Complexity of the HVR-1 quasispecies and disease activity in patients with hepatitis C.

BACKGROUND: Hepatitis C virus (HCV) easily undergoes genomic changes, especially in the hypervariable region (HVR) in the N-terminus of the E2/NS1 region. The quasispecies nature of HCV may have important biological implications in relation to viral persistence; however, the relationship between disease activity of chronic HCV infection and development of the genomic complexity have yielded conflicting results. We explored the changes in the complexity of the HVR-1 in the natural course of chronic HCV infection with and without elevation of serum alanine transaminase (ALT) levels. MATERIALS AND METHODS: Ten patients with chronic hepatitis C proven by liver biopsy, who showed persistent elevation of the serum ALT levels, and 15 patients with chronic HCV infection and persistently normal serum ALT levels (PNAL) were enrolled in this study. The number of the HCV quasispecies was determined twice for each patient at an interval of mean 2.5 years by fluorescence single-strand conformation polymorphism and sequence analysis. RESULTS: There was no significant difference in the changes in the number of quasispecies during the follow-up period between chronic hepatitis C and PNAL. There was also no significant difference in the change in the number of variable nucleotides sites between the two groups. In these patients, the number of quasispecies and the diversity of HVR-1 were correlated with platelet counts and serum hyaluronic acid levels previously shown to be associated with disease progression. CONCLUSION: Our results suggested that the disease activity is not always related to the generation of the HVR-1 quasispecies complexity.

Polymorphisms of NS5B protein relates to early clearance of hepatitis C virus by interferon plus ribavirin: a pilot study.

Although randomized trials have shown enhancement of efficacy for combination therapy with interferon (IFN) alpha-2b and ribavirin compared with IFN monotherapy as first-line treatment for chronic hepatitis C, infection with genotype 1b and high viremia are still associated with significantly low response rates compared with non-1 genotypes and low viremia. We analysed amino acid sequences of the viral RNA-dependent RNA polymerase (RdRP) or nonstructural protein 5B (NS5B), responsible for ribavirin misincorporation into RNA products in patients with genotype 1b-related chronic hepatitis C and high viremia, and examined the relationship between such RdRp polymorphisms, and the initial decline in viral load induced by combination therapy with IFN-alpha and ribavirin. Substitution of glutamic acid to lysine at the 124th position (E124K) and of isoleucine to valine at the 85th position (I85V) were found to be closely associated with a potent decline of viral load and viral clearance at 8 weeks of treatment (five of five patients, coincidence rate 100%). In conclusion, our results suggest that the polymorphisms of E124K and I85V identified in NS5B protein are crucial for early viral clearance in patients with genotype 1b and high viremia by combination therapy with IFN and ribavirin, and that detection of amino acid sequence motifs might enable prediction of clinical efficacy.

Effort- and time-cost effects on demand curves for food by pigeons under short session closed economies.

Demand curves for food were compared under the effort- and time-cost conditions using response-initiated fixed-ratio (FR) and fixed-interval (FI) schedules. For the effort-cost conditions, two pigeons were exposed to FR 3, 30, 90, and 150 for six sessions each. The time equivalent of each ratio was a FI schedule, each FI value equal to an average time from the first peck on the ratio to reinforcement (3-s access to mixed grain). The experiment was repeated in 1.5-, 3.0-, and 4.5-h closed economies in a different order for each pigeon. Food consumption as a function of time-based unit price (time equivalent per reinforcement duration) for each session length showed moderate convergence on a single demand function for the two cost conditions. When the demand function was separately fitted to each cost condition, however, the ranges of inelastic demand were generally larger in time-cost than effort-cost conditions. These curve-fitting analyses suggest that although time is a critical cost factor decreasing consumption at moderate prices, food intake under the effort-cost condition decreases more rapidly than under the time-cost condition as unit price increases. The analyses provide useful descriptions for the functional difference of costs.

Interferon regulatory factor-1 gene abnormality and loss of growth inhibitory effect of interferon-alpha in human hepatoma cell lines.

The effect of IFN-alpha on the growth of 5 hepatoma cell lines and a normal liver-derived cell line were examined. IFN dose-dependently inhibited the growth of cell lines except for HLE and PLC/PRF/5 in which the inhibition only occurred at a high concentration over 10,000 IU/ml. IFN-alpha induced the G1 arrest of these cells according to upregulation of p21WAF-1 expression, which is induced in PLC/PRF/5 and HLE only at a high IFN concentration. The receptor for IFN-alpha was well expressed in all the cell lines. DNA rearrangement of IRF-1 was detected in HLE and PLC/PRF/5 by Southern blotting, while IRF-2 gene was preserved. IFN-induced gene expressions were compared between HCC-T, HCC-M and PLC/PRF/5. RT-PCR demonstrated that the full-length IRF-1 and -2 mRNA was transcribed in all cell lines, but the mRNA amount of former gene in PLC/PRF/5 was less than that in HCC-T and HCC-M, about 1/10 by competitive RT-PCR. The sequence analysis of IRF-1 cDNA was performed and the full-length mRNA transcription was reconfirmed in PLC/PRF/5, but no significant point mutation was detected. These results suggest that IFN-alpha inhibits hepatoma growth by increasing p21WAF-1 expression only when the IRF-1 gene is preserved normally.

Role of H-ras gene in chronic liver damage in mice. By using transgenic mice carrying a human C-H-ras proto-oncogene without mutations.

Hepatic tumors including hepatocellular carcinoma were generated by carbon tetrachloride in transgenic mice carrying a human c-H-ras gene (rasH2 mice). RasH2 mice express 2 to 3 times more ras protein (ras p21) in the liver than do non-Tg mice. When carbon tetrachloride was administered, the rasH2 mice produced about 5 times as many hepatic tumors than did the non-transgenic mice. However, neither the 10-100 times higher ras p21 expression required for murine fibroblast transformation by itself nor the mutational activation of the H-ras gene was observed in carbon tetrachloride-induced hepatic tumors. These results show that H-ras proto-oncogene expression in the murine liver, even if it is not high enough to transform cells, also causes liver tumors when CC1(4) are repeatedly given.

Susceptibility of experimental autoimmune hepatitis in transgenic mice overexpressing the c-H-ras gene.

Results from a recent study of ours have demonstrated the significant role of the wild-type ras gene in the development of hepatocellular carcinoma in rasH2 mice having prototype human c-H-ras genes. Chronic cell death and regeneration have been considered to work as co-carcinogens with wild-type ras gene overexpression in this model. To elucidate a role of gene overexpression in the occurrence of chronic inflammation, we tried to induce inflammation in the liver of rasH2 mice by immunizing them with the supernatant of a freshly prepared syngenic liver homogenate. Immunization resulted in a dense inflammatory infiltrate in the portal tract and focal necrosis with spots of fatty or foamy degeneration in the transgenic mouse liver; however, these observations were less frequently observed in non-transgenic mouse liver. Monocytes, granulocytes and plasma cell infiltration were observed in the livers of transgenic mice. An immunohistochemical study showed that CD3-positive lymphocytes also infiltrated the liver. The inflammatory infiltrate was still present in the transgenic liver 24 weeks after the last injection, but little infiltrate was observed at the same time in non-transgenic mice. No hepatic tumours could be produced over the 6 months duration of the study and the results are only preliminary. However, these results do suggest that overexpression of wild-type ras is partially responsible for the occurrence of autoimmune chronic hepatitis.

Reduction of LAK-sensitivity and changes in antigen expression on hepatoma cells by sodium butyrate.

We demonstrated that sodium butyrate (SB) induced differentiation of functions in human hepatocellular carcinoma (HCC) cell lines. To investigate relationship between the sensitivity for cellular cytotoxicity and the cellular differentiation of HCC cells, the effect of SB on lymphokine-activated killer (LAK) sensitivity and antigen expression of a human HCC cells were studied. SB induced LAK-resistance of human HCC cell lines, HCC-T and HCC-M, time-dependently. A flowcytometric analysis of cell surface antigens revealed that SB markedly reduced the expression of laminin and fibronectin and increased the expression of liver-specific antigen defined by a mouse monoclonal antibody time-dependently, but did not modify that of major histocompatibility complex antigens, intercellular adhesion molecule (ICAM)-1, or CEA. Leukocyte function-associated antigen (LFA)-3 expression on HCC-T was reduced slightly by SB treatment. LAK sensitivity was inhibited by anti-laminin, but not with anti-beta 2-microglobulin, anti-HLA DR, anti-ICAM-1, anti-fibronectin, or anti-CEA. Anti-LFA-3 reduced LAK sensitivity of HCC-T, but not HCC-M, although the reduction was less than that obtained by anti-laminin treatment. These results provided evidence that SB induced LAK-resistance of human HCC cells according to cellular differentiation and extracellular matrix functionality played an important role in this LAK-mediated cell killing. Moreover, the structure expressed on HCC cells, which contributed to LAK cytolysis, was different for each HCC cell.

Enhancing effect of the liver extract and flavin adenin dinucleotide mixture on anti-viral efficacy of interferon in patients with chronic hepatitis C.

A combined preparation of liver extract and flavin adenin dinucleotide (FAD) (Adelavin) has been widely used in patients with chronic liver diseases in Japan. One milliliter of this agent contains 15 microliters of phenol-soluble phase of liver nucleic acid fraction and 10 mg of FAD. To examine the advantages of using this preparation in the elimination of hepatitis C virus (HCV) from patients with chronic hepatitis (CH)-C receiving interferon (IFN), 2 ml of this preparation was intravenously (n = 9) or intramuscularly (n = 8) administered daily for 5 days before 6 million units of IFN-alpha was intramuscularly injected once. Before and 48 hours after the injection of IFN, serum ALT, 2'5'-oligoadenylate synthetase (2'5-AS) activity, and HCV RNA levels were measured. The daily administration of this preparation alone for 5 days did not significantly change serum ALT, 2'5-AS activities, and HCV RNA levels. The 2'5-AS activities were significantly increased by IFN after the intravenous injection of this preparation (p < 0.01), while an injection of IFN alone of this dose did not change its activities (n = 10). HCV RNA levels were significantly decreased by IFN only after the administration of the preparation (intramuscular, p < 0.01; intravenous, p < 0.01). The effect of intravenous injection of this preparation was also elicited in patients with HCV genotype II and with HCV more than 10(5) copies/ml. These results suggest that this preparation may enhance the 2'5-AS production by IFN as a result of the increase in mitochondrial adenosin triphosphate production and may be a potent agent to enhance the anti-viral efficacy of IFN in patients with CH-C.

Assessment of histological features and outcome of interferon therapy in chronic hepatitis C.

The correlation between the histological features of liver biopsy specimens before interferon (IFN) treatment and the clinical effect of IFN administration on chronic hepatitis C was investigated. A study of the relation between several histological features that were graded in 60 liver biopsy specimens from chronic hepatitis C patients before IFN treatment disclosed that the grade of portal fibrosis was positively correlated with the grade of other inflammatory features, including piecemeal necrosis and portal and lobular inflammation. The degree of portal fibrosis adversely affected the rate of normalization of ALT levels in chronic hepatitis C during and after IFN treatment. We reexamined 36 liver biopsy specimens that showed a moderate degree of portal fibrosis, and found that the degree of piecemeal necrosis was inversely correlated with the extent of lymphoid follicle formation in the portal tracts. During IFN therapy, the group of chronic hepatitis C patients who showed marked piecemeal necrosis and less lymphoid follicle formation in the liver specimens had a poor response to IFN treatment, whereas another group that showed marked lymphoid follicle formation and little piecemeal necrosis in the liver specimens had a good response to IFN. These relationships gradually disappeared after the completion of IFN treatment.

Histopathological study of microspherophakia in the Weill-Marchesani syndrome.

A surgically obtained lens from a 66-year-old man with the Weill-Marchesani syndrome was examined histopathologically by light microscopy, transmission electron microscopy and scanning electron microscopy. The lens was diffusely opaque and brown. It was microspherophakic in appearance, 6.0 mm in equatorial diameter and 4.8 mm in anteroposterior diameter. The lens fibers were well preserved, and ran circularly in the cortex and elliptically in the fetal nucleus. The lens fibers had undergone hyaloid degeneration in the area from the deep cortex to the superficial portion of the adult nucleus. Hyaloid degeneration also extended from the anterior to the posterior pole and was more marked in the equator. The distribution of lens fibers suggested that microspherophakia had developed postnatally. It is surmised that later changes in the shape of the lens affected the lens fibers, inducing hyaloid degeneration.

Changes of antigen expression on human hepatoma cell lines caused by sodium butyrate, a differentiation inducer.

We have previously reported the effect of a differentiation inducer, sodium butyrate (SB), on human hepatocellular carcinoma (HCC) cell lines, demonstrating that it was a potent inducer of differentiation. In the present study, we investigated the alteration in expression of an antigen defined by a murine monoclonal antibody, H2, as well as alterations in the expression of other antigens, on the HCC cell lines HCC-T, HCC-M, and PLC/PRF/5, since it is known that specific antigenic changes occur during the differentiation of leukemic cells. The expression of the antigen defined by H2 increased immunocytochemically on HCC-T, HCC-M, and PLC/PRF/5 during treatment with SB. A flowcytometric study showed that almost all the HCC-T and HCC-M cells treated with SB highly expressed this antigen after 5 days' treatment. The antigen expression detected by H2 decreased after the removal of SB from the medium. On the other hand, antigen expression detected by another monoclonal antibody, 5C11, was not changed by this treatment. The expression of intracellular adhesion molecule (ICAM)-1 in HCC-T increased slightly, but that of beta 2-microglobulin and HLA-DR did not change. These results demonstrated that some antigen expression was changed by SB treatment and that the antigen defined by H2 seemed to be highly expressed on human HCC cells in the differentiated state.

Hepatic tumors induced by carbon tetrachloride in transgenic mice carrying a human c-H-ras proto-oncogene without mutations.

Hepatic tumors were generated in mice by repeated administration of carbon tetrachloride (CCl4). Eight transgenic (Tg) mice carrying a human c-H-ras proto-oncogene (rasH2 line) and 9 non-Tg mice were killed at 20 weeks. Tg mice developed more tumors than did non-Tg littermates. Most tumors were neoplastic nodules, but 1 hepatocellular carcinoma (HCC) was found in a Tg mouse at 20 weeks. Three Tg and 2 non-Tg mice were kept without further administration of CCl4. Two Tg mice died at 30 weeks of HCC with intra-abdominal bleeding, and 1 Tg mouse developed HCC with a mesenteric metastasis at 32 weeks. No HCC was found in 2 non-Tg mice at 32 weeks. Although mutations at codon 12, 13, and 61 of the H-ras gene are often found in murine hepatocarcinogenesis, neither the tumors, including one HCC, nor the normal cells revealed any such mutations. These results showed that the unmutated human c-H-ras gene facilitates malignant transformation of hepatocytes when continuous liver-cell death and regeneration is caused by repeated administration of CCl4.

A pilot study of long-term weekly interferon-beta administration for chronic hepatitis B.

Interferon-beta was given weekly for 24 wk, at a dose of 3 million units, intravenously, to 10 patients with chronic hepatitis B who were serologically positive for HBsAg and HBeAg. Their condition was followed for 6 months after the end of therapy. Both serum hepatitis B virus-associated DNA-polymerase activity and alanine aminotransferase level became significantly lower during therapy and during the 6 months after the end of therapy than at the beginning of therapy. In five of 10 patients, the seroconversion from HBeAg positive to anti-HBe positive had occurred by 6 months after the end of therapy, and in four of these five patients, serum alanine aminotransferase level became normal. Weekly interferon-beta administration over 6 months seems effective in inducing seroconversion and in normalizing serum alanine aminotransferase level.

A randomized, controlled trial of weekly administration of lymphoblastoid interferon in patients with chronic hepatitis C.

To evaluate the efficacy of a treatment of weekly interferon administration in patients with chronic hepatitis C, 36 patients were randomly assigned to two groups. In one group lymphoblastoid interferon was given at a dose of 6 million units, intramuscularly, once per week for 24 weeks, and no treatment was given to the other. Serum alanine aminotransferase levels in the treated group were significantly lower during therapy than in the control group, although there was no significant difference between these two groups before therapy. The normalization of serum alanine aminotransferase levels at the end of therapy was observed in 50% of the treated group, and in 11.1% of the control group. This difference was statistically significant (p < 0.03). Response to interferon was better in patients with chronic persistent hepatitis or with chronic active hepatitis than in patients with chronic active hepatitis with cirrhosis. Relapse after the end of therapy was observed in 83.3% of the responders. These results indicate that the weekly administration of 6 million units of lymphoblastoid interferon is effective in decreasing serum alanine aminotransferase levels in patients with type C chronic persistent hepatitis or chronic active hepatitis.

Effect of dexamethasone, dimethylsulfoxide and sodium butyrate on a human hepatoma cell line PLC/PRF/5.

The effects of agents which are known to be differentiation inducers on a human hepatoma cell line PLC/PRF/5 were investigated. Dexamethasone (DEX), sodium butyrate (SB) or dimethylsulfoxide (DMSO) were examined. They all reduced cell proliferation but differ from each other in effect on the secretion of alphafetoprotein (AFP) and hepatitis B surface antigen (HBsAg), changes in morphology and RNA transcription. SB changed the cell from polygonal into a fibroblast-like type and decreased AFP secretion. DMSO decreased the cell size and changed AFP secretion in the same manner as SB. DEX changed the cell into a larger size, as well as increased AFP secretion. HBsAg secretion and also HB virus DNA transcription was enhanced by 3 agents. AFP and myc gene transcriptions were reduced by SB but DMSO reduced only AFP. Albumin gene transcription was enhanced by SB and DEX. These results indicate that the decrease of PLC/PRF/5 proliferation is induced through different mechanisms by these 3 agents.