Publications by authors named "Roper C"

Increasing the use of microphysiological systems (MPS) in Three Rs and regulatory applications is a nuanced but important goal, which would also help increase their scientific impact. There are three distinct and important stakeholder groups that each play a unique role in expediting the use of MPS for regulatory purpose - namely, commercial MPS developers, end-users and regulators. Additionally, non-profit organisations, such as the 3Rs Collaborative (3RsC), can help coordinate these efforts.

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Background: Among the several strategies recommended for the fight against malaria, seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine combination (SPAQ) targets children 3 months to 5 years in Sahel regions of Africa to reduce mortality and mortality. Since SMC with SPAQ is administered to symptoms-free children for prevention of malaria, it is anticipated that a proportion of asymptomatic parasitaemic children will also be treated and may result in a drop in both the overall population prevalence of asymptomatic malaria infections, subsequent risk of symptomatic malaria infections and transmission. Age-specific carriage of asymptomatic Plasmodium spp.

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The ED is increasingly the first point of contact for people who have no alternative when they are in a mental health crisis. However, there is mounting evidence of inadequate and negative responses to mental health crises in the ED, which has been identified as a 'human rights flashpoint'. This paper presents the desired crisis support from people who have accessed the ED in a mental health crisis and offers significant opportunities to use lived experience knowledge to reshape crisis care.

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The use of new approach methodologies (NAMs) to assess respiratory irritation depends on several factors, including the specifics of exposure methods and cell/tissue-based test systems. This topic was examined in the context of human health risk assessment for cleaning products at a 1-day public workshop held on 2 March 2023, organized by the American Cleaning Institute (ACI). The goals of this workshop were to (1) review NAMs for evaluation of respiratory irritation, (2) examine different perspectives on current challenges and suggested solutions, and (3) publish a manuscript of the proceedings.

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Fine particulate matter (PM) is hypothesized to induce oxidative stress, and has been linked to acute and chronic adverse health effects. To better understand the risks and underlying mechanisms following exposure, PM is collected onto filters but prior to toxicological analysis, particles must be removed from filters. There is no standard method for filter extraction, which creates the possibility that the methods of extraction selected can alter the chemical composition and ultimately the biological implications.

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Article Synopsis
  • Standard information reporting is essential for consistent assay conditions and data, enabling easier comparisons between laboratories.
  • The publication presents the Minimum Information for Reporting on the TEER assay (MIRTA), a key method used to assess cell culture models and toxicity potential.
  • Developed through an international collaboration, the recommendations from the RespTox Collaborative aim to improve data transparency, reproducibility, and quality in both respiratory and other cell systems.
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Background: The World Health Organization 2022 malaria chemoprevention guidelines recommend providing a full course of antimalarial treatment at pre-defined intervals, regardless of malaria status to prevent illness among children resident in moderate to high perennial malaria transmission settings as perennial malaria chemoprevention (PMC) with sulfadoxine-pyrimethamine (SP). The dhps I431V mutation circulating in West Africa has unknown effect on SP protective efficacy.

Methods: This protocol is for a three-arm, parallel, double-blinded, placebo-controlled, randomised trial in Cameroon among children randomly assigned to one of three directly-observed treatment groups: (i) Group 1 (n = 450) receives daily artesunate (AS) placebo on days - 7 to -1, then active SP plus placebo amodiaquine (AQ) on day 0, and placebo AQ on days 1 and 2; (ii) Group 2 (n = 250) receives placebo AS on days - 7 to -1, then active SP and AQ on day 0, and active AQ on days 1 and 2; and (iii) Group 3 (n = 200) receives active AS on days - 7 to -1, then placebo SP on day 0 and placebo AQ on days 0 to 2.

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Organismal phenotyping to identify fitness traits is transforming our understanding of adaptive responses and ecological interactions of species within changing environments. Here we present a portable Multi-Taxa Phenotyping (MTP) system that can retrieve a suite of metabolic and photophysiological parameter across light, temperature, and/or chemical gradients, using real time bio-optical (oxygen and chlorophyll a fluorescence) measurements. The MTP system integrates three well-established technologies for the first time: an imaging Pulse Amplitude Modulated (PAM) chlorophyll a fluorometer, custom-designed well plates equipped with optical oxygen sensors, and a thermocycler.

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AcutoX is a human in vitro test method for the evaluation of acute oral toxicity developed using a library of 67 curated test chemicals. These chemicals cover a wide variety of chemistries, indus­trial sectors, rodent toxicities, and all EPA and GHS hazard categories. The test uses two different cytotoxicity endpoints (neutral red uptake and MTT metabolism), performed both in the presence and absence of pooled human liver extract (S9), to produce four EC50 values.

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Robotic assisted partial nephrectomy (RPN) has emerged in urologic practice for the management of appropriately sized renal masses. We provide a 20-year comparison of the outcomes of open partial nephrectomy (OPN) versus RPN for renal cell carcinoma (RCC) at our institution. An IRB-approved retrospective review was conducted of RCC patients at a single institution from 2000 to 2022 who underwent RPN or OPN.

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Background: Medical interventions have a place in crisis support; however, narrow biomedical and risk-driven responses negatively impact people seeking crisis care. With increasing shifts towards involving people with lived experience (service users) in designing services, foregrounding people's desired responses is critical. Accordingly, the aim of the study was to explore the wished-for crisis responses from the perspective of people who have experienced crisis and accessed crisis care.

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Interactions between polycyclic aromatic hydrocarbons (PAHs) and titanium dioxide (TiO) nanoparticles (NPs) can produce unforeseen photoproducts in the aqueous phase. Both PAHs and TiO-NPs are well-studied and highly persistent environmental pollutants, but the consequences of PAH-TiO-NP interactions are rarely explored. We investigated PAH photoproduct formation over time for benzo[a]pyrene (BaP), fluoranthene (FLT), and pyrene (PYR) in the presence of ultraviolet A (UVA) using a combination of analytical and computational methods including, identification of PAH photoproducts, assessment of expression profiles for gene indicators of PAH metabolism, and computational evaluation of the reaction mechanisms through which certain photoproducts might be formed.

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Background: Recently revised WHO guidelines on malaria chemoprevention have opened the door to more tailored implementation. Countries face choices on whether to replace old drugs, target additional age groups, and adapt delivery schedules according to local drug resistance levels and malaria transmission patterns. Regular routine assessment of protective efficacy of chemoprevention is key.

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Octocrylene is a common sun filter ingredient used to protect the skin from damaging UV rays. Benzophenone is an impurity found in formulations containing octocrylene. [C]-Benzophenone was spiked (0.

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Purpose: Holmium laser enucleation of the prostate (HoLEP) is a surgical treatment option for benign prostatic hyperplasia (BPH). Many men develop retrograde ejaculation postprocedure, but there is conflicting evidence regarding sexual function outcomes post-HoLEP. We sought to examine significant variations in patient-reported erectile and ejaculatory function within 12 months post-HoLEP.

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New approach methodologies (NAMs) can deliver improved chemical safety assessment through the provision of more protective and/or relevant models that have a reduced reliance on animals. Despite the widely acknowledged benefits offered by NAMs, there continue to be barriers that prevent or limit their application for decision-making in chemical safety assessment. These include barriers related to real and perceived scientific, technical, legislative and economic issues, as well as cultural and societal obstacles that may relate to inertia, familiarity, and comfort with established methods, and around regulatory expectations and acceptance.

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Coral propagation and out-planting based restoration approaches are increasingly being applied to assist natural recovery of coral reefs. However, many restoration methods rely on plastic zip-ties to secure coral material which is potentially problematic for the marine environment. Plastic-free biodegradable alternatives may however pose unique risks to coral-associated bacterial communities integral to coral health.

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To investigate ideological symmetries and asymmetries in the expression of online prejudice, we used machine-learning methods to estimate the prevalence of extreme hostility in a large dataset of Twitter messages harvested in 2016. We analyzed language contained in 730,000 tweets on the following dimensions of bias: (1) threat and intimidation, (2) obscenity and vulgarity, (3) name-calling and humiliation, (4) hatred and/or racial, ethnic, or religious slurs, (5) stereotypical generalizations, and (6) negative prejudice. Results revealed that conservative social media users were significantly more likely than liberals to use language that involved threat, intimidation, name-calling, humiliation, stereotyping, and negative prejudice.

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Fine particulate matter (PM) exposure has been linked to diverse human health impacts. Little is known about the potential heterogeneous impacts of PM generated from different indoor fuel sources and how exposure differs between personal and indoor environments. Therefore, we used PM collected by one stationary sampler in a kitchen and personal samplers (female and male participants), in homes ( = 24) in Kheri, India, that used either biomass or liquified petroleum gas (LPG) as primary fuel sources.

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Objectives: Partial artemisinin resistance, mediated by Plasmodium falciparum K13 (PfK13) mutations, has been confirmed in certain areas of East Africa that are historically associated with high-level antimalarial resistance. The Democratic Republic of Congo (DRC) borders these areas in the East. This study aimed to determine the prevalence of resistance markers in six National Malaria Control Program surveillance sites; Boende, Kabondo, Kapolowe, Kimpese, Mikalayi, and Rutshuru.

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Current practices for structural analysis of extremely large-molecular-weight polysaccharides via solution-state nuclear magnetic resonance (NMR) spectroscopy incorporate partial depolymerization protocols that enable polysaccharide solubilization in suitable solvents. Non-specific depolymerization techniques utilized for glycosidic bond cleavage, such as chemical degradation or ultrasonication, potentially generate structural fragments that can complicate complete and accurate characterization of polysaccharide structures. Utilization of appropriate enzymes for polysaccharide degradation, on the other hand, requires prior structural knowledge and optimal enzyme activity conditions that are not available to an analyst working with novel or unknown compounds.

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In vitro absorption through human skin is a critical component in the safety assessment of chemicals, crop protection products, consumer healthcare products and cosmetics. A barrier integrity assay is used to identify skin samples which are potentially damaged. A retrospective analysis of 9978 electrical resistance (ER) measurements generated in a single laboratory (DTL) over a 15-year period was performed.

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The skin is a potential route of exposure to antimicrobial cleaning products (ACP). Skin irritation, reversible damage to the skin, is an endpoint for protecting consumers and operators accidently exposed to these complex mixtures. To assess skin irritation of 24 ACP formulations, a new protocol was developed and adapted from OECD Test Guideline No.

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