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

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 effect of ingesting cellulose, pectin, and psyllium with orally administered lactose in water or milk was tested in six lactose malabsorbers. Breath hydrogen tests were used to evaluate lactose malabsorption and mouth-to-cecum transit times. Addition of psyllium significantly reduced the breath hydrogen response, and symptoms in each subject; whereas, less diminution of expired hydrogen was seen after cellulose or pectin was added. The effect of each fiber on gastric emptying rates of an equal volume liquid meal was evaluated in three volunteers. Pectin had no effect, while the cellulose and psyllium modestly delayed emptying at approximately 30 min.
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PMID:Effect of fiber on breath hydrogen response and symptoms after oral lactose in lactose malabsorbers. 628 6

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

Because of the high prevalence of metabolic bone disease in older persons, we investigated the possibility of impaired intestinal absorptive capacity for vitamin D3 in aging animals. Using a single-pass technique, we measured vitamin D absorption and mucosal accumulation in male rats 9 to 101 weeks of age. Intestinal length, water absorption, and vitamin D3 intestinal tissue concentration remained constant after 41 weeks of age. Vitamin D3 absorption increased from 1209 pmol/100 cm/hr at 9 weeks of age to 2114 pmol/100 cm/hr at 41 weeks of age and remained relatively constant thereafter. Because vitamin D3 absorption rate is partly regulated by the dimensions of the unstirred water layer, we assessed the dimensions of the UWL of our aging animals. As the animals aged, the surface area of the UWL increased from 197 to 316 cm2/100 cm, and its resistance decreased from 1.2 to 0.7 min/cm3/100 cm by 41 weeks of age and remained stable thereafter. Inasmuch as the UWL is a major regulatory step in the absorption of vitamin D, its constant dimensions after 41 weeks of age explain the normal absorption of vitamin D3 observed in our aging animals. If these findings are found to be true in humans as well, they would argue against the possibility of vitamin D3 malabsorption as a cause of metabolic bone disease seen in aging individuals.
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PMID:Influence of aging on vitamin D absorption and unstirred water layer dimensions in the rat. 632 19

Loose stools, one of the most frequent adverse reactions ascribed to the orally absorbed gold compound auranofin (AF), was studied during a longterm trial. At some time during the study 44% of 25 patients reported the occurrence of loose stools. No infection or signs of malabsorption were found; nor were loose stools caused by the presence of osmotically active substances in the gut lumen. Arguments for a direct effect of AF on the ion and water absorption in the intestine are given. Although no morphological studies on biopsy material are available, the known side effects of the drug do not seem to warrant its discontinuation in suitable patients.
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PMID:Loose stools during auranofin treatment: clinical study and some pathogenetic possibilities. 640 56

Malabsorption occurs frequently in chronic alcoholics. Alcoholics may malabsorb fat, nitrogen, sodium, water, thiamine, folic acid, vitamin B12 and D-xylose. Malabsorption is due to an abnormal luminal phase of digestion as well as a diffuse functional mucosal abnormality. Malabsorption may, therefore, contribute to clinically significant malnutrition, diarrhoea, folate-deficiency and to abnormalities in tests of xylose and vitamin B12 absorption. Factors producing malabsorption in alcoholics include dietary folic acid and protein deficiency, pancreatic insufficiency, abnormalities of biliary secretions and direct effects of alcohol on the gastrointestinal tract. Many of the absorptive abnormalities are reversed when alcoholics are given a nutritious diet, even with continued intake of alcohol. This highlights the causal role of nutritional deficiencies in the malabsorption of chronic alcoholics.
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PMID:Alcohol, nutrition and malabsorption. 640 71

Therapy of the malabsorption syndrome centers on adequate diagnosis of the underlying pathology, with vigorous therapeutic efforts directed at correcting this and thereby preventing ongoing losses of nutrients. Dietary therapy includes a high-protein, high-calorie, low-fat diet often supplemented with MCTs in an effort to minimize steatorrhea. Water-soluble vitamin deficiency is rare, but supplementation with small daily doses is innocuous and probably should be prescribed. Significant fat-soluble vitamin deficiencies are seen more commonly and can be monitored by physical examination and the prothrombin time. Calcium, magnesium, and vitamin D deficiencies are more common than originally suspected. Adequate therapy requires monitoring of the serum calcium, magnesium, parathyroid hormone levels, and, optimally, 24-hour urinary collections for calcium. Supplementation of these mineral deficiencies requires ongoing close observation to prevent hypercalcemia. Iron deficiency can be easily diagnosed by available serum iron determination, and replacement with oral supplements is curative. Trace metal deficiencies occur, but our capabilities of detecting and treating them is still in its infancy. Figure 3 outlines our approach to the evaluation and treatment of the patients suspected of having the malabsorption syndrome.
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PMID:Nutritional aspects of malabsorption syndromes. 641 33

A steady-state perfusion technique has been used in vivo in normal subjects to show that at concentrations occurring during therapeutic use (500 mg/1, 1.1 mmol/l) the antibiotic clindamycin reversibly inhibits bicarbonate-stimulated water and electrolyte absorption from the human jejunum. Lactose-stimulated water and electrolyte absorption was not affected by the addition of clindamycin at the same concentration. Clindamycin-induced malabsorption of water and electrolytes may contribute significantly to the diarrhoea that occurs during clindamycin therapy in the absence of pseudomembranous colitis.
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PMID:Inhibition of jejunal water and electrolyte absorption by therapeutic doses of clindamycin in man. 642 96

Patients who had undergone proctocolectomy and ileostomy for ulcerative colitis have been studied. One group (contrast group) had undergone resection of only small amounts of terminal ileum (median = 4 cm), the other group of patients (study group) had undergone resection of greater lengths of small bowel (median = 60 cm). Gastric emptying and transit of a standard meal through the small bowel were estimated, whilst the amounts of fat, nitrogen, glucose, sodium and potassium excreted by the ileostomy were simultaneously determined. Significantly greater amounts of fat, nitrogen, sodium, potassium and water were excreted by patients who had undergone resection compared with contrast patients (P less than 0.01). The rate of gastric emptying was not increased in patients who had undergone ileal resection compared with contrast patients but small bowel transit within 4 hours of ingestion of the meal was significantly faster. A significant correlation between transit times and excretion of fat was also noted in patients (P less than 0.02). Thus, quite modest ileal resection in addition to proctocolectomy leads to rapid small bowel transit and marked malabsorption of nutrients as well as water and electrolytes.
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PMID:The effect of resection of the distal ileum on gastric emptying, small bowel transit and absorption after proctocolectomy. 647 55

The pathogenesis of diarrhea caused by rotavirus infection was studied in miniature swine piglets. The animals were inoculated orally with 2 X 10(7) plaque-forming units of porcine rotavirus (OSU strain). During the height of diarrhea, intestinal function was investigated by in vivo perfusion of a 30-cm segment of proximal jejunum and a 30-cm segment of distal ileum. Absorption of Na+ and water decreased and 3-O-methylglucose transport was markedly reduced, P less than 0.01 compared to control animals. Mucosal lactase and sucrase levels were depressed in both the jejunum and ileum, P less than 0.001. Na+,K+-ATPase activity was significantly depressed only in the ileum, P less than 0.001. These changes were associated with a marked reduction in villous height, suggesting that the diarrhea could be an osmotic diarrhea due to nutrient (carbohydrate) malabsorption. Fresh stool samples were obtained and analyzed immediately for NA+,K+, osmolarity, glucose, and lactose; the osmotic gap was also determined. Stool osmolarity continually increased from 248 +/- 20 mosm/liter prior to inoculation to 348 +/- 20 mosm/liter at 75 +/- 1 hr postinoculation (P less than 0.005); the majority of the fecal osmotic gap could be accounted for by the amount of lactose present in the stools. Stool sodium increased from 34 +/- 6 mM prior to inoculation to a maximum of 65 +/- 4 mM at 53 +/- 1 hr postinoculation, P less than 0.001. There was no significant change in potassium concentration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pathogenesis of rotavirus-induced diarrhea. Preliminary studies in miniature swine piglet. 648 82


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