Table 1.
Figures of merit obtained from the calibration curves used for quantitation.
Table 2.
Concentrations of the analytes in the pooled urine sample.
Table 3.
MS/MS acquisition parameters.
Table 4.
Back calculated accuracy and precision levels of calibration standards and spiked samples during the validation.
Figure 1.
Typical chromatograms of the selected biomarkers extracted from the analysis of spiked urine sample.
Note: Spiking concentrations were 73 nmol/L for 8OhdG and m-Tyr, 182 nmol/L for 2-dG, o-Tyr, 3NO2-Tyr and 3Cl-Tyr and 23 μM for p-Tyr and Phe.
Figure 2.
Non-zero concentrations found from the analysis of 222 urine samples of extremely low birth-weight infants included in the double-blinded randomized clinical study REOX (REOX 2012-2013, EUDRACT 2088-005047-42).
The percentages of concentrations<LOD in the sample set were: 15% for o-Tyr, 79% for m-Tyr, 0% for p-Tyr and Phe, 93% for NO2-Tyr, 68% for 3Cl-Tyr, 0.4% for 8OH-dG and 0.4% for 2dG. Boxes indicate the 1st and the 3rd quartiles, the median is shown as a black line, whiskers mark the 9th and 91st percentiles, red triangles represent mean concentrations and blue circles are outliers.
Figure 3.
Boxplots of the ratios of o-Tyr/Phe, m-Tyr/Phe, 3NO2-Tyr/p-Tyr, 3Cl-Tyr/p-Tyr and 8OHdG/2dG for the set of non-zero urine samples included in the REOX clinical study.
Boxes indicate the 1st and the 3rd quartiles, the median is shown as a black line, whiskers mark the 9th and 91st percentiles, red triangles represent mean concentrations and blue circles are outliers.
Table 5.
Results control group (n = 6) consisting of term newborn infants born by vaginal delivery and lacking perinatal complications.