title: Intranuclear structures in pyrimethamine-resistant isolates of the malaria parasite Plasmodium falciparum.
abstract: The ultrastructure of the malaria parasite Plasmodium falciparum is well known, both from natural infections and from culture material ( Aikawa , 1977, Langreth et al., 1978). It is noteworthy that all of these studies were done with pyrimethamine-sensitive strains, e.g. FCR-3/Gambia. Except for spindle microtubules during schizogony, no intranuclear structures have been described in any of the asexual erythrocytic stages. In the course of isolating clones from the pyrimethamine-resistant strain Honduras I/CDC (V.K. Bhasin and W. Trager , in print) and checking by electron microscopy for the presence or absence of knobs, we noticed intranuclear structures that might be correlated with pyrimethamine resistance. For comparison, we then examined the multi-drug-resistant strain Indochina 1. We present here a first report on these structures as a basis for further studies.
mesh_terms: D000818:Animals; D002466:Cell Nucleolus / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure*; D002999:Clone Cells; D004352:Drug Resistance, Microbial; D010963:Plasmodium falciparum / Q000187:drug effects / Q000648:ultrastructure*; D011739:Pyrimethamine / Q000494:pharmacology*
chemical_list: D011739:Pyrimethamine