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)

The biliary and pancreatic secretions have been determined in patients given pelvic or para-aortic irradiation, with a dose of 50 Gy in the former group and between 36 and 40 Gy in the latter. A test meal containing polyethylene glycol (PEG) as reference substance was used. Each sample of the duodenal content was assayed for volume, PEG content, amylase and trypsin activity, pH and biliary secretion. No significant modifications of biliary and pancreatic secretions were demonstrated after irradiation, suggesting that these functions are not involved in the pathogenesis of the malabsorption radiation syndrome.
 ...
PMID:Biliary and pancreatic secretions in abdominal irradiation. 4 Mar 99

Intestinal perfusion studies performed in man have suggested that amino acid nitrogen may be absorbed more rapidly from peptides than free amino acids. The aim of the present study was to compare the effects of the oral administration of peptides and free amino acids. Two isonitrogenous liquid test meals, one containing 50 g of a partial enzymic hydrolysate of fish protein in which approximately 80% of the nitrogen content was present as small peptides (peptide meal), and the other a mixture of free amino acids (amino acid meal) the composition and molar pattern of which simulated that of the peptide meal, were administered on separate occasions to six normal subjects intubated with a triple lumen tube. Both meals contained the reference marker polyethylene glycol. Fractional absorption of amino acid residues one and two hours after ingestion of the two meals was similar at three intestinal locations situated 120, 160, and 200 cm from the mouth of each subject, and at two hours 73.8% and 72.0% of the amino acid residues had been absorbed respectively by the time the contents of the peptide and amino acid meals reached the middle sampling port of the tube. The total sum of individual amino acid increments in plasma was significantly greater 30 minutes (p < 0.025) and one hour (p < 0.05) after ingestion of the peptide than amino acid meals. By three hours the total area under the two plasma curves was similar. Normal human subjects thus appeared to be capable of assimilating orally administered mixtures of peptides and free amino acids with equal efficiency. Secretion of fluid into the lumen of the upper small intestine, assessed by reference to dilution of the polyethylene glycol, was less after ingestion of the peptide meal. In clinical situations characterised by fluid and electrolyte malabsorption consideration might be given to using small peptides rather than free amino acids as the nitrogen source in nutritional diets.
 ...
PMID:Comparison of oral feeding of peptide and amino acid meals to normal human subjects. 44 9

Thirty-seven patients undergoing routine investigation for malabsorption were given radio-opaque pellets (ROP) which were compared with polyethylene glycol and chromic oxide as continuous faecal markers. Percentage recovery of all markers showed a wide range. The recovery of all markers was very similar, and radio-opaque pellet-corrected daily faecal fat correlated very closely with PEG-and chromic oxide-corrected fat results. Estimation of ROP is precise, simple, and minimises faecal handling. ROP are suitable for routine use in faecal fat studies and have advantages over markers used at present.
 ...
PMID:Radio-opaque pellets as faecal markers for faecal fat estimation in malabsorption. 48 54

Bile acid studies were performed in patients with Crohn's disease, radiologically confined to the colon. The bile acid pool size of 10 patients with isolated Crohn's colitis was significantly lower than that of 10 normal control subjects (P less than 0.001) and of 10 ulcerative colitis patients (P less than 0.005). Measurements of 14C-excretion in breath and in 24 hours stool collections after the administration of 5 muCi 14C-glycocholate showed a normal 14C-excretion in breath and usually a markedly increased loss of 14C in the stool (greater than 7% of the dose). The simultaneous administration of 5 muCi 3H-polyethylene glycol MW 4000 (3H-PEG) as a marker indicated that the 14C/3H ratio in the patients with Crohn's colitis was significantly greater than in a control series of patients with diarrhoea not due to bile acid malabsorption. Studies on the composition of duodenal bile showed a significantly decreased concentration of deoxycholic acid in duodenal bile. These observations suggest bile acid malabsorption in patients with Crohn's disease apparently confined to the colon.
 ...
PMID:Bile acid studies in patients with Crohn's colitis. 52 81

The influence of malabsorption of lactose, as a result of primary lactase deficiency, on the absorption of the nutrients in milk was tested in four healthy controls and four subjects with lactase deficiency. An ileal perfusion technique was used to quantify arrival in the ileum of nutrients and a nonabsorbable marker (polyethylene glycol, PEG 4000) ingested as a test meal of milk. The meal was 250 ml of whole milk or milk in which the lactose had been hydrolyzed to glucose and galactose. In the fasting state, ileal flow of volume, protein, carbohydrate, and electrolytes was small and not different in controls and lactase-deficient subjects. Ileal flow increased in all subjects after the test meal of milk; more fluid and nutrient was recovered from the ileum in lactase-deficient subjects after whole milk than in control subjects or in lactase deficiency after hydrolyzed milk. Two deficient subjects showed marked malabsorption of lactose (35 and 50%); two did not. Protein, calcium, magnesium, and phosphorus were also recovered from the ileum in greater quantities in lactase deficients after whole milk. However, apart from decreased absorption of lactose, the nutritional consequences of malabsorption in association with primary lactase deficiency in adults are probably minimal.
 ...
PMID:Absorption of nutrients in lactase deficiency. 58 2

Fecal excretion of labeled bile acid (14C-24-cholic acid) was distinctly increased in two infants with protracted diarrhea, whereas four patients with steatorrhea due to pancreatic or mucosal abnormalities and five patients with mild chronic diarrhea had no excess fecal loss of bile acid. The loss of 14C-24-cholic acid in our patients with intractable diarrhea was similar to that observed in four infants who had undergone ileal resection. The ratio of mean 24-hour excretion of bile acid to that of a non-absorbable marker, polyethylene glycol, confirmed the malabsorption of bile acid in the patients with intractable diarrhea or ileal resection. These results differ significantly (p less than 0.05) from excretion ratios obtained in patients with either steatorrhea or chronic diarrhea. The extent of the loss of bile acid was not significantly related to the rate of fecal fat excretion. There was no direct correlation of fecal weight with the rate of bile acid excretion. Ileal function, as further assessed by the Schilling test with exogenous intrinsic factor, was grossly abnormal in both of the patients with intractable diarrhea.
 ...
PMID:Bile acid malabsorption--a consequence of terminal ileal dysfunction in protracted diarrhea of infancy. 83 Aug 89

The quantity of lactose not absorbed by 4 normal and 6 lactase-deficient subjects was determined by three indirect methods which involved: (1) measurement of pulmonary hydrogen (H2) excretion, (2) pulmonary (14)CO2 excretion, and (3) stool (14)C excretion, after ingestion of 12.5 g of 1-(14)C-lactose and 4 g of polyethylene glycol (PEG). Results were compared with absorption determined directly from the (14)C:PEG ratio of multiple terminal ileal aspirates. The fraction of lactose not absorbed determined by ileal aspiration ranged from 0 to 8% in normals and 42 to 75% in mild-intolerant subjects. Whereas all three indirect methods were useful in qualitatively separating normal from deficient subjects, the quantity of lactose absorbed as determined by H2 excretion correlated most closely with ileal measurements (r = 0.94). Pulmonary (14)CO2 excretion for 24 hr after (14)C-lactose ingestion did not distinguish normal (17 +/- 4% (SEM) of ingested (14)C per 24 hr) from lactase-deficient subjects (21.1 +/- 3%). Likewise, stool (14)C:PEG ratios grossly underestimated malabsorption with less than one-quarter of the nonabsorbed (14)C appearing in the stool. This study suggests that individual differences in susceptibility to diarrhea after milk ingestion by lactase-deficient subjects may be due to differences in the quantity of lactose not absorbed and/or differences in the rate of bacterial metabolism of lactose in the colon. Analysis of ileal fluid collected during passage of the lactose meal indicated that about two-thirds of the osmotic load delivered to the colon consists of endogenous electrolytes. Thus the water load delivered to the colon is about 3 times that calculated to be osmotically held by the nonabsorbed sugar.
 ...
PMID:Quantitative measurement of lactose absorption. 126 65

The efficacy of cholylsarcosine, a synthetic deconjugation-resistant and nonsecretory conjugated bile acid analog for the treatment of fat malabsorption caused by severe bile acid malabsorption, was assessed in an animal model. In two dogs, the ileum and ileocecal valve were resected, causing severe diarrhea, steatorrhea, bile acid malabsorption, and progressive weight loss. Cholylsarcosine was administered as the water-soluble sodium salt by mixing with the dog food. Various doses were explored as well as varying intakes of dog food. Fat absorption was assessed by gravimetric measurement of fecal fat; a nonabsorbable recovery marker (polyethylene glycol mol wt 4000) was used to correct for incomplete fecal collections. Cholylsarcosine caused a 5- to 30-fold increase in fat absorption but had no significant effect on weight loss or fecal weight. Duodenal content was collected during digestion of a meal via a surgically placed Thomas cannula; the aspirates were dilute, acidic, and had a low bile acid concentration. The bile acid concentration increased modestly when cholylsarcosine was administered, but remained below the critical micellization concentration. The results indicate that oral administration of cholylsarcosine improved dietary fat absorption in a canine model of severe bile acid malabsorption with associated steatorrhea and bile acid deficiency in the proximal small intestine. Studies with this compound in patients with nutritional problems because of steatorrhea and severe bile acid malabsorption appear warranted.
 ...
PMID:Effect of replacement therapy with cholylsarcosine on fat malabsorption associated with severe bile acid malabsorption. Studies in dogs with ileal resection. 1050 37

Rickets and osteopenia, common problems in chronic childhood cholestasis, have been attributed to vitamin D malabsorption leading to reduced serum levels of 25(OH)-vitamin D. d-alpha-Tocopheryl polyethylene glycol-1000 succinate (TPGS), a water-soluble form of vitamin E, forms micelles at low concentration. We evaluated the potential role of TPGS in enhancing vitamin D absorption in eight children (aged 5 mo to 19 y) with severe chronic cholestasis (three extrahepatic biliary atresia, three nonsyndromic intrahepatic cholestasis, and two Alagille syndrome). To evaluate vitamin D absorption, the subjects received vitamin D3 1000 IU/kg (maximum dose of 50,000 IU); they then received the same dose of vitamin D3 mixed with TPGS (25 IU/kg). Serial serum vitamin D3 levels and areas under the curve were measured. All patients had enhanced absorption of vitamin D when it was administered in a mixture with TPGS. Mean area under the curve for serum vitamin D3 was 403.0 +/- 83.1 nmol x h/L (155.6 +/- 32.1 ng x h/mL), with a mean rise above baseline of 13.5 +/- 1.8 nmol/L (5.2 +/- 0.7 ng/mL) with vitamin D/TPGS compared with no rise when vitamin D was given alone (both p less than 0.001). Seven patients have been followed for at least 3 mo while receiving the vitamin D/TPGS combination. Those with initially low serum 25(OH)-vitamin D levels (less than 37.5 nmol/L or 15 ng/mL) had normalization (range 37.5-146 nmol/L) within 1 mo, whereas those with initially normal levels remained normal. While the patients were receiving vitamin D/TPGS, serum vitamin E to total lipid ratio either normalized or remained normal.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:d-Alpha-tocopheryl polyethylene glycol-1000 succinate enhances the absorption of vitamin D in chronic cholestatic liver disease of infancy and childhood. 154 43

Although the osmotic gap of fecal fluid is often used to distinguish osmotic diarrhea from secretory diarrhea, there has never been a scientific evaluation of the validity of this concept. Similarly, although a low fecal fluid pH value is used to indicate that diarrhea is mediated by carbohydrate malabsorption, the validity of this method is unproven. Therefore, in the present study, diarrhea was induced in normal subjects by different mechanisms and fecal fluid osmotic gap (using an assumed fecal fluid osmolality of 290 mOsm/kg) and pH were measured. In secretory diarrhea caused by phenolphthalein, the osmotic gap was always less than 50 mOsm/kg, whereas in osmotic diarrhea caused by polyethylene glycol, magnesium hydroxide, lactulose, and sorbitol, the osmotic gap always exceeded 50 mOsm/kg. In osmotic diarrhea caused by sodium sulfate, the fecal fluid osmotic gap was less than 50 mOsm/kg, but phenolphthalein-induced secretory diarrhea could be distinguished from sodium sulfate-induced osmotic diarrhea by the fecal chloride concentration. When diarrhea was caused by carbohydrate malabsorption (lactulose or sorbitol), the fecal fluid pH was always less than 5.6 and usually less than 5.3; by contrast, other causes of diarrhea rarely caused a fecal pH as low as 5.6 and never caused a pH less than 5.3. It is concluded that measurement of fecal fluid osmotic gap and pH can distinguish various mechanisms of experimental diarrhea in normal subjects. The concepts on which these tests are based are therefore verified experimentally.
 ...
PMID:Fecal osmotic gap and pH in experimental diarrhea of various causes. 163 87


1 2 3 Next >>