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F Negro

Publications and source records attributed to F Negro.

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

Epstein-Barr virus detection by in situ hybridization in fine-needle aspiration biopsies.

Metastasis to neck lymph nodes is often the presenting symptom of occult head and neck tumors, including undifferentiated nasopharyngeal carcinoma (UNPC). The diagnosis of the primary site of the tumor by conventional cytological analysis of tissue obtained by fine-needle aspiration (FNA) may be difficult. As Epstein-Barr virus (EBV) infection is consistently associated with UNPC, we evaluated the diagnostic significance of EBV detection using a nonradioisotopic in situ hybridization assay. The data obtained by FNA from metastatic head and neck tumors was correlated with the histology of the corresponding surgical specimens. In a series of 25 FNA specimens of cervical lymph node metastases of tumors of unknown origin, EBV was found expressed in all seven metastases of UNPC but in none of 18 metastases of tumors of different types. Therefore, detection of EBV in cervical metastatic adenopathy may be successfully used to identify the presence of occult UNPC.

Adult↗
PubMed1994

Infection by Epstein-Barr virus in Hodgkin's disease is not restricted to the Reed-Sternberg cells.

The presence of Epstein-Barr virus (EBV) DNA was analysed by a non-radioisotopic in situ hybridization procedure within eight Hodgkin's disease tissues. Seven specimens contained EBV DNA, that was found not only within the Reed-Sternberg tumour cells, but also, to a varying degree, within the surrounding lymphocytes. The staining was more diffuse in the nodular sclerosis and interfollicular types, whereas it involved only a minority of lymphocytes in cases with mixed cellularity. Appropriate controls established the specificity of these findings. The widespread expression of EBV DNA within Hodgkin's disease tissue heavily underscores the involvement of EBV in the pathogenesis of this illness.

DNA, Viral↗
PubMed1994

Detection of human androgen receptor mRNA in hepatocellular carcinoma by in situ hybridisation.

Recent evidence suggests that anti-androgen therapy may be useful in patients with androgen receptor (AR)-positive hepatocellular carcinomas (HCC), as determined by a steroid binding assay. To evaluate the AR expression of HCC, in both histological and cytological material, we developed a non-radioisotopic in situ hybridisation (NISH) assay specific for the human AR mRNA. A synthetic oligonucleotide complementary to positions 661-695 of the human AR coding sequence was end-labelled with digoxigenin-dUTP and revealed by an alkaline phosphatase-conjugated anti-digoxigenin antibody. We analysed 22 formalin-fixed, paraffin-embedded HCC, obtained at surgery, together with the corresponding non-neoplastic liver tissues (19 cases). In six cases, cell blocks obtained by fine-needle aspiration (FNA) prior to surgery were also available. Positive controls included seminal vesicles and prostate tissues. Sixteen HCCs (73%) expressed a variable amount of AR mRNA, with the proportion of positive cells ranging from very few to more than 90%. Normal hepatocytes were stained weakly and focally in eight cases (42%). Appropriate controls, inclusive of immunohistochemical detection of the AR protein in selected cases, established the specificity of the assay. Data obtained on FNA specimens were predictive of the results on histologic material. However, in two cases the NISH assay was negative on the cytological specimen but stained rare hepatocytes within the surgically resected tumor. In conclusion, NISH is a novel procedure for rapid and specific assessment of the expression of AR in HCC tissue. Its clinical significance, in terms of predictivity of response to anti-androgen treatment, needs to be assessed in large correlative studies.

Adult↗
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

Urachal adenocarcinoma. A case report.

A 21-year-old woman, previously operated for an acute abdomen from an infected urachal cyst, developed an urachal carcinoma. The importance of systematically and completely exciding urachal cysts is stressed by clinical considerations of the uncommon neoplasm that is associated with a poor prognosis.

Adenocarcinoma↗
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

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

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

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

Pathobiology of hepatitis delta virus.

Early observations in humans and infectivity studies in the chimpanzee suggested a direct cytotoxic effect as the major pathogenetic factor in delta hepatitis. Data acquired in liver transplant patients, as well as additional experimental and clinical evidence, have modified this view and indicate instead that liver damage depends on several factors. To explain the array of different clinical presentations, the replication strategy of hepatitis delta virus, the helper function and genetic heterogeneity of the co-infecting Hepadnavirus, and the response of the host immune system should all be taken into consideration.

Animals↗
PubMed1993

Clinical significance of the antibody to the putative core protein of hepatitis C virus in patients with chronic liver disease.

We evaluated the clinical significance of the antibody to hepatitis C core protein (anti-p22) analysing 147 sera from 99 patients; 45 of them had post-transfusion non A non B (NANB) hepatitis, 28 cryptogenic non A non B hepatitis, 12 chronic hepatitis B, 7 chronic hepatitis D, 6 other forms of liver disease (4 primary biliary cirrhosis, 2 autoimmune hepatitis) and 1 rheumatoid arthritis. All sera were tested by commercial 1st and 2nd-generation ELISAs and anti-p22 single antibody ELISA. We found a highly significant correspondence between anti-p22 and commercial assays (p = 0.0001). HCV-RNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR) in sera showing positive or negative concordant results and in all sera (24) that showed discordant results by anti-p22 and commercial ELISAs. HCV-RNA was found in 14 of 17 (82%) anti-p22 positive sera that were negative by commercial ELISAs, in 1 of 7 (14.3%) anti-p22 negative sera that were positive by commercial ELISAs (p = 0.001) and in all control sera from patients with positive concordant results. It was undetectable in 7 sera from patients with autoimmune diseases (negative by all ELISAs). We studied follow-up sera from 16 patients treated with interferon: 8 long-term responders (with persistently normal ALT levels for at least 24 months after discontinuation of therapy and histological remission) and 8 non-responders. Sera were also tested by a 4-antigen recombinant immunoblotting assay (RIBA II).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Detection of intrahepatic replication of hepatitis C virus RNA by in situ hybridization and comparison with histopathology.

A nonisotopic in situ hybridization (NISH) assay was used to detect hepatitis C virus (HCV) RNA. A synthetic oligonucleotide complementary to bases 252-301 of the highly conserved 5' noncoding region of the HCV genome was end-labeled by terminal deoxynucleotidyltransferase using digoxigenin-conjugated dUTP. The hybridized oligomer was revealed by an immunohistochemical reaction after incubation with an alkaline phosphatase-conjugated anti-digoxigenin antibody and subsequent amplification with a complex of alkaline phosphatase and anti-alkaline phosphatase antibodies. The intracellular distribution of HCV RNA was monitored in the livers of two chimpanzees experimentally infected with the H strain of HCV and compared with the serum alanine aminotransferase activity, serum HCV RNA, and liver histopathology. Most cells were stained in the cytoplasm as early as 2 days after inoculation, 1 and 2 days, respectively, before the appearance of viral RNA in the serum. The time course of HCV RNA replication was correlated with increases in serum alanine aminotransferase. However, neither one paralleled the appearance of liver cell necrosis nor showed any correlation with the inflammatory response. The NISH signal was not found in liver biopsy specimens taken from these two animals before inoculation with HCV, from chimpanzees with acute hepatitis type A, B, or delta, or from two animals never experimentally infected with any hepatitis agent; moreover, it disappeared when the positive specimens were predigested with RNase and it was not observed after hybridization of positive controls with a labeled oligomer unrelated to HCV RNA. Thus, detection of liver HCV RNA by NISH is a sensitive and specific method for studying HCV replication at the cellular level. Intracellular replication of HCV did not appear to be associated with histopathologic changes in the liver, although the correlation with increases of liver enzyme activity in the serum suggested possible damage to the liver cell membrane.

Alanine Transaminase↗
PubMed1992

Detection of hepatitis delta virus RNA by a nonradioactive in situ hybridization procedure.

A digoxigenin-tailed, synthetic oligodeoxynucleotide was used to detect genomic hepatitis delta virus (HDV) RNA in formalin-fixed, paraffin-embedded liver sections by a nonisotopic in situ hybridization (NISH) procedure. Twenty-three liver samples from chronically HDV-infected patients were studied. Eight liver specimens from humans and chimpanzees without markers of active HDV infection served as negative controls. In three samples, the NISH findings were compared with characteristic nuclear features and with the distribution of the HDV encoded antigen, HDAg, as detected by direct immunofluorescence. All samples from HDV-infected patients were positive for HDV RNA by NISH. The viral genome was exclusively observed within the hepatocytic nuclei. No enzymatic reaction was detected after hybridization with the negative controls. "Sanded" nuclei, a cytopathologic change associated with HDV infection, were HDV RNA-positive, but only a small percentage of infected cells showed that feature. Hepatocytes containing the HDV RNA were sometimes binucleated or exhibited giant nuclei. When HDAg and HDV RNA were sequentially detected within the same sections, the localization of the viral antigen almost completely overlapped with the expression of the HDV transcripts, and vice versa. In conclusion, detection of intrahepatic HDV RNA by NISH is a rapid, sensitive, and specific technique that is easily applicable to routine histopathology and allows correlation of HDV with the morphology of hepatocyte nuclei.

Antigens, Viral↗