Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.108 (lactase)
 2,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using an electrical technique for measuring transjejunal potential differences (PDs) in conscious man, we have estimated the electrogenic absorption of the hexoses liberated by hydrolysis of lactose which was infused into the jejunum of one normal control and 21 patients with diarrhoea. The results were compared with jejunal lactase levels determined from biopsy specimens taken from the recording site immediately after infusion. The PD evoked by 100 mM lactose was very significantly lower in patients with lactase levels below 4 units (lactase deficient) compared with subjects with normal lactase levels. There was also a significant correlation (r = 0.87, P less than 0.005) between the magnitude of the lactose potential (expressed as the ratio of the maximum glucose transfer potential) and the mucosal lactase level in the hypolactasic subjects but not in patients with normal lactase levels. Thus, in the subjects with lactase deficiency, the electrogenic transfer of hexose is clearly limited by the rate of lactose hydrolysis. Unlike other assessments of functional lactase activity, the electrical test provides a specific index of jejunal function and, moreover, can be adapted to investigate the possible disorders of small intestinal motility and secretion associated with hypolactasia.
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PMID:Electrical assessment of functional lactase activity in conscious man. 89 9

The incidence of lactose intolerance and by inference intestinal lactase deficiency was investigated by means of the oral lactose tolerance test in 30 East Indians born in Trinidad but of Indian heritage. Twenty showed flat curves (67%) and twenty had cramps and diarrhoea following the lactose load (67%). In India milk consumption is less than in Trinidad. Since all subjects were of the same racial origin the findings are interpreted as suggesting that lactase deficiency among East Indians is inherited on a genetic basis.
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PMID:Lactose intolerance in East Indians of Trinidad. 101 74

An experiment was conducted to investigate the mechanisms responsible for the brain lesions, diarrhoea and haemorrhages produced by amprolium poisoning of preruminant lambs. The encephalopathy was preceded by a reduction of cerebrocortical transketolase activity. Diarrhoea was not associated with histological evidence of pathological change in the small intestine, and in lambs with severe diarrhoea the small intestinal levels of alkaline phosphatase and lactase were unaffected. Haemorrhages were associated with a thrombocytopenia which was attributed to degeneration of bone marrow megakaryocytes. The bone marrow of the majority of the lambs which had received amprolium for 3 wk or more was severely depopulated, erythrocyte precursors being the most severely affected. The marrow depopulation was atrributed to decreased cell production, as the majority of the remaining cells showed little evidence of degeneration and the number of mitotic figures in the marrow of amprolium-treated lambs was considerably reduced as compared with the controls.
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PMID:Amprolium poisoning of preruminant lambs: an investigation of the encephalopathy and the haemorrhagic and diarrhoeic syndromes. 115 27

Marsupial milk has been found to be high in fats, protein and ash compared to eutherian milk. The generally low lactose content of marsupial milk and the corresponding low intestinal lactase activity of pouch young marsupials, when considered with the incidence of diarrhoea and the occasional formation of cataracts in orphan kangaroos fed on cow's milk (which has a high lactose content), suggests that a lactose-free milk be fed to orphan marsupials. Of the lactose-free milk substitutes for children now available, it is recommended that Pregestimil, Glucose Nutramigen and particularly CFI be used for very young orphan marsupial herbivores (especially kangaroos), as these are both lactose- and sucrose-free. Isomil, Prosobee and Triglyde, containing sucrose, may be suitable for older kangaroos which are also ingesting solids and brush-tailed possums of all ages. The appropriate natural diet of the orphan marsupial should be available at the time when initial solid food ingestion would occur in the natural state. It is suggested that milk substitute continue to be given until the orphan animal reaches the age where, in the natural state, it would be full independent.
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PMID:Nutrition of orphan marsupials. 120 Sep 26

The quantity of lactose not absorbed by 4 normal and 6 lactase-deficient subjects was determined by three indirect methods which involved: (1) measurement of pulmonary hydrogen (H2) excretion, (2) pulmonary (14)CO2 excretion, and (3) stool (14)C excretion, after ingestion of 12.5 g of 1-(14)C-lactose and 4 g of polyethylene glycol (PEG). Results were compared with absorption determined directly from the (14)C:PEG ratio of multiple terminal ileal aspirates. The fraction of lactose not absorbed determined by ileal aspiration ranged from 0 to 8% in normals and 42 to 75% in mild-intolerant subjects. Whereas all three indirect methods were useful in qualitatively separating normal from deficient subjects, the quantity of lactose absorbed as determined by H2 excretion correlated most closely with ileal measurements (r = 0.94). Pulmonary (14)CO2 excretion for 24 hr after (14)C-lactose ingestion did not distinguish normal (17 +/- 4% (SEM) of ingested (14)C per 24 hr) from lactase-deficient subjects (21.1 +/- 3%). Likewise, stool (14)C:PEG ratios grossly underestimated malabsorption with less than one-quarter of the nonabsorbed (14)C appearing in the stool. This study suggests that individual differences in susceptibility to diarrhea after milk ingestion by lactase-deficient subjects may be due to differences in the quantity of lactose not absorbed and/or differences in the rate of bacterial metabolism of lactose in the colon. Analysis of ileal fluid collected during passage of the lactose meal indicated that about two-thirds of the osmotic load delivered to the colon consists of endogenous electrolytes. Thus the water load delivered to the colon is about 3 times that calculated to be osmotically held by the nonabsorbed sugar.
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PMID:Quantitative measurement of lactose absorption. 126 65

Intestinal disaccharidase activities were determined in 294 jejunal biopsies obtained from 254 children with various disorders of the small bowel, and alkaline phosphatase activity was measured in 251 biopsies. In normal mucosa a broad range of enzyme activity was found corresponding with the data in the literature. A primary disaccharidase deficiency was observed in 5 children with congenital sucrase-isomaltase deficiency and in a 12-year-old Egyptian boy with acquired lactase deficiency. A secondary generalized depression of disaccharidase activity and a diminution of alkaline phosphatase activity existed chiefly in patients who had severe or moderate mucosal damage, also in active coeliac disease and during gluten loading, in protracted diarrhoea of infancy, chronic malabsorption of unknown origin and agammaglobulinemia. During remissions enzyme activities recovered together with mucosal improvement. Low levels of enzyme activities were also seen in some cases of protracted diarrhoea of infancy and chronic malabsorption of unknown origin although only mild mucosal lesions were demonstrated.
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PMID:[Intestinal disaccharidase and alkaline phosphatase activities of jejunal biopsies in small bowel diseases of children (author's transl)]. 127 85

The chronic diarrhea observed in young malnourished infants that is sensitive to dietary glucose and other carbohydrates is associated with variable degrees of patchy mucosal villous atrophy. To explore intrinsic mucosal function in the pathogenesis of this alimentary intolerance, we have conducted an immunohistologic investigation of brush-border enzyme proteins of clinically obtained, mucosal biopsy samples. We used a group of monoclonal antibodies against human brush-border aminopeptidase, sucrase/isomaltase (SI), maltase, and lactase enzyme proteins. SI was strongly and uniformly expressed in crypts and villi of 11 of the 14 subjects; in 3 subjects, however, SI was expressed in a mosaic pattern. Maltase and lactase were occasionally absent, but more commonly were expressed in a mosaic distribution. The mosaic expression of brush-border enzyme proteins has been reported in congenital enzyme deficiencies associated with normal intestinal histology. We report the mosaic expression of brush-border enzyme proteins as a functional alteration associated with a pathological lesion of the mucosa in infants with chronic diarrhea. Our observation challenges the existing concept of ontogenic regulation of brush-border enzyme activity.
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PMID:Mosaic expression of brush-border enzymes in infants with chronic diarrhea and malnutrition. 135 33

During a six-year period, 29 children (aged 0.7-13.5 years, mean 3.3 years) suffering from chronic diarrhoea due to giardiasis were studied. The incidence of this illness was 81 per 1,000,000 children aged 0- < 7 years per year. According to growth charts, relative height and weight of the patients decreased significantly (approximately 0.5 SD) from before the onset of diarrhoea to the time of diagnosis and subsequently increased up to the end of catch-up growth. Small intestinal mucosal specimens were studied. Two patients had severe villous atrophy, 8 moderate abnormalities, 6 only light changes and 13 biopsies were normal. D-xylose or lactose malabsorption was detected in 25% of the patients. The lactose malabsorption was due to hereditary low lactase levels. None of the patients with a Danish ethnic background showed lactose malabsorption. D-xylose absorption and the relative weight loss of the patients correlated with the degree of mucosal damage. Patients with persistent diarrhoea (n = 19) were younger and had a shorter duration of diarrhoeal illness and a more significant weight reduction than those with intermittent diarrhoea (n = 10). However, the age at onset of symptoms was similar in the two groups (medians 1.3 years). Seven patients contracted the disease abroad. They all developed persistent diarrhoea and had a more severe course of the illness than those who acquired the disease in Denmark.
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PMID:Giardiasis causing chronic diarrhoea in suburban Copenhagen: incidence, physical growth, clinical symptoms and small intestinal abnormality. 146 10

UNICEF promotes the use of a very effective, inexpensive treatment of dehydration in developing countries: oral rehydration therapy (ORT), which is oral administration of a solution with equimolar concentrations of sodium and glucose (osmolality of about 300 mosmol). The solution is isotonic with respect to total body water when it reaches the small intestine. It expands the extracellular fluid without changing serum osmolality, thus, brain edema does not occur. Further, metabolic degradation of glucose eventually releases free water. On the other hand, intravenous rehydration with saline solution can be lethal, causing excess free water to expand shrunken cells and, thereby, causing brain swelling, rupture of blood vessels and hemorrhage. Yet, physicians and other health workers in developed countries have been quite sow to accept ORT. Leading conditions of dehydration include insensible loss of water and heat through evaporation from the respiratory tract and skin (common in dry air, hot environment, and fever), sensible loss of water and heat through perspiration (common in hot, humid environment and with warm and absorbent clothing), and irritation of the intestinal mucosa by allergies, infections, toxins, and intolerance to some nutrients, resulting in diarrhea. Diarrhea is indeed the main cause of dehydration. Other causes of dehydration are: failure of the hypothalamus to secrete antidiuretic hormone (ADH), kidney unresponsiveness to ADH, diabetes mellitus, protein-rich nutrition, catabolic states, and brush-border lactase after weaning. Physiological changes in dehydration consist of rigidity of the connective tissue (vascular system and lungs) and intracellular fluid loss to the extracellular spaces, resulting in dry mucous membranes, shrunken muscle cells in the lips and the tongue, soft eyes, and adverse effects to the central nervous system. Children become dehydrated more readily than adults, but they tolerate it better.
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PMID:Water: mechanism of oral rehydration, water deficiency = deficiency in salt. 150 31

A study was made of the morphofunctional status and local defence of the gastrointestinal tract in 122 children aged 4 months to 6 years, suffering from food intolerance showed up by atopic dermatitis in 52 children and by chronic diarrhea in 70 children. Based on the allergological anamnesis, scarification cutaneous tests with food allergens, detection of antibodies to food antigens (RAST, HAIT) food allergy was revealed in all the children. Chronic gastroduodenitis was identified in all the children suffering from atopic dermatitis and in 95% of the children with chronic diarrhea. It should be mentioned that one-third of that group had a graver illness--diffuse duodenitis with sub-atrophy of the villi. The allergic genesis of the impairment of the gastroduodenal mucosa was confirmed. It was more remarkable in atopic dermatitis (tissue eosinophilia and high content of IgE-plasmacytes in the duodenal mucosa). The decrease of local immune defence of the mucous membrane, lactase deficiency, elevated growth of microorganisms in the duodenal contents promote the rise of intestinal barrier permeability for food antigens and enhancement of sensitization.
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PMID:[Immunological aspects of food intolerance in children during first years of life]. 151 44


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