Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cystic fibrosis (CF) is associated with many clinical complications including steatosis for which the relation to defective CF transmembrane conductance regulator protein is unclear. Choline deficiency results in hepatic steatosis. Choline is the precursor of betaine, which donates methyl groups for remethylation of homocysteine to methionine and dimethylglycine. Previously, we have shown phospholipid malabsorption and increased plasma homocysteine in children with CF. In these studies we used normal phase HPLC with tandem mass spectrometry to determine plasma choline, betaine, and dimethylglycine in children with CF (n = 34) and healthy control children without CF (n = 15). Plasma choline, betaine, and dimethylglycine were significantly lower in children with CF (means +/- SEM, 6.48 +/- 0.35, 23.8 +/- 1.49, 1.49 +/- 0.13 mumol/L, respectively) than in children without CF (8.98 +/- 0.46, 37.3 +/- 1.84, 3.01 +/- 0.17 mumol/L, respectively). Plasma choline (r = 0.373, P = 0.007) and betaine (r = 0.399, P = 0.005) were positively related to methionine, and choline was inversely related to homocysteine (r = -0.316, P = 0.03). Choline, betaine, and dimethylglycine were all significantly and positively related to the plasma S-adenosylmethionine:S-adenosylhomocysteine (SAM:SAH) ratio (r = 0.294, r = 0.377, r = 0.442, respectively; P < 0.05). The plasma choline:betaine and betaine:dimethylglycine ratios did not differ between the children with CF and the control children, suggesting no increase in betaine synthesis, or betaine-dependent remethylation of homocysteine. These studies suggest that choline depletion may contribute to increased homocysteine in children with CF. Choline depletion and altered thiol metabolism may contribute to the clinical complications associated with CF.
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PMID:Evidence of choline depletion and reduced betaine and dimethylglycine with increased homocysteine in plasma of children with cystic fibrosis. 1685 45

There are three families of glucose transporters in the human genome, SLC2, SLC5 and SLC50. Here I review the structure and function of the SLC5 and SLC50 genes. The human sodium glucose cotransporter family (SLC5) has 12 human genes expressed in tissues ranging from epithelia to the central nervous system. The functions of all are known based on studies using heterologous expression systems: 10 are tightly coupled plasma membrane Na(+)/substrate cotransporters for solutes such as glucose, myoinositol, and anions; 1 is a Na(+)/Cl(-)/Choline cotransporter; and another is a glucose activated ion channel. The exon organization of most of the genes is similar in that they contain 14-15 exons. However, the choline transporter CHT is encoded in by the 8 exon SLC5A7 gene and the myoinositol SMIT transporter by the 1 exon SLC5A3 gene. Mutations in 3 SLC5 genes produce genetic phenotypes (glucose-galactose-malabsorption, renal glucosuria and hypothyroidism). Members of the SLC5 family are multifunctional membrane proteins in that they also behave as uniporters, urea and water channels, and urea and water cotransporters. The atomic structure of a closely related bacterial homolog has been solved and the structural core is common to six unrelated transporters, e.g. members of the SLC6 family of neurotransporters, and this leads to the conclusion that these work by a similar mechanism. The new SWEET class of glucose uniporters, SLC50, only has only one member in the human genome, SLC50A1. The SWEETs are found mostly in plants where they appear to be responsible for sugar efflux and are targeted by pathogens and symbionts for nutrition.
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PMID:Glucose transport families SLC5 and SLC50. 2350 65