Architect c8000 analyzer

An ELISA kit (OxiSelect^™ Oxidative DNA Damage ELISA Kit, Cat. No: STA-320; Cell Biolabs Inc., San Diego, CA, USA) was used to detect urine 8-Oxo-2’-deoxyguanosine (8-OHdG) concentration, which was stated as ng/mg creatinine. Coefficients of intra- and inter-assay variations were 3.0% (n=20), and 3.9% (n=20), respectively.
Other biochemical parameters were measured using routine methods with commercial kits. Urine creatinine (spot) level was measured using Jaffe method with Architect c8000 analyzer (Abbott Diagnostics, Lake Forest, IL, USA). Serum creatinine clearance was calculated using Cockroft-Gault formula. Albumin excretion in 24-hour urine samples was measured using Roche Hitachi P800 analyzer (Roche Diagnostics, Rotkreuz, Switzerland) with ALBT2 microalbumin kit in 24-hour urine samples and mean value was calculated as daily albumin excretion (11 ). Normoalbuminuria was defined as albumin excretion of ≤30 mg/24h. Microalbuminuria (MAU) and clinical albuminuria were defined as albumin excretion of 30–299 mg/24h and ≥300/24h, respectively (11 ).

A separate set of animals were decapitated 30 min or two hours after HTS/ITS administrations, and their trunk blood was collected in EDTA tubes. The blood samples were centrifuged, and the separated plasma was collected. Other set of animals were anesthetized with a mixture of ketamine (100 mg/kg) and dexmedetomidine (0.5 mg/kg) administered together subcutaneously (2 mL/kg) 30 min or two hours after HTS/ITS administrations, and CSF samples were collected via a cannula placed in the CM in a similar manner as before intracisternal tracer administrations. The osmolalities of the plasma and CSF samples were measured by the freezing-point method using a Type 15 Micro-Osmometer (Löser Meßtechnik). Sodium concentration of the plasma samples were determined with ion-selective electrode-based method using an ARCHITECT c8000 analyzer (Abbott Diagnostics).

Blood samples were collected following an overnight fast. Blood was centrifuged at 2000×g for 20 min and the plasma was frozen at −40°C until analysis (within 3 months). Plasma glucose, calcium, phosphorus, and C-reactive protein (CRP) were assessed on Architect C8000 analyzer (Abbott Laboratories, Abbott Park, IL), using the respective reagents kits. Plasma 25-hydroxyvitamin D (25-OHD) and insulin concentrations were measured by chemiluminescence immunoassay methods using the Liaison analyzer (DiaSorin Inc., Stillwater, MN) and the respective reagents kit. Vitamin D status was evaluated according to the standards of the Institute of medicine (IOM). Vitamin D deficiency, insufficiency, and sufficiency were defined as plasma 25-OHD concentrations below 12 µg/L, 12 to 20 µg/L, and over 20 µg/L, respectively (24 ). Insulin sensitivity/resistance was assessed using two indexes; the homeostasis model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI), according to the following equations (25 (link), 26 (link)): HOMA-IR=[(fasting insulin in µU/mL) − (fasting glucose in mg/dL)/405]; QUICKI=1/[log(fasting insulin in µU/mL)+log(fasting glucose in mg/dL)].