**Exhibit
        10.1**
  
  **FIRST
        AMENDMENT TO**
 **SUBORDINATED
        REVOLVING LINE OF CREDIT AGREEMENT**
 
 **THIS
        FIRST AMENDMENT TO SUBORDINATED REVOLVING LINE OF CREDIT
        AGREEMENT** (this
“ Amendment ”)
        is
        made and effective as of August 11, 2007, by and between ECHO
        HEALTHCARE ACQUISITION CORP. ,
        a
        Delaware corporation (the “ Borrower ”),
        and
        the individuals and entities set forth on Schedule A (the “ Lenders ”)
        of the
        Credit Agreement (as defined herein).
 
 **RECITALS**
 
 A. The
        Borrower and the Lenders are parties to that certain Subordinated Revolving
        Line
        of Credit Agreement, dated as of March 22, 2006 (the “ Credit
        Agreement ”).
 
 B. The
        Borrower and the Lenders have agreed to amend the Credit Agreement upon the
        terms and conditions set forth in this Amendment.
 
 **STATEMENT
        OF AGREEMENT**
 
 **NOW,
        THEREFORE,** for and
        in consideration of the premises, the mutual covenants herein contained,
        and
        other good and valuable consideration, the receipt, adequacy and sufficiency
        of
        which is hereby acknowledged, the Purchaser and the Sellers hereby agree
        as
        follows:
 
 1. Section
        1.2.4 of the Credit Agreement is hereby deleted in its entirety and replaced
        with the following:
 
 March
        22,
        2008, provided that Borrower may request advances after that date solely
        to pay
        reasonable costs and expenses in connection with liquidation of Borrower;
 
 2. Agreement
        Ratified .
        Except
        as modified by this Amendment, the Borrower and the Lenders do hereby ratify
        and
        reaffirm each and every provision of the Credit Agreement. The Credit Agreement
        shall remain in full force and effect in accordance with its terms, as modified
        by this Amendment. This Amendment shall bind and inure to the benefit of
        the
        Borrower and the Lenders and their respective successors and permitted assigns
        under the Credit Agreement.
 
 3. Defined
        Terms .
        All
        defined terms used herein and not separately defined herein shall have the
        meaning set forth in the Credit Agreement.
 
 4. Governing
        Law. This
        Amendment shall be construed and interpreted under the laws of the State
        of
        Delaware.
 
 5. Counterparts;
        Facsimile Signatures .
        This
        Amendment may be executed in any number of counterparts, each of which when
        executed shall be deemed to be an original and all of which counterparts
        taken
        together shall constitute but one and the same instrument. The parties agree
        that facsimile signatures shall be sufficient to bind them hereto.
 
   
  IN
        WITNESS WHEREOF, each of the parties hereto has caused this Amendment to
        be
        executed on this 11th day, of August, 2007.
  
 **Borrower**:
                
                Echo
                  Healthcare Acquisition Corp.
                
                By:/s/
                  Kevin Pendergest
                Kevin
                  Pendergest, Chief Financial Officer
                
                
                **Lenders**:
                
                
                /s/
                  Richard O. Martin
                Richard
                  O. Martin, Ph.D.
                
                /s/
                  Gene E. Burleson
                Gene
                    E. Burleson
                  
                  
                  Chicago
                    Investments, Inc.
                  
                  By:/s/
                    Josh S. Kanter
                  Josh
                    S. Kanter, President