Antela, A.; Casado, J. L.; González, M. J.*; Pérez, P.*; Pérez-Elías, M. J.; Montilla, P.†; Buzón, L.†
*Infectious Diseases Department, Hospital Ramón y Cajal, Regional Program on Drugs and †Coordinating Office for Actions against HIV/AIDS, Madrid, Spain.
Date of receipt: 17 September 1996; revised: 23 April 1997; accepted: 7 May 1997.
