Clin Lab
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We evaluated the chemiluminescence immunoassays for the detection of the cardiac markers troponin I, myoglobin and CK-MB on the IMMULITE System (Diagnostic Products Corporation) in comparison to the same analytes of other companies. The IMMULITE assays are two-site solid phase immunometric assays using a murine monoclonal capture antibody on the solid phase and a polyclonal antibody conjugated with alkaline phosphatase (except CK-MB monoclonal, murine) for detection. Precision was investigated using serum pools with a low, a cutoff and a high concentration of the respective analyte. ⋯ The Abbott-Troponin I showed the highest diagnostic sensitivity within 4 hours after admission. All compared methods showed a similar diagnostic sensitivity (close to 100%) > 4 hours after admission. For all investigated methods the percentage of discrepant results decreased to a minimum 4 hours after admission.
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Natriuretic peptides, atrial natriuretic peptide and brain natriuretic peptide, are key regulators in the homeostasis of salt and water excretion and in the maintenance of blood pressure. During heart failure, these peptides are highly activated because of volume overload and increased myocardial wall tension. Among all natriuretic peptides and neurohormones, brain natriuretic peptide and its N-terminal prohormone fragment have been shown to be the best markers to identify patients with heart failure. ⋯ Sensitive and specific assays without the need for plasma extraction are commercially available. The available data indicate that natriuretic peptides are powerful diagnostic and prognostic markers in heart failure patients. First data on treatment guidance are promising.
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Protease inhibitors are known by their inhibition of a viral protease that leads to production of immature and non-infectious virus particles. The novel protease inhibitor KALETRA is a co-formulation of lopinavir and ritonavir. Ritonavir reduces the metabolization of lopinavir by the cytochrome P450 3A4 isoenzyme which leads to markedly increased plasma levels of lopinavir(4). ⋯ An aliquot of 500 microl plasma, spiked with internal standard, was extracted with 500 microl 0.1 M ammonium hydroxide solution and 5 ml tert. -butyl ether. After drying under a nitrogen stream, the residue was redissolved in an eluent consisting of 50 mM phosphate buffer, pH 5.40 and acetonitrile (50:50, v/v). Chromatographic separation was accomplished on a C-18 column using a non-linear gradient elution and ultraviolet detection at 215 nm.
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Comparative Study
Precision and comparability of Abuscreen OnLine assays for drugs of abuse screening in urine on Hitachi 917 with other immunochemical tests and with GC/MS.
Abuscreen OnLine assays for drugs of abuse screening in urine have recently been developed for use on Hitachi 917 analyzers (Roche Diagnostics GmbH). The assays are based on the kinetic interaction of microparticles as measured by changes in light transmission. Drug in a sample inhibits the formation of particle aggregates and diminishes absorbance change increases. ⋯ GC/MS was performed for clarification of the discrepant results. In summary, Abuscreen OnLine tests on Hitachi 917 give precise results which compare well when analyzed in different laboratories. They can be rated as convenient and flexible methods for drugs of abuse screening in the routine.
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Comparative Study
Effect of 6-hour exposure to 20 degrees C on the ATP content and other biochemical measures of CPDA-1 packed red cells.
Blood donations for clinical use are routinely stored at 2 degrees C to 6 degrees C for 35 to 42 days. It is common practice for RBCs exposed to temperatures above 10 degrees C to be destroyed, although the American Association of Blood Banks Technical Manual states "Blood exposed to temperatures above 10 degrees C is not necessarily unsuitable for transfusion". To clarify this issue we investigated the effect of 6-hour storage at 20 degrees C on the content of ATP and other biochemical measures of CPDA-1 packed red cells. ⋯ Our data show that a shorter period of moderate warming (6h, 20 degrees C) does not lead to a critical decline of ATP and glucose concentrations in CPDA-1 packed RBCs. The survival of RBCs stored in CPDA-1 is most highly correlated with maintaining ATP concentrations above a value of about 2 mumol per g of Hb [3]. The ATP levels in our study were well above this threshold.