<PAGE>


                                                                   Exhibit 10.2

Lease with Audubon Biomedical Science and Technology Park

================================================================================

                                      LEASE

                                     Between

                       THE TRUSTEES OF COLUMBIA UNIVERSITY
                            IN THE CITY OF NEW YORK

                                  as Landlord,

                                       and

                           ORTEC INTERNATIONAL, INC.,

                                    as Tenant

                           Dated as of March 14, 1996

================================================================================









<PAGE>

                                Table of Contents

<TABLE>
<CAPTION>
                                                                            Page
                                                                            ----
<S>                                                                          <C>
ARTICLE 1     Demised Premises/Term......................................     1
ARTICLE 2     Ground Lease...............................................     2
ARTICLE 3     Rent.......................................................     2
ARTICLE 4     Use of Demised Premises....................................     5
ARTICLE 5     Demised Premises "As Is"...................................     7
ARTICLE 6     Operating Covenants; Signs.................................     7
ARTICLE 7     Window Cleaning............................................     9
ARTICLE 8     Legal Requirements/Environmental Legal Requirements........    10
ARTICLE 9     Access to Demised Premises.................................    11
ARTICLE 10    Default....................................................    12
ARTICLE 11    Remedies/Damages...........................................    15
ARTICLE 12    Eminent Domain.............................................    18
ARTICLE 13    Quiet Enjoyment............................................    18
ARTICLE 14    No Waiver..................................................    18
ARTICLE 15    Waiver of Trial............................................    19
ARTICLE 16    Inability to Perform.......................................    19
ARTICLE 17    Fees and Expenses..........................................    20
ARTICLE 18    Estoppel...................................................    20
ARTICLE 19    Surrender..................................................    21
ARTICLE 20    Subordination/Attornment...................................    21
ARTICLE 21    Consents...................................................    23
ARTICLE 22    [Intentionally Deleted]....................................    23
ARTICLE 23    Assignment and Subletting..................................    23
ARTICLE 24    Bankruptcy.................................................    30
</TABLE>


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<PAGE>

                           Table of Contents (cont'd)

<TABLE>
<CAPTION>
                                                                            Page
                                                                            ----
<S>                                                                          <C>
ARTICLE 25    Alterations................................................    32
ARTICLE 26    Services...................................................    36
ARTICLE 27    Windows; Machinery.........................................    39
ARTICLE 28    Insurance..................................................    40
ARTICLE 29    Notices....................................................    43
ARTICLE 30    Non-Liability/Indemnification..............................    43
ARTICLE 31    Casualty...................................................    45
ARTICLE 32    Maintenance/Repairs........................................    45
ARTICLE 33    Additional Rent............................................    46
ARTICLE 34    Parking....................................................    50
ARTICLE 35    Broker.....................................................    51
ARTICLE 36    Security Deposit...........................................    51
ARTICLE 37    Miscellaneous..............................................    53
ARTICLE 38    Renewal Option.............................................    55
ARTICLE 39    Expansion Right............................................    56
ARTICLE 40    Intentionally Deleted......................................    56
ARTICLE 41    REA/Security...............................................    57
ARTICLE 42    Index of Definitions.......................................    57
ARTICLE 43    Tenant's Equipment.........................................    61
ARTICLE 44    Equity Participation.......................................    61
ARTICLE 45    Human and Animal Research..................................    62
ARTICLE 46    Payment for Tenant's Work..................................    62
</TABLE>


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<PAGE>

                                    EXHIBITS

<TABLE>
<S>  <C>
A.   Floor Plan/Demised Premises
B.   Tenant's Regulatory Compliance Plan
C.   Plans and Specifications
D.   Cleaning Specifications
E.   Tenant's Equipment
</TABLE>


                                      iii










<PAGE>

                                     LEASE

     LEASE ("Lease") dated as of March 14, 1996, by and between THE TRUSTEES OF
COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK, having an address c/o Executive
Director, Audubon Research Park, 3960 Broadway, New York, New York 10032
("Landlord") and ORTEC INTERNATIONAL, INC., having an address at 8000 Cooper
Avenue, Building 26, Glendale New York 11385 ("Tenant").

                                   WITNESSETH:

     WHEREAS, The City of New York, as landlord ("the City") and the New York
City Economic Development Corporation ("EDC"), as tenant, entered into that
certain Agreement of Lease, dated as of November 20, 1992, covering the premises
described therein which was assigned by EDC to Landlord by assignment, dated as
of November 20, 1992 (such Agreement of Lease, as so assigned, being hereinafter
the "Ground Lease").

     WHEREAS, Tenant desires to let the space located in the building commonly
known as the Audubon Business and Technology Center (the "Building") at 3960
Broadway, in the City, County and State of New York (the Building and the land
on which it is located hereinafter, together, being the "Premises"), shown by
the area cross batched on the floor plan annexed hereto and made a part hereof
as Exhibit A (the "Demised Premises") located on the second floor of the
Building, and Landlord desires to let the Demised Premises to Tenant.

     NOW, THEREFORE, in consideration of the mutual obligations of the parties
hereto, the adequacy of which is hereby acknowledged, the parties for themselves
and their permitted successors and assigns, hereby covenant and agree as
follows:

                                   ARTICLE 1

                             Demised Premises/Term

     Section 1.01. Subject to the terms and conditions set forth in the Ground
Lease and that certain Reciprocal Easement Agreement, dated as of November 20,
1992, among Landlord, the City and EDC (the "REA") and the resolution of the New
York City Board of Estimate (Calendar Number 6) adopted on August 16-17, 1990
(the "Special Permit") (copies of which Ground Lease, Special Permit and REA
Tenant acknowledges having received and read), Landlord hereby leases to Tenant
and Tenant hereby hires from Landlord, upon and subject to the terms, covenants,
provisions and conditions of this Lease, the Demised Premises.

     Section 1.02. The Demised Premises are leased for a term


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<PAGE>

(the "Term") to commence on the date hereof ("Commencement Date") and to expire
on the last day of the calendar month in which occurs the fifth anniversary of
the Rent Commencement Date (as hereinafter defined) (the "Expiration Date") or
on such earlier date upon which the Term may expire or be cancelled or
terminated pursuant to the provisions of this Lease or pursuant to law.

     Section 1.03. Subject to the provisions of Section 25.07(a)(iii) the "Rent
Commencement Date" shall be the the earlier to occur of (a) June 17, 1996 or (b)
the date Tenant or anyone claiming under or through Tenant shall occupy any part
of the Demised Premises for the purposes set forth in Article 4 hereof. Landlord
and Tenant shall execute a written amendment to this Lease prepared by Landlord
and reasonably satisfactory to Landlord and Tenant setting forth such date
(provided, however, that failure by either party to execute or deliver such
amendment shall not impair the effectiveness of the provisions of this
paragraph).

                                    ARTICLE 2

                                  Ground Lease

     Section 2.01. This Lease is subject and subordinate to the Ground Lease.
Except to the extent inconsistent with the terms of this Lease or to the extent
applicable only to the relationship between the City and Landlord, all of the
terms and provisions of the Ground Lease applicable to the Demised Premises,
including, without limitation, the provisions of Section 10.03 (Required
Sublease Clauses), Section 10.04 (Subtenant Non-Disturbance) and Section 23.03
(New Building Space Leasing Requirements), are hereby incorporated in and made a
part of this Lease.

                                    ARTICLE 3

                                      Rent

     Section 3.01. Tenant shall pay to Landlord, without notice or demand, in
lawful money of the United States, by check drawn on a bank which is a member of
the New York Clearinghouse Association, at the address set forth above or at
such other address as Landlord may by notice designate, without any set off or
deduction whatsoever, the following:

          (i) annual fixed rent ("Fixed Rent") and annual fixed repayment
          ("Fixed Repayment") in the amounts set forth in Section 3.02, Section
          3.03 and Section 3.04 below, in monthly installments in advance on the
          Rent Commencement Date and, thereafter, on the first day of


                                       2










<PAGE>

          each month or portion thereof during the Terms and

          (ii) additional rent ("Additional Rent") consisting of all other sums
          of money that shall become due from and payable by Tenant to Landlord
          hereunder when same shall be due and payable hereunder.

     Tenant agrees that Landlord shall have the same remedies for any default in
payment of Additional Rent or Fixed Repayment as it has for a default in payment
of Fixed Rent.

     Section 3.02. From the Rent Commencement Date through the last day of the
month in which the third anniversary of the Rent Commencement Date occurs, Fixed
Rent shall be payable at the rate of $129,712.56 per annum in equal monthly
installments of $10,809.38.

     Section 3.03. Thereafter Fixed Rent shall be payable as follows:

          (i) For the period commencing on the first day of the month
          immediately following the month in which the third anniversary of the
          Rent Commencement Date shall occur (the "Rent Adjustment Date") and
          ending on the day immediately preceding the first anniversary of the
          Rent Adjustment Date, at the rate of $136,198.08 per annum in equal
          monthly installments of $11,349.84; and

          (ii) for the period commencing an the first anniversary of the Rent
          Adjustment Date and ending on the Expiration Date, at the rate of
          $143,007.96 per annum in equal monthly installments of $11,917.33.

     Section 3.04. Fixed Repayment shall be payable in equal monthly
installments commencing on the first day of the month following the date which
is thirty days from the date on which Landlord's lending institution (the
"Lender") advances the Loan (as hereinafter defined) to Landlord, in an amount
equal to the sum of (a) one-twelfth of the annual principal and interest payment
of a $500,000.00 self-amortizing loan (the "Loan") amortizing on a straight line
basis over ten (10) years at an interest rate (the "Interest Rate") to be
determined by Lender and charged by the Lender to Landlord and (b) one-one
hundred and twentieth of the amount of all closing costs (the "Closing Costs")
imposed by the Lender with respect to Landlord obtaining the Loan. The portion
of such monthly installment amount described in clause (a) of the preceding
sentence may be adjusted as provided in Section 25.07 and Section 43.01 hereof.
By way of illustration, if the Interest Rate is 6.75% then the annual Fixed
Repayment shall be $68,894.52, payable in equal monthly installments of
$5,741.25. At such time as Landlord's lending


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<PAGE>

institution shall determine the Interest Rate to charge Landlord, Landlord and
Tenant shall enter into a written agreement setting forth the exact amount of
the monthly installment of Fixed Repayment. Fixed Repayment constitutes agreed
upon consideration payable by Tenant for Landlord's paying for (i) a portion of
the improvements made in the Demised Premises to prepare the Demised Premises
for Tenant's occupancy substantially in accordance with the plans and
specifications listed on Exhibit C annexed hereto and made a part hereof
("Tenant's Work") (ii) the equipment ("Tenant's Equipment") set forth in Exhibit
E annexed hereto and made a part hereof and (iii) architectural and engineering
fees, as provided in Section 25.07 (c) hereof.

     Section 3.05. Intentionally Deleted.

     Section 3.06. If Tenant shall fail to pay any rent when due and such
failure shall continue for a period of ten (10) days after the same shall have
become due and payable, such unpaid amount shall bear interest at the maximum
legal rate permitted by law (the "Default Interest Rate"), calculated on the
basis of actual days elapsed, based on a 360-day year, from the due date of such
rent to the date of payment, and such interest shall be deemed Additional Rent.

     Section 3.07. If by reason of any of the provisions of this Lease, Tenant's
obligation to pay Fixed Rent and Fixed Repayment shall commence on a day other
than the first day of a month, Fixed Rent and Fixed Repayment for such month
shall be prorated on a per diem basis, and Landlord shall credit the excess
amount paid on account of Fixed Rent and Fixed Repayment upon the execution of
this Lease on a per diem basis toward the payment of the installment of Fixed
Rent and Fixed Repayment due and payable hereunder for the next succeeding
calendar month.

     Section 3.08. If any of the rent payable under the terms of this Lease
shall be or become uncollectible, reduced or required to be refunded because of
any legal rent restriction, Tenant shall enter into such agreement(s) and take
such other steps (without additional expense to Tenant) as Landlord may
reasonably request and as may be legally permissible to permit Landlord to
collect the maximum rents which from time to time during the continuance of such
legal rent restriction may be legally permissible (and not in excess of the
amounts reserved therefor under this Lease). Upon the termination of such legal
rent restriction, (a) the rents shall become and thereafter be payable in
accordance with the amounts reserved herein for the periods following such
termination, and (b) Tenant shall pay to Landlord, to the maximum extent legally
permissible, an amount equal to (i) the rents which would have been paid
pursuant to this Lease but for such legal rent restrictions, less (ii) the rents
and payments in lieu of rents paid by Tenant during the period such legal
restriction was in effect.


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<PAGE>

     Section 3.09. The term "rent" or "rents" as used herein shall mean all
amounts described in Sections 3.01, 3.02, 3.03 and 3.04 above.

                                    ARTICLE 4

                             Use of Demised Premises

     Section 4.01. Subject to and in accordance with the Special Permit, Tenant
shall use and occupy the Demised Premises only in accordance with this Lease,
the REA, the Special Permit and the Ground Lease, as laboratory and office space
for (i) research on and development of composite cultured skin for application
in medical procedures or for any other laboratory use permitted pursuant to this
Lease, the REA, the Special Permit and the Ground Lease, provided however, that
Tenant shall submit to Landlord a revised Plan (as hereinafter defined) for
Landlord's review; and (ii) such ancillary use as may be permitted by Section
4.03 hereof and for no other purpose. Landlord hereby acknowledges that Tenant
has heretofore delivered to Landlord its Regulatory Compliance Plan (the "Plan")
which Plan is attached hereto as Exhibit B and made a part hereof and which Plan
(i) identities those activities of and materials to be used by Tenant which are
or may be subject to Environmental Legal Requirements or Legal Requirements and
(ii) details Tenant's plans and procedures for compliance with Environmental
Legal Requirements and Legal Requirements as to each specific regulated material
and activity. From time to time, at any time during the Term, Tenant shall
revise the Plan to reflect any changes in its activities, materials,
Environmental Legal Requirements or Legal Requirements. All such revisions shall
be subject to Landlord's prior review and approval, which approval shall not be
unreasonably withheld.

     Section 4.02. Tenant shall not use, occupy, suffer or permit the Demised
Premises, or any part thereof, to be used in any manner, or suffer or permit
anything to be brought into or kept therein, which would, in Landlord's
judgment, (a) violate any of the provisions of the Ground Lease, the Special
Permit, the REA, any other Superior Lease or any Superior Mortgage, including,
without limitation the provisions of Section 23.02 (Prohibited Uses) of the
Ground Lease, (b) violate any Environmental Legal Requirement, Legal Requirement
or Insurance Requirement, (c) constitute an extra-hazardous condition so as to
increase the risks involved in Tenant's operations beyond the level of risk
normally attendant upon the operation of comparable laboratory space for the use
permitted under Section 4.01 above, (d) make void or voidable any insurance
policy then in force with respect to any portion of the Premises or the Demised
Premises, (e) make it impossible or difficult to obtain any of the insurance
coverage required to be maintained pursuant to this


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<PAGE>

Lease or Article 7 of the Ground Lease, (f) cause, or be likely to cause, injury
or damage to the Premises or any part thereof or to any Building Equipment, (g)
constitute a public or private nuisance, (h) violate any certificate of
occupancy which may now exist or hereafter be obtained for the Demised Premises
or the Premises, (i) emit or discharge unusual, noxious or objectionable noise,
fumes, vapors or odors into the Building or the Building Equipment, or which can
be detected outside of the Demised Premises, (j) cause any vibration that will
cause, or might tend to cause, damage to the Demised Premises and/or the
Building, or which would disturb other tenants or occupants of the Building or
any other persons outside of the Demised Premises; (k) impair or interfere with
the effectiveness or accessibility of the Building Equipment or any Building
service. (1) impair or interfere with the use of any area of the Building by, or
occasion discomfort, annoyance or inconvenience to, Landlord or any other
occupant or tenant. (m) interfere with access to the Demised Premises by fire
prevention personnel and/or equipment, (n) cause Tenant to default in any of its
obligations under this Lease or (o) cause Landlord to be in default of any of
its obligations under the Ground Lease or the REA.

     Section 4.03. Tenant shall be permitted to use a portion of the Demised
Premises for tissue processing relating to Tenant's use as set forth in Section
4.01 above.

     Section 4.04. Tenant acknowledges that no temporary or permanent
certificate of occupancy has been issued for the Demised Premises. Tenant shall
upon completion of Tenant's Work obtain a temporary certificate of occupancy for
the premises. Landlord makes no representation and shall have no liability to
Tenant with respect to the permissibility of Tenant's use and occupancy of the
Demised Premises under applicable zoning ordinances and regulations. If an
amendment to a certificate of occupancy, a new certificate of occupancy or a
zoning variance is required as a result of Tenant's use and/or occupancy of the
Demised Premises, then Tenant shall, at Tenant's sole cost and expense, obtain
such amended certificate of occupancy, new certificate of occupancy or zoning
variance for the Building and the Demised Premises. If Landlord determines, in
its sole and exclusive judgment, that the Demised Premises may not be lawfully
occupied by Tenant, then Landlord may, upon thirty (30) days' written notice to
Tenant, cancel this Lease.

     Section 4.05. Tenant shall have access in common with all other tenants,
licensees and other occupants of the Building to all areas of the Building
designated as common areas by Landlord. In addition, Tenant shall have access to
and be permitted to use on a "first come-first served" basis, subject to such
reasonable rules and regulations applicable to all tenants, licensees and other
occupants of the Building as Landlord may from time to time reasonably
promulgate, such facilities to be constructed at a


                                       6










<PAGE>

later date and located within the Building as Landlord shall from time to time
designate, such as (by way of example only) conference room(s), copying room(s)
and/or a lunch room.

     Section 4.06. Promptly after the Commencement Date, Landlord shall
provide Tenant and Tenant's employees with identification cards permitting
Tenant and Tenant's employees to enter on and use certain campus facilities of
Landlord, in accordance with the rules and regulations of Landlord, including,
without limitation, requirements for payment of Landlord's applicable fees and
charges therefor, as Landlord may from time to time promulgate. Failure of
Tenant or Tenant's employees to abide by such rules and regulations may result
in the revocation of any and all privileges accorded by Landlord from time to
time to the holders of such identification cards.

                                    ARTICLE 5

                            Demised Premises "As Is"

     Section 5.01. Landlord agrees to perform Landlords's Work substantially in
accordance with the plans and specifications, a list of which is annexed hereto
as Exhibit C and made a part hereof, and the applicable provisions of this
Lease, including, without limitation, Section 25.07 hereof. Tenant has inspected
the Demised Premises and, Tenant accepts same in "as is" condition as of the
date hereof.

     Section 5.02. Neither Landlord nor Landlord's agents have made, nor do they
make, any representations or promises regarding the physical condition of the
Premises or the Demised Premises, the rents, leases, operating expenses or any
other matter or thing affecting or related to the Demised Premises or the
Premises. All understandings and agreements heretofore made between the parties
are merged with this Lease, which alone fully and completely expresses the
agreement and understanding of the parties hereto.

                                    ARTICLE 6

                           Operating Covenants, Signs

     Section 6.01. As an additional inducement to Landlord to enter into this
Lease, Tenant covenants and agrees that it shall,

     (a) conduct its operations in an orderly and proper manner so as not to
disturb or be offensive to others in the Building;

     (b) take all reasonable measures to minimize the noise level of Tenant's
operations in the Demised Premises;


                                       7










<PAGE>

     (c) apply for, secure, maintain and deliver to Landlord and, except to the
extent that compliance is not the Tenant's responsibility under any Additional
Services Agreement (as defined in Article 26 hereof), comply with all licenses,
approvals or permits which may be required for the conduct by Tenant of its
business and operations in the Demised Premises in accordance with the permitted
use hereunder, and pay, if, as and when due, all license and permit fees and
charges of a similar nature in connection therewith, and deliver copies of all
such licenses, approvals and permits, and all renewals thereof to Landlord. In
no event shall Tenant's failure to procure or maintain any such license,
approval or permit relieve Tenant of any of its obligations hereunder;

     (d) maintain the interior of the Demised Premises in a clean, orderly, safe
and sanitary condition and state of repair at all times;

     (e) paint the Demised Premises as and when in the judgment of Landlord may
be necessary in order to maintain the appearance of the Demised Premises;

     (f) not bring into or have delivered from the street to the Demised
Premises any stock, supplies merchandise or other items or materials in such a
manner as would block the surrounding sidewalks and streets or the Building
hallways, fire exits, lobbies or other areas set aside for the common use of
tenants of and/or visitors to the Building;

     (g) comply with all Environmental Legal Requirements and Legal
Requirements, including but not limited to those pertaining to equal opportunity
and affirmative action in the use and operation of the Demised Premises and in
connection with any construction, maintenance or alteration at the Demised
Premises;

     (h) not use, except to identify Tenant's address (i) as part of its mailing
address on letterhead and other similar materials or (ii) for purposes of
Tenant's publications, the name of Landlord or Columbia University or any of its
officers, trustees, agents, employees, students or faculty members for any
purpose whatsoever without receiving the prior written approval of Landlord.
Without limiting the generality of the foregoing, Tenant shall not conduct its
operations at the Demised Premises under any name which includes the word
"Columbia", or otherwise hold itself or its business out as having any
affiliation with Landlord or Columbia University or Columbia Presbyterian
Medical Center;

     (i) comply strictly with the Plan (as defined in Section 4.01 hereof);

     (j) not use biohazardous agents requiring a degree of


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<PAGE>

containment in excess of that described as National Institutes of Health
Biosafety Level 2, as defined in the U.S. Department of Health and Human
Services, Public Health Service, Centers for Disease Control and National
Institutes of Health, Biosafety in Microbiological and Biomedical Laboratories,
dated May, 1988 and any updates or revisions thereto (the "DHH Specifications").

     (k) conduct all scientific research and development activities in
conformity with at least the minimum practices, equipment and facilities
recommended for such activities in the DHH Specifications; and

     (l) not use any human subjects or live animals on or at the Demised
Premises for any research purposes.

     Section 6.02. Tenant shall not, without the prior written consent of Owner,
exhibit, inscribe, paint, affix, place or permit any sign, insignia,
advertisement, awning, canopy, banner, flag, pennant, aerial, antenna lettering,
notice or other object on any part of the outside or inside of the Demised
Premises or the Premises or on corridor walls or which would be visible from the
public areas or from the surrounding streets and sidewalks. Landlord may
withhold its consent to any sign proposed by Tenant for any reason, or for no
reason. In the event of the violation of any of the provisions of this Section
by Tenant, Landlord, with or without notice to Tenant, may remove such object
without any liability, and may charge the expense incurred in such removal to
Tenant as Additional Rent. Each such object consented to by Landlord shall, to
Landlord's satisfaction, be kept clean and in good order and repair and
appearance by and at the expense of Tenant, including, whenever necessary in
Landlord's judgment, the replacement thereof with materials approved by
Landlord.

     Section 6.03. Landlord shall cause Tenant's name, and the names of
subtenants or assignees, if any, and office location to be listed in a lobby
sign board in plain view. Tenant's name, and names of subtenants or assignees,
if any, and office location shall also be posted in all locations designated by
the Landlord for such purpose. Tenant shall also have the right to place an
identifying sign on its office door and shall have the right to affix an
identifying sign on the wall of the second floor elevator landing, subject to
Landlord's approval of the size, materials and design of same.

                                    ARTICLE 7

                                 Window Cleaning

     Section 7.01. Tenant shall not clean or require, permit, suffer or allow
any window in the Demised Premises to be cleaned from the outside in violation
of Legal Requirements.


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<PAGE>

                                    ARTICLE 8

               Legal Requirements/Environmental Legal Requirements

     Section 8.01. Tenant, at its sole cost and expense, shall comply with all
Legal Requirements applicable to the Building and the Demised Premises and the
use and occupancy thereof by Tenant. The term "Legal Requirements" shall mean
any and all laws, statutes, ordinances, orders, rules, regulations, directives
and requirements (including, without limitation, building codes, zoning
regulations and ordinances) of all federal, state, county, city and borough
departments, bureaus, boards, agencies, offices, commissions and other
subdivisions thereof, or of any other governmental, public or quasi-public
authority whether now or hereafter in force, and all requirements, obligations
and instruments of record that may be applicable to this Lease, the Premises or
the Demised Premises or any part thereof.

     Section 8.02. The term "Hazardous Materials" shall mean any flammable,
explosive, radioactive, chemical or infectious materials, hazardous (or
biohazardous) materials or wastes, hazardous or toxic substances, pollutants,
gas, vapor, radiation, chemical or related materials, asbestos or any material
containing asbestos, or any other substance or materials as defined in or
regulated by any Environmental Legal Requirements. "Environmental Legal
Requirements" shall mean (a) any and all policies and procedures of Landlord
(including, without limitation, Landlord's Joint Radiation Safety Committee and
Landlord's Office of Environmental Health and Safety) governing the use,
handling or disposal of Hazardous Materials by its tenants, contractors,
employees or researchers, now or hereafter in effect and (b) any effective,
applicable or relevant federal, state or local statute, code, ordinance, rule or
regulation, any judicial or administrative order (whether or not on consent) or
judgment applicable to Tenant including, without limitation, any judgment or
settlement based on common law theories, and any provisions or condition of any
permit, license, franchise, concession, agreement or other authorization binding
on Tenant relating to (i) the protection of the environment, the safety and
health of persons (including employees) or the public welfare from actual or
potential exposure (or effects of exposure) to any actual or potential release,
discharge, disposal or emission (whether past or present) of any Hazardous
Materials or (ii) the manufacture, processing, distribution, use, treatment,
storage, disposal, transport or handling of any Hazardous Materials, including,
but not limited to, the Comprehensive Environmental Response, Compensation and
Liability Act of 1980 ("CERCLA"), as amended by the Superfund Amendments and
Reauthorization Act of 1986, 42 U.S.C. 'SS' 9601 et seq., the Solid Waste
Disposal Act, as amended by the Resource Conservation and Recovery Act of 1976,
as amended by the Solid and Hazardous Waste Amendments of 1984, 42


                                       10










<PAGE>

U.S.C. 'SS' 6901 et seq., the Federal Water Pollution Control Act, as amended
by the Clean Water Act of 1977, 33 U.S.C. 'SS' 1251 et seq., the Toxic
Substances Control Act of 976, 15 U.S.C. 'SS' 2601 et. seq., the Emergency
Planning and Community Sight-to-Know Act of 1986, 42 U.S.C. 'SS' 1101 et
seq., the Clean Air act of 1966, as amended, 42 U.S.C. 'SS' 7401 et seq., the
National Environmental Policy Act of 975, 42 U.S.C. 'SS' 4321 et seq., the
Rivers and Harbours Act of 1899, 33 U.S.C. 'SS' 401 et seq., the Endangered
Species Act of 1973, as amended, 16 U.S.C. 'SS' 1531 et seq., the
Occupational Safety and Health Act of 1970, as amended, 29 U.S.C. 'SS' 651 et
seq., and the Safe Drinking Water Act of 1974, as amended, 42 U.S.C. 'SS' 300
et seq., the Atomic Energy Act of 1954, 42 U.S.C.A. 'SS' 2011 et seq.,
Article 27, 'SS' 15 of the New York State Environmental Conservation Law,
Title IV, Article 175 of the New York City Health Code and all rules,
regulations and guidance documents promulgated or published thereunder.

     Section 8.03. Tenant represents, warrants and covenants that Tenant and the
Plan are in compliance with and will comply at all times during the Term with
all Environmental Legal Requirements and all Legal Requirements and Tenant
hereby indemnifies, defends, and holds Landlord harmless from and against all
liability for any and all damages, claims, costs, expenses and fees (including,
without limitation, attorney's fees and disbursements and court costs) that
might arise from (a) Tenant's (i) breach of the foregoing representation,
covenant and warranty or (ii) failure to operate in accordance with the Plan,
all Environmental Legal Requirements or Legal Requirements or (b) from
Landlord's cooperation with Tenant or participation in the removal or disposal
of Tenant's Hazardous Materials in accordance with the Plan and Environmental
Legal Requirements. Any amounts hereunder shall be deemed Additional Rent and
become immediately due and payable, together with interest at the Default
Interest Rate, by Tenant to Landlord.

                                    ARTICLE 9

                           Access to Demised Premises

     Section 9.01. Tenant shall permit Landlord, Landlord's agents and public
utilities servicing the Building to erect, use and maintain, concealed ducts,
pipes and conduits in and through the Demised Premises. Landlord or Landlord's
agents shall have the right at any reasonable time (and, in the event of an
emergency, at any time) to enter the Demised Premises to examine the same, to
show them to prospective purchasers, mortgagees or lessees of the Building or
space therein, and to make such repairs, alterations, improvements or additions
as Landlord may deem necessary or desirable to the Demised Premises or to any
other portion of the Building, or which Landlord may elect to perform following
Tenant's failure to make repairs or perform any


                                       11










<PAGE>

work which Tenant is obligated to make or perform under this Lease, and Landlord
shall be allowed to take all material into and upon the Demised Premises that
may be required therefor without the same constituting an eviction or
constructive eviction of Tenant in whole or in part and rent shall not abate
whatsoever while said repairs, alterations, improvements or additions are being
made, by reason of loss or interruption of business of Tenant, or otherwise.

     Section 9.02. Without limiting the generality of the foregoing, Tenant
shall permit Landlord, Landlord's agents and representatives of any entity
responsible for enforcement of Environmental Legal Requirements or Legal
Requirements to enter the Demised Premises at any time for inspection and
monitoring Tenant's activities for compliance with Environmental Legal
Requirements, Legal Requirements and the Plan.

                                   ARTICLE 10

                                    Default

     Section 10.01. Each of the following events shall be an "Event of Default"
hereunder:

               (1) if Tenant shall fail to pay any installment of Fixed Rent or
Fixed Repayment when due; or

               (2) if Tenant shall fail to pay Additional Rent for thirty (30)
days after receipt of notice from Landlord that such payment is due; or

               (3) if Tenant's interest in this Lease shall devolve upon or pass
to any person, whether by operation of law or otherwise, except as expressly
permitted hereby; or

               (4) (a) if Tenant shall generally not, or shall be unable to, or
shall admit in writing its inability to, pay its debts as they become due; or

          (b) if Tenant shall commence or institute any case, proceeding or
          other action (A) seeking relief on its behalf as debtor, or to
          adjudicate it as bankrupt or insolvent, or seeking reorganization,
          arrangement, adjustment, winding-up, liquidation, dissolution,
          composition or other relief with respect to it or its debts under any
          existing or future law of any jurisdiction, domestic or foreign,
          relating to bankruptcy, insolvency, reorganization or relief of
          debtors, or (B) seeking appointment of a receiver, trustee, custodian
          or other similar official for it or for all or any substantial part of
          its property; or


                                       12










<PAGE>

          (c) if Tenant shall make a general assignment for the benefit of
          creditors; or

          (d) if any case, proceeding or other action shall be commenced or
          instituted against Tenant (A) seeking to have an order for relief
          entered against it as debtor or to adjudicate it a bankrupt or
          insolvent, or seeking reorganisation, arrangement, adjustment,
          winding-up, liquidation, dissolution, composition or other relief with
          respect to it or its debts under any existing or future law of any
          jurisdiction, domestic or foreign, relating to bankruptcy, insolvency,
          reorganization or relief of debtors, or (B) seeking appointment of a
          receiver, trustee, custodian or other similar official for it or for
          all of any substantial part of its property, which either (i) results
          in any such entry of an order for relief, adjudication of bankruptcy
          or insolvency or such an appointment or the issuance or entry of any
          other order having a similar effect or (ii) remains undismissed for a
          period of sixty (60) days; or

          (e) if any case, proceeding or other action shall be commenced or
          instituted against Tenant seeking issuance of a warrant of attachment,
          execution, distraint or similar process against all or any substantial
          part of its property which results in the entry of an order for any
          such relief which shall not have been vacated, discharged, or stayed
          or bonded pending appeal within sixty (60) days from the entry
          thereof; or

          (f) if Tenant shall consent to, approve of, or acquiesce in, any of
          the acts set forth in clauses (b), (c) , (d) or (e) above; or

          (g) if a trustee, receiver or other custodian is appointed for any
          substantial part of the assets of Tenant which appointment is not
          vacated or effectively stayed with thirty (30) business days; or

               (5) if Tenant shall not be in compliance with the Plan and all
Environmental Legal Requirements and such noncompliance shall continue for ten
(10) days after notice by Landlord to Tenant or if such noncompliance is of a
nature that it cannot be completely remedied within said period of ten (10) days
and Tenant shall not commence within said period of ten (10) days, or shall not
thereafter diligently prosecute to completion all steps necessary to remedy such
noncompliance; or

               (6) if Tenant shall fail to occupy the Demised Premises within
thirty (30) days of the Rent Commencement Date or shall abandon the Demised
Premises; or


                                       13









<PAGE>

               (7) If Tenant shall default in the observance or performance of
any other term, covenant or condition of this Lease on Tenant's part to be
observed or performed and Tenant shall fail to remedy such default within thirty
(30) days after notice by Landlord to Tenant of such default, or if such default
is of such a nature that it cannot be completely remedied within said period of
thirty (30) days and Tenant shall not commence within said period of thirty (30)
days, or shall not thereafter diligently prosecute to completion, all steps
necessary to remedy such default.

     Section 10.02. If an Event of Default (i) described in Section 10.01(4)
hereof shall occur, or (ii) described in Section 10.01(3), 10.01 (5), 10.01(6)
or 10.01(7) shall occur and Landlord, at any time thereafter, at its option
gives written notice to Tenant stating that this Lease and the Term shall expire
and terminate on the date specified in such notice, and if, on the date
specified in such notice, Tenant shall have failed to cure the default which was
the basis for the Event of Default, then this Lease and the Term and all rights
of Tenant under this Lease shall expire and terminate as if the date on which
the Event of Default described in clause (i) above occurred or the date
specified in the notice given pursuant to clause (ii) above, as the case may be,
were the Expiration Date and Tenant immediately shall quit and surrender the
Demised Premises. Anything contained herein to the contrary notwithstanding, if
such termination shall be stayed by order of any court having jurisdiction over
any proceeding described in Section 10.01(4) hereof, or by federal or state
statute, then; following the expiration of any such stay, or if the trustee
appointed in any such proceeding, Tenant or Tenant as debtor-in-possession shall
fail to assume Tenant's obligations under this Lease within the period
prescribed therefor by law of within ninety (90) days after entry of the order
for relief or as may be allowed by the court, or if said Trustee, Tenant or
Tenant as debtor-in-possession shall fail to provide adequate protection of
Landlord's right, title and interest in and to the Demised Premises or adequate
assurance of the complete and continuous future performance of Tenant's
obligations under this Lease as provided in Article 24 (Bankruptcy), Landlord,
to the extent permitted by law or by leave of the court having jurisdiction over
such proceeding, shall have the right, at its election, to terminate this Lease
on five (5) days' notice to Tenant, Tenant as debtor-in-possession or said
trustee, and upon the expiration of said five (5) period, this Lease shall cease
and expire as aforesaid and Tenant, Tenant as debtor-in-possession or said
trustee shall immediately quit and surrender the Demised Premises as aforesaid.

     Section 10.03. If this Lease shall be terminated as provided in Section
10.02 hereof, Landlord, without notice, may reenter and repossess the Demised
Premises using such force for


                                       14










<PAGE>

that purpose as may be necessary without being liable to indictment, prosecution
or damages therefor and may dispossess Tenant by summary proceedings or
otherwise.

     Section 10.04. If at any time, (i) Tenant shall comprise two (2) or more
Persons, or (ii) Tenant's obligations under this Lease shall have been
guaranteed by any person other than Tenant, or (iii) Tenant's interest in this
Lease shall have been assigned, the word "Tenant", as used in Section 10.01,
shall be deemed to mean any one or more of the persons primarily or secondarily
liable for Tenant's obligations under this Lease. Any monies received by
Landlord from or on behalf of Tenant during the pendency of any proceeding of
the types referred to in Section 10.01 shall be deemed paid as compensation for
the use and occupation of the Demised Premises and the acceptance of any such
compensation by Landlord shall not be deemed an acceptance of rent or a waiver
on the part of Landlord of any rights under Section 10.02.

                                   ARTICLE 11

                                Remedies/Damages

     Section 11.01. If this Lease shall be terminated as provided in Section
10.02:

          (a) Tenant shall quit and peacefully surrender the Demised Premises to
          Landlord, and Landlord and its agents may immediately, after the date
          upon which this Lease and the Term shall expire and come to an end,
          re-enter the Demised Premises or any part thereof, without notice,
          either by summary proceedings, or by any other applicable action or
          proceeding, or by force or otherwise (without being liable to
          indictment, prosecution or damages therefor), and may repossess the
          Demised Premises and dispossess Tenant and any other persons from the
          Demised Premises and remove any and all of their property and effects
          from the Demised Premises; and

          (b) Landlord, at Landlord's option, may relet the whole or any part of
          the Demised Premises from time to time, either in the name of Landlord
          or otherwise, to such tenant or tenants, for such term or terms ending
          before, on or after the Expiration Date, at such rental or rentals and
          upon such other conditions, which may include concessions and free
          rent periods, as Landlord, in its sole discretion, may determine;
          provided, however, that Landlord shall have no obligation to relet the
          Demised Premises or any part thereof and shall in no event be liable
          for refusal or failure to


                                       15










<PAGE>

          relet the Demised Premises or any part thereof, or, in the event of
          any such reletting, for refusal or failure to collect any rent due
          upon any such reletting, and no such refusal or failure shall operate
          to relieve Tenant of any liability under this Lease or otherwise
          affect any such liability, and Landlord, at Landlord's option, may
          make such repairs, replacements, alterations, additions, improvements,
          decorations and other physical changes in and to the Demised Premises
          as Landlord, in its sole discretion, considers advisable or necessary
          in connection with any such reletting or proposed reletting, without
          relieving Tenant of any liability under this Lease or otherwise
          affecting any such liability.

     Section 11.02. Tenant, on its own behalf and on behalf of all persons
claiming through or under Tenant, including all creditors, does further hereby
waive any and all rights which Tenant and all such persons might otherwise have
under any present or future law to redeem the Demised Premises, or to re-enter
or repossess the Demised Premises, or to restore the operation of this Lease,
after (a) Tenant shall have been dispossessed by a judgment or by warrant of any
court or judge, or (b) any expiration or termination of this Lease and the Term,
whether such dispossess, expiration or termination shall be by operation of law
or pursuant to the provisions of this Lease. The words "re-enter", "re-entry"
and "re-entered" as used in this Lease shall not be deemed to be restricted to
their technical legal meanings. In the event of a breach or threatened breach by
Tenant, or any persons claiming through or under Tenant, of any term, covenant
or condition of this Lease, Landlord shall have the right to enjoin such breach
or threatened breach and the right to invoke any other remedy allowed by law or
in equity as if re-entry, summary proceedings and other special remedies were
not provided in this Lease for such breach. The right to invoke the remedies
hereinbefore set forth are cumulative and shall not preclude Landlord from
invoking any other remedy allowed at law or in equity.

     Section 11.03. If this Lease and the Term shall expire and come to an end
as provided in Article 10 hereof, or by or under any summary proceeding or any
other action or proceeding, or if Landlord shall re-enter the Demised Premises
as provided in Section 11.01, or by or under any summary proceeding or any other
action or proceeding, then, in any of said events.

          (a) Tenant shall pay to Landlord all Fixed Rent, Fixed Repayment and
          Additional Rent payable under this Lease by Tenant to Landlord to the
          date upon which this Lease and the Term shall have expired and come to
          an end or to the date of re-entry upon the Demised Premises by
          Landlord, as the case may be;


                                       16










<PAGE>

          (b) Tenant shall also be liable for and shall pay to Landlord, as
          damages, any deficiency (referred to as "Deficiency") between the rent
          for the period which otherwise would have constituted the unexpired
          portion of the Term and the net amount, if any, of rents collected
          under any reletting effected pursuant to the provisions of Section
          11.01 for any part of such period (first deducting from the rents
          collected under any such reletting all of Landlord's reasonable
          expenses in connection with the termination of this Lease, Landlord's
          re-entry upon the Demised Premises and such reletting, including, but
          not limited to, all repossession costs, brokerage commissions, legal
          expenses, attorneys' fees and disbursements, alteration costs and
          other expenses of preparing the Demised Premises for such reletting),
          any such Deficiency shall be paid in monthly installments by Tenant on
          the days specified in this Lease for payment of installments of Fixed
          Rent, Landlord shall be entitled to recover from Tenant each monthly
          Deficiency as the same shall arise, and no suit to collect the amount
          of the Deficiency for any month shall prejudice Landlord's right to
          collect the Deficiency for any subsequent month by a similar
          proceeding; and

          (c) Whether or not Landlord shall have collected any monthly
          Deficiency as aforesaid, Landlord shall be entitled to recover from
          Tenant, and Tenant shall pay to Landlord, on demand, in lieu of any
          further Deficiency as and for liquidated and agreed final damages, a
          sum equal to the amount by which Fixed Rent, Fixed Repayment and
          Additional Rent for the period which otherwise would have constituted
          the unexpired portion of the Term exceeds the then fair and reasonable
          rental value of the Demised Premises for the same period, both
          discounted to present worth at the then current "base" rate charged by
          Citibank N.A., or its successor, as of the date the Lease is
          terminated, less the aggregate amount of Deficiencies theretofore
          collected by Landlord pursuant to the provisions of Section 11.03 for
          the same period; if, before presentation of proof of such liquidated
          damages to any court, commission or tribunal, the Demised Premises, or
          any part thereof, shall have been relet by Landlord for the period
          which otherwise would have constituted the unexpired portion of the
          Term or any part thereof, the amount of rent reserved upon such
          reletting shall be deemed, prima facie, to be the fair and reasonable
          rental value for the part of the whole of the Demised Premises so
          relet during the term of the reletting.

     If the Demised Premises, or any part thereof, shall be


                                       17










<PAGE>

relet, together with other space in the Building, the rents collected or
reserved under any such reletting and the expenses of any such reletting shall
be equitably apportioned for the purposes of this Section 11.03. Tenant shall in
no event be entitled to any rents collected or payable under any reletting,
whether or not such rents shall exceed the Fixed Rent reserved in this Lease.
Solely for the purposes of this Article 11, the term "Fixed Rent" and "Fixed
Repayment" as used in this Section 11.03 shall mean the Fixed Rent and Fixed
Repayment in effect immediately prior to the date upon which this Lease and the
Term shall have expired and come to an end, or the date of re-entry upon the
Demised Premises by Landlord, as the case may be. Nothing contained in Article
10 hereof or this Article 11 shall be deemed to limit or preclude the recovery
by Landlord from Tenant of the maximum amount allowed to be obtained as damages
by any statute or rule of law, or of any sums or damages to which Landlord may
be entitled in addition to the damages set forth in this Section 11.03.

                                   ARTICLE 12

                                 Eminent Domain

     Section 12.01. If the whole or any part of the Demised Premises shall be
acquired or condemned by eminent domain for any public or quasi-public purpose,
then, and in that event, this Lease shall terminate as of the date of title
vesting in such proceeding and Tenant shall have no claim for any condemnation
award or for the value of any unexpired Term.

                                   ARTICLE 13

                                 Quiet Enjoyment

     Section 13.01. Provided that no Event of Default has occurred, Tenant may
peaceably and quietly enjoy the Demised Premises, subject to the terms and
conditions of this Lease, the REA, the Special Permit and the Ground Lease and
any other Superior Leases and Superior Mortgages now or hereafter affecting the
Demised Premises.

                                   ARTICLE 14

                                    No Waiver

     Section 14.01. The failure of Landlord to seek redress for violation of, or
to insist upon the strict performance of, any covenant or condition of this
Lease shall not prevent a subsequent act, which would have originally
constituted a


                                       18










<PAGE>

violation, from having all of the force and effect of an original violation. The
receipt by Landlord of Fixed Rent, Fixed Repayment or Additional Rent with
knowledge of the breach of any covenant of this Lease shall not be deemed a
waiver of such breach. No provision of this Lease shall be deemed to have been
waived by Landlord, unless such waiver be in writing signed by Landlord. No
payment by Tenant or receipt by Landlord of a lesser amount than the monthly
Fixed Rent, Fixed Repayment or Additional Rent shall be deemed to be other than
on account of the earliest stipulated Fixed Rent, Fixed Repayment or Additional
Rent, or as Landlord may elect to apply same nor shall any endorsement or
statement on any check or any letter accompanying any check or payment as Fixed
Rent, Fixed Repayment or Additional Rent be deemed an accord and satisfaction,
and Landlord may accept such check or payment without prejudice to Landlord's
right to recover the balance of such Fixed Rent, Fixed Repayment or Additional
Rent or pursue any other remedy in this Lease provided. Any executory agreement
hereafter made shall be ineffective to change, modify, discharge or effect an
abandonment of this Lease in whole or in part unless such executory agreement
is in writing and signed by the party against whom enforcement of the change,
modification, discharge or abandonment is sought.

                                   ARTICLE 15

                                 Waiver of Trial

     Section 15.01. The respective parties hereto shall and they hereby do waive
trial by jury in any action, proceeding or counterclaim brought by either of the
parties hereto against the other (except for personal injury or property
damage) on any matters whatsoever arising out of or in any way connected with
this Lease, the relationship of Landlord and Tenant, Tenant's use or occupancy
of the Demised Premises, or for the enforcement of any remedy under any statute,
emergency of otherwise. If Landlord commences any summary proceeding against
Tenant, Tenant will not interpose any counterclaim of whatever nature or
description in any such proceeding (unless failure to interpose such
counterclaim would preclude Tenant from asserting in a separate action the claim
which is the subject of such counterclaim), and will not seek to consolidate
such proceeding with any other action which may have been or will be brought in
any other court by Tenant.

                                   ARTICLE 16

                              Inability to Perform

     Section 16.01. This Lease and the obligation of Tenant to pay rent
hereunder and perform all of the other covenants and


                                       19










<PAGE>

agreements hereunder on the part of Tenant to be performed shall in no wise be
affected, impaired or excused because Landlord is unable to fulfill any of its
obligations under this Lease expressly or implied to be performed by Landlord
or because Landlord is unable to make, or is delayed in making any repairs,
additions, alterations, improvements or decorations or is unable to supply or is
delayed in supplying any equipment or fixtures, if Landlord is prevented or
delayed from so doing by reason of strikes or labor troubles or by accident,
adjustment of insurance or by any cause whatsoever reasonably beyond Landlord's
control, including but not limited to, laws, governmental preemption in
connection with a national emergency or by reason of any Environmental Legal
Requirements or Legal Requirements or by reason of the conditions of supply and
demand which have been or are affected by war or other emergency.

                                   ARTICLE 17

                                Fees and Expenses

     Section 17.01. If Tenant shall default in the observance or performance of
any term, covenant or provision of this Lease, Landlord may (but shall not be
obligated to) immediately (or at any time thereafter) without notice perform the
obligation of Tenant hereunder. If Landlord shall pay or incur any cost or
expense in connection with such performance (including attorney's fees,
disbursements and court costs), such sums so paid or incurred, together with
interest at the Default Interest Rate, shall be deemed Additional Rent hereunder
and shall be paid by Tenant to Landlord with five (5) days Of demand therefor.

                                   ARTICLE 18

                                    Estoppel

     Section 18.01. Tenant, within ten (10) days of Landlord's notice requesting
same, shall, from time to time and at any time upon at least ten (10) days'
notice from Landlord, execute and deliver to Landlord or any person designated
by Landlord, a statement certifying that (i) this Lease is in full force and
effect and is unmodified (or if modified, stating the modifications), (ii) the
dates through which Fixed Rent, Fixed Repayment and Additional Rent have been
paid, (iii) whether it has received notice of any Event of Default hereunder,
(iv) whether Landlord is in default hereunder and (v) such further facts and
information with respect to this Lease as Landlord may reasonably request.

     Section 18.02. Landlord, within ten (10) days of Tenant notice requesting
same, shall, from time to time and at any time upon at least ten (10) days'
notice from Tenant, execute and


                                       20










<PAGE>

deliver to Tenant or any person designated by Tenant, a statement certifying
that (i) this Lease is in full force and effect and is unmodified (or if
modified, stating the modifications), (ii) the dates through which Fixed Rent,
Fixed Repayment and Additional Rent have been paid, and (iii) such further facts
and information with respect to the Lease as Tenant may reasonably request.

                                   ARTICLE 19

                                    Surrender

     Section 19.01. Upon the expiration or earlier termination of the Term,
Tenant shall quit and surrender to Landlord, the Demised Premises, broom clean,
in good order and condition and Tenant shall remove all of Tenant's Property and
any Alterations as defined in Section 25.01 hereof) that Landlord has not
previously given Tenant permission to leave and repair and restore the Demised
Premises to the condition existing prior to their installation and repair any
damage to the Demised Premises caused by such removal. Tenant shall remove all
Hazardous Materials in accordance with all applicable Environmental Legal
Requirements.

     Section 19.02. If the Demised Premises are not surrendered upon the
termination of this Lease, Tenant hereby indemnifies Landlord against any and
all loss, cost, expense or liability resulting from the delay by Tenant in so
surrendering the Demised Premises, including any claims made by any succeeding
tenant or prospective tenant founded upon such delay.

     Section 19.03. In the event Tenant remains in possession of the Demised
Premises after the termination of this Lease without the execution of a new
lease, Tenant, at the option of Landlord, shall be deemed to be occupying the
Demised Premises as a tenant from month-to-month, at a monthly rental equal to
the sum of (i) three times the sum of (a) the monthly installment of Fixed Rent
and payable during the last month of the Term, and (b) one-twelfth (1/12th) of
the Additional Rent payable during the last year of the Term; and (ii) the
monthly installment (at such time) of Fixed Repayment, subject to all of the
other terms of this Lease insofar as the same are applicable to a month-to-month
tenancy.

                                   ARTICLE 20

                            Subordination/Attornment

     Section 20.01. Subject to the provisions of Section 10.04 of the Ground
Lease, this Lease shall be subject and subordinate to the Ground Lease, any
other Superior Lease and to any Superior


                                       21










<PAGE>

Mortgage. This section shall be self-operative and no further instrument of
subordination shall be required; provided, however, that if confirmation of such
subordination is requested, Tenant shall promptly execute and deliver a
certificate to this effect to Landlord.

     Section 20.02. If, at any time prior to the termination of this Lease, any
Superior Lessor or Superior Mortgagee or any person, or any Superior Lessor's or
Superior Mortgagee's or such person's successors or assigns (Superior Lessor,
Superior Mortgagee and any such person or successor or assign being herein
collectively referred to as "Successor Owner") shall succeed to the rights of
Landlord under this Lease through possession or foreclosure or delivery of a new
lease or deed or otherwise, Tenant agrees, at the election and upon request of
any such Successor Owner, from time to time, to fully and completely attorn to
and recognize any such Successor Owner, as Tenant's landlord under this Lease
upon the then executory terms of this Lease; provided such Successor Owner shall
agree in writing to accept Tenant's attornment. The foregoing provisions of this
Section shall inure to the benefit of any such Successor Owner, shall apply
notwithstanding that, as a matter of law, this Lease may terminate upon the
termination of a Superior Lease, shall be self-operative upon any such demand,
and no further instrument shall be required to give effect to said provisions.
Tenant, however, upon demand of any such Successor Owner, shall execute, from
time to time, instruments to evidence and confirm the foregoing provisions of
this section, satisfactory to any such Successor Owner, acknowledging such
attornment and setting forth the terms and conditions of its tenancy and Tenant
hereby constitutes and appoints Landlord attorney-in-fact for Tenant to execute
any such instrument for and on behalf of Tenant, such appointment being coupled
with an interest. Upon such attornment, this Lease shall continue in full force
and effect as a direct lease between such Successor Owner and Tenant upon all of
the then executory terms of this Lease, except that such Successor Owner shall
not be (a) liable for any previous act or omission or negligence of Landlord
under this Lease; (b) subject to any counterclaim, defense or offset, which
heretofore shall have accrued to Tenant against this Lease or by any previous
prepayment of more than one month's rent, unless such modification or prepayment
shall have been approved in writing by the Superior Lessor or Superior Mortgagee
through or by reason of which the Successor Owner shall have succeeded to the
rights of Landlord under this Lease; (d) liable for any security deposited
pursuant to this Lease unless such security has actually been delivered to
Successor Owner; (e) obligated to repair the Demised Premises or the Building or
any part thereof, in the event of total or substantial damage, beyond such
repair as can reasonably be accomplished from the net proceeds of insurance
actually made available to Successor Owner; or (f) obligated to repair the
Demised Premises or the Building or any part thereof, in the


                                       22










<PAGE>

event of partial condemnation, beyond such repair as can reasonably be
accomplished from the net proceeds of any award actually made available to
Successor Owner, as consequential damages allocable to the part of the Demised
Premises or the Building not taken. Nothing contained in this Section 20.02
shall be construed to impair any right otherwise exercisable by any such
Successor Owner.

     Section 20.03. As applied to the City, any conflict between the provisions
of Section 20.01 above and Section 10.04 of the Ground Lease shall be resolved
in favor of Section 10.04 of the Ground Lease.

     Section 20.04. Landlord shall use reasonable efforts to obtain a
non-disturbance agreement on terms and conditions reasonably acceptable to the
parties-thereto from the holder of any future Superior Mortgage or Superior
Lease. Landlord shall, upon request from Tenant, take appropriate action to
obtain such a non-disturbance agreement from the City pursuant to section 10.04
of the Ground Lease.

                                   ARTICLE 21

                                    Consents

     Section 21.01. Tenant hereby waives any claim against Landlord which it may
have based upon any assertion that Landlord has unreasonably withheld or
unreasonably delayed any requested consent, and Tenant agrees that its sole
remedy shall be an action or proceeding to enforce any such provision or for
specific performance, injunction or declaratory judgment. In the event of such a
determination, the requested consent shall be deemed to have been granted;
however, Landlord shall have no liability to Tenant for its refusal or failure
to give such consent. The sole remedy for Landlord's unreasonably withholding or
delaying of consent shall be as provided in this section.

                                   ARTICLE 22

                             [Intentionally Deleted]

                                   ARTICLE 23

                            Assignment and Subletting

     Section 23.01. Neither this Lease nor the term and estate hereby granted
shall be assigned, mortgaged, pledged, encumbered or otherwise transferred by
Tenant, by operation of law or


                                       23










<PAGE>

otherwise, and neither the Demised Premises, nor any part thereof, nor any of
the Tenant's Property shall be encumbered or sublet or used or occupied or
permitted to be used or occupied, or utilized for desk space or for mailing
privileges by anyone other than Tenant and its employees, except as set forth in
Section 23.03 hereof. For purposes of this Section 23.01. (a) the issuance of
interests in any entity, or the transfer of interests in any entity (whether
stock, partnership interest or otherwise) to any person or group of related
persons, whether in a single transaction or a series of related or unrelated
transactions, in such quantities that after such issuance or transfer, as the
case may be, such transferee shall have control (as hereinafter defined) of such
entity, but only if such issuance or transfer shall have been made for the
principal purpose of transferring this leasehold estate or the subleasehold
estate of the subtenant, as the case may be, shall be deemed an assignment,
except that the transfer of the outstanding capital stock of any corporate
Tenant by persons or parties through the "over-the-counter" market or any
recognized national securities exchange, shall not be included in the
calculation of such transfer of control, (b) a "take-over agreement" pursuant to
which one or more persons shall agree to assume the obligations of Tenant
hereunder in consideration of Tenant leasing space in another building shall be
deemed an assignment of this Lease, and (c) a modification or amendment of a
sublease which decreases the rent, extends the term or increases or decreases
the subleased space shall be deemed a sublease. For the purposes of the
preceding sentence, stock ownership shall be determined in accordance with the
principles set forth in Section 544 of the Internal Revenue Code of 1986, as the
same existed on January 1, 1987. For the purposes hereof, "control" shall mean
with respect to any corporation, partnership or other business entity, the
possession of the power directly or indirectly to direct or cause the direction
of management and policy of such corporation, partnership or other business
entity, whether through the ownership of voting securities, by contract, common
directors or officers, the contractual right to manage the business affairs of
any such corporation, partnership or business entity, or otherwise. Any person
or legal representative of Tenant, to whom Tenant's interest under this Lease
passes by operation of law or otherwise, shall be bound by the provisions of
this Article 23.

     Section 23.02. A, Tenant may, upon ten (10) days' prior written notice to
Landlord, assign this Lease to a Related Entity (as hereinafter defined) or
permit any corporation(s) or other business entities, that directly or
indirectly control, are controlled by, or under common control with, Tenant,
(any such corporation or entity being hereinafter referred to as "Related
Entity") to sublet, occupy or use (any such subletting, occupancy or use being
hereinafter called a "letting") all or part of the Demised Premises for any of
the purposes permitted to Tenant hereunder provided that (a) Tenant shall not be
in default beyond


                                       24










<PAGE>

any applicable grace period in the performance of any of its obligations under
this Lease, and (b) prior to the effective date of such letting or assignment
Landlord shall have been provided with proof reasonably satisfactory to it that
such sublessee or assignee is a Related Entity. In the event of an assignment of
this Lease to a Related Entity, Tenant shall remain fully liable for the
performance of all of Tenant's obligations hereunder and Tenant and assignee
shall enter into an instrument of assignment and assumption in form and
substance reasonably satisfactory to Landlord. Within ten (10) days after the
commencement of the term of any such letting or the date of such assignment, as
the case may be, notice of such commencement or assignment and a duplicate
original of such sublease or assignment shall be delivered by Tenant to
Landlord. If at any time such Tenant or assignee shall cease to be a Related
Entity of Tenant, said letting or assignment shall be null and void as of the
date of cessation of such relationship and such sublessee or assignee shall
vacate the Demised Premises within sixty (60) days of such date. Each such
sublease or assignment shall be and shall provide that it is subject and
subordinate to all of the terms, provisions and agreements of this Lease and the
Ground Lease;

     B. Tenant may, upon ten (10) days prior written notice, assign this Lease
to or effect a letting to a Successor Corporation (as hereinafter defined) of
Tenant, any such subletting to be for all or part of the Demised Premises for
any of the purposes permitted to Tenant hereunder, provided that (a) Tenant
shall not be in default beyond any applicable grace period in the performance of
any of its obligations under this Lease, (b) prior to the effective date of such
letting or assignment, Landlord shall have been provided with proof reasonably
satisfactory to it that such sublessee or assignee is a Successor Corporation,
and (c) after any merger or consolidation described in the next succeeding
sentence of this paragraph, the assets, capitalization and net worth of such
Successor Corporation shall be greater than or equal to the assets,
capitalization and net worth of Tenant at the commencement of the term or
immediately prior to such merger or consolidation, whichever is greater. A
"Successor Corporation", as such term is used in this section, shall mean a
corporation into which or with which Tenant is merged or consolidated in
accordance with applicable statutory provisions for the merger or consolidation
of corporations, provided that by operation of law or by effective provisions
contained in the instrument of merger or consolidation, the liabilities of
Tenant under this Lease are assumed by the corporation surviving such merger or
consolidation. Within ten (10) days after the commencement of the term of any
such letting or the date of such assignment, as the case may be, notice of such
commencement or assignment and duplicate originals of any instruments with
respect to such transaction shall be delivered to Landlord by Tenant or the
Successor Corporation, as appropriate. Any such sublease or assignment shall be


                                       25










<PAGE>

subordinate to all of the terms, provisions and agreements of this Lease and the
Ground Lease.

     C. Except as expressly permitted pursuant to any other provision of this
Article 23. (i) if at any time, Tenant desires to sublet all or any portion of
the Demised Premises or to assign its interest in this Lease, Tenant shall send
a notice (the "Subleasing Notice") to Landlord and shall be deemed to have
granted to Landlord the option, with respect to any such portion of the Demised
Premises which Tenant proposes to sublet or assign pursuant to this Article 23
(or any proposed or actual sublet assignment or occupancy which Tenant
undertakes in violation of the provisions of this Article 23 regardless of when
and how Landlord receives notice of such proposed or actual sublet, assignment
or occupancy), an option (the "Recapture Right") to be exercised by notice
given to Tenant within thirty (30) business days after receipt of the Subleasing
Notice or thirty (30) business days after Landlord has been made aware of any
proposed or actual sublet, assignment or occupancy undertaken by Tenant in
violation of the provisions of this Article 23, to terminate this Lease on the
terms and conditions hereinafter set forth with respect only to the portion of
the Demised Premises which is subject to any such proposed or actual subletting,
assignment or occupancy (the "Recaptured Area"). In the event that Landlord
exercises the Recapture Right then, as to the Recaptured Area:

          (a) Tenant shall vacate and surrender the Recaptured Area on or before
     the day immediately preceding the proposed commencement date of the
     proposed assignment, sublease or occupancy and the Lease shall terminate
     with respect to such Recaptured Area on such proposed commencement date as
     if such date were the Expiration Date.

          (b) from and after such date of termination, this Lease shall be
     deemed amended to (1) eliminate the Recaptured Area from the Demised
     Premises, (2) reduce the Fixed Rent payable hereunder by an amount equal to
     the Fixed Rent payable with respect to the Recaptured Area immediately
     prior to such termination, (3) reduce any Additional Rent to reflect the
     elimination of the Recaptured Area from the Premises and (4) make such
     other changes as are appropriate to reflect the elimination of the
     Recaptured Area from the Demised Premises. Landlord and Tenant shall
     execute a written amendment to this Lease prepared by Landlord and
     reasonably satisfactory to Landlord and Tenant setting forth the foregoing
     modifications (provided, however, that failure by either party to execute
     or deliver such amendment shall not impair the effectiveness of the
     provisions of this paragraph);

          (c) Landlord may, and shall have no liability to


                                       26










<PAGE>

     Tenant if Landlord shall, sublease the Recaptured Area (or any part
     thereof) to Tenant's prospective subtenant, assignee or occupant or to any
     other Person for all or any portion of the term of the proposed subletting,
     assignment or occupancy; and

          (d) Landlord, at its expense, shall make such alterations as may be
     required to separate physically the Recaptured Area from the remainder of
     the Demised Premises and to comply with all Legal Requirements and
     Insurance Requirements (unless the same would have been the responsibility
     of the sublessee pursuant to the proposed assignment, sublease or
     occupancy), and, at Landlord's expense (unless the same would have been the
     responsibility of Tenant pursuant to the proposed assignment, sublease or
     occupancy agreement), shall repair or restore to tenantable condition any
     part of the remainder of the Demised Premises which is damaged by such
     separation. If required by Legal Requirements and Insurance Requirements,
     Landlord shall afford Tenant and its agents, tenants, undertenants, or
     licensees reasonably appropriate means of ingress to and egress from the
     Recaptured Area, and, if required by Legal Requirements and Insurance
     Requirements, Tenant shall afford Landlord and its agents, undertenants and
     licensees reasonably appropriate means of ingress to and egress from the
     remainder of the Demised Premises; and

          (e) on or prior to the Expiration Date, Tenant shall restore, or
     reimburse Landlord for its restoration cost with respect to, the Recaptured
     Area to the condition required by this Lease and/or the Ground Lease,
     except as otherwise set forth herein, including removal of any alterations
     made in the Recaptured Area by any party to the extent required by this
     Lease and/or the Ground Lease.

     D. If at any time Tenant desires to sublet all or any portion of the
Demised Premises or to assign its interest in this Lease and Landlord has
elected not to exercise its Recapture Right as set forth in Paragraph C above,
Tenant shall submit to Landlord the name and address of the proposed sublessee
or assignee, its proposed use of the Demised Premises or portion thereof
proposed to be subleased, a reasonably detailed description of such proposed
sublessee's or assignee's business and any other information about such proposed
sublessee or assignee reasonably requested by Landlord. Landlord agrees not to
unreasonably withhold or delay its consent to any such subletting or assignment
by Tenant, provided that the following conditions shall have been satisfied.

          (a) The use which the proposed assignee or subtenant intends for the
     Demised Premises shall be that permitted by Article 2 hereof;


                                       27










<PAGE>

          (b) In the reasonable judgment of Landlord, the proposed assignee or
     subtenant (i) is of good character; and (ii) is of substantial means and
     finances and in a position to finance satisfactorily its business,

          (c) The proposed assignment or sublease shall require the assignee or
     subtenant to undertake to operate its business in the Demised Premises with
     policies substantially similar to Tenant.

          (d) In the reasonable judgment of Landlord, the proposed assignment or
     subletting shall not adversely affect the Building or the interest of
     Landlord therein,

          (e) Tenant shall not have advertised or publicized in any way the
     availability of the demised premises without Landlord's consent, and no
     advertisement or other publicity shall state the proposed rental;

          (f) The proposed assignment contains an acceptance of such assignment
     by the assignee pursuant to which such assignee assumes and agrees to
     perform, directly for the benefit of Landlord, all of the terms, covenants
     and conditions of this lease on Tenant's part to be performed;

          (g) Tenant shall pay to Landlord Landlord's reasonable administrative
     costs, attorneys' fees, disbursements and any reasonable costs that may be
     incurred by Landlord in connection with such assignment or subletting,
     including, without limitation, the costs of making investigations as to the
     acceptability of the proposed assignee or subtenant;

          (h) The proposed assignment or sublease shall prohibit any further
     assignment or subletting by the assignee or subtenant, as the case may be;

          (i) Tenant shall not be in default in the performance of any of its
     obligations under this Lease either at the time Landlord's consent to such,
     assignment or subletting is requested or upon the proposed effective date
     of any such assignment or subletting;

          (j) The proposed assignee or subtenant shall not then be a tenant of
     any space in any building owned by Landlord, any related corporation of
     Landlord or The Presbyterian Hospital in the City of New York
     ("Presbyterian") or a related corporation of any such tenant, nor a party
     who dealt with Landlord or Landlord's agent, a related corporation of
     Landlord or its agent, or Presbyterian or any agent of Presbyterian (either
     directly or through a broker) for the rental of any space in any building
     owned by Landlord, a related corporation of Landlord or Presbyterian


                                       28










<PAGE>

     within the six (6) months immediately preceding Tenant's request for
     Landlord's consent;

          (k) The proposed assignee or subtenant shall not be a person then
     negotiating with Landlord or Landlord's agent, a related corporation of
     Landlord or its agent or Presbyterian or any agent of Presbyterian (either
     directly or through a broker) for the rental of any space in any building
     owned by Landlord, a related corporation of Landlord or Presbyterian, and

          (1) The proposed assignee or subtenant shall not be an employee of (1)
     Landlord, (2) a related corporation of Landlord, or (3) Presbyterian.

Within ten (10) business days after the commencement of the term of any such
subletting, or within ten (10) business days after the effective date of any
such assignment, notice of such commencement or effective date and a duplicate
original of such sublesse or assignment shall be delivered by Tenant to
Landlord.

          Notwithstanding anything to the contrary contained herein, if (1)
Tenant shall sublet the Demised Premises or any portion thereof for rents,
additional charges or other consideration which, after deducting from the amount
of such rents, charges or other consideration, any brokerage commissions, actual
and reasonable costs for labor and materials in preparing the space for
subletting, and attorneys' fees and disbursements reasonably incurred by Tenant
for such subletting (the "Deductions"), shall, for any period, exceed the rents
(excluding the Fixed Repayment) payable for the subleased space under this Lease
for the same period (computed on a per square foot basis in the event of a
subletting of less than the whole of the Demised Premises), or (2) Tenant shall
assign its interest in this Lease for consideration (other than assumption by
the assignee of Tenant's obligations hereunder) which exceeds any Deductions
applicable thereto, then Tenant shall pay to Landlord, as Additional Rent,
within ten (10) days after the date or dates on which such rents, charges and
other consideration shall be payable to Tenant, any such excess.

          Tenant hereby indemnifies Landlord against liability from any claims
that may be made against Landlord by any proposed assignee or sublessee by
reason of Landlord's failure to consent in accordance with this Lease to any
assignment or subletting or by any broker, finder or similar person claiming a
commission or similar compensation in connection with any assignment or
subletting or any proposed assignment or subletting.

     E. Notwithstanding anything to the contrary contained herein, Tenant may
lease or finance purchases of Tenant's Property provided that any vendor, lessor
or lender from whom


                                       29










<PAGE>

Tenant has purchased or leased or borrowed money for any of Tenant's Property
has no right to remove such fixtures and/or equipment except in accordance with
the terms of Article 19 of this Lease and upon notice to Landlord.

     Section 23.03. In the event that Landlord grants its consent to any
assignment or subletting, Tenant shall not be released from and shall remain
fully liable for the performance of all of Tenant's obligations hereunder,
including without limitation, the payment of rent hereunder. Landlord's consent
to any assignment, mortgaging or subletting in any specific instance shall not
constitute a waiver of the provisions of this Article as to any future or
further assignment, mortgaging or subletting.

     Section 23.04. If Tenant's interest in this Lease is assigned or the
Demised Premises or any portion thereof are sublet in violation of the
provisions of this Article 23, such assignment or sublease shall be void and of
no force and effect against Landlord, provided however, that Landlord may
collect an amount equal to the then Fixed Rent and all other Additional Rent
from the assignee or sublessee as a fee for its use and occupancy.

                                   ARTICLE 24

                                   Bankruptcy

     Section 24.01. In the event this Lease becomes subject to the provisions of
the Bankruptcy Code, the rights and obligations of the parties hereunder shall
be governed by the Bankruptcy Code as in effect on the date it becomes so
subject.

     Section 24.02. If this Lease is assigned to any person pursuant to the
provisions of the Bankruptcy Code, all monies or other consideration payable or
otherwise to be delivered in connection with such assignment shall be paid or
delivered to Landlord, shall be and remain the exclusive property of Landlord
and shall not constitute property of Tenant or of the estate of Tenant within
the meaning of the Bankruptcy Code. Any and all monies or other consideration
constituting Landlord's property under the preceding sentence not paid or
delivered to Landlord shall be held in trust for the benefit of Landlord and
shall be promptly paid to or turned over to Landlord.

     Section 24.03. If Tenant assumes this Lease and proposes to assign the
same pursuant to the provisions of the Bankruptcy Code to any person or entity
who shall have made a bona fide offer to accept an assignment of the Lease on
terms acceptable to the Tenant, then notice of such proposed assignment shall be
given to Landlord by Tenant no later than twenty (20) days after receipt by
Tenant, but in any event no later than ten (10) days prior to the date that
Tenant shall make application to a court of


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<PAGE>

competent jurisdiction for authority and approval to enter into such assignment
and assumption. Such notice shall set forth (a) the name and address of such
person, (b) all of the terms and conditions of such offer, and (c) adequate
assurance of future performance by such person under the Lease, including,
without limitation, the assurance referred to in Section 365(b)(3) of the
Bankruptcy Code. Landlord shall have the prior right and option, to be exercised
by notice to Tenant given at any time prior to the effective date of such
proposed assignment, to accept an assignment of this Lease upon the same terms
and conditions and for the same consideration, if any, as the bona fide offer
made by such person, less any brokerage commissions which would otherwise be
payable by Tenant out of the consideration to be paid by such person in
connection with the assignment of this Lease. The term "adequate assurance of
future performance" as used in this Lease shall mean that any assignee proposed
pursuant to this Section shall, among other things, (a) deposit with Landlord on
the assumption of this Lease an amount equal to the then annual Fixed Rent and
Fixed Repayment payable hereunder (the "Assignee Security") as security for the
faithful performance and observance by such assignee of the terms and
obligations of this Lease, which sum shall be held and applied as set forth in
Section 24.04, (b) furnish Landlord with financial statements of such assignee
for the prior three (3) fiscal years, as finally determined after an audit and
certified as correct by a certified public accountant, which financial
statements shall show a net worth equal to at least one-half (1/2) the Fixed
Rent and Fixed Repayment then payable by Tenant at the time of the proposed
assignment for each of such three (3) years, (c) grant to Landlord a security
interest in such property of the proposed assignee as Landlord shall deem
necessary to secure such assignee's future performance under this Lease, and (d)
provide such other information or take such action as Landlord, in its
reasonable judgment shall determine is necessary to provide adequate assurance
of the performance by such assignee of its obligations under the Lease.

     Section 24.04. If an assignee under Section 24.03 defaults in respect of
any of the terms, provisions and conditions of this Lease, including, but not
limited to, the payment of rent, Landlord may apply or retain the whole or any
part of the Assignee Security so deposited to the extent required for the
payment of any rent as to which assignee is in default or offer any sum which
Landlord may expend or may be required to expend by reason of assignee's default
in respect of any of the terms, covenants and conditions of this Lease,
including, but not limited to, any damages or deficiency in the reletting of the
Demised Premises, whether such damage or deficiency accrued or accrues before or
after summary proceedings or other re-entry by Landlord. If Landlord applies or
retains any part of the Assignee Security so deposited, assignee, upon demand,
shall deposit with Landlord the amount so applied or retained so that


                                       31










<PAGE>

Landlord shall have the full deposit on hand at all times during the Term. If
assignee shall fully and faithfully comply with all of the terms, provisions,
covenants and conditions of this Lease, the Assignee Security shall be returned
to assignee after the Expiration Date and after delivery of possession of the
entire Demised Premises to Landlord. In the event of a sale or leasing of the
Premises or the Building, Landlord shall have the right to transfer the Assignee
Security to the vendee or lessee and Landlord shall thereupon be released by
assignee from all liability for the return of such security, and assignee shall
look solely to the new landlord for the return of said Assignee Security. The
provisions hereof shall apply to every transfer or assignment made of the
Assignee Security to a new landlord. Assignee will not assign or encumber or
attempt to assign or encumber the monies deposited herein as Assignee Security
and neither Landlord nor its successors or assigns shall be bound by any such
assignment, encumbrance, attempted assignment or attempted encumbrance.

                                   ARTICLE 25

                                   Alterations

     Section 25.01. Tenant shall make no changes, additions or alterations
("Alterations") in on or to the Demised Premises without the prior written
consent of Landlord, which consent shall not be unreasonably withheld provided
such alterations are non-structural and do not affect any of the Building
systems. Landlord shall, within ten (10) Business Days of any written request
from Tenant grant such consent or provide written reasons for not granting such
consent.

     Section 25.02. (a) If Landlord shall consent to any Alterations proposed by
Tenant, then such Alterations, shall be completed strictly in accordance with
plans and specifications approved by Landlord and Landlord's Construction
Requirements, a copy of which Construction Requirements will be delivered to
Tenant upon request therefor, at Tenant's sole cost and expense, in a good and
first-class workmanlike manner, using new materials and equipment or materials
of equal quality to new materials and which shall be at least equal in quality
to the standards for the Building then established by Landlord, and in
accordance with all Legal Requirements and the terms of this Lease and the
Ground Lease, and shall be commenced promptly after approval is received and
thereafter prosecuted diligently to completion. Any Alterations for which
consent has been received shall be performed strictly in accordance with the
approved plans and specifications therefor, and no amendments or additions
thereto shall be made without the prior consent of Landlord. Tenant shall pay to
Landlord as Additional Rent Landlord's out-of-pocket expenses (including the
fees of Landlord's architect and


                                       32










<PAGE>

engineer) for reviewing said plans and specifications and inspecting the
Alterations.

     (b) Tenant shall coordinate its construction with Landlord and with other
tenants in the Building so that it will not interfere with or delay the
completion of any other construction work in the Building, and, to that end,
Tenant and its contractors and subcontractors shall use only the Demised
Premises for the performance of Tenant's Alterations.

     Section 25.03. Tenant shall use only duly licensed, reputable contractors
reasonably approved in advance by Landlord to perform any Alterations. Each such
contractor shall (i) carry such workers' compensation, general liability,
personal and property insurance as Landlord shall require and (ii) prior to the
commencement of any Alterations, if requested by Landlord, furnish Landlord with
payment and performance bonds at least equal to 150% of the full amount of the
reasonably estimated costs (as determined by Landlord) of the Alterations to be
made.

     Section 25.04. Tenant agrees that it will not at any time prior to or
during the Term, either directly or indirectly, employ or permit the employment
of any contractor, mechanic or laborer, or permit any materials in the Demised
Premises, if the use of such contractor, mechanic or laborer or such materials
would, in Landlord's opinion, create any difficulty, strike or jurisdictional
dispute with other contractors, mechanics or laborers engaged by Tenant,
Landlord, the City or others, or would in any way disturb the construction,
maintenance, cleaning, repair, management, security or operation of the Building
or any part thereof. In the event of any interference or conflict, Tenant, upon,
demand of Landlord, shall cause all contractors, mechanics or laborers, or all
materials causing such interference, difficulty or conflict, to leave or be
removed from the Building immediately.

     Section 25.05. No approval of plans or specifications by Landlord or
consent by Landlord allowing Tenant to make Alterations in the Demised Premises
shall in any way be deemed to be an agreement by Landlord that the contemplated
Alterations comply with any Legal Requirements or Insurance Requirements or any
certificate of occupancy for the Building nor shall it be deemed to be a waiver
by Landlord of the compliance by Tenant with any of the terms of this Lease.
Nothing in this Lease shall be deemed or construed in any way as constituting
the consent or request of Landlord, express or implied, by inference or
otherwise, to any contractor, subcontractor, laborer or materialman for the
performance of any labor or the furnishing of any materials for any Alteration
to, or repair of, the Demised Premises, the Building or any part thereof, nor as
giving Tenant any right, power or authority to contract for or permit the
rendering of any services or the furnishing of any materials that


                                       33










<PAGE>

would give rise to the filing of any mechanic's liens against Landlord's
interest in the Demised Premises, the Building or the Premises. Notice is hereby
given that neither Landlord nor Landlord's agents, nor any Superior Lessor or
Superior Mortgagee shall be liable for any labor or materials furnished or to be
furnished to Tenant upon credit, and that no mechanic's or other lien for such
labor or materials shall attach to or affect any estate or interest of Landlord
or any Superior Lessor or Superior Mortgagee in and to the Demised Premises or
the Premises. If any mechanic's lien is filed against the Demised Premises or
the Premises for work claimed to have been done for, or material furnished to,
Tenant, such lien shall be discharged, immediately, at Tenant's expense by
payment or by filing the bond required by law.

     Section 25.06. Prior to commencing any Alteration, Tenant shall deliver to
Landlord certificates evidencing additional insurance of such types and in such
amounts as Landlord or the Insurance Requirements shall reasonably require
Tenant or any contractor to maintain. The policies of such additional insurance
shall name Landlord, the City, EDC, UDC and such other Persons as Landlord shall
reasonably require as additional insureds.

     Section 25.07. (a) For purposes of this Lease, the following terms shall
have the following meanings:

          (i) "substantial completion", "substantially complete" or similar
          words to that effect shall mean Tenant's completion of Tenant's Work
          substantially in accordance with the Plans and Specifications and all
          Change Orders (as hereinafter defined) but for minor "punch list"
          items which would not interfere with Tenant's ability to occupy the
          Demised Premises and conduct its business therein for the purposes
          set forth in this Lease.

          (ii) "Plans and Specifications" shall mean the Plans and
          Specifications a list of which is annexed hereto as Exhibit C and made
          a part hereof.

          (iii) "Change Order" shall mean any change in the Plans and
          Specifications requested by Tenant and approved by Landlord. The cost
          of any such Change Order shall be agreed upon by the parties at the
          time of its approval. Upon substantial completion of Tenant's Work,
          the Construction Loan (as hereinafter defined) shall be adjusted to
          reflect the net amount of all such Change Orders and the monthly Fixed
          Repayment shall be adjusted to an amount equal to one-twelfth of the
          annual principal and interest payments of a self amortizing loan in
          the amount of $500,000.00 as adjusted by the net amount of all such
          Change Orders


                                       34










<PAGE>

          amortizing on a straight line basis over ten (10) years at the
          Interest Rate plus one-one hundred and twentieth of the Closing Costs
          as described in Section 3.04 hereof. In the event that Landlord shall
          approve in writing a Change Order which is estimated (as expressly set
          forth in such Change Order) to delay the substantial completion of
          Tenant's Work beyond June 17, 1996, then the Rent Commencement Date
          shall be deemed to be the earlier to occur of (a) such new estimated
          substantial completion date or (b) the date Tenant or anyone claiming
          under or through Tenant shall occupy any part of the Demised Premises
          for the purposes set forth in Article 4 thereof.

     (b) Landlord and Tenant hereby agree that the cost of performing Tenant's
Work in accordance with the Plans and Specifications shall be paid as follows:
(i) $400,000.00 (the "Grant") shall be paid outright by Landlord and (ii)
$250,000.00 shall be paid in the form of a loan from Landlord to Tenant (the
"Construction Loan") which shall be repaid to Landlord as set forth in Section
3.04 hereof. The Grant and the Construction Loan shall be disbursed as set forth
in Article 46.

     (c) In addition to the Grant and the Construction Loan, Landlord shall make
a loan to Tenant (the "Soft Cost Loan") by paying to Tenant up to an aggregate
amount of $100,000 actually incurred by Tenant in connection with Tenant's Work
for (i) architectural fees, (ii) engineering fees and (iii) the fees of the
representative of Tenant observing that the performance of Tenant's Work by the
Construction Manager (as hereinafter defined) is being performed in accordance
with the Plans and Specifications. The Soft Cost Loan shall be repaid to
Landlord as set forth in Section 3.04 hereof.

     (d) If substantial completion of Landlord's Work shall be delayed due to
(i) any Change Order, (ii) any delays by Tenant beyond two (2) business days in
responding to any questions arising in connection with the prosecution of
Landlord's Work, (iii) any failure to submit plans or working drawings necessary
for any Change Order within five (5) days of Landlord's request or (iv) delays
by Tenant in approving any item or document requiring Tenant's approval (all of
the above being "Tenant's Delay"), then the Commencement Date shall be
conclusively presumed to have occurred on the date that Landlord's Work would
have been substantially complete but for Tenant's Delay.


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<PAGE>

                                   ARTICLE 26

                                    Services

     Section 26.01. Provided that no Event of Default has occurred, Landlord
shall provide 24-hour, 7-day-a-week access to the Building and unlimited
passenger elevator service to the Demised Premises. Landlord shall provide
freight elevator service on Business Days from 8 a.m. to 4 p.m. If Tenant shall
require freight elevator service during any other time, Landlord shall furnish
same provided that Tenant gives Landlord advance notice and that Tenant pays, on
demand, as Additional Rent, Landlord's then established charges therefor.

     Section 26.02. (a) Landlord shall provide electric energy to the Demised
Premises. Tenant shall pay Landlord for electricity consumed by Tenant in the
Demised Premises. Landlord will permit the electrical risers, feeders and wiring
in the Building serving the Demised Premises on a submetered basis to be used by
Tenant for such purpose to the extent that they are available, suitable, safe
and within the plan and design capacities of the Building. Tenant shall not be
required to pay Landlord more than the amount calculated by applying to the
measured demand and/or usage of electrical current in or furnished to the
Building, the average rate per unit of measurement, inclusive of applicable
taxes, surcharges, time of day and other charges, payable by Landlord for
electrical current furnished to the Demised Premises by the utility company
serving the Building. Should any tax or charge in the nature of a tax be imposed
upon Landlord's receipts from the sale or resale of electrical current to the
Demised Premises, then the pro rata share thereof allocable to the electrical
current furnished to the Demised Premises shall be passed on to and paid by
Tenant. Bills for Tenant's usage of electrical current shall be paid within ten
(10) days of receipt thereof by Tenant as Additional Rent hereunder. If due to
any change in Legal Requirements, Landlord shall not be permitted to provide
electric energy to the Demised Premises, then this Lease shall not be affected
and Tenant shall arrange to obtain electric energy directly from the public
utility company furnishing electrical service to the Building. In such event
Tenant shall no longer pay Landlord for electricity consumed.

     (b) Tenant's use of electrical energy shall never exceed the capacity of
the then existing risers or wiring installation, in each case. In order to
insure that such electrical capacity is not exceeded and to avert possible
adverse effect upon the Building's electrical system, Tenant shall not, without
the prior written consent of Landlord, make or perform or permit any alteration
to wiring installations or other electrical facilities in or serving the Demised
Premises or any additions to the electrical fixtures, machines or equipment or
appliances in the


                                       36










<PAGE>

Demised Premises. Landlord shall not be obligated to consent to any such
alteration or installation if, in Landlord's judgment, the same are unnecessary
or will cause permanent damage or injury to the Building, the Building Equipment
or the Demised Premises or will cause or create a hazardous condition or entail
excessive or unreasonable alterations, repairs or expense or interfere with or
disturb other tenants or occupants. Only rigid conduit or such other wiring or
conduit as shall not violate Legal Requirements will be allowed.

     (c) The Building electrical system shall include emergency generator
back-up power in the event of a loss of power or service.

     (d) Landlord shall have no liability to Tenant for any loss, damage or
expense which Tenant may sustain or incur by reason of any change, failure,
inadequacy or defect in the supply or character of the electrical energy or
emergency generator back-up power furnished to the Demised Premises or if the
quantity or character of the electrical energy is no longer available or
suitable for Tenant's requirements, except for any actual damage suffered by
Tenant by reason of any such failure, inadequacy or defect caused by Landlord's
negligence, and then only after actual notice thereof.

     Section 26.03. (a) Provided that no Event of Default has occurred, Landlord
shall make available from the public water supply to a point or points at or
near the Demised Premises selected by Landlord such quantities of domestic cold
and hot water as Landlord, in its sole and absolute judgment, deems adequate for
normal laboratory and ordinary lavatory, cleaning and drinking purposes. In the
event that the Tenant requires hot or cold water for any purposes other than
those specified in the preceding sentence, including, but not limited to high
volume laboratory usage, Tenant shall pay Landlord, as Additional Rent, for
water consumed, as shown on separate submeters for cold and hot water
maintained (and replaced, if necessary) by Tenant, at Tenant's expense, (and
installed by Tenant if no such submeters are in place or if there are existing
submeters for the Demised Premises that are broken), together with all sewer
charges and any other rent, tax, levy or charge based thereon which now or
hereafter is assessed, imposed or a lien upon the Demised Premises or the
Premises, as and when bills are rendered. Payment for cold water shall be at the
rate charged by the city for cold water. Payment for hot water shall be at three
(3) times such rate. Landlord shall have no liability to Tenant for any loss,
damage or expense which Tenant may sustain or incur if the quantity or character
of water service changes or is no longer available or suitable for Tenant's
purposes.

     (b) Tenant shall notify Landlord, within ten (10) days after the
Commencement Date, of the water meter number of each


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<PAGE>

water meter serving the Demised Premises and whether such meter is for hot water
or cold water. If any such meter is installed subsequent to the taking of
possession by Tenant, then Tenant shall notify Landlord of such information
within ten (10) days after such installation.

     Section 26.04. Provided that no Event of Default has occurred, Landlord
shall make available to a point or points at or near the Demised Premises such
piping, systems, equipment and facilities as Landlord, in its sole and absolute
judgment, deems adequate to provide gas service for normal laboratory
consumption. In the event that Tenant requires gas service for any purpose other
than normal laboratory usage, including, without limitation, gas service in
excess of quantities adequate (in Landlord's sole judgment) for normal
laboratory usage, Tenant shall pay Landlord, as Additional Rent, for gas
consumed, as shown on a separate submeter, installed and maintained (and
replaced, if necessary) by Tenant at the direction of Landlord, or Tenant's sole
cost and expense. The rates charged by Landlord therefor shall not exceed the
rates charged by the utility company providing such service. Payment for such
excess gas consumed by Tenant in the Demised Premises shall be made by Tenant to
Landlord within ten (10) days of Tenant's receipt of Landlord's bill therefor.
Tenant shall make no alteration, addition or repair to the gas connection,
installations, equipment and/or facilities without the prior written consent of
Landlord in each instance. Landlord shall have no liability to Tenant for any
loss, damage or expense which Tenant may sustain or incur if the quantity or
character of the gas service is changed or is no longer available or suitable
for Tenant's requirements.

     Section 26.05. Provided that no Event of Default has occurred, Landlord
shall supply hot water for heat, chilled water from May 1 through October 31 of
each calendar year during the Term, condenser water from November l through
April 30 of each calendar year during the Term and ventilation ("HVAC")
to the Demised Premises through existing Building risers, radiators and air
handlers and additional HVAC equipment that may be installed as part of Tenant's
Work (subject to the requirements set forth in Article 25 hereof) during
appropriate seasons as may reasonably be required by Tenant for ambient heating
and cooling seven days a week, 24 hours a day. If Tenant shall requires
additional chilled water, condenser water or hot water in excess of that which
Landlord deems adequate for the purposes set forth above, Landlord shall
furnish same at Landlord's then established rates and same shall be
payable on demand by Tenant as Additional Rent. Any HVAC equipment supplementing
that described in the first sentence of this Section 26.05 shall be installed
and maintained by Tenant at Tenant's sole cost and expense.

     Section 26.06. Tenant shall, at Tenant's sole cost and


                                       38










<PAGE>

expense, keep the Demised Premises free from vermin, rodents or anything of a
similar nature. If Tenant fails to keep the Demised Premises free from vermin,
Landlord shall have the right, at Tenant's sole cost and expense, to take any
and all measures deemed necessary or desirable by Landlord to eradicate all
vermin from the Demised Premises. In lieu of the foregoing provisions with
respect to infestation control, Landlord, at its option, may select an
exterminator to perform such services on behalf of Tenant. If Landlord does so,
Tenant agrees to use such exterminator to the exclusion of all other
exterminators, equipment or services, Tenant shall pay the charges therefor for
such exterminator.

     Section 26.07. Provided that no Event of Default has occurred hereunder,
Landlord shall provide cleaning services in accordance with the specifications
annexed hereto as Exhibit D and made a part hereof. Landlord shall, as part of
said cleaning services, remove Tenant's normal accumulations of non-Hazardous
Materials, rubbish and waste paper. Subject to the provisions of Section 26.09
hereof, Landlord shall provide reasonable storage in the basement of the
Building for Tenant's Hazardous Materials in reasonable quantities for
reasonable periods of time prior to the removal of such Hazardous Materials from
the Building.

     Section 26.08. Provided no Event of Default has occurred hereunder,
Landlord shall supply compressed air and vacuum air to a point or points near
the Demised Premises in quantities which Landlord deems adequate for normal
laboratory purposes. If Tenant shall require additional compressed air and
vacuum air in excess of that which Landlord deems adequate for the purposes set
forth herein, Landlord shall furnish same at Landlord's then established rates
and same shall be payable on demand by Tenant as Additional Rent hereunder.

     Section 26.09 Tenant shall be responsible for the proper storage and
removal from the Demised Premises and the Building and the disposal of all of
Tenant's Hazardous Materials. Tenant shall contract for the disposal of
Hazardous Materials, at Tenant's cost and expense, with vendors approved by
Landlord, in its sole and absolute discretion. In contracting with any such
vendor, Landlord shall endeavor to ensure that Tenant shall receive the benefit
of any volume discount granted to Landlord by such vendor.

                                   ARTICLE 27

                               Windows; Machinery

     Section 27.01. (a) If at any time any windows of the Demised Premises are
temporarily closed, darkened or bricked up (or permanently closed, darkened or
bricked up, if required by


                                       39










<PAGE>

law) for any reason whatsoever including, but not limited to, Landlord's own
acts, Landlord shall not be liable for any damage Tenant may sustain thereby and
Tenant shall not be entitled to any compensation therefor nor abatement or
diminution of rent nor shall the same release Tenant from its obligations
hereunder nor constitute an eviction.

          (b) Tenant shall not move any safe, heavy machinery, heavy equipment,
bulky matter, or fixtures into or out of the Building without Landlord's prior
written consent, which consent shall not be unreasonably withheld. If such
safe, machinery, equipment, bulky matter or fixtures require special handling,
all work in connection therewith shall comply with all Legal Requirements
applicable thereto and shall be done during such hours as Landlord may
designate.

                                   ARTICLE 28

                                    Insurance

     Section 28.01. Tenant shall, at Tenant's sole cost and expense, obtain and
maintain the following types of insurance in not less than the indicated amounts
with insurance carriers reasonably acceptable to Landlord:

          (a)  Workers' Compensation and Employer's Liability insurance with
               respect to all persons employed by Tenant at the Demised Premises
               (including, during the period during which any Alterations are
               being constructed, all contractors and sub-contractors) with a
               limit of liability in accordance with applicable law in the case
               of Workers' Compensation and with a limit of liability of not
               less than the following in the case of Employer's Liability.

          Bodily Injury by Accident - $100,000 each accident;
          Bodily Injury by Disease  - $500,000 policy limit;
          Bodily Injury by Disease  - $100,000 each employee;

          (b)  Comprehensive general liability (bodily injury and property
               damage) with a combined single limit of liability for bodily
               injury and property damage of $2,000,000 per occurrence.

          (c)  "All risk" property insurance (including breakage of glass and
               water damage from any source whatsoever) which provides coverage
               for all property of Tenant, including Tenant's Work and all
               Alterations, within the Demised Premises in an amount equal to
               the replacement cost of such


                                       40










<PAGE>

               property, and

          (d)  Such different or the same types of insurance set forth above in
               such amounts as may from time to time be reasonably required by
               Landlord against such other insurable hazards as at the time are
               commonly insured against in the case of premises similarly
               situated.

     Section 28.02. (a) All insurance shall be written in form and substance
reasonably satisfactory to Landlord, and issued by companies licensed to do
business in New York State and authorized to issue such policies that have a
"Best's" rating of B+11 or better or another rating acceptable to Landlord.
All policies of insurance procured by Tenant shall contain endorsements
providing that (a) such policies may not be reduced or cancelled (including for
non-payment of premium) or allowed to lapse with respect to Landlord, the City,
EDC, UDC or any other Superior Lessor or any Superior Mortgagee, or materially
changed or amended, except after sixty (60) days prior notice from the insurance
company by registered mail to (i) Tenant, (ii) Landlord at the address provided
for in Article 29, (iii) Landlord in care of the Director of Risk Management,
Columbia University 475 Riverside Drive, Suite 401, New York, New York, 10115,
and (iv) the City, EDC, UDC, any other Superior Lessor and any Superior
Mortgagee, and (b) Tenant shall be solely responsible for the payment of
premiums therefor notwithstanding that Landlord is named as an additional
insured. On or before the Commencement Date, duly executed certificates of
insurance (specifying each of the coverages enumerated above and including
evidence of the waivers of subrogation required pursuant to Subparagraph (d),
together with reasonably satisfactory evidence of payment of the premiums
therefor, shall be delivered to Landlord in care of the following address:
Executive Director, Audubon Research Park, PH 1525 East, 630 West 168th Street,
New York, New York 10032, Certificates evidencing any endorsements to any such
policies shall also be so delivered upon issuance thereof and a certificate
evidencing each renewal or replacement of a policy shall be so delivered at
least sixty (60) days prior to the expiration of such policy. Notwithstanding
the foregoing requirements for delivery of certificates of insurance,
certificates evidencing any endorsement and certificates of renewals and
replacements, in any instance where Landlord or a Superior Lessor or Superior
Mortgagee shall so require, an original policy or endorsement or renewal or
replacement policy, as the case may be, shall be delivered in addition to or in
place of such certificate(s). Tenant shall not carry any separate or additional
insurance concurrent in form or contributing in the event of any loss or damage
with any insurance required to be maintained by Tenant under this Lease.
Further, all policies of insurance procured by Tenant shall be written as
primary policies not contributing with nor in excess of coverage that Landlord
may


                                       41








<PAGE>

carry.

     (b) All insurance procured by Tenant under this Article 28, except for the
Worker's Compensation and Employer's Liability insurance described in Section
28.01(a) and the "all-risk" property insurance described in Section 28.01(c),
shall name Landlord, Tenant, the City, EDC, UDC and any other Superior Lessor
and any Superior Mortgagee as additional insureds, as their respective interests
may appear, and shall contain an endorsement that each of Landlord, the City,
EDC, UDC and any other Superior Lessor and any Superior Mortgagee, although
named as insureds, nevertheless shall be entitled to recover under said policies
any loss or damages occasioned to it, its agents, employees, contractors,
directors, shareholder, partners, trustees and principals (disclosed or
undisclosed) by reason of the negligence or tortious acts of Tenant, its
servants, agents employees and contractors.

     (c) Tenant covenants that (a) Tenant shall pay all premiums due on policies
required to be maintained by the terms of this Lease, and (b) Tenant shall not
violate, or permit the violation of, any term or condition of such policies, and
shall maintain the policies in full force and effect throughout the Term.

     (d) Tenant agrees to use its best efforts to include in each of its
insurance policies a waiver of the insurer's right of subrogation against
Landlord, or if such waiver should be unobtainable or unenforceable (a) an
express agreement that such policy shall not be invalidated if the insured
waives or has waived before the casualty the right of recovery against any party
responsible for a casualty covered by the policy, or (b) any other form of
permission for the release of Landlord. If such waiver agreement or permission
shall not be, or shall cease to be obtainable without additional charge or at
all, Tenant shall so notify Landlord promptly after learning thereof. In such
case, if Landlord shall agree in writing to pay the insurer's additional charge
therefor, such waiver, agreement or permission shall (if obtainable) be included
in the policy. As long as Tenant's casualty insurance policies include the
waiver of subrogation or agreement or permission to release liability referred
to above, Tenant, to the extent that such insurance is in force and collectible,
hereby waives (a) any obligation on the part of Landlord to make repairs to the
Tenant's Property necessitated or occasioned by fire or other insured casualty,
and (b) any right of recovery against Landlord, and any of Landlord's employees,
agents or contractors, for any loss occasioned by fire or other insured
casualty.


                                       42










<PAGE>

                                   ARTICLE 29

                                     Notices

     Section 29.01. Any bill, notice, request or other communication given or
made hereunder shall be in writing and either (a) sent by registered or
certified mail, return receipt requested, postage prepaid, or (b) delivered in
person or by overnight courier, with receipt acknowledged to, in the case of
Tenant, the address given at the beginning of this Lease, and, in the case of
Landlord, to Executive Director, Audubon Research Park, PH 1525 East, 630 West
l68th Street, New York, New York, 10032, or to such other address for such party
as said party shall hereafter designate by Notice given to the other party
pursuant to this Section 29.01. Each notice mailed shall be deemed given on the
third day following the date of mailing the same and each notice delivered in
person or by overnight courier shall be deemed given when delivered. Copies of
notices given to Landlord pursuant to the provisions of this Lease shall be sent
by registered or certified mail, postage prepaid and return receipt requested to
(i) Office of the General Counsel, Columbia University, 110 Law Memorial
Library, New York, New York, 10027, and (ii) Rosenman & Colin LLP, 575 Madison
Avenue, New York, New York, 10022, Attention: Donald H. Siskind, counsel to
Landlord.

                                   ARTICLE 30

                          Non-Liability/Indemnification

     Section 30.01. Neither Landlord nor Landlord's agents, officers, directors,
shareholders, partners, trustees or principals (disclosed or undisclosed), nor
the City, any other Superior Lessor, EDC, UDC or any Superior Mortgagee shall be
liable to Tenant or Tenant's agents, employees, contractors, invitees,
customers, concessionaires or licensees or any other occupant of the Demised
Premises, and Tenant shall indemnify Landlord and hold Landlord harmless from
and against any liabilities in connection with or arising from any injury to
Tenant or to any other Persons or any damage to, or loss (by theft or otherwise)
of, any of Tenant's Property or the property of any other Person, irrespective
of the cause of such injury, damage or loss, unless due to the gross negligence
or wilful misconduct of Landlord or Landlord's agents without contributory
negligence on the part of Tenant, or its employees, agents, contractors,
invitees, customers, concessionaires, licensees or other occupants of the
Building. Tenant waives, to the full extent permitted by law, any right it might
otherwise have to claim consequential damages in connection with the negligence
of Landlord or Landlord's agents. Any Building employee to whom any property
shall be entrusted by or on behalf of Tenant shall be deemed to be acting as
Tenant's agent with respect to such


                                       43










<PAGE>

property, and neither Landlord nor Landlord's agents shall be liable for any
loss or damage to any such property by theft or otherwise.

     Section 30.02. Neither (a) performance by Landlord, Tenant or others of any
repairs or improvements to the Demised Premises, (b) failure of Landlord or
others to make any such repairs or improvements, (c) damage to equipment, the
Demised Premises or Tenant's Property, (d) any injury to any Persons caused by
other Persons in the Building, or by operations in the construction of any
private, public or quasi-public work, or by any other cause, (e) latent defect
in the Building or Building Equipment, nor (f) injury to or interruption of
Tenant's business or operations by reason of any of the events or occurrences
referred to in the foregoing subdivisions (a) through (f) shall impose any
liability on Landlord to Tenant.

     Section 30.03. Tenant hereby indemnifies Landlord in connection with or
arising from (a) any default by Tenant in the performance of any of the terms of
this Lease on Tenant's part to be performed, (b) the use or occupancy or manner
of use or occupancy of the Demised Premises by Tenant or any Person claiming
under Tenant, (c) any Alterations or improvements made to the Demised Premises
by Landlord, Tenant or any other Person, (d) any acts, omissions or negligence
of Tenant or any Person (other than Landlord or Landlord's agents) claiming
under Tenant, or the contractors, agents, employees, invitees or licensees of
Tenant or any such Person, in or about the Demised Premises, the Building or the
Premises either prior to, during or after the expiration of the Term of this
lease, or (e) the use of the Building lobby or corridors for ingress and egress
to and from the Demised Premises by Tenant, or the contractors, agents,
employees, invitees or licensees of Tenant, whether or not in violation of the
provisions of this Lease or (f) any failure by Tenant or its agents,
contractors, employees or licensees to comply with any Environmental Legal
Requirement or Legal Requirement.

     Section 30.04. Tenant shall pay to Landlord as Additional Rent, within five
(5) days following rendition by Landlord to Tenant of bills or statements
therefor, sums equal to all losses, costs, liabilities, claims, damages, fines,
penalties and expenses referred to in this Article 30, together with interest at
the Default Interest Rate.

     Section 30.05. To the extent that any liability is imposed upon Landlord as
a matter of law, Tenant shall look solely to Landlord's estate and interest in
the Building for the satisfaction of any right of Tenant for the collection of a
judgment or other judicial process or arbitration award requiring the payment of
money by Landlord and no other property or assets of Landlord, Landlord's
agents, officers, directors, partners,


                                       44










<PAGE>

joint venturers, trustees or principals (disclosed or undisclosed) or affiliates
shall be subject to levy, lien execution, attachment or other enforcement
procedure for the satisfaction of Tenant's rights and remedies under or with
respect to this Lease, the relationship of Landlord and Tenant hereunder or
under law, or Tenant's use and occupancy of the Demised Premises or any other
liability of Landlord to Tenant.

                                   ARTICLE 31

                                    Casualty

     Section 31.01. Tenant shall notify Landlord immediately if all or any
portion of the Demised Premises are damaged or destroyed by fire or other
casualty, and this Lease shall remain in full force and effect without abatement
of rent hereunder, except as set forth below.

     Section 31.02. If all or any portion of the Demised Premises are damaged or
rendered unusable by fire or other casualty, the damages thereto shall be
promptly repaired by and at the expense of Tenant and, provided that Tenant
continuously and diligently prosecutes such repairs to completion, Fixed Rent
shall be abated from the date of the occurrence of such casualty to the date of
substantial completion with respect to the portion of the Demised Premises so
unusable based upon the relationship that the square footage of the unusable
portion of the Demised Premises bears to the total square footage of the Demised
Premises.

     If the Building is so damaged that the Demised Premises is totally or
partially unusable or access thereto is not possible, then, Landlord shall
promptly restore such portion of the Building at Landlord's expense and Fixed
Rent shall be abated from the date of occurrence of such casualty to the date of
substantial completion with respect to the portion of the Demised Premises so
unusable based upon the relationship that the square footage of the unusable
portion of the Demised Premises bears to the total square footage of the Demised
Premises.

                                   ARTICLE 32

                               Maintenance/Repairs

     Section 32.01. Landlord shall maintain and repair the public portions of
the Building, interior and exterior and the Building Equipment. Tenant shall
maintain, repair and keep in good order and condition, at Tenant's cost and
expense, the Demised Premises and all improvements thereto, including without
limitation, lighting, custom plumbing, window glass, electrical


                                       45










<PAGE>

installations and supplemental HVAC, during the Term.

     Section 32.02. Landlord shall have the option at any time to reasonably
require Tenant to enter into a maintenance contract or contract with a
contractor or contractors reasonably chosen by Landlord or with Landlord
directly for the provision of maintenance and repair and heavy cleaning services
which are Tenant's obligation under this Article 32. The fee or fees payable by
Tenant under any such contract shall not exceed Landlord's actual cost therefor.

                                   ARTICLE 33

                                 Additional Rent

     Section 33.01. In addition to any other amounts that may become due and
payable by Tenant to Landlord under this Lease, Tenant shall pay to Landlord on
demand as Additional Rent hereunder, Tenant's Proportionate Share (hereinafter
defined) of the amount by which any PILOT payment attributable to the Premises
under Section 3.06 of the Ground Lease (or payment for services rendered in lieu
thereof (or any portion thereof) pursuant to the Ground Lease or any separate
agreement between Landlord and the City) and payments of Impositions and Taxes
(as defined in the Ground Lease) under Article 4 of the Ground Lease due and
payable by Landlord in any PILOT year (hereinafter defined) or Tax Year (as
defined in the Ground Lease) exceed the amount of the PILOT payment and the
amount of the payments for Impositions and Taxes for the Base Year (hereinafter
defined).

     Section 33.02. Tenant's Proportionate Share shall be 11%.

     Section 33.03. The term "Base Year" shall mean the first year in which
Landlord is obligated to make any PILOT payment or payment of Impositions or
Taxes under the Ground Lease. The term "PILOT Year" shall mean each twelve (12)
month period, commencing on the first day of July of each such period occurring
during the Term hereof or such other 12 month period as may hereafter be adopted
as the fiscal year for PILOT payment purposes by the City of New York.

     Section 33.04. In the event that Landlord shall become the fee owner of the
land which is a part of the Premises (the "Real Property") and shall no longer
be obligated to make payments under the Ground Lease as described in Section
33.01 hereof, then the following provisions of this Section 33.04 and Sections
33.05 and 33.06 shall apply:

     (a) The term "Landlord's Statement" shall mean an instrument containing a
computation of Additional Rent due pursuant to the provisions of this Article 33
furnished by


                                       46










<PAGE>

Landlord to Tenant.

     (b) The term "Base Tax Year" shall mean the first Tax Year (as defined in
subparagraph (d) below) for which Landlord is obligated to pay Taxes as fee
owner of the Real Property.

     (c) The term "Taxes" shall mean (i) all real estate taxes, assessments
(special or otherwise), sewer and water rents, rates and charges and any other
governmental levied, impositions or charges of a similar or dissimilar nature,
whether general, special, ordinary, extraordinary, foreseen or unforeseen, all
computed without taking into account any exemption or abatement due to
Landlord's tax exempt status, which may be assessed, levied or imposed upon all
or any part of the Real Property, whether or not the same constitute one or more
tax lots, and whether levied by the City of New York or any other taxing
authority, and (ii) any expenses (including attorneys' fees and disbursements
and experts' and other witness' fees) incurred by Landlord in contesting any of
the foregoing or the assessed valuation of all or any part of the Real Property;
but "Taxes" shall not include (a) any net income, franchise, "value added",
inheritance or estate tax imposed upon Landlord, the Demised Premises or the
Real Property, except to the extent set forth in the last sentence of this
subsection, or (b) any interest or penalties incurred by Landlord as a result of
Landlord's late payment of Taxes, except for interest payable in connection with
the installment payments of assessments pursuant to the next sentence. If by
law, any assessment may be divided and paid in annual installments, then,
provided the same is not prohibited, under the terms of any Superior Lease or
Superior Mortgage, for the purposes of this Article, (x) such assessment shall
be deemed to have been so divided and to be payable in the maximum number of
annual installments permitted by law and (y) there shall be deemed included in
Taxes for each Tax Year the annual installment of such assessment becoming
payable during such Tax Year, together with interest payable during such Tax
Year on such annual installment and on all installments thereafter becoming due
as provided by law, all as if such assessment had been so divided. If at any
time after the date hereof the methods of taxation prevailing at the date hereof
shall be altered so that in lieu of or as an addition to or as a substitute for
the whole or any part of the taxes, assessments, rents, rates, charges, levies
or impositions now assessed, levied or imposed upon all or any part of the Real
Property, there shall be assessed, levied or imposed (a) a tax, assessment,
levy, imposition or charge based on the income or rents received therefrom
whether or not wholly or partially as a capital levy or otherwise, or (b) a tax,
assessment, levy, imposition or charge measured by or based in whole or in part
upon all or any part of the Real Property and imposed upon Landlord, or (c) a
license fee measured by the rents, or (d) a net income, franchise, "value
added", inheritance, estate or other tax, assessment, levy, imposition,


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<PAGE>

charge or license fee however described or imposed, then all such taxes,
assessments, levies, impositions, charges or license fees or the part thereof so
measured or based shall be deemed to be Taxes; provided that any tax,
assessment, levy, imposition or charge imposed, on income from the Real Property
shall be calculated as if the Real Property were the only asset of Landlord.

     (d) The Term "Tax Year" shall mean the twelve (12) month period commencing
July 1 of each year, or such other period of twelve (12) months as may be duly
adopted as the fiscal year for real estate tax purposes in The City of New York.

     (e) The term "Commercial Portion" shall mean the portion of the Building
not used or held for university purposes or as common areas.

     (f) The term "Commercial Portion Taxes" payable for a Tax Year shall mean
100% of the Taxes payable for such Tax Year.

     Section 33.05. (a) Tenant shall pay as Additional Rent for each Tax Year
all or any portion of which shall be within the term of this Lease, a sum
("Tenant's Tax Payment") equal to Tenant's Proportionate Share of the amount by
which the Commercial Portion Taxes payable for such Tax Year exceed the
Commercial Portion Taxes payable for the Base Tax Year, as finally adjusted and
determined. Tenant's Tax Payment for each Tax Year shall be due and payable, in
advance, on the first day of each July during each Tax Year, based upon the
Landlord's Statement furnished prior to or after the commencement of such Tax
Year, until such time as a new Landlord's Statement shall become effective. If a
Landlord's Statement is furnished to Tenant after the commencement of a Tax Year
in respect of which such Landlord's Statement is rendered, Tenant shall, within
fifteen (15) days thereafter, pay to Landlord an amount equal to the amount of
any underpayment of Tenant's Tax Payment with respect to such Tax Year as stated
in the Landlord's Statement. In the event of an overpayment, Landlord shall
either pay to Tenant, or, at Landlord's election, credit against subsequent
payments under this Section 33.05, the amount of Tenant's overpayment as stated
in the Landlord's Statement. If there shall be any increase in Taxes for any Tax
Year, whether during or after such Tax Year, or if there shall be any decrease
in the Taxes for any Tax Year during or after such Tax Year, Landlord may
furnish a revised Landlord's Statement for such Tax Year, and Tenant's Tax
Payment for such Tax Year shall be adjusted and paid or credited or refunded, as
the case may be, substantially in the same manner as provided in the preceding
sentence. If at any time after the date hereof, Taxes are required to be paid
(either to the appropriate taxing authorities or as tax escrow payments to a
Superior Lessor or Superior Mortgagee) on any other date or dates than as
presently required, the Tenant's Tax Payments shall


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<PAGE>

be correspondingly accelerated or revised so that said Tenant's Tax Payments are
due at least thirty (30) days prior to the date payments are due to the taxing
authorities or a Superior Lessor or Superior Mortgagee. The benefit of any
discount for any early payment or prepayment of Taxes and of any tax exemption
or abatement relating to all or any part of the Real Property (due to Landlord's
tax exempt status) shall accrue solely to the benefit of Landlord, and Taxes
shall be computed without subtracting such discount or taking into account any
such exemption or abatement.

     (b) Only Landlord shall have the right to institute tax reduction or other
proceedings to reduce the assessed valuation of the Real Property. If Landlord
shall receive a refund of Taxes for any Tax Year after the Base Tax Year, and if
such refund shall be attributable to the Commercial Portion, Landlord shall
either pay to Tenant or, at Landlord's election, credit against subsequent
payments under this Section 33.05 Tenant's Proportionate Share of any part of
such refund attributable to the Commercial Portion, not to exceed Tenant's Tax
Payment paid for the Tax Year for which such refund was received; provided,
however, that Tenant shall not be entitled to receive any portion of any refund
received by Landlord, or receive the benefit of any abatement or reduction in
Taxes, attributable, in whole or in part, to Landlord's tax exempt status.
Nothing herein shall obligate Landlord to file any application or institute any
proceeding seeking a reduction in Taxes or assessed valuation.

     (c) Tenant's Tax Payment and any credits with respect thereto as provided
in this Section 33.05 shall be made as provided in this Section 33.05 regardless
of the fact that Tenant may be exempt, in whole or in part, from the payment of
any taxes by reason of Tenant's diplomatic or other tax exempt status or for any
other reason whatsoever.

     (d) Tenant shall pay to Landlord, within five (5) business days after
demand, as Additional Rent, any occupancy tax or rent tax now in effect or
hereafter enacted and payable with respect to the Demised Premises or this
Lease, if payable by Landlord in the first instance or hereafter required to be
paid by Landlord.

     (e) If only a portion of a Tax Year shall be included within the Term, any
Additional Rent under this Section 33.05 for such Tax Year shall be apportioned
in the ratio which the number of days in such Tax Year which occur during the
Term bears to the total number of days in such Tax Year. In the event of a
termination of this Lease, any Additional Rent under this Section 33.05 shall be
paid or adjusted within 30 days after the submission of Landlord's Statement. In
no event shall Fixed Rent or Fixed Repayment ever be reduced by operation of
this Section 33.05 and the rights and obligations of Landlord and Tenant under
the provisions of this Section 33.05 with respect to any


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<PAGE>

Additional Rent shall survive the termination of this Lease.

     Section 33.06. (a) Landlord's failure to render Landlord's Statements with
respect to any Tax Year shall not prejudice Landlord's right to thereafter
render a Landlord's Statement with respect thereto or with respect to any
subsequent Tax Year nor shall the rendering of a Landlord's Statement prejudice
Landlord's right to thereafter render a corrected Landlord's Statement for that
Tax Year provided that such Landlord's Statement, or corrected Landlord's
statement is rendered within one year of the later of the end of such Tax Year
or the date of changes affecting determination of the amounts in Landlord's
Statement. Nothing herein contained shall restrict Landlord from issuing a
Landlord's Statement at any time there is an increase in Taxes during any Tax
Year or any time thereafter.

     (b) Each Landlord's Statement shall be conclusive and binding upon Tenant
unless within thirty (30) days after receipt of such Landlord's Statement.
Tenant shall notify Landlord that it disputes the correctness of Landlord's
Statement, specifying the particular respects in which such Landlord's Statement
is claimed to be incorrect. Pending the resolution of such dispute. Tenant shall
pay Tenant's Tax Payment in accordance with the applicable Landlord's Statement,
without prejudice to Tenant's position. If such dispute is ultimately determined
in Tenant's favor, Landlord shall promptly after such determination pay to
Tenant any amount so overpaid by Tenant.

     Section 33.07. In the event that pursuant to the Ground Lease and the REA,
Landlord becomes the owner of any additional real property treated, for purpose
of Taxes, as part of the Real Property, appropriate adjustments with respect to
Tenant's obligations pursuant to this Article 33 shall be made and Tenant shall
be liable for payments under this Article 33, as so adjusted.

                                   ARTICLE 34

                                     Parking

     Section 34.01. Tenant and its employees, clients, visitors and agents shall
have the right seven days a week, twenty-four hours a day to use two (2)
floating reserved parking spaces at no cost to Tenant and up to eight (8)
unreserved parking spaces which will be available on advance request therefor
and upon payment by Tenant to Landlord monthly of Landlord's standard rates. All
such spaces ("Tenant's Parking Spaces") are located in the lot adjacent to the
Building until such time as Landlord begins construction of a new building to be
erected on such lot. Landlord shall give Tenant sixty (60) days' written notice
in advance of commencing such construction and Tenant shall have


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<PAGE>

removed all vehicles from such lot on or before the date set forth in such
notice. From and after the date of such notice. Landlord shall use reasonable
efforts to provide reasonably equivalent and suitable substitute temporary
parking space for Tenant's use and agrees that Tenant's Parking Spaces shall be
made available at a permanent location convenient to the Building, if, as and
when same are constructed, on the same terms and conditions as set forth herein.
In addition, the executive director of the Audubon Research Park shall use all
reasonable efforts to obtain one-day parking on Columbia University's
Morningside Campus if Tenant requests it.

                                   ARTICLE 35

                                     Broker

     Section 35.01. Tenant represents, warrants and covenants to Landlord that
there is no broker, finder, consultant or similar person entitled to a
commission, fee or other compensation in connection with the consummation of the
Lease and no conversations or prior negotiations were had by Tenant or anyone
acting on behalf of Tenant with any broker, finder, or consultant or similar
person concerning the renting of the Demised Premises. Tenant shall indemnify
Landlord against all costs, expenses, losses, damages and liabilities, including
attorneys' fees and costs, arising from any claims for brokerage commissions,
finder's fees or other compensation resulting from or arising out of any
conversations, negotiations or actions had by Tenant or anyone acting on behalf
of Tenant with any broker, finder, consultant or similar person. Landlord shall
have no liability for brokerage commissions arising out of an assignment or
sublease by Tenant and Tenant shall indemnify Landlord against all liability for
brokerage commissions arising out of any such assignment or sublease. The
provisions of this Article 35 shall survive the termination or expiration of
this Lease.

                                   ARTICLE 36

                                Security Deposit

     Section 36.01. Landlord and Tenant hereby agree that the total amount of
$43,237.00 is to be deposited with Landlord as security for the full and
faithful performance and observance by Tenant of the terms, provisions and
covenants of this Lease. Tenant has deposited $21,618.50 of such security and
shall deposit the balance of such security on the first anniversary of the
Commencement Date. In the event Tenant fails to perform any of its obligations
hereunder. Landlord may use, apply or retain the whole or any part of such
security to the extent required for the payment of any amounts as to which
Tenant is in default or of


                                       51








<PAGE>

any amounts which Landlord may expand or may be required to expand by reason of
Tenant's default, including, without limitation any damages or eficiency in
reletting the Demised Premises. In the event that Tenant shall have fully and
faithfully complied with all of the terms, covenants and conditions of this
Lease, such security shall be returned to Tenant after the Expiration Date and
delivery of the Demised Premises to Landlord in the condition required
hereunder.

     Section 36.02. In the event of a sale or lease of the Premises and the
Building, Landlord shall have the right to assign or transfer the security to
the purchaser or lessee, as the case may be, whereupon Landlord shall be
released by Tenant from all liability for the return of such security. Tenant
covenants that it will not attempt to assign, assign or otherwise attempt to
encumber or encumber such security and that neither Landlord nor any successor
or assign of Landlord shall be bound by any such assignment or attempted
assignment, encumbrance or attempted encumbrance.

     Section 36.03. In the case of every use, application or retention by
Landlord of all or any part of the security deposited pursuant to Section 36.01,
Tenant shall, on demand, pay to Landlord the sum so used, applied or retained
which shall be added to the security deposited hereunder so that the same shall
be replenished to its former amount, and any failure by Tenant to pay such sum
on demand shall constitute an Event of Default under this Lease.

     Section 36.04. Landlord agrees that the security deposited hereunder shall
earn interest at a passbook savings rate. The interest accrued with respect
thereto shall be added to and constitute a part of the security deposited
hereunder, to be held and disposed of by Landlord in accordance with the terms
of this Article 36. All security deposited and not used, applied, or retained
pursuant to the terms of this Article 36 with respect to a default plus any
interest payable with respect to the sum deposited by Tenant on account of the
security deposited hereunder shall be paid to Tenant promptly after the
Expiration Date, less an amount equal to one percent (1%) per annum for
Landlord's administrative costs in connection with the security deposited
hereunder.

     Section 36.05. Tenant shall, concurrently with execution and delivery of
the Lease, and thereafter at any time upon request by Landlord, deliver to
Landlord a fully completed Form W-9 (Request for Taxpayer Identification Number
and Certification).


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<PAGE>

                                   ARTICLE 37

                                  Miscellaneous

     Section 37.01. Landlord shall have the right to erect a gate, chain or
other obstruction or to close off any portion of the Premises to the public at
any time to the extent necessary to prevent a dedication thereof for public use,
provided that such gate, chain or obstruction shall not prevent Tenant's ingress
to or egress from the Demised Premises.

     Section 37.02. The submission by Landlord to Tenant of this Lease in draft
form shall be deemed submission solely for Tenant's consideration and not for
acceptance and execution. Such submission shall have no binding force and
effect, shall not constitute an option for the leasing of the Demised Premises,
and shall not confer any rights or impose any obligations upon either party. The
submission by Landlord of this Lease for execution by Tenant and the actual
execution and delivery thereof by Tenant to Landlord shall similarly have no
binding force and effect on Landlord unless and until Landlord shall have
executed this Lease and a counterpart thereof shall have been delivered to
Tenant.

     Section 37.03. This Lease contains the entire agreement between the parties
and all prior negotiations and agreements are merged into this Lease. This Lease
may not be changed, modified abandoned or discharged, in whole or in part, nor
may any of its provisions be waived except by a written instrument which (a)
expressly refers to this Lease, (b) is executed by both parties hereto and (c)
is permissible under any Superior Mortgage, the Ground Lease and any other
Superior Lease.

     Section 37.04. No vault, vault space or area is leased hereunder.

     Section 37.05. if an excavation shall be made upon land adjacent to the
Building or shall be authorized to be made, Tenant shall afford the person so
authorized or so making to enter upon the Demised Premises for the purpose of
performing such work as such person shall deem necessary to preserve any wall or
the Building of which the Demised Premises are a part from damage and to support
same by proper foundation without claim for damage, indemnity or abatement of
rent.

     Section 37.06. If any of the provisions of this Lease, or the application
thereof to any person or circumstance, shall, to any extent, be invalid or
unenforceable, the remainder of this Lease, or the application of such provision
or provisions to persons or circumstances other than those as to whom or which
it is held invalid or unenforceable, shall not be affected thereby, and every
provision of this Lease shall be valid and enforceable


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<PAGE>

to the fullest extent permitted by law.

     Section 37.07. For the purposes of this Lease and all agreements
supplemental to this Lease, unless the context otherwise requires:

          (a) Reference to "termination of the Lease" and words of like import
includes expiration or sooner termination of this Lease and the Term and the
estate hereby granted or cancellation of this Lease pursuant to any of the
provisions of this Lease or to law. Upon the termination of this Lease, the term
and estate granted by this Lease shall end at noon of the date of termination as
if such date were the Expiration Date and neither party shall have any further
obligation or liability to the other after such termination except (i) as shall
be expressly provided for in this Lease, and (ii) for such obligations as by
their nature or under the circumstances can only be, or by the provisions of
this Lease, may be, performed after such termination and, in any event, unless
expressly otherwise provided in this Lease, any liability for a payment (which
shall be apportioned as of such termination) which shall have accrued to or with
respect to any period ending at the time of termination shall survive the
termination of this Lease.

          (b) The words "Tenant hereby indemnifies Landlord" and words of
similar import shall mean that Tenant hereby agrees to and hereby does
indemnify, defend, and hold and save Landlord, Landlord's agents, New York
State, the City, EDC, UDC and any other Superior Lessor or any Superior
Mortgagee and their respective agents, employees, contractors, officers,
directors, shareholders, partners, trustees and principals (disclosed or
undisclosed), successors and assigns harmless from and against any and all cost,
liability, claim, damage, fine, penalty and expense, including, without
limitation, attorneys' fees and disbursements.

          (c) Each term, covenant, agreement, obligation or other provision of
this Lease on Tenant's part to be performed shall be deemed and construed as a
separate and independent covenant of Tenant, not dependent upon any of the other
terms of the Lease. This Lease shall be construed without regard to any
presumption or other rule requiring construction against the party causing this
Lease to be drafted. In the event of any action, suit, arbitration, dispute or
proceeding affecting the terms of this Lease, no weight shall be given to any
deletions or striking out of any of the terms of this Lease contained in any
draft of this Lease and no such deletion or strike out shall be entered, into
evidence in any such action, suit, arbitration, dispute or proceeding nor used
to interpret the intent of the parties nor given any weight whatsoever.


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<PAGE>

                                   ARTICLE 38

                                 Renewal Option

     Section 38.01. Provided that both at the time of the exercise of the option
contained in this Section 38.01 and at the time of the commencement of the
Renewal Term, no Event of Default shall have occurred and be continuing, Tenant
shall have the right to renew the term of this Lease for an additional term of
five (5) years (the "Renewal Term") commencing on the day immediately following
the Expiration Date and ending one (1) day prior to the tenth anniversary of the
Rent Commencement Date ("Renewal Term Expiration Date"), upon the same terms
and conditions of this Lease except as set forth in Section 38.02 hereof. If
Tenant so elects to renew the Term for the Renewal Term. Tenant shall give
notice to Landlord of such election on or before a date which is six (6) months
prior to the commencement of the Renewal Term.

     Section 38.02. In the event that Tenant timely exercises such right and
provided that no Event of Default shall have occurred and then be continuing
hereunder, the Expiration Date of this Lease shall be automatically extended on
the Expiration Date for the Renewal Term as if the Renewal Term had been
originally included in the Term, provided, however, that (i) the Fixed
Repayment shall continue to be due and payable monthly throughout the Renewal
Term at the same rate as provided in Section 3.04 hereof (as the same may have
been adjusted pursuant to Sections 25.07 and 43.01 hereof); (ii) the terms of
this Lease relating to Tenant's Work (other than the Fixed Repayment) shall not
be applicable to the Renewal Term; (iii) Tenant shall have no right to renew the
term of this Lease for any period beyond the Renewal Term; and (iv) annual Fixed
Rent shall be as follows:

      Period                             Amount
      ------                             ------

Renewal Term Year 1   $147,298.20 per annum, payable in equal monthly
                      installments of $12,274.85 each;

Renewal Term Year 2   $151,717.20 per annum, payable in equal monthly
                      installments of $12,643.10 each;

Renewal Term Year 3   $156,268.68 per annum, payable in equal monthly
                      installments of $13,022.39 each;

Renewal Term Year 4   $160,956.72 per annum, payable in equal monthly
                      installments of $13,413.06 each; and


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<PAGE>

Renewal Term Year 5   $165,785.40 per annum, payable in equal monthly
                      installments of $13,815.45 each.

                                   ARTICLE 39

                                 Expansion Right

     Provided that no Event of Default shall have occurred and be continuing, in
the event that Landlord shall have a bona fide third party (the "Third Party")
apply to rent some or all of the remaining space on the second floor of the
Building, Tenant shall have a right to expand into all of the space on the
second floor of the Building not initially demised hereunder. Landlord shall
give Tenant written notice of such Third Party's application for such space. The
remaining space on the second floor shall be available to Tenant for inclusion
in this Lease on the terms and conditions contained herein (including the rental
rate per rentable square foot for the applicable period), except that (a)
Tenant's obligation to pay Fixed Rent with respect to such expansion space shall
commence on the date which is six (6) months following Tenant's exercise of the
option set forth in this Article 39 and (b) in the event that such exercise is
made prior to the first anniversary of the Commencement Date, Landlord shall
contribute an amount equal to difference between $1,200,000 and the sum of the
Grant, the Construction Loan, the Soft Cost Loan and the Equipment Loan (as
hereinafter defined), for amounts actually paid by Tenant to unrelated parties
to install or construct alterations for Tenant's initial occupancy of such space
on terms and conditions to be set forth in a modification of this Lease to be
executed by the parties hereto as promptly as practicable after the exercise of
Tenant of its rights pursuant to this Article 39. Landlord shall have no other
obligations to perform work or pay for work or loan money to Tenant to perform
work in such space. Tenant shall have thirty (30) days from the date of receipt
of the notice from Landlord to give Landlord written notice of its exercise of
such right. If Tenant shall exercise its right within the requisite time period,
then by amendment hereto such space shall be added to the Demised Premises, and
necessary modifications to this Lease, including, without limitation, the Fixed
Rent and Tenant's Proportionate Share, shall be included in such amendment. In
the event that Tenant shall not exercise its right within the requisite time
period, then Landlord shall have the right to rent all or any portion of the
remaining space on the second floor to such Third Party.

                                   ARTICLE 40

                              Intentionally Deleted


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<PAGE>

                                   ARTICLE 41

                                  REA/Security

     Section 41.01. Tenant acknowledges that pursuant to the REA, the City, EDC
and Landlord have granted each other certain mutual easements for access,
ingress and egress in and to the Premises in order to conduct and perform
certain maintenance, repair and security obligations which are common to the
parties thereto. In particular, the City, EDC and Landlord have agreed to devise
and implement an integrated security system for certain areas of the Premises
from which tenants of the Building will derive some benefit.

     Section 41.02. The parties hereto expressly understand and agree that
Landlord's obligations under the REA, including, without limitation, those
relating to the provision of security under Section 4.02 of the REA, shall not
(i) create (or create the inference of or be deemed to create) an affirmative
obligation on Landlord's part or on the part of the City or EDC to provide any
security, alarm or other system or protection to Tenant hereunder or thereunder
or (ii) create or imply any right of Tenant under this Lease or the REA to
receive any such security. Tenant shall have no claim against Landlord,
Landlord's agents, the City or EDC nor shall Landlord, Landlord's agents, the
City or EDC be liable to Tenant for any injury to persons or property arising
from Landlord's action or failure to act in connection with its obligations
under the REA.

                                   ARTICLE 42

                              Index of Definitions

     "Abatement Period" shall have the meaning set forth in Section 3.09.

     "Additional Rent", "Fixed Rent", and "rent" shall have the meanings set
forth in Article 3.

     "Alterations" shall have the meaning set forth in Section 25.01.

     "Assignee Security" shall have the meaning set forth in Section 24.03.

     "Base Year" shall have the meaning set forth in Section 33.03.

     "Broker" shall have the meaning set forth in Section 35.01.


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<PAGE>

     "Building Equipment" shall mean all machinery, apparatus, equipment,
personal property, fixtures and systems of every kind and nature whatsoever now
or hereafter attached to or used in connection with the operation of maintenance
of the Building, including all electrical, heating, mechanical, sanitary,
sprinkler, utility, sewage, drainage, power, plumbing, cleaning, fire
prevention, refrigeration, ventilating, air cooling, air conditioning, elevator,
communication (including telephone, telegraph, teleregister, and pneumatic tube
dispatch) and escalator systems, apparatus and equipment and any and all
renewals and replacements of any thereof, whether presently installed or
installed after the date of this lease, but excluding, however, (i) Tenant's
Property, (ii) property of any other tenant, (iii) property of contractors
servicing the Building and (iv) improvements for water, gas, steam and
electricity and other similar equipment owned by any public utility company or
any governmental agency or body.

     "Building" shall have the meaning set forth in the recitals.

     "Business Days" shall mean weekdays, other than those weekdays which are
legal holidays observed by the City of New York.

     "City" shall mean the City of New York.

     "Commencement Date" shall have the meaning set forth in Section 1.03.

     "Construction Loan" shall have the meaning set forth in Section 25.07.

     "Construction Manager" shall have the meaning set forth in Section 46.01.

     "Default Interest Rate" shall have the meaning set forth in Section 3.05.

     "Deficiency" shall have the meaning set forth in Section 11.03.

     "Demised Premises" shall have the meaning set forth in the recitals.

     "DHH Specifications" shall have the meaning set forth in Section 6.01.

     "EDC" shall have the meaning set forth in the recitals.

     "Environmental Legal Requirements" shall have the meaning set forth in
Section 8.02.


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<PAGE>

     "Equipment Loan" shall have the meaning set forth in Section 43.01.

     "Event of Default" shall have the meaning set forth in Section 10.01.

     "Expiration Date" shall have the meaning set forth in Section l.02.

     "Grant" shall have the meaning set forth in Section 25.07.

     "Ground Lease" shall have the meaning set forth in the recitals.

     "Hazardous Materials" shall have the meaning set forth in Section 8.01.

     "Insurance Requirements" shall mean all requirements of the Ground Lease or
of any insurance policy covering or applicable to all or any part of the
Premises, the Demised Premises, the Building or the use thereof, all
requirements of the issuer of any such policy and all orders, rules,
regulations, recommendations and other requirements of the New York Board of
Fire Underwriters or the Insurance Service Organization or any other body
exercising the same or similar functions and having jurisdiction or cognizance
of all or any part of the Premises, the Demised Premises or the Building.

     "Interest Rate" shall have the meaning set forth in Section 3.04.

     "Landlord" shall mean only the owner at the time in question of the present
Landlord's interest in the Lease or the Building and in the event of a sale or
transfer of the Building (by operation of law or otherwise); (a) the grantor or
other transferor, as the case may be, shall be (to the extent of the interest in
or portion of the Building or the Lease sold or transferred) automatically and
entirely released and discharged, from and after the date of such sale or other
transfer of all liability in respect of the performance of any of the terms of
this Lease on the part of Landlord thereafter to be performed, (b) the
purchaser or other transferee (collectively "Transferee") shall be deemed to
have assumed and agreed to perform, during and in respect of the Transferee's
period of ownership of the Landlord's interest under this Lease, all of the
terms of this Lease on the part of the Landlord to be performed, and (c) the
Transferee shall have all rights of the Landlord under this Lease.

     "Legal Requirements" shall have the meaning set forth in Section 8.01.


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<PAGE>

     "Person" shall mean any individual, corporation, partnership, joint
venture, estate, trust, unincorporated association, any federal, state, county
or municipal government, or any bureau, department or agency thereof and any
fiduciary acting in such capacity on behalf of any of the foregoing.

     "PILOT Year" shall have the meaning set forth in Section 33.03.

     "Plan" shall have the meaning set forth in Section 4.01.

     "Premises" shall have the meaning set forth in the recitals.

     "REA" shall have the meaning set forth in Section 1.01.

     "Soft Cost Loan" shall have the meaning set forth in Section 25.07.

     "Special Permit" shall have the meaning set forth in Section 4.01.

     "Successor Owner" shall have the meaning set forth in Section 20.02.

     "Superior Lessor" shall mean the City or any other lessor under any other
Superior Lease.

     "Superior Lease" shall mean all present and future ground leases, operating
leases, superior leases, overriding leases and underlying leases, including,
without limitation, the Ground Lease, covering all or any part of the Demised
Premises and all renewals, modifications, replacements and extensions of any of
the above.

     "Superior Mortgage" shall mean all mortgages and building loan agreements,
including, without limitation, leasehold mortgages and spreader and
consolidation agreements, which may now or hereafter affect the Premises,
the Building, the Demised Premises or any Superior Lease and all renewals,
modifications, replacements and extensions of any of the above.

     "Superior Mortgagee" shall mean the holder of any Superior Mortgage.

     "Tax Year" and "Taxes" and "Impositions" shall have the meanings given them
in the Ground Lease or as set forth in Section 33.04, as applicable.

     "Tenant" shall have the meaning set forth in the recitals and, as
applicable, the meaning set forth in Section 10.04.

     "Tenant's Equipment" shall mean the equipment set forth in


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<PAGE>

Exhibit E.

     "Tenant's Property" shall mean all fixtures, trade fixtures,
stock-in-trade, furniture, partitions and other property (i) installed or
purchased at the sole expense of Tenant, (ii) with respect to which Tenant has
not been granted any credit or allowance by Landlord other than as specifically
set forth herein, and (iii) which are removable without material damage to the
Demised Premises.

     "Tenant's Proportionate Share" shall have the meaning set forth in Section
33.02.

     "Tenant's Work" shall have the meaning set forth in Section 3.04.

     "Term" shall have the meaning set forth in Section 1.02.

     "UDC" shall mean the New York State Urban Development Corporation.

                                   ARTICLE 43

                               Tenant's Equipment

     Section 43.01 In addition to the $650,000 being made available by Landlord
for Tenant's Work pursuant to Section 25.07(b), Landlord shall provide funds not
to exceed a maximum amount of $250,000 (the "Equipment Loan") for the purchase
of Tenant's Equipment. After the Tenant's Equipment has been purchased, the
monthly installments of Fixed Repayment may be decreased, to an amount equal to
one-twelfth of the annual principal and interest payments of a self-amortizing
loan in the amount of $500,000, as such amount may have been adjusted pursuant
to Section 25.07 hereof, minus the difference, if any, between $250,000 and the
amounts actually expended for Tenant's Equipment, amortizing on a straight line
basis over ten (10) years at the Interest Rate subject to adjustment as set
forth in Section 25.07, plus, in any case, one-one hundred and twentieth of the
Closing Costs described in Section 3.04, hereof.

                                   ARTICLE 44

                              Equity Participation

     Section 44.01 As further consideration for Landlord entering into this
Lease, Tenant has delivered to Landlord that certain Warrant for the Purchase of
Shares of Common Stock, dated March 11, 1996 (the "Warrant"), whereby Landlord
shall have the option, exercisable within five (5) years of the date of the


                                       61










<PAGE>

warrant, to purchase 5,000 shares of common stock of Tenant for the purchase
price of $10.00 per share. Tenant hereby acknowledges that the delivery to
Landlord of such Warrant or the exercise by Landlord of any rights pursuant to
such Warrant does not and will not create any partnership or joint venture
between the parties and does not and will not diminish any of the rights of
Landlord, as landlord, pursuant to this Lease.

                                   ARTICLE 45

                           Human and Animal Research

     Section 45.01. Human subjects and live animals may not be used in research
at the Building by Tenant or any assignee, subtenant, licensee, agent, employee
or contractor of Tenant.

                                   ARTICLE 46

                           Payment for Tenant's Work

     Section 46.01. As long as Tenant has entered into and maintains a
construction contract for performance of Tenant's Work with HRH Construction
Interiors, Inc. (the "Construction Manager"), which contract (including any and
all amendments thereto) shall have been approved by Landlord, Landlord shall pay
the Construction Manager not more often than monthly, up to a maximum aggregate
amount of the Construction Loan and the Grant, for amounts actually incurred by
the Construction Manager to install or construct Tenant's Work. As a condition
precedent to each such payment, Landlord shall receive (i) a requisition from
the Construction Manager for work and materials incorporated into the Demised
Premises covering all services, labor and materials theretofore furnished in
connection with Tenant's Work at least equal in amount to the portion of the
Grant and Construction Loan that is being applied for, (ii) a certificate from
the Tenant's architect that the work for which payment is requested has been
completed, and (iii) a certificate from the Construction Manager that all prior
payments made by Landlord have been for payments made to the Construction
Manager for Construction Manager fees and/or for payments made by the
Construction Manager to contractors and/or subcontractors for performance of the
Tenant's Work, and provided, further, that (x) all Tenant's Work theretofore
completed shall have been constructed in accordance with the Plans and
Specifications therefor, and Landlord, Tenant and the Construction Manager shall
have agreed in writing to that effect, and (y) Landlord received copies of all
required approvals, permits and certificates for the Tenant's Work from all
governmental authorities having jurisdiction. It is expressly understood that
the requirements of this Article 46 are solely for the benefit of Landlord and
Tenant and that no


                                       62










<PAGE>

contractor, subcontractor, materialman or other person (including, without
limitation, the Construction Manager and Tenant's architect) shall have or
acquire any claim against Landlord as a result of any failure of Landlord
actually to obtain the evidences, certifications or other documentation provided
for herein. No portion of the Grant or the Construction Loan shall vest in
Tenant or the Construction Manager, and under no circumstances shall Tenant
sell, transfer, assign, pledge, hypothecate, or otherwise encumber all or any
portion of the Grant or the Construction Loan or any purported interest therein.

     IN WITNESS WHEREOF, the parties hereto have executed this Lease on the day
and year first above written.

LANDLORD:                               THE TRUSTEES OF COLUMBIA UNIVERSITY
                                        IN THE CITY OF NEW YORK


                                        By: JOAN M. LEIMAN
                                            ------------------------------------
                                            Name: JOAN M LEIMAN
                                            Title: EXECUTIVE DEPUTY VICE
                                                   PRESIDENT FOR HEALTH SCIENCES


TENANT:                                 ORTEC INTERNATIONAL, INC.


                                        By: RON LIPSTEIN
                                            ------------------------------------
                                            Name: RON LIPSTEIN
                                            Title: Secretary


                                       63










<PAGE>

                                   EXHIBIT A

                                   [GRAPHIC]

The general layout of the building has a central core around which
elevators and stairwells are located. There is space on the east and west
sides of the core for building occupants (space for offices, labs, storage,
meetings, etc.). Ortec's 2nd floor layout is as follows: The lobby is on
the north end of the building core, adjacent to two passenger elevators.
In the northeast corner of the 2nd floor, Ortec has approximately 1,000
square feet of R&D lab space. The balance of the east side of the 2nd floor
(approx 3,000 square feet) is office space for quality control, manufacturing,
management, and other support personnel. There is a small shipping/storage
area (400 square feet) in the southeast corner of the building. The northwest
corner of the building houses Ortec's manufacturnig area. This is an
approximately 2,000 square foot area containing one Class 10,000 clean
room, one Class 100,000 clean room, as well as a laboratory area and storage
space for raw materials, in process materials, and finished product. There
is approximately 2,000 square feet of office space in the southwest corner
of the building. This space houses the executive offices, cubicles for
technical and administrative staff, and a conference room. The remainder of
the 2nd floor is comprised of corridors, closets, bathrooms, and other
miscellaneous space.











<PAGE>

                                    EXHIBIT B

                            Melvin Silberklang, Ph.D.

Memo
To: Ron Lipstein
From: Mel Silberklang
Subject: Environmental Impact of Biological Materials and Chemicals in
         Ortec's Scientific Work
Date: 1/15/96

The manufacture of composite cultured skin begins with the harvest of normal
human skin cells, epidermal keratinocytes and dermal fibroblasts, from donor
neonatal foreskin specimens (which are recovered from circumcisions). This
constitutes a source of medical waste. The further expansion, cryopreservation
and eventual processing of these cells into composite cultured skin creates more
biological/medical waste, as well as some chemical waste resulting from the use
of several solvents and chemicals in the manufacturing process. Our operations
do not use any radioactive materials. Specific waste issues may be summarized
as follows:

Biological/medical waste

New cells from new donor foreskins, like all untested medical specimens, must be
considered at risk of carrying a viral or other microbiological contamination,
and biowaste generated during cell culture work with them would therefore be
categorized as "infectious medical waste". Our operations generate up to a total
of one 50-gallon drum-full of such waste per day, which is put into either of
two types of special containers, one for soft materials and one for pipets and
other plastic and glass, following Cornell Medical College's standard. At the
Audubon center, we will, of course, use appropriate waste storage containers
which are in compliance with Columbia University's standard. Liquid waste is
treated by adding a strong chemical disinfectant, storing it only for a very
brief holding period, and then pouring it down the drain. New cell line work may
generate up to 5 gallons of such aqueous "biological" liquid waste per day.

The subsequent production of Composite Cultured Skin uses only cell lines which
have already been fully screened, tested and certified virus-free and sterile.
The risk of infectious agents is therefore minute. Nevertheless, for the sake
of simplicity and consistency in our waste management practices, all dry and wet
waste are handled as "infectious medical waste", identically as described above
for new cell lines. The volume of waste generation may be up to double that of
the new cell work, namely two 50-gallon drum equivalents of dry waste and 10
gallons of liquid waste per day.

Chemical Waste

Ortec's operations use only common laboratory chemicals and solvents, which,
depending on the agent, are either poured down the drain or stored in bottles
for chemical waste pickup in compliance with Cornell University
regulations. Chemicals include but are not limited to the following (an
exhaustive list is beyond the scope of this memo):

Ethyl Alcohol (CAS#           )       Acetic Acid (CAS#             )
Methyl Alcohol (CAS#              )   Hydrochloric Acid (CAS#         )
Isopropyl Alcohol (CAS#           )   Sodium Hydroxide (CAS#          )
Formaldehyde (CAS#            )       Sodium Chloride (CAS#           )
Glutaraldehyde (CAS#              )   Sodium Phosphate (CAS#          )
Acetone (CAS#                 )       EDTA (CAS#                    )

A complete list can be filed upon move-in.










<PAGE>

                                    EXHIBIT C

================================================================================

                     [SAVALDI & HADAS ARCHITECTS LETTERHEAD]

MARCH 8TH, 1996

MR. RON LIPSTEIN, PRESIDENT
ORTEC INTERNATIONAL CORPORATION
8000 COOPER AVENUE, GLENDALE,  NEW YORK

DEAR MR. LIPSTEIN,

AS PER YOUR REQUEST, ENCLOSED PLEASE FIND A LIST OF DRAWINGS, FOR THE NEW
ORTEC FACILITY LOCATED AT 3960 BROADWAY, NEW YORK NEW YORK, ON THE SECOND
FLOOR OF THE AUDUBON BUSINESS AND TECHNOLOGY CENTER.

THESE DRAWINGS HAD BEEN FILED AND APPROVED BY THE NEW YORK CITY DEPARTMENT OF
BUILDINGS. A BUILDING PERMIT HAD BEEN ISSUED ON FEB 15TH 1996.

BUILDING APPLICATION # 101246386:
A-1   COVER SHEET                  DATED: 11.21.95
A-2   FLOOR PLAN                   DATED: 11.21.95
A-3   PARTITION SCHEDULE           DATED: 11.21.95
A-4   FLOOR SCHEDULE               DATED: 11.21.95
A-5   REFLECTED CLG. PLAN          DATED: 11.21.95
A-6   INTERIOR PLAN, FINISHES      DATED: 11.21.95
A-7   INTERIOR ELEVATIONS          DATED: 11.21.95

M-l   HVAC- FLOW DIAGRAM           DATED: 2.7.96
M-2   HVAC- FLOOR PLAN             DATED: 2.7.96
M-3   HVAC- DETAILS                DATED: 2.7.96
M-4   HVAC- NOTES                  DATED: 2.7.96
M-5   HVAC- SPECS                  DATED: 2.7.96

P-l   PLUMBING PLAN                DATED: 11.20.95
P-2   PLUMBING NOTES & SCHEDULES   DATED: 11.20.95

BUILDING APPLICATIONS # 101246395
SP-1  FIRE PROTECTION              DATED: 11.20.95
SP-2  FIRE PROTECTION NOTES        DATED: 11.20.95
SP-3  RISER DIAGRAM                DATED: 11.20.95
F-l   ELECTRICAL SPECS             DATED: 11.20.95
E-2   LIGHTING PLAN                DATED: 11.20.95
E-3   POWER PLAN                   DATED: 11.20.95
L-4   RISER DIAGRAM                DATED: 11.20.95

IF YOU HAVE ANY QUESTIONS, PLEASE CALL,
SINCERELY,      DOV HADAS, ARCHITECT

================================================================================










<PAGE>

                                    EXHIBIT D
                            CLEANING SPECIFICATIONS

AUDUBON BUSINESS AND TECHNOLOGY CENTER

--------------------------------------------------------------------------------
GENERAL

a.   Bathrooms and restrooms

     Daily:

     o    Wash all mirrors
     o    Wash all basins and hardware
     o    Wash urinals
     o    Wash toilet seats using disinfectant in water
     o    Wash toilet bowls
     o    Damp-wipe, clean and disinfect all tile surfaces

b.   Dusting

(1)  Daily, Weekly:

     All furniture, business equipment and appliances, windowsills and the like
     will be dusted daily with a chemically treated cloth. Desks and tables not
     cleared of paper and work materials will only be dusted where surface is
     exposed.

(2)  Monthly:

     Pipes, ledges, ceiling, moldings, picture frame_ and anything decorative
     above hand-high areas will be cleaned.

c.   Dust-mopping floors

(1)  Daily:

     All noncarpeted floor areas will be dust-mopped with a treated yarn dust
     mop. Floor-dusting will be done after furniture has been dusted.

d.   Waste paper

(1)  daily, monthly: Waste baskets to be emptied daily.

e.   Vacuuming

(1)  daily, weekly: All rugs and carpets in office areas, as well as public
     spaces, are to be vacuumed daily in all traffic areas. Corners,
     hard-to-reach places, and areas under desks, tables and chairs will be
     vacuumed weekly, using accessory tools as required.

f.   Carpet cleaning

(1)  semiannually: All carpeted areas in public corridors will be shampooed once
     every six months.










<PAGE>

g.   Stairways and landings

(1)  weekly: All stairways and landings will be dust-mopped with a treated yarn
     dust mop daily. Railings, ledges, and equipment will be dusted weekly. Spot
     cleaning of walls and doors will be done weekly; these areas will be
     damp-mopped weekly and scrubbed when necessary.

h.   Wet mopping

(1)  daily, as needed: Floors will be scrubbed or wet-mopped whenever required
     to prevent a build-up of wax.

i.   Tile floors

(1)  Waxing and buffing will only be done on an as-needed basis.

j.   Water coolers or fountains

(1)  daily; Water coolers or fountains will be cleaned and polished daily.

k.   Spot cleaning of vertical surfaces

(1)  Walls and woodwork will be spot-cleaned weekly

i.   Entrance lobby

(1)  daily: The entrance lobby will be cleaned daily. Lobby glass and metal will
     be cleaned and dusted daily. The lobby floor and entranceways will be
     cleaned nightly. Directory board glass will be damp-cleaned and wiped.

m.   Polishing

(l)  monthly: Door plates, kick plates, and brass and metal fixtures within the
     building will be wiped daily and polished monthly.

n.   Light fixtures-periodically

(1)  annually: the exterior of all light fixtures will be dusted as needed. The
     entire light fixture will be washed annually.

o.   Venetian blinds

(1)  weekly, annually: Venetian blinds will be dusted weekly and washed
     annually.

p.   Walls, woodwork and partitions

(1)  weekly, quarterly, semi-annually: Finger and hand prints, spots and other
     grimy areas will be removed weekly using a damp cloth or sponge. All walls
     and ceilings will be







<PAGE>

     brushed down with an approved wall duster or a vacuum cleaner every three
     months. Partitions of wood or steel will be washed with a neutral soap
     every six months.

q.   Glass partitions and doors

(1)  weekly: All glass partitions and doors will be damp-cleaned weekly or as
     needed.

r.   HVAC grills

(1)  monthly: All areas around HVAC outlet and return air grill will be cleaned
     once a month.

Window Washing

Inside and outside window washing will be scheduled four times a year
(quarterly). However, first-floor windows will be washed outside once a month,
unless the space is occupied by retail tenants.

Trash Removal

(1)  daily:

a.   Trash will be removed from the premises daily between the hours of 10:00
     p.m. and 7:00 a.m., Monday through Friday.

b.   Trash pickup will be scheduled through the building engineer or management.








<PAGE>

                        EXTENSION AND AMENDMENT OF LEASE

          This Amendment and Renewal of Lease dated December 31, 2002 made
between THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK, a New York
non-profit corporation, having an address at 412 Low Memorial Library, 535 West
116th Street, New York, New York 10027 ("Landlord") and ORTEC INTERNATIONAL,
INC., a ___________ corporation, having an address at 3960 Broadway, 2nd Floor,
New York, New York 10032 ("Tenant").

                                   WITNESSETH

          WHEREAS, Landlord and Tenant entered into a Lease dated as of March
14, 1996 covering certain premises, as more fully described in the Lease, in the
building located at and known as 3960 Broadway, New York, New York, and more
particularly described in the Lease;

          WHEREAS, the Lease was amended by First Amendment of Lease (the "First
Amendment") dated as of April 1, 1998 in which Landlord and Tenant agreed to
expand the premises (as expanded, the "Demised Premises"), as more fully
described in the First Amendment of Lease;

          WHEREAS, the Lease was amended by Renewal and Amendment of Lease (as
amended by the First Amendment and the Renewal and Amendment of Lease, the
"Lease") dated as of June 20, 2001 in which Landlord and Tenant agreed to renew
the term of the Lease;

          WHEREAS, the Lease will expire by its terms on June 30, 2003 and
Tenant has requested that Landlord agree to extend the term of the Lease on
terms other than as set forth in Article 38 (Renewal Option) of the Lease;

          WHEREAS, Landlord and Tenant have agreed to amend the Lease and extend
the term of the Lease, upon the terms and conditions hereinafter set forth;

          WHEREAS, Tenant acknowledges that Tenant is in default under the Lease
in that Tenant has failed to pay rent (the "Past Due Rent") during portions of
the term of the Lease prior to the date hereof, and Tenant agrees to pay the
Past Due Rent upon the terms and conditions hereinafter set forth thereby curing
such default;

          NOW, THEREFORE, in consideration of the premises and other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereby agree as follows:

     1. All capitalized terms utilized herein shall, unless defined herein, have
the meanings ascribed to them in the Lease.







<PAGE>

     2. Landlord and Tenant agree that Article 38 of the Lease is hereby amended
in its entirety and replaced with the following substitute Article 38:

                                   Article 38

                      Renewal Option and Extension of Lease

     Section 38.01 Tenant has advised Landlord that Tenant wishes to renew the
     term of the Lease, as amended hereby, for an additional term of two (2)
     years (the "Renewal Term") commencing on July 1, 2001 and, unless the
     Renewal Term shall sooner cease and expire as provided in the Lease, as
     amended hereby, ending on June 30, 20O3 (the "Renewal Term Expiration
     Date"), upon the same terms, covenants and conditions as contained in the
     Lease, as amended hereby. Provided that from the date hereof through the
     time of the commencement of the Renewal Term, no Event of Default shall
     have occurred and be continuing this Lease, as amended hereby, shall be
     deemed renewed for the Renewal Term. All references in the Lease, as
     amended hereby, to: (i) the Renewal Term shall be deemed to refer to the
     two (2) year period commencing on July 1, 2001 and ending on the Renewal
     Term Expiration Date, and (ii) the Renewal Term Expiration Date shall be
     deemed to be June 30, 2003.

     Section 38.02 The annual Fixed Rent payable by Tenant during each year of
     the Renewal Term shall be in the following amounts:

     Renewal Term Year 1   $289,230.88 per annum, payable in equal monthly
                           installments of $24,102.57 each;

     Renewal Term Year 2   $297,907,86 per annum, payable in equal monthly
                           installments of $24,825.66 each;

     Section 38.03 Tenant has advised Landlord that Tenant wishes to extend the
     term of the Lease, as amended hereby, for an additional term of one (1)
     year (the "Extension Term") commencing on July 1, 2003 and, unless the
     Extension Term shall sooner cease and expire as provided in the Lease, as
     amended hereby, ending on June 30, 2004 (the "Extension Term Expiration
     Date"), upon the same terms, covenants and conditions as contained in the
     Lease, as amended hereby, Provided that from the date hereof through the
     time of the commencement of the Extension Term, no Event of Default shall
     have occurred and be continuing other than the Event of Default existing as
     of the date hereof with respect to Tenant's failure to pay Past Due Rent in
     the amount of $588,527.65, this Lease, as amended hereby, shall be deemed
     renewed for the Extension Term. All references in the Lease, as amended
     hereby, to: (i) the Extension Term shall be deemed to refer to the one (1)
     year period commencing on July 1, 2003 and ending on the Extension Term
     Expiration Date, and (ii) the Extension Term Expiration Date shall be
     deemed to be June 30, 2004.

     Section 38.04 The annual Fixed Rent payable by Tenant during the Extension
     Term shall be in $306,845.04 per annum, payable in equal monthly
     installments of $25,570.42 each.


                                       2





<PAGE>

     3. The Fixed Repayment shall continue to be due and payable monthly by
Tenant throughout the Renewal Term and the Extension Term at the same rale as
provided in the Lease, as amended hereby (as the same may have been adjusted
pursuant to the Lease, as amended hereby). The terms of the Lease, as amended
hereby, relating to Tenant's Work (other than the Fixed Repayment) shall not be
applicable to (a) the Renewal Term or (b) the Extension Term.

     4. In addition to all other sums of money that shall become due from and
payable by Tenant to Landlord under the terms of this Lease, as amended hereby,
Tenant shall pay to Landlord Past Due Rent in the following amounts:

<TABLE>
<S>                             <C>
March 1, 2003                   $73,565.96
April 1, 2003                   $73,565.96
May 1, 2003                     $73,565.96
June 1, 2003                    $36,782.98
July 1, 2003                    $36,782.98
August 1, 2003                  $36,782.98
September 1, 2003               $36,782.98
October 1, 2003                 $36,782.98
November 1, 2003                $36,782.98
December 1, 2003                $36,782.98
January 1, 2004                 $36,782.98
February 1, 2004                $36,782,98
March 1, 2004                   $36,782.98
</TABLE>

The obligations of Tenant under the provisions of this Paragraph 4 with respect
to any Past Due Rent shall survive the termination of this Lease, as amended
hereby. Tenant acknowledges that the payments due pursuant to this Paragraph 4
arise out of Tenant's default and are not in connection with any future term. In
the event of any additional default under this Lease, as amended hereby,
including, but not limited to Tenant's failure to pay Past Due Rent, any
remaining balance of payments due under this Paragraph 4 shall be accelerated
and shall due in their entirety within ten (10) days of Landlord's notice to
Tenant of such additional default.

     5. Except as may be expressly set forth herein, nothing herein contained
shall be construed to (a) modify, waive, impair or affect any of the provisions
contained in the Lease, as amended hereby, (b) waive any present or future
breach of, or default under, the Lease, as amended hereby, or any rights of
Landlord against any person, firm, association or corporation liable or
responsible for the performance thereof, or (c) enlarge or increase Landlord's


                                       3





<PAGE>

obligations or Tenant's rights under the Lease, as amended hereby, or otherwise;
and all provisions qf the Lease, as amended hereby, are hereby declared to be in
full force and effect.

     6. In the event of any default by Tenant in the full performance and
observance of any of its obligations hereunder or in the event any
representation of Tenant contained herein should prove to be untrue, such event
may, at Landlord's option, be deemed to be a default under the Lease, as amended
hereby, and Landlord shall have all of the rights, powers and remedies provided
for in the Lease, as amended hereby, or at law or in equity or by statute or
otherwise with respect to defaults.

     7. This Agreement shall not be effective until executed by and delivered to
all the parties hereto and may be executed in several counterparts, each of
which will constitute an original instrument and all of which will together
constitute one and the same instrument.

     8. The Lease, as amended hereby, constitutes the entire agreement of the
parties hereto with respect to the matters stated herein and may not be
altered, amended, modified or changed orally and any such alteration, amendment,
modification or change shall be in writing and signed by the party against whom
enforcement of any such alteration, amendment, modification or change is being
sought.

     9. The terms, covenants and conditions contained in this Agreement shall
bind and inure to the benefit of the parties hereto and their respective heirs,
executors, administrators, successors and assigns.

     10. This Agreement will for all purposes be construed in accordance with
and governed by the laws of the State of New York applicable to agreements made
and to be performed wholly therein, without giving effect to the
principles-of-law.

     11. Each party represents and warrants to the other party that it has not
dealt with any broker, finder or similar person in connection with this
Agreement. Each party hereby agrees to hold harmless, defend and indemnify the
other party from and against all losses, costs, damages and expenses (including,
without limitation, reasonable attorney's fees) arising out of or in connection
with a breach by the indemnifying party of the foregoing representation.

     12. All references in the Lease to "this Lease" shall hereafter be deemed
to refer to the Lease as amended and modified by this Agreement.

                            [Signature Page Follows]



                                       4








<PAGE>

          IN WITNESS WHEREOF, the parties hereto have caused these presents to
be duly executed as of the 31 day of December 2002.

                                          THE TRUSTEES OF COLUMBIA UNIVERSITY IN
                                              THE CITY OF NEW YORK, Landlord


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


                                          ORTEC INTERNATIONAL, INC., Tenant


                                          By:        Ron Lipstein
                                              ----------------------------------
                                          Name: Ron Lipstein
                                          Title: Vice Chairman/CFO


                                       5