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F Paronetto

Publications and source records attributed to F Paronetto.

At least 37 records · Page 2Linked to original sources
PubMed1990

A nude mouse model for the in vivo production of hepatitis B virus.

Hepatitis B virus genome-transfected HepG2 cells (2.2.15 cells) inoculated into nude mice produced tumors within 2-8 wk. Dane particles, hepatitis B virus deoxyribonucleic acid polymerase activity, hepatitis B surface antigen, and hepatitis B e antigen were detected in the serum, and 36% of mice developed antibodies to hepatitis B core antigen. In the tumors, hepatitis B surface, core, and e antigens were observed by electron microscopy and immunoenzymatic techniques. In-situ hybridization and Southern blot analysis showed hepatitis B virus deoxyribonucleic acid in the tumor. Tumors could be propagated by injection of minced tumor tissue or of a tumor-derived cell line. Liver of tumor-bearing mice as well as sera and tissues of mice inoculated with control cell lines did not show hepatitis B virus genome or viral markers. Tumors induced by both 2.2.15 and nontransfected HepG2 cells exhibited myc oncogene protein and various hepatoma-associated antigens (alpha-fetoprotein, alpha-1-antitrypsin, alpha-1-antichymotrypsin, carcinoembryonic antigen, cytokeratin), suggesting that viral formation does not interfere with expression of these antigens. This experimental model will be helpful to study the effect of drugs on in-vivo hepatitis B virus replication and viral antigen expression.

Animals↗
PubMed1989

Distribution of basement membrane components in human hepatocellular carcinoma.

The distribution of fibronectin (FN), laminin (LAM), and collagen IV (Coll IV), three components of the basement membranes (BM), was investigated in human hepatocellular carcinoma (HCC) and the surrounding uninvolved liver and was compared with the grade of differentiation of the tumor. The following three patterns of BM antigens were observed in HCC: (1) peritrabecular or periacinar, (2) pericellular, and (3) stromal-vascular. In the more differentiated tumors, FN, LAM, and Coll IV were observed in a peritrabecular or periacinar pattern whereas a pericellular pattern was only seen with anti-FN antisera that occasionally stained the content of acini. Double staining showed that the four antigens were usually codistributed. Occasionally, however, there was a different distribution along the BM suggesting an heterogeneity in the composition of BM. In the more anaplastic tumors and in the intrahepatic metastasis, BM components were seen around vessels and in the stroma and they were usually fragmented. The finding that FN can be located pericellularly or within acini supports the concept that FN is synthesized, at least in part, by hepatoma cells. The peritrabecular and periacinar location of Coll IV and LAM suggests a sinusoidal cell derivation of these two antigens. The immunohistochemical staining patterns for BM in HCC reflect the differentiation of the tumor, with differentiated tumors showing a relatively intact BM and poorly differentiated tumors showing a sharply defective BM.

Basement Membrane↗
PubMed1989

Isolation of a nonparenchymal liver cell fraction enriched in cells with biliary epithelial phenotypes.

In the present study we have isolated and purified fractions of nonparenchymal liver cells were isolated by collagenase-pronase digestion of the biliary and connective hepatic tissue, which remained undissociated after collagenase perfusion of the liver. Fractionation of the nonparenchymal fractions was then achieved by centrifugal elutriation. Both normal rats and rats with proliferated bile duct-like structures, which were induced either by a 14-day bile duct ligation or by feeding 0.1% alpha-naphthylisothiocyanate for 28 days, were used in these studies. Using a normal rat liver, the fraction richest in biliary epithelial cells was that obtained at a pump flow rate of 36-40 ml/min. In this fraction 1.8-3.8 x 10(6) cells per liver were recovered and up to 55% of them were positive for gamma-glutamyl transpeptidase and cytokeratins 7 and 19, all of which were histochemically or immunohistochemically detected solely in the biliary structures in the intact rat liver. When the nonparenchymal cells were isolated from hyperplastic livers, the number of cells recovered in such a fraction ranged from 12 to 19 x 10(6) per liver, and as many as 60%-85% of the cells expressed phenotypes of biliary epithelial cells. These results indicate that (a) by centrifugal elutriation a fraction of nonparenchymal cells enriched in cells with biliary epithelial phenotypes can be obtained from rat liver and (b) the hepatic hyperplasia induced by biliary obstruction or alpha- naphthylisothiocyanate feeding is a useful and valid strategy for improving both the yield and the purity of the isolated biliary epithelial cells.

Animals↗
PubMed1989

Blood-group-related antigen Lewis(x) and Lewis(y) in the differential diagnosis of cholangiocarcinoma and hepatocellular carcinoma.

Distribution of Lewis(x) (Le(x)) and Lewis(y) (Le(y)) blood-group antigens was studied in nine formaldehyde-fixed, paraffin-embedded cholangiocarcinomas (CCs), 26 hepatocellular carcinomas (HCCs), and eight normal livers. All CCs, with one exception, expressed both Le(x) and Le(y) antigens on few or many cells. In HCCs Lex was expressed infrequently (8%), while Le(y) was detected in 31% of cases. Both markers, when present in HCCs, tended to be spotty. Fibrolamellar carcinomas and normal livers did not react with either Le(x) or Le(y) antigens; however, Le(y) antigen was observed occasionally in bile duct epithelial and ductular cells. In conclusion, inappropriate tissue distribution of Le(y) blood-group antigens was observed in CCs and, much less frequently, in HCCs. The high frequency of Le(x) antigen in CCs but not in HCCs may help in the differential diagnosis of these two tumors.

Adenoma, Bile Duct↗
PubMed1989

ras oncogene p21 expression in hepatocellular carcinoma.

Aberrant proto-oncogene expression has been implicated in hepatic cell proliferation, transformation and carcinogenesis using a rat model. To investigate the role of ras p21 product expression in human hepatocellular carcinoma (HCC), we have localized ras p21 in formalin fixed, paraffin-embedded normal and abnormal livers utilizing the avidin-biotin peroxidase method and a monoclonal antibody to ras-gene product p21. A semi-quantitative estimate of p21 expression was performed by serial dilutions of primary antibody. While low dilutions of anti-p21 stained normal hepatocytes, higher dilutions failed to react with normal hepatocytes and these dilutions were used for assessment of p21 enhancement. Increased p21 expression of ras oncogene in HCC occurs in fibrolamellar carcinomas and other better differentiated HCC. Tumor dedifferentiation is associated with an attenuation of p21 expression. Liver adjacent to HCC exhibits p21 enhancement, in contrast to liver surrounding metastatic carcinoma, suggesting increased p21 expression in HCC induction.

Carcinoma, Hepatocellular↗
PubMed1989

Relationship between c-myc gene protein, nucleic acids and hepatitis B virus expression in hepatoma cell lines and their corresponding tumors in nude mice.

myc gene protein--a 62,000 molecular weight protein (p62c-myc)--was localized in the nuclei of a human hepatoblastoma cell line (HepG2) and its corresponding tumors in nude mice but not in the mouse liver cells using immunoenzymatic and immunogold techniques. Double staining revealed that myc protein and nucleic acids are mutually exclusive and that myc protein is located in the nucleoplasm. Immunoelectron microscopic observation confirmed that the myc protein is part of the nuclear sap. To study the relationship between myc protein and hepatitis B virus (HBV) marker expression, we have utilized the cell line HepG2 transfected with the HBV genome as well as the corresponding tumors induced in nude mice. HBsAg- and HBcAg-positive cells were not always associated with over-expression of myc gene protein suggesting that HBV expression is not required for increased expression of myc gene protein.

Animals↗
PubMed1988

Application of microwave irradiation to immunohistochemistry: preservation of antigens of the extracellular matrix.

Microwave irradiation as a means of fixation was evaluated for the preservation of extracellular matrix antigens such as collagen III, IV, fibronectin and laminin in both lung and liver specimens. Small tissue samples were placed in normal saline or periodate-lysine-paraformaldehyde (PLP) and irradiated for 30 sec to bring them to a temperature of 50 C. The tissue was then processed rapidly in a tissue processor adjusted to a 2 hr cycle and embedded in paraffin. Sections were immunostained. For comparison, routine cryostat sections as well as sections of formalin fixed tissue were used. Microwave irradiation in saline gave excellent morphological detail, comparable to that in formalin fixed tissue. All four antigens evaluated were well preserved without the necessity of prior pepsin digestion. Microwave fixation is promising for preservation of antigenicity and morphological detail, and considerably reduces the time required for processing.

Extracellular Matrix↗
PubMed1987

Immunocytochemical localization of p21 ras gene product in human hepatoma cell lines and corresponding tumors in athymic mice.

The development of monoclonal antibodies (MAb) against ras protein has made possible to study the expression of ras oncogene by immunohistochemical methods in many human solid tumors. Using the MAb RAP-5 generated against a synthetic peptide having the sequence of amino acids 10-17 of the human T24 ras gene product and the peroxidase anti-peroxidase (PAP) technique, we have observed increased level of ras p21 protein in four human hepatoma cell lines and corresponding tumors in athymic mice. The increased level of p21 is not correlated with the grade of differentiation of tumor cells, nor with the expression of HBsAg. The continuous enhanced expression of ras gene product at the cell line level and after transplantation in athymic mice suggests that the increase in p21 level may be important in the maintenance of the transformed phenotype of the hepatoma cells.

Animals↗
PubMed1986

Lymphocyte subpopulations in patients with alcoholic liver disease.

To determine whether abnormalities of the lymphocyte populations are associated with alcoholic liver disease, we have characterized the subpopulations of lymphocytes in 30 alcoholic patients with and without liver disease. Total T lymphocytes were decreased in patients with alcoholic hepatitis and alcoholic cirrhosis. However, T4 (helper) and T8 (suppressor/cytotoxic) cells and the T4 and T8 cell ratio were similar to the values in controls. In these patients, the sums of T4/T8 cells exceeded that of total T cells, an alteration apparently related to severe liver damage. Cells reacting with antisera to immunoglobulins (B lymphocytes) and to Dr determinants were also within the normal range. In contrast, NK/K (natural killer/killer) cells were increased in the group of patients with steatosis or without liver alteration. Increase of NK/K cells was not observed in patients who were abstinent from alcohol for a period of two weeks or more, suggesting that alcohol may have been responsible for the increase in this lymphocyte population.

Adult↗
PubMed1986

In situ characterization of the cell-surface antigens of the mononuclear cell infiltrate and bile duct epithelium in primary biliary cirrhosis.

To analyze the tissue distribution of mononuclear cells and HLA antigens in primary biliary cirrhosis, we studied liver biopsies of 12 patients at different stages of the disease, using the avidin-biotin-peroxidase technique and monoclonal antibodies directed against T and B lymphocytes, T-cell subsets, macrophages, NK/K cells, dendritic cells, and HLA class I and II antigens. To evaluate the proportion of activated T cells we used anti-interleukin-2-receptor antibodies and a double-staining technique for T cells and class II HLA antigens. In all biopsies activated T cells predominated in the portal areas and around the damaged bile ducts. T4 cells almost always outnumbered T8 cells. While B cells, NK/K cells, and dendritic cells were always scarce, macrophages constituted about 30% of the cellular infiltrate. Biliary epithelium, which normally expresses HLA class I antigens, displayed mainly HLA class II antigens. The predominance of T4 cells around the bile ducts, which express class II antigens, suggests that class II-restricted T4 lymphocytes may mediate liver damage in primary biliary cirrhosis.

Antigens, Surface↗
PubMed1986

Cell-mediated immunity in liver disease.

Four liver diseases in which cell-mediated immunity seems to be of major importance but in which the exact pathogenic event has been not fully clarified have been briefly discussed. More precise delineation of the phenotypes of mononuclear cells and the advent of in vitro techniques for the study of lymphocyte function and cytotoxicity have led to better understanding of the importance of cell-mediated immunity in some liver diseases. It seems that the liver itself may be variously affected by different immunologic reactions, not only in various diseases but also in different locations in the same disease.

Antigens↗
PubMed1986

Acute hepatitis B in children with papular acrodermatitis.

Thirteen children who had repeated liver biopsies over a period of 2-16 years after the onset of papular acrodermatitis (PAC) were studied retrospectively. Six patients, rebiopsied within 36 months after the onset of PAC, had histologic evidence of chronic periportal hepatitis. However, repeated biopsies in 3 of the patients revealed a normal liver or chronic portal hepatitis. Whereas all patients had at the end of the observation markers of hepatitis B virus infection, 8 of the 10 patients studied had HBs antigenemia. These data indicate that severe active liver disease may regress without treatment in patients who have had PAC. However, the high frequency of a chronic HBsAg-carrier state among these patients suggests either an inefficient clearance of the virus or an altered immune reaction.

Acrodermatitis↗
PubMed1986

Varying nuclear staining intensity of hepatitis B virus DNA in human hepatocellular carcinoma.

An in situ hybridization technique with biotinylated hepatitis B virus (HBV)-DNA probes was used to localize HBV-related DNA sequences in cells of human hepatocellular carcinoma (HCC). Formalin fixed, paraffin-embedded liver biopsies of 11 patients with HCC studied; nuclear HBV-DNA hybridization was observed in 7 of the patients. Sensitivity and specificity of the method were determined by examining appropriate controls. The number of cells exhibiting nuclear fluorescence and intensity of fluorescence varied from tumor to tumor. In two instances liver tissue adjacent to HCC exhibited nuclear staining. HBV-DNA nuclear staining did not correlate with tumor localization of HBsAg or HBcAg, nor with type or with differentiation of the tumor. The use of biotinylated HBV-DNA probes offers a powerful and reproducible technique to localize HBV-related DNA sequences even in formalin-fixed, paraffin-embedded tumor tissue, and also to compare the presence of HBV-DNA with that of viral antigens stained in parallel sections. The frequent localization of HBV-DNA in nuclei of HCC cells fortifies the important epidemiologic association between infection and HCC. The random cellular localization of HBV-DNA sequences in HCC suggests that HBV-DNA may be incorporated, or perhaps replicated, unequally in tumor cells.

Adult↗
PubMed1985

Fibronectin patterns in hepatocellular carcinoma and its clinical significance.

Fibronectin, a high molecular weight glycoprotein component of the extracellular matrix, was localized extracellularly and intracellularly in the nuclei and the cytoplasm of hepatocellular carcinomas (HCC) by the use of the biotin-avidin method on paraffin-embedded, pepsin-treated tissue. The specificity of the staining was confirmed by absorbing the antibodies with purified fibronectin. Twenty HCC were investigated (7 were autopsy specimens and 13 biopsy and surgical specimens). The fibronectin was either increased or decreased. When increased the fibronectin consisted of thin or thick feathery strands and was either pericellular, sinusoidal, periglandular, or stromal. Marked increase of fibronectin was seen in fibrolamellar HCC, clear cell HCC, and encapsulated HCC, correlating with the better prognosis. Decreased fibronectin was seen in two undifferentiated HCC. HCC obtained at autopsy displayed nuclear and cytoplasmic fibronectin staining. Nuclear fibronectin may be an expression of the DNA binding ability of fibronectin which becomes demonstrable in cells with increased membrane permeability.

Carcinoma, Hepatocellular↗
PubMed1985

Globular Mallory-like bodies in renal cell carcinoma: report of a case and review of cytoplasmic eosinophilic globules.

The case of a patient who had renal cell carcinoma with cytoplasmic eosinophilic globular hyaline bodies antigenically similar to Mallory bodies, highly suggestive of globular type III alcoholic hyalin, is presented. Mallory bodies are not found exclusively in the liver, having also been demonstrated in the lung. The renal tumor in this case represents an additional extrahepatic site.

Aged↗
PubMed1985

Detection of two forms of HBeAg (free-and IgG-bound HBeAg) in patients with HBe antigenemia using staphylococcus bearing protein A.

Protein A-bearing Staphylococcus aureus organisms (STA) were used to separate free HBeAg from IgG-bound HBeAg. Free HBeAg was detected in the supernate while IgG-bound HBeAg could be liberated from the pellets using MgCl2 or a glycine buffer. HBeAg was determined by radioimmunoassay and the results expressed as patient's cpm/normal control's cpm ratio (S/N ratio). This ratio was demonstrated to be proportionate to the antigen concentration and used as a titer of HBeAg. Sera of 40 HBsAg-negative healthy volunteers and 82 HBeAg-positive patients who were either asymptomatic HBsAg carriers or had various diseases including chronic persistent hepatitis (CPH), chronic active hepatitis (CAH), and renal disease undergoing hemodialysis, were tested for free HBeAg and IgG-bound HBeAg. Patients with CAH from two different countries were compared. Free HBeAg was detected in all patients but one, IgG-bound HBeAg was detected with similar prevalences (from 56% to 67%) in HBsAg asymptomatic carriers, hemodialysis patients, CPH and Italian CAH patients. In contrast, all CAH patients from New York, who had frequently been exposed to HBV infection, had detectable levels of IgG-bound HBeAg, with the highest S/N ratios observed in the study, and frequently showed an unfavorable outcome. In AVH due to HBV and delta agent co-infection, IgG-bound HBeAg was detected in two of four patients only in the initial stage of the disease. The data reported indicate that a separate determination of free- and IgG-bound HBeAg may have clinical value.

Adolescent↗