Analysis of nitrate, nitrite, and [15N]nitrate in biological fluids
Abstract
A new automated system for the analysis of nitrate via reduction with a high-pressure cadmium column is described. Samples of urine, saliva, deproteinized plasma, gastric juice, and milk can be analyzed for nitrate, nitrite, or both with a lower limit of detection of 1.0 nmol NO3− or NO2−/ml. The system allows quantitative reduction of nitrate and automatically eliminates interference from other compounds normally present in urine and other biological fluids. Analysis rate is 30 samples per hour, with preparation for most samples limited to simple dilution with distilled water. The application of gas chromatography/mass spectrometry for the analysis of 15NO3− in urine after derivatization to 15NO2-benzene is also described.
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Masson Pine pollen (Pinus massoniana) activate HD11 chicken macrophages in vitro
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The present study tested if and how MP material activates HD11 chicken macrophages in vitro using material from different production sites and harvest years.
We applied twelve batches of MP from different Chinese production sites and harvest years. Materials were subjected to LAL tests (endotoxic activity), GC-MS (fatty acid analysis), and plate techniques (microbiological background, antimicrobial activity). Furthermore, HD11 chicken macrophages were challenged (6 h, 37 °C) with MP or LPS (E. coli O111:B4), respectively, to quantify nitric oxide (NO) production and immune gene expression (RT-qPCR).
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