Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several trials for chronic hepatitis B in children have shown the usefulness of interferon-alpha (IFN-alpha) in eliminating hepatitis B virus (HBV) replication, by an improvement in the liver damage. Optimal doses of IFN-alpha are 10 MU/m2 of body surface, three times a week for 24 weeks. With this schedule, clearance of HBV-DNA was achieved in 58% of treated children. In nonresponder children, because of the progression of the disease, there is a need to try new antiviral approaches. In a pilot study, 11 nonresponder children were retreated with IFN-alpha 10 MU/m2 body surface, three times a week for 24 weeks. At the end of treatment, 27% of the children had cleared serum HBV-DNA. Thus, retreatment has some benefit in nonresponder children.
 ...
PMID:Interferon treatment in children with chronic hepatitis B. 760 77

The antiviral and cytotoxic effects of ara-arabinoside monophosphate, 2',3', dideoxy-cytidine, ganciclovir, 9-2(-phosphonylmethoxyethyl) adenine, 2',3'-dideoxy-3'-thiacytidine and recombinant interferon-alpha were studied using two human hepatitis B virus transfected hepatoma cell lines, HepG2 2.2.15 and HB 611. After 9 days of exposure, starting on day 3 after seeding, inhibition of extracellular HBV-DNA expressed as ID50 was in the 0.1-1.0 microM range for 2',3'-dideoxy-3'-thiacytidine and 9-2(-phosphonylmethoxyethyl) adenine and > 10 microM for dideoxy-cytidine, ara-arabinoside monophosphate and ganciclovir in both cell lines. At 2.500 U/ml recombinant interferon-alpha showed less than 20% inhibition in both cell lines. The HBV-DNA inhibitory effects of 2',3'-dideoxy-3'-thiacytidine and 9-2(-phosphonylmethoxyethyl) adenine were also investigated after 1 and 3 days of exposure. In that setting ID50's were 10 and 3.3 microM for 2',3'-dideoxy-3'-thiacytidine and > 100 and 30 microM for 9-2(-phosphonylmethoxyethyl) adenine, respectively. No major inhibitory effect on hepatitis B surface antigen and hepatitis B e antigen secretion was observed for any agent in this study, except for 9-2(-phosphonylmethoxyethyl) adenine in HB 611 cells. Cytotoxicity measured by inhibition of [3H-methyl] deoxythymidine incorporation and expressed as CD50 on day 4 was in the 10-100 microM range for ara-arabinoside monophosphate; in the 100-1000 microM range for 9-2(-phosphonylmethoxyethyl) adenine, ganciclovir and dideoxy-cytidine; and > 1000 microM for 2',3'-dideoxy-3'-thiacytidine.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Antiviral agents in hepatitis B virus transfected cell lines: inhibitory and cytotoxic effect related to time of treatment. 760 75

We report the case of man with a history of post-transfusion chronic persistent hepatitis due to hepatitis B virus (HBV), who secondarily developed polyarteritis nodosa (PN) and membranous nephropathy (MN) simultaneously. At that time, liver biopsy yielded the diagnosis of active chronic hepatitis, and serological tests showed a high replication rate of HBV. PN was due to HBV infection, but the etiology of MN was uncertain, as it has never been described in PN, even in its microscopic form. There was no evidence of paraneoplastic syndrome or other causes of MN. Although the renal biopsy did not give any indication of HBV-related glomerulonephritis, the patient was considered to have an association of classic PN and MN, both related to HBV. Treatment combined plasmapheresis and interferon-alpha.
 ...
PMID:Hepatitis B virus-related polyarteritis nodosa and membranous nephropathy. 761 54

In the 35 years since the discovery of interferon, significant biological activity has been described for interferon-alpha (IFN alpha) in various cancers, particularly haematological malignancies such as hairy cell leukaemia and chronic myelogenous leukaemia. Except for localised therapy in bladder and ovarian cancer, activity against most solid tumours has been disappointing. Other notable exceptions include Kaposi's sarcoma, renal cell carcinoma and malignant melanoma, tumours known to be susceptible to immunological attack. More recently, broad spectrum antiviral activity has been demonstrated for both recombinant and naturally occurring IFN alpha. Hepatitis C is responsive to IFN alpha in about 40% of patients, but long term remissions are rare. In contrast, long term suppression of hepatitis B is common following IFN alpha therapy. Both diseases respond in a dose proportional fashion, with daily doses of 5 million units (MU) significantly more effective than lower doses. The mechanism of action in viral diseases involves the expression of unique antiviral proteins such as endonuclease and 2'-5'-oligoadenylate synthetase which enhance the destruction of viral RNA. General cellular protein synthesis is also inhibited, including cytochrome P450 enzymes. This forms the basis for potential drug interactions, with IFN alpha slowing the clearance of highly metabolised drugs such as theophylline. As an antitumour agent, the mechanism of action of IFN alpha is unclear, particularly in haematological cancers. In melanoma and renal cell carcinoma, antitumour effects may be mediated by augmented immune responses including activation of natural killer lymphocytes and enhanced expression of cell surface antigens (e.g. MHC I and II). Conversely, antibody formation to recombinant IFN alpha may result in a loss of activity. This has been observed in both renal cell cancer and hepatitis B and C. The elimination half-life of IFN alpha is short, 4 to 5 hours, but biological activity extends for 2 to 3 days after administration, which facilitates daily or thrice weekly administration. Clearance of IFN alpha is mediated by catabolism in the renal tubules; no intact drug is excreted in the urine. It is probable that the antiviral indications of IFN alpha will expand as the agent is more clearly recognised as a primary endogenous defence against various viral conditions.
 ...
PMID:Interferon-alpha in malignant and viral diseases. A review. 768 71

To determine the relationship between hepatitis B virus (HBV) replication and HLA antigen display at a cellular level, the hepatic expression of HLA antigens and HBV genome (HBV-DNA)/gene products (HBsAg/HBcAg) was studied in 24 patients with chronic HBV infection using simultaneously immunohistochemistry and nonisotopic in situ hybridization. The effect of interferon-alpha and interferon-gamma on hepatocyte HLA antigen expression was also evaluated using primary hepatocyte culture in eight patients with chronic HBV infection. HLA class I antigens were detected on hepatocyte membrane in 23 patients (95.8%). Hepatocytes positive for HBcAg and HBV-DNA (cytoplasmic +/- nuclear) were either negative or only faintly positive for HLA class I antigens, while hepatocytes positive for HBsAg showed similar levels of HLA class I antigen expression compared with those hepatocytes with no HBsAg expression. In contrast, hepatocytes adjacent to inflammatory infiltrates, whether positive for HBV-DNA or HBV antigens or not, were always strongly positive for HLA class I antigens. Furthermore, active liver histology (N = 12) was associated with a higher overall level of hepatic HLA class I antigen expression as compared with inactive histology (N = 12, P = 0.003). Both interferon-alpha and interferon-gamma treatment in vitro enhanced hepatocyte HLA class I antigen expression. These data indicate that expression of HLA class I antigens is not enhanced on the membrane of hepatocytes with HBV replication, and this may be one factor that permits the development of viral persistence.
 ...
PMID:Hepatic HLA antigen display in chronic hepatitis B virus infection. Relation to hepatic expression of HBV genome/gene products and liver histology. 768 63

Hepatitis B virus (HBV) infection in children is worldwide in distribution, but the features of HBV-associated liver disease differ depending on the route of transmission and the time of acquisition of the infection. The degree of liver injury varies from a mild disease to the development of cirrhosis and hepatocellular carcinoma, and depends on the replicative status of the viral genome. It is believed that the immune function plays a key role in the severity of HBV disease, and the impact of HBV mutants needs to be assessed. The goals of antiviral therapy in children are therefore, the clearance of viremia and HBV sequences from infected tissues, together with an improvement in the liver disease. Administration of 10 MU/m2 b.s. 3 times weekly over 6 months resulted in a significantly higher clearance of viremia, with normalization of ALT values and greater improvement in liver histology in treated than in untreated patients. Long-term follow-up of these cases reveals the presence of the viral genome in serum and liver by PCR without clearance of HBsAg. Complete eradication of HBV might need more years of evolution as for adult patients. The combination of more than one antiviral agent, as well as the potentiation of the immune system, needs to be assessed to improve the actual response rate obtained with interferon-alpha.
 ...
PMID:Chronic hepatitis B in children. Natural history and treatment. 768 64

We quantified IgG antibodies to structural (core) and nonstructural (C100-3) hepatitis C virus proteins in 42 patients with chronic hepatitis C treated with a 6-mo course of interferon-alpha. Sera were drawn before and at the end of therapy and also 6 mo after therapy withdrawal; they were stored for later analysis of antibodies and serum hepatitis C virus RNA. Sustained virus clearance was observed at the end of therapy and 6 mo after therapy withdrawal in nine cases; it was accompanied with sustained reductions of antibody to hepatitis C virus core protein and antibody to C100-3 protein. A sustained reduction of antibody to hepatitis C virus core protein was specific to sustained virus clearance, although that of antibody to C100-3 protein was not. None of the patients who did not show reductions of levels of both antibodies at the end of therapy displayed sustained virus clearance. Five patients showed hepatitis C virus RNA negativity and normal aminotransferase levels at the end of therapy without reduction of antibody to hepatitis C virus core protein levels. Of these five patients, relapse of hepatitis occurred in four, and viremia was present 6 mo after therapy withdrawal in all cases. These results demonstrate that testing for antibody titers may add information for evaluating virus clearance after interferon therapy.
 ...
PMID:Quantitative analysis of antibodies to hepatitis C virus during interferon-alpha therapy. 768 34

To evaluate the possible usefulness of simultaneous administration of levamisole and interferon, we randomly allocated 38 children with chronic hepatitis B to receive either 10 MU/m2 interferon-alpha-2a, three times a week for 6 mo (group 1, n = 20) or 90 mg/m2 of levamisole for 45 days, together with 10 MU/m2 of interferon-alpha-2a, three times a week for 6 mo (group 2, n = 18). At the end of the follow-up period (15 mo), no significant differences were observed between the groups with respect to loss of hepatitis B virus DNA and HBeAg from serum and normalization of serum ALT levels. During therapy, a significant increase in the serum levels of ALT and soluble interleukin-2 receptor was observed in both groups but was higher in patients from group 2. The combination of levamisole with interferon was associated with severe side effects. In summary, the combination of levamisole with interferon in children with chronic hepatitis B does not improve the results obtained with interferon alone.
 ...
PMID:Levamisole and interferon in children with chronic hepatitis B. 768 78

The authors studied the interrelationship of antibody to hepatitis C virus core protein (anti-HCV core), antibody to C100-3 antigen (anti-C100-3) and serum hepatitis C virus RNA positivity in chronic liver disease patients. Anti-HCVcore was detected with high titers in 95% (69/73) of chronic non-A, non-B hepatitis patients, while anti-C100-3 was found in 60% (44/73). A close relationship was observed between detection of anti-HCVcore and viremia. Anti-HCVcore was also detected with low titers in 24% (10/41) of hepatitis B virus carriers negative for anti-C100-3. Hepatitis C virus RNA was found in 3 of the 10 anti-HCVcore-positive carriers. A significant correlation was observed between the occurrence of high titers of anti-HCVcore and serum hepatitis C virus RNA positivity. In chronic hepatitis C patients treated with interferon-alpha, a sustained reduction of anti-HCVcore was more closely associated with sustained virus clearance than that of anti-C100-3. These results indicate that anti-HCVcore may serve as a reliable marker of hepatitis C virus infection.
 ...
PMID:Antibodies to hepatitis C virus and hepatitis C virus infection. 768 12

Eighty patients with chronic hepatitis C who completed a previously reported randomized controlled trial on the efficacy of interferon-alpha 2b were followed up for at least 36 mo after therapy discontinuation. Seventeen patients (21.2%) maintained normal ALT values throughout the follow-up; 63 (78.8%) either did not normalize the levels of ALT or relapsed during the follow-up. A significantly greater proportion of patients treated with 3 million units of interferon three times a week subcutaneously for 48 wk were long-term responders compared with patients treated for 24 wk. Sex, age, hepatitis C virus antibody status, source of infection and pretreatment levels of ALT were not predictive of long-term response. Cirrhosis was found to be an unfavorable predictive factor. After 3 yr of follow-up, clearance of viremia was observed in 58.9% of the 17 long-term responders but in none of the non-responders (p = 0.002). E2-NS1 antibody tested negative in 88.2% of long-term responders and in 14.3% of nonresponders (p = 0.001). Fifty-nine percent of long-term responders tested negative for C100-NS4 antibody compared with 14.3% of nonresponders (p = 0.031). No significant change was observed in other antibodies. Four long-term responders underwent liver biopsy 2 yr after discontinuation of therapy. All four patients had normal liver histology compared with baseline assessment of chronic active hepatitis in three and chronic persistent hepatitis in the other. Three of the four were negative for serum hepatitis C virus RNA.
 ...
PMID:Long-term follow-up of patients with chronic hepatitis C treated with different doses of interferon-alpha 2b. 769 94


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>