Toshinari Kobayashi

Electron and Immunoelectron Microscopic Study of Dane Particle Formation in Chronic Hepatitis B Virus Infection

The site of Dane particle formation in hepatocytes was studied by routine electron and immunoelectron microscopy of liver biopsy specimens from 10 patients with hepatitis B e antigen-positive chronic active hepatitis. With routine electron microscopy, core particles were abundant in cytosol, often adjacent to the cell membrane, and occasionally in the microvilli. Figures suggestive of budding of endoplasmic reticulum with a core particle into the cisternae of endoplasmic reticulum were observed frequently. There were also figures suggestive of direct budding with a core particle from the surface of the cell. With the immunoelectron microscopy, the core particles were found to be positive for hepatitis B core antigen and the endoplasmic reticulum and the plasma membrane were positive for hepatitis B surface antigen. These findings suggest that the most plausible mode of formation of the Dane particle is by budding of hepatitis B surface antigen-positive endoplasmic reticulum membrane into the cisternae. In addition, formation of the Dane particle may also take place at the surface of the hepatocyte by a similar mechanism.

Cellular immune response in liver of patients with chronic hepatitis B —Electron microscopic observation of lymphocyte subsets by the immunoperoxidase method using monoclonal antibodies

SummaryThe morphological association between lymphocytes and hepatocytes was studied at the light and electron microscopic levels by the peroxidase-labeled antibody method using mouse monoclonal antibodies against Leu-1, Leu-2a, Leu-3a, Leu-7 and Leu-10 antigens in liver biopsy specimens from patients with chronic hepatitis B. Leu-1 + cells (T cells), especially Leu-2a + cells (cytotoxic/suppressor T cells), infiltrated mostly in periportal areas with piecemeal necrosis and in parenchymal areas with focal necrosis. By double staining techniques, Leu-2a + cells were often seen in contact with hepatocytes containing membranous hepatitis B surface and/or core antigens in patients with chronic active hepatitis. At the ultrastructural level, Leu-2a + cells frequently occupied the sinusoid and also migrated into both the space of Disse and between hepatocytes. Furthermore, they often showed intimate surface-contact with hepatocytes having hepatitis B surface and/or core antigens, and, occasionally, injured hepatocytes were surrounded by several Leu-2a + cells. In contrast, Leu-3a + cells, Leu-7 + cells and Leu-10 + cells sometimes appeared in the sinusoid, but seldom in the space of Disse and between hepatocytes. These findings suggest that cytotoxic T lymphocytes may be associated with the necrosis of hepatocytes in chronic hepatitis B.

Langerhans Cells among Bile Duct Epithelial Cells in Chronic Liver Disease

Langerhans cells were found among bile duct epithelial cells in a biopsy specimen from a patient with chronic liver disease showing cholangitic features. The bile duct was 90 μm In diameter and surrounded with mononuclear cell infiltration. Under the electron microscope, the cell had a clear cytoplasm and contained a deeply indented nucleus, a centriole, well‐developed Golgi complexes and many rod‐shaped bodies (Birbeck granules).

Electron microscopy of granulomatous lesions of the liver in primary biliary cirrhosis.

Three granulomas in the portal tract and 9 bile ducts with typical features of chronic non‐suppurative destructive cholangitis (CNSDC) associated with dispersed epithelioid.cells were examined by electron microscopy in 10 patients with primary biliary cirrhosis (PBC). Vesicular epithelioid cells, which contained numerous single‐membrane bound vesicles, predominated in the granulomas. On the other hand, immature epithelioid cells and activated macrophages were more often observed near epithelial cells of the bile ducts with CNSDC than in the granulomas. These macrophages seemed to be activated by epithelial cells of the bile ducts and develop into epithelioid cells. Honeycomb‐like membranous labyrinths containing electron dense substances were frequently observed in epithelioid cells and were likely a special form of phagosome. The substances in the labyrinths seemed to be derived from organellae of necrotic cells and extracellular interstitial tissues. Subplas‐malemmal linear densities (SPLD) were observed at the cytoplasmic boundary and at intracytoplasmic membranous labyrinth. The roles of SPLD were discussed. ACTA PATHOL. JPN. 35 : 1309–1318, 1985.

Immunoelectron microscopic observation of α-fetoprotein synthesis in human non-malignant liver tissues using immunoperoxidase methods

SummaryAlpha-fetoprotein (AFP) synthesis in non-malignant liver tissue of 34 patients with chronic hepatitis or liver cirrhosis, some of whom also had hepatocellular carcinoma (HCC), was studied by light and ultrastructural immunohistochemistry using peroxidase-labeled anti-human AFP. Simultaneously, the serum level of AFP was measured in these patients by radioimmunoassay. AFP-positive cells were identified in non-malignant liver tissue of 7 patients with elevation of serum AFP. AFP was demonstrated in several hepatocytes which were clustered in hepatic lobules, and also in some bile ductular cells which were distributed in the periphery of portal tracts. In an immunoelectron microscopic study of AFP-positive hepatocytes, dense reaction products of anti-AFP were localized in the membranes and cisternae of rough endoplasmic reticulum (r-ER), perinuclear space (PNS) and Golgi apparatus. The prominent feature of AFP-positive hepatocytes was abundant r-ER encompassing many mitochondria. As to AFP-positive bile ductular cells, they had scanty cytoplasm and few intracytoplasmic organelles and were surrounded by basement membrane. AFP was focally localized in the r-ER of such bile ductular cells. These observations suggest that AFP can be produced by malignant and non-malignant liver cells and that in non-malignant liver tissues, AFP can be produced by two distinct cell types; bile ductular cells and hepatocytes themselves.