Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study is intended to establish biological correlation between the expression of lymphoid associated features in acute myeloid leukaemia (AML). In 62 AML patients, predominantly enrolled on Eastern Cooperative Oncology Group (ECOG) treatment protocols, in whom immunoglobulin (Ig) as well as T-cell receptor beta chain (TCR-beta) gene rearrangement analyses had been performed, morphology, cytochemistry, antigen profile and karyotype were reviewed retrospectively. Nuclear reactivity with anti-TdT antibody was demonstrated in 34 patients (55%) and confirmed by ribonuclease protection assay in all patients tested. Five TdT-protein negative patients were TdT-transcript positive. Lymphoid antigens (lyA) were detected in 24 of 51 cases tested (47%) with B-cell antigens (CD19, CD10) being restricted to TdT+ AML (P = 0.03). Only two patients had Ig heavy, none had Ig light chain or TCR-beta gene rearrangements. Although both patients with rearranged Ig loci were TdT+, either by protein or RNA analysis, the low incidence of such rearrangement within the TdT+ AML group (6%) argues against a significant association between the presence of TdT and crosslineage Ig gene rearrangements in AML. While FAB-diagnoses did not differ between TdT+ and TdT- or lyA+ and lyA- AML, particular immunophenotypic features correlated with TdT positively, e.g. the presence of early antigens, CD34 and HLA-DR, and the absence of the more mature myelo-monocytic antigens, CDw65 and CD14. Certain cytogenetic abnormalities were associated with TdT+ AML such as inv(16) (p13q22) or t(16;16) (p12;q22) (five patients; P = 0.03) and t(8;21) (q22;q22) (three patients). A greater number of TdT- than TdT+ AML patients had only normal karyotypes (P = 0.06). Neither immunophenotypic nor karyotypic correlations could be established for lyA+ AML.
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PMID:Lymphoid lineage-associated features in acute myeloid leukaemia: phenotypic and genotypic correlations. 141 14

The role of direct virus infection as a determining factor in acquired immunodeficiency syndrome (AIDS) dementia was investigated using in situ hybridisation for human immunodeficiency virus (HIV) and human cytomegalovirus (HCMV). Four of the five AIDS dementia patients in this series demonstrated HIV infected cells distributed in widely different parts of the brain, but only one case showed HCMV infected cells. The greater abundance of HIV was in subcortical white matter in nodular areas consisting of monocyte/macrophage infiltrates. The cells were occasionally arranged as a multinucleated syncitium. In two cases, a few large cells with the appearance of neurons were positive for HIV hybridisation. By appropriate treatment with ribonuclease, it was shown that hybridisation was primarily to HIV RNA. HCMV infected cells were observed in small numbers in only one of the positive cases, suggesting that HCMV is not a determining factor in AIDS dementia. HCMV positive cells were located in the grey matter, with an appearance suggestive of neurons. Cells expressing the MHC-class II antigen HLA-DR, a marker of reactive microglia and macrophages, were observed to be extensive in affected brain sections in the one case examined. These cells were present in greater number than HIV infected cells. In this case, extensive numbers of HIV infected cells were noticed along the peripheral margin of the substantia innominata. This could indicate infection in this case of a critical brain region from the cerebrospinal fluid.
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PMID:Examination of brains of AIDS cases for human immunodeficiency virus and human cytomegalovirus nucleic acids. 254 95

Activated endothelial cells up-regulate the expression of several molecules on their plasma membranes, including intercellular adhesion molecule-1 (ICAM-1). The role of heparin in regulating endothelial cell gene expression is unclear. We thus have investigated the ability of heparin to regulate ICAM- gene expression by using flow cytometry and the ribonuclease protection assay with human umbilical vein and aortic endothelial cells cultured in growth medium supplemented with 90 [microg/ml heparin (heparin-sufficient, HS) or in growth medium without added heparin (heparin-deficient, HD). We found that HD medium increased plasma membrane protein and mRNA for ICAM-1 but not for HLA-DR, even though both ICAM-1 and HLA-DR protein and mRNA were inducible by gamma interferon (IFN-gamma). In addition, phorbol ester and IFN-gamma increased the expression of plasma membrane ICAM-1 or ICAM-1 and HLA-DR, respectively, more in HD medium than in HS medium. We found that the HD-mediated increase of ICAM- mRNA was reversible by the addition of heparin, and that the half-life of ICAM-1 mRNA was the same in both HS- and HD-treated cells. Also, heparin was found to suppress increases in ICAM-1 mRNA at a concentration as low as 5 microg/ml. These findings indicate that heparin deficiency induces endothelial activation characterized by increased ICAM-1, and that such induction is not dependent on cytokines or endotoxin. The modulation of ICAM-1 expression by heparin appears to occur at the transcriptional level. Thus, heparin may have a role in regulating endothelial function by affecting the expression of ICAM-1, thereby impacting upon the trans-endothelial trafficking of leukocytes.
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PMID:Heparin regulates ICAM-1 expression in human endothelial cells: an example of non-cytokine-mediated endothelial activation. 975 31