Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twelve healthy volunteers were studied for two test periods, at the beginning of which they ingested a diarrheogenic load (60 g) of lactulose in 350 mL water with 10 g polyethylene glycol 4000 (PEG); the two periods were separated by a lactulose feeding period of 8 d, during which a nondiarrheogenic load (20 g) of lactulose was taken twice daily. The transit time and flow rates of water and lactulose in the distal ileum of four subjects were not different before and after the lactulose feeding period. In the other eight subjects, stool weight and frequency, fecal pH, and fecal outputs of carbohydrates and osmotic moieties after the ingestion of 60 g lactulose dropped significantly (P < 0.05) after the lactulose feeding period, whereas the orofecal transit time and fecal concentrations of beta-galactosidase and lactic acid increased (P < 0.05). We conclude that changes in colonic function induced by prolonged exposure to a nondiarrheogenic amount of lactulose mitigate the severity of the diarrhea because of the larger dose of lactulose.
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PMID:Can diarrhea induced by lactulose be reduced by prolonged ingestion of lactulose? 823 48

We conducted blinded, controlled crossover studies to determine the effect of daily lactose feeding on colonic adaptation and intolerance symptoms. The initial study with nine lactose maldigesters showed a threefold increase in fecal beta-galactosidase activity after 16 d of lactose feeding. To determine the effects of this adaptation on breath hydrogen and intolerance symptoms, 20 lactose-maldigesting adults were randomly assigned to lactose or dextrose supplementation for 10 d (days 1-10), crossing over to the other period for days 12-21. The sugar dosage was increased from 0.6 to 1.0 g.kg-1.d-1, subdivided into three equal doses, by adjusting the dose every other day. Symptoms during lactose supplementation and comparison of symptoms during the lactose and dextrose feeding periods showed no significant differences. On days 11 and 22, challenge doses of lactose (0.35 g/kg) were administered after an overnight fast, and breath hydrogen and intolerance symptoms (abdominal pain, flatulence, and diarrhea) were carefully monitored for 8 h. Frequency of flatus passage and flatus severity ratings after the lactose challenge decreased 50% when studied at the end of the lactose period compared with the dextrose period. The sum of hourly breath-hydrogen concentrations (1-8 h) was significantly reduced after the lactose feeding period (9 +/- 38 ppm.h) compared with after the dextrose period (385 +/- 52 ppm.h, P < 0.001). We conclude that there is colonic adaptation to regular lactose ingestion and this adaptation reduces lactose intolerance symptoms.
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PMID:Colonic adaptation to daily lactose feeding in lactose maldigesters reduces lactose intolerance. 869 25

The disaccharide lactose is present as a natural component of foods only in milk and dairy products. In the gastrointestinal tract, lactose is hydrolysed by the enzyme beta-galactosidase (lactase) into glucose and galactose. These components are absorbed. With the exception of the caucasian race, the lactase activity decreases in most people at an age of 4 to 6 years. Lactose intake can cause symptoms of bloating, flatulence, abdominal pain, and diarrhea due to the lactose reaching the large intestine. This phenomenon is called lactose intolerance. It is generally recommended to those persons that they refrain from the consumption of milk and dairy products. However, most lactose intolerant people are able to digest small amounts of milk. They can also consume cheese that contains no (hard and semi-hard) or only small amounts of lactose (present in only 10% of soft cheeses). These products are very important sources of calcium. Compared to milk, the lactose content of yogurt is usually lower by about one third. Studies during the last 10 years have shown that in spite of its lactose content yogurt is very well tolerated by lactose intolerant persons. This advantage is ascribed to the presence of living lactic acid bacteria in fermented dairy products which survive passage through the stomach and also to the lactase present in these products.
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PMID:[Lactose intolerance and consumption of milk and milk products]. 946 38

Dog myoblasts obtained from muscle biopsies were infected in vitro with a defective retroviral vector containing a cytoplasmic beta-galactosidase (beta-Gal) gene. These myoblasts were initially transplanted in the irradiated muscles of SCID mice and beta-Gal positive muscle fibers were observed. beta-Gal myoblasts were also transplanted back either in the donor dogs (autotransplantation model) or in unrelated recipient dogs (allotransplantation model). Following these myoblast injections, a rapid inflammatory reaction developed within the muscle as indicated by an expression of P-selectin and of pro-inflammatory cytokine mRNAs (interleukin 6 (IL-6) and transforming growth factor beta (TGF-beta), and by a neutrophil infiltration. Following either auto- or allotransplantation in inadequately or non-immunosuppressed dogs, a specific immune reaction also developed within 2 weeks as indicated by the infiltration of CD4+ and of CD8+ lymphocytes, the increased expression of IL-10 and granzyme B mRNAs and the presence of antibodies reacting with the injected cells. Some dogs were immunosuppressed with several combinations of FK506, cyclosporine (CsA) and RS-61443. In dogs immunosuppressed with CsA combined with RS-61443, only a few myoblasts and myotubes expressing beta-Gal were observed 1-2 weeks after the transplantation, but no muscle fibers expressing beta-Gal were observed after 4 weeks, and antibodies against the injected cells were formed. In dogs immunosuppressed with FK506 alone, although no antibodies against the injected cells were produced, there were no small cells and no muscle fibers expressing beta-Gal 1 month after the transplantation. However, FK506 triggered diarrhea and vomiting in dogs. When the dogs were immunosuppressed with FK506 combined with CsA and RS-61443, muscle fibers expressing beta-Gal were present 4 weeks after the transplantation and no antibodies reacting with donor myoblasts were detected. These results indicate that the combination of three immunosuppressive agents (i.e., FK506, CsA and RS-61443) is effective in controlling the specific immune reactions following myoblast transplantation in dogs and they underline that the outcome of myoblast transplantation is dependent in part on an adequate immunosuppression. These results obtained here in normal dogs may justify myoblast transplantation in dystrophic dogs despite the side effects of FK506.
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PMID:Myoblast transplantation in non-dystrophic dog. 960 63

The effectiveness of a new beta-D-galactosidase pellet formulation in the treatment of lactose intolerance was studied. The encapsuled beta-D-galactosidase (lactase) pellets were first tested in vitro for their enzymatic activity within an environment simulating gastric conditions and subsequently within an environment simulating duodenal conditions. Effectiveness was measured by the % of glucose formed by hydrolysis of lactose. The pellets were found to retain their enzymatic activity in gastric pH conditions (mean 69 +/- 1 mg/dl glucose) and were found to hydrolyse lactose in human duodenal fluid (106.35 +/- 1 mg/dl). Finally the effectiveness of the new lactase formulation on glucose absorption was studied in 8 lactose intolerant subjects in a randomized, double blind, crossover trial. After fasting, the subjects were given one capsule containing 100 u/ml beta-galactosidase (i.e. 10 pellets of 10 u/ml each) or one capsule containing placebo pellets, followed by 100 g lactose dissolved in water. The washout period between lactose challenges was one week. Plasma glucose concentrations were measured before and at intervals after the challenges and the subjects completed symptom questionnaires every eight hours for 24 hours. Results showed a statistically significant increase in plasma glucose levels 30, 60, 90 and 120 min after lactose ingestion (repeated measures analysis of variance, p<0.01). Subjective ratings of the severity of abdominal cramping, belching, flatulence, vomiting and diarrhoea were significantly decreased following ingestion of the lactase pellets and lactose (no incidence of diarrhoea) compared with after ingestion of placebo and lactose. The results of the study were considered to be very promising as the beta-D-galactosidase formulation (which was produced at very low cost and with great ease) resisted inactivation in the stomach, effectively transformed lactose to glucose in vivo and reduced symptoms of lactose intolerance.
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PMID:Treatment of lactose intolerance with exogenous beta-D-galactosidase in pellet form. 972 5

The disaccharide lactose is naturally present as a component of foods in milk and dairy products. In the gastrointestinal tract, lactose is hydrolysed by the enzyme beta-galactosidase (lactase) into glucose and galactose. These components are absorbed. In most people lactase activity decreases at the age of approximately 2 years of age. After this lactose intake can cause symptoms of bloating, flatulence, abdominal pain and diarrhoea due to the lactose reaching the large intestine. This phenomenon is called lactose intolerance. It is generally recommended that these people abandon the consumption of milk and dairy products. However, most lactose-intolerant people are able to digest small amounts of milk (approximately 200 ml). They can also consume cheese without (hard and semi-hard cheese) or only low lactose content (only present in 10% of soft cheese). These products are a very important source of calcium.
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PMID:[Lactose in human nutrition]. 978 54

Recent clinical trials of cancer gene therapy have shown encouraging results for controlling localized tumors. However, to control metastatic or disseminated tumor cells, further modification of vectors is required to enhance specificity and infectivity against targets. We investigated whether utilization of the Cre recombinase(Cre)/loxP system contributes to enhanced antitumor effects together with minimal adverse reactions in specific gene therapy against disseminated carcinoembryonic antigen (CEA)-producing cancer cells in the peritoneal cavity of mice. CEA-producing cancer would be a good therapeutic target because it is found in lung, stomach and colon sites, which account for most cancers. We constructed a pair of recombinant adenoviral vectors (Ads), one of which expresses the Cre gene under the control of the CEA promoter (Ad.CEA-Cre); the other expresses the herpes simplex virus thymidine kinase (HSV-TK) gene (Ad.lox-TK), or the beta-galactosidase gene (beta-gal) by Cre (Ad.lox-beta-gal). Intraperitoneal coinjection of Ad.CEA-Cre and Ad.lox-beta-gal into mice with peritonitis carcinomatosa by CEA-producing tumor cells showed selective expression of the beta-gal gene in tumor foci. Coinfection of Ad.CEA-Cre and Ad.lox-TK followed by ganciclovir (GCV) administration significantly suppressed the total tumor weight in the peritoneal cavity of the mice to 13% of that of the untreated mice and 22% of that of the mice treated with Ad.CEA-TK/GCV, an Ad that expressed the HSV-TK gene driven by the CEA promoter alone. Moreover, treatment with Ad.CEA-Cre and Ad.lox-TK/GCV completely suppressed tumors in 4 of 10 (40%) mice without significant weight loss, although 2 of 10 mice treated with Ad.CAG-TK/GCV, an adenovirus vector that strongly but nonspecifically expressed the TK gene, died due to severe side effects including diarrhea, weight loss and liver dysfunction. These findings suggest that cell type-specific gene therapy using the Cre/loxP system is effective against disseminated cancer cells without significant side effects.
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PMID:Gene therapy utilizing the Cre/loxP system selectively suppresses tumor growth of disseminated carcinoembryonic antigen-producing cancer cells. 1174 23

The intake of large amounts of lactulose and other non-digestible oligosaccharides can cause diarrhoea in rats and humans. The purpose of our study was to estimate tendency and scope of changes in caecum development, amount and composition of caecal digesta and activity of caecal microbial enzymes under the influence of lactulose-rich diet evoking or not evoking diarrhoea. Male Wistar rats were fed on 8%-lactulose diet for 4 weeks. Feeding with lactulose induced enlargement of the caecum (digesta and wall) compared to the control group. However, the hypertrophy of the caecal wall in rats with diarrhoea was less than in these without that ailment. Dry matter of caecal digesta was significantly decreased in rats with diarrhoea. Diarrhoea lowered concentrations of enzymatic protein and short-chain fatty acids in the caecum, and the activity of bacterial beta-glucuronidase, alpha- and beta-galactosidase, alpha- and beta-glucosidase in caecal digesta, compared to rats without diarrhoea. The ammonia concentration in the caecum was enhanced by diarrhoea symptoms. Occurrence of diarrhoea significantly deteriorated functioning of the caecal ecosystem what in turn limited potential benefits of diet supplementation with lactulose.
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PMID:Lactulose-induced diarrhoea in rats: effects on caecal development and activities of microbial enzymes. 1220 11

The effects of diarrhoea on the activities of brush-border disaccharidases namely lactase (EC 3.2.1.23), maltase (EC 3.2.1.20) and sucrase (EC 3.2.1.48) of Sprague-Dawley strain albino rats were induced in the rats with mannitol while secretory diarrhoea was induced with Salmonella typhimurium after an initial treatment with streptomycin. The activities of the enzymes were significantly reduced by diarrhoea. The extent of reduction in enzyme activity varied in the different segment of the small intestine in all the groups. The jejuno-ileal region had more changes in enzyme activities than in the duodenum. Higher activity levels were observed for maltase than for lactase. In the osmotic diarrhoea model, lactase activity was significantly lowered (P < 0.05) in the experimental group from day 5 to 10. Maltase activity on the other hand was significantly lowered (P < 0.001) at the peak of diarrhoea. Sucrase activity was also lowered significantly (P < 0.025) in the experimental animals within the first 10 days of diarrhoeal induction. In the secretory diarrhoea model, lactase activity was similar in all the experimental groups except for the streptomycin-salmonella-treated groups and control (P < 0.05). Higher lactase activity levels were observed in the secretory diarrhoea model compared to level in the osmotic diarrhoea model. Maltase activity levels were also lowered significantly (P < 0.05) in the experimental animals. Streptomycin had no effect on the activity of maltase.
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PMID:Comparative effects of osmotic and secretory diarrhoea on brush-border disaccharide hydrolases in rat. 1597 34

Diarrhea is one of the most common infirmities affecting international travelers, occurring in 20 to 50% of persons from industrialized countries visiting developing regions. Enterotoxigenic Escherichia coli (ETEC) is the most common causative agent and is isolated from approximately half of the cases of traveler's diarrhea. Rifaximin, a largely water-insoluble, nonabsorbable (<0.4%) antibiotic that inhibits bacterial RNA synthesis, is approved for use for the treatment of traveler's diarrhea caused by diarrheagenic E. coli. However, the drug has minimal effect on the bacterial flora or the infecting E. coli strain in the aqueous environment of the colon. The purpose of the present study was to evaluate the antimicrobial effect and bioavailability of rifaximin in aqueous solution in the presence and absence of physiologic concentrations of bile acids. The methods used included growth measurement of ETEC (strain H10407), rifaximin solubility measurements, total bacterial protein determination, and assessment of the functional activity of rifaximin by monitoring inhibition of bacterial beta-galactosidase expression. Solubility studies showed rifaximin to be 70- to 120-fold more soluble in bile acids (approximately 30% in 4 mM bile acids) than in aqueous solution. Addition of both purified bile acids and human bile to rifaximin at subinhibitory and inhibitory concentrations significantly improved the drug's anti-ETEC effect by 71% and 73%, respectively, after 4 h. This observation was confirmed by showing a decrease in the overall amount of total bacterial protein expressed during incubation of rifaximin plus bile acids. Rifaximin-treated samples containing bile acids inhibited the expression of ETEC beta-galactosidase at a higher magnitude than samples that did not contain bile acids. The study provides data showing that bile acids solubilize rifaximin on a dose-response basis, increasing the drug's bioavailability and antimicrobial effect. These observations suggest that rifaximin may be more effective in the treatment of infections in the small intestine, due to the higher concentration of bile in this region of the gastrointestinal tract than in the colon. The water insolubility of rifaximin is the likely explanation for the drug's minimal effects on colonic flora and fecal pathogens, despite in vitro susceptibility.
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PMID:Bile acids improve the antimicrobial effect of rifaximin. 2054 7


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