All Outputs (118)

Using many different voltage protocols to characterise discrepancy in mathematical ion channel models (2023)
Journal Article
Shuttleworth, J. G., Lok Lei, C., Windley, M., Hill, A. P., Perry, M. D., Preston, S., & Mirams, G. R. (2023). Using many different voltage protocols to characterise discrepancy in mathematical ion channel models. Biophysical Journal, 122(3, Suppl. 1), 242a. https://doi.org/10.1016/j.bpj.2022.11.1415

The Kv11.1 protein encoded by the hERG gene forms the primary subunit of a voltage-sensitive ion channel responsible for IKr in cardiomyocytes. Mathematical models of the macroscopic current are fitted to data from patch-clamp experiments - in which... Read More about Using many different voltage protocols to characterise discrepancy in mathematical ion channel models.

Modelling the Effect of Intracellular Calcium in the Rundown of L-Type Calcium Current (2022)
Presentation / Conference Contribution
Agrawal, A., Clerx, M., Wang, K., Polonchuk, L., Gavaghan, D. J., & Mirams, G. R. (2022, September). Modelling the Effect of Intracellular Calcium in the Rundown of L-Type Calcium Current. Presented at 2022 Computing in Cardiology Conference, Tampere, Finland

The L-type calcium current (ICaL) is a key current of the heart playing an important role in the contraction of the cardiomyocyte. Patch-clamp recordings of ionic currents can be associated with a reduction of the current magnitude with time (termed... Read More about Modelling the Effect of Intracellular Calcium in the Rundown of L-Type Calcium Current.

Derivative-based Inference for Cell and Channel Electrophysiology Models (2022)
Presentation / Conference Contribution
Clerx, M., Augustin, D., Dale-Evans, A. R., & Mirams, G. R. (2022, September). Derivative-based Inference for Cell and Channel Electrophysiology Models. Presented at 2022 Computing in Cardiology Conference, Tampere, Finland (online)

Models of ionic currents or of the cardiac action potential (AP) are frequently calibrated by defining an error function that quantifies the mismatch between simulations and data, and using numerical optimisation to find the parameter values that min... Read More about Derivative-based Inference for Cell and Channel Electrophysiology Models.

Normalisation of Action Potential Data Recorded with Sharp Electrodes Maximises Its Utility for Model Development (2022)
Presentation / Conference Contribution
Barral, Y. S. H., Polonchuk, L., R. Mirams, G., Clerx, M., Page, G., Sweat, K., Abi-Gerges, N., Wang, K., & Gavaghan, D. J. (2022, September). Normalisation of Action Potential Data Recorded with Sharp Electrodes Maximises Its Utility for Model Development. Presented at 2022 Computing in Cardiology Conference, Tampere, Finland

In silico models of cardiomyocyte electrophysiology describe the various ionic currents and fluxes that lead to the formation of action potentials (APs). Experimental data used to create such models can be recorded in adult human cardiac trabeculae u... Read More about Normalisation of Action Potential Data Recorded with Sharp Electrodes Maximises Its Utility for Model Development.

Uncertainty and error in SARS-CoV-2 epidemiological parameters inferred from population-level epidemic models (2022)
Journal Article
Whittaker, D. G., Herrera-Reyes, A. D., Hendrix, M., Owen, M. R., Band, L. R., Mirams, G. R., Bolton, K. J., & Preston, S. P. (2023). Uncertainty and error in SARS-CoV-2 epidemiological parameters inferred from population-level epidemic models. Journal of Theoretical Biology, 558, Article 111337. https://doi.org/10.1016/j.jtbi.2022.111337

During the SARS-CoV2 pandemic, epidemic models have been central to policy-making. Public health responses have been shaped by model-based projections and inferences, especially related to the impact of various non-pharmaceutical interventions. Accom... Read More about Uncertainty and error in SARS-CoV-2 epidemiological parameters inferred from population-level epidemic models.

Nuanced Interactions between AKAP79 and STIM1 with Orai1 Ca 2+ Channels at Endoplasmic Reticulum-Plasma Membrane Junctions Sustain NFAT Activation (2022)
Journal Article
Lin, Y.-P., Scappini, E., Landaverde, C., Parekh-Glitsch, F., Tucker, C. J., Mirams, G. R., & Parekh, A. B. (2022). Nuanced Interactions between AKAP79 and STIM1 with Orai1 Ca 2+ Channels at Endoplasmic Reticulum-Plasma Membrane Junctions Sustain NFAT Activation. Molecular and Cellular Biology, 42(11), Article e00175-22. https://doi.org/10.1128/mcb.00175-22

A-kinase anchoring protein 79 (AKAP79) is a human scaffolding protein that organizes Ca2+/calmodulin-dependent protein phosphatase calcineurin, calmodulin, cAMP-dependent protein kinase, protein kinase C, and the transcription factor nuclear factor o... Read More about Nuanced Interactions between AKAP79 and STIM1 with Orai1 Ca 2+ Channels at Endoplasmic Reticulum-Plasma Membrane Junctions Sustain NFAT Activation.

Models of the cardiac L-type calcium current: A quantitative review (2022)
Journal Article
Agrawal, A., Wang, K., Polonchuk, L., Cooper, J., Hendrix, M., Gavaghan, D. J., Gavaghan, D. J., Mirams, G. R., & Clerx, M. (2022). Models of the cardiac L-type calcium current: A quantitative review. Wiley Interdisciplinary Reviews: Mechanisms of Disease, 15(1), Article e1581. https://doi.org/10.1002/wsbm.1581

The L-type calcium current ((Formula presented.)) plays a critical role in cardiac electrophysiology, and models of (Formula presented.) are vital tools to predict arrhythmogenicity of drugs and mutations. Five decades of measuring and modeling (Form... Read More about Models of the cardiac L-type calcium current: A quantitative review.

Ion channel model reduction using manifold boundaries (2022)
Journal Article
Whittaker, D. G., Wang, J., Shuttleworth, J., Venkateshappa, R., Kemp, J. M., Claydon, T. W., & Mirams, G. R. (2022). Ion channel model reduction using manifold boundaries. Journal of the Royal Society, Interface, 19(193), Article 20220193. https://doi.org/10.1098/rsif.2022.0193

Mathematical models of voltage-gated ion channels are used in basic research, industrial and clinical settings. These models range in complexity, but typically contain numerous variables representing the proportion of channels in a given state, and p... Read More about Ion channel model reduction using manifold boundaries.

cellmlmanip and chaste_codegen: automatic CellML to C++ code generation with fixes for singularities and automatically generated Jacobians (2022)
Journal Article
Hendrix, M., Clerx, M., Tamuri, A. U., Keating, S. M., Johnstone, R. H., Cooper, J., & Mirams, G. R. (2022). cellmlmanip and chaste_codegen: automatic CellML to C++ code generation with fixes for singularities and automatically generated Jacobians. Wellcome Open Research, 6, Article 261. https://doi.org/10.12688/wellcomeopenres.17206.2

Hundreds of different mathematical models have been proposed for describing electrophysiology of various cell types. These models are quite complex (nonlinear systems of typically tens of ODEs and sometimes hundreds of parameters) and software packag... Read More about cellmlmanip and chaste_codegen: automatic CellML to C++ code generation with fixes for singularities and automatically generated Jacobians.

A Parameter Representing Missing Charge Should Be Considered when Calibrating Action Potential Models (2022)
Journal Article
Barral, Y.-S. H. M., Shuttleworth, J., Clerx, M., Whittaker, D. G., Wang, K., Polonchuk, L., Gavaghan, D. J., & Mirams, G. R. (2022). A Parameter Representing Missing Charge Should Be Considered when Calibrating Action Potential Models. Frontiers in Physiology, 13, Article 879035. https://doi.org/10.3389/fphys.2022.879035

Computational models of the electrical potential across a cell membrane are longstanding and vital tools in electrophysiology research and applications. These models describe how ionic currents, internal fluxes, and buffering interact to determine me... Read More about A Parameter Representing Missing Charge Should Be Considered when Calibrating Action Potential Models.

chaste codegen: automatic CellML to C++ code generation with fixes for singularities and automatically generated Jacobians (2022)
Journal Article
Hendrix, M., Clerx, M., Tamuri, A. U., Keating, S. M., Johnstone, R. H., Cooper, J., & Mirams, G. R. (2022). chaste codegen: automatic CellML to C++ code generation with fixes for singularities and automatically generated Jacobians. Wellcome Open Research, 6, Article 261. https://doi.org/10.12688/wellcomeopenres.17206.1

Hundreds of different mathematical models have been proposed for describing electrophysiology of various cell types. These models are quite complex (nonlinear systems of typically tens of ODEs and sometimes hundreds of parameters) and software packag... Read More about chaste codegen: automatic CellML to C++ code generation with fixes for singularities and automatically generated Jacobians.

A Quantitative Systems Pharmacology Perspective on the Importance of Parameter Identifiability (2022)
Journal Article
Sher, A., Niederer, S. A., Mirams, G. R., Kirpichnikova, A., Allen, R., Pathmanathan, P., Gavaghan, D. J., van der Graaf, P. H., & Noble, D. (2022). A Quantitative Systems Pharmacology Perspective on the Importance of Parameter Identifiability. Bulletin of Mathematical Biology, 84(3), Article 39. https://doi.org/10.1007/s11538-021-00982-5

There is an inherent tension in Quantitative Systems Pharmacology (QSP) between the need to incorporate mathematical descriptions of complex physiology and drug targets with the necessity of developing robust, predictive and well-constrained models.... Read More about A Quantitative Systems Pharmacology Perspective on the Importance of Parameter Identifiability.

A nonlinear and time-dependent leak current in the presence of calcium fluoride patch-clamp seal enhancer (2021)
Journal Article
Lei, C. L., Fabbri, A., Whittaker, D. G., Clerx, M., Windley, M. J., Hill, A. P., Mirams, G. R., & de Boer, T. P. (2021). A nonlinear and time-dependent leak current in the presence of calcium fluoride patch-clamp seal enhancer. Wellcome Open Research, 5, 1-34. https://doi.org/10.12688/wellcomeopenres.15968.2

Automated patch-clamp platforms are widely used and vital tools in both academia and industry to enable high-throughput studies such as drug screening. A leak current to ground occurs whenever the seal between a pipette and cell (or internal solution... Read More about A nonlinear and time-dependent leak current in the presence of calcium fluoride patch-clamp seal enhancer.

Electrophysiological characterization of the hERG R56Q LQTS variant and targeted rescue by the activator RPR260243 (2021)
Journal Article
Kemp, J. M., Whittaker, D. G., Venkateshappa, R., Pang, Z. K., Johal, R., Sergeev, V., Tibbits, G. F., Mirams, G. R., & Claydon, T. W. (2021). Electrophysiological characterization of the hERG R56Q LQTS variant and targeted rescue by the activator RPR260243. Journal of General Physiology, 153(10), Article e202112923. https://doi.org/10.1085/jgp.202112923

Human Ether-à-go-go (hERG) channels contribute to cardiac repolarization, and inherited variants or drug block are associated with long QT syndrome type 2 (LQTS2) and arrhythmia. Therefore, hERG activator compounds present a therapeutic opportunity f... Read More about Electrophysiological characterization of the hERG R56Q LQTS variant and targeted rescue by the activator RPR260243.

Neural Network Differential Equations For Ion Channel Modelling (2021)
Journal Article
Lei, C. L., & Mirams, G. R. (2021). Neural Network Differential Equations For Ion Channel Modelling. Frontiers in Physiology, 12, Article 708944. https://doi.org/10.3389/fphys.2021.708944

Mathematical models of cardiac ion channels have been widely used to study and predict the behaviour of ion currents. Typically models are built using biophysically-based mechanistic principles such as Hodgkin-Huxley or Markov state transitions. Thes... Read More about Neural Network Differential Equations For Ion Channel Modelling.

Immediate and Delayed Response of Simulated Human Atrial Myocytes to Clinically-Relevant Hypokalemia (2021)
Journal Article
Clerx, M., Mirams, G. R., Rogers, A. J., Narayan, S. M., & Giles, W. R. (2021). Immediate and Delayed Response of Simulated Human Atrial Myocytes to Clinically-Relevant Hypokalemia. Frontiers in Physiology, 12, Article 651162. https://doi.org/10.3389/fphys.2021.651162

Although plasma electrolyte levels are quickly and precisely regulated in the mammalian cardiovascular system, even small transient changes in K+, Na+, Ca2+, and/or Mg2+ can significantly alter physiological responses in the heart, blood vessels, and... Read More about Immediate and Delayed Response of Simulated Human Atrial Myocytes to Clinically-Relevant Hypokalemia.

Cardiac TdP risk stratification modelling of anti-infective compounds including chloroquine and hydroxychloroquine (2021)
Journal Article
Whittaker, D. G., Capel, R. A., Hendrix, M., Chan, X. H. S., Herring, N., White, N. J., Mirams, G. R., & Burton, R. A. B. (2021). Cardiac TdP risk stratification modelling of anti-infective compounds including chloroquine and hydroxychloroquine. Royal Society Open Science, 8(4), Article 210235. https://doi.org/10.1098/rsos.210235

Hydroxychloroquine (HCQ), the hydroxyl derivative of chloroquine (CQ), is widely used in the treatment of rheumatological conditions (systemic lupus erythematosus, rheumatoid arthritis) and is being studied for the treatment and prevention of COVID-1... Read More about Cardiac TdP risk stratification modelling of anti-infective compounds including chloroquine and hydroxychloroquine.

Development, Implementation and Testing of a Multicellular Dynamic Action Potential Clamp Simulator for Drug Cardiac Safety Assessment (2020)
Presentation / Conference Contribution
Camporesi, M., Bartolucci, C., Lei, C. L., Mirams, G. R., De Boer, T. P., & Severi, S. (2020, September). Development, Implementation and Testing of a Multicellular Dynamic Action Potential Clamp Simulator for Drug Cardiac Safety Assessment. Presented at Computing in Cardiology, Rimini, Italy

© 2020 Creative Commons; the authors hold their copyright. As drugs can be multichannel blockers it is important to assess their cardiac safety taking into account multiple currents. In silico action potential (AP) models have been proposed for being... Read More about Development, Implementation and Testing of a Multicellular Dynamic Action Potential Clamp Simulator for Drug Cardiac Safety Assessment.

Use of Patient Health Records to Quantify Drug-Related Pro-arrhythmic Risk (2020)
Journal Article
Davies, M. R., Martinec, M., Walls, R., Schwarz, R., Mirams, G. R., Wang, K., Steiner, G., Surinach, A., Flores, C., Lavé, T., Singer, T., & Polonchuk, L. (2020). Use of Patient Health Records to Quantify Drug-Related Pro-arrhythmic Risk. Cell Reports Medicine, 1(5), Article 100076. https://doi.org/10.1016/j.xcrm.2020.100076

There is an increasing expectation that computational approaches may supplement existing human decision-making. Frontloading of models for cardiac safety prediction is no exception to this trend, and ongoing regulatory initiatives propose use of high... Read More about Use of Patient Health Records to Quantify Drug-Related Pro-arrhythmic Risk.

A nonlinear and time-dependent leak current in the presence of calcium fluoride patch-clamp seal enhancer [version 1; peer review: 2 approved with reservations] (2020)
Journal Article
Lei, C. L., Fabbri, A., Whittaker, D. G., Clerx, M., Windley, M. J., Hill, A. P., Mirams, G. R., & de Boer, T. P. (2020). A nonlinear and time-dependent leak current in the presence of calcium fluoride patch-clamp seal enhancer [version 1; peer review: 2 approved with reservations]. Wellcome Open Research, 5, Article 152. https://doi.org/10.12688/wellcomeopenres.15968.1

Automated patch-clamp platforms are widely used and vital tools in both academia and industry to enable high-throughput studies such as drug screening. A leak current to ground occurs whenever the seal between a pipette and cell (or internal solution... Read More about A nonlinear and time-dependent leak current in the presence of calcium fluoride patch-clamp seal enhancer [version 1; peer review: 2 approved with reservations].