In case of low-dose exposure to a substance, its concentration in cells is likely to be stochastic. Assessing the consequences of this stochasticity in toxicological risk assessment requires the coupling of macroscopic dynamics models describing whole-body kinetics with microscopic tools designed to simulate stochasticity. In this article, we propose an approach to approximate stochastic cell concentration of butadiene in the cells of diverse organs. We adapted the dynamics equations of a physiologically based pharmacokinetic (PBPK) model and used a stochastic simulator for the system of equations that we derived. We then coupled kinetics simulations with a deterministic hockey stick model of carcinogenicity. Stochasticity induced substantial modifications relative to dose-response curve, compared with the deterministic situation. In particular, there was nonlinearity in the response and the stochastic apparent threshold was lower than the deterministic one. The approach that we developed could easily be extended to other biological studies to assess the influence of stochasticity at macroscopic scale for compound dynamics at the cell level.
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http://dx.doi.org/10.1111/j.1539-6924.2009.01242.x | DOI Listing |
JAMA Netw Open
January 2025
Clinical Product Development, Waymark, San Francisco, California.
Importance: Rising prescription medication costs under Medicaid have led to increased procedural prescription denials by health plans. The effect of unresolved denials on chronic condition exacerbation and subsequent acute care utilization remains unclear.
Objective: To examine whether procedural prescription denials are associated with increased net spending through downstream acute care utilization among Medicaid patients not obtaining prescribed medication following a denial.
Neurochem Res
January 2025
Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.
In recent decades, researchers and clinicians have increasingly focused on glial cell function. One of the primary mechanisms influencing these functions is through extracellular vesicles (EVs), membrane-bound particles released by cells that are essential for intercellular communication. EVs can be broadly categorized into four main types based on their size, origin, and biogenesis: large EVs, small EVs (sEVs), autophagic EVs, and apoptotic bodies.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hong Kong 999077, China.
Sample pretreatment for mass spectrometry (MS)-based metabolomics and lipidomics is normally conducted independently with two sample aliquots and separate matrix cleanup procedures, making the two-step process sample-intensive and time-consuming. Herein, we introduce a high-throughput pretreatment workflow for integrated nontargeted metabolomics and lipidomics leveraging the enhanced matrix removal (EMR)-lipid microelution 96-well plates. The EMR-lipid technique was innovatively employed to effectively separate and isolate non-lipid small metabolites and lipids in sequence using significantly reduced sample amounts and organic solvents.
View Article and Find Full Text PDFJ Exp Bot
January 2025
Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan.
Organisms adapt to predictable environmental changes via a biological mechanism called priming. Phototropin (phot) is a plant-specific blue light photoreceptor that mediates daily light-induced responses, such as chloroplast relocation, stomatal opening, and phototropism, to optimize photosynthesis. Phot also functions as a thermosensor for chloroplast relocation that may sense daily temperature decreases at night, thereby modulating light-induced responses at dawn; however, this hypothesis has not yet been fully explored.
View Article and Find Full Text PDFScand J Public Health
January 2025
Norwegian Institute of Public Health, Oslo, Norway.
Socioeconomic conditions remain an important factor in determining health outcomes in Northern Europe. In this commentary, we argue for evidence-based temperature-related climate adaptation policies in Northern Europe that account for disparities in socioeconomic conditions and aim at universal health coverage. We highlight the role of spatial and occupational disparities in urban areas that can be important factors in increased physical and mental health impacts related to heat and cold.
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