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)

Thin sections in mouse mast cells and thymic cells are stained with cobalt thiocyanate a compound known to form insoluble complexes with organic bases. Chromatin, nucleolus, ribosomes and mast cell granules are contrasted. Different blockade reactions and enzymatic digestions indicate the staining corresponds to the basic protein amino-groups. The silver methenamine reaction stains the same cellular structures. However, the specificity control reactions show the staining mainly corresponds to protein sulphydryle groups and in a lesser extent to aldehyde and polyanions.
 ...
PMID:Cobalt thiocyanate as a stain for basic proteins and other organic bases on thin sections. 7 73

After a review on the historical development of morphological investigations of entero-endocrine cells, dating back to 1870, a detailed synoptical review of the current stage of findings in this field is given. At the present time nine different endocrine cell types can be distinguished in the epithelium of the gastrointestinal tract. Criteria for this differentiation are properties concerning specific staining methods, aldehyde-induced fluorescence, immunohistochemistry, and ultrastructure. From present results it is obvious that distinct cell types are responsible for the synthesis of defined polypeptide hormones (e.g. gastrin, secretin, enterogastrone). The metabolism of amines, in relation to the endocrine cells of the gastrointestinal tract is of particular interest here. Points investigated include the uniqueness of endocrine cells, with regard to the metabolism of biogenic amines ("APUD-cells") and the possibility of serotonin synthesis by a definite cell type, i.e. by the EC-cell ("enterochromaffin" cell). In our experimental animal, male Wistarrats, seven different entero-endocrine cell types can be discerned by ultrastructural means: EC-, ECL-, G-, AL-, EG-, D- and D1-cells. The I-cell (found in other species) can hardly be distinguished from the AL-cell by ultrastructural means and the S-cells, as found in other species, are not to be found at all. Only some of the cited cell types can be seen by fluorescence microscopy. After formaldehyde-treatment of the tissue, the "enterochromaffin" cell shows a yellow, serotonin-specific fluorescence. This cell corresponds in shape, number and distribution to the ultrastructurally defined EC-cell. EC-cells are found predominantly in the pyloric region and the duodenum and less frequently in the middle- and hindgut and the cardiac region; seldomly EC-cells are encountered in the oxyntic gland area of the stomach. In the rat gastro-intestinal tract, number and fluorescent intensity of EC-cells does not always correspond with the serotonin content of a certain region--sometimes the level of serotonin is largely determined by the mast cells, which in the rat also contain serotonin. For example, the high serotonin content of the oxyntic gland area, which contains very few EC-cells, has to be contributed nearly exclusively to mast cell serotonin. Mast cells can be domonstrated by fluorescence microscopy, due to their histamine content, after treatment of the tissue with o-phthalaldehyde (OPD). It seems likely that the histamine content, especially that of the so-called "atypical mast cells" of the mucosa, is inversely related to their respective serotonin content. --In addition to mast cells, OPD-treatment leads to a fluorescence in some of the entero-endocrine cells of the gastrointestinal epithelium. In the gastric epithelium these fluorescing cells should be regarded as histamine-containing ECL-cells and glucagon-containing AL-cells while in the colonic epithelium they are considered to be glucagon-containing AL-cells...
 ...
PMID:[The endocrine cells of the gastrointestinal epithelium and the metabolism of biogenic amines in the gastrointestinal tract (author's transl)]. 13 9

We compared three different staining methods to determine if the dermal elastic fiber content of the HRS/Skh-1 hairless mouse could be accurately measured by color image analysis. Comparisons were made among Kligman's modification of Luna's mast cell stain for elastin, Unna's orcein stain with or without potassium permanganate preoxidation, and Gomori's aldehyde fuchsin stain with potassium permanganate preoxidation. The color image analysis system could be used to identify and quantify murine dermal elastin fibers in sections stained by all three methods. Gomori's aldehyde fuchsin stain with preoxidation demonstrated twice the content of dermal elastic fibers demonstrated by either Kligman's modification of Luna's mast cell stain or Unna's orcein stain with or without preoxidation. Gomori's aldehyde fuchsin method with preoxidation should be considered the stain of choice for evaluating murine dermal elastic fiber content.
 ...
PMID:Quantitative determination of murine dermal elastic fibers by color image analysis: comparison of three staining methods. 137 3

Mast cells secrete many biologically active compounds upon stimulation by immunoglobulin E (IgE) and specific antigen (Ag), anaphylatoxins, as well as a number of cationic compounds which include drugs, kinins and neuropeptides. The effects of the two naturally occurring polyamines, spermine (SP) and spermidine (SPD), on mast cell secretion were studied because they have been implicated in the modulation of cellular processes, possibly through their cationic charge or the regulation of calcium ions. SP and SPD over the range of 10(-7) to 10(-4) M inhibited the release of 5-hydroxytryptamine (5-HT, serotonin) triggered by compound 48/80 (C48/80) in a time- and concentration-dependent manner, as long as at least 2% calf serum (CS) was present. SP also inhibited secretion of both histamine and serotonin stimulated immunologically by using IgE and anti-rat IgE. This inhibition was not accompanied by cytotoxicity. The major available polyamine metabolites tested, N1-acetyl spermine (N1-acSP) and N8-acetyl spermidine (N8-acSPD), also showed inhibition in the presence of CS, whereas putrescine, N8,N1-hexamethylene-bis-acetamide (HMBA) and benzylamine did not. Fetal bovine serum (FBS), as well as human and rat serum, which do not contain polyamine oxidase, did not result in any inhibition with the polyamines tested. Inhibitors of the polyamine oxidase blocked the polyamine effect, indicating that the inhibition of mast cell secretion must derive from aldehydes produced from these polyamines. Addition of the aldehyde inhibitor phenylhydrazine (phi-HDZ), simultaneously with, but not following the polyamines, blocked their inhibitory effect, further strengthening the involvement of aldehydes. These results indicate that naturally occurring polyamines may regulate mast cell secretion through metabolic products of polyamine oxidase, a similar enzyme of which is also present in human liver, placenta and pregnant serum.
 ...
PMID:Inhibition of mast cell secretion by oxidation products of natural polyamines. 159 9

Two distinct types of mast cells are recognized in the rat: connective tissue mast cells (CTMCs), found in the peritoneal cavity, skin, tongue, etc. and mucosal mast cells (MMCs), found in the intestinal mucosa. The two subsets differ functionally and can be defined by histochemical methods. The aim here was to characterize the mast cell population in various oral mucosal sites. Biopsies were taken from the tongue, buccal mucosa, gingival mucosa and intestine (jejunum) of 20 rats. For optimal preservation of the MMCs, a fixative with low aldehyde concentration and low pH was used. The biopsies were embedded in paraffin. The first of three consecutive sections (5 microns) was stained with toluidine blue for 30 s, the second with toluidine blue for 7 days and the third with astra blue/safranine. Cells positive with toluidine blue after 30 s were classified as CTMCs, and those positive after 7 days but not after 30 s as MMCs. Cells positive to safranine in the astra blue/safranine staining sequence were classified as CTMCs and those positive to astra blue as MMCs. The total number of mast cells was similar in the superficial layers of all oral tissues studied. There were more mast cells in the deeper than in the superficial portions of the tongue. Mast cells with staining characteristics and size similar to those observed in the intestinal mucosa (MMCs) were found together with 'classical' connective tissue mast cells (CTMCs). The results suggest that the mast cell population of oral mucosal tissues of the rat contains both CTMC- and MMC-like cells.
 ...
PMID:Mast cell heterogeneity in various oral mucosal sites in the rat. 163 59

Various N-alpha-hydroxyalkyl derivatives of N-acyl amino acids and di- and tripeptides were prepared by hydrolysis or aminolysis of N-acyl 5-oxazolidinones. The stability of these derivatives was studied in aqueous solution as a function of pH. The compounds were all degraded quantitatively to their parent N-acylated amino acid or peptide and aldehyde but with vastly different rates. At pH 7.4 and 37 degrees C the half-lives of decomposition ranged from 4 min to 1500 hr. The structural factors influencing the stability included both steric and polar effects within the acyl and N-alpha-hydroxyalkyl moieties as well as within the amino acid attached to the N-alpha-hydroxyalkylated N-acyl amino acid. Whereas the N-benzyloxycarbonyl (Z) derivatives of the dipeptides Gly-L-Leu and Gly-L-Ala were readily hydrolyzed by carboxypeptidase A, the N-hydroxymethylated compounds, i.e., Z-Gly(CH2OH)-Leu and Z-Gly(CH2OH)-Ala, were resistant to cleavage by the enzyme as revealed by their similar rates of decomposition in the presence or absence of the enzyme at pH 7.4 and 37 degrees C. The results suggest that N-alpha-hydroxyalkylation of a peptide bond protects not only this bond but also an adjacent peptide bond against proteolytic cleavage. Since the N-alpha-hydroxyalkyl derivatives are readily bioreversible, undergoing spontaneous hydrolysis at physiological pH, this prodrug approach promises to overcome the enzymatic barrier to absorption of various peptides.
 ...
PMID:Prodrugs of peptides. 9. Bioreversible N-alpha-hydroxyalkylation of the peptide bond to effect protection against carboxypeptidase or other proteolytic enzymes. 205 17

We developed a simple technique that greatly facilitates the ultrastructural examination of cells growing in small, widely dispersed colonies in agar medium, and used the method to examine the development of morphologically mature mast cells and actively phagocytic macrophages in agar cultures of mouse bone marrow cells. The bone marrow cells of genetically mast cell-deficient WBB6F1-W/Wv or congenic normal (+/+) mice were cultured in semisolid agar medium supplemented with supernatants of concanavalin A-stimulated splenocytes. To prepare the colonies of hematopoietic cells for transmission electron microscopy, all the colonies within the agar-containing medium in a 96-well culture plate were removed with a Pasteur pipette and placed in a dilute, mixed aldehyde fixative. After fixation, the agar still enmeshing and separating individual colonies of cells was melted at 94 degrees C, rapidly mixed with molten 2% agar in a microfuge tube, centrifuged for 1 minute, and then the plastic tube was cooled in ice for 30 minutes. The plastic was removed with a razor blade, the agar block was hemisected from top to bottom, and then the blocks were processed for electron microscopy, embedded flat, and sectioned for light and electron microscopy. The culture conditions tested resulted in the development of morphologically mature mast cells and actively phagocytic macrophages, whether cultures were initiated with bone marrow cells from WBB6F1-W/Wv or congenic +/+ mice.
 ...
PMID:A simple technique to facilitate the ultrastructural analysis of cells in soft agar culture systems: demonstration of the development in vitro of morphologically mature mast cells and phagocytic macrophages from the bone marrow cells of genetically mast cell-deficient W/Wv or congenic normal mice. 235 61

The mast cell distribution and number were studied in skin biopsies of 18 mastocytosis patients and 10 controls. The biopsies were stained for mast cells with toluidine blue at pH 0.5. The number in the upper dermis of lesional abdominal skin was at least twice as high as that of normal adjacent skin. Fixation in iso-osmotic 0.6% formaldehyde and 0.5% acetic acid, revealed more mast cells than conventional 4% formaldehyde fixation. Staining for 5 days, when compared to the normal for 30 min, increased the number of demonstrable mast cells just as did the change in fixation. Conventional formaldehyde fixation thus partially blocks the dye-binding of cutaneous mast cells, about 20% of the cells escaping detection. The degree of aldehyde blocking was similar in lesional and normal skin. A more pronounced blocking of dye-binding has been demonstrated previously in gut mucosal mast cells. Whether the blocking of dye-binding is an expression of heterogeneity in dermal mast cells remains to be determined.
 ...
PMID:Dermal mast cells in mastocytosis: fixation, distribution and quantitation. 242 9

Proteases present in mast cell granules have been harnessed to demonstrate mast cells in human tissues. A number of substrate mixtures were tested. D-Val-Leu-Arg-4-methoxy-2-naphthylamide (MNA) plus Fast Blue B was the best for identifying human mast cells, yielding the most specific and complete staining. The procedure is simple and the results are permanent. Cryostat sections of aldehyde-fixed routine preparations or paraffin sections of Carnoy-fixed tissues give the most satisfactory results. Mast cells are stained a strong red color that stands out distinctly from the surrounding tissues, so that they can be easily identified by simple microscopy. A double-staining technique, first for protease and subsequently using Alcian Blue, showed that as progressive protease staining occurs, the alcianophilia of mast cells is lost. This procedure demonstrated that mast cells in the mucosa of human gut generally required longer incubations to develop protease staining than in other connective tissue sites. In post-mortem tissues, mast cells retain their protease activity well and so can be demonstrated in cryostat sections of aldehyde-fixed material, giving a more complete picture than with Alcian Blue. The synthetic substrate D-Val-Leu-Arg-MNA can be recommended for routine identification of mast cells in human tissues.
 ...
PMID:Selection of a simple protease procedure for identifying mast cells in routinely processed human tissues. 243 82

Rat uterine tissue was dissociated by enzymatic digestion with collagenase and viable mast cells were obtained. Their viability was assessed by the ability to exclude trypan blue dye and to respond functionally to different stimuli. Challenge with anti-IgE gave a calcium-dependent histamine release of 49%, whilst the undigested uterine fragments gave 23%. Moreover, they were capable of releasing histamine on challenge with the compound 48/80, suggesting a similarity with connective tissue mast cells. This similarity was further supported by their insensitivity to aldehyde blocking of dye binding. The final dispersed cell preparation contained 3 X 10(5) mast cells/g of uterine tissue, representing about 2% of total nucleated cells. The total histamine content of the undigested uterus was 2.5 micrograms/g of tissue, whilst after digestion the histamine determined was 1.2 pg per mast cell with a yield of 14%. The total histamine content of the uterus changed throughout the reproductive cycle, increasing before ovulation, reaching a maximum during ovulation and then decreasing after embryo implantation. This suggests that the implanting embryo, interacting with the uterus, may be capable of inducing the release of histamine. The embryo-derived histamine releasing factor (EHRF) that we have described previously is capable of inducing 22% histamine-release on uterine mast cells, thus supporting this hypothesis.
 ...
PMID:Dispersal of rat uterine mast cells and their functional response to an embryo-derived histamine releasing factor: a possible model for embryo implantation. 246 97


1 2 3 4 Next >>