Journal: Physiological Reports

Article Title: Validation of a routine two‐sample iohexol plasma clearance assessment of GFR and an evaluation of common endogenous markers in a rat model of CKD

doi: 10.14814/phy2.13205

Figure Lengend Snippet: Sensitivity and normalization of kidney function measurements. (A–E) Change in trapezoidal plasma clearance of both iohexol and inulin and endogenous biomarkers: plasma creatinine, urea, and cystatin‐C by week of adenine diet‐induced kidney dysfunction. Results analyzed using a repeated measures one‐way ANOVA with post hoc paired T ‐tests with a Tukey correction on the P ‐value comparing each week to week 0 (* P < 0.05, ** P < 0.001, *** P < 0.0001). Error bars show SD . (F–J) The kidney function estimated by inulin plasma clearance as a reference method and the % estimated by the biomarker or iohexol were plotted against each other. An F ‐test was employed to determine whether a straight line or sixth‐order polynomial fit the data better and the result was plotted. Iohexol plasma clearance fit a straight line. Creatinine, urea, and cystatin‐C fit to a sixth‐order polynomial. Gray dotted line indicates inulin plasma clearance plotted against itself – unity.

Article Snippet: Protein precipitation was carried out by adding 100 μ L of 0.2 mol/L zinc sulfate, 450 μ L of methanol, and 1 μ g of penta‐deuterated (d5) iohexol internal standard (Toronto Research Chemicals), and mixed by vortexing after addition of each component.

Techniques: Clinical Proteomics, Biomarker Discovery

Journal: Physiological Reports

Article Title: Validation of a routine two‐sample iohexol plasma clearance assessment of GFR and an evaluation of common endogenous markers in a rat model of CKD

doi: 10.14814/phy2.13205

Figure Lengend Snippet: Comparison of inulin and iohexol trapezoidal plasma clearance to simplified one‐compartment model. (A) Plot of inulin plasma clearance as measured by trapezoidal approximation plotted against the one‐compartment model estimation. The gray dotted line indicates unity. (B) Bland–Altman plot of absolute bias of inulin one‐compartment model compared to the reference measure of inulin trapezoidal plasma clearance plotted against the mean of both clearances. The center line indicates the mean bias of −0.57 mL/min with the dotted line indicating the 95% confidence interval or 2 SD (±0.74 mL/min). (C) Plot of iohexol plasma clearance as measured by trapezoidal approximation plotted against the one‐compartment model estimation. The gray dotted line indicates unity. (D) Bland–Altman plot of absolute bias of iohexol one‐compartment model compared to the reference measure of iohexol trapezoidal plasma clearance plotted against the mean of both clearances. The center line indicates the mean bias of −0.02 mL/min with the dotted line indicating the 95% confidence interval or 2 SD (±0.26).

Article Snippet: Protein precipitation was carried out by adding 100 μ L of 0.2 mol/L zinc sulfate, 450 μ L of methanol, and 1 μ g of penta‐deuterated (d5) iohexol internal standard (Toronto Research Chemicals), and mixed by vortexing after addition of each component.

Techniques: Comparison, Clinical Proteomics

Journal: Physiological Reports

Article Title: Validation of a routine two‐sample iohexol plasma clearance assessment of GFR and an evaluation of common endogenous markers in a rat model of CKD

doi: 10.14814/phy2.13205

Figure Lengend Snippet: Iohexol plasma clearance calculated by two blood samples at 30 and 90 min. (A) Plot of iohexol two‐sample plasma clearance (30, 90) against the full 12‐sample trapezoidal approximation. The gray dotted line indicates unity. (B) Bland–Altman plot of absolute bias of two‐sample iohexol plasma clearance compared to the reference measure of iohexol trapezoidal plasma clearance plotted against the mean of both clearances. The center line indicates the mean bias of −0.04 mL/min with the dotted line indicating the 95% confidence interval or 2 SD (±0.30 mL/min). (C) Sensitivity of two‐sample iohexol plasma clearance (30, 90) to change by the week of adenine diet‐induced kidney dysfunction. Results analyzed using a one‐way ANOVA with post hoc T ‐tests with a Tukey correction on the P ‐value comparing each week to week 0 (*** P < 0.0001). Error bars show SD.

Article Snippet: Protein precipitation was carried out by adding 100 μ L of 0.2 mol/L zinc sulfate, 450 μ L of methanol, and 1 μ g of penta‐deuterated (d5) iohexol internal standard (Toronto Research Chemicals), and mixed by vortexing after addition of each component.

Techniques: Clinical Proteomics

Journal: Physiological Reports

Article Title: Validation of a routine two‐sample iohexol plasma clearance assessment of GFR and an evaluation of common endogenous markers in a rat model of CKD

doi: 10.14814/phy2.13205

Figure Lengend Snippet: Linear regression coefficients, mean bias, precision, and accuracy comparing all plasma clearance measures of both inulin and iohexol

Article Snippet: Protein precipitation was carried out by adding 100 μ L of 0.2 mol/L zinc sulfate, 450 μ L of methanol, and 1 μ g of penta‐deuterated (d5) iohexol internal standard (Toronto Research Chemicals), and mixed by vortexing after addition of each component.

Techniques: Clinical Proteomics

Journal: Physiological Reports

Article Title: Validation of a routine two‐sample iohexol plasma clearance assessment of GFR and an evaluation of common endogenous markers in a rat model of CKD

doi: 10.14814/phy2.13205

Figure Lengend Snippet: Two‐sample permutations of iohexol one‐compartment plasma clearance compared to iohexol plasma clearance calculated by trapezoidal, one‐, and two‐compartment models – linear regression coefficients, bias, precision, and accuracy

Article Snippet: Protein precipitation was carried out by adding 100 μ L of 0.2 mol/L zinc sulfate, 450 μ L of methanol, and 1 μ g of penta‐deuterated (d5) iohexol internal standard (Toronto Research Chemicals), and mixed by vortexing after addition of each component.

Techniques: Clinical Proteomics