Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The intrahepatic distribution of hepatitis B core antigen (HBcAg) was studied in 14 HBeAg-positive patients with chronic active hepatitis B who were treated with interferon. Patients received 5 to 6 million units daily of human lymphoblastoid interferon or human diploid fibroblast interferon for 28 days. Intrahepatic HBcAg was detected by the indirect immunoperoxidase technique. Before interferon therapy, the intrahepatic HBcAg was detected almost equally in both the nucleus and cytoplasm. The expression of nuclear HBcAg decreased significantly (p less than 0.001) after interferon therapy, irrespective of the outcome for DNA polymerase and/or HBeAg/anti-HBe status. The expression of cytoplasmic HBcAg decreased significantly (p less than 0.05) only in the patients who lost DNA polymerase after treatment, whereas it increased in patients with DNA polymerase and/or HBeAg in the serum. These findings suggested that a shift of intrahepatic HBcAg from the nucleus to the cytoplasm occurred in HBeAg-positive patients with chronic active hepatitis B receiving interferon therapy.
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PMID:Changes of intrahepatic localization of hepatitis B core antigen in HBeAg positive patients with chronic active hepatitis B treated with interferon. 219 93

Twenty-six patients, positive for hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), hepatitis B virus (HBV)-deoxyribonucleic acid (DNA), and DNA polymerase activity, were treated with human lymphoblastoid interferon (IFN-alpha) or human fibroblast interferon (IFN-beta) after enoxolone glycoside (glycyrrhizinic acid), given for four weeks and then withdrawn. The interferons were given continuously for four weeks. Four months after the treatment, six of 12 patients treated with IFN-alpha were both HBeAg-negative and HBV-DNA-negative while three of 14 patients treated with IFN-beta were HBV-DNA-negative and one was HBeAg-negative. None of the ten untreated control patients became negative for either HBeAg or HBV-DNA. All patients studied remained HBsAg-positive. Both interferons were generally well tolerated. A persistent low-grade fever was reported by more patients in the IFN-beta group and hair and weight loss were more common in the IFN-alpha group. The results indicate that the combination of enoxolone glycoside withdrawal and IFN-alpha treatment reduces HBV replication more effectively than does interferon alone.
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PMID:Human lymphoblastoid and fibroblast interferon in the treatment of chronic hepatitis B. 232 24

The replication of herpes simplex virus (HSV) type 1 in macrophages grown from spleen cells of mouse strains susceptible to HSV infection in vivo was very sensitive to interferon (IFN). Different types of mouse IFN (alpha, beta, gamma) exhibited similar antiviral activities. However, treatment of cells with IFN-gamma in combination with IFN-alpha or IFN-beta resulted in a synergistic inhibition of virus growth. As shown by assaying HSV DNA polymerase, IFN inhibited expression of the beta-genes. Inhibition of enzyme induction correlated well with the reduction of viral yield. Induction of HSV DNA polymerase was delayed by IFN in a dose-dependent manner. These results show that IFN inhibits HSV replication at an early step prior to or during the synthesis of beta-proteins.
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PMID:Inhibition of replication of herpes simplex virus in mouse macrophages by interferons. 241 65

To identify factors predicting response to antiviral therapy, we reviewed the clinical features of 38 male hepatitis B surface antigen (HBsAg) carriers who received adenine arabinoside or lymphoblastoid interferon. All patients were followed for one year or longer. Response was defined as loss of hepatitis B e antigen, hepatitis B virus DNA and DNA polymerase from the serum. Only 2 of 19 (11%) homosexual men responded, compared with 10 of 19 (53%) heterosexual men (P less than 0.02). Both responders in the homosexual group had received lymphoblastoid interferon. None of the 13 homosexual men, but 8 of 16 heterosexual men, responded to adenine arabinoside or its monophosphate (P less than 0.01). Responders to antiviral therapy had higher (P less than 0.05) serum levels of aspartate aminotransferase (median 115, range 51-344) than did non-responders (median 83, range 32-181). The decreased responsiveness of homosexual men to antiviral therapy may be a result of more severe immunologic abnormalities in homosexual than in heterosexual men with HBsAg-positive chronic liver disease.
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PMID:Diminished responsiveness of homosexual men to antiviral therapy for HBsAg-positive chronic liver disease. 241 58

Mouse macrophages grown from spleen cells were found to be very sensitive to the interferon (IFN) activity against herpes simplex virus type 1 (HSV-1). Therefore we have used these cells to investigate the level at which IFN blocks the replication of HSV-1. IFN treatment resulted in a strong inhibition of the induction of HSV DNA polymerase and other beta proteins. RNA hybridization experiments revealed that the amount of mRNA for the beta protein thymidine kinase was strongly reduced in IFN treated HSV-1 infected cells. Analysis of the effect of IFN on expression of the alpha genes indicated a strong inhibition of alpha protein synthesis. In contrast the synthesis of mRNA of the alpha protein ICP 4 was only moderately inhibited. The results indicate that IFN primarily acts on the translation of HSV alpha proteins.
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PMID:Synthesis of herpes simplex virus proteins and nucleic acids in interferon-treated macrophages. 242 81

The mode of action of antiviral agents (interferon and adenine arabinoside) was studied in human and in animals chronically infected with hepadna virus. Interferon (36-100 megaunits) was given to 20 carrier patients, and hepatitis B virus (HBV)-DNA replicative forms were studied in pre- and post-treatment biopsies. ARA-A was given intravenously to duck hepatitis B virus (DHBV)-infected ducks. Changes in intrahepatic viral replicative forms were studied by Southern blotting using 32P-labelled HBV or DHBV probe. Our study indicates that both interferon and ARA-A seem to effectively decrease 'mature' forms of viral DNA by an effect on either mRNA or DNA polymerase. However, the supercoiled viral DNA tends to resist the treatment, and may become the transcribing template for a new cycle of viral replication after cessation of the drugs.
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PMID:In vivo study of the mechanism of action of antiviral agents against hepadna virus replication in the liver. Resistance of supercoiled viral DNA. 243 76

Eleven patients with hepatitis B e antigen (HBeAg)-positive chronic active hepatitis B were treated with an 8-wk course of prednisone followed by 28 days of adenine arabinoside 5'-monophosphate. Five individuals had a complete response (loss of HBeAg and DNA polymerase) whereas 3 had a partial response (sustained loss of DNA polymerase but persistence of HBeAg). At the present time 27 +/- 3 mo has elapsed since the completion of therapy, and 4 of 5 complete responders remain negative for replicative markers while the fifth person exhibited transient reactivation of infection. Elevated DNA polymerase has reappeared in two of the three partial responders, in one 22 mo after completion of therapy. These encouraging results have led to a randomized, controlled trial using short-term prednisone followed by recombinant alpha-interferon.
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PMID:The use of corticosteroids in conjunction with antiviral therapy in chronic hepatitis B with ongoing viral replication. 243 77

The synthesis and steady state level of immediate early vaccinia virus-specific RNAs in interferon-treated chick embryo fibroblasts were determined by blot hybridization analysis using the cloned restriction endonuclease fragment pEJ 18 containing the gene of vaccinia virus WR-specific DNA polymerase as a probe. Even though early vaccinia virus WR RNA was still synthesized, accumulation of immediate early viral RNAs was strongly inhibited. Accumulation of beta-actin RNA was not affected. This indicated an enhanced degradation of vaccinia virus WR-specific early RNAs in interferon-treated chick embryo fibroblasts. This notion was supported by Northern blot analysis which revealed degradation of residual RNA of vaccinia virus WR-specific DNA polymerase. In contrast to interferon-treated mouse L 929 cells, ribosomal RNA is not degraded in interferon-treated vaccinia WR-infected chick embryo fibroblasts.
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PMID:Increased turnover of vaccinia virus-specific immediate early RNAs in interferon-treated chick embryo fibroblasts. 244 63

We measured 2',5'-oligoadenylate synthetase activities in serum and peripheral blood mononuclear cells from 10 patients with chronic hepatitis B who were being treated with interferon so as to determine whether 2',5'-oligoadenylate synthetase activity in serum reflected 2',5'-oligoadenylate synthetase activity in peripheral blood mononuclear cells, and whether it could be used to monitor interferon treatment. Pretreatment values of 2',5'-oligoadenylate synthetase activity in patients' serum and peripheral blood mononuclear cells were not statistically different from values from control subjects. When interferon was administered, serum levels of 2',5'-oligoadenylate synthetase began to rise within 3 hr, reached peak values at 12 hr and then declined. The levels of 2',5'-oligoadenylate synthetase activity both in serum and peripheral blood mononuclear cells increased substantially during interferon treatment, ranging 2- to 50-fold greater than initial levels. The levels of 2',5'-oligoadenylate synthetase in serum correlated closely with levels in peripheral blood mononuclear cells. In addition, when the levels of 2',5'-oligoadenylate synthetase rose during interferon administration, serum hepatitis B virus DNA polymerase values fell, and, in some cases, DNA polymerase rose again when 2',5'-oligoadenylate synthetase fell after discontinuation of interferon. These findings suggest that 2',5'-oligoadenylate synthetase activity in serum accurately reflects the antiviral effect of interferon and could be used to monitor interferon treatment.
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PMID:Serum 2',5'-oligoadenylate synthetase activity during interferon treatment of chronic hepatitis B. 245 34

Two years or more after 35 patients (29 men and six women) with chronic hepatitis B were treated by interferon, we studied relationships of age, ALT activity, activity of serum DNA polymerase associated with the hepatitis B virus, serum levels of hepatitis B e antigen and activity of 2',5'-oligoadenylate synthetase in peripheral blood mononuclear cells when treatment started in comparison with treatment results. Seventeen patients were given human lymphoblastoid interferon-alpha; the other 18 patients were given interferon-beta. We measured the activity of 2',5'-oligoadenylate synthetase in these mononuclear cells and found the rate of increase in vivo and in vitro; the correlation between the two was r = 0.68. This enzyme activity in the patients who became negative for DNA polymerase after interferon treatment increased more both in vivo and in vitro than in patients who did not became negative. Also, both the in vivo and in vitro activity increased more in patients who became negative for the e antigen after interferon therapy than in those who remained positive. In the first group, interferon was considered to be effective; in the second, ineffective. Of the patients who became negative, some developed e antibodies and some did not; the increase in this enzyme activity in the two groups was not significantly different. The increase in the activity of 2',5'-oligoadenylate synthetase activity could be used to predict the results of interferon treatment and is an index that can be used before treatment to predict the response.
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PMID:Relationship of the effects of interferon on chronic hepatitis B and the induction of 2',5'-oligoadenylate synthetase. 247 40


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