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                                                                  EXHIBIT 10.31



                                    AMENDMENT

        THIS AMENDMENT effective the 30th day of April, 2001 is by and between
WellCheck, Inc. (the "Company") and GMR Marketing Inc., a Wisconsin corporation
("GMR").

                                   WITNESSETH:

        WHEREAS, GMR entered into a letter agreement with Company dated January
23, 2001, pursuant to which GMR engaged the Company to perform lipid, glucose
and blood pressure screenings and other services in connection with the Pfizer
Screen Test for Health 2001 (the "Program");

        WHEREAS, the Company has collected and will continue to collect
participant data in connection with the Program, including the names, addresses,
demographic information, answers to risk assessment questionnaires, test results
of participants and summaries and reports ("Participant Data"); and

        WHEREAS, GMR and Company acknowledge that Pfizer, Inc. ("Pfizer") owns
the Participant Data, and that GMR and the Company should take all steps
consistent with Pfizer's ownership rights in the Participant Data.

        NOW THEREFORE, in consideration of the foregoing and of the mutual
covenants and agreements hereinafter contained, the parties agree as follows:

        1. Ownership of Participant Data. The paragraph denoted as Participant
Data in Exhibit A of the Letter Agreement is hereby deleted and the following
text is inserted in its place:

                Participant Data. GMR and Company acknowledge that any
        participant data collected in connection with the Screenings, including
        names, addresses, demographic information, answers to risk assessment
        questionnaires, test results and reports and summaries ("Participant
        Data") shall belong to Pfizer, Inc. Company agrees to use the
        Participant Data only in accordance with Pfizer's instructions and in
        accordance with applicable laws and each party's respective privacy
        policies.

                To this end, all Participant Data meeting the definition of
        "Works for Hire" as set forth in the Copyright Act of 1976 shall be
        deemed "Works for Hire" for the benefit of Pfizer. To the extent the
        Participant Data might not be considered "Works for Hire," Company
        hereby assigns to Pfizer all of its right, title and interest in the
        Participant Data.

        2. Further Assurance. Company shall, from time to time, take such action
as Pfizer requests in order to ensure Pfizer's ownership and control over the
Participant Data, including sending the Participant Data.

        3. Counterparts. The Amendment may be executed in counterparts each of
which when so executed and delivered shall be deemed to be an original and all
of which together shall constitute one instrument.


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



                                            GMR MARKETING INC.


                                            By:  /s/  Bryan J. Buske
                                               --------------------------------
                                            Name:  Bryan J. Buske
                                            Title: Chief Operating Officer


                                            WELLCHECK, INC.


                                            By:  /s/  Warren E. Pinckert II
                                               --------------------------------
                                            Name:  Warren E. Pinckert II
                                            Title: President



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