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

In recent years it has become possible by means of a radioimmunoassay to measure Digoxin concentration in the serum of digitalized patients. With this method it could be shown that the resorption of Digoxin is decreased by partial resection of the samll intestines, by malabsorption syndromes, after ingestion of Neomycin, Colestyramine and antacids. In renal insufficiency, however, the elimination half-life period of Digoxin is increased conspiciously (from about 35 hours up to about 120 hours). This results in a raised serum concentration of cardiac glycosides unless the dosage is decreased considerably. The incidence of Digitalis intoxication in Digitalis treated patients has been reported to rank as high as 20%. There is, however, no strict correlation between the serum glycoside level and the clinical symptoms, because the glykoside concentration in the serum does not represent the pharmacologically active concentration at the receptor. Experimental investigations of cardiac glycoside binding to the receptor for cardiac glycosides in human heart cell membranes revealed, that receptor bound Digoxin for instance is diminished in serious renal insufficiency and it depends on the serum concentration of potassium, calcium and magnesium. In hypoxia, after myocardial infarction and in myxedema the sensitivity for cardiac glycosides is increased. The opposite is true in hyperthyreoidism, fever and in children. All of these factors have to be kept in mind and paid attention to in the clinical evaluation of the measured Digoxin concentration in the serum.
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PMID:[Significance of serum digoxin concentration and its influencing factors]. 6 Nov 53

Effects of neomycin were studied on serum cholesterol and fecal steroids in hypercholesterolemic patients during a short treatment period (4 wk) and a long treatment period (16 mo), using small (1.5 g/d) and large (up to 6 g/d) doses alone and in combination with cholestyramine. In the short-term low-dose study the decrease in serum cholesterol by 21% was associated with a proportionate increase in fecal cholesterol elimination as neutral sterols through impaired cholesterol absorption. Serum cholesterol remained low and fecal steroid excretion remained elevated in the long-term neomycin study. Increasing the dosage from 1.5 to 6 g/d at the end of the 16-mo period brought about a further slight decrease in serum cholesterol and a small further increase in fecal neutral and acidic steroids. The increases in fecal bile acids and fat but not in neutral sterols were positively correlated with the increases in the neomycin dosage. Thus, large neomycin doses can also cause bile acid malabsorption. In another series of patients, a decrease (25%) in serum cholesterol by cholestyramine was associated with a proportional increase in the fecal elimination of cholesterol (2.5-fold) as bile acids. The inclusion of neomycin in cholestyramine therapy further increased fecal steroid output (solely as neutral sterols) by only about one-fifth of that due to cholestyramine, but further decreased serum cholesterol almost to the same extent (-17%) as cholestyramine alone. The overall decrease was 38%, no side effects occurred, and the patients found combination therapy convenient. Neomycin decreased serum cholesterol in different studies by 10+/-2, 17+/-4, and 12+/-4% per 100 mg/d of the increment in fecal steroids, the respective decrease for cholestyramine being only 2.2+/-0.5%. Thus, neomycin effectively reduced serum cholesterol by a relatively small increase in cholesterol elimination (via cholesterol malabsorption) compared with cholestyramine-induced bile acid malabsorption.
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PMID:Effects of neomycin alone and in combination with cholestyramine on serum cholesterol and fecal steroids in hypercholesterolemic subjects. 38 20

To investigate whether vitamin B12 malabsorption in rats with choledochocolic fistulae is caused by bacterial overgrowth, we studied intestinal bacterial metabolic activity in choledochocolic fistula-operated rats, self-filling blind-loop-operated rats, and sham-operated rats. Fistula-operated rats had a moderate indicanuria compared with sham-operated ones, whereas the faecal excretion of nitrogen was unchanged. There was no difference in the amounts of radioactivity recovered in sediments of intestinal contents after an oral dose of 57CoB12, indicating unaltered bacterial uptake of vitamin B12 in fistula rats. The 14C-xylose breath test showed bacterial overgrowth in blind-loop rats only. Neomycin treatment of fistula rats diminished the excretion of indican but did not alter the absorption of vitamin B12. The results suggest moderately increased activity of indole-producing bacteria in fistula rats, but they do not support the hypothesis that vitamin B12 malabsorption is caused by bacterial overgrowth.
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PMID:Is vitamin B12 malabsorption in bile fistula rats due to bacterial overgrowth? A study of bacterial metabolic activity in the small bowel. 313 37

The effect of oral neomycin (2 g/kg for 4 or 7 days) on drug absorption from the small intestine was studied in anaesthetized rats in situ. Neomycin did not greatly affect the small intestinal morphology. Only in some cases there were slightly edematous and low villi in the intestines of the rats treated for 7 days, and there was "nuclear debris" in the mucosal cells as a sign of neomycin toxicity. Neomycin did not modify isoniazid or quinidine absorption, nor did it have any effects on intestinal fluid absorption. Sulphafurazole absorption was retarded, but the change was significant only after a 7-day neomycin treatment. The mechanisms of neomycin-induced changes in absorption still remain largely speculative, but the findings support the concept of the rat being fairly resistant to oral neomycin with respect to eventual malabsorption.
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PMID:The effect of oral neomycin on the absorption of isoniazid, quinidine and sulphafurazole from the rat small intestine in situ. 719 17