1. Department of Biochemistry-Immunology,1
2. Department of Morphology,2 and
3. UFMG Medical Center,3
4. Belo Horizonte, Minas Gerais, UFBA Medical Center,4 and
5. CPqGM-FIOCRUZ,5 Salvador, Bahia, Brazil, and
6. Department of Parasitology,6 Universidade Federal de Minas Gerais (UFMG) and
7. UCSF Medical Center, San Francisco, California7