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                                                                      EXHIBIT 99

                NATIONAL NEPHROLOGY ASSOCIATES TO ACQUIRE RENEX



               NASHVILLE, TN and CORAL GABLES, FL---December 28, 1999 --
National Nephrology Associates, Inc. ("NNA") and Renex Corp. (Nasdaq -NMS: RENX)
("Renex") jointly announced today that they have entered into a definitive
agreement pursuant to which a wholly-owned subsidiary of NNA will offer to
purchase all of the outstanding shares of Renex for $10.00 per share in cash.
The total transaction value, including consideration for shares, stock options
and warrants is approximately $75 million. Pursuant to the agreement, NNA's
subsidiary will promptly commence a tender offer for all outstanding shares of
Renex. The definitive agreement has been approved by both parties' Boards of
Directors. If shares constituting a majority of Renex' outstanding shares on a
fully diluted basis are acquired pursuant to the offer and the other conditions
to the offer are satisfied, any remaining shares will be acquired at the same
price by means of a cash merger of NNA's subsidiary with and into Renex.

               Completion of the tender offer is subject to a number of
conditions, including there having been validly tendered shares constituting a
majority of the outstanding shares of Renex on a fully diluted basis, expiration
or termination of the Hart-Scott-Rodino waiting period, NNA having obtained
financing in accordance with the commitments issued by its lenders and other
customary conditions.

               In connection with the merger agreement, NNA has entered into a
shareholder agreement with the directors and executive officers of Renex who
collectively own approximately 31% of the outstanding Renex shares on a fully
diluted basis. Pursuant to the shareholder agreement, these directors and
executive officers have agreed to tender their shares in the Offer and have
granted NNA an option to purchase their shares.

               The Board of Directors of Renex has approved the offer and
determined that the price to be paid in the offer and in the subsequent merger
is fair to its shareholders and has recommended that Renex shareholders accept
the offer and tender their shares. In connection with the transaction, Renex was
advised by, and received a fairness opinion from, Prudential Vector Healthcare
Group, a unit of Prudential Securities Incorporated.

               Milton J. Wallace, Chairman of the Board said, "Our management is
proud that Renex Corp., established in 1993, is realizing value for its
shareholders of approximately $75 million. The Board of Directors recommends
that the shareholders tender their shares in the Offer. We look forward to the
consummation of the transaction and the successful integration of our company
with NNA."

               "Renex is an outstanding company with excellent clinical
operations, " said Jerome S. Tannenbaum, M. D., Chairman and Chief Executive
Officer of NNA. "We are pleased to be acquiring a provider of dialysis services
which is known for its high quality of care."

               Renex Corp was formed in 1993 by Milton J. Wallace, Chairman and
Arthur Shapiro, M. D., Vice Chairman. James P. Shea is the President and Chief
Executive Officer.

               Renex Corp. provides dialysis and ancillary services to
approximately 1,300 patients suffering from kidney failure, generally referred
to as end stage renal disease. The Company provides dialysis services through 21
outpatient facilities and a staff assisted home dialysis program. Additionally,
the Company provides in-patient acute dialysis services at 21 hospitals.



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               NNA owns and operates 32 dialysis clinics in 5 states. NNA
commenced operations in December 1998 and its principal shareholders are J. W.
Childs Equity Partners II, L. P., Credit Agricole Indosuez and the NNA
management team.

               The tender offer will be made only upon and subject to the terms
and conditions of the Offer to Purchase and the related Letter of Transmittal.

               THE FOREGOING INFORMATION REGARDING THE SALE OF RENEX CORP. IS
PRELIMINARY AND CONSTITUTES FORWARD-LOOKING STATEMENTS THAT INVOLVE RISKS,
UNCERTAINTIES AND OTHER FACTS WHICH MAY RESULT IN THE SALE OF RENEX NOT
OCCURRING OR IF IT OCCURS, NOT ON THE TERMS PROVIDED ABOVE.


Contacts

Renex Corp
James P. Shea
(305) 444-9991

NNA
Lief Murphy
(615) 777-6484




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