Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using the Southern blot technique and cloned hepatitis B virus (HBV) DNA as a probe, we studied the state of HBV DNA in the liver of 13 patients with hepatocellular carcinoma, 17 patients with chronic hepatitis, and 2 patients with acute hepatitis. The hybridization results were compared with the serological and immunohistological data. Integration of HBV DNA in cellular DNA of the liver from patients with hepatocellular carcinoma was demonstrated. In two patients from which tumorous and nontumorous liver tissue samples were available the integration patterns were different. In one patient with hepatitis B e antigen (HBeAg)-positive early hepatocellular carcinoma, free viral DNA was present in the liver. In some patients with HBeAg-negative chronic hepatitis, without tumor, integration of HBV DNA in cellular DNA was also demonstrated. This suggests that HBV is not the only factor involved in the development of a tumor. In patients with HBeAg-positive chronic hepatitis, free viral DNA was detected in the liver. In the two acute hepatitis patients analyzed, the restriction endonuclease patterns strongly suggested HBV DNA integration. Therefore, viral DNA integration seems to occur early in infection. Whatever the form of the disease, discrete bands were observed, suggesting the existence of limited and specific integration sites in host cellular DNA. The presence of integrated or free DNA sequences has implications for antiviral therapy. In addition, detection of HBV DNA in the liver is another sensitive viral marker that could be useful for diagnostic purposes.
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PMID:State of hepatitis B virus DNA in hepatocytes of patients with hepatitis B surface antigen-positive and -negative liver diseases. 626 9

We designed a mispairing primer, which could introduce a Bsu36I restriction site into the amplified fragment of A83 mutant. Following PCR, the 102bp was diagnosed by the restriction endonuclease, and the variation was detected by demonstration of 82bp and 20bp bands on gel electrophoresis (RFLP). With the method, 77 cases of acute and chronic HBV infections were analysed. Among those, 31 (65%) mutants were detected in 48 anti-HBe-positive cases, and in 29 HBeAg-positive cases, 11 (38%) were co-infected with mutated and wild isolates. No pre C defect was found in acute hepatitis B and chronic asymptomatic carriers, suggesting that mutation occurs only after immune selection. The HBeAg defective variant appears to be involved in the loss of virus tolerance, and therefore in the pathogenesis of acute exacerbation of chronic carriage as demonstrated in this study. The various chronic liver diseases had an approximate mutation frequency, and it seems that A83 mutation nearly makes HBV infection persist.
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PMID:[Distribution of pre-core A83 point mutation in hepatitis B virus infections]. 799 56

Leptospira interrogans serovar grippotyphosa was isolated from the skin of a 14-year-old male dog with deteriorating health. Necropsy revealed numerous lesions characteristic of aged dogs, but no evidence of acute hepatitis or nephritis, which are common features of pathogenic Leptospira infections. Antibody to Leptospira was not detected in the dog's serum by microagglutination. Leptospires grew slowly in Barbour-Stoenner-Kelly medium, a medium commonly used to isolate Borrelia, but then grew abundantly in Tween 80-bovine albumin leptospire medium. The isolate was pathogenic to a hamster and was identified by microagglutination and restriction endonuclease analysis.
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PMID:Isolation of Leptospira interrogans serovar grippotyphosa from the skin of a dog. 828 77

Hepatitis E virus (HEV) is the major agent of acute hepatitis in developing countries where the infection occurs sporadically or in large waterborne epidemics. HEV, classified in the Caliciviridae, is not culturable. The detection of HEV RNA by RT-PCR in serum and stool samples is reliable during the 7 to 15 days following the onset of the disease. Restriction endonuclease analysis, cloning and sequencing of PCR products allow a phylogenetic analysis of HEV isolates. Although they belong to a single serotype, strains recovered from different geographical regions display a significant genetic heterogeneity. Sequencing data from ORF1 and ORF2 regions has led to the characterization of 3 distinct genotypes: genotype I gathering the Asian and African subgenotypes; genotype II gathering swine and human US strains; genotype III limited to the Mexico prototype. Novel variants are currently described from Africa (Nigeria), China and Europe (Greece and Italy). Each genotype appears to be related to a well defined geographical area. Nevertheless, a genetic variability is observed within endemic regions such as Asia or Africa. Nigerian endemic isolates especially could represent an intermediate stage in the evolutionary process towards genetic diversity. The animal reservoir, proved by the detection of HEV sequences by PCR among pigs in Nepal and in the USA, could help to resolve unanswered questions about the origin of HEV genotypes, their spread and evolution.
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PMID:[Geographical distribution of hepatitis E virus genotypes]. 1057 64