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)

Distribution of carbohydrate moieties in the membrane system of the human blood platelet was studied by electron microscopy employing lectins as a probe. Glutaraldehyde-fixed platelets were treated with biotinylated-lectins (ConA, RCA, WGA, PNA, SBA, DBA and UEA-1) and labeled with horseradish peroxidase-conjugated avidin. Among the lectins used, ConA bound uniformly to the plasma membrane as well as to the membrane of the open-canalicular system (OCS). Other lectins showed more or less reduced binding on the OCS membrane compared with that on the plasma membrane, indicating that there exist regional differences in the distribution pattern of glycoconjugates in the membrane system of the platelet. The relationship of the distribution pattern of the glycoconjugates with the distribution of the major platelet glycoproteins GPIb and GPIIbIIIa is discussed.
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PMID:Distribution of glycoconjugates on the plasma membrane and on membranes of the open-canalicular system in human platelets. A cytochemical study. 292 44

To assess the significance of humoral immune mechanisms in host reactivity against the P815X2 mastocytoma grown in syngeneic DBA/2 mice, an approach was made to correlate immunomorphology of the lymph nodes with the functional assays measuring cytotoxic and tumor cell membrane-bound antibodies in mouse sera. Regional and non-regional (RLN, NRLN) lymph nodes, were subjected to stereological analysis to determine the volume fractions (Vv) of the cortex (C), the paracortex (PCA), the germinal centers (GC), and the medulla (M), using a computerized analysis system (IBAS I, Kontron). In both RLN:s and NRLN:s, lymphocyte subsets were identified and their ratios determined using the ABC (avidin-biotin peroxidase complex) technique and following monoclonal antibodies; Anti-Thy 1.2, Anti-Lyt 1, Anti-Lyt 2, and Anti-I-Ad. The 51Cr release assay was used to test the mouse sera for cytotoxic antibodies, and an indirect immunofluorescence (IF) technique to assess the sera for tumor cell membrane-bound antibodies. There was a marked enlargement of the RLN:s reaching the peak on day 12, due to increase of the Vv of the B-zone as well as of the T-zone. Evidence of distinct B-cell stimulation by the growing of P815X2 was provided by an early decrease of Thy1.2+/I-Ad+ cell ratio both in the RLN:s and in NRLN:s. This activation of B-cells seems to be parallel to the elevation of Lyt1+/Lyt2+ ratio in T-cell region on day 6. The IF-tests for or the presence of tumor cell membrane-bound antibodies were almost invariably negative. With exception of two sera, the 51Cr-release assay for cytotoxic antibodies against P815X2 targets was negative. The present study confirms the previous observations on failure to find circulating cytotoxic or cell membrane-bound antibodies in DBA/2 mice bearing P815X2 mastocytoma, despite the morphologically well definable activation in RLN:s and in NRLN:s of the B-cell areas. This is in alignment with the findings in the majority of human tumors, where B-cell predominance in RLN:s does not represent a favourable prognostic sign.
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PMID:Immune response against P815X2 mastocytoma growing in syngeneic DBA/2 mice. I. Morphometric assessment of lymph node immunoreactivity and analysis of circulating antibodies. 309 73

Polycyclic aromatic hydrocarbons, e.g., 7,12-dimethylbenz(a)anthracene (DMBA), cause various toxic effects in rat testis. To clarify the mechanism of action of DMBA in adult rat testis microsomes and mitochondria from this organ were investigated in vitro with respect to their capacity to metabolize DMBA. Qualitatively, both preparations showed DMBA-hydroxylase activities which were influenced by cytochrome P-450 inhibitors, chelators, and free-radical scavengers, suggesting that the DMBA metabolism was accounted for by different metabolic pathways in these organelles. Metabolism of DMBA was also accompanied by a pronounced covalent binding to both microsomal and mitochondrial protein, catalyzed primarily by a free-radical mechanism involving free or loosely bound iron which may involve superoxide anion shown to be generated by testis mitochondria. With microsomes covalent binding was markedly enhanced by added horseradish peroxidase but not by hydrogen peroxide whereas the mitochondrial binding was affected neither by added horseradish peroxidase nor by hydrogen peroxide. Antibodies raised against cytochrome P-450 c from rat liver inhibited the microsomal DMBA-hydroxylase but not the mitochondrial DMBA metabolism. It is concluded that the microsomal DMBA conversion and covalent binding are due to a mixture of cytochrome P-450 and free-radical-dependent metabolic pathways whereas the corresponding mitochondrial reaction is due mainly to a free-radical-dependent pathway. However, the data do not allow for a conclusion as to the quantitative importance of these pathways. It is proposed that both pathways may be important in DMBA-dependent testis toxicity but also in polycyclic aromatic hydrocarbon-dependent testis toxicity in general.
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PMID:Evidence for a free-radical-dependent metabolism of 7,12-dimethylbenz(a)anthracene in rat testis. 309 26

Immunization of C57BL mice with one inoculum of 10(7) DBA/2-derived SL2 lymphosarcoma cells resulted in a +/- 20-fold increase in the total number of peritoneal cells. The number of macrophages showed a 10-fold increase from 3 x 10(6) (control mice) to 3.4 x 10(7) cells at day 8 after immunization. Within this macrophage population, four different cell types, based on the ultrastructural peroxidatic activity patterns, could be distinguished: exudate macrophages, resident macrophages, resident-exudate macrophages and peroxidatic-activity-negative macrophages. The number of exudate macrophages significantly increased in the peritoneal cavity after immunization: at day 8 after immunization, a peak value of 10(7) cells was observed. At the same time, there were 2.2 x 10(7) peroxidase-activity-negative macrophages present (representing the control value x 50). Significant in vitro tumoricidal activity of the isolated macrophages could not be measured until 8 days after immunization. At that time, a cytotoxicity index of 68 was reached. After immunization of the C57BL mice with 3 injections with allogeneic SL2 cells, there were no dramatic changes in the number of peritoneal cells after the last immunization. Only immediately after the last immunization was a minor increase in peroxidatic-activity-negative macrophages seen. But already at 5 days after the last immunization, the composition of the peritoneal suspension was similar to that of non-immunized mice with predominantly resident macrophages. The cytotoxicity of the peritoneal macrophages from hyperimmunized mice was constantly high during 1-15 days after the last immunization (cytotoxicity index ranged from 66-72). In order to study which type(s) of macrophage(s) (resident, exudate, resident-exudate or peroxidatic-activity-negative) is/are responsible for the cytotoxicity measured in vitro, peritoneal cell suspensions (obtained after immunization) were fractionated according to their affinity to wheat germ agglutinin (WGA) coupled to Sepharose columns. Comparison of the values of cytotoxicity measured before and after separation into "subtypes" of the macrophages revealed that the expression of cytotoxicity is not correlated with any of the "sub-types", especially when the peroxidatic activity pattern is is taken as a criterion.
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PMID:Lack of correlation between in vivo peroxidatic activity patterns and tumoricidal activity in vitro of peritoneal macrophages after intraperitoneal immunization with tumor cells. 316 42

In order to evaluate the staining pattern of glycoconjugate profiles in adenocarcinomas of the lung, pulmonary adenocarcinomas were classified according to their: (a) degree of differentiation; (b) cellular subtyping and mucus secretion; and (c) immunohistochemical characteristics. Studies were performed on 42 pulmonary adenocarcinomas using eight lectins. Formalin-fixed, paraffin-embedded tissues were stained with avidin-biotin peroxidase complex methods. Four lectins [wheat germ (WGA), succinylated WGA (SucWGA), peanut (PNA) with neuraminidase (N) treatment, and Ricinus communis (RCA-I)] showed strong positive staining reactions in well-differentiated adenocarcinomas. Bronchial surface epithelial type, one of the subtypes among 26 cases of well- and moderately differentiated adenocarcinomas, displayed strong positive staining for WGA, SucWGA, PNA N(+), RCA-I, and Bandeirea simplicifolia (BSA-I). Goblet cell types stained positive for all lectins except Dolichos biflorus (DBA). Bronchial gland cell types also showed a strongly positive stain for WGA, SucWGA, soybean (SBA), PNA N(+), RCA-I, and Ulex europaeus (UEA-I). The lectin positive staining reaction was related to the degree of mucus secretion within the tumor cells. These results revealed that the glycoconjugate profile of pulmonary adenocarcinomas was basically sialic acid, together with N-acetyl-glucosamine and beta-D-galactose. The observation that UEA-I showed a strong staining reaction in mucus-producing adenocarcinomas, such as goblet cell and bronchial gland cell types, indicates that localization of alpha-L-fucose may be a specific carbohydrate from non-mucus-producing pulmonary adenocarcinomas.
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PMID:Lectin histochemistry of normal lung and pulmonary adenocarcinoma. 322 57

In the present study carbohydrate residues in taste buds (TBs) and adjacent epithelial formations of a teleostean fish, a frog and the rabbit were detected by means of lectin histochemistry. Biotinylated lectins from Pisum sativum (PSA), Arachis hypogaea (PNA), Dolichos biflorus (DBA), Triticum vulgaris (WGA and succinylated WGA), Glycine max (SBA) and Ulex europaeus (UEA I) have been applied. The lectins were bound to an avidin-biotin-peroxidase-complex (ABC) and visualized by diaminobenzidine/H2O2. Most intensive reactivity was observed at the taste disc cells of the frog with DBA, S-WGA and SBA. PNA did not bind to the TBs of any of the animals tested. As shown in SBA preparations, sialic acid is present in a nonacylated and an acylated form in the mucosa of the frog's tongue. The TBs of the fish possess all the sugars we looked for except for the disaccharide D-galactose-(1-3)-beta-D-N-acetyl-galactosamine (Gal/GalNAc) and sialic acid. The TBs of the rabbit contain GalNAc, as detected with DBA, but not with SBA; and fucose (Fuc), mannose (Man) and N-acetyl-glucosamine (GlcNAc). As revealed by preincubation of the tissue sections with neuraminidase in TB cells of the rabbit, sialic acid masks Gal/GalNAc and GalNAc. These lectin-binding characteristics show that in the TBs of some selected representatives which belong to different vertebrate classes exist different mucous substances. These substances possess different binding characteristics to specific sugars, and this is possibly of particular interest to chemoreception phenomena.
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PMID:Lectin histochemistry on mucous substances of the taste buds and adjacent epithelia of different vertebrates. 325 18

Non-neoplastic prostatic epithelium from 39 patients obtained at transurethral resection for outflow tract obstruction and 5 normal prostates from men under 35 years of age obtained at postmortem were formalin-fixed and paraffin-embedded. The distribution of 8 lectin receptors were studied using a peroxidase anti-peroxidase method and an avidin-biotin method. Con A, WGA, and PNA bound to most epithelial cells. Con A and WGA also showed major stromal binding. Approximately 5% to 10% of cells bound UEA1, GS1, DBA, SBA and BPA. No major differences in lectin receptor expression were observed between normal and hyperplastic epithelium with either of the immunohistochemical techniques except that hyperplastic cells stained more strongly than normal epithelium.
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PMID:Carbohydrate residues in non-malignant prostatic epithelium as revealed by lectins. 330 88

The mouse monoclonal antibody LS1 recognizes a membrane epitope present on circulating hemocytes of the gastropod mollusc Lymnaea stagnalis. In both juvenile and adult pond snails, LS1+ (LS1 positive) hemocytes have the morphology of immature cells. The percentage of LS1+ hemocytes is higher in juveniles (ca. 39%) than it is in adults (ca. 14%). Functional characteristics of LS1+ hemocytes and lectin binding to these cells were studied. In both age groups, the proliferative activity, as measured by the incorporation of deoxybromouridine, is much higher for LS1+ hemocytes than it is for LS1- (LS1 negative) cells. LS1+ hemocytes are phagocytically less active and have a lower lysosomal enzyme (peroxidase) content as compared to hemocytes that lack the epitope. Histochemical staining of the total population of circulating hemocytes shows that the lectins DBA, BS-l-A4 and BS-l-B4, PNA, SBA and ECA do not react with the hemocytes. LTA, APA, WGA, Con A and LCA bind to all hemocytes. RCA and STA recognize surface carbohydrate moieties present on subpopulations of hemocytes only. The LS1+ hemocyte population virtually lacks the carbohydrate residues recognized by STA, whereas the LS1- population never shows binding of RCA. Our results support the findings that the LS1 epitope is a membrane marker of less differentiated hemocytes in both juvenile and adult L. stagnalis. Furthermore, they suggest a correlation between the presence of the LS1 epitope and the absence of STA binding, whereas absence of the LS1 marker may correlate with the presence of a sugar recognized by RCA.
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PMID:Monoclonal antibody recognized hemocyte subpopulations in juvenile and adult Lymnaea stagnalis: functional characteristics and lectin binding. 335 Jan 88

The binding of peroxidase-conjugated Dolichos biflorus (DBA), Triticum vulgaris (WGA), Canavalia ensiformis (Con A), Arachis hypogaea (PNA), Lotus tetragonolobus, and Bandeiraea simplicifolia I (BSAI) to gastrointestinal carcinoid tumours was studied. The results indicate that carcinoid tumour cells express certain carbohydrates similar to those present in the adjacent surface epithelium. The differences in the lectin-binding properties of carcinoid tumours of different sites of the gastrointestinal tract are closely related to the regional differences in the lectin binding of adjacent surface epithelium. These observations therefore form a useful basis for further studies in the application of lectin histochemistry to elucidate the histogenesis of carcinoid tumours.
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PMID:Lectin expression in carcinoid tumours of the gastrointestinal tract. 335 72

The binding of horseradish peroxidase-labelled Dolichos biflorus agglutinin (HRP-DBA) to the olfactory system of NMRI-mice was investigated histochemically during the pre- and postnatal period. DBA bound with high affinity to a group of olfactory receptor neurons of both the olfactory epithelium proper and the vomeronasal organ from gestation days (g.d.) 14 and 15 onward respectively. Furthermore, there was also extensive binding to axon bundles and to the glomeruli of the main and accessory olfactory bulbs. In addition, DBA-binding was observed in goblet cells and some glands of the nasal septum. From g.d. 17 onward the number of DBA-positive neurons increased significantly and the glomeruli within the olfactory bulbs became DBA-reactive for the first time. Concomitantly, the endothelium of vessels within the olfactory epithelium's submucosa lost its DBA-affinity, though the respiratory submucosal vessels still remained DBA-positive. Possible interrelationships between DBA-affinity of blood vessel endothelium and the neighbouring olfactory neurons are discussed.
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PMID:Dolichos biflorus agglutinin: a marker of the developing olfactory system in the NMRI-mouse strain. 336 49


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