| 1. |
- Kia, Richard, et al.
(författare)
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MicroRNA-122 : a novel hepatocyte-enriched in vitro marker of drug-induced cellular toxicity
- 2015
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Ingår i: Toxicological Sciences. - : Oxford University Press. - 1096-6080 .- 1096-0929. ; 144:1, s. 173-185
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Tidskriftsartikel (refereegranskat)abstract
- Emerging hepatic models for the study of drug-induced toxicity include pluripotent stem cell-derived hepatocyte-like cells (HLCs) and complex hepatocyte-non-parenchymal cellular coculture to mimic the complex multicellular interactions that recapitulate the niche environment in the human liver. However, a specific marker of hepatocyte perturbation, required to discriminate hepatocyte damage from non-specific cellular toxicity contributed by non-hepatocyte cell types or immature differentiated cells is currently lacking, as the cytotoxicity assays routinely used in in vitro toxicology research depend on intracellular molecules which are ubiquitously present in all eukaryotic cell types. In this study, we demonstrate that microRNA-122 (miR-122) detection in cell culture media can be used as a hepatocyte-enriched in vitro marker of drug-induced toxicity in homogeneous cultures of hepatic cells, and a cell-specific marker of toxicity of hepatic cells in heterogeneous cultures such as HLCs generated from various differentiation protocols and pluripotent stem cell lines, where conventional cytotoxicity assays using generic cellular markers may not be appropriate. We show that the sensitivity of the miR-122 cytotoxicity assay is similar to conventional assays that measure lactate dehydrogenase activity and intracellular adenosine triphosphate when applied in hepatic models with high levels of intracellular miR-122, and can be multiplexed with other assays. MiR-122 as a biomarker also has the potential to bridge results in in vitro experiments to in vivo animal models and human samples using the same assay, and to link findings from clinical studies in determining the relevance of in vitro models being developed for the study of drug-induced liver injury.
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| 2. |
- Cusack, Daniela Francis, et al.
(författare)
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Tradeoffs and Synergies in Tropical Forest Root Traits and Dynamics for Nutrient and Water Acquisition : Field and Modeling Advances
- 2021
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Ingår i: Frontiers in Forests and Global Change. - : Frontiers Media S.A.. - 2624-893X. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Vegetation processes are fundamentally limited by nutrient and water availability, the uptake of which is mediated by plant roots in terrestrial ecosystems. While tropical forests play a central role in global water, carbon, and nutrient cycling, we know very little about tradeoffs and synergies in root traits that respond to resource scarcity. Tropical trees face a unique set of resource limitations, with rock-derived nutrients and moisture seasonality governing many ecosystem functions, and nutrient versus water availability often separated spatially and temporally. Root traits that characterize biomass, depth distributions, production and phenology, morphology, physiology, chemistry, and symbiotic relationships can be predictive of plants’ capacities to access and acquire nutrients and water, with links to aboveground processes like transpiration, wood productivity, and leaf phenology. In this review, we identify an emerging trend in the literature that tropical fine root biomass and production in surface soils are greatest in infertile or sufficiently moist soils. We also identify interesting paradoxes in tropical forest root responses to changing resources that merit further exploration. For example, specific root length, which typically increases under resource scarcity to expand the volume of soil explored, instead can increase with greater base cation availability, both across natural tropical forest gradients and in fertilization experiments. Also, nutrient additions, rather than reducing mycorrhizal colonization of fine roots as might be expected, increased colonization rates under scenarios of water scarcity in some forests. Efforts to include fine root traits and functions in vegetation models have grown more sophisticated over time, yet there is a disconnect between the emphasis in models characterizing nutrient and water uptake rates and carbon costs versus the emphasis in field experiments on measuring root biomass, production, and morphology in response to changes in resource availability. Closer integration of field and modeling efforts could connect mechanistic investigation of fine-root dynamics to ecosystem-scale understanding of nutrient and water cycling, allowing us to better predict tropical forest-climate feedbacks.
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| 3. |
- Falster, Daniel, et al.
(författare)
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AusTraits, a curated plant trait database for the Australian flora
- 2021
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Ingår i: Scientific Data. - : Nature Portfolio. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
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| 4. |
- Forsberg, Anna, et al.
(författare)
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Once-only colonoscopy or two rounds of faecal immunochemical testing 2 years apart for colorectal cancer screening (SCREESCO): preliminary report of a randomised controlled trial
- 2022
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Ingår i: The Lancet Gastroenterology & Hepatology. - : ELSEVIER INC. - 2468-1253. ; 7:6, s. 513-521
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Tidskriftsartikel (refereegranskat)abstract
- Background Screening for colorectal cancer is done with lower gastrointestinal endoscopy or stool-based tests. There is little evidence from randomised trials to show primary colonoscopy reduces mortality in colorectal cancer We aimed to investigate the effect of screening with once-only colonoscopy or two rounds of faecal immunochemical test screening on colorectal cancer mortality and incidence. Methods We did a randomised controlled trial in Sweden (SCREESCO). Residents in 18 of 21 regions who were age 60 years in the year of randomisation were identified from a population register maintained by the Swedish Tax Agency. A statistician with no further involvement in the trial used a randomised block method to assign individuals to once-only colonoscopy, two rounds of faecal immunochemical testing (OC-Sensor; 2 years apart), or a control group (no intervention; standard diagnostic pathways), in a ratio of 1:6 for colonoscopy versus control and 1:2 for faecal immunochemical testing versus control. Masking was not possible due to the nature of the trial. The primary endpoints of the trial are colorectal cancer mortality and colorectal cancer incidence. Here, we report preliminary participation rates, baseline findings, and adverse events from March, 2014, to December, 2020, in the two intervention groups after completion of recruitment and screening, up to the completion of the second faecal immunochemical testing round. Analyses were done in the intention-to-screen population, defined as all individuals who were randomly assigned to the respective study group. This study is registered with Clinical Trials.gov, NCT02078804. Findings Between March 1, 2014, and Dec 31, 2020, 278 280 people were induded in the study; 31 140 were assigned to the colonoscopy group, 60 300 to the faecal immunochemical test group, and 186 840 to the control group. 10 679 (35.1%) of 30 400 people who received an invitation for colonoscopy participated. 33 383 (55.5%) of 60 137 people who received a postal faecal immunochemical test participated. In the intention-to-screen analysis, colorectal cancer was detected in 49 (0.16%) of 31140 people in the colonoscopy group versus 121 (0. 20%) of 60 300 in the faecal immunochemical test group (relative risk [RR] 0.78, 95% CI 0.56-1.09). Advanced adenomas were detected in 637 (2.05%) people in the colonoscopy group and 968 (1.61%) in the faecal immunochemical test group (RR 1.27, 95% CI 1.15-1.41). Colonoscopy detected more right-sided advanced adenomas than faecal immunochemical testing. There were two perforations and 15 major bleeds in 16 555 colonoscopies. No intervention-related deaths occurred. Interpretation The diagnostic yield and the low number of adverse events indicate that the design from this trial, both for once-only colonoscopy and faecal immunochemical test screening, could be transferred to a population-based screening service if a benefit in disease-specific mortality is subsequently shown. Copyright (C) 2022 Elsevier Ltd. All rights reserved.
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| 5. |
- Ibanez, Thomas, et al.
(författare)
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Damage to tropical forests caused by cyclones is driven by wind speed but mediated by topographical exposure and tree characteristics
- 2024
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 30:5
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Tidskriftsartikel (refereegranskat)abstract
- Each year, an average of 45 tropical cyclones affect coastal areas and potentially impact forests. The proportion of the most intense cyclones has increased over the past four decades and is predicted to continue to do so. Yet, it remains uncertain how topographical exposure and tree characteristics can mediate the damage caused by increasing wind speed. Here, we compiled empirical data on the damage caused by 11 cyclones occurring over the past 40 years, from 74 forest plots representing tropical regions worldwide, encompassing field data for 22,176 trees and 815 species. We reconstructed the wind structure of those tropical cyclones to estimate the maximum sustained wind speed (MSW) and wind direction at the studied plots. Then, we used a causal inference framework combined with Bayesian generalised linear mixed models to understand and quantify the causal effects of MSW, topographical exposure to wind (EXP), tree size (DBH) and species wood density (ρ) on the proportion of damaged trees at the community level, and on the probability of snapping or uprooting at the tree level. The probability of snapping or uprooting at the tree level and, hence, the proportion of damaged trees at the community level, increased with increasing MSW, and with increasing EXP accentuating the damaging effects of cyclones, in particular at higher wind speeds. Higher ρ decreased the probability of snapping and to a lesser extent of uprooting. Larger trees tended to have lower probabilities of snapping but increased probabilities of uprooting. Importantly, the effect of ρ decreasing the probabilities of snapping was more marked for smaller than larger trees and was further accentuated at higher MSW. Our work emphasises how local topography, tree size and species wood density together mediate cyclone damage to tropical forests, facilitating better predictions of the impacts of such disturbances in an increasingly windier world.
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| 6. |
- Nowack, Bernd, et al.
(författare)
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Potential scenarios for nanomaterial release and subsequent alteration in the environment
- 2012
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 31:1, s. 50-59
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Tidskriftsartikel (refereegranskat)abstract
- The risks associated with exposure to engineered nanomaterials (ENMs) will be determined in part by the processes that control their environmental fate and transformation. These processes act not only on ENMs that might be released directly into the environment, but more importantly also act on ENMs in consumer products and those that have been released from the product. The environmental fate and transformation is likely to differ significantly for each of these cases. The ENM released from actual direct use or from nano-containing products are much more relevant for ecotoxicological studies and risk assessment than pristine ENMs. The released ENMs may have a greater or lesser environmental impact than the starting materials, depending on the transformation reactions and the material. Almost nothing is known about the environmental behavior and the effects of released and transformed ENMs, although these are the materials that are actually present in the environment. Further research is needed to show if the release and transformation processes result in a similar or more diverse set of ENMs and ultimately how this affects environmental behavior. These questions are addressed in this article using four brief hypothetical case studies that cover a wide range of ENMs, their direct use or product applications, and their likely fate in the environment. Furthermore, a more definitive classification scheme for ENMs should be adopted that reflects their surface condition, which is a result of both industrial and environmental processes acting on the ENM. The authors conclude that it is not possible to assess the risks associated with the use of ENMs by investigating only the naked (pristine) form of the ENM, without considering alterations and transformation processes. Environ. Toxicol. Chem. © 2011 SETAC.
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| 7. |
- Palm, Anna, et al.
(författare)
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Assessing the environmental fate of chemicals of emerging concern: a case study of the polybrominated diphenyl ethers
- 2002
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Ingår i: Environmental Pollution. - 0269-7491 .- 1873-6424. ; 117:2, s. 195-213
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Tidskriftsartikel (refereegranskat)abstract
- It is suggested that assessments of chemicals of emerging concern can be rationally structured around a multistage process in which fate and risk are evaluated with increasing accuracy as new data become available. An initial tentative and approximate assessment of fate and risk can identify key data gaps and justify and direct further investigations, which progressively improve the reliability of the assessment. This approach is demonstrated for a class of chemicals, the polybrominated diphenyl ethers (PBDEs), which is of increasing concern, but about which there is presently a lack of comprehensive data on properties, sources, fate and effects. Specifically, 20 PBDE congeners are investigated using the suggested approach and research needs are identified.For chemicals of emerging concern, an initial and approximate assessment of fate and risk can identify key data gaps.
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| 8. |
- Simpkin, Andrew J, et al.
(författare)
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Development, validation and evaluation of an instrument for active monitoring of men with clinically localised prostate cancer : systematic review, cohort studies and qualitative study
- 2015
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Ingår i: Health Services and Delivery Research. - : National Institute for Health Research. - 2050-4349 .- 2050-4357. ; 3:30
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Tidskriftsartikel (refereegranskat)abstract
- Background:Active surveillance [(AS), sometimes called active monitoring (AM)],is a National Institute for Health and Care Excellence-recommended management option for men with clinically localised prostate cancer (PCa). It aims to target radical treatment only to those who would benefit most. Little consensus exists nationally or internationally about safe and effective protocols for AM/AS or triggers that indicate if or when men should move to radical treatment.Objective:The aims of this project were to review how prostate-specific antigen (PSA) has been used in AM/AS programmes; to develop and test the validity of a new model for predicting future PSA levels; to develop an instrument, based on PSA, that would be acceptable and effective for men and clinicians to use in clinical practice; and to design a robust study to evaluate the cost-effectiveness of the instrument.Methods:A systematic review was conducted to investigate how PSA is currently used to monitor men in worldwide AM/AS studies. A model for PSA change with age was developed using Prostate testing for cancer and Treatment (ProtecT) data and validated using data from two PSA-era cohorts and two pre-PSA-era cohorts. The model was used to derive 95% PSA reference ranges (PSARRs) across ages. These reference ranges were used to predict the onset of metastases or death from PCa in one of the pre-PSA-era cohorts. PSARRs were incorporated into an active monitoring system (AMS) and demonstrated to 18 clinicians and 20 men with PCa from four NHS trusts. Qualitative interviews investigated patients’ and clinicians’ views about current AM/AS protocols and the acceptability of the AMS within current practice.Results:The systematic review found that the most commonly used triggers for clinical review of PCa were PSA doubling time (PSADT) < 3 years or PSA velocity (PSAv) > 1 ng/ml/year. The model for PSA change (developed using ProtecT study data) predicted PSA values in AM/AS cohorts within 2 ng/ml of observed PSA in up to 79% of men. Comparing the three PSA markers, there was no clear optimal approach to alerting men to worsening cancer. The PSARR and PSADT markers improved the model c-statistic for predicting death from PCa by 0.11 (21%) and 0.13 (25%), respectively, compared with using diagnostic information alone [PSA, age, tumour stage (T-stage)]. Interviews revealed variation in clinical practice regarding eligibility and follow-up protocols. Patients and clinicians perceive current AM/AS practice to be framed by uncertainty, ranging from uncertainty about selection of eligible AM/AS candidates to uncertainty about optimum follow-up protocols and thresholds for clinical review/radical treatment. Patients and clinicians generally responded positively to the AMS. The impact of the AMS on clinicians’ decision-making was limited by a lack of data linking AMS values to long-term outcomes and by current clinical practice, which viewed PSA measures as one of several tools guiding clinical decisions in AM/AS. Patients reported that they would look to clinicians, rather than to a tool, to direct decision-making.Limitations:The quantitative findings were severely hampered by a lack of clinical outcomes or events (such as metastases). The qualitative findings were limited through reliance on participants’ reports of practices and recollections of events rather than observations of actual interactions.Conclusions:Patients and clinicians found that the instrument provided additional, potentially helpful, information but were uncertain about the current usefulness of the risk model we developed for routine management. Comparison of the model with other monitoring strategies will require clinical outcomes from ongoing AM/AS studies.Funding:The National Institute for Health Research Health Services and Delivery Research programme.
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| 9. |
- Simpkin, Andrew J., et al.
(författare)
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Prostate-specific antigen patterns in US and European populations : comparison of six diverse cohorts
- 2016
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Ingår i: BJU International. - : Wiley. - 1464-4096 .- 1464-410X. ; 118:6, s. 911-918
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine whether there are differences in prostate-specific antigen (PSA) levels at diagnosis or changes in PSA levels between US and European populations of men with and without prostate cancer (PCa).SUBJECTS AND METHODS: We analysed repeated measures of PSA from six clinically and geographically diverse cohorts of men: two cohorts with PSA-detected PCa, two cohorts with clinically detected PCa and two cohorts without PCa. Using multilevel models, average PSA at diagnosis and PSA change over time were compared among study populations.RESULTS: The annual percentage PSA change of 4-5% was similar between men without cancer and men with PSA-detected cancer. PSA at diagnosis was 1.7 ng/mL lower in a US cohort of men with PSA-detected PCa (95% confidence interval 1.3-2.0 ng/mL), compared with a UK cohort of men with PSA-detected PCa, but there was no evidence of a different rate of PSA change between these populations.CONCLUSION: We found that PSA changes over time are similar in UK and US men diagnosed through PSA testing and even in men without PCa. Further development of PSA models to monitor men on active surveillance should be undertaken in order to take advantage of these similarities. We found no evidence that guidelines for using PSA to monitor men cannot be passed between US and European studies.
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| 10. |
- Simpkin, Andrew J, et al.
(författare)
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Systematic Review and Meta-analysis of Factors Determining Change to Radical Treatment in Active Surveillance for Localized Prostate Cancer.
- 2015
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Ingår i: European Urology. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 67:6
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Many men with clinically localized prostate cancer are being monitored as part of active surveillance (AS) programs, but little is known about reasons for receiving radical treatment.OBJECTIVES: A systematic review of the evidence about AS was undertaken, with a meta-analysis to identify predictors of radical treatment.EVIDENCE ACQUISITION: A comprehensive search of the Embase, MEDLINE and Web of Knowledge databases to March 2014 was performed. Studies reporting on men with localized prostate cancer followed by AS or monitoring were included. AS was defined where objective eligibility criteria, management strategies, and triggers for clinical review or radical treatment were reported.EVIDENCE SYNTHESIS: The 26 AS cohorts included 7627 men, with a median follow-up of 3.5 yr (range of medians 1.5-7.5 yr). The cohorts had a wide range of inclusion criteria, monitoring protocols, and triggers for radical treatment. There were eight prostate cancer deaths and five cases of metastases in 24,981 person-years of follow-up. Each year, 8.8% of men (95% confidence interval 6.7-11.0%) received radical treatment, most commonly because of biopsy findings, prostate-specific antigen triggers, or patient choice driven by anxiety. Studies in which most men changed treatment were those including only low-risk Gleason score 6 disease and scheduled rebiopsies.CONCLUSIONS: The wide variety of AS protocols and lack of robust evidence make firm conclusions difficult. Currently, patients and clinicians have to make judgments about the balance of risks and benefits in AS protocols. The publication of robust evidence from randomized trials and longer-term follow-up of cohorts is urgently required.PATIENT SUMMARY: We reviewed 26 studies of men on active surveillance for prostate cancer. There was evidence that studies including men with the lowest risk disease and scheduled rebiopsy had higher rates of radical treatment.
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