1470 wizard

Blood samples were collected from the antecubital vein of each participant after at least 12 h of fasting. The samples were processed, immediately refrigerated, transported in cold storage to the Central Testing Institute in Seoul, Korea, and analyzed within 24 h of arrival at the testing facility. Serum ferritin level was measured by immunoradiometric assay using a γ-counter (1470 Wizard, PerkinElmer, Turku, Finland), and serum alkaline phosphatase was measured using an auto-analyzer (Hitachi Automatic Analyzer 7600, Hitachi, Japan). Serum total 25-hydroxyvitamin D concentrations were measured by radioimmunoassay methods using a γ-counter (1470 Wizard, PerkinElmer, Turku, Finland), and the standard deviation index was 0.50 or less during three times assessment in Vitamin D External Quality Assessment Scheme. The coefficients of variation for intra- and inter-assay were 2.9-5.5 and 6.3-12.9% respectively and the limits of detection were 1.5 ng/mL.

Each participant’s antecubital vein was used to draw blood after they had fasted for more than eight hours in order to measure the levels of insulin, white blood cell count, fasting plasma glucose (FPG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and serum 25-hydroxyvitamin D. Blood samples were properly prepared, quickly chilled, and sent to the Central Testing Institute in cold storage (Seoul, Korea). In the course of the 24 h transportation period, blood samples were tested.
Using a 25-hydroxyvitamin D ¹²⁵I RIA kit (DiaSorin, Stillwater, MN, USA), serum 25-hydroxyvitamin D levels were determined using a gamma counter (1470 Wizard; PerkinElmer, Wallac, Turku, Finland). A Hitachi Automatic Analyzer 7600 (Hitachi, Tokyo, Japan) was used to measure the levels of FPG, TC, HDL-C, and TG utilizing enzymatic techniques using commercially available kits (1470 Wizard, Perkin Elmer). Using a gamma counter and an immunoradiometric test kit (Biosource INS-IRMA kit, Biosource Europe SA, Nivelles, Belgium), the levels of insulin were measured. Laser flow cytometry (XE-2100D, Sysmex, Kobe, Japan) was used to calculate the white blood cell counts [14 (link)].

Recombinant human leptin (R&D Systems) was labelled with ¹²⁵Iodine (Perkin Elmer) using the Iodogen method (Thermo Scientific). Mice were injected intravenously via the lateral tail vein with 12 ng (14.4 kBq) leptin in a total volume of 100 µL made up with phosphate-buffered solution. Animals were then placed in an individual cage with access to food and water until the specified time when the animal was killed by rapid CO₂ asphyxiation with n = 4 for each time point, to observe distribution over a time course. Tissues were dissected and weighed with duplicate samples placed in polypropylene tubes and measured for total γ-radioactivity (1470 Wizard, Perkin Elmer). Background radiation was subtracted from all samples. Due to equipment failure, no data were collected for brain or digestive tract at 120 min.
Blood was collected via cardiac puncture and transferred to vial containing 20 IU heparin and measured in duplicate. Total blood volume was calculated as 84.7 mL/kg body mass as previously reported (34 (link)). The skin was removed apart from that around the snout and ‘cuffs’ around the limbs and weighed intact. Four samples were taken from the left forelimb, right hindlimb, interscapular and dorsal cervical regions. Gut tissues were measured with contents.