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)

The diagnostic value of 1-14C-lactose breath test was compared with the standard lactose tolerance test and lactase assay in jejunal biopsies in 16 control subjects, 14 patients with lactase deficiency (LD) proven by lactase assay and 20 patients with irritable bowel syndrome (IBS). 14CO2 specific activity in the 2-hr breath collection after administration of 1-14C-lactose (5 muCi) provided a satisfactory separation between the control and LD group. Values were 7.0 +/- 2.0% dose administered/mmoles 14CO2 X 10(-3) (mean +/- SD) in the control group versus 2.1 +/- 1.5 in LD (P less than 0.001) versus 4.9 +/- 2.3 in IBS (P less than 0.01). 1-14C-lactose breath test was superior to standard lactose tolerance test in specificity (P less than 0.05) and provided a satisfactory correlation between 14C-lactose absorption and lactase assay (r = 0.77). The prevalence of LD in IBS was 40% by the breath test and 35% by lactase assay, suggesting that lactose malabsorption may play a role in the symptoms in the population of some patients with IBS. It appears that 1-14C-lactose breath test is a sensitive, specific and accurate method for the diagnosis of LD in clinical practice and suitable for large scale epidemiological surveys.
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PMID:Lactase deficiency--a comparative study of diagnostic methods. 41 Feb 88

Small intestinal lactase activity in the health adult is either the same as in early infancy or may drop to very low levels. The behavior of the enzymatic state varies with the ethnic group studied. In those adults with low lactase activity little information is availalbe as to the age at which the lactase decreases. We attempted to determine a) the frequency of low intestinal lactase activity and b) the age at which the change occurs. For this purpose we reviewed in a large number of intestinal biopsies both histologically as well as for disaccharidase activities. The biopsies were obtained from a heterogeneous group of Caucasians, including patients, their siblings and parents. The patients were those with failure to thrive in whom no organic cause could be elicited, and those with the irritable colon syndrome. Patients ranged in age from 6 weeks to 50 years and out of a total of 1, 077 jejunal biopsies, 172 morphologically normal biopsies were selected. The milk drinking habits of 118 subjects and their families were elicited and 31 oral lactose tolerance tests performed. The mucosal lactase activity and sucrase-to-lactase ratio in those 172 individuals were plotted against age. In the first 3 years the mean lactase activity was 32.1 plus or minus 10.1 mumoles/g protein per min and the sucrase-to-lactase ratio was 1.7 plus or minus 0.5 with no change from year to year. However, after age 5 two separate groups emerge. A small group (24.6% of the population) with low lactase activity, and a second group possessing the same mean value for lactase activity as noted in the first 3 years. The low lactase activity group included children and adults with clinical lactose intolerance. These individuals consumed relatively small amounts of milk and when 12 of them were tested with an oral lactose tolerance test the result was a "flat" curve with a maximum rise in blood glucose of 9 plus or minus 3.2 mg/100 ml. The second group consumed more milk averaging 1 quart/day with no discomfort and when 19 were tested with oral lactose tolerance tests the values were normal. This study indicates that low lactase activity in the Caucasian population may make its appearance at the age of 5 years.
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PMID:Correlation of lactase activity, lactose tolerance and milk consumption in different age groups. 117 20

A retrospective analysis was made of jejunal biopsies performed on 62 patients with Crohn's disease for disaccharidase levels and routine histology. Thirteen patients with irritable bowel syndrome acted as a control group. Two patients with Crohn's disease had hypolactasia. Two patients had marginally low sucrase levels, but all patients had normal maltase levels. Only one patient with irritable bowel syndrome had hypolactasia with normal histology. There were no significant differences between the two groups. Four patients with Crohn's disease had abnormal jejunal histology. The prevalence of hypolactasia in patients with Crohn's disease is not increased. Ideally lactase deficiency in patients with Crohn's disease should be confirmed before starting a lactose-free diet which can produce further restrictions on dietary intake.
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PMID:Hypolactasia and Crohn's disease: a myth. 211 83

1. In order to develop an improved differential sugar absorption test for simultaneously assessing intestinal permeability and lactose intolerance, methods were established for determining raffinose, lactose and L-arabinose in human urine. Using NAD(P)H-coupled enzymatic assays and fluorimetry, each sugar was measurable over a concentration range of approximately 3-300 mumol/l in diluted urine specimens. 2. After an overnight fast, 40 normal volunteers drank an iso-osmotic solution containing raffinose, lactose and L-arabinose. The median 5 h urinary sugar excretion was 0.26% of the ingested raffinose, 0.05% of lactose and 17.5% of L-arabinose. 3. In 143 patients with gastrointestinal disease, excretion of both ingested raffinose and lactose was significantly increased in coeliac disease in relapse or in partial remission and in Crohn's disease, but not in the irritable bowel syndrome, coeliac disease in remission or ulcerative colitis. Excretion of lactose, but not raffinose, was increased in patients with mucosal lactase deficiency, whereas excretion of L-arabinose was reduced in all disease groups except ulcerative colitis. 4. Discrimination between diseases was poor when based on individual sugar recoveries, but improved dramatically when excretion was expressed relative to that of L-arabinose. The raffinose/L-arabinose excretion ratio, an index of intestinal permeability, was greater than 0.08 in 15/15 untreated coeliac patients but less than 0.06 in all normal subjects and in 9/9 lactase-deficient patients, 15/16 recovered coeliac patients, 5/6 patients with ulcerative colitis, 13/16 patients with Crohn's disease and 61/62 patients with irritable bowel syndrome.
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PMID:Simultaneous assessment of intestinal permeability and lactose tolerance with orally administered raffinose, lactose and L-arabinose. 216 7

Diarrhea is one manifestation of GI disturbance. Symptoms may be acute if caused by such things as infections, drug reactions, alterations in diet, heavy metal poisoning, or fecal impaction. Chronic diarrhea is a symptom of GI diseases such as irritable bowel syndrome, lactase deficiency, cancer of the colon, inflammatory bowel disease, and malabsorption diseases. Chronic diarrhea may also be associated with GI surgery, radiation therapy, laxative abuse, alcohol abuse, and chemotherapeutic agents. When interventions are required to deal with diarrhea, they may include such things as alteration in tube feeding products and methods of administration, fluid replacement by oral rehydration procedures, a rapid return to feeding, and education aimed at the health information clients need to prevent or control the symptom of diarrhea.
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PMID:Diarrhea. 223 42

A double-blind, cross-over, therapeutic, clinical trial of the efficacy of exogenous, microbial beta-D-galactosidase to reduce the symptoms of the irritable bowel syndrome (IBS) was conducted in 12 patients whose customary diets regularly included milk. Eight of the 12 subjects (67%) proved to be lactase-nonpersistent, lactose-maldigesters when challenged with a aqueous dose of 12.5 g. The study lasted 4 months, with the first month a non-intervention, control period and the latter 3 months alternating in the sequence, treatment/placebo/treatment, or placebo/treatment/placebo. When symptoms during trial months were analyzed by the cumulative sum procedure, gastrointestinal symptoms were found to be independent of lactase treatment. We found a positive temporal association of the severity of both gastrointestinal and non-gastrointestinal symptomatology. In populations with a high prevalence of lactose deficiency, IBS symptoms appear to be independent of lactose maldigestion.
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PMID:Lactase and placebo in the management of the irritable bowel syndrome: a double-blind, cross-over study. 250 Aug 48

Food intolerant symptoms can have various causes, including enzyme deficiencies (of lactase or aldehyde dehydrogenase) and pharmacological effects (e.g., caffeine, salicylates). The irritable bowel syndrome can also be associated with intolerance to specific foods in some cases, but the mechanism is unclear. Immunological causes are less common but may explain the small bowel mucosal changes associated with gluten enteropathy, as well as the childhood enteropathy provoked by cow's milk or, rarely, by other foods. Food allergy of the more immediate and classical type is associated with reactions both within and outside the gastrointestinal tract. Where these include urticaria, asthma and eczema, immunoglobulin E antibodies are often demonstrable by skin or radioallergosorbent tests, but pseudo-allergic reactions can produce a similar clinical picture. Diagnosis of food intolerance depends on withdrawing the food concerned and assessing the response to a blind challenge. Objective ways of detecting subclinical reactions are also useful, including the detection of a mediator response involving prostaglandins, histamine or serotonin.
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PMID:Food intolerance. 392 73

Acidophilus milk has been reported to help patients with irritable bowel syndrome by correcting the "imbalance of flora" and to be tolerated better by lactase-deficient subjects by providing bacterial lactase in the small intestine. In a double-blind randomized study, 61 lactase-sufficient patients with irritable bowel syndrome each ingested 240 ml of milk three times a day for 2 wk and the same amount of acidophilus milk for an additional 2 wk. The degree of symptoms during the two milk-drinking periods was the same as during the control periods. Also, 18 lactase-deficient patients ingested unaltered milk for 1 wk and acidophilus milk for 1 additional wk. There was no difference in the degree of tolerance to the two varieties of milk. In summary, patients with irritable bowel syndrome were not helped by the ingestion of acidophilus milk, and lactase-deficient patients were as intolerant to acidophilus milk as to unaltered milk.
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PMID:Response of patients with irritable bowel syndrome and lactase deficiency using unfermented acidophilus milk. 641 Aug 97

77 hospitalized patients with chronic unspecific abdominal complaints, in whom any other organic disease had been previously excluded, were investigated for lactose malabsorption; they were subdivided into two groups: 46 patients complaining primarily of colicky abdominal pain and/or intermittent diarrhoea (group 1) and 31 patients presenting with dyspepsia as the predominant symptom (group 2). To establish the exact prevalence of isolated lactase deficiency in the healthy adult population served by our hospital, 40 Italian adult healthy subjects were also studied. The prevalence of lactose malabsorption was significantly higher (p less than 0.005) in patients of the 1st group than in patients of the 2nd group, and in the healthy adult population seen at our hospital (74% vs 35.5% and 37.5%, respectively). Furthermore a high prevalence of lactose intolerance, determined by means of a three-week diet trial (lactose free-diet versus normal diet), was documented among lactose malabsorbers of the 1st group. We concluded therefore that lactose intolerance is a factor in some Italian adult patients who suffer from long-standing aspecific abdominal discomfort, and it should be always considered in these patients, especially when colicky abdominal pain and diarrhoea are present, before the diagnosis of irritable bowel syndrome is made.
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PMID:Lactose intolerance in adults with chronic unspecific abdominal complaints. 667 46

The prevalence of lactase deficiency in British adults is unknown. Examination of the distribution of lactase activities in single and multiple biopsies of jejunum indicated that 0.8 U/g wet weight was a suitable cut-off point to separate lactase deficient patients from others. One hundred and fifty white British adults were selected, none of whom had significant intestinal disease and all of whom had normal histopathology of a jejunal biopsy and normal activities of other disaccharidases measured in the biopsy. The prevalence of lactase deficiency in this group was 4.7%. In contrast, 15 of 20 non-white adults were lactase deficient. Lactase deficiency was found in only three of 36 patients investigated because of diarrhoea after gastric surgery, and in 16 of 200 patients with irritable bowel syndrome (8%). As the prevalence of lactase deficiency is no higher in irritable bowel syndrome than in 'normal' individuals, lactase deficiency clearly is not a predisposing factor for irritable bowel syndrome in white British adults although the two conditions may occasionally coexist.
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PMID:Prevalence of lactase deficiency in British adults. 669 44


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