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Query: KEGG:D00046 (lactose)
16,692 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Physiological bases of digestion and absorption of carbohydrates are reviewed, as a preliminary step, in order to draw a general scheme of its patholophysiology. Clasification of different types of carbohydrate malabsorption is presented. Various exploration methods are discussed in terms of autors' own experiences. Relationship between a sugar screening test, faecal lactic acid contents and a simplified lactose tolerance test, is described in detail. Systematic diagnoses of these diseases are established. Different clinical pictures are reviewed. It is not yet well defined if a starch malabsorption can be caused by either a primary or secondary duodenal amylase deficiency. The clinical forms of congenital sucrose-isomaltose intolerance may be more attenuated than its classical form; incertain cases, secondary sucrose intolerance may also be present due to mucosa anatomic lesions. Maltose malabsorption has no clinical implications. As compared to other alpha-glycosidades, the trehalase activity has been not more affected by not using trehalose in feeding. Primary congenital lactase deficiency is not frequent, whereas secondary forms as much more usual and appear, in primary malabsorption syndromes and in the coeliac disease, very often along with clinical tolerance to lactose. In Spain, lactose nonabsorbers in 16.5% for adults 11.2% for adolescents and 18.3% for children, meaning, that it is being favored by environmental factors in the latter. The unspecified sugar malabsorption during the child's first year is still the most frequent cause of carbohydrate intolerance in children and, although certain progress has been achieved in its diagnosis and therapy, its pathogenic mechanism is not satisfactorily known yet.
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PMID:[Malabsorption of carbohydrates in children (author's transl)]. 23 44

We examined 31 formerly hypotrophic newborn children (birth weight < 5th Kyank percentile) with failure to grow in infancy (weight < 3th Prader percentile). The rates of digestion and absorption of carbohydrates were determined by segmental perfusion of the small intestine and compared to the results of 21 patients with florid coeliac disease. Despite the normal structure of the mucous membrane of the small intestine, the rates of absorption of glucose in 14 formerly hypotrophic children and, additionally, in 12 and 10 of these children, respectively, the rates of hydrolysis of lactose and sucrose were nearly as low as in patients with florid coeliac disease. The reduced absorption and digestion of carbohydrates, respectively, could be a cause of subsequent failure to grow in some of the hypotrophic newborn children.
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PMID:[Failure to thrive in young children--disorders of carbohydrate absorption?]. 143 36

The Nutrition Committee of the Austrian Pediatric Society recommends that weaning foods should be introduced between 4 and 6 months of age, which agrees with the recommendations in the EC and the U.S. Opinion against early introduction of solid foods have focused on concerns about renal solute load, obesity, coeliac disease, and food allergy. On the other hand, when weaning was postponed after 6 months of age, growth faltering in some breastfed infants and iron-deficiency anemia in infants fed non-fortified formulas or cow's milk were observed. Two broad categories--"baby foods" and "cereal-based weaning foods"--are on the market in Austria. "Baby foods" include complete meals sold in jars, soups, desserts and puddings, fruit juices, nectars, and vegetable juices. "Cereal-based weaning foods" are composed of one or more cereals either alone, or with the addition of vegetables, fruits, milk and milk products, egg, or other ingredients. Weaning food labelling should include information if sugars, salt, iron, vitamins minerals and trace elements have been added and if the product is free from gluten, cow's milk and egg protein, and lactose.
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PMID:[The Nutrition Committee of the Austrian Society of Pediatrics and Adolescent Medicine. Comment on nutrition with solid foods in infancy and early childhood]. 163 82

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

The determination of hydrogen in exhaled air by gas chromatography was used for investigation of patients with relapsing diarrhea of various genesis. An increased H level on an empty stomach, regarded as a sign of bacterial growth in the intestine, was detected in 45% of examines, mainly in celiac disease immunodeficiency, intestinal tuberculosis, diverticulosis, diabetic enteropathy, and erosive duodenitis. An increase in the H level in exhaled air after a lactose tolerance test (50 g of lactose) made it possible to diagnose lactose deficiency in 38% of patients with chronic relapsing diarrhea. In the irritable colon syndrome lactose deficiency was detected in 40% of patients.
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PMID:[Hydrogen test: its diagnostic possibilities in intestinal diseases]. 229 Mar 43

We have estimated lactose absorption indirectly by the breath H test to see if disaccharide exclusion is necessary for untreated celiac children. Lactose at 2 g/kg body weight (maximum 50 g) was administered to 42 infants and children (ranging in age from 9 months to 12 years) with flat small intestinal mucosa. Later, different amounts of lactose were given to determine the quantities tolerated and absorbed. One hundred percent of patients expired hydrogen more than 20 ppm over the baseline after an oral lactose load of 2 g/kg (maximum 50 g). Thirty-eight percent of them did not tolerate this quantity. Thirty-seven subjects aged 0-6 years absorbed and tolerated 0.5-1.5 g/kg (5-12.5 g total), and five patients aged 6-12 years absorbed and tolerated 0.5-0.6 g/kg (12-16.2 g total). We conclude that in many subjects with untreated celiac disease, lactase activity is sufficient for absorption and tolerance of the amount of lactose present in 250-300 ml cow's milk. Because of lactose's nutritional value, it should not be excluded unless necessary.
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PMID:Extent of lactose absorption in children with active celiac disease. 261 14

Diet therapy is an important factor in overall care of most GI patients. Historically, diets have been used unscientifically in many of these patients without positive results. Nutritional care and diet therapy are critical for two reasons. First, malnutrition is an expected sequelae to most, if not all, GI diseases or disorders. Failure to eat, digest, or assimilate nutrients can provoke malnutrition in just a few weeks, although careful assessment of anthropometric, clinical, biochemical, and nutritional history by a trained professional can protect against this. Diet therapy through the elimination of offending foods such as wheat gluten or lactose, or inclusion of specialized products such as medium chain triglycerides or elemental formulas, can sustain nutritional status. Dietary components such as insoluble fiber appear to have physiologic effects, while soluble fibers may have metabolic effects important to diabetes and cardiovascular disease. There is a high potential for malnutrition in Crohn's disease during active and remittent phases. Elemental enteral formulas or TPN are used during the active phase to ensure optimal nutritional status and bowel rest. Hyperalimentation using the GI tract during remittent stage maintains this. Avoiding offending foods by Crohn's patients is an acceptable practice as long as entire categories of foods are not deleted. Avoiding all foods containing gluten from wheat, rye, barley, and oats, however, is a crucial prerequisite to recovery from celiac disease. Gluten is commonly used as a stabilizer, emulsifier, and extender in the food industry and is not always shown on food labels. Careful consultation with a registered dietitian can identify hidden sources of gluten in the diet.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Dietary therapy in gastrointestinal disease. 264 90

The relationship between lactose hydrolysis and absorption of released glucose was investigated by determining the kinetics of lactose digestion by jejunal biopsies incubated in vitro. Lactase activity in intact biopsies correlated with conventional assay of tissue homogenates (r = 0.85, p less than 0.001), and glucose uptake from 28 mM lactose was directly proportional to lactase activity (r = 0.95, p less than 0.001) in 21 subjects with normal lactase levels, six with hypolactasia (primary or secondary to coeliac disease) and two with lactose intolerance but normal lactase activity. Kinetic analysis at 0.56-56 mM lactose in five normal subjects showed saturable kinetics for hydrolysis (app Km = 33.9 +/- 2.2 mM; app Vmax = 26.5 +/- 1.1 nmol/min/mg dry weight) but glucose uptake could be fitted to a model either of saturable uptake (app Kt = 47.2 +/- 0.3 mM; app Jmax = 14.1 +/- 0.2 nmol/min/mg) or saturable uptake plus a linear component (app Kt = 21.3 +/- 1.15; app Jmax = 4.59 +/- 0.12; app Kd = 0.093 +/- 0.010 nmol/min/mg/mM). The proportion of glucose taken into the tissue did not significantly exceed 50% of the total released at any lactose concentration suggesting the lack of an efficient capture mechanism for the released glucose. The results suggest that lactose hydrolysis is the rate limiting step in the overall absorption of glucose from lactose in vitro, and that the relationship between hydrolysis and absorption is the same in normal subjects and in hypolactasic subjects.
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PMID:Lactose digestion by human jejunal biopsies: the relationship between hydrolysis and absorption. 308 46

Changes in intestinal permeability and lactose hydrolysis have been investigated in three adults and fifteen infants with acute rotaviral gastroenteritis by differential sugar absorption. The method involves chromatographic measurement of urinary lactose, lactulose and L-rhamnose excretion following combined ingestion in an iso-osmolar test solution. All patients had abnormal intestinal permeability indicated by raised urine lactulose/L-rhamnose excretion, ratio of percentages recovered in 5 h, of 0.462 (0.100-1.227) mean and range, compared with 0.027 (0.008-0.052) for healthy controls (P less than 0.001). Ten patients also had urinary lactose/lactulose excretion ratios raised above the normal range (0.014-0.41, mean 0.258) during their acute illness, indicating impaired intestinal lactose hydrolysis. Both indices had become normal 4 weeks after the acute illness, serial investigation of five patients showing that improvement was complete much earlier. Except for the short duration these changes are similar to those associated with villous atrophy in coeliac disease. The test procedure was verified with respect to intestinal lactose hydrolysis by demonstrating a linear relationship between lactose/lactulose excretion and log jejunal mucosal lactase activity by in vitro assay (R2 = 0.95) in a further group of subjects. Differential lactose/lactulose/L-rhamnose absorption provides a non-invasive and sensitive index of small intestinal integrity of value for the interpretation of prolonged or otherwise complicated enteritis and the distinction of primary secondary intestinal lactase deficiency.
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PMID:Intestinal permeability and lactose hydrolysis in human rotaviral gastroenteritis assessed simultaneously by non-invasive differential sugar permeation. 308 18

Fifty-one adult patients with coeliac disease, verified by a proximal small-intestinal biopsy, were investigated. Before treatment with a gluten-free and low-lactose diet 52% showed a slight rise in blood glucose during the lactose tolerance test. Seventy-nine per cent of these patients had watery stools, and 88% had three or more bowel movements a day--statistically significantly different from the coeliac patients with a normal lactose tolerance test. After treatment 12% had a flat lactose tolerance curve. Half of them (6%) had specific lactase deficiency. This is approximately the incidence of lactose malabsorption in the general Danish population. The small-intestinal disaccharidases and alkaline phosphatase levels were severely depressed before treatment. After treatment the activities increased, but not to normal. We conclude that lactose malabsorption is a clinically important condition in many patients with untreated coeliac disease, giving rise to more frequent and more watery stools. In well-treated coeliac disease lactose malabsorption is not commoner than in the general population. The lactose activity in a proximal intestinal biopsy specimen was found to be an unreliable indicator of lactose malabsorption in coeliac disease.
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PMID:Incidence and clinical significance of lactose malabsorption in adult coeliac disease. 313 38


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