Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

5'-Nucleotidase (5'N) activity and Ia expression of hepatic nonparenchymal cells (NPCs) of the autoimmune (NZB X NZW)F1 and MRL-lpr/lpr and nonautoimmune C3H/FeJ, DBA/2J, and A/J strains were assayed to determine endogenous activation of the hepatic reticuloendothelial system (RES). Pretreatment of the nonautoimmune strains with Corynebacterium parvum resulted in decreases in Fc receptor expressor and 5'N and an increase in Ia expression of NPCs. Endogenous hepatic RES activation, as measured by low 5'N and high Ia expression, was observed in both the autoimmune MRL-lpr/lpr and (NZB X NZW)F1 strains even without C. parvum pretreatment. However, in the MRL-lpr/lpr strain, age is a dependent variable in activation and correlates with delayed clearance from the circulation of soluble IgG immune complexes. In the (NZB X NZW)F1 strain, the observation of decreased 5'-nucleotidase activity and increased percentage of Ia-positive cells at all ages suggests a primary abnormality. Therefore, different genetic or exogenous factors may be responsible for the activation of the hepatic RES in these autoimmune strains.
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PMID:Hepatic reticuloendothelial system activation in autoimmune mice: differences between (NZB X NZW)F1 and MRL-lpr/lpr strains. 303 May 89

Two human monocyte subsets from the peripheral blood of healthy donors have been isolated in greater than 90% purity by countercurrent centrifugal elutration and human serum albumin gradients and their functional capabilities have been assessed. We have demonstrated that one subset ("regular" monocytes, RM) showed intense cytoplasmic peroxidase staining and contained substantial peroxidase activity. In contrast, another subset ("intermediate" monocytes, IM) stained poorly for peroxidase and had low peroxidase activity. By electron microscopic analysis combined with peroxidase localization, it was found that IM had fewer peroxidase-positive granules per cell than did RM. IM coelutriated with some lymphocytes and by cell sizing analysis were shown to be slightly smaller than RM. Functional and cytochemical analysis of these subsets indicated that IM had less activity than RM in assays such as accessory cell function for mitogen-induced T lymphocyte proliferation and antibody-dependent cellular cytotoxicity, and that fewer IM expressed OKM1 antigen and pokeweed mitogen (PWM) receptors on their membranes than did RM. The subset of IM not bearing either the PWM receptor or the OKM1 antigen had very low peroxidase activity. IM also were found to have a greater sensitivity to polyriboinosinic and polyribocytidilic acid (100 micrograms/ml)-induced secretion of interferon. There was no significant difference in the phagocytic capability, the percentage of Fc receptor-positive cells, 5'-nucleotidase activity, DR antigen expression, or the responsiveness to migration inhibitory factor of IM as compared with RM. Furthermore, it was found that the ratio of IM to RM increased after prolonged cytapheresis, which suggests that IM are more mobilizable than RM from the extravascular reservoirs of human monocytes.
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PMID:Characterization of a human blood monocyte subset with low peroxidase activity. 619 41

A plasma membrane-rich fraction was prepared from guinea pig peritoneal polymorphonuclear leucocytes (PMNs) by a nitrogen cavitation method. Fc receptor activity was measured in the fraction. The activity showed a Kd of 5 X 10(-7) M IgG and a maximum binding of 33 pmol IgG/mg protein when measured with an immune complex made with bovine serum albumin and rabbit anti-(bovine serum albumin) immunoglobulin G. Properties of the Fc receptor in the plasma membrane fraction were similar to that in intact PMNs. It is proposed that the Fc receptor activity and 5'-nucleotidase activity are markers for plasma membranes of these cells.
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PMID:Preparation of polymorphonuclear leucocyte-plasma membranes which show Fc receptor activity. 716 Dec 63