Electron microscopic studies of Dane particles in hepatocytes with special reference to intracellular development of Dane particles and their relation with HBeAg in serum.

Electron microscopic observations in 30 cases of HBsAg positive liver disease and 12 asymptomatic carriers of HBsAg suggested the following mechanism of intracellular development of Dane particles: core particles migrated from the nucleus into the cytoplasm through the nuclear pores. Intracytoplasmic core particles protruded into the cisternae of endoplasmic reticulum by budding the outer coat of Dane particles being derived from the membrane of endoplasmic reticulum. Release of Dane particles into the blood stream by reversed pinocytosis was suggested by the finding of submembranous localization of endoplasmic reticulum containing these particles. No budding from the cell surface of the hepatocytes was encountered. Dane particles in the hepatocytes were detected in 14 of 15 cases positive for serum HBeAg while no particles were seen in 27 HBeAg negative cases, thus suggesting that serum HBeAg reflected ongoing replication of hepatitis B virus in the hepatocytes.