Vitamin B12 status, methylmalonic acidemia, and bacterial overgrowth in short bowel syndrome.

Pediatric Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, IL 60637, USA.
Journal of pediatric gastroenterology and nutrition (Impact Factor: 2.18). 05/2009; 48(4):495-7. DOI:10.1097/MPG.0b013e31817f9e5b
Source: PubMed
0 0
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Neonatal short bowel syndrome is a disease with a high morbidity and mortality. The management of these patients is complex and requires a multidisciplinary approach. Recent advances in medical and surgical treatment options have improved outcomes. The following review highlights salient points in the management of this challenging patient population.
    Seminars in Fetal and Neonatal Medicine 03/2011; 16(3):157-63. · 3.51 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Cobalamin deficiency is relatively common, but the great majority of cases in epidemiologic surveys have subclinical cobalamin deficiency (SCCD), not classical clinical deficiency. Because SCCD has no known clinical expression, its diagnosis depends solely on biochemical biomarkers, whose optimal application becomes crucial yet remains unsettled. This review critically examines the current diagnostic concepts, tools, and interpretations. Their exploration begins with understanding that SCCD differs from clinical deficiency not just in degree of deficiency but in fundamental pathophysiology, causes, likelihood and rate of progression, and known health risks (the causation of which by SCCD awaits proof by randomized clinical trials). Conclusions from SCCD data, therefore, often may not apply to clinical deficiency and vice versa. Although many investigators view cobalamin testing as unreliable, cobalamin, like all diagnostic biomarkers, performs satisfactorily in clinical deficiency but less well in SCCD. The lack of a diagnostic gold standard limits the ability to weigh the performance characteristics of metabolic biomarkers such as methylmalonic acid (MMA) and holotranscobalamin II, whose specificities remain incompletely defined outside their relations to each other. Variable cutoff selections affect diagnostic conclusions heavily and need to be much better rationalized. The maximization of reliability and specificity of diagnosis is far more important today than the identification of ever-earlier stages of SCCD. The limitations of all current biomarkers make the combination of ≥2 test result abnormalities, such as cobalamin and MMA, the most reliable approach to diagnosing deficiency in the research setting; reliance on one test alone courts frequent misdiagnosis. Much work remains to be done.
    American Journal of Clinical Nutrition 07/2011; 94(1):348S-358S. · 6.50 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The mechanical properties of SiCf/SiC composites have been investigated, based on detailed analyses of their microstructure. SiCf/SiC composites were prepared from fiber preforms by a slurry infiltration technique, in which a mixture with SiC, Al2O3, and Y2O3 particles was impregnated into the fabric structure. SiCf/SiC composites were consolidated by liquid phase sintering process, associated with the creation of secondary phases by the addition of Al2O3 and Y2O3 particles. The reinforcing material was a plain weave Tyranno SA SiC fabric with a carbon interfacial layer. The sintered density and the pore volume fraction of SiCf/SiC composites were about 3.0Mg/m3 and about 10%, respectively. These SiCf/SiC composites had an average flexural strength of about 250MPa at room temperature. They exhibited pseudo-ductile fracture behavior, due to the carbon interfacial layer. The introduction of the carbon interfacial layer greatly improved the fracture energy of SiCf/SiC composites.
    Journal of Nuclear Materials 01/2011; 417(1):344-347. · 1.21 Impact Factor