[1] ABC Med Ctr, Dept Pathol, Mexico City 1120, DF, Mexico
[2] Univ Panamer, Dept Cell & Tissue Biol, Mexico City, DF, Mexico
[3] Hosp Materno Infantil CNS, Dept Pathol, La Paz, Bolivia
[4] Univ Mayor San Andres, Dept Histol & Pathol, La Paz, Bolivia