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

---

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

In a series of 130 cases of acute leukemia studied by cytochemical staining techniques, 10 cases cytochemically diagnosed as "pure" monocytic leukemia were seen. Cytochemical staining of bone marrow aspirates from these patients revealed all leukemic cells to be Sudan black negative. No positive reactions were observed for peroxidase or naphthol AS-D chloroacetate esterase. All cases demonstrated strong alpha-naphthyl acetate esterase positivity; and fluoride-inhibited naphthol AS-D acetate esterase positivity was observed in 8 of 9 cases tested. The P.A.S. reaction showed diffuse fine to coarse granules. Oil red O stain was positive in 8 of 9 cases, and the beta-glucuronidase activity was strong in 5 of 9 cases. Light microscopy revealed cells with monocytic or histiocytic morphology. Electron microscopic studies in 2 cases demonstrated features consistent with leukemic monocytic or histiocytic morphology; none was suggestive of granulocytic or lymphocytic leukemia. Five of 6 patients treated with drug regimens including prednisone and vincristine entered a complete remission; the other obtained a partial remission. Two patients achieved complete remission after treatment with Adriamycin, 1 following a relapse. Three patients who received cytosine arabinoside as their only therapy died soon after treatment was commenced. It is suggested that the cytochemical similarity but morphological differences in those patients may be objectively used to group them as cases of histiomonocytic leukemia.
...
PMID:"Pure" monocytic or histiomonocytic leukemia: a revised concept. 4 89

In order to determine the possible mechanisms whereby interactions between phagocytic cells and crystals of monosodium urate (MSU) lead to cell death with simultaneous release of both cytoplasmic and lysosomal enzymes, phagocytic leukocytes of the smooth dogfish shart Mustelus canis were studied by means of light and electron microscopy, and biochemistry. Lysosomes of these cells can be stained supravitally with toluidine blue and are large enough (0.7-0.8 mu) to be clearly resolved with the light microscope. Light microscopic observations showed that of cells exposed to MSU 87% of those containing visible ingested crystals died within 1 hour, whereas 92% of adjacent cells in the same wet mount without such srystals survived. Cell death occured after a latent period of 10-15 minutes following fusion of lysosomes with crystal-containing phagosomes. Electron microscopic examination of both dogfish and human leukocytes exposed to MSU for more than 1 hour and then fixed in situ revealed occasional discontinuities or ruptures in secondary lysosome membranes. Endogenous peroxidase activity could be cytochemically localized in primary and secondary lysosomes and in the cytoplasm adjacent to such ruptured secondary lysosomes. It was not seen adjacent to primary lysosomes, a result indicating that the cytoplasmic reaction product was not a diffusion artifact. To exclude the possibility that crystals were exercising their affect primarily upon the plasma membrane, suspensions of dogfish buffy coat cells were incubated with cytochalasin B (5 mug/ml, 10 minutes), which inhibits phagocytosis but not exocytosis of lysosomal enzymes by stimulated phagocytes. Whereas cells exposed to MSU crystals released 30% of their content of lysosomal beta-glucuronidase activity and 28% of their cytoplasmic lactate dehydrogenase (LDH) activity within 3 hours, preincubation with cytochalasin B reduced the release of LDH activity within that period to 6% but reduced the release of beta-glucuronidase activity only to 20%. Preincubation with 10-3 M cyclic adenosine monophosphate (cAMP) and theophylline (10-3 M), which inhibit lysosomal fusion, reduced the release of both LDH and beta-glucuronidase activities to 7% and 6% respectively. Cells that were preincubated with both cytochalasin B and cAMP + theophylline released only 1% LDH activity and 4% beta-blucuronidase activity. These results are compatible with the "suicide sac" hypothesis of lysosomal enzyme release mediated by MSU for the following reasons: a) cell death was seen to follow uptake, not mere exposure to crystals, b) ultrastructural studies indicated that the primary injury was to the secondary lysosome membrane, and c) cell death was reduced when either phagocytosis or lysosomal fusion was inhibited.
...
PMID:Mechanisms of lysosomal enzyme release from leukocytes. IV. Interaction of monosodium urate crystals with dogfish and human leukocytes. 4 82

Coelomocytes of the earthworm, Lumbricus terrestris, were stained by cytochemical techniques to determine the biochemical composition of the seven different cell types and subtypes. The enzymes acid phosphatase and beta-glucuronidase are present in all types of coelomocytes, but are especially abundant in basophils and neutrophils; the differences in enzyme amounts correlate well with the differences in phagocytic activity of the various cell types. No peroxidase is present. The cytoplasmic basophilia of basophils is due primarily to ribonucleic acid. Basophils also contain large deposits of glycogen, with neutrophils and chloragogen cells containing somewhat lesser amounts. The predominant granules of the two types of acidophils and of granulocytes are composed of a basic protein and a neutral mucopolysaccharide or glycoprotein. A second granule population, present in low numbers in acidophils and granulocytes, but in larger numbers in basophils and neutrophils, is small in size and lipid-positive and may, in part, represent lysosomes. Lipid is especially abundant in the vesicles and granules of the two types of chloragogen cells. Some granules of chloragogen cells also contain ferrous and ferric iron and a substance with pseudoperoxidase activity. The cytoplasm contains protein, glycogen, and a neutral mucopolysaccharide. In addition, acid mucopolysaccharides are variably present in the cytoplasm of chloragogen cells, the only coelomocytes to contain this class of substances.
...
PMID:Cytochemical observations of coelomocytes from the earthworm, Lumbricus terrestris. 15 40

The disruption of the molecular organization of the plasma membrane of leukocytes by phagocytosable particles, or by agents such as surfactants, antibodies, phospholipase C, fatty acids and chemotactic factors, leads to a stimulation of the phagocyte oxidative metabolism. Concanavalin A (Con A) has been used as a tool to study the mechanism of this metabolic regulation. The binding of Con A to the surface of polymorphonuclear leukocytes (PMNL) or macrophages produces a rapid enhancement of oxygen uptake and glucose oxidation through the hexose monophosphate pathway (HMP). This is explained by an activation of the granular NADPH oxidase, the key enzyme in the metabolic stimulation. The effect of Con A is not due to endocytosed lectin, since Con A covalently coupled to large sepharose beads still acts as stimulant. The metabolic changes caused by Con A are reversible. If, after the onset of stimulation, sugars with high affinity for Con A are added to the leukocyte suspension, the activity of granular NADPH oxidase and the rate of respiration and glucose oxidation return to their resting values. The metabolic burst, while partially supressed by treatment of PMNL with iodoacetate, sodium flouride and cytochalasin B, is slightly increased by colchicine. Con A induces a selective release of granular enzymes (beta-glucuronidase, peroxidase, alkaline phosphatase) from PMNL, whereas no leakage of cytoplasmic enzymes is observed. The enzyme release is inhibited by iodoacetate and by drugs known to increase cell levels of cyclic AMP. Based on a current view of the mode of interaction between Con A and cell surfaces, a model of the metabolic disruption of leukocytes is presented.
...
PMID:Concanavalin A as a probe for studying the mechanism of metabolic stimulation of leukocytes. 16 45

Polar solvents induce terminal differentiation in the human promyelocytic leukemia cell line HL-60. The present studies describe the functional changes that accompany the morphologic progression from promyelocytes to bands and poly-morphonuclear leukocytes (PMN) over 9 d of culture in 1.3 percent dimethylsulfoxide (DMSO). As the HL-60 cells mature, the rate of O(2-) production increase 18-fold, with a progressive shortening of the lag time required for activation. Hexosemonophosphate shunt activity rises concomitantly. Ingestin of paraffin oil droplets opsonized with complement or Ig increases 10-fold over 9 d in DMSO. Latex ingestion per cell by each morphologic type does not change significantly, but total latex ingestion by groups of cells increases with the rise in the proportion of mature cells with greater ingestion capacities. Degranulation, as measured by release of beta-glucuronidase, lysozyme, and peroxidase, reaches maximum after 3-6 d in DMSO, then declines. HL-60 cells contain no detectable lactoferrin, suggesting that their secondary granules are absent or defective. However, they kill staphylococci by day 6 in DMSO. Morphologically immature cells (days 1-3 in DMSO) are capable of O(2-) generation, hexosemonophosphate shunt activity, ingestion, degranulation, and bacterial killing. Maximal performance of each function by cells incubated in DMSO for longer periods of time is 50-100 percent that of normal PMN. DMSO- induced differentiation of HL-60 cells is a promising model for myeloid development.
...
PMID:Functional changes in human leukemic cell line HL-60. A model for myeloid differentiation. 22 36

Alveolar macrophages have been shown to bind glycoproteins and synthetic glycoconjugates (neoglycorpoteins) that have mannose, N-acetylglucosamine, or glucose in the exposed, nonreducing position. Galactose-terminal glycoproteins are not bound. Binding of radiolabeled ligands to cells is nearly completely impaired by the presence of an excess of yeast mannan. Binding is temperature sensitive and proceeds optimally at pH 7.0. Prior treatment of the cells with trypsin severely decreases their capacity to bind ligands. An inhibition assay has been developed, using radioiodinated glucose-albumin conjugate, agalacto-orosomucoid, beta-glucuronidase, and RNase B as ligands. Various glycoproteins have been shown to be effective inhibitors of ligand binding including horseradish peroxidase, agalacto-orosomucoid, beta-glucuronidase, ovalbumin, agalacto-fetuin, and RNase B. RNase A and asialo-fetuin are ineffective as antagonists. The results suggest the presence of a cell surface receptor on alveolar macrophages that binds glycoproteins having terminal sugars with the mannose or glucose configuration.
...
PMID:Evidence for receptor-mediated binding of glycoproteins, glycoconjugates, and lysosomal glycosidases by alveolar macrophages. 27 29

Phorbol myristate acetate (PMA, 2 to 100 ng/ml) and ionophore A23187 (10(-7) to 10(-6) M) cause human neutrophils to release up to 50% of the granule-associated enzyme lysozyme extracellularly without release of beta-glucuronidase or the cytoplasmic enzyme LDH. When azurophil and specific granules are separated from neutrophil lysates by sucrose density centrifugation, it is found that lysozyme release from neutrophils exposed to PMA or to A23187 reflects a selective disappearance of the small, peroxidase-negative (specific) granules from the cells. These studies demonstrate that neutrophils can mobilize the specific and azurophil granules independently. These studies also demonstrate that under certain conditions the specific granules of human neutrophils behave like the storage granules of secretory cells. Finally, these studies show that techniques of separating neutrophil granules according to their sedimentation characteristics successfully divide these granules into populations that are distinct not only by cytochemical and morphologic criteria but also according to their availability for mobilization and extracellular release. (APM J Pathol 87:273-284, 1977).
...
PMID:The differential mobilization of human neutrophil granules. Effects of phorbol myristate acetate and ionophore A23187. 32 7

The distributions of lipid, glycogen, peroxidase, acid and alkaline phosphatases, beta-glucuronidase and naphthol AS-D chloroacetate esterase have been studied in the cells of peripheral smears from the wall ghecko and the crocodile. The erythrocytes react differently from those of mammalian erythrocytes with regard to peroxidase reactivity. The need to take such species differences into consideration when engaged in histochemical investigations is stressed.
...
PMID:Cytochemistry of blood cells in peripheral smears of some West African reptiles. 59 35

The presence of acid phosphatase, beta-glucuronidase and aryl sulfatase in juxtaglomerular cell granules (JGG) as well as the uptake and concentration of certain low molecular weight dyes by these granules have repeatedly suggested that they are akin to lysosomes. In the present experiments, rats were injected with three substances of widely different molecular weight and physicochemical properties--sucrose, iron sorbitol-citric acid complex (Jectofer) and horseradish peroxidase--that are well known to selectively concentrate in renal tubular cell lysosomes. None of these substances was found to enter the JGG to any significant degree, although both sucrose and Jectofer were evident in juxtaglomerular cells. Contrary to previous reports, thorium dioxide (Thorotrast) particles were not detected in the JGG after parenteral injection. These results indicate that JGG do not possess any significant lysosomal function and raise the question of the role of hydrolytic enzymes in the physiology of these granules.
...
PMID:On the lysosomal function of juxtaglomerular granules. 61 Jul 7

Neuronal ceroid-lipofuscinosis is characterized by pigmentary degeneration of the retina, psychomotor degeneration, epilepsy and intracellular deposition of ceroidlipofuscin. Recent reports have suggested that deficiency of peroxidase is the basic genetic defect. However, deficiency of myeloperoxidase could be demonstrated in some but not all patients; this deficiency was noted only when p-phenylenediamine (PPD) was used as hydrogen donor and could not be confirmed with guaiacol. We found that horseradish peroxidase (HR-P) oxidized PPD in the absence of added H2O2. The oxidative product of PPD showed the same absorption spectrum as the peroxidative product. The oxidation of PPD by HR-P was not inhibited by catalase or superoxide dismutase. In addition, catalase oxidized PPD in the presence of H2O2. Soluble and granular fractions obtained from human polymorphonuclear leukocytes (PMN) also oxidized PPD in the absence of H2O2. Addition of H2O2 inhibited the oxidation of PPD in some cell fractions. This inhibition could be partially eliminated by dialysis of the cell fractions. Thus, PPD is not a suitable hydrogen donor for the study of peroxidase. This may explain the variable results obtained by the previous investigators. In contrast, guaiacol did not show these undesirable characteristics. The PMN peroxidase (measured with guaiacol), catalase, beta-glucuronidase, acid and alkaline phosphatases were studied in individuals from three families with juvenile neuronal ceroid-lipofuscinosis. Family 1: an affected boy and healthy parents; all showed normal enzyme activities in both soluble and granular fractions. Family 2: two affected sisters, one healthy sib and mother, and Family 3: one affected boy; all showed reduced peroxidase activities in the granular fractions. Other enzymes were normal. The role of peroxidase deficiency in the pathogenesis of neuronal ceroid-lipofuscinosis is not clear. The basic defect of this syndrome remains uncertain.
...
PMID:Neuronal ceroid-lipofuscinosis. Studies of granulocyte enzyme activities. 65 Feb 51


1 2 3 4 5 6 7 8 9 10 Next >>

---