<PAGE>

                                                                   Exhibit 10.10

     THIS FIRST AMENDMENT OF LEASE CONTRACT (the "First Amendment") is entered
into between CRESCENT REAL ESTATE FUNDING III, L.P., a Delaware limited
partnership ("Landlord"), and PHYSIX, INC., a Texas corporation ("Tenant"), with
reference to the following:

     A.   Greenway Plaza, Ltd. (predecessor-in-interest to Landlord) and Tenant
entered into a Lease Contract dated October 2, 1996 covering approximately 7,433
square feet of Rentable Area (the "Original Leased Premises") on the sixth (6th)
floor of Two Greenway Plaza, Houston, Texas (the "Building").

     B.   Landlord and Tenant now wish to amend the Commencement and Expiration
Dates set forth in Paragraph 2 of the Lease; further expand the Leased Premises
pursuant to Tenant's exercise of its First Preferential Right; and otherwise
amend the Lease as set forth more fully below.  Unless otherwise expressly
provided herein, capitalized terms used herein shall have the same meanings as
in the Lease.

     FOR GOOD AND VALUABLE CONSIDERATION, the receipt and sufficiency of which
are acknowledged, the parties agree as follows:

1.   First Preferential Space.

     (a)  Pursuant to Paragraph 26.A. of the Lease, Landlord leases to Tenant
and Tenant leases from Landlord approximately 3,144 square feet of additional
Rentable Area located on the sixth (6th) floor of the Building shown outlined
and hatched on Exhibit "B" attached hereto and made a part hereof (the "First
Preferential Space"). The term of the Lease with respect to the First
Preferential Space shall commence upon Substantial Completion (as defined in
Paragraph 5(c) of the Construction Agreement attached hereto as Exhibit "D') of
leasehold improvements therein and shall expire upon the expiration of the
initial term of the Lease.

     (b)  Landlord shall, at its expense, use reasonable good faith efforts to
achieve Substantial Completion in the First Preferential Space on or before July
1, 1997.  If Substantial Completion has not been achieved by such date for any
reason, Landlord shall not be liable to Tenant for any claims, damages, costs or
liabilities arising by reason of such delay.  However, in such event, Landlord
and Tenant shall, promptly upon request, execute an agreement specifying the
date of Substantial Completion in the First Preferential Space, with a
corresponding adjustment to the schedule of Base Rental set forth below.

     (c)  Upon Substantial Completion of the First Preferential Space, the term
"Leased Premises" as used in the Lease shall mean and include approximately
10,577 square feet of Rentable Area, being the sum of the Original Leased
Premises and the First Preferential Space.

2.   Commencement Date.  In Paragraph 2 of the Lease, the Commencement Date
shall be changed to "November 15, 1996" and the Expiration Date shall be changed
to "March 31, 2004."

3.   Base Rental.

     (a)  Tenant shall pay Landlord Base Rent for the First Preferential Space
in accordance with the following schedule:


          FROM                  TO                      MONTHLY BASE RENTAL

          July 1, 1997          September 14, 2000            $3,144.00
          September 15, 2000    March 31, 2004                $3,406.00

5.   Construction.

     (a)  The Work.  Subject to the terms of this Construction Agreement,
Landlord agrees to construct leasehold improvements (the "Work") in a good and
workmanlike manner in and upon the First Preferential Space in accordance with
the Approved Construction Documents.
<PAGE>

     (b)  General Construction Terms.  Landlord will employ an experienced,
licensed contractor to construct the Work and will require in the construction
contract that such contractor construct the Work in a good and workmanlike
manner and in compliance with all Applicable Laws, except as otherwise provided
herein or in the Lease.  The parties acknowledge that Landlord is not an
architect or engineer, and that the Work will be designed and performed by
independent architects, engineers and contractors.  Accordingly, Landlord does
not guarantee or warrant that the Approved Construction Documents will be free
from errors or omissions, nor that the Work will be free from defects, and
Landlord will have no liability therefor. In the event of such errors,
omissions, or defects, Landlord will use reasonable efforts to cooperate in any
action Tenant desires to bring against such parties.

     (c)  Substantial Completion.  All work shall be deemed "Substantially
Completed" when completed in accordance with this Exhibit and the Approved
Construction Documents, to the extent that Tenant would have access to the First
Preferential Space and be able to conduct its business in a reasonable manner
and Landlord has obtained final inspection approval from the City of Houston,
even though adjustments or corrections may be necessary and minor "punch-list"
items remain to be completed.

     (d)  ADA Compliance.  Landlord shall be responsible for costs and
implementation associated with compliance with the Americans with Disabilities
Act, including any state or local laws relating thereto ("ADA") for the Project
and all points of access into the Project ("the Landlord's ADA Work").  Tenant
shall be responsible for all costs and implementation associated with ADA
compliance within the First Preferential Space (including restrooms). Landlord
shall not be responsible for determining whether Tenant is a public
accommodation under ADA or whether the Approved Construction Documents comply
with such laws and the regulations thereunder.  Such determinations, if desired
by Tenant, shall be the sole responsibility of Tenant.

6.   Costs.

     (a)  Overruns.  Costs incurred by Landlord in excess of the Construction
Allowance shall be paid by Tenant to Landlord promptly within ten (10) calendar
days following delivery of Landlord's invoice. Change orders requested by Tenant
and approved by Landlord which increase the cost of construction shall be paid
by Tenant to Landlord promptly upon demand.

     (b)  Construction Management Fee.  Within ten (10) calendar days following
the date of invoice, Tenant shall pay Landlord a "Construction Management Fee"
equal to ten percent (10%) of the contract price for the Work in excess of the
Design and Construction Allowance for supervision and administration of the
construction and installation of the Work. Tenant agrees that in the event of
default of payment thereof, Landlord (in addition to all other remedies) shall
have the same rights as in the event of default of payment of rent under the
Lease.

7.   Delays. If Landlord is delayed in completing construction of the Work for
any reason other than Tenant Delays, the delay in commencement of Tenant's
obligation to pay rent under the Lease shall constitute full settlement of all
claims that Tenant may have against Landlord based on the delay. If Landlord is
delayed in completing the Work due to a delay caused by Tenant or for any other
cause related to Tenant's acts or omissions, Tenant's rental obligations under
the Lease shall begin on the date on which Landlord would have delivered
possession of the First Preferential Space to Tenant absent such delay, and such
date shall be the Commencement Date.

                                      -2-