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                                                                 Exhibit 10.49.6

                                UNCONDITIONAL GUARANTY

KNOW ALL MEN BY THESE PRESENTS:   

    For a valuable consideration and specifically for the purpose of inducing
Simmons First National Bank, a national banking institution, ("Lender") to loan
and to continue to loan funds to TSI Redfield Laboratories, Inc., an Arkansas
corporation ("Borrower"), the undersigned ("Guarantor"), does hereby agree for
itself, its successors and assigns with and unto the Lender as follows:

    1.  Guarantee of Payment.  The Guarantor hereby unconditionally guarantees
the full and timely payment of all indebtedness of every kind and nature of the
Borrower to the Lender, direct or indirect, without limit as to the amount of
such indebtedness, whether now existing or hereinafter incurred, whether or not
such indebtedness shall be similar or dissimilar, related or unrelated to any
existing indebtedness, including but not limited to an indebtedness evidenced by
two promissory notes in the amount of $700,000.00 and $350,000.00, of even date
herewith (collectively "Indebtedness"). 

    2.  Guarantee of Performance. The Guarantor further unconditionally
guarantees prompt, timely, and complete performance of and compliance by
Borrower of all the terms and conditions contained in any of the instruments and
documents, including but not limited to promissory notes, mortgages, security
agreements, pledges and collateral assignments ("Loan Documents"), given in
connection with the origination, extension or collection of the Indebtedness;
the timely payment of all real and personal property taxes, special assessments,
and premiums for insurance of every kind required under the terms of any of the
Loan Documents; and generally, the performance of each and every other covenant
and condition set forth and contained in the Loan Documents.

    3.  Waivers of Notice and Additional Authority.  The Guarantor waives
notice of any default by Borrower upon the Indebtedness or of any transfer of
the title to any property securing any of the Indebtedness pursuant to any Loan
Document, and the Lender, or the holder of any note evidencing any of the
Indebtedness, shall not be required to resort to any collateral other than this
guaranty or attempt to recover upon the liability of Borrower in any way as a
condition prerequisite to recovering upon this Guaranty.  The Lender and any
subsequent holder of any note evidencing any of the the Indebtedness, may,
without notice to the Guarantor, deal with the Borrower, or any one on its
behalf or if title to any property shall have been transferred, the owner
thereof, from time to time with respect to any of the Indebtedness and the
security therefor in any manner whatsoever, including the release of any obligor
or of any of the collateral, and Guarantor hereby specifically waives each and
every defense predicable upon such dealing including, without limitation, the
release of any part of the security for any of the Indebtedness or any of the
obligors thereon, except the defense of actual payment in cash on the
Indebtedness.      

    4.  Continuation of the Guaranty.  This Guaranty shall continue with
respect to the Indebtedness, and all continuations, extensions or renewals
thereof, in favor of the Lender and all subsequent holders of any note
evidencing any of the Indebtedness, notwithstanding that the 

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Borrower shall have conveyed its title and notwithstanding that other obligors
may have assumed or guaranteed payment.  It is understood and agreed that this
Guaranty shall, in all respects, run in favor of the holders of any note
evidencing any of the Indebtedness and notice to the Guarantor of any transfer,
endorsement or assignment of any such note shall not be required.

    5.  Waiver of Acceptance.  The Guarantor further waives notice of the
acceptance of this Guaranty by the Lender and presentment, demand, notice of
nonpayment, notice of extension of the time of payment or of any dealings with
any obligor or any collateral.

    6.  Additional Covenants of Guarantor.  The Guarantor agrees that the
liability of the Guarantor hereunder shall not in anyway be released,
diminished, impaired, reduced, or affected by:

    (a)  The taking or accepting of any other security or guaranty for any or
all of the Indebtedness;

    (b)  Any release, withdrawal, surrender, exchange, substitution,
subordination, or loss of any security or other guaranty at any time existing in
connection with any or all of the Indebtedness; any partial release of the
liability of any other Guarantor hereunder or under any of the Loan Documents
had, or to be had, in connection with, or as security for, any of the
Indebtedness, or the corporate dissolution, insolvency, bankruptcy, disability,
or lack of authority of Borrower, Guarantor, or any other guarantor or any party
at any time liable for the payment of any or all of the Indebtedness, whether
now existing or hereafter occurring;

    (c)  Any renewal, extension, modification, or rearrangement of the payment
of any or all of the Indebtedness, or the performance of any covenant contained
in any Loan Document had, or to be had, in connection with, or as security for,
the Indebtedness, either with or without notice to, or consent of, such
Guarantor or any adjustment, indulgence, forbearance, or compromise that may be
granted or given by Lender to any party; or

    (d)  Any neglect, delay, omission, failure, or refusal of Lender to take or
prosecute any action for the collection of any of the Indebtedness or to
foreclose or take or prosecute any action in connection with any lien, right, or
security existing or to exist in connection with, or as security for, any of the
Indebtedness; or to take any action hereunder; it being the intention hereof
that Guarantor shall remain liable as principal until the full amount of the
Indebtedness, together with interest, and any other sums due or to become due
upon or in connection with any of the same, shall have been fully paid,
performed and observed by Borrower.

    IN WITNESS WHEREOF, the undersigned has caused these presents to be
executed this 22nd day of May, 1997.


                             TSI CORPORATION, INC.


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