Zika virus infection of the central nervous system of mice

A chronological study of experimental scrapie in mice

The development of scrapie-associated particles and lesions in four regions of the brain was studied in mice over a period of 30 weeks. Characteristic tubulovesicular particles, identical to those previously described, were first found about half way through the incubation period in mice inoculated by four different routes. The particles are found in brains with scrapie and other spongiform encephalopathies; they have never been seen in other conditions, and potentially represent the infectious agent.

Further observations on particulate structures in scrapie affected brain

A search procedure at the ultrastructural level revealed characteristic particulate structures in mice of two further laboratory stocks experimentally inoculated with scrapie. The structures represent a specific change related to scrapie disease; their relationship to the scrapie agent is discussed.

Electron microscopic observations on Aedes albopictus cells infected with dengue viruses

In dengue virus infected Aedes albopictus cells, electron-dense particles, larger than single ribosomes, were arranged on the cytoplasmic sides of rough endoplasmic reticulum (RER) membranes. Mature virions 40--45 nm in diameter as well as vesiculotubular structures 50--120 nm in diameter appeared in enlarged cisternae of RER filled with fine granular substance. Many of the mature virions and somewhat degenerated vesiculotubular structures remained to be enclosed in membranous structures presumably derived from RER, even after degeneration of infected cells. The findings suggest that development of dengue viruses in cultured A. albopictus cells takes place in close relationship with the activated membranes of RER. Other morphological changes observed in dengue infected A. albopictus cells were 1. electron-dense "double-track structures" in areas of virion morphogenesis, 2. fine crystalline structures in type-2 dengue infected cells, and 3. aggregates of nucleoid structures, in cells persistently infected with type 2 dengue virus. The implication and nature of these structures in relation to virion morphogenesis remain to be investigated.