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https://www.readbyqxmd.com/read/28416773/changes-in-t-cell-subpopulations-and-cytokine-network-during-early-period-of-ibrutinib-therapy-in-chronic-lymphocytic-leukemia-patients-the-significant-decrease-in-t-regulatory-cells-number
#1
Monika Podhorecka, Aneta Goracy, Agnieszka Szymczyk, Malgorzata Kowal, Blanca Ibanez, Olga Jankowska-Lecka, Arkadiusz Macheta, Aleksandra Nowaczynska, Elzbieta Drab-Urbanek, Sylwia Chocholska, Dariusz Jawniak, Marek Hus
B cell receptor (BCR) stimulation signal plays an important role in the pathogenesis of chronic lymphocytic leukemia (CLL), and kinase inhibitors directed toward the BCR pathway are now the promising anti-leukemic drugs. Ibrutinib, a Bruton tyrosine kinase inhibitor, demonstrates promising clinical activity in CLL. It is reported that ibrutinib, additionally to directly targeting leukemic cells, also inhibits the interactions of these cells with T cells, macrophages and accessory cells. Assessment of these mechanisms is important because of their non -direct anti-leukemic effects and to identify possible side effects connected with long-term drug administration...
March 13, 2017: Oncotarget
https://www.readbyqxmd.com/read/28408874/editorial-mapping-psychopathology-with-fmri-and-effective-connectivity-analysis
#2
EDITORIAL
Baojuan Li, Adeel Razi, Karl J Friston
No abstract text is available yet for this article.
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28399440/altered-effective-brain-connectivity-at-early-response-of-antipsychotics-in-first-episode-schizophrenia-with-auditory-hallucinations
#3
Leilei Zheng, Weibo Liu, Wei He, Shaohua Yu, Guodong Zhong
OBJECTIVE: This study aimed to examine the alterations of cortical connectivity in first-episode schizophrenia (FES) with auditory hallucinations at early response of antipsychotics. METHODS: This was a nonexperimental control of medication study. We measured the cortical activity of 20 medicated patients with FES (medicated group), 19 nonmedicated patients with FES (nonmedicated group), and 22 healthy controls using electroencephalogram during eye-open resting state...
February 20, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28397708/effective-brain-network-analysis-with-resting-state-eeg-data-a-comparison-between-heroin-abstinent-and-non-addicted-subjects
#4
Bin Hu, Qunxi Dong, Yanrong Hao, Qinglin Zhao, Jian Shen, Fang Zheng
Abstract-Objective. Neuro-electrophysiological tools have been widely used in heroin addiction studies. Previous studies indicated that chronic heroin abuse would result in abnormal functional organization of the brain. While few heroin addiction studies apply the effective connectivity tool to analyze the brain functional system (BFS) alterations induced by heroin abuse. The present study aims to identify the abnormality of resting-state heroin abstinent BFS using source decomposition and effective connectivity tools...
April 11, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28386778/gaba-content-within-medial-prefrontal-cortex-predicts-the-variability-of-fronto-limbic-effective-connectivity
#5
Stefano Delli Pizzi, Piero Chiacchieretta, Dante Mantini, Giovanna Bubbico, Richard A Edden, Marco Onofrj, Antonio Ferretti, Laura Bonanni
The amygdala-medial prefrontal cortex (mPFC) circuit plays a key role in social behavior. The amygdala and mPFC are bidirectionally connected, functionally and anatomically, via the uncinate fasciculus. Recent evidence suggests that GABA-ergic neurotransmission within the mPFC could be central to the regulation of amygdala activity related to emotions and anxiety processing. However, the functional and neurochemical interactions within amygdala-mPFC circuits are unclear. In the current study, multimodal magnetic resonance imaging techniques were combined to investigate effective connectivity within the amygdala-mPFC network and its relationship with mPFC neurotransmission in 22 healthy subjects aged between 41 and 88 years...
April 6, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28378705/comparison-of-connectivity-analyses-for-resting-state-eeg-data
#6
Elzbieta Olejarczyk, Laura Marzetti, Vittorio Pizzella, Filippo Zappasodi
OBJECTIVE: In the present work, a nonlinear measure (transfer entropy, TE) was used in a multivariate approach for the analysis of effective connectivity in high density resting state EEG data in eyes open and eyes closed. Advantages of the multivariate approach in comparison to the bivariate one were tested. Moreover, the multivariate TE was compared to an effective linear measure, i.e. directed transfer function (DTF). Finally, the existence of a relationship between the information transfer and the level of brain synchronization as measured by phase synchronization value (PLV) was investigated...
April 5, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28364641/tracking-reorganization-of-large-scale-effective-connectivity-in-aphasia-following-right-hemisphere-stroke
#7
David W Gow, Seppo P Ahlfors
In this paper we demonstrate the application of new effective connectivity analyses to characterize changing patterns of task-related directed interaction in large (25-55 node) cortical networks following the onset of aphasia. The subject was a left-handed woman who became aphasic following a right-hemisphere stroke. She was tested on an auditory word-picture verification task administered one and seven months after the onset of aphasia. MEG/EEG and anatomical MRI data were used to create high spatiotemporal resolution estimates of task-related cortical activity...
March 29, 2017: Brain and Language
https://www.readbyqxmd.com/read/28364547/stable-functional-networks-exhibit-consistent-timing-in-the-human-brain
#8
Julio I Chapeton, Sara K Inati, Kareem A Zaghloul
Despite many advances in the study of large-scale human functional networks, the question of timing, stability, and direction of communication between cortical regions has not been fully addressed. At the cellular level, neuronal communication occurs through axons and dendrites, and the time required for such communication is well defined and preserved. At larger spatial scales, however, the relationship between timing, direction, and communication between brain regions is less clear. Here, we use a measure of effective connectivity to identify connections between brain regions that exhibit communication with consistent timing...
March 1, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28342831/inference-of-direct-and-multistep-effective-connectivities-from-functional-connectivity-of-the-brain-and-of-relationships-to-cortical-geometry
#9
Grishma Mehta-Pandejee, P A Robinson, James A Henderson, K M Aquino, Somwrita Sarkar
BACKGROUND: The problem of inferring effective brain connectivity from functional connectivity is under active investigation, and connectivity via multistep paths is poorly understood. NEW METHOD: A method is presented to calculate the direct effective connection matrix (deCM), which embodies direct connection strengths between brain regions, from functional CMs (fCMs) by minimizing the difference between an experimental fCM and one calculated via neural field theory from an ansatz deCM based on an experimental anatomical CM...
March 22, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28341164/expectation-violation-and-attention-to-pain-jointly-modulate-neural-gain-in-somatosensory-cortex
#10
Francesca Fardo, Ryszard Auksztulewicz, Micah Allen, Martin J Dietz, Andreas Roepstorff, Karl J Friston
The neural processing and experience of pain are influenced by both expectations and attention. For example, the amplitude of event-related pain responses is enhanced by both novel and unexpected pain, and by moving the focus of attention towards a painful stimulus. Under predictive coding, this congruence can be explained by appeal to a precision-weighting mechanism, which mediates bottom-up and top-down attentional processes by modulating the influence of feedforward and feedback signals throughout the cortical hierarchy...
March 21, 2017: NeuroImage
https://www.readbyqxmd.com/read/28340406/a-local-adjustment-strategy-for-the-initialization-of-dynamic-causal-modelling-to-infer-effective-connectivity-in-brain-epileptic-structures
#11
Wentao Xiang, Ahmad Karfoul, Huazhong Shu, Régine Le Bouquin Jeannès
This paper addresses the question of effective connectivity in the human cerebral cortex in the context of epilepsy. Among model based approaches to infer brain connectivity, spectral Dynamic Causal Modelling is a conventional technique for which we propose an alternative to estimate cross spectral density. The proposed strategy we investigated tackles the sub-estimation of the free energy using the well-known variational Expectation-Maximization algorithm highly sensitive to the initialization of the parameters vector by a permanent local adjustment of the initialization process...
March 7, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28334882/decreased-integration-and-information-capacity-in-stroke-measured-by-whole-brain-models-of-resting-state-activity
#12
Mohit H Adhikari, Carl D Hacker, Josh S Siegel, Alessandra Griffa, Patric Hagmann, Gustavo Deco, Maurizio Corbetta
While several studies have shown that focal lesions affect the communication between structurally normal regions of the brain, and that these changes may correlate with behavioural deficits, their impact on brain's information processing capacity is currently unknown. Here we test the hypothesis that focal lesions decrease the brain's information processing capacity, of which changes in functional connectivity may be a measurable correlate. To measure processing capacity, we turned to whole brain computational modelling to estimate the integration and segregation of information in brain networks...
April 1, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28334138/working-memory-modulation-of-frontoparietal-network-connectivity-in-first-episode-schizophrenia
#13
Jesper Duemose Nielsen, Kristoffer H Madsen, Zheng Wang, Zhening Liu, Karl J Friston, Yuan Zhou
Working memory (WM) impairment is regarded as a core aspect of schizophrenia. However, the neural mechanisms behind this cognitive deficit remain unclear. The connectivity of a frontoparietal network is known to be important for subserving WM. Using functional magnetic resonance imaging, the current study investigated whether WM-dependent modulation of effective connectivity in this network is affected in a group of first-episode schizophrenia (FES) patients compared with similarly performing healthy participants during a verbal n-back task...
February 25, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28333586/modulation-of-context-dependent-spatiotemporal-patterns-within-packets-of-spiking-activity
#14
Miho Itoh, Timothée Leleu
Recent experiments have shown that stereotypical spatiotemporal patterns occur during brief packets of spiking activity in the cortex, and it has been suggested that top-down inputs can modulate these patterns according to the context. We propose a simple model that may explain important features of these experimental observations and is analytically tractable. The key mechanism underlying this model is that context-dependent top-down inputs can modulate the effective connection strengths between neurons because of short-term synaptic depression...
May 2017: Neural Computation
https://www.readbyqxmd.com/read/28323165/on-the-importance-of-modeling-fmri-transients-when-estimating-effective-connectivity-a-dynamic-causal-modeling-study-using-asl-data
#15
Martin Havlicek, Alard Roebroeck, Karl J Friston, Anna Gardumi, Dimo Ivanov, Kamil Uludag
Effective connectivity is commonly assessed using blood oxygenation level-dependent (BOLD) signals. In (Havlicek et al., 2015), we presented a novel, physiologically informed dynamic causal model (P-DCM) that extends current generative models. We demonstrated the improvements afforded by P-DCM in terms of the ability to model commonly observed neuronal and vascular transients in single regions. Here, we assess the ability of the novel and previous DCM variants to estimate effective connectivity among a network of five ROIs driven by a visuo-motor task...
March 16, 2017: NeuroImage
https://www.readbyqxmd.com/read/28300640/consistency-of-eeg-source-localization-and-connectivity-estimates
#16
Keyvan Mahjoory, Vadim V Nikulin, Loïc Botrel, Klaus Linkenkaer-Hansen, Marco M Fato, Stefan Haufe
As the EEG inverse problem does not have a unique solution, the sources reconstructed from EEG and their connectivity properties depend on forward and inverse modeling parameters such as the choice of an anatomical template and electrical model, prior assumptions on the sources, and further implementational details. In order to use source connectivity analysis as a reliable research tool, there is a need for stability across a wider range of standard estimation routines. Using resting state EEG recordings of N=65 participants acquired within two studies, we present the first comprehensive assessment of the consistency of EEG source localization and functional/effective connectivity metrics across two anatomical templates (ICBM152 and Colin27), three electrical models (BEM, FEM and spherical harmonics expansions), three inverse methods (WMNE, eLORETA and LCMV), and three software implementations (Brainstorm, Fieldtrip and our own toolbox)...
March 12, 2017: NeuroImage
https://www.readbyqxmd.com/read/28290245/differentiated-effective-connectivity-patterns-of-the-executive-control-network-in-progressive-mci-a-potential-biomarker-for-predicting-ad
#17
Suping Cai, Yanlin Peng, Tao Chong, Yun Zhang, Karen M von Deneen, Liyu Huang, Aibl Research Group
Mild cognitive impairment (MCI) is often a transitional state between normal aging and Alzheimer's disease (AD). When observed longitudinally, some MCI patients convert to AD, while a considerable portion either remain MCI or revert to a normal functioning state. This divergence has provided some enlightenment on a potential biomarker be represented in the resting state brain activities of MCI patients with different post-hoc labels. Recent studies have shown impaired executive functions, other than typically explicated memory impairment with AD/MCI patients...
March 9, 2017: Current Alzheimer Research
https://www.readbyqxmd.com/read/28290073/prefrontal-dysconnectivity-links-to-working-memory-deficit-in-first-episode-schizophrenia
#18
Xiaojing Fang, Yulin Wang, Luqi Cheng, Yuanchao Zhang, Yuan Zhou, Shihao Wu, Huan Huang, Jilin Zou, Cheng Chen, Jun Chen, Huiling Wang, Tianzi Jiang
Working memory (WM) deficit is a core feature of schizophrenia and is characterized by abnormal functional integration in the prefrontal cortex, including the dorsolateral prefrontal cortex (dLPFC), dorsal anterior cingulate cortex (dACC), and ventrolateral prefrontal cortex (vLPFC). However, the specific mechanism by which the abnormal neuronal circuits that involve these brain regions contribute to this deficit is still unclear. Therefore, this study focused on these regions and sought to answer which abnormal causal relationships in these regions can be linked to impaired WM in schizophrenia...
March 13, 2017: Brain Imaging and Behavior
https://www.readbyqxmd.com/read/28286918/altered-effective-connectivity-network-in-childhood-absence-epilepsy-a-multi-frequency-meg-study
#19
Caiyun Wu, Jing Xiang, Wenwen Jiang, Shuyang Huang, Yuan Gao, Lu Tang, Yuchen Zhou, Di Wu, Qiqi Chen, Zheng Hu, Xiaoshan Wang
Using multi-frequency magnetoencephalography (MEG) data, we investigated whether the effective connectivity (EC) network of patients with childhood absence epilepsy (CAE) is altered during the inter-ictal period in comparison with healthy controls. MEG data from 13 untreated CAE patients and 10 healthy controls were recorded. Correlation analysis and Granger causality analysis were used to construct an EC network at the source level in eight frequency bands. Alterations in the spatial pattern and topology of the network in CAE were investigated by comparing the patients with the controls...
March 12, 2017: Brain Topography
https://www.readbyqxmd.com/read/28274168/resting-state-effective-connectivity-allows-auditory-hallucination%C3%A2-discrimination
#20
Manuel Graña, Leire Ozaeta, Darya Chyzhyk
Hallucinations are elusive phenomena that have been associated with psychotic behavior, but that have a high prevalence in healthy population. Some generative mechanisms of Auditory Hallucinations (AH) have been proposed in the literature, but so far empirical evidence is scarce. The most widely accepted generative mechanism hypothesis nowadays consists in the faulty workings of a network of brain areas including the emotional control, the audio and language processing, and the inhibition and self-attribution of the signals in the auditive cortex...
February 1, 2017: International Journal of Neural Systems
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