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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acute truncal vagotomy causes increased net secretion of water, sodium and potassium from the proximal portion of the jejunum. This is presumed to occur because of the sudden loss of vagal cholinergic tone. Glucose absorption from the proximal part of the jejunum was not affected by acute vagotomy despite the large changes in net water and electrolyte fluxes. Adaptation after vagotomy and pyloroplasty was associated with a significant increase in jejunal absorptive capacity for glucose, water, sodium and potassium. These findings contribute another dimension to the understanding of the rapid rises in postprandial blood sugar observed in patients after vagotomy to help explain the abnormal glucose tolerance in the presence of glucose malabsorption. The increased jejunal absorptive capacity observed in the chronic vagotomy group is believed to occur in compensation for malabsorption resulting from rapid intestinal transit.
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PMID:Acute and chronic effects of truncal vagotomy upon glucose absorption, water and electrolyte fluxes in the small intestine of the rabbit. 401 42

We review here the case histories and results of in vivo and in vitro tests for eight children with congenital selective glucose and galactose malabsorption (GGM) whom our laboratory has followed up since 1971. Clinically, GGM was manifested by intractable, acidic, sugar-containing diarrhea that started during the neonatal period. Diarrhea only abated when glucose and galactose were removed from the diet. The disease was notable for the absence of other symptoms, although mellituria was a common finding. Defective sugar transport was permanent, but sugar tolerance appeared to increase with age. In vitro, intracellular mucosal glucose concentration (C) was significantly below control level in GGM intestinal tissue for concentrations (M) of 10 and 0.1 mM glucose in the medium. C/M for galactose also decreased, while the C/M ratios for alanine and xylose were within the control range. Glucose influxes across the luminal membrane, net glucose transepithelial fluxes, and electrical parameters were all consistent with defective sodium and glucose cotransport at the brush border membrane of jejunal epithelial cells. However, the present results are also consistent with a small residual active transport system observed only at low glucose concentration in the medium. Further observations are needed to establish the role of glucose transport systems in absorption of other monosaccharides, the relationship between kidney and intestinal sodium-glucose cotransport systems, and their genetic control.
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PMID:Congenital selective malabsorption of glucose and galactose. 406 75

A double-lumen perfusion technique has been used to study amino acid and peptide absorption in eight normal control subjects, 13 patients with untreated adult coeliac disease, and 16 patients with dermatitis herpetiformis who had varying morphological abnormalities of the small bowel. All subjects were perfused with isotonic solutions containing 10 mM glycyl-L-alanine and 10 mM glycine + 10 mM L-alanine. Patients with adult coeliac disease had impaired absorption of glycine (p < 0.01) and L-alanine (p < 0.05) from the amino acid solution compared with the control subjects. Amino acid uptake from the dipeptide solution was not significantly impaired, although four individual patients had impaired uptake of both amino acids. In contrast to these findings, very few patients with dermatitis herpetiformis had impaired amino acid absorption from either solution. Sodium absorption was impaired from both solutions when the groups of patients with adult coeliac disease and dermatitis herpetiformis with subtotal villous atrophy and partial villous atrophy were studied, and there were patients in each group who secreted sodium and water. The results suggest that malabsorption of dietary protein is unlikely to occur in dermatitis herpetiformis but may occur and contribute to protein deficiency seen in some severe cases of adult coeliac disease. The impairment of sodium and water absorption provides evidence that there may be functional impairment of the jejunal mucosa in dermatitis herpetiformis as well as in adult coeliac disease.
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PMID:Amino acid and peptide absorption in patients with coeliac disease and dermatitis herpetiformis. 482 Jun 29

A procedure is described for the determination of the separate amounts of two gamma-emitting radioisotopes present simultaneously in large liquid volumes using an annular cell placed over a standard well-type crystal of sodium iodide and a reference source of (137)Cs. This sensitive technique is illustrated with particular reference to the double radioisotope urinary excretion test, using orally administered (57)CoB(12) bound to human gastric juice and (58)CoB(12) simultaneously, for the differentiation between patients with intrinsic factor deficiency and other causes of vitamin B(12) malabsorption.
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PMID:Standardized annular assay of dual radioisotopes on a well type sodium iodide crystal. 543 Apr 23

Severe osteomalacia of uncertain etiology was observed in a 44-year-old woman. There was no evidence of chronic renal insufficiency, malabsorption, or of the renal tubular defects classically associated with osteomalacia. However, the dietary history suggested vitamin D deficiency and most of the biochemical findings were compatible with this condition. The unusual feature of the case was a decrease in plasma bicarbonate levels which appeared to be due to a lowered renal tubular threshold for bicarbonate reabsorption. There was no renal tubular defect with respect to hydrogen ion excretion.Rapid symptomatic and radiologic improvement occurred when the dietary intake of vitamin D was increased to approximately 200 I.U. per day and the acidosis was simultaneously corrected with sodium bicarbonate. Although no firm conclusions could be drawn about the relative importance of vitamin D deficiency or chronic acidosis in the production of the osteomalacia, the possibility that the chronic acidosis may have been a major contributing factor is discussed.
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PMID:Osteomalacia associated with renal bicarbonate loss. 594 Jun 37

Small-intestinal function was studied in 10 patients with visceral leishmaniasis. Vitamin-A absorption was impaired in 7 and d-xylose in 1. In 5 of the 10 patients Leishmania were demonstrated in biopsy specimens of intestinal mucosa. Parasitised macrophages were present in villous tips and less commonly in the lamina propria and submucosa; a moderate inflammatory infiltrate was composed of lymphocytes and plasma cells. 2 patients had partial villous atrophy. There was no correlation between intensity of parasitisation and severity of malabsorption. After treatment with sodium stibogluconate there was a significant improvement in absorption of vitamin A and d-xylose, and biopsy specimens became normal. In 1 patient visceral leishmaniasis was thought to be the cause of chronic diarrhoea.
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PMID:Jejunal function and pathology in visceral Leishmaniasis. 613 44

Jaundice phototherapy is associated with a significant incidence of watery diarrhea. We have postulated that acute intestinal secretion, rather than malabsorption of dietary carbohydrate, is an effect of a photoproduct of bilirubin upon the intestinal mucosa. Because of major effect of phototherapy is the hepatic excretion of nonconjugated bilirubin, we investigated the effect of bilirubin on small intestinal function in the hamster in vivo. The entire small intestine was luminally perfused in vivo with solutions containing bilirubin (0.125 to 0.75 mmole/liter) and net water and sodium fluxes were measured. Control animals absorbed both water (J H2O(net) = 58.9 microliter/min/g) and sodium (J Na(net) = 4.55 microEq/min/g), but animals perfused with bilirubin (greater than or equal to 0.25 mmole/liter) exhibited secretion of water (J H2O(net) = -39.0--85.9) and sodium (J Na(net)=-9.91--18.24). The rate of water secretion was positively related to the concentration of bilirubin in the infusate (r=0.749; p less than 0.001). The concentration of bilirubin in ultrafiltrates of perfusate was likewise positively related to its concentration in the infusate (r = 0.844; p less than 0.001), indicating the potential importance of soluble forms of bilirubin in inducing secretion. Possible epithelial injury was studied by measuring the concentration of DNA in the perfusate and the activity of disaccharidases in postperfusion mucosa, and the possible role of cyclic adenosine monophosphate as a mediator of the secretory process was investigated by determining its concentration in postperfusion mucosa. Perfusion with 0.5 mM bilirubin, which produced significant secretion, did not cause loss of DNA (0.284 versus 0.244 mg/liter) or mucosal lactase activity (56 versus 53 units/g) or enhancement of cyclic adenosine monophosphate concentration (14.9 versus 14.12 pmoles/mg protein).
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PMID:The effect of bilirubin on the function of hamster small intestine. 626 58

The traditional radioimmunoassay for gastric intrinsic factor, in which this protein is measured on the basis of immunoreactivity rather than function, is of no value for identifying intrinsic factor that binds cobalamin but does not bind to the ileal receptor site, or for detecting animal intrinsic factor, which does not cross react with human intrinsic factor. Accordingly, we have applied a radioassay for the intrinsic factor receptor protein to measure the functional activity of intrinsic factor in gastric juice. The receptor protein reagent was partly purified from guniea pig ilea and its interaction with intrinsic factor--CN[57Co]-cobalamin was determined by precipitation with sodium sulfate at a final concentration of 150 g/L. Results of this assay were comparable with results obtained for intrinsic factor by radioimmunoassay. The receptor protein did not bind immunoreactive intrinsic factor that was functionally abnormal. This functional radioassay for intrinsic factor is not species specific and will be of value when specific antiserum to intrinsic factor is not available and when cobalamin malabsorption is to be evaluated in patients who are secreting normal amounts of immunoreactive intrinsic factor.
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PMID:Functional activity of intrinsic factor measured by using solubilized receptor protein. 628 8

Net electrolyte and water transport and unidirectional Na+ fluxes were examined in ligated colonic loops of clinically normal pigs and in pigs with swine dysentery (etiologic agent Treponema hyodysenteriae) in the presence or absence of theophylline. In normal pigs, theophylline abolished net Na+ absorption via a reduction in the lumen-to-blood flux, decreased Cl- absorption, and increased HCO3- accumulation in the lumen. In infected pigs, all net ion transport was abolished, with the addition of theophylline producing little effect. The absence of net Na+ absorption in infected pigs was also the result of a decreased lumen-to-blood flux. Seemingly, colonic malabsorption may be the primary transport alteration in swine dysentery. Concentrations of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were measured in samples of colonic mucosa from normal and infected pigs after in vitro exposure to a Ringer's solution containing 0 or 20 mM theophylline. Basal values of cAMP or cGMP did not increase in infected colonic mucosa. There was a diminished capacity of the infected mucosa to respond to theophylline. Alterations in ion transport in conjunction with measurements of cAMP and cGMP indicated that the pathogenic mechanism(s) in swine dysentery were not similar to those of Salmonella, Shigella, Vibrio cholerae, or Escherichia coli diarrhea.
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PMID:Pathophysiologic features of swine dysentery: cyclic nucleotide-independent production of diarrhea. 630 41

The literature on oral sugar-electrolyte mixtures for treatment of acute diarrhoea is reviewed. Several trials have shown that the solution proposed by the WHO for developing countries containing inter alia 90 mmol/l of sodium and 111 mmol/l of glucose is safe for short term oral rehydration. When used in this manner there is no risk for development of hypernatraemia. The surplus base of the solution is not essential and, furthermore, other anions e.g. acetate may be substitute for bicarbonate. Other modifications of the WHO formula have also been successfully tried, e.g. sucrose 4% (117 mmol/l) instead of glucose 2% (111 mmol/l). A somewhat lower concentration of sucrose may, however, prove to be better. Most acute childhood diarrhoeas are not mediated by enterotoxin and thus not of the secretory type, but temporary malabsorption is common. Therefore, the amount of carbohydrate in oral sugar-electrolyte mixtures should be limited. Osmotic diarrhoea due to carbohydrate malabsorption is a more likely cause of hypernatraemia in dehydrated children than too much dietary sodium. In developed countries prepacked oral sugar-electrolyte mixtures are mainly designed for moderately sick children treated at home. There is no reason to raise the carbohydrate content of these mixtures above that of the WHO formula, but the sodium content must be lower. For most situations in home treatment 50 mmol/l of sodium will be adequate.
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PMID:High sugar worse than high sodium in oral rehydration solutions. 634 Apr 10


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