title: Junín virus infection of guinea pigs: electron microscopic studies of peripheral blood and bone marrow.
abstract: Thin sections of peripheral white blood cells and samples of bone marrow from guinea pigs infected with Junín virus were examined by electron microscopy. In peripheral blood cells, 40% of the granulocytes showed cytoplasmic lysis seven days after viral infection. After day 11 up to 80% of these cells showed morphological alterations. However, no intra- or extracellular viral particles were detected in these samples. Microscopy of bone marrow preparations revealed that 10% of the cells were altered five days after infection, and approximately 50% were affected after nine days. At this stage the megakaryocyte channels were seen to contain pleomorphic particles with a mean diameter of 80-100 nm. These particles had a unit membrane envelope and internal dense granules similar to those observed during other arenavirus infections. Therefore, it is suggested that the effect of Junín virus upon megakaryocytes may be a factor responsible for the acute thrombocytopenia observed in Argentine hemorrhagic fever.
mesh_terms: D000818:Animals; D006477:Arenaviruses, New World / Q000302:isolation & purification*; D001769:Blood / Q000382:microbiology; D001773:Blood Cells / Q000648:ultrastructure*; D001853:Bone Marrow / Q000382:microbiology / Q000648:ultrastructure*; D004195:Disease Models, Animal; D006168:Guinea Pigs; D006478:Hemorrhagic Fever, American / Q000382:microbiology / Q000473:pathology*; D007962:Leukocytes / Q000648:ultrastructure; D008214:Lymphocytes / Q000648:ultrastructure; D008533:Megakaryocytes / Q000648:ultrastructure; D012328:RNA Viruses / Q000302:isolation & purification*