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                                                                Exhibit 10.16(b)

                               SUBLEASE AGREEMENT

      This Sublease Agreement ("Sublease") is entered into by and between The
Alexander Group, Inc., a New York corporation ("Alexander") and Integrated
Physician Networks Inc., a Delaware corporation ("Integrated") as of the 18th
day of May, 1996.

      The parties agree as follows:

      1. Alexander hereby subleases to Integrated, and Integrated hereby
subleases from Alexander, subject to all of the provisions of this sublease and
the Lease (as defined below), those certain premises (the "Premises") depicted
on Exhibit A attached hereto, consisting of approximately 1,098 rentable square
feet (967 usable square feet) located in the building at 8777 North Gainey
Center Drive, Scottsdale, Arizona 85258, which is a portion of the premises
leased by Alexander pursuant to that certain Gainey Ranch Corporate Center
Office Lease having a commencement date of September 18, 1992 and that certain
Addendum to Lease for Parking Purposes, Gainey Ranch Corporate Center Rules and
Regulations, Third Addendum to Lease, Forth Addendum, and Fifth Addendum to
Lease (as amended and supplemented, the "Lease"), between Alexander and the
landlord ("Landlord") of the Premises. This Sublease includes up to a maximum of
4 of Alexander's covered parking spaces pursuant to the Lease; any additional
parking requested or required by or with respect to Integrated shall be at
Landlord's then current rate and conditions and subject to availability.
Integrated shall have no right to use any portion of Alexander's premises not
specifically subject to this Sublease.

      2. This Sublease is subject to the consent of the Landlord. If the parties
cannot obtain the consent of the Landlord to this Sublease after good faith
efforts to do so, then either party must terminate this Sublease by notice to
the other party and neither party shall thereafter have any obligation or
liability under this Sublease.

      3. This Sublease is subject in all respects to the Lease. Integrated has
only the right to occupy the Premises and such other rights under the Lease as
are specifically assigned to Integrated hereunder. All rights not specifically
assigned to Integrated under this Sublease are reserved to Alexander.
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      4. The term of this Sublease shall commence on or before June 15, 1996
(the "Sublease Commencement Date") and shall expire on the day immediately
preceding the first anniversary of the Sublease Commencement Date. Thereafter,
this Sublease shall continue in effect as a month to month tenancy until the
earlier of the following dates: (i) fifteen (15) days after either party
notifies the other party of termination, which notice Alexander agrees it will
give to Integrated only if Alexander in good faith desires to use the Premises
in the conduct of Alexander's business; or (ii) December 16, 1997; or (iii) upon
earlier expiration or termination of the Lease for any reason or the Landlord's
relocation of Alexander to other premises. Alexander has no obligation of any
kind to extend or renew the term of the Lease or to extend or renew this
Sublease beyond December 16, 1997.

      5. The annual Sublease rent shall be $18,000.00, payable to Alexander in
advance in monthly installments of $1,500.00. The monthly rent during any month
to month tenancy shall be $1,500.00. The first and last monthly installments in
advance are due on or before the Sublease Commencement Date. The Sublease rent
shall be prorated for any partial month or partial year of the Sublease term.

      6. Upon execution hereof, Integrated shall pay all costs of the
improvements necessary to prepare the premises for its occupancy, including all
improvements within and without the Premises, currently estimated by the parties
to be approximately $7,800.00 as set forth on Exhibit B attached hereto.
Integrated shall pay any additional or other costs associated with improvements
necessary to prepare the premises for its occupancy, regardless of whether the
improvements are identified on Exhibit B or the costs vary from the estimate set
forth on Exhibit B. With the exception of such improvements, Integrated hereby
accepts the Premises in completely "as is" condition. Integrated's moving costs,
the costs of any installation and wiring of computers, telephones, new locks and
other equipment and any other costs of any kind related to Integrated's
occupation of the Premises shall be at Integrated's sole expense. Any
modifications or alterations to the Premises or Alexander's remaining premises
made in connection with Sublease and not described on Exhibit B shall require
prior written approval of Alexander and Landlord. Integrated shall bear any
other costs related to the Premises that Alexander would otherwise be
responsible for under the Lease, except that Alexander shall be responsible for
paying the monthly installments of rent to the Landlord under the Lease for the
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Premises and the remainder of the premises that are subject to the Lease,
including the differential between the rent Alexander receives from Integrated
under this Sublease and the rent Alexander owes the Landlord under the Lease.

      7. Integrated shall maintain the Premises in good, clean and safe
condition and shall promptly repair any damage thereto at Integrated's expense.
Upon the expiration or termination of this Sublease, Integrated shall leave the
Premises in a condition that is at least as good, clean, safe and ready for
occupancy as on the Sublease Commencement Date (excepting only ordinary wear and
use), and Integrated shall arrange and pay for any repairs or cleaning required
by Landlord due to obligations under the Lease, or by Alexander to restore
Alexander's furniture or other improvements to their condition and location as
of the Sublease Commencement Date, at Integrated's sole expense. The parties
acknowledge that the Premises are currently in a condition acceptable to
Landlord. Therefore, any expense of any kind necessary to restore the Premises
to a condition required under the Lease, and acceptable to Landlord at the
expiration or termination of this Sublease or thereafter, including without
limitation cleaning, repairs or removal of modifications, as well as, upon
Landlord's request, returning the Premises and Alexander's remaining premises
back to one suite per the Lease (i.e., removal of the wall described on Exhibit
B separating the Premises from the remainder of Alexander's premises and removal
of the door at the corridor described on Exhibit B and replacing it with
standard corridor wall), shall be at Integrated's sole expense. Integrated shall
promptly and directly incur or pay all expenses that are Integrated's obligation
under this Sublease.

      8. Rental payments under this Sublease shall be due on the first day of
each month, in advance. If any payment is not received in full by Alexander
within five (5) days after the date it is due, a late charge of 5% of the
payment shall be immediately due and payable. If any payment is not received in
full by Alexander within fifteen (15) days after the date it is due, then
Alexander shall additionally be entitled to terminate this Sublease upon fifteen
(15) days written notice to Integrated and/or shall be entitled to all other
rights and remedies available to Alexander under applicable law. All rights and
remedies of Alexander under this Sublease shall be cumulative and not exclusive.

      9. Integrated shall not make any modifications to the Premises without the
prior written consent of Landlord and
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Alexander, and any such permitted modification, together with any restoration
thereof at the expiration of this Sublease, shall be at Integrated's sole
expense. Any cleaning, re-keying or other services or expenses of any kind
desired or used by Integrated, other than the basic services provided by the
Landlord at no extra charge to Alexander or Integrated pursuant to the Lease,
shall be at the sole expense of Integrated. Integrated shall be entitled to make
ordinary office use of Alexander's furniture, telephone and computer conduit and
other improvements in the Premises during the term of this Sublease; provided,
however, that Integrated shall obtain the prior written consent of Alexander
before moving, altering or modifying any of same. All such furniture and
improvements shall remain the sole property of Alexander, and Integrated shall
not remove any of same from the Premise.

      10. Without limiting any other provision of this Sublease, Integrated
hereby assumes and agrees to perform all of the obligations of Alexander under
the Lease during the term of this Sublease with respect to the Premises, except
as otherwise specifically provided herein. Alexander shall have the right but
not the obligation to cure any breach of the Lease by Integrated at Integrated's
expense after reasonable (but not more than ten (10) day advance) written notice
to Integrated, and to enter the Premises after prior notice to Integrated if
reasonably necessary in connection with any such cure.

      11. In the event suit is brought (or arbitration instituted) or an
attorney is retained by either party to enforce the terms of this Sublease or to
collect any money due hereunder or to collect money damages for breach hereof,
the prevailing party shall be entitled to recover reimbursement for reasonable
attorneys' fees, court costs, costs of investigation and other related expenses
incurred in connection therewith.

      12. Each of the parties represents and warrants to the other party that
this Sublease has been duly authorized by all necessary action and that this
Sublease constitutes and will constitute a binding obligation of each such
party, and that this Sublease had been duly and validly executed on behalf of
such party.

      13. This Sublease shall not be assignable by Integrated without
Alexander's prior written consent, which consent may be withheld in Alexander's
sole discretion, and any purported assignment of all or any portion of
Integrated's interest in this Sublease without such consent shall be void.
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      14. Each party agrees to indemnify the other party and hold it harmless
from and against all liabilities, losses, claims, damages, costs and expenses
(including attorneys' fees) arising from or related directly or indirectly to
the breach by such indemnifying party of any obligation to the other party
hereunder or the inaccuracy of any representation or warranty made by such
indemnifying party to the other party herein.

EXECUTED as of the date first written above.

THE ALEXANDER GROUP, INC.,
a New York corporation

By:______________________________

Printed name:____________________
Its______________________________

INTEGRATED PHYSICIAN NETWORKS INC.,
a ________________ corporation

By:______________________________

Printed name:_____________________
Its_______________________________
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                               LANDLORD'S CONSENT

      Nationwide Life Insurance Company, an Ohio corporation, as Landlord under
the Lease identified in this Sublease Agreement, hereby (i) consents to this
Sublease, (ii) consents to the tenant improvements described herein, and (iii)
agrees that numbered paragraph 52 of the Third Addendum to Lease remains in
effect notwithstanding clause (iv) of said paragraph, provided Alexander
covenants and agrees Alexander will remain fully liable to the Landlord for all
of the obligations set forth in said Lease, as well as for, upon Landlord's
request, returning the Premises and Alexander's remaining premises back to one
suite per the Lease (i.e., removal of the wall described on Exhibit B separating
the Premises from the remainder of Alexander's premises and removal of the door
at the corridor described on Exhibit B and replacing it with Standard corridor
wall). Alexander's covenant and agreement is signified by Alexander's execution
of this Sublease.

By:_______________________________

Printed name:_____________________
Its________________________________

                                                                         5/17/96<PAGE>   1
                                                                Exhibit 10.16(c)

                         AMENDMENT TO SUBLEASE AGREEMENT

         This Amendment to Sublease Agreement ("Amendment") is entered into as
of the 1st day of June, 1998, by and between The Alexander Group, Inc., a
Delaware corporation ("Alexander"), and Integrated Physician Networks Inc., a
Delaware corporation ("Integrated"). This Amendment amends certain provisions of
that Sublease Agreement between the parties dated as of May, 18, 1996 (the
"Sublease").

         1. All references in the Sublease to covered parking are deleted;
Integrated shall have no further right to use any of Alexander's covered
parking.

         2. Paragraph 2 of the Sublease concerning the requirement for consent
of the Landlord applies to this Amendment in the same manner as it applied to
the Sublease.

         3. Paragraph 4 of the Sublease is amended to provide that the term of
the Sublease is extended for a period of 18 months, commencing June 1, 1998 and
ending November 30, 1999. The date in subparagraph 4(ii) of the Sublease and in
the last sentence of paragraph 4 is changed to May 31, 2000.

         4. The rent for the 18-month extension of the Sublease term shall be
$37,800.00, payable to Alexander in advance in monthly installments of
$2,100.00. The monthly rent during any month to month tenancy shall be
$2,100.00.

         5. The Sublease premises are accepted by Integrated in their current
"as is" condition.

         6. Alexander's conference room is available to Integrated, but only at
times when it is not reasonably needed by Alexander, at the rate of $50.00 for a
period of 0 to 4 hours, and $100.00 for a period of 4 to 8 hours, in any given
day. Subject to availability of the conference room, Integrated is entitled to 1
use of 4 or less hours per month without payment of this additional fee.

         7. This Amendment shall not become effective until it is executed by
both parties hereto and consented to by the Landlord.

         8. Except as specifically amended herein, the Sublease remains
unmodified and in full force and effect.
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         EXECUTED as of the date first written above.

         THE ALEXANDER GROUP, INC.,
         a Delaware corporation

         By:____________________________

         Printed name:__________________
         Its:___________________________

         INTEGRATED PHYSICIAN NETWORKS INC.,
         a Delaware corporation

         By:____________________________

         Printed name:__________________
         Its:___________________________

                               LANDLORD'S CONSENT
         Nationwide Realty Investors, Ltd., and Ohio limited liability company,
as Landlord, hereby consents to this Amendment, provided that the conditions of
its consent to the Sublease are incorporated herein by this reference.

         By:___________________________

         Printed name:__________________
         Its:___________________________

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