Document:

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                                                                   Exhibit 10.53

                               GUARANTY AGREEMENT

      This GUARANTY AGREEMENT (this "Guaranty") is entered into by KEITH RAYMOND
DREW ("Guarantor") in favor of TEXAS MEZZANINE FUND INC., a Texas corporation
("Lender").

                                   WITNESSETH:

      WHEREAS, Drew Scientific, Inc., a Texas corporation ("Borrower"), desires
to borrow from Lender an aggregate principal sum of Five Hundred Fifty-Eight
Thousand and No/100 Dollars ($558,000.00) (the "Loan");

      WHEREAS, the Loan is evidenced by a promissory note in the stated
principal amount of Five Hundred Fifty-Eight Thousand and No/100 Dollars
($558,000.00) (the "Note") executed by Borrower in favor of Lender;

      WHEREAS, said Note is to be executed and delivered pursuant to the terms
of a Loan Agreement dated of even date herewith between Borrower and Lender (the
"Loan Agreement") (The Note, the Loan Agreement and any of the other documents
executed in connection with the Loan are hereinafter collectively referred to as
the "Loan Documents"); and

      WHEREAS, the Lender requires, as a condition precedent to funding the
Loan, a guaranty in the form hereof be executed by the undersigned.

      NOW, THEREFORE, in consideration of the premises and to induce the Lender
to enter into the Loan, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the undersigned hereby
agrees as follows:

      1. Guaranteed Indebtedness. Guarantor hereby guarantees to Lender and to
every subsequent holder or holders of the Note that (a) the principal of and
interest on, and attorneys' fees provided in the Note will be promptly paid when
due in accordance with the provisions thereof, or, in the case of extension of
time of payment, in whole or in part of the Note, all sums will be promptly paid
when due in accordance with the terms of the extensions, (b) all covenants and
agreements of the Borrower contained in the Loan Documents will be duly and
promptly observed and performed, and (c) all additional amounts owing or which
hereafter become owing by the Borrower under the terms of the Loan Documents
will be promptly paid when due.

      2. Guaranty of Payment and Performance: Waiver of Defenses. The
obligations of the Guarantor shall be performable without demand of Lender. The
obligations of the Guarantor hereunder shall not be affected by or dependent
upon the genuineness, validity, regularity or enforceability of the Loan
Documents or any other circumstance which might otherwise constitute a legal or
equitable discharge of a surety or a guarantor. The Guarantor hereby (except as
otherwise provided herein) waives diligence, presentment, demand or payment,
protest, all notices (whether of nonpayment, dishonor, protest or otherwise)
with respect to the Note, notice of acceptance of this Guaranty and of the
incurring by the Borrower of any of the obligations hereinbefore mentioned, and
all rights to require the Lender to (a) proceed against the Borrower, (b)
proceed against or exhaust any collateral held by the Lender to secure the
payment of the indebtedness guaranteed hereby, or (c) pursue any other remedy it
may now or hereafter have against the Borrower or any other endorser, guarantor
or surety. Guarantor waives all defenses given to sureties or guarantors at law
or in equity other than the actual payment of the indebtedness guaranteed hereby
and Guarantor waives all defenses based upon questions as to the validity,
legality or enforceability of the Loan and/or the obligations in connection with
the Loan and agrees that Guarantor shall be primarily liable hereunder.

      3. Extensions or Modifications of Obligations. The Guarantor hereby agrees
that, at any time or from time to time, without notice or the consent of the
Guarantor, Lender may do any of the following acts without affecting the
liability of the Guarantor:

      (a) Extend the time for payment of the principal of or interest on the
Note, or any part thereof, or renew the Note in whole or in part, or accept
another note containing other or different provisions in substitution therefor;

GUARANTY AGREEMENT - Page 1

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      (b) Extend the time for, waive, renew, rearrange, modify or amend (whether
material or otherwise), any of Borrower's covenants, agreements, duties or
obligations contained in any of the Loan Documents;

      (c) Accelerate the maturity of the Note as provided therein or in the Loan
Agreement or any and all other Loan Documents;

      (d) Modify, exchange, surrender, abandon or release any security for the
Note;

      (e) Foreclose on any security for the Note in any manner authorized by law
or the Loan Documents;

      (f) Waive any condition precedent to the making of any advance to Borrower
required by the terms of any of the Loan Documents or make such advance
notwithstanding the existence at the time of such advance of an Event of Default
or potential default under any of the Loan Documents; or

      (g) Do any other act, or make any other agreement with the Borrower or any
other party interested in property given as security for the Loan, or with any
endorser, guarantor or surety who may be liable to pay the indebtedness
guaranteed hereby in whole or in part, as Lender may deem necessary and
appropriate.

In the event of any extension or modification of any of the indebtedness or
obligations of Borrower, this Guaranty shall also cover, and Guarantor hereby
guarantees the timely payment and performance of the indebtedness and
obligations of Borrower as so extended or modified.

      4. Subordination. Any indebtedness of the Borrower now or hereafter held
by the Guarantor is hereby subordinated to all indebtedness of the Borrower to
the Lender guaranteed hereby and such indebtedness of the Borrower shall be
collected, enforced, and received by the Guarantor as trustee for the Lender,
but without reducing or affecting in any manner the liability of the Guarantor
under the other provisions of this Guaranty. So long as any amount of the Loan
remains outstanding and unpaid, Guarantor shall not be subrogated to any rights
of Lender provided in the Loan Documents against Borrower or any property
securing the Loan.

      5. Costs and Attorneys' Fees. If this Guaranty shall be placed in the
hands of an attorney for collection or should it be collected by legal
proceedings or through any probate or bankruptcy court, the Guarantor agrees to
pay to the Lender all costs, reasonable attorneys' and collection fees incurred
in connection therewith.

      6. Assignability and Successors. The Lender may assign its rights
hereunder in whole or in part, and upon any such assignment all the terms and
provisions of this Guaranty shall inure to the benefit of such assignee, to the
extent so assigned. The terms used to designate any of the parties herein shall
be deemed to include the heirs, legal representatives, successors and assigns of
such parties; and the term "Lender" shall include, in addition to Texas
Mezzanine Fund Inc., any lawful owner, holder or pledgee of any indebtedness
guaranteed hereby.

      7. Severability. The Lender is relying and is entitled to rely upon each
and all of the provisions of this Guaranty; and accordingly, if any provision
or provisions of this instrument should be held to be invalid or ineffective,
then all other provisions shall continue in full force and effect to the same
extent and in the same manner as though such invalid or unenforceable provision
had never been contained herein.

      8. Representations and Warranties. The Guarantor represents and warrants
to the Lender that (a) this Guaranty is a legal, valid and binding obligation of
Guarantor, enforceable against Guarantor in accordance with its terms; (b) the
execution, delivery, and performance by Guarantor of this Guaranty does not and
will not violate any authority having the force of law or any indenture,
agreement, or other instrument to which Guarantor is a party or by which
Guarantor or any of the properties or assets of Guarantor are or may be bound;
(c) there are no actions, suits or proceedings pending, or to the knowledge of
Guarantor, threatened against or affecting Guarantor or Borrower; (d) Guarantor
shall not, without the prior written consent of Lender, sell, lease, assign,
encumber, transfer or otherwise dispose of all or a substantial or material part
of Guarantor's assets other than in the ordinary course of Guarantor's business;
(e) all balance sheets, earning statements and other financial data which have
been furnished by Guarantor to

GUARANTY AGREEMENT - Page 2

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Lender to induce it to enter into this Guaranty or the Loan (i) are true and
correct in all material respects, having been prepared in accordance with
generally accepted accounting practices applied on a consistent basis throughout
the period covered thereby, (ii) fairly represent the financial condition of
Guarantor and the results of Guarantor's operations for the periods for which
the same are furnished, and (iii) since the date thereof, there has been no
material adverse change in the financial condition of Guarantor; (f) all other
information, reports and other papers and data furnished to Lender by or on
behalf of Guarantor are or shall be at the time the same are so furnished,
accurate and correct in all material respects and complete insofar as necessary
to give Lender a true and accurate knowledge of the subject matter; and (g)
Guarantor is solvent.

      9. Further Assurances. Guarantor agrees to execute, re-execute and/or
initial any such document or instrument as may be requested by Lender in order
to (a) correct any errors or omissions in this Guaranty or any other Loan
Document, whether such error or omission is due to the unilateral mistake of
Lender, mutual mistake on the part of Lender and Borrower or Guarantor or any
other guarantor, clerical mistake, calculation error, computer malfunction,
printing error or similar error, or (b) give further assurances of any of the
rights granted or provided for in this Guaranty. Guarantor further agrees that
Lender shall not be liable to Guarantor for any damages incurred by Guarantor
that are directly or indirectly caused by any such mistake, error or omission.

      10. Financial Reports. Within thirty (30) days of Lender's request,
Guarantor shall provide to Lender current (i.e., within 90 days) financial
statements (all in form and substance and in reasonable detail satisfactory to
Lender), and copies of filed tax returns. Guarantor shall also provide Lender
with such other information respecting the business, properties or condition or
the operations, financial or otherwise, of Guarantor, as Lender may from time to
time reasonably request.

      11. Rights Against Borrower or Collateral. The Guarantor agrees that
Lender, in its discretion, may (a) bring suit against the Guarantor and any
other endorser, guarantor, or surety of the Note jointly and severally or
against any one or more of them, in either case with or without joinder of the
Borrower, (b) compound or settle with the Borrower, the Guarantor or any other
endorser, guarantor or surety for such consideration as the Lender may deem
proper, (c) release the Borrower, the Guarantor or any other endorser,
guarantor, or surety of the Note from liability thereunder, or (d) release or
abandon any property securing the indebtedness hereby guaranteed or any part
thereof or dispose of any such property in any manner and for any consideration
deemed appropriate by Lender, and that no such action shall impair the rights of
the Lender to collect the indebtedness hereby guaranteed from the Guarantor.
Nothing contained in this paragraph, and no action by Lender permitted under
this paragraph, shall in any way affect or impair the rights or obligations of
the Guarantor with respect to any other guarantor, endorser or surety of the
Note.

      12. Benefit to Guarantor. The Guarantor acknowledges and warrants that he
has derived or expects to derive financial and other advantage and benefit,
directly or indirectly, from the Loan and each and every advance thereof and
from each and every renewal, extension, amendment, increase, replacement,
release of collateral or other relinquishment of legal rights made or granted or
to be made or granted by Lender to Borrower.

      13. Lawful Interest. All agreements between Guarantor and Lender, whether
now existing or hereafter arising and whether written or oral, are hereby
limited so that in no contingency or event whatsoever, whether by reason of
demand or acceleration of the maturity or otherwise, shall the interest
contracted for, charged, received, paid or agreed to be paid to Lender exceed
interest computed at the Maximum Rate (as defined below). If, from any
circumstance whatsoever, interest would otherwise be payable to Lender in excess
of interest computed at the Maximum Rate, the interest payable to Lender shall
be reduced to interest computed at the Maximum Rate; and if from any
circumstance Lender shall ever receive anything of value deemed interest by
applicable law in excess of interest computed at the Maximum Rate, an amount
equal to any excessive interest shall be applied to the reduction of the
principal balance of the Loan and not to the payment of interest, or if such
excessive interest exceeds the unpaid balance of principal of the Loan, such
excess shall be refunded. All interest paid or agreed to be paid to Lender
shall, to the extent permitted by applicable law, be amortized, prorated,
allocated, and spread throughout the full period until payment in full of the
principal (including the period of any renewal or extension) so that the
interest for such full period shall not exceed interest computed at the Maximum
Rate. This section shall control all agreements between Guarantor and Lender.
The term "Maximum Rate" shall mean the highest lawful rate of interest
applicable to the loan transaction evidenced by the

GUARANTY AGREEMENT - Page 3

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Note taking into account whichever of applicable federal law or Texas law
permits the higher rate of interest, and after also taking into consideration
all compensation deemed interest under applicable law.

      14. GOVERNING LAW AND VENUE. THIS GUARANTY AND ALL RIGHTS, OBLIGATIONS AND
LIABILITIES ARISING HEREUNDER SHALL BE CONSTRUED ACCORDING TO THE LAWS OF THE
STATE OF TEXAS. ALL OBLIGATIONS ARISING UNDER THIS GUARANTY SHALL BE PERFORMABLE
IN DALLAS COUNTY, TEXAS. VENUE OF ANY SUIT ARISING HEREUNDER SHALL LIE IN DALLAS
COUNTY, TEXAS.

      15. Notice. Any notice required or permitted hereunder shall be in
writing, and shall be deemed to have been given and received when deposited in a
post office or official depository of the United States Postal Service, sent by
certified mail, postage prepaid, return receipt requested, addressed as follows:

        Guarantor:               Keith Raymond Drew
                                 #2616 Camden Oasis
                                 Euless, Texas 76040

        Lender:                  Texas Mezzanine Fund Inc.
                                 351 West Jefferson Blvd., Suite 800
                                 Dallas, Texas 75208
                                 Attn: Theresa Lee

The addresses set forth in this Guaranty may be changed by any party by giving
notice of such change to the other party in the manner provided herein for
giving notice.

      16. Number and Gender. In construing this Guaranty, the singular number
shall include the plural and vice versa, and all pronouns shall include male,
female and neuter gender, regardless of gender used.

      17. FINAL AGREEMENT. THIS WRITTEN GUARANTY AND THE OTHER LOAN DOCUMENTS
REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY
EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES.
THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

      IN WITNESS WHEREOF, this Guaranty has been duly executed by the
undersigned this 20th day of November, 2003.

                                                /s/ Keith Raymond Drew
                                                ------------------------
                                                KEITH RAYMOND DREW

GUARANTY AGREEMENT - Page 4<PAGE>
                                                                   Exhibit 10.54

                             SUBORDINATION AGREEMENT

Dallas, Texas                                                November 20th, 2003

      WHEREAS, Drew Scientific, Inc., hereinafter called "Borrower", is indebted
to Texas Mezzanine Fund Inc., hereinafter called "Lender", pursuant to, among
other things, a certain Promissory Note in the stated principal amount of
$558,000.00, dated of even date herewith, executed by Borrower and payable to
the order of Lender; and

      WHEREAS, it is contemplated that Borrower may from time to time in the
future become indebted to Lender for other and additional sums;

      WHEREAS, all debts and liabilities of Borrower to Lender, whether such
debts or liabilities may now exist or are hereafter incurred or arise, and
whether the obligation or liability of Borrower thereon be direct, contingent,
primary, secondary, joint, several, joint and several, or otherwise, and
irrespective of the manner in which, or other person or persons in whose favor
such debts or liabilities may at their inception, have been, or may hereafter be
created, or the manner in which they may have been or may hereafter be acquired
by Lender, shall hereinafter be referred to as the "Indebtedness"; and

      WHEREAS, Borrower is likewise indebted to the undersigned, Drew Scientific
Group, PLC ("Subordinated Creditor"), pursuant to, among other things, a certain
Promissory Note in the stated principal amount of $3,112,629.04, dated November
18, 2003, executed by Borrower and payable to the order of Subordinated Creditor
(the "Prior Indebtedness").

      NOW, THEREFORE, for and in consideration of the mutual covenants and
agreements contained herein, and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, Lender and the
Subordinated Creditor hereby agree as follows:

      (1) Any and all indebtedness of the Borrower now or hereafter held by
Subordinated Creditor, including, but not limited to, the Prior Indebtedness
(all such indebtedness hereinafter referred to as the "Subordinated Debt"), is
hereby subordinated to the Indebtedness.

      (2) Until such time as Lender notifies Subordinated Creditor that the
Indebtedness is fully paid and satisfied, the Subordinated Creditor shall not be
entitled to accept or retain any payments, remittances or disbursements on
account of or pursuant to the Subordinated Debt. Any payments received by the
Subordinated Creditor on account of or pursuant to the Subordinated Debt will be
held in trust for the benefit of Lender and, upon demand from Lender, be
immediately forwarded to Lender.

      (3) Should Borrower become involved in any receivership, bankruptcy,
reorganization, arrangement, debtor's relief or other insolvency proceedings and
the Subordinated Creditor receives payment upon the Prior Note, or if, for any
other reason, the Subordinated Creditor should actually receive from any source
whatever any payment upon the Prior Note, the Subordinated Creditor agrees to
hold in trust for Lender all funds so received and agrees that she shall have
absolutely no dominion over such funds except to pay them promptly to Lender,
and the Subordinated Creditor covenants promptly to pay the same to Lender. The
payments so received by Lender shall be applied by it in such order as it shall
elect upon the Indebtedness.

      (4) In the event of receivership, bankruptcy, reorganization, arrangement,
debtor's relief, or other insolvency proceedings, Lender shall have the right to
prove its claim in any such proceedings, so as to establish its rights hereunder
and receive directly from the receiver, trustee, or other court custodian, any
amounts which would otherwise be payable upon the Prior Note.

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      (5) Should Lender receive, for application upon the Indebtedness, any such
payment which would otherwise be payable to the Subordinated Creditor, and
which, as between Borrower and the Subordinated Creditor, shall constitute a
credit upon the Subordinated Debt, upon receipt by Lender of an amount
sufficient to pay fully all of the Indebtedness, the Subordinated Creditor shall
become subrogated to the rights of Lender to the extent that such payments have
contributed toward the liquidation of the Indebtedness, and such subrogation
shall be in respect of that proportion of the Lender's debt which would have
been unpaid if Lender had not received the applicable payments.

      (6) Lender may, in its discretion at any time and from time to time,
without further consent of or notice to the Subordinated Creditor, and with or
without valuable consideration, release any person primarily or secondarily
liable upon the Indebtedness, or may permit substitutions or withdrawals of any
security or collateral at any time securing the payment of the Indebtedness, or
release any such proper substitutions or withdrawals of any security or
collateral at any time securing the payment of the Indebtedness, or release upon
the Indebtedness, or alter, in such manner as Lender shall deem proper, the
terms or any instrument evidencing or securing the Indebtedness, or any part
thereof, without in any manner impairing its rights thereunder. It shall not be
necessary for Lender, in order to enforce its rights hereunder, to institute
suit or exhaust its remedies against any person obligated to pay the
Indebtedness. All rights and privileges accorded Lender in this paragraph may be
exercised after as well as before the receipt by Lender of a notice as provided
in the succeeding Paragraph (7).

      (7) This agreement constitutes a continuing subordination; however, the
Subordinated Creditor may give to an officer of Lender written notice that the
Subordinated Creditor desires to terminate this agreement as to additional
indebtedness hereafter incurred by Borrower to Lender, and is such event this
agreement shall not constitute a subordination to the obligations of the
Borrower to Lender for the additional indebtedness incurred after the receipt of
such notice by Lender, but as to all other of the Indebtedness and all renewals
or extensions of the same, or any part thereof, this agreement shall continue in
full force and effect.

      (8) This instrument is cumulative of all other rights and remedies of
Lender. No waiver by Lender of any right hereunder, with respect to a particular
payment, shall effect or impair its rights to any matters thereafter occurring.

      (9) The Subordinated Creditor and Borrower agree to execute such further
instruments as may be, in the opinion of Lender, from time to time necessary or
appropriate to fully carry out the purposes hereof.

      (10) The Subordinated Creditor covenants that he will not assign the
Subordinated Debt, or any part thereof, without making the rights and interests
of the assignee subject in all respects to the terms of this instrument.

      (11) Any notice or notification required, permitted or contemplated
hereunder shall be in writing, shall be addressed to the party to be notified at
the address for notice set forth below or at such other address as each party
may designate for itself from time to time by notice hereunder, and shall be
deemed to have been validly served, given or delivered (a) when deposited in the
United States mail, postage prepaid, registered or certified mail, return
receipt requested, or (b) upon personal delivery.

      (12) This instrument is binding upon the Subordinated Creditor and
Borrower and their respective heirs, executors, administrators, successors, and
assigns shall inure to the benefit of Lender, its successors and assigns.

                    - remainder of page intentionally blank -

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      EXECUTED this 20th day of November, 2003.

SUBORDINATED CREDITOR:                        Address for Notice:
                                              Drew Scientific Group, PLC
DREW SCIENTIFIC GROUP,  PLC,                  Park Road
a public limited company organized            Barrow in Furness
under the laws of England and Wales           Cumbria LA14 4QR
                                              United Kingdom
By:    /s/ K.R. Drew                          Attn: DAVID BLAIN
       ------------------------------
Name:  K.R. DREW
Title: DIRECTOR

LENDER:

TEXAS MEZZANINE FUND INC.,                   Address for Notice:
a Texas corporation                          Texas Mezzanine Fund Inc.
                                             351 West Jefferson Blvd., Suite 800
By:    /s/ Theresa Lee                       Dallas, Texas 75208
       ------------------------------        Attn.: Theresa Lee
Name:  Theresa Lee
Title: Vice-President

                    ACKNOWLEDGMENT AND AGREEMENT OF BORROWER

      The undersigned, as the "Borrower" defined in the foregoing instrument,
hereby acknowledges, agrees and consents to the matters set forth therein.
Borrower further acknowledges and agrees that this instrument does not confer
any additional rights upon Borrower.

                                              DREW SCIENTIFIC, INC.,
                                              a Texas corporation

                                              By: /s/ Keith Drew
                                                  ------------------------------
                                              Name:  Keith Drew
                                              Title: President

                                       -3-

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