Clinical chemistry
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Comparative Study
Frequency, risk factors, and outcome of hyperlactatemia in HIV-positive persons: implications for the management of treated patients.
The nucleoside reverse transcriptase inhibitors used for the treatment of HIV-positive persons are now clearly associated with metabolic disorders. We determined the prevalence of and risk factors for hyperlactatemia in HIV-positive persons to assess the relevance of lactate venous blood concentrations during antiretroviral therapy. ⋯ Chronic compensated and moderate hyperlactatemia was common in our population study. Measurement of lactate, under standardized conditions, may be useful in optimizing management of HIV-positive persons on antiretroviral therapy.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Clinical and analytical performance of the liaison cardiac troponin I assay in unstable coronary artery disease, and the impact of age on the definition of reference limits. A FRISC-II substudy.
Measurements of cardiac troponins are currently used as the standard for the detection of myocardial injury. None of the current assays complies with the new requirements on assay imprecision as proposed by the European Society of Cardiology/American College of Cardiology. Our aim was to evaluate the clinical and analytical performance of the Liaison cardiac troponin I (cTnI) assay. ⋯ The Liaison cTnI assay is a sensitive assay with a CV < or =10% at the 99th percentile URL. The ability to detect age-related differences among apparently healthy individuals is unique among today's commercial assays. The results indicate that different assays seem to identify different patient cohorts for cardiac risk in the lower range of cTnI concentrations.
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Malignant hyperthermia (MH) is a fatal autosomal dominant pharmacogenetic disorder characterized by skeletal muscle hypertonicity that causes a sudden increase in body temperature after exposure to common anesthetic agents. The disease is genetically heterogeneous, with mutations in the gene encoding the skeletal muscle ryanodine receptor (RYR1) at 19q13.1 accounting for up to 80% of the cases. To date, at least 42 RYR1 mutations have been described that cause MH and/or central core disease. Because the RYR1 gene is huge, containing 106 exons, molecular tests have focused on the regions that are more frequently mutated. Thus the causative defect has been identified in only a fraction of families as linked to chromosome 19q, whereas in others it remains undetected. ⋯ Because of its sensitivity and speed, DHPLC could be the method of choice for the detection of unknown mutations in the RYR1 gene.
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Localized overheating of packed red blood cells (PRBCs) after microwave warming with consequent damage to erythrocytes has been reported. We therefore compared possible cellular markers of erythrocyte damage, as measured by flow cytometry, with laboratory indicators of hemolysis to evaluate the effects of microwave warming on PRBCs. ⋯ All markers of cellular damage were altered after heating to >47 degrees C, and a substantial part of hemolysis was delayed. The methodology can be used for future testing of other blood warming devices.