236 research outputs found

    Oscillatory Control over Representational States in Working Memory

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    In the visual world, attention is guided by perceptual goals activated in visual working memory (VWM). However, planning multiple-task sequences also requires VWM to store representations for future goals. These future goals need to be prevented from interfering with the current perceptual task. Recent findings have implicated neural oscillations as a control mechanism serving the implementation and switching of different states of prioritization of VWM representations. We review recent evidence that posterior alpha-band oscillations underlie the flexible activation and deactivation of VWM representations and that frontal delta-to-theta-band oscillations play a role in the executive control of this process. That is, frontal delta-to-theta appears to orchestrate posterior alpha through long-range oscillatory networks to flexibly set up and change VWM states during multitask sequences

    PTEN Is Associated With Worse Local Control in Early Stage Supraglottic Laryngeal Cancer Treated With Radiotherapy

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    Objectives: The aim of this study was to establish the prognostic value of the epidermal growth factor receptor (EGFR) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression on local control in patients with early stage supraglottic laryngeal squamous cell carcinoma (LSCC) treated with radiotherapy only. Study design: Retrospective cohort study. Methods: Immunohistochemical staining for EGFR and PTEN was performed on pretreatment biopsies of a selected well-defined homogeneous group of 52 patients with T1-T2 supraglottic LSCC treated with radiotherapy between 1990 and 2008. Kaplan-Meier analysis and univariate and multivariate Cox Regression analyses were performed to correlate clinical data and expression levels of EGFR and PTEN with local control. Results: Kaplan-Meier survival analysis and Cox Regression analysis showed a significant association between PTEN expression and local control (hazard ratio [HR] = 3.26, 95% confidence interval [CI] = 1.14-9.33, P = .027) and between lymph node status and local control (HR = 3.60, 95% CI = 1.26-10.31, P = .017). Both were independent prognostic factors in a multivariate analysis (HR = 3.28, 95% CI = 1.14-9.39, P = .027 and HR = 3.62, 95% CI = 1.26-10.37, P = .017, respectively). There was no significant association between EGFR expression and local control (HR = 1.32, 95% CI = 1.17-10.14, P = .79). Conclusion: This study showed an association between both high PTEN expression and the presence of lymph node metastasis and deteriorated local control in early stage supraglottic LSCC treated with radiotherapy. Level of Evidence: NA

    Distinct Biomarker Profiles and Clinical Characteristics in T1-T2 Glottic and Supraglottic Carcinomas

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    Background: In early stage laryngeal squamous cell carcinoma (LSCC) radiotherapy with curative intent is a major treatment modality. TNM classification is used to define patients eligible for radiotherapy. Studies in early stage glottic LSCC identified several predictive biomarkers associated with local control. However, we recently reported that this predictive value could not be confirmed in supraglottic LSCC. Objective: To examine whether clinical behavior and protein expression patterns of these biomarkers differ between glottic and supraglottic LSCC. Study Design: Retrospective cohort study. Methods: Tumor tissue sections of 196 glottic and 80 supraglottic T1-T2 LSCC treated primarily with RT were assessed immunohistochemically for expression of pAKT, Ki-67 and β-Catenin. Expression data of HIF-1α, CA-IX, OPN, FADD, pFADD, Cyclin D1, Cortactin and EGFR in the same cohort of glottic and supraglottic LSCC, were retrieved from previously reported data. The relationship between glottic and supraglottic sublocalization and clinicopathological, follow-up, and immunohistochemical staining characteristics were evaluated using logistic regression and Cox regression analyses. Results: Glottic LSCC were correlated with male gender (P =.001), hoarseness as a primary symptom (P <.001), T1 tumor stage (P <.001), negative lymph node status (P <.001), and an older age at presentation (P =.004). Supraglottic LSCC patients developed more post-treatment distant metastasis when adjusted for gender, age, and T-status. While supraglottic LSCC was associated with higher expression of HIF-1α (P =.001), Cortactin (P <.001), EGFR (P <.001), and Ki-67 (P =.027), glottic LSCC demonstrated higher expression of CA-IX (P =.005) and Cyclin D1 (P =.001). Conclusion: Differences in clinicopathological and immunohistochemical staining characteristics suggest that T1-T2 glottic and supraglottic LSCC should be considered as different entities. Level of Evidence: N/A. Laryngoscope, 2020

    Transrectus sheath pre-peritoneal (TREPP) procedure versus totally extraperitoneal (TEP) procedure and Lichtenstein technique:a propensity-score-matched analysis in Dutch high-volume regional hospitals

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    PURPOSE: Results of the most commonly used inguinal hernia repair techniques often originate from expert centers or from randomized controlled studies. In this study, we portray daily-practice results of a high-volume, regional surgical group in the Netherlands, comparing TREPP (open (posterior) transrectus sheath pre-peritoneal) with Lichtenstein (open anterior) and TEP (endoscopic (posterior) totally extraperitoneal). We hypothesize that the TREPP shows more favorable outcome compared to the current gold standard procedures: TEP and Lichtenstein. METHODS: Between January 2016 and December 2018, 3285 consecutive patients underwent surgical treatment and were included for analysis. The outcome measures were postoperative pain, recurrence rate and other surgical complications. Propensity-score matching was used to address potential selection bias. RESULTS: After propensity-score matching, there was no statistically significant difference in postoperative pain in the TREPP group compared to the Lichtenstein group (TREPP 7.3% versus Lichtenstein 6.3%; p = 0.67) nor in TREPP compared to TEP (TREPP 7.4% versus TEP 4.1%; p = 0.064). There was no statistically significant difference in recurrences in the TREPP group compared to Lichtenstein (3.8% vs 2.5%; p = 0.42), nor in the TREPP versus TEP comparison (3.9% vs 2.8%; p = 0.55) CONCLUSION: This study compares TREPP with Lichtenstein and TEP in the presence of postoperative pain, recurrences and other adverse outcomes. After propensity-score matching, no statistically significant difference in postoperative pain or recurrences remained between either TREPP compared to Lichtenstein, or TREPP compared to TEP. Based on these results, TREPP, Lichtenstein and TEP showed comparable results in postoperative pain, recurrences and other surgical site complications

    Cochlear-optimized treatment planning in photon and proton radiosurgery for vestibular schwannoma patients

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    ObjectiveTo investigate the potential to reduce the cochlear dose with robotic photon radiosurgery or intensity-modulated proton therapy planning for vestibular schwannomas.Materials and MethodsClinically delivered photon radiosurgery treatment plans were compared to five cochlear-optimized plans: one photon and four proton plans (total of 120). A 1x12 Gy dose was prescribed. Photon plans were generated with Precision (Cyberknife, Accuray) with no PTV margin for set-up errors. Proton plans were generated using an in-house automated multi-criterial planning system with three or nine-beam arrangements, and applying 0 or 3 mm robustness for set-up errors during plan optimization and evaluation (and 3 % range robustness). The sample size was calculated based on a reduction of cochlear Dmean > 1.5 Gy(RBE) from the clinical plans, and resulted in 24 patients.ResultsCompared to the clinical photon plans, a reduction of cochlear Dmean > 1.5 Gy(RBE) could be achieved in 11/24 cochlear-optimized photon plans, 4/24 and 6/24 cochlear-optimized proton plans without set-up robustness for three and nine-beam arrangement, respectively, and in 0/24 proton plans with set-up robustness. The cochlea could best be spared in cases with a distance between tumor and cochlea. Using nine proton beams resulted in a reduced dose to most organs at risk.ConclusionCochlear dose reduction is possible in vestibular schwannoma radiosurgery while maintaining tumor coverage, especially when the tumor is not adjacent to the cochlea. With current set-up robustness, proton therapy is capable of providing lower dose to organs at risk located distant to the tumor, but not for organs adjacent to it. Consequently, photon plans provided better cochlear sparing than proton plans.Otorhinolaryngolog

    Identification of Two Protein-Signaling States Delineating Transcriptionally Heterogeneous Human Medulloblastoma

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    Summary: The brain cancer medulloblastoma consists of different transcriptional subgroups. To characterize medulloblastoma at the phosphoprotein-signaling level, we performed high-throughput peptide phosphorylation profiling on a large cohort of SHH (Sonic Hedgehog), group 3, and group 4 medulloblastomas. We identified two major protein-signaling profiles. One profile was associated with rapid death post-recurrence and resembled MYC-like signaling for which MYC lesions are sufficient but not necessary. The second profile showed enrichment for DNA damage, as well as apoptotic and neuronal signaling. Integrative analysis demonstrated that heterogeneous transcriptional input converges on these protein-signaling profiles: all SHH and a subset of group 3 patients exhibited the MYC-like protein-signaling profile; the majority of the other group 3 subset and group 4 patients displayed the DNA damage/apoptotic/neuronal signaling profile. Functional analysis of enriched pathways highlighted cell-cycle progression and protein synthesis as therapeutic targets for MYC-like medulloblastoma. : Using peptide phosphorylation profiling, Zomerman et al. identify two medulloblastoma phosphoprotein-signaling profiles that have prognostic value and are potentially targetable. They find that these profiles extend across transcriptome-based subgroup borders. This suggests that diverse genetic information converges on common protein-signaling pathways and highlights protein-signaling as a unique information layer. Keywords: medulloblastoma, protein-signaling, protein synthesis, MYC, TP53, proteome, phosphoproteom

    Occipital gamma activation during Vipassana meditation

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    Long-term Vipassana meditators sat in meditation vs. a control rest (mind-wandering) state for 21 min in a counterbalanced design with spontaneous EEG recorded. Meditation state dynamics were measured with spectral decomposition of the last 6 min of the eyes-closed silent meditation compared to control state. Meditation was associated with a decrease in frontal delta (1–4 Hz) power, especially pronounced in those participants not reporting drowsiness during meditation. Relative increase in frontal theta (4–8 Hz) power was observed during meditation, as well as significantly increased parieto-occipital gamma (35–45 Hz) power, but no other state effects were found for the theta (4–8 Hz), alpha (8–12 Hz), or beta (12–25 Hz) bands. Alpha power was sensitive to condition order, and more experienced meditators exhibited no tendency toward enhanced alpha during meditation relative to the control task. All participants tended to exhibit decreased alpha in association with reported drowsiness. Cross-experimental session occipital gamma power was the greatest in meditators with a daily practice of 10+ years, and the meditation-related gamma power increase was similarly the strongest in such advanced practitioners. The findings suggest that long-term Vipassana meditation contributes to increased occipital gamma power related to long-term meditational expertise and enhanced sensory awareness

    Mindful breath awareness meditation facilitates efficiency gains in brain networks: A steady-state visually evoked potentials study

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    The beneficial effects of mindfulness-based therapeutic interventions have stimulated a rapidly growing body of scientific research into underlying psychological processes. Resulting evidence indicates that engaging with mindfulness meditation is associated with increased performance on a range of cognitive tasks. However, the mechanisms promoting these improvements require further investigation. We studied changes in behavioural performance of 34 participants during a multiple object tracking (MOT) task that taps core cognitive processes, namely sustained selective visual attention and spatial working memory. Concurrently, we recorded the steady-state visually evoked potential (SSVEP), an EEG signal elicited by the continuously flickering moving objects, and indicator of attentional engagement. Participants were tested before and after practicing eight weeks of mindful breath awareness meditation or progressive muscle relaxation as active control condition. The meditation group improved their MOT-performance and exhibited a reduction of SSVEP amplitudes, whereas no such changes were observed in the relaxation group. Neither group changed in self-reported positive affect and mindfulness, while a marginal increase in negative affect was observed in the mindfulness group. This novel way of combining MOT and SSVEP provides the important insight that mindful breath awareness meditation may lead to refinements of attention networks, enabling more efficient use of attentional resources
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