62 research outputs found

    Current measures of metabolic heterogeneity within cervical cancer do not predict disease outcome

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    <p>Abstract</p> <p>Background</p> <p>A previous study evaluated the intra-tumoral heterogeneity observed in the uptake of F-18 fluorodeoxyglucose (FDG) in pre-treatment positron emission tomography (PET) scans of cancers of the uterine cervix as an indicator of disease outcome. This was done via a novel statistic which ostensibly measured the spatial variations in intra-tumoral metabolic activity. In this work, we argue that statistic is intrinsically <it>non</it>-spatial, and that the apparent delineation between unsuccessfully- and successfully-treated patient groups via that statistic is spurious.</p> <p>Methods</p> <p>We first offer a straightforward mathematical demonstration of our argument. Next, we recapitulate an assiduous re-analysis of the originally published data which was derived from FDG-PET imagery. Finally, we present the results of a principal component analysis of FDG-PET images similar to those previously analyzed.</p> <p>Results</p> <p>We find that the previously published measure of intra-tumoral heterogeneity is intrinsically non-spatial, and actually is only a surrogate for tumor volume. We also find that an optimized linear combination of more canonical heterogeneity quantifiers does not predict disease outcome.</p> <p>Conclusions</p> <p>Current measures of intra-tumoral metabolic activity are not predictive of disease outcome as has been claimed previously. The implications of this finding are: clinical categorization of patients based upon these statistics is invalid; more sophisticated, and perhaps innately-geometric, quantifications of metabolic activity are required for predicting disease outcome.</p

    Protection of Spanish Ibex (Capra pyrenaica) against Bluetongue Virus Serotypes 1 and 8 in a Subclinical Experimental Infection

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    Many wild ruminants such as Spanish ibex (Capra pyrenaica) are susceptible to Bluetongue virus (BTV) infection, which causes disease mainly in domestic sheep and cattle. Outbreaks involving either BTV serotypes 1 (BTV-1) and 8 (BTV-8) are currently challenging Europe. Inclusion of wildlife vaccination among BTV control measures should be considered in certain species. In the present study, four out of fifteen seronegative Spanish ibexes were immunized with a single dose of inactivated vaccine against BTV-1, four against BTV-8 and seven ibexes were non vaccinated controls. Seven ibexes (four vaccinated and three controls) were inoculated with each BTV serotype. Antibody and IFN-gamma responses were evaluated until 28 days after inoculation (dpi). The vaccinated ibexes showed significant (P<0.05) neutralizing antibody levels after vaccination compared to non vaccinated ibexes. The non vaccinated ibexes remained seronegative until challenge and showed neutralizing antibodies from 7 dpi. BTV RNA was detected in the blood of non vaccinated ibexes from 2 to the end of the study (28 dpi) and in target tissue samples obtained at necropsy (8 and 28 dpi). BTV-1 was successfully isolated on cell culture from blood and target tissues of non vaccinated ibexes. Clinical signs were unapparent and no gross lesions were found at necropsy. Our results show for the first time that Spanish ibex is susceptible and asymptomatic to BTV infection and also that a single dose of vaccine prevents viraemia against BTV-1 and BTV-8 replication

    Editorial: Cutting-Edge Metastructures: Micro-Architected and Active Metamaterials

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    The present Research Topic collects articles dealing with the optimal design, the realization and the testing of meta-structures capable of achieving dynamic high-performance. The common thread linking these articles is using metamaterials concepts to conceive intriguing internal architecture for wave propagation control. Due to their interdisciplinary nature and their broad range of applications, metamaterials have increasingly inspired researchers of different communities. In the last years, mathematicians, physicists, engineers, and material scientists have mobilized massive effort to move the limits beyond state-of-the-art to realize extreme materials. Charming behaviors such as filtering, wave-guiding, negative refraction, cloaking, seismic protection, noise reduction and band-gap control have been demonstrated to be possible theoretically, via numerical simulations and by real experiments. Different techniques have been developed for achieving such exotic effects. A non-exhaustive list of these includes i) mass, inertia and stiffness modifications, ii) the use of local inertial or Helmholtz resonators or gyroscopes elements embedded into lattice or continuum materials, iii) the use of a multi-field electro-mechanical coupling via piezoelectric active phases. Within this framework, the current research topics of the articles provide a new perspective for using the metamaterial idea to achieve phenomena such as cloaking, seismic protection, dynamic wave propagation attenuation, and wave localization
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