Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The localization of neutral mucin and acidic mucins in both control and fasted rat gastric fundic mucosa were examined by microscopic and electron microscopic histochemical methods. By Carnoy's fixation, the surface mucous coat of the control rat gastric fundic mucosa was found to be composed of alternating layers of acidic mucins and neutral mucin, indicating the synchronous and cyclic secretions of them. In many gastric pits of the fundic glands, the acidic mucins were found to spring out from the deep foveolar regions like volcanoes. This phenomenon may suggest that the acidic mucins play a fundamental role in protecting the pit cells against HCl during its passage, and the layers of neutral mucin and acidic mucins in the surface coat is the safeguard against the HCl and digestive enzymes in the gastric lumen. In the fasting rat gastric fundic mucosa, the acidity and the amount of the gastric juice were markedly decreased, indicating the suppressed secretions of mucins and HCl. The decreased production of sulfomucin was directly demonstrated by 35SO4-autoradiography. Many mucous neck cells existing in close association with the parietal cells were ballooned due to accumulation of alcian blue (AB)-positive but high iron-diamine (HID)-negative sialomucin, which was not demonstrable in the control. The secretory granules of sialomucin contained in the ballooned mucous neck cells were positively stained ultrastructurally with cacodylate-ferric colloid to stain acid mucopolysaccharides.
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PMID:Importance of acidic mucin secretions by foveolar and mucous neck cells of rat fundic mucosa as the defence mechanisms against HCl as revealed by fasting. 138 Aug 50

Histochemical properties of mucosubstances in normal mucosa and neoplasms of 100 operated cases with colonic carcinoma were investigated by using several new methods, such as paradoxical concanavalin A (con A) staining and modified PAS reactions for sialic acids. Acidity of goblet cell-type mucin (GCM) of the normal mucosa varied with the depth of the crypt, as well as with different segments of the large intestine, whereas surface coat-type mucin (SCM) mainly consisted of sulfomucin throughout the large intestine. In addition, the PAS reactivity revealing the presence of O-acetylated sialic acid and the labile class III con A reactivity were demonstrated as hallmarks characterizing the colonic GCM. In carcinoma tissues, sialomucin was more abundant than in the normal mucosa. Goblet-type tumor cells were found in 59 cases. Moreover, O-acetylated sialic acid and the labile class III con A reactivity persisted in GCM of the goblet-type tumor cells. GCM of the adjacent mucosa of the neoplasms showed a decrease in sulfomucin in 95 cases and a marked increase in the labile class III con A reactivity in 97 cases, while the histochemical properties of SCM in this region remained unchanged.
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PMID:Mucosubstance histochemistry of the normal mucosa and epithelial neoplasms of the large intestine. 241 Nov 6

50 carcinoid tumors of different locations in the gastrointestinal and respiratory tracts were examined histochemically for mucin production. Isolated discrete aggregates of mucosubstances were identified in a large number of cases (46% of all carcinoid tumors, ranging from 53 to 36% in different organ locations). Acidity and composition of mucosubstances (sulfomucin vs. sialomucin contents) in carcinoids were not different from those described in their corresponding locations. These data support numerous other observations that point to a common stem cell precursor for both enterochromaffin and mucus-secreting epithelial cells in gastrointestinal and respiratory tract mucosal membranes. A shared endodermal derivation is favored over a separate neuroectodermal origin for the chromaffin cell system.
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PMID:Carcinoid tumors with focal mucin production. 264 Aug 95