<PAGE>   1
EXHIBIT 10.53

                          ASSIGNMENT AND ASSUMPTION OF
                         SUBLEASES AND SECURITY DEPOSITS


         THIS ASSIGNMENT AND ASSUMPTION OF SUBLEASES AND SECURITY DEPOSITS (this
"Assignment") is made as of the 9th day of September, 1999 by and between UNITED
AMERICAN HEALTHCARE CORPORATION, a Michigan corporation (the "Assignor") and
INTERNATIONAL BUSINESS MACHINES CORPORATION, a New York corporation (the
"Assignee").

                                   WITNESSETH:

         WHEREAS, pursuant to a Sublease dated August 29, 1994 (the "Over
Sublease"), the Assignee subleased to the Assignor 67,144 square feet of
rentable area in the building commonly known as One Commerce Square, 2005 Market
Street, Philadelphia, PA 19103 (the "Premises");

         WHEREAS, pursuant to those certain subleases described on Exhibit A
attached hereto and made a part hereof (the "Subleases"), the Assignor, as
sublandlord, subleased portions of the Premises;

         WHEREAS, the Assignor has requested that the Assignee accept: (i) a
lump sum payment in advance in satisfaction of all of the Assignor's obligations
under the Over Sublease; (ii) an assignment of all of the Assignor's right,
title and interest, as sublandlord, in and to the Subleases; and (iii) an
assignment of any and all security deposits tendered and held under the
Subleases (the "Security Deposits"); and

         WHEREAS, the Assignee has agreed to do so on the terms and conditions
hereinafter set forth.

         NOW, THEREFORE, in consideration of the mutual promises contained
herein and other good and valuable consideration, the receipt and sufficiency of
which is hereby acknowledged, the Assignor and the Assignee intending to be
legally bound hereby, agree as follows:

         1.   Over Sublease. Contemporaneously with the execution of this
Agreement, the Assignor has paid the Assignee the sum of $357,093.79. This sum
represents: $312,500.00 on account of Assignor's obligations under the Over
Sublease; and $44,593.79 on account of the difference between the tenant
improvement allowance available under the Hatch Sublease and the remaining
available balance of the tenant improvement allowance under the Over Sublease.
The Assignee agrees that such payment is in full satisfaction of all of the
Assignor's obligations under the Over Sublease and the Assignee agrees not to
seek any further sums from the Assignor with respect to its obligations
thereunder.


<PAGE>   2

         As further consideration for the Assignee's execution of this
Agreement, the Assignor hereby releases any claims which the Assignor may have
against the Assignee, its agents or employees under the Over Sublease arising
from the Assignee's, its agents' or employees' acts or omissions or any other
matter related to the Over Sublease, from August 29, 1994 to the date hereof.

         2.   Subleases and Security Deposits. The Subleases and the Security
Deposits are described on Exhibit "A" attached hereto and made a part hereof.

         3.   Assignment. The Assignor hereby assigns, transfers, conveys and
delivers to the Assignee, all of the Assignor's right, title and interest in
and to the Subleases, together with the Security Deposits. In lieu of actually
transferring the Security Deposits from the Assignor to the Assignee, the
parties agree that the Assignee will retain the Assignor's security deposit
given pursuant to the Over Sublease.

         4.   Indemnity by the Assignor. The Assignor shall indemnify, defend
and hold the Assignee harmless from and against any and all losses, damages,
costs, penalties, claims, actions, causes of action, liabilities, obligations or
expenses, including without limitation, reasonable attorneys' fees and court
costs, arising from the Assignor's failure to comply, prior to the date hereof,
with any of the terms, conditions or obligations to be kept, observed or
performed by the Assignor, as sublandlord, under the Subleases.

         5.   Assumption by the Assignee. The Assignee hereby accepts the
foregoing assignment and assumes and agrees to perform all of the obligations to
be kept, observed and performed as sublandlord, under the Subleases, arising
from and after the date hereof, including the obligation to hold, apply and/or
return the Security Deposits in accordance with the provisions of the Subleases,
and the Assignee acknowledges its receipt of the Security Deposits.

         6.   Indemnity by the Assignee. The Assignee shall indemnify, defend
and hold the Assignor harmless from and against any and all losses, damages,
costs, penalties, claims, actions, causes of action, liabilities, obligations or
expenses, including without limitation, reasonable attorneys' fees and court
costs, arising from the Assignee's failure to comply, from and after the date
hereof, with any of the terms, conditions or obligations to be kept, observed or
performed by the Assignee, as sublandlord, under the Subleases, including, but
not limited to, the holding, application and/or return of the Security Deposits.

         7.   Absolute Assignment. This Assignment is absolute and unconditional
and shall apply to any existing or further amendment, supplement, modification,
extension or renewal of any of the Subleases.


<PAGE>   3


         8.   Representations and Warranties by the Assignor. The Assignor
hereby represents and warrants to the Assignee as follows:

              (a) The Assignee is not in default of the Over Sublease;

              (b) The Assignor is not in default of the Over Sublease and has no
claim or offset thereunder, against rents or any other sums due or to become due
thereunder;

              (c) The Over Sublease is in full force and effect and it
represents the entire agreement between the Assignor and the Assignee with
respect to the Premises;

              (d) Other than the Subleases, the Assignor has not subleased all
or any portion of its interest in the Premises. The Assignor has paid the
Assignee a security deposit of $81,132, which shall be applied by the Assignee
on account of the Security Deposits;

              (e) Neither the Assignor nor any of the subtenants are in default
of any of the Subleases;

              (f) The description of the Subleases and the Security Deposits as
described on Exhibit A is true, correct and complete;

              (g) Each of the estoppel certificates delivered by the subtenants
with respect to each of the Subleases is true, correct and complete;

              (h) There are no leasing commissions owed to any persons or
entities in connection with any of the Subleases;

              (i) All improvements required by each of the Subleases to be
completed by the sublandlord thereunder have been satisfactorily completed and
delivered by the Assignor;

              (j) The available balance of the tenant improvement allowance
under the Hatch Sublease is $63,652.92;

              (k) The Assignor has not assigned or pledged its interest in the
Over Sublease or any of the Subleases or the Security Deposits; and

              (l) The execution and delivery of this Assignment has been duly
authorized by the Assignor's Board of Directors.

         9.   Governing Law. This assignment shall be governed by and construed
in accordance with the laws of the Commonwealth of Pennsylvania.

<PAGE>   4

         10.  Successors and Assigns. This Assignment shall be binding upon and
shall inure to the benefit of the parties hereto and their respective successors
and assigns.





                           ASSIGNOR:

                           UNITED AMERICAN HEALTHCARE CORPORATION, a Michigan
                           corporation


                           By:
                                  -------------------------------
                                  Name:
                                  Title:

                           Attest:
                                  ----------------------------
                                  Name:
                                  Title:

                           ASSIGNEE:

                           INTERNATIONAL BUSINESS MACHINES CORPORATION, a
                           New York corporation


                            By:
                                  -------------------------------
                                  Name:
                                  Title:

                            By:
                                  ----------------------------
                                  Name:
                                  Title:



<PAGE>   5

                                    EXHIBIT A

                     LIST OF SUBLEASES AND SECURITY DEPOSITS

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
DATE OF         SUBTENANT          PREMISES        MONTHLY        OPERATING         R.E. TAXES      EXPIRATION        SECURITY
SUBLEASE                                            RENT           EXPENSES                            DATE            DEPOSIT
-------------------------------------------------------------------------------------------------------------------------------
<S>            <C>               <C>             <C>           <C>                <C>                <C>             <C>
7/1/97         ADR               8,205 sq.ft.    $ 9,914.38    $7.40 Base Stop    $3.55 Base Stop    9/29/02         $ 9,914.38
               Options, Inc.
-------------------------------------------------------------------------------------------------------------------------------
5/1/96         Amtrak            8,035 sq.ft.    $10,043.75    $7.40 Base Stop    $3.55 Base Stop    9/29/02         $        0
amended
6/10/96;
6/18/96;
3/4/98
-------------------------------------------------------------------------------------------------------------------------------
4/15/98        HLM              10,350 sq.ft.    $12,506.25    $7.40 Base Stop    $3.55 Base Stop    9/29/02         $25,012.50
               Design, Inc.
-------------------------------------------------------------------------------------------------------------------------------
12/20/96       Hatch            13,562 sq.ft.    $17,517.58    $7.40 Base Stop    $3.55 Base Stop    9/29/02         $16,087.51
amended        Associates
5/2/97;        Consultants
2/21/98
-------------------------------------------------------------------------------------------------------------------------------
5/1/96         Accountants on    3,200 sq.ft.    $ 3,866.67    $7.40 Base Stop    $3.55 Base Stop    9/30/02         $ 3,866.67
amended        Call of Phila.
6/18/96 &
2/26/97
-------------------------------------------------------------------------------------------------------------------------------
11/7/96        Management        9,316 sq.ft.    $   11,645    $7.40 Base Stop    $3.55 Base Stop    9/29/02         $20,879.89
amended        Recruiters
2/14/97,
3/13/97,
4/16/97 &
11/1/96
-------------------------------------------------------------------------------------------------------------------------------
7/1/99         Philcare          1,568 sq.ft.    $ 1,894.66    $7.40 Base Stop    $3.55 Base Stop    3/31/00         $ 3,789.32
                                                                                                     (renewal option
                                                                                                     to 9/29/02)
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>