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)

1. Intestinal brush border enzymes have heterogeneous rates of turnover, the largest proteins having the fastest turnover. Since the membrane faces the intestinal lumen, the effects of pancreatic factors were examined in mediating this turnover. Surgical subtotal pancreatectomy was used as an experimental model to study the turnover of brush border proteins in the absence of most pancreatic secretions. 2. Subtotal (95%) pancreatectomy of rats was found to cause elevations by about 50% of total activity and specific activities of certain brush border enzymes (maltase, sucrase, lactase), but not of others (alkaline phosphatase, trehalase). Rats were judged to be functionally deficient in pancreatic proteolytic enzymes (a) by demonstration of vitamin B-12 malabsorption, which was corrected by trypsin, and (b) by the finding of only about 20% of proteolytic activity appearing in the lumen after a test meal when compared to control. 3. To measure protein turnover in vivo the method of double labelling was used, where [3H]- and [14C]valine were administered intraduodenally in sequence 10 h apart. With this technique, a high 3H/14C ratio is correlated with rapid turnover. Proteins with apparent molecular weights of about 200 000-270 000 were found to turn over more rapidly than smaller proteins. 3H/14C ranged from 4.7 to 6.2 in animals without pancreatic insufficiency. In the face of decreased pancreatic proteolysis, the 3H/14C ratio was 2.3-3.1, similar to that of proteins with a slow half life. 4. Estimates of relative synthetic rates of large brush border proteins were lower than normal in pancreatectomized animals, but were constant over the period of the labelling experiment. The high enzyme levels in the face of lower synthetic rates confirms that, at the new steady rate, degradation rates must be slower for large brush border proteins in pancreatic insufficiency. 5. In vitro, using purified brush borders, unfractionated pancreatic enzymes were found to remove sucrase, maltase and lactase, but not alkaline phosphatase and trehalase. The enzyme most potent in this respect was the pancreatic protease, elastase. Non-proteolytic enzymes (amylase, lipase, phospholipase A) were inactive in removing enzyme from the brush border. The addition of elastase to pancreatectomized animals in vivo restored the rapid turnover rate of large brush border proteins. 6. A model is thus proposed for the normal catabolism of some large intestinal brush border proteins. It is suggested that the surface of intestinal absorptive cells is being constantly remodelled, and that certain surface enzymes are in part removed from the membrane by the action of pancreatic proteases. A possible special role for elastase is suggested.
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PMID:The possible role of pancreatic proteases in the turnover of intestinal brush border proteins. 114 88

The vitamin A absorption test and its interaction with the secretin-pancreozymin test, the d-xylose absorption test, fecal fat content and the small intestine biopsy are estimated on their significance in the diagnosis and course of sprue and pancreatic insufficiency. The investigation includes 39 patients with different stages of pancreatic insufficiency and 10 patients with sprue. First it results relatively wide spread normal values in a control collective with sometimes unexplained low values, the significance of the vitamin A absorption test as screening test therefore is limited. Secondly the absent rise after vitamin A ingestion in serum after 3 and 6 hours favours the diagnosis of sprue, correlates with the histological findings of the mucosa and appears more reliable than the d-xylose test. Thirdly this test seems to allow the differentiation between malabsorption and maldigestion when steathorroe is proved: In contrast to sprue-syndromes pancreatic insufficiency shows significant reduced 3 hour values at subnormal 6 hour values after vitamin A ingestion.
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PMID:[Vitamin A absorption test. I. Pancreatic insufficiency and sprue (author's transl)]. 118 78

It is reported on the estimation of the vitamin A absorption test in 17 patients with chronic liver diseases, 26 patients with diseases of the extrahepatic biliary system, and in 12 patients with diseases of the stomach. In the latter there are no changes in the vitamin A test. On the contrary patients with diseases of the liver and biliary system show differences in the serum vitamin A levels. A separate consideration of active liver cirrhosis and active cholangitis indicates individualities in the constellation of the 3 and 6 hour values after vitamin A ingestion: in liver cirrhosis the first value is normal while the 6 hour value seems significant lowered so that the maximum vitamin A concentration is found near 3 hours. In active cholangitis both values are reduced, the first one more than the second one. The reason is to be seen in a decrease of the conjugated bile acids, whereas in the group of liver diseases an interpretation is somewhat problematic. It is to discuss whether these results depend on the development of portal hypertension, while the intestinal absorption seems normal and liver damage only of secondary importance. The fact that this test is influenced by diseases of the liver and biliary system shortens its significance as a screening test for malabsorption or maldigestion though a further differentiation between sprue and pancreatic insufficiency seems possible.
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PMID:[Vitamin A absorption test. II. Diseases of the liver, the extrahepatic biliary system and the stomach (author's transl)]. 118 79

Cystic fibrosis (CF) is the most frequent inheritable disease with a lethal course. One of the major problems of the disease is malabsorption and malnutrition, due to pancreatic insufficiency which is already present at birth in more than 85% of the patients. Characteristically the mucoid secretion products of the epithelial tissues in lung, pancreas, liver and intestine have a high viscosity. The pathophysiology is characterized by obstruction of these organs with secondary damage and finally destruction. For a long period intestinal obstruction syndromes in CF were ascribed only to the pancreatic insufficiency. Malabsorption is not only caused by enzyme deficiency but is also related to transport processes to the surface of the enterocytes. This indicates that the intestinal disorders in CF are partly the result of mucoid plugging and not only of pancreatic insufficiency. Recently in vitro studies have shown a blockade of secretion through chloride channels in the mucosal membrane of CF tissues. In vivo measurements of chloride fluxes in the rectum showed a disturbed regulation in CF patients. The high viscosity of the mucus and plugging is directly related to the diminished chloride secretion. So it is postulated that the abnormal chloride secretion is responsible for the intestinal obstruction and partially also for the malabsorption.
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PMID:Relationship between intestinal function and chloride secretion in patients with cystic fibrosis. 128 10

Cystic fibrosis (CF) is the most common hereditary disease amongst Caucasians with a potentially lethal outcome. The basic defect is a dysregulation of the chloride channels leading to a relative dehydration of the luminal surface of the exocrine cells. The prognosis of CF patients is predominantly related to the progression of their pulmonary disease. This prognosis has improved dramatically during the last decennia and many patients live into adulthood. Gastrointestinal disturbances and, consequently, malabsorption of nutrients represent a major therapeutic problem in CF. A better understanding of the nutritional problems, including the treatment of pancreatic insufficiency, appears to contribute to an improved prognosis. However, the nutritional status of many patients is still poor and studies to optimise treatment are of paramount importance. In addition, with the increased life span, hepatobiliary complications will contribute to the morbidity of these patients and preventive treatment may be warranted. The aim of this Symposium was to improve our knowledge in this important field by considering the interesting and up-to-date contributions of many experts.
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PMID:Gastroenterological Aspects of Cystic Fibrosis. Symposium proceedings. The Hague, The Netherlands, 10 April 1992. 136 64

Cystic fibrosis is an inherited, multisystem disorder characterized by an abnormality in exocrine gland function. It leads to chronic pulmonary disease in most cases and pancreatic insufficiency in 85 percent of patients. Although this disease is not uncommon in Caucasians, it has been considered very rare among Japanese. The majority of patients are diagnosed in infancy or childhood. The patient in this case report was a 45-year-old Japanese man who had not been diagnosed as having cystic fibrosis. This patient had recurrent episodes of pulmonary infection that started in childhood, and plain films of the chest showed increased interstitial markings, hyperaeration, and bronchiectasis. CT of the upper abdomen showed a generally enlarged pancreas with complete fatty replacement. Serum and urine pancreatic enzyme levels were low, suggesting pancreatic insufficiency. Repeated sweat tests were positive. A roentgenologic skeletal survey showed general demineralization, which may be multifactorial. In this case, it was concluded that vitamin D deficiency caused by vitamin D malabsorption and/or insufficient sunlight exposure was mainly responsible for the demineralization and that chronic respiratory acidosis might also be partially responsible.
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PMID:A Japanese adult case of cystic fibrosis causing bone demineralization. 141 May 64

An individual who has cystic fibrosis (CF) may suffer from gastrointestinal problems related to inadequately controlled intestinal absorption secondary to the pancreatic insufficiency. These include neonatal meconium ileus, distal intestinal obstruction syndrome (DIOS), constipation and acquired megacolon, rectal prolapse and rarely pancreatitis. If the intestinal malabsorption is well controlled with an effective pancreatic enzyme preparation, DIOS, constipation and rectal prolapse are infrequent. Persisting gastrointestinal symptoms should be investigated thoroughly to exclude other disorders not directly related to the cystic fibrosis; these include cows' milk intolerance, coeliac disease, giardiasis, Crohn's disease and intra-abdominal malignancy. Both appendicitis and intussusception may cause difficult diagnostic problems particularly in patients who may also have distal ileal obstruction syndrome.
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PMID:Cystic fibrosis: gastrointestinal complications. 145 4

Pancreatic insufficiency is the second most important pathophysiological expression of cystic fibrosis (CF) and occurs in the majority of patients. It leads to fat malabsorption and high energy losses in the stools and is one of the major causes of malnutrition often seen in CF. Although the development of enteric-coated enzyme preparations offers a dramatic improvement in therapy, it is still difficult to achieve complete correction of fat malabsorption. The cause for this treatment failure is the relative acidic environment in the duodenum induced by a decreased pancreatic bicarbonate output. To improve the efficacy of enteric-coated preparations the dissolution of these preparations in the duodenum must be optimised in order to achieve a high intraduodenal enzyme concentration. With the aim to increase intraduodenal pH, additional therapy with H2-antagonists and oral prostaglandins has been tested without unequivocal success. Omeprazole, a gastric acid inhibitor with more potency and duration of action compared to H2-antagonists, improves the efficacy of enteric-coated capsules of pancreatin dramatically. With a daily dose of 20 mg in addition to Pancrease (3 x 4 capsules) near normalization of faecal fat excretion will be reached in most CF patients with persistent steatorrhoea.
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PMID:New modalities in the treatment of exocrine pancreatic insufficiency in cystic fibrosis. 147 Feb 78

Pancreatic insufficiency due to chronic pancreatitis may lead to symptomatic malabsorption of both starch and fat. The absorption capacity of wheat starch has not been studied previously in patients with chronic pancreatitis, although this carbohydrate is a quantitatively important component of the Western diet. We studied the absorption of wheat starch and the effect of pancreatic enzyme substitution in seven patients with chronic pancreatitis and steathorrea. The malabsorption was determined from hydrogen breath tests with lactulose standards as reference. Without enzyme substitution, wheat starch (50 g) was absorbed to a lesser extent than in healthy controls (p less than 0.05). The mouth-to-cecum transit time was prolonged and correlated positively to the fat excretion before substitution with pancreatic enzymes (sigma = 1). The enzyme substitution increased the absorption of wheat starch to values seen in healthy controls (p less than 0.05) and reduced the mouth-to-cecum transit time by 19.8%.
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PMID:Assimilation of wheat starch in patients with chronic pancreatitis. Positive effect of enzyme replacement. 152 77

To evaluate the impact of early pancreatic insufficiency on growth and nutritional status in cystic fibrosis, we studied 49 infants identified by a newborn screening program. Pancreatic insufficiency, determined by increased 72-hour fecal fat excretion, was present in 59% (23/39) of infants at diagnosis (7.0 +/- 0.8 weeks; mean +/- SEM). Before initiation of pancreatic enzyme replacement, growth and nutritional status of pancreatic-insufficient (n = 16) and pancreatic-sufficient (n = 13) infants were compared. Pancreatic-insufficient infants gained less weight from birth to diagnosis (13.4 +/- 3.4 vs 22.3 +/- 4.0 gm/day; p = 0.05), had decreased triceps skin-fold thicknesses (4.5 +/- 0.3 vs 6.1 +/- 0.4 mm; p less than 0.005), and had lower blood urea nitrogen (3.07 +/- 0.42 vs 4.62 +/- 0.65 mg/dl; p = 0.02) and albumin (2.99 +/- 0.14 vs 3.54 +/- 0.14 gm/dl; p less than 0.01) levels despite higher gross calorie (154 +/- 8 vs 116 +/- 13 kcal/kg per day; p less than 0.01) and protein intakes (2.81 +/- 0.21 vs 2.14 +/- 0.33 gm/kg per day; p = 0.03). Fecal nitrogen loss was correlated with fat loss (r = 0.79; p less than 0.001). Fat malabsorption was present in 79% (30/38) and 92% (33/36) of infants tested at 6 months and 12 months of age, respectively, indicating that pancreatic insufficiency persists and increases in frequency throughout infancy. We conclude that pancreatic insufficiency is prevalent in young infants with cystic fibrosis and has a significant impact on growth and nutrition.
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PMID:Pancreatic insufficiency, growth, and nutrition in infants identified by newborn screening as having cystic fibrosis. 155 90


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