Evaluation of intraosseous sampling for measurements of alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, creatinine kinase, gamma-glutamyl transferase and lactate dehydrogenase.

BACKGROUND: Intraosseous (IO) access can be established faster than a venous or arterial access when there is an urgent need for rapid initiation of treatment. The access can also be used to draw marrow samples. The aim of the present study was to evaluate the potential use of IO samples for enzyme determinations using a porcine model. MATERIALS AND METHODS: Bilateral tibial intraosseous cannulae and an arterial catheter were used for blood sampling from five healthy anesthetized pigs. Samples were collected at baseline and thereafter hourly for 6 h and analyzed for alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, creatinine kinase, gamma-glutamyl transferase and lactate dehydrogenase. RESULTS: Creatinine kinase, lactate dehydrogenase and alkaline phosphatase levels decreased over time. The differences between IO and arterial sampling were limited for all studied markers. CONCLUSION: The correlation between marrow and blood analysis for liver function tests and CK is sufficiently accurate in an emergency situation.

Immunohistochemical evidence for the myeloperoxidase/H2O2/halide system in human atherosclerotic lesions: colocalization of myeloperoxidase and hypochlorite-modified proteins.

The 'oxidation theory' of atherosclerosis proposes that oxidation of low density lipoprotein (LDL) contributes to atherogenesis. Although the precise mechanisms of in vivo oxidation are widely unknown, increasing evidence suggests that myeloperoxidase (MPO, EC 1.11.1.7), a protein secreted by activated phagocytes, generates modified/oxidized (lipo)proteins via intermediate formation of hypochlorous acid (HOCl). In vitro generation of HOCl transforms lipoproteins into high uptake forms for macrophages giving rise to cholesterol-engorged foam cells. To identify HOCl-modified-epitopes in human plaque tissues we have raised monoclonal antibodies (directed against human HOCl-modified LDL) that do not cross-react with other LDL modifications, i.e. peroxynitrite-LDL, hemin-LDL, Cu2+-oxidized LDL, 4-hydroxynonenal-LDL, malondialdehyde-LDL, glycated-LDL, and acetylated-LDL. The antibodies recognized a specific epitope present on various proteins after treatment with OCl- added as reagent or generated by the MPO/H2O2/halide system. Immunohistochemical studies revealed pronounced staining for HOCl-modified-epitopes in fibroatheroma (type V) and complicated (type VI) lesions, while no staining was observed in aortae of lesion-prone location (type I). HOCl-oxidation-specific epitopes are detected in cells in the majority of atherosclerotic plaques but not in control segments. Staining was shown to be inside and outside monocytes/macrophages, endothelial cells, as well as in the extracellular matrix. A similar staining pattern using immunohistochemistry could be obtained for MPO. The colocalization of immunoreactive MPO and HOCl-modified-epitopes in serial sections of human atheroma (type IV), fibroatheroma (type V) and complicated (type VI) lesions provides further convincing evidence for MPO/H2O2/halide system-mediated oxidation of (lipo)proteins under in vivo conditions. We propose that MPO could act as an important link between the development of atherosclerotic plaque in the artery wall and chronic inflammatory events.