Dimension rxl max analyzer

After overnight fasting (>10 h), blood samples were collected in tubes containing separating gel for the measurement of the biomarkers. The samples were maintained at 4°C for <2 h before being centrifuged at 1200 g for 15 min at 4°C. Serum aliquots were frozen at -80°C. Levels of TC, LDL-C, triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), ALT, AST, and CK were determined using Roche enzymatic assays (Roche Diagnostics GmbH, Germany) and a Roche auto-analyzer (Roche Diagnostics, USA). Levels of serum creatinine (Scr) were measured by an enzymatic assay (Roche Diagnostics GmbH) on a Hitachi 7600 auto-analyzer (Hitachi, Japan). Levels of high-sensitivity C-reactive protein (hs-CRP) was determined by an immunoturbidimetric assay (Siemens Healthcare Diagnostics, USA) using a Dimension RxL Max analyzer (Siemens Healthcare Diagnostics). Serum homocysteine (Hcy) levels were measured by a competitive immunoassay using direct chemiluminescence (Siemens Centaur Immunoassay Systems, USA). Serum matrix metalloproteinase-9 (MMP-9) levels were determined using a commercial ELISA kit (R&D Systems Inc., USA).

All blood samples were obtained immediately before the mid-week dialysis session after a 12-hour fast. The following serum parameters were considered: urea, creatinine, and potassium, C-reactive protein (CRP), hemoglobin (Hb), total cholesterol, HDL- and LDL-cholesterol, triglycerides, albumin, iron, vitamin D, and intact parathyroid hormone (iPTH). After the dialysis procedure serum urea, creatinine and potassium analyses were repeated. Concentrations of biochemical blood parameters were obtained spectrophotometrically using the Siemens Dimension Rxl Max analyzer. The value of CRP was calculated via enhanced turbidimetric-immunoassay (PETIA) using the Siemens Dimension RxlMax analyzer. The Kt/V value quantifying the hemodialysis efficiency was calculated using the formula proposed by Daugirdas and Blake (38 (link)). Aliquots of the remaining serum were made immediately, and these samples were stored at −80 °C for further analysis of trace metal profiles (zinc, copper) and fatty acids.

The patients were part of a previous research series [16 ] created to study the left ventricular mass in patients with HIV infection. The patients in this serie who were aged over 40 years were invited to cooperate in the present study, to determine levels of NT-proBNP in peripheral blood. When consent was given, a serum sample was extracted, frozen to −70°C and stored until needed for the NT-proBNP analysis.
NT-proBNP (amino acid residues 1–76) was measured using the Dimension RxL Max Analyzer (Siemens), lower limit of detection 10 ng/l. For all patients, epidemiological such as age and gender, and clinical (duration of HIV, duration of ART, BMI…) data were compiled, together with the classical cardiovascular risk factors and variables associated with HIV infection status.
These aspects are described in detail in the descriptive part of the series as a whole.