Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A radioimmunoassay for the detection of antibodies in human serum to tritium-labeled HeLa cell cytoplasmic ribosomes was developed with the use of Macaloid for the inhibition of endogenous ribonuclease activity. Antibodies were observed in the serum of patients with systemic lupus erythematosus in high incidence and titer. Patients with rheumatoid arthritis and chronic active hepatitis manifested a lower incidence and titer of antibodies to ribosomes, whereas serums from normal individuals and from patients with sarcoidosis, chronic glomerulonephritis, and malignant tumors showed no significant reactivity with cytoplasmic ribosomes. Maximum inhibition of the reaction was achieved with unlabeled HeLa cell ribosomes or rat liver ribosomes and partial inhibition by purified ribosomal RNA.
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PMID:Radioimmunoassay for antibodies to cytoplasmic ribosomes in human serum. 91 Jan 57

Autoantibody reactive with tRNA was identified by immunoprecipitation of Hela cell extract. Four out of 56 sera from patients with autoimmune chronic active hepatitis (CAH), and four out of 35 sera from patients with primary biliary cirrhosis (PBC) contained antibody directed against gel-purified tRNA in Hela cell extract, but no sera obtained from CAH type B, CAH non-A, non-B, or healthy volunteers did. Further studies on these eight anti-tRNA sera disclosed that 6 of the 8 sera that immunoprecipitated tRNA from Hela cell extract, reacted with purified tRNA, but reacted with neither 5sRNA nor ribosomal RNA species. After proteinase and deoxyribonuclease digestion of Hela cell extract, the epitope for these 6 sera was conserved, and the antigen was sensitive to ribonuclease (anti-tRNA serum). Purified Hela cell DNA digested with Eco RI or Hind III (denatured or non-denatured) could not be immunoprecipitated by these sera. In a patient with autoimmune CAH, the anti-tRNA antibody was weakly positive at week 2 and disappeared 2 months after steroid therapy started, "in parallel" with disappearance of anti-nuclear antibody. In the other 2 sera, the antigen was sensitive to proteinase.
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PMID:Autoantibody specific for transfer ribonucleic acid (tRNA) in patients with autoimmune chronic active hepatitis and primary biliary cirrhosis. 177 87

1. Activated hepatic lipocytes are central to the pathogenesis of liver fibrosis as the principal source of both interstitial collagens and matrix-degrading metalloproteinases. In progressive fibrosis there is a failure to degrade interstitial collagens with a reported decrease in collagenase activity. In these studies we investigate expression of the potent collagenase inhibitor, tissue inhibitor of metalloproteinase-1, and interstitial collagenase in end-stage autoimmune chronic active hepatitis and activated human hepatic lipocytes in culture. 2. Messenger RNA transcripts for interstitial collagenase and tissue inhibitor of metalloproteinase-1 in explanted human liver were quantified by ribonuclease protection assay and densitometric analysis. This indicated that tissue inhibitor of metalloproteinase-1 and interstitial collagenase expression in autoimmune chronic active hepatitis were also coordinately up-regulated. 3. Using Northern analysis of RNA from human lipocytes in primary culture on plastic, mRNA for interstitial collagenase could not be detected in unstimulated cells but was present after stimulation with tumour necrosis factor alpha. Tissue inhibitor of metalloproteinase-1 mRNA was present in unstimulated lipocytes and up-regulated fivefold in response to tumour necrosis factor alpha. Using activity assay of serum-free conditioned media, interstitial collagenase could not be detected in unstimulated primary cultures, primary cultures stimulated with tumour necrosis factor alpha or transforming growth factor beta-1 (n = 3 and n = 4 respectively) or in passaged lipocytes (n = 6). In contrast, free tissue inhibitor of metalloproteinase-1 activity was present in unstimulated and passaged cultures and this was increased in response to tumour necrosis factor alpha and transforming growth factor beta-1.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Tissue inhibitor of metalloproteinase-I and interstitial collagenase expression in autoimmune chronic active hepatitis and activated human hepatic lipocytes. 767 71