Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatitis B antigen (HB Ag) in the hepatocytic cytoplasm is detected by immunofluorescence after reaction with fluoresceinated antiserum to HB Ag or by electron microscopy as numerous 20- to 30-nm. tubular and circular structures in dilated cisternae of excess endoplasmic reticulum. On light microscopy, these hepatocytes can be recognized because their cytoplasm has a ground-glass appearance and stains with Gomori's aldehyde fuchsin. Aldehyde fuchsin-positive ground-glass hepatocytes were detected in all 14 asymptomatic carriers of HB Ag and in 16 of 60 HB Ag-seropositive patients with chronic hepatitis, but not in HB Ag-seropositive acute viral hepatitis or in various other HB Ag-seronegative liver diseases. These cells are helpful in identifying on light microscopy HB Ag carriers and a portion of patients with HB Ag-positive chronic hepatitis. Nuclear HB Ag did not stain with aldehyde fuchsin. Nucleic acids were not detected in the ground-glass cytoplasm by special stains at the light or electron microscopic level. We suggest that the tubular and circular structures in the hepatocytic cytoplasm are coat material of the hepatitis B virus or virally coded host cell reaction product rather than the complete hepatitis B virus.
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PMID:Incidence and nature of cytoplasmic hepatitis B antigen in hepatocytes. 4 30

The ultrastructural study of liver tissues from 38 patients with type B viral hepatitis consistently showed the presence of hepatitis B core antigen of 21-25 nm size in the liver cell nuclei and to a lesser extent in the cytoplasm. This finding and the demonstration of the tubular form of hepatitis B surface antigen in the proliferative degranulated endoplasmic reticulum constituted the etiologic criterion for the diagnosis of the disease. The double-shelled Dane-like particles were frequently found in association with the tubular form of the surface antigen. The core particles were found in the protoplasmic processes of hepatocytes and this correlated with the immunofluorescent microscopic findings that the antigen may be shed into circulation with the protoplasm. The core antigen was found to resist digestion by various enzymes such as protease, DNase, RNase, phospholipase C, lipase, lysozyme, diastase, neuraminidase and hyaluronidase, all of which did not destroy the immunoreactivity as demonstrated by immunoelectron and immunofluorescent microscopy. Similarly, sodium dodecyl sulfate, Tween 80 and mercaptoethanol also had no effect. The formalin-fixed paraffin-embedded liver tissue sections could be treated with protease to facilitate the immunofluorescent staining for the core antigen in tissue.
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PMID:Structural and immunoreactive characteristics of hepatitis B core antigen. 5 6

The presence of hepatitis B virus (HBV) antigens was examined in specimens of liver tissue obtained at necropsy from black Senegalese patients suffering from primary hepatocellular carcinoma (PHC). The results were correlated with markers of hepatitis B infection in serum. Hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) were sought for in 15 liver extracts. HBsAg was found in the liver in 10 of 12 cases with HBsAg-positive serum. HBcAg was detected in three livers. The HBsAg was detected in seven of eight livers by immunofluorescence and orcein staining. HBsAg-positive cells were mainly located in the peri-tumoral cirrhotic tissue, although positive hepatocytes were also found in tumour nodules in liver from one of the patients. HBcAg was found in five of seven cases by immunofluorescence in hepatocytes of the cirrhotic areas. HBcAg fluorescence was primarily nuclear but, in some lobules, a patchy cytoplasmic fluorescence was observed. This suggests a cytoplasm-nucleus pathway in the synthesis of the HBV core antigen. Electron microscopy was performed on two HBsAg- and HBcAg-positive cases. Fibrillar and crystalline cytoplasmic inclusions were observed in tumour cells. In the same cells, 20-25 nm virus-like particles were present in swollen cisternae of the endoplasmic reticulum.
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PMID:Hepatitis B virus antigens in human primary hepatocellular carcinoma tissues. 9 79

Hepatitis B core antigen (HBcAg) and hepatitis B surface antigen (HBsAg) were localized in human liver tissues by the peroxidase-labeled antibody method at the light and electron microscopic levels. Several methods of fixation, staining, and inhibition of endogenous peroxidase activity were studied. The periodate-lysine-paraformaldehyde fixative effectively preserved the tissue structure and the antigenicity of both antigens, and the peroxidase-labeled Fab' fraction of IgG penetrated well into hepatocytes. HBcAg was present in nuclei, or cytoplasm of hepatic cells, or both. In nuclei, the antigen was found both in virus-like particles of approximately 20 nm. diameter and in nuclear ground substance. In the cytoplasm, the antigen was found on membrane-bound ribosomes and free polysomes, and also in the ground substance of the cytosol near ribosomes and around nuclear membranes, especially near nuclear pores. HBcAg-positive virus-like particles were also demonstrated sparsely or in clusters in the cytoplasm. HBsAg was not present in nuclei but was found in the perinuclear space and in cisternae of endoplasmic reticulum, and on nuclear, endoplasmic reticulum, and cell membranes of hepatic cells. HBsAg-positive 25- to 30-nm. wide tubular forms, round particles (probably cross-sections of tubular forms), and a few large particles of 40 to 50 nm. diameter were seen in cisternae. Such HBsAg-positive particles were also present in the intercellular space and in Disse's space. These findings suggest that HBcAg produced on the cytoplasmic ribosomes migrates through nuclear pores to the nucleus and is assembled into core particles there. These particles may then move through nuclear pores to the cytoplasm where they are invested with HBsAg-positive membrane in cisternae of endoplasmic reticulum or as they enter the endoplasmic reticulum. These virus particles are then released together with other HBsAg-positive forms into the intercellular space by reversed phagocytosis.
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PMID:Hepatitis B core and surface antigens in liver tissue. Light and electron microscopic localization by the peroxidase-labeled antibody method. 32 96

Indirect immunoperoxidase stainings for hepatitis B core and surface antigens (HBc&s Ag) were applied to formalin-fixed paraffin sections in 113 liver specimens from 56 patients. Many cytomorphologic staining characteristics of HBc&s Ag were illustrated, and the percentages of the cellular population positive for HBc&s Ag were estimated for all specimens in order to provide the basis for general analyses. The quantitative expressions and the topographic distribution of HBc&s Ag were assessed with respect to their significance and implication in histopathologic reactions. A definitive relationship or relevance was neither established nor completely excluded due to the size of samples. However, cytomorphologically the membranous expression of HBc&s Ag was shown often in association with acute lobular hepatitis and chronic active hepatitis. This observation supports the concept that the membranous expression may be the prerequisite for immune mediated hepatitic injury in viral hepatitis. In this study we also carried out indirect immunoferritin and immunoperoxidase electron microscopy for HBc&s Ag on formalin-fixed liver specimens. The results assured the validity of the light microscopic immunohistologic procedures. The immunoelectron microscopy confirmed the presence of core antigen in the Dane particles formation that takes place in the cisternae of endoplasmic reticulum. The significance of the cytoplasmic core antigen and the possible role of immunoelectron microscopy in the elucidation of mechanisms of hepatitic injury were discussed.
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PMID:Immunohistologic demonstration of hepatitis B viral antigens in liver with reference to its significance in liver injury. 36 33

Electron microscopical studies were carried out on coded liver biopsy specimens from chimpanzees inoculated with human hepatitis A or B virus. Hepatitis B was recognized by the presence of hepatitis B core particles in hepatocellular nuclei. Hepatitis A was characterized by unidentified large, dense, and more irregular heterochromatin-like particles in hepatocellular nuclei coincidental with peak aminotransferase activities. As type A hepatitis illness became manifest in the chimpanzees, mitochondrial cristae were curled and attenuated, and clusters of endoplasmic reticulum were tightly packed. In contrast, the livers in viral hepatitis B showed mainly hypertrophy of tubular smooth endoplasmic reticulum. This suggested different pathogenetic mechanisms in A and B chimpanzee viral hepatitis.
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PMID:Chimpanzee livers after infection with human hepatitis viruses A and B: Ultrastructural studies. 40 99

"Ground-glass" hepatocytes are liver cells which have eosinophilic granular, glassy cytoplasm on light microscopy. This appearance corresponds to a proliferated smooth endoplasmic reticulum ultrastructure. These changes may be drug-induced or associated with hepatitis B antigenaemia, particularly in carriers. In the latter case, hepatitis B antigen may be demonstrated in the liver cell cytoplasm, with a modified orcein stain, by immunofluorescence, electron microscopy and immuno-electron microscopy. Two patients are described in whom "ground-glass" hepatocytes were noted on liver biopsy. One patient had been treated with high doses of phenobarbitone, the other is a hepatitis B antigen carrier as was demonstrated by the modified orcein stain.
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PMID:"Ground-glass" hepatocytes. 116 16

Ultrastructure of liver biopsy specimens obtained from normal and hepatitis B (HBV) and hepatitis C virus (HCV) infected livers of patients and chimpanzees were compared. Nuclear alterations (glycogen particles, nuclear bodies, "vermicellar bodies", etc.), intracytoplasmic crystalloid inclusions were observed before and after the HBV and HCV infections both in human and chimpanzee hepatocytes, however, some of them were more common during the viral infection. Extreme endoplasmic reticulum dilatation characterized the human, while the presence of membranous cytoplasmic inclusions the hepatocytes of chimpanzees during HCV infection. Interferon-associated membrane alterations were noted during acute or chronic hepatitis, however, in slightly different forms in humans and chimpanzees. Data suggest to be precautions in the interpretation of the ultrastructural alteration observed in different species even to be so closely related as humans and chimpanzees especially during infection with hepatotropic viruses.
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PMID:Ultrastructure of normal and hepatitis virus infected human and chimpanzee liver: similarities and differences. 136 64

The hepatitis B virus envelope gene encodes three transmembrane proteins in frame; S, the product of S gene; M, the product of M (pre-S2 + S) gene; and L, the product of L (pre-S1 + pre-S2 + S) gene. Unlike the S and M proteins, attempts to efficiently synthesize L proteins and assemble them into L protein particles in various eukaryotic cells have been unsuccessful, probably because of the presence of the pre-S1 peptide with an unknown function which appears to be inhibitory to the host secretory apparatus. To investigate the role of the pre-S1 peptide, we constructed an L gene fused with a synthetic gene for chicken-lysozyme signal peptide (C-SIG) at the 5'-terminal and placed the resultant gene under the control of the yeast glyceraldehyde-3-phosphate dehydrogenase gene promoter. After the fused-C-SIG peptide was correctly processed by the yeast secretory apparatus, a yeast transformant synthesized a protein with a molecular mass of approximately 52 kDa at a level of 42% of the total soluble protein. Electron micrographic observation showed that the gene products assembled into 23-nm spherical and filamentous particles. The pre-S peptide of the gene product was deposited into the endoplasmic reticulum (ER) lumen and well-glycosylated. It seemed that the gene products were accumulated as particles in certain specific membrane structures of the yeast secretory apparatus. Moreover, both the amount of mRNAs specific for the L gene and the in vivo stability of the synthesized L proteins did not change significantly by the addition of the C-SIG gene. These findings indicated that, if the pre-S1 peptide penetrates the ER membrane efficiently, the L proteins can be synthesized cotranslationally, translocate across the ER membrane with its S region, and then assemble by themselves into the particle form. Therefore, the pre-S1 peptide may involve weak or reduced signal peptide activity for recognition by the secretory apparatus and/or for the transport of the pre-S peptide into the ER lumen.
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PMID:Hepatitis B virus envelope L protein particles. Synthesis and assembly in Saccharomyces cerevisiae, purification and characterization. 137 Apr 86

The major surface protein of hepatitis B virus produced in Saccharomyces cerevisiae can be recovered from cell lysates in the form of 22-mm lipoprotein particles. Immunoelectron microscopy was applied to investigate site and time of particle assembly. Thin sections of yeast cells revealed that production of the S protein provoked a dilation of the endoplasmic reticulum. Dilated areas were specifically labeled with a polyclonal antibody raised against glutaraldehyde-treated yeast-derived HBsAg particles. In contrast to previous postulates of particle formation during cell lysis and extract preparation, these results suggest that particle formation in yeast occurs in the endoplasmic reticulum and that transport of particles along the secretion pathway is blocked.
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PMID:Immunoelectron microscopic detection of the hepatitis B virus major surface protein in dilated perinuclear membranes of yeast cells. 138 33


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