PROMISSORY NOTE

$1,300,000                                                      December 9, 1998


      FOR VALUED RECEIVED, Medical Sterilization, Inc. ("Maker"), a New York
corporation, with offices at 225 Underhill Boulevard, Syosset, New York 11791,
promises to pay to the order of TFX Equities, Inc. ("Payee"), the sum of
$1,300,000 together with interest on the unpaid balance as set forth below. All
sums are payable by mail to the Payee at 155 South Limerick Road, Limerick,
Pennsylvania 19468, Attention: Treasury. The issuance of this instrument shall
be construed as a discharge of all rights, claims, or demands that Payee may
have against Maker under those certain Promissory Notes issued by Maker to Payee
dated August 12, 1998, September 30, 1998, October 26, 1998 and November 18,
1998, with the exception of accrued interest thereon.

                                    Interest

      1. The unpaid principal balance shall bear interest at the rate of 8%.
Interest is calculated on the basis of actual days elapsed divided by 360 days
per year.

                        Payment of Principal and Interest

      2. The outstanding principal of this Note and interest then due shall be
due and payable on January 3, 2000. This Note may be prepaid in whole or in part
at any time, provided interest accrued on the amount prepaid is paid at the same
time.

      3. Interest shall be payable monthly on the last day of each month, first
payment being due December 31, 1998.

                                     Default

      4. On default of any payments of interest or principal due or other
default under this Note and the failure of Maker to cure that default within
five (5) days after receipt by Maker at its address, above, of a written notice
of such default addressed to its Chief Financial Officer, the Payee, at its
election, may accelerate the due date of the entire principal, in which event
the remaining unpaid balance of principal, and interest accrued to that date,
shall become immediately due and payable. The dissolution, termination of
existence, insolvency, business failure, appointment of receiver for any part of
the property of, assignment for the benefit of creditors by, or commencement of
any proceedings in bankruptcy or insolvency by or against Maker and which is not
dismissed within thirty (30) days shall be a default under this Note. The
default by the Maker under any other agreement or instrument for borrowed money
shall be a default hereunder.
<PAGE>

                                     Waiver

      5. Except as otherwise provided in this Note, Maker, sureties, and
endorsers of this Note severally waive demand, notice of dishonor, diligence in
collecting, grace, and notice of protest. Any failure by Payee to exercise any
right hereunder shall not be construed as a waiver of the right to exercise the
same or any other right at any time, or from time to time thereafter.

                                 Attorneys' Fees

      6. If this Note is not paid at maturity and is placed in the hands of an
attorney for collection, or if it is collected through a bankruptcy court, a
probate court, or any other court after maturity, then the Payee shall be
entitled to reasonable attorneys' fees.

                           Compliance With Usury Laws

      7. All agreements between the Maker and the Payee are hereby expressly
limited so that in no contingency or event shall the amount paid or agreed to be
paid to the Payee for the use, forbearance, or detention of the money to be
loaned under this Note exceed the maximum amount permissible under the laws of
Pennsylvania. If, at the time of any interest payment, the payment amount due
under this Note exceeds the legal limit, the obligation shall be reduced to the
legal limit. If the Payee should ever receive as interest an amount that exceeds
the highest lawful rate, the amount that would be excessive as interest shall be
applied to the reduction of the principal amount owing under this Note, and not
to the payment of interest.

                                 Choice of Laws

      8. This Note and the rights and duties of the parties hereto shall be
construed and enforced in accordance with the laws of the Commonwealth of
Pennsylvania.

      9. Maker represents and warrants that this Note has been duly authorized
by all proper corporate authority of Maker and is the valid, legal and binding
obligation of Maker enforceable against Maker in accordance with its terms.

      IN WITNESS WHEREOF, the Maker has caused this Note to be signed by its
President and Chief Financial Officer and its corporate seal to be affixed
hereto this 8th day of December, 1993.


ATTEST:                                 MEDICAL STERILIZATION, INC.


/s/ [ILLEGIBLE]                         By: /s/ D. Michael Deignan
------------------------                    ------------------------------------
                                        Name:  D. Michael Deignan
                                        Title: CEO