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)

Rickets and osteopenia, common problems in chronic childhood cholestasis, have been attributed to vitamin D malabsorption leading to reduced serum levels of 25(OH)-vitamin D. d-alpha-Tocopheryl polyethylene glycol-1000 succinate (TPGS), a water-soluble form of vitamin E, forms micelles at low concentration. We evaluated the potential role of TPGS in enhancing vitamin D absorption in eight children (aged 5 mo to 19 y) with severe chronic cholestasis (three extrahepatic biliary atresia, three nonsyndromic intrahepatic cholestasis, and two Alagille syndrome). To evaluate vitamin D absorption, the subjects received vitamin D3 1000 IU/kg (maximum dose of 50,000 IU); they then received the same dose of vitamin D3 mixed with TPGS (25 IU/kg). Serial serum vitamin D3 levels and areas under the curve were measured. All patients had enhanced absorption of vitamin D when it was administered in a mixture with TPGS. Mean area under the curve for serum vitamin D3 was 403.0 +/- 83.1 nmol x h/L (155.6 +/- 32.1 ng x h/mL), with a mean rise above baseline of 13.5 +/- 1.8 nmol/L (5.2 +/- 0.7 ng/mL) with vitamin D/TPGS compared with no rise when vitamin D was given alone (both p less than 0.001). Seven patients have been followed for at least 3 mo while receiving the vitamin D/TPGS combination. Those with initially low serum 25(OH)-vitamin D levels (less than 37.5 nmol/L or 15 ng/mL) had normalization (range 37.5-146 nmol/L) within 1 mo, whereas those with initially normal levels remained normal. While the patients were receiving vitamin D/TPGS, serum vitamin E to total lipid ratio either normalized or remained normal.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:d-Alpha-tocopheryl polyethylene glycol-1000 succinate enhances the absorption of vitamin D in chronic cholestatic liver disease of infancy and childhood. 154 43

Alagille syndrome (AGS) is frequently associated with growth failure, which has been attributed to concurrent congenital anomalies, cholestasis, and malabsorption and/or malnutrition. However, the underlying cause of the growth failure is not well understood. Our objective is to analyze the growth pattern in 26 patients with AGS and the possible effect that orthotopic liver transplantation (OLT) may have on this pattern. The standardized height, weight, and growth velocity of 26 pair-matched patients with AGS were compared. Thirteen patients underwent OLT. Repeated-measure ANOVA methods were used for the statistical analysis. The overall mean standardized height (z score) was -2.92 in the OLT group versus -1.88 in the non-OLT group (P =.03). The overall mean standardized weight was -1. 21 in the non-OLT group and -1.67 in the OLT group (P =.23). In 15 patients, birth weight was 2.82 +/- 0.4 kg, for a mean standardized weight of -0.95, and weight at diagnosis was 4.53 +/- 2.12 kg, for a mean standardized weight of -1.56. Bone age was delayed in the 9 patients who underwent bone-age analysis. Growth hormone therapy administered to 2 patients did not improve growth. Patients with AGS had growth failure secondary to other factors in addition to liver disease. Growth failure beginning in the prenatal period supports a genetic basis for this feature. Growth improvement up to normal levels should not be expected as a benefit of OLT in these patients. Growth failure as a primary indication for OLT should be cautiously examined in patients with AGS.
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PMID:Does liver transplantation affect growth pattern in Alagille syndrome? 1098 57

Growth retardation is one of the most prominent consequences of childhood cholestatic liver diseases. The pathogenesis of malnutrition is multifactorial and includes reduced calorie intake, fat malabsorption, abnormal protein metabolism, and increased energy expenditure. Poor growth is a typical feature of biliary atresia, cystic fibrosis, progressive familial intrahepatic cholestasis and Alagille syndrome. In some of these features it is not only directly related to impaired nutrient absorption. Liver transplantation is required if liver disease progresses to liver failure - improved nutritional status is achieved within weeks after surgery. Still, patients with Alagille syndrome present with only slight catch-up growth after transplantation, while patients with PFIC and biliary atresia grow significantly.<br />
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PMID:Factors affecting catch-up growth after liver transplantation in children with cholestatic liver diseases. 2030 23

Loss-of-function mutations in the Notch ligand, Jagged1 (Jag1), result in multi-system developmental pathologies associated with Alagille syndrome (ALGS). ALGS patients present with skeletal manifestations including hemi-vertebrae, reduced bone mass, increased fracture incidence and poor bone healing. However, it is not known whether the increased fracture risk is due to altered bone homeostasis (primary) or nutritional malabsorption due to chronic liver disease (secondary). To determine the significance of Jag1 loss in bone, we characterized the skeletal phenotype of two Jag1-floxed conditional knockout mouse models: Prx1-Cre;Jag1(f/f) to target osteoprogenitor cells and their progeny, and Col2.3-Cre;Jag1(f/f) to target mid-stage osteoblasts and their progeny. Knockout phenotypes were compared to wild-type (WT) controls using quantitative micro-computed tomography, gene expression profiling and mechanical testing. Expression of Jag1 and the Notch target genes Hes1 and Hey1 was downregulated in all Jag1 knockout mice. Osteoblast differentiation genes were downregulated in whole bone of both groups, but unchanged in Prx1-Cre;Jag1(f/f) cortical bone. Both knockout lines exhibited changes in femoral trabecular morphology including decreased bone volume fraction and increased trabecular spacing, with males presenting a more severe trabecular osteopenic phenotype. Prx1-Cre;Jag1(f/f) mice showed an increase in marrow mesenchymal progenitor cell number and, counterintuitively, developed increased cortical thickness resulting from periosteal expansion, translating to greater mechanical stiffness and strength. Similar alterations in femoral morphology were observed in mice with canonical Notch signaling disrupted using Prx1-Cre-regulatable dominant-negative mastermind like-protein (dnMAML). Taken together, we report that 1) Jag1 negatively regulates the marrow osteochondral progenitor pool, 2) Jag1 is required for normal trabecular bone formation and 3) Notch signaling through homotypic Jag1 signaling in osteochondral progenitors, but not mature osteoblasts, inhibits periosteal expansion. Therefore, Jag1 signaling within the osteoblast lineage regulates bone metabolism in a compartment-dependent manner. Moreover, loss of Jag1 function in osteoblast lineage cells may contribute to the skeletal phenotype associated with ALGS.
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PMID:Jagged1 expression by osteoblast-lineage cells regulates trabecular bone mass and periosteal expansion in mice. 2741 9

The study of human growth and skeletal development by human biologists is framed by the larger theoretical concerns regarding the underpinnings of population variation and human evolution. This unique perspective is directly relevant to the assessment of child health and well-being at the individual and group level, as well as the construction of growth charts. Environmental, behavioral (nutrition and physical activity), and disease-related factors can prevent attainment of full genetic potential for growth. Undernutrition is most often the cause of growth faltering and poor skeletal development. Disease related factors, such as malabsorption, inflammation, and immobility also have profound effects. These effects will be illustrated with examples from diseases such as cystic fibrosis, inflammatory bowel disease, and Down syndrome. The need for separate growth charts for children with genetic disorders is often controversial because of potential medical and/or nutritional complications associated with some disorders. Children with Alagille syndrome and Down syndrome will be used to illustrate the advantages and limitations of syndrome-specific charts. This overview of health and disease effects on growth and skeletal development provides insights into the plasticity of human growth and its sensitivity to overall health and well-being.
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PMID:Influence of complex childhood diseases on variation in growth and skeletal development. 2823 Feb 93