article 12 nonhuman 12 controlled study 10 eflornithine 10 ornithine decarboxylase 10 putrescine 10 spermidine 10 Cyclohexylamine 8 priority journal 8 spermidine synthase 8 Ornithine Decarboxylase 6 Ornithine decarboxylase 6 Putrescine 6 Spermidine 6 Spermine 6 Trypanosoma cruzi 6 enzyme activity 6 enzyme stability 6 polyamine 6 polyamine synthesis 6 spermine 6 Animals 4 Arbuscular mycorrhizal fungus 4 Arginine decarboxylase 4 Crithidia fasciculata 4 Cyclohexylamines 4 Eflornithine 4 Enzyme Inhibitors 4 Fungi 4 Gigaspora 4