quantikine human vegf d immunoassay kit  (R&D Systems)

Journal: Investigative Ophthalmology & Visual Science

Article Title: Modeling the Ocular Pharmacokinetics and Pharmacodynamics of Ranibizumab for Improved Understanding and Data Collection Strategies in Ocular Diseases

doi: 10.1167/iovs.66.6.20

Figure Lengend Snippet: Schematic diagram of the two-compartment pharmacodynamic model of VEGF (V) and ranibizumab (R) interactions in the eye. We assume that the eye is composed of the vitreous (left) and the aqueous humor (right) compartments. Experimental samples of VEGF and ranibizumab were collected from the aqueous humor compartment, and the injection of ranibizumab at time t = 0 is delivered to the vitreous compartment. Figure adapted from Hutton-Smith et al.

Article Snippet: The ELISA technique used by Niwa et al. (Quantikine Human VEGF Immunoassay; R&D Systems, Minneapolis, MN, USA) is supposed to measure only free VEGF via locating the free binding sites on the VEGF molecules.

Techniques: Injection

Journal: Investigative Ophthalmology & Visual Science

Article Title: Modeling the Ocular Pharmacokinetics and Pharmacodynamics of Ranibizumab for Improved Understanding and Data Collection Strategies in Ocular Diseases

doi: 10.1167/iovs.66.6.20

Figure Lengend Snippet: Sensitivity indices for each parameter considering the key pharmacokinetic metrics and v aq and r aq over time. ( A ) The key pharmacokinetic metrics (PM) and phases (P) annotated across a sample aqueous VEGF concentration profile: PM1 = time of initial VEGF increase; PM2 + VEGF relaxation time; P1 = the initial VEGF concentration data point; P2 = region of VEGF suppression; P3 = the VEGF transition region; and P4 = the VEGF return to equilibrium. ( B – D ) The first-order ( gray ) and total sensitivity indices ( black ) for ( B ) the point of initial v aq return (PM1), ( C ) the v aq relaxation time (PM2), and ( D ) the r aq half-life (PM3). For each sensitivity index in B through D , the lines protruding from the bars give the upper region of the 95% CI. Note that some values are near zero and the first order sensitivity indices for many parameters are near zero. ( E and F ) The first-order ( solid ) and total sensitivity indices ( dashed ) change over time as v aq and r aq evolve. The 95% CI is shown in the narrow shaded region in E and F , which is often too small to be visible. The color code for E and F is shown in F .

Article Snippet: The ELISA technique used by Niwa et al. (Quantikine Human VEGF Immunoassay; R&D Systems, Minneapolis, MN, USA) is supposed to measure only free VEGF via locating the free binding sites on the VEGF molecules.

Techniques: Concentration Assay

Journal: Investigative Ophthalmology & Visual Science

Article Title: Modeling the Ocular Pharmacokinetics and Pharmacodynamics of Ranibizumab for Improved Understanding and Data Collection Strategies in Ocular Diseases

doi: 10.1167/iovs.66.6.20

Figure Lengend Snippet: Semi-mechanistic two-compartment model of intraocular ranibizumab and VEGF PK/PD following a single intravitral bolus of ranibizumab. The mean model fits using data extracted from Niwa et al. are shown in blue . The gray regions show 1 SD around the mean model fit. From left to right, the top row shows the vitreous concentration of ( A ) VEGF (V), ( B ) ranibizumab (R), ( C ) partially bound VEGF (VR), and ( D ) fully bound VEGF (RVR). Similarly, the bottom row ( E – H ) shows the aqueous concentration of each molecular species in the same order. The mean SD of the aqueous VEGF and the aqueous ranibizumab data extracted from Niwa et al. are shown by the black circles and error bars in E and F .

Article Snippet: The ELISA technique used by Niwa et al. (Quantikine Human VEGF Immunoassay; R&D Systems, Minneapolis, MN, USA) is supposed to measure only free VEGF via locating the free binding sites on the VEGF molecules.

Techniques: Concentration Assay

Journal: Investigative Ophthalmology & Visual Science

Article Title: Modeling the Ocular Pharmacokinetics and Pharmacodynamics of Ranibizumab for Improved Understanding and Data Collection Strategies in Ocular Diseases

doi: 10.1167/iovs.66.6.20

Figure Lengend Snippet: The posterior distributions for the molecular half-life values for ( A ) ranibizumab ( t 1 / 2 r ), ( B ) VEGF ( t 1 / 2 v ), ( C ) VR ( t 1 / 2 c ), and ( D ) RVR ( t 1 / 2 h ). The dashed line in ( A ) denotes the estimated ranibizumab half-life from Niwa et al., and the dashed lines in ( B – D ) denote the estimated half-life calculated using the Hutton-Smith et al. scaling relationship. The gray normal distribution shows the distribution of ranibizumab half-life values sourced from the literature as presented by Caruso et al. ( E ) The theoretical relationship between the aqueous humor VEGF recovery time (weeks) with anti-VEGF antibody hydrodynamic radius (nm).

Article Snippet: The ELISA technique used by Niwa et al. (Quantikine Human VEGF Immunoassay; R&D Systems, Minneapolis, MN, USA) is supposed to measure only free VEGF via locating the free binding sites on the VEGF molecules.

Techniques:

Journal: Investigative Ophthalmology & Visual Science

Article Title: Modeling the Ocular Pharmacokinetics and Pharmacodynamics of Ranibizumab for Improved Understanding and Data Collection Strategies in Ocular Diseases

doi: 10.1167/iovs.66.6.20

Figure Lengend Snippet: ( A ) The posterior distributions inferred from the Niwa et al. data set assuming the measured aqueous VEGF contains some proportion (γ) of the partially boundary VEGF ( Equation 4 ). The upper diagonal panels show the marginal posterior distributions for each parameter, while the off-diagonal panels show the 2D marginal joint posterior distribution for each parameter pair. ( B ) This plot shows the mean and interquartile range of the log profile likelihood, which decreases as γ increases. Plots ( C ) and ( D ) show the optimal model fits for aqueous humor VEGF and ranibizumab, respectively, when γ is fixed at zero, 0.5, and 1.

Article Snippet: The ELISA technique used by Niwa et al. (Quantikine Human VEGF Immunoassay; R&D Systems, Minneapolis, MN, USA) is supposed to measure only free VEGF via locating the free binding sites on the VEGF molecules.

Techniques:

Journal: Investigative Ophthalmology & Visual Science

Article Title: Modeling the Ocular Pharmacokinetics and Pharmacodynamics of Ranibizumab for Improved Understanding and Data Collection Strategies in Ocular Diseases

doi: 10.1167/iovs.66.6.20

Figure Lengend Snippet: Inferred posterior distributions for each parameter obtained from ten series of synthetic data sets following the removal of a selected phase of the VEGF curve ( A ) or with varying data density in the transition region (P3) of the VEGF curve ( B ). ( A ) Inferred posterior distributions with full data sets ( row 1 ) and then following the removal of P1, the initial data point ( row 2 ); P2, the suppressed region ( row 3 ); P3, the transition region ( row 4 ); P4, the VEGF return to equilibrium ( row 5 ); or the initial data point and the VEGF return to equilibrium ( row 6 ). ( B ) The inferred posterior distributions become increasingly informative for the elimination rate constants and V in as the number of data points in the VEGF transition region (P3) increases from zero data points ( top row ; N0), to one data point ( second row ; N1), to three data points ( third row ; N3), to finally five data points ( bottom row ; N5). The right most column shows the model fits for each synthetic data set in both ( A ) and ( B ). All distributions represent the mean distribution obtained from ten synthetic data sets and are normalized to the maximum value of the distribution.

Article Snippet: The ELISA technique used by Niwa et al. (Quantikine Human VEGF Immunoassay; R&D Systems, Minneapolis, MN, USA) is supposed to measure only free VEGF via locating the free binding sites on the VEGF molecules.

Techniques: