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:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The properties of peroxidase insolubilized by covalent binding to CH- and AH-Sepharose 4 B in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) are described. CH-Sepharose 4 B bound peroxidase yields an enzyme preparation with a residual specific activity of 60.6%. When bound to AH-Sepharose 4 B, the residual specific activity is to 78%. The reasons of these differences in the catalytic activity of the two insolubilized enzyme preparations are discussed. By covalent binding on CH- and AH-Sepharose 4 B, peroxidase exibits no changes in its pH optimum; it virtually keeps the same activity after being used ten times. Insolubilized peroxidase preparations, dried and reimbibed after being stored for 6 weeks at room temperature still display 50% of the initial specific activity of the insolubilized enzyme. Stored in acetate buffer, the enzyme preparations maintain their activity during all this interval.
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PMID:[Covalent binding of peroxidase to CH- and AH-Sepharose 4 B]. 0 Aug 78

Extracts of specific granules and azurophil granules from human neutrophils were tested for their bactericidal activity against various lipopolysaccharide mutants of Salmonella typhimurium LT-2. Three purified granule populations, one specific and two azurophil, were obtained by isopycnic centrifugation of homogenized neutrophils. Each was extracted with 0.2 M acetate buffer (pH 4), and the extracts were dialyzed against phosphate-buffered saline (pH 7) to remove acetate. These extracts contained >/=84% of the lysozyme, lactoferrin, or myeloperoxidase initially present in the whole granules. The S. typhimurium mutants possessed Ra, Rc, Rd(1), Rd(2), or Re lipopolysaccharide. As the carbohydrate content of the lipopolysaccharide decreased, the bacteria became increasingly more susceptible to the bactericidal activity of all granule extracts. Bactericidal activity of the extracts was in the order: mixed (azurophil + specific) >/= azurophil >> specific. Specific granules were bacteriostatic for S through Rd(2) bacteria. They were bactericidal only for the Re mutant. Both azurophil granule populations were equally bactericidal. Extracts boiled for 30 min retained none of their bactericidal activity for any of the bacteria; however, they remained bacteriostatic for the deep rough (Rd(2), Re) mutants. Bactericidal activity was dependent upon pH, in that mixed and azurophil granule contents killed the smooth parent and Ra mutant best at pH 5, the Rc and Rd(1) mutants to the same degree at pH 5 to 8, and the deep rough mutants (Rd(2) and Re) best at pH 8. Specific granule contents were most bacteriostatic for S through Rd(2) bacteria at pH 5 and killed the Re mutant only at pH 8. Thus, as the S. typhimurium lipopolysaccharide content decreased, the bactericidal pH optimum increased. Killing by all extracts was dependent upon incubation temperature, with almost no bactericidal or bacteriostatic activity observed when bacteria and granule fractions were incubated on ice (2 degrees C) and plated immediately. Intermediate killing was observed at 22 degrees C. If bacteria were incubated with granule extracts at 2 degrees C, washed free of extract, suspended in medium without extract, and reincubated at 37 degrees C, killing was observed. This suggested that a component(s) of the extracts was sticking to the bacteria at 2 degrees C but killing only at 37 degrees C.
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PMID:Bactericidal activity of specific and azurophil granules from human neutrophils: studies with outer-membrane mutants of Salmonella typhimurium LT-2. 2

The morphology and development of junctional complexes between blastomeres of the preimplantation rabbit embryo were investigated using several approaches. Electron microscopic examination of embryos stained en bloc with uranyl acetate, and the study of junction permeability using horseradish peroxidase and lanthanum nitrate provided information on structure, intermembrane spacing and permeability of the junctional complexes. In addition, the freeze fracture technique was used with day 5 and day 6 blastocysts, since the large size of these embryos facilitated use of this method. These experiments showed that although rudimentary junctions were present between blastomeres of the early cleavage stages, effective tight junctions were not present until the blastocyst stage. Electron microscopic examination of thin sections revealed apical foci of membrane approximation or "fusion" between trophoblast cells by day 4. Freeze fracturing revealed a lattice of interconnecting ridges (on the A face) and grooves (on the B face) in the apical region between trophoblast cells of the day 5 blastocyst. This lattice formed a continuous band along the apical margin of each cell, and therefore constituted a zonula occludens. The zonula occludens of the day 5 blastocyst averages 2-3 ridges per lattice, while day 6 blastocysts had lattices that averaged 5-6 ridges. Also seen in the freeze fracture replicas from the day 5 and day 6 blastocysts were local accumulations of intramembranous particles on the A face. These particles were often observed in aggregates similar to those of previously described gap junctions. It could not be determined whether these small regions of particles were true gap junctions or a possible primitive form of gap junction because the complementary pitted surfaces (B face pits) were not demonstrated.
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PMID:Junctional complexes in the preimplantation rabbit embryo. 4 78

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.
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PMID:"Pure" monocytic or histiomonocytic leukemia: a revised concept. 4 89

Lymph nodes were biopsied from seven patients with the presumptive clinical diagnosis of lymphoma and studied for their ability to form spontaneous rosettes with sheep erythrocytes (T cell marker), for surface immunoglobulins (B cell marker), for cytochemical reactivity with peroxidase, alpha-naphthyl acetate and butyrate esterases, naphthol ASD chloroacetate esterase, acid phosphatase, periodic acid-Schiff, Sudan black B, and Wright-Giemsa on touch preparations, as well as in hematoxylin and eosin-stained sections. Lymph nodes from patients without hematologic malignancy served as control. Diagnoses of diffuse histiocytic lymphoma were made in five cases and diffuse mixed histiocytic-lymphocytic lymphoma in 2 cases. The cytochemical staining of the lymphoma cells were typical of lymphoid cells rather than macrophages. In five cases neoplastic cells contained surface immunoglobulins, suggesting a B cell origin, and in one case a paucity of cell surface markers was found. Cells from uninvolved nodes of lymphoma patients could not be differentiated from those of the control group.
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PMID:Immunologic and cytochemical properties of histiocytic and mixed histiocytic-lymphocytic lymphomas. 4 98

Granulocytes from the peripheral blood of normal subjects and a patient with hereditary myeloperoxidase deficiency were homogenized in 0.34 M sucrose. A granule-rich fraction, prepared by sedimentation at 27,000 x g for 20 min, contained components that killed C. parapsilosis in vitro. These were extractable with 0.01 M citric acid and were shown by micropreparative polyacrylamide electrophoresis to be multiple. The candidacidal activity of these neutrophil components was heat stable and they were somewhat more active at pH 5.0 than at pH 7.0. When rabbit or guinea pig heterophils were obtained from sterile peritoneal exudates and similarly fractionated, they also were found to contain components that killed C. parapsilosis in vitro. These were primarily associated with a group of lysosomal cationic proteins lacking direct counterpart in human neutrophils. Among the candidacidal components of the human neutrophil was a protein, more cationic than lysozyme, that exhibited naphthol-ASD acetate esterase activity.
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PMID:Nonoxidative fungicidal mechanisms of mammalian granulocytes: demonstration of components with candidacidal activity in human, rabbit, and guinea pig leukocytes. 4 98

A cytochemical investigation was carried out on the cells that make up the clusters forming in agar cultures of normal human bone marrow after 3, 4, and 5 days of incubation. All the clusters were found to comprise young monocytes that were PAS, peroxidase, Sudan Black, and alpha-naphthyl and naphthol-ASD-acetate esterase positive. Lysozyme activity, investigated by the cytobacterial test, was absent in all cases. After 3 days of incubation a large number of pairs of lymphomonocytes or monocytes with the same cytochemical characteristics were observed. When a method of double esterase incubation (alpha-naphthyl or naphthol-ASD-acetate and naphthol-ASD-chloroacetate) was performed on the same slide, no cells of the granulocytic line or intermediate cells between these and the monocytes were observed in any of the clusters. These results indicate that there is direct monocytic differentiation of the colony-forming cells cultured. The origins and stages observed in the maturation of the monocytes are discussed.
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PMID:Monocytic differentiation of cluster cells in agar culture of normal human bone marrow. A cytochemical investigation. 7 25

We have been developing a procedure for localizing intracellular antigens in cultured cells, by using peroxidase-labeled antibodies, that allows good morphologic preservation. Although useful, our previous technique did not preserve the morphology of membranes, and the location of the peroxidase reaction product was difficult to establish. In this paper, we report major improvements on the basic technique that markedly enhance the quality of localization and of morphology. Saponin is used to permeabilize membranes without destroying their morphology. The amount of reaction product is enhanced with a peroxidase-antiperoxidase label. The clarity of morphologic detail and contrast of reaction product density are increased by using postsectioning staining with the osmium/thiocarbohydrazide/osmium and uranyl acetate/lead citrate procedures. We have applied this technique to the ultrastructural localization of alpha2-macroglobulin and demonstrated that it is localized in membrane-limited vesicles. We have also used this method to improve the preservation of structures for localization by fluorescence microscopy.
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PMID:Ultrastructural antibody localization of alpha2-macroglobulin in membrane-limited vesicles in cultured cells. 8 88

Reactions using diaminobenzidine (DAB) to localize the enzyme peroxidase in neutrophils and peroxidase-antiperoxidase (PAP) complex during immunological staining are usually performed in Tris-HCl or phosphate buffer at pH 7.2-7.6. However, DAB solutions at pH 7.2-7.6 often demonstrate erythrocyte pseudoperoxidase as well. By lowering the pH of the DAB solutions, it is possible to selectively suppress the reactivity of pseudoperoxidase while maintaining optimal reactions in neutrophils and PAP complex. For this purpose we recommend ammonium acetate-citric acid buffer at pH 5.5 (pH 5.0-6.0) containing 44 mg DAB per 100 ml buffer and 0.003%-0.03% with respect to H2O2.
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PMID:A comparison of methods using diaminobenzidine (DAB) to localize peroxidases in erythrocytes, neutrophils, and peroxidase-antiperoxidase complex. 8 20

Biochemical characterization of serologically detected human melanoma antigens was undertaken for the development of immunodiagnostic assays in melanoma. An antiserum from a human melanoma patient, which detected melanoma antigens expressed on a large proportion of different melanoma cells, was used in leucocyte-dependent cytotoxic antibody (LDA) 51Cr-release assays to monitor the purification of melanoma antigens in urea/acetate extracts of lactoperoxidase 125I-labelled melanoma cell membranes. The separation procedures included affinity chromatography on Concanavalin A, gel filtration on porous polyacrylamide beads and preparative isoelectric focusing. The fractions were also monitored by polyacrylamide electrophoresis in sodium dodecyl sulphate and by measurement of beta 2 microglobulin and carcinoembryonic antigen content. The antigens detected by this antiserum appeared to be acidic (pI 3.5) low-mol.-wt glycoproteins of approximately 15,000 daltons which were resistant to heating at 56 degrees C and digestion with neuraminidase, but susceptible to repeated freeze-thawing and trypsin digestion. They did not appear to be related to HLA antigens, beta 2 microglobulin or known foetal antigens. The nature of the antigens detected in these studies is as yet unknown, but they appear similar to those described in the sera and urine of melanoma patients in previous reports. Thes combined results and the frequent expression of these antigens on melanoma cells from different patients suggest that assays to detect this antigen may provide a valuable immunodiagnostic aid in the management of melanoma.
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PMID:Detection of a low-molecular-weight antigen on melanoma cells by a human antiserum in leukocyte-dependent antibody assays. 9 79


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