Tubular structures in the hepatic nuclei of a patient with delta agent.

Liver biopsy specimens obtained from a 31-year-old female with delta-positive hepatitis were studied by routine electron microscopy. In several nuclei of hepatocytes, there were filamentous or microtubular structures 15 to 20 nm in diameter, in the vicinity of which, round particles, probably cross sections of tubular ones, were seen. In these nuclei, irregular granules approximately 20 to 30 nm in diameter were also found in clusters. However, cores of Dane particles were not found in such hepatocytes. These intranuclear microtubular structures may be associated with delta agent.