Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.108 (lactase)
 2,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The incidence of lactose intolerance was determined in 31 women with idiopathic postmenopausal osteoporosis. Nine subjects exhibited a pathological rise in blood glucose (less than 20 mg/100 ml) after receiving 50 g lactose. The absorption of glucose and galactose, xylose, and fat was normal in the 31 patients. Daily intake of calcium was below the normal range in 3 subjects with and in 6 subjects without lactose intolerance. The association between lactase deficiency and osteoporosis is stressed.
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PMID:[Incidence of lactose intolerance in postmenopausal osteoporosis]. 73 31

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

In 63 infants and children with a histological normal mucosa of the duodenum, without an isolated defect of enzyme and with a normal increase of xylose and glucose in serum after a combined xylose-lactose loading test the activities of disaccharidases were log normal distributed. The asymmetric distributions were transformed into symmetric ones and the geometric mean (x) as well as the range (+/- 2 s) of maltase, saccharase, isomaltase, lactase and trehalase were calculated. Only the activity of lactase shows a significant dependency on age. In the first year of age the lower limit (x -- 2 s) of this enzyme is much higher than later.
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PMID:[Disaccharidases of the small intestine mucosa in infants and children. "Normal values", log normal distribution and age dependence]. 122 50

During a six-year period, 29 children (aged 0.7-13.5 years, mean 3.3 years) suffering from chronic diarrhoea due to giardiasis were studied. The incidence of this illness was 81 per 1,000,000 children aged 0- < 7 years per year. According to growth charts, relative height and weight of the patients decreased significantly (approximately 0.5 SD) from before the onset of diarrhoea to the time of diagnosis and subsequently increased up to the end of catch-up growth. Small intestinal mucosal specimens were studied. Two patients had severe villous atrophy, 8 moderate abnormalities, 6 only light changes and 13 biopsies were normal. D-xylose or lactose malabsorption was detected in 25% of the patients. The lactose malabsorption was due to hereditary low lactase levels. None of the patients with a Danish ethnic background showed lactose malabsorption. D-xylose absorption and the relative weight loss of the patients correlated with the degree of mucosal damage. Patients with persistent diarrhoea (n = 19) were younger and had a shorter duration of diarrhoeal illness and a more significant weight reduction than those with intermittent diarrhoea (n = 10). However, the age at onset of symptoms was similar in the two groups (medians 1.3 years). Seven patients contracted the disease abroad. They all developed persistent diarrhoea and had a more severe course of the illness than those who acquired the disease in Denmark.
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PMID:Giardiasis causing chronic diarrhoea in suburban Copenhagen: incidence, physical growth, clinical symptoms and small intestinal abnormality. 146 10

4-O-beta-D-Galactopyranosyl-D-xylose (2) was prepared from benzyl 2,3-O-isopropylidene-beta-D-xylopyranoside by glycosylation with 2,3,4,6-tetra-O-benzoyl-alpha-D-galactopyranosyl bromide and subsequent deprotection. Compound 2 was hydrolyzed in vitro by intestinal lactase; the Vmax was 25% of that with lactose and the Km was 370mM (cf. 27mM for lactose). Oral administration of 2 suckling rats led to urinary excretion of D-xylose which could be estimated colorimetrically.
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PMID:4-O-beta-D-galactopyranosyl-D-xylose: a new synthesis and application to the evaluation of intestinal lactase. 151 83

The thermodynamics of 10 industrially-important, enzyme-catalyzed reactions are examined. The reactions discussed are: the conversions of penicillin G to 6-amino-penicillinic acid using the enzyme penicillin acylase; starch to glucose using amylases; glucose to fructose using glucose (xylose) isomerase; cellulose to glucose using cellulase; fumaric acid and ammonia to L-aspartic acid using L-aspartase; transcinnamic acid and ammonia to L-phenylalanine using L-phenylalanine ammonia lyase; L-histidine to urocanic acid and ammonia using L-histidine ammonia lyase; lactose to glucose and galactose using lactase; and the reactions catalyzed by amino acylases and proteases. The selection of these processes was based on the economic value of the products and their intrinsic industrial importance. The available thermodynamic properties, such as equilibrium constants, Gibbs energies (delta G degrees), enthalphies (delta H degrees), and heat capacity changes (delta Cp degrees) of these enzyme-catalyzed reactions, are reviewed and summarized. Recommendations are made for future research in this area.
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PMID:Thermodynamics of industrially-important, enzyme-catalyzed reactions. 169 84

1. In order to develop an improved differential sugar absorption test for simultaneously assessing intestinal permeability and lactose intolerance, methods were established for determining raffinose, lactose and L-arabinose in human urine. Using NAD(P)H-coupled enzymatic assays and fluorimetry, each sugar was measurable over a concentration range of approximately 3-300 mumol/l in diluted urine specimens. 2. After an overnight fast, 40 normal volunteers drank an iso-osmotic solution containing raffinose, lactose and L-arabinose. The median 5 h urinary sugar excretion was 0.26% of the ingested raffinose, 0.05% of lactose and 17.5% of L-arabinose. 3. In 143 patients with gastrointestinal disease, excretion of both ingested raffinose and lactose was significantly increased in coeliac disease in relapse or in partial remission and in Crohn's disease, but not in the irritable bowel syndrome, coeliac disease in remission or ulcerative colitis. Excretion of lactose, but not raffinose, was increased in patients with mucosal lactase deficiency, whereas excretion of L-arabinose was reduced in all disease groups except ulcerative colitis. 4. Discrimination between diseases was poor when based on individual sugar recoveries, but improved dramatically when excretion was expressed relative to that of L-arabinose. The raffinose/L-arabinose excretion ratio, an index of intestinal permeability, was greater than 0.08 in 15/15 untreated coeliac patients but less than 0.06 in all normal subjects and in 9/9 lactase-deficient patients, 15/16 recovered coeliac patients, 5/6 patients with ulcerative colitis, 13/16 patients with Crohn's disease and 61/62 patients with irritable bowel syndrome.
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PMID:Simultaneous assessment of intestinal permeability and lactose tolerance with orally administered raffinose, lactose and L-arabinose. 216 7

An experiment was conducted using 16 Holstein male calves from 4 to 21 d of age to compare 1) the effects of an all-milk protein milk replacer (MPR) and a milk replacer with 20% of the protein from soy protein concentrate (SPC) on morphological and enzymic small intestinal variables, and 2) the effects of SPC plus putrescine (SPP) or SPC plus ethylamine (SPE) on intestinal variables. Small intestinal absorption, based on xylose absorption tests, was greater in calves fed MPR than in those fed SPC (P less than 0.01) and was intermediate in SPP- and SPE-fed calves. Small intestinal segments were surgically excised from the proximal and distal jejunum of all calves at 7, 14 and 21 d of age. Villus length tended to be greatest in calves fed MPR, and mitotic index was least in SPC-fed calves (P less than 0.05). Mucosal protein concentration was 46, 41, 44 and 44 micrograms/mg mucosa for calves fed MPR, SPC, SPP and SPE, respectively. The ratio of mucosal protein:RNA was greatest in calves fed MPR, least in those fed SPC at d 7 (P less than 0.01) and d 14 (P less than 0.05), and intermediate in calves fed SPP and SPE. In proximal jejunum, activity of mucosal ornithine decarboxylase (ODC, EC 4.1.1.17; the rate-limiting enzyme in polyamine biosynthesis) in calves fed SPP was less than 50% of that in calves fed MPR, SPC or SPE. The activity of lactase (EC 3.2.1.108) and ODC in distal jejunum was 50% less in calves fed soybean protein than in those fed MPR.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of dietary amines on the small intestine in calves fed soybean protein. 275 10

The activities of the enterocyte brush border enzymes lactase (beta-D galactoside galactohydrolase, EC 3.2.1.23) and sucrase (sucrose alpha-D glucohydrolase, EC 3.2.1.48) were measured at set percentage lengths along the small intestines of 112 piglets killed between 21 and 32 days of age. The influences on these activities of consumption of creep feed and of weaning were recorded. Weaning at three weeks old resulted in large, rapid reductions in lactase activity at most sites along the small intestine; sucrase activity declined temporarily and then recovered. Minimum values were recorded about four to five days after weaning. Similar changes were observed whether or not creep feed was consumed before weaning. Continued consumption of creep feed by unweaned pigs over the 21 to 32 day period also produced small but significant reductions in lactase activities. The large loss of digestive enzyme activities at brush borders in weaned animals coincided with a reduced ability to absorb xylose and to checks in growth rate in otherwise healthy piglets.
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PMID:Influence of creep feeding and weaning on brush border enzyme activities in the piglet small intestine. 308 80

The results of studies on disaccharidase activities and on intestinal absorption in cases of complete and incomplete congenital small bowel obstruction are presented. Assays of the activities of maltase, isomaltase, sucrase, trehalase, and lactase have been performed on biopsy specimens taken at the time of surgery. In specimens taken from above the site of obstruction, the activities are reduced for all disaccharidases, and are particularly low for trehalase and lactase. There was no difference between the cases with complete and incomplete obstruction. Distal to a complete obstruction, trehalase and lactase were reduced, whereas in cases of incomplete obstruction, the activities of all disaccharidases were within what is considered normal in the reference material. Two months after surgery, the disaccharidase activities were found to be normal. One month after surgery, the absorption of glucose and vitamin A was markedly impaired in cases with complete obstruction, whereas that of D-xylose was not significantly reduced from normal. In cases with incomplete obstruction, the results did not differ from those found in normal infants. The fact that failure to thrive is common during the first months after birth in patients with congenital intestinal atresia, even when surgery is successful, may be explained by deficient intestinal absorption, particularly in patients with complete obstruction.
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PMID:Disaccharidase activities and intestinal absorption in infants with congenital intestinal obstruction. 312 31


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