1,817 research outputs found

    Alveolar Rhabdomyosarcoma of the foot metastasizing to the Iris: report of a rare case

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    BACKGROUND: Intraocular iris rhabdomyosarcoma is extremely rare, and in the 3 cases reported to date occurred as the primary site of tumour growth. We report a case of rhabdomyosarcoma of the foot metastasizing to the iris. CASE PRESENTATION: An 18-year-old white female was referred to the London Ocular Oncology Service for management of a metastatic rhabdomyosarcomatous deposit in the iris, a metastasis from alveolar rhabdomyosarcoma of the foot. She was diagnosed nearly 2 years earlier with the primary sarcoma with extensive systemic spread and treated by resection of the foot lesion and chemotherapy, and achieved a partial remission. The left iris deposit was noted while she was receiving systemic chemotherapy, heralding a relapse. However, anterior uveitis and raised intraocular pressure developed and she was referred to our service for further management. A left iris secondary rhabdomyosarcoma deposit was noticed and in addition a lacrimal gland mass, as indicated by ultrasound B scan of the eye and orbit. The patient was treated with external beam radiotherapy to the globe and orbit, but died 2 months after treatment completion. CONCLUSION: Rhabdomyosarcoma of the iris is very rare and was previously documented only as a primary malignancy in this location. We report that secondary spread to the iris can also occur, in this case as the first sign of widely disseminated systemic relapse

    Planar chromatography - Current practice and future prospects

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    Planar chromatography, in the form of thin-layer or high-performance thin-layer chromatography (TLC, HPTLC), continues to provide a robust and widely used separation technique. It is unrivaled as a simple and rapid qualitative method for mixture analysis, or for finding bioactive components in mixtures. The format of TLC/HPTLC also provides a unique method for preserving the separation, enabling further investigation of components of interest (including quantification/structure determination) separated in both time and space from the original analysis. The current practice of planar chromatography and areas of development of the technology are reviewed and promising future directions in the use of TLC/HPTLC are outlined

    Obesity and cage environment modulate metabolism in the Zucker rat: a multiple biological matrix approach to characterizing metabolic phenomena

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    Obesity and its comorbidities are increasing worldwide imposing a heavy socioeconomic burden. The effects of obesity on the metabolic profiles of tissues (liver, kidney, pancreas), urine, and the systemic circulation were investigated in the Zucker rat model using 1H NMR spectroscopy coupled to multivariate statistical analysis. The metabolic profiles of the obese ( fa/ fa) animals were clearly differentiated from the two phenotypically lean phenotypes, ((+/+) and ( fa/+)) within each biological compartment studied, and across all matrices combined. No significant differences were observed between the metabolic profiles of the genotypically distinct lean strains. Obese Zucker rats were characterized by higher relative concentrations of blood lipid species, cross-compartmental amino acids (particularly BCAAs), urinary and liver metabolites relating to the TCA cycle and glucose metabolism; and lower amounts of urinary gut microbial-host cometabolites, and intermatrix metabolites associated with creatine metabolism. Further to this, the obese Zucker rat metabotype was defined by significant metabolic alterations relating to disruptions in the metabolism of choline across all compartments analyzed. The cage environment was found to have a significant effect on urinary metabolites related to gut-microbial metabolism, with additional cage-microenvironment trends also observed in liver, kidney, and pancreas. This study emphasizes the value in metabotyping multiple biological matrices simultaneously to gain a better understanding of systemic perturbations in metabolism, and also underscores the need for control or evaluation of cage environment when designing and interpreting data from metabonomic studies in animal models

    Age and Microenvironment Outweigh Genetic Influence on the Zucker Rat Microbiome

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    Animal models are invaluable tools which allow us to investigate the microbiome-host dialogue. However, experimental design introduces biases in the data that we collect, also potentially leading to biased conclusions. With obesity at pandemic levels animal models of this disease have been developed; we investigated the role of experimental design on one such rodent model. We used 454 pyrosequencing to profile the faecal bacteria of obese (n = 6) and lean (homozygous n = 6; heterozygous n = 6) Zucker rats over a 10 week period, maintained in mixed-genotype cages, to further understand the relationships between the composition of the intestinal bacteria and age, obesity progression, genetic background and cage environment. Phylogenetic and taxon-based univariate and multivariate analyses (non-metric multidimensional scaling, principal component analysis) showed that age was the most significant source of variation in the composition of the faecal microbiota. Second to this, cage environment was found to clearly impact the composition of the faecal microbiota, with samples from animals from within the same cage showing high community structure concordance, but large differences seen between cages. Importantly, the genetically induced obese phenotype was not found to impact the faecal bacterial profiles. These findings demonstrate that the age and local environmental cage variables were driving the composition of the faecal bacteria and were more deterministically important than the host genotype. These findings have major implications for understanding the significance of functional metagenomic data in experimental studies and beg the question; what is being measured in animal experiments in which different strains are housed separately, nature or nurture

    An experimental assessment of detection dog ability to locate great crested newts (Triturus cristatus) at distance and through soil

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    Detection dogs are increasingly used to locate cryptic wildlife species, but their use for amphibians is still rather underexplored. In the present paper we focus on the great crested newt (Triturus cristatus), a European species which is experiencing high conservation concerns across its range, and assess the ability of a trained detection dog to locate individuals during their terrestrial phase. More specifically, we used a series of experiments to document whether a range of distances between target newts and the detection dog (odour channelled through pipes 68 mm in diameter) affects the localisation, and to assess the ability and efficiency of target newt detection in simulated subterranean refugia through 200 mm of two common soil types (clay and sandy soil, both with and without air vents to mimic mammal burrows, a common refuge used by T. cristatus). The detection dog accurately located all individual T. cristatus across the entire range of tested distances (0.25 m-2.0 m). The substrate trials revealed that the detection dog could locate individuals also through soil. Contrary to existing studies with detection dogs in human forensic contexts, however, detection was generally slower for T. cristatus under sandy soil compared to clay soil, particularly when a vent was absent. Our study provides a general baseline for the use of detection dogs in locating T. cristatus and similar amphibian species during their terrestrial phase

    Carbon-enhanced stars with short orbital and spin periods

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    Many characteristics of dwarf carbon stars are broadly consistent with a binary origin, including mass transfer from an evolved companion. While the population overall appears to have old-disc or halo kinematics, roughly 2 per cent of these stars exhibit Hα emission, which in low-mass main-sequence stars is generally associated with rotation and relative youth. Its presence in an older population therefore suggests either irradiation or spin-up. This study presents time-series analyses of photometric and radial-velocity data for seven dwarf carbon stars with Hα emission. All are shown to have photometric periods in the range 0.2–5.2 d, and orbital periods of similar length, consistent with tidal synchronisation. It is hypothesised that dwarf carbon stars with emission lines are the result of close-binary evolution, indicating that low-mass, metal-weak or metal-poor stars can accrete substantial material prior to entering a common-envelope phase

    Paracetamol metabolism, hepatotoxicity, biomarkers and therapeutic interventions: a perspective

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    After over 60 years of therapeutic use in the UK, paracetamol (acetaminophen, N-acetyl-p-aminophenol, APAP) remains the subject of considerable research into both its mode of action and toxicity. The pharmacological properties of APAP are the focus of some activity, with the role of the metabolite N-arachidonoylaminophenol (AM404) still a topic of debate. However, that the hepatotoxicity of APAP results from the production of the reactive metabolite N-acetyl-p-benzoquinoneimine (NAPQI/NABQI) that can deplete glutathione, react with cellular macromolecules, and initiate cell death, is now beyond dispute. The disruption of cellular pathways that results from the production of NAPQI provides a source of potential biomarkers of the severity of the damage. Research in this area has provided new diagnostic markers such as the microRNA miR-122 as well as mechanistic biomarkers associated with apoptosis, mitochondrial dysfunction, inflammation and tissue regeneration. Additionally, biomarkers of, and systems biology models for, glutathione depletion have been developed. Furthermore, there have been significant advances in determining the role of both the innate immune system and genetic factors that might predispose individuals to APAP-mediated toxicity. This perspective highlights some of the progress in current APAP-related research

    Impacts of removing badgers on localised counts of hedgehogs

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    This is the final version of the article. Available from Public Library of Science via the DOI in this record.Experimental evidence of the interactions among mammalian predators that eat or compete with one another is rare, due to the ethical and logistical challenges of managing wild populations in a controlled and replicated way. Here, we report on the opportunistic use of a replicated and controlled culling experiment (the Randomised Badger Culling Trial) to investigate the relationship between two sympatric predators: European badgers Meles meles and western European hedgehogs Erinaceus europaeus. In areas of preferred habitat (amenity grassland), counts of hedgehogs more than doubled over a 5-year period from the start of badger culling (from 0.9 ha-1 pre-cull to 2.4 ha-1 post-cull), whereas hedgehog counts did not change where there was no badger culling (0.3-0.3 hedgehogs ha-1). This trial provides experimental evidence for mesopredator release as an outcome of management of a top predator.The study was funded by the United Kingdom Government’s Department for Environment, Food and Rural Affairs (http://www.defra.gov.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    High performance Reversed-Phase Thin-Layer Chromatography-Desorption electrospray ionisation - time of flight high resolution mass spectrometric detection and imaging (HPTLC/DESI/ToFMS) of phytoecdysteroids

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    Reversed-phase high performance thin-layer chromatography (RP-HPTLC) on C18 bonded silica gel was combined with desorption electrospray ionization (DESI) and high resolution time of flight mass spectrometry (HRToFMS) to detect, characterize and image (MSI) phytoecdysteroids (plant-derived insect moulting hormones) in ethanolic extracts of members of the Silene plant family. As seen previously for silica gel, DESI provided a simple and convenient method for recovering polar polyhydoxysteroids from RP-HPTLC plates for the purposes of both the MS and MSI of extracts obtained from three species of the Silene family (Silene otites, S. nutans and S. viridiflora). Using RP-HPTLC/DESI/MSI/HRToFMS a number of ecdysteroids, including 20-hydroxyecdysone, polypodine-B, 2-deoxy-20-hydroxyecdysone and 2-deoxyecdysone were identified in these extracts. Differences were noted in the mass spectra obtained depending upon both the stationary phase on which they were separated, and the temperatures used in the heated transfer line used for introduction into the ion source. Ecdysteroids detected after chromatography on C18 bonded silica showed increased fragmentation due to water loss compared to those imaged from silica. In addition, the benefits of the additional resolution provided by 2-dimensional TLC for increasing spectral quality compared to a 1-dimensional separation are demonstrated
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