Abstract: The present invention refers to novel gem-difluoro compounds of formula: ##STR1## wherein: R.sub.1 can be hydrogen, acyl or acyl substituted; R.sub.2 is hydrogen, lower alkyl, lower alkyl substituted, nitro, halogen, methylenedioxy, trifluoromethyl or OR';Y is oxygen, sulfur or NR";R.sub.3 is hydrogen, lower alkyl, lower alkyl substituted, phenyl, aryl group substituted or metal selected of the group consisting of sodium, potassium, clcium, magnesium, zinc or aluminum;R' and R" are hydrogen, lower alkyl, lower alkyl substituted, phenyl or aryl substituted; and(a) in the group C.sub.1 -C.sub.

Abstract: This patent deals with the use of Trypanosoma cruzi antigens obtained using recombinant DNA techniques, or synthetic peptides derived from these antigens, and their use in the immunological diagnosis of Chagas Disease using either ELISA, or western blot, or dot-blot, or hemagglutination, or agglutination, or monoclonal antibodies, or radioimmunoassay. The antigens or synthetic peptides are characterized by displaying the following aminoacid sequences: Ag1: valine (or alanine), alanine, glutamic acid, alanine (orthreonine), glutamic acid, lysine, glutamine, lysine (or arginine), alanine, alanine, glutamic acid, alanine (or serine), threonine (or methionine or alanine) and lysine.

Abstract: The present invention relates to helminthic derived antigenic material capable of inducing effective and long lasting protection against parasites, in particular to antigens that mediate protective immunity against helminths.