999 research outputs found
Increased Pituitary Fluorine-18-Fluorodeoxyglucose Uptake in Patients with Differentiated Thyroid Cancer in Hypothyroidism versus under Recombinant Human Thyroid-Stimulating Hormone Stimulation.
The incidental pituitary hypermetabolism on 18F-FDG PET/CT should be further evaluated for discriminating between pathologic and physiologic uptake, but a recent study suggests that pituitary hypermetabolism is common in patients with differentiated thyroid carcinoma (DTC) undergoing thyroid hormone withdrawal (THW). The aim of this retrospective study was to compare pituitary metabolism in patients with DTC undergoing 18F-FDG PET/CT under THW versus recombinant human thyroid-stimulating hormone (rhTSH) stimulation. We confirmed a higher pituitary SUVmax and SUVratio with a higher prevalence of pituitary hypermetabolism in the THW group compared to the rhTSH group. A positive correlation between serum TSH levels and pituitary SUVmax was observed only in the THW group. The present findings support the hypothesis that pituitary hypermetabolism on 18F-FDG PET/CT in patients with DTC undergoing THW is a common physiological response to hypothyroidism. Awareness of this physiological hypermetabolism is important to avoid potential pitfalls in image interpretation that could trigger unnecessary investigations
Patientsâ understandings about cellulitis and views about how best to prevent recurrent episodes: mixed methods study in primary and secondary care
BackgroundCellulitis is a common painful infection of the skin and underlying tissues that recurs in approximately a third of cases. The only proven strategy to reduce the risk of recurrence is longâterm, lowâdose antibiotics. Given current concerns about antibiotic resistance and the pressure to reduce antibiotic prescribing, other prevention strategies are needed.ObjectivesTo explore patientsâ views about cellulitis and different ways of preventing recurrent episodes.MethodsAdults aged 18 or over with a history of first episode or recurrent cellulitis were invited through primary care, hospitals and advertising to complete a survey, take part in an interview, or both.ResultsThirty interviews were conducted between August 2016 and July 2017. Two hundred and forty surveys were completed (response rate 17%). Triangulation of quantitative and qualitative data showed that people who have had cellulitis have wideâranging beliefs about what can cause cellulitis and are often unaware of risk of recurrence or potential strategies to prevent recurrence. Enhanced foot hygiene, applying emollients daily, exercise and losing weight were more popular potential strategies than use of compression stockings or longâterm antibiotics. Participants expressed caution about longâterm oral antibiotics, particularly those who had experienced only one episode of cellulitis.ConclusionsPeople who have had cellulitis are keen to know about possible ways to prevent further episodes. Enhanced foot hygiene, applying emollients daily, exercise and losing weight were generally viewed to be more acceptable, feasible strategies than compression or antibiotics, but further research is needed to explore uptake and effectiveness in practice
The homotopy type of the loops on -connected -manifolds
For we compute the homotopy groups of -connected closed
manifolds of dimension . Away from the finite set of primes dividing
the order of the torsion subgroup in homology, the -local homotopy groups of
are determined by the rank of the free Abelian part of the homology.
Moreover, we show that these -local homotopy groups can be expressed as a
direct sum of -local homotopy groups of spheres. The integral homotopy type
of the loop space is also computed and shown to depend only on the rank of the
free Abelian part and the torsion subgroup.Comment: Trends in Algebraic Topology and Related Topics, Trends Math.,
Birkhauser/Springer, 2018. arXiv admin note: text overlap with
arXiv:1510.0519
Regulation of Motor Function and Behavior by Atypical Chemokine Receptor 1
The final publication is available at Springer via http://dx.doi.org/10.1007/s10519-014-9665-7Atypical Chemokine Receptor 1 (ACKR1), previously known as the Duffy Antigen Receptor for Chemokines, stands out among chemokine receptors for its high selective expression on Purkinje cells of the cerebellum, consistent with the ability of ACKR1 ligands to activate Purkinje cells in vitro. Nevertheless, evidence for ACKR1 regulation of brain function in vivo has been lacking. Here we demonstrate that Ackr1â/â mice have markedly impaired balance and ataxia when placed on a rotating rod and increased tremor when injected with harmaline, a drug that induces whole-body tremor by activating Purkinje cells. Ackr1â/â mice also exhibited impaired exploratory behavior, increased anxiety-like behavior and frequent episodes of marked hypoactivity under low-stress conditions. The behavioral phenotype of Ackr1â/â mice was the opposite of the phenotype occurring in mice with cerebellar degeneration and the defects persisted when Ackr1 was deficient only on non-hematopoietic cells. We conclude that normal motor function and behavior depend in part on negative regulation of Purkinje cell activity by Ackr1
Animal tissue-based quantitative comparison of dual-energy CT to SPR conversion methods using high-resolution gel dosimetry
Dual-energy computed tomography (DECT) has been shown to allow for more accurate ion therapy treatment planning by improving the estimation of tissue stopping power ratio (SPR) relative to water, among other tissue properties. In this study, we measured and compared the accuracy of SPR values derived using both dual- and single-energy CT (SECT) based on different published conversion algorithms. For this purpose, a phantom setup containing either fresh animal soft tissue samples (beef, pork) and a water reference or tissue equivalent plastic materials was designed and irradiated in a clinical proton therapy facility. Dosimetric polymer gel was positioned downstream of the samples to obtain a three-dimensional proton range distribution with high spatial resolution. The mean proton range in gel for each tissue relative to the water sample was converted to a SPR value. Additionally, the homogeneous samples were probed with a variable water column encompassed by two ionization chambers to benchmark the SPR accuracy of the gel dosimetry. The SPR values measured with both methods were consistent with a mean deviation of 0.2%, but the gel dosimetry captured range variations up to 5 mm within individual samples.
Across all fresh tissue samples the SECT approach yielded significantly greater mean absolute deviations from the SPR deduced using gel range measurements, with an average difference of 1.2%, compared to just 0.3% for the most accurate DECT-based algorithm. These results show a significant advantage of DECT over SECT for stopping power prediction in a realistic setting, and for the first time allow to compare a large set of methods under the same conditions
Two-parameter Quantum Affine Algebra , Drinfel'd Realization and Quantum Affine Lyndon Basis
We further define two-parameter quantum affine algebra
after the work on the finite cases
(see [BW1], [BGH1], [HS] & [BH]), which turns out to be a Drinfel'd double. Of
importance for the quantum {\it affine} cases is that we can work out the
compatible two-parameter version of the Drinfel'd realization as a quantum
affinization of and establish the Drinfel'd isomorphism
Theorem in the two-parameter setting, via developing a new combinatorial
approach (quantum calculation) to the quantum {\it affine} Lyndon basis we
present (with an explicit valid algorithm based on the use of Drinfel'd
generators).Comment: 31 page
Viewpoint: Estimating the causal effects of policies and programs
Estimation, inference and interpretation of the causal effects of programs and policies have all advanced dramatically over the past 25 years. We highlight three particularly important intellectual trends: an improved appreciation of the substantive importance of heterogeneous responses and of their methodological implications, a stronger focus on internal validity brought about by the âcredibility revolution,â and the scientific value that follows from grounding estimation and interpretation in economic theory. We discuss a menu of commonly employed partial equilibrium approaches to the identification of causal effects, emphasizing that the researcherâs central intellectual contribution always consists of making an explicit case for a specific causal interpretation given the relevant economic theory, the data, the institutional context and the economic question of interest. We also touch on the importance of general equilibrium effects and full costâbenefit analyses.RĂ©sumĂ©Point de vue: Sur lâestimation des effets causatifs des politiques et programmes. Dans le monde de lâestimation, lâinfĂ©rence et lâinterprĂ©tation des effets causatifs des programmes et des politiques, il y a eu des progrĂšs dramatiques au cours des derniers 25 ans. Les auteurs soulignent trois tendances intellectuelles particuliĂšrement importantes : une apprĂ©ciation amĂ©liorĂ©e de lâimportance substantielle des rĂ©ponses hĂ©tĂ©rogĂšnes et de leur importance mĂ©thodologique, une focalisation plus robuste sur la validitĂ© interne engendrĂ©e par la « rĂ©volution de la crĂ©dibilitĂ© », et la valeur scientifique qui dĂ©coule dâun ancrage de lâestimation et de lâinterprĂ©tation dans la thĂ©orie Ă©conomique. On discute un Ă©ventail dâapproches dâĂ©quilibre partiel Ă lâidentification des effets causatifs, mettant au premier plan que la contribution intellectuelle centrale du chercheur consiste Ă bĂątir un argumentaire explicite pour une interprĂ©tation causale spĂ©cifique compte tenu de la thĂ©orie Ă©conomique pertinente, des donnĂ©es, du contexte institutionnel, et de la question Ă©conomique dâintĂ©rĂȘt. On mentionne aussi lâimportance des effets dâĂ©quilibre gĂ©nĂ©ral et des analyses de tous les coĂ»ts et avantages.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134884/1/caje12217.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134884/2/caje12217_am.pd
A Membrane Protein/Signaling Protein Interaction Network for Arabidopsis Version AMPv2
Interactions between membrane proteins and the soluble fraction are essential for signal transduction and for regulating nutrient transport. To gain insights into the membrane-based interactome, 3,852 open reading frames (ORFs) out of a target list of 8,383 representing membrane and signaling proteins from Arabidopsis thaliana were cloned into a Gateway-compatible vector. The mating-based split ubiquitin system was used to screen for potential proteinâprotein interactions (pPPIs) among 490 Arabidopsis ORFs. A binary robotic screen between 142 receptor-like kinases (RLKs), 72 transporters, 57 soluble protein kinases and phosphatases, 40 glycosyltransferases, 95 proteins of various functions, and 89 proteins with unknown function detected 387 out of 90,370 possible PPIs. A secondary screen confirmed 343 (of 386) pPPIs between 179 proteins, yielding a scale-free network (r2â=â0.863). Eighty of 142 transmembrane RLKs tested positive, identifying 3 homomers, 63 heteromers, and 80 pPPIs with other proteins. Thirty-one out of 142 RLK interactors (including RLKs) had previously been found to be phosphorylated; thus interactors may be substrates for respective RLKs. None of the pPPIs described here had been reported in the major interactome databases, including potential interactors of G-protein-coupled receptors, phospholipase C, and AMT ammonium transporters. Two RLKs found as putative interactors of AMT1;1 were independently confirmed using a split luciferase assay in Arabidopsis protoplasts. These RLKs may be involved in ammonium-dependent phosphorylation of the C-terminus and regulation of ammonium uptake activity. The robotic screening method established here will enable a systematic analysis of membrane protein interactions in fungi, plants and metazoa
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