Biomedical subjects

K A Bardadin

Publications and source records attributed to K A Bardadin.

7 recordsLinked to original sources

PubMed1991

Immunocytochemical observations on macrophage populations in normal fetal and adult human liver.

Phenotypic expression of macrophages was studied immunocytochemically in 25 human fetal livers at various stages of development and in 20 normal human adult livers. A panel of commercially available polyclonal and monoclonal antibodies (KP1, Mac387, LN3, CR3/43, and antibodies against muramidase, alpha-1-antitrypsin, and factor XIIIa) was applied to paraffin sections. From the seventh week of gestation macrophages in the fetal liver showed differences in distribution with the various antibodies. Macrophages in adult liver similarly varied in morphology and phenotypic expression. In the light of these results, we conclude that the population of human liver macrophages is heterogeneous from an early stage of fetal development and that this heterogeneity extends into adult life.

Adult↗

PubMed1989

Liver cell shedding and phagocytic reaction in alcoholic liver disease. An ultrastructural study.

Sinusoidal macrophages were studied by light and electron microscopy in 49 liver biopsies from alcohol-abusers with a variety of alcohol-related liver lesions or with near-normal livers. Changes were related to those in nearby hepatocytes. A reduction in the number of macrophages was noted in the more severely damaged livers. Hepatocytes formed blebs at their sinusoidal poles, and these protruded into the space of Disse and into the sinusoidal lumen. It is postulated that reduced phagocytic activity in the livers of patients with severe alcohol-related liver disease leads to increased shedding of hepatocellular material into the circulation. This may promote the development of autoimmune reactions directed against hepatocytes.

Cytoplasm↗

PubMed1986

Mast cells in acute hepatitis.

The prevalence and morphological characteristics of mast cells were studied in 41 liver biopsies from patients with acute hepatitis of different causes. In 17 of these biopsies mast cells were found both in portal tracts and sinusoids. They were mainly found in the classical and periportal types of hepatitis, and were more abundant in the later stages of the disease. Their presence was established both by staining for mast cells at light microscopic level and by electron microscopy. Two types of mast cells were found. Those in the portal tracts had the characteristics of connective tissue mast cells in other organs. The second type was the sinusoidal mast cell. These were closely associated with a variety of myeloid cells, and ultrastructural evidence suggests that they may be derived from the latter. Mast cells are considered to participate in the inflammatory response in acute hepatitis.

Acute Disease↗

PubMed1985

Plasma cells in acute hepatitis: an ultrastructural study.

Plasma cells and their precursors were studied by electron microscopy in liver biopsies from 41 patients with acute viral or drug-induced hepatitis. Mature plasma cells showed the ultrastructural features of the reticular or lymphatic type. Blast cells of different types were also observed. Type 1 predominated in classical acute hepatitis, and appears to transform directly into mature plasma cells. Type 2 corresponds to the centroblast of lymphoid tissue. It was found in fully developed hepatitis, especially when necrosis was severe. Type 3 resembled the centrocyte of lymphoid organs; it was seen particularly in viral hepatitis, and only in severe cases with extensive necrosis. The type 4 plasmablast had the ultrastructural characteristics of a plasmacytoid T cell.

Chemical and Drug Induced Liver Injury↗

PubMed1985

Ultrastructural observations on sinusoidal endothelial cells in chronic active hepatitis.

Ultrastructural features of 12 liver biopsies from patients with chronic active hepatitis were studied, particular attention being paid to endothelial cells. In areas of piecemeal necrosis and parenchymal inflammation sinusoidal endothelial cells show swelling of the cytoplasm, protrusion of the cell body into the sinusoidal lumen, increase in micropinocytotic vesicles and appearance of numerous dense bodies. This cell type is termed 'active endothelial cell'. Subsequent changes include enlargement of the Golgi complex, increase of rough endoplasmic reticulum in cytoplasmic processes with concomitant decrease of dense bodies, appearance of a fuzzy coat and formation of hemidesmosomes in close relationship to basement membrane-like material and reticulin fibres in the space of Disse. The latter ultrastructural characteristics correspond to those of 'fibroblastic reticulum cells' described in lymph nodes. Active endothelial cells and fibroblastic reticulum cells may play a protective role in liver parenchymal inflammation by reducing the accessibility of noxious agents from the blood stream to liver parenchymal cells, and be crucial in the initiation of perisinusoidal fibrosis.

Biopsy, Needle↗

PubMed1984

Endothelial cell changes in acute hepatitis. A light and electron microscopic study.

Hepatic endothelial cells were studied by light and electron microscopy in 48 patients with acute hepatitis due to virus infection or drug idiosyncrasy. Light microscopy revealed cell swelling and appearance of dense refractile intracytoplasmic granules staining with the amylase PAS reaction and for iron by Perls' method. They were orcein-negative. These cells, regarded as 'activated' endothelial cells, were found throughout the parenchyma, especially in the classical form of acute hepatitis. In acute hepatitis with bridging, panacinar or periportal necrosis, activated endothelial cells were prominent in the necrotic areas. They were constantly seen lining newly formed capillaries in these sites. By electron microscopy, the intracytoplasmic granules had the characteristics of primary or secondary siderosomes. In areas of capillarization, basement membrane material was seen on the aspect of the activated cells facing the space of Disse. Activated endothelial cells may play a part in protecting hepatocytes from injury.

Acute Disease↗

PubMed1984

Interdigitating and dendritic reticulum cells in chronic active hepatitis.

An ultrastructural study of the cytology of piecemeal necrosis in 12 liver biopsies from patients with chronic active (aggressive) hepatitis revealed a variety of cell types. This communication deals with two particular cell types, only observed in areas of severe piecemeal necrosis--interdigitating reticulum cells (IDRCs) and dendritic reticulum cells (DRCs). IDRCs are typical components of T-cell regions in lymphoid organs. Cells with the characteristics of IDRCs were found in severe piecemeal necrosis at the periphery of portal tracts and in periportal areas. This suggests that areas of periportal piecemeal necrosis are analogous to the T-cell regions of lymphoid organs during immune reactions. DRCs are typical components of B-cell regions in lymphoid organs. Cells with the characteristics of DRCs were found in the central parts of portal tracts with follicle-like aggregations of lymphocytes, as seen in some cases with pronounced piecemeal necrosis. This finding suggest that follicle-like lymphocytic aggregates in portal tracts are analogous to the B-cell regions of lymphoid organs during immune reactions. A mesenchymal origin of DRCs is suggested. The finding of IDRCs and DRCs in severe piecemeal necrosis emphasizes the fundamental similarity of immune reactions in the liver to those in lymphoid organs. These data are discussed in relation to immunological findings in chronic active hepatitis.

Adult↗