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Biomedical subjects

F Bonino

Publications and source records attributed to F Bonino.

At least 91 records · Page 5Linked to original sources
PubMed1994

Precore mutant hepatitis B virus and outcome of chronic infection and hepatitis in hepatitis B e antigen-positive children.

Mutant hepatitis B virus (HBV), responsible for the lack of hepatitis B virus "e" antigen (HBeAg) secretion because of a translational stop codon at nucleotide 1896 of the HBV-DNA precore region (HBeAg minus HBV), has been detected worldwide in acute and chronic HBV infections and diseases. HBeAg minus HBV appears to condition the outcome of infection and to be involved in the pathogenesis of hepatitis B. We investigated the mutant prevalence and its clinical implications in 30 hepatitis B surface antigen/HBeAg-positive children (17 treated with interferon) with chronic hepatitis B. Wild-type and HBeAg minus HBV were characterized by quantitative oligohybridization assays in sera from 29 children followed up for a mean of 33 mo (12 mo to 9 y). At admission, 18 children (62%) circulated wild-type HBV alone; mutant HBV became detectable in two of them during the follow-up before HBeAg/anti-HBe seroconversion. Wild-type and HBeAg minus HBV were detected in 10 children (34.5%); mutant HBV levels were lower than 20% of total viremia in four of them and higher in six. Serum HBV-DNA from one child did not hybridize with our probes. HBeAg minus HBV was associated with older age (p < 0.009) and higher histologic activity (p < 0.069). HBeAg/anti-HBe seroconversion occurred independently from HBeAg minus HBV detection; it was observed in six (37.5%) of 16 children with wild-type HBV alone and in four (33.3%) of 12 children with mixed viremia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Expression of the c-myc protooncogene product in cells infected with the hepatitis delta virus.

The intrahepatic accumulation of the c-myc protooncogene product was observed on immunofluorescence in each of six patients with chronic hepatitis delta virus infection who exhibited the hepatitis D antigen in their livers. The c-myc product was stained in the same nuclei that contained the hepatitis D antigen. C-myc was not observed in acute hepatitis D or in cases of chronic hepatitis delta virus infection without expression of the hepatitis D antigen. The protooncogene product was detected in only 1 of 32 viral and nonviral liver disorders unrelated to hepatitis delta virus. To confirm these observations, we transfected HBsAg-positive (PCL/PRF/5) and HBsAg-negative (HepG2) transformed liver cell lines with a plasmid containing a hepatitis delta virus cDNA trimer under the control of the SV40 early enhancer/promoter sequences. Whereas baseline c-myc expression was barely detectable in mock-transfected PLC/PRF/5 or HepG2 cells, strong c-myc nuclear fluorescence was observed when these same cells were transfected with the hepatitis D antigen expression vector. Similar results were obtained after infection of HeLa cells with a recombinant vaccinia virus expressing the hepatitis D antigen. Detection of c-myc mRNA sequences by means of in situ hybridization suggested that the c-myc product accumulation was not due to increased amounts of its mRNA. The c-myc protein accumulates selectively in the livers of patients with chronic hepatitis delta virus infection and in the same nuclei that contain the hepatitis D antigen. The expression of c-myc in hepatitis D antigen-containing cells does not require the presence of hepatitis B virus infection.

Amino Acid Sequence↗
PubMed1994

Intramuscular natural beta interferon in the treatment of chronic hepatitis B: a multicentre trial. Italian Hepatitis B Study Group.

A randomized controlled multicentre trial was undertaken to assess the effectiveness of natural IFN beta (Frone) administered by intramuscular injection to chronic hepatitis B patients. Sixty-five HBsAg and HBeAg carriers with chronic hepatitis and intrahepatic HBcAg histologically proven by immunohistochemistry were included in the study. Fifty-nine patients completed the study: 30 of them (mean age 27 years, range 14-55 years, 16M/14F) were treated with 5 Million Units (MU)/m2 of Frone three times weekly for six months and 29 (mean age 28 years, range 14-59 years, 18M/11F) were not treated. The 2 groups of patients were similar in their clinical and histological (CAH/CPH ratio 25/5 and 20/9) characteristics. In the treated patients, a significant reduction in viremia was observed starting from the 6th month of the follow-up (p < 0.01), accompanied by a significant reduction of serum aminotransferase levels (p < 0.005). At the end of therapy serum HBeAg was undetectable in 7 of 30 (23%) treated patients and in 1 of 29 (3%) controls. Six months after the end of treatment 8 of 30 (26%) treated patients and 5 of 29 (17%) controls were HBeAg negative. A significant difference (p < 0.05) was observed in the rate of anti-HBe seroconversion between the 2 groups starting from the 8th month of follow-up. Mild side effects, namely fever < 38 degrees C and asthenia were observed in 20% and 37% of treated patients. In conclusion natural beta interferon given intramuscularly is effective in HBeAg positive patients suffering from chronic hepatitis B with optimal compliance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Albumin gene expression in liver tumors: diagnostic interest in fine needle aspiration biopsies.

Albumin is a specific product of normal and transformed hepatocytes, but unfortunately its immunohistochemical demonstration proves unreliable because of diffusion artifacts. An in situ hybridization procedure to reveal albumin mRNA was applied to fine needle aspiration specimens of liver nodes with the aim of testing the usefulness of this marker in the cytological diagnosis of hepatocellular carcinomas (HCC). A 51-base pair oligonucleotide probe was labeled with digoxigenin and used on paraffin sections of alcohol-fixed cell blocks. A series of 97 cases originally interpreted, on the basis of cytology alone, as "hepatocellular carcinoma" (62 cases), as "carcinoma cells, not otherwise specified" (15 cases), as "adeno-carcinoma" (16 cases), and as "non-epithelial neoplastic cells" (4 cases), was studied. In all cases, clinical and follow-up information was obtained; a diagnosis of HCC was reached with certainty in 44 cases and suspected in 22. Thirty-one other cases were proven to be bile duct adenocarcinomas or metastatic tumors. Taking into account proven cases only, albumin mRNA was found in 42/44 HCC and in none of the control cases (sensitivity, 95.5%; specificity, 100%). Of 22 cytologically suspected HCC, albumin mRNA was positive in 19 cases. Also, high grade pleomorphic HCCs expressed albumin gene, and this finding is of value in the differential diagnosis with liver metastases of anaplastic tumors from lung, adrenal, pancreas, etc. The diagnosis of HCC on a cytological basis is becoming increasingly important because most cases are unresectable and have to be included in different therapeutic protocols.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1993

Compartmentalization of T lymphocytes to the site of disease: intrahepatic CD4+ T cells specific for the protein NS4 of hepatitis C virus in patients with chronic hepatitis C.

The adult liver is an organ without constitutive lymphoid components. Therefore, any intrahepatic T cell found in chronic hepatitis should have migrated to the liver after infection and inflammation. Because of the little information available on the differences between intrahepatic and peripheral T cells, we used recombinant proteins of the hepatitis C virus (HCV) to establish specific T cell lines and clones from liver biopsies of patients with chronic hepatitis C and compared them with those present in peripheral blood mononuclear cells (PBMC). We found that the protein nonstructural 4 (NS4) was able to stimulate CD4+ T cells isolated from liver biopsies, whereas with all the other HCV proteins we consistently failed to establish liver-derived T cell lines from 16 biopsies. We then compared NS4-specific T cell clones obtained on the same day from PBMC and liver of the same patient. We found that the 22 PBMC-derived T cell clones represent, at least, six distinct clonal populations that differ in major histocompatibility complex restriction and response to superantigens, whereas the 27 liver-derived T cell clones appear all identical, as further confirmed by cloning and sequencing of the T cell receptor (TCR) variable and hypervariable regions. Remarkably, none of the PBMC-derived clones has a TCR identical to the liver-derived clone, and even with polymerase chain reaction oligotyping we did not find the liver-derived clonotypic TCR transcript in the PBMC, indicating a preferential intrahepatic localization of these T cells. Functionally, the liver-derived T cells provided help for polyclonal immunoglobulin (Ig)A production by B cells in vitro that is 10-fold more effective than that provided by the PBMC-derived clones, whereas there is no difference in the help provided for IgM and IgG production. Altogether these results demonstrate that the protein NS4 is highly immunogenic for intrahepatic CD4+ T cells primed by HCV in vivo, and that there can be compartmentalization of some NS4-specific CD4+ T cells to the liver of patients with chronic hepatitis C.

Adult↗
PubMed1993

Expression of estrogen receptor mRNA in tumorous and non-tumorous liver tissue as detected by in situ hybridization.

Estrogen receptor mRNA was detected by a non-radioactive in situ hybridization assay in tumor and non-neoplastic liver tissues. A synthetic oligonucleotide complementary to the human estrogen receptor mRNA was 3'-labeled with digoxigenin-deoxyuridine triphosphate (dUTP). Hybrids were revealed by an alkaline phosphatase-conjugated anti-digoxigenin antibody. Fourteen primary hepatocellular carcinoma tissues (and one metastatic) were obtained at surgery from 15 patients. The corresponding non-neoplastic liver tissues were available in 13 cases. The estrogen receptor mRNA was detected in 11 tumorous and 7 non-tumorous liver specimens. The staining was cytoplasmic and involved the majority of transformed hepatocytes, whereas a less widespread and weaker signal was found in normal hepatocytes. Within non-neoplastic tissue, bile duct epithelial cells could also be occasionally stained, whereas other cell types, such as vasal endothelial cells, were negative. Appropriate controls established the specificity of the reaction. Detection of the estrogen receptor protein by immunohistochemistry in these same specimens was invariably negative. This in situ hybridization assay can therefore be used as a complementary tool to evaluate the estrogen receptor expression within liver cancer.

Adolescent↗
PubMed1993

Infectious hepatitis B virus variant defective in pre-S2 protein expression in a chronic carrier.

All human hepatitis B viruses characterized so far express three envelope proteins, pre-S1, pre-S2, and HBs, which are believed to function as binding proteins for the cellular receptor, as targets for immune-mediated virus elimination, and in virion morphogenesis and secretion. Here we report the characterization of infectious HBV variant genomes that are unable to express a pre-S2 protein and which were derived from serum of a highly viremic chronic carrier. Direct sequencing of the amplified pre-S region and sequencing of 50 cloned amplified pre-S DNA fragments revealed that in all molecules, in addition to numerous nucleotide changes, there were deletions of the pre-S2 translation initiation codon and three codons 54 nucleotides downstream thereof. No pre-S2 protein and altered pre-S1 proteins were found in the serum of the patient. Cloned infectious HBV DNA genomes having the pre-S region substituted by the variant pre-S region were replication competent in cultured hepatoblastoma cells. Morphologically normal virions were efficiently secreted and were infectious for primary human hepatocyte cultures. These data demonstrate that HBV devoid of pre-S2 protein can occur in vivo as a dominant or exclusive virus population and that expression of the pre-S2 protein is not essential for HBV replication, virion morphogenesis, secretion, or in vitro infectivity.

Adult↗
PubMed1993

Hepatitis C virus infection in type II essential mixed cryoglobulinemias.

The possible relationship between essential mixed cryoglobulinemias (EMCs) and hepatitis C virus (HCV) has been investigated in eight patients with type II EMCs and biochemical signs of liver damage, whose serum tested positive in the ELISA for anti-HCV. Sera were tested using the 2nd generation RIBA assay, while serum HCV-RNA was measured semiquantitatively by a RT-PCR in whole serum, cryoprecipitates and supernatants. In all patients a percutaneous liver biopsy and a bone marrow biopsy were performed. At liver biopsy, chronic active hepatitis and/or cirrhosis were present in 6 patients; in the remaining two, a lymphoplasmacytoid infiltration of elements positive for kappa light chains was found. In all patients a bone marrow biopsy showed a paratrabecular infiltration of monoclonal lymphoplasmacytoid elements similar to those found in the liver of the two patients described above. Antibodies against structural and non-structural HCV proteins were detectable in the serum of all patients. HCV-RNA was amplified from the whole sera, cryoprecipitates and supernatants: significantly higher concentrations were found in cryoprecipitates than in supernatants. Our results confirm the high prevalence of HCV infection and ongoing viral replication in patients with type II EMC and suggest the possible implication of HCV in EMC pathogenesis.

Aged↗
PubMed1993

Role of IgM antibody to hepatitis B core antigen in the diagnosis of hepatitis B exacerbations.

IgM anti-HBc levels were measured by the IMx Core-M Abbott assay in 939 serum samples in order to define a specific and sensitive cut-off value for diagnosis of chronic hepatitis B. The sera used were obtained from 52 chronic HBV patients and 10 HBV carriers with HCV or HDV co-infections and 155 asymptomatic subjects without evidence of liver disease. A Youden index value of 95.4% with 98% sensitivity and 97.4% specificity was obtained for an IMx Index value of 0.204 as cut-off. A one-year follow-up study with monthly tests has shown that quantitative analysis of IgM anti-HBc can serve as a noninvasive tool for monitoring HBV infection, and provides an accurate diagnosis of hepatitis B exacerbations. Significant elevations of IgM anti-HBc levels were associated with hepatitis B exacerbations in 96.2% of the cases but with none of the ALT flare-ups observed in HCV or HDV infected individuals. These results suggest that quantitative analysis of IgM anti-HBc provides the highest degree of confidence in definition of spontaneous and therapy-induced exacerbations or remissions of hepatitis B.

Adolescent↗
PubMed1993

Accumulation of a cellular protein bearing c-myc-like antigenicity in hepatic and non-hepatic delta antigen expressing cells.

Patients with chronic but not acute hepatitis delta virus infection undergo a strong accumulation of a protein of cellular origin which specifically reacts with a panel of anti-c-myc antibodies and which is expressed in the same nuclei that express the delta antigen. In this paper we report on the in vitro characterization of this phenomenon. The delta antigen induced c-myc antigen accumulation can occur in vitro upon transfection of HBsAg positive and negative cell lines with HDAg expression vectors. Using recombinant vaccinia viruses expressing only p24 or p27 we demonstrate that structures common to the two isoforms of HDAg are responsible for the phenomenon, which is not restricted to cells of hepatic origin.

Antigens, Viral↗
PubMed1993

Propafenone-induced liver injury: report of a case and review of the literature.

A case of an acute cholestatic syndrome associated with use of the antiarrhythmic drug propafenone is reported here. The close time relationship between the administration of the drug and the acute onset of the liver damage, the histological findings, and the reappearance of biochemical signs of liver dysfunction upon rechallenge with the same medication strongly suggest that propafenone was involved in the pathogenesis of this syndrome. Although rare, hepatotoxicity from this widely used antiarrhythmic medication should be kept in mind in the differential diagnosis of sudden cholestatic syndrome of obscure origin.

Aged↗
PubMed1993

T-lymphocyte response to hepatitis C virus in different clinical courses of infection.

BACKGROUND: To assess the role played by the immune response in the outcome of hepatitis C virus infection, the CD4+ T-lymphocyte response to viral antigens was studied in infected individuals with different clinical courses. METHODS: Using six recombinant proteins of hepatitis C virus, the study assessed the proliferative responses of peripheral blood mononuclear cells from 41 patients with chronic hepatitis C, 11 patients whose chronic hepatitis was successfully treated with interferon alfa and 11 healthy HCV seropositive individuals. RESULTS: (1) Sixty-five percent of hepatitis C virus-seropositive individuals had CD4+ T-cell responses to viral proteins. (2) All viral proteins were immunogenic for T cells, although NS4 was the most immunogenic. (3) There was a significant correlation between the presence of CD4+ T cell responses to Core and a benign course of infection in healthy seropositives, most of whom were viremic. CONCLUSIONS: CD4+ T-cell responses to Core, although they do not coincide with virus clearance, are associated with a benign course of infection and may be required to maintain humoral and cellular responses protective against the disease.

Adolescent↗
PubMed1993

Hepatitis B virus heterogeneity, one of many factors influencing the severity of hepatitis B.

The pathogenesis of hepatitis B can be subdivided into three sequentially correlated events: (a) loss of virus tolerance, (b) liver cell necrosis mediated by virus specific inflammatory response, (c) non-specific death of functionally compromised hepatocytes mediated by inflammatory cytochines released by virus specific inflammatory response. The severity of liver damage depends on the occurrence of these events as well as other factors. The HBeAg defective mutant appears to be involved in the loss of virus tolerance and therefore in the pathogenesis of acute hepatitis B. In addition it is positively selected by antiviral immunoreaction, behaves as an escape mutant, and it also contributes to the pathogenesis of chronic hepatitis B. The combination of these characteristics explains the relative prevalence of this mutant over wild-type HBV in patients with severe acute hepatitis B and in chronic HBsAg carriers during anti-HBe seroconversion and/or hepatitis B exacerbations. However, the absence of HBeAg defective mutants in some cases of severe and fulminant hepatitis B as well as its detection in asymptomatic carriers of HBsAg should not be surprising. The severity of hepatitis is influenced by many other factors: the number of virus infected cells, the competence and genetic heterogeneity of the immune system, the vigor and extent of non-specific inflammatory response and the killing of hepatocytes endangered by other diseases or infected with other hepatotropic viruses.

Animals↗
PubMed1993

Colon cancer seeding after percutaneous fine needle aspiration of liver metastasis.

Fine needle aspiration or biopsy is used for cytologic diagnosis of many intra-abdominal tumors including focal liver lesions. The incidence of needle tract seeding is quite low. In this paper the first case of cutaneous seeding after percutaneous fine needle aspiration of liver metastasis is reported in a case of colon cancer. We suggest using this method for cytologic diagnosis in hepatic tumors when surgical resection is not possible and when patients will be treated with invasive therapies and to avoid fine needle aspiration biopsy in patients undergoing surgical resection or when there is a confident diagnosis of HCC by non-invasive procedures.

Adenocarcinoma↗
PubMed1993

Hepatitis C virus infection and disease. Diagnostic problems.

Hepatitis C virus (HCV) is a lipid-enveloped single-stranded RNA virus with an unknown physical structure as only putative HCV particles have been identified by electron microscopy. Although HCV lacks the retroviral properties of being able to integrate into host DNA, it causes chronic infection in a considerable number of infected individuals (40-60%). Chronic infection is associated with a wide spectrum of liver diseases ranging from normal presentation to the different forms of chronic hepatitis, cirrhosis (about 20% of cases) and hepatocellular carcinoma. HCV therefore is not invariably and equally pathogenic, and genetic heterogeneity could be a major cause of such variability. Diagnosis of HCV infection relies on anti-HCV and HCV-RNA detection. Using second-generation assays, diagnostic sensitivity has increased to about 95%, but detection of anti-HCV does distinguish past from present infections. Only rising anti-HCV titres or anti-HCV seroconversion confirm a recent HCV infection. In anti-HCV-negative infections and cases of early acute hepatitis, HCV-RNA detection by RT-PCR represents a valid diagnostic alternative. In patients undergoing interferon therapy, testing for anti-HCV by immunoblotting represents a valid routine tool to monitor response. Anti-C-22 has the highest titre and persists longer while anti-C-100 is the earliest antibody to disappear in responders. The significant association between serum anti-C-100, HCV-RNA and liver disease suggests that anti-C-100 is an indirect marker of hepatitis C, but true markers of HCV-induced liver disease are still lacking.

Diagnosis, Differential↗
PubMed1993

Monitoring the natural course and response to therapy of chronic hepatitis B with an automated semi-quantitative assay for IgM anti-HBc.

The clinical significance of a semi-quantitative microparticle enzyme immunoassay (IMx Core-M, Abbott) was evaluated for detection of IgM-class antibodies against the hepatitis B core antigen (IgM anti-HBc) in 136 hepatitis B surface antigen (HBsAg) positive individuals (96 chronic HBV carriers, 20 patients with chronic HBV-HDV infections and 20 patients with acute hepatitis B) and 50 HBV-negative controls. Baseline and follow-up sera (4-11 samples) were analysed from 79 carriers with chronic hepatitis B, 44 of whom were treated with interferon. IMx indexes above 3,000 were found in 95% of the acute hepatitis B patients and above 0.300 in 91.5% of patients with ongoing chronic hepatitis B. IMx indexes between 0.200 and 0.300 were observed in (a) patients with recent HBeAg to anti-HBe seronconversion (6-12 months) and normal serum ALT levels, (b) patients immuno-tolerant to HBV infection and without liver disease despite high levels of viremia, and (c) patients with anti-HBe-positive chronic hepatitis B during 7-13-month intervals of asymptomatic carriage between episodes of disease reactivation. IMx indexes below 0.200 were detected in all HBV-negative individuals and healthy HBV carriers, in 14 (70%) of 20 chronic hepatitis D patients and in all but 1 of 22 interferon-treated patients with histological remission of liver disease, 5-12 months after clearance of viremia and normalization of serum ALT levels. In contrast, IMx indexes remained above 0.200 in all patients with hepatitis B reactivation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Problems in diagnosing viral hepatitis.

The most reliable method of making a specific aetiological diagnosis of chronic viral hepatitis would be to identify virus specific cytotoxic T lymphocytes responsible for the killing of virus infected hepatocytes in each patient's liver. Unfortunately, this can not be proposed for routine diagnosis and surrogate tests are required. The detection of virus markers, and even of the virus itself, does not imply that liver damage is caused by virus infection. Indirect markers of the host's antiviral immunoresponse have to be used to confirm more specifically the diagnosis of viral hepatitis. IgM antibodies against viral antigens implicated in the elimination of the virus seem to be suitable alternative candidates. Significant changes in the serum values of viraemia and aminotransferases occur within a few days, while a significant variation in liver histology takes much longer. Only the kinetics of the highly variable parameters can be used for an appropriate study of the relationship between viraemia, antiviral immunoresponse, and liver cell necrosis. Quantitative and dynamic analyses of hepatitis virus markers seem the most suitable and reliable methods of monitoring the patients eligible for antiviral treatment and identifying the most appropriate time to start this.

Antibodies, Viral↗