487 research outputs found

    Ontogenetic changes in shape and growth rate during postnatal development in false killer whales (<i>Pseudorca crassidens</i>) vertebral column

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    Intraspecific variation in cetacean vertebral anatomy as a result of ageing, growth, and sexual dimorphism is poorly understood. Using 3D geometric morphometrics, we investigated allometric patterns, sexual dimorphism, and ontogenetic trajectories in the vertebral column of false killer whale (Pseudorca crassidens). Our data set includes thoracic, lumbar, and caudal vertebrae of 30 specimens, including neonates, juveniles, and adults of both sexes. Vertebral shape was significantly correlated with size within each region. Neonatal vertebral shape differed significantly from juveniles and adults, displaying ontogenetic shape change. Allometric and growth patterns of the vertebral regions, particularly of the lumbar region with the thoracic and caudal regions, differed significantly, which may influence the function and mobility patterns of the vertebral regions during different life stages. Using quantitative methods, we could not conclude that the Pseudorca vertebrae are sexually dimorphic. This study describes for the first time intraspecific vertebral patterns in a cetacean species across ontogenetic stages. Pseudorca individuals live in large pods and swim together, sharing the same swimming mode. The neonates have a more flexible column and swim less efficiently following their mothers to nurse

    Self-management Interventions for Pain and Physical Symptoms Among People Living With HIV:A Systematic Review of the Evidence

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    Introduction: Pain and symptoms still persist among people living with HIV/AIDS. Evidence-based self-management interventions have the potential to help people with HIV/AIDS to successfully manage pain and symptoms. We aimed to identify and appraise the evidence regarding the effectiveness of self-management interventions for pain and/or physical symptoms in people living with HIV/AIDS. Methods: We searched for controlled intervention studies in Amed, Assian, CINAHL, Cochrane Library, Embase, Medline, PsycInfo, Scopus, and Web of Science data bases, from 1984 to February 2017. Two reviewers screened and extracted data, assessed risk of bias (using Joanna Briggs Institute Critical Appraisal checklist for randomized and nonrandomized trials), and rated the quality of evidence (GRADE tool). Results: We identified 22 original papers reporting 19 different studies. Of these, 17 used randomized controlled trial designs. Three studies reported data on pain severity, and 2 studies reported data on pain interference outcomes with one study reporting positive effect on both outcomes. Outcomes for physical symptoms were reported in 13 studies with 6 studies reporting positive effect. The quality of evidence was moderate for pain outcomes. For physical symptoms, one study was rated as moderate; the rest were rated as low n = 8 and very low n = 4 quality. Conclusions: There is some evidence to suggest that self-management interventions delivered either online, face-to-face, or group-based consisting of booklet, leaflet, or manuals are effective in improving pain and physical symptoms. Findings suggest the need for theoretically plausible high-quality clinical trials of pain and physical symptom self-management among culturally diverse people with HIV

    DNA sequence conservation between the Bacillus anthracis pXO2 plasmid and genomic sequence from closely related bacteria

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    BACKGROUND: Complete sequencing and annotation of the 96.2 kb Bacillus anthracis plasmid, pXO2, predicted 85 open reading frames (ORFs). Bacillus cereus and Bacillus thuringiensis isolates that ranged in genomic similarity to B. anthracis, as determined by amplified fragment length polymorphism (AFLP) analysis, were examined by PCR for the presence of sequences similar to 47 pXO2 ORFs. RESULTS: The two most distantly related isolates examined, B. thuringiensis 33679 and B. thuringiensis AWO6, produced the greatest number of ORF sequences similar to pXO2; 10 detected in 33679 and 16 in AWO6. No more than two of the pXO2 ORFs were detected in any one of the remaining isolates. Dot-blot DNA hybridizations between pXO2 ORF fragments and total genomic DNA from AWO6 were consistent with the PCR assay results for this isolate and also revealed nine additional ORFs shared between these two bacteria. Sequences similar to the B. anthracis cap genes or their regulator, acpA, were not detected among any of the examined isolates. CONCLUSIONS: The presence of pXO2 sequences in the other Bacillus isolates did not correlate with genomic relatedness established by AFLP analysis. The presence of pXO2 ORF sequences in other Bacillus species suggests the possibility that certain pXO2 plasmid gene functions may also be present in other closely related bacteria

    \u3ci\u3e Glioblastoma derived exosomes contribute to tumor immune evasion \u3c/i\u3e

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    Glioblastoma multiforme (GBM) is the most frequent and lethal primary brain tumor in adults. Despite intense biomedical research, the median survival after diagnosis is 15 months. One factor contributing to this poor prognosis is the immune protection afforded by the tumor microenvironment. Tumors have a diverse repertoire of immune-evasive techniques. One method of evasion not well explored is the release of tumor-derived exosomes. Exosomes are tiny membrane-bound vesicles of endocytic origin that contain viable mRNA and functional proteins that can affect the physiology of recipient cells. Exosome release has been reported for numerous cancer types, including GBM. Exosomes from colon cancer have been shown to carry Fas ligand (FasL) and to induce apoptosis of activated T cells. The aim of this study was to elucidate whether the same immune-evasive technique is used in GBM. GBM exosomes were isolated from the serum-free culture medium of U87 MG and U138 MG cells by using differential ultracentrifugation and were then resuspended in phosphate-buffered saline. The protein concentration of the resulting exosome pellet was determined, and subsequent exosome treatments were based on protein concentration. A3T T cells were plated at a concentration of 10,000 cells per well in 96-well plates and were treated with quantified exosome fractions or with recombinant FasL, and T cell proliferation was determined. Our data demonstrated that tumor-derived exosomes significantly inhibited the proliferation of T cells and that the cellular inhibition resulting from the exosomes was comparable to that seen with the recombinant FasL. These results suggest that targeting FasL in GBM could greatly decrease the amount of immune suppression that occurs at the tumor site

    \u3ci\u3e Glioblastoma Derived Exosomes Induce Apoptosis in Cytotoxic T Cells Through a Fas Ligand Mediated Mechanism \u3c/i\u3e

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    INTRODUCTION: Glioblastoma multiforme deploy s a number of weapons to thwart the immune system. Within the tumor microenvironment, cytotoxic T cells fall victim to Fas ligand (FasL) induced apoptosis. In prostate and colorectal cancer, exosomes can mediate this FasL induced T cell apoptosis. Exosomes are tiny, membrane bound vesicles that are released from a cell. They contain functional mRNA and protein and have cell surface molecules representative of their parent cell. It is not known if GBM derived exosomes can also mediate FasL triggered apoptosis. In this study, the role of tumor derived exosomes as the delivery vehicle for FasL is explored. METHODS: Exosomes are isolated from the T98 cell line using differential ultracentrifugation. FasL expression in the cell line and derived exosomes is determined using reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. GBM derived exosomes, recombinant FasL, and exosomes treated with an anti-FasL antibody are co-cultured with Jurkat A3 T cells. Apoptosis is measured using a caspase-8 luminescent assay. RESULTS: FasL is expressed by the T98 cell line and is present on the surface of the cells and their exosomes (Figure 1). Caspase-8 activation is seen in T cells treated with GBM derived exosomes and recombinant FasL, but not with exosomes treated with anti-FasL antibody or exosome free supernatant (Figure 2). CONCLUSION: GBM derived exosomes induce T cell apoptosis through a FasL mediated mechanism. This method of immune suppression has not previously been described. This research opens new avenues to antagonize GBM related immune system malfunction

    Curating Ocean Ecology at the Natural History Museum: Miranda Lowe and Richard Sabin in conversation with Pandora Syperek and Sarah Wade

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    The current ecological crisis and the call to decolonise museums can be catalysts for change, manifested both physically through exhibitions or redisplays of historical collections and conceptually through new curatorial approaches or interventions. This interview examines the strategies and considerations involved in a major redisplay at the Natural History Museum, London, in 2017. Here, ‘Dippy’ the Diplodocus was removed from the prime central hall location, causing a furore that soon gave way to celebration of its newly installed resident ‘Hope’ the blue whale, heralding a new paradigm of scientific display where an anthropogenic extinction narrative took centre stage in a world-renowned museum. Alongside the blue whale, a series of ‘Wonder Bays’ were installed which tell stories of evolution, biodiversity and sustainability. Curators Miranda Lowe and Richard Sabin discuss these recent displays in relation to extinction narratives, public ecological awareness, ideals of authenticity and the crossover of art and science. They reflect on how the politics of natural history display extend to broader global issues, including the illegal wildlife trade and decolonising the museum, focusing on presentations of marine life and ocean ecology to reflect their principal areas of expertise and the Natural History Museum’s recent ocean-themed programming

    Revealing the maternal demographic history of Panthera leo using ancient DNA and a spatially explicit genealogical analysis

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    Background: Understanding the demographic history of a population is critical to conservation and to our broader understanding of evolutionary processes. For many tropical large mammals, however, this aim is confounded by the absence of fossil material and by the misleading signal obtained from genetic data of recently fragmented and isolated populations. This is particularly true for the lion which as a consequence of millennia of human persecution, has large gaps in its natural distribution and several recently extinct populations. Results: We sequenced mitochondrial DNA from museum-preserved individuals, including the extinct Barbary lion (Panthera leo leo) and Iranian lion (P. l. persica), as well as lions from West and Central Africa. We added these to a broader sample of lion sequences, resulting in a data set spanning the historical range of lions. Our Bayesian phylogeographical analyses provide evidence for highly supported, reciprocally monophyletic lion clades. Using a molecular clock, we estimated that recent lion lineages began to diverge in the Late Pleistocene. Expanding equatorial rainforest probably separated lions in South and East Africa from other populations. West African lions then expanded into Central Africa during periods of rainforest contraction. Lastly, we found evidence of two separate incursions into Asia from North Africa, first into India and later into the Middle East. Conclusions: We have identified deep, well-supported splits within the mitochondrial phylogeny of African lions, arguing for recognition of some regional populations as worthy of independent conservation. More morphological and nuclear DNA data are now needed to test these subdivisions.European Union�s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. FP7-PEOPLE-2011-IEF-298820.Scopu

    Measurement of retinal vessels as a biomarker of cerebrovascular ageing in older HIV positive men compared to controls

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    Background: To compare retinal vascular measurements, biomarkers of cerebral small vessel disease (SVD), in HIV positive men aged 50 years and above with similarly-aged HIV negative men and younger HIV positive men. Methods: We recruited white, non-diabetic men to a cross-sectional substudy of a larger cohort including three demographically-matched groups. Optic disc centred 45° colour fundus photographs were used to calculate central retinal arterial and venous calibre and the arterial- venous ratio (AVR). We used univariate and multivariable linear regression to compare retinal vessel measurements in the three groups and to identify factors associated with AVR. Results: All HIV positive men were virologically suppressed. In a multivariable model, study group was not associated with AVR (adjusted β 0.010 for HIV positive men 50 years [n=120], 95% CI -0.018 to 0.038, p=0.47; adjusted β 0.00002 for HIV negative men >50 years [n=52], 95% CI -0.022 to 0.022, p=0.99). Factors associated with lower AVR were systolic BP (adjusted β -0.009 per +10 mmHg, 95% CI - 0.015 to -0.003, p=0.002), history of stroke or transient ischemic attack (adjusted β -0.070, 95% CI -0.12 to -0.015, p=0.01), and recent recreational drug use (adjusted β -0.037, 95% CI -0.057 to -0.018, p=0.0002). Conclusion: There were no differences in retinal vascular indices between HIV positive men aged >50 years and HIV negative men aged >50 years or HIV positive men aged <50 years, suggesting that HIV is not associated with an increased burden of cerebral SVD

    Range-wide variation in grey seal (Halichoerus grypus) skull morphology

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    The large interspecific variation in marine mammal skull and dental morphology reflects ecological specialisa-tions to foraging and communication. At the intraspecific level, the drivers of skull shape variation are less well understood, having implications for identifying putative local foraging adaptations and delineating populations and subspecies for taxonomy, systematics, management and conservation. Here, we assess the range-wide intraspecific variation in 71 grey seal skulls by 3D surface scanning, collection of cranial landmarks and geo-metric morphometric analysis. We find that skull shape differs slightly between populations in the Northwest Atlantic, Northeast Atlantic and Baltic Sea. However, there was a large shape overlap between populations and variation was substantially larger among animals within populations than between. We hypothesize that this pattern of intraspecific variation in grey seal skull shape results from balancing selection or phenotypic plasticity allowing for a remarkably generalist foraging behaviour. Moreover, the large overlap in skull shape between populations implies that the separate subspecies status of Atlantic and Baltic Sea grey seals is questionable from a morphological point of view.Peer reviewe
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