75 research outputs found

    The mirror illusion induces high gamma oscillations in the absence of movement

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    We tested whether mirror visual feedback (MVF) from a moving hand induced high gamma oscillation (HGO) response in the hemisphere contralateral to the mirror and ipsilateral to the self-paced movement. MEG was recorded in 14 subjects under three conditions: bilateral synchronous movements of both index fingers (BILATERAL), movements of the right hand index finger while observing the immobile left index finger (NOMIRROR), and movements of the right hand index finger while observing its mirror reflection (MIRROR). The right hemispheric spatiospectral regions of interests (ROIs) in the sensor space, sensitive to bilateral movements, were found by statistical comparison of the BILATERAL spectral responses to baseline. For these ROIs, the post-movement HGO responses were compared between the MIRROR and NOMIRROR conditions. We found that MVF from the moving hand, similarly to the real movements of the opposite hand, induced HGO (55–85 Hz) in the sensorimotor cortex. This MVF effect was frequency-specific and did not spread to oscillations in other frequency bands. This is the first study demonstrating movement-related HGO induced by MVF from the moving hand in the absence of proprioceptive feedback signaling. Our findings support the hypothesis that MVF can trigger the feedback-based control processes specifically associated with perception of one's own movements

    Ictal and interictal MEG in pediatric patients with tuberous sclerosis and drug resistant epilepsy

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    Purpose: Drug resistant epilepsy (DRE) is common in patients with tuberous sclerosis (TS). Interictal MEG has been shown as a valuable instrument in the presurgical workup. The goal of our study was to evaluate the role of ictal MEG in epileptogenic tuber selection, especially in patients with multiple irritative zones. Methods: The clinical and MEG data of 23 patients with TS and DRE from two medical/research centers were reviewed. Seven pediatric patients, who had seizures during MEG recording and underwent resection or disconnection surgery, were included into the study. Cortical sources of ictal and interictal epileptiform MEG discharges were compared with epileptogenic zone location in six patients with favorable surgery outcome. Results: In patients who improved substantially after surgery all resected and several other tubers demonstrated epileptiform activity on interictal MEG. Ictal MEG provided crucial information about lobar location of the seizure onset zone (SOZ) in two cases, and in the other four it confirmed the SOZ location derived from the interictal data. In one case, ictal MEG findings were unreliable. In one patient, who did not benefit from surgical treatment, the resected tubers did not overlap with interictal and ictal MEG sources. Conclusion: The combination of interictal and ictal MEG is a valuable tool for identification of the epileptogenic tuber/tubers in presurgical work-up in patients with TS.Peer reviewe

    EEG Correlates of Attentional Load during Multiple Object Tracking

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    While human subjects tracked a subset of ten identical, randomly-moving objects, event-related potentials (ERPs) were evoked at parieto-occipital sites by task-irrelevant flashes that were superimposed on either tracked (Target) or non-tracked (Distractor) objects. With ERPs as markers of attention, we investigated how allocation of attention varied with tracking load, that is, with the number of objects that were tracked. Flashes on Target discs elicited stronger ERPs than did flashes on Distractor discs; ERP amplitude (0–250 ms) decreased monotonically as load increased from two to three to four (of ten) discs. Amplitude decreased more rapidly for Target discs than Distractor discs. As a result, with increasing tracking loads, the difference between ERPs to Targets and Distractors diminished. This change in ERP amplitudes with load accords well with behavioral performance, suggesting that successful tracking depends upon the relationship between the neural signals associated with attended and non-attended objects

    Эндоскопические критерии и перспективные биомаркеры зубчатых аденом ободочной кишки (обзор литературы)

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    Colorectal cancer (CRC) is one of the leading causes of death from cancer in many countries of the world, both in men and women, and these rates are on the rise. The probability of suffering from CRC is about 4–5 % and the risk for developing CRC is associated with personal features or habits such as age, chronic disease history and lifestyle, but in most cases colorectal cancer develops as a result of the degeneration of adenomatous formations or along the jagged path. Immune dysregulation, dysbiosis, and epithelial destruction contribute to colorectal cancer carcinogenesis. The gut microbiota has a relevant role, and dysbiosis situations can induce colonic carcinogenesis through a chronic inflammation mechanism. Some of the bacteria responsible for this multiphase process include Fusobacterium spp., Bacteroides fragilis and enteropathogenic Escherichia coli. moreover, CRC is caused by mutations that target oncogenes, tumour suppressor genes and genes related to DNA repair mechanisms.Considering that the average time for the development of adenocarcinoma from precancer takes about 10 years, changes in the microbiota can be a prospective marker for screening precancerous conditions of the colon, as well as the detection of changes in DNA.The work will discuss the relationship between changes in the microbial composition of the colon with the genetic mutations identified by molecular genetic sequencing.Колоректальный рак (КРР) является одной из ведущих причин смертности от онкологических заболеваний во многих странах мира, как у мужчин, так и у женщин, и эти показатели имеют тенденцию к росту. Вероятность развития КРР составляет около 4–5 %, риск его развития связан с индивидуальными особенностями организма, вредными привычками, возрастом, хроническими заболеваниями и образом жизни, однако в большинстве случаев КРР развивается вследствие перерождения аденоматозных образований или по пути метаплазии из зубчатых аденом, его канцерогенезу содействуют иммунная дисрегуляция, дисбиоз и разрушение эпителия. Микробиота кишечника играет важную роль в канцерогенезе, вероятно, через механизм хронического воспаления. Некоторые из бактерий, ответственных за этот многофазный процесс, включают Fusobacterium spp., Bacteroides fragilis и энтеропатогенные Escherichia coli. кроме того, КРР вызывается мутациями, нацеленными на онкогены, гены – супрессоры опухолей и гены, связанные с механизмами репарации ДНК.С учетом того, что среднее время развития аденокарциномы из предрака занимает около 10 лет, изменение кишечной микрофлоры может являться перспективным маркером для скрининга предраковых состояний толстой кишки, как и обнаружение изменений в ДНК.В работе пойдет речь о взаимосвязи изменений микробного состава толстой кишки с выявленными путем молекулярно-генетического секвенирования генными мутациями

    Наследственный диффузный рак желудка, ассоциированный с неописанным герминальным вариантом с.1596G>A в гене CDH1

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    Gastric cancer is one of the most common malignancies worldwide. Approximately 10 % of patients with gastric cancer are characterized by accumulation of gastric cancer cases in their family. The hereditary forms of gastric cancer account for 1–3 % of all gastric cancer cases. Hereditary diffuse GC syndrome is caused by germline mutations in CDH1 gene and determines a high risk of developing diffuse GC and lobular breast cancer. In this article, we present a clinical case of a 41-year-old patient with diffuse gastric cancer, who was found to be a carrier of novel germline mutation in the CDH1 gene. Next-generation sequencing (NGS) has facilitated an identification of CDH1 c.1596G>A genetic variant, thus enabling an accurate clinical diagnosis hereditary diffuse gastric cancer.Рак желудка является одним из наиболее распространенных злокачественных новообразований во всем мире. Около 10 % пациентов с данной патологией сообщают об отягощенном семейном анамнезе; наследственную форму заболевания выявляют в 1–3 % случаев. Синдром наследственного диффузного рака желудка возникает в результате герминальных мутаций в гене CDH1 и характеризуется высоким риском развития диффузного рака желудка у обоих полов и долькового рака молочной железы у женщин. В статье приведен клинический случай диагностики и лечения пациента, 41 года, с диффузным раком желудка, у которого методом массового параллельного секвенирования (next generation sequencing, NGS) выявлена неописанная герминальная мутация с.1596G>A в гене CDH1, что позволило установить точный диагноз

    Stronger Neural Modulation by Visual Motion Intensity in Autism Spectrum Disorders

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    Theories of autism spectrum disorders (ASD) have focused on altered perceptual integration of sensory features as a possible core deficit. Yet, there is little understanding of the neuronal processing of elementary sensory features in ASD. For typically developed individuals, we previously established a direct link between frequency-specific neural activity and the intensity of a specific sensory feature: Gamma-band activity in the visual cortex increased approximately linearly with the strength of visual motion. Using magnetoencephalography (MEG), we investigated whether in individuals with ASD neural activity reflect the coherence, and thus intensity, of visual motion in a similar fashion. Thirteen adult participants with ASD and 14 control participants performed a motion direction discrimination task with increasing levels of motion coherence. A polynomial regression analysis revealed that gamma-band power increased significantly stronger with motion coherence in ASD compared to controls, suggesting excessive visual activation with increasing stimulus intensity originating from motion-responsive visual areas V3, V6 and hMT/V5. Enhanced neural responses with increasing stimulus intensity suggest an enhanced response gain in ASD. Response gain is controlled by excitatory-inhibitory interactions, which also drive high-frequency oscillations in the gamma-band. Thus, our data suggest that a disturbed excitatoryinhibitory balance underlies enhanced neural responses to coherent motion in ASD

    Thermal Perceptual Thresholds are typical in Autism Spectrum Disorder but Strongly Related to Intra-individual Response Variability

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    Individuals with autism spectrum disorder (ASD) are often reported to exhibit an apparent indifference to pain or temperature. Leading models suggest that this behavior is the result of elevated perceptual thresholds for thermal stimuli, but data to support these assertions are inconclusive. An alternative proposal suggests that the sensory features of ASD arise from increased intra-individual perceptual variability. In this study, we measured method-of-limits warm and cool detection thresholds in 142 individuals (83 with ASD, 59 with typical development [TD], aged 7–54 years), testing relationships with diagnostic group, demographics, and clinical measures. We also investigated the relationship between detection thresholds and a novel measure of intra-individual (trial-to-trial) threshold variability, a putative index of “perceptual noise.” This investigation found no differences in thermal detection thresholds between individuals with ASD and typical controls, despite large differences between groups in sensory reactivity questionnaires and modest group differences in intra-individual variability. Lower performance IQ, male sex, and higher intra-individual variability in threshold estimates were the most significant predictors of elevated detection thresholds. Although no psychophysical measure was significantly correlated with questionnaire measures of sensory hyporeactivity, large intra-individual variability may partially explain the elevated psychophysical thresholds seen in a subset of the ASD population

    Resting state EEG abnormalities in autism spectrum disorders

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    The influence of the pathogenesis of maxillary sinusitis on the distribution of glucoconjugates in the Schneider membrane

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    We assume that the nature of the pathological changes in the mucous membrane of the maxillary sinus should also depend on the nature of the stomatology procedures that were carried out before the development of maxillary sinusitis. The literature suggests that changes in the composition of glycoconjugates correlate with the transformation of chronic maxillary sinusitis, with hyperplasia of the sinus mucosa and hypersecretion. Thus, changes in the microenvironment and in local inflammatory reactions in sinusitis can affect the carbon fragments of the cell surface. The aim: to study the pathogenetic bases of differentiation of maxillary sinusitis, which develop on the background of dental manipulations. Sampling of biomaterial, a portion of the mucous membrane of the maxillary sinus was performed with 129 (100.0 %) patients, which were distributed according to etio-pathogenetic groups of stomatological maxillary sinusitis. Into the group of odontogenic form of stomatogenic maxillary sinusitis (OMS) there were 14 (10.9 %) patients who had inflammation in the sinus developed from previously untreated teeth. Into the group of infectious-allergic form of iatrogenic maxillary sinusitis (IAFIMS) there were 22 (19.1 %) patients who had established a periapical infection of previously treated teeth in the sinus in the etiology of the disease; The group of the mixed form of iatrogenic maxillary sinusitis (MixFINS) included 24 (20.9 %) patients with a filling material or a fragment of the tooth root in the lumen of the sinus. 12 (10.4 %) patients (who iatrogenic maxillary sinusitis of stomatologic origin which of chronic used medication hormones, antibiotics, drugs) were included in the medical form group (MFIMS). In the group of traumatic form of iatrogenic maxillary sinusitis (TFIMS) there were 57 (49.6%) patients with sinusitis which developed against surgical manipulations in the area of the alveolar process or the body of the upper jaw

    Magneto encephalography (MEG): perspectives of speech areas functional mapping in human subjects

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    One of the main problems in clinical practice and academic research is how to localize speech zones in the human brain. Two speech areas (Broca and Wernicke areas) that are responsible for language production and for understanding of written and spoken language have been known since the past century. Their location and even hemispheric lateralization have a substantial inter-individual variability, especially in neurosurgery patients. Wada test is one of the most frequently used invasive methodology for speech hemispheric lateralization in neurosurgery patients. However, besides relatively high-risk of Wada test for patient's health, it has its own limitation, e. g. low reliability of Wada-based evidence of verbal memory brain lateralization. Therefore, there is an urgent need for non-invasive, reliable methods of speech zones mapping.The current review summarizes the recent experimental evidence from magnitoencephalographic (MEG) research suggesting that speech areas are included in the speech processing within the first 200 ms after the word onset. The electro-magnetic response to deviant word, mismatch negativity wave with latency of 100—200 ms, can be recorded from auditory cortex within the oddball-paradigm. We provide the arguments that basic features of this brain response, such as its automatic, pre-attentive nature, high signal to noise ratio, source localization at superior temporal sulcus, make it a promising vehicle for non-invasive MEG-based speech areas mapping in neurosurgery
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