the undersigned ALLIANCE HOSPITAL, LTD., a Texas
limited partnership (hereinafter, "Borrower"), having an address at 515 North
Adams, Odessa, Texas 79761, promises to pay to the order of MPT OF ODESSA
HOSPITAL, L.P., a Delaware limited partnership (hereinafter, "Lender"), at its
office at 1000 Urban Center Drive, Suite 501, Birmingham, Alabama 35242, or at
such other address as the holder of this Promissory Note (this "Note") may from
time to time designate in writing, the principal sum of FORTY MILLION and NO/100
DOLLARS ($40,000,000.00), or as much thereof as may be advanced from time to
time hereunder, together with interest thereon and other amounts payable as
provided herein.

     1. DEFINED TERMS. All capitalized terms not otherwise defined herein shall
have the meanings ascribed to such terms in the Loan Agreement (defined below).

     2. SECURITY. The indebtedness evidenced by this Note and the obligations
evidenced hereby are secured by, inter alia, (a) that certain Deed of Trust and
Fixture Filing (as amended, consolidated, modified, severed or spread from time
to time, the "Mortgage") from Borrower to Lender of even date herewith, (b) that
certain Loan Agreement (the "Loan Agreement") by and among Lender, Borrower, and
SRI-SAI Enterprises, Inc., a Texas corporation (the "General Partner"), of even
date herewith, and (c) certain other Security Documents (as such term is defined
in the Loan Agreement). All of the terms and provisions of the Loan Documents
are incorporated herein by reference.

     3. BASE INTEREST. Interest shall be payable on so much principal as is from
time to time outstanding and unpaid hereunder at a per annum rate equal to Ten
Percent (10.000%) (the "Base Interest"). Base Interest shall be computed
hereunder based on a Three Hundred Sixty (360) day year and paid for the actual
number of days elapsed (based on the assumption of a thirty (30) day month) for
any whole or partial calendar month in which interest is being calculated. In
computing the number of days during which Base Interest accrues, the day on
which funds are initially advanced shall be included (regardless of the time of
day such advance is made), and the day on which funds are repaid shall be
included unless repayment is credited prior to close of business. Payments in
federal funds immediately available in the place designated for payment and
received by Lender prior to 2:00 p.m. local time on a Business Day in
Birmingham, Alabama shall be credited prior to close of business, while other
payments may, at the option of Lender, not be credited until immediately
available to Lender in federal funds at the place designated for payment prior
to 2:00 p.m. local time at said place of payment on a day on which Lender is
open for business.

     4. PAYMENTS. On January 1, 2006 and the first (1st) day of each calendar
month thereafter (each a "Scheduled Payment Date"), and ending on the Maturity
Date (defined below), Borrower shall pay to Lender all accrued and unpaid
interest on the outstanding principal balance hereof (each such payment, a
"Scheduled Monthly Payment"). If not sooner repaid in

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accordance with the terms hereof, on December 1, 2020 (the "Maturity Date"),
Borrower shall pay to Lender the entire outstanding principal balance of this
Note, together with all accrued and unpaid interest thereon and all other sums
due Lender hereunder and under the other Loan Documents. So long as no Event of
Default exists, each Scheduled Monthly Payment shall be applied, first, to any
amounts hereafter advanced by Lender and otherwise due hereunder or under any
other Loan Document, second, to any late fees and other amounts payable to
Lender, third, to the payment of accrued interest, and, last, any remaining
funds may, at the option of Lender, be retained by Lender as additional security
for the Loan Obligations.

     5. PREPAYMENT. Borrower may not voluntarily prepay this Note in whole or in
part at any time prior to the Maturity Date, except in accordance with the
following:

          (a) Provided no Event of Default has occurred and is continuing,
Borrower may prepay the Loan in whole at any time provided such prepayment is in
connection with a bona fide Purchase Offer (as defined below), by a party
unrelated to Borrower Parties or their Affiliates, to acquire, directly or
indirectly, more than fifty percent (50%) of the ownership interests in, or
substantially all of the assets of, Borrower; provided, however, that, upon the
occurrence of such prepayment, Borrower shall pay to Lender, together with all
outstanding Loan Obligations, the applicable Yield Maintenance Premium (defined
below in Section 7). A "Purchase Offer" shall consist of a binding agreement for
a third-party purchaser to acquire, and the Borrower to sell, in consideration
for cash or cash equivalents, more than fifty percent (50%) of the equity
interest, and more than fifty percent (50%) of the value of the equity interest,
in, or substantially all of the value of the assets of, Borrower.
Notwithstanding anything to the contrary contained herein, in the absence of a
consummated Purchase Offer, Borrower may not repay the Loan in whole or in part
prior to the eighth Loan Year (defined in Section 8(a) below).

          (b) Borrower may prepay the Loan in whole at any time during the
eighth Loan Year or thereafter, provided that (i) no Event of Default has
occurred and is continuing, (ii) all outstanding Loan Obligations shall be paid
in full, and (iii) such prepayment is accompanied by the applicable Yield
Maintenance Premium.

          (c) Any prepayment made in accordance with Section 5(a) or 5(b) above
shall be made on a Scheduled Payment Date and upon not less than sixty (60)
days' prior written notice to Lender.

     6. ADDITIONAL INTEREST; PAYMENTS. Commencing on January 1, 2007 and on each
January 1st thereafter during the Loan Term, Borrower shall, in addition to Base
Interest due hereunder, pay to Lender additional interest ("Additional
Interest") at a per annum rate equal to the greater of (i) Three and One-Half
Percent (3.5%) or (ii) the rate of the Consumer Price Index ("CPI") increase for
such prior year multiplied by the Annual Interest Payable (as hereinafter
defined). Additional Interest for each Loan Year shall be payable in twelve (12)
equal monthly installments, due on each Scheduled Payment Date during such Loan
Year. "Annual Interest Payable" shall mean, for each Loan Year subsequent to the
first Loan Year, the sum of (A) Base Interest, and (B) Additional Interest, with
all due Lender in the immediately preceding Loan Year. For the first Loan Year,
Annual Interest Payable shall mean the annualized Base Interest.


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     7. LATE CHARGES; INTEREST ON OVERDUE INSTALLMENTS; COLLECTION COSTS.

          (a) Borrower will pay to Lender a late charge equal to five percent
(5%) of the amount of any payment due hereunder which is unpaid for more than
ten (10) days after the applicable Scheduled Payment Date (provided, however,
that no grace period is provided for the payment of sums due and payable on the
Maturity Date). Collection or acceptance by Lender of such late charge shall not
constitute a waiver of any other rights or remedies of Lender provided herein,
in the Mortgage, or in any other Loan Document.

          (b) So long as any Event of Default exists hereunder or under any
other Loan Document, regardless of whether or not there has been an acceleration
of the indebtedness evidenced hereby, and at all times after maturity of the
indebtedness evidenced hereby (whether by acceleration or otherwise), interest
(the "Default Interest") shall accrue on the outstanding principal balance of
this Note at a rate per annum equal to ten percent (10%) plus the sum of the
Base Interest and the Additional Interest which would be in effect hereunder
absent such default or maturity, or, if such increased rate of interest may not
be charged or collected under applicable law, then at the maximum rate of
interest, if any, which may be charged or collected from Borrower under
applicable law (the "Default Rate"), and such Default Interest shall be
immediately due and payable.

          (c) Borrower acknowledges that it would be extremely difficult or
impracticable to determine Lender's actual damages resulting from any late
payment or Event of Default, and such Default Interest and the late charges
payable pursuant to Sections 7(a) and 7(b) above are reasonable estimates of
those damages and do not constitute a penalty.

          (d) Lender shall be entitled to recover all costs of collecting,
securing or attempting to collect or secure this Note, including, without
limitation, court costs and reasonable attorneys' fees, including attorneys'
fees on any appeal by either Borrower or Lender. The remedies of Lender in this
Note, the Loan Agreement, the Mortgage, or the other Loan Documents, or at law
or in equity, shall be cumulative and concurrent and may be pursued singly,
successively, or together in Lender's discretion.

     8. YIELD MAINTENANCE PREMIUM.

          (a) As used herein, the term "Yield Maintenance Premium" shall mean a
sum paid to Lender at the time of a prepayment, which shall be equal in amount
to the sum of: (1) the present value of the Scheduled Monthly Payments under
this Note from the date of prepayment to the Applicable Repayment Date, and (2)
the present value of the amount of principal and interest due on the Applicable
Repayment Date (assuming all Scheduled Monthly Payments due prior to the
Applicable Repayment Date were made when due), minus the outstanding principal
balance of this Note as of the date of prepayment (which outstanding principal
balance shall be paid in accordance with Section 5 hereof). The present values
described in the foregoing clauses (1) and (2) shall be computed on a monthly
basis as of the date of prepayment, discounted at the rate equal to the sum of
(x) the U.S. Treasury obligation closest in maturity to the Applicable Repayment
Date as reported in The Wall Street Journal (or, if not then published, a
similar publication acceptable to Lender) or, as applicable, from the Federal
Reserve Bank of New York on the fifth (5th) business day preceding the date of
prepayment, plus (y) two hundred (200) basis


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points. Lender's determination of the Yield Maintenance Premium shall be
conclusive absent manifest error. "Loan Year" shall mean each twelve (12) month
period with an anniversary of January 1st during the Loan Term, commencing
January 1, 2006. "Applicable Repayment Date" shall mean (i) in the event that
prepayment is made pursuant to a bona fide Purchase Offer as described in
Section 5(a) hereof, December 1, 2013, and (ii) in the event of any other
prepayment, December 1, 2015. Notwithstanding anything herein to the contrary,
no Yield Maintenance Premium shall be payable with respect to any prepayment
after the Applicable Repayment Date.

          (b) Involuntary Prepayment. Except as hereinafter provided in this
Section 8(b), in the event that any prepayment is received by Lender other than
in accordance with Section 5(a) or 5(b) above or if a prepayment results from
Lender's exercise of its remedies hereunder or under any other Loan Document,
Borrower shall pay Lender a Yield Maintenance Premium in connection with such
prepayment. Partial prepayments of this Note shall be permitted without the
imposition of a Yield Maintenance Premium in connection with Lender's
application of insurance or condemnation proceeds on account of the Loan in
accordance with the terms and provisions of the Mortgage (as defined in Section
2 hereof), however, if an Event of Default shall have occurred and be continuing
at the time of the related casualty or condemnation, in addition to applying
such proceeds as provided in the Mortgage, Borrower shall pay a Yield
Maintenance Premium to Lender. No notice of prepayment by Borrower shall be
required, and provided no Event of Default then exists and is continuing, no
Yield Maintenance Premium shall be due and payable in connection with an
application of insurance or condemnation proceeds pursuant to the terms and
conditions of the Loan Agreement. No tender of a prepayment of this Note with
respect to which a Yield Maintenance Premium is due shall be effective unless
such prepayment is accompanied by such Yield Maintenance Premium.

          (c) No principal amount repaid may be re-borrowed.

     9. EVENT OF DEFAULT.

     The principal sum evidenced by this Note, together with all accrued but
unpaid interest thereon, shall become immediately due and payable at the option
of Lender upon the occurrence of any of the following events, each of which
shall constitute an "EVENT OF DEFAULT" hereunder:

               (i) Nonpayment of Indebtedness. Failure by Borrower to make any
          payment of interest, principal or any other sum when due, whether by
          acceleration or otherwise, under the terms of this Note, the Loan
          Agreement, the Mortgage or any other Loan Document.

               (ii) Failure to Perform Obligations. Failure by Borrower to
          perform any term, condition or covenant herein (other than terms,
          conditions or covenants requiring the payment of money), which failure
          is not cured within any applicable grace or cure period provided
          therefor; or

               (iii) Default Under Loan Documents. The occurrence under any of
          the other Loan Documents of (A) an "Event of Default" or (B) any
          default which is not cured within any applicable grace or cure period
          provided therefor.


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     Notwithstanding the foregoing, no notice of default as provided hereunder
or in the other Loan Documents shall be required and an event shall constitute
an Event of Default hereunder if Lender is prevented from giving notice by
bankruptcy or other applicable law, and the cure period, if any, specified with
respect to such event shall commence on the date of such event rather than from
the date of notice. Nothing herein shall require any notice to Borrower except
as expressly set forth herein or in the Mortgage or other Loan Documents.

     10. USURY. In no event shall the amount of interest due or payable
hereunder exceed the maximum rate of interest allowed by applicable law, and in
the event any such payment is inadvertently paid by Borrower or inadvertently
received by Lender, then Lender may elect, in its sole discretion, to do one or
more of the following with all or any portion of such excess: (a) apply such
excess to other sums due, if any, under this Note or the other Loan Documents,
(b) credit such excess as a prepayment of principal, (c) retain such excess as
additional security for the Loan or (d) refund such excess to Borrower, which
refund Borrower shall forthwith accept. It is the express intent hereof that
Borrower not pay and Lender not receive, directly or indirectly, interest in
excess of that which may be legally paid by Borrower under applicable law.

     11. RELATIONSHIP OF PARTIES. Borrower and Lender agree that the
relationship between them shall be solely that of debtor and creditor. Nothing
contained in this Note or in any other Loan Document shall be deemed to create a
partnership, tenancy-in-common, joint tenancy, joint venture or co-ownership by
or between Borrower and Lender. Lender shall not be in any way responsible or
liable for debts, losses, obligations or duties of Borrower with respect to the
Hospital, the Real Property, the Improvements, or otherwise. Borrower, at all
times consistent with the terms and provisions of this Note and the other Loan
Documents, shall be free to determine and follow its own policies and practices
in the conduct of its business.

     12. NOTICES. Any notice required herein or by applicable law shall be
deemed properly given (a) when personally delivered (to the person or department
if one is designated below), (b) as of the delivery date shown on the return
receipt when sent by United States Mail, certified or registered, postage
prepaid, return receipt requested, or (c) one day after the date sent by Federal
Express or overnight United States Mail or other national overnight carrier, and
addressed in each such case as set forth below:

          If to Borrower:   Alliance Hospital, Ltd.
                            515 North Adams
                            Odessa, Texas 79761
                            Attention: Chief Executive Officer

          With a copy to:   Hollmann, Lyon, Patterson & Durell, Inc.
                            5030 E. University Boulevard
                            Suite D-103
                            Odessa, Texas 79762-8148
                            Attention: Daniel J. Hollmann, Esq.

          If to Lender      Medical Properties Trust, Inc.
                            1000 Urban Center Drive, Suite 501
                            Birmingham, AL 35242


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                            Attention: Michael G. Stewart, Esq.

          With a copy to:   Baker, Donelson, Bearman, Caldwell & Berkowitz, PC
                            420 20th Street North, Suite 1600
                            Birmingham, Alabama 35203
                            Attention: Thomas O. Kolb, Esq.

Either party may by notice given as herein provided change its address to
another single address.

     13. GOVERNING LAW; JURISDICTION AND VENUE; WAIVER OF JURY TRIAL.

          (a) THIS NOTE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH
THE LAWS OF THE STATE OF DELAWARE APPLICABLE TO CONTRACTS EXECUTED AND PERFORMED
IN SUCH STATE, WITHOUT GIVING EFFECT TO CONFLICTS OF LAW PRINCIPLES.
NOTWITHSTANDING THE FOREGOING, THE TERMS AND PROVISIONS OF THIS NOTE PERTAINING
TO THE PRIORITY, PERFECTION, ENFORCEMENT, OR REALIZATION BY THE LENDER OF ITS
RIGHTS AND REMEDIES UNDER THIS NOTE OR THE MORTGAGE WITH RESPECT TO THE REAL
PROPERTY SHALL BE GOVERNED, CONSTRUED, AND ENFORCED IN ACCORDANCE WITH THE
INTERNAL LAWS OF THE STATE OF TEXAS.

          (b) THE BORROWER CONSENTS TO PERSONAL JURISDICTION IN THE STATE OF
DELAWARE. THE BORROWER AGREES THAT ANY ACTION OR PROCEEDING ARISING FROM OR
RELATED TO THIS AGREEMENT SHALL BE BROUGHT AND TRIED EXCLUSIVELY IN THE STATE OR
FEDERAL COURTS OF THE STATE OF DELAWARE. THE BORROWER IRREVOCABLY AND
UNCONDITIONALLY WAIVES ANY OBJECTION TO THE LAYING OF VENUE OF ANY SUCH ACTION
OR PROCEEDING BROUGHT IN ANY SUCH COURT. BORROWER EXPRESSLY ACKNOWLEDGES THAT
DELAWARE IS A FAIR, JUST AND REASONABLE FORUM AND BORROWER AGREES NOT TO SEEK
REMOVAL OR TRANSFER OF ANY ACTION FILED BY THE LENDER OR ITS AFFILIATES IN SAID
COURTS. FURTHER, BORROWER IRREVOCABLY AND UNCONDITIONALLY WAIVES ANY CLAIM THAT
SUCH SUIT, ACTION OR PROCEEDING HAS BEEN BROUGHT IN AN INCONVENIENT FORUM.
SERVICE OF ANY PROCESS, SUMMONS, NOTICE OR DOCUMENT BY CERTIFIED MAIL ADDRESSED
TO A PARTY AT THE ADDRESS DESIGNATED IN SECTION 12 OF THIS NOTE, SHALL BE
EFFECTIVE SERVICE OF PROCESS AGAINST SUCH PARTY FOR ANY ACTION OR PROCEEDING
BROUGHT IN ANY SUCH COURT. A FINAL JUDGMENT IN ANY SUCH ACTION OR PROCEEDING
BROUGHT IN ANY SUCH COURT MAY BE ENFORCED IN ANY OTHER COURT TO WHOSE
JURISDICTION ANY OF THE PARTIES IS OR MAY BE SUBJECT.

     14. MISCELLANEOUS.

          (a) All amounts due hereunder shall be payable in lawful money of the
United States of America.


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          (b) With respect to the amounts due under this Note, Borrower waives
the following to the fullest extent permitted by law:

               (i) All rights of exemption of property from levy or sale under
          execution or other process for the collection of debts under the
          Constitution or laws of the United States of America or any state
          thereof;

               (ii) Demand, presentment, protest, notice of protest, notice of
          dishonor, notice of non-payment, diligence in collection, and all
          other requirements necessary to charge or hold the Borrower liable on
          any Loan Obligations; and

               (iii) Any further receipt for or acknowledgment of any collateral
          now or hereafter deposited as security for the Loan Obligations.

          (c) Borrower hereby acknowledges that Lender shall not by any act,
delay, omission, or otherwise be deemed to have waived any of its rights or
remedies under the Loan Documents, and no waiver of any kind shall be valid
unless in writing and signed by Lender. All rights and remedies of Lender under
the terms of this Note and the other Loan Documents and applicable statutes or
rules of law shall be cumulative and may be exercised successively or
concurrently. Any provision in this Note which may be unenforceable or invalid
under any law shall be ineffective to the extent of such unenforceability or
invalidity without affecting the enforceability or validity of any other
provision hereof.

          (d) Borrower agrees that, as of the date hereof, and as of the date of
each future advance of loan proceeds hereunder, there are and shall be no
defenses, equities, or setoffs with respect to the Loan Obligations.

          (e) This Note and the obligations of Borrower hereunder shall be
binding upon and enforceable against Borrower and its successors and assigns,
and shall inure to the benefit of Lender and its successors and assigns,
including any subsequent holder of this Note.

          (f) Lender may, at its option, release any collateral given to secure
the indebtedness evidenced hereby, or release any guarantor from its obligations
under any guaranty, and no such release shall impair the Loan Obligations under
this Note and the other Loan Documents.

          (g) Section headings are inserted for convenience of reference only
and shall be disregarded in the interpretation of this Note. The provisions of
this Note shall be construed without regard to the party responsible for the
drafting and preparation hereof.

          (h) Time is of the essence with respect to this Note and the
performance of each of the covenants and agreements contained herein.

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     IN WITNESS WHEREOF, Borrower has caused this instrument to be duly executed
and delivered to Lender as of the day and year first above written.

                                        BORROWER:

                                        ALLIANCE HOSPITAL, LTD.

                                        BY: SRI-SAI ENTERPRISES, INC.
                                        ITS: GENERAL PARTNER


                                        By: /s/ Steven C. Riley
                                            ------------------------------------
                                        Name: Steven C. Riley
                                        Title: Co-Chairman


                                        By: /s/ Jayaram B. Naidu
                                            ------------------------------------
                                        Name: Jayaram B. Naidu
                                        Title: Co-Chairman


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