Microglia
Research has discovered dystrophic (defective development) human microglia. "These cells are characterized by abnormalities in their cytoplasmic structure, such as deramified, atrophic, fragmented or unusually tortuous processes, frequently bearing spheroidal or bulbous swellings." The incidence of dystrophic microglia increases with aging. Microglial degeneration and death have been reported in research on Prion disease, Schizophrenia and Alzheimer's disease, indicating that microglial deterioration might be involved in neurodegenerative diseases. A complication of this theory is the fact that it is difficult to distinguish between "activated" and "dystrophic" microglia in the human brain.
Microcotyle brevis
"Microcotyle brevis" was first described by Dillon & Hargis in 1965, based on one specimen from the gills of striped triplefin, "Forsterygion varium". Dillon & Hargis (1965) noted the need for a study of this species based on more adequate material due to the contracted nature of the single specimen used for the description and thus the limitations of the given measurement. 
The type and only specimen of "Microcotyle brevis" was inadvertently destroyed during shipment to the U. S. National Museum.