32 research outputs found

    Adaptable Categorization of Hands and Tools in Prosthesis Users.

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    Some theories propose that tools become incorporated into the neural representation of the hands (a process known as tool embodiment; Maravita & Iriki, 2004). Others suggest that conceptual body representation is rigid and that experience with one’s own body is insufficient for adapting bodily cognition, as shown in individuals born without hands (Vannuscorps & Caramazza, 2016) and in amputees with persistent phantom hand representation (Kikkert et al., 2016). How sharp is the conceptual boundary between hands and tools? This question is particularly relevant for individuals who have lost one hand and use prosthetic hands as tools to supplement their missing hand function. Although both congenital one-handers (i.e., amelia patients) and one-handed amputees are encouraged to use prostheses, the former show a greater tendency than the latter to use prosthetic hands in daily tasks (Jang et al., 2011). One-handers have a fully functional remaining hand (allowing them to use handheld tools, etc.), which makes them less likely to show semantic distortions in hand and tool representation. However, their bodies and their interactions with their environment are fundamentally altered by their disability (Makin et al., 2013; Makin, Wilf, Schwartz, & Zohary, 2010). To determine how real-world experience shapes conceptual categorization of hands, tools, and prostheses, we recruited one-handers with congenital or acquired unilateral hand loss to take part in a study involving a priming task. We predicted that one-handers, particularly congenital one-handers, would show more conceptual blurring between hands and tools than control participants would, as a result of less experience with a hand and more reliance on prostheses (which are essentially tools) for typical hand functions. We further predicted that individual differences in prosthesis usage would be reflected in implicit categorization of hands, manual tools, and prostheses

    Prognostic value of histopathologic traits independent of stromal tumor-infiltrating lymphocyte levels in chemotherapy-naïve patients with triple-negative breast cancer

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    Background: In the absence of prognostic biomarkers, most patients with early-stage triple-negative breast cancer (eTNBC) are treated with combination chemotherapy. The identification of biomarkers to select patients for whom treatment de-escalation or escalation could be considered remains an unmet need. We evaluated the prognostic value of histopathologic traits in a unique cohort of young, (neo)adjuvant chemotherapy-naïve patients with early-stage (stage I or II), node-negative TNBC and long-term follow-up, in relation to stromal tumor-infiltrating lymphocytes (sTILs) for which the prognostic value was recently reported. Materials and methods: We studied all 485 patients with node-negative eTNBC from the population-based PARADIGM cohort which selected women aged &lt;40 years diagnosed between 1989 and 2000. None of the patients had received (neo)adjuvant chemotherapy according to standard practice at the time. Associations between histopathologic traits and breast cancer-specific survival (BCSS) were analyzed with Cox proportional hazard models. Results: With a median follow-up of 20.0 years, an independent prognostic value for BCSS was observed for lymphovascular invasion (LVI) [adjusted (adj.) hazard ratio (HR) 2.35, 95% confidence interval (CI) 1.49-3.69], fibrotic focus (adj. HR 1.61, 95% CI 1.09-2.37) and sTILs (per 10% increment adj. HR 0.75, 95% CI 0.69-0.82). In the sTILs &lt;30% subgroup, the presence of LVI resulted in a higher cumulative incidence of breast cancer death (at 20 years, 58%; 95% CI 41% to 72%) compared with when LVI was absent (at 20 years, 32%; 95% CI 26% to 39%). In the ≥75% sTILs subgroup, the presence of LVI might be associated with poor survival (HR 11.45, 95% CI 0.71-182.36, two deaths). We confirm the lack of prognostic value of androgen receptor expression and human epidermal growth factor receptor 2 -low status. Conclusions: sTILs, LVI and fibrotic focus provide independent prognostic information in young women with node-negative eTNBC. Our results are of importance for the selection of patients for de-escalation and escalation trials.</p

    Disrupting Circadian Homeostasis of Sympathetic Signaling Promotes Tumor Development in Mice

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    and why disruption of circadian rhythm may lead to tumorigenesis. oncogenic potential, leading to tumor development in the same organ systems in wild-type and circadian gene-mutant mice. is a clock-controlled physiological function. The central circadian clock paces extracellular mitogenic signals that drive peripheral clock-controlled expression of key cell cycle and tumor suppressor genes to generate a circadian rhythm in cell proliferation. Frequent disruption of circadian rhythm is an important tumor promoting factor

    The impact of using an upper-limb prosthesis on the perception of real and illusory weight differences

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    Little is known about how human perception is affected using an upper-limb prosthesis. To shed light on this topic, we investigated how using an upper-limb prosthesis affects individuals’ experience of object weight. First, we examined how a group of upper-limb amputee prosthetic users experienced real mass differences and illusory weight differences in the context of the ‘size-weight’ illusion. Surprisingly, the upper-limb prosthetic users reported a markedly smaller illusion than controls, despite equivalent perceptions of a real mass difference. Next, we replicated this dissociation between real and illusory weight perception in a group of non-amputees who lifted the stimuli with an upper-limb myoelectric prosthetic simulator, again noting that the prosthetic users experienced illusory, but not real, weight differences as being weaker than controls. These findings not only validate the use of a prosthetic simulator as an effective tool for investigating perception and action, but also highlight a surprising dissociation between the perception of real and illusory weight differences

    Effects of circadian disruption on physiology and pathology: from bench to clinic (and back)

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    Nested within the hypothalamus, the suprachiasmatic nuclei (SCN) represent a central biological clock that regulates daily and circadian (i.e., close to 24 h) rhythms in mammals. Besides the SCN, a number of peripheral oscillators throughout the body control local rhythms and are usually kept in pace by the central clock. In order to represent an adaptive value, circadian rhythms must be entrained by environmental signals or zeitgebers, the main one being the daily light?dark (LD) cycle. The SCN adopt a stable phase relationship with the LD cycle that, when challenged, results in abrupt or chronic changes in overt rhythms and, in turn, in physiological, behavioral, and metabolic variables. Changes in entrainment, both acute and chronic, may have severe consequences in human performance and pathological outcome. Indeed, animal models of desynchronization have become a useful tool to understand such changes and to evaluate potential treatments in human subjects. Here we review a number of alterations in circadian entrainment, including jet lag, social jet lag (i.e., desynchronization between body rhythms and normal time schedules), shift work, and exposure to nocturnal light, both in human subjects and in laboratory animals. Finally, we focus on the health consequences related to circadian/entrainment disorders and propose a number of approaches for the management of circadian desynchronization.Fil: Chiesa, Juan José. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Duhart, José Manuel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Casiraghi, Leandro Pablo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paladino, Natalia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bussi, Ivana Leda. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andrés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Speed of saccade execution and inhibition associated with fractional anisotropy in distinct fronto-frontal and fronto-striatal white matter pathways

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    Fast cancellation or switching of action plans is a critical cognitive function. Rapid signal transmission is key for quickly executing and inhibiting responses, and the structural integrity of connections between brain regions plays a crucial role in signal transmission speed. In this study, we used the search-step task, which has been used in nonhuman primates to measure dynamic alteration of saccade plans, in combination with functional and diffusion-weighted MRI. Functional MRI results were used to identify brain regions involved in the reactive control of gaze. Probabilistic tractography was used to identify white matter pathways connecting these structures, and the integrity of these connections, as indicated by fractional anisotropy (FA), was correlated with search-step task performance. Average FA from tracts between the right frontal eye field (FEF) and both right supplementary eye field (SEF) and the dorsal striatum were associated with faster saccade execution. Average FA of connections between the dorsal striatum and both right SEF and right inferior frontal cortex (IFC) as well as between SEF and IFC predicted the speed of inhibition. These relationships were largely behaviorally specific, despite the correlation between saccade execution and inhibition. Average FA of connections between the IFC and both SEF and the dorsal striatum specifically predicted the speed of inhibition, and connections between the FEF and SEF specifically predicted the speed of execution. In addition, these relationships were anatomically specific; correlations were observed after controlling for global FA. These data suggest that networks supporting saccade initiation and inhibition are at least partly dissociable.

    Speed of saccade execution and inhibition associated with fractional anisotropy in distinct fronto-frontal and fronto-striatal white matter pathways

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    Fast cancellation or switching of action plans is a critical cognitive function. Rapid signal transmission is key for quickly executing and inhibiting responses, and the structural integrity of connections between brain regions plays a crucial role in signal transmission speed. In this study, we used the search-step task, which has been used in nonhuman primates to measure dynamic alteration of saccade plans, in combination with functional and diffusion-weighted MRI. Functional MRI results were used to identify brain regions involved in the reactive control of gaze. Probabilistic tractography was used to identify white matter pathways connecting these structures, and the integrity of these connections, as indicated by fractional anisotropy (FA), was correlated with search-step task performance. Average FA from tracts between the right frontal eye field (FEF) and both right supplementary eye field (SEF) and the dorsal striatum were associated with faster saccade execution. Average FA of connections between the dorsal striatum and both right SEF and right inferior frontal cortex (IFC) as well as between SEF and IFC predicted the speed of inhibition. These relationships were largely behaviorally specific, despite the correlation between saccade execution and inhibition. Average FA of connections between the IFC and both SEF and the dorsal striatum specifically predicted the speed of inhibition, and connections between the FEF and SEF specifically predicted the speed of execution. In addition, these relationships were anatomically specific; correlations were observed after controlling for global FA. These data suggest that networks supporting saccade initiation and inhibition are at least partly dissociable

    Is extensive screening for cancer in idiopathic venous thromboembolism warranted?

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    Background: Patients with a first episode of idiopathic venous thromboembolism (IVTE) have an estimated 10% incidence of cancer within 12 months after diagnosis. However, the utility of screening for cancer in this population is controversial. Methods: In this prospective concurrently controlled cohort study, limited and extensive cancer screening strategies were compared. All 630 patients underwent baseline screening consisting of history, physical examination, basic laboratory tests and chest X-ray. In the extensive screening group abdominal and chest CT scan and mammography were added. Outcomes were incidence and curability of cancer, and cancer-related and overall mortality. Results: In 12 of the 342 (3.5%) patients in the extensive screening group malignancy was diagnosed at baseline compared with 2.4% (seven of 288 patients) in the limited screening group. Extensive screening detected six additional cancers (2.0%; 95% CI, 0.74-4.3), of which three were potentially curable. During a median 2.5 years of follow-up, cancer was diagnosed in 3.7% and 5.0% in the extensive and limited screening groups, respectively. In the extensive screening group 26 patients (7.6%) died compared with 24 (8.3%) in the limited screening group; adjusted hazard ratio 1.22 (95% CI, 0.69-2.22). Of these deaths 17 (5.0%) in the extensive screening group and 8 (2.8%) in the limited screening group were cancer related; adjusted hazard ratio 1.79 (95% CI, 0.74-4.35). Conclusions: The low yield of extensive screening and lack of survival benefit do not support routine screening for cancer with abdominal and chest CT scan and mammography in patients with a first episode of IVTE

    Individually shortened duration versus standard duration of elastic compression therapy for prevention of post-thrombotic syndrome: a cost-effectiveness analysis

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    Item does not contain fulltextBACKGROUND: The IDEAL DVT study showed that it was safe to shorten the duration of elastic compression therapy on an individualised basis after deep vein thrombosis for prevention of post-thrombotic syndrome. In this study, we assessed the cost-effectiveness of this strategy. METHODS: IDEAL DVT was a multicentre, randomised, non-inferiority trial that included patients with acute proximal deep vein thrombosis of the leg. After 6 months of elastic compression therapy, patients were randomly assigned (1:1) to the standard 2 years of elastic stocking compression therapy or shortened duration of compression therapy based on the patient's Villalta score. For our cost-effectiveness analysis, we assessed quality-adjusted life-years (QALYs), measured with the three-level version of EQ-5D (EQ-5D-3L; Dutch and UK tariff) and the 36-item Short Form Health Survey (SF-36), and costs in euro (health-care and societal perspective) according to the intention-to-treat approach. Data were collected at 3, 6, 12, and 24 months after diagnosis of thrombosis. We calculated incremental net monetary benefit using a QALY threshold of euro30 000, and obtained bootstrapped means and 95% CIs. IDEAL DVT is registered with ClinicalTrials.gov, number NCT01429714. FINDINGS: Between March 22, 2011, and July 1, 2015, 865 patients were enrolled in IDEAL DVT. 437 were assigned to individualised duration of elastic compression therapy and 428 to standard duration of elastic compression therapy. Nine patients were eventually excluded because of recurrent venous thromboembolism within 6 months after the first event. From a societal perspective, for every QALY lost measured with the EQ-5D Dutch tariff, cost savings were euro305.992 (incremental net monetary benefit euro3205, 95% CI 502-5741), and for every QALY lost based on the Short-Form Six-Dimension (SF-6D) utility score (derived from SF-36), cost savings were euro6030.941 (euro3540, 95% CI 1174-5953). Using the UK tariff for EQ-5D, the individualised strategy was more effective and less costly (euro4071, 1452-6647). The probability that the individualised strategy was cost-effective was 99% at a threshold of euro30 000 per QALY (EQ-5D Dutch tariff). INTERPRETATION: Individually shortened duration of elastic compression therapy was cost-effective compared with standard duration elastic compression therapy. Use of an individualised approach to elastic stocking compression therapy for the prevention of post-thrombotic syndrome after deep vein thrombosis could lead to substantial costs savings without loss in health-related quality of life. FUNDING: Netherlands Organisation for Health Research and Development
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