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

A 10-year-old boy with severe familial lactose intolerance in infancy (vomiting, failure to thrive, lactosuria (5.25 g/l), sucrosuria (12 g/l), and aminoaciduria. Intestinal disaccharidases (including lactase and sucrase) normal at age 6 and 20 weeks. Oral lactose tolerance test at this age resulted in lactosuria (4.6 g/l); sucrose tolerance test, in sucrosuria (18.5 g/l). In contrast, intraduodenal lactose tolerance test gave only low lactose excretion in urine (0.28 g/l). He improved rapidly and had no lactosuria on intraduodenal feeding with citric acid milk. The lactosuria diminished as age increased, but was still higher at age 6 years than that of controls. He tolerated normal disaccharide containing food after 1.5 years of age. At 5.5 to 6 years, he had symptoms of lactose malabsorption, and an isolated lactase deficiency was proved. At 10 years, he still tolerates only limited amounts of milk. The defect in severe familial infantile lactose intolerance seems to be localized in the gastric mucosa. Acquired lactase deficiency can appear later in childhood in this syndrome.
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PMID:A boy with severe infantile gastrogen lactose intolerance and acquired lactase deficiency. 52 43

Infants undergoing phototherapy may develop loose stools. Acquired lactase deficiency secondary to this treatment modality was suggested as a cause for the diarrhea. The effects of light energy directly on intestinal enzymes and indirectly through bilirubin photooxidation products were studied. Adult homozygote and heterozygote Gunn rats were treated with light for varying periods while littermate controls were kept in the dark. Intestinal lactase, sucrase and GGTP activities and serum bilirubin concentrations were determined. Jaundiced and non-jaundiced 1-week-old suckling Gunn rats were treated with light for 96 h, and intestinal lactase activity determined. No decreases in lactase, sucrase or GGTP activities were observed suggesting the reported diarrheal states following phototherapy are not related to light energy or photooxidation products.
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PMID:The effect of phototherapy on intestinal mucosal enzyme activity in the Gunn rat. 610 92

To determine the sensitivity and specificity of breath hydrogen (H2) in detecting lactase deficiency, breath H2 collected by end-expiratory sampling and capillary blood glucose were measured after ingestion of 50 g of lactose in 36 patients with biopsy-proved isolated lactase deficiency, 42 with normal lactase activity and 6 with lactase deficiency secondary to mucosal lesions. All patients had digestive symptoms clinically compatible with lactose malabsorption. The maximum increase in breath H2 concentration was more than 1.1 mumol/l (25 ppm) in all patients with isolated lactase deficiency, and less than 0.88 mumol/l (20 ppm) in 88% of patients with normal lactase activity; there were 5 false-positive results, attributed in one case to small bowel colonization and in another case to rapid transit after gastric surgery. Secondary lactase deficiency was accurately detected by neither breath H2 nor blood glucose.
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PMID:[Diagnosis of lactase deficiency with the expired hydrogen (H2) test]. 722 24