Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inability to absorb lactose due to low intestinal lactase is common in many population groups. This study is the first to compare lactose tolerance in 282 Mexican-American (MA) children and 51 Anglo-American (AA) children 2 to 14 years of age with the dietary intake of selected nutrients found in milk. A lactose tolerance test and a 24-hr dietary recall were obtained for each child. Gastrointestinal symptoms were carefully recorded for a 24-hr period following the lactose load. Overall prevalence of lactose malabsorption was 37% in MA children and 8% in AA children, and it increased with age. Number of symptoms occurring in lactose malabsorbers of both ethnic groups also increased with age. Mean protein intake exceeded Recommended Dietary Allowances at all ages for both ethnic groups. Mean consumption of vitamin A, calcium, and energy was below the Recommended Dietary Allowance for MA children. There were no differences in calories, nutrient, or milk intakes between lactose absorbers and malabsorbers, but AA children drank more milk than MA children. Fifteen percent of lactose-absorbing MA, 23% of malabsorbing MA, but no AA children reported having symptoms after drinking milk. There was a significantly greater incidence of lactose intolerance in MA as compared to AA children. This suggests that Mexican-Americans share in the high incidence of primary lactose intolerance characteristic of the majority of the orld's peoples.
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PMID:Lactose malabsorption in Mexican-American children. 94 57

On the basis of comparative determinations of the activities of dipeptidases and disaccharidases of the mucous membrane of the small intestine (proximal jejunum) clear correspondences between the morphological findings and the biochemical parameters were the result. L-alanyl-L-prolin-dipeptidase and glycyl-L-valin-dipeptidase as well as lactase, saccharase, maltase and trehalase were determined in altogether 45 children with various malabsorption syndromes of different age in different stages of disease. Diminutions of the activity of the dipeptidases were to be proved analogously to maltase, saccharase and lactase, too, in most cases of subtotal or total villous atrophy. From the results conclusions may be derived to the restricted ability of protein absorption in chronic disease of the small intestine.
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PMID:[L-alanyl-L-proline-dipeptidase and glycyl-L-valine-depeptidase in malabsorption syndrome]. 96 Sep 1

For evaluation of 14CO2-breath-tests the three most employed tests, namely glycero-14C-tripalmitate-test, 14C-lactose-tolerance-test, and 14C-glycin-cholate-test, were performed in healthy volunteers (n = 69), patients with chronic pancreatitis (n = 18), manifest malassimilation (n = 8), lactase deficiency (n = 15), and patients, in whom a disturbed enterohepatic bile salt circulation was suspected (n = 19). Usefulness of malabsorption tests was limited by many false normal results. Cholylglycin-breath-test on the other hand was sensitive, but clinical significance remained questionable. In our opinion simple performance and lacking discomfort are no sufficient arguments for 14CO2-breath-test.
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PMID:[14CO2 exhalation tests. Diagnostic improvement in gastroenterologic diseases]. 96 89

Lactose-tolerance-test (LTT), ethanol-lactose-tolerance-test (ELTT), 14CO2 breath test and 14C-glucose determination were simultaneously performed in 27 healthy subjects, 16 patients with a Billroth II gastrectomy and 6 patients with a malabsorption syndrome. Intestinal mucosal lactase was absent or significant diminished in 5 of the B II cases and in all patients with malabsorption. In the lactase deficient patients a diminished serum glucose rise after ingestion of 50 g lactose was observed in LTT as well as in ELTT. False positive results in LTT could not be prevented by performing the ELTT. Furthermore the ELTT is not suitable for ambulant investigations because of the required high ethanol load of 0.5 g/kg. Most reliable results were obtained by determination of 14C-serum-glucose after oral application of about 15 muCi of 14C lactose. In respect to lactase level neither false positive nor false negative results were observed. For clinical investigations the procedure of isolation and measurement of 14C-glucose is too laborious however. 14CO2-exhalation test cannot be recommended because of many false positive and false negative results. Moreover 14CO2-exhalation seemed to be insensible and predominant depending on factors other than lactose absorption.
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PMID:[Diagnostics of lactose-malabsorption: value of tolerance tests and 14CO2 exhalation test in patients with and without lactase deficiency (author's transl)]. 99 41

Lactase deficiency, manifested clinically by lactose malabsorption, is often the only biochemical evidence of a residual disturbance of jejunal mucosal function after Escherichia coli enteropathy in the infant. Villous morphology is usually normal. A sustained depression of the processes of biochemical differentiation of lactase biosynthesis has been postulated to explain similar states of lactase deficiency, but a possible influence of altered epithelial cell turnover on the mucosal lactase levels has not been investigated. In ten infants with a residual lactose malabsorption, after E. coli infection, jejunal cell renewal activity and disaccharidase activities were studied by analysis of the exfoliated cells collected by lumenal perfusion. Significant increases in DNA and protein exfoliation and in the brush border activities of sucrase and lactase were observed during recovery from the malabsorptive disturbance. DNA and protein efflux increased almost linearly during a 20-day period. Lactase was initially four times more deficient than sucrase activity in the exfoliated cells. Both enzyme activities increased at almost identical rates. Therefore, it took longer for lactase activity to return to normal levels. The lactase/sucrase ratios approached normal at the end of the 20-day period. The changes in the exfoliating levels of the two enzymes, when analysed in relation to the increases in cell renewal activity, suggested a relationship between sucrase and lactase levels and cell age.
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PMID:Intestinal exfoliated cells in infant diarrhoea: changes in cell renewal and disaccharidase activities. 104 54

Activities of the small intestinal mucosal enzymes lactase, sucrase, maltase, alkaline phosphatase and N-acetyl-beta-glucosaminidase were studied in rats with surgically-induced upper intestinal stasis and in control animals. The first four are brush border enzymes, the latter a lysosomal enzyme. There was a reduction in the activities of all enzymes in the operated animals. The change lining was significant and most marked in mucosa the blind loop and gut distal to it; areas in which there is gross bacterial overgrowth and excessive levels of intraluminal deconjugated bile salts. The significance of these findings in relation to malabsorption consequent on bacterial contamination of the upper gut is uncertain and requires further study.
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PMID:Effect of stasis on intestinal enzyme activities. 105 24

In 12 patients suffering from ulcerative colitis the small-intestinal disaccharidase activity has been determined during an acute exacerbation of the disease as well as after remission. The lactase activity was significantly lower during the acute stage. No case of transitoric lactose malabsorption was found.
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PMID:The small intestinal disaccharidase activity in ulcerative colitis. 112 57

1. Intestinal brush border enzymes have heterogeneous rates of turnover, the largest proteins having the fastest turnover. Since the membrane faces the intestinal lumen, the effects of pancreatic factors were examined in mediating this turnover. Surgical subtotal pancreatectomy was used as an experimental model to study the turnover of brush border proteins in the absence of most pancreatic secretions. 2. Subtotal (95%) pancreatectomy of rats was found to cause elevations by about 50% of total activity and specific activities of certain brush border enzymes (maltase, sucrase, lactase), but not of others (alkaline phosphatase, trehalase). Rats were judged to be functionally deficient in pancreatic proteolytic enzymes (a) by demonstration of vitamin B-12 malabsorption, which was corrected by trypsin, and (b) by the finding of only about 20% of proteolytic activity appearing in the lumen after a test meal when compared to control. 3. To measure protein turnover in vivo the method of double labelling was used, where [3H]- and [14C]valine were administered intraduodenally in sequence 10 h apart. With this technique, a high 3H/14C ratio is correlated with rapid turnover. Proteins with apparent molecular weights of about 200 000-270 000 were found to turn over more rapidly than smaller proteins. 3H/14C ranged from 4.7 to 6.2 in animals without pancreatic insufficiency. In the face of decreased pancreatic proteolysis, the 3H/14C ratio was 2.3-3.1, similar to that of proteins with a slow half life. 4. Estimates of relative synthetic rates of large brush border proteins were lower than normal in pancreatectomized animals, but were constant over the period of the labelling experiment. The high enzyme levels in the face of lower synthetic rates confirms that, at the new steady rate, degradation rates must be slower for large brush border proteins in pancreatic insufficiency. 5. In vitro, using purified brush borders, unfractionated pancreatic enzymes were found to remove sucrase, maltase and lactase, but not alkaline phosphatase and trehalase. The enzyme most potent in this respect was the pancreatic protease, elastase. Non-proteolytic enzymes (amylase, lipase, phospholipase A) were inactive in removing enzyme from the brush border. The addition of elastase to pancreatectomized animals in vivo restored the rapid turnover rate of large brush border proteins. 6. A model is thus proposed for the normal catabolism of some large intestinal brush border proteins. It is suggested that the surface of intestinal absorptive cells is being constantly remodelled, and that certain surface enzymes are in part removed from the membrane by the action of pancreatic proteases. A possible special role for elastase is suggested.
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PMID:The possible role of pancreatic proteases in the turnover of intestinal brush border proteins. 114 88

Among 135 infants and children with a supposed malabsorption syndrome, a deficiency of isomaltase-saccharase of the duodenal mucosa was detected in 5 cases by measuring the disaccharidases directly in the mucosa homogenate. In one instance a deficiency of lactase was found in addition. In all patients the villi were of normal length, with an increased cell infiltration of the stroma detected in two cases. The loading tests with xylose-sucrose yielded a diminuished rise in the blood glucose level. Three of the patients were dwarfish, but only one showed an increased growth after the reduction of sucrose in the supplied diet. As a result of adaptation difficulties in the change of diet, one patient had to be treated with an additional saccharase substitution.
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PMID:[Hereditary deficiency of isomaltase and saccharase responsible for a malabsorption syndrone (author's transl)]. 116 88

Thirty-eight specimens obtained by jejunal biopsy from 22 children suffering from mucoviscidosis were examined by histochemical techniques. In 27% of the patients the findings were within normal limits. In 18% of cases, associated coeliacal sprue was disclosed. The remaining cases displayed slight morphological abnormalities associated with trehalase and/or lactase deficiency, and in 41% there was hypersecretion of viscous mucus filling up dilated crypts and adhering to the surface of villi. The findings as observed in enterobiopsis are not pathognostic of mucoviscidosis. They however, should make one to think of it, particularly if trehalase and/or lactase deficiency is found associated with hypersecretion of viscous mucus and an almost normal morphological appearance. Neither normal findings nor that of coeliacal sprue exclude the diagnosis of mucoviscidosis. It appears that malabsorption in mucoviscidosis is not only pancreatogenic; the intestinal mucosa may be contributory to a various degree as well.
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PMID:[Jejunal mucosa in children with mucoviscidosis]. 120 86


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