Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.31 (beta-glucuronidase)
7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two types of rosette-forming cells were identified: rosette-forming cells with membrane-bound receptors for sheep erythrocytes (E-RFC) and rosette-forming cells with Fc receptors (EA-RFC). In both types of lymphocytes the activity of acid phosphatase, beta-glucuronidase, non-specific esterase and the content of glycogen were studied. A significant difference was established between E-RFC and EA-RFC lymphocytes as concerns acid phosphatase activity; corresponding mean values being 72.4 +/- 7.5 respectively 44.4 +/- 4.5 (p less than 0.01). As oppose to the acid phosphatase activity the glycogen was significantly higher in EA-RFC lymphocytes (mean 67.2 +/- 6.9), as compared with E-RFC (mean 41.6 +/- 9.2). It seems to us that estimations of acid phosphatase activity may be of value in differentiating 2 populations of lymphocytes.
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PMID:Cytochemical studies of rosette-forming cells. 12 52

We have used a new technique for extraction of myocardial membranes (0.25 M sucrose, 0.6 M KCl) to isolate particulate and soluble proteins and enzymatic activities in an effort to quantify changes characteristic of progressive ischemia. Myocardial blood flow (MBF) was measured with microspheres (15 micrometer diameter) in all samples of tissue used for assay of proteins and enzymatic activities; MBF to the moderately ischemic areas (M-ischemia) was 53% of control (H-control); MBF to the severely ischemic areas (L-ischemia) was 9% of control. Significant decreases (P less than 0.001) in content of protein were seen in all post 1,000 g pellets and supernatant fluids in the L-ischemia zones; particulate lysosomal enzymatic activity was significantly decreased (P less than 0.001) in all four post 1,000 g pellets (2,500 g to 140,000 g) of the L-ischemic areas (for N-acetyl-beta-glucosaminidase and beta-glucuronidase). The increase in percent free activity of lysosomal enzymes (index of loss of latency) also was highly significant (P less than 0.001) in all particulate fractions of the L-ischemic areas. In addition, about 45% of the total activity of the microsomal marker enzyme, rotenone-insensitive NADH cytochrome C reductase (RINCR), was found in the 140,000 g pellet of H-control tissue (9.9 micronmol/min per g); this activity fell to 8.1 micronmol/min per g in M-ischemic areas (P less than 0.001) and to 5.3 micronmol/min per g in L-ischemic areas (P less than 0.001). This study demonstrates that changes in myocardial proteins, lysosomes, and other membrane-bound enzymes (RINCR) may provide reproducible bichemical parameters for assessing ischemic myocardial injury.
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PMID:Effects of well-defined ischemia on myocardial lysosomal and microsomal enzymes in a canine model. 21 2

The carotid artery of the rabbit is a suitable blood vessel to study radiation induced atheromatosis in hypercholesteremic animals, because no plaque formation occurs within two months after the start of a 0.5% cholesterol diet. Cholesterol contents as high as 2% however, do give atheromatous plaques in the carotid artery without prior irradiation. As early as five hours after local irradiation of the carotid artery activation of the plasma membrane-bound enzyme alkaline phosphatase could be observed in some intimal cells. Two to three days after irradiation the activity disappeared. This phenomenon was observed in normo-and hypercholesteremic irradiated arteries. Depending on the lipid content of the blood, infiltration of lipids was observed at one day after the irradiation or later, accompanied by activation of beta-glucuronidase in the innermost layer of medial cells. Hereafter plaque formation started and cell proliferation could be found in the subendothelial space. It is assumed that because of the irradiation, the endothelial cells of the carotid artery are damaged in such a way that they do not function properly as a barrier against lipoprotein entrance from the blood into the arterial wall. The lipid infiltration caused lysosomal activation and probably cellular proliferation.
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PMID:Initial events in radiation-induced atheromatosis. II. Damage to intimal cells. 71 13

Seven spleens and two peripheral blood specimens from eight patients with hairy cell leukemia were examined with enzyme cytochemical and histochemical methods. Hairy cells consistently exhibited acid phosphatase and tartrate-resistant acid phosphatase. However, nonspecific esterases characteristic of monocytes and histiocytes were consistently absent or very weak. beta-glucuronidase and cytoplasmic membrane-bound ATPase were positive in four cases, suggesting a possible relationship to the B-lymphocytic series. Fundamental splenic changes were accumulation of hairy cells and benign macrophages within the pulp cords, with resulting extreme expansion of the cords. Abnormally well developed ellipsoids were identified around the sheathed arteries within the cords. Sinuses, specifically delineated with the NASDA reaction, were atrophic and often destroyed. No cytogeneologic relationship was found between sinus endothelial cells and hairy cells. The pulp cords are the primary site of involvement of the spleen in hairy cell leukemia. A simultaneous proliferation of neoplastic cells, histiocytes and reticulum fibers accounts for the splenomegaly and clinical hypersplenism characteristic of the disease.
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PMID:Hairy cell leukemia. Enzyme histochemical characterization, with special reference to splenic stromal changes. 87 31

The effect of the mycotoxin of Fusarium sporotrichiella v. sporotrichioides (sporofusarin) was studied in vitro on the total and nonsedimenting activity of eight lysosomal enzymes: acid ribonuclease, aryl sulfatases A and B, beta-glucuronidase, alpha- and beta-galactosidases, beta-glucosidase, beta-acetylglucosaminidase, and alpha-mannosidase. Incubation of a suspension of rat liver lysosomes with an aqueous solution of sporofusarin led to inhibition of the total activity of the membrane-bound lysosomal enzyme beta-glucosidase. In a dose of only 1.6 x 10-5 M sporofusarin caused a significant increase in the nonsedimenting activity of nearly all the enzymes; in a concentration of 1.6 x 10-3 M most of the enzymes of the lysosomal matrix (beta-glucuronidase, beta-galactosidase, aryl sulfatases A and B) were liberated almost completely into the supernatant, and nearly all the beta-glucosidase also was liberated. It is postulated that damage to the subcellular membranes is an important component of the toxic action of sporofusarin.
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PMID:Action of the mycotoxin of Fusarium sporotrichiella v. sporotrichioides on lysosomal membranes. 111 54

Early changes in lysosomal enzymes must occur if their role is significant in irreversible myocardial injury. Therefore, we ligated the anterior descending coronary artery in 14 dogs and after 60 min excised epicardial and endocardial samples from the ischemic and adjacent normal heart. The collateral flow measured with radioactive microspheres in the endocardial samples averaged 19% of control. The muscle was disrupted and fractionated by ultracentrifugation into nuclear pellet (NP), heavy lysosomal pellet (HL), light lysosomal pellet (LL), microsomal pellet (M) and supernate (S). Electron microscopy demonstrated changes characteristic of sichemia in whole tissues and sedimented fractions. Acid phosphatase reaction product was present in residual bodies in the HL fraction and membrane-bound vesicles in the LL fraction and in the intact tissue. Significant decreases in the specific activity of N-acetyl-beta-glucosaminidase and beta-glucuronidase occurred in the endocardial LL fraction, while significant increases in both were found in the ts fraction (P less than 0.05). Losses of acid phosphatase occurred in both LL and S fractions. Moreover, decreases of total N-acetyl-beta-glucosaminidase in the HL fraction and of total beta-glucuronidase and acid phosphatase in the LL fraction were positively correlated (P less than 0.01) with the degree of ischemia measured with radioactive microspheres. Only insignificant enzymatic changes were found when the collateral flow was greater than 40%, and the differences were less significant in epicardial samples where the flow averaged 29%. The early loss of enzymes from the lysosomal fractions in severe ischemia suggests a role for lysosomal hydrolases in the necrosis that follows coronary occlusion.
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PMID:Effect of collateral flow on epicardial and endocardial lysosomal hydrolases in acute myocardial ischemia. 115 94

To evaluate lysosomal involvement in myocardial infarction, coronary artery thrombosis was induced by ligation in 16 dogs. Biopsies of infarcted and normal left ventricles were studied by ultrastructural cytochemistry and subcellular fractionation (0.25 M sucrose) from 30 min to 96 hrs post injury. Normal myocardium contained few "classical" (residual body) lysosomes: instead, acid phosphatase and aryl sulfatase were localized to longitudinal and to lateral sac elements of the sarcoplasmic reticulum. In postnuclear (450 X gm, 10 min) supernates, lysosomal acid phosphatase and beta-glucuronidase were divided 60:40 between sedimentable (98,000 X gm, 15 min) and non-sedimentable fractions of normal endocardium and epicardium (studied separately). At 2 hrs post infarction, ischemic muscle showed: 1) loss of membrane-bound acid phosphatase and aryl sulfatase; 2) mitochondrial damage; 3) loss of glycogen and disappearance of I but not A bands; and 4) entry into cells of colloidal lanthanum (= loss of plasma membrane integrity. Total lysosomal hydrolase did not increase until 6-5 hrs post infarct. At 2 hrs, significant increments (32 +/- 7%) were found in nonsedimentable acid phosphatase and beta-glucuronidase of endocardium (P less than 0.005 vs. normal) but the epicardium. In dogs given methylprednisolone (50 mg/k) 30 min post infarct, ultrastructural cytochemistry showed retention of lysosomal enzymes within endocardial sarcoplasmic reticulum and no significant redistribution of enzymes into non-sedimentable fractions (vs. eight paired, infarcted, untreated controls). Data show early disruption of lysosomes in myocardial infarction and their protection by steroid given after the acute insult.
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PMID:Lysosomes in myocardial infarction: studies by means of cytochemistry and subcellular fractionation, with observations on the effects of methylprednisolone. 125 66

Phagosomes are membrane-bound vesicles, formed by the receptor-mediated internalization of particulate ligands, which exchange soluble and membrane proteins with other endocytic compartments as a part of their maturation process. This exchange of material is undoubtedly mediated by fusion of phagosomes with other membrane-bound compartments of the endocytic pathway. By using a particulate probe (fixed Staphylococcus aureus coated with mouse anti-dinitrophenol monoclonal antibody) localized in phagosomes and a soluble probe (dinitrophenol-derivitized beta-glucuronidase) internalized by receptor-mediated endocytosis, we have studied phagosome-endosome and phagosome-lysosome fusion in intact cells and in a cell-free system. Vesicle fusion was assessed by measuring beta-glucuronidase activity associated with S. aureus particles after lysis of the membranes. In intact macrophages, newly formed phagosomes fused with early endosomes and with lysosomes. Fusion with lysosomes was observed to commence after a short lag period of about 5 min. In broken-cell preparations, phagosomes were able to fuse with early endosomes. It was not possible to reconstitute phagosome-lysosome fusion in vitro. In vitro phagosome-endosome fusion required energy and cytosolic- and membrane-associated proteins. A nonhydrolyzable analog of GTP stimulated fusion at low cytosol concentrations and inhibited fusion at high cytosol concentrations. These observations indicate that the mechanisms mediating phagosome-endosome fusion are similar to those described for endosome-endosome fusion. Our results suggest that exchange of material with endosomes is an important step in the process of phagosome maturation.
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PMID:Fusion of newly formed phagosomes with endosomes in intact cells and in a cell-free system. 200

Small clusters of extra large muscle fibres were identified in hindlimb muscles of neonatal mice (strain C57BL/10ScSn). At two days of age they had a significantly greater cross-sectional area than their normal counterparts (P less than 0.01). Fibre typing methods (NADH-tetrazolium reductase, ATPase and phosphorylase) classified them as 2A fast oxidative glycolytic (FOG fibres). The activity of NADH-tetrazolium reductase and the lysosomal enzymes beta-glucuronidase, acid phosphatase and dipeptidyl peptidase II were all elevated in the large fibres. Microsomal aminopeptidase (mAPP), a membrane-bound enzyme, also showed increased activity. The fibres are probably the mouse equivalent of the Wohlfart B fibres of the human fetus, with which comparison is made.
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PMID:An enzyme histochemical study of large muscle fibres in the neonatal mouse. 225 60

We have used monospecific antisera to two lysosomal membrane glycoproteins, lgp120 and a similar protein, lgp110, to compare the biosynthesis and intracellular transport of lysosomal membrane components, plasma membrane proteins, and lysosomal enzymes. In J774 cells and NRK cells, newly synthesized lysosomal membrane and plasma membrane proteins (the IgG1/IgG2b Fc receptor or influenza virus hemagglutinin) were transported through the Golgi apparatus (defined by acquisition of resistance to endo-beta-N-acetylglucosaminidase H) with the same kinetics (t1/2 = 11-14 min). In addition, immunoelectron microscopy of normal rat kidney cells showed that lgp120 and vesicular stomatitis virus G-protein were present in the same Golgi cisternae demonstrating that lysosomal and plasma membrane proteins were not sorted either before or during transport through the Golgi apparatus. To define the site at which sorting occurred, we compared the kinetics of transport of lysosomal and plasma membrane proteins and a lysosomal enzyme to their respective destinations. Newly synthesized proteins were detected in dense lysosomes (lgp's and beta-glucuronidase) or on the cell surface (Fc receptor or hemagglutinin) after the same lag period (20-25 min), and accumulated at their final destinations with similar kinetics (t1/2 = 30-45 min), suggesting that these two lgp's are not transported to the plasma membrane before reaching lysosomes. This was further supported by measurements of the transport of membrane-bound endocytic markers from the cell surface to lysosomes, which exhibited additional lag periods of 5-15 min and half-times of 1.5-2 h. The time required for transport of newly synthesized plasma membrane proteins to the cell surface, and for the transport of plasma membrane markers from the cell surface to lysosomes would appear too long to account for the rapid transport of lgp's from the Golgi apparatus to lysosomes. Thus, the observed kinetics suggest that lysosomal membrane proteins are sorted from plasma membrane proteins at a post-Golgi intracellular site, possibly the trans Golgi network, before their delivery to lysosomes.
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PMID:Kinetics of intracellular transport and sorting of lysosomal membrane and plasma membrane proteins. 282 Oct 12


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