Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

110 children suffering from malabsorption underwent several biopsies of the gut to confirm coeliac disease (CD) following the ESPGAN criteria. We studied the values for alkaline phosphatase (AP) in the intestinal mucosa after gluten challenge. In 42 patients the after challenge biopsy was normal, thus excluding coeliac disease. In 68 children the mucosa was severely damaged confirming CD. In all biopsy specimens lactase, invertase, maltase and alkaline phosphatase were measured. We found a good correlation between PA values and severity of mucosal damage, showing that measurement of PA in the mucosa is helpful in assessing the degree of mucosal atrophy in children suffering from malabsorption.
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PMID:[Alkaline phosphatase in the intestinal mucosa of children with the malabsorption syndrome]. 250 30

By use of a radiometric assay transglutaminase activity was demonstrated for the first time in human jejunal mucosa. The activity is similar to that in other tissues, with a pH optimum of 9.0, an absolute requirement for Ca2+ and an apparent Km for putrescine of 0.15 mmol/l. Assay of jejunal transglutaminase activity with a variety of dietary proteins as acceptors showed high activity with gliadin, comparable with that of the standard substrate, dimethylcasein. Deamidation of the gliadin markedly reduced its acceptor activity. Collagen, ovalbumin, elastin and zein exhibited very low acceptor activities. Increased transglutaminase activity was demonstrated in jejunal biopsies from four patients with untreated coeliac disease compared with 14 control subjects and eight patients with inflammatory bowel disease. Eight patients with coeliac disease in remission, with normal levels of brush border alpha-glucosidase, showed elevated transglutaminase activities compared with those of controls. It is postulated that intestinal transglutaminase activity may be important in gliadin binding to tissues and thus in the pathogenesis of coeliac disease.
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PMID:Human jejunal transglutaminase: demonstration of activity, enzyme kinetics and substrate specificity with special relation to gliadin and coeliac disease. 285 82

1. Biochemical estimates of lactase, sucrase and maltase activities, carried out on intestinal biopsies appearing histologically normal, were compared with those obtained from children suffering from coeliac disease, cow's milk protein intolerance/postenteritis syndrome and the intractable diarrhoea syndrome of infancy. Lactase deficiency in these children was found to be more pronounced than sucrase or maltase deficiencies. 2. Quantitative cytochemical investigations showed characteristic disease-induced changes in the ability of enterocytes to express alpha- and beta-glucosidases, but not alkaline phosphatase activities, during migration along stunted villi. 3. Separate estimates of the time course describing hydrolase development in normal and coeliac tissue showed the initial rate of lactase appearance to be halved in coeliac patients, while that for alpha-glucosidases remained constant and that for alkaline phosphatase increased by a factor of four. Enteroblastic replacement of mature enterocytes cannot provide a general explanation for hydrolase deficiency in diseased intestine.
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PMID:Selective alteration of brush-border hydrolases in intestinal diseases in childhood. 312 20

Jejunal segments from fetal rats of 18 days gestation were maintained in an organ culture system for up to 72 h. During this period, villi developed within the intestinal lumen and the epithelium changed from stratified to simple columnar. Peristaltic activity was observed during in-vitro culture. Alkaline phosphatase specific activity of the bowel segments fell after 48 hours culture, compared with pre-culture values (P less than 0.05), but that of alpha-glucosidase increased. The addition of Frazer's gluten fraction III to the culture medium caused slowing in the rate of morphological maturation of the jejunal explants, but there was no additional effect on enzyme specific activities compared with segments cultured in gluten-free medium. The place of organ culture of fetal rat intestine as an animal model for testing cereal toxicity in the study of coeliac disease remains unclear.
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PMID:Organ culture of fetal rat small intestine for testing gluten toxicity: a reappraisal. 381 99

Activities of lactase, sucrase, and maltase were determined in small intestinal biopsies of 125 children with coeliac disease, cow's milk protein intolerance, transient gluten intolerance, nonspecific enteropathies, and controls. Four cases of primary disaccharidase deficiencies could be identified. In the enteropathies, morphometric data were more closely correlated to the degree of the mucosal lesion (r = -0.92 for crypt depth) than were disaccharidase activities (r = 0.61 for lactase). In a stepwise discriminant analysis of the patient groups, based upon immunological, morphometric, and biochemical variables, lactase activity was a valuable secondary criterion, ranking third among the variables used.
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PMID:[Disaccharidase activity as a diagnostic criterion for the mucosa of the small intestine]. 641 Jan 84

In 30 children presenting with complaints characteristic of malabsorption in whom congenital enzyme deficiency could be excluded, determination of the enzymes lactase, saccharase and maltase was performed in the tissue sample obtained by jejunal biopsy; histology was also carried out in all cases. In 23 cases the diagnosis of coeliac disease could subsequently be confirmed, in the other 7 cases the diagnosis could neither be rejected nor established with certainty. All three enzymes had a decreased activity in cases displaying subtotal or total villous atrophy, the most sensitive among them being lactase: in 69% of cases no lactase activity could be shown while saccharase and maltase were absent in 29 respectively 4% of the cases. No close correlation exists between the light-microscopic findings and the activity of enzymes since total absence of enzyme activity may be associated with only moderate villous atrophy. Lack of disaccharidase activity in the upper section of the small bowel does not necessarily mean disaccharide malabsorption exhibiting clinical symptoms, it only indicates a reduced capacity of disaccharide splitting. It has been concluded that routine determination of disaccharidase activities is not justified within the diagnostic procedure of coeliac disease.
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PMID:Disaccharidases in coeliac disease. 641 72

A naturally occurring enteropathy was identified in Irish setter dogs and wheat-sensitivity was demonstrated in a litter bred from two of the affected animals. The morphological and biochemical features of this enteropathy are described and compared to coeliac disease in man. Affected animals comprised 10 dogs that presented with poor weight gain or weight loss, with or without diarrhoea. Exocrine pancreatic function was normal and culture of duodenal juice demonstrated no marked bacterial overgrowth. Serum vitamin B12 concentrations were unaltered, but in some cases low serum and erythrocyte folate concentrations and reduced xylose absorption provided indirect evidence for proximal small intestinal disease. Examination of peroral jejunal biopsies revealed patchy morphological changes within individual animals, comprising predominantly partial, but in one case subtotal, villous atrophy. Brush border enzymes were selectively altered: the specific activities of alkaline phosphatase, leucyl-2-naphthylamidase and of zinc-resistant alpha-glucosidase were reduced by approximately 40 per cent, while activities of maltase, sucrase, lactase and gamma-glutamyl transferase were unaltered. Activity of a lysosomal enzyme was increased and there was evidence for enhanced lysosomal fragility. The activity of malate dehydrogenase, with a dual mitochondrial and cytoplasmic localisation, was decreased but there were no changes in the activities of marker enzymes for basal-lateral membranes, endoplasmic reticulum or peroxisomes. These findings, particularly the specific biochemical abnormalities, were comparable to those in partially treated coeliac disease in man; however, a specific role for wheat in the pathogenesis of the disease has yet to be defined.
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PMID:Morphological and biochemical studies of a naturally occurring enteropathy in the Irish setter dog: a comparison with coeliac disease in man. 652 28

A series of marker enzymes for brush borders, basolateral membrane, and lysosomes were assayed in mucosal biopsy specimens from patients with untreated and treated coeliac disease and from controls. The brush border enzymes lactase, sucrase, neutral alpha-glucosidase, alkaline phosphatase, and leucyl-beta-naphthylamidase showed reduced activities in the untreated state and complete or partial normalization during treatment. The lysosomal marker enzyme acid phosphatase increased in activity in untreated coeliac disease and was normalized by treatment. The brush border enzyme gamma-glutamyl transferase was nearly normal in untreated patients and slightly increased in treated patients. The basolateral membrane marker, 5'-nucleotidase, was reduced both in untreated and treated patients, whereas the lysosomal marker N-acetyl-beta-glucosaminidase was normal in the untreated state and decreased during treatment. The possible pathogenetic role of the three latter enzymes in coeliac disease is discussed. The patterns of the other enzymes are suggested to be attributable to the morphologic changes in the mucosa.
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PMID:Jejunal mucosal enzymes in untreated and treated coeliac disease. 667 55

The effect of the topical corticosteroid clobetasone butyrate on enzyme activity and morphology of duodenal mucosa was studied in 9 patients with coeliac disease and 10 controls using organ culture techniques. There was significant increase in mucosal alkaline phosphatase, lactase and maltase activities, but inclusion of a soluble extract of gluten reduced this effect. When clobetasone butyrate was also included in the culture medium significant elevations in enzymes were again observed. Enterocyte height was not affected by incorporation of gluten into the medium. Intra-epithelial lymphocyte counts fell significantly during the culture period. This improvement was also inhibited by gluten and overcome by addition of steroid.
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PMID:The effect of the topical steroid clobetasone butyrate on coeliac mucosa maintained in organ culture. 678 33

Jejunal biopsies from controls and coeliac patients were maintained in organ culture for up to 48 hours. The in vitro effect of gluten fraction III during the period of culture was assessed by measurement of the activity of the brush border enzymes alkaline phosphatase and alpha-glucosidase. Mucosa from controls and treated and untreated coeliacs behaved similarly and no reproducible in vitro effect of gluten was demonstrated. These results cast doubt on the in vitro diagnosis of coeliac disease by monitoring brush border enzyme activity.
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PMID:In vitro diagnosis of coeliac disease: an assessment. 703 Aug 78


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