Repeated dietary dose testing is used to assess longer term toxicity of chemicals, such as pesticides, to mammals. However, the internal pesticide concentration varies significantly as feeding rate relative to body size fluctuates over time. Toxicokinetic-toxicodynamic (TK-TD) models can estimate internal toxicant concentration over time and link this directly to observed effects on endpoints such as the growth rate of laboratory rats.
View Article and Find Full Text PDFEcotoxicol Environ Saf
April 2024
Modelling approaches to estimate the bioaccumulation of organic chemicals by earthworms are important for improving the realism in risk assessment of chemicals. However, the applicability of existing models is uncertain, partly due to the lack of independent datasets to test them. This study therefore conducted a comprehensive literature review on existing empirical and kinetic models that estimate the bioaccumulation of organic chemicals in earthworms and gathered two independent datasets from published literature to evaluate the predictive performance of these models.
View Article and Find Full Text PDFThe uptake and elimination kinetics of pesticides from soil to earthworms are important in characterising the risk of pesticides to soil organisms and the risk from secondary poisoning. However, the understanding of the relative importance of chemical, soil, and species differences in determining pesticide bioconcentration into earthworms is limited. Furthermore, there is insufficient independent data in the literature to fully evaluate existing predictive bioconcentration models.
View Article and Find Full Text PDFCombinatorial optimization is a broadly attractive area for potential quantum advantage, but no quantum algorithm has yet made the leap. Noise in quantum hardware remains a challenge, and more sophisticated quantum-classical algorithms are required to bolster their performance. Here, we introduce an iterative quantum heuristic optimization algorithm to solve combinatorial optimization problems.
View Article and Find Full Text PDFThe European environmental risk assessment (ERA) of plant protection products follows a tiered approach. The approach for soil invertebrates currently consists of two steps, starting with a Tier 1 assessment based on reproduction toxicity tests with earthworms, springtails, and predatory mites. In case an unacceptable risk is identified at Tier 1, field studies can be conducted as a higher-tier option.
View Article and Find Full Text PDFMevalonate kinase deficiency (MKD) is characterized by recurrent fevers and flares of systemic inflammation, caused by biallelic loss-of-function mutations in MVK. The underlying disease mechanisms and triggers of inflammatory flares are poorly understood because of the lack of in vivo models. We describe genetically modified mice bearing the hypomorphic mutation p.
View Article and Find Full Text PDFIsoprenoids, also known as terpenes or terpenoids, are a very large and diverse group of natural compounds. These compounds fulfil a myriad of critical roles in biology as well as having a wide range of industrial uses. Isoprenoids are produced via two chemically distinct metabolic pathways, the mevalonate (MVA) pathway and the methylerythritol phosphate (MEP) pathway.
View Article and Find Full Text PDFBackground: The risk of esophageal adenocarcinoma (EAC) is associated with gastro-esophageal reflux disease (GERD) and obesity. Lipid metabolism-targeted therapies decrease the risk of progressing from Barrett's esophagus (BE) to EAC, but the precise lipid metabolic changes and their roles in genotoxicity during EAC development are yet to be established.
Methods: Esophageal biopsies from the normal epithelium (NE), BE, and EAC, were analyzed using concurrent lipidomics and proteomics (n = 30) followed by orthogonal validation on independent samples using RNAseq transcriptomics (n = 22) and immunohistochemistry (IHC, n = 80).
Ecotoxicol Environ Saf
March 2022
A major limitation of dietary toxicity studies on rodents is that food consumption often differs between treatments. The control treatment serves as a reference of how animals would have grown if not for the toxicant in their diet, but this comparison unavoidably conflates the effects of toxicity and feeding rate on body weight over time. A key advantage of toxicity models based on dynamic energy budget theory (DEB) is that chemical stress and food consumption are separate model inputs, so their effects on growth rate can be separated.
View Article and Find Full Text PDFBisphosphonates drugs target the skeleton and are used globally for the treatment of common bone disorders. Nitrogen-containing bisphosphonates act by inhibiting the mevalonate pathway in bone-resorbing osteoclasts but, surprisingly, also appear to reduce the risk of death from pneumonia. We overturn the long-held belief that these drugs act only in the skeleton and show that a fluorescently labelled bisphosphonate is internalised by alveolar macrophages and large peritoneal macrophages in vivo.
View Article and Find Full Text PDFSRSF1 protein and U1 snRNPs are closely connected splicing factors. They both stimulate exon inclusion, SRSF1 by binding to exonic splicing enhancer sequences (ESEs) and U1 snRNPs by binding to the downstream 5' splice site (SS), and both factors affect 5' SS selection. The binding of U1 snRNPs initiates spliceosome assembly, but SR proteins such as SRSF1 can in some cases substitute for it.
View Article and Find Full Text PDFNicotinamide adenine dinucleotide (NAD) is a key metabolic intermediate found in all cells and involved in numerous cellular functions. Perturbances in the NAD metabolome are linked to various diseases such as diabetes and schizophrenia, and to congenital malformations and recurrent miscarriage. Mouse models are central to the investigation of these and other NAD-related conditions because mice can be readily genetically modified and treated with diets with altered concentrations of NAD precursors.
View Article and Find Full Text PDFAbundance and distribution of earthworms in agricultural fields is frequently proposed as a measure of soil quality assuming that observed patterns of abundance are in response to improved or degraded environmental conditions. However, it is not clear that earthworm abundances can be directly related to their edaphic environment, as noted in Darwin's final publication, perhaps limiting or restricting their value as indicators of ecological quality in any given field. We present results from a spatially explicit intensive survey of pastures within United Kingdom farms, looking for the main drivers of earthworm density at a range of scales.
View Article and Find Full Text PDFManaging soil to support biodiversity is important to sustain the ecosystem services provided by soils upon which society depends. There is increasing evidence that functional diversity of soil biota is important for ecosystem services, and has been degraded by intensive agriculture. Importantly, the spatial distribution of reservoirs of soil biota in and surrounding arable fields is poorly understood.
View Article and Find Full Text PDFCardiac regeneration requires dedifferentiation and proliferation of mature cardiomyocytes, but the mechanisms underlying this plasticity remain unclear. Here, we identify a potent cardiomyogenic role for Krüppel-like factor 1 (Klf1/Eklf), which is induced in adult zebrafish myocardium upon injury. Myocardial inhibition of Klf1 function does not affect heart development, but it severely impairs regeneration.
View Article and Find Full Text PDFGlobal climate change is leading to a significant increase in flooding events in many countries. Current practices to prevent damage to downstream urban areas include allowing the flooding of upstream agricultural land. Earthworms are ecosystem engineers, but their abundances in arable land are already reduced due to pressure from farming practices.
View Article and Find Full Text PDFEsophageal adenocarcinoma (EAC) incidence has been rapidly increasing, potentially associated with the prevalence of the risk factors gastroesophageal reflux disease (GERD), obesity, high-fat diet (HFD), and the precursor condition Barrett's esophagus (BE). EAC development occurs over several years, with stepwise changes of the squamous esophageal epithelium, through cardiac metaplasia, to BE, and then EAC. To establish the roles of GERD and HFD in initiating BE, we developed a dietary intervention model in C57/BL6 mice using experimental HFD and GERD (0.
View Article and Find Full Text PDFBackground: The human gut microbiome plays a critical role in the carcinogenesis of colorectal cancer (CRC). However, a comprehensive analysis of the interaction between the host and microbiome is still lacking.
Results: We found correlations between the change in abundance of microbial taxa, butyrate-related colonic metabolites, and methylation-associated host gene expression in colonic tumour mucosa tissues compared with the adjacent normal mucosa tissues.
Land-based enhanced rock weathering (ERW) is a biogeochemical carbon dioxide removal (CDR) strategy aiming to accelerate natural geological processes of carbon sequestration through application of crushed silicate rocks, such as basalt, to croplands and forested landscapes. However, the efficacy of the approach when undertaken with basalt, and its potential co-benefits for agriculture, require experimental and field evaluation. Here we report that amending a UK clay-loam agricultural soil with a high loading (10 kg/m ) of relatively coarse-grained crushed basalt significantly increased the yield (21 ± 9.
View Article and Find Full Text PDFVolatile isoprenoids produced by plants are emitted in vast quantities into the atmosphere, with substantial effects on global carbon cycling. Yet, the molecular mechanisms regulating the balance between volatile and non-volatile isoprenoid production remain unknown. Isoprenoids are synthesised via sequential condensation of isopentenyl pyrophosphate (IPP) to dimethylallyl pyrophosphate (DMAPP), with volatile isoprenoids containing fewer isopentenyl subunits.
View Article and Find Full Text PDFHistone deacetylases (HDACs) drive innate immune cell-mediated inflammation. Here we identify class IIa HDACs as key molecular links between Toll-like receptor (TLR)-inducible aerobic glycolysis and macrophage inflammatory responses. A proteomic screen identified the glycolytic enzyme pyruvate kinase M isoform 2 (Pkm2) as a partner of proinflammatory Hdac7 in murine macrophages.
View Article and Find Full Text PDFEffects of earthworms on soil physico-hydraulic and chemical properties, herbage production and wheat growth in long-term arable soils following conversion to ley were investigated. Seven intact soil monoliths were collected from each of four arable fields. One monolith per field served as a control.
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