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)

Jejunal biopsies from six patients having the small bowel enteropathy associated with common variable immunodeficiency have been subjected to analytical subcellular fractionation and enzymic and regulatory peptide microassay to define the organelle pathology of this syndrome. Compared with normal subjects, the immunodeficient patients had decreased activities of the three brush border enzymes: alkaline phosphatase, gamma-glutamyl transferase and alpha-glucosidase. The other organelle marker enzyme activities and all the regulatory peptide concentrations did not differ from the controls. Density gradient experiments showed a complete loss of particulate beta-glucosidase (lactase) with activity entirely located in the cytosol. The integrity of other organelles was normal. These data indicate that the enteropathy of common variable immunodeficiency is associated with abnormalities in the jejunal brush border analogous to those present in tropical malabsorption syndrome.
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PMID:Jejunal mucosal enzyme activities, regulatory peptides and organelle pathology of the enteropathy of common variable immunodeficiency. 369 46

A male born to first cousins presented at 12 months with hypocalcemic convulsions, rickets, epistaxis due to vitamin K deficiency, and extremely low serum levels of beta-carotene and vitamin A. Liver function was altered moderately (glutamic-oxaloacetic transaminase, 55 U/L; glutamic-pyruvic transaminase, 37 U/L; lactate dehydrogenase, 255 U/L; alkaline phosphatase, 437 U/L). To correct the deficiencies, 8,000 IU vitamin D/day, 10,000 IU vitamin A/day, and intramuscular administration of vitamin K1 were required. At 9 years, he presented signs of neuromuscular affection, and the serum vitamin E level (measured for the first time) was extremely low. Classic lipid malabsorption syndromes (abetalipoproteinemia, chronic cholestasis, mucoviscidosis, coeliac disease, Whipple's disease) were excluded by appropriate examinations. Composition of duodenal bile acids was characterized by undetectable levels of cholic acid metabolites, and only chenodeoxycholic acid metabolites were present. Serum total bile acid concentration was normal, with an atypical low cholic acid/chenodeoxycholic acid ratio and abnormal presence of 3 beta-OH-delta 5-cholenic acid and 6-OH-bile acids. Urinary bile acid composition was also characterized by elevated 6-OH-bile acids. Known enzymopathies of the bile acid synthetic pathway were excluded (cerebrotendinous xanthomatosis, cerebro-hepato-renal syndrome of Zellweger, coprostanic acidemia). Bile acid pool sizes were determined by using stable isotopes: cholic acid pool size [2.90 (N, 32 +/- 16) microM/kg] and chenodeoxycholic acid pool size [10.8 (N, 32.6 +/- 9.9) microM/kg] were extremely low; fractional turnover rates of both bile acids were in a normal range.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Malabsorption of liposoluble vitamins in a child with bile acid deficiency. 379 31

We have studied some effects of small doses of 1,25-dihydroxycalciferol (calcitriol) and calcium, either combined or separately, in 45 patients with osteoporosis and malabsorption of calcium. In 24 patients on 0.25 micrograms/d of calcitriol the hourly fractional rate of radiocalcium absorption rose from 0.37 +/- 0.02 to 0.55 +/- 0.04 (p less than 0.001) and in 21 patients on 0.50 micrograms/d it rose from 0.36 +/- 0.02 to 0.69 +/- 0.05 (p less than 0.001). These responses were seen within 5 days and were not increased further at 6 weeks to 3 months. The combined therapy significantly reduced the fasting urinary hydroxyproline/creatine ratio (OHPr/Cr) and plasma alkaline phosphatase activity (ALP) in 6-12 weeks, the smaller dose of calcitriol (0.25 micrograms/d) being as effective as the larger one (0.50 micrograms/d) in this respect. Calcium alone (1 g/d) had no effect and calcitriol alone (0.25 mcg/d) had a lesser effect on both OHPr/Cr and ALP than the combined therapy. The falls in OHPr/Cr and ALP tended to be greatest in the cases with the highest initial levels but constituted only partial suppression of these variables towards the theoretical non-bone components. These results suggest that treatment with calcitriol and calcium suppresses bone resorption in osteoporosis associated with malabsorption of calcium and is more effective than calcium or calcitriol given alone.
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PMID:1,25-Dihydroxycalciferol and calcium therapy in osteoporosis with calcium malabsorption. Dose response relationship of calcium absorption and indices of bone turnover. 383 58

We performed iliac bone histomorphometry after in vivo double tetracycline labeling 3-14 years after intestinal bypass surgery for obesity in 21 patients, selected because of clinical suspicion of metabolic bone disease, and compared the results with those of 40 age-matched normal control subjects. Osteomalacia defined by rigorous kinetic criteria was found in six cases, histologic features of secondary hyperparathyroidism without significantly impaired mineralization in one case, and possible osteomalacia masked by impaired matrix synthesis in one case. In the patients with definite osteomalacia, nonfracture bone pain was more frequent, corrected plasma calcium lower, plasma alkaline phosphatase and magnesium higher, and secondary hyperparathyroidism more severe than in the other patients. In the patients without osteomalacia there was a 24.5% reduction in trabecular bone volume compared to the controls; in contrast to age-related bone loss and post-menopausal osteoporosis, this was due mainly to reduction in the thickness rather than the density of trabecular plates. About two-thirds of the reduction in trabecular thickness was due to reduction in interstitial bone thickness, representing the cumulative effect of increased depth of osteoclastic resorption cavities, probably due in part to secondary hyperparathyroidism. About one-third of the reduction in trabecular thickness was the result of reduced mean wall thickness, representing insufficient osteoblastic matrix synthesis, probably due in part to malabsorption of an unidentified nutrient necessary for normal bone health. Resorption indices were not increased at the time of the biopsy, but there were persistent defects in the recruitment and activity of osteoblasts. Clinically significant bone loss after intestinal shunt surgery, as in several other clinical situations, results from the combined effects of an unsustained increase in bone resorption and a sustained decrease in bone formation.
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PMID:Metabolic bone disease with and without osteomalacia after intestinal bypass surgery: a bone histomorphometric study. 384 Mar 79

Low duodenal vitamin D-dependent calcium-binding protein has been reported in juvenile Hyp mice. Levels of this protein improved in adult Hyp mice. This led to the search for possible abnormal intestinal calcium absorption in juvenile Hyp mice and for evidence that calcium malabsorption, if present, would exacerbate the bone disease. A balance study was performed in 10 sets of normal and Hyp male mice at 5 and 12 weeks of age. Twelve-week-old Hyp mice had balances (24-h intake minus excretion) of Ca, P, Mg, Na, and K that were not significantly different from those of 12-week-old normal mice. However, 5-week-old Hyp mice had a significantly lower balance of Ca with higher fecal Ca and lower urinary Ca. No balance was also lower due to higher fecal Na. The balances of P, Mg, and K were not significantly affected in young Hyp mice. Growth and mineralization of the femur were compared in normal and heterozygous female Hyp mice from 3.5-46 weeks of age. The femora of Hyp mice gained ash weight at a rate comparable to that for normal mice, except for a lag between 3.5 and 7 weeks. There was life-long hypophosphatemia and elevated plasma alkaline phosphatase. It was concluded that the period of low levels of duodenal vitamin D-dependent calcium-binding protein was associated with low intestinal absorption and low skeletal mineralization. This dysfunction of the intestine in juvenile, rapidly growing Hyp mice may exacerbate the bone disease.
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PMID:A role for the intestine in the bone disease of juvenile X-linked hypophosphatemic mice: malabsorption of calcium and reduced skeletal mineralization. 609 Jan 1

During the past two decades, the essentiality of zinc for man has been established. Deficiency of zinc in man due to nutritional factors and several diseased states has been recognized. High phytate content of cereal proteins decreases availability of zinc; thus the prevalence of zinc deficiency is likely to be high in a population subsisting mainly on cereal proteins. Alcoholism is known to cause hyperzincuria and thus may play a role in producing zinc deficiency in man. Malabsorption, cirrhosis of the liver, chronic renal disease and other chronically debilitating diseases may similarly induce zinc deficiency in human subjects. A severe deficiency of zinc has recently been recognized to occur in patients with sickle cell anemia and a beneficial effect of zinc therapy in such patients has been reported. Growth retardation, male hypogonadism, skin changes, poor appetite, mental lethargy and delayed wound healing are some of the manifestations of chronically zinc-deficient human subjects. Taste abnormalities, correctable with zinc supplementation, have been observed in uremic subjects. Recently, abnormal dark adaptation related to zinc deficiency in patients with cirrhosis of the liver and sickle cell disease has been reported. In severely zinc-deficient patients, dermatological manifestations, diarrhea, alopecia, mental disturbances and intercurrent infections predominate and if untreated the condition becomes fatal. Zinc deficiency is known to affect testicular functions adversely in man and animals. This effect of zinc is at the end organ level and it appears that zinc is essential for spermatogenesis and testosterone steroidogenesis. Zinc is involved in many biochemical functions. Several zinc metalloenzymes have been recognized in the past decade. Zinc is required for each step of cell cycle in microorganisms and is essential for DNA synthesis. Thymidine kinase, RNA polymerase, DNA-polymerase from various sources and RNA-dependent DNA polymerase from viruses have been shown to be zinc-dependent enzymes. Zinc also regulates the activity of RNase; thus the catabolism of RNA appears to be zinc-dependent. The effect of zinc on protein synthesis may be attributable to its vital role in nucleic acid metabolism. The activities of many zinc-dependent enzymes have been shown to be affected adversely in zinc-deficient tissues. Three enzymes, alkaline phosphatase, carboxypeptidase and thymidine kinase, appear to be most sensitive to zinc restriction in that their activities are affected adversely within three to six days of institution of a zinc-deficient diet to experimental animals.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Zinc deficiency in human subjects. 636 78

Distal common bile duct stenosis was observed in 16 (9%) of 170 alcoholic patients admitted to a Veterans Administration Medical Center in the last five years. The following clinical and biochemical features were significantly more common (P less than 0.05) among the 16 patients with common bile duct stenosis than in 154 without: jaundice, cholangitis, hyperbilirubinemia, alkaline phosphatasemia, pancreatic calcification, and malabsorption. Surgical decompression of biliary tree was necessitated in 13 of 16 cases due to obstructive jaundice in seven, cholangitis in four, portal fibrosis in one, and persistent abdominal pain in one. The mean (+/- SE) time interval between initial serum alkaline phosphatase elevation and surgical intervention was 308 +/- 108 days. Liver histology in eight cases was remarkable for portal fibrosis in seven and biliary cirrhosis in one. These data suggest that distal common bile duct stenosis is a progressive lesion which is quite prevalent in patients with advanced pancreatic disease of alcoholic etiology.
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PMID:Prevalence and natural history of distal common bile duct stenosis in alcoholic pancreatitis. 647 79

Rickets, hypocalcemia, hypophosphatemia, and hyperparathyroidism were found in a low-birth-weight premature infant. The concentration of plasma calcitriol (1,25-dihydroxyvitamin D) was 145 pg/mL. With additional exogenous calcitriol (37.5 ng/kg/24 hr) given for eight weeks, the biochemical abnormalities were corrected and healing of rickets was evident. Three months later, while receiving only 400 IU of ergocalciferal daily, the patient had normal levels of serum calcium, phosphate, and alkaline phosphatase with a serum calcitriol concentration of 36 pg/mL. These observations suggest that rickets of prematurity may involve a malabsorption of calcium and phosphorus with an elevated calcitriol level needed to overcome this inadequate absorption. Additional doses of calcitriol may be of benefit in these infants, although it must be given carefully. Furthermore, the role of phosphate supplementation in these infants requires consideration.
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PMID:Rickets of prematurity. Supranormal levels of serum 1,25-dihydroxyvitamin D. 696 86

Twenty-nine patients with chronic liver disease, nine of whom had symptoms suggesting bone disease, were studied by bone histology. Nine had osteomalacia; six associated with cholestatic liver disease and three with primarily hepatocellular disease. Two of these had clinical and biochemical features of cholestasis for at least a year and the other had alcoholic cirrhosis associated with severe malnutrition. Excluding the latter patient, histological osteomalacia was significantly associated with presence and duration of cholestasis. Plasma 25-hydroxyvitamin D was low and fasting urine hydroxyproline/creatinine ratio was high in all patients with osteomalacia but were abnormal also in some patients who did not have histological osteomalacia. Serum calcium, phosphate, alkaline phosphatase, vitamin D-binding protein and radiology were unhelpful in many patients with osteomalacia. Vitamin D-deficiency correlated significantly with deficiency of other fat-soluble vitamins and those patients with rachitic levels of plasma 25-hydroxyvitamin D showed no seasonal variation, suggesting a combination of malabsorption of vitamin D and reduced sunlight exposure. We suggest that patients with chronic liver disease with cholestasis for at least a year are at risk from osteomalacia and that those likely to have this complication may be identified by plasma 25-hydroxyvitamin D and/or fasting urine hydroxyproline/creatinine ratio measurements. The diagnosis can only be made with certainty by bone biopsy.
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PMID:Osteomalacia, vitamin D deficiency and cholestasis in chronic liver disease. 698 Nov 20

It is well established that Giardia infection causes malabsorption. However, the precise mechanism of such a malabsorption is not known. To investigate this, transport studies, using the tissue accumulation technique, were carried out in mice infected with G. lamblia obtained from human stools. There was a significant fall in the transport of D-glucose, L-alanine and glycine in the infected animals compared with the controls. Kinetics of the D-glucose and glycine transport system were examined by measuring the tissue uptake in the presence of different concentrations of the substrate. For glucose, the affinity constant (Km) for the transport site was the same (4 . 37mM) in normal and infected animals but the maximal transport rate (V max) was considerably reduced in infected animals (158 . 7 mu moles/hr/g tissue) compared with (357 . 1 microgram moles/hr/g tissue) in controls. Results with glycine were similar; the Km was similar in control and infected animals (5 . 7 mM) whereas the V max was reduced in infected animals (27 . 02 microgram moles/hr/g tissue) compared with controls (45 . 5 micrograms moles/hr/g tissue). Analysis of the intestinal enzymes showed a significant decrease in the levels of brush border sucrase, lactase and alkaline phosphatase in infected animals; the cellular enzymes, LDH, GOT and GPT remained unaffected. The observed aberrations in the transport functions and brush border enzymes suggest that G. lamblia causes malabsorption by damaging the epithelial membrane of the enterocyte.
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PMID:Transport studies and enzyme assays in mice infected with human Giardia lamblia. 717 14


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