Exhibit 10.16

                            STOCK PURCHASE AGREEMENT


         This STOCK PURCHASE AGREEMENT (the "Agreement"), dated July 22, 1987,

BETWEEN                    MEDICAL STERILIZATION, INC., a New York corporation
                           ("MSI"), with offices at 225 Underhill Boulevard,
                           Syosset, New York 11791

AND                        SUMITOMO HEAVY INDUSTRIES, LTD., a Japanese
                           corporation ("SHI"), with offices at 2-1, Ohtemachi
                           2-chome, Chiyoda-Ku, Tokyo 100, Japan

                              W I T N E S S E T H:

         WHEREAS, the authorized capital stock of MSI consists of 5,000,000
shares of common stock, par value $.01 per share, of which there is issued and
outstanding 2,207,400 shares of common stock, and MSI plans to issue 271,429
shares of its common stock to SHI.

         WHEREAS, SHI desires to purchase and MSI desires to sell 271,429 shares
of its common stock, Par Value $.01 per share (the "Stock") on the terms and
conditions herein set forth;

         NOW, THEREFORE, in consideration of the premises, and the mutual
covenants and agreements herein contained, the parties hereby agree as follows:

         1. ISSUE AND SALE OF STOCK; CLOSING.

            1.1 Sale of Stock; Closing. MSI agrees to issue and sell to SHI
271,429 shares of its Stock for a purchase price of $3.50 per share or a total
purchase price for the 271,429 shares of $950,001.50.

                1.1.1 Delivery of the certificates evidencing the Stock to be
purchased by the Purchaser will be made at a closing (the "Closing"), at the
offices of SHI, 1 World Trade Center, Suite 3669, New York, New York, at 10:00
a.m., local time, on July 30, 1987 or at such other date, time or place as the
parties hereto may agree (the "Closing Date"), against SHI's payment of the
purchase price therefor in the amount of $950,001.50.


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            1.2 Stock Certificate. MSI will deliver to SHI at the Closing one
stock certificate (the "Certificate") for 271,429 shares of Stock registered in
SHI's name.

                1.2.1 The Certificate evidencing the Stock to be delivered to
SHI at the Closing shall bear the following legend, in addition to any legends
required by New York law:

            THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEE REGISTERED
            UNDER THE SECURITIES ACT OF 1933. THE SHARES REPRESENTED BY THIS
            CERTIFICATE MAY NOT BE TRANSFERRED, SOLD, OFFERED FOR SALE, PLEDGED,
            HYPOTHECATED OR OTHERWISE DISPOSED OF UNLESS (A) THEY ARE COVERED BY
            A REGISTRATION STATEMENT, OR POST-EFFECTIVE AMENDMENT THERETO,
            EFFECTIVE UNDER THE SECURITIES ACT OF 1933 OR (B) IN THE OPINION OF
            COUNSEL SATISFACTORY TO MSI, SUCH TRANSFER, SALE, PLEDGE,
            HYPOTHECATION OR OTHER DISPOSITION IS EXEMPT FROM THE PROVISIONS OF
            SECTION 5 OF THAT ACT OR (C) A NO-ACTION LETTER FROM THE SECURITIES
            AND EXCHANGE COMMISSION, SATISFACTORY TO COUNSEL FOR MSI, SHALL HAVE
            BEEN OBTAINED WITH RESPECT TO SUCH TRANSFER, SALE, PLEDGE,
            HYPOTHECATION OR OTHER DISPOSITION.

            1.3 Payment. At the Closing, SHI shall pay to MSI the sum of US
$905,001.50 by bank check.

         2. CLOSING CONDITIONS. SHI's obligation to purchase the Stock provided
for herein shall be subject to the performance by MSI of its agreements in form
and substance satisfactory to SHI which by the terms hereof are to be performed
at or prior to the Closing and to the satisfaction of the following conditions
at or before the Closing:

            2.1 Purchase Permitted by Applicable Laws; Legal Investment. SHI's
purchase of and payment for the Stock (i) shall not be prohibited by Regulations
G, T, U or X of the Board of Governors of the Federal Reserve System, (ii) shall
not be prohibited by any applicable law or governmental regulation, (iii) shall
not subject SHI to any penalty or, in the reasonable judgment of SHI, other
onerous condition under or pursuant to any applicable law or governmental
regulation, and (iv) shall be permitted by the laws and regulations of the
jurisdictions to which SHI is subject.


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                                       -3-


            2.2 Proceedings and Documents. All proceedings taken in connection
with the transactions contemplated by this Agreement, and all documents
necessary to the consummation thereof, shall be satisfactory in form and
substance to SHI.

            2.3 Payment of Fees. All fees and taxes in connection with the
offer, issue, sale and delivery of the Stock and the Certificate or in
connection with the execution, delivery and performance of this Agreement
payable to any governmental or administrative board or body shall have been paid
by MSI.

            2.4 Litigation. At the Closing Date, no suit, action, investigation
or other proceeding will be pending or threatened before any court or
administrative or governmental agency which seeks (or, in the case of an
investigation, may lead to a suit, action or proceeding which seeks) to
restrain, prohibit or obtain damages or other relief in connection with the
consummation of the transaction contemplated by this Agreement.

            2.5 Board of Directors. Immediately after the Closing, a designee of
SHI will be proposed by SHI for the election to the Board of Directors of MSI,
and MSI ensures that such designee will be elected as a board member of MSI at a
special directors meeting to be held as soon as practicably possible after the
Closing.

            2.6 Consents and Approvals. All consents and approvals required by
any court, administrative, governmental authority or regulatory agency to
consummate the proposed transaction will have been obtained.

            2.7 Accuracy of Representations and Warranties. The representations
and warranties of MSI herein contained will be true and correct on the Closing
Date as though made on and as of such date.

            2.8 Actions and Proceedings. MSI shall have performed or complied
with all provisions of this agreement required to be performed or complied with
before the Closing Date, and all actions, proceedings, instruments and documents
required to carry out the transactions contemplated by this Agreement or
incidental hereto and all other related legal matters shall have been completed
in form and substance satisfactory to SHI, and SHI shall have received



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counterpart originals and/or certified or other copies of such documents as SHI
shall reasonably request relative to this Agreement.

         3. REPRESENTATIONS AND WARRANTIES.

            3.1 Representations of SHI. SHI represents and warrants to MSI that:

                3.1.1 The Stock to be acquired by SHI hereunder is being
acquired for its own account (as principal and not as trustee or agent) and is
being acquired by it for investment and not with a view to, or for sale in
connection with, any distribution thereof, but without prejudice, however, to
SHI's right that the disposition of such Stock shall at all times be within its
control. SHI hereby acknowledges that the Stock may be sold only upon
registration thereof under the Securities Act of 1933 as amended (the
"Securities Act"), or in accordance with an available exemption from the
registration requirements thereof, and that the Stock is not registered under
the Securities Act.

                3.1.2 SHI has full legal right, power and authority to enter
into and perform this Agreement and the execution and delivery of this Agreement
by SHI and the consummation of the transactions contemplated hereby have been
duly authorized by the Board of Directors of SHI, and no consent, waiver or
authorization, or filing with any person (including, without limitation, any
governmental authority) is required in connection with the execution, delivery,
performance by or the validity or enforceability against SHI of this Agreement.
This Agreement has been duly executed and delivered by SHI and constitutes a
legal, valid and binding obligation of SHI, enforceable against it in accordance
with its terms, except to the extent that its enforceability may be limited by
applicable bankruptcy, insolvency, reorganization, moratorium and other laws
relating to or affecting creditors' rights generally and by general equity
principles.

            3.2 Representations of MSI. MSI represents and warrants to SHI that:

                3.2.1 MSI is a corporation duly organized, validly existing and
in good standing under the laws of the State of New York, with all the requisite
corporate power and authority to own its properties and to conduct its business
as now and proposed to be conducted. 


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MSI is duly qualified to transact business in and is in good standing in each
jurisdiction in which the failure so to qualify would have a material adverse
effect on its business or properties. Copies of MSI's Restated Certificate of
Incorporation and By-Laws have been delivered to SHI.

                3.2.2 As of the close of business on the day before the Closing
Date, the authorized capital stock of MSI will consist of 5,000,000 shares of
common stock, par value $.01 per share (the "Common Stock"), of which 2,207,400
shares will be issued and outstanding, and 2,000,000 authorized shares of
preferred stock, par value $.01 per share, of which 1,064 shares will be issued
and outstanding. Except as set forth in the Notes to the Financial Statements in
the Annual Report for the year ended December 31, 1986 and the Quarterly Report
for the quarter ended March 31, 1987, no options, warrants or other rights to
purchase, agreements or other obligations to issue, or agreements or other
rights to convert any obligation into, any shares of capital stock of MSI have
been granted or entered into by MSI except warrants to purchase 53,333 shares of
Common Stock granted to Bernard Livingston, Ben Shames and Michael L. Morris and
options to purchase 50,000 shares of Common Stock granted to Kennard H.
Morganstern and Robert S. Luniewski.

                3.2.3 The Stock, when issued and delivered by MSI and paid for
by SHI pursuant to the terms of this Agreement, will be duly authorized, validly
issued, fully paid and non-assessable, free and clear of all liens,
encumbrances, charges and claims, and subject to no restriction on transfer
except as contemplated by this Agreement and will be issued in compliance with
all federal and state securities laws with no personal liability attaching to
the ownership thereof and shall be entitled to all of the special rights set
forth herein.

                3.2.4 MSI has full legal right, power and authority to enter
into and perform this Agreement, and the execution and delivery of this
Agreement by MSI and the consummation of the transactions contemplated hereby
including any increase in shares of Common Stock issued have been duly
authorized by the Board of Directors of MSI and all corporate action on the part
of MSI, its officers, directors and shareholders necessary for the
authorization, execution and delivery of this Agreement and the performance of
all obligations 


<PAGE>
                                       -6-


hereunder and the authorization, issuance and delivery of the Stock being sold
hereunder has been taken prior to the Closing Date and no consent, waiver or
authorization, or filing with any person (including without limitation, any
court, regulatory or administrative agency or governmental authority) is
required in connection with the execution, delivery, performance by, or the
validity or enforceability against MSI of this Agreement. This Agreement has
been duly executed and delivered by MSI and constitutes a legal, valid and
binding obligation of MSI, enforceable against it in accordance with its terms,
except to the extent that its enforceability may be limited by applicable
bankruptcy, insolvency, reorganization, moratorium and other laws relating to or
affecting creditors' rights generally and by general equity principles.

                3.2.5 The execution, delivery and performance of this Agreement
and the consummation of the transactions contemplated hereby do not and will not
(i) violate any provisions of MSI's Restated Certificate of Incorporation or
By-Laws, or (ii) contravene any law, rule or regulation of any state or the
United States or any political subdivision thereof or therein, or any order,
writ, judgment, injunction, decree, determination or award presently in effect,
or (iii) result in, or require, the creation or imposition of any lien, charge,
encumbrance or claim on any of its properties or revenues pursuant to any
contractual obligation to which MSI is a party or by which any of its assets may
be bound or affected.

                3.2.6 No action, suit, litigation, investigation or proceeding
of or before any arbitrator or governmental authority is pending or (to the best
of MSI's knowledge) threatened by or against MSI or against any of its
properties or revenues (i) with respect to this Agreement or any of the
transactions contemplated hereby, or (ii) which, if adversely determined, would
have a material adverse effect on the business, operations, property, prospects
or condition (financial or otherwise) of MSI.

                3.2.7 MSI is not in violation of or default under any provision
of its Restated Certificate of Incorporation or By-Laws or of any contract,
instrument, judgment, order, writ or decree to which it is a party or by which
it is bound or of any provision of any federal or state statute, rule or
regulation applicable to MSI which could be materially adverse to the 


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                                       -7-


business, operations, property, prospects or condition (financial or otherwise)
of MSI, or which could materially adversely affect the ability of MSI to perform
its obligations under this Agreement and the transactions contemplated hereby.

                3.2.8 At the Closing Date, MSI will be in compliance, in all
material respects, with all material laws, ordinances, governmental rules and
regulations to which it is subject, where the failure to so comply would have a
material adverse effect on the business of MSI or would have an effect on the
enforceability against MSI of this Agreement.

                3.2.9 The offer and sale of the Stock hereunder is exempt from
the registration and prospectus delivery requirements of the Securities Act, and
the rules and regulations thereunder and any other applicable securities laws.

                3.2.10 MSI has heretofore delivered to SHI a copy of its 1986
Annual Report to shareholders and its Annual Report on Form 10-K, both
containing (i) its audited balance sheet as of December 31, 1986, and the
related audited statement of loss, statement of shareholders' equity and
statement of changes in financial position for the fiscal year ended December
31, 1986, accompanied by the report of MSI's independent public accountants
thereon, and (ii) its quarterly report on Form 10-Q containing an unaudited
balance sheet at March 31, 1987, and the related unaudited statement of loss for
the three months ended March 31, 1987. Such financial statements fairly present
the financial position of MSI as of the respective dates thereof and the results
of its operations and (to the extent covered thereby) changes in its financial
position and shareholders' equity for the periods indicated, in accordance with
generally accepted accounting principles in U.S.A., which, except as disclosed
therein, have been consistently applied. Except as disclosed in the financial
statements, including the notes thereto, referred to above, since March 31,
1987, there has not been any material adverse change in the general business
affairs, financial position or results of operations of MSI. MSI has no material
liability or obligation, absolute or contingent.

                3.2.11 This Agreement, representations and warranties by MSI and
any exhibits, schedules, attachments, documents, certificates and other written
items and materials 


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                                       -8-


prepared and supplied to SHI by or on behalf of MSI, with respect to the
transactions contemplated hereby, do not and will not, as the case may be,
contain any untrue statement of a material fact or omit to state any material
fact necessary to make the statements contained therein not misleading in the
context made. There is no fact known to MSI which MSI has not disclosed to SHI
in writing and which is reasonably likely to have a material adverse effect on
the financial condition, operating results, assets or business prospects of MSI
or would have an effect on the enforceability against MSI of this Agreement or
any material contract, agreement or instrument to which MSI is a party.

                3.2.12 Copies of MSI's Restated Certificates of Incorporation
and By-Laws heretofore delivered to SHI are true and correct.

                3.2.13 MSI has all governmental licenses and permits necessary
to conduct its business.

         4. REGISTRATION UNDER THE SECURITIES ACT OF 1933.

            4.1 MSI agrees that prior to any filing by it of a registration
statement under the Securities Act, it will, at least 30 days prior to such
filing, notify SHI of its intention to file such registration statement and,
upon the request of SHI, will include in such registration the shares of Stock
issued to SHI, if, in the opinion of counsel for MSI such registration statement
is required to permit sale of such Stock in the manner contemplated by SHI.

            4.2 Whenever pursuant to Paragraph 4.1 a registration statement
relating to any Stock is filed under the Securities Act, amended or
supplemented, MSI shall indemnify and hold harmless SHI and SHI's officers and
directors (or SHI's assignees if SHI can assign registration rights) and
underwriter for SHI, within the meaning of the Securities Act, who may purchase
from or sell for SHI any shares of Stock from and against any and all losses,
claims, damages and liabilities joint or several caused by any untrue statement
or alleged untrue statement of a material fact contained in the registration
statement or any post-effective amendment or supplement thereto or any
registration statement under the Securities Act or any prospectus included
therein required to be filed or furnished by reason of this Paragraph 4 or


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                                       -9-


caused by any omission or alleged omission to state therein a material fact
required to be stated therein or necessary to make the statement therein not
misleading, and MSI will reimburse SHI, each officer, director, underwriter
(within the meaning of the Securities Act) or controlling person for any legal
or other expenses reasonably incurred by them in connection with investigating
or defending any such loss, claim, damage, liability or action, except insofar
as such losses, claims, damages or liabilities are caused by any such untrue
statement or alleged untrue statement or omission or alleged omission based upon
information furnished or required to be furnished in writing to MSI by SHI or
underwriter for SHI expressly for use therein, which indemnification shall
include each person, if any, who controls any such underwriter within the
meaning of such Securities Act; provided, however, that MSI shall not be obliged
so to indemnify SHI or underwriter or controlling person unless SHI or such
underwriter shall at the same time indemnify MSI, its directors, each officer
signing the related registration statement and each person, if any, who controls
MSI within the meaning of such Securities Act, from and against any and all
losses, claims, damages and liabilities caused by any untrue statement or
alleged untrue statement of a material fact contained in any registration
statement or any prospectus required to be filed or furnished by reason of this
Paragraph 4 or caused by any omission to state therein a material fact required
to be stated therein or necessary to make the statement therein not misleading,
insofar as such losses, claims, damages or liabilities are caused by any untrue
statement or alleged untrue statement or omission based upon information
furnished in writing to MSI by SHI or underwriter expressly for use therein.

            4.3 MSI will assist SHI in its filing of a registration statement
relating to the Stock with the Securities and Exchange Commission under the
Securities Act if and when SHI informs MSI of its desire to transfer, sell or
dispose of the Stock, in part or in whole. Any such filing will be at SHI's sole
cost and expense.

         5. COVENANTS OF MSI.

            5.1 Delivery of Financial Statements to SHI. MSI shall deliver to
SHI, so long as SHI holds any common stock;


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                                      -10-


                5.1.1 as soon as practicable after the end of each fiscal year
of MSI, but in any event within 90 days thereafter, a balance sheet of MSI as of
the end of such fiscal year and the related income (loss) statement, statement
of shareholders' equity and statement of changes in financial position for such
fiscal year, together with related notes, all audited and certified by
independent public accountants of nationally recognized standing selected by
MSI;

                5.1.2 as soon as practicable after the end of each of the first
three quarters of each fiscal year of MSI, but in no event within 45 days
thereafter, an unaudited balance sheet as of the end of such quarter together
with related unaudited income (loss) statement and unaudited statement of
changes in financial position for such quarter.

                5.1.3 With respect to the financial statements required by
Paragraph 5.1.2, MSI shall deliver to SHI a certificate executed by the chief
financial officer or President of MSI certifying that such financial statements
were prepared in accordance with generally accepted accounting principles
applied consistently with prior practice for earlier periods and fairly present
the financial condition of MSI and its results of operations for the period
specified, subject to year-end audit adjustments.

            5.2 Delivery of Other Financial Information. MSI shall deliver to
SHI's nominee on the Board of Directors of MSI as such director;

                5.2.1 within 30 days after the end of each month, an unaudited
balance sheet as of the end of such month together with the related income
(loss) statement for such month;

                5.2.2 not later than sixty (60) days prior to the beginning of
each fiscal year of MSI, an annual business plan prepared on a monthly basis and
promptly after preparation, any revisions to such forecasts;

                5.2.3 from time to time, but on a timely basis such other
information and materials, such as reports of adverse developments, copies of
management letters, press releases and registration statements;



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                                      -11-


                5.2.4 such other information relating to the financial
condition, business, prospects or affairs of MSI as may be provided to the Board
of Directors, provided, however, that MSI shall not be obligated to provide
information which it reasonably considers to be confidential.

            5.3 Inspection. MSI shall cooperate with SHI and shall make its
books of account and records and personnel reasonably available to SHI so as to
enable them, at their expense, to conduct a legal and financial audit of MSI
prior to the Closing if they or any of them elect to do so.


         6. MISCELLANEOUS.

            6.1 Expenses. Whether or not the transactions contemplated hereby
are consummated, all cost and expenses incurred by SHI in connection with this
Agreement and the transactions contemplated hereby shall be paid by it and all
expenses incurred by MSI in connection with this Agreement and the transactions
contemplated hereby shall be paid by it.

            6.2 Notices.

                6.2.1 All communications under this Agreement shall be in
writing and shall be mailed by first class mail, postage prepaid,

            (i)      if to SHI, to:
                     Sumitomo Heavy Industries, Ltd.
                     2-1, Ohtemachi 2-chome, Chiyoda-Ku
                     Tokyo 100, Japan
                     Attn:  Managing Director

or at such other address as it may have furnished MSI in writing, or

            (ii)     if to MSI, to:
                     Medical Sterilization, Inc.
                     225 Underhill Boulevard
                     Syosset, New York  11791
                     Attn:  President


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                                      -12-


                     with a copy to:

                     Murtagh, Cohen & Byrne
                     1122 Franklin Avenue
                     Garden City, New York  11530
                     Attn:  Harvey Cohen, Esq.

or at such other address as MSI may have furnished in writing to SHI.

                6.2.2 Any notice so addressed and mailed by registered or
certified mail shall be deemed to have been given when mailed.

            6.3 Survival. All warranties, representations, and covenants made
herein or in any certificate or other instrument delivered by the parties hereto
or on their behalf under this Agreement shall be considered to have been relied
upon and shall survive the delivery of the Stock and payment therefor,
regardless of any investigation made by any such party or on its behalf. All
statements in any such certificate or other instrument shall constitute
warranties and representations by such party hereunder.

            6.4 Amendments, Modifications and Waivers. Any covenant, agreement,
provision or condition of this Agreement may be amended or modified, or
compliance therewith may be waived (either generally or in any particular
instance and either retroactively or prospectively), by (and only by) an
instrument in writing signed by SHI and MSI.

            6.5 Assignability; Successors and Assigns. This Agreement shall not
be assignable by MSI without the prior written consent of SHI or by SHI without
the prior written consent of MSI; provided, however, that SHI may assign its
interest in this Agreement to any of its affiliates if such affiliate undertakes
to perform SHI's obligations hereunder. This Agreement shall be binding upon and
shall inure to the benefit of the parties hereto and their respective successors
and assigns.

            6.6 Severability. Should any part of this Agreement for any reason
be declared invalid, such decision shall not affect the validity of any
remaining portion, which remaining portion shall remain in full force and effect
as if this Agreement had been executed 


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                                      -13-


with the invalid portion thereof eliminated and it is hereby declared the
intention of the parties hereto that they would have executed the remaining
portion of this Agreement without including therein any such part or parts which
may, for any reason, be hereafter declared invalid.

            6.7 Captions. The descriptive headings of the various Paragraphs or
parts of this Agreement are for convenience only and shall not affect the
meaning or construction of any of the provisions hereof.

            6.8 Governing Law. This Agreement shall be governed by and construed
in accordance with the laws of the State of New York.

            6.9 Entire Agreement. This Agreement, together with the Stock, is
intended by the parties as a final expression of their agreement and intended to
be a complete and exclusive statement of the agreement and understanding of the
parties hereto in respect of the subject matter contained herein and therein.
There are no restrictions, promises, warranties and undertakings, other than
those set forth or referred to herein and therein. This Agreement, together with
the Stock, supersedes all prior agreements and understandings between the
parties with respect to such subject matter.

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date first above written.

                                       MEDICAL STERILIZATION, INC.


                                       By:________________________________
                                                Kennard H. Morganstern
                                                Chairman and President


                                       SUMITOMO HEAVY INDUSTRIES, LTD.


                                       By:________________________________
                                                Atsushi Naito
                                                Managing Director


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                                      -14-



                                   SIGNATURES

         Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized on March 27, 1989.

                                             (Registrant) MEDICAL
                                             STERILIZATION, INC.

                                             By:______________________________
                                                   Kennard H. Morganstern,
                                                   President

         Pursuant to the requirements of the Securities Exchange Act of 1934,
this report has been signed below by the following persons on behalf of the
Registrant and in the capacities and on the dates indicated.

<TABLE>
<CAPTION>
              Signature                                    Title                              Date
              ---------                                    -----                              ----
<S>                                 <C>                                                   <C> 
                                    President, Chairman of the Board of Directors,        March 27, 1989
_______________________________     Principal Executive Officer & Director
(Kenneth H. Morganstern)

                                    Treasurer, Principal Financial and Accounting         March 27, 1989
_______________________________     Officer
(John M. Sharpe, Jr.)

_______________________________
(Harvey Cohen)                      Director                                              March 27, 1989


_______________________________     Director                                              March 27, 1989
(John R. Hoover)


_______________________________     Director                                              March 27, 1989
(Yoshiyuki Nagashima)


_______________________________     Director                                              March 27, 1989
(Kenneth W. Rind)


_______________________________     Director                                              March 27, 1989
(Albert T. Sommers)
</TABLE>

393LMM5962/1.198711-1