Clinical chemistry
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Hyperhomocysteinemia has been associated with a higher risk of cardiovascular disease (CVD) in epidemiological studies, but recent trials have failed to show a benefit of lowering homocysteine. To address this apparent paradox, we explored whether interaction between genetic and dietary factors related to homocysteine metabolism contributes to CVD risk. ⋯ In this large-scale prospective study, the association of homocysteine with CVD was markedly attenuated after adjusting for risk factors and was not modified by MTHFR 677C>T or intake of folate or B-vitamins.
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Comparative Study
Diagnostic accuracy of ELISA and xMAP technology for analysis of amyloid beta(42) and tau proteins.
Cerebrospinal fluid (CSF) concentrations of amyloid beta(42) (Abeta(42)) peptides and tau proteins may serve as biomarkers for Alzheimer disease (AD). Recently, the xMAP technology has been introduced as an alternative to ELISA for measurement of these markers. ⋯ A constant conversion factor cannot be used successfully to recalculate results obtained with xMAP assays to those from the ELISAs. With the use of analysis of a combination of Abeta(42), t-tau, and p-tau in CSF, however, differentiation of clinical groups is equivalent when either xMAP technology or conventional ELISA is used.
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Although the blood lactate-to-pyruvate (L:P) molar ratio is used to distinguish between pyruvate dehydrogenase deficiency (PDH-D) and other causes of congenital lactic acidosis (CLA), its diagnostic accuracy for differentiating between these 2 types of CLA has not been evaluated formally. ⋯ Usefulness of the L:P ratio for differentiating non-PDH and PDH-D types of CLA increases at higher lactate concentrations.
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Ischemic-reperfusion injury of the brain is a major adverse event after cardiac surgery, especially when extracorporeal circuits are used. Because brain injury induces local overproduction of activin A, we measured plasma concentrations in children after open heart surgery with cardiopulmonary bypass (CPB) to investigate the potential of measuring activin A for early identification of infants at risk for brain damage. ⋯ Activin A increases in children who experience poor neurologic outcomes after open heart surgery, and its assay may help in early identification of infants at risk for brain damage.
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Human beta-defensins (hBDs) are epithelial cell-derived antimicrobial and immunoregulatory cationic peptides. Our objective was to establish an analytical tool to quantify inducible hBD-2 and -3 in body fluids. ⋯ These ELISA assays can measure inducible hBD peptide concentrations in body fluids by overcoming masking effects of anionic molecules. This approach may therefore be applicable for quantifying these peptides in health and disease.