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

Mongolian gerbils were infected with a human pathogenic Giardia lamblia strain and compared with sham-treated control animals 6 days after inoculation. Infection resulted in crypt hyperplasia associated with an increased enterocyte migration rate. Villus height was decreased in the duodenum, unchanged in the jejunum, and increased in the ileum of infected animals. Epithelial microvilli were markedly shortened, and brush border surface area decreased in the jejunum and ileum of infected animals. Thymidine kinase activity was increased in isolated duodenal villus enterocytes but did not differ in the jejunum and ileum. In vitro and in vivo experiments showed that the infection resulted in decreased jejunal glucose-stimulated electrolyte, water, and 3-O-methyl-D-glucose absorption, whereas in the ileum in vitro electrolyte and 3-O-methyl-D-glucose absorption was similar in infected and control animals. Thus, in the jejunum infection causes electrolyte, solute, and fluid malabsorption associated with decreased brush border surface area. The results indicate that the diarrhea associated with giardiasis is caused by malabsorption rather than active secretion.
 ...
PMID:Pathophysiology of small intestinal malabsorption in gerbils infected with Giardia lamblia. 851 55

Short-chain (C2-C6) fatty acids (SCFA) are the major anions in colonic contents and the result of anaerobic fermentation of mainly saccharides. The effects and regulation of saccharide fermentation were studied in vitro and in vivo. In vitro faecal incubation was used to study the effects of lactose, glucose, and galactose and of pH on SCFA formation. Changing the pH to below 5 or above 11 abolished SCFA formation in the faecal incubates; in the pH 5-9 interval SCFA production was high, with only minor pH dependence. Adding glucose, galactose, or lactose to the incubation system increased SCFA production, but at high saccharide concentrations (100-300 mmol/l) SCFA formation was inhibited by the pH change. In vivo disaccharide malabsorption with increasing doses of lactulose caused a decrease in faecal pH to less than 5, values inhibitory to fermentation, before the appearance of carbohydrate in faeces. In 6 of 12 volunteers diarrhoea occurred suddenly and was caused by malabsorbed non-fermented carbohydrate. The six other volunteers had a gradual increase in faecal output with lactulose dose and developed diarrhoea before the appearance of saccharide in faeces. The intake of lactulose tolerated before diarrhoea ensued varied between individuals, with the majority having diarrhoea of more than 11/day at 160 g lactulose per day. At this dose SCFA absorption was estimated to be in the range 550 to 1150 mmol/day.
 ...
PMID:The colon in carbohydrate malabsorption: short-chain fatty acids, pH, and osmotic diarrhoea. 164 81

In order to collect data on (1) the prevalence of lactose malabsorption and (2) the value of indirect diagnostic methods for hypolactasia in diabetics, we compared lactose tolerance tests using serum glucose, serum galactose (after oral ethanol intake) and breath hydrogen excretion as diagnostic cutoff in 144 nondiabetic and 46 diabetic subjects. A good rate of concordance was found for the hydrogen breath test and galactose-dependent lactose tolerance test. The glucose-dependent lactose tolerance test was found to be of satisfactory diagnostic value in nondiabetic subjects and was useless for diagnostic purposes in diabetics. Lactose malabsorption was no more frequent in diabetics than in controls and lactose intolerance was found to be less frequent in the diabetic group. A distinction between hypolactasia and other gastrointestinal disorders in diabetics is possible by ambulatory indirect tests.
 ...
PMID:Concordance of indirect methods for the detection of lactose malabsorption in diabetic and nondiabetic subjects. 186 74

Microvillus inclusion disease is an inherited intestinal brush border membrane defect that causes severe fluid and electrolyte malabsorption. In an infant with microvillus inclusion disease (confirmed by electron microscopic evaluation of rectal, jejunal, and gallbladder mucosae), basal stool output was massive (greater than 125 mL . kg-1 . day-1) and was not altered by treatment with clonidine or octreotide. A proximal jejunostomy with mucous fistula was placed, allowing separation of proximal from distal tract outputs (60 mL . kg-1 . day-1 and 100 mL . kg-1 . day-1, respectively). A 10-cm jejunal segment was excised during surgery and mounted in Ussing chambers for determination of transepithelial Na+ and Cl fluxes. Compared with intestine of normal infants, this infant's epithelium showed transmural conductance and unidirectional ion fluxes that were only 30% of normal. With respect to both Na+ and Cl, the excised jejunum was in a net secretory state. Theophylline (5 mmol/L) increased net Cl secretion slightly. In response to mucosal D-glucose (30 mmol/L), jejunal mucosal-to-serosal Na+ flux doubled. In the infant, glucose-electrolyte solution administered intrajejunally did not significantly change stool output, suggesting that all of the solution (40 mL/kg) was absorbed. Subtotal enterocolectomy, in theory, could have decreased purging by 66% in this infant with microvillus inclusion disease, but diarrhea would still have been significant.
 ...
PMID:Microvillus inclusion disease. In vitro jejunal electrolyte transport. 165 50

Glucose/galactose malabsorption (GGM) is an autosomal recessive disease manifesting within the first weeks of life and characterized by a selective failure to absorb dietary glucose and galactose from the intestine. The consequent severe diarrhoea and dehydration are usually fatal unless these sugars are eliminated from the diet. Intestinal biopsies of GGM patients have revealed a specific defect in Na(+)-dependent absorption of glucose in the brush border. Normal glucose absorption is mediated by the Na+/glucose cotransporter in the brush border membrane of the intestinal epithelium. Cellular influx is driven by the transmembrane Na+ electrochemical potential gradient; thereafter the sugar moves to the blood across the basolateral membrane via the facilitated glucose carrier. We have previously cloned and sequenced a Na+/glucose cotransporter from normal human ileum and shown that this gene, SGLT1, resides on the distal q arm of chromosome 22. We have now amplified SGLT1 complementary DNA and genomic DNA from members of a family affected with GGM by the polymerase chain reaction. Sequence analysis of the amplified products has revealed a single missense mutation in SGLT1 which cosegregates with the GGM phenotype and results in a complete loss of Na(+)-dependent glucose transport in Xenopus oocytes injected with this complementary RNA.
 ...
PMID:Glucose/galactose malabsorption caused by a defect in the Na+/glucose cotransporter. 200 13

The objective of this study was to investigate the mechanisms involved in intestinal absorption of fructose. The results indicate that adult rats readily absorbed 0.4 g of fructose, an amount equivalent to 1.4-1.6 g fructose/kg body wt. Acute malabsorption of fructose occurred with doses greater than 0.6 g (2.1-2.4 g/kg body wt). Continued exposure to dietary fructose resulted in a decrease in the evidence of colonic fermentation. Glucose or galactose administered with fructose enhanced the absorption of fructose. The greatest absorption was observed when equal amounts of fructose and glucose were given simultaneously. If glucose was ingested as a polymer (starch or dextrin), the stimulatory effect was dependent on the digestibility of the polymer. Sucrose given with the fructose and glucose diminished the absorption of fructose. Acarbazone, a specific inhibitor of alpha-glucosidases, including sucrase, also inhibited the facilitating effect of glucose and galactose in absorption of fructose. These results give evidence for joint absorption of the two monosaccharides, fructose and glucose.
 ...
PMID:Intestinal absorption of fructose in the rat. 206 11

Home parenteral nutrition has prevented malnutrition in patients who cannot maintain adequate nutrition by enteral feedings alone. The risk of bone and mineral abnormalities in these patients is significant for several reasons. Pre-existing skeletal disease can occur from factors known to affect the population at large as well as from malnutrition, malabsorption, and corticosteroid use related to the underlying disease process. Long-term use of infused nutrients and potential toxins can further alter bone turnover. Hypercalciuria is frequently present during HPN, yet its etiology is poorly defined. Parenteral nutrition admixture concentrations of calcium, phosphorus, protein, sodium, and dextrose may all play a role. Any development of acidosis can certainly aggravate hypercalciuria, which may be an indirect marker of abnormal bone turnover. Although increased protein intake can promote the development of acidosis-induced calciuresis, infused phosphorus and acetate can help reduce calcium excretion. Parenteral nutrition contamination by aluminum can cause a spectrum of osteomalacic bone disease similar to aluminum-associated changes seen in renal failure patients. Even with recent attempts to remove aluminum from the parenteral admixture, low-turnover bone disease can still occur. At present, HPN-related bone disease is a poorly understood entity because of its multifaceted nature. Patients receiving long-term parenteral nutrition should be considered to have an increased risk for the development of metabolic bone disease. Early monitoring for and treatment of bone disease should be considered in all patients receiving HPN.
 ...
PMID:Long-term parenteral nutrition and metabolic bone disease. 211 69

D-glucose absorption in vivo in mice decreased as a function of dose and time after irradiation returning to normal within a week after irradiation. The lamina propria is seen full of polymorphonuclear leukocytes, other infiltrative cells, capillary and lymphatic network, which seem closely related to chronic enteritis. Since acute and chronic diarrhea after irradiation can be reduced by cholestyramine or acetylsalicylate, malabsorption of bile salts or prostaglandin E of the luminal content has been regarded as a cause of radiation-induced diarrhea. LD 50 of irradiated mice was increased by SOD. From the clinical data, thin physique, previous operation, and total dose of more than 50 Gy could be predisposing factors of radiation-related enteritis.
 ...
PMID:[Radiation enteritis: mucosal regeneration and stromal reaction of the small intestine after irradiation]. 225 Mar 50

Intestinal malabsorption of nutrients may be a critical factor in aging. For this reason, we investigated the nutrient absorption in mice of different ages of the life span, representing growth (3 mo), young adult (12 mo), mature (24 mo), old (30 mo), and very old (33-36 mo) periods. The everted sac technique was used to study the transepithelial transport of D-glucose, 3-O-methyl-D-glucose (3MG), and L-tyrosine. There was a 32% increase in the rate of D-glucose transepithelial transport during growth followed by a 55% decrease in the old mouse, and the same pattern occurred with 3MG, a nonmetabolized glucose derivative. However, L-tyrosine transepithelial transport was not impaired until the mouse reached the very old, 33-36 mo period. Also, the rate of D-glucose metabolism measured by lactate production in the very old mouse was only 45% of the mature mouse value. In addition, these transepithelial transport changes were accompanied by decreases in the number and the height of villi. The results indicate that intestinal transepithelial transport and the surface area for absorption decrease in aging.
 ...
PMID:Intestinal transport during the life span of the mouse. 236 62

Glucose-galactose intolerance is a rare form of monosaccharide malabsorption. We report a Chinese family with 2 affected male children. They presented with watery diarrhoea since birth and the diarrhoea improved only after the offending carbohydrates were withdrawn from the diet.
 ...
PMID:Glucose-galactose malabsorption--a report in a Chinese family. 263 17


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>