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

Mast cell heterogeneity has been described on the basis of differential staining reactions, light microscopic morphology, anatomic location, degranulation after polyamines, biochemical contents, growth requirements, and reactions to lymphokines. We have demonstrated typical "connective-tissue mast cells" by using anatomic criteria, histological staining reactions, electron microscopy, and reaction to compound 48/80 in the guinea pig conjunctiva, eyelid skin, and ileum. A second, much larger population of cells in the ileal mucosa and the conjunctiva, and rarely in the eyelid skin stained reddish-blue with acid toluidine blue in tissue fixed in ethanol-acetate-lead subacetate (BLA) and with alkaline Giemsa in formaldehyde-fixed tissue, did not stain with ethanolic or acid toluidine blue in formaldehyde-fixed tissue or with alkaline Giemsa in BLA-fixed tissue, and did not degranulate after 48/80 treatment. These are features of the rat intestinal "mucosal mast cells"; however, ultrastructural and light microscopic studies with the orcein Giemsa stain demonstrated these cells in the guinea pig to be eosinophils. Tissue culture, biochemical, and immunological studies indicate the existence of a second type of mast cell (bone-marrow-derived mast cell), ultrastructurally almost indistinguishable from the connective tissue mast cell. Our studies demonstrate only one mast cell type in the guinea pig and support the contention that other forms of mast cells are immature forms or variants of the connective-tissue mast cell.
 ...
PMID:Eosinophils and mast cell homogeneity of the guinea pig eyelid skin, conjunctiva, and ileum. 258 20

Ocular cicatricial pemphigoid (OCP) is characterized by progressive conjunctival subepithelial fibrosis often leading ultimately to corneal blindness. Mast cells have been shown to play a role in several fibrotic disorders, but the role of mast cells in OCP is unknown. The authors compared the mast cell population in conjunctival biopsy specimens from 14 OCP patients and from six controls by using specific histochemical stains for mast cell subsets. The total mast cell number and the ratio of connective tissue mast cells to mucosal mast cells (MMCs) were significantly higher in OCP than in normal conjunctiva (P less than 0.05). This report is the first analysis of mast cell subsets in human ocular tissue. The results suggest that connective tissue mast cells (CTMCs) may play an important role in OCP and that therapy directed toward mast cells and their mediators may be an appropriate avenue for further exploration.
 ...
PMID:Mast cells in conjunctiva affected by cicatricial pemphigoid. 267 49

To investigate the role of the eosinophil in vernal keratoconjunctivitis and contact lens-associated giant papillary conjunctivitis, we assessed the presence of eosinophil granule major basic protein in conjunctival tissues by immunofluorescence. Biopsy specimens of conjunctiva were taken from nine patients with vernal keratoconjunctivitis, seven patients with giant papillary conjunctivitis, and five control subjects. We performed a masked semiquantitative assessment of immunofluorescence on sections from each specimen. The vernal keratoconjunctivitis and giant papillary conjunctivitis groups had significantly (P less than .05) more major basic protein deposition than controls. No significant correlation between severity of disease and degree of major basic protein deposition was found. We found extracellular eosinophil granules in one of three vernal keratoconjunctivitis specimens examined by transmission electron microscopy. Thus, eosinophil degranulation commonly occurs in vernal keratoconjunctivitis and giant papillary conjunctivitis with release of eosinophil granule major basic protein and presumably other toxic granule proteins onto affected tissues. These cationic proteins are potent cytotoxins and are able to stimulate mast cell degranulation.
 ...
PMID:Conjunctival deposition of eosinophil granule major basic protein in vernal keratoconjunctivitis and contact lens-associated giant papillary conjunctivitis. 275 Aug 34

The recent development of a technique for quantitative measurement of conjunctival microvascular permeability has permitted detailed pharmacological evaluation of H1- and H2-receptor involvement in histamine-induced increases in conjunctival microvascular permeability and the role of histamine in microvascular permeability changes associated with immediate hypersensitivity responses in the conjunctiva. The conjunctival microvascular permeability response to histamine appears to be entirely mediated by H1-receptors. Pyrilamine (H1-receptor antagonist) virtually abolished the increase in conjunctival extravascular albumin content produced by graded doses of histamine, whereas cimetidine (H2-receptor antagonist) was ineffective. Moreover, selective histamine H2-receptor agonists did not elicit a dose-dependent vasopermeability response in the conjunctiva. Although H1-receptor blockade essentially abolished the microvascular permeability response to histamine, it only partially attenuated the conjunctival microvascular permeability response associated with immediate hypersensitivity and compound 48-80. It appears that conjunctival inflammation caused by mast cell degranulation comprises both a histaminergic and a nonhistaminergic component.
 ...
PMID:Conjunctival immediate hypersensitivity: re-evaluation of histamine involvement in the vasopermeability response. 293 47

We sought to determine the effect on rat conjunctival mast cells of chronic exposure to a degranulating agent. Compound 48/80 (250 micrograms in 10 microliter) was applied daily to the ocular surface of rats for a total of 13 treatments administered in 17 days. A single application of compound 48/80 was given to rats for comparison. Four groups of animals (6 in each group) were evaluated 1 or 48 h after the last application of compound 48/80 in both chronic exposure and single exposure studies. Although a single exposure to compound 48/80 induced significant degranulation of mast cells in animals observed 1 h after treatment, no significant degranulation of mast cells was observed 1 h after the last dose of compound 48/80 was given to rats whose conjunctiva had been chronically exposed to this degranulating agent. Thus, multiple applications of compound 48/80 attenuated the mast cell response to compound 48/80. This acquired tolerance to compound 48/80 was reflected in the lessened clinical signs in rats receiving repeated applications compared with those given a single application.
 ...
PMID:Effect of multiple applications of compound 48/80 on mast cells of rat conjunctiva. 366 Nov 42

Tissue mast cells play a central role in the pathogenesis of allergic eye diseases. In the study reported here the authors investigated whether human corneal epithelial cells and a human epitheloid conjunctival cell line (Chang) can produce an interleukin 3 (IL 3)-like mast cell-activating factor. The activity was detected at a m.w. of 15 and 30 kD, the isoelectric points were located at a pH of 7.85, 7.15 and 6.75. The authors believe that this cytokine, which is produced by epithelial cells of the cornea and conjunctiva, might play an important role in the pathogenesis of allergic ocular diseases.
 ...
PMID:[Corneal epithelial cells and human conjunctival cell line (Chang) produce an interleukin 3-like factor]. 393 69

The antiallergic compound, lodoxamide, was evaluated for its abilities to attenuate a local allergic reaction in rat conjunctiva in vivo and to inhibit rat conjunctival mast cell mediator release in vitro. Topically applied lodoxamide (0.01, 0.10 and 1.0%, w/v) dose-dependently reduced the allergic response (23, 43 and 72%, respectively) in vivo. Lodoxamide was more effective than cromolyn sodium, N-acetyl aspartyl glutamic acid (Naaxia) and levocabastine, and 25 (7-200) times more potent than nedocromil sodium in direct comparisons. Addition of lodoxamide (10 micrograms/ml) to sensitized conjunctival tissue in vitro immediately prior to antigen challenge significantly reduced the amount of histamine released by the tissue. These data suggest that lodoxamide's in vivo anti-allergic activity in the conjunctiva is associated with its ability to prevent allergic mediator release from mast cells contained in this same tissue.
 ...
PMID:Effect of lodoxamide on in vitro and in vivo conjunctival immediate hypersensitivity responses in rats. 768 28

Allergic eye disease has a variety of clinical manifestations including seasonal atopic conjunctivitis (SAC), perennial atopic conjunctivitis (PAC), atopic keratoconjunctivitis (AKC), and atopic blepharoconjunctivitis (ABC). We have investigated the number, distribution and protease expression of mast cells in normal and diseased conjunctiva with the use of immunohistochemistry in water-miscible resin sections. The median mast cell densities in normal subjects were 17 mm-2 in the bulbar substantia propria and 9 mm-2 in tarsal substantia propria. Mast cells were absent from the normal conjunctival epithelium at both sites. Mast cell densities were increased in the bulbar substantia propria in SAC, AKC and ABC. Tarsal substantia propria showed a significant increase in mast cells in ABC and AKC disease states. Mast cells express a range of proteases which varies according to their anatomic site. Mast cells in connective tissue are described to contain tryptase, chymase, cathepsin-G and carboxypeptidase-A, whereas mucosal mast cells contain only tryptase. In the diseased conjunctiva there was a marked reduction in proteases other than tryptase in the intraepithelial mast cells. There were also significant reductions in protease expression other than tryptase in the bulbar substantia propria in AKC and ABC. There appear to be specific alterations in the distribution of mast cells in the sub-categories of allergic eye disease. The distinction between mucosal and connective tissue mast cell phenotypes is not clear-cut and may depend on the functional state of the mast cells in relation to the microenvironment.
 ...
PMID:Mast cell distribution and neutral protease expression in acute and chronic allergic conjunctivitis. 772 24

In patients with chronic renal failure treated by long-term dialysis, inflammatory reactions occasionally develop in the bulbar conjunctiva; the episcleral tissue is only rarely involved. Diffuse congestion of both the conjunctiva and episclera was present in 5.3% of our patients and was associated with a sudden, marked rise in serum calcium. Histopathological examination suggests that this form of hyperemia, clinically preceded by a marked shedding of calcific precipitates, is the result of a neurogenic-driven inflammatory reaction in which mast cell degranulation is mediated by the axon reflex. Focal hyperemia associated with elastosis ("pingueculitis") was present in 6.7% of the patients. This type of hyperemia was observed after an extended period of increasing levels of BUN and seemed independent of both serum calcium and phosphorus. Diffuse hyperemia of the conjunctiva, being clinically distinctly different from the combined diffuse conjunctival and episcleral hyperemia, was also observed in 6.7%. Diffuse conjunctival hyperemia seemed to be associated with low BUN. Here, again, there was no association with serum calcium and phosphorus levels.
 ...
PMID:The role of serum calcium in the development of the acute red eye in chronic renal failure. 779 5

Tryptase is useful as a specific and accurate indicator of mast cell activation, whereas histamine, a mast cell's major mediator, also exists in basophils. The aim of this study is to investigate histamine and tryptase levels in allergic conjunctiva. We measured histamine and tryptase levels in conjunctival epithelial cell suspension of children with allergic conjunctivitis (AC) and vernal kerato-conjunctivitis (VKC), and controls, and we evaluated correlations with clinical observations. Both the histamine and tryptase levels in VKC were significantly higher than controls (p < 0.05, p < 0.01), and histamine levels in VKC was also greater than AC (p < 0.05). The histamine/tryptase (H/T) ratios were 0.03 +/- 0.04 in AC, 0.08 +/- 0.09 in VKC and 0.006 +/- 0.006 in controls. The H/T ratios in VKC were significantly higher than controls (p < 0.05) and AC (p < 0.05), and were also found to correlate with the superficial punctate keratopathy (SPK) score (r2 = 0.89). Analyzing the histamine and tryptase levels in conjunctival epithelium may be useful in evaluating the allergic ocular surface, especially in the cases with SPK, where the increase in the histamine levels is not accompanied by an increase in tryptase levels. This suggests an important role for inflammatory cells such as basophils infiltrating into the conjunctival epithelium in allergic reactions.
 ...
PMID:Histamine and tryptase levels in allergic conjunctivitis and vernal keratoconjunctivitis. 792 35


<< Previous 1 2 3 4 5 6 7 Next >>