82 research outputs found

    Visual Rivalry Without Spatial Conflict

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    Visual rivalry has been extensively characterized in the literature. It is thought to require spatial conflict between overlapping visual presentations, even in studies that have found nonspatial (i.e. nonretinal) influences on rivalry. Unexpectedly, we identified visual rivalry in the complete absence of spatial conflict. Participants experienced visual rivalry when we placed a nonambiguous motion stimulus in a nonspatial (in our case, object-based) reference frame. Moreover, a stimulus that was displaced within a nonspatial reference frame did not induce rivalry despite the presence of spatial conflict. This finding shows that nonspatial, object-based processing can overrule retinotopic processing and prevent rivalry from occurring when a perceived stimulus exists unambiguously in an object-based reference frame. our results identify a potent high-level conflict-resolution stage independent of low-level spatial visual conflict. This independence of spatial overlap provides an advantage to the visual system, allowing conflict resolution when an object is nonstationary on the retina (e.g., during frequently occurring eye movements)

    Consciousness and Attention: On Sufficiency and Necessity

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    Recent research has slowly corroded a belief that selective attention and consciousness are so tightly entangled that they cannot be individually examined. In this review, we summarize psychophysical and neurophysiological evidence for a dissociation between top-down attention and consciousness. The evidence includes recent findings that show subjects can attend to perceptually invisible objects. More contentious is the finding that subjects can become conscious of an isolated object, or the gist of the scene in the near absence of top-down attention; we critically re-examine the possibility of “complete” absence of top-down attention. We also cover the recent flurry of studies that utilized independent manipulation of attention and consciousness. These studies have shown paradoxical effects of attention, including examples where top-down attention and consciousness have opposing effects, leading us to strengthen and revise our previous views. Neuroimaging studies with EEG, MEG, and fMRI are uncovering the distinct neuronal correlates of selective attention and consciousness in dissociative paradigms. These findings point to a functional dissociation: attention as analyzer and consciousness as synthesizer. Separating the effects of selective visual attention from those of visual consciousness is of paramount importance to untangle the neural substrates of consciousness from those for attention

    Comparison of Outcome After Percutaneous Mitral Valve Repair With the MitraClip in Patients With Versus Without Atrial Fibrillation

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    Percutaneous mitral valve repair with the MitraClip is an established treatment for patients with mitral regurgitation (MR) who are inoperable or at high risk for surgery. Atrial Fibrillation (AF) frequently coincides with MR, but only scarce data of the influence of AF on outcome after MitraClip is available. The aim of the current study was to compare the clinical outcome after MitraClip treatment in patients with versus without atrial fibrillation. Between January 2009 and January 2016, all consecutive patients treated with a MitraClip in 5 Dutch centers were included. Outcome measures were survival, symptoms, MR grade, and stroke incidence. In total, 618 patients were treated with a MitraClip. Patients with AF were older, had higher N-terminal B-type natriuretic peptide levels, more tricuspid regurgitation, less often coronary artery disease and a better left ventricular function. Survival of patients treated with the MitraClip was similar for patients with AF (82%) and without AF (non-AF; 85%) after 1 year (p = 0.30), but significantly different after 5-year follow-up (AF 34%; non-AF 47%; p = 0.006). After 1 month, 64% of the patients with AF were in New York Heart Association class I or II, in contrast to 77% of the patients without AF (p = 0.001). The stroke incidence appeared not to be significantly different (AF 1.8%; non-AF 1.0%; p = 0.40). In conclusion, patients with AF had similar 1-year survival, MR reduction, and stroke incidence compared with non-AF patients. However, MitraClip patients with AF had reduced long-term survival and remained more symptomatic compared with those without AF.</p

    Dried blood spot UHPLC-MS/MS analysis of oseltamivir and oseltamivircarboxylate—a validated assay for the clinic

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    The neuraminidase inhibitor oseltamivir (Tamiflu®) is currently the first-line therapy for patients with influenza virus infection. Common analysis of the prodrug and its active metabolite oseltamivircarboxylate is determined via extraction from plasma. Compared with these assays, dried blood spot (DBS) analysis provides several advantages, including a minimum sample volume required for the measurement of drugs in whole blood. Samples can easily be obtained via a simple, non-invasive finger or heel prick. Mainly, these characteristics make DBS an ideal tool for pediatrics and to measure multiple time points such as those needed in therapeutic drug monitoring or pharmacokinetic studies. Additionally, DBS sample preparation, stability, and storage are usually most convenient. In the present work, we developed and fully validated a DBS assay for the simultaneous determination of oseltamivir and oseltamivircarboxylate concentrations in human whole blood. We demonstrate the simplicity of DBS sample preparation, and a fast, accurate and reproducible analysis using ultra high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer. A thorough validation on the basis of the most recent FDA guidelines for bioanalytical method validation showed that the method is selective, precise, and accurate (≤15% RSD), and sensitive over the relevant clinical range of 5–1,500 ng/mL for oseltamivir and 20–1,500 ng/mL for the oseltamivircarboxylate metabolite. As a proof of concept, oseltamivir and oseltamivircarboxylate levels were determined in DBS obtained from healthy volunteers who received a single oral dose of Tamiflu®

    Human extrahepatic and intrahepatic cholangiocyte organoids show region-specific differentiation potential and model cystic fibrosis-related bile duct disease

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    The development, homeostasis, and repair of intrahepatic and extrahepatic bile ducts are thought to involve distinct mechanisms including proliferation and maturation of cholangiocyte and progenitor cells. This study aimed to characterize human extrahepatic cholangiocyte organoids (ECO) using canonical Wnt-stimulated culture medium previously developed for intrahepatic cholangiocyte organoids (ICO). Paired ECO and ICO were derived from common bile duct and liver tissue, respectively. Characterization showed both organoid types were highly similar, though some differences in size and gene expression were observed. Both ECO and ICO have cholangiocyte fate differentiation capacity. However, unlike ICO, ECO lack the potential for differentiation towards a hepatocyte-like fate. Importantly, ECO derived from a cystic fibrosis patient showed no CFTR channel activity but normal chloride channel and MDR1 transporter activity. In conclusion, this study shows that ECO and ICO have distinct lineage fate and that ECO provide a competent model to study extrahepatic bile duct diseases like cystic fibrosis

    A systematic review and meta-analysis of the effects of clinical pathways on length of stay, hospital costs and patient outcomes

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    Background. To perform a systematic review about the effect of using clinical pathways on length of stay (LOS), hospital costs and patient outcomes. To provide a framework for local healthcare organisations considering the effectiveness of clinical pathways as a patient management strategy. Methods. As participants, we considered hospitalized children and adults of every age and indication whose treatment involved the management strategy "clinical pathways". We include only randomised controlled trials (RCT) and controlled clinical trials (CCT), not restricted by language or country of publication. Single measures of continuous and dichotomous study outcomes were extracted from each study. Separate analyses were done in order to compare effects of clinical pathways on length of stay (LOS), hospital costs and patient outcomes. A random effects meta-analysis was performed with untransformed and log transformed outcomes. Results. In total 17 trials met inclusion criteria, representing 4,070 patients. The quality of the included studies was moderate and studies reporting economic data can be described by a very limited scope of evaluation. In general, the majority of studies reporting economic data (LOS and hospital costs) showed a positive impact. Out of 16 reporting effects on LOS, 12 found significant shortening. Furthermore, in a subgroup-analysis, clinical pathways for invasive procedures showed a stronger LOS reduction (weighted mean difference (WMD) -2.5 days versus -0.8 days)). There was no evidence of differences in readmission to hospitals or in-hospital complications. The overall Odds Ratio (OR) for re-admission was 1.1 (95% CI: 0.57 to 2.08) and for in-hospital complications, the overall OR was 0.7 (95% CI: 0.49 to 1.0). Six studies examined costs, and four showed significantly lower costs for the pathway group. However, heterogeneity between studies reporting on LOS and cost effects was substantial. Conclusion. As a result of the relatively small number of studies meeting inclusion criteria, this evidence base is not conclusive enough to provide a replicable framework for all pathway strategies. Considering the clinical areas for implementation, clinical pathways seem to be effective especially for invasive care. When implementing clinical pathways, the decision makers need to consider the benefits and costs under different circumstances (e.g. market forces)

    The BAF complex inhibitor pyrimethamine reverses HIV-1 latency in people with HIV-1 on antiretroviral therapy

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    Reactivation of the latent HIV-1 reservoir is a first step toward triggering reservoir decay. Here, we investigated the impact of the BAF complex inhibitor pyrimethamine on the reservoir of people living with HIV-1 (PLWH). Twenty-eight PLWH on suppressive antiretroviral therapy were randomized (1:1:1:1 ratio) to receive pyrimethamine, valproic acid, both, or no intervention for 14 days. The primary end point was change in cell-associated unspliced (CA US) HIV-1 RNA at days 0 and 14. We observed a rapid, modest, and significant increase in (CA US) HIV-1 RNA in response to pyrimethamine exposure, which persisted throughout treatment and follow-up. Valproic acid treatment alone did not increase (CA US) HIV-1 RNA or augment the effect of pyrimethamine. Pyrimethamine treatment did not result in a reduction in the size of the inducible reservoir. These data demonstrate that the licensed drug pyrimethamine can be repurposed as a BAF complex inhibitor to reverse HIV-1 latency in vivo in PLWH, substantiating its potential advancement in clinical studies.</p

    Transanal minimally invasive surgery (TAMIS) versus endoscopic submucosal dissection (ESD) for resection of non-pedunculated rectal lesions (TRIASSIC study):study protocol of a European multicenter randomised controlled trial

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    BACKGROUND: In the recent years two innovative approaches have become available for minimally invasive en bloc resections of large non-pedunculated rectal lesions (polyps and early cancers). One is Transanal Minimally Invasive Surgery (TAMIS), the other is Endoscopic Submucosal Dissection (ESD). Both techniques are standard of care, but a direct randomised comparison is lacking. The choice between either of these procedures is dependent on local expertise or availability rather than evidence-based. The European Society for Endoscopy has recommended that a comparison between ESD and local surgical resection is needed to guide decision making for the optimal approach for the removal of large rectal lesions in Western countries. The aim of this study is to directly compare both procedures in a randomised setting with regard to effectiveness, safety and perceived patient burden. METHODS: Multicenter randomised trial in 15 hospitals in the Netherlands. Patients with non-pedunculated lesions > 2 cm, where the bulk of the lesion is below 15 cm from the anal verge, will be randomised between either a TAMIS or an ESD procedure. Lesions judged to be deeply invasive by an expert panel will be excluded. The primary endpoint is the cumulative local recurrence rate at follow-up rectoscopy at 12 months. Secondary endpoints are: 1) Radical (R0-) resection rate; 2) Perceived burden and quality of life; 3) Cost effectiveness at 12 months; 4) Surgical referral rate at 12 months; 5) Complication rate; 6) Local recurrence rate at 6 months. For this non-inferiority trial, the total sample size of 198 is based on an expected local recurrence rate of 3% in the ESD group, 6% in the TAMIS group and considering a difference of less than 6% to be non-inferior. DISCUSSION: This is the first European randomised controlled trial comparing the effectiveness and safety of TAMIS and ESD for the en bloc resection of large non-pedunculated rectal lesions. This is important as the detection rate of these adenomas is expected to further increase with the introduction of colorectal screening programs throughout Europe. This study will therefore support an optimal use of healthcare resources in the future. TRIAL REGISTRATION: Netherlands Trial Register, NL7083 , 06 July 2018

    ESC Joint Working Groups on Cardiovascular Surgery and the Cellular Biology of the Heart Position Paper: Perioperative myocardial injury and infarction in patients undergoing coronary artery bypass graft surgery

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