Hepatitis B virus X protein transactivates the inducible nitric oxide synthase promoter.

The capability of hepatitis B virus (HBV) to increase the transcription of the human hepatic inducible nitric oxide synthase (iNOS) by transactivating its promoter has been studied. We have observed by reverse-transcription polymerase chain reaction (RT-PCR) that although the mRNA for the iNOS was almost undetectable in the human hepatoblastoma cell line, HepG2, it was constitutively expressed in the 2.2.15 cell line (a derivative of the HepG2 that produces complete HBV particles). Transfection of HepG2 and 2.2.15 cells with the p1iNOS-CAT plasmid (containing a 1.1-kb fragment of the iNOS promoter) resulted in an increase in chloramphenicol acetyl transferase (CAT) activity in 2.2.15 cells. Similar results were observed when HepG2 and Chang liver cell lines were cotransfected with the p1iNOS-CAT plasmid and the complete HBV genome. It was shown that pX was responsible for the transactivation by cotransfection of HepG2 cells with the p1iNOS-CAT and plasmids expressing the HBV-encoded pX protein, core antigen, and e antigen. Cotransfection of HepG2 cells with the pX expression plasmids and a series of deletion mutants of the 1.1-kb iNOS promoter fragments established that transactivation by pX depends on the presence of at least one nuclear factor-kappaB (NF-kappaB) binding site. This was further confirmed by cotransfecting cells with a plasmid expressing the NF-kappaB inhibitor, IkappaB.

Phylogenetic analysis of hepatitis GB virus type C/hepatitis G virus in Spanish patients with chronic hepatitis B or C virus infection.

The nucleotide sequence of hepatitis GB virus type C (HGBV-C)/hepatitis G virus (HGV) NS3/helicase and 5'-untranslated regions from 23 Spanish patients were analyzed to assign the HGV isolates one of the proposed HGBV-C/HGV genotypes. The analysis of the evolutionary distance frequency showed that the distances among all sequences in NS3/helicase region were distributed around a single peak of 0.20, suggesting that all included sequences belonged to the same HGBV-C/HGV genotype. By contrast, in the 5'-untranslated region, all the distances corresponding to our sequences and those of the HGBV-C/HGV types 2 and 3 were distributed around a major peak of 0.03. The remaining distances corresponding to the HGBV-C/HGV type 1 sequences were distributed around a minor peak of 0.11. The phylogenetic tree and pairwise comparison of evolutionary distances among the 5'-untranslated region of the infected patients and each HGBV-C/HGV genotype demonstrated that our HGBV-C/HGV isolates belonged to subtype 2a (17/23; 78%) and 2b (5/23; 22%). No relation was found between HGBV-C/HGV subtype and hepatitis B or C virus infection.

Hepatitis C and G virus infection and liver dysfunction after allogeneic bone marrow transplantation: results from a prospective study.

Acute and chronic liver dysfunction is common after allogeneic bone marrow transplantation (BMT). Although toxicity, graft versus-host disease (GVHD), and viral infections are the major causes, etiologic diagnosis is difficult and often remains unknown. We conducted a prospective study to establish the role of the infection with both the hepatitis C virus (HCV) and the recently discovered hepatitis G virus (HGV) in liver dysfunction after BMT. From January 1994 to December 1995, 59 patients who had undergone an allogeneic BMT at our institution were enrolled in the study. HGV-RNA was identified in serum by nested polymerase chain reaction (PCR), and HCV was studied by the presence of second generation enzyme-linked immunosorbent assay (ELISA)-antibodies and HCV-RNA by nested PCR. HGV-RNA was detected in 25 patients (42%) (before BMT in 18 and after BMT in 7). HCV-RNA was present in 12 patients (20%) (before BMT in 11 and after BMT in one). The presence of HCV-RNA and HGV-RNA was clearly associated with a previous history of blood transfusions. No significant association was found between viral infection and acute liver toxicity. Some degree of liver dysfunction was present 6 months after BMT in 25 of 40 evaluable patients (62%). Long-term liver dysfunction was more common among patients infected with HCV alone (3 of 4) or with both HCV and HGV (3 of 3) than in those infected with either HGV alone (eight of 13) or with no virus infection (10 of 20). We found a high prevalence of HGV infection in our BMT population. However, no role for HGV in liver disease could be established in this study, and the relationship between HGV infection and liver dysfunction requires further clarification.

Decreased nitric oxide production in chronic viral hepatitis B and C.

Nitric oxide is a free radical gas molecule which may be implicated in antiviral defense. However, there is no information about its possible role in chronic viral hepatitis B and C. In this study we have analyzed the serum levels of NO2- (as an index of nitric oxide generation) from patients with chronic viral hepatitis B and C and relationship of same with the response to interferon therapy. Serum samples were analysed from 61 patients with chronic hepatitis B, 60 patients with chronic hepatitis C, 11 with chronic liver disease of nonviral origin, and 23 healthy controls. Levels of NO2- were statistically higher in healthy controls (P < 0.001) than in patients with chronic liver disease. No relation was found between NO2- and viremia or response to interferon therapy in patients with chronic hepatitis B. In contrast in chronic hepatitis C, responder patients had significantly higher NO2- than nonresponders (P < 0.01). With respect to the relation between NO2- levels and liver damage, patients with cirrhosis had lower NO2- levels than the rest of the patients (P < 0.001). In conclusion, patients with chronic viral hepatitis have low serum NO2- levels.

[Calcium antagonists in the treatment of congestive heart failure]. / Os antagonistas do cálcio no tratamento da insuficiência cardíaca congestiva.

The authors present a revision of the clinical studies using calcium antagonists to treat chronic heart failure. They analyse cases where calcium antagonists seem to be of no use (and can even have an adverse effect), particularly in patients with significant left ventricular systolic dysfunction, with normal afterload, high levels of renin, very high levels of right atrium pressure or low sodium. On the opposite, patients with increased afterload or valvular regurgitation can receive some benefit, although care must be taken in the administration of this kind of drugs. New calcium antagonists may show more benefit because they seem not to stimulate the adrenergic system and do not have significant negative inotropic effects. They conclude with a reference to the multiple situations that can be the basis for heart failure, suggesting that probably, in the future, therapy shall be more individually tailored and that in some cases calcium antagonists can be included in such therapy.