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                                                                Exhibit 10.49.1

                                    LOAN AGREEMENT

    THIS AGREEMENT made and entered into by and between TSI Redfield
Laboratories, Inc., an Arkansas corporation, ("Borrower"), and Simmons First
National Bank, a national banking association ("Lender"), WITNESSETH:

    WHEREAS, Borrower has applied to Lender for a loan ("Loan") in the amount
of $1,050,000.00, to re-finance certain existing indebtedness and to provide
permanent financing for certain recently constructed improvements toBorrower's
operating facility in Redfield, Arkansas, and Lender has agreed to extend the
loan to Borrower upon certain conditions set forth herein.

    NOW, THEREFORE, for and in consideration of the premises and other valuable
considerations, the receipt and sufficiency of which is hereby acknowledged, it
is hereby agreed by and between the parties hereto as follows, to-wit:

    l.  Loan.  Lender agrees to lend to Borrower up to the total sum of
$1,050,000.00 upon the conditions set forth herein.

    2.  Promissory Notes.  Borrower will execute two (2) promissory notes to
evidence the indebtedness in the amount of $700,000.00 ("Note I") and
$350,000.00 ("Note II").  Note I shall bear interest at the rate of ten percent
(10%) per annum, be payable in twelve (12) monthly installments, the first
eleven (11) of which shall be in the amount of $9,250.55 each and the twelfth
(12th) and final installment in the amount of the outstanding principal and
accrued interest and shall contain Lender's customary terms and provisions. 
Note II shall bear interest at the rate of ten percent (10%) per annum, be
payable in one hundred twenty (120) monthly installments, the first one hundred
nineteen (119) of which shall be in the amount of $4,625.28 each and the
one-hundred twentieth (120th) and final installment in the amount of the
outstanding principal and accrued interest and shall contain Lender's customary
terms and provisions.

    3.  Security.  This indebtedness shall be secured by a mortgage
("Mortgage") on certain real property owned by the Borrower in Jefferson County,
Arkansas and a security interest in personal property belonging to Borrower as
described in that certain Security Agreement of even date here with.  In
addition, Genzyme Transgenics Corporation ("GTC") and TSI Corporation,
affiliates of the Borrower, shall unconditionally guarantee all obligations of
the Borrower under all indebtedness of the Borrower to the Lender, including but
not limited to the Loan.

    4.  Financial Information.  Borrower shall cause GTC to deliver to Lender
copies of its 10-Q and 10-K reports filed with the Securities and Exchange
Commission at the time such reports are so filed.  Additionally, Borrower shall 
furnish to Lender, from time to time, such financial information regarding the
operations and conditions of Borrower as may be reasonably requested by Lender.

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    5.  Warranties, Representations and Covenants.  Borrower warrants,
represents and covenants with and unto Lender that commencing upon the date
hereof and continuing until the repayment in full of all indebtedness evidenced
by Note I and Note II:

    (a)  Borrower shall remain in existence and in good standing with the State
of Arkansas. 

    (b)  Borrower warrants and represents that there has been no material
adverse change in its financial condition since the date of the most recent
financial statements delivered to Lender. 

    (c)  Borrower represents that on the date hereof and continuing through the
term of Note I and Note II, that the Borrower shall not: (i) have a receiver
appointed for all or any part of its assets; (ii) assign any of its properties
for the benefit of creditors; (iii) file any voluntary bankruptcy proceeding or
have been the object of any involuntary bankruptcy proceeding; and (iv) have
encountered any material adverse change in its financial condition or property
ownership.

    (d) Borrower covenants, represents and warrants that to the extent it uses,
generates, manufactures, stores or disposes of, on, under or about the property
described in the Mortgage ("Property") or transports to or from the Property any
flammable explosives, radioactive materials, hazardous wastes, toxic substances,
or related materials (hereinafter "Hazardous Materials"), it will do so only in
full compliance with the Comprehensive Environmental Response, Compensation and
Liability Act of 1980, as amended (42 U.S.C. Section 9601 et seq.); the
Hazardous Materials Transportation Act (49 U.S.C. Section 1801, et seq.); the
Resource Conservation and Recovery Act (42 U.S.C. Section 6901 et seq.); and all
other statutes and regulations governing, defining or regulating the manner and
method of storage, transportation or disposition of Hazardous Materials. 
Borrower further agrees to indemnify and hold harmless Lender, its directors,
officers, employees and agents, from and against any and all liability (i)
including foreseeable and unforeseeable consequential damages, directly or
indirectly arising out of use, generation, storage or disposition of Hazardous
Materials by the Borrower or any operator of the Property during Borrower's
ownership thereof, and (ii) including, without limitation, the cost of any
required or necessary remediation, repair, cleanup or detoxification and the
preparation of any closure or other required plans, whether such action is
required or necessary prior to or following transfer of title to the Property,
to the full extent that such action is attributable, directly or indirectly, to
the presence or use, generation, storage, release, threatened release, or
disposal of Hazardous Materials by any person on the Property during Borrower's
ownership thereof, and the Borrower's obligations pursuant to this indemnity
shall survive satisfaction or discharge of this Loan and the Mortgage, and shall
survive, notwithstanding that the alleged liability of the Borrower shall be by
reason of any exercise by it of control or dominion over the Property or the
activities of the Borrower.

    (f) Neither the Borrower nor any of the guarantors shall engage in or be
involved in any transaction, in which the majority ownership of the stock of
Borrower or TSI Corporation is acquired by any person, other than any person
which owned majority interest in such entity on the date of execution of this
Note, without the prior written consent of Lender.

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    6.  Default.  A default by Borrower under the terms of this Agreement shall
constitute a default with regard to any and all indebtedness outstanding
hereunder and Lender may, at its option, thereupon immediately declare all such
indebtedness immediately due and payable, without notice, and may proceed to
enforce its rights and exercise its remedies under the Notes and under the
security therefor, together with any other rights and remedies Lender may have
at law or in equity.

    7.  Continuing Agreement.  This Loan Agreement shall remain in effect 
throughout the term of this loan and any promissory note or notes executed 
pursuant hereto, and any extensions or renewals of this loan  and shall apply 
to all indebtedness of Borrower to Lender arising under this loan, even if in 
excess of $1,050,000.00, the original principal amount.
 
    IN WITNESS WHEREOF, the parties have hereunto placed their hands and seals
and caused this instrument to be executed this 22nd day of May, 1997.



                        TSI REDFIELD LABORATORIES, INC..


                        By  /s/ John B. Green
                            --------------------------------- 
                                John B. Green, Treasurer




                        SIMMONS FIRST NATIONAL BANK


                        By: /s/ John W. Kelly
                            --------------------------------- 
                           Title: Vice President







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