The Experts below are selected from a list of 12849 Experts worldwide ranked by ideXlab platform
Hassan Y. Naim - One of the best experts on this subject based on the ideXlab platform.
-
transient sucrose and starch intolerance
Journal of Pediatric Gastroenterology and Nutrition, 2012Co-Authors: Klauspeter Zimmer, Dietmar Scholz, Hassan Y. NaimAbstract:9. Protein and amino acids. In: Otten JJ, Hellwig JP, Meyers LD, eds. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington DC: The National Academies Press; 2006: 144–155. 10. Congenital Sucrase-isomaltase deficiency. www.CSIDinfo.com. Published December 18, 2006. Accessed February 15, 2012. 11. Sucrose and starch in foods. www.CSIDinfo.com. Published December 18, 2006. Accessed February 15, 2012. 12. Treem WR, McAdams L, Stanford L, et al. Sacrosidase therapy for congenital Sucrase-isomaltase deficiency. J Pediatr Gastroenterol Nutr 1999;28:137–42. 13. Genetics Home Reference. Congenital Sucrase isomaltase deficiency. http://ghr.nlm.nih.gov/condition/congenital-Sucrase-isomaltase-deficiency. Published July 2008. Accessed September 16, 2011.
-
congenital and putatively acquired forms of Sucrase isomaltase deficiency in infancy effects of sacrosidase therapy
Journal of Pediatric Gastroenterology and Nutrition, 2009Co-Authors: Thomas Lucke, Hassan Y. Naim, Michael J. Lentze, Markus Keiser, Sabine Illsinger, Anibh M DasAbstract:Sucrase-isomaltase (SI) is localised at the brush-border membrane of the small intestine and is responsible for the hydrolysis of sucrose and other carbohydrates such as palatinose (1,2). Deficiency of this enzyme leads to sucrose and glucan malabsorption resulting in osmotic diarrhoea. Onset of clinical symptoms is usually after the first year of life when sucrose consumption increases. This often results in failure to thrive (3,4). Clinical reports on patients with SI deficiency (SID) are rare. Only limited information about therapeutic success is available in the literature (5-7). We present 4 patients, 3 with congenital and 1 with a putatively acquired SID, who clinically improved after therapy with sacrosidase was initiated.
-
compound heterozygous mutations affect protein folding and function in patients with congenital Sucrase isomaltase deficiency
Gastroenterology, 2009Co-Authors: Marwan Alfalah, Klauspeter Zimmer, Markus Keiser, Tosso Leeb, Hassan Y. NaimAbstract:BACKGROUND & AIMS: Congenital Sucrase-isomaltase (SI) deficiency is an autosomal-recessive intestinal disorder characterized by a drastic reduction or absence of Sucrase and isomaltase activities. Previous studies have indicated that single mutations underlie individual phenotypes of the disease. We investigated whether compound heterozygous mutations, observed in some patients, have a role in disease pathogenesis. METHODS: We introduced mutations into the SI complementary DNA that resulted in the amino acid substitutions V577G and G1073D (heterozygous mutations found in one group of patients) or C1229Y and F1745C (heterozygous mutations found in another group). The mutant genes were expressed transiently, alone or in combination, in COS cells and the effects were assessed at the protein, structural, and subcellular levels. RESULTS: The mutants SI-V577G, SI-G1073D, and SI-F1745C were misfolded and could not exit the endoplasmic reticulum, whereas SI-C1229Y was transported only to the Golgi apparatus. Co-expression of mutants found on each SI allele in patients did not alter the protein's biosynthetic features or improve its enzymatic activity. Importantly, the mutations C1229Y and F1745C, which lie in the Sucrase domains of SI, prevented its targeting to the cell's apical membrane but did not affect protein folding or isomaltase activity. CONCLUSIONS: Compound heterozygosity is a novel pathogenic mechanism of congenital SI deficiency. The effects of mutations in the Sucrase domain of SIC1229Y and SIF1745C indicate the importance of a direct interaction between isomaltase and sucrose and the role of sucrose as an intermolecular chaperone in the intracellular transport of SI.
Buford L Nichols - One of the best experts on this subject based on the ideXlab platform.
-
13c labeled starch breath test in congenital Sucrase isomaltase deficiency
Journal of Pediatric Gastroenterology and Nutrition, 2018Co-Authors: Claudia C Robayotorres, Marisela Diazsotomayor, Bruce R Hamaker, Susan S Baker, Bruno P Chumpitazi, Antone R Opekun, Buford L NicholsAbstract:ABSTRACTBackground and Hypotheses:Human starch digestion is a multienzyme process involving 6 different enzymes: salivary and pancreatic α-amylase; Sucrase and isomaltase (from sucrose-isomaltase [SI]), and maltase and glucoamylase (from maltase-glucoamylase [MGAM]). Together these enzymes cleave st
-
improved starch digestion of Sucrase deficient shrews treated with oral glucoamylase enzyme supplements
Journal of Pediatric Gastroenterology and Nutrition, 2017Co-Authors: Buford L Nichols, Stephen E Avery, Roberto Quezadacalvillo, Shadi B Kilani, Amy Huimei Lin, Douglas G Burrin, Benjamin E Hodges, Shaji K ChackoAbstract:BACKGROUND AND OBJECTIVE Although named because of its sucrose hydrolytic activity, this mucosal enzyme plays a leading role in starch digestion because of its maltase and glucoamylase activities. Sucrase-deficient mutant shrews, Suncus murinus, were used as a model to investigate starch digestion in patients with congenital Sucrase-isomaltase deficiency.Starch digestion is much more complex than sucrose digestion. Six enzyme activities, 2 α-amylases (Amy), and 4 mucosal α-glucosidases (maltases), including maltase-glucoamylase (Mgam) and Sucrase-isomaltase (Si) subunit activities, are needed to digest starch to absorbable free glucose. Amy breaks down insoluble starch to soluble dextrins; mucosal Mgam and Si can either directly digest starch to glucose or convert the post-α-amylolytic dextrins to glucose. Starch digestion is reduced because of Sucrase deficiency and oral glucoamylase enzyme supplement can correct the starch maldigestion. The aim of the present study was to measure glucogenesis in suc/suc shrews after feeding of starch and improvement of glucogenesis by oral glucoamylase supplements. METHODS Sucrase mutant (suc/suc) and heterozygous (+/suc) shrews were fed with C-enriched starch diets. Glucogenesis derived from starch was measured as blood C-glucose enrichment and oral recombinant C-terminal Mgam glucoamylase (M20) was supplemented to improve starch digestion. RESULTS After feedings, suc/suc and +/suc shrews had different starch digestions as shown by blood glucose enrichment and the suc/suc had lower total glucose concentrations. Oral supplements of glucoamylase increased suc/suc total blood glucose and quantitative starch digestion to glucose. CONCLUSIONS Sucrase deficiency, in this model of congenital Sucrase-isomaltase deficiency, reduces blood glucose response to starch feeding. Supplementing the diet with oral recombinant glucoamylase significantly improved starch digestion in the Sucrase-deficient shrew.
Anil K. Ghosh - One of the best experts on this subject based on the ideXlab platform.
-
Characterisation of an acid trehalase of Saccharomyces cerevisiae present in trehalase-Sucrase aggregate
Biochimica et Biophysica Acta, 1996Co-Authors: Nilima Biswas, Anil K. GhoshAbstract:Abstract An acid trehalase-Sucrase aggregate was purified (by 780-fold) from Saccharomyces cerevisiae, following conventional protein purification techniques, to an apparent yield of 18.5%. The aggregate was electrophoretically homogeneous but contained 175, 90, 68, 60, 40 molar mass (kDa) bands on SDS-electrophoresis. The purified aggregate had a specific activity (acid trehalase) of 22 u/mg; a Km value of 5.0 mM but contained 3-times more Sucrase activity. Only sucrose and trehalose were hydrolysed by this aggregate and both activities were inhibited by acetate or phosphate. Temperature and pH optima for trehalose hydrolysis appeared to be 40–45°C and 5.0, respectively. The purified aggregate appeared to be disaggregating spontaneously resulting in inactivation of both enzymes, which was enhanced either at pH 3.5 or at pH 7.0. Separation of acid trehalase from the aggregate by hydrophobic interaction chromatography resulted in inactivation. Rechromatography (HPGPLC) of the purified aggregate also gave disaggregation as well as inactivation of both enzymes. Disaggregated acid trehalase and Sucrase contained 20-fold and 13-fold lower specific activities, respectively, and appeared to be unstable. Based on these observations we suggest that acid trehalase is stabilised by aggregation with Sucrase.
Jeffrey S. Hyams - One of the best experts on this subject based on the ideXlab platform.
-
Evaluation of liquid yeast-derived Sucrase enzyme replacement in patients with Sucrase-isomaltase deficiency
Gastroenterology, 1993Co-Authors: William R. Treem, Naheedt Ahsan, Barbara A. Sullivan, Thomas M. Rossi, Ronald Holmes, Joseph Fitzgerald, Roy Proujansky, Jeffrey S. HyamsAbstract:Abstract Background: No enzyme replacement therapy exists for patients with congenital Sucrase-isomaltase deficiency (CSID). A by-product of the manufacture of baker's yeast is a liquid preparation containing high Sucrase activity. The aim of the present study was to investigate the activity and stability of this preparation and its effect on breath hydrogen excretion and gastrointestinal symptoms after sucrose ingestion in 14 patients with CSID. Methods: The homogeneity of yeast Sucrase was studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its activity was measured. Stability at various temperatures and pH ranges and in the presence of gastric aspirate, pepsin, and bovine serum albumin was assessed. Fourteen patients with CSID underwent double-blind placebo-controlled breath tests with yeast Sucrase. They then completed an 8-week dose response study that used different enzyme concentrations while consuming a sucrose-containing diet. Results: Liquid yeast Sucrase is highly glycosylated, contains no lactase activity, and is stable at 4 °C and over a wide range of pH. Pepsin digestion of the enzyme in vitro can be blunted by bovine serum albumin and by increasing the pH. Yeast Sucrase reduces breath hydrogen excretion in patients with CSID who are given a sucrose load ( P Conclusions: Liquid yeast Sucrase offers effective enzyme replacement therapy for patients with CSID.
V Zamvar - One of the best experts on this subject based on the ideXlab platform.
-
congenital Sucrase isomaltase deficiency diagnostic challenges and response to enzyme replacement therapy
Archives of Disease in Childhood, 2015Co-Authors: J W L Puntis, V ZamvarAbstract:Congenital Sucrase-isomaltase (SI) deficiency is a rare genetic condition characterised by a deficiency in the brush-border SI enzyme, resulting in an inability to metabolise sucrose and starches. Six cases of congenital SI deficiency treated with Sucraid (sacrosidase, a yeast-derived enzyme that facilitates sucrose digestion) are described. Typical presenting symptoms were watery diarrhoea, abdominal pain and bloating, sometimes noticeably worse after ingestion of fruit. Diagnosis is challenging since conventional hydrogen breath testing after an oral sucrose load is impractical in young children, and many laboratories no longer look for maldigested sucrose using faecal sugar chromatography. Confirmation is by disaccharidase assay of duodenal or jejunal mucosa obtained endoscopically. All six patients showed little improvement following advice regarding dietary management, but experienced a marked reduction in symptoms with sacrosidase administration; no adverse events were reported. Sacrosidase is an effective and well-tolerated treatment for patients with congenital SI deficiency. Gene testing and clinical trial of sacrosidase may become an alternative to endoscopic biopsies for diagnosis.
