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Cotton-top tamarins (Saguinus oedipus) are a critically endangered primate found only in Colombia. Proyecto Tití has been leading conservation efforts in Colombia and has developed successful conservation education programs that engage communities in activities that promote the long-term survival of cotton-top tamarins. TITIRITIANDO is an educational theatrical program that introduces children to cotton-top tamarins and the challenges they face in the illegal pet trade. We presented this program to 4018 elementary school children to determine if using puppets and interactive messaging created an emotional connection between children and cotton-top tamarins that inspired them to engage in actions that aid cotton-top tamarin conservation. Pre- and post-test evaluations were conducted on 1917 students. Pre-surveys found 34% of the children were unable to identify at least one action to help cotton-top tamarins. Following the program students could on average identify at least 3 actions that positively impacted cotton-top tamarins with "not having a cotton-top tamarin as a pet" (75%) as the most frequently sited response. Misconceptions regarding the health and wellbeing of pet cotton-top tamarins was evident with 20% of the students believing that animals were well cared for and had a better life living with people than in the forest. Following the program, students were able to understand and empathize with pet cotton-top tamarins and on average could identify at least 3 negative impacts on individual welfare/well-being with the most common answers as they (1) are sad/depressed (91%), (2) die (87%), (3) are fed an inappropriate diet (80%), (4) have lost their family (74%) and (5) have lost their freedom (39%). This study demonstrates the effectiveness of educational theater in helping children to understand the impact the illegal pet trade has on cotton-top tamarins and how they can engage in activities to protect them.
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Doublet microtubules (DMTs) are flagellar components required for the protist Trichomonas vaginalis (Tv) to swim through the human genitourinary tract to cause trichomoniasis, the most common non-viral sexually transmitted disease. Lack of DMT structures has prevented structure-guided drug design to manage Tv infection. Here, we determined the cryo-EM structure of native Tv-DMTs, identifying 29 unique proteins, including 18 microtubule inner proteins and 9 microtubule outer proteins. While the A-tubule is simplistic compared to DMTs of other organisms, the B-tubule features specialized, parasite-specific proteins, such as TvFAP40 and TvFAP35 that form filaments near the inner and outer junctions, respectively, to stabilize DMTs and enable Tv locomotion. Notably, a small molecule, assigned as IP6, is coordinated within a pocket of TvFAP40 and has characteristics of a drug molecule. This first atomic model of the Tv-DMT highlights the diversity of eukaryotic motility machinery and provides a structural framework to inform rational design of therapeutics.
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Doublet microtubules (DMTs) are flagellar components required for the protist Trichomonas vaginalis ( Tv ) to swim through the human genitourinary tract to cause trichomoniasis, the most common non-viral sexually transmitted disease. Lack of DMT structures has prevented structure-guided drug design to manage Tv infection. Here, we determined the cryo-EM structure of native Tv- DMTs, identifying 29 unique proteins, including 18 microtubule inner proteins and 9 microtubule outer proteins. While the A-tubule is simplistic compared to DMTs of other organisms, the B-tubule features specialized, parasite-specific proteins, like Tv FAP40 and Tv FAP35 that form filaments near the inner and outer junctions, respectively, to stabilize DMTs and enable Tv locomotion. Notably, a small molecule, assigned as IP6, is coordinated within a pocket of Tv FAP40 and has characteristics of a drug molecule. This first atomic model of the Tv -DMT highlights the diversity of eukaryotic motility machinery and provides a structural framework to inform the rational design of therapeutics.
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Human cytomegalovirus (HCMV) replication relies on a nucleocapsid coat of the 150 kDa, subfamily-specific tegument phosphoprotein (pp150) to regulate cytoplasmic virion maturation. While recent structural studies revealed pp150-capsid interactions, the role of specific amino-acids involved in these interactions have not been established experimentally. In this study, pp150 and the small capsid protein (SCP), one of pp150's binding partners found atop the major capsid protein (MCP), were subjected to mutational and structural analyses. Mutations to clusters of polar or hydrophobic residues along the pp150-SCP interface abolished viral replication, with no replication detected in mutant virus-infected cells. Notably, a single amino acid mutation (pp150 K255E) at the pp150-MCP interface significantly attenuated viral replication, unlike in pp150-deletion mutants where capsids degraded outside host nuclei. These functionally significant mutations targeting pp150-capsid interactions, particularly the pp150 K255E replication-attenuated mutant, can be explored to overcome the historical challenges of developing effective antivirals and vaccines against HCMV infection.
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Proteínas do Capsídeo , Citomegalovirus , Fosfoproteínas , Replicação Viral , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/química , Humanos , Citomegalovirus/genética , Citomegalovirus/fisiologia , Citomegalovirus/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fosfoproteínas/química , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/metabolismo , Proteínas da Matriz Viral/química , Ligação Proteica , Mutagênese , Mutação , Linhagem Celular , Modelos MolecularesRESUMO
BACKGROUND: Artificial intelligence and machine learning (AI/ML) technologies like generative and ambient AI solutions are proliferating in real-world healthcare settings. Clinician trust affects adoption and impact of these systems. Organizations need a validated method to assess factors underlying trust and acceptance of AI for clinical workflows in order to improve adoption and the impact of AI. OBJECTIVE: Our study set out to develop and assess a novel clinician-centered model to measure and explain trust and adoption of AI technology. We hypothesized that clinicians' system-specific Trust in AI is the primary predictor of both Acceptance (i.e., willingness to adopt), and post-adoption Trusting Stance (i.e., general stance towards any AI system). We validated the new model at an urban comprehensive cancer center. We produced an easily implemented survey tool for measuring clinician trust and adoption of AI. METHODS: This survey-based, cross-sectional, psychometric study included a model development phase and validation phase. Measurement was done with five-point ascending unidirectional Likert scales. The development sample included N = 93 clinicians (physicians, advanced practice providers, nurses) that used an AI-based communication application. The validation sample included N = 73 clinicians that used a commercially available AI-powered speech-to-text application for note-writing in an electronic health record (EHR). Analytical procedures included exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and partial least squares structural equation modeling (PLS-SEM). The Johnson-Neyman (JN) methodology was used to determine moderator effects. RESULTS: In the fully moderated causal model, clinician trust explained a large amount of variance in their acceptance of a specific AI application (56%) and their post-adoption general trusting stance towards AI in general (36%). Moderators included organizational assurances, length of time using the application, and clinician age. The final validated instrument has 20 items and takes 5 min to complete on average. CONCLUSIONS: We found that clinician acceptance of AI is determined by their degree of trust formed via information credibility, perceived application value, and reliability. The novel model, TrAAIT, explains factors underlying AI trustworthiness and acceptance for clinicians. With its easy-to-use instrument and Summative Score Dashboard, TrAAIT can help organizations implementing AI to identify and intercept barriers to clinician adoption in real-world settings.
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Inteligência Artificial , Atitude do Pessoal de Saúde , Confiança , Humanos , Estudos Transversais , Reprodutibilidade dos Testes , Tecnologia , Inquéritos e Questionários , PsicometriaRESUMO
INTRODUCTION: Acetyl-coenzyme A carboxylase (ACCase) inhibition is an attractive herbicide target. However, issues with fetal developmental toxicity identified at the late stages of the development process can halt progression of previously promising candidates. OBJECTIVES: To select and verify predictive lipid biomarkers of ACCase inhibition activity in vivo using liver samples obtained from early stage 7 day repeat dose studies in non-pregnant female Han Wistar rats that could be translated to developmental toxicity endpoints discovered during late-stage studies to provide an early screening tool. METHODS: Liver samples from eight rat repeat dose studies, exposed to six ACCase inhibitors from three different chemistries and one alternative mode of action (MoA) that also perturbs lipid biochemistry, were analysed using liquid chromatography - high resolution accurate mass - mass spectrometry. Multivariate and univariate data analysis methods were used for biomarker discovery and validation. RESULTS: A biomarker signature consisting of sixteen lipids biomarkers were selected. Verification of the signature as indicative of ACCase inhibition was established by demonstrating consistent perturbations in the biomarkers using two different ACCase inhibitor chemistries and the lack thereof with an alternate MoA. The fold change profile pattern was predictive of which test substance doses would or would not cause developmental toxicity. CONCLUSION: A strategy for selecting and verifying a robust signature of lipid biomarkers for predicting a toxicological end point has been described and demonstrated. Differences in lipidomic profiles correlated with developmental toxicity suggesting that indicators of a molecular initiation event resulting in pup developmental toxicity can be predicted from short term, toxicity studies conducted in non-pregnant adult female Han Wistar rats.
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Acetil-CoA Carboxilase , Lipidômica , Feminino , Ratos , Animais , Ratos Wistar , Biomarcadores , Fígado , Coenzima A , LipídeosRESUMO
Remodeling of extracellular matrix proteins underlies the development of cardiovascular disease. Herein, we utilized a novel molecular probe, collagen hybridizing peptide (CHP), to target collagen molecular damage during atherogenesis. The thoracic aorta was dissected from ApoE-/- mice that had been on a high-fat diet for 0-18 weeks. Using an optimized protocol, tissues were stained with Cy3-CHP and digested to quantify CHP with a microplate assay. Results demonstrated collagen molecular damage, inferred from Cy3-CHP fluorescence, was a function of location and time on the high-fat diet. Tissue from the aortic arch showed a significant increase in collagen molecular damage after 18 weeks, while no change was observed in tissue from the descending aorta. No spatial differences in fluorescence were observed between the superior and inferior arch tissue. Our results provide insight into the early changes in collagen during atherogenesis and present a new opportunity in the subclinical diagnosis of atherosclerosis.
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Aterosclerose , Camundongos , Animais , Aterosclerose/metabolismo , Colágeno/metabolismo , Aorta Torácica , Dieta Hiperlipídica , Apolipoproteínas E/metabolismo , Camundongos Knockout , Modelos Animais de DoençasRESUMO
Trichomonas vaginalis, the causative pathogen for the most common nonviral sexually transmitted infection worldwide, is itself frequently infected with one or more of the four types of small double-stranded RNA (dsRNA) Trichomonas vaginalis viruses (TVV1 to 4, genus Trichomonasvirus, family Totiviridae). Each TVV encloses a nonsegmented genome within a single-layered capsid and replicates entirely intracellularly, like many dsRNA viruses, and unlike those in the Reoviridae family. Here, we have determined the structure of TVV2 by cryo-electron microscopy (cryoEM) at 3.6 Å resolution and derived an atomic model of its capsid. TVV2 has an icosahedral, T = 2*, capsid comprised of 60 copies of the icosahedral asymmetric unit (a dimer of the two capsid shell protein [CSP] conformers, CSP-A and CSP-B), typical of icosahedral dsRNA virus capsids. However, unlike the robust CSP-interlocking interactions such as the use of auxiliary "clamping" proteins among Reoviridae, only lateral CSP interactions are observed in TVV2, consistent with an assembly strategy optimized for TVVs' intracellular-only replication cycles within their protozoan host. The atomic model reveals both a mostly negatively charged capsid interior, which is conducive to movement of the loosely packed genome, and channels at the 5-fold vertices, which we suggest as routes of mRNA release during transcription. Structural comparison of TVV2 to the Saccharomyces cerevisiae L-A virus reveals a conserved helix-rich fold within the CSP and putative guanylyltransferase domain along the capsid exterior, suggesting conserved mRNA maintenance strategies among Totiviridae This first atomic structure of a TVV provides a framework to guide future biochemical investigations into the interplay between Trichomonas vaginalis and its viruses.IMPORTANCETrichomonas vaginalis viruses (TVVs) are double-stranded RNA (dsRNA) viruses that cohabitate in Trichomonas vaginalis, the causative pathogen of trichomoniasis, the most common nonviral sexually transmitted disease worldwide. Featuring an unsegmented dsRNA genome encoding a single capsid shell protein (CSP), TVVs contrast with multisegmented dsRNA viruses, such as the diarrhea-causing rotavirus, whose larger genome is split into 10 dsRNA segments encoding 5 unique capsid proteins. To determine how TVVs incorporate the requisite functionalities for viral replication into their limited proteome, we derived the atomic model of TVV2, a first for TVVs. Our results reveal the intersubunit interactions driving CSP association for capsid assembly and the properties that govern organization and maintenance of the viral genome. Structural comparison between TVV2 capsids and those of distantly related dsRNA viruses indicates conserved strategies of nascent RNA release and a putative viral guanylyltransferase domain implicated in the cytoplasmic maintenance of viral messenger and genomic RNA.
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Vírus de RNA/ultraestrutura , RNA de Cadeia Dupla/química , Totiviridae/ultraestrutura , Trichomonas vaginalis/virologia , Capsídeo/química , Capsídeo/metabolismo , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Microscopia Crioeletrônica , Genoma Viral , Conformação Proteica em alfa-Hélice , Vírus de RNA/classificação , Vírus de RNA/genética , Vírus de RNA/isolamento & purificação , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , RNA Viral/química , RNA Viral/genética , RNA Viral/metabolismo , Totiviridae/classificação , Totiviridae/genética , Totiviridae/isolamento & purificaçãoRESUMO
By extending our Paraquat (PQ) work to include primates we have implemented a modelling and simulation strategy that has enabled PQ pharmacokinetic data to be integrated into a single physiologically based pharmacokinetic (PBPK) model that enables more confident extrapolation to humans. Because available data suggested there might be differences in PQ kinetics between primates and non-primates, a radiolabelled study was conducted to characterize pharmacokinetics and excretion in Cynomolgus monkeys. Following single intravenous doses of 0.01 or 0.1 mg paraquat dichloride/kg bw, plasma PQ concentration-time profiles were dose-proportional. Excretion up to 48 h (predominantly urinary) was 82.9%, with ca. 10% remaining unexcreted. In vitro blood binding was similar across Cynomolgus monkeys, humans and rat. Our PBPK model for the rat, mouse and dog, employing a single set of PQ-specific parameters, was scaled to Cynomolgus monkeys and well represented the measured plasma concentration-time profiles over 14 days. Addition of a cartilage compartment to the model better captured the percent remaining in the monkeys at 48 h, whilst having negligible effect on model predictions for the other species. The PBPK model performed well for all four species, demonstrating there is little difference in PQ kinetics between non-primates and primates enabling a more confident extrapolation to humans. Scaling of the PBPK model to humans, with addition of a human-specific dermal submodel based on in vitro human dermal absorption data, provides a valuable tool that could be employed in defining internal dosimetry to complement human health risk assessments.
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Herbicidas/farmacocinética , Modelos Biológicos , Paraquat/farmacocinética , Animais , Simulação por Computador , Herbicidas/administração & dosagem , Herbicidas/sangue , Herbicidas/toxicidade , Humanos , Infusões Intravenosas , Eliminação Intestinal , Macaca fascicularis , Paraquat/administração & dosagem , Paraquat/sangue , Paraquat/toxicidade , Ratos , Eliminação Renal , Medição de Risco , Absorção Cutânea , Especificidade da Espécie , Distribuição Tecidual , ToxicocinéticaRESUMO
Paraquat dichloride (PQ) is a non-selective herbicide which has been the subject of numerous toxicology studies over more than 50 years. This paper describes the development of a physiologically-based pharmacokinetic (PBPK) model of PQ kinetics for the rat, mouse and dog, firstly to aid the interpretation of studies in which no kinetic measurements were made, and secondly to enable the future extension of the model to humans. Existing pharmacokinetic data were used to develop a model for the rat and mouse. Simulations with this preliminary model were then used to identify key data gaps and to design a new blood binding study to reduce uncertainty in critical aspects of the model. The new data provided evidence to support the model structure, and its predictive performance was then assessed against dog and rat datasets not used in model development. The PQ-specific model parameters are the same for all three species, with only the physiological parameters varying between species. This consistency across species provides a strong basis for extrapolation to other species, as demonstrated here for the dog. The model enables a wide range of PQ data to be linked together to provide a broad understanding of PQ pharmacokinetics in rodents and the dog, showing that the key aspects of PQ kinetics in these species are understood and adequately encapsulated within the model.
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Herbicidas/farmacocinética , Modelos Biológicos , Paraquat/farmacocinética , Animais , Simulação por Computador , Cães , Herbicidas/sangue , Herbicidas/toxicidade , Eliminação Intestinal , Camundongos , Paraquat/sangue , Paraquat/toxicidade , Ligação Proteica , Ratos , Eliminação Renal , Medição de Risco , Especificidade da Espécie , Distribuição Tecidual , ToxicocinéticaRESUMO
Blindness early in life induces permanent alterations in brain anatomy, including reduced surface area of primary visual cortex (V1). Bilateral enucleation early in development causes greater reductions in primary visual cortex surface area than at later times. However, the time at which cortical surface area expansion is no longer sensitive to enucleation is not clearly established, despite being an important milestone for cortical development. Using histological and MRI techniques, we investigated how reductions in the surface area of V1 depends on the timing of blindness onset in rats, ferrets and humans. To compare data across species, we translated ages of all species to a common neuro-developmental event-time (ET) scale. Consistently, blindness during early cortical expansion induced large (~40%) reductions in V1 surface area, in rats and ferrets, while blindness occurring later had diminishing effects. Longitudinal measurements on ferrets confirmed that early enucleation disrupted cortical expansion, rather than inducing enhanced pruning. We modeled the ET associated with the conclusion of the effect of blindness on surface area at maturity (ETc), relative to the normal conclusion of visual cortex surface area expansion, (ETdev). A final analysis combining our data with extant published data confirmed that ETc occurred well before ETdev.
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Cegueira/patologia , Cegueira/fisiopatologia , Furões/anatomia & histologia , Furões/crescimento & desenvolvimento , Privação Sensorial/fisiologia , Córtex Visual/crescimento & desenvolvimento , Córtex Visual/patologia , Idade de Início , Animais , Córtex Cerebral/crescimento & desenvolvimento , Córtex Cerebral/patologia , Humanos , Ratos , Especificidade da EspécieRESUMO
We investigated the metabolic capabilities of C. elegans using compounds whose metabolism has been well characterised in mammalian systems. We find that similar metabolites are produced in C. elegans as in mammals but that C. elegans is deficient in CYP1-like metabolism, as has been seen in other studies. We show that CYP-34A9, CYP-34A10 and CYP-36A1 are the principal enzymes responsible for the metabolism of tolbutamide in C. elegans. These are related to the mammalian enzymes that metabolise this compound but are not the closest homologs suggesting that sequence comparison alone will not predict functional conservation among cytochrome P450s. In mammals, metabolite production from amytryptiline and dextromethorphan is dependent on specific cytochrome P450s. However, in C. elegans we did not find evidence of similar specificity: the same metabolites were produced but in small amounts by numerous cytochrome P450s. We conclude that, while some aspects of cytochrome P450 mediated metabolism in C. elegans are similar to mammals, there are differences in the production of some metabolites and in the underlying genetics of metabolism.
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Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Sistema Enzimático do Citocromo P-450/metabolismo , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Sistema Enzimático do Citocromo P-450/genética , Tolbutamida/metabolismoRESUMO
Compounds and products in the biocide and plant protection sector can only be registered after formal risk assessment to ensure safety for users and the environment. In bird and mammal risk assessment, this is routinely done using generic focal species as models, which are of particular exposure risk. Such a species is the common vole (Microtus arvalis) due to its high food intake relative to the low body weight. For wild species, biological samples, data and hence realistic exposure estimations are particularly difficult to obtain. In recent years, advances have been made in the techniques related to serial microsampling of laboratory mice and rats that allow for a reduction in sampling volumes. Similar progress in wild species sampling is missing. This study presents a proof of concept to dose wild rodents with relevant compounds and to draw serial, low volume blood samples suitable for state-of-the art toxicokinetic analyses. For the first time, the jugular vein of common voles was used to administer compounds (two frequently used fungicidal components). This procedure and the following microsampling of blood (2 × 10 µl six times within 24 hours) from the lateral tail vein did not affect body weight and mortality of voles. Samples were sufficient to detect dissipation patterns of the compounds from blood in toxicokinetic analysis. These results suggest that microsampling can be well translated from laboratory mice to wild rodent species and help to obtain realistic exposure estimates in wild rodents for ecotoxicological studies as well as to promote the 3R concept in studies with wild rodent species.
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Arvicolinae/sangue , Coleta de Amostras Sanguíneas/métodos , Dioxóis/toxicidade , Ecotoxicologia/métodos , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental/métodos , Fungicidas Industriais/toxicidade , Pirimidinas/toxicidade , Pirróis/toxicidade , Administração Intravenosa , Animais , Dioxóis/administração & dosagem , Dioxóis/sangue , Dioxóis/farmacocinética , Feminino , Fungicidas Industriais/administração & dosagem , Fungicidas Industriais/sangue , Fungicidas Industriais/farmacocinética , Masculino , Pirimidinas/administração & dosagem , Pirimidinas/sangue , Pirimidinas/farmacocinética , Pirróis/administração & dosagem , Pirróis/sangue , Pirróis/farmacocinética , Reprodutibilidade dos Testes , Medição de Risco , ToxicocinéticaRESUMO
Langguth et al. (2006) described a method for targeting primary auditory cortex (PAC) during transcranial magnetic stimulation (TMS) using the 10-20 electroencephalography system. Study aims were to measure the degree of accuracy in placing the TMS coil on the scalp overlying PAC using the 10-20 method and determine the extent to which accuracy depends on the hemisphere of the coil placement. Twelve participants underwent anatomical magnetic resonance imaging (MRI) of their head in a 3T scanner. Before imaging, a fiducial marker was placed on their scalp corresponding to the TMS coil position. MRI scans were analyzed to determine the distance from the fiducial marker to PAC for each participant. On average, the 10-20 method resulted in distances in the medial-lateral, anterior-posterior, and inferior-superior dimensions that were within a few millimeters (~ 4 mm) of each other between the left and right hemispheres. The fiducial marker was, on average, 10.4 mm superior and 10.8 mm posterior to the optimal scalp location that minimized the distance to PAC. Individual asymmetries and other systematic differences found in this study raise important considerations to keep in mind that might necessitate using an MRI-guided method of coil-positioning when targeting PAC for TMS.
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Córtex Auditivo/diagnóstico por imagem , Zumbido/terapia , Estimulação Magnética Transcraniana/métodos , Adulto , Idoso , Eletroencefalografia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Zumbido/diagnóstico por imagemRESUMO
For the purposes of chemical safety assessment, the value of using non-animal (in silico and in vitro) approaches and generating mechanistic information on toxic effects is being increasingly recognised. For sectors where in vivo toxicity tests continue to be a regulatory requirement, there has been a parallel focus on how to refine studies (i.e. reduce suffering and improve animal welfare) and increase the value that in vivo data adds to the safety assessment process, as well as where to reduce animal numbers where possible. A key element necessary to ensure the transition towards successfully utilising both non-animal and refined safety testing is the better understanding of chemical exposure. This includes approaches such as measuring chemical concentrations within cell-based assays and during in vivo studies, understanding how predicted human exposures relate to levels tested, and using existing information on human exposures to aid in toxicity study design. Such approaches promise to increase the human relevance of safety assessment, and shift the focus from hazard-driven to risk-driven strategies similar to those used in the pharmaceutical sectors. Human exposure-based safety assessment offers scientific and 3Rs benefits across all sectors marketing chemical or medicinal products. The UK's National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) convened an expert working group of scientists across the agrochemical, industrial chemical and pharmaceutical industries plus a contract research organisation (CRO) to discuss the current status of the utilisation of exposure-driven approaches, and the challenges and potential next steps for wider uptake and acceptance. This paper summarises these discussions, highlights the challenges - particularly those identified by industry - and proposes initial steps for moving the field forward.
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Alternativas aos Testes com Animais , Exposição Ambiental/efeitos adversos , Modelos Animais , Modelos Biológicos , Testes de Toxicidade/métodos , Toxicocinética , Animais , Simulação por Computador , Humanos , Reprodutibilidade dos Testes , Medição de Risco , Fatores de RiscoRESUMO
Current research in connectomics highlights that self-organized functional networks or "communities" of cortical areas can be detected in the adult brain. This perspective may provide clues to mechanisms of treatment response in psychiatric conditions. Here we examine functional brain community topology based on resting-state fMRI in adult Attention-Deficit/Hyperactivity Disorder (ADHD; n = 22) and controls (n = 31). We sought to evaluate ADHD patterns in adulthood and their modification by short term stimulants administration. Participants with ADHD were scanned one or two weeks apart, once with medication and once without; comparison participants were scanned at one time-point. Functional connectivity was estimated from these scans and community detection applied to determine cortical network topology. Measures of change in connectivity profile were calculated via a graph measure, termed the Node Dissociation Index (NDI). Compared to controls, several cortical networks had atypical connectivity in adults with ADHD when withholding stimulants, as measured by NDI. In most networks stimulants significantly reduced, but did not eliminate, differences in the distribution of connections between key brain systems relative to the control sample. These findings provide an enriched model of connectivity in ADHD and demonstrate how stimulants may exert functional effects by altering connectivity profiles in the brain.
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Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Estimulantes do Sistema Nervoso Central/uso terapêutico , Adolescente , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Estudos de Coortes , Conectoma , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/diagnóstico por imagem , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiopatologia , Escalas de Graduação Psiquiátrica , Descanso , Resultado do Tratamento , Adulto JovemRESUMO
A 2,000-m time-trial performance, aerobic capacity, and anaerobic capacity were assessed in 16 trained oarsmen after sprint interval training (SIT) replaced a portion of an endurance-based training program (EBTSIT) vs. an endurance-based program alone (EBTAlone). The EBTSIT involved 10 SIT sessions over 4 weeks, in addition to 12 continuous exercise sessions, 2 anaerobic threshold exercise sessions, and 4 strength training sessions. The EBTAlone consisted of 20 continuous, 6 anaerobic threshold, 2 interval exercise sessions, and 8 strength training sessions. Time-trial performance (2,000-m erg performance) improved with EBTSIT (baseline = 414.6 ± 18.5, post = 410.6 ± 17.5 seconds; p < 0.001) but only approached significance in EBTAlone (baseline = 413.0 ± 27.7, post = 411.4 ± 27.9 seconds; p = 0.06). In a 60-second "all-out" anaerobic capacity test, peak power output (PPO) increased significantly with EBTSIT (PPO: EBTSIT: baseline = 566 ± 82, post = 623 ± 60 W; p = 0.02) but not with EBTAlone (EBTAlone: baseline = 603 ± 81, post = 591 ± 123 W; p = 0.59). Changes in average power output (APO) also approached significance (p = 0.07) (APO: EBTSIT: baseline = 508 ± 48, post = 530 ± 52 W; EBTAlone: baseline = 532 ± 55, post = 533 ± 68 W). Neither group experienced any change in aerobic capacity ((Equation is included in full-text article.)or ventilatory threshold; p ≥ 0.16). We conclude that replacing a portion of EBT with SIT can improve both 2,000-m erg performance and anaerobic capacity, while maintaining aerobic fitness in trained oarsmen. Incorporating SIT within endurance training programs may be useful during periods of low-volume training, to improve performance without sacrificing aerobic capacity.
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Desempenho Atlético/fisiologia , Exercícios em Circuitos/métodos , Resistência Física/fisiologia , Adolescente , Limiar Anaeróbio , Teste de Esforço , Humanos , Masculino , Consumo de Oxigênio , Adulto JovemRESUMO
The efficacy of the recently approved drug fingolimod (FTY720) in multiple sclerosis patients results from the action of its phosphate metabolite on sphingosine-1-phosphate S1P1 receptors, while a variety of side effects have been ascribed to its S1P3 receptor activity. Although S1P and phospho-fingolimod share the same structural elements of a zwitterionic headgroup and lipophilic tail, a variety of chemotypes have been found to show S1P1 receptor agonism. Here we describe a study of the tolerance of the S1P1 and S1P3 receptors toward bicyclic heterocycles of systematically varied shape and connectivity incorporating acidic, basic, or zwitterionic headgroups. We compare their physicochemical properties, their performance in in vitro and in vivo pharmacokinetic models, and their efficacy in peripheral lymphocyte lowering. The campaign resulted in the identification of several potent S1P1 receptor agonists with good selectivity vs S1P3 receptors, efficacy at <1 mg/kg oral doses, and developability properties suitable for progression into preclinical development.