Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have used ferritin-conjugated divalent and monovalent anti-Ig antibodies to study simultaneously, histamine secretion and the ultrastructural distribution and redistribution of Ig receptors on rat peritoneal mast cells. We conclude that (a) divalent anti-Ig is required for both receptor redistribution and for calcium-dependent degranulation and histamine release, (b) divalent anti-Ig induces patching and pinocytosis but not capping of Ig molecules, (c) neither capping nor pinocytosis are required for triggering and if clustering is necessary, then less than 10 Ig molecules are required per cluster, and (d) degranulation (and histamine release) is not an all or none response of the mast cell.
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PMID:Anti-immunoglobulin-induced histamine secretion by rat peritoneal mast cells studied by immunoferritin electron microscopy. 4 87

The bovine exocrine pancreatic cell produces a variety of enzymes and proenzymes for export. Biochemical studies by Greene L.J., C.H. Hirs, and G.E. Palade (J. Biol. Chem. 1963. 238:2054) have shown that the mass proportions of several of these proteins in resting pancreatic juice and zymogen granule fractions are identical. In this study we have used immunocytochemical techniques at the electron microscope level to determine whether regional differences exist in the bovine gland with regard to production of individual secretory proteins and whether specialization of product handling occurs at the subcellular level. The technique used is a modification of one previously reported (McLean, J.D., and S.J. Singer. 1970. Proc. Natl. Acad. Sci U.S.A. 69:1771) in which immunocytochemical reagents are applied to thin sections of bovine serum albumin-imbedded tissue and zymogen granule fractions. A double antibody technique was used in which the first step consisted of rabbit F(ab')2 antibovine secretory protein and the detection step consisted of sheep (F(ab')2 antirabbit F(ab')2 conjugated to ferritin. The results showed that all exocrine cells in the gland, and all zymogen granules and Golgi cisternae in each cell, were qualitatively alike with regard to their content of secretory proteins examined (trypsinogen, chymotrypsinogen A, carboxypeptidase A, RNase, and DNase). The data suggest that these secretory proteins are transported through the cisternae of the Golgi complex where they are intermixed before copackaging in zymogen granules; passage through the Golgi complex is apparently obligatory for these (and likely all) secretory proteins, and is independent of extent of glycosylation, e.g., trypsinogen, a nonglycoprotein vs. DNase, a glycoprotein.
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PMID:Immunocytochemical localization of secretory proteins in bovine pancreatic exocrine cells. 31

The relation between average duodenal mast cell count, duodenal mucosal mast cell numbers, duodenal connective tissue mast cell numbers, circulating basophil numbers, heterophil-to-lymphocyte ratio, and lesion score were studied to gain an understanding of the events that may lead to intestinal lesion formation associated with hemorrhagic enteritis virus (HEV) infection. Changes in vascular permeability in the duodenum in birds inoculated with HEV were examined, using colloidal carbon and ferritin as vascular markers. Turkeys inoculated with HEV had significantly (P less than 0.05) higher duodenal mast cell counts than did noninfected controls. Birds inoculated with HEV had significantly (P less than 0.05) more mucosal mast cells than did phosphate-buffered saline solution-inoculated birds. Connective tissue mast cell and basophil numbers were unaffected by viral inoculation. Thermal stress did not have significant effect on lesion severity, but did increase number of birds that developed the characteristic intestinal lesions. The heterophil-to-lymphocyte ratio was significantly (P less than 0.05) higher in HEV-inoculated birds, compared with phosphate-buffered saline solution-inoculated controls. Increase in vascular permeability was only detected in HEV-inoculated birds with intestinal lesions. Results indicate that mast cells, and the vasoactive mediators contained within mast cells, may be important in the early manifestation of HEV infection. They also provide a possible mechanism through which biochemical and physiologic changes characteristic of HEV infection can occur.
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PMID:Increased numbers of duodenal mucosal mast cells in turkeys inoculated with hemorrhagic enteritis virus. 132 44

We investigated the effects of unilateral electrical trigeminal ganglion stimulation (0.1 or 1.0 mA, 5 Hz, 5 ms, 5 min) on the morphology of blood vessels within the rat dura mater and tongue using light and transmission electron microscopy. Stimulation at both intensities caused changes which were confined to the ipsilateral post-capillary venules except in the tongue where arterioles were affected as well. Changes were more marked after 1.0 mA. Dramatic increases in the numbers of endothelial pinocytotic vesicles were found along the luminal and abluminal surfaces ipsilateral to the stimulation. Tight junctions remained largely intact, except that injected ferritin particles were occasionally trapped inside these junctions. Cytoplasmic microvilli and endothelial blebs were sometimes present as well. Approximately 80% of the examined dural post-capillary venules showed one or more of these endothelial changes. Horseradish peroxidase injected intravenously 5 min prior to stimulation was detected in the extracellular space surrounding dural blood vessels and within pinocytotic vesicles. Ferritin injected similarly, was also localized in post-capillary venule walls, interstitial spaces, intraendothelial vesicles and in vacuoles. Platelet accumulation and aggregation were present in approximately 10% of post-capillary venules in dura and tongue. These changes were associated with mast cell secretion, but neither vascular nor mast cell activation was observed in adult rats in whom C-fibers were destroyed during the neonatal period with capsaicin. The present observations provide morphological evidence which supports findings from previously reported albumin tracer studies suggesting enhanced transport and endothelial activation following electrical stimulation of small caliber afferent fibers.
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PMID:Ultrastructural evidence for neurogenically mediated changes in blood vessels of the rat dura mater and tongue following antidromic trigeminal stimulation. 137 61

An antiserum was produced against a chymotryptic proteinase purified from human skin. The antiserum did not cross-react with human leukocyte cathepsin G and elastase, rat mast cell proteinase I, and human skin tryptase. Indirect immunofluorescent staining of frozen skin sections to localize the proteinase showed cytoplasmic staining of cells scattered about the papillary dermis and around blood vessels and appendages. Restaining these sections with toluidine blue revealed that the fluorescently stained cells contained metachromatically staining granules, the major distinguishing feature of mast cells. A similar correlation was found in lung tissue. Ultrastructural studies employing the ferritin bridge technique to immunologically identify the proteinase additionally localized the proteinase to mast cell granules. Biochemical and immunochemical characterization of chymotryptic activity solubilized from isolated human lung mast cells identified a chymotryptic proteinase that may be identical to the skin chymotryptic proteinase. These studies establish that human skin mast cells contain a chymotrypsin-like proteinase that is a granule constituent and provide evidence that indicates a comparable proteinase is also present in lung mast cells.
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PMID:Identification of a chymotrypsin-like proteinase in human mast cells. 242 94

Clinical evidence for the phagocytic capability of neoplastic feline mast cells was provided by recognition of endocytosed erythrocytes in seven of 12 cytological smears of mast cell neoplasms, particularly in those cells collected from splenic tumors. The capability of these neoplastic mast cells to endocytose particulate substances was also studied in vitro. Evidence is presented that under cultural conditions, feline neoplastic mast cells are capable of endocytosing a variety of substances including polystyrene latex microspheres, zymosan particles, horse spleen ferritin, salmon sperm nuclei, horseradish peroxidase, and carbon particles.
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PMID:Endocytosis of erythrocytes in vivo and particulate substances in vitro by feline neoplastic mast cells. 313 17

Mast cells isolated from the peritoneal fluid of Wistar rats were purified by centrifugation on Percoll gradient with a yield of 2x10(6) cells/ml. Cell morphology was well preserved as shown by light and electron microscopy. The mast cells capacity to bind histamine was assayed using either [3H]-histamine or histamine-ferritin conjugate as electron-opaque probe for electron microscopic examination. The [3H]-histamine binding performed at 4 degrees C in Ca2+-free phosphate-buffered saline pH 7.3 completed within 30 min was found to be specific, with an IC50 value of 0.72 +/- 0.23 nM. The data analyses by Scatchard and Hill's representations showed a KD of 0.60 +/- 0.24 nM and Bmax of 4.9 +/- 1.2 pM/10(6) cells suggesting that on mast cells the histamine receptors are restricted to the plasma membrane. According to Hill's analysis neither positive nor negative cooperativity (n = 1.06) appeared to be involved in the specific histamine-receptor binding. Competition experiments with 4-methylhistamine and SK&F 93479, revealed that mast cells express H2-histamine receptors. At electron microscopic level, the histamine-ferritin conjugate interstitially injected in the hamster cheek pouch was localized on the mast cell membrane.
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PMID:Histamine receptor on mast cells. 325 80

The distribution of iron and mycobacteria was examined in the intestinal tract of ruminants with naturally-occurring M. paratuberculosis infection and compared with mycobacterial infections in several species. This distribution was compared with that of iron in chronic lesions caused by other microbial or parasitic agents. In the clinical form of paratuberculosis in cattle, sheep and goats there was marked lymphangiectasis and a high proportion of the granulomatous lesions contained siderotic macrophages with a high mycobacterial content. In cattle with preclinical lesions of granulomatous enteropathy, the greatest number of acid-fast organisms was present in siderotic, non-differentiated, ileo-caecal macrophages; concurrent mast cell-associated allergic enteropathy was also apparent in the duodenum, proximal and mid-ileum of most animals. In paratuberculosis-affected herds, a high proportion of non-productive cows were without classical granulomatous change but had cultural or immunological evidence of M. paratuberculosis infection and similar allergic catarrhal enteropathy of the upper intestinal tract. Interstitial haemorrhage of the ileocaecal valve, with the accumulation of haemosiderin and ferritin in undifferentiated macrophages was observed in some of these cattle and also in others with experimentally-induced copper deficiency and acute ostertagiasis. Colonisation of the ileo-caecal or caecal glandular crypts by large, apparently saprophytic acid-fast organisms indicated regional tolerance to such organisms in all cattle. In other mycobacterioses such as bovine or avian tuberculosis, undifferentiated, siderotic macrophages containing mycobacteria were also seen in early granulomas, but epithelioid and giant cell differentiation invariably led to the disappearance of intracellular iron and a reduction in mycobacterial numbers. In possums in which epithelioid and giant cells did not occur in response to M. bovis infection, siderosis persisted in many macrophages and overwhelming mycobacterial multiplication occurred. These studies indicate that, in most infections with mycobacteria, differentiation of macrophages radically reverses their iron acquisitive properties, creating an intracellular environment unsuitable for mycobacterial multiplication. It seems likely that allergically mediated microvascular haemorrhage, local tolerance of commensal mycobacteria and attenuation of the macrophage siderosis reversal mechanism provide unique conditions for early, uninhibited, intracellular multiplication of M. paratuberculosis in the ileo-caecal valve of certain mature ruminants.
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PMID:Intracellular iron storage and the pathogenesis of paratuberculosis. Comparative studies with other mycobacterial, parasitic or infectious conditions of veterinary importance. 334 90

The events associated with antigen-induced, IgE-mediated degranulation of human basophils from allergic donors were studied ultrastructurally. Partially purified cells were examined prior to addition of antigen and after incubation with antigen or control buffer for 15 seconds to 60 minutes. Reactions were stopped instantaneously by adding fixative directly to the cell suspension. After fixation the cells were exposed to cationized ferritin as a sensitive probe for demonstrating possible continuities between the cytoplasmic granules and the cell surface. Ficoll-Hypaque-isolated basophils were of three types: Type I, cells containing basophil granules with a full complement of particles; type II, cells containing some full granules but also variable numbers of cytoplasmic vacuolar structures having the size and shape of basophilic granules but having reduced or no particle content (partially fixed or empty granules); and type III, basophils containing only empty granules. Following exposure to specific antigen, basophils of all three types underwent degranulation characterized by the fusion of the membranes bounding single basophilic granules with the plasma membrane and leading to extrusion of content. Cells in the process of degranulation (type IV and V basophils) were characterized by communications between individual granules and the cell exterior. Identification of such communications was facilitated by cationized ferritin which entered granules having open communications with the cell surface. Without this marker, the number of such communications would have been seriously underestimated, either because they were extremely narrow, tortuous, or outside the plane of section. The majority of individual basophilic granules fused singly and separately with the plasma membrane, in contrast to guinea pig basophil and rat mast cell degranulation where intercommunicating clusters of granules fused with the plasma membrane at a single point. The particle and membrane contents of extruded granules frequently remained adherent to the surface of type IV and V basophils and were not immediately solubilized. Morphologic evidence of degranulation progressed with time of exposure to antigen, exhibiting kinetics that paralleled histamine release. Cells in control incubations, and rare basophils that had been exposed to antigen E, failed to degranulate. Fully degranulated (type VI) basophils were viable cells that had a markedly irregular surface and were devoid of basophilic granules but retained the minor population of small perinuclear granules.
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PMID:Antigen-induced IgE-mediated degranulation of human basophils. 615 54

Chrysotile asbestos interacts with mucin-secreting cells of tracheal organ cultures, causing an increase in secretion of mucin into the culture medium. This response occurs in the absence of obvious morphologic damage to tracheal epithelial cells. We speculated that asbestos-induced hypersecretion was regulated by the interaction of fibers with specific carbohydrate residues on the cell surface. To test this hypothesis, lectins, i.e., proteins with a high affinity for mono- and oligosaccharides on the plasma membrane, were added to tissues 30 min before addition of chrysotile. Secretion of mucin into the medium was then determined over a 2-hr period by using incorporation of 3H-glucosamine. Blocking of alpha-D-mannose and alpha-D-glucose residues inhibited chrysotile-induced hypersecretion (p less than 0.05), whereas lectins blocking residues of alpha-D-N-acetylgalactosamine, beta-D-N-acetylglucosamine, alpha-L-fucose and sialic acids were ineffective. Preincubation of cultures with carboxypeptidase A or phospholipase A2, but not with neuraminidase, diminished mucin secretion caused by chrysotile. To determine if the positive surface charge of chrysotile was important in interaction with mucin cells, we examined comparatively the effects of various polycations (cationic ferritin, polylysine, DEAE-dextran) and chrysotile after leaching of fibers to remove Mg2+. Although use of polycations enhanced secretion of mucin, effects were not as striking as those observed with chrysotile. In contrast, leached chrysotile failed to elicit a hypersecretory response. These results suggest the interaction of a positively charged component (presumably Mg2+) of chrysotile with glycolipids and glycoproteins containing terminal residues of alpha-D-mannose or alpha-D-glucose.
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PMID:Studies using lectins to determine mineral interactions with cellular membranes. 631 63


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