104 research outputs found

    TP53 mutations in head and neck cancer cells determine the Warburg phenotypic switch creating metabolic vulnerabilities and therapeutic opportunities for stratified therapies

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    Patients with mutated TP53 have been identified as having comparatively poor outcomes compared to those retaining wild-type p53 in many cancers, including squamous cell carcinomas of the head and neck (SCCHN). We have examined the role of p53 in regulation of metabolism in SCCHN cells and find that loss of p53 function determines the Warburg effect in these cells. Moreover, this metabolic adaptation to loss of p53 function creates an Achilles’ heel for tumour cells that can be exploited for potential therapeutic benefit. Specifically, cells lacking normal wild-type p53 function, whether through mutation or RNAi-mediated downregulation, display a lack of metabolic flexibility, becoming more dependent on glycolysis and losing the ability to increase energy production from oxidative phosphorylation. Thus, cells that have compromised p53 function can be sensitised to ionizing radiation by pre-treatment with a glycolytic inhibitor. These results demonstrate the deterministic role of p53 in regulating energy metabolism and provide proof of principle evidence for an opportunity for patient stratification based on p53 status that can be exploited therapeutically using current standard of care treatment with ionising radiation

    Hitting the target: Mathematical attainment in children is related to interceptive timing ability

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    Interceptive timing (IntT) is a fundamental ability underpinning numerous actions (e.g. ball catching), but its development and relationship with other cognitive functions remains poorly understood. Piaget (1955) suggested that children need to learn the physical rules that govern their environment before they can represent abstract concepts such as number and time. Thus, learning how objects move in space and time may underpin the development of related abstract representations (i.e. mathematics). To test this hypothesis, we captured objective measures of IntT in 309 primary school children (4-11 years), alongside ‘general motor skill’ and ‘national standardized academic attainment’ scores. Bayesian estimation showed that IntT (but not general motor capability) uniquely predicted mathematical ability even after controlling for age, reading and writing attainment. This finding highlights that interceptive timing is distinct from other motor skills with specificity in predicting childhood mathematical ability independent of other forms of attainment and motor capability

    Contrasting physiological responses between invasive sea lamprey and non-target bluegill in response to acute lampricide exposure

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    Control of invasive sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes of North America uses lampricides, which consist of 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide. Lampricides are thought to inhibit aerobic energy synthesis, with TFM having a relatively greater selective action against lampreys. While the toxicity and physiological effects of TFM are known, the impacts associated with exposure to niclosamide and TFM:niclosamide mixtures are poorly characterized in fishes. Therefore, focusing on energy metabolism, we quantified the physiological responses of larval sea lamprey and bluegill (Lepomis macrochirus), a non-target, native species. Exposures consisted of each lampricide alone (TFM at the species-specific 24 h LC10; niclosamide at 1.5% of the mixture's TFM concentration) or a mixture of the two (larval sea lamprey at TFM 24 h LC10 + 1.5% niclosamide; bluegill at sea lamprey's TFM 24 h LC99.9 + 1.5% niclosamide) for 24 h. Tissues (brain, skeletal muscle, and liver) were sampled at 6, 12, and 24 h of exposure and assayed for concentrations of ATP, phosphocreatine, glycogen, lactate, and glucose and tissue lampricide levels. In larval sea lamprey, TFM had little effect on brain and skeletal muscle, but niclosamide resulted in a depletion of high energy substrates in both tissues. Mixture-exposed lamprey showed depletion of high energy substrates, accumulation of lactate, and high mortality rates. Bluegill were largely unaffected by toxicant exposures. However, bluegill liver showed lower glycogen and lactate under all three toxicant exposures suggesting increased metabolic turnover. Bluegill also had lower concentrations of TFM and niclosamide in their tissues when compared to lamprey. Our results indicate that lampricide toxicity in sea lamprey larvae is mediated through a depletion of high energy substrates because of impaired aerobic ATP synthesis. We also confirmed that non-target bluegill showed high tolerance to lampricide exposure, an effect potentially mediated through a high detoxification capacity relative to lampreys.Fisheries and Oceans Canada||Great Lakes Fishery Commission (Grant #2018_JEF_54072)||University of Manitoba||Natural Sciences and Engineering Research Council of Canada(#05479

    Laparoscopic motor learning and workspace exploration

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    Background: Laparoscopic surgery requires operators to learn novel complex movement patterns. However, our understanding of how best to train surgeons’ motor skills is inadequate and research is needed to determine optimal laparoscopic training regimes. This difficulty is confounded by variables inherent in surgical practice – e.g. the increasing prevalence of morbidly obese patients presents additional challenges related to restriction of movement due to abdominal wall resistance and reduced intra-abdominal space. The aim of this study was to assess learning of a surgery related task in constrained and unconstrained conditions using a novel system linking a commercially available robotic arm with specialised software creating the novel kinematic assessment tool (Omni-KAT). Methods: We created an experimental tool that records motor performance by linking a commercially available robotic arm with specialised software that presents visual stimuli and objectively measures movement outcome (kinematics). Participants were given the task of generating aiming movements along a horizontal plane to move a visual cursor on a vertical screen. One group received training that constrained movements to the correct plane whilst the other group was unconstrained and could explore the entire ‘action space’. Results: The tool successfully generated the requisite force fields and precisely recorded the aiming movements. Consistent with predictions from structural learning theory, the unconstrained group produced better performance after training as indexed by movement duration (p < .05). Conclusion: The data showed improved performance for participants who explored the entire action space, highlighting the importance of learning the full dynamics of laparoscopic instruments. These findings, alongside the development of the Omni-KAT, open up exciting prospects for better understanding of the learning processes behind surgical training and investigating ways in which learning can be optimised

    Identification of the first ATRIP-deficient patient and novel mutations in ATR define a clinical spectrum for ATR-ATRIP Seckel Syndrome

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    A homozygous mutational change in the Ataxia-Telangiectasia and RAD3 related (ATR) gene was previously reported in two related families displaying Seckel Syndrome (SS). Here, we provide the first identification of a Seckel Syndrome patient with mutations in ATRIP, the gene encoding ATR-Interacting Protein (ATRIP), the partner protein of ATR required for ATR stability and recruitment to the site of DNA damage. The patient has compound heterozygous mutations in ATRIP resulting in reduced ATRIP and ATR expression. A nonsense mutational change in one ATRIP allele results in a C-terminal truncated protein, which impairs ATR-ATRIP interaction; the other allele is abnormally spliced. We additionally describe two further unrelated patients native to the UK with the same novel, heterozygous mutations in ATR, which cause dramatically reduced ATR expression. All patient-derived cells showed defective DNA damage responses that can be attributed to impaired ATR-ATRIP function. Seckel Syndrome is characterised by microcephaly and growth delay, features also displayed by several related disorders including Majewski (microcephalic) osteodysplastic primordial dwarfism (MOPD) type II and Meier-Gorlin Syndrome (MGS). The identification of an ATRIP-deficient patient provides a novel genetic defect for Seckel Syndrome. Coupled with the identification of further ATR-deficient patients, our findings allow a spectrum of clinical features that can be ascribed to the ATR-ATRIP deficient sub-class of Seckel Syndrome. ATR-ATRIP patients are characterised by extremely severe microcephaly and growth delay, microtia (small ears), micrognathia (small and receding chin), and dental crowding. While aberrant bone development was mild in the original ATR-SS patient, some of the patients described here display skeletal abnormalities including, in one patient, small patellae, a feature characteristically observed in Meier-Gorlin Syndrome. Collectively, our analysis exposes an overlapping clinical manifestation between the disorders but allows an expanded spectrum of clinical features for ATR-ATRIP Seckel Syndrome to be define

    Heliogyro Solar Sail Research at NASA

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    The recent successful flight of the JAXA IKAROS solar sail has renewed interest within NASA in spinning solar sail concepts for high-performance solar sailing. The heliogyro solar sail, in particular, is being re-examined as a potential game-changing architecture for future solar sailing missions. In this paper, we present an overview of ongoing heliogyro technology development and feasibility assessment activities within NASA. In particular, a small-scale heliogyro solar sail technology demonstration concept will be described. We will also discuss ongoing analytical and experimental heliogyro structural dynamics and controls investigations and provide an outline of future heliogyro development work directed toward enabling a low cost heliogyro technology demonstration mission ca. 2020

    The neighbourhood environment and use of neighbourhood resources in older adults with and without lower limb osteoarthritis:results from the Hertfordshire Cohort Study

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    This study aimed to examine the associations of perceptions of neighbourhood cohesion and neighbourhood problems and objectively measured neighbourhood deprivation with the use of neighbourhood resources by older adults with and without lower limb osteoarthritis (LLOA), and to assess whether these relationships are stronger in older persons with LLOA than in those without the condition. Data from the Hertfordshire Cohort Study were used. American College of Rheumatology classification criteria were used to diagnose clinical LLOA (knee and/or hip osteoarthritis). Use of neighbourhood resources was assessed using the Home and Community Environment instrument. Participants were asked about their perceptions of neighbourhood cohesion and neighbourhood problems. Objective neighbourhood deprivation was assessed using the Index of Multiple Deprivation score based on 2010 census data. Of the 401 participants (71–80 years), 74 (18.5 %) had LLOA. The neighbourhood measures were not significantly associated with use of resources in the full sample. A trend for a negative association between use of public transport and perceived neighbourhood problems was observed in participants with LLOA (OR = 0.77, 99 % CI = 0.53–1.12), whereas a trend for a positive association between perceived neighbourhood problems and use of public transport was found in participants without LLOA (OR = 1.18, 99 % CI = 1.00–1.39). The perception of more neighbourhood problems seems only to hinder older adults with LLOA to make use of public transport. Older adults with LLOA may be less able to deal with neighbourhood problems and more challenging environments than those without the condition

    Measuring local depletion of terrestrial game vertebrates by central-place hunters in rural Amazonia

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    The degree to which terrestrial vertebrate populations are depleted in tropical forests occupied by human communities has been the subject of an intense polarising debate that has important conservation implications. Conservation ecologists and practitioners are divided over the extent to which community-based subsistence offtake is compatible with ecologically functional populations of tropical forest game species. To quantify depletion envelopes of forest vertebrates around human communities, we deployed a total of 383 camera trap stations and 78 quantitative interviews to survey the peri-community areas controlled by 60 semi-subsistence communities over a combined area of over 3.2 million hectares in the Médio Juruá and Uatumã regions of Central-Western Brazilian Amazonia. Our results largely conform with prior evidence that hunting large-bodied vertebrates reduces wildlife populations near settlements, such that they are only found at a distance to settlements where they are hunted less frequently. Camera trap data suggest that a select few harvest-sensitive species, including lowland tapir, are either repelled or depleted by human communities. Nocturnal and cathemeral species were detected relatively more frequently in disturbed areas close to communities, but individual species did not necessarily shift their activity patterns. Group biomass of all species was depressed in the wider neighbourhood of urban areas rather than communities. Interview data suggest that species traits, especially group size and body mass, mediate these relationships. Large-bodied, large-group-living species are detected farther from communities as reported by experienced informants. Long-established communities in our study regions have not “emptied” the surrounding forest. Low human population density and low hunting offtake due to abundant sources of alternative aquatic protein, suggest that these communities represent a best-case scenario for sustainable hunting of wildlife for food, thereby providing a conservative assessment of game depletion. Given this ‘best-case’ camera trap and interview-based evidence for hunting depletion, regions with higher human population densities, external trade in wildlife and limited access to alternative protein will likely exhibit more severe depletion
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