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)

Urticaria and angioedema are usually the clinical consequence of vasoactive mediators derived from mast cells in the skin or mucosal tissues. Efforts to classify mast cell-mediated causes of urticaria and angioedema have generally been frustrated by their diverse pathogenesis and clinical course. The term acute is typically used to describe fleeting lesions whose recurrence does not extend beyond 6 weeks. Chronic is the term used to describe lesions that persist for more than a few hours but usually less than a day, and recurrences extend for more than 6 weeks. These definitions do not take histology into account. Skin biopsies of fleeting lesions demonstrate a paucity of inflammatory cells, whereas more persistent lesions display a spectrum of perivascular cuffing by predominantly T cells and monocytes. The presence of leukocytoclastic vasculitis in persistent lesions indicates an underlying immune complex disease. Many of the physical urticarias have fleeting lesions that can be induced with the appropriate stimulus for years. This review article has emphasized the clinical course and histology of urticaria and angioedema lesions in an effort to provide a more complete understanding of the pathogenesis and appropriate treatment. Clearly, avoidance of an identifiable inciting stimulus is optimum management, although most patients have no etiology defined or the cause is not realistically avoidable. At present, treatment options for these patients rely on antihistamines to control the immediate consequence of mast cell degranulation. Corticosteroids are reserved for the treatment of patients whose urticaria or angioedema lesions persist, reflecting the increasing involvement of mononuclear cells in the disease process. For leukocytoclastic vasculitis, corticosteroids are indicated, and cytotoxic drugs may be required for adequate treatment. Future treatments of urticaria and angioedema will evolve based on elucidation of the relevant cells and soluble mediators and will include counterregulatory or antagonistic peptides and drugs. C1 esterase inhibitor deficiency is a relatively uncommon cause of angioedema but is important to understand because of its ability to clinically mimic mast cell-mediated angioedemas and its unique pathogenesis and treatment. HAE can be divided into two serologic subtypes that simply reflect the location of the defect in one of the codominantly expressed C1-INH genes on chromosome 11. AAE can be divided into two serologic subtypes. AAE type I is due to massive consumption of C1-INH, presumably by tumor-related immune complexes. AAE type II is due to an anti-C1-INH autoantibody.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Urticaria and angioedema. 161 35

Mast cells in adenoid liver tumours of 32 rats induced with nitrosomorpholine were observed ultrastructurally, and among them, some were studied immunocytochemically via immunogold techniques. Data indicated that mast cells which located in tumour tissues presented positive expression of rat mast cell protein (RMCP) II, indicating origination from the mucosal mast cells, while those in the connective tissues around tumours were largely stained negatively with either RMCP II or RMCP I antisera, with the exception of only a few cells showing positive RMCP II staining. Ultrastructural observation showed that mast cells in tumors contacted closely with the tumor cells. Membranes of the intracellular granules in these mast cells were fusing together. The content inside the granules were discharged and spread along the intercellular space between the tumor cells. There was not any lesion obtained ultrastructurally at the contacting point between the tumor cells and the mast cells. The significance of mucosal mast cells in adenoid liver tumors is briefly discussed.
 ...
PMID:[The phenotype of mast cells in primary adenoid liver tumours of rats and its relation to tumor cells]. 161 43

Transforming growth factor-beta (TGF beta) promotes deposition of extracellular matrix and is associated with fibrotic conditions both in experimental animals and in humans. Although a role for mast cells has been suspected in the pathogenesis of fibrosis, no potent mediator capable of stimulating fibroblast growth or extracellular matrix deposition has been identified in mast cell supernatants. We report here the constitutive production of TGF beta 1 by four dog mastocytoma cell lines. TGF beta 1 was identified by characteristic biologic activity, blockade of biologic effect by specific neutralizing antibody, and by recognition of a band with the appropriate migration by western blot. TGF beta 1 mRNA, but not TGF beta 2 or TGF beta 3 mRNA, was also produced constitutively by all four cell lines. Quantitation by bioassay revealed baseline TGF beta secretion of approximately 1 ng/10(6) cells over 48 h. Stimulation of mastocytoma cells with phorbol ester increased the rate of release of TGF beta 1, most markedly in the first 30 min after stimulation, without increasing TGF beta 1 mRNA. Dog mastocytoma cells produced TGF beta 1 primarily in a latent form, inactive until treated with acid. Both pure TGF beta 1 and TGF beta-containing mastocytoma cell-conditioned media inhibited mitogenesis and proliferation in dog mastocytoma cell lines, suggesting that mast cell tumor lines would not grow preferentially based on their ability to produce TGF beta. These studies may make possible further investigation of the mechanism by which mast cells contribute to the induction of fibrosis.
 ...
PMID:Dog mastocytoma cells produce transforming growth factor beta 1. 163 19

Activation of a novel adenosine receptor in a rat tumor mast cell line (RBL-2H3 cells) elicits a transient generation of inositol 1,4,5-trisphosphate and an equally transient increase in the level of free cytosol Ca++: Such responses promote little exocytosis, but markedly enhance the secretory response to antigen. A variety of xanthine adenosine receptor antagonists did not suppress the responses to the adenosine analog 5-N-ethylcarboxamidoadenosine. However, 3-isobutyl-1-methylxanthine (IBMX) and certain related xanthines inhibited antigen (dinitrophenylated bovine serum albumin, DNP-BSA)-induced generation of inositol phosphates, the increase in level of free cytosolic Ca++ and exocytosis in RBL-2H3 cells that were primed with a monoclonal DNP-specific immunoglobulin E (from hybridoma H1 DNP-epsilon-26.82). The same compounds inhibited the binding of antigen to cell attached DNP-specific IgE in a highly selective manner. Incorporation of an aromatic or cycloalkyl group in the 8-position of IBMX or theophylline, for example, resulted in compounds that were more potent inhibitors than the parent compounds. Conversely, substituents in the 7- or 9-position of IBMX resulted in inactive compounds. 1,3-Diethylxanthine and 1,3-dipropylxanthine had no activity, suggesting that substituents as large as ethyl or propyl are not tolerated at the 1-position. Inhibition by IBMX was not observed when cells were activated by nonimmunological stimulants or when cells were primed with certain other monoclonal preparations of DNP-specific IgE and stimulated by DNP-BSA.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Methylxanthines block antigen-induced responses in RBL-2H3 cells independently of adenosine receptors or cyclic AMP: evidence for inhibition of antigen binding to IgE. 171 13

Antigenic stimulation of rat basophilic leukemia (RBL-2H3) cells, a tumor mast cell line, is associated with an increase in intracellular free Ca2+ concentrations ([Ca2+]i) and membrane polarization. We recorded whole cell and single-channel currents through the inwardly rectifying K+ channel, a major resting conductance of cells, using the patch-clamp technique, and we examined interactions between channel activity and [Ca2+]i. With 10 microM Ca2+ in the pipette, the amplitude of whole cell currents gradually declined within 5 min to 48 +/- 13% of that immediately after rupture of the patch membrane, in the presence of 1 mM ATP which minimized intrinsic rundown. In inside-out patches, activity of the channel was reduced by increasing the concentration of Ca2+ in the internal medium, both in the presence and absence of 1 mM ATP, with no apparent change in single-channel conductance. Time-averaged mean current activity in inside-out patches in the presence of 5 microM Ca2+ was less than 50% of that with Ca2+ of 100 nM or less. These results suggest that a rise in [Ca2+]i leads to a closure of the inwardly rectifying K+ channel. In some inside-out patches, inward currents characterized by burst composed of rapid transitions between open and closed states were observed (flickering currents). Single-channel properties of the flickering currents are similar to the inwardly rectifying K+ channel except for kinetics (single-channel conductance of 24.5 +/- 7.9 pS, inward rectification, and permeability to K+).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Calcium-dependent inactivation of inwardly rectifying K+ channel in a tumor mast cell line. 173 36

A total of 340 cases of cutaneous neoplasia were diagnosed in 340 of 3,564 cats that were examined by biopsy or necropsy during a 41-month period from January 1, 1986 through May 31, 1989. Eighteen types of tumor occurred, but four types comprised 77% of the cases. These were basal cell tumor, 89 cases (26%, mean age 10.3); mast cell tumor, 72 cases (21%, mean age 8.6); squamous cell carcinoma, 52 cases (15%, mean age 11.6); and fibrosarcoma, 50 cases (15%, mean age 10.2). For each of these four types of tumors, peak number of cases occurred in cats older than 10 years. Mast cell tumor was the only tumor diagnosed in cats younger than 1 year. The head was the most common site for basal cell tumors, mast cell tumors, and squamous cell carcinomas. The legs were the most common location of fibrosarcomas. Siamese cats had approximately three times as many mast cell tumors as statistically expected, but only one-fourth as many squamous cell carcinomas. Breed predilection for other skin tumors was not apparent. Sex predilection was not detected for any skin tumor.
 ...
PMID:Cutaneous neoplasia in 340 cats. 175 Jan 64

Four examples of a mesenchymal tumor of undetermined histogenesis occurred in three mixed-breed dogs and one Yorkshire terrier. All tumors occurred as solitary, soft to firm, solid, tan, and ulcerated masses in the digits of dogs aged 11 to 15 years. The compact cellular tumor had cells with anisokaryotic round, oval, or irregular nuclei, some of which were multinucleated. The neoplastic cells appeared to arise in the tissue near the third phalanx in the area of dense collagenous trabeculae located proximal to the fat pad and sweat glands. The unclassifiable cells had some features of histiocytes by transmission electron microscopy, but failed to stain for lysozyme and alpha-1-antichymotrypsin, markers for monocyte-macrophage derived cells. Immunohistochemically, the cells stained for vimentin but not for cytokeratins, desmin, S-100 protein, epithelial membrane antigen, alpha-lactalbumin, lysozyme, alpha-1-antichymotrypsin, alpha-lactalbumin, casein, and heavy and light chain immunoglobulins. The combined findings of light and transmission electron microscopy and immunohistochemistry exclude tumor histogenesis from an epithelial cell, melanocyte, mast cell, plasma cell, Schwann cells, and Merkel cell.
 ...
PMID:Distinctive unclassified mesenchymal tumor of the digit of dogs. 175 Jan 65

This is the first report on the photodynamic treatment with a second-generation sensitizer, chloro-aluminum sulfonated phthalocyanine (CASPc) of spontaneously arising tumors and on the photodynamic therapy (PDT) of snake neoplasms. Each of 10 cats, 2 dogs, and 3 snakes presenting with a variety of tumor types (squamous cell carcinoma, mast cell malignant tumor, and mixed carcinoma/sarcoma) was given an intravenous injection of 1 mg of CASPc per kilogram body weight 48 hours prior to irradiation with 675-nm light. Some larger tumors (greater than 1.5 cm deep) were surgically debulked prior to PDT. No significant systemic toxicity or skin photosensitization was observed in any animal. The tumor responses were comparable to those seen with conventional cryotherapy, hyperthermia, or surgery. PDT with CASPc of these cases led to 67% (12 of 18) complete response, 22% (4 of 18) partial response, and 11% (2 of 18) no response (less than 50% reduction in tumor size). Four cases could not be evaluated. Since the overall tumor response to CASPc is very good, and the problem of skin photosensitivity is nonexistent, it is expected that using CASPc-PDT to eradicate human tumors would also yield comparable results. Further studies with long-term follow-up are necessary to optimize the use of CASPc-PDT in veterinary and human medicine.
 ...
PMID:Photodynamic therapy of spontaneous cancers in felines, canines, and snakes with chloro-aluminum sulfonated phthalocyanine. 182 98

Earlier studies have shown that the mast cell receptor IgE (Fc epsilon RI) for is expressed on COS-7 cells transfected with the cDNA for each of the three types of subunits that form the tetrameric, alpha beta gamma 2, receptor. Although such transfected COS cells fail to exhibit some of the early biochemical perturbations initiated by aggregation of the receptor on normal mast cells and related tumor lines, we show here that other characteristics of the endogenous Fc epsilon RI are retained. Thus, the unaggregated transfected wild-type receptors were found to have a restricted translational diffusion similar to that observed for endogenous receptors on mast cells as assessed by fluorescence photobleaching and recovery. Similarly, as with endogenous receptors the mobility of transfected receptors was sharply reduced when the receptors were aggregated by reaction with small oligomers of IgE. In addition, aggregation of the transfected Fc epsilon RI caused them to be internalized by the COS cells by a cytochalasin-sensitive mechanism, albeit at a considerably slower rate than was seen with endogenous receptors on mast cells or with transfected receptors in a line of receptor-deficient mast cells. We also examined the mobility and internalization before and after aggregation, of some 13 different combinations of receptor subunit mutants in which one or more of the five cytoplasmic domains of the receptor had been truncated. Our results show that whatever interactions between the receptor and cellular components may account for the phenomena we studied, such interactions do not critically depend upon the bulk of the cytoplasmic domains of the receptor.
 ...
PMID:Immobilization and internalization of mutated IgE receptors in transfected cells. 182 51

Thirty equine cutaneous mastocytomas were examined histologically and two were studied ultrastructurally. Lesions were characterized by distinct sheets of well-differentiated mast cells with variable degrees of eosinophil infiltration, collagen degeneration, necrosis, granulomatous inflammation and fibrosis. Twenty-two of 25 growths did not recur for up to 6 years after surgical excision, two recurred at the surgical site and one spontaneously regressed less than 3 months after obtaining a biopsy sample. Equine cutaneous mastocytoma is a benign proliferative lesion which seldom recurs after excision. The varied histological presentation of equine mastocytoma can be attributed to a sequence of events initiated by a cutaneous mast cell proliferation. It is suggested that these mast cells release chemotactic factors for eosinophils which accumulate and degranulate, initiating collagen degeneration and cellular necrosis with subsequent granulomatous inflammation and fibrosis. The focal spontaneous nature of the primary mast cell proliferation is typical of neoplasia.
 ...
PMID:Equine cutaneous mastocytoma: morphology, biological behaviour and evolution of the lesion. 186 26


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>