Hansen KE, et al. Assay variation confounds the diagnosis of hypovitaminosis D: a call for standardization. J Clin Endocrinol Metab 2004;89: 3152–7. 4. Souberbielle JC, Fayol V, Sault C, Lawson-Body E, Kahan A, Cormier C. Assay-specific decision limits for two new automated parathyroid hormone and 25-hydroxyvitamin D assays. Clin Chem 2005;51:395–400. 5. Singh RJ, Taylor RL, Reddy GS, Hollis BW...

Activated polymorphonuclear leucocytes (neutrophils) can generate both intracellular and extracellular luminol dependent chemiluminescence. As luminol dependent chemiluminescence largely measures the activity of the myeloperoxidase-H2O2 system, and as the extracellular activity of this enzyme may be responsible for the tissue damage associated with inflammatory conditions such as rheumatoid art...

Hydroquinone, a metabolite of benzene, is converted by human myeloperoxidase to 1,4-benzoquinone, a highly toxic species. This conversion is stimulated by phenol, another metabolite of benzene. Here we report that peroxidase-dependent hydroquinone metabolism is also stimulated by catechol, resorcinol, o-cresol, m-cresol, p-cresol, guaiacol, histidine, and imidazole. In order to gain insights in...

The relationship between the toxic effect of propylthiouracil (PTU) and myeloperoxidase activity of rat bone marrow was examined. The administration of PTU for 1 or 2 weeks caused a decrease in leukocyte count with the concomitant inhibition of the activity of myeloperoxidase in the bone marrow. The decreases in both leukocyte counts and myeloperoxidase activity were restored to control levels ...