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17
result(s) for
"Mershina, Elena A"
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Modulation of Intrinsic Brain Connectivity by Implicit Electroencephalographic Neurofeedback
by
Liudmila D. Litvinova
,
Olga R. Dobrushina
,
Ekaterina V. Pechenkova
in
Biofeedback
,
Brain mapping
,
Brain research
2020
Despite the increasing popularity of neurofeedback, its mechanisms of action are still poorly understood. This study aims to describe the processes underlying implicit electroencephalographic neurofeedback. Fifty-two healthy volunteers were randomly assigned to a single session of infra-low frequency neurofeedback or sham neurofeedback with electrodes over the right middle temporal gyrus and the right inferior parietal lobule. They observed a moving rocket, the speed of which was modulated by the waveform derived from a band-limited infra-low frequency filter. Immediately before and after the session the participants underwent a resting state fMRI. Network-based statistical analysis was applied, comparing post- vs. pre-session and real vs. sham neurofeedback conditions. As a result, two phenomena were observed. First, we described a brain circuit related to the implicit neurofeedback process itself, consisting of the lateral occipital cortex, right dorsolateral prefrontal cortex, right ventral and bilateral dorsal striatum. Second, we found increased connectivity between key regions of the salience, language and visual networks, which is indicative of integration in sensory processing. Thus, it appears that a single session of implicit infra-low frequency electroencephalographic neurofeedback leads to significant changes in intrinsic brain connectivity.
Journal Article
Neural Correlates of Group Versus Individual Problem Solving Revealed by fMRI
by
Pechenkova, Ekaterina V.
,
Shpurov, Ilya Yu
,
Vlasova, Roza M.
in
Brain mapping
,
Communication
,
Cooperation
2020
Group problem solving is a prototypical complex collective intellectual activity. Psychological research provides compelling evidence that problem solving in groups is both qualitatively and quantitatively different from doing so alone. However, the question of whether individual and collective problem solving involve the same neural substrate has not yet been addressed, mainly due to methodological limitations. In the current study, functional magnetic resonance imaging was performed to compare brain activation when participants solved Raven-like matrix problems in a small group and individually. In the group condition, the participant in the scanner was able to discuss the problem with other team members using a special communication device. In the individual condition, the participant was required to think aloud while solving the problem in the silent presence of the other team members. Greater activation was found in several brain regions during group problem solving, including the medial prefrontal cortex; lateral parietal, cingulate and retrosplenial cortices; and frontal and temporal poles. These areas have been identified as potential components of the so-called “social brain” on the basis of research using offline judgments of material related to socializing. Therefore, this study demonstrated the actual involvement of these regions in real-time social interactions, such as group problem solving. However, further connectivity analysis revealed that the social brain components are co-activated, but do not increase their coupling during cooperation as would be suggested for a holistic network. We suggest that the social mode of the brain may be described instead as a re-configuration of connectivity between basic networks, and we found decreased connectivity between the language and salience networks in the group compared to the individual condition. A control experiment showed that the findings from the main experiment cannot be entirely accounted for by discourse comprehension. Thus, the study demonstrates affordances provided by the presented new technique for neuroimaging the ‘group mind’, implementing the single-brain version of the second-person neuroscience approach.
Journal Article
Multiwavelength Fluorescence and Diffuse Reflectance Spectroscopy for an In Situ Analysis of Kidney Stones
by
Tsigura, Daria A.
,
Armaganov, Artashes G.
,
Kamalov, Armais A.
in
Analytical chemistry
,
Calculi
,
Classification
2023
This study explores the use of diffuse reflectance spectroscopy (DRS) and multiwavelength fluorescence spectroscopy for real-time kidney stone identification during laser lithotripsy. Traditional methods are not suitable for in situ analysis, so the research focuses on optical techniques that can be integrated with lithotripsy fibers. Experiments were conducted ex vivo, using DRS and multiwavelength fluorescence spectroscopy (emission–excitation matrix (EEM)) to distinguish between 48 urinary stones of three types: urate, oxalate and hydroxyapatite, with infrared spectroscopy as a reference. A classification model was developed based on EEM and DRS data. Initial classification relying solely on EEM data achieved an f1-score of 87%, which increased to 92% when DRS data were included. The findings suggest that optical spectroscopy can effectively determine stone composition during laser lithotripsy, potentially enhancing surgical outcomes via the real-time automatic optimization of laser radiation parameters.
Journal Article
The Association of PLAUR Genotype and Soluble suPAR Serum Level with COVID-19-Related Lung Damage Severity
by
Shmakova, Anna A.
,
Nazarova, Galina B.
,
Rubina, Kseniya A.
in
Adult
,
Blood tests
,
Coronaviruses
2022
Uncovering the risk factors for acute respiratory disease coronavirus 2019 (COVID-19) severity may help to provide a valuable tool for early patient stratification and proper treatment implementation, improving the patient outcome and lowering the burden on the healthcare system. Here we report the results of a single-center retrospective cohort study on 151 severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-infected symptomatic hospitalized adult patients. We assessed the association of several blood test measurements, soluble urokinase receptor (uPAR) serum level and specific single nucleotide polymorphisms of ACE (I/D), NOS3 (rs2070744, rs1799983), SERPINE1 (rs1799768), PLAU (rs2227564) and PLAUR (rs344781, rs2302524) genes, with the disease severity classified by the percentage of lung involvement on computerized tomography scans. Our findings reveal that the T/C genotype of PLAUR rs2302524 was independently associated with a less severe lung damage (odds ratio 0.258 [0.071–0.811]). Along with high C-reactive protein, fibrinogen and soluble uPAR serum levels turned out to be independently associated with more severe lung damage in COVID-19 patients. The identified factors may be further employed as predictors of a possibly severe COVID-19 clinical course.
Journal Article
Regional pericarditis following uncomplicated catheter ablation procedure: a case report
by
Topchyan, Arpi H
,
Mershina, Elena A
,
Sinitsyn, Valentin E
in
Ablation
,
Ablation (Surgery)
,
Arrhythmia
2022
Abstract
Background
Acute post-ablation pericarditis is the most common complication of epicardial ablation of ventricular arrhythmias, while regional pericarditis following an initially uneventful endocardial catheter ablation (CA) procedure is a rare and elusive diagnosis.
Case summary
We report a case of a 66-year-old Russian female who developed chest pain accompanied by electrocardiogram (ECG) changes—biphasic T waves in V1–V4 leads after an initially uncomplicated premature ventricular complex CA procedure. After examination and investigations, including transthoracic echocardiography (TTE), cardiac magnetic resonance imaging (CMR) and cardiac computed tomography (CCT), she was diagnosed with regional pericarditis, which occurred even though the ablation was uneventful with the limited number of radiofrequency applications. Furthermore, the diagnosis was difficult due to normal body temperature and the absence of pericardial effusion and myocardial abnormalities on TTE, findings that are not characteristic of pericarditis. The patient’s last office visit was in 6 months after the procedure. Neither patient had any complaintsnor there were any changes on ECG and TTE.
Discussion
Regional post-ablation pericarditis is a relatively rare type of post-cardiac injury syndrome (PCIS). The varying severity of the PCIS clinical course makes the diagnosis of post-ablation pericarditis initially difficult, especially in patients undergoing an uneventful CA procedure. Non-invasive imaging modalities as CMR and CCT should be considered initially in elusive cases of PCIS.
Journal Article
A Splice Variant of the MYH7 Gene Is Causative in a Family with Isolated Left Ventricular Noncompaction Cardiomyopathy
by
Kiseleva, Anna V.
,
Yudin, Sergey M.
,
Abisheva, Alexandra A.
in
Alternative splicing
,
Cardiac Myosins - genetics
,
Cardiomyopathies
2022
Variants of the MYH7 gene have been associated with a number of primary cardiac conditions, including left ventricular noncompaction cardiomyopathy (LVNC). Most cases of MYH7-related diseases are associated with such variant types as missense substitutions and in-frame indels. Thus, truncating variants in MYH7 (MYH7tv) and associated mechanism of haploinsufficiency are usually considered not pathogenic in these disorders. However, recent large-scale studies demonstrated evidence of the significance of MYH7tv for LVNC and gave rise to an assumption that haploinsufficiency may be the causal mechanism for LVNC. In this article, we present a family with isolated LVNC and a heterozygous splice variant of the MYH7 gene, analyze possible consequences of this variant and conclude that not all variants that are predicted truncating really act through haploinsufficiency. This study can highlight the importance of a precise assessment of MYH7 splicing variants and their participation in the development of LVNC.
Journal Article
Digenic Contribution of Heterozygous ALPK3 and TRIM63 Variants to End-Stage Hypertrophic Cardiomyopathy in a Young Adult
Hypertrophic cardiomyopathy (HCM), the most common inherited cardiac disorder, is usually caused by pathogenic variants in sarcomeric genes and is inherited in an autosomal dominant manner. Around 5% of cases are caused by variants in non-sarcomeric genes, which may involve alternative modes of inheritance. This study presents the first reported case of HCM associated with digenic contribution of heterozygous variants in two non-sarcomeric genes: ALPK3 and TRIM63. The patient was incidentally diagnosed with non-obstructive HCM in childhood and developed extreme myocardial hypertrophy with moderate heart failure at the age of 18. Rapid progressive left ventricular dysfunction promptly resulted in death at the age of 26. Genetic testing with an extended HCM panel identified no sarcomeric variants but revealed two truncating variants in the ALPK3 and TRIM63 genes. Whole-genome sequencing excluded any other causes of the disease. Heterozygous ALPK3 variants are typically associated with late-onset HCM, whereas TRIM63 variants are only considered pathogenic in a recessive state. This case, therefore, suggests a synergistic contribution of both variants to the development of a severe phenotype. The potential mechanisms of interaction between the protein products of ALPK3 and TRIM63 within the M-band of the sarcomere are discussed.
Journal Article
A Splice Variant of the IMYH7/I Gene Is Causative in a Family with Isolated Left Ventricular Noncompaction Cardiomyopathy
by
Mershina, Elena A
,
Petukhova, Anna V
,
Kulikova, Olga V
in
Cardiomyopathy
,
Computational biology
,
Development and progression
2022
Variants of the MYH7 gene have been associated with a number of primary cardiac conditions, including left ventricular noncompaction cardiomyopathy (LVNC). Most cases of MYH7-related diseases are associated with such variant types as missense substitutions and in-frame indels. Thus, truncating variants in MYH7 (MYH7tv) and associated mechanism of haploinsufficiency are usually considered not pathogenic in these disorders. However, recent large-scale studies demonstrated evidence of the significance of MYH7tv for LVNC and gave rise to an assumption that haploinsufficiency may be the causal mechanism for LVNC. In this article, we present a family with isolated LVNC and a heterozygous splice variant of the MYH7 gene, analyze possible consequences of this variant and conclude that not all variants that are predicted truncating really act through haploinsufficiency. This study can highlight the importance of a precise assessment of MYH7 splicing variants and their participation in the development of LVNC.
Journal Article
Brain Functional Connectivity During First- and Third-Person Visual Imagery
by
Vasilenko, Varvara
,
Blazhenkova, Olesya
,
Mershina, Elena
in
Cognition & reasoning
,
first-person perspective
,
Functional magnetic resonance imaging
2025
The ability to adopt different perspectives, or vantage points, is fundamental to human cognition, affecting reasoning, memory, and imagery. While the first-person perspective allows individuals to experience a scene through their own eyes, the third-person perspective involves an external viewpoint, which is thought to demand greater cognitive effort and different neural processing. Despite the frequent use of perspective switching across various contexts, including modern media and in therapeutic settings, the neural mechanisms differentiating these two perspectives in visual imagery remain largely underexplored. In an exploratory fMRI study, we compared both activation and task-based functional connectivity underlying first-person and third-person perspective taking in the same 26 participants performing two spatial egocentric imagery tasks, namely imaginary tennis and house navigation. No significant differences in activation emerged between the first-person and third-person conditions. The network-based statistics analysis revealed a small subnetwork of the early visual and posterior temporal areas that manifested stronger functional connectivity during the first-person perspective, suggesting a closer sensory recruitment loop, or, in different terms, a loop between long-term memory and the “visual buffer” circuits. The absence of a strong neural distinction between the first-person and third-person perspectives suggests that third-person imagery may not fully decenter individuals from the scene, as is often assumed.
Journal Article
Diagnostic Value of Dynamic Magnetic Resonance Imaging (dMRI) of the Pelvic Floor in Genital Prolapses
2023
Pelvic organ prolapse is a chronic disease resulting from a weakening of the musculoskeletal apparatus of the pelvic organs. For the diagnosis of this pathology, it is insufficient to conduct only a clinical examination. An effective diagnostic tool is the method of dynamic magnetic resonance imaging (MRI) of the pelvic floor, which allows a comprehensive assessment of the anatomical and functional characteristics of the walls of the pelvis and pelvic organs. The aim of the study was to analyze the literature data on the possibilities and limitations of using dynamic MRI in pelvic organ prolapse. The widespread use of the dynamic MRI method is due to the high quality of the resulting image, good reproducibility, and the maximum ability to display the characteristics of the pelvic floor. Dynamic MRI of the small pelvis allows a comprehensive assessment of the anatomical and functional features of the pelvis, excluding the effect of ionizing radiation on the body. The method is characterized by good visualization with high resolution and excellent soft tissue contrast. The method allows for assessing the state of the evacuation function of visualized structures in dynamics. Simultaneous imaging of all three parts of the pelvic floor using dynamic MRI makes it possible to assess multicompartment disorders. The anatomical characteristics of the state of the pelvic organs in the norm and in the event of prolapse are considered. The technique for performing the method and the procedure for analyzing the resulting images are described. The possibilities of diagnosing a multicomponent lesion are considered, while it is noted that dynamic MRI of the pelvic organs provides visualization and functional analysis of all three parts of the pelvis and often allows the choice and correction of tactics for the surgical treatment of pelvic organ prolapse. It is noted that dynamic MRI is characterized by a high resolution of the obtained images, and the advantage of the method is the ability to detect functional changes accompanying the pathology of the pelvic floor.
Journal Article