1
|
Foster RR, Smith B, Ellwein Fix L. Thoracoabdominal asynchrony in a virtual preterm infant: computational modeling and analysis. Am J Physiol Lung Cell Mol Physiol 2023; 325:L190-L205. [PMID: 37338113 PMCID: PMC10396271 DOI: 10.1152/ajplung.00123.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/21/2023] Open
Abstract
Thoracoabdominal asynchrony (TAA), the asynchronous volume changes between the rib cage and abdomen during breathing, is associated with respiratory distress, progressive lung volume loss, and chronic lung disease in the newborn infant. Preterm infants are prone to TAA risk factors such as weak intercostal muscles, surfactant deficiency, and a flaccid chest wall. The causes of TAA in this fragile population are not fully understood and, to date, the assessment of TAA has not included a mechanistic modeling framework to explore the role these risk factors play in breathing dynamics and how TAA can be resolved. We present a dynamic compartmental model of pulmonary mechanics that simulates TAA in the preterm infant under various adverse clinical conditions, including high chest wall compliance, applied inspiratory resistive loads, bronchopulmonary dysplasia, anesthesia-induced intercostal muscle deactivation, weakened costal diaphragm, impaired lung compliance, and upper airway obstruction. Sensitivity analyses performed to screen and rank model parameter influence on model TAA and respiratory volume outputs show that risk factors are additive so that maximal TAA occurs in a virtual preterm infant with multiple adverse conditions, and addressing risk factors individually causes incremental changes in TAA. An abruptly obstructed upper airway caused immediate nearly paradoxical breathing and tidal volume reduction despite greater effort. In most simulations, increased TAA occurred together with decreased tidal volume. Simulated indices of TAA are consistent with published experimental studies and clinically observed pathophysiology, motivating further investigation into the use of computational modeling for assessing and managing TAA.NEW & NOTEWORTHY A novel model of thoracoabdominal asynchrony incorporates literature-derived mechanics and simulates the impact of risk factors on a virtual preterm infant. Sensitivity analyses were performed to determine the influence of model parameters on TAA and respiratory volume. Predicted phase angles are consistent with prior experimental and clinical results, and influential parameters are associated with clinical scenarios that significantly alter phase angle, motivating further investigation into the use of computational modeling for assessing and managing thoracoabdominal asynchrony.
Collapse
Affiliation(s)
- Richard R Foster
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, Virginia, United States
| | - Bradford Smith
- Department of Bioengineering, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado, United States
- Department of Pediatric Pulmonary and Sleep Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Laura Ellwein Fix
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, Virginia, United States
| |
Collapse
|
2
|
McDaniel M, Flores KB, Akpa BS. Predicting Inter-individual Variability During Lipid Resuscitation of Bupivacaine Cardiotoxicity in Rats: A Virtual Population Modeling Study. Drugs R D 2021; 21:305-320. [PMID: 34279844 PMCID: PMC8363697 DOI: 10.1007/s40268-021-00353-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2021] [Indexed: 12/01/2022] Open
Abstract
Introduction Intravenous lipid emulsions (ILE) have been credited for successful resuscitation in drug intoxication cases where other cardiac life-support methods have failed. However, inter-individual variability can function as a confounder that challenges our ability to define the scope of efficacy for lipid interventions, particularly as relevant data are scarce. To address this challenge, we developed a quantitative systems pharmacology model to predict outcome variability and shed light on causal mechanisms in a virtual population of rats subjected to bupivacaine toxicity and ILE intervention. Materials and Methods We combined a physiologically based pharmacokinetic–pharmacodynamic model with data from a small study in Sprague-Dawley rats to characterize individual-specific cardiac responses to lipid infusion. We used the resulting individual parameter estimates to posit a population distribution of responses to lipid infusion. On that basis, we constructed a large virtual population of rats (N = 10,000) undergoing lipid therapy following bupivacaine cardiotoxicity. Results Using unsupervised clustering to assign resuscitation endpoints, our simulations predicted that treatment with a 30% lipid emulsion increases bupivacaine median lethal dose (LD50) by 46% when compared with a simulated control fluid. Prior experimental findings indicated an LD50 increase of 48%. Causal analysis of the population data suggested that muscle accumulation rather than liver accumulation of bupivacaine drives survival outcomes. Conclusion Our results represent a successful prediction of complex, dynamic physiological outcomes over a virtual population. Despite being informed by very limited data, our mechanistic model predicted a plausible range of treatment outcomes that accurately predicts changes in LD50 when extrapolated to putatively toxic doses of bupivacaine. Furthermore, causal analysis of the predicted survival outcomes indicated a critical synergy between scavenging and direct cardiotonic mechanisms of ILE action. Supplementary Information The online version contains supplementary material available at 10.1007/s40268-021-00353-4.
Collapse
Affiliation(s)
- Matthew McDaniel
- Department of Mathematics, North Carolina State University, Raleigh, NC, USA
| | - Kevin B Flores
- Department of Mathematics, North Carolina State University, Raleigh, NC, USA
| | - Belinda S Akpa
- Division of Biosciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA. .,Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, USA. .,Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC, USA.
| |
Collapse
|
3
|
Blazquez-Navarro A, Schachtner T, Stervbo U, Sefrin A, Stein M, Westhoff TH, Reinke P, Klipp E, Babel N, Neumann AU, Or-Guil M. Differential T cell response against BK virus regulatory and structural antigens: A viral dynamics modelling approach. PLoS Comput Biol 2018; 14:e1005998. [PMID: 29746472 PMCID: PMC5944912 DOI: 10.1371/journal.pcbi.1005998] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 01/24/2018] [Indexed: 12/26/2022] Open
Abstract
BK virus (BKV) associated nephropathy affects 1-10% of kidney transplant recipients, leading to graft failure in about 50% of cases. Immune responses against different BKV antigens have been shown to have a prognostic value for disease development. Data currently suggest that the structural antigens and regulatory antigens of BKV might each trigger a different mode of action of the immune response. To study the influence of different modes of action of the cellular immune response on BKV clearance dynamics, we have analysed the kinetics of BKV plasma load and anti-BKV T cell response (Elispot) in six patients with BKV associated nephropathy using ODE modelling. The results show that only a small number of hypotheses on the mode of action are compatible with the empirical data. The hypothesis with the highest empirical support is that structural antigens trigger blocking of virus production from infected cells, whereas regulatory antigens trigger an acceleration of death of infected cells. These differential modes of action could be important for our understanding of BKV resolution, as according to the hypothesis, only regulatory antigens would trigger a fast and continuous clearance of the viral load. Other hypotheses showed a lower degree of empirical support, but could potentially explain the clearing mechanisms of individual patients. Our results highlight the heterogeneity of the dynamics, including the delay between immune response against structural versus regulatory antigens, and its relevance for BKV clearance. Our modelling approach is the first that studies the process of BKV clearance by bringing together viral and immune kinetics and can provide a framework for personalised hypotheses generation on the interrelations between cellular immunity and viral dynamics.
Collapse
Affiliation(s)
- Arturo Blazquez-Navarro
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin, Berlin, Germany
- Systems Immunology Lab, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Thomas Schachtner
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin, Berlin, Germany
- Department of Nephrology and Internal Intensive Care, Charité-Universitätsmedizin, Berlin, Germany
| | - Ulrik Stervbo
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin, Berlin, Germany
- Medical Clinic I, Marien Hospital Herne, Ruhr University Bochum, Herne, Germany
| | - Anett Sefrin
- Department of Nephrology and Internal Intensive Care, Charité-Universitätsmedizin, Berlin, Germany
| | - Maik Stein
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin, Berlin, Germany
| | - Timm H Westhoff
- Medical Clinic I, Marien Hospital Herne, Ruhr University Bochum, Herne, Germany
| | - Petra Reinke
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin, Berlin, Germany
- Department of Nephrology and Internal Intensive Care, Charité-Universitätsmedizin, Berlin, Germany
| | - Edda Klipp
- Theoretical Biophysics Group, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Nina Babel
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin, Berlin, Germany
- Medical Clinic I, Marien Hospital Herne, Ruhr University Bochum, Herne, Germany
| | - Avidan U Neumann
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin, Berlin, Germany
- Institute of Environmental Medicine, UNIKA-T, Helmholtz Zentrum München, Augsburg, Germany
- Institute of Computational Biology, Helmholtz Zentrum München, Munich, Germany
| | - Michal Or-Guil
- Systems Immunology Lab, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| |
Collapse
|
4
|
Lagergren J, Reeder A, Hamilton F, Smith RC, Flores KB. Forecasting and Uncertainty Quantification Using a Hybrid of Mechanistic and Non-mechanistic Models for an Age-Structured Population Model. Bull Math Biol 2018; 80:1578-1595. [PMID: 29611108 DOI: 10.1007/s11538-018-0421-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 03/23/2018] [Indexed: 11/30/2022]
Abstract
In this paper, we present a new method for the prediction and uncertainty quantification of data-driven multivariate systems. Traditionally, either mechanistic or non-mechanistic modeling methodologies have been used for prediction; however, it is uncommon for the two to be incorporated together. We compare the forecast accuracy of mechanistic modeling, using Bayesian inference, a non-mechanistic modeling approach based on state space reconstruction, and a novel hybrid methodology composed of the two for an age-structured population data set. The data come from cannibalistic flour beetles, in which it is observed that the adults preying on the eggs and pupae result in non-equilibrium population dynamics. Uncertainty quantification methods for the hybrid models are outlined and illustrated for these data. We perform an analysis of the results from Bayesian inference for the mechanistic model and hybrid models to suggest reasons why hybrid modeling methodology may enable more accurate forecasts of multivariate systems than traditional approaches.
Collapse
Affiliation(s)
- John Lagergren
- Department of Mathematics, Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC, USA
| | - Amanda Reeder
- Department of Mathematics, Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC, USA
| | - Franz Hamilton
- Department of Mathematics, Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC, USA
| | - Ralph C Smith
- Department of Mathematics, Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC, USA
| | - Kevin B Flores
- Department of Mathematics, Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC, USA.
| |
Collapse
|
5
|
Banks HT, Hu S, Rosenberg E. A Dynamical Modeling Approach for Analysis of Longitudinal Clinical Trials in the Presence of Missing Endpoints. APPLIED MATHEMATICS LETTERS 2017; 63:109-117. [PMID: 28344385 PMCID: PMC5363994 DOI: 10.1016/j.aml.2016.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Randomized longitudinal clinical trials are the gold standard to evaluate the effectiveness of interventions among different patient treatment groups. However, analysis of such clinical trials becomes difficult in the presence of missing data, especially in the case where the study endpoints become difficult to measure because of subject dropout rates or/and the time to discontinue the assigned interventions are different among the patient groups. Here we report on using a validated mathematical model combined with an inverse problem approach to predict the values for the missing endpoints. A small randomized HIV clinical trial where endpoints for most of patients are missing is used to demonstrate this approach.
Collapse
Affiliation(s)
- H T Banks
- Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC 27695-8212
| | - Shuhua Hu
- Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC 27695-8212; Certara, Inc., Cary, NC 27518
| | - Eric Rosenberg
- Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC 27695-8212; Departments of Pathology and Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114
| |
Collapse
|