Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two different methods for evaluating 'in vitro' cytotoxicity against antibody-coated target cells mediated by mononuclear leukocytes were compared. One was a plaque assay for identification of the cytotoxic cell and the other the classical chromium release assay for antibody-dependent cytotoxicity (ADCC). A marked decrease in plaque-forming cells (PFC) was observed in a cell suspension depleted of peroxidase-positive cells and cells with membrane-bound Ig (B lymphocytes) by fractionation on a nylon fiber column. In contrast, the ADCC activity was considerably increased by these depletions. A similar effect was obtained by removal of phagocytic cells with iron. These results, together with the observations after depletion of E-RFC (T lymphocytes) or EA-RFC (Fc-receptor-bearing cells), suggest that the PFC in the assay system used were of monocytic origin and differnet from the cells responsible for the ADCC.
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PMID:Studies of antibody-dependent cytotoxicity in a plaque assay: evidence of human monocyte-like effector cells. 34 29

The lactoperoxidase (LPO) activity in guinea-pig milk and saliva has been investigated in sows suckling normal young, and young orally infected with Escherichia coli. There was a 5-fold increase in activity in milk during the 3--4 weeks of lactation; infection of the young did not alter this. There was no comparable increase in lactoperoxidase activity of saliva during this same period, either in the infected or non-infected group. The antibacterial activity of milk from sows suckling normal young increased with the lactoperoxidase, and this bactericidal activity could be reversed by LPO inhibitors such as penicillamine and cysteine but not by addition of sufficient iron to saturate the lactoferrin. In milk from sows suckling infected young, bacteriostatic activity occurring in samples from about 14 days after infection needed iron or both iron and penicillamine (or cysteine) for reversal, indicating that both the antibody-lactoferrin system and the LPO system may be involved in the infected state.
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PMID:Lactoperoxidase activity in guinea-pig milk and saliva: correlation in milk of lactoperoxidase with bactericidal activity against Escherichia coli. 38 28

Lymphocytes from 6 patients with 3 types of genetic mucopolysaccharidoses (Hurler's syndrome, Hunter's syndrome and Morquio's syndrome) contained numberous vacuoles in their cytoplasm. The size of the vacuoles ranged from approximately 300 nm to 750 nm. The percentage of the lymphocytes with vacuoles varied from 10% to 38%. The vacuoles showed acid phosphatase activity, which indicated their lysosommal nature. Staining with dialyzed iron solution usually localized acid mucosubstance in the peripheral region of these vacuoles after glutaraldehyde fixation. Ferritin and horseradish peroxidase were observed in the vacuoles after incubation of the patient's lymphocytes with these tracers. This finding indicates the participation of endocytosis in the formation of these vacuoles.
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PMID:Fine structural and ultracytochemical studies on the lymphocytes in three types of genetic mucopolysaccharidoses. 41 6

Compounds were studied that inhibit the oxidative degradation of human serum albumin by peroxidase and the enzyme model, iron hydroxide. Differences between the two oxidants gave clues for the mechanism of inhibition. The inhibitors studied were inorganic anions, phosphate, sulfate, carbonate and molybdate; organic anions, decanoate and glycocholate; and the nonionic species, glycogen. Such inhibitors might be considered as adjuvants in senescence: by decreasing the rate of enzymic oxidation of essential body proteins, they would, in the course of aging, reduce some of the physiological changes occurring as a result of accumulation of degraded protein.
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PMID:Inhibitors of oxidative degradation of protein: gerontological implications. 44 Feb 99

The prosthetic group of milk lactoperoxidase has been isolated from a Pronase hydrolysate of the enzyme and identified spectroscopically and chromatographically as protoheme IX. Partial degradation of the heme occurred during the proteolysis, possibly as a result of coupled oxidation in the presence of glycine and oxygen. The heme is assumed to be buried in the protein molecule in a crevice, which allows ligands to bind to the iron on one side only. The pyridine hemochrome of lactoperoxidase with alpha-band at 563 nm is interpreted as a mixed ligand complex with pyridine on one side of the heme and a ligand originating from the protein on the other. No experimental evidence supports the view that the heme is covalently bound to the protein through an ester linkage.
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PMID:The prosthetic group of milk lactoperoxidase is protoheme IX. 46 28

Analyses of the cells present in human colostrum obtained from fifty-four healthy donors during the first four days of lactation revealed that there were 3.3 x 10(6) (range 1.1 x 10(5)--1.2 x 10(7)) cells per ml of colostrum. Based on histochemical examinations, it was found that this population consisted of 30--47% macrophages, 40--60% polymorphonuclear leucocytes, 5.2--8.9% lymphocytes, and 1.3--2.8% colostral corpuscles; epithelial cells were rarely encountered. The identity of various cell types was confirmed by Wright's stain and by a series of histochemical techniques which disclosed the presence of non-specific esterase, peroxidase, and lipids. For further characterization, the different types of cells were separated by various methods, such as Ficoll-Hypaque density centrifugation, isokinetic centrifugation on a linear Ficoll gradient, adherence to glass or plastic, and phagocytosis of carbonyl iron. Immunohistochemical staining with FITC- and/or TRITC-labelled reagents to IgA, IgM, IgG, K- and lambda-chains, secretory component, lactoferrin, and alpha-lactalbumin were applied to unseparated as well as separated colostral cells. Polymorphonuclear leucocytes (staining for peroxidase) as well as macrophages and colostral corpuscles (staining for non-specific esterase) exhibited numerous intracellular vesicles that contained lipids as well as various combinations of milk proteins. Lymphoid cells did not stain with any of these reagents and plasma cells were not detected among the colostral cells. Individual phagocytic cells contained immunoglobulins of the IgA and IgM classes, both K and lambda light chains, secretory component, lactoferrin, and alpha-lactalbumin. The coincidental appearance of these proteins in single, phagocytic cells but not in lymphoid cells indicate that the cells acquired these proteins by ingestion from the environment. Markers commonly used for the identification of B lymphocytes (surface immunoglobulins) and T lymphocytes (receptors for sheep red blood cells) were unreliable for the analysis of colostral cells (unless accompanied by subsequent morphological characterization) because strong fluorescence was observed on the surface of many non-lymphoid cells and because numerous macrophages and colostral corpuscles formed rosettes with sheep red blood cells (SRBC). Lymphocytes, often found in association with colostral macrophages or corpuscles, were classified as T cells.
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PMID:Human colostral cells. I. Separation and characterization. 53 89

An iron rich tissue with an important pseudo-peroxidase activity and which specifically incorporates 55Fe and 3H delta aminolevulinic acid is localized around some vessels of the investigated Annelids : parapodial vessels of Nephthys, chloragogen coeca of Arenicola. This tissue which can be considered as haemopoietic has been studied at the EM level : it is characterized by numerous dense inclusions with pseudo-peroxidase activity and well developed granular endoplasmic reticulum and Golgi.
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PMID:[Localization of the haemopoietic tissue of polychaete annelids. I. Site of haemoglobin (erythrocruorin) synthesis (author's transl)]. 55 39

The perivasal tissue of some blood vessels (antero-lateral vessels of Pomatoceros triqueter, ventral and lateral vessels of Sabella pavonina) shows a remarkable quantity of iron and pseudo-peroxidase activity. At the EM level, this tissue is characterized by numerous dense DAB positive inclusions and well developed granular endoplasmic reticulum and Golgi. Its function in chlorocruorin synthesis is discussed.
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PMID:[Localization of the haemopoietic tissue of polychaete annelids. II. Site of chlorocruorin synthesis (author's transl)]. 55 40

A method of cell surface mapping has been developed on spermatozoa. Concanavalin A binding sites have been simultaneously revelaed both by peroxidase DAB reaction and by iron dextran coupling. The areas are examined in scanning and transmission electron microscopes and submitted to electron probe X-ray microanalysis.
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PMID:Detection of concanavalin A receptors by affinity to peroxidase and iron dextran by scanning and transmission electron microscopy and x-ray microanalysis. 55 67

The spot test carried on filter paper strips appears as a very suitable technique to investigate the reactivity of catalases, peroxidases, porphyrins (bilirubin and protoporphyrin), metalloporphyrins (haemoglobin, haemin, haematin, chlorophyll and cyanocobalamin), ferric and ferrous salts. By using this technique the specificity of the already proposed techniques admitted as appropriate to detect histochemically peroxidases and catalases was investigated. The results shown from the already proposed techniques to detect peroxidases only the alpha-naphthol reaction is somewhat specific for this enzyme, if the results were taken immediately. However, if the results were taken after 24 h, the reaction loose all specificity. The other techniques proposed to detect peroxidase are not specific, either concerning the discrimination between catalases and peroxidases activity or regarding the possibility to differenciate an enzymic from a catalytic activity provided by haemic iron containing compounds and sometimes by iron salts. Our histochemical technique already proposed as suitable to detect catalases seams to be specific, since peroxidases do not react positively. By replacing benzidine for some others hydrogen donors the peroxidases histochemical techniques remain not specific and are unable to discriminate this enzyme from catalases. Porphyrins (protoporphyrin and bilirubin), magnesium and cobalt containing metalloporhyrins (chlorophyll and cyanocobalamin) do not produce oxidation of any hydrogen donors used. Iron salts are also able to give positive results with some techniques already proposed as suitable for peroxidases and catalases detection.
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PMID:An analysis on the specificity of the histochemical techniques already proposed to detect catalases and peroxidases. 57 53


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