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                                                                   EXHIBIT 10(p)

                            SPLIT DOLLAR AGREEMENT


     Agreement made the  23rd  day of October, 1996, by and between Gamma
Biologicals, Inc. and Raul F. Alvarez.

     WHEREAS, Raul F. Alvarez (hereinafter sometimes called "Alvarez")
previously assigned to Gamma Biologicals, Inc. (hereinafter called "the
Corporation") without consideration his entire interest in the insurance policy
on his own life issued by the Massachusetts Mutual Life Insurance Company
(Policy Number 9 890 347) in the face amount of $500,000 (hereinafter called
"the Policy");

     WHEREAS, Raul F. Alvarez is a valued employee and/or director of the
Corporation, which wishes to retain the benefit of his services;

     NOW, THEREFORE, it is agreed between the two parties hereto as follows:

                                  Article 1.

     As soon as possible, the corporation shall cause the right to the death
benefits payable under the Policy to be endorsed pursuant to the provisions of
Articles 3 and 10 of this Agreement.

                                  Article 2.

     The Corporation will be the owner of the Policy and it may exercise all the
rights of ownership with respect to the Policy except as otherwise hereinafter
provided.

                                  Article 3.

     The right to designate the beneficiary or beneficiaries to receive any
proceeds payable under the Policy in excess of the amount of proceeds payable to
the Corporation under Article 10(B) of this Agreement, as well as the right to
elect the settlement option with respect to such portion of such proceeds, shall
remain with Alvarez.

                                  Article 4.

     All dividends declared by the Massachusetts Mutual Life Insurance Company
on the Policy or any part thereof as may be necessary, shall be applied to
purchase one-year term insurance on the life of Raul F. Alvarez in an amount
equal to the guaranteed cash value of the Policy as of the end of the next
Policy anniversary and any balance of the dividend shall be applied to buy
additional paid-up insurance.  Whenever the dividend is not adequate to purchase
the required amount of term insurance, the entire dividend shall be applied to
purchase whatever amount of term insurance the dividend will purchase.
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                                  Article 5.

     All premiums due on the Policy shall be paid by the Corporation.  However,
Alvarez agrees to reimburse the Corporation within 30 days of each premium
payment an amount such that for federal income tax purposes the reimbursement
for each year is equal to the value of the economic benefit of the life
insurance protection enjoyed by Alvarez under the terms of this Agreement.  For
purposes of this Agreement, the term "net premium payment" means such part of
each gross premium which is not reimbursable to the Corporation by Alvarez
pursuant to the preceding sentence.

                                  Article 6.

     Alvarez shall be obligated to repay the Corporation the amount of the
aggregate net premium payments under Article 5 of this Agreement, plus interest
on each net premium payment calculated at the rate of 3% per annum.  This
obligation of Alvarez to the Corporation shall be payable as provided in
Articles 10, 11(e) and 12 of this Agreement.

                                  Article 7.

     The Corporation may add a rider to the Policy for its own benefit.  Upon
written request made by Alvarez, the Corporation may add a rider to the Policy
for his benefit.  Any additional premium for any rider which is added to the
Policy shall be paid by the party which will be entitled to receive the proceeds
of the rider.

                                  Article 8.

     A.  The Corporation shall have the right to obtain loans secured by the
Policy.  These loans may be obtained either from the Massachusetts Mutual Life
Insurance Company or from others.  The Corporation shall have the right to
assign the Policy as security for the repayment of such loans.  The amount of
such loans together with the interest thereon shall at no time exceed the cash
surrender value of the Policy as of the date to which the premiums on the Policy
have been paid.  All interest charges with respect to any such loans shall be
paid by the Corporation.  The Corporation may also consent to policy loans to
Alvarez, in which case all interest charges with respect to any such policy
loans shall be paid by Alvarez, unless otherwise agreed to by the Corporation.

     B.  If the Policy is assigned or is encumbered in any way, other than by a
policy loan, on the date of the death of Raul F. Alvarez, the Corporation will
promptly take all steps which may be necessary to secure release or discharge of
the assignment or encumbrance so that the portion of the death proceeds payable
under the Policy to the beneficiary or beneficiaries named therein will be paid
promptly.
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                                  Article 9.

     Except as otherwise herein provided, the Corporation agrees that while this
Agreement remains in force and effect it will not, without the consent of
Alvarez, transfer, assign or terminate the Policy.

                                  Article 10.

     A.  Upon the death of Raul F. Alvarez, the Corporation will promptly take
all steps which may be necessary to obtain the death benefits provided under the
Policy.

     B.  Upon the death of Raul F. Alvarez, the Corporation shall be entitled to
receive a portion of the death benefits provided under the Policy.  The amount
to which the Corporation will be entitled shall be the amount of its aggregate
net premium payments pursuant to Article 5 of this Agreement, plus the
aggregate amount of any interest charges in respect of any policy loans to
Alvarez paid by the Corporation pursuant to Article 8 of the Agreement, less the
amount of any indebtedness which may exist against the Policy and any interest
due on such indebtedness (but only to the extent the proceeds of such
indebtedness were provided to the Corporation), plus interest on each net
premium payment and interest payment made by the Corporation in respect of any
policy loans to Alvarez calculated at the rate of 3% per annum.  The amount to
which the Corporation will be entitled will not, however, exceed the cash value
of the Policy (without reduction for any policy loans or other indebtedness
which may exist against the Policy) at the end of the policy year in which the
death of Raul F. Alvarez occurs, plus the aggregate amount of interest payments
made by the Corporation in respect of any policy loans to Alvarez, plus interest
on each net premium payment and interest payment made by the Corporation in
respect of any policy loan to Alvarez calculated at the rate of 3% per annum.
The receipt of this amount by the Corporation shall constitute satisfaction of
this obligation of Alvarez under Article 6 of this Agreement.

     C.  Upon the death of Raul F. Alvarez, the beneficiary or beneficiaries
named in accordance with the provisions of Article 3 of this Agreement shall be
entitled to receive the amount of the death benefits provided under the Policy
in excess of the amount payable to the Corporation under paragraph B of this
Article.

                                  Article 11.

     This Agreement shall terminate on the occurrence of any of the following
events:  (a)  cessation of the business of the Corporation;  (b)  written notice
given by Alvarez to the Corporation;  (c)  bankruptcy, receivership or
dissolution of the Corporation;  (d)  upon the election of aggrieved party if
either the Corporation or Alvarez fails for any reason to make the payment or
reimbursement required by Article 5 of this Agreement toward payment of any
premium due on this Policy, provided that any election to terminate this
Agreement under this clause must be made within 90 days after the failure to
make the required payment or reimbursement occurs;  (e)  repayment in full by
Alvarez 
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of the aggregate net premium payments made by the Corporation under Article 5 of
this Agreement and the aggregate interest payments made by the Corporation in
respect of any policy loans to Alvarez under Article 8 of this Agreement, plus
interest on each net premium payment and interest payment calculated at the rate
of 3% per annum, provided that upon receipt of such repayment the Corporation
shall transfer ownership of the Policy to Alvarez.

                                  Article 12.

     If this Agreement is terminated under paragraph (a), (b), (c), or (d) of
Article 11, Alvarez shall have the option to pay the Corporation, within 90 days
of such termination, the amount of the aggregate net premium payments made by
the Corporation under Article 5 of this Agreement, plus the amount of the
aggregate interest payments made by the Corporation in respect of any policy
loans to Alvarez under Article 8 of this Agreement, plus interest on each such
net premium payment and interest payment calculated at the rate of 3% per annum.
If the Policy is encumbered by a policy loan at the time ownership is to be
transferred, the Corporation shall either remove the encumbrance or reduce the
price to be paid for the Policy by the amount of the indebtedness (but only to
the extent the proceeds of such indebtedness were provided to the Corporation).
If the Policy is assigned to a third party at the time ownership is to be
transferred, the Corporation shall take all steps necessary to secure release of
the assignment.  If Alvarez does not exercise his option to acquire the Policy,
ownership of the Policy by the Corporation shall constitute satisfaction of the
obligation of Alvarez to the Corporation under Article 6 of this Agreement.

                                  Article 13.

     This Agreement shall not be modified or amended except by a writing signed
by the Corporation and by Alvarez.  This Agreement shall be binding upon the
heirs, administrators or executors and the successors and assigns of each party
to  this Agreement.

                                  Article 14.

     This Agreement shall be subject to and shall be construed under the laws of
the State of Texas.
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     IN WITNESS WHEREOF, the parties hereto have executed this Agreement at
Houston, Texas.



                                    /s/ Raul F. Alvarez
                                    -------------------------------
                                    Raul F. Alvarez

                                    Gamma Biologicals, Inc.


                                    By:  /s/ Margaret J. O'Bannion
                                       ----------------------------
                                    Margaret J. O'Bannion
                                    Vice President - Finance