Role of surgical interventions in the treatment of patients with trophoblastic tumor resistant to chemotherapy

A novel strategy for anti-viral intervention of hepatitis B virus (HBV) through the disruption of the proper folding and transport of the hepadnavirus glycoproteins is described. Laboratory reared woodchucks chronically infected with woodchuck hepatitis virus (WHV) were treated with N-nonyl-deoxynojirimycin (N-nonyl-DNJ), an inhibitor of the endoplasmic reticulum (ER) alpha-glucosidases. The woodchucks experienced significant dose dependent decreases in enveloped WHV, resulting in undetectable amounts in some cases. The reduction in viremia correlated with the levels of hyperglucosylated glycan in the serum of treated animals. This correlation supports the mechanism of action associated with the drug and highlights the extreme sensitivity of the virus to this type of glycan inhibitor. At N-nonyl-DNJ concentrations that prevented WHV secretion, the glycosylation of most serum glycoproteins appeared unaffected, suggesting great selectivity for this class of therapeutics. Indeed, this may account for the low toxicity of the compound over the treatment period. We provide the first evidence that glucosidase inhibitors can be used in vivo to alter specific steps in the N-linked glycosylation pathway and that this inhibition has anti-viral effects.     

Systemic distribution of talc after intrapleural administration in rats

BMS-200475 was recently shown to have potent antiviral activity against hepatitis B virus (50% effective concentration = 3.7 nM; 50% cytotoxic concentration = 30 microM). In metabolic studies in both HepG2 and hepatitis B virus-transfected 2.2.15 human hepatoma cell lines, the metabolism was similar, the primary products being the di- and triphosphates. The accumulation of triphosphate was rapid and detectable down to a 5 nM concentration of added drug. When cells were labeled at 25 microM, the intracellular triphosphate concentration attained 30 pmol/10(6) cells ( approximately 30 microM). The intracellular half-life of the triphosphate was about 15 h. Compared with five other nucleoside analogs of medical interest (lamivudine, penciclovir, ganciclovir, acyclovir, and lobucavir), BMS-200475 was most efficiently phosphorylated to the triphosphate in HepG2 cells.     

Serum hepatitis G virus RNA in patients with chronic viral hepatitis

OBJECTIVES: The hepatitis G virus (HGV) is a newly described flavivirus that affects a high proportion of patients with chronic viral hepatitis: our objective was to determine what role HGV might play in the course of disease. METHODS: We evaluated stored serum samples from 108 patients with chronic hepatitis B and 99 patients with chronic hepatitis C who participated in trials of alpha-interferon or ribavirin for the presence of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA by branched DNA and for the presence of HGV RNA by polymerase chain reaction (PCR), using primers from the NS5 region of the genome. RESULTS: Initially, 20 (19%) patients with hepatitis B and 11 (11%) with hepatitis C had HGV RNA in their serum. Patients with and without HGV infection were similar with regard to clinical features, laboratory tests, and hepatic histology. HGV RNA levels fell during interferon therapy and became undetectable in those receiving the highest doses; however, HGV RNA levels returned to pretreatment values when therapy was stopped. With ribavirin therapy, HGV RNA levels did not change. Two- to 12-yr follow-up serum samples were available from 17 initially HGV RNA-positive patients, of whom only 10 (59%) were still positive. CONCLUSIONS: HGV infection is common among patients with chronic hepatitis B and C but has little effect on the short-term course of disease or response to therapy. HGV RNA levels are suppressed but not eradicated by alpha-interferon and are unaffected by ribavirin treatment. Spontaneous loss of HGV RNA occurs over time in a proportion of patients.     

Evaluation of enzyme immunoassay for hepatitis B virus DNA based on anti-double-stranded DNA

We have evaluated a new enzyme immunoassay technology to detect the products of PCR-based amplification that may be applicable to routine testing of hepatitis B virus (HBV) DNA. Two hundred eight serum samples were studied: 73 were basal samples and 135 were sequential serum samples from patients with chronic hepatitis, some of whom were being treated with alpha interferon. We compared the new detection method (PCR-DNA enzyme immunoassay [DEIA]) with dot blot hybridization performed without prior PCR amplification and with two other methods for detection of PCR products: agarose gel electrophoresis with ethidium bromide staining (PCR-EB) and dot blot (PCR-dot blot). For hepatitis B-antigen-positive basal samples, HBV DNA was detected in 70.4% by dot blot, 74.1% by PCR-EB, and 100% by PCR-DEIA and PCR-dot blot; for anti-hepatitis B e-antigen basal samples, HBV DNA was found in 10.5% by dot blot and PCR-EB and in 42.1% by PCR-DEIA and PCR-dot blot. Chi-square tests showed a strong association between dot blot and PCR-EB and between PCR-DEIA and PCR dot blot. Using PCR-dot blot as the reference, dot blot shows a 56.9% sensitivity and a 100% specificity, PCR-EB shows a 55.0% sensitivity and a 100% specificity, and PCR-DEIA shows a 95.4% sensitivity and a 97% specificity. We conclude that the technical advantages of the DEIA method and its high sensitivity and specificity may facilitate the use of PCR in routine testing for HBV DNA in clinical microbiology laboratories.     

A multicenter controlled, randomized, open trial of interferon alpha2b treatment of anti-human immunodeficiency virus-negative hemophilic patients with chronic hepatitis C. Hepatitis Study Group of the Association of Italian Hemophilia Centers

There is limited information about the long-term efficacy of prolonged therapy (more than 6 months) with interferon alpha in hemophilic patients with chronic hepatitis C who are not coinfected with the human immunodeficiency virus (HIV-1). One hundred and seven hemophiliacs were randomly assigned to 3 million U of interferon alpha2b three times weekly for 12 months or no therapy. The patients were followed up for at least 12 months posttreatment. Response was assessed by both serial alanine aminotransferase (ALT) levels and hepatitis C virus (HCV)-RNA measured by reverse transcribed polymerase chain reaction (RT-PCR) method. Before treatment, serum levels of HCV-RNA were measured quantitatively by second-generation branched-DNA assay and the HCV genotype was determined by RT-PCR. Serum HGV-RNA, a marker of infection with the hepatitis G virus, was also measured by RT-PCR. Normalization of ALT was sustained and serum HCV-RNA was cleared in 6 of 45 treated patients, compared with none of the 50 untreated controls (13% v 0% P < .01). Low pretreatment viremia was the only feature that was associated with an increased likelihood of sustained response (P < .01). This study shows that multitransfused hemophiliacs with chronic hepatitis C not coinfected with HIV-1 respond at low rates to prolonged interferon therapy.     

Evaluation of pedicle screw insertion monitored by intraoperative evoked electromyography

The clinical importance of hepatitis B virus (HBV) genome variability has been reported recently. One example is the occurrence of hepatitis B virus pre-core mutants, which arise during spontaneous or interferon-induced seroconversion from HBeAg to anti-HBe and are thought to be selected by immune pressure. A survey of HBV pre-core mutants and viral genotypes in 35 HBeAg negative patients during interferon therapy was carried out to understand viral pathogenesis in this form of chronic hepatitis B. Seventeen patients responded to interferon therapy as assessed by the sustained normalization of serum ALT levels and the significant decrease of viremia levels. The response rate to interferon was independent of both initial serum viral DNA level and interferon doses. During interferon therapy, a significant decrease of M0 (wild-type pre-core sequence at pos. 1887-1908), M1 (TGG to TAG at pos. 1896) or M2 (TGG to TAG at pos. 1896, and GGC to GAC at pos. 1899) positive viral genomes was found in 48%, 42%, and 33% of patients, respectively. A higher response rate to interferon therapy was observed in patients infected with HBV genotype A (70%) or M0 positive strains (75%) as compared to patients infected with genotype D/E (40%) or M1/M2 positive strains (44%). The data support the hypothesis that pre-core defective HBV represent viral mutants with an increased capacity to resist exogenous alpha interferon. These findings emphasize that characterization of HBV genome variability prior to interferon therapy may help to predict antiviral response in HBeAg negative patients.     

Relative quantification and mapping of hepatitis C virus by in situ hybridization and digital image analysis

Although several reports concerning the detection of hepatitis C virus (HCV) by in situ hybridization have been published, there are no data concerning the relative viral load in infected hepatocytes or about its relation with serum viremia levels. To address these issues, liver biopsies from 10 patients with chronic hepatitis C were analyzed by in situ hybridization and digital image analysis of hybridization signals. Serum HCV RNA levels were measured using the Amplicor Monitor test. HCV RNA was detected by in situ hybridization in the hepatocytes of the ten liver samples. The hybridization signals were mainly found in the cytoplasm. The relative viral load per infected cell fit the second order polynomial curves in all cases. The minimum and maximum relative viral load per infected hepatocyte differed in the ten cases; however, large differences were not observed in the mean relative viral load among the samples, especially when compared with the increasing values detected for copy number per milliliter in serum. The percentage of infected cells ranged from 4.8% to 87.6% in the ten cases. The percentage of positive cells correlated with the serum viremia levels. Our data suggest that HCV viremia does not depend on the relative viral load per infected cell but on the number of infected hepatocytes.     

Use of quantitative assays for hepatitis B e antigen and IgM antibody to hepatitis B core antigen to monitor therapy in chronic hepatitis B

OBJECTIVES: We evaluated the clinical utility of IgM antibody to the hepatitis B (HB) core antigen (anti-HBc) and HB e antigen (HBeAg) serum levels in patients with chronic HB receiving interferon alfa. METHODS: Stored serum from 47 patients with chronic HB participating in a controlled trial of interferon alfa therapy (10 million U three times a week for 16 wk) were analyzed. All were seropositive for HB surface Ag, HBeAg, and HB virus (HBV) DNA before entry. IgM anti-HBc index values and HBeAg standard values were determined by automated microparticle enzyme immunoassay on samples drawn just before therapy and 6 months later. Ten normal subjects were tested as controls. IgM anti-HBc and HBeAg levels were compared to initial serum HBV DNA, DNA polymerase, serum aminotransferase levels, and demographic features. Serial IgM anti-HBc levels were also obtained during and after therapy in 10 responders and five nonresponders, and serial HBeAg levels were also obtained during and after therapy in four responders and four nonresponders. RESULTS: Neither IgM anti-HBc nor HBeAg levels correlated significantly with values for serum HBV DNA, DNA polymerase, aminotransferases, or demographic features. The initial mean IgM anti-HBc level among the 15 responders to therapy (loss of HBeAg and HBV DNA from serum) was no different from that in nonresponders (mean 1.15 vs 1.27, p = not significant). However, the initial mean HBeAg level was significantly lower in responders than in nonresponders (749.4 vs 1356.4, p = 0.019). Among 10 responders, IgM anti-HBc levels decreased progressively over time, so that at latest follow-up (1.5-4 yr later, mean 2.6 yr), the mean had decreased from 1.325 to 0.312 (p = < 0.001). Among five nonresponders, the mean did not change significantly over 1.5-3 yr (mean 2.2 yr) (1.26 vs 1.08, p = not significant). HBeAg values fell in parallel with HBV DNA and DNA polymerase values in four responders tested but remained elevated in four nonresponders. CONCLUSIONS: HBeAg levels, but not IgM anti-HBc levels, are useful in predicting response to interferon alfa, with responders tending to have lower pretreatment HBeAg levels than nonresponders. HBeAg levels may be used to monitor response to interferon alfa in patients with chronic HB.     

Urea denaturation of staphylococcal nuclease monitored by Fourier transform infrared spectroscopy

Hepadnavirus invasion in woodchucks has been identified as a potent inducer of autoantibodies against asialoglycoprotein receptor (anti-ASGPR), a molecule essentially unique to hepatocytes that mediate clearance of desialylated serum proteins. We evaluated the possible pathogenetic importance of anti-ASGPR triggered by woodchuck hepatitis virus (WHV), using anti-ASGPR-reactive serum immunoglobulins (Igs) from five animals with different stages of WHV hepatitis or self-limited WHV infection and isolated woodchuck hepatocytes or HepG2 cells as targets. The results revealed that WHV-induced anti-ASGPR can specifically inhibit asialoglycoprotein recognition by both homologous and heterologous liver cells, as tested in an asialofetuin (ASFN)-binding radioassay. However, the extent of the interference significantly varied (from 85% inhibition to none) for anti-ASGPR with similar titer from different animals, indicating a high degree of heterogeneity in the ASGPR epitope specificity and in the potential biological effects of these autoantibodies. The WHV-triggered anti-ASGPR also induced complement-mediated hepatocytolysis in a microculture tetrazolium (MTT) assay, which ranged from 8.9% +/- 0.3% to 33.6% +/- 3.6% (mean +/- SD) for different animals and target cell numbers. This cytopathic effect was strictly ASGPR-specific, complement-dependent, and was not related to the anti-ASGPR ability to inhibit ligand-hepatocyte binding. Our findings indicate that among pathways by which anti-ASGPR autoimmunity could cause liver damage, hepadnavirus-induced anti-ASGPR might impair hepatocytes by both disrupting clearance of desialylated proteins and activation of the complement-mediated cytolysis. These cytopathic effects might contribute to the pathogenesis, aggravate severity, and prolong recovery from liver injury in viral hepatitis.     

T-Cell response to woodchuck hepatitis virus (WHV) antigens during acute self-limited WHV infection and convalescence and after viral challenge

The infection of woodchucks with woodchuck hepatitis virus (WHV) provides an experimental model to study early immune responses during hepadnavirus infection that cannot be tested in patients. The T-cell response of experimentally WHV-infected woodchucks to WHsAg, rWHcAg, and WHcAg peptides was monitored by observing 5-bromo-2'-deoxyuridine and [2-3H]adenine incorporation. The first T-cell responses were directed against WHsAg 3 weeks after infection; these were followed by responses to rWHcAg including the immunodominant T-cell epitope of WHcAg (amino acids 97 to 110). Maximal proliferative responses were detected when the animals seroconvered to anti-WHs and anti-WHc (week 6). A decrease in the T-cell response to viral antigens coincided with clearance of viral DNA. Polyclonal rWHcAg-specific T-cell lines were established 6, 12, 18, and 24 weeks postinfection, and their responses to WHcAg peptides were assessed. Five to seven peptides including the immunodominant epitope were recognized throughout the observation period (6 months). At 12 months after infection, T-cell responses to antigens and peptides were not detected. Reactivation of T-cell responses to viral antigens and peptides occurred within 7 days after challenge of animals with WHV. These results demonstrate that a fast and vigorous T-cell response to WHsAg, rWHcAg, and amino acids 97 to 110 of the WHcAg occurs within 3 weeks after WHV infection. The peak of this response was associated with viral clearance and may be crucial for recovery from infection. One year after infection, no proliferation of T cells in response to antigens was observed; however, the WHV-specific T-cell response was reactivated after challenge of woodchucks with WHV and may be responsible for protection against WHV reinfection.     

Woodchuck hepatitis virus enhancer I and enhancer II are both involved in N-myc2 activation in woodchuck liver tumors

Direct activation of the N-myc2 oncogene by insertion of woodchuck hepatitis virus (WHV) DNA is a major oncogenic step in woodchuck hepatocarcinogenesis. We previously reported that WHV enhancer II (We2), which controls expression of the core/pregenome RNA, can also activate the N-myc2 promoter in hepatoma cell lines. To better define the integrated WHV regulatory sequences responsible for N-myc2 promoter activation in woodchuck liver tumors, we analyzed the structure and enhancer activity of a single viral integrant found at the win locus in tumor 2260T1 and mapping approximately 175 kb 3' of N-myc2. This viral insert was made of 11 concatemerized WHV fragments, 5 of which overlapped with We2 sequences and 1 with WHV sequence homologous to that of hepatitis B virus enhancer I (We1). In transient transfection assays in hepatoma-derived cells, the We2 activator was found to be fully effective only when inserted in close proximity to the N-myc2 promoter whereas the We1 element by itself was apparently devoid of activity. In contrast, the 2260T1 viral insert exhibited a potent enhancer capacity that depended both on multimerized We2 and on We1 sequences. In a survey of different woodchuck hepatomas, both elements were commonly found within integrated viral sequences involved in long-range N-myc2 activation.     

Assessment of hepatitis C viremia using molecular amplification technologies: correlations and clinical implications

OBJECTIVE: To compare two recently developed molecular techniques for quantitating the levels of hepatitis C virus (HCV) RNA in the serum of patients with a wide spectrum of chronic hepatitis C. DESIGN: Serum samples from 299 patients with HCV viremia, 101 control patients without HCV infection, and 19 consecutive patients receiving systemic interferon therapy were evaluated by a commercially available branched-chain DNA (bDNA) assay and a quantitative competitive polymerase chain reaction (PCR). SETTING: University-based hepatology clinics and reference virology laboratory. PATIENTS: Patients with HCV viremia as defined by results of qualitative RNA PCR, including 53 HCV-infected blood donors, 34 patients receiving renal dialysis, and 212 patients attending a hepatology clinic. RESULTS: Results of in vitro and in vivo experiments indicated that the sensitivity and dynamic range of the PCR assays were greater than those of the bDNA assay. Detection of HCV viremia by the bDNA assay was highly dependent on viral RNA titers, with a sensitivity of 5% at HCV RNA titers of 5.0 logs per mL or less and 94% at titers of 5.5 logs per mL or greater. The best correlation between assays was observed in specimens with HCV RNA titers between 6.0 and 7.5 logs per mL (r = 0.73). In patients with high-titer HCV viremia, including liver transplant recipients and patients with cirrhosis, quantitative PCR results were an average of 12-fold higher than bDNA assay results. Results of repetitive testing of discordant specimens showed that these discrepancies were caused by a high kit-to-kit coefficient of variation (112%) in the bDNA assay. Of 19 patients receiving interferon therapy, 9 (47%) became bDNA negative, but only 5 became quantitative PCR negative. The bDNA-negative, quantitative PCR-positive patients all had relapse when therapy was discontinued. CONCLUSIONS: The bDNA assay has a narrower linear range for quantitation of HCV viremia than quantitative PCR. Because persons with low HCV titers may respond well to therapy, seropositive persons with negative bDNA results should be retested with PCR-based assays. Similarly, the bDNA assay may underestimate the true degree of HCV viremia in persons with end-stage infection (> 10(7) RNA equivalents/mL of sera). Despite these limitations, the combination of bDNA- and PCR-based assays appears to be optimal for selecting and following patients during interferon therapy.     

Covalently closed circular viral DNA formed from two types of linear DNA in woodchuck hepatitis virus-infected liver

We found that livers from woodchucks chronically infected with woodchuck hepatitis virus (WHV) contained covalently closed circular DNA (cccDNA) molecules with deletions and insertions indicative of their formation from linear viral DNA by nonhomologous recombination, as we previously described for the duck hepatitis B virus (W. Yang and J. Summers, J. Virol. 69:4029-4036, 1995). However, evidence for two different types of linear precursors was obtained by analysis of the recombination joints in WHV cccDNA. Type 1 linear precursors possessed the structural properties that correspond to those of in situ-primed linear DNA molecules, which constitute between 7 and 20% of all viral DNA replicative intermediates synthesized in the liver. Type 2 linear precursors are hypothetical species of linear DNAs with a terminal duplication of the cohesive-end region, between DR1 and DR2. This type of linear DNA has not been previously described and was not detected among the DNA species present in nucleocapsids. A fraction of cccDNAs formed from both type 1 and type 2 linear DNAs are predicted to be functional for further DNA synthesis, and some evidence for the formation of two or more generations of cccDNA from linear DNA was observed.     

Influence of labour on epidermal growth factor receptor distribution of the human chorion at term gestation

Ten patients with biopsy verified chronic hepatitis C virus (HCV) infection were treated with oral ribavirin at a dose of 1,000-1,200 mg per day in two divided doses for 12 weeks. Serum alanine aminotransferase (ALT) levels and hepatitis C viral ribonucleic acid (RNA) levels in serum were followed prior to, during, and 12 weeks posttreatment. ALT levels decreased significantly in all patients during therapy from a mean level of 3.21 mukat/l (range 1.22 to 7.79) before, to 1.25 mukat/l (range 0.78 to 2.04) at the end of treatment (P < 0.005). Hereafter, relapse to pretreatment levels was seen within 12 weeks after treatment stop. The hepatitis C viral RNA levels decreased from a mean 10 log titer of 4.1 (range 1-6) before treatment to 3.4 (range 1-5) at treatment stop. Five patients did not change their HCV RNA titers during treatment. Twelve weeks posttreatment only 3 patients had lower titers than prior to treatment. We conclude that oral ribavirin seems to reduce the viral load, at least temporarily, in some patients with chronic viremic HCV infection. Further studies are needed to evaluate fully the effect of oral ribavirin on chronic HCV infection.     

The clinical importance of carpal instabilities following distal radial fractures

The association of viremia, elevated serum alanine aminotransferase (ALT) levels, and hepatocyte inflammatory activity in hepatocellular carcinoma (HCC) patients was studied. Serum samples from 114 HCC patients undergoing surgery were assayed for hepatitis B, C, and D viral nucleic acids by polymerase chain reaction (PCR) prior to surgery. Of these patients, 65 had HBV infection alone, 15 had HCV infection alone, 4 had HDV infection, 20 had HBV and HCV superinfection, 1 had triple viral infection, and 9 were negative for HBV and HCV infections. The prevalence of active viral replication was significantly higher in HCV than in HBV (92% versus 70%; P = 0.006) patients, and significantly higher mean serum ALT levels were also noted in the HCV group than in the HBV group (P = 0.02). The incidence of marked ALT elevation (>200 U/l) was highest in the HCV (27%) and the HDV (25%) groups. Patients in the HCV group were 10 years older than those in the HBV group. Viral superinfection did not accelerate the development of HCC. Viral replication persisted in a significant portion of HCC patients and a higher prevalence of hepatic inflammation was noted in patients with HCV- and, possibly, HDV-related HCC.