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)

In an attempt to evaluate the relationship between circulating immune complexes (CIC) and alpha-fetoprotein (AFP), CIC and AFP were detected in 93 hepatitis B surface antigen-positive (HBsAg+) patients with hepatocellular carcinoma (HCC) and 54 healthy controls. The median level of 3% PEG (polyethylene glycol)-CIC and Clq-CIC were higher in patients than in controls (p less than 0.001). In patients with HCC, the prevalence of elevated 3% PEG-CIC, Clq-CIC, and AFT was 27.9%, 55.9%, and 77.4%, respectively. There was association between AFP and 3% PEG-CIC positivity (p less than 0.01). The median level of 3% PEG-CIC and Clq-CIC increased as AFP levels elevated (p less than 0.05), but decreased as AFP exceeded 1599 ng/ml (p less than 0.05). For adjusting the effect of impaired liver function on the level of CIC, multivariate analysis with stepwise logistic regression revealed that 3% PEG-CIC was associated, in a dose-related fashion, with an increased risk for developing HCC (odds ratio = 1.003, p less than 0.001). These results imply that elevation of 3% PEG-CIC may be related to tumor mass. Additionally, 3% PEG-CIC is a useful marker to monitor therapy with transcatheter arterial embolization in patients with HBsAg+ HCC.
 ...
PMID:Elevation of circulating immune complexes and its relationship to alpha-fetoprotein levels in patients with hepatitis B surface antigen-positive hepatocellular carcinoma. 171 4

Circulating immune complexes (CIC) containing HBsAg and HBeAg were identified in sera of 5 out of 6 children with hepatitis B mediated membranous glomerulonephritis. CIC were precipitated from sera by 3.5% PEG, washed and subsequently analysed after acid dissociation and trypsin digestion. HBsAg, anti-HBs and albumin; HBeAg, anti-HBe and anti-HBc were recovered from the isolated complexes and these findings are discussed. Analysis of 3.5% PEG mediated precipitate of human serum proteins showed the relatively high content of IgG classical pathway complement components: C1q, C4 and C3.
 ...
PMID:Isolation and partial characterization of circulating immune complexes in sera of children with HBV-mediated glomerulonephritis. 184 49

The prevalence of asymptomatic HBsAg carriers and positive rate of HBsAg immune complexes (HBsAg-CICs) were comparatively higher among Chinese. The former is considered to be related with hepatitis B e antigen and the latter is not clear yet. In order to investigate the relationship between HBsAg-CICs and e antigen antibody among asymptomatic carriers. 90 subjects of carriers was tested for HBsAg-CICs by PEG-trypsinisation method and for e antigen antibody by radio-immunoassay. HBsAg-CICs were positive in 66 subjects among 90 carriers. The concentration of HBsAg-CICs (ng/ml) was significantly higher among 32 subjects with positive HBeAg (333.87 +/- 265.39) than 27 subjects with positive anti-HBe (181.03 +/- 162.05), p less than 0.02. Furthermore, the positive rate of e antigen and e antibody was just contrary among carriers with positive and negative HBsAg-CICs. Among 24 subjects with negative HBsAg-CICs, the percentage of positive HBeAg was much lower than positive e antibody. A significant interrelationship was present between positive or negative HBsAg-CICs and e antigen, antibody, the statistically significant was proved by the Chi square test. The above results showed that the high prevalence of asymptomatic HBsAg carriers among Chinese may be related to e antigen.
 ...
PMID:[The interrelationships of hepatitis B e antigen antibody and HBsAg-circulating immune complexes in asymptomatic HBsAg carriers]. 325 66

As first generation hepatitis B vaccines are derived from human plasma, detailed information is required concerning the elimination of hepatitis B virus and other potential transmissible infectious agents during vaccine preparation. To demonstrate the safety of a hepatitis B vaccine, the efficiency of each of the six main steps used in the preparation process to remove or destroy pathogens was determined for representatives of major groups of animal viruses. Infectivity of all the tested viruses was reduced 10(5)-fold to a factor of 10(9)-fold by the first and last steps, namely PEG fractionation and formalin treatment. The four successive zonal ultracentrifugations decreased virus infectivity by at least 10(7)-fold. Five of these steps tend also to purify the hepatitis B surface antigen (HBsAg) which increases the HBsAg: protein ratio by at least 10(5)-fold. Considering the high degree of purity obtained, checked on each batch, it is concluded that the procedure consistently eliminates any potential virus with a ide safety margin.
 ...
PMID:Elimination of serum proteins and potential virus contaminants during hepatitis B vaccine preparation. 624 69

The composition of immune complexes (IC) found in 28 patients with HBsAg positive and negative acute and chronic hepatitis was analysed. Components were defined in PEG-precipitated material isolated by preparative ultracentrifugation on linear sucrose density gradients and analysed by the Ouchterlony plate technique and by the radioimmunoassay of hepatitis B virus markers. Sedimentation rate ranged from 8 to 19s in the serum of patients with chronic hepatitis, whereas heavier IC (greater than 19s) were present in the active phase of the disease. The participation of hepatitis B virus in acute hepatitis was shown by the presence of its antigens. In contrast, a low incidence of vital components was seen in IC of chronic active hepatitis and liver cirrhosis. Thus, other causes must contribute to the formation of IC in chronic liver disease.
 ...
PMID:Characterization of the circulating immune complexes in acute and chronic liver diseases. 686 64

Interferons display a wide range of antiviral, antiproliferative, and immunomodulatory activities on a variety of cell types and have been used to treat many diseases including hairy-cell leukemia and hepatitis B and C and have also been applied to other therapeutic areas. To improve the pharmacological properties of interferon (IFN) alpha-2b, a long-acting pegylated form (PEG-IFN) has been developed [PEG, monomethoxy poly(ethylene glycol) with average molecular mass of 12 000 Da]. PEG-IFN is a mixture of pegylated proteins with differing sites of PEG attachment. To identify the major positional isomer in the pegylated material [PEG-IFN(His-34)], NMR studies were conducted on a subtilisin-digested N-acetylated peptide of the major positional isomer [PEG-IFN(His-34)dig], synthetic peptide analogues containing His-34, as well as unmodified IFN and PEG-IFN(His-34). Our studies reveal a novel interferon-polymer attachment site as a histidine-linked interferon conjugate. We show that the major component of PEG-IFN is pegylated in the imidazole side chain of histidine-34. Chemical shift data suggest that pegylation occurs mainly at the N(delta)(1) position in the imidazole side chain of this residue. This positional isomer, PEG-IFN(His-34), comprises approximately 47% of the total pegylated species when PEG-IFN is synthesized under the current experimental conditions at pH 6.5 with an electrophilic derivative of PEG, succinimidyl carbonate PEG. The reversibility of the histidine modification was examined. The PEG-imidazole adduct in the intact protein, PEG-IFN(His-34), is labile but much more stable than in the peptide, PEG-IFN(His-34)dig. Apparently, the tertiary structure of the intact protein protects the His(34)-imidazole ring from depegylation.
 ...
PMID:Identification of the major positional isomer of pegylated interferon alpha-2b. 1097 46

Hoffmann-La Roche has developed a PEGylated interferon alpha-2a, Pegasys, for the potential treatment of chronic hepatitis C and hepatitis B virus infection. It was first approved in Switzerland in August 2001 [418260] and was expected to be launched in September/October 2001 [419333]. In May 2000, Roche submitted a BLA to the US FDA, for approval to market Pegasys for the treatment of chronic HCV infection in non-cirrhotic and cirrhotic patients with compensated liver disease [329872], [348368], [367781]. Approval was still pending in December 2000 [387363], [392481]. Roche expects the US launch to take place in the second half of 2001 [400857]. In April 2001, Roche received a complete response letter from the FDA for Pegasys and was working with the FDA to address the questions raised in the letter [407595], [418310]. In August 2001, Roche expected approval for HCV in the US in 2002 and for HBV in 2004 [419333]. At this time, Roche planned to file an sNDA for combination with ribavirin [421285]. By March 2001, EU and Canadian filings had been made [401793]. Roche also planned to launch the product for chronic HBV infection and various malignancies in 2004 and 2005, respectively [400857]. Pegasys was filed for registration in Brazil in the first part of 2000 [418310]. As of December 1999, the drug was in phase II for HCV infection in Japan. It is being developed by Nippon Roche, which intended to extrapolate foreign phase III data for use in an NDA application in Japan [351804]. As a result of a meeting of Japan's PMSB in March 2001, Pegasys may be given priority in the review of its NDA, if submitted [403782]. In August 2001, Schering-Plough entered into a licensing agreement with F Hoffman-La Roche Ltd and Hoffmann-La Roche Inc that settles all patent disputes regarding the two companies' PEGinterferon products. Under the terms of the agreement, Schering-Plough and Roche will cross license to each other all patents applicable to Peg-Intron and Pegasys. The settlement agreement also includes a Schering-Plough sublicense of Enzon's branched PEG patents to Roche [418935], [418956]. Roche is collaborating with Maxim Pharmceuticals to develop PEG-IFN alpha-2a in conjunction with Maxim's Maxamine [378609]. In July 1998, Hoffmann-La Roche and Weston Medical signed a global agreement to license INTRAJECT (Weston's single-use, disposable, prefilled, needle-free injector for subcutaneous delivery of injectable liquid pharmaceuticals) for delivery of Pegasys [292119]. In April 1999, ABN Amro predicted annual sales of SFr 25 million in 2000, rising to SFr 75 million in 2002 [328676]. In September 2000, Merrill Lynch predicted sales of SFr 70 million in 2001, rising to SFr 700 million in 2004 [383742]. In March 2001, Deutsche Bank estimated that the product has sales potential of SFr 1600 million [421009].
 ...
PMID:Pegasys (Hoffmann-La Roche). 1176 53

Two antiviral treatments have been approved for hepatitis B virus (HBV) infection by the US Food and Drug Administration (FDA) for use in children: interferon (IFN)-alpha, 6 MU/m(2) three times a week subcutaneously for 6 months, and lamivudine, 3 mg/kg/d orally for 12 months. Twenty-six percent to 58% of children treated with IFN become HBV DNA negative, and up to 38% become negative to hepatitis B e antigen (HBeAg). Lamivudine, a nucleoside analogue that blocks viral replication by inhibition of the HBV polymerase, has been associated with comparable rates of seroconversion of HBeAg to anti-HBe. Loss of surface antigen occurs in less than 5% of patients treated with lamivudine, compared with 3% to 33% in those treated with IFN-alpha. Fifty percent to 65% of children treated with lamivudine clear HBV DNA after 12 months of therapy, but relapse rates have not been clarified. Patients treated with lamivudine develop drug-resistant (YMDD) mutants in the HBV polymerase at the rate of 16% to 32% per year. No treatments for children with hepatitis C virus (HCV) have been approved by the FDA. However, published reports describe treatment with IFN monotherapy and combination therapy with IFN and ribavirin. Trials of PEG-IFN alone or in combination with ribavirin are in progress. Given the lack of data regarding treatment of HCV in children, it is generally agreed among pediatric hepatologists that the optimal treatment is within the context of randomized, controlled trials.
 ...
PMID:Pediatric issues in new therapies for hepatitis B and C. 1273 46

Previous studies in Caucasian patients showed treatment of chronic hepatitis C with pegylated interferon/ribavirin was well tolerated, and produced a higher response rate especially in genotype 1 infections. However, it is unknown whether this conclusion can be extrapolated to patients with Chinese ethnic origin. A total of 153 patients with biopsy-proven chronic hepatitis C were randomly assigned to receive either weekly injection of peginterferon alpha-2b 1.5 mcg/kg plus oral ribavirin (1000 or 1200 mg/day, depending on body weight) (PEG group, n = 76) or 3 MU of interferon alpha-2b t.i.w. plus ribavirin (IFN group, n = 77) for 24 weeks. Sustained virological response (SVR) was defined as the sustained disappearance of serum hepatitis C virus (HCV) RNA at 24 weeks after the end of treatment by polymerase chain reaction assay. Baseline demographic, viral and histological characteristics were comparable between the two groups. Using an intent-to-treat analysis, HCV genotype 1 patients showed a significantly higher SVR in patients receiving PEG-IFN rather than IFN (65.8%vs 41.0%, P = 0.019), but no difference was found in genotype non-1 patients (PEG vs IFN: 68.4%vs 86.8%, P = 0.060). Genotype 1 patients (28.6%) in the PEG-IFN group relapsed, as compared with 52.9% in the IFN group (P = 0.040). Multivariate analyses showed early virological response at week 12 of therapy and genotype non-1 were significant predictors to SVR. As compared with the IFN group, patients receiving PEG-IFN had a significantly higher rate of discontinuation, dose reduction, fever, headache, insomnia, leucopenia and thrombocytopenia. In genotype 1 chronic hepatitis C Chinese patient, PEG-IFNalpha2b ribavirin had significantly better SVR and lower relapse rate when compared to IFN/ribavirin. Both regimens can be recommended for genotype non-1 chronic hepatitis C Chinese patients. However, a higher rate of adverse events and discontinuance of therapy were noted in patients treated with PEG-IFNalpha2b ribavirin.
 ...
PMID:Comparison of a 6-month course peginterferon alpha-2b plus ribavirin and interferon alpha-2b plus ribavirin in treating Chinese patients with chronic hepatitis C in Taiwan. 1585 Apr 69

The human recombinant Interferon-alpha(2a) (IFNalpha(2a)) is a potent drug (Roferon-A) to treat various types of cancer and viral diseases including Hepatitis B/C infections. To improve the pharmacological properties of the drug, a new pegylated form of IFNalpha(2a) was developed (PEGASYS). This 40 kDa PEG-conjugated IFNalpha(2a) ((40)PEG-IFNalpha(2a)) is obtained by the covalent binding of one 40 kDa branched PEG-polymer to a lysine side chain of IFNalpha(2a). (40)PEG-IFNalpha(2a) is a mixture of mainly six monopegylated positional isomers modified at K31, K134, K131, K121, K164, and K70, respectively. Here we report the detailed structural and biophysical characterization of (40)PEG-IFNalpha(2a) and its positional isomers, in comparison with IFNalpha(2a), using NMR spectroscopy, analytical ultracentrifugation, circular dichroism, fluorescence spectroscopy, and differential scanning calorimetry. Our results show that the three-dimensional structure of IFNalpha(2a) is not modified by the presence of the polymer in all positional isomers constituting (40)PEG-IFNalpha(2a). Regardless of where the PEG-polymer is attached, it adopts a very mobile and flexible random coil conformation, producing a shield for the protein without a permanent coverage of the protein surface. Hydrodynamic data indicate that the protein-attached PEG has a slightly more compact random-coil structure than the free PEG-polymer. Our results also provide evidence of significant structural and physicochemical advantages conferred by the pegylation: increase of the effective hydrodynamic volume and modification of the molecular shape, higher temperature stability, and reduced tendency for aggregation. These results are of tremendous pharmacological interest and benefit as was clinically shown with PEGASYS. This study constitutes a new standard for the characterization of pegylated proteins and enables an important step toward the understanding on a molecular level of the binding of (40)PEG-IFNalpha(2a) and its positional isomers to its cellular receptors.
 ...
PMID:Structural and biophysical characterization of the 40 kDa PEG-interferon-alpha2a and its individual positional isomers. 1589 16


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