The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Pierre Ronco - One of the best experts on this subject based on the ideXlab platform.
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antiphospholipase a2 receptor antibody Titer and subclass in idiopathic membranous nephropathy
Journal of The American Society of Nephrology, 2012Co-Authors: Julia M Hofstra, Hanna Debiec, C D Short, Timothee Pelle, Robert Kleta, Peter W Mathieson, Pierre RoncoAbstract:The phospholipase A(2) receptor (PLA(2)R) is the major target antigen in idiopathic membranous nephropathy. The technique for measuring antibodies against PLA(2)R and the relationship between antibody Titer and clinical characteristics are not well established. Here, we measured anti-PLA(2)R (aPLA(2)R) antibody Titer and subclass in a well defined cohort of 117 Caucasian patients with idiopathic membranous nephropathy and nephrotic-range proteinuria using both indirect immunofluorescence testing (IIFT) and ELISA. We assessed agreement between tests and correlated antibody Titer with clinical baseline parameters and outcome. In this cohort, aPLA(2)R antibodies were positive in 74% and 72% of patients using IIFT and ELISA, respectively. Concordance between both tests was excellent (94% agreement, ?=0.85). Among 82 aPLA(2)R-positive patients, antibody Titer significantly correlated with baseline proteinuria (P=0.02). Spontaneous remissions occurred significantly less frequently among patients with high antibody Titers (38% versus 4% in the lowest and highest tertiles, respectively; P<0.01). IgG4 was the dominant subclass in the majority of patients. Titers of IgG4, but not IgG1 or IgG3, significantly correlated with the occurrence of spontaneous remission (P=0.03). In summary, these data show high agreement between IIFT and ELISA assessments of aPLA(2)R antibody Titer and highlight the pathogenetic role of these antibodies, especially the IgG4 subclass, given the observed relationships between aPLA(2)R Titer, baseline proteinuria, and outcome.
Suzanne S Farid - One of the best experts on this subject based on the ideXlab platform.
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Economic Drivers and Trade-Offs in Antibody Purification Processes : The future of therapeutic MAbs lies in the development of economically feasible downstream processes
Biopharm International, 2020Co-Authors: Suzanne S FaridAbstract:Increasing Titers in mammalian cell culture has recently shifted the focus of process development efforts towards improving the economics of product recovery and purification processes. Some argue that a paradigm shift may be required to ensure timely and cost-effective delivery of future antibody candidates. This paper discusses the key process economic drivers and the impact of scale and Titer on downstream processing (DSP) economic trade-offs.
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decisional tool to assess current and future process robustness in an antibody purification facility
Biotechnology Progress, 2012Co-Authors: Adam Stonier, Ana S Simaria, Martin Smith, Suzanne S FaridAbstract:Increases in cell culture Titers in existing facilities have prompted efforts to identify strategies that alleviate purification bottlenecks while controlling costs. This article describes the application of a database-driven dynamic simulation tool to identify optimal purification sizing strategies and visualize their robustness to future Titer increases. The tool harnessed the benefits of MySQL to capture the process, business, and risk features of multiple purification options and better manage the large datasets required for uncertainty analysis and optimization. The database was linked to a discrete-event simulation engine so as to model the dynamic features of biopharmaceutical manufacture and impact of resource constraints. For a given Titer, the tool performed brute force optimization so as to identify optimal purification sizing strategies that minimized the batch material cost while maintaining the schedule. The tool was applied to industrial case studies based on a platform monoclonal antibody purification process in a multisuite clinical scale manufacturing facility. The case studies assessed the robustness of optimal strategies to batch-to-batch Titer variability and extended this to assess the long-term fit of the platform process as Titers increase from 1 to 10 g/L, given a range of equipment sizes available to enable scale intensification efforts. Novel visualization plots consisting of multiple Pareto frontiers with tie-lines connecting the position of optimal configurations over a given Titer range were constructed. These enabled rapid identification of robust purification configurations given Titer fluctuations and the facility limit that the purification suites could handle in terms of the maximum Titer and hence harvest load. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 1019–1028, 2012
Rachel Sacksdavis - One of the best experts on this subject based on the ideXlab platform.
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modeling of patient virus Titers suggests that availability of a vaccine could reduce hepatitis c virus transmission among injecting drug users
Science Translational Medicine, 2018Co-Authors: Marian E Major, Alexander Gutfraind, Louis M Shekhtman, Alla Kachko, Scott J Cotler, Behzad Hajarizadeh, Rachel SacksdavisAbstract:The major route of hepatitis C virus (HCV) transmission in the United States is injection drug use. We hypothesized that if an HCV vaccine were available, vaccination could affect HCV transmission among people who inject drugs by reducing HCV Titers after viral exposure without necessarily achieving sterilizing immunity. To investigate this possibility, we developed a mathematical model to determine transmission probabilities relative to the HCV RNA Titers of needle/syringe-sharing donors. We simulated sharing of two types of syringes fitted with needles that retain either large or small amounts of fluid after expulsion. Using previously published viral kinetics data from both naive subjects infected with HCV and reinfected individuals who had previously cleared an HCV infection, we estimated transmission risk between pairs of serodiscordant injecting drug users, accounting for syringe type, rinsing, and sharing frequency. We calculated that the risk of HCV transmission through syringe sharing increased ~10-fold as viral Titers (log 10 IU/ml) increased ~25-fold. Cumulative analyses showed that, assuming sharing episodes every 7 days, the mean transmission risk over the first 6 months was >90% between two people sharing syringes when one had an HCV RNA Titer >5 log 10 IU/ml. For those with preexisting immunity that rapidly controlled HCV, the cumulative risk decreased to 1 to 25% depending on HCV Titer and syringe type. Our modeling approach demonstrates that, even with transient viral replication after exposure during injection drug use, HCV transmission among people sharing syringes could be reduced through vaccination if an HCV vaccine were available.
Yuchan Chao - One of the best experts on this subject based on the ideXlab platform.
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rapid Titer determination of baculovirus by quantitative real time polymerase chain reaction
Biotechnology Progress, 2008Co-Authors: Hueiru Lo, Yuchan ChaoAbstract:Titer determination is a prerequisite for the study of viruses. However, the current available methods are tedious and time-consuming. To improve the efficiency of Titer determination, we have developed a rapid and simple method for the routine detection of baculovirus Titers using a quantitative real-time PCR. This method is based on the amplification of approximately 150-bp fragments located in the coding regions of selected genes. The PCR was found to be quantitative in a range of 10 3 to 10 9 virus particles per 200 IL of supernatant, and the results were closely correlated with Titers detected from 50% tissue culture infectious doses (TCID50) of baculovirus. This quantitative real-time PCR requires only 30 min to perform, and the entire Titer determination can be accomplished within 1 h without the need for cell seeding or further virus dilution and infection. Because this technology is easy to operate, generates data with high precision, and most importantly is very quick, it will certainly be broadly applied for Titer determination of baculoviruses in the future.
Hanna Debiec - One of the best experts on this subject based on the ideXlab platform.
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antiphospholipase a2 receptor antibody Titer and subclass in idiopathic membranous nephropathy
Journal of The American Society of Nephrology, 2012Co-Authors: Julia M Hofstra, Hanna Debiec, C D Short, Timothee Pelle, Robert Kleta, Peter W Mathieson, Pierre RoncoAbstract:The phospholipase A(2) receptor (PLA(2)R) is the major target antigen in idiopathic membranous nephropathy. The technique for measuring antibodies against PLA(2)R and the relationship between antibody Titer and clinical characteristics are not well established. Here, we measured anti-PLA(2)R (aPLA(2)R) antibody Titer and subclass in a well defined cohort of 117 Caucasian patients with idiopathic membranous nephropathy and nephrotic-range proteinuria using both indirect immunofluorescence testing (IIFT) and ELISA. We assessed agreement between tests and correlated antibody Titer with clinical baseline parameters and outcome. In this cohort, aPLA(2)R antibodies were positive in 74% and 72% of patients using IIFT and ELISA, respectively. Concordance between both tests was excellent (94% agreement, ?=0.85). Among 82 aPLA(2)R-positive patients, antibody Titer significantly correlated with baseline proteinuria (P=0.02). Spontaneous remissions occurred significantly less frequently among patients with high antibody Titers (38% versus 4% in the lowest and highest tertiles, respectively; P<0.01). IgG4 was the dominant subclass in the majority of patients. Titers of IgG4, but not IgG1 or IgG3, significantly correlated with the occurrence of spontaneous remission (P=0.03). In summary, these data show high agreement between IIFT and ELISA assessments of aPLA(2)R antibody Titer and highlight the pathogenetic role of these antibodies, especially the IgG4 subclass, given the observed relationships between aPLA(2)R Titer, baseline proteinuria, and outcome.
