Current concepts in nuclear pore electrophysiology.

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Bustamante, José Omar

2006-01-01

Over 4 decades ago, microelectrode studies of in situ nuclei showed that, under certain conditions, the nuclear envelope (NE) behaves as a barrier opposing the nucleocytoplasmic flow of physiological ions. As the nuclear pore complexes (NPCs) of the NE are the only pathways for direct nucleocytoplasmic flow, those experiments implied that the NPCs are capable of restricting ion flow. These early studies validated electrophysiology as a useful approach to quantify some of the mechanisms by which NPCs mediate gene activity and expression. Since electron microscopy (EM) and other non-electrophysiological investigations, showed that the NPC lumen is a nanochannel, the opinion prevailed that the NPC could not oppose the flow of ions and, therefore, that electrophysiological observations resulted from technical artifacts. Consequently, the initial enthusiasm with nuclear electrophysiology faded out in less than a decade. In 1990, nuclear electrophysiology was revisited with patch-clamp, the most powerful electrophysiological technique to date. Patch-clamp has consistently demonstrated that the NE has intrinsic ion channel activity. Direct demonstrations of the NPC on-off ion channel gating behavior were published for artificial conditions in 1995 and for intact living nuclei in 2002. This on-off switching/gating behavior can be interpreted in terms of a metastable energy barrier. In the hope of advancing nuclear electrophysiology, and to complement the other papers contained in this special issue of the journal, here I review some of the main technical, experimental, and theoretical issues of the field, with special focus on NPCs.

A relationship between bruxism and orofacial-dystonia? A trigeminal electrophysiological approach in a case report of pineal cavernoma.

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Frisardi, Gianni; Iani, Cesare; Sau, Gianfranco; Frisardi, Flavio; Leornadis, Carlo; Lumbau, Aurea; Enrico, Paolo; Sirca, Donatella; Staderini, Enrico Maria; Chessa, Giacomo

2013-10-28

In some clinical cases, bruxism may be correlated to central nervous system hyperexcitability, suggesting that bruxism may represent a subclinical form of dystonia. To examine this hypothesis, we performed an electrophysiological evaluation of the excitability of the trigeminal nervous system in a patient affected by pineal cavernoma with pain symptoms in the orofacial region and pronounced bruxism. Electrophysiological studies included bilateral electrical transcranial stimulation of the trigeminal roots, analysis of the jaw jerk reflex, recovery cycle of masseter inhibitory reflex, and a magnetic resonance imaging study of the brain. The neuromuscular responses of the left- and right-side bilateral trigeminal motor potentials showed a high degree of symmetry in latency (1.92 ms and 1.96 ms, respectively) and amplitude (11 mV and 11.4 mV, respectively), whereas the jaw jerk reflex amplitude of the right and left masseters was 5.1 mV and 8.9 mV, respectively. The test stimulus for the recovery cycle of masseter inhibitory reflex evoked both silent periods at an interstimulus interval of 150 ms. The duration of the second silent period evoked by the test stimulus was 61 ms and 54 ms on the right and left masseters, respectively, which was greater than that evoked by the conditioning stimulus (39 ms and 35 ms, respectively). We found evidence of activation and peripheral sensitization of the nociceptive fibers, the primary and secondary nociceptive neurons in the central nervous system, and the endogenous pain control systems (including both the inhibitory and facilitatory processes), in the tested subject. These data suggest that bruxism and central orofacial pain can coexist, but are two independent symptoms, which may explain why numerous experimental and clinical studies fail to reach unequivocal conclusions.

Logo Effects on Brand Extension Evaluations from the Electrophysiological Perspective.

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Shang, Qian; Pei, Guanxiong; Dai, Shenyi; Wang, Xiaoyi

2017-01-01

Brand extension typically has two strategies: brand name extension (BN) and brand logo extension (BL). The current study explored which strategy (BN or BL) better enhanced the success of dissimilar brand extension and product promotion in enterprises. Event-related potentials (ERPs) were used to investigate electrophysiological processes when subjects evaluated their acceptance of the brand extension using a combined picture of S1 and S2. S1 was a famous brand presented by two identity signs (brand name and brand logo). S2 was a picture of an extension product that belonged to a dissimilar product category than S1. The behavior data showed that BL was more acceptable than BN in the dissimilar brand extension. The neurophysiology process was reflected by a less negative N2 component and a larger P300 component in the BL than in the BN. We suggested that N2 reflected a whole conflict between the brand-product combination and the long-term memory and that P300 could be regarded as the reflection of the categorization process in the working memory.

A novel radiation protection drape reduces radiation exposure during fluoroscopy guided electrophysiology procedures.

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Germano, Joseph J; Day, Gina; Gregorious, David; Natarajan, Venkataraman; Cohen, Todd

2005-09-01

The purpose of this study was to evaluate a novel disposable lead-free radiation protection drape for decreasing radiation scatter during electrophysiology procedures. In recent years, there has been an exponential increase in the number of electrophysiology (EP) procedures exposing patients, operators and laboratory staff to higher radiation doses. The RADPAD was positioned slightly lateral to the incision site for pectoral device implants and superior to the femoral vein during electrophysiology studies. Each patient served as their own control and dosimetric measurements were obtained at the examiner's elbow and hand. Radiation badge readings for the operator were obtained three months prior to RADPAD use and three months after introduction. Radiation dosimetry was obtained in twenty patients: 7 electrophysiology studies, 6 pacemakers, 5 catheter ablations, and 2 implantable cardioverter-defibrillators. Eleven women and nine men with a mean age of 63 +/- 4 years had an average fluoroscopy time of 2.5 +/- 0.42 minutes per case. Mean dosimetric measurements at the hand were reduced from 141.38 +/- 24.67 to 48.63 +/- 9.02 milliroentgen (mR) per hour using the protective drape (63% reduction; p < 0.0001). Measurements at the elbow were reduced from 78.78 +/- 7.95 mR per hour to 34.50 +/- 4.18 mR per hour using the drape (55% reduction; p < 0.0001). Badge readings for three months prior to drape introduction averaged 2.45 mR per procedure versus 1.54 mR per procedure for 3 months post-initiation (37% reduction). The use of a novel radiation protection surgical drape can significantly reduce scatter radiation exposure to staff and operators during a variety of EP procedures.

The reliability of commonly used electrophysiology measures.

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Brown, K E; Lohse, K R; Mayer, I M S; Strigaro, G; Desikan, M; Casula, E P; Meunier, S; Popa, T; Lamy, J-C; Odish, O; Leavitt, B R; Durr, A; Roos, R A C; Tabrizi, S J; Rothwell, J C; Boyd, L A; Orth, M

Electrophysiological measures can help understand brain function both in healthy individuals and in the context of a disease. Given the amount of information that can be extracted from these measures and their frequent use, it is essential to know more about their inherent reliability. To understand the reliability of electrophysiology measures in healthy individuals. We hypothesized that measures of threshold and latency would be the most reliable and least susceptible to methodological differences between study sites. Somatosensory evoked potentials from 112 control participants; long-latency reflexes, transcranial magnetic stimulation with resting and active motor thresholds, motor evoked potential latencies, input/output curves, and short-latency sensory afferent inhibition and facilitation from 84 controls were collected at 3 visits over 24 months at 4 Track-On HD study sites. Reliability was assessed using intra-class correlation coefficients for absolute agreement, and the effects of reliability on statistical power are demonstrated for different sample sizes and study designs. Measures quantifying latencies, thresholds, and evoked responses at high stimulator intensities had the highest reliability, and required the smallest sample sizes to adequately power a study. Very few between-site differences were detected. Reliability and susceptibility to between-site differences should be evaluated for electrophysiological measures before including them in study designs. Levels of reliability vary substantially across electrophysiological measures, though there are few between-site differences. To address this, reliability should be used in conjunction with theoretical calculations to inform sample size and ensure studies are adequately powered to detect true change in measures of interest. Copyright © 2017 Elsevier Inc. All rights reserved.

Electrophysiological signal analysis and visualization using Cloudwave for epilepsy clinical research.

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Jayapandian, Catherine P; Chen, Chien-Hung; Bozorgi, Alireza; Lhatoo, Samden D; Zhang, Guo-Qiang; Sahoo, Satya S

2013-01-01

Epilepsy is the most common serious neurological disorder affecting 50-60 million persons worldwide. Electrophysiological data recordings, such as electroencephalogram (EEG), are the gold standard for diagnosis and pre-surgical evaluation in epilepsy patients. The increasing trend towards multi-center clinical studies require signal visualization and analysis tools to support real time interaction with signal data in a collaborative environment, which cannot be supported by traditional desktop-based standalone applications. As part of the Prevention and Risk Identification of SUDEP Mortality (PRISM) project, we have developed a Web-based electrophysiology data visualization and analysis platform called Cloudwave using highly scalable open source cloud computing infrastructure. Cloudwave is integrated with the PRISM patient cohort identification tool called MEDCIS (Multi-modality Epilepsy Data Capture and Integration System). The Epilepsy and Seizure Ontology (EpSO) underpins both Cloudwave and MEDCIS to support query composition and result retrieval. Cloudwave is being used by clinicians and research staff at the University Hospital - Case Medical Center (UH-CMC) Epilepsy Monitoring Unit (EMU) and will be progressively deployed at four EMUs in the United States and the United Kingdomas part of the PRISM project.

Comparison of electrophysiological findings in axonal and demyelinating Guillain-Barre syndrome

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Yadegari, Samira; Nafissi, Shahriar; Kazemi, Neda

2014-01-01

Background: Incidence and predominant subtype of Guillain-Barre syndrome (GBS) differs geographically. Electrophysiology has an important role in early diagnosis and prediction of prognosis. This study is conducted to determine the frequent subtype of GBS in a large group of patients in Iran and compare nerve conduction studies in axonal and demyelinating forms of GBS. Methods: We retrospectively evaluated the medical records and electrodiagnostic study (EDS) of 121 GBS patients who were managed in our hospital during 11 years. After regarding the exclusion criteria, patients classified as three groups: acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and acute motor sensory axonal neuropathy (AMSAN). The most frequent subtype and then electrophysiological characteristic based on the time of EDS and their cerebrospinal fluid (CSF) profile were assessed. Results: Among 70 patients finally included in the study, 67% were men. About 63%, 23%, and 14% had AIDP, AMAN, and AMSAN, respectively. AIDP patients represented a wider range of ages compared with other groups. Higher levels of CSF protein, abnormal late responses and sural sparing were more frequent in AIDP subtype. Five AMSAN patients also revealed sural sparing. Conduction block (CB) was observed in one AMAN patient. Prolonged F-wave latency was observed only in AIDP cases. CB and inexcitable sensory nerves were more frequent after 2 weeks, but reduced F-wave persistency was more prominent in the early phase. Conclusion: AIDP was the most frequent subtype. Although the electrophysiology and CSF are important diagnostic tools, classification should not be made based on a distinct finding. PMID:25422732

Clinical and Electrophysiological Report of a Unilateral Retinitis Pigmentosa Case

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Sedaghat MR

2014-04-01

Full Text Available Introduction: To describe clinical and electrophysiological features of a patient with unilateral Retinitis Pigmentosa (RP. Case: A 29-year-old female with a long history of progressive visual disturbance in the right eye has undergone multiple eye examinations during the past eight years. There was nothing noticeable in her past medical and ocular history. Comprehensive eye examinations were done in the first visit. All data was suggestive of right eye RP. Posterior segment fundal examination findings were: a pallor waxy disc, vessel attenuation, and extended pigmentary degeneration of the mid-peripheral retina. The left eye examination was normal. Comparing the automated 60 degree and 30 degree visual fields of both eyes obviously showed significant defects in the right eye visual field but normal in the left eye.  All of the probable infectious agents, which can cause similar ocular manifestations, were ruled out by serological tests. The standard photopic and scotopic electroretinographies were significantly reduced in amplitude in the right eye; however, they were normal in the left eye. Also, the standard Electro-Oculography (EOG results were the same as the Electro-Retinography (ERG ones in both eyes. Eye examinations were normal in other family members. Over an eight-year follow-up period, progressive deteriorating vision has gradually become more noticeable in the right eye. The left eye has been completely normal since.  This data was compatible with the Francois and Verriesr unilateral RP diagnostic criteria. Conclusion: Clinical signs and symptoms, a minimum of a five-year follow-up period, and confirmatory ERG and EOG are very helpful to diagnose andaffirm the case of unilateral RP.

Evidence-based medicine evaluation of electrophysiological studies of the anxiety disorders.

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Clark, C Richard; Galletly, Cherrie A; Ash, David J; Moores, Kathryn A; Penrose, Rebecca A; McFarlane, Alexander C

2009-04-01

We provide a systematic, evidence-based medicine (EBM) review of the field of electrophysiology in the anxiety disorders. Presently, electrophysiological studies of anxiety focus primarily on etiological aspects of brain dysfunction. The review highlights many functional similarities across studies, but also identifies patterns that clearly differentiate disorder classifications. Such measures offer clinical utility as reliable and objective indicators of brain dysfunction in individuals and indicate potential as biomarkers for the improvement of diagnostic specificity and for informing treatment decisions and prognostic assessments. Common to most of the anxiety disorders is basal instability in cortical arousal, as reflected in measures of quantitative electroencephalography (qEEG). Resting electroencephalographic (EEG) measures tend to correlate with symptom sub-patterns and be exacerbated by condition-specific stimulation. Also common to most of the anxiety disorders are condition-specific difficulties with sensory gating and the allocation and deployment of attention. These are clearly evident from evoked potential (EP) and event-related potential (ERP) electrical measures of information processing in obsessive compulsive disorder (OCD), post-traumatic stress disorder (PTSD), panic disorder (PD), generalized anxiety disorder (GAD) and the phobias. Other'ERP measures clearly differentiate the disorders. However, there is considerable variation across studies, with inclusion and exclusion criteria, medication status and control group selection not standardized within condition or across studies. Study numbers generally preclude analysis for confound removal or for the derivation of diagnostic biomarker patterns at this time. The current trend towards development of databases of brain and cognitive function is likely to obviate these difficulties. In particular, electrophysiological measures of function are likely to play a significant role in the development and

Electrophysiological gap detection thresholds: effects of age and comparison with a behavioral measure.

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Palmer, Shannon B; Musiek, Frank E

2014-01-01

Temporal processing ability has been linked to speech understanding ability and older adults often complain of difficulty understanding speech in difficult listening situations. Temporal processing can be evaluated using gap detection procedures. There is some research showing that gap detection can be evaluated using an electrophysiological procedure. However, there is currently no research establishing gap detection threshold using the N1-P2 response. The purposes of the current study were to 1) determine gap detection thresholds in younger and older normal-hearing adults using an electrophysiological measure, 2) compare the electrophysiological gap detection threshold and behavioral gap detection threshold within each group, and 3) investigate the effect of age on each gap detection measure. This study utilized an older adult group and younger adult group to compare performance on an electrophysiological and behavioral gap detection procedure. The subjects in this study were 11 younger, normal-hearing adults (mean = 22 yrs) and 11 older, normal-hearing adults (mean = 64.36 yrs). All subjects completed an adaptive behavioral gap detection procedure in order to determine their behavioral gap detection threshold (BGDT). Subjects also completed an electrophysiologic gap detection procedure to determine their electrophysiologic gap detection threshold (EGDT). Older adults demonstrated significantly larger gap detection thresholds than the younger adults. However, EGDT and BGDT were not significantly different in either group. The mean difference between EGDT and BGDT for all subjects was 0.43 msec. Older adults show poorer gap detection ability when compared to younger adults. However, this study shows that gap detection thresholds can be measured using evoked potential recordings and yield results similar to a behavioral measure. American Academy of Audiology.

Normal Values for Heart Electrophysiology Parameters of Healthy Swine Determined on Electrophysiology Study.

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Noszczyk-Nowak, Agnieszka; Cepiel, Alicja; Janiszewski, Adrian; Pasławski, Robert; Gajek, Jacek; Pasławska, Urszula; Nicpoń, Józef

2016-01-01

Swine are a well-recognized animal model for human cardiovascular diseases. Despite the widespread use of porcine model in experimental electrophysiology, still no reference values for intracardiac electrical activity and conduction parameters determined during an invasive electrophysiology study (EPS) have been developed in this species thus far. The aim of the study was to develop a set of normal values for intracardiac electrical activity and conduction parameters determined during an invasive EPS of swine. The study included 36 healthy domestic swine (24-40 kg body weight). EPS was performed under a general anesthesia with midazolam, propofol and isoflurane. The reference values for intracardiac electrical activity and conduction parameters were calculated as arithmetic means ± 2 standard deviations. The reference values were determined for AH, HV and PA intervals, interatrial conduction time at its own and imposed rhythm, sinus node recovery time (SNRT), corrected sinus node recovery time (CSNRT), anterograde and retrograde Wenckebach points, atrial, atrioventricular node and ventricular refractory periods. No significant correlations were found between body weight and heart rate of the examined pigs and their electrophysiological parameters. The hereby presented reference values can be helpful in comparing the results of various studies, as well as in more accurately estimating the values of electrophysiological parameters that can be expected in a given experiment.

Role of Electrophysiological Study and Catheter Ablation for Recurrent Ventricular Tachycardia Complicating Myocarditis

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Emanuele Cecchi

2012-01-01

Full Text Available Here we report the case of a 31-year-old man admitted to our hospital with echocardiografic and Cardiac Magnetic Resonance signs of myocarditis complicated by ventricular tachycardia, initially resolved with direct current shock. After the recurrence of ventricular tachycardia the patient was submitted to electrophysiological study revealing a re-entrant circuit at the level of the medium segment of interventricular septum, successfully treated with transcatheter ablation. This case highlights how the presence of recurrent ventricular arrhythmias at the onset of acute myocarditis, suspected or proven, could be associated with a pre-existing arrhythmogenic substrate, therefore these patients should be submitted to electrophysiological study in order to rule out the presence of arrhythmogenic focuses that can be treated with transcatheter ablation.

Breakdown evaluation of corneal epithelial barrier caused by antiallergic eyedrops using an electrophysiologic method.

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Nakashima, Mikiro; Nakamura, Tadahiro; Teshima, Mugen; To, Hideto; Uematsu, Masafumi; Kitaoka, Takashi; Taniyama, Kotaro; Nishida, Koyo; Nakamura, Junzo; Sasaki, Hitoshi

2008-02-01

The aim of this study was to examine the usefulness of an electrophysiologic method for predicting corneal epithelial breakdown by antiallergic eyedrops and comparing the results with those in other appraisal methods. Six kinds of antiallergic eyedrops, including benzalkonium chloride (BK) as an ophthalmic preservative and two kinds of BK-free antiallergic eyedrops, were used in this study. Eyedrops were applied to excise rabbit corneas and monitoring was performed according to an electrophysiologic method, using a commercially available chamber system to mimic human tear turnover. Changes in transepithelial electrical resistance (TEER) in the corneal surface were recorded. The cytotoxicity of each kind of eyedrops in a normal rabbit corneal epithelial (NRCE) cell line and a human endothelial cell line EA.hy926 was also examined. The extent of decrease in the corneal TEER after applying antiallergic eyedrops was dependent on the concentration of the BK included as a preservative, but it was also affected by the different kinds of drugs when the BK concentration was low. Higher cytotoxicity of the eyedrops against the NRCE and EA.hy926 cell lines was observed with a reduction of TEER. Monitoring changes in the corneal TEER, according to the electrophysiologic method with the application of antiallergic eyedrops, is useful for predicting corneal epithelial breakdown caused by their instillation.

Intraoperative high-field magnetic resonance imaging, multimodal neuronavigation, and intraoperative electrophysiological monitoring-guided surgery for treating supratentorial cavernomas.

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Li, Fang-Ye; Chen, Xiao-Lei; Xu, Bai-Nan

2016-09-01

To determine the beneficial effects of intraoperative high-field magnetic resonance imaging (MRI), multimodal neuronavigation, and intraoperative electrophysiological monitoring-guided surgery for treating supratentorial cavernomas. Twelve patients with 13 supratentorial cavernomas were prospectively enrolled and operated while using a 1.5 T intraoperative MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring. All cavernomas were deeply located in subcortical areas or involved critical areas. Intraoperative high-field MRIs were obtained for the intraoperative "visualization" of surrounding eloquent structures, "brain shift" corrections, and navigational plan updates. All cavernomas were successfully resected with guidance from intraoperative MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring. In 5 cases with supratentorial cavernomas, intraoperative "brain shift" severely deterred locating of the lesions; however, intraoperative MRI facilitated precise locating of these lesions. During long-term (>3 months) follow-up, some or all presenting signs and symptoms improved or resolved in 4 cases, but were unchanged in 7 patients. Intraoperative high-field MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring are helpful in surgeries for the treatment of small deeply seated subcortical cavernomas.

The Consistency Between Clinical and Electrophysiological Diagnoses

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Esra E. Okuyucu

2009-09-01

Full Text Available OBJECTIVE: The aim of this study was to provide information concerning the impact of electrophysiological tests in the clinical management and diagnosis of patients, and to evaluate the consistency between referring clinical diagnoses and electrophysiological diagnoses. METHODS: The study included 957 patients referred to the electroneuromyography (ENMG laboratory from different clinics with different clinical diagnoses in 2008. Demographic data, referring clinical diagnoses, the clinics where the requests wanted, and diagnoses after ENMG testing were recorded and statistically evaluated. RESULTS: In all, 957 patients [644 (67.3% female and 313 (32.7% male] were included in the study. Mean age of the patients was 45.40 ± 14.54 years. ENMG requests were made by different specialists; 578 (60.4% patients were referred by neurologists, 122 (12.8% by orthopedics, 140 (14.6% by neurosurgeons, and 117 (12.2% by physical treatment and rehabilitation departments. According to the results of ENMG testing, 513 (53.6% patients’ referrals were related to their referral diagnosis, whereas 397 (41.5% patients had normal ENMG test results, and 47 (4.9% patients had a diagnosis that differed from the referring diagnosis. Among the relation between the referral diagnosis and electrophysiological diagnosis according to the clinics where the requests were made, there was no statistical difference (p= 0.794, but there were statistically significant differences between the support of different clinical diagnoses, such as carpal tunnel syndrome, polyneuropathy, radiculopathy-plexopathy, entrapment neuropathy, and myopathy based on ENMG test results (p< 0.001. CONCLUSION: ENMG is a frequently used neurological examination. As such, referrals for ENMG can be made to either support the referring diagnosis or to exclude other diagnoses. This may explain the inconsistency between clinical referring diagnoses and diagnoses following ENMG

Clinical, Electrophysiological, and Serological Evaluation of Patients with Cramp-Fasciculation Syndrome.

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Poyraz, Mürüvvet; Matur, Zeliha; Aysal, Fikret; Tüzün, Erdem; Hanoğlu, Lütfü; Öge, A Emre

2017-06-01

Cramp-fasciculation syndrome (CFS) is a rare peripheral nerve hyperexcitability syndrome. There are only a few reports on clinical and serological profile of a CFS cohort that was followed up by a single outpatient clinic. Clinical, electrophysiological, and serological features of 6 CFS patients (5 men, 1 woman; 27-65 years old) were investigated. All patients presented with cramps, fasciculations, muscle pain, and autonomic symptoms, and 2 also reported numbness and burning sensation in limbs, suggestive of neuropathic pain. Antibodies to uncharacterized voltage-gated potassium channel (VGKC)-complex proteins were found in 2 patients and to contactin-associated protein-like 2 (CASPR2) in 1 patient. None of the patients had a tumor. Most of the patients revealed prolonged after-discharges following tibial nerve stimulation. Nerve conduction studies and R-R interval variability tests were normal, whereas sympathetic skin responses were increased in amplitude in 3 seronegative patients. Five patients showed favorable response to carbamazepine or pregabalin treatment, whereas 1 VGKC-antibody-positive patient was resistant to carbamazepine and immunosuppressant treatment. Neuropathic pain and VGKC-complex antibodies may be encountered in CFS patients. Although autonomic symptoms are commonly found in CFS, routine autonomic system tests which are done in electrophysiology laboratories might yield normal results.

Serum cytokine contents in schizophrenia patient with metabolic syndrome and their correlation with nerve electrophysiology

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Li-Yong Chen

2016-07-01

Full Text Available Objective: To analyze serum cytokine contents in schizophrenia patient with metabolic syndrome (MS and their correlation with nerve electrophysiology. Methods: A total of 90 chizophrenia patient with MS, including 41 cases with simple schizophrenia and 39 cases with simple metabolic syndrome were included for study. The values of nerve electrophysiology indexes and serum illness-related indexes were compared among included patients, and the correlation between the two was further analyzed. Results: Compared with simple schizophrenia group and simple MS group, P300 latency of schizophrenia with MS group was longer, and the amplitude was shorter; N2-P3 latency and amplitude were shorter (P<0.05; serum SOD, S100b, BDNF, ABAb, PAI-1, 毩-HBDH, AST, cystatin c, TG, FBG and 2hPG values of schizophrenia with MS group were higher, IGF1, HMW-APN and HDL-C levels were lower, and compared with simple schizophrenia group and simple MS group, differences were significant (P<0.05; P300 latency, P300 amplitude, N2-P3 latency and N2- P3 amplitude of schizophrenia with MS group were directly correlated with serum cytokine contents (P<0.05. Conclusions: There are significantly abnormal serum cytokines and nerve electrophysiology indexes in schizophrenia patient with MS, and nerve electrophysiology detection can be used as the means to judge disease and guide treatment.

Ion Channel ElectroPhysiology Ontology (ICEPO) - a case study of text mining assisted ontology development.

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Elayavilli, Ravikumar Komandur; Liu, Hongfang

2016-01-01

Computational modeling of biological cascades is of great interest to quantitative biologists. Biomedical text has been a rich source for quantitative information. Gathering quantitative parameters and values from biomedical text is one significant challenge in the early steps of computational modeling as it involves huge manual effort. While automatically extracting such quantitative information from bio-medical text may offer some relief, lack of ontological representation for a subdomain serves as impedance in normalizing textual extractions to a standard representation. This may render textual extractions less meaningful to the domain experts. In this work, we propose a rule-based approach to automatically extract relations involving quantitative data from biomedical text describing ion channel electrophysiology. We further translated the quantitative assertions extracted through text mining to a formal representation that may help in constructing ontology for ion channel events using a rule based approach. We have developed Ion Channel ElectroPhysiology Ontology (ICEPO) by integrating the information represented in closely related ontologies such as, Cell Physiology Ontology (CPO), and Cardiac Electro Physiology Ontology (CPEO) and the knowledge provided by domain experts. The rule-based system achieved an overall F-measure of 68.93% in extracting the quantitative data assertions system on an independently annotated blind data set. We further made an initial attempt in formalizing the quantitative data assertions extracted from the biomedical text into a formal representation that offers potential to facilitate the integration of text mining into ontological workflow, a novel aspect of this study. This work is a case study where we created a platform that provides formal interaction between ontology development and text mining. We have achieved partial success in extracting quantitative assertions from the biomedical text and formalizing them in ontological

A case of typical atrioventricular nodal (AVN) reentrant tachycardia confined to the compact AV node, showing a variety of rare electrophysiological findings, including eccentric AVN echoes

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Tanaka, Kazushi; Shiotani, Shinji; Fukuda, Keisuke; Fujihara, Masahiko; Higashimori, Akihiro; Morioka, Nobuyuki; Yokoi, Yoshiaki; Fujimura, Osamu

2014-01-01

Herein, we report the case of a 49-year-old woman with typical atrioventricular nodal (AVN) reentrant tachycardia, confined to the compact atrioventricular node, showing numerous rare electrophysiological findings such as unique AVN reentrant echoes, double ventricular responses, latent retrograde dual AVN pathways, antegrade triple AVN pathways, and longitudinal dissociation within the lower final common pathway.

A case of typical atrioventricular nodal (AVN reentrant tachycardia confined to the compact AV node, showing a variety of rare electrophysiological findings, including eccentric AVN echoes

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Kazushi Tanaka, M.D., Ph.D.

2014-12-01

Full Text Available Herein, we report the case of a 49-year-old woman with typical atrioventricular nodal (AVN reentrant tachycardia, confined to the compact atrioventricular node, showing numerous rare electrophysiological findings such as unique AVN reentrant echoes, double ventricular responses, latent retrograde dual AVN pathways, antegrade triple AVN pathways, and longitudinal dissociation within the lower final common pathway.

Electrophysiologic and cellular characteristics of cardiomyocytes after X-ray irradiation

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Frieß, Johannes L., E-mail: johannes.friess@h-ab.de [University for Applied Sciences Aschaffenburg, biomems lab, Würzburger Straße 45, 63743 Aschaffenburg (Germany); Heselich, Anja [Technische Universität Darmstadt, Developmental Biology and Neurogenetics, Schnittspahnstraße 13, 64287 Darmstadt (Germany); Ritter, Sylvia [Helmholtz Institute for Heavy Ion Research (GSI), Biophysics Department, Planckstraße 1, 64291 Darmstadt (Germany); Haber, Angelina; Kaiser, Nicole; Layer, Paul G. [Technische Universität Darmstadt, Developmental Biology and Neurogenetics, Schnittspahnstraße 13, 64287 Darmstadt (Germany); Thielemann, Christiane [University for Applied Sciences Aschaffenburg, biomems lab, Würzburger Straße 45, 63743 Aschaffenburg (Germany)

2015-07-15

Highlights: • Electrophysiologic and cellular effects of X-rays on primary cardiac cell cultures. • X-ray doses between 0.5 and 7 Gy. • Higher beat rate at reduced field action potential durations 7 days after exposure. • More increased cell cycle checkpoint arrest in G2/M than in G1/S phase. • Induced DSBs were mostly repaired within 24 h after irradiation. - Abstract: The aim of this study was to investigate possible effects of ionizing irradiation on the electrophysiological functionality of cardiac myocytes in vitro. Primary chicken cardiomyocytes with spontaneous beating activity were irradiated with X-rays (dose range of 0.5–7 Gy). Functional alterations of cardiac cell cultures were evaluated up to 7 days after irradiation using microelectrode arrays. As examined endpoints, cell proliferation, apoptosis, reactive oxygen species (ROS) and DNA damage were evaluated. The beat rate of the cardiac networks increased in a dose-dependent manner over one week. The duration of single action potentials was slightly shortened. Additionally, we observed lower numbers of mitotic and S-phase cells at certain time points after irradiation. Also, the number of cells with γH2AX foci increased as a function of the dose. No significant changes in the level of ROS were detected. Induction of apoptosis was generally negligibly low. This is the first report to directly show alterations in cardiac electrophysiology caused by ionizing radiation, which were detectable up to one week after irradiation.

Electrophysiologic and cellular characteristics of cardiomyocytes after X-ray irradiation

International Nuclear Information System (INIS)

Frieß, Johannes L.; Heselich, Anja; Ritter, Sylvia; Haber, Angelina; Kaiser, Nicole; Layer, Paul G.; Thielemann, Christiane

2015-01-01

Highlights: • Electrophysiologic and cellular effects of X-rays on primary cardiac cell cultures. • X-ray doses between 0.5 and 7 Gy. • Higher beat rate at reduced field action potential durations 7 days after exposure. • More increased cell cycle checkpoint arrest in G2/M than in G1/S phase. • Induced DSBs were mostly repaired within 24 h after irradiation. - Abstract: The aim of this study was to investigate possible effects of ionizing irradiation on the electrophysiological functionality of cardiac myocytes in vitro. Primary chicken cardiomyocytes with spontaneous beating activity were irradiated with X-rays (dose range of 0.5–7 Gy). Functional alterations of cardiac cell cultures were evaluated up to 7 days after irradiation using microelectrode arrays. As examined endpoints, cell proliferation, apoptosis, reactive oxygen species (ROS) and DNA damage were evaluated. The beat rate of the cardiac networks increased in a dose-dependent manner over one week. The duration of single action potentials was slightly shortened. Additionally, we observed lower numbers of mitotic and S-phase cells at certain time points after irradiation. Also, the number of cells with γH2AX foci increased as a function of the dose. No significant changes in the level of ROS were detected. Induction of apoptosis was generally negligibly low. This is the first report to directly show alterations in cardiac electrophysiology caused by ionizing radiation, which were detectable up to one week after irradiation

Electrophysiological mechanisms of the SI SII SIII electrocardiographic morphology

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Bayes de Luna, A.; Carrio, I.; Subirana, M.T.; Torner, P.; Cosin, J.; Sagues, F.; Guindo, J.

1987-01-01

We studied three groups of individuals by means of spatial-velocity electrocardiograms and thallium-201 myocardial imaging to figure out the electrophysiological explanation of the SI SII SIII electrocardiographic morphology. We studied twelve healthy individuals without SI SII SIII, seven healthy individuals with SI SII SIII and fifteen patients with chronic obstructive pulmonary disease with SI SII SIII. The average values of the QRS-E and QRS-F intervals were higher in the second and third groups than in the first. One patient of the second group and thirteen of the third showed right ventricular enlargement. The slowing down of the right ventricular conduction explained the SI SII SIII morphology in normal individuals in more than half the cases. In patients with chronic obstructive pulmonary disease with SI SII SIII the conduction delay plays an important part in the electrogenesis of the right ventricular enlargement electrocardiographic morphology. We think that these observations can give further data about the electrophysiologic mechanism of the SI SII SIII morphology

The Electrophysiological Phenomenon of Alzheimer's Disease: A Psychopathology Theory.

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Holston, Ezra C

2015-08-01

The current understanding of Alzheimer's disease (AD) is based on the Aβ and tau pathology and the resulting neuropathological changes, which are associated with manifested clinical symptoms. However, electrophysiological brain changes may provide a more expansive understanding of AD. Hence, the objective of this systematic review is to propose a theory about the electrophysiological phenomenon of Alzheimer's disease (EPAD). The review of literature resulted from an extensive search of PubMed and MEDLINE databases. One-hundred articles were purposively selected. They provided an understanding of the concepts establishing the theory of EPAD (neuropathological changes, neurochemical changes, metabolic changes, and electrophysiological brain changes). Changes in the electrophysiology of the brain are foundational to the association or interaction of the concepts. Building on Berger's Psychophysical Model, it is evident that electrophysiological brain changes occur and affect cortical areas to generate or manifest symptoms from onset and across the stages of AD, which may be prior to pathological changes. Therefore, the interaction of the concepts demonstrates how the psychopathology results from affected electrophysiology of the brain. The theory of the EPAD provides a theoretical foundation for appropriate measurements of AD without dependence on neuropathological changes. Future research is warranted to further test this theory. Ultimately, this theory contributes to existing knowledge because it shows how electrophysiological changes are useful in understanding the risk and progression of AD across the stages.

Electrophysiologic Assessments of Involuntary Movements: Tremor and Myoclonus

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Hyun-Dong Park

2009-05-01

Full Text Available Tremor is defined as a rhythmical, involuntary oscillatory movement of a body part. Although neurological examination reveals information regarding its frequency, regularity, amplitude, and activation conditions, the electrophysiological investigations help in confirming the tremor, in differentiating it from other hyperkinetic disorders like myoclonus, and may provide etiological clues. Accelerometer with surface electromyogram (EMG can be used to document the dominant frequency of a tremor, which may be useful as certain frequencies are more characteristic of specific etiologies than others hyperkinetic disorders. It may show rhythmic bursts, duration and activation pattern (alternating or synchronous. Myoclonus is a quick, involuntary movement. Electrophysiological studies may helpful in the evaluation of myoclonus, not only for confirming the clinical diagnosis but also for understanding the underlying physiological mechanisms. Electroencephalogram (EEG-EMG correlates can give us important information about myoclonus. Jerk-locked back-averaging and evoked potentials with recording of the long-latency, long-loop reflexes are currently available to study the pathophysiology of myoclonus.

Parieto-occipital encephalomalacia in children; clinical and electrophysiological features of twenty-seven cases.

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Karaoğlu, Pakize; Polat, Ayşe İpek; Yiş, Uluç; Hız, Semra

2015-01-01

Brain injuries occurring at a particular time may cause damages in well-defined regions of brain. Perinatal hypoxic ischemic encephalopathy and hypoglycemia are some of the most common types of brain injuries. Neonatal hypoglycemia can cause abnormal myelination in parietal and occipital lobes resulting in parieto-occipital encephalomalacia. There is a small number of studies about clinical and electroencephalographic (EEG) features of children with parieto-occipital encephalomalacia. They might have important neurologic sequelae such as cortical visual loss, seizures, and psychomotor retardation. We aimed to evaluate the causes of parieto-occipital encephalomalacia and evaluate the clinical and electrophysiological features of children with parieto-occipital encephalomalacia. We evaluated clinical features and EEGs of 27 children with parieto-occipital encephalomalacia. Descriptive statistics were used. Hospitalization during the neonatal period was the most common cause (88.9%) of parieto-occipital brain injury. Eleven patients (40.7%) had a history of neonatal hypoglycemia. Twenty-three patients (85.2%) had epilepsy and nine of the epileptic patients (39%) had refractory seizures. Most of the patients had bilateral (50%) epileptic discharges originating from temporal, parietal, and occipital lobes (56.2%). However, some patients had frontal sharp waves and some had continuous spike and wave discharges during sleep. Visual abnormalities were evident in 15 (55.6%) patients. Twenty-two (81.5%) had psychomotor retardation. Fine motor skills, social contact and language development were impaired more than gross motor skills. In our study, most of the patients with parieto-occipital encephalomalacia had an eventful perinatal history. Epilepsy, psychomotor retardation, and visual problems were common neurologic complications.

Electrophysiological Monitoring in Patients With Tumors of the Skull Base Treated by Carbon-12 Radiation Therapy

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Carozzo, Simone [Department of Neuroscience, Ophthalmology, and Genetics, University of Genova, Genova (Italy); Schardt, Dieter [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Narici, Livio [Department of Physics, University of Rome Tor Vergata, Rome (Italy); Combs, Stephanie E.; Debus, Jürgen [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Sannita, Walter G., E-mail: wgs@dism.unige.it [Department of Neuroscience, Ophthalmology, and Genetics, University of Genova, Genova (Italy); Department of Psychiatry, State University of New York, Stony Brook, New York (United States)

2013-03-15

Purpose: To report the results of short-term electrophysiologic monitoring of patients undergoing {sup 12}C therapy for the treatment of skull chordomas and chondrosarcomas unsuitable for radical surgery. Methods and Materials: Conventional electroencephalogram (EEG) and retinal and cortical electrophysiologic responses to contrast stimuli were recorded from 30 patients undergoing carbon ion radiation therapy, within a few hours before the first treatment and after completion of therapy. Methodologies and procedures were compliant with the guidelines of the International Federation for Clinical Neurophysiology and International Society for Clinical Electrophysiology of Vision. Results: At baseline, clinical signs were reported in 56.6% of subjects. Electrophysiologic test results were abnormal in 76.7% (EEG), 78.6% (cortical evoked potentials), and 92.8% (electroretinogram) of cases, without correlation with neurologic signs, tumor location, or therapy plan. Results on EEG, but not electroretinograms and cortical responses, were more often abnormal in patients with reported clinical signs. Abnormal EEG results and retinal/cortical responses improved after therapy in 40% (EEG), 62.5% (cortical potentials), and 70% (electroretinogram) of cases. Results on EEG worsened after therapy in one-third of patients whose recordings were normal at baseline. Conclusions: The percentages of subjects whose EEG results improved or worsened after therapy and the improvement of retinal/cortical responses in the majority of patients are indicative of a limited or negligible (and possibly transient) acute central nervous system toxicity of carbon ion therapy, with a significant beneficial effect on the visual pathways. Research on large samples would validate electrophysiologic procedures as a possible independent test for central nervous system toxicity and allow investigation of the correlation with clinical signs; repeated testing over time after therapy would demonstrate, and may

Subthalamic stimulation: toward a simplification of the electrophysiological procedure.

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Fetter, Damien; Derrey, Stephane; Lefaucheur, Romain; Borden, Alaina; Wallon, David; Chastan, Nathalie; Maltete, David

2016-06-01

The aim of the present study was to assess the consequences of a simplification of the electrophysiological procedure on the post-operative clinical outcome after subthalamic nucleus implantation in Parkinson disease. Microelectrode recordings were performed on 5 parallel trajectories in group 1 and less than 5 trajectories in group 2. Clinical evaluations were performed 1 month before and 6 months after surgery. After surgery, the UPDRS III score in the off-drug/on-stimulation and on-drug/on-stimulation conditions significantly improved by 66,9% and 82%, respectively in group 1, and by 65.8% and 82.3% in group 2 (P<0.05). Meanwhile, the total number of words (P<0.05) significantly decreased for fluency tasks in both groups. Motor disability improvement and medication reduction were similar in both groups. Our results suggest that the electrophysiological procedure should be simplified as the team's experience increases.

Evaluation of mRNA expression levels and electrophysiological function of neuron-like cells derived from canine bone marrow stromal cells.

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Nakano, Rei; Edamura, Kazuya; Sugiya, Hiroshi; Narita, Takanori; Okabayashi, Ken; Moritomo, Tadaaki; Teshima, Kenji; Asano, Kazushi; Nakayama, Tomohiro

2013-10-01

To investigate the in vitro differentiation of canine bone marrow stromal cells (BMSCs) into functional, mature neurons. Bone marrow from 6 adult dogs. BMSCs were isolated from bone marrow and chemically induced to develop into neurons. The morphology of the BMSCs during neuronal induction was monitored, and immunocytochemical analyses for neuron markers were performed after the induction. Real-time PCR methods were used to evaluate the mRNA expression levels of markers for neural stem or progenitor cells, neurons, and ion channels, and western blotting was used to assess the expression of neuronal proteins before and after neuronal induction. The electrophysiological properties of the neuron-like cells induced from canine BMSCs were evaluated with fluorescent dye to monitor Ca(2)+ influx. Canine BMSCs developed a neuron-like morphology after neuronal induction. Immunocytochemical analysis revealed that these neuron-like cells were positive for neuron markers. After induction, the cells' mRNA expression levels of almost all neuron and ion channel markers increased, and the protein expression levels of nestin and neurofilament-L increased significantly. However, the neuron-like cells derived from canine BMSCs did not have the Ca(2)+ influx characteristic of spiking neurons. Although canine BMSCs had neuron-like morphological and biochemical properties after induction, they did not develop the electrophysiological characteristics of neurons. Thus, these results have suggested that canine BMSCs could have the capacity to differentiate into a neuronal lineage, but the differentiation protocol used may have been insufficient to induce development into functional neurons.

Effects of aspartame on the evaluation of electrophysiological responses in Wistar albino rats

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Arbind Kumar Choudhary

2016-07-01

Full Text Available Aspartame is a non-nutritive sweetener that is used predominantly in various ‘diet’ and ‘low-calorie’ products, such as beverages, instant breakfasts, desserts, breath mints, sugar-free chewing gum, vitamins, and pharmaceuticals, consumed by millions of people who are attempting weight loss, young adults and diabetic persons. On a weight basis, the metabolism of aspartame generates approximately 50% phenylalanine, 40% aspartic acid and 10% methanol. The detailed mechanisms of the effects of aspartame on the electrophysiological response are still unclear; therefore, this study was designed to clarify whether longer-term aspartame consumption has any effect on the electrophysiological response in Wistar albino rats. The oral administration of aspartame in a safe dose of 40 mg/kg bodyweight/day (as recommended by EFSA, 2012 was tested in Wistar albino rats for a longer period (90 days. Electrophysiological responses, including heart rate variability (HRV and electroencephalogram (EEG pattern, were assessed in a folate-deficient animal model along with control animals using BIOPAC and EEG equipment (model RMS EEG–24 brain new-plus: RMS – Recorder and Medicare systems. In this study, the folate-deficient animal model was used to mimic human methanol metabolism in rats. After 90 days of aspartame treatment, a significant alteration was observable in the time domain [Mean RR (ms SDNN (ms RMSSD (ms PNN50 (%] and the frequency domain [LF, HF, and LF/HF ratio] with significantly impaired frequency and amplitude of the fronto-parietal and occipital EEG waves at p ≤ 0.05. The results of this study clearly indicate that the oral consumption of aspartame reduced HRV, with sympathetic dominance and loss of vagal tone, and altered sympathovagal activity along with impairment of learning and memory, showing an additional effect on health within this study duration. The aspartame metabolites methanol and formaldehyde may be the causative factors

A time course analysis of the electrophysiological properties of neurons differentiated from human induced pluripotent stem cells (iPSCs.

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Deborah Prè

Full Text Available Many protocols have been designed to differentiate human embryonic stem cells (ESCs and human induced pluripotent stem cells (iPSCs into neurons. Despite the relevance of electrophysiological properties for proper neuronal function, little is known about the evolution over time of important neuronal electrophysiological parameters in iPSC-derived neurons. Yet, understanding the development of basic electrophysiological characteristics of iPSC-derived neurons is critical for evaluating their usefulness in basic and translational research. Therefore, we analyzed the basic electrophysiological parameters of forebrain neurons differentiated from human iPSCs, from day 31 to day 55 after the initiation of neuronal differentiation. We assayed the developmental progression of various properties, including resting membrane potential, action potential, sodium and potassium channel currents, somatic calcium transients and synaptic activity. During the maturation of iPSC-derived neurons, the resting membrane potential became more negative, the expression of voltage-gated sodium channels increased, the membrane became capable of generating action potentials following adequate depolarization and, at day 48-55, 50% of the cells were capable of firing action potentials in response to a prolonged depolarizing current step, of which 30% produced multiple action potentials. The percentage of cells exhibiting miniature excitatory post-synaptic currents increased over time with a significant increase in their frequency and amplitude. These changes were associated with an increase of Ca2+ transient frequency. Co-culturing iPSC-derived neurons with mouse glial cells enhanced the development of electrophysiological parameters as compared to pure iPSC-derived neuronal cultures. This study demonstrates the importance of properly evaluating the electrophysiological status of the newly generated neurons when using stem cell technology, as electrophysiological properties of

Assessment of cortical and sub-cortical function in neonates by electrophysiological monitoring

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Jennekens, W.

2012-01-01

The aim of this thesis was the assessment of cortical and sub-cortical function in neonates by electrophysiological monitoring, i.e. to evaluate the function of the neonatal cortex and brainstem through quantitative analysis of signals readily available in the NICU. These signals include

Spinal myoclonus following a peripheral nerve injury: a case report

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Erkol Gokhan

2008-08-01

Full Text Available Abstract Spinal myoclonus is a rare disorder characterized by myoclonic movements in muscles that originate from several segments of the spinal cord and usually associated with laminectomy, spinal cord injury, post-operative, lumbosacral radiculopathy, spinal extradural block, myelopathy due to demyelination, cervical spondylosis and many other diseases. On rare occasions, it can originate from the peripheral nerve lesions and be mistaken for peripheral myoclonus. Careful history taking and electrophysiological evaluation is important in differential diagnosis. The aim of this report is to evaluate the clinical and electrophysiological characteristics and treatment results of a case with spinal myoclonus following a peripheral nerve injury without any structural lesion.

Autoclave Sterilization of PEDOT:PSS Electrophysiology Devices.

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Uguz, Ilke; Ganji, Mehran; Hama, Adel; Tanaka, Atsunori; Inal, Sahika; Youssef, Ahmed; Owens, Roisin M; Quilichini, Pascale P; Ghestem, Antoine; Bernard, Christophe; Dayeh, Shadi A; Malliaras, George G

2016-12-01

Autoclaving, the most widely available sterilization method, is applied to poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) electrophysiology devices. The process does not harm morphology or electrical properties, while it effectively kills E. coli intentionally cultured on the devices. This finding paves the way to widespread introduction of PEDOT:PSS electrophysiology devices to the clinic. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

LBM-EP: Lattice-Boltzmann method for fast cardiac electrophysiology simulation from 3D images.

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Rapaka, S; Mansi, T; Georgescu, B; Pop, M; Wright, G A; Kamen, A; Comaniciu, Dorin

2012-01-01

Current treatments of heart rhythm troubles require careful planning and guidance for optimal outcomes. Computational models of cardiac electrophysiology are being proposed for therapy planning but current approaches are either too simplified or too computationally intensive for patient-specific simulations in clinical practice. This paper presents a novel approach, LBM-EP, to solve any type of mono-domain cardiac electrophysiology models at near real-time that is especially tailored for patient-specific simulations. The domain is discretized on a Cartesian grid with a level-set representation of patient's heart geometry, previously estimated from images automatically. The cell model is calculated node-wise, while the transmembrane potential is diffused using Lattice-Boltzmann method within the domain defined by the level-set. Experiments on synthetic cases, on a data set from CESC'10 and on one patient with myocardium scar showed that LBM-EP provides results comparable to an FEM implementation, while being 10 - 45 times faster. Fast, accurate, scalable and requiring no specific meshing, LBM-EP paves the way to efficient and detailed models of cardiac electrophysiology for therapy planning.

Electrophysiologic studies of neronal activities under ischemia condition.

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Huang, Shun-Ho; Wang, Ping-Hsien; Chen, Jia-Jin Jason

2008-01-01

Substrate with integrated microelectrode arrays (MEAs) provides an alternative electrophysiological method. With MEAS, one can measure the impedance and elicit electrical stimulation from multiple sites of MEAs to determine the electrophysiological conditions of cells. The aims of this research were to construct an impedance and action potential measurement system for neurons cultured on MEAs for observing the electrophysiological signal transmission in neuronal network during glucose and oxygen deprivation (OGD). An extracellular stimulator producing the biphasic micro-current pulse for neuron stimulation was built in this study. From the time-course recording of impedance, OGD condition effectively induced damage in neurons in vitro. It is known that the results of cell stimulation are affected by electrode impedance, so does the result of neuron cells covered on the electrode can measure the sealing resistance. For extracellular stimulation study, cortical neuronal activity was recorded and the suitable stimulation window was determined. However, the stimulation results were affected by electrode impedance as well as sealing impedance resulting from neuron cells covering the electrode. Further development of surface modification for cultured neuron network should provide a better way for in vitro impedance and electrophysiological measurements.

Clinical and electrophysiological findings in patients with phenylketonuria and epilepsy: Reflex features.

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Yildiz Celik, Senay; Bebek, Nerses; Gurses, Candan; Baykan, Betul; Gokyigit, Aysen

2018-03-23

Phenylketonuria (PKU) is the most common form of amino acid metabolism disorders with autosomal recessive inheritance. The brain damage can be prevented by early diagnosis and a phenylalanine-restricted diet. Untreated or late-treated patients may show mental retardation and other cognitive dysfunctions, as well as motor disability and/or epilepsy. Three patients with PKU and epilepsy were recognized to have reflex epileptic features, and there were ten consecutive adult patients with PKU and epilepsy who were evaluated retrospectively. Medical history, ages at diagnosis and therapy onset, age at seizure onset, seizure types and reflex features, neurological findings, cranial imaging, electroencephalography (EEG) findings, and final clinical condition were evaluated. Reflex epilepsy features were examined in detail. The cases (6 females, 4 males) were diagnosed at ages between 3.5months and 12years. All patients had various degrees of mental-motor retardation and focal or generalized seizures with age at seizure onset varied between neonatal period and 15years. Three patients had febrile seizure, 3 patients had myoclonia, and 3 patients had status epilepticus. All patients had abnormal EEG findings except one. There was a slowing of background activity, and generalized discharges were observed in 7 patients; 3 of them had asymmetrical discharges. One patient had right hippocampal sclerosis (HS), and another patient had hypointensities in the basal ganglia and corpus callosum. Reflex features were clinically observed in 3 of the patients; however, EEG results did not show any related findings. One patient had reflex seizures triggered by photic stimuli, hot water, and startling; one by photic stimuli; and the other one by startling. Reports on the clinical and electrophysiological features of adult patients with PKU were scant. We emphasized that reflex clinical features may be observed in this metabolic disease, and focal epileptiform abnormalities and asymmetry

Software and hardware infrastructure for research in electrophysiology.

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Mouček, Roman; Ježek, Petr; Vařeka, Lukáš; Rondík, Tomáš; Brůha, Petr; Papež, Václav; Mautner, Pavel; Novotný, Jiří; Prokop, Tomáš; Stěbeták, Jan

2014-01-01

As in other areas of experimental science, operation of electrophysiological laboratory, design and performance of electrophysiological experiments, collection, storage and sharing of experimental data and metadata, analysis and interpretation of these data, and publication of results are time consuming activities. If these activities are well organized and supported by a suitable infrastructure, work efficiency of researchers increases significantly. This article deals with the main concepts, design, and development of software and hardware infrastructure for research in electrophysiology. The described infrastructure has been primarily developed for the needs of neuroinformatics laboratory at the University of West Bohemia, the Czech Republic. However, from the beginning it has been also designed and developed to be open and applicable in laboratories that do similar research. After introducing the laboratory and the whole architectural concept the individual parts of the infrastructure are described. The central element of the software infrastructure is a web-based portal that enables community researchers to store, share, download and search data and metadata from electrophysiological experiments. The data model, domain ontology and usage of semantic web languages and technologies are described. Current data publication policy used in the portal is briefly introduced. The registration of the portal within Neuroscience Information Framework is described. Then the methods used for processing of electrophysiological signals are presented. The specific modifications of these methods introduced by laboratory researches are summarized; the methods are organized into a laboratory workflow. Other parts of the software infrastructure include mobile and offline solutions for data/metadata storing and a hardware stimulator communicating with an EEG amplifier and recording software.

Evaluation of serum indexes and electrophysiological characteristics after ziprasidone combined with modified electroconvulsive therapy for schizophrenian

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Hong-Bo Cao

2017-06-01

Full Text Available Objective: To study the effect of ziprasidone combined with modified electroconvulsive therapy (MECT on serum indexes and electrophysiological characteristics of schizophrenia. Methods: A total of 44 patients with schizophrenia treated in our hospital between May 2014 and July 2016 were selected and randomly divided into MECT group and control group, MECT group received ziprasidone combined with MECT therapy and control group received ziprasidone therapy. Before treatment as well as 1 month, 2 months and 3 months after treatment, serum nerve cytokine levels and inflammatory factor levels as well as nerve electrophysiology parameters were detected. Results: 1 month, 2 months and 3 months after treatment, serum BDNF, GDNF and NGF levels of both groups were significantly higher than those before treatment, IL-1β, IL-6, IL-17 and TNF-α levels were significantly lower than those before treatment, P300 and N2-P3 latency were significantly shorter than those before treatment, and P300 and N2-P3 amplitude were significantly higher than those before treatment; serum BDNF, GDNF and NGF levels of MECT group were significantly higher than those of control group, IL-1β, IL-6, IL-17 and TNF-α levels were significantly lower than those of control group, P300 and N2-P3 latency were significantly shorter than those of control group, and P300 and N2-P3 amplitude were significantly higher than those of control group. Conclusion: Ziprasidone combined with modified electroconvulsive therapy can improve neuron function, reduce neuron damage and adjust nerve electrophysiology function.

Clinical Characteristics, Electrophysiology, and Skin Biopsy of 38 Peripheral Neuropathy Cases with Small Fiber Involvement of Various Etiologies

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Bo Sun

2017-01-01

Conclusions: IENFD of patients included in the present study weakly correlated with various electrophysiological parameters. Small and large fibers are more involved in patients with MS-related PN than in patients with idiopathic PN.

Large-scale electrophysiology: acquisition, compression, encryption, and storage of big data.

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Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt

2009-05-30

The use of large-scale electrophysiology to obtain high spatiotemporal resolution brain recordings (>100 channels) capable of probing the range of neural activity from local field potential oscillations to single-neuron action potentials presents new challenges for data acquisition, storage, and analysis. Our group is currently performing continuous, long-term electrophysiological recordings in human subjects undergoing evaluation for epilepsy surgery using hybrid intracranial electrodes composed of up to 320 micro- and clinical macroelectrode arrays. DC-capable amplifiers, sampling at 32kHz per channel with 18-bits of A/D resolution are capable of resolving extracellular voltages spanning single-neuron action potentials, high frequency oscillations, and high amplitude ultra-slow activity, but this approach generates 3 terabytes of data per day (at 4 bytes per sample) using current data formats. Data compression can provide several practical benefits, but only if data can be compressed and appended to files in real-time in a format that allows random access to data segments of varying size. Here we describe a state-of-the-art, scalable, electrophysiology platform designed for acquisition, compression, encryption, and storage of large-scale data. Data are stored in a file format that incorporates lossless data compression using range-encoded differences, a 32-bit cyclically redundant checksum to ensure data integrity, and 128-bit encryption for protection of patient information.

Software and Hardware Infrastructure for Research in Electrophysiology

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Roman eMouček

2014-03-01

Full Text Available As in other areas of experimental science, operation of electrophysiological laboratory, design and performance of electrophysiological experiments, collection, storage and sharing of experimental data and metadata, analysis and interpretation of these data, and publication of results are time consuming activities. If these activities are well organized and supported by a suitable infrastructure, work efficiency of researchers increases significantly.This article deals with the main concepts, design, and development of software and hardware infrastructure for research in electrophysiology. The described infrastructure has been primarily developed for the needs of neuroinformatics laboratory at the University of West Bohemia, the Czech Republic. However, from the beginning it has been also designed and developed to be open and applicable in laboratories that do similar research.After introducing the laboratory and the whole architectural concept the individual parts of the infrastructure are described. The central element of the software infrastructure is a web-based portal that enables community researchers to store, share, download and search data and metadata from electrophysiological experiments. The data model, domain ontology and usage of semantic web languages and technologies are described. Current data publication policy used in the portal is briefly introduced. The registration of the portal within Neuroscience Information Framework is described. Then the methods used for processing of electrophysiological signals are presented. The specific modifications of these methods introduced by laboratory researches are summarized; the methods are organized into a laboratory workflow. Other parts of the software infrastructure include mobile and offline solutions for data/metadata storing and a hardware stimulator communicating with an EEG amplifier and recording software.

Electrophysiological Evidence in Schizophrenia in Relation to Treatment Response

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Kazuki Sueyoshi

2018-06-01

Full Text Available Several domains of cognitive function, e.g., verbal memory, information processing, fluency, attention, and executive function are impaired in patients with schizophrenia. Cognitive impairments in schizophrenia have attracted interests as a treatment target, because they are considered to greatly affect functional outcome. Electrophysiological markers, including electroencephalogram (EEG, particularly, event-related potentials, have contributed to psychiatric research and clinical practice. In this review, we provide a summary of studies relating electrophysiological findings to cognitive performance in schizophrenia. Electrophysiological indices may provide an objective marker of cognitive processes, contributing to the development of effective interventions to improve cognitive and social outcomes. Further efforts to understand biological mechanisms of cognitive disturbances, and develop effective therapeutics are warranted.

Electrophysiology in visually impaired children

NARCIS (Netherlands)

Genderen, Maria Michielde van

2006-01-01

Inherited retinal disorders and posterior visual pathway abnormalities are important causes of visual impairment in children. Visual electrophysiology often is indispensable in diagnosing these conditions. This thesis shows the wide range of use of pediatric electro-ophthalmology, and demonstrates

Electrophysiologic similarities of overdose between digoxin and bufadienolides found in a Chinese aphrodisiac

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Maxwell Bressman

2017-02-01

Full Text Available Classically derived from toad venom, bufadienolides are a group of cardioactive steroids with properties similar to digoxin. Some traditional Chinese medications, including several aphrodisiacs, contain bufadienolides. Owing to their physiologic similarities to digoxin, bufadienolides have been shown to produce a toxic profile similar to that of digoxin and there have been multiple case reports of the use of these aphrodisiacs resulting in death. This report will describe a case that illustrates the electrophysiologic similarities between bufadienolide toxicity and digoxin toxicity as well as the treatment of bufadienolide toxicity.

Electrophysiologic characteristics of tremor in Parkinson?s disease and essential tremor

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Ederson Cichaczewski

2014-04-01

Full Text Available Tremor in essential tremor (ET and Parkinson’s disease (PD usually present specific electrophysiologic profiles, however amplitude and frequency may have wide variations. Objective: To present the electrophysiologic findings in PD and ET. Method: Patients were assessed at rest, with posture and action. Seventeen patients with ET and 62 with PD were included. PD cases were clustered into three groups: predominant rest tremor; tremor with similar intensity at rest, posture and during kinetic task; and predominant kinetic tremor. Results: Patients with PD presented tremors with average frequency of 5.29±1.18 Hz at rest, 5.79±1.39 Hz with posture and 6.48±1.34 Hz with the kinetic task. Tremor in ET presented with an average frequency of 5.97±1.1 Hz at rest, 6.18±1 Hz with posture and 6.53±1.2 Hz with kinetic task. Seven (41.2% also showed rest tremor. Conclusion: The tremor analysis alone using the methodology described here, is not sufficient to differentiate tremor in ET and PD.

Female preponderance in atrioventricular node reentrant tachycardia, but no sex related electrophysiological differences

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Claes Williamsson

2014-01-01

Full Text Available The mechanism behind the female preponderance for atrio-ventricular node reentrant tachycardia (AVNRT is not clear. We compared baseline electrophysiological measurements and clinical data in 141 consecutive patients (96 women who underwent successful AVNRT ablation at their fi rst therapeutic procedure. Women had on average 9% higher resting heart rate than men (p<0.05, but were similar in all measures of AV node function. Isoproterenol infusion was required for AVNRT induction in 69 cases (49%, and the need for isoproterenol was associated with lower resting heart rate and longer anterograde and retrograde AV node refractory periods (p<0.05 for comparisons, but not with sex. We conclude that the spectrum of baseline AV node physiology in AVNRT patients is wide, and is similar in men and women. The female preponderance for AVNRT cannot be explained from comparisons of baseline AV node electrophysiological properties.

4 cases of 'ataxic hemiparesis'

International Nuclear Information System (INIS)

Eguchi, Kiyoshi; Kamei, Hidekazu; Kitamura, Eiko; Komatsuzaki, Satoshi; Yamane, Kiyomi; Takemiya, Toshiko; Kobayashi, Itsuro; Maruyama, Shoichi

1984-01-01

Ataxic hemiparesis is described as a syndrome in which pyramidal and cerebellar signs occur ipsilaterally. Fisher who suggestd the designation ''ataxic hemiparesis'' for this syndrome confirmed by pathological study that causative lesion was in the basis pontis at the level of the junction of the upper one third and lower two thirds on the opposite side of the neurological deficit and he also reported that CT might fail to show the lesion. We observed 4 patients with ataxic hemiparesis and examined them in auditory brainstem response (ABR), somatosensory evoked potential (SEP), and blink reflex as electrophysiological study. Their CT and electrophysiological findings were compared with each others to define the responsible lesion more clearly. Essentially, these abnormal electrophysiological findings were recognized only in the case of pontine hemorrhage, and these findings recovered to normal as clinical and CT findings were improved. In the other cases, the electrophysiological findings were not prominent and CT revealed the lesions in deep frontal region, internal capsule and cerebellar hemispheres respectively. These results might show that many cases of extra-pontine lesions could develop the syndrome of ataxic hemiparesis. However, the relation between responsible lesions for ataxic hemiparesis and electrophysiological findings are still uncertain. Further evidences including clinicopathological studies will be required to clarify this relation and to get the more accurate anatomical interpretation of ataxic hemiparesis from lesions besides the pontine region. (author)

RTIME: a program for time-series measurements and evaluation in electrophysiology with the AT-PC.

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Gras, H; Hackenberg, K

1992-02-01

This work describes a program which uses a standard RS232-serial interface of an IBM-AT-compatible microcomputer to receive via four data lines input from any laboratory equipment (spike discriminators, stimulus equipment, etc.) generating pulses between 0 to -15 V (low) and +5 to +15 V (high). Therefore, program operation is independent from any hardware extensions of the computer. The time of occurrence of input pulses is recorded with a resolution of 10 microseconds. Depending on processor speed and optional on-line display of interval histograms, a maximum sampling rate of 1.3-6 kHz is attained. Designed primarily for electrophysiological applications, the program comprises an extensive set of functions for off-line analysis of data either in the time- or in the phase-domain. The program is controlled by menu-selectable commands with detailed on-line explanation and is therefore suited for use even by operators without computer experience, e.g., students on courses in experimental physiology. Elaborate schemes of evaluation can be defined as macro commands to speed up and simplify complex data analysis in actual research.

Zika virus infection and Guillain-Barré syndrome: a review focused on clinical and electrophysiological subtypes.

Science.gov (United States)

Uncini, Antonino; Shahrizaila, Nortina; Kuwabara, Satoshi

2017-03-01

In 2016, we have seen a rapid emergence of Zika virus-associated Guillain-Barré syndrome (GBS) since its first description in a French-Polynesian patient in 2014. Current evidence estimates the incidence of GBS at 24 cases per 100 000 persons infected by Zika virus. This will result in a sharp rise in the number of GBS cases worldwide with the anticipated global spread of Zika virus. A better understanding of the pathogenesis of Zika-associated GBS is crucial to prepare us for the current epidemic. In this review, we evaluate the existing literature on GBS in association with Zika and other flavivirus to better define its clinical subtypes and electrophysiological characteristics, demonstrating a demyelinating subtype of GBS in most cases. We also recommend measures that will help reduce the gaps in knowledge that currently exist. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Electrophysiological measurements of diabetic peripheral neuropathy: A systematic review.

Science.gov (United States)

Shabeeb, Dheyauldeen; Najafi, Masoud; Hasanzadeh, Gholamreza; Hadian, Mohammed Reza; Musa, Ahmed Eleojio; Shirazi, Alireza

2018-03-28

Peripheral neuropathy is one of the main complications of diabetes mellitus. One of the features of diabetic nerve damage is abnormality of sensory and motor nerve conduction study. An electrophysiological examination can be reproduced and is also a non-invasive approach in the assessment of peripheral nerve function. Population-based and clinical studies have been conducted to validate the sensitivity of these methods. When the diagnosis was based on clinical electrophysiological examination, abnormalities were observed in all patients. In this research, using a review design, we reviewed the issue of clinical electrophysiological examination of diabetic peripheral neuropathy in articles from 2008 to 2017. For this purpose, PubMed, Scopus and Embase databases of journals were used for searching articles. The researchers indicated that diabetes (both types) is a very disturbing health issue in the modern world and should be given serious attention. Based on conducted studies, it was demonstrated that there are different procedures for prevention and treatment of diabetes-related health problems such as diabetic polyneuropathy (DPN). The first objective quantitative indication of the peripheral neuropathy is abnormality of sensory and motor nerve conduction tests. Electrophysiology is accurate, reliable and sensitive. It can be reproduced and also is a noninvasive approach in the assessment of peripheral nerve function. The methodological review has found that the best method for quantitative indication of the peripheral neuropathy compared with all other methods is clinical electrophysiological examination. For best results, standard protocols such as temperature control and equipment calibration are recommended. Copyright © 2018. Published by Elsevier Ltd.

An animal model (guinea pig) of ocular siderosis: histopathology, pharmacology, and electrophysiology.

Science.gov (United States)

Mumcuoglu, Tarkan; Ozge, Gokhan; Soykut, Bugra; Erdem, Onur; Gunal, Armagan; Acikel, Cengizhan

2015-03-01

Ocular siderosis is a rare sight-threatening complication that occurs after a penetrating ocular injury by an iron-containing foreign body. The purposes of this study were to (i) investigate the histopathology, electrophysiology and iron levels/accumulation in ocular siderosis using an animal (Guinea pig) model and (ii) determine the appropriate timing for follow-up foreign body-removal surgery. Thirty guinea pigs were divided into five groups (n = 6 animals/group). On day-1, an iron body was inserted into the vitreous of the right eye of all animals; the left eyes were left undisturbed and were used as controls. At the end of each week during the 5-week study period, electroretinography (ERG) was performed on all animals in one of the five groups. Each animal in that group was sacrificed, after which both eyes were enucleated for histopathological and pharmacological evaluation of intraocular iron. Accumulated iron levels of study eyes were significantly higher than those of control eyes (135.13 and 13.55 μg/g, respectively, p < 0.01). In addition, there was a significant decrease in electrophysiological responses of study eyes. During the first week, iron levels were higher in study eyes than control eyes, but neither histological iron accumulation nor decreased electrophysiological responses could be detected. By the end of the second week, increased iron accumulation was observed histologically in intraocular tissues, along with signs of retinal toxicity, as verified by decreased electrophysiological responses. The present study indicates that the 14th day after a penetrating eye injury by an iron-containing intraocular foreign body represents a clinically critical threshold, after which structural damage to and functional alterations in ocular tissues occur.

The assessment of visually impaired persons working capacities using electrophysiological and ophthalmic ergonomics methods

Directory of Open Access Journals (Sweden)

M. I. Razumovsky

2014-07-01

Full Text Available Aim was to analyze working capacities of visually impaired persons by means of complex electrophysiological and ophthalmic ergonomics eye examination.Materials and methods. Standard clinical ophthalmologic examination (visual acuity measurement, refractometry, biomicroscopy, ophthalmoscopy as well as electrophysiological (electrooculography, electrical sensitivity of the eye, critical flicker fusion frequency and ophthalmic ergonomics tests (accommodation measurement, professional testing using automated system «Proftest-1» were performed.Results. Complex electrophysiological and ophthalmic ergonomics tests were performed in 20 visually impaired persons. Their results revealed direct correlation between electrophysiological and ophthalmic ergonomics indices.Conclusion. Working capacities of visually impaired persons can be assessed reliably using complex electrophysiological and ophthalmic ergonomics eye examination only.

The assessment of visually impaired persons working capacities using electrophysiological and ophthalmic ergonomics methods

Directory of Open Access Journals (Sweden)

M. I. Razumovsky

2014-01-01

Full Text Available Aim was to analyze working capacities of visually impaired persons by means of complex electrophysiological and ophthalmic ergonomics eye examination.Materials and methods. Standard clinical ophthalmologic examination (visual acuity measurement, refractometry, biomicroscopy, ophthalmoscopy as well as electrophysiological (electrooculography, electrical sensitivity of the eye, critical flicker fusion frequency and ophthalmic ergonomics tests (accommodation measurement, professional testing using automated system «Proftest-1» were performed.Results. Complex electrophysiological and ophthalmic ergonomics tests were performed in 20 visually impaired persons. Their results revealed direct correlation between electrophysiological and ophthalmic ergonomics indices.Conclusion. Working capacities of visually impaired persons can be assessed reliably using complex electrophysiological and ophthalmic ergonomics eye examination only.

Dynamics of intrinsic electrophysiological properties in spinal cord neurones

DEFF Research Database (Denmark)

Russo, R E; Hounsgaard, J

1999-01-01

The spinal cord is engaged in a wide variety of functions including generation of motor acts, coding of sensory information and autonomic control. The intrinsic electrophysiological properties of spinal neurones represent a fundamental building block of the spinal circuits executing these tasks. ....... Specialised, cell specific electrophysiological phenotypes gradually differentiate during development and are continuously adjusted in the adult animal by metabotropic synaptic interactions and activity-dependent plasticity to meet a broad range of functional demands....

[Automated processing of electrophysiologic signals].

Science.gov (United States)

Korenevskiĭ, N A; Gubanov, V V

1995-01-01

The paper outlines a diagram of a multichannel analyzer of electrophysiological signals while are significantly non-stationary (such as those of electroencephalograms, myograms, etc.), by using a method based on the ranging procedure by the change-over points which may be the points of infection, impaired locality, minima, maxima, discontinuity, etc.

Electrophysiological Source Imaging: A Noninvasive Window to Brain Dynamics.

Science.gov (United States)

He, Bin; Sohrabpour, Abbas; Brown, Emery; Liu, Zhongming

2018-06-04

Brain activity and connectivity are distributed in the three-dimensional space and evolve in time. It is important to image brain dynamics with high spatial and temporal resolution. Electroencephalography (EEG) and magnetoencephalography (MEG) are noninvasive measurements associated with complex neural activations and interactions that encode brain functions. Electrophysiological source imaging estimates the underlying brain electrical sources from EEG and MEG measurements. It offers increasingly improved spatial resolution and intrinsically high temporal resolution for imaging large-scale brain activity and connectivity on a wide range of timescales. Integration of electrophysiological source imaging and functional magnetic resonance imaging could further enhance spatiotemporal resolution and specificity to an extent that is not attainable with either technique alone. We review methodological developments in electrophysiological source imaging over the past three decades and envision its future advancement into a powerful functional neuroimaging technology for basic and clinical neuroscience applications.

NeuroElectro: A Window to the World's Neuron Electrophysiology Data

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Shreejoy J Tripathy

2014-04-01

Full Text Available The behavior of neural circuits is determined largely by the electrophysiological properties of the neurons they contain. Understanding the relationships of these properties requires the ability to first identify and catalog each property. However, information about such properties is largely locked away in decades of closed-access journal articles with heterogeneous conventions for reporting results, making it difficult to utilize the underlying data. We solve this problem through the NeuroElectro project: a Python library, RESTful API, and web application (at http://neuroelectro.org for the extraction, visualization, and summarization of published data on neurons' electrophysiological properties. Information is organized both by neuron type (using neuron definitions provided by NeuroLex and by electrophysiological property (using a newly developed ontology. We describe the techniques and challenges associated with the automated extraction of tabular electrophysiological data and methodological metadata from journal articles. We further discuss strategies for how to best combine, normalize and organize data across these heterogeneous sources. NeuroElectro is a valuable resource for experimental physiologists looking to supplement their own data, for computational modelers looking to constrain their model parameters, and for theoreticians searching for undiscovered relationships among neurons and their properties.

Anatomical and Electrophysiological Clustering of Superficial Medial Entorhinal Cortex Interneurons

Science.gov (United States)

2017-01-01

Abstract Local GABAergic interneurons regulate the activity of spatially-modulated principal cells in the medial entorhinal cortex (MEC), mediating stellate-to-stellate connectivity and possibly enabling grid formation via recurrent inhibitory circuitry. Despite the important role interneurons seem to play in the MEC cortical circuit, the combination of low cell counts and functional diversity has made systematic electrophysiological studies of these neurons difficult. For these reasons, there remains a paucity of knowledge on the electrophysiological profiles of superficial MEC interneuron populations. Taking advantage of glutamic acid decarboxylase 2 (GAD2)-IRES-tdTomato and PV-tdTomato transgenic mice, we targeted GABAergic interneurons for whole-cell patch-clamp recordings and characterized their passive membrane features, basic input/output properties and action potential (AP) shape. These electrophysiologically characterized cells were then anatomically reconstructed, with emphasis on axonal projections and pial depth. K-means clustering of interneuron anatomical and electrophysiological data optimally classified a population of 106 interneurons into four distinct clusters. The first cluster is comprised of layer 2- and 3-projecting, slow-firing interneurons. The second cluster is comprised largely of PV+ fast-firing interneurons that project mainly to layers 2 and 3. The third cluster contains layer 1- and 2-projecting interneurons, and the fourth cluster is made up of layer 1-projecting horizontal interneurons. These results, among others, will provide greater understanding of the electrophysiological characteristics of MEC interneurons, help guide future in vivo studies, and may aid in uncovering the mechanism of grid field formation. PMID:29085901

Stimfit: quantifying electrophysiological data with Python

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Segundo Jose Guzman

2014-02-01

Full Text Available Intracellular electrophysiological recordings provide crucial insights into elementary neuronal signals such as action potentials and synaptic currents. Analyzing and interpreting these signals is essential for a quantitative understanding of neuronal information processing, and requires both fast data visualization and ready access to complex analysis routines. To achieve this goal, we have developed Stimfit, a free software package for cellular neurophysiology with a Python scripting interface and a built-in Python shell. The program supports most standard file formats for cellular neurophysiology and other biomedical signals through the Biosig library. To quantify and interpret the activity of single neurons and communication between neurons, the program includes algorithms to characterize the kinetics of presynaptic action potentials and postsynaptic currents, estimate latencies between pre- and postsynaptic events, and detect spontaneously occurring events. We validate and benchmark these algorithms, give estimation errors, and provide sample use cases, showing that Stimfit represents an efficient, accessible and extensible way to accurately analyze and interpret neuronal signals.

Denervation syndromes of the shoulder girdle: MR imaging with electrophysiologic correlation

International Nuclear Information System (INIS)

Bredella, M.A.; Wischer, T.K.; Stork, A.; Genant, H.K.; Tirman, P.F.J.; Fritz, R.C.

1999-01-01

Objective. To investigate the use of MR imaging in the characterization of denervated muscle of the shoulder correlated with electrophysiologic studies.Design and patients. We studied with MR imaging five patients who presented with shoulder weakness and pain and who underwent electrophysiologic studies. On MR imaging the distribution of muscle edema and fatty infiltration was recorded, as was the presence of masses impinging on a regional nerve.Results. Acute/subacute denervation was best seen on T2-weighted fast spin-echo images with fat saturation, showing increased SI related to neurogenic edema. Chronic denervation was best seen on T1-weighted spin-echo images, demonstrating loss of muscle bulk and diffuse areas of increased signal intensity within the muscle. Three patients showed MR imaging and electrophysiologic findings of Parsonage Turner syndrome. One patient demonstrated an arteriovenous malformation within the spinoglenoid notch, impinging on the suprascapular nerve with associated atrophy of the infraspinatus muscle. The fifth patient demonstrated fatty atrophy of the teres minor muscle caused by compression by a cyst of the axillary nerve and electrophysiologic findings of an incomplete axillary nerve block.Conclusion. MR imaging is useful in detecting and characterizing denervation atrophy and neurogenic edema in shoulder muscles. MR imaging can provide additional information to electrophysiologic studies by estimating the age (acute/chronic) and identifying morphologic causes for shoulder pain and atrophy. (orig.)

NeuroPigPen: A Scalable Toolkit for Processing Electrophysiological Signal Data in Neuroscience Applications Using Apache Pig.

Science.gov (United States)

Sahoo, Satya S; Wei, Annan; Valdez, Joshua; Wang, Li; Zonjy, Bilal; Tatsuoka, Curtis; Loparo, Kenneth A; Lhatoo, Samden D

2016-01-01

The recent advances in neurological imaging and sensing technologies have led to rapid increase in the volume, rate of data generation, and variety of neuroscience data. This "neuroscience Big data" represents a significant opportunity for the biomedical research community to design experiments using data with greater timescale, large number of attributes, and statistically significant data size. The results from these new data-driven research techniques can advance our understanding of complex neurological disorders, help model long-term effects of brain injuries, and provide new insights into dynamics of brain networks. However, many existing neuroinformatics data processing and analysis tools were not built to manage large volume of data, which makes it difficult for researchers to effectively leverage this available data to advance their research. We introduce a new toolkit called NeuroPigPen that was developed using Apache Hadoop and Pig data flow language to address the challenges posed by large-scale electrophysiological signal data. NeuroPigPen is a modular toolkit that can process large volumes of electrophysiological signal data, such as Electroencephalogram (EEG), Electrocardiogram (ECG), and blood oxygen levels (SpO2), using a new distributed storage model called Cloudwave Signal Format (CSF) that supports easy partitioning and storage of signal data on commodity hardware. NeuroPigPen was developed with three design principles: (a) Scalability-the ability to efficiently process increasing volumes of data; (b) Adaptability-the toolkit can be deployed across different computing configurations; and (c) Ease of programming-the toolkit can be easily used to compose multi-step data processing pipelines using high-level programming constructs. The NeuroPigPen toolkit was evaluated using 750 GB of electrophysiological signal data over a variety of Hadoop cluster configurations ranging from 3 to 30 Data nodes. The evaluation results demonstrate that the toolkit

Identifying Treatment Response of Sertraline in a Teenager with Selective Mutism using Electrophysiological Neuroimaging.

Science.gov (United States)

Eugene, Andy R; Masiak, Jolanta

2016-06-01

Selective Mutism is described as the inability to verbally express oneself in anxiety provoking social situations and may result in awkward social interactions in school-aged children. In this case-report we present the baseline electrophysiological neuroimaging results and after treatment with Sertraline for 6-weeks. A 20-channel EEG event-related potential recording was acquired during an internal voice task at baseline prior to the initiation of 50mg of Sertraline and then repeated 6-weeks after treatment with Sertraline. EEG signals were processed for movement, eye-blink, and muscle artifacts and ERP signal averaging was completed. ERPs were analyzed using Standard Low Resolution Brain Electromagnetic Tomography (sLORETA). At baseline, Sertraline increased the neuronal activation in the middle temporal gyrus and the anterior cingulate gyrus from baseline in the patient following 6-weeks of treatment. Our findings suggest that electrophysiological neuroimaging may provide a creative approach for personalizing medicine by providing insight to the pharmacodynamics of antidepressants.

Wearable carbon nanotube based dry-electrodes for electrophysiological sensors

Science.gov (United States)

Kang, Byeong-Cheol; Ha, Tae-Jun

2018-05-01

In this paper, we demonstrate all-solution-processed carbon nanotube (CNT) dry-electrodes for the detection of electrophysiological signals such as electrocardiograms (ECG) and electromyograms (EMG). The key parameters of P, Q, R, S, and T peaks are successfully extracted by such CNT based dry-electrodes, which is comparable with conventional silver/chloride (Ag/AgCl) wet-electrodes with a conducting gel film for the ECG recording. Furthermore, the sensing performance of CNT based dry-electrodes is secured during the bending test of 200 cycles, which is essential for wearable electrophysiological sensors in a non-invasive method on human skin. We also investigate the application of wearable CNT based dry-electrodes directly attached to the human skins such as forearm for sensing the electrophysiological signals. The accurate and rapid sensing response can be achieved by CNT based dry-electrodes to supervise the health condition affected by excessive physical movements during the real-time measurements.

Re-visiting the electrophysiology of language.

Science.gov (United States)

Obleser, Jonas

2015-09-01

This editorial accompanies a special issue of Brain and Language re-visiting old themes and new leads in the electrophysiology of language. The event-related potential (ERP) as a series of characteristic deflections ("components") over time and their distribution on the scalp has been exploited by speech and language researchers over decades to find support for diverse psycholinguistic models. Fortunately, methodological and statistical advances have allowed human neuroscience to move beyond some of the limitations imposed when looking at the ERP only. Most importantly, we currently witness a refined and refreshed look at "event-related" (in the literal sense) brain activity that relates itself more closely to the actual neurobiology of speech and language processes. It is this imminent change in handling and interpreting electrophysiological data of speech and language experiments that this special issue intends to capture. Copyright © 2015 Elsevier Inc. All rights reserved.

NeoAnalysis: a Python-based toolbox for quick electrophysiological data processing and analysis.

Science.gov (United States)

Zhang, Bo; Dai, Ji; Zhang, Tao

2017-11-13

In a typical electrophysiological experiment, especially one that includes studying animal behavior, the data collected normally contain spikes, local field potentials, behavioral responses and other associated data. In order to obtain informative results, the data must be analyzed simultaneously with the experimental settings. However, most open-source toolboxes currently available for data analysis were developed to handle only a portion of the data and did not take into account the sorting of experimental conditions. Additionally, these toolboxes require that the input data be in a specific format, which can be inconvenient to users. Therefore, the development of a highly integrated toolbox that can process multiple types of data regardless of input data format and perform basic analysis for general electrophysiological experiments is incredibly useful. Here, we report the development of a Python based open-source toolbox, referred to as NeoAnalysis, to be used for quick electrophysiological data processing and analysis. The toolbox can import data from different data acquisition systems regardless of their formats and automatically combine different types of data into a single file with a standardized format. In cases where additional spike sorting is needed, NeoAnalysis provides a module to perform efficient offline sorting with a user-friendly interface. Then, NeoAnalysis can perform regular analog signal processing, spike train, and local field potentials analysis, behavioral response (e.g. saccade) detection and extraction, with several options available for data plotting and statistics. Particularly, it can automatically generate sorted results without requiring users to manually sort data beforehand. In addition, NeoAnalysis can organize all of the relevant data into an informative table on a trial-by-trial basis for data visualization. Finally, NeoAnalysis supports analysis at the population level. With the multitude of general-purpose functions provided

Electrophysiological Monitoring of Brain Injury and Recovery after Cardiac Arrest

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Ruoxian Deng

2015-10-01

Full Text Available Reliable prognostic methods for cerebral functional outcome of post cardiac-arrest (CA patients are necessary, especially since therapeutic hypothermia (TH as a standard treatment. Traditional neurophysiological prognostic indicators, such as clinical examination and chemical biomarkers, may result in indecisive outcome predictions and do not directly reflect neuronal activity, though they have remained the mainstay of clinical prognosis. The most recent advances in electrophysiological methods—electroencephalography (EEG pattern, evoked potential (EP and cellular electrophysiological measurement—were developed to complement these deficiencies, and will be examined in this review article. EEG pattern (reactivity and continuity provides real-time and accurate information for early-stage (particularly in the first 24 h hypoxic-ischemic (HI brain injury patients with high sensitivity. However, the signal is easily affected by external stimuli, thus the measurements of EP should be combined with EEG background to validate the predicted neurologic functional result. Cellular electrophysiology, such as multi-unit activity (MUA and local field potentials (LFP, has strong potential for improving prognostication and therapy by offering additional neurophysiologic information to understand the underlying mechanisms of therapeutic methods. Electrophysiology provides reliable and precise prognostication on both global and cellular levels secondary to cerebral injury in cardiac arrest patients treated with TH.

A highly versatile and easily configurable system for plant electrophysiology.

Science.gov (United States)

Gunsé, Benet; Poschenrieder, Charlotte; Rankl, Simone; Schröeder, Peter; Rodrigo-Moreno, Ana; Barceló, Juan

2016-01-01

In this study we present a highly versatile and easily configurable system for measuring plant electrophysiological parameters and ionic flow rates, connected to a computer-controlled highly accurate positioning device. The modular software used allows easy customizable configurations for the measurement of electrophysiological parameters. Both the operational tests and the experiments already performed have been fully successful and rendered a low noise and highly stable signal. Assembly, programming and configuration examples are discussed. The system is a powerful technique that not only gives precise measuring of plant electrophysiological status, but also allows easy development of ad hoc configurations that are not constrained to plant studies. •We developed a highly modular system for electrophysiology measurements that can be used either in organs or cells and performs either steady or dynamic intra- and extracellular measurements that takes advantage of the easiness of visual object-oriented programming.•High precision accuracy in data acquisition under electrical noisy environments that allows it to run even in a laboratory close to electrical equipment that produce electrical noise.•The system makes an improvement of the currently used systems for monitoring and controlling high precision measurements and micromanipulation systems providing an open and customizable environment for multiple experimental needs.

Pelvic floor electrophysiology patterns associated with faecal ...

African Journals Online (AJOL)

Hussein Al-Moghazy Sultan

2012-12-28

Dec 28, 2012 ... pelvic floor electrophysiological abnormalities associated with. FI were illustrated in ... detection of a localized anal sphincter defect clinically and ..... Woods R, Voyvodic F, Schloithe A, Sage M, Wattchow D. Anal sphincter ...

Prognostic significance of electrophysiological tests for facial nerve outcome in vestibular schwannoma surgery.

Science.gov (United States)

van Dinther, J J S; Van Rompaey, V; Somers, T; Zarowski, A; Offeciers, F E

2011-01-01

To assess the prognostic significance of pre-operative electrophysiological tests for facial nerve outcome in vestibular schwannoma surgery. Retrospective study design in a tertiary referral neurology unit. We studied a total of 123 patients with unilateral vestibular schwannoma who underwent microsurgical removal of the lesion. Nine patients were excluded because they had clinically abnormal pre-operative facial function. Pre-operative electrophysiological facial nerve function testing (EPhT) was performed. Short-term (1 month) and long-term (1 year) post-operative clinical facial nerve function were assessed. When pre-operative facial nerve function, evaluated by EPhT, was normal, the outcome from clinical follow-up at 1-month post-operatively was excellent in 78% (i.e. HB I-II) of patients, moderate in 11% (i.e. HB III-IV), and bad in 11% (i.e. HB V-VI). After 1 year, 86% had excellent outcomes, 13% had moderate outcomes, and 1% had bad outcomes. Of all patients with normal clinical facial nerve function, 22% had an abnormal EPhT result and 78% had a normal result. No statistically significant differences could be observed in short-term and long-term post-operative facial function between the groups. In this study, electrophysiological tests were not able to predict facial nerve outcome after vestibular schwannoma surgery. Tumour size remains the best pre-operative prognostic indicator of facial nerve function outcome, i.e. a better outcome in smaller lesions.

Clinical, electrophysiological, and prognostic study of postinjection sciatic nerve injury: An avoidable cause of loss of limb in the peripheral medical service

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Wani Maqbool

2009-01-01

Full Text Available Background: Post injection sciatic nerve injury is a common cause of sciatic nerve mononeuropathy in the developing world largely due to inadequate health care facilites in the rural regions. Objective: The study was conducted to analyse the pattern of this nerve lesion in clinical and electrophysiological parameters and also to study the outcome in a conservatively treated cohort. Materials and Methods: One hundred and six patients who underwent evaluation at our laboratory from 2000 to 2006 for post injection sciatic neuropathy formed the study population. Twenty two of these were followed up (mean 6.6 months for the outcome. Results: In the cases with full data, common peroneal division of the sciatic nerve was affected alone or predominantly. On follow up, 72% cases showed little or partial recovery. Thirty two percent patients had residual trophic changes and causalgia at their last visit. Conclusion: The majority of cases of postinjection sciatic nerve injury have poor prognosis on conservative treatment.

Magnetic resonance imaging guided transatrial electrophysiological studies in swine using active catheter tracking - experience with 14 cases

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Grothoff, Matthias; Gutberlet, Matthias [University of Leipzig - Heart Center, Department of Radiology, Leipzig (Germany); Hindricks, Gerhard; Sommer, Philipp; Hilbert, Sebastian [University of Leipzig - Heart Center, Department of Electrophysiology, Leipzig (Germany); Fleiter, Christian [Helios Klinikum Berlin-Buch, Department of Orthopaedic Surgery, Berlin (Germany); Schnackenburg, Bernhard [Philips Healthcare, Hamburg (Germany); Weiss, Steffen; Krueger, Sascha [Philips Innovative Technologies, Hamburg (Germany); Piorkowski, Christopher; Gaspar, Thomas [University of Dresden - Heart Center, Department of Electrophysiology, Dresden (Germany); Wedan, Steve; Lloyd, Thomas [Imricor Medical Systems, Burnsville, MN (United States)

2017-05-15

To evaluate the feasibility of performing comprehensive Cardiac Magnetic resonance (CMR) guided electrophysiological (EP) interventions in a porcine model encompassing left atrial access. After introduction of two femoral sheaths 14 swine (41 ± 3.6 kg) were transferred to a 1.5 T MR scanner. A three-dimensional whole-heart sequence was acquired followed by segmentation and the visualization of all heart chambers using an image-guidance platform. Two MR conditional catheters were inserted. The interventional protocol consisted of intubation of the coronary sinus, activation mapping, transseptal left atrial access (n = 4), generation of ablation lesions and eventually ablation of the atrioventricular (AV) node. For visualization of the catheter tip active tracking was used. Catheter positions were confirmed by passive real-time imaging. Total procedure time was 169 ± 51 minutes. The protocol could be completed in 12 swine. Two swine died from AV-ablation induced ventricular fibrillation. Catheters could be visualized and navigated under active tracking almost exclusively. The position of the catheter tips as visualized by active tracking could reliably be confirmed with passive catheter imaging. Comprehensive CMR-guided EP interventions including left atrial access are feasible in swine using active catheter tracking. (orig.)

How to Evaluate Phase Differences between Trial Groups in Ongoing Electrophysiological Signals

Science.gov (United States)

VanRullen, Rufin

2016-01-01

A growing number of studies endeavor to reveal periodicities in sensory and cognitive functions, by comparing the distribution of ongoing (pre-stimulus) oscillatory phases between two (or more) trial groups reflecting distinct experimental outcomes. A systematic relation between the phase of spontaneous electrophysiological signals, before a stimulus is even presented, and the eventual result of sensory or cognitive processing for that stimulus, would be indicative of an intrinsic periodicity in the underlying neural process. Prior studies of phase-dependent perception have used a variety of analytical methods to measure and evaluate phase differences, and there is currently no established standard practice in this field. The present report intends to remediate this need, by systematically comparing the statistical power of various measures of “phase opposition” between two trial groups, in a number of real and simulated experimental situations. Seven measures were evaluated: one parametric test (circular Watson-Williams test), and three distinct measures of phase opposition (phase bifurcation index, phase opposition sum, and phase opposition product) combined with two procedures for non-parametric statistical testing (permutation, or a combination of z-score and permutation). While these are obviously not the only existing or conceivable measures, they have all been used in recent studies. All tested methods performed adequately on a previously published dataset (Busch et al., 2009). On a variety of artificially constructed datasets, no single measure was found to surpass all others, but instead the suitability of each measure was contingent on several experimental factors: the time, frequency, and depth of oscillatory phase modulation; the absolute and relative amplitudes of post-stimulus event-related potentials for the two trial groups; the absolute and relative trial numbers for the two groups; and the number of permutations used for non-parametric testing

How to achieve ultrasound-guided femoral venous access: the new standard of care in the electrophysiology laboratory.

Science.gov (United States)

Wiles, Benedict M; Child, Nicholas; Roberts, Paul R

2017-06-01

Bedside vascular ultrasound machines are increasingly available. They are used to facilitate safer vascular access across a number of different specialties. In the electrophysiology laboratory however, where patients are frequently anticoagulated and require the insertion of multiple venous sheaths, anatomical landmark techniques predominate. Despite the high number of vascular complications associated with electrophysiological procedures and the increasing evidence to support its use in electrophysiology, ultrasound remains underutilised. A new standard of care is required. A comprehensive technical report, providing a detailed explanation of this important technique, will provide other electrophysiology centres with the knowledge and justification for adopting ultrasound guidance as their standard practice. We review the increasing body of evidence which demonstrates that routine ultrasound usage can substantially improve the safety of femoral venous access in the electrophysiology laboratory. We offer a comprehensive technical report to guide operators through the process of ultrasound-guided venous access, with a specific focus on the electrophysiology laboratory. Additionally, we detail a novel technique which utilises real-time colour Doppler ultrasound to accurately identify needle tip location during venous puncture. The use of vascular ultrasound to guide femoral venous cannulation is rapid, inexpensive and easily learnt. Ultrasound is readily available and offers the potential to significantly reduce vascular complications in the unique setting of the electrophysiology laboratory. Ultrasound guidance to achieve femoral venous access should be the new standard of care in electrophysiology.

Electrophysiological properties and calcium handling of embryonic stem cell-derived cardiomyocytes

Directory of Open Access Journals (Sweden)

Jae Boum Youm

2016-03-01

Full Text Available Embryonic stem cell-derived cardiomyocytes (ESC-CMs hold great interest in many fields of research including clinical applications such as stem cell and gene therapy for cardiac repair or regeneration. ESC-CMs are also used as a platform tool for pharmacological tests or for investigations of cardiac remodeling. ESC-CMs have many different aspects of morphology, electrophysiology, calcium handling, and bioenergetics compared with adult cardiomyocytes. They are immature in morphology, similar to sinus nodal-like in the electrophysiology, higher contribution of trans-sarcolemmal Ca2+ influx to Ca2+ handling, and higher dependence on anaerobic glycolysis. Here, I review a detailed electrophysiology and Ca2+ handling features of ESC-CMs during differentiation into adult cardiomyocytes to gain insights into how all the developmental changes are related to each other to display cardinal features of developing cardiomyocytes.

Electrophysiology of Cranial Nerve Testing: Trigeminal and Facial Nerves.

Science.gov (United States)

Muzyka, Iryna M; Estephan, Bachir

2018-01-01

The clinical examination of the trigeminal and facial nerves provides significant diagnostic value, especially in the localization of lesions in disorders affecting the central and/or peripheral nervous system. The electrodiagnostic evaluation of these nerves and their pathways adds further accuracy and reliability to the diagnostic investigation and the localization process, especially when different testing methods are combined based on the clinical presentation and the electrophysiological findings. The diagnostic uniqueness of the trigeminal and facial nerves is their connectivity and their coparticipation in reflexes commonly used in clinical practice, namely the blink and corneal reflexes. The other reflexes used in the diagnostic process and lesion localization are very nerve specific and add more diagnostic yield to the workup of certain disorders of the nervous system. This article provides a review of commonly used electrodiagnostic studies and techniques in the evaluation and lesion localization of cranial nerves V and VII.

Wolff-Parkinson-White syndrome in young people, from childhood to young adulthood: relationships between age and clinical and electrophysiological findings

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Jung, Hae Jung; Ju, Hwang Young; Hyun, Myung Chul; Lee, Sang Bum

2011-01-01

Purpose The aim of the present study was to evaluate the characteristics of electrophysiologic studies (EPS) and radiofrequency ablation (RFA) performed in subjects aged less than 30 years with Wolff-Parkinson-White (WPW) syndrome, particularly pediatric patients under 18 years of age, based on our experience. Methods Two hundred and one consecutive patients with WPW syndrome were recruited and divided to 3 groups according to age: group 1, 6 to 17 years; group 2, 18 to 29 years; and group 3, 30 to 60 years. The clinical, electrophysiological, and therapeutic data for these patients were evaluated by a retrospective medical record review. Results A total of 73 (36%) of these patients were syndrome. Therefore, when EPS and RFA are performed in children and adolescence with WPW syndrome, we recommend that these characteristics be considered. PMID:22323907

Motor Neuropathy in Hypothyroidism: Clinical and Electrophysiological Findings

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Sabina Yeasmin

2009-11-01

Full Text Available Background: Hypothyroidism is a clinical condition associated with low levels of thyroid hormones with raised TSH. Peripheral neuropathy may be associated with hypothyroidism which usually develops insidiously over a long period of time due to irregular taking of drugs or lack of thyroid hormone replacement. Objectives: The present study was done to evaluate the clinical and electro-physiological findings in hypothyroid patients in order to evaluate the neuromuscular dysfunction as well as motor neuropathy. Method: In this study, 70 subjects with the age range from 20 to 50 years of both sexes were included of whom 40 hypothyroids were taken in study group (B with the duration of 6 months to 5 years and 30 healthy euthyroid subjects were taken as control (Group A. On the basis of their TSH level, group B was further divided into group B1 with TSH level <60 MIU /L (less severe and group B2 with TSH >60 MIU /L (severe group. The d latency and NCV for motor nerve function were measured by NCV machine in median and ulnar nerve for upper limb and in common peroneal nerve for lower limb. TT3, TT4 were measured by RIA and TSH by IRMA method. All these parameters were measured on the day 1 (one of their first visit. Data were analysed statistically by ANOVA and Z test. Result: Both TT3, TT4 levels were significantly (P<0.01 lower in hypothyroids in comparison to those of control. Diminished or absence of most of the deep tendon reflexes were found in all the hypothyroids. Most of the patients (67.5% showed significantly higher (P <0.01 motor distal latencies (MDL with lower (P> 0.001 conduction velocities (MNCV and all these changes were more marked in group B2. Conclusion: So, the study revealed that motor neuropathy may be a consequence of hypothyroidism.DOI: 10.3329/bsmmuj.v1i1.3692 Key Words: Hypothyroidism; neuropathy; electrophysiology BSMMU J 2008; 1(1: 15-18

Electrophysiological assessment of water stress in fruit-bearing woody plants.

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Ríos-Rojas, Liliana; Tapia, Franco; Gurovich, Luis A

2014-06-15

Development and evaluation of a real-time plant water stress sensor, based on the electrophysiological behavior of fruit-bearing woody plants is presented. Continuous electric potentials are measured in tree trunks for different irrigation schedules, inducing variable water stress conditions; results are discussed in relation to soil water content and micro-atmospheric evaporative demand, determined continuously by conventional sensors, correlating this information with tree electric potential measurements. Systematic and differentiable patterns of electric potentials for water-stressed and no-stressed trees in 2 fruit species are presented. Early detection and recovery dynamics of water stress conditions can also be monitored with these electrophysiology sensors, which enable continuous and non-destructive measurements for efficient irrigation scheduling throughout the year. The experiment is developed under controlled conditions, in Faraday cages located at a greenhouse area, both in Persea americana and Prunus domestica plants. Soil moisture evolution is controlled using capacitance sensors and solar radiation, temperature, relative humidity, wind intensity and direction are continuously registered with accurate weather sensors, in a micro-agrometeorological automatic station located at the experimental site. The electrophysiological sensor has two stainless steel electrodes (measuring/reference), inserted on the stem; a high precision Keithley 2701 digital multimeter is used to measure plant electrical signals; an algorithm written in MatLab(®), allows correlating the signal to environmental variables. An electric cyclic behavior is observed (circadian cycle) in the experimental plants. For non-irrigated plants, the electrical signal shows a time positive slope and then, a negative slope after restarting irrigation throughout a rather extended recovery process, before reaching a stable electrical signal with zero slope. Well-watered plants presented a

Multiscale electrophysiology format: an open-source electrophysiology format using data compression, encryption, and cyclic redundancy check.

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Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt

2009-01-01

Continuous, long-term (up to 10 days) electrophysiological monitoring using hybrid intracranial electrodes is an emerging tool for presurgical epilepsy evaluation and fundamental investigations of seizure generation. Detection of high-frequency oscillations and microseizures could provide valuable insights into causes and therapies for the treatment of epilepsy, but requires high spatial and temporal resolution. Our group is currently using hybrid arrays composed of up to 320 micro- and clinical macroelectrode arrays sampled at 32 kHz per channel with 18-bits of A/D resolution. Such recordings produce approximately 3 terabytes of data per day. Existing file formats have limited data compression capabilities, and do not offer mechanisms for protecting patient identifying information or detecting data corruption during transmission or storage. We present a novel file format that employs range encoding to provide a high degree of data compression, a three-tiered 128-bit encryption system for patient information and data security, and a 32-bit cyclic redundancy check to verify the integrity of compressed data blocks. Open-source software to read, write, and process these files are provided.

Sedation for paediatric auditory electrophysiology in South Africa

African Journals Online (AJOL)

emergency departments and nuclear medicine.1 Added to this is the periodic need ... electrophysiology in the paediatric population in South Africa were not found. ..... to inadequate information technology infrastructure as well as limited data ...

Casing Out Evaluation: Expanding Student Interest in Program Evaluation through Case Competitions.

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Obrecht, Michael; Porteous, Nancy; Haddock, Blair

1998-01-01

Describes the authors' experiences in organizing bilingual evaluation case competitions for the National Capital Chapter of the Canadian Evaluation Society for three years. Competition structure, eligibility, judging, contestant recruiting, and preparing cases are outlined. (SLD)

An electrophysiological approach to the diagnosis of neurogenic dysphagia: implications for botulinum toxin treatment.

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Alfonsi, E; Merlo, I M; Ponzio, M; Montomoli, C; Tassorelli, C; Biancardi, C; Lozza, A; Martignoni, E

2010-01-01

Botulinum toxin (BTX) injection into the cricopharyngeal (CP) muscle has been proposed for the treatment of neurogenic dysphagia due to CP hyperactivity. The aim was to determine whether an electrophysiological method exploring oropharyngeal swallowing could guide treatment and discriminate responders from non-responders, based on the association of CP dysfunction with other electrophysiological abnormalities of swallowing. Patients with different neurological disorders were examined: Parkinson disease, progressive supranuclear palsy, multiple system atrophy-Parkinson variant, multiple system atrophy cerebellar variant, stroke, multiple sclerosis and ataxia telangiectasia. All patients presented with clinical dysphagia, and with complete absence of CP muscle inhibition during the hypopharyngeal phase of swallowing. Each patient underwent clinical and electrophysiological investigations before and after treatment with BTX into the CP muscle of one side (15 units of Botox). Clinical and electrophysiological procedures were performed in a blind manner by two different investigators. The following electrophysiological measures were analysed: (1) duration of EMG activity of suprahyoid/submental muscles (SHEMG-D); (2) duration of laryngopharyngeal mechanogram (LPM-D); (3) duration of the inhibition of the CP muscle EMG activity (CPEMG-ID); and (4) interval between onset of EMG activity of suprahyoid/submental muscles and onset of laryngopharyngeal mechanogram (I-SHEMG-LPM). Two months after treatment, 50% of patients showed a significant improvement. Patients with prolonged or reduced SHEMG-D values and prolonged I-SHEMG-LPM values did not respond to BTX. Therefore, values for which BTX had no effect (warning values) were identified. This electrophysiological method can recognise swallowing abnormalities which may affect the outcome of the therapeutic approach to dysphagia with BTX treatment.

Effects of indocyanine green videoangiography and electrophysiological monitoring on surgery for intracranial aneurysms

International Nuclear Information System (INIS)

Arai, Yoshikazu; Kitai, Ryuhei; Awara, Kosuke

2011-01-01

We analyzed the outcome of 62 consecutive patients with unruptured intracranial aneurysm treated by surgical clipping. Thirty-one cases were operated without intraoperative monitoring, 17 cases with indocyanine green videoangiography (ICGA), and 14 cases with electrophysiological monitoring (EPM) in addition to ICGA. Complete obliteration of the aneurysm was confirmed in all 62 cases. Diffusion-weighted imaging of MRI disclosed no ischemic lesions after surgery in any of the cases. Asymptomatic venous infarction was detected by CT study in 2 cases. Cranial nerve palsy occurred in 4 cases but EPM could not detect it. There was no difference among the group without monitoring, the group with ICGA and the group with ICGA and EPM. The mortality and morbidity of all cases was calculated as 0% and 6.5%, respectively. ICGA appeared to be useful in surgery for aneurysms encasing perforators or for repair of problems such as premature rupture. eicosapentaenoic acid (EPA) seemed effective in surgery for anterior choroidal artery aneurysms or aneurysms requiring trapping before clipping. However, monitoring would not have been effective without extensive dissection of aneurysms, suggesting that basic microsurgical techniques are crucial for successful surgery. (author)

On the identification of multiple space dependent ionic parameters in cardiac electrophysiology modelling

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Abidi, Yassine; Bellassoued, Mourad; Mahjoub, Moncef; Zemzemi, Nejib

2018-03-01

In this paper, we consider the inverse problem of space dependent multiple ionic parameters identification in cardiac electrophysiology modelling from a set of observations. We use the monodomain system known as a state-of-the-art model in cardiac electrophysiology and we consider a general Hodgkin-Huxley formalism to describe the ionic exchanges at the microscopic level. This formalism covers many physiological transmembrane potential models including those in cardiac electrophysiology. Our main result is the proof of the uniqueness and a Lipschitz stability estimate of ion channels conductance parameters based on some observations on an arbitrary subdomain. The key idea is a Carleman estimate for a parabolic operator with multiple coefficients and an ordinary differential equation system.

Wolff-Parkinson-White syndrome in young people, from childhood to young adulthood: relationships between age and clinical and electrophysiological findings

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Hae Jung Jung

2011-12-01

Full Text Available Purpose : The aim of the present study was to evaluate the characteristics of electrophysiologic studies (EPS and radiofrequency ablation (RFA performed in subjects aged less than 30 years with Wolff-Parkinson-White (WPW syndrome, particularly pediatric patients under 18 years of age, based on our experience. Methods : Two hundred and one consecutive patients with WPW syndrome were recruited and divided to 3 groups according to age: group 1, 6 to 17 years; group 2, 18 to 29 years; and group 3, 30 to 60 years. The clinical, electrophysiological, and therapeutic data for these patients were evaluated by a retrospective medical record review. Results : A total of 73 (36% of these patients were &lt;30 years of age. Although there were more males than females in group 2 (male:female, 31:11, there was no sex difference in group 1 (male:female, 16:15. Left accessory pathway was detected less frequently in group 1 (32%, 10/31 than in group 2 (57%, 24/42 and group 3 (63%, 81/128 (P=0.023 and P=0.002, respectively. Conclusion : The present study describes several different electrophysiological characteristics in children and adolescents with WPW syndrome. Therefore, when EPS and RFA are performed in children and adolescence with WPW syndrome, we recommend that these characteristics be considered.

Scalable electrophysiology in intact small animals with nanoscale suspended electrode arrays

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Gonzales, Daniel L.; Badhiwala, Krishna N.; Vercosa, Daniel G.; Avants, Benjamin W.; Liu, Zheng; Zhong, Weiwei; Robinson, Jacob T.

2017-07-01

Electrical measurements from large populations of animals would help reveal fundamental properties of the nervous system and neurological diseases. Small invertebrates are ideal for these large-scale studies; however, patch-clamp electrophysiology in microscopic animals typically requires invasive dissections and is low-throughput. To overcome these limitations, we present nano-SPEARs: suspended electrodes integrated into a scalable microfluidic device. Using this technology, we have made the first extracellular recordings of body-wall muscle electrophysiology inside an intact roundworm, Caenorhabditis elegans. We can also use nano-SPEARs to record from multiple animals in parallel and even from other species, such as Hydra littoralis. Furthermore, we use nano-SPEARs to establish the first electrophysiological phenotypes for C. elegans models for amyotrophic lateral sclerosis and Parkinson's disease, and show a partial rescue of the Parkinson's phenotype through drug treatment. These results demonstrate that nano-SPEARs provide the core technology for microchips that enable scalable, in vivo studies of neurobiology and neurological diseases.

A comparison of neuronal growth cone and cell body membrane: electrophysiological and ultrastructural properties.

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Guthrie, P B; Lee, R E; Kater, S B

1989-10-01

This study investigated a broad set of general electrophysiological and ultrastructural features of growth cone and cell body membrane of individual neurons where membrane from different regions of the same neuron can be directly compared. Growth cones were surgically isolated from identified adult Helisoma neurons in culture and compared with the cell body using whole-cell patch-clamp recording techniques. All isolated growth cones generated overshooting regenerative action potentials. Five neurons (buccal neurons B4, B5, and B19; pedal neurons P1 and P5) were selected that displayed distinctive action potential waveforms. In all cases, the growth cone action potential was indistinguishable from the cell body action potential and different from growth cones from other identified neurons. Two of these neurons (B5 and B19) were studied further using voltage-clamp procedures; growth cones and cell bodies again revealed major similarities within one neuron type and differences between neuron types. The only suggested difference between the growth cone and cell body was an apparent reduction in the magnitude of the A-current in the growth cone. Peak inward and outward current densities, as with other electrophysiological features, were different between neuron types, but were, again, similar between the growth cone and the cell body of the same neuron. Freeze-fracture analysis of intramembraneous particles (IMPs) was also performed on identified regions of the same neuron in culture. Both the density and the size distribution of IMPs were the same in growth cone, cell body, and neurite membranes. In these general electrophysiological and ultrastructural characteristics, therefore, growth cone membranes appear to retain the identity of the parent neuron cell body membrane.

Ultraconformable Temporary Tattoo Electrodes for Electrophysiology

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Ferrari, Laura M.; Sudha, Sudha; Tarantino, Sergio; Esposti, Roberto; Bolzoni, Francesco; Cavallari, Paolo; Cipriani, Christian

2018-01-01

Abstract Electrically interfacing the skin for monitoring personal health condition is the basis of skin‐contact electrophysiology. In the clinical practice the use of stiff and bulky pregelled or dry electrodes, in contrast to the soft body tissues, imposes severe restrictions to user comfort and mobility while limiting clinical applications. Here, in this work dry, unperceivable temporary tattoo electrodes are presented. Customized single or multielectrode arrays are readily fabricated by inkjet printing of conducting polymer onto commercial decal transfer paper, which allows for easy transfer on the user's skin. Conformal adhesion to the skin is provided thanks to their ultralow thickness (Tattoo electrode–skin contact impedance is characterized on short‐ (1 h) and long‐term (48 h) and compared with standard pregelled and dry electrodes. The viability in electrophysiology is validated by surface electromyography and electrocardiography recordings on various locations on limbs and face. A novel concept of tattoo as perforable skin‐contact electrode, through which hairs can grow, is demonstrated, thus permitting to envision very long‐term recordings on areas with high hair density. The proposed materials and patterning strategy make this technology amenable for large‐scale production of low‐cost sensing devices. PMID:29593975

Electrophysiological and structural remodeling in heart failure modulate arrhythmogenesis. 2D simulation study.

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Juan F Gomez

Full Text Available Heart failure is operationally defined as the inability of the heart to maintain blood flow to meet the needs of the body and it is the final common pathway of various cardiac pathologies. Electrophysiological remodeling, intercellular uncoupling and a pro-fibrotic response have been identified as major arrhythmogenic factors in heart failure.In this study we investigate vulnerability to reentry under heart failure conditions by incorporating established electrophysiological and anatomical remodeling using computer simulations.The electrical activity of human transmural ventricular tissue (5 cm × 5 cm was simulated using the human ventricular action potential model Grandi et al. under control and heart failure conditions. The MacCannell et al. model was used to model fibroblast electrical activity, and their electrotonic interactions with myocytes. Selected degrees of diffuse fibrosis and variations in intercellular coupling were considered and the vulnerable window (VW for reentry was evaluated following cross-field stimulation.No reentry was observed in normal conditions or in the presence of HF ionic remodeling. However, defined amount of fibrosis and/or cellular uncoupling were sufficient to elicit reentrant activity. Under conditions where reentry was generated, HF electrophysiological remodeling did not alter the width of the VW. However, intermediate fibrosis and cellular uncoupling significantly widened the VW. In addition, biphasic behavior was observed, as very high fibrotic content or very low tissue conductivity hampered the development of reentry. Detailed phase analysis of reentry dynamics revealed an increase of phase singularities with progressive fibrotic components.Structural remodeling is a key factor in the genesis of vulnerability to reentry. A range of intermediate levels of fibrosis and intercellular uncoupling can combine to favor reentrant activity.

Electrophysiological changes in rats after modulated microwave irradiation

International Nuclear Information System (INIS)

Szabo, L.D.; Thuroczy, G.; Kubinyi, G.; Bakos, J.

1992-01-01

The effects of modulated microwave irradiation on the electrophysiological changes in rats were studied. The response of the central nervous system (CNS) was observed simultaneously to the cardiovascular system by using quantitative polygraphic measuring system. In acute experiments on rat the electroencephalogram (EEG), rheoencephalogram (REG) as an index of cerebral blood flow (CBF), brain tissue DC impedance and temperature, ECG were recorded in parallel before, during and after exposure of the brain localized amplitude (AM) modulated (16 Hz) and continuous wave (CW) microwave exposure. The average specific absorption rates (SAR) in the brain were 8.4 mW/g, 16.8 mW/g and 42 mW/g (CW) respectively. At thermal level CW exposure the delta band of EEG increased. In case of low intensities modulated exposure the beta band of EEG spectrum increased. No changes were observed during athermal CW irradiation on the EEG. Moderate modulation depended changes were measured in cerebral metabolism, cerebral blood flow and cardiorespiratoric system during microwave irradiation. (author)

Electrophysiological evaluation of phrenic nerve injury during cardiac surgery – a prospective, controlled, clinical study

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Ege Turan

2004-01-01

Full Text Available Abstract Background According to some reports, left hemidiaphragmatic paralysis due to phrenic nerve injury may occur following cardiac surgery. The purpose of this study was to document the effects on phrenic nerve injury of whole body hypothermia, use of ice-slush around the heart and mammary artery harvesting. Methods Electrophysiology of phrenic nerves was studied bilaterally in 78 subjects before and three weeks after cardiac or peripheral vascular surgery. In 49 patients, coronary artery bypass grafting (CABG and heart valve replacement with moderate hypothermic (mean 28°C cardiopulmonary bypass (CPB were performed. In the other 29, CABG with beating heart was performed, or, in several cases, peripheral vascular surgery with normothermia. Results In all patients, measurements of bilateral phrenic nerve function were within normal limits before surgery. Three weeks after surgery, left phrenic nerve function was absent in five patients in the CPB and hypothermia group (3 in CABG and 2 in valve replacement. No phrenic nerve dysfunction was observed after surgery in the CABG with beating heart (no CPB or the peripheral vascular groups. Except in the five patients with left phrenic nerve paralysis, mean phrenic nerve conduction latency time (ms and amplitude (mV did not differ statistically before and after surgery in either group (p > 0.05. Conclusions Our results indicate that CPB with hypothermia and local ice-slush application around the heart play a role in phrenic nerve injury following cardiac surgery. Furthermore, phrenic nerve injury during cardiac surgery occurred in 10.2 % of our patients (CABG with CPB plus valve surgery.

Misonidazole neurotoxicity in the mouse: evaluation of functional, pharmacokinetic, electrophysiologic and morphologic parameters

International Nuclear Information System (INIS)

Conroy, P.J.; Von Burg, R.; Passalacqua, W.; Penney, D.P.; Sutherland, R.M.

1979-01-01

The neurotoxic effects of chronic administration of misonidazole (0.3 mg/g/day, 5 times weekly) were investigated in Balb/cKa mice over 12 weeks; a variety of measurements were used, including functional and clinical performance, morphologic, electrophysiologic and pharmacokinetic parameters. The half life of drug for a single dose was greater in brain (3 hrs) compared to serum (1.2 hrs); these values decreased to 1.9 hrs and 1.0 hrs respectively after 3 weeks. Misonidazole induced a peripheral lesion after three weeks with a total administered dose of 13.5 g/m 2 or exposure dose of 57 to 75 mM X hrs, which is similar to the doses that cause neuropathy in humans. There was some suggestion of a central neurological deficit related to locomotor control and balance; however, no gross morphological damage was found in the brain. The sequence of effects demonstrated began at 3 to 4 weeks and included: 1) morphologic damage to peripheral nerves; 2) hyperactivity and listlessness; 3) a decrease in rotarod retention time which reached a value 50% of that of saline injected control mice at 8 to 10 weeks; 4) walking on tip-toes with a slightly hunched back (4 to 6 weeks); and 5) an increase in hind foot splay (6 to 7 weeks). The morphologic damage primarily involved the more distal portions of the nerves supplying the interosseous muscles and footpads of the hind limbs. The damage was more severe and progressed more rapidly with time in these distal areas compared to the more proximal regions of the nerves. No marked changes were found in nerve conduction velocity although neuropathy produced by acrylamide produced significant decreases. The changes in neurological parameters reported here may be useful in the further evaluation of hypoxic cell radiosensitizers

Retinal Electrophysiology Is a Viable Preclinical Biomarker for Drug Penetrance into the Central Nervous System

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Jason Charng

2016-01-01

Full Text Available Objective. To examine whether retinal electrophysiology is a useful surrogate marker of drug penetrance into the central nervous system (CNS. Materials and Methods. Brain and retinal electrophysiology were assessed with full-field visually evoked potentials and electroretinograms in conscious and anaesthetised rats following systemic or local administrations of centrally penetrant (muscimol or nonpenetrant (isoguvacine compounds. Results. Local injections into the eye/brain bypassed the blood neural barriers and produced changes in retinal/brain responses for both drugs. In conscious animals, systemic administration of muscimol resulted in retinal and brain biopotential changes, whereas systemic delivery of isoguvacine did not. General anaesthesia confounded these outcomes. Conclusions. Retinal electrophysiology, when recorded in conscious animals, shows promise as a viable biomarker of drug penetration into the CNS. In contrast, when conducted under anaesthetised conditions confounds can be induced in both cortical and retinal electrophysiological recordings.

Electrophysiological study for comparing the effect of biological activity between type A botulinum toxins in rat gastrocnemius muscle.

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Kim, C-S; Jang, W S; Son, I P; Nam, S H; Kim, Y I; Park, K Y; Kim, B J; Kim, M N

2013-09-01

New cosmetic applications and products based on the effects of botulinum toxin (BTX) treatment have stimulated demand for this class of natural compounds. This demand generates the need for appropriate standardized protocols to test and compare the effectiveness of new BTX preparations. Based on the previously described electrophysiological methods, we measured and compared the inhibitory effects of two BTX type A (BTX-A) preparations on neuromuscular transmission through split-body test. The effectiveness was evaluated in terms of the compound muscle action potential (CMAP) and conduction velocity after BTX-A injection. We used a split-body method to compare two different BTX-As in the rat. Based on the changes in the CMAP, the two different BTX-As induced paralytic effect on the rat tibialis anterior muscle. However, the two different BTX-A preparations did not differ significantly in effectiveness and did not induce a delay in conduction velocity. The new BTX-A preparation used in this electrophysiological study had similar effect compared with the previously marketed BTX-A.[AQ: Please approve the edits made to the sentence "The new BTX-A preparation…") We propose that a split-body electrophysiological protocol will be useful in establishing the comparative effectiveness of new BTX products.

Electrophysiological and histological changes in extrinsic muscles proximal to post burn contractures of hand.

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Bhattacharya, V; Purwar, Shammi; Joshi, D; Kumar, M; Mandal, S; Chaudhuri, G R; Bhattacharya, S

2011-06-01

Burn scar hand contractures of variable degree are frequently encountered. Although the forearm is apparently spared, it was clinically observed that there was disuse atrophy in the unburnt extrinsic forearm muscles. Usually the clinicians do not give much importance to this fact. The girth at the midforearm was significantly reduced as compared to normal side. The flexion of the hand joints are governed by two components (a) intrinsic and (b) extrinsic muscles. The intrinsic muscles are directly involved in the contracted tissue. Therefore it was thought essential to evaluate the extrinsic group of muscles for their contribution in the final functional recovery following corrective surgery. Thirty patients having unilateral post thermal burn contracture sparing forearm were studied. A detailed clinical evaluation was made including grade of contracture and reduction in the forearm girth. The forearm unburnt muscles were evaluated by preoperative electrophysiological studies. Intraoperative biopsies were taken from these muscles for histopathological examination. On histopathological examination, there were significant abnormal changes in the form of muscle fiber atrophy, fibrolipomatous tissue replacement of atrophic muscle fibers and sarcolemmal changes. These changes were directly proportional to the severity of contractures. The electrophysiological studies showed proportionate changes in the form of reduction in amplitude, duration and interference. This study suggests that if these changes are mild and in reversible stage, they will favourably affect the functional recovery following surgery. However if these changes are of severe grade and irreversible, in spite of adequate surgery, splinting and physiotherapy, the functional recovery may not be complete. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

Electrophysiological and pathological study of focal cortical dysplasia

International Nuclear Information System (INIS)

Hodozuka, Akira; Hashizume, Kiyotaka; Hayashi, Yoshimitsu; Tanaka, Tatsuya

2008-01-01

Clinical and experimental studies on focal cortical dysplasia (FCD) were carried out. For the experimental study, an experimental FCD model of rats was developed. Twenty Wistar rats at 0-2 days after birth were used for the study. Kainic acid (KA) solution was injected stereotaxically into medial and lateral sites of the sensori-motor cortex. Bipolar electrodes were inserted. The behavior of the rats and electroencephalography (EEG) were recorded using a digital video-EEG monitoring system. After observation periods of 1, 2 and 6 months, the rats were perfused for pathological study. FCD was observed adjacent to the site of KA injection in all rats more than one month after the injection. EEG recording demonstrated focal spike discharges in and around the site of injection. However, clinical seizure was not observed. Pathological studies showed decrease in gamma aminobutyric acid (GABA)-A receptors and increase in GABA-B receptors not only in the lesion but also in perilesional areas. Fifteen surgical cases of FCD with intractable epilepsy were included in the clinical study. Neuro-imaging studies including high-resolution MRI and single photon emission computed tomography (SPECT) were performed. Conventional EEG studies demonstrated focal EEG abnormalities with epileptic phenomena. At surgery, intraoperative electrocorticography (ECoG) was performed in order to localize epileptic foci under neuroleptanalgesia. Fourteen patients showed epileptiform discharges on preresection ECoG. All foci in non-eloquent areas were resected. Pathological studies including immunohistochemical staining were performed, and characteristics of the FCD in relation to EEG findings were analyzed. Electrophysiological examination revealed epileptogenecity not only in the lesions but also in perilesional areas. In the lesions, immunohistochemical studies showed decrease in GABA-A receptors and increase in GABA-B receptors in both the lesions and perilesional areas, but N

Value of Noninvasive Electrophysiological Examination in Choice of Management of Children with Sinus Node Dysfunction

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N.V. Nagornaya

2012-02-01

Full Text Available In the article there are presented the data about noninvasive electrophysiological examination and its application in pediatrics. The clinical case of observation of 15-year-old child who went in for sports for a long time, with sick sinus syndrome supposed in the beginning of diagnostic search, is resulted. The difficulties of differential diagnosis of this syndrome and vegetative dysfunction of sinus node are presented. The role of transesophageal pacing in making a diagnosis and solution of a question about necessity of artificial pacemaker implantation is shown.

Review: electrophysiology of basal ganglia and cortex in models of Parkinson disease.

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Ellens, Damien J; Leventhal, Daniel K

2013-01-01

Incomplete understanding of the systems-level pathophysiology of Parkinson Disease (PD) remains a significant barrier to improving its treatment. Substantial progress has been made, however, due to the availability of neurotoxins that selectively target monoaminergic (in particular, dopaminergic) neurons. This review discusses the in vivo electrophysiology of basal ganglia (BG), thalamic, and cortical regions after dopamine-depleting lesions. These include firing rate changes, neuronal burst-firing, neuronal oscillations, and neuronal synchrony that result from a combination of local microanatomic changes and network-level interactions. While much is known of the clinical and electrophysiological phenomenology of dopamine loss, a critical gap in our conception of PD pathophysiology is the link between them. We discuss potential mechanisms by which these systems-level electrophysiological changes may emerge, as well as how they may relate to clinical parkinsonism. Proposals for an updated understanding of BG function are reviewed, with an emphasis on how emerging frameworks will guide future research into the pathophysiology and treatment of PD.

Breadboard Amplifier: Building and Using Simple Electrophysiology Equipment.

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Crisp, Kevin M; Lin, Hunter; Prosper, Issa

2016-01-01

Electrophysiology is a valuable skill for the neuroscientist, but the learning curve for students can be steep. Here we describe a very simple electromyography (EMG) amplifier that can be built from scratch by students with no electronics experience in about 30 minutes, making it ideal for incorporating into a laboratory activity. With few parts and no adjustments except the gain, students can begin physiology experiments quickly while having the satisfaction of having built the equipment themselves. Because the output of the circuit goes to a computer sound card, students can listen to electrophysiological activity as they see it on the computer screen, a feature many of our students greatly appreciated. Various applications are discussed, including dual channel recording, using streaming media platforms with remote lab partners and acquiring data in the field on a smart phone. Our students reported that they enjoyed being able to build a working device and using it to record from their own muscles.

Brain imaging and electrophysiology biomarkers: is there a role in poverty and education outcome research?

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Pavlakis, Alexandra E; Noble, Kimberly; Pavlakis, Steven G; Ali, Noorjahan; Frank, Yitzchak

2015-04-01

Prekindergarten educational interventions represent a popular approach to improving educational outcomes, especially in children from poor households. Children from lower socioeconomic groups are at increased risk for delays in cognitive development that are important for school success. These delays, which may stem from stress associated with poverty, often develop before kindergarten. Early interventions have been proposed, but there is a need for more information on effectiveness. By assessing socioeconomic differences in brain structure and function, we may better be able to track the neurobiologic basis underlying children's cognitive improvement. We conducted a review of the neuroimaging and electrophysiology literature to evaluate what is known about differences in brain structure and function as assessed by magnetic resonance imaging and electrophysiology and evoked response potentials among children from poor and nonpoor households. Differences in lower socioeconomic groups were found in functional magnetic resonance imaging, diffusion tensor imaging, and volumetric magnetic resonance imaging as well as electroencephalography and evoked response potentials compared with higher socioeconomic groups. The findings suggest a number of neurobiologic correlates for cognitive delays in children who are poor. Given this, we speculate that magnetic resonance imaging and electrophysiology parameters might be useful as biomarkers, after more research, for establishing the effectiveness of specific prekindergarten educational interventions. At the very least, we suggest that to level the playing field in educational outcomes, it may be helpful to foster communication and collaboration among all professionals involved in the care and education of children. Copyright © 2015 Elsevier Inc. All rights reserved.

Distinct electrophysiological potentials for intention in action and prior intention for action

DEFF Research Database (Denmark)

Vinding, Mikkel C; Jensen, Mads; Overgaard, Morten

2014-01-01

The role of conscious intention in relation to motoric movements has become a major topic of investigation in neuroscience. Traditionally, reports of conscious intention have been compared to various features of the readiness-potential (RP) – an electrophysiological signal that appears before...... electrophysiological “intention potential” above the mid-frontal areas at the time participants formed a distal intention. This potential was only found when the distal intention was self-paced and not when the intention was formed in response to an external cue....

Resuscitation great. Luigi Galvani and the foundations of electrophysiology.

Science.gov (United States)

Cajavilca, Christian; Varon, Joseph; Sternbach, George L

2009-02-01

Luigi Galvani became one of the greatest scientists of the 18th century with his research and the development of his theory on animal electricity. His work was appreciated by many scientists. Nevertheless, it gave rise to one of the most passionate scientific debates in history when Alessandro Volta postulated that Galvani had confused intrinsic animal electricity with small currents produced by metals. This debate would result in the creation of electrophysiology, electromagnetism, electrochemistry and the electrical battery. Galvani responded to each of the postulated theories of Volta giving irrefutable proof of the involvement of electricity in the contraction of muscles. However, his work was subsequently abandoned and silenced for many years but his ideas and theories were finally confirmed by the creation of new instruments and the interest of new scientists who helped position Galvani as the father of electrophysiology.

Electrophysiological studies in thyrotoxicosis with and without associated sick sinus syndrome

International Nuclear Information System (INIS)

Talwar, K.K.; Gupta, V.; Kaul, U.; Ahuja, M.M.; Bhatia, M.L.

1987-01-01

Electrophysiological studies in 13 patients with thyrotoxicosis (5 men and 8 women, aged 17 to 76 years) are reported. Five patients presented with features of sick sinus syndrome (SSS) (Group A) while the remaining 8 patients (Group B) had no detectable cardiovascular abnormality. Sinus node function (corrected sinus node recovery and sinoatrial conduction time) was abnormal in all Group A but normal in Group B patients. Intra-atrial, artioventricular (AV) nodal, and infranodal conduction time and effective refractory period of atrium were normal in all patients in both groups. Effective refractory period of AV node was decreased in 6 patients (3 in each group). All Group A patients received radioiodine with complete clinical remission of sick sinus state in 4 subjects. Repeat electrophysiological studies in two of these patients, 6 and 12 months after treatment, showed complete normalization of sinus node function. This is the first reported electrophysiological study documenting the occurrence of SSS in thyrotoxicosis reversed by effective antithyroid treatment. We suggest that attempts should be made to identify underlying thyrotoxicosis in all patients with SSS, especially in the older age group. Appropriate medical treatment may prevent unnecessary implantation of permanent pacemakers in such patients

Electrophysiological evidence for enhanced representation of food stimuli in working memory.

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Rutters, Femke; Kumar, Sanjay; Higgs, Suzanne; Humphreys, Glyn W

2015-02-01

Studies from our laboratory have shown that, relative to neutral objects, food-related objects kept in working memory (WM) are particularly effective in guiding attention to food stimuli (Higgs et al. in Appetite, 2012). Here, we used electrophysiological measurements to investigate the neural representation of food versus non-food items in WM. Subjects were presented with a cue (food or non-food item) to either attend to or hold in WM. Subsequently, they had to search for a target, while the target and distractor were each flanked by a picture of a food or non-food item. Behavioural data showed that a food cue held in WM modulated the deployment of visual attention to a search target more than a non-food cue, even though the cue was irrelevant for target selection. Electrophysiological measures of attention, memory and retention of memory (the P3, LPP and SPCN components) were larger when food was kept in WM, compared to non-food items. No such effect was observed in a priming task, when the initial cue was merely identified. Overall, our electrophysiological data are consistent with the suggestion that food stimuli are particularly strongly represented in the WM system.

Existence of a sex pheromone in Triatoma infestans (Hemiptera: Reduvidae: II. Electrophysiological correlates

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Maria G. de Brito Sanchez

1995-10-01

Full Text Available The stimulus provided by a copulating pair of Triatoma infestans significantly affects the electrical activity of the nervous system of Triatoma infestans. Electrophysiological recordings were perfomed on stationary adult males presented with stimuli of an air current carrying odors from males, females, non-copulating pairs and mating pairs. The electrophysiological response was characterized by the low frequency occurrence of biphasic compound impulses. A significant increase in the frequency of the impulses occurred in stationary males when exposed to air currents of mating pairs, when compared to that evoked by a clean air stream. Analysis of the time course of the assays, showed that the electrophisiological activity during the copula was higher than prior to or after copula. The electrophysiological evidence presented here strongly supports the existence of pheromone(s released by one or both sexes during mating and which is perceived by male chemoreceptors located on the antennae.

Electrophysiological studies in healthy subjects involving caffeine

OpenAIRE

Carvalho, Mamede de; Marcelino, Erica; Mendonça, Alexandre de

2010-01-01

Copyright ©2012 IOS Press All rights reserved. We review the electrophysiological studies concerning the effects of caffeine on muscle, lower and upper motor neuron excitability and cognition. Several different methods have been used, such as electromyography, recruitment analysis, H-reflex, transcranial magnetic stimulation (TMS), electroencephalography and event-related potentials. The positive effect of caffeine on vigilance, attention, speed of reaction, information processing and arou...

Automatic Parameterization Strategy for Cardiac Electrophysiology Simulations

OpenAIRE

Costa, Caroline Mendonca; Hoetzl, Elena; Rocha, Bernardo Martins; Prassl, Anton J; Plank, Gernot

2013-01-01

Driven by recent advances in medical imaging, image segmentation and numerical techniques, computer models of ventricular electrophysiology account for increasingly finer levels of anatomical and biophysical detail. However, considering the large number of model parameters involved parameterization poses a major challenge. A minimum requirement in combined experimental and modeling studies is to achieve good agreement in activation and repolarization sequences between model and experiment or ...

Electrophysiological evidence for phenomenal consciousness.

Science.gov (United States)

Revonsuo, Antti; Koivisto, Mika

2010-09-01

Abstract Recent evidence from event-related brain potentials (ERPs) lends support to two central theses in Lamme's theory. The earliest ERP correlate of visual consciousness appears over posterior visual cortex around 100-200 ms after stimulus onset. Its scalp topography and time window are consistent with recurrent processing in the visual cortex. This electrophysiological correlate of visual consciousness is mostly independent of later ERPs reflecting selective attention and working memory functions. Overall, the ERP evidence supports the view that phenomenal consciousness of a visual stimulus emerges earlier than access consciousness, and that attention and awareness are served by distinct neural processes.

History of Bioelectrical Study and the Electrophysiology of the Primo Vascular System

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Sang Hyun Park

2013-01-01

Full Text Available Background. Primo vascular system is a new anatomical structure whose research results have reported the possibility of a new circulatory system similar to the blood vascular system and cells. Electrophysiology, which measures and analyzes bioelectrical signals tissues and cells, is an important research area for investigating the function of tissues and cells. The bioelectrical study of the primo vascular system has been reported by using modern techniques since the early 1960s by Bonghan Kim. This paper reviews the research result of the electrophysiological study of the primo vascular system for the discussion of the circulatory function. We hope it would help to study the electrophysiology of the primo vascular system for researchers. This paper will use the following exchangeable expressions: Kyungrak system = Bonghan system = Bonghan circulatory system = primo vascular system = primo system; Bonghan corpuscle = primo node; Bonghan duct = primo vessel. We think that objective descriptions of reviewed papers are more important than unified expressions when citing the papers. That said, this paper will unify the expressions of the primo vascular system.

Electrophysiological assessment in patients with Mobius syndrome and clumsiness.

NARCIS (Netherlands)

Verzijl, H.T.F.M.; Padberg, G.W.A.M.; Zwarts, M.J.

2005-01-01

The authors studied the nature of clumsiness in Mobius syndrome in terms of motor or sensory deficits, and sought to clarify the pathophysiological mechanism of the syndrome. Standardized electrophysiologic studies were conducted, with special emphasis on the long motor and sensory tracts and

An electrophysiological study of the impact of a Forward Collision Warning System in a simulator driving task.

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Bueno, Mercedes; Fabrigoule, Colette; Deleurence, Philippe; Ndiaye, Daniel; Fort, Alexandra

2012-08-27

Driver distraction has been identified as the most important contributing factor in rear-end collisions. In this context, Forward Collision Warning Systems (FCWS) have been developed specifically to warn drivers of potential rear-end collisions. The main objective of this work is to evaluate the impact of a surrogate FCWS and of its reliability according to the driver's attentional state by recording both behavioral and electrophysiological data. Participants drove following a lead motorcycle in a simplified simulator with or without a warning system which gave forewarning of the preceding vehicle braking. Participants had to perform this driving task either alone (simple task) or simultaneously with a secondary cognitive task (dual task). Behavioral and electrophysiological data contributed to revealing a positive effect of the warning system. Participants were faster in detecting the brake light when the system was perfect or imperfect, and the time and attentional resources allocation required for processing the target at higher cognitive level were reduced when the system was completely reliable. When both tasks were performed simultaneously, warning effectiveness was considerably affected at both performance and neural levels; however, the analysis of the brain activity revealed fewer differences between distracted and undistracted drivers when using the warning system. These results show that electrophysiological data could be a valuable tool to complement behavioral data and to have a better understanding of how these systems impact the driver. Copyright © 2012 Elsevier B.V. All rights reserved.

Optimizing Nanoelectrode Arrays for Scalable Intracellular Electrophysiology.

Science.gov (United States)

Abbott, Jeffrey; Ye, Tianyang; Ham, Donhee; Park, Hongkun

2018-03-20

Electrode technology for electrophysiology has a long history of innovation, with some decisive steps including the development of the voltage-clamp measurement technique by Hodgkin and Huxley in the 1940s and the invention of the patch clamp electrode by Neher and Sakmann in the 1970s. The high-precision intracellular recording enabled by the patch clamp electrode has since been a gold standard in studying the fundamental cellular processes underlying the electrical activities of neurons and other excitable cells. One logical next step would then be to parallelize these intracellular electrodes, since simultaneous intracellular recording from a large number of cells will benefit the study of complex neuronal networks and will increase the throughput of electrophysiological screening from basic neurobiology laboratories to the pharmaceutical industry. Patch clamp electrodes, however, are not built for parallelization; as for now, only ∼10 patch measurements in parallel are possible. It has long been envisioned that nanoscale electrodes may help meet this challenge. First, nanoscale electrodes were shown to enable intracellular access. Second, because their size scale is within the normal reach of the standard top-down fabrication, the nanoelectrodes can be scaled into a large array for parallelization. Third, such a nanoelectrode array can be monolithically integrated with complementary metal-oxide semiconductor (CMOS) electronics to facilitate the large array operation and the recording of the signals from a massive number of cells. These are some of the central ideas that have motivated the research activity into nanoelectrode electrophysiology, and these past years have seen fruitful developments. This Account aims to synthesize these findings so as to provide a useful reference. Summing up from the recent studies, we will first elucidate the morphology and associated electrical properties of the interface between a nanoelectrode and a cellular membrane

Minimum Information about a Cardiac Electrophysiology Experiment (MICEE): standardised reporting for model reproducibility, interoperability, and data sharing

NARCIS (Netherlands)

Quinn, T. A.; Granite, S.; Allessie, M. A.; Antzelevitch, C.; Bollensdorff, C.; Bub, G.; Burton, R. A. B.; Cerbai, E.; Chen, P. S.; Delmar, M.; DiFrancesco, D.; Earm, Y. E.; Efimov, I. R.; Egger, M.; Entcheva, E.; Fink, M.; Fischmeister, R.; Franz, M. R.; Garny, A.; Giles, W. R.; Hannes, T.; Harding, S. E.; Hunter, P. J.; Iribe, G.; Jalife, J.; Johnson, C. R.; Kass, R. S.; Kodama, I.; Koren, G.; Lord, P.; Markhasin, V. S.; Matsuoka, S.; McCulloch, A. D.; Mirams, G. R.; Morley, G. E.; Nattel, S.; Noble, D.; Olesen, S. P.; Panfilov, A. V.; Trayanova, N. A.; Ravens, U.; Richard, S.; Rosenbaum, D. S.; Rudy, Y.; Sachs, F.; Sachse, F. B.; Saint, D. A.; Schotten, U.; Solovyova, O.; Taggart, P.; Tung, L.; Varró, A.; Volders, P. G.; Wang, K.; Weiss, J. N.; Wettwer, E.; White, E.; Wilders, R.; Winslow, R. L.; Kohl, P.

2011-01-01

Cardiac experimental electrophysiology is in need of a well-defined Minimum Information Standard for recording, annotating, and reporting experimental data. As a step towards establishing this, we present a draft standard, called Minimum Information about a Cardiac Electrophysiology Experiment

The Age-ility Project (Phase 1): Structural and functional imaging and electrophysiological data repository.

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Karayanidis, Frini; Keuken, Max C; Wong, Aaron; Rennie, Jaime L; de Hollander, Gilles; Cooper, Patrick S; Ross Fulham, W; Lenroot, Rhoshel; Parsons, Mark; Phillips, Natalie; Michie, Patricia T; Forstmann, Birte U

2016-01-01

Our understanding of the complex interplay between structural and functional organisation of brain networks is being advanced by the development of novel multi-modal analyses approaches. The Age-ility Project (Phase 1) data repository offers open access to structural MRI, diffusion MRI, and resting-state fMRI scans, as well as resting-state EEG recorded from the same community participants (n=131, 15-35 y, 66 male). Raw imaging and electrophysiological data as well as essential demographics are made available via the NITRC website. All data have been reviewed for artifacts using a rigorous quality control protocol and detailed case notes are provided. Copyright © 2015. Published by Elsevier Inc.

Electrophysiological biomarkers of epileptogenicity after traumatic brain injury.

Science.gov (United States)

Perucca, Piero; Smith, Gregory; Santana-Gomez, Cesar; Bragin, Anatol; Staba, Richard

2018-06-05

Post-traumatic epilepsy is the architype of acquired epilepsies, wherein a brain insult initiates an epileptogenic process culminating in an unprovoked seizure after weeks, months or years. Identifying biomarkers of such process is a prerequisite for developing and implementing targeted therapies aimed at preventing the development of epilepsy. Currently, there are no validated electrophysiological biomarkers of post-traumatic epileptogenesis. Experimental EEG studies using the lateral fluid percussion injury model have identified three candidate biomarkers of post-traumatic epileptogenesis: pathological high-frequency oscillations (HFOs, 80-300 Hz); repetitive HFOs and spikes (rHFOSs); and reduction in sleep spindle duration and dominant frequency at the transition from stage III to rapid eye movement sleep. EEG studies in humans have yielded conflicting data; recent evidence suggests that epileptiform abnormalities detected acutely after traumatic brain injury carry a significantly increased risk of subsequent epilepsy. Well-designed studies are required to validate these promising findings, and ultimately establish whether there are post-traumatic electrophysiological features which can guide the development of 'antiepileptogenic' therapies. Copyright © 2017. Published by Elsevier Inc.

Pyramidal cell development: postnatal spinogenesis, dendritic growth, axon growth, and electrophysiology.

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Guy eElston

2014-08-01

Full Text Available Here we review recent findings related to postnatal spinogenesis, dendritic and axon growth, pruning and electrophysiology of neocortical pyramidal cells in the developing primate brain. Pyramidal cells in sensory, association and executive cortex grow dendrites, spines and axons at different rates, and vary in the degree of pruning. Of particular note is the fact that pyramidal cells in primary visual area (V1 prune more spines than they grow during postnatal development, whereas those in inferotemporal (TEO and TE and granular prefrontal cortex (gPFC; Brodmann’s area 12 grow more than they prune. Moreover, pyramidal cells in TEO, TE and the gPFC continue to grow larger dendritic territories from birth into adulthood, replete with spines, whereas those in V1 become smaller during this time. The developmental profile of intrinsic axons also varies between cortical areas: those in V1, for example, undergo an early proliferation followed by pruning and local consolidation into adulthood, whereas those in area TE tend to establish their territory and consolidate it into adulthood with little pruning. We correlate the anatomical findings with the electrophysiological properties of cells in the different cortical areas, including membrane time constant, depolarizing sag, duration of individual action potentials, and spike-frequency adaptation. All of the electrophysiological variables ramped up before 7 months of age in V1, but continued to ramp up over a protracted period of time in area TE. These data suggest that the anatomical and electrophysiological profiles of pyramidal cells vary among cortical areas at birth, and continue to diverge into adulthood. Moreover, the data reveal that the use it or lose it notion of synaptic reinforcement may speak to only part of the story, use it but you still might lose it may be just as prevalent in the cerebral cortex.

Serial electrophysiological findings in Guillain-Barré syndrome not fulfilling AIDP or AMAN criteria.

Science.gov (United States)

Hosokawa, Takafumi; Nakajima, Hideto; Unoda, Kiichi; Yamane, Kazushi; Doi, Yoshimitsu; Ishida, Shimon; Kimura, Fumiharu; Hanafusa, Toshiaki

2016-09-01

Guillain-Barré syndrome (GBS) is categorized into two major subtypes: acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). However, a proportion of patients are electrophysiologically unclassified because of electrophysiological findings that do not fulfil AIDP or AMAN criteria, and underlying pathophysiological mechanisms and lesion distributions of unclassified patients are not well defined. The aims of this study are to elucidate disease pathophysiology and lesion distribution in unclassified patients. We retrospectively studied 48 consecutive GBS patients. Patients were classified on the basis of initial electrophysiological findings according to Ho's criteria. Clinical and serial electrophysiological examinations of unclassified patients were conducted. Twelve (25 %) GBS patients were unclassified. All unclassified patients were able to walk independently at 21 days after onset. No unclassified patients, except one patient with diabetes mellitus, had sensory nerve involvement. Eight patients underwent a follow-up study within 15 days of the initial study. Distal motor latencies (DMLs) of the left median motor nerve were found to be significantly and uniformly decreased compared with initial studies (p = 0.008). DMLs (p < 0.0001) and distal compound action potential (CMAP) durations (p = 0.002) of all nerves were significantly decreased, and distal CMAP amplitudes (p = 0.026) significantly increased compared with initial studies. In unclassified GBS patients, DML values during initial electrophysiological studies would be prolonged compared with expected values in the same patient unaffected by GBS and later improve rapidly with increased distal CMAP amplitudes without the development of excessive temporal dispersions. Lesions are also present in distal nerve segments caused by reversible conduction failure.

Subjective symptoms of carpal tunnel syndrome correlate more with psychological factors than electrophysiological severity

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Firosh Khan

2017-01-01

Full Text Available Aim: Carpal tunnel syndrome (CTS is the most common entrapment neuropathy and is one of the most common requests for electrodiagnosis. We aimed to note the relationship of subjective symptom severity of CTS, with objective electrophysiological severity and psychological status of patients. Patients and Methods: One hundred and forty-four consecutive patients of CTS referred to neurophysiology laboratory of a tertiary care hospital over 1 year were prospectively studied. Boston CTS Assessment Questionnaire (BCTSAQ and visual analog scale (VAS were used to assess subjective symptom severity. Psychological status was assessed by Hospital Anxiety and Depression Scale (HADS. Electrophysiological severity of CTS was estimated by median motor distal latency and median to ulnar peak sensory latency difference across the wrist. Each parameter in both hands was scored from 0 to 3 depending on the severity grade, and a composite electrophysiological severity score (CEPSS was calculated for each patient by summing up the scores in both hands. Statistical analysis was done by Spearman's rank correlation test. Results: There was significant correlation of BCTSAQ with VAS (P = 0.001, HADS anxiety score (P < 0.001, and HADS depression score (P = 0.01. CEPSS had no significant correlation with VAS (P = 0.103, HADS anxiety score (P = 0.211, or HADS depression score (P = 0.55. CEPSS had a borderline correlation with BCTSAQ (P = 0.048. Conclusions: While the subjective symptoms of CTS are well correlated with psychological factors, their correlation with objective electrophysiological severity is weak. Hence, prompt treatment of psychological comorbidity is important in symptomatic management of CTS; decision about surgical intervention should be based on electrophysiological severity rather than symptom severity.

The sound of feelings: electrophysiological responses to emotional speech in alexithymia.

Directory of Open Access Journals (Sweden)

Katharina Sophia Goerlich

Full Text Available Alexithymia is a personality trait characterized by difficulties in the cognitive processing of emotions (cognitive dimension and in the experience of emotions (affective dimension. Previous research focused mainly on visual emotional processing in the cognitive alexithymia dimension. We investigated the impact of both alexithymia dimensions on electrophysiological responses to emotional speech in 60 female subjects.During unattended processing, subjects watched a movie while an emotional prosody oddball paradigm was presented in the background. During attended processing, subjects detected deviants in emotional prosody. The cognitive alexithymia dimension was associated with a left-hemisphere bias during early stages of unattended emotional speech processing, and with generally reduced amplitudes of the late P3 component during attended processing. In contrast, the affective dimension did not modulate unattended emotional prosody perception, but was associated with reduced P3 amplitudes during attended processing particularly to emotional prosody spoken in high intensity.Our results provide evidence for a dissociable impact of the two alexithymia dimensions on electrophysiological responses during the attended and unattended processing of emotional prosody. The observed electrophysiological modulations are indicative of a reduced sensitivity to the emotional qualities of speech, which may be a contributing factor to problems in interpersonal communication associated with alexithymia.

Clinical and electrophysiological characteristics of patients with paroxysmal intra-His block with narrow QRS complexes.

Science.gov (United States)

Ragupathi, Loheetha; Johnson, Drew; Greenspon, Arnold; Frisch, Daniel; Ho, Reginald T; Pavri, Behzad B

2018-04-18

Atrioventricular (AV) block is usually due to infranodal disease and associated with a wide QRS complex; such patients often progress to complete AV block and pacemaker dependency. Uncommonly, infranodal AV block can occur within the His bundle with a narrow QRS complex. The aims of this study were to define clinical/echocardiographic characteristics of patients with AV block within the His bundle and report progression to pacemaker dependency. We retrospectively identified patients with narrow QRS complexes and documented intra-His delay or block at electrophysiology study (group A) or with electrocardiogram-documented Mobitz II AV block/paroxysmal AV block (group B). Clinical, electrophysiological, and echocardiographic variables at presentation and pacemaker parameters at the last follow-up visit were evaluated. Twenty-seven patients (19 women) were identified (mean age 64 ± 13 years; range, 38-85 years). Four patients who had block with narrow QRS complexes rarely progress to pacemaker dependency and require infrequent pacing. This entity is more common in women, with a higher prevalence of aortic and/or mitral annular calcification. If confirmed by additional studies, single-chamber pacemaker may be sufficient. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Electrophysiological studies in healthy subjects involving caffeine.

Science.gov (United States)

de Carvalho, Mamede; Marcelino, Erica; de Mendonça, Alexandre

2010-01-01

We review the electrophysiological studies concerning the effects of caffeine on muscle, lower and upper motor neuron excitability and cognition. Several different methods have been used, such as electromyography, recruitment analysis, H-reflex, transcranial magnetic stimulation (TMS), electroencephalography and event-related potentials. The positive effect of caffeine on vigilance, attention, speed of reaction, information processing and arousal is supported by a number of electrophysiological studies. The evidence in favor of an increased muscle fiber resistance is not definitive, but higher or lower motor neuron excitability can occur as a consequence of a greater excitation of the descending input from the brainstem and upper motor neurons. TMS can address the influence of caffeine on the upper motor neuron. Previous studies showed that cortico-motor threshold and intracortical excitatory and inhibitory pathways are not influenced by caffeine. Nonetheless, our results indicate that cortical silent period (CSP) is reduced in resting muscles after caffeine consumption, when stimulating the motor cortex with intensities slightly above threshold. We present new data demonstrating that this effect is also observed in fatigued muscle. We conclude that CSP can be considered a surrogate marker of the effect of caffeine in the brain, in particular of its central ergogenic effect.

FGF-23 dysregulates calcium homeostasis and electrophysiological properties in HL-1 atrial cells.

Science.gov (United States)

Kao, Yu-Hsun; Chen, Yao-Chang; Lin, Yung-Kuo; Shiu, Rong-Jie; Chao, Tze-Fan; Chen, Shih-Ann; Chen, Yi-Jen

2014-08-01

Fibroblast growth factor (FGF)-23 is a key regulator of phosphate homeostasis. Higher FGF-23 levels are correlated with poor outcomes in cardiovascular diseases. FGF-23 can produce cardiac hypertrophy and increase intracellular calcium, which can change cardiac electrical activity. However, it is not clear whether FGF-23 possesses arrhythmogenic potential through calcium dysregulation. Therefore, the purposes of this study were to evaluate the electrophysiological effects of FGF-23 and identify the underlying mechanisms. Patch clamp, confocal microscope with Fluo-4 fluorescence, and Western blot analyses were used to evaluate the electrophysiological characteristics, calcium homeostasis and calcium regulatory proteins in HL-1 atrial myocytes with and without FGF-23 (10 and 25 ng/mL) incubation for 24 h. FGF-23 (25 ng/mL) increased L-type calcium currents, calcium transient and sarcoplasmic reticulum Ca(2+) contents in HL-1 cells. FGF-23 (25 ng/mL)-treated cells (n = 14) had greater incidences (57%, 17% and 15%, P calcium/calmodulin-dependent protein kinase IIδ and phospholamban (PLB) at threonine 17 but had similar phosphorylation extents of PLB at serine 16, total PLB and sarcoplasmic reticulum Ca(2+) -ATPase protein. Moreover, the FGF receptor inhibitor (PD173074, 10 nM), calmodulin inhibitor (W7, 5 μM) and phospholipase C inhibitor (U73122, 1 μM) attenuated the effects of FGF-23 on calcium/calmodulin-dependent protein kinase II phosphorylation. FGF-23 increases HL-1 cells arrhythmogenesis with calcium dysregulation through modulating calcium-handling proteins. © 2014 Stichting European Society for Clinical Investigation Journal Foundation.

Evaluation of a compact tinnitus therapy by electrophysiological tinnitus decompensation measures.

Science.gov (United States)

Low, Yin Fen; Argstatter, Heike; Bolay, Hans Volker; Strauss, Daniel J

2008-01-01

Large-scale neural correlates of the tinnitus decompensation have been identified by using wavelet phase stability criteria of single sweep sequences of auditory late responses (ALRs). Our previous work showed that the synchronization stability in ALR sequences might be used for objective quantification of the tinnitus decompensation and attention which link to Jastreboff tinnitus model. In this study, we intend to provide an objective evaluation for quantifying the effect of music therapy in tinnitus patients. We examined neural correlates of the attentional mechanism in single sweep sequences of ALRs in chronic tinnitus patients who underwent compact therapy course by using the maximum entropy auditory paradigm. Results by our measure showed that the extent of differentiation between attended and unattended conditions improved significantly after the therapy. It is concluded that the wavelet phase synchronization stability of ALRs single sweeps can be used for the objective evaluation of tinnitus therapies, in this case the compact tinnitus music therapy.

Reversible electrophysiological abnormalities in acute secondary hyperkalemic paralysis

OpenAIRE

Karkal R Naik; Aralikatte O Saroja; Mallikarjun S Khanpet

2012-01-01

Hyperkalemia manifests clinically with acute neuromuscular paralysis, which can simulate Guillain Barr? syndrome (GBS) and other causes of acute flaccid paralysis. Primary hyperkalemic paralysis occurs from genetic defects in the sodium channel, and secondary hyperkalemic paralysis (SHP) from diverse causes including renal dysfunction, potassium retaining drugs, Addison's disease, etc. Clinical characteristics of SHP have been addressed in a number of publications. However, electrophysiologic...

Predicting haemodynamic networks using electrophysiology: The role of non-linear and cross-frequency interactions

Science.gov (United States)

Tewarie, P.; Bright, M.G.; Hillebrand, A.; Robson, S.E.; Gascoyne, L.E.; Morris, P.G.; Meier, J.; Van Mieghem, P.; Brookes, M.J.

2016-01-01

Understanding the electrophysiological basis of resting state networks (RSNs) in the human brain is a critical step towards elucidating how inter-areal connectivity supports healthy brain function. In recent years, the relationship between RSNs (typically measured using haemodynamic signals) and electrophysiology has been explored using functional Magnetic Resonance Imaging (fMRI) and magnetoencephalography (MEG). Significant progress has been made, with similar spatial structure observable in both modalities. However, there is a pressing need to understand this relationship beyond simple visual similarity of RSN patterns. Here, we introduce a mathematical model to predict fMRI-based RSNs using MEG. Our unique model, based upon a multivariate Taylor series, incorporates both phase and amplitude based MEG connectivity metrics, as well as linear and non-linear interactions within and between neural oscillations measured in multiple frequency bands. We show that including non-linear interactions, multiple frequency bands and cross-frequency terms significantly improves fMRI network prediction. This shows that fMRI connectivity is not only the result of direct electrophysiological connections, but is also driven by the overlap of connectivity profiles between separate regions. Our results indicate that a complete understanding of the electrophysiological basis of RSNs goes beyond simple frequency-specific analysis, and further exploration of non-linear and cross-frequency interactions will shed new light on distributed network connectivity, and its perturbation in pathology. PMID:26827811

Characterization of the in vitro propagation of epileptiform electrophysiological activity in organotypic hippocampal slice cultures coupled to 3D microelectrode arrays.

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Pisciotta, Marzia; Morgavi, Giovanna; Jahnsen, Henrik

2010-10-28

Dynamic aspects of the propagation of epileptiform activity have so far received little attention. With the aim of providing new insights about the spatial features of the propagation of epileptic seizures in the nervous system, we studied in vitro the initiation and propagation of traveling epileptiform waves of electrophysiological activity in the hippocampus by means of substrate three-dimensional microelectrode arrays (MEAs) for extracellular measurements. Pharmacologically disinhibited hippocampal slices spontaneously generate epileptiform bursts mostly originating in CA3 and propagating to CA1. Our study specifically addressed the activity-dependent changes of the propagation of traveling electrophysiological waves in organotypic hippocampal slices during epileptiform discharge and in particular our question is: what happens to the epileptic signals during their propagation through the slice? Multichannel data analysis enabled us to quantify an activity-dependent increase in the propagation velocity of spontaneous bursts. Moreover, through the evaluation of the coherence of the signals, it was possible to point out that only the lower-frequency components (propagation of electrophysiological activity becomes ineffective for those firing rates exceeding an upper bound or that some noise of neuronal origin was added to the signal during propagation. Copyright © 2010 Elsevier B.V. All rights reserved.

Effectiveness of a Forward Collision Warning System in simple and in dual task from an electrophysiological perspective.

Science.gov (United States)

Bueno, Mercedes; Fort, Alexandra; Francois, Mathilde; Ndiaye, Daniel; Deleurence, Philippe; Fabrigoule, Colette

2013-04-29

Forward Collision Warning Systems (FCWS) are expected to assist drivers; however, it is not completely clear whether these systems are of benefit to distracted drivers as much as they are to undistracted drivers. This study aims at investigating further the analysis of the effectiveness of a surrogate FCWS according to the attentional state of participants. In this experiment electrophysiological and behavioural data were recording while participants were required to drive in a simple car simulator and to react to the braking of the lead vehicle which could be announced by a warning system. The effectiveness of this warning system was evaluated when drivers were distracted or not by a secondary cognitive task. In a previous study, the warning signal was not completely effective likely due to the presence of another predictor of the forthcoming braking which competes with the warning. By eliminating this secondary predictor in the present study, the results confirmed the negative effect of the secondary task and revealed the expected effectiveness of the warning system at behavioural and electrophysiological levels. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Whole-Retina Reduced Electrophysiological Activity in Mice Bearing Retina-Specific Deletion of Vesicular Acetylcholine Transporter.

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Jake Bedore

Full Text Available Despite rigorous characterization of the role of acetylcholine in retinal development, long-term effects of its absence as a neurotransmitter are unknown. One of the unanswered questions is how acetylcholine contributes to the functional capacity of mature retinal circuits. The current study investigates the effects of disrupting cholinergic signalling in mice, through deletion of vesicular acetylcholine transporter (VAChT in the developing retina, pigmented epithelium, optic nerve and optic stalk, on electrophysiology and structure of the mature retina.A combination of electroretinography, optical coherence tomography imaging and histological evaluation assessed retinal integrity in mice bearing retina- targeted (embryonic day 12.5 deletion of VAChT (VAChTSix3-Cre-flox/flox and littermate controls at 5 and 12 months of age. VAChTSix3-Cre-flox/flox mice did not show any gross changes in nuclear layer cellularity or synaptic layer thickness. However, VAChTSix3-Cre-flox/flox mice showed reduced electrophysiological response of the retina to light stimulus under scotopic conditions at 5 and 12 months of age, including reduced a-wave, b-wave, and oscillatory potential (OP amplitudes and decreased OP peak power and total energy. Reduced a-wave amplitude was proportional to the reduction in b-wave amplitude and not associated with altered a-wave 10%-90% rise time or inner and outer segment thicknesses.This study used a novel genetic model in the first examination of function and structure of the mature mouse retina with disruption of cholinergic signalling. Reduced amplitude across the electroretinogram wave form does not suggest dysfunction in specific retinal cell types and could reflect underlying changes in the retinal and/or extraretinal microenvironment. Our findings suggest that release of acetylcholine by VAChT is essential for the normal electrophysiological response of the mature mouse retina.

Behavioral and electrophysiological signatures of word translation processes.

Science.gov (United States)

Jost, Lea B; Radman, Narges; Buetler, Karin A; Annoni, Jean-Marie

2018-01-31

Translation is a demanding process during which a message is analyzed, translated and communicated from one language to another. Despite numerous studies on translation mechanisms, the electrophysiological processes underlying translation with overt production remain largely unexplored. Here, we investigated how behavioral response patterns and spatial-temporal brain dynamics differ in a translation compared to a control within-language word-generation task. We also investigated how forward and backward translation differs on the behavioral and electrophysiological level. To address these questions, healthy late bilingual subjects performed a translation and a within-language control task while a 128-channel EEG was recorded. Behavioral data showed faster responses for translation compared to within-language word generation and faster responses for backward than forward translation. The ERP-analysis revealed stronger early ( processes for between than within word generation. Later (424-630ms) differences were characterized by distinct engagement of domain-general control networks, namely self-monitoring and lexical access interference. Language asymmetry effects occurred at a later stage (600ms), reflecting differences in conceptual processing characterized by a larger involvement of areas implicated in attention, arousal and awareness for forward versus backward translation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heterogeneity of Monosymptomatic Resting Tremor in a Prospective Study: Clinical Features, Electrophysiological Test, and Dopamine Transporter Positron Emission Tomography.

Science.gov (United States)

Zheng, Hua-Guang; Zhang, Rong; Li, Xin; Li, Fang-Fei; Wang, Ya-Chen; Wang, Xue-Mei; Lu, Ling-Long; Feng, Tao

2015-07-05

The relationship between monosymptomatic resting tremor (mRT) and Parkinson's disease (PD) remains controversial. In this study, we aimed to assess the function of presynaptic dopaminergic neurons in patients with mRT by dopamine transporter positron emission tomography (DAT-PET) and to evaluate the utility of clinical features or electrophysiological studies in differential diagnosis. Thirty-three consecutive patients with mRT were enrolled prospectively. The Unified Parkinson's Disease Rating Scale and electromyography were tested before DAT-PET. Striatal asymmetry index (SAI) was calculated, and a normal DAT-PET was defined as a SAI of hygiene score, walking in motor experiences of daily living (Part II) and motor examination (Part III) were significant different between two groups (P postural tremor tend to be higher in the SWEDDs group (P = 0.08 and P = 0.05, respectively). mRT is heterogeneous in presynaptic nigrostriatal dopaminergic degeneration, which can be determined by DAT-PET brain imaging. Clinical and electrophysiological features may provide clues to distinguish PD from SWEDDs.

Pelvic floor electrophysiology in spinal cord injury.

Science.gov (United States)

Tankisi, H; Pugdahl, K; Rasmussen, M M; Clemmensen, D; Rawashdeh, Y F; Christensen, P; Krogh, K; Fuglsang-Frederiksen, A

2016-05-01

The study aimed to investigate sacral peripheral nerve function and continuity of pudendal nerve in patients with chronic spinal cord injury (SCI) using pelvic floor electrophysiological tests. Twelve patients with low cervical or thoracic SCI were prospectively included. Quantitative external anal sphincter (EAS) muscle electromyography (EMG), pudendal nerve terminal motor latency (PNTML) testing, bulbocavernosus reflex (BCR) testing and pudendal short-latency somatosensory-evoked potential (SEP) measurement were performed. In EAS muscle EMG, two patients had abnormal increased spontaneous activity and seven prolonged motor unit potential duration. PNTML was normal in 10 patients. BCR was present with normal latency in 11 patients and with prolonged latency in one. The second component of BCR could be recorded in four patients. SEPs showed absent cortical responses in 11 patients and normal latency in one. Pudendal nerve and sacral lower motor neuron involvement are significantly associated with chronic SCI, most prominently in EAS muscle EMG. The frequent finding of normal PNTML latencies supports earlier concerns on the utility of this test; however, BCR and pudendal SEPs may have clinical relevance. As intact peripheral nerves including pudendal nerve are essential for efficient supportive therapies, pelvic floor electrophysiological testing prior to these interventions is highly recommended. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Solid-state NMR, electrophysiology and molecular dynamics characterization of human VDAC2

International Nuclear Information System (INIS)

Gattin, Zrinka; Schneider, Robert; Laukat, Yvonne; Giller, Karin; Maier, Elke; Zweckstetter, Markus; Griesinger, Christian; Benz, Roland; Becker, Stefan; Lange, Adam

2015-01-01

The voltage-dependent anion channel (VDAC) is the most abundant protein of the outer mitochondrial membrane and constitutes the major pathway for the transport of ADP, ATP, and other metabolites. In this multidisciplinary study we combined solid-state NMR, electrophysiology, and molecular dynamics simulations, to study the structure of the human VDAC isoform 2 in a lipid bilayer environment. We find that the structure of hVDAC2 is similar to the structure of hVDAC1, in line with recent investigations on zfVDAC2. However, hVDAC2 appears to exhibit an increased conformational heterogeneity compared to hVDAC1 which is reflected in broader solid-state NMR spectra and less defined electrophysiological profiles

Solid-state NMR, electrophysiology and molecular dynamics characterization of human VDAC2

Energy Technology Data Exchange (ETDEWEB)

Gattin, Zrinka; Schneider, Robert; Laukat, Yvonne; Giller, Karin [Max Planck Institute for Biophysical Chemistry (Germany); Maier, Elke [Theodor-Boveri-Institut (Biozentrum) der Universität Würzburg, Lehrstuhl für Biotechnologie (Germany); Zweckstetter, Markus; Griesinger, Christian [Max Planck Institute for Biophysical Chemistry (Germany); Benz, Roland [Theodor-Boveri-Institut (Biozentrum) der Universität Würzburg, Lehrstuhl für Biotechnologie (Germany); Becker, Stefan; Lange, Adam, E-mail: alange@fmp-berlin.de [Max Planck Institute for Biophysical Chemistry (Germany)

2015-04-15

The voltage-dependent anion channel (VDAC) is the most abundant protein of the outer mitochondrial membrane and constitutes the major pathway for the transport of ADP, ATP, and other metabolites. In this multidisciplinary study we combined solid-state NMR, electrophysiology, and molecular dynamics simulations, to study the structure of the human VDAC isoform 2 in a lipid bilayer environment. We find that the structure of hVDAC2 is similar to the structure of hVDAC1, in line with recent investigations on zfVDAC2. However, hVDAC2 appears to exhibit an increased conformational heterogeneity compared to hVDAC1 which is reflected in broader solid-state NMR spectra and less defined electrophysiological profiles.

Time course of electrophysiologic effects induced by di-n-butyl-2,2-dichlorovinyl phosphate (DBCV) in the adult hen.

Science.gov (United States)

Robertson, D G; Mattson, A M; Bestervelt, L L; Richardson, R J; Anderson, R J

1988-01-01

Previous work in our laboratory indicated that di-n-butyl-2,2-dichlorovinyl phosphate (DBCV) produced electrophysiologic changes in hen peripheral nerve that coincided with the development of histopathologic changes and neurologic signs of peripheral neuropathy. The purpose of the present study was to follow the time course for the development of the electrophysiologic changes and to determine whether pretreatment with the phosphinate analog of DBCV (DBCV-P), a nonageable organophosphorus compound, prevented these effects. Although significant electrophysiologic deficits occurred in the tibial and sciatic nerve 24 h after DBCV treatment, the most marked changes coincided with the onset of clinical signs of organophosphorus-induced delayed neuropathy (14-21 d). The sciatic and tibial nerves were equally susceptible to DBCV in producing deficits characterized by changes in the relative refractory period and an increased strength-duration threshold. Pretreatment with DBCV-P prevented the clinical signs and also attenuated the electrophysiologic deficits induced by DBCV treatment. These data suggest that electrophysiologic deficits occur before clinical signs of organophosphorus-induced delayed neuropathy (OPIDN) and may be indicative of a link between neurotoxic esterase (NTE) inhibition and onset of overt clinical toxicity.

Automatic fitting of spiking neuron models to electrophysiological recordings

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Cyrille Rossant

2010-03-01

Full Text Available Spiking models can accurately predict the spike trains produced by cortical neurons in response to somatically injected currents. Since the specific characteristics of the model depend on the neuron, a computational method is required to fit models to electrophysiological recordings. The fitting procedure can be very time consuming both in terms of computer simulations and in terms of code writing. We present algorithms to fit spiking models to electrophysiological data (time-varying input and spike trains that can run in parallel on graphics processing units (GPUs. The model fitting library is interfaced with Brian, a neural network simulator in Python. If a GPU is present it uses just-in-time compilation to translate model equations into optimized code. Arbitrary models can then be defined at script level and run on the graphics card. This tool can be used to obtain empirically validated spiking models of neurons in various systems. We demonstrate its use on public data from the INCF Quantitative Single-Neuron Modeling 2009 competition by comparing the performance of a number of neuron spiking models.

Painful legs and moving toes syndrome: a 76-patient case series.

Science.gov (United States)

Hassan, Anhar; Mateen, Farrah J; Coon, Elizabeth A; Ahlskog, J Eric

2012-08-01

To better characterize the clinical features, electrophysiologic features, and treatment outcomes of painful legs and moving toes (PLMT) syndrome. Large case series. Neurology outpatient clinic at a tertiary referral center, 1983-2011. All cases of PLMT seen at our institution during an 18-year period were identified using our medical record linkage system. Key demographic, clinical, imaging, and electrophysiologic features of PLMT. Treatment outcomes and long-term follow-up are also reported. Of 76 cases identified (including 50 women [66%]), the mean age at onset was 58 years (range, 24-86 years) and at neurologic evaluation was 63 years (range, 26-88 years). Pure lower limb involvement was most common (69 patients [91%]), and 44 cases (58%) were bilateral. The most frequently diagnosed causes were peripheral neuropathy (21 cases [28%]), previous trauma (8 [11%]), and radiculopathy (7 [9%]); 32 cases (42%) were cryptogenic. Electromyography consistently showed irregular 50-millisecond to 1-second bursts of normal motor unit potential firing at 2 to 200 Hz accompanying the movements. Pain occurred first in nearly all cases and was more distressing to patients than the movements. Both components were difficult to treat, with no consistent benefit from a variety of drugs and therapeutic modalities. The syndrome persisted in most patients (83%) during the mean follow-up of 4.6 years, suggesting low likelihood of spontaneous resolution. Painful legs and moving toes syndrome is a debilitating clinical syndrome, not because of the movements but rather because of the pain, which often is refractory to treatment. Segmental lower limb involvement is most common, and neurophysiologic findings support a pathophysiologic process localizing to a central generator at the spinal cord or brainstem level.

Electrophysiological properties of computational human ventricular cell action potential models under acute ischemic conditions.

Science.gov (United States)

Dutta, Sara; Mincholé, Ana; Quinn, T Alexander; Rodriguez, Blanca

2017-10-01

Acute myocardial ischemia is one of the main causes of sudden cardiac death. The mechanisms have been investigated primarily in experimental and computational studies using different animal species, but human studies remain scarce. In this study, we assess the ability of four human ventricular action potential models (ten Tusscher and Panfilov, 2006; Grandi et al., 2010; Carro et al., 2011; O'Hara et al., 2011) to simulate key electrophysiological consequences of acute myocardial ischemia in single cell and tissue simulations. We specifically focus on evaluating the effect of extracellular potassium concentration and activation of the ATP-sensitive inward-rectifying potassium current on action potential duration, post-repolarization refractoriness, and conduction velocity, as the most critical factors in determining reentry vulnerability during ischemia. Our results show that the Grandi and O'Hara models required modifications to reproduce expected ischemic changes, specifically modifying the intracellular potassium concentration in the Grandi model and the sodium current in the O'Hara model. With these modifications, the four human ventricular cell AP models analyzed in this study reproduce the electrophysiological alterations in repolarization, refractoriness, and conduction velocity caused by acute myocardial ischemia. However, quantitative differences are observed between the models and overall, the ten Tusscher and modified O'Hara models show closest agreement to experimental data. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Audiological and electrophysiological assessment of professional pop/rock musicians.

Science.gov (United States)

Samelli, Alessandra G; Matas, Carla G; Carvallo, Renata M M; Gomes, Raquel F; de Beija, Carolina S; Magliaro, Fernanda C L; Rabelo, Camila M

2012-01-01

In the present study, we evaluated peripheral and central auditory pathways in professional musicians (with and without hearing loss) compared to non-musicians. The goal was to verify if music exposure could affect auditory pathways as a whole. This is a prospective study that compared the results obtained between three groups (musicians with and without hearing loss and non-musicians). Thirty-two male individuals participated and they were assessed by: Immittance measurements, pure-tone air conduction thresholds at all frequencies from 0.25 to 20 kHz, Transient Evoked Otoacoustic Emissions, Auditory Brainstem Response (ABR), and Cognitive Potential. The musicians showed worse hearing thresholds in both conventional and high frequency audiometry when compared to the non-musicians; the mean amplitude of Transient Evoked Otoacoustic Emissions was smaller in the musicians group, but the mean latencies of Auditory Brainstem Response and Cognitive Potential were diminished in the musicians when compared to the non-musicians. Our findings suggest that the population of musicians is at risk for developing music-induced hearing loss. However, the electrophysiological evaluation showed that latency waves of ABR and P300 were diminished in musicians, which may suggest that the auditory training to which these musicians are exposed acts as a facilitator of the acoustic signal transmission to the cortex.

Audiological and electrophysiological assessment of professional pop/rock musicians

Directory of Open Access Journals (Sweden)

Alessandra G Samelli

2012-01-01

Full Text Available In the present study, we evaluated peripheral and central auditory pathways in professional musicians (with and without hearing loss compared to non-musicians. The goal was to verify if music exposure could affect auditory pathways as a whole. This is a prospective study that compared the results obtained between three groups (musicians with and without hearing loss and non-musicians. Thirty-two male individuals participated and they were assessed by: Immittance measurements, pure-tone air conduction thresholds at all frequencies from 0.25 to 20 kHz, Transient Evoked Otoacoustic Emissions, Auditory Brainstem Response (ABR, and Cognitive Potential. The musicians showed worse hearing thresholds in both conventional and high frequency audiometry when compared to the non-musicians; the mean amplitude of Transient Evoked Otoacoustic Emissions was smaller in the musicians group, but the mean latencies of Auditory Brainstem Response and Cognitive Potential were diminished in the musicians when compared to the non-musicians. Our findings suggest that the population of musicians is at risk for developing music-induced hearing loss. However, the electrophysiological evaluation showed that latency waves of ABR and P300 were diminished in musicians, which may suggest that the auditory training to which these musicians are exposed acts as a facilitator of the acoustic signal transmission to the cortex.

To4, the first Tityus obscurus β-toxin fully electrophysiologically characterized on human sodium channel isoforms.

Science.gov (United States)

Duque, Harry Morales; Mourão, Caroline Barbosa Farias; Tibery, Diogo Vieira; Barbosa, Eder Alves; Campos, Leandro Ambrósio; Schwartz, Elisabeth Ferroni

2017-09-01

Many scorpion toxins that act on sodium channels (NaScTxs) have been characterized till date. These toxins may act modulating the inactivation or the activation of sodium channels and are named α- or β-types, respectively. Some venom toxins from Tityus obscurus (Buthidae), a scorpion widely distributed in the Brazilian Amazon, have been partially characterized in previous studies; however, little information about their electrophysiological role on sodium ion channels has been published. In the present study, we describe the purification, identification and electrophysiological characterization of a NaScTx, which was first described as Tc54 and further fully sequenced and renamed To4. This toxin shows a marked β-type effect on different sodium channel subtypes (hNa v 1.1-hNa v 1.7) at low concentrations, and has more pronounced activity on hNa v 1.1, hNa v 1.2 and hNa v 1.4. By comparing To4 primary structure with other Tityus β-toxins which have already been electrophysiologically tested, it is possible to establish some key amino acid residues for the sodium channel activity. Thus, To4 is the first toxin from T. obscurus fully electrophysiologically characterized on different human sodium channel isoforms. Copyright © 2017 Elsevier Inc. All rights reserved.

Computational Intelligence Techniques for Electro-Physiological Data Analysis

OpenAIRE

Riera Sardà, Alexandre

2012-01-01

This work contains the efforts I have made in the last years in the field of Electrophysiological data analysis. Most of the work has been done at Starlab Barcelona S.L. and part of it at the Neurodynamics Laboratory of the Department of Psychiatry and Clinical Psychobiology of the University of Barcelona. The main work deals with the analysis of electroencephalography (EEG) signals, although other signals, such as electrocardiography (ECG), electroculography (EOG) and electromiography (EMG) ...

Electrophysiological safety of sertindole in dogs with normal and remodeled hearts

DEFF Research Database (Denmark)

Thomsen, Morten Bækgaard; Volders, Paul G A; Stengl, Milan

2003-01-01

Inhibition of the potassium current IKr and QT prolongation are associated with drug-induced torsades de pointes arrhythmias (TdP) and sudden cardiac death. We investigated the cardiac electrophysiological effects of sertindole, an antipsychotic drug reported to prolong the QT interval...

Hand-arm vibration syndrome: clinical characteristics, conventional electrophysiology and quantitative sensory testing.

Science.gov (United States)

Rolke, Roman; Rolke, Silke; Vogt, Thomas; Birklein, Frank; Geber, Christian; Treede, Rolf-Detlef; Letzel, Stephan; Voelter-Mahlknecht, Susanne

2013-08-01

Workers exposed to vibrating tools may develop hand-arm vibration syndrome (HAVS). We assessed the somatosensory phenotype using quantitative sensory testing (QST) in comparison to electrophysiology to characterize (1) the most sensitive QST parameter for detecting sensory loss, (2) the correlation of QST and electrophysiology, and (3) the frequency of a carpal tunnel syndrome (CTS) in HAVS. QST, cold provocation tests, fine motor skills, and median nerve neurography were used. QST included thermal and mechanical detection and pain thresholds. Thirty-two patients were examined (54 ± 11 years, 91% men) at the more affected hand compared to 16 matched controls. Vibration detection threshold was the most sensitive parameter to detect sensory loss that was more pronounced in the sensitivity range of Pacinian (150 Hz, x12) than Meissner's corpuscles (20 Hz, x3). QST (84% abnormal) was more sensitive to detect neural dysfunction than conventional electrophysiology (37% abnormal). Motor (34%) and sensory neurography (25%) were abnormal in HAVS. CTS frequency was not increased (9.4%). Findings are consistent with a mechanically-induced, distally pronounced motor and sensory neuropathy independent of CTS. HAVS involves a neuropathy predominantly affecting large fibers with a sensory damage related to resonance frequencies of vibrating tools. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Prevalence, morphological and electrophysiological characteristics of confluent inferior pulmonary veins in patients with atrial fibrillation

International Nuclear Information System (INIS)

Yamane, Teiichi; Date, Taro; Tokuda, Michifumi

2008-01-01

Although the common trunk of left pulmonary veins (PVs) has been reported as a relatively popular anatomical variation of PVs, little is known about the coalescence of contralateral PVs. The present study was conducted to reveal the prevalence and electrophysiologic characteristics of the confluent inferior common PVs. Anatomical variation in the PV drainage to the left atrium (LA) was assessed using the multidetector computed tomography scan in 326 patients with atrial fibrillation (AF) who underwent the PV isolation procedure. Coalescence of inferior PVs was observed in 5 cases (1.5%). Both inferior PVs conjoined prior to the junction with the LA in 3 cases, while they coalesced at the LA junction in the other 2 cases. The arrhythmogenic activities of the confluent inferior PVs were generally low in all cases without any ectopic firings triggering the observed AF. All inferior PVs, as well as the superior PVs, were successfully isolated either en bloc at the common trunk or individually at the orifice of each PV. Confluent inferior PVs were present in 1.5% of cases in patients with AF who underwent the PV isolation procedure. Preoperative recognition of this venous anomaly by 3-dimensional imaging is important for smooth and safe ablation. (author)

Electrophysiological evidence for enhanced representation of food stimuli in working memory

NARCIS (Netherlands)

Rutters, F.; Kumar, S.; Higgs, S.; Humphreys, G.W.

2015-01-01

Studies from our laboratory have shown that, relative to neutral objects, food-related objects kept in working memory (WM) are particularly effective in guiding attention to food stimuli (Higgs et al. in Appetite, 2012). Here, we used electrophysiological measurements to investigate the neural

Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives.

Science.gov (United States)

Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa; Thielscher, Axel; Siebner, Hartwig Roman

2016-10-15

Non-invasive transcranial brain stimulation (NTBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (TCS) are important tools in human systems and cognitive neuroscience because they are able to reveal the relevance of certain brain structures or neuronal activity patterns for a given brain function. It is nowadays feasible to combine NTBS, either consecutively or concurrently, with a variety of neuroimaging and electrophysiological techniques. Here we discuss what kind of information can be gained from combined approaches, which often are technically demanding. We argue that the benefit from this combination is twofold. Firstly, neuroimaging and electrophysiology can inform subsequent NTBS, providing the required information to optimize where, when, and how to stimulate the brain. Information can be achieved both before and during the NTBS experiment, requiring consecutive and concurrent applications, respectively. Secondly, neuroimaging and electrophysiology can provide the readout for neural changes induced by NTBS. Again, using either concurrent or consecutive applications, both "online" NTBS effects immediately following the stimulation and "offline" NTBS effects outlasting plasticity-inducing NTBS protocols can be assessed. Finally, both strategies can be combined to close the loop between measuring and modulating brain activity by means of closed-loop brain state-dependent NTBS. In this paper, we will provide a conceptual framework, emphasizing principal strategies and highlighting promising future directions to exploit the benefits of combining NTBS with neuroimaging or electrophysiology. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Electrophysiology of Axonal Constrictions

Science.gov (United States)

Johnson, Christopher; Jung, Peter; Brown, Anthony

2013-03-01

Axons of myelinated neurons are constricted at the nodes of Ranvier, where they are directly exposed to the extracellular space and where the vast majority of the ion channels are located. These constrictions are generated by local regulation of the kinetics of neurofilaments the most important cytoskeletal elements of the axon. In this paper we discuss how this shape affects the electrophysiological function of the neuron. Specifically, although the nodes are short (about 1 μm) in comparison to the distance between nodes (hundreds of μm) they have a substantial influence on the conduction velocity of neurons. We show through computational modeling that nodal constrictions (all other features such as numbers of ion channels left constant) reduce the required fiber diameter for a given target conduction velocity by up to 50% in comparison to an unconstricted axon. We further show that the predicted optimal fiber morphologies closely match reported fiber morphologies. Supported by The National Science Foundation (IOS 1146789)

Review Article. Electrophysiological Methods for Study of Changes in Visual Analyzer in Patients with Diabetes Mellitus

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Elena Mermeklieva

2017-03-01

Full Text Available The electrophysiological (EF methods are objective methods for studying the visual analyzer function. These include electroretinography (ERG, electrooculography (EOG and visual evoked potentials (VEPs. ERG and EOG are used for diagnosis and monitoring of a number of diseases of the retina. VEPs depend on the functional integrity of the entire optical path from the retina through the optic nerve, optic tract, the optical radiation to the visual cortex. The electrophysiological methods are widely used in studying the function of the visual analyzer in the ophthalmic and neurological practice, for objectively measuring the visual acuity and the visual field in non-cooperative patients, small children and in simulation. Diabetes mellitus (DM is a group of metabolic diseases characterized by hyperglycemia. One of the late complications of DM is diabetic retinopathy (DR. It is one of the most serious complications of diabetes, often leading to blindness. Nowadays, DR includes retinal neurodegeneration and microvascular complications. By EF studies can evaluate the function of the retina in diabetic patients in an objective manner using ERG, that reflects the EF activity of the neurons in the retina and VEPs, which indicate the electrical conductivity across the optic tract to the visual cortex.

IMPROVING QUALITY OF WORK LIFE THROUGH ELECTROPHYSIOLOGY: AN IDEA ACCEPTED BY INDUSTRY

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Evanthia Giagloglou

2015-12-01

Full Text Available Quality of Work Life (QWL and Occupational Health and Safety (OHS are two interconnected and important human needs. Modern industry shows a clear will for improving QWL and OHS, nevertheless, existent automatization and technological advances may negatively influence employees' wellbeing and result as triggers to their health deterioration. Subjective measures of employees workload can help, however, the lack of objectivity may be an issue. Improvement of working life needs objective measures. There is technology for measuring objectively employees' psychophysiology, but is considered to interfere with the flexibility needed for performing working tasks. Today electrophysiological methods require minimal dimensions, are wireless connected, allow movement and are proved to be useful in capturing psychophysical wellbeing. This study shows that the industry is ready to accept electrophysiological measures for monitoring and improving the employees' wellbeing.

Automated Electrophysiology Makes the Pace for Cardiac Ion Channel Safety Screening

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Clemens eMoeller

2011-11-01

Full Text Available The field of automated patch-clamp electrophysiology has emerged from the tension between the pharmaceutical industry’s need for high-throughput compound screening versus its need to be conservative due to regulatory requirements. On the one hand, hERG channel screening was increasingly requested for new chemical entities, as the correlation between blockade of the ion channel coded by hERG and Torsades de Pointes cardiac arrhythmia gained increasing attention. On the other hand, manual patch-clamping, typically quoted as the gold-standard for understanding ion channel function and modulation, was far too slow (and, consequently, too expensive for keeping pace with the numbers of compounds submitted for hERG channel investigations from pharmaceutical R&D departments. In consequence it became more common for some pharmaceutical companies to outsource safety pharmacological investigations, with a focus on hERG channel interactions. This outsourcing has allowed those pharmaceutical companies to build up operational flexibility and greater independence from internal resources, and allowed them to obtain access to the latest technological developments that emerged in automated patch-clamp electrophysiology – much of which arose in specialized biotech companies. Assays for nearly all major cardiac ion channels are now available by automated patch-clamping using heterologous expression systems, and recently, automated action potential recordings from stem-cell derived cardiomyocytes have been demonstrated. Today, most of the large pharmaceutical companies have acquired automated electrophysiology robots and have established various automated cardiac ion channel safety screening assays on these, in addition to outsourcing parts of their needs for safety screening.

Avaliação audiológica e eletrofisiológica da audição na síndrome de Landau-Kleffner Audiologic and electrophysiologic evaluation in Landau-Kleffner syndrome

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Carla Gentile Matas

2007-06-01

speech audiometry and electrophysiological evaluation (short, middle and long-latency auditory evoked potentials. RESULTS: All individuals showed alterations in at least one of the evaluations performed, and it was observed a higher rate of alterations in the middle latency response (100% of the individuals showed alterations. CONCLUSIONS: A great occurrence of auditory disorders in audiological and electrophysiological evaluation of individuals with Landau-Kleffner syndrome was observed. It is emphasized the importance of the audiological investigation of these individuals, in order to verify possible relations between communication and auditory disorders in this population.

Heart beats in the cloud: distributed analysis of electrophysiological 'Big Data' using cloud computing for epilepsy clinical research.

Science.gov (United States)

Sahoo, Satya S; Jayapandian, Catherine; Garg, Gaurav; Kaffashi, Farhad; Chung, Stephanie; Bozorgi, Alireza; Chen, Chien-Hun; Loparo, Kenneth; Lhatoo, Samden D; Zhang, Guo-Qiang

2014-01-01

The rapidly growing volume of multimodal electrophysiological signal data is playing a critical role in patient care and clinical research across multiple disease domains, such as epilepsy and sleep medicine. To facilitate secondary use of these data, there is an urgent need to develop novel algorithms and informatics approaches using new cloud computing technologies as well as ontologies for collaborative multicenter studies. We present the Cloudwave platform, which (a) defines parallelized algorithms for computing cardiac measures using the MapReduce parallel programming framework, (b) supports real-time interaction with large volumes of electrophysiological signals, and (c) features signal visualization and querying functionalities using an ontology-driven web-based interface. Cloudwave is currently used in the multicenter National Institute of Neurological Diseases and Stroke (NINDS)-funded Prevention and Risk Identification of SUDEP (sudden unexplained death in epilepsy) Mortality (PRISM) project to identify risk factors for sudden death in epilepsy. Comparative evaluations of Cloudwave with traditional desktop approaches to compute cardiac measures (eg, QRS complexes, RR intervals, and instantaneous heart rate) on epilepsy patient data show one order of magnitude improvement for single-channel ECG data and 20 times improvement for four-channel ECG data. This enables Cloudwave to support real-time user interaction with signal data, which is semantically annotated with a novel epilepsy and seizure ontology. Data privacy is a critical issue in using cloud infrastructure, and cloud platforms, such as Amazon Web Services, offer features to support Health Insurance Portability and Accountability Act standards. The Cloudwave platform is a new approach to leverage of large-scale electrophysiological data for advancing multicenter clinical research.

Evidence for Acute Electrophysiological and Cognitive Changes Following Routine Soccer Heading

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Thomas G. Di Virgilio

2016-11-01

Discussion: Sub-concussive head impacts routine in soccer heading are associated with immediate, measurable electrophysiological and cognitive impairments. Although these changes in brain function were transient, these effects may signal direct consequences of routine soccer heading on (long-term brain health which requires further study.

Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

International Nuclear Information System (INIS)

Gimelli, Alessia; Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia; Marzullo, Paolo

2016-01-01

To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic "9"9"mTc-tetrofosmin and "1"2"3I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target. (orig.)

Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

Energy Technology Data Exchange (ETDEWEB)

Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia [University Hospital of Pisa, Cardio-Thoracic and Vascular Department, Pisa (Italy); Marzullo, Paolo [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); CNR, Institute of Clinical Physiology, Pisa (Italy)

2016-12-15

To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic {sup 99m}Tc-tetrofosmin and {sup 123}I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target

Somatomotor and oculomotor inferior olivary neurons have distinct electrophysiological phenotypes

Science.gov (United States)

Urbano, Francisco J.; Simpson, John I.; Llinás, Rodolfo R.

2006-01-01

The electrophysiological properties of rat inferior olive (IO) neurons in the dorsal cap of Kooy (DCK) and the adjacent ventrolateral outgrowth (VLO) were compared with those of IO neurons in the principal olive (PO). Whereas DCK/VLO neurons are involved in eye movement control via their climbing fiber projection to the cerebellar flocculus, PO neurons control limb and digit movements via their climbing fiber projection to the lateral cerebellar hemisphere. In vitro patch recordings from DCK/VLO neurons revealed that low threshold calcium currents, Ih currents, and subthreshold oscillations are lacking in this subset of IO neurons. The recordings of activity in DCK neurons obtained by using voltage-sensitive dye imaging showed that activity is not limited to a single neuron, but rather that clusters of DCK neurons can be active in unison. These electrophysiological results show that the DCK/VLO neurons have unique properties that set them apart from the neurons in the PO nucleus. This finding indicates that motor control, from the perspective of the olivocerebellar system, is fundamentally different for the oculomotor and the somatomotor systems. PMID:17050678

Analyzing the electrophysiological effects of local epicardial temperature in experimental studies with isolated hearts

International Nuclear Information System (INIS)

Tormos, Alvaro; Millet, José; Guill, Antonio; Chorro, Francisco J; Cánoves, Joaquín; Mainar, Luis; Such, Luis; Alberola, Antonio; Trapero, Isabel; Such-Miquel, Luis

2008-01-01

As a result of their modulating effects upon myocardial electrophysiology, both hypo- and hyperthermia can be used to study the mechanisms that generate or sustain cardiac arrhythmias. The present study describes an original electrode developed with thick-film technology and capable of controlling regional temperature variations in the epicardium while simultaneously registering its electrical activity. In this way, it is possible to measure electrophysiological parameters of the heart at different temperatures. The results obtained with this device in a study with isolated and perfused rabbit hearts are reported. An exploration has been made of the effects of local temperature changes upon the electrophysiological parameters implicated in myocardial conduction. Likewise, an analysis has been made of the influence of local temperature upon ventricular fibrillation activation frequency. It is concluded that both regional hypo- and hyperthermia exert reversible and opposite effects upon myocardial refractoriness and conduction velocity in the altered zone. The ventricular activation wavelength determined during constant pacing at 250 ms cycles is not significantly modified, however. During ventricular fibrillation, the changes in the fibrillatory frequency do not seem to be transmitted to normal temperature zones

Biofeedback in psychomotor training. Electrophysiological basis.

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Bazanova, O M; Mernaya, E M; Shtark, M B

2009-06-01

The influences of individual musical practice and the same practice supplemented with biofeedback using electrophysiological markers for optimum music-performing activity were studied in 39 music students. Traditional technical practice produced increases in integral EMG power and decreases in alpha activity in most of the students with initially low maximum alpha activity peak frequencies. Similar practice but combined with individual sessions of alpha-EEG/EMG biofeedback were accompanied by increases in the frequency, bandwidth, and activation responses of EEG alpha rhythms in all subjects, along with decreases in EEG integral power. The efficacy of training with biofeedback and the ability to experience psychomotor learning depended on the initial individual characteristics of EEG alpha activity.

Lyme carditis. Electrophysiologic and histopathologic study

International Nuclear Information System (INIS)

Reznick, J.W.; Braunstein, D.B.; Walsh, R.L.; Smith, C.R.; Wolfson, P.M.; Gierke, L.W.; Gorelkin, L.; Chandler, F.W.

1986-01-01

To further define the nature of Lyme carditis, electrophysiologic study and endomyocardial biopsy were performed in a patient with Lyme disease, whose principal cardiac manifestation was high-degree atrioventricular block. Intracardiac recording demonstrated supra-Hisian block and complete absence of an escape mechanism. Gallium 67 scanning demonstrated myocardial uptake, and right ventricular endomyocardial biopsy revealed active lymphocytic myocarditis. A structure compatible with a spirochetal organism was demonstrated in one biopsy specimen. It is concluded that Lyme disease can produce active myocarditis, as suggested by gallium 67 imaging and confirmed by endomyocardial biopsy. Furthermore, the presence of high-grade atrioventricular block in this disease requires aggressive management with temporary pacemaker and corticosteroid therapy

A low-energy x-ray irradiator for electrophysiological studies

International Nuclear Information System (INIS)

Schauer, D.A.; Zeman, G.H.; Pellmar, T.C.

1989-01-01

A 50 kVp molybdenum target/filter x-ray tube has been installed inside a lead-shielded Faraday cage. High-dose rates of up to 1.54 Gy min -1 (17.4 keV weighted average photons) have been used to conduct local in vitro irradiations of the hippocampal region of guinea pig brains. Electrophysiological recordings of subtle changes in neuronal activity indicate this system is suitable for this application. (author)

Anatomical and electrophysiological changes in striatal TH interneurons after loss of the nigrostriatal dopaminergic pathway.

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Ünal, Bengi; Shah, Fulva; Kothari, Janish; Tepper, James M

2015-01-01

Using transgenic mice that express enhanced green fluorescent protein (EGFP) under the control of the tyrosine hydroxylase (TH) promoter, we have previously shown that there are approximately 3,000 striatal EGFP-TH interneurons per hemisphere in mice. Here, we report that striatal TH-EGFP interneurons exhibit a small, transient but significant increase in number after unilateral destruction of the nigrostriatal dopaminergic pathway. The increase in cell number is accompanied by electrophysiological and morphological changes. The intrinsic electrophysiological properties of EGFP-TH interneurons ipsilateral to 6-OHDA lesion were similar to those originally reported in intact mice except for a significant reduction in the duration of a characteristic depolarization induced plateau potential. There was a significant change in the distribution of the four previously described electrophysiologically distinct subtypes of striatal TH interneurons. There was a concomitant increase in the frequency of both spontaneous excitatory and inhibitory post-synaptic currents, while their amplitudes did not change. Nigrostriatal lesions did not affect somatic size or dendritic length or branching, but resulted in an increase in the density of proximal dendritic spines and spine-like appendages in EGFP-TH interneurons. The changes indicate that electrophysiology properties and morphology of striatal EGFP-TH interneurons depend on endogenous levels of dopamine arising from the nigrostriatal pathway. Furthermore, these changes may serve to help compensate for the changes in activity of spiny projection neurons that occur following loss of the nigrostriatal innervation in experimental or in early idiopathic Parkinson's disease by increasing feedforward GABAergic inhibition exerted by these interneurons.

Late-onset Becker muscular dystrophy: Refining the clinical features and electrophysiological findings.

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Beltran Papsdorf, Tania; Howard, James F; Chahin, Nizar

2015-11-01

The aim of this study was to characterize a unique distribution of muscle involvement in sporadic Becker muscle dystrophy (BMD). Retrospective chart review, clinical examination, electrophysiological studies, cardiac testing, and genetic testing were performed in 5 patients. Predominant weakness and atrophy of biceps brachii, hip adduction, and quadriceps muscles was noted along with calf and extensor forearm hypertrophy. Finger flexor muscles were severely weak in 3 of 5 patients, a feature that could lead to a misdiagnosis of inclusion body myositis. Creatinine kinase was only mildly elevated in most patients. Electromyography was abnormal in all patients. Muscle biopsy in 1 patient demonstrated normal immunostaining for dystrophin. We found a unique and uniform distribution of muscle involvement in 5 sporadic cases of BMD. Recognizing these features is important for differentiating it from other myopathies that may have similar features and avoids unnecessary invasive procedures such as muscle biopsy. © 2015 Wiley Periodicals, Inc.

Grammatical markers switch roles and elicit different electrophysiological responses under shallow and deep semantic requirements.

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Soshi, Takahiro; Nakajima, Heizo; Hagiwara, Hiroko

2016-10-01

Static knowledge about the grammar of a natural language is represented in the cortico-subcortical system. However, the differences in dynamic verbal processing under different cognitive conditions are unclear. To clarify this, we conducted an electrophysiological experiment involving a semantic priming paradigm in which semantically congruent or incongruent word sequences (prime nouns-target verbs) were randomly presented. We examined the event-related brain potentials that occurred in response to congruent and incongruent target words that were preceded by primes with or without grammatical case markers. The two participant groups performed either the shallow (lexical judgment) or deep (direct semantic judgment) semantic tasks. We hypothesized that, irrespective of the case markers, the congruent targets would reduce centro-posterior N400 activities under the deep semantic condition, which induces selective attention to the semantic relatedness of content words. However, the same congruent targets with correct case markers would reduce lateralized negativity under the shallow semantic condition because grammatical case markers are related to automatic structural integration under semantically unattended conditions. We observed that congruent targets (e.g., 'open') that were preceded by primes with congruent case markers (e.g., 'shutter-object case') reduced lateralized negativity under the shallow semantic condition. In contrast, congruent targets, irrespective of case markers, consistently yielded N400 reductions under the deep semantic condition. To summarize, human neural verbal processing differed in response to the same grammatical markers in the same verbal expressions under semantically attended or unattended conditions.

Electrophysiological correlates of the BOLD signal for EEG-informed fMRI

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Murta, Teresa; Leite, Marco; Carmichael, David W; Figueiredo, Patrícia; Lemieux, Louis

2015-01-01

Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are important tools in cognitive and clinical neuroscience. Combined EEG–fMRI has been shown to help to characterise brain networks involved in epileptic activity, as well as in different sensory, motor and cognitive functions. A good understanding of the electrophysiological correlates of the blood oxygen level-dependent (BOLD) signal is necessary to interpret fMRI maps, particularly when obtained in combination with EEG. We review the current understanding of electrophysiological–haemodynamic correlates, during different types of brain activity. We start by describing the basic mechanisms underlying EEG and BOLD signals and proceed by reviewing EEG-informed fMRI studies using fMRI to map specific EEG phenomena over the entire brain (EEG–fMRI mapping), or exploring a range of EEG-derived quantities to determine which best explain colocalised BOLD fluctuations (local EEG–fMRI coupling). While reviewing studies of different forms of brain activity (epileptic and nonepileptic spontaneous activity; cognitive, sensory and motor functions), a significant attention is given to epilepsy because the investigation of its haemodynamic correlates is the most common application of EEG-informed fMRI. Our review is focused on EEG-informed fMRI, an asymmetric approach of data integration. We give special attention to the invasiveness of electrophysiological measurements and the simultaneity of multimodal acquisitions because these methodological aspects determine the nature of the conclusions that can be drawn from EEG-informed fMRI studies. We emphasise the advantages of, and need for, simultaneous intracranial EEG–fMRI studies in humans, which recently became available and hold great potential to improve our understanding of the electrophysiological correlates of BOLD fluctuations. PMID:25277370

3D stereotaxis for epileptic foci through integrating MR imaging with neurological electrophysiology data

International Nuclear Information System (INIS)

Luo Min; Peng Chenglin; Wang Kang; Lei Wenyong; Luo Song; Wang Xiaolin; Wang Xuejian; Wu Ruoqiu; Wu Guofeng

2005-01-01

Objective: To improve the accuracy of the epilepsy diagnoses by integrating MR image from PACS with data from neurological electrophysiology. The integration is also very important for transmiting diagnostic information to 3D TPS of radiotherapy. Methods: The electroencephalogram was redisplayed by EEG workstation, while MR image was reconstructed by Brainvoyager software. 3D model of patient brain was built up by combining reconstructed images with electroencephalogram data in Base 2000. 30 epileptic patients (18 males and 12 females) with their age ranged from 12 to 54 years were confirmed by using the integrated MR images and the data from neurological electrophysiology and their 3D stereolocating. Results: The corresponding data in 3D model could show the real situation of patients' brain and visually locate the precise position of the focus. The suddessful rate of 3D guided operation was greatly improved, and the number of epileptic onset was markedly decreased. The epilepsy was stopped for 6 months in 8 of the 30 patients. Conclusion: The integration of MR image and information of neurological electrophysiology can improve the diagnostic level for epilepsy, and it is crucial for imp roving the successful rate of manipulations and the epilepsy analysis. (authors)

Clinical and electrophysiological aspects of tics in children.

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Safiullina, G I; Safiullina, A A

2015-01-01

Tics are diverse in nature inappropriate movements or vocalizations. They significantly degrade patients' quality of life, lead to social difficulties, and disturbance of learning especially during exacerbations. The prevalence of tics among children ranges from 4% to 24%, thus emphasizing the relevance of the problem. To study clinical and electrophysiological features of tics in children with development of new treatment methods. We conducted a comprehensive clinical and electrophysiological examination of 50 patients with tics, aged 5 to 15 years. The control group consisted of 20 healthy children. The research included a thorough study of the history, neurological examination, manual testing of skeletal muscles, psychological testing. Electrophysiological examination included a review of the functional state of corticospinal tract (CST) by the method of magnetic stimulation (MS), study of polysynaptic reflex excitability (PRE) according to a late component of the blink reflex (BR). Statistical analysis included parametric and nonparametric methods of data processing. All children of the study group showed signs of minimal brain dysfunction (MBD), they had complicated antenatal and postnatal history (trauma, disease, occurring with intoxication). There was a trend towards the increase of MBD signs with worsening of tics. Manual diagnosis in patients identified functional blockade at different levels of the vertebral column, sacroiliac joints, we identified latent myofascial trigger points (MFTP) mainly in the cervical-collar zone, in the area of the paravertebral muscles, periosteal triggers in the area of the sacroiliac joints.The research allowed determining decrease in propagation velocity of excitation (PVE) throughout CST in patients with tics. Correlation analysis revealed a negative correlation between the severity of tics and PVE (r = -0.38; p tics: I - low and moderate type of reflex responses; and II - high type of reflex responses. Collation of data

Importance of Thickness in Human Cardiomyocyte Network for Effective Electrophysiological Stimulation Using On-Chip Extracellular Microelectrodes

Science.gov (United States)

Hamada, Tomoyo; Nomura, Fumimasa; Kaneko, Tomoyuki; Yasuda, Kenji

2012-06-01

We have developed a three-dimensionally controlled in vitro human cardiomyocyte network assay for the measurements of drug-induced conductivity changes and the appearance of fatal arrhythmia such as ventricular tachycardia/fibrillation for more precise in vitro predictive cardiotoxicity. To construct an artificial conductance propagation model of a human cardiomyocyte network, first, we examined the cell concentration dependence of the cell network heights and found the existence of a height limit of cell networks, which was double-layer height, whereas the cardiomyocytes were effectively and homogeneously cultivated within the microchamber maintaining their spatial distribution constant and their electrophysiological conductance and propagation were successfully recorded using a microelectrode array set on the bottom of the microchamber. The pacing ability of a cardiomyocyte's electrophysiological response has been evaluated using microelectrode extracellular stimulation, and the stimulation for pacing also successfully regulated the beating frequencies of two-layered cardiomyocyte networks, whereas monolayered cardiomyocyte networks were hardly stimulated by the external electrodes using the two-layered cardiomyocyte stimulation condition. The stability of the lined-up shape of human cardiomyocytes within the rectangularly arranged agarose microchambers was limited for a two-layered cardiomyocyte network because their stronger force generation shrunk those cells after peeling off the substrate. The results indicate the importance of fabrication technology of thickness control of cellular networks for effective extracellular stimulation and the potential concerning thick cardiomyocyte networks for long-term cultivation.

PET evaluation of refractory epilepsy in children and adolescents

International Nuclear Information System (INIS)

Luh, K.E.; Kim, F.; Yasillo, N.J.; Awh, E.; Chou, J.S.; Lin-Dunham, J.; Levin, D.N.; Cooper, M.

1990-01-01

In many cases of intractable epilepsy, the focus is difficult to localize. In this paper positron emission tomography (PET) and MR imaging are compared for accuracy in identifying seizure foci. Cerebral glucose utilization was measured using conventional fluorodeoxyglucose technique in 29 children with epilepsy. All subjects also underwent MR imaging and were evaluated clinically and electrophysiologically. The authors evaluated 34 regions of interest (ROIs) within eight tomographic sections for rCMRglu metabolism. In 17 of 29 patients, MR imaging yielded normal results; PET results were abnormal in 12 of these patients, 11 of whom went on to surgery. The five patients in whom both PET and MR imaging results were normal did not go to surgery, and no definitive diagnoses were made

Nucleus accumbens core medium spiny neuron electrophysiological properties and partner preference behavior in the adult male prairie vole, Microtus ochrogaster.

Science.gov (United States)

Willett, Jaime A; Johnson, Ashlyn G; Vogel, Andrea R; Patisaul, Heather B; McGraw, Lisa A; Meitzen, John

2018-04-01

Medium spiny neurons (MSNs) in the nucleus accumbens have long been implicated in the neurobiological mechanisms that underlie numerous social and motivated behaviors as studied in rodents such as rats. Recently, the prairie vole has emerged as an important model animal for studying social behaviors, particularly regarding monogamy because of its ability to form pair bonds. However, to our knowledge, no study has assessed intrinsic vole MSN electrophysiological properties or tested how these properties vary with the strength of the pair bond between partnered voles. Here we performed whole cell patch-clamp recordings of MSNs in acute brain slices of the nucleus accumbens core (NAc) of adult male voles exhibiting strong and weak preferences for their respective partnered females. We first document vole MSN electrophysiological properties and provide comparison to rat MSNs. Vole MSNs demonstrated many canonical electrophysiological attributes shared across species but exhibited notable differences in excitability compared with rat MSNs. Second, we assessed male vole partner preference behavior and tested whether MSN electrophysiological properties varied with partner preference strength. Male vole partner preference showed extensive variability. We found that decreases in miniature excitatory postsynaptic current amplitude and the slope of the evoked action potential firing rate to depolarizing current injection weakly associated with increased preference for the partnered female. This suggests that excitatory synaptic strength and neuronal excitability may be decreased in MSNs in males exhibiting stronger preference for a partnered female. Overall, these data provide extensive documentation of MSN electrophysiological characteristics and their relationship to social behavior in the prairie vole. NEW & NOTEWORTHY This research represents the first assessment of prairie vole nucleus accumbens core medium spiny neuron intrinsic electrophysiological properties and

Paroxysmal atrioventricular block: Electrophysiological mechanism of phase 4 conduction block in the His-Purkinje system: A comparison with phase 3 block.

Science.gov (United States)

Shenasa, Mohammad; Josephson, Mark E; Wit, Andrew L

2017-11-01

Paroxysmal atrioventricular (A-V) block is relatively rare, and due to its transient nature, it is often under recognized. It is often triggered by atrial, junctional, or ventricular premature beats, and occurs in the presence of a diseased His-Purkinje system (HPS). Here, we present a 45-year-old white male who was admitted for observation due to recurrent syncope and near-syncope, who had paroxysmal A-V block. The likely cellular electrophysiological mechanisms(s) of paroxysmal A-V block and its differential diagnosis and management are discussed. Continuous electrocardiographic monitoring was done while the patient was in the cardiac unit. Multiple episodes of paroxysmal A-V block were documented in this case. All episodes were initiated and terminated with atrial/junctional premature beats. The patient underwent permanent pacemaker implantation and has remained asymptomatic since then. Paroxysmal A-V block is rare and often causes syncope or near-syncope. Permanent pacemaker implantation is indicated according to the current guidelines. Paroxysmal A-V block occurs in the setting of diseased HPS and is bradycardia-dependent. The detailed electrophysiological mechanisms, which involve phase 4 diastolic depolarization, and differential diagnosis are discussed. © 2017 Wiley Periodicals, Inc.

The Acoustic Lens Design and in Vivo Use of a Multifunctional Catheter Combining Intracardiac Ultrasound Imaging and Electrophysiology Sensing

Science.gov (United States)

Stephens, Douglas N.; Cannata, Jonathan; Liu, Ruibin; Zhao, Jian Zhong; Shung, K. Kirk; Nguyen, Hien; Chia, Raymond; Dentinger, Aaron; Wildes, Douglas; Thomenius, Kai E.; Mahajan, Aman; Shivkumar, Kalyanam; Kim, Kang; O’Donnell, Matthew; Sahn, David

2009-01-01

A multifunctional 9F intracardiac imaging and electrophysiology mapping catheter was developed and tested to help guide diagnostic and therapeutic intracardiac electrophysiology (EP) procedures. The catheter tip includes a 7.25-MHz, 64-element, side-looking phased array for high resolution sector scanning. Multiple electrophysiology mapping sensors were mounted as ring electrodes near the array for electrocardiographic synchronization of ultrasound images. The catheter array elevation beam performance in particular was investigated. An acoustic lens for the distal tip array designed with a round cross section can produce an acceptable elevation beam shape; however, the velocity of sound in the lens material should be approximately 155 m/s slower than in tissue for the best beam shape and wide bandwidth performance. To help establish the catheter’s unique ability for integration with electrophysiology interventional procedures, it was used in vivo in a porcine animal model, and demonstrated both useful intracardiac echocardiographic visualization and simultaneous 3-D positional information using integrated electroanatomical mapping techniques. The catheter also performed well in high frame rate imaging, color flow imaging, and strain rate imaging of atrial and ventricular structures. PMID:18407850

Analyzing clinical and electrophysiological characteristics of Paroxysmal Dyskinesia

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Jue-qian Zhou

2011-01-01

Full Text Available The classification, clinical and electrophysiological characteristics, treatment outcome and pathogenesis of paroxysmal dyskinesia were summarized and analyzed. Paroxysmal dyskinesia was classified into three types. Different types had different incentives in clinical practice. Patients were mostly male adolescents, and the attacks, which were in various forms, manifested as dysmyotonia of choreoathetosis, body torsion and facemaking; no disturbance of consciousness during attacks. Electroencephalogram and other examinations showed no specific abnormalities during both the attacks and interictal period. Paroxysmal dyskinesia was an independent disease and different from epilepsy.

High throughput electrophysiology: new perspectives for ion channel drug discovery

DEFF Research Database (Denmark)

Willumsen, Niels J; Bech, Morten; Olesen, Søren-Peter

2003-01-01

. A cornerstone in current drug discovery is high throughput screening assays which allow examination of the activity of specific ion channels though only to a limited extent. Conventional patch clamp remains the sole technique with sufficiently high time resolution and sensitivity required for precise and direct....... The introduction of new powerful HTS electrophysiological techniques is predicted to cause a revolution in ion channel drug discovery....

Pediatric Electrophysiology in India: A Sub-speciality Come of Age

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Johnson Francis

2008-05-01

Full Text Available Electrophysiology started in India in the early 70's with the earliest published diagnostic His bundle studies coming from the All India Institute of Medical Sciences by Bhatia ML et al and the GB Pant Hospital by Khalilullah et al . That era was remarkable with the first indigenously made temporary pacemaker being used to treat complete heart block as early as in 1970

Neo: an object model for handling electrophysiology data in multiple formats

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Samuel eGarcia

2014-02-01

Full Text Available Neuroscientists use many different software tools to acquire, analyse and visualise electrophysiological signals. However, incompatible data models and file formats make it difficult to exchange data between these tools. This reduces scientific productivity, renders potentially useful analysis methods inaccessible and impedes collaboration between labs.A common representation of the core data would improve interoperability and facilitate data-sharing.To that end, we propose here a language-independent object model, named Neo, suitable for representing data acquired from electroencephalographic, intracellular, or extracellular recordings, or generated from simulations. As a concrete instantiation of this object model we have developed an open source implementation in the Python programming language.In addition to representing electrophysiology data in memory for the purposes of analysis and visualisation, the Python implementation provides a set of input/output (IO modules for reading/writing the data from/to a variety of commonly used file formats.Support is included for formats produced by most of the major manufacturers of electrophysiology recording equipment and also for more generic formats such as MATLAB.Data representation and data analysis are conceptually separate: it is easier to write robust analysis code if it is focused on analysis and relies on an underlying package to handle data representation.For that reason, and also to be as lightweight as possible, the Neo object model and the associated Python package are deliberately limited to representation of data, with no functions for data analysis or visualisation.Software for neurophysiology data analysis and visualisation built on top of Neo automatically gains the benefits of interoperability, easier data sharing and automatic format conversion; there is already a burgeoning ecosystem of such tools. We intend that Neo should become the standard basis for Python tools in

Evaluating Diagnostic Value of Electrophysiological Testing (EMG-NCV Compared to the Activity Level of Acetylcholinesterase in Serum and Red Blood Cells of Patients with Moderate to Severe Organophosphate Poisoning

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Fares Najari

2017-05-01

Full Text Available Background Organophosphate compounds cause poisoning and death more than any other insecticide. These toxins can cause peripheral neuropathy which is delayed for about 3 - 6 weeks and no method has been known for predicting the incidence. It has been claimed that electrophysiological tests (EMG - NCV can help in predicting the disorder. Objectives The main purpose of this research was to study EMG - NCV tests in patients with moderate to severe organophosphate poisoning. Methods This was a cross-sectional study conducted on patients with moderate to severe organophosphate poisoning from 2014 to 2016 in Imam Reza hospital of Mashhad. The minimum sample size was calculated as 68 patients and then all data was collected on the basis of inclusion and exclusion criteria using data collection form designed by the researcher, and finally data were analyzed using SPSS V.21 software, descriptive tests (including mean, median, mode and analytical tests (K square, ANOVA. Results Of all 78 patients with the mean age of 27.50 ± 10.0, 45 were female and the rest were male. Totally 29.5% of the patients had abnormal EMG - NCV. Although no significant differences were observed between electro diagnostic tests (EMG - NCV and age, gender, clinical symptoms and levels of acetylcholinesterase serum activity, the relationship between EMG - NCV and RBC levels of acetylcholinesterase activity was significant. Conclusions Electrophysiological tests are not associated with clinical symptoms (muscle weakness and they cannot be considered as a determining factor to discharge the patients; therefore, careful examination of the patients or evaluating the level of AChE activity in red blood cells is needed.

Electrophysiological Evidence of Developmental Changes in the Duration of Auditory Sensory Memory.

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Gomes, Hilary; And Others

1999-01-01

Investigated developmental change in duration of auditory sensory memory for tonal frequency by measuring mismatch negativity, an electrophysiological component of the auditory event-related potential that is relatively insensitive to attention and does not require a behavioral response. Findings among children and adults suggest that there are…

Wearable Multi-Channel Microelectrode Membranes for Elucidating Electrophysiological Phenotypes of Injured Myocardium

Science.gov (United States)

Cao, Hung; Yu, Fei; Zhao, Yu; Zhang, Xiaoxiao; Tai, Joyce; Lee, Juhyun; Darehzereshki, Ali; Bersohn, Malcolm; Lien, Ching-Ling; Chi, Neil C.; Tai, Yu-Chong; Hsiai, Tzung K.

2014-01-01

Understanding the regenerative capacity of small vertebrate models has provided new insights into the plasticity of injured myocardium. Here, we demonstrated the application of flexible microelectrode arrays (MEAs) in elucidating electrophysiological phenotypes of zebrafish and neonatal mouse models of heart regeneration. The 4-electrode MEA membranes were designed to detect electrical signals in the aquatic environment. They were micro-fabricated to adhere to the non-planar body surface of zebrafish and neonatal mice. The acquired signals were processed to display electrocardiogram (ECG) with high signal-to-noise-ratios, and were validated via the use of conventional micro-needle electrodes. The 4-channel MEA provided signal stability and spatial resolution, revealing the site-specific electrical injury currents such as ST-depression in response to ventricular cryo-injury. Thus, our polymer-based and wearable MEA membranes provided electrophysiological insights in long-term conduction phenotypes for small vertebral models of heart injury and regeneration with a translational implication for monitoring cardiac patients. PMID:24945366

Obesity, Cardiovascular Fitness, and Inhibition Function: An Electrophysiological Study

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Tai-Fen Song

2016-07-01

Full Text Available The purpose of the present study was to examine how obesity and cardiovascular fitness are associated with the inhibition aspect of executive function from behavioral and electrophysiological perspectives. One hundred college students, aged 18 to 25 years, were categorized into four groups of equal size on the basis of body mass index and cardiovascular fitness: a normal-weight and high-fitness (NH group, an obese-weight and high-fitness (OH group, a normal-weight and low-fitness (NL group, and an obese-weight and low-fitness (OL group. Behavioral measures of response time and number of errors, as well as event-related potential (ERP measures of P3 and N1, were assessed during the Stroop Task. The results revealed that, in general, the NH group exhibited shorter response times and larger P3 amplitudes relative to the OH, NL, and OL groups, wherein the OL group exhibited the longest response time in the incongruent condition. No group differences in N1 indices were also revealed. These findings suggest that the status of being both normal weight and having high cardiovascular fitness is associated with better behavioral and later stages of electrophysiological indices of inhibition. However, these benefits in inhibition function would be lost in an individual who is obese or has low cardiovascular fitness, reflecting the importance keeping both normal weight and having high cardiovascular fitness.

Grammatical markers switch roles and elicit different electrophysiological responses under shallow and deep semantic requirements

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Takahiro Soshi

2016-10-01

Full Text Available Static knowledge about the grammar of a natural language is represented in the cortico-subcortical system. However, the differences in dynamic verbal processing under different cognitive conditions are unclear. To clarify this, we conducted an electrophysiological experiment involving a semantic priming paradigm in which semantically congruent or incongruent word sequences (prime nouns–target verbs were randomly presented. We examined the event-related brain potentials that occurred in response to congruent and incongruent target words that were preceded by primes with or without grammatical case markers. The two participant groups performed either the shallow (lexical judgment or deep (direct semantic judgment semantic tasks. We hypothesized that, irrespective of the case markers, the congruent targets would reduce centro-posterior N400 activities under the deep semantic condition, which induces selective attention to the semantic relatedness of content words. However, the same congruent targets with correct case markers would reduce lateralized negativity under the shallow semantic condition because grammatical case markers are related to automatic structural integration under semantically unattended conditions. We observed that congruent targets (e.g., ‘open' that were preceded by primes with congruent case markers (e.g., ‘shutter-object case' reduced lateralized negativity under the shallow semantic condition. In contrast, congruent targets, irrespective of case markers, consistently yielded N400 reductions under the deep semantic condition. To summarize, human neural verbal processing differed in response to the same grammatical markers in the same verbal expressions under semantically attended or unattended conditions. Keyword: Neuroscience

Reducing radiation exposure in an electrophysiology lab with introduction of newer fluoroscopic technology

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Munish Sharma

2017-09-01

Full Text Available The use of fluoroscopic devices exposes patients and operators to harmful effects of ionizing radiation in an electrophysiology (EP lab. We sought to know if the newer fluoroscopic technology (Allura Clarity installed in a hybrid EP helps to reduce prescribed radiation dose. We performed radiation dose analysis of 90 patients who underwent various procedures in the EP lab at a community teaching hospital after the introduction of newer fluoroscopic technology in June of 2016.Watchman device insertion, radiofrequency ablation procedures, permanent pacemaker (PPM/implantable cardioverter defibrillator (ICD placement and battery changes were included in the study to compare radiation exposure during different procedures performed commonly in an EP lab. In all cases of watchman device placement, radiofrequency ablation procedures, PPM/ICD placement and battery changes, there was a statistically significant difference (<0.05 in radiation dose exposure. Significant reduction in radiation exposure during various procedures performed in an EP lab was achieved with aid of newer fluoroscopic technology and better image detection technology.

Positive Behavioral and Electrophysiological Changes following Neurofeedback Training in Children with Autism

Science.gov (United States)

Pineda, J. A.; Brang, D.; Hecht, E.; Edwards, L.; Carey, S.; Bacon, M.; Futagaki, C.; Suk, D.; Tom, J.; Birnbaum, C.; Rork, A.

2008-01-01

Two electrophysiological studies tested the hypothesis that operant conditioning of mu rhythms via neurofeedback training can renormalize mu suppression, an index of mirror neuron activity, and improve behavior in children diagnosed with autism spectrum disorders (ASD). In Study 1, eight high-functioning ASD participants were assigned to placebo…

Generation and customization of biosynthetic excitable tissues for electrophysiological studies and cell-based therapies.

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Nguyen, Hung X; Kirkton, Robert D; Bursac, Nenad

2018-05-01

We describe a two-stage protocol to generate electrically excitable and actively conducting cell networks with stable and customizable electrophysiological phenotypes. Using this method, we have engineered monoclonally derived excitable tissues as a robust and reproducible platform to investigate how specific ion channels and mutations affect action potential (AP) shape and conduction. In the first stage of the protocol, we combine computational modeling, site-directed mutagenesis, and electrophysiological techniques to derive optimal sets of mammalian and/or prokaryotic ion channels that produce specific AP shape and conduction characteristics. In the second stage of the protocol, selected ion channels are stably expressed in unexcitable human cells by means of viral or nonviral delivery, followed by flow cytometry or antibiotic selection to purify the desired phenotype. This protocol can be used with traditional heterologous expression systems or primary excitable cells, and application of this method to primary fibroblasts may enable an alternative approach to cardiac cell therapy. Compared with existing methods, this protocol generates a well-defined, relatively homogeneous electrophysiological phenotype of excitable cells that facilitates experimental and computational studies of AP conduction and can decrease arrhythmogenic risk upon cell transplantation. Although basic cell culture and molecular biology techniques are sufficient to generate excitable tissues using the described protocol, experience with patch-clamp techniques is required to characterize and optimize derived cell populations.

Electrophysiological Properties of Melanin-Concentrating Hormone and Orexin Neurons in Adolescent Rats

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Victoria Linehan

2018-03-01

Full Text Available Orexin and melanin-concentrating hormone (MCH neurons have complementary roles in various physiological functions including energy balance and the sleep/wake cycle. in vitro electrophysiological studies investigating these cells typically use post-weaning rodents, corresponding to adolescence. However, it is unclear whether these neurons are functionally mature at this period and whether these studies can be generalized to adult cells. Therefore, we examined the electrophysiological properties of orexin and MCH neurons in brain slices from post-weaning rats and found that MCH neurons undergo an age-dependent reduction in excitability, but not orexin neurons. Specifically, MCH neurons displayed an age-dependent hyperpolarization of the resting membrane potential (RMP, depolarizing shift of the threshold, and decrease in excitatory transmission, which reach the adult level by 7 weeks of age. In contrast, basic properties of orexin neurons were stable from 4 weeks to 14 weeks of age. Furthermore, a robust short-term facilitation of excitatory synapses was found in MCH neurons, which showed age-dependent changes during the post-weaning period. On the other hand, a strong short-term depression was observed in orexin neurons, which was similar throughout the same period. These differences in synaptic responses and age dependence likely differentially affect the network activity within the lateral hypothalamus where these cells co-exist. In summary, our study suggests that orexin neurons are electrophysiologically mature before adolescence whereas MCH neurons continue to develop until late adolescence. These changes in MCH neurons may contribute to growth spurts or consolidation of adult sleep patterns associated with adolescence. Furthermore, these results highlight the importance of considering the age of animals in studies involving MCH neurons.

A Quantitative Electrophysiological Biomarker of Duplication 15q11.2-q13.1 Syndrome.

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Joel Frohlich

Full Text Available Duplications of 15q11.2-q13.1 (Dup15q syndrome are highly penetrant for autism spectrum disorder (ASD. A distinct electrophysiological (EEG pattern characterized by excessive activity in the beta band has been noted in clinical reports. We asked whether EEG power in the beta band, as well as in other frequency bands, distinguished children with Dup15q syndrome from those with non-syndromic ASD and then examined the clinical correlates of this electrophysiological biomarker in Dup15q syndrome.In the first study, we recorded spontaneous EEG from children with Dup15q syndrome (n = 11, age-and-IQ-matched children with ASD (n = 10 and age-matched typically developing (TD children (n = 9 and computed relative power in 6 frequency bands for 9 regions of interest (ROIs. Group comparisons were made using a repeated measures analysis of variance. In the second study, we recorded spontaneous EEG from a larger cohort of individuals with Dup15q syndrome (n = 27 across two sites and examined age, epilepsy, and duplication type as predictors of beta power using simple linear regressions.In the first study, spontaneous beta1 (12-20 Hz and beta2 (20-30 Hz power were significantly higher in Dup15q syndrome compared with both comparison groups, while delta (1-4 Hz was significantly lower than both comparison groups. Effect sizes in all three frequency bands were large (|d| > 1. In the second study, we found that beta2 power was significantly related to epilepsy diagnosis in Dup15q syndrome.Here, we have identified an electrophysiological biomarker of Dup15q syndrome that may facilitate clinical stratification, treatment monitoring, and measurement of target engagement for future clinical trials. Future work will investigate the genetic and neural underpinnings of this electrophysiological signature as well as the functional consequences of excessive beta oscillations in Dup15q syndrome.

Automatic Parameterization Strategy for Cardiac Electrophysiology Simulations.

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Costa, Caroline Mendonca; Hoetzl, Elena; Rocha, Bernardo Martins; Prassl, Anton J; Plank, Gernot

2013-10-01

Driven by recent advances in medical imaging, image segmentation and numerical techniques, computer models of ventricular electrophysiology account for increasingly finer levels of anatomical and biophysical detail. However, considering the large number of model parameters involved parameterization poses a major challenge. A minimum requirement in combined experimental and modeling studies is to achieve good agreement in activation and repolarization sequences between model and experiment or patient data. In this study, we propose basic techniques which aid in determining bidomain parameters to match activation sequences. An iterative parameterization algorithm is implemented which determines appropriate bulk conductivities which yield prescribed velocities. In addition, a method is proposed for splitting the computed bulk conductivities into individual bidomain conductivities by prescribing anisotropy ratios.

Electrophysiological Markers of Categorical Perception of Color in 7-Month Old Infants

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Clifford, Alexandra; Franklin, Anna; Davies, Ian R. L.; Holmes, Amanda

2009-01-01

The origin of color categories has been debated by psychologists, linguists and cognitive scientists for many decades. Here, we present the first electrophysiological evidence for categorical responding to color before color terms are acquired. Event-related potentials were recorded on a visual oddball task in 7-month old infants. Infants were…

Cardiac autonomic modulation by estrogen in female mice undergoing ambulatory monitoring and in vivo electrophysiologic testing.

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Saba, Samir; Shusterman, Vladimir; Usiene, Irmute; London, Barry

2004-04-01

Estrogen is an important modulator of cardiovascular risk, but its mechanism of action is not fully understood. We investigated the effect of ovariectomy and its timing on the cardiac electrophysiology in mice. Thirty female mice (age 18.8 +/- 3.1 weeks) underwent in vivo electrophysiologic testing before and after autonomic blockade. Fifteen mice were ovariectomized prepuberty (PRE) and ten postpuberty (POST), 2 weeks prior to electrophysiologic testing. Five age-matched sham-operated female mice (Control) served as controls. A subset of 13 mice (5 PRE, 3 POST, and 5 Controls) underwent 24-hour ambulatory monitoring. With ambulatory monitoring, the average (668 +/- 28 vs 769 +/- 52 b/min, P = 0.008) and minimum (485 +/- 47 vs 587 +/- 53 b/min, P = 0.02) heart rates were significantly slower in the ovariectomized mice (PRE and POST groups) compared to the Control group. At baseline electrophysiologic testing, there were no significant differences among the ovariectomized and intact mice in any of the measured parameters. With autonomic blockade, the Control group had a significantly larger change (delta) in the atrioventricular (AV) nodal Wenckebach (AVW) periodicity (deltaAVW = 11.3 +/- 2.9 vs 2.1 +/- 7.3 ms, P = 0.05) and functional refractory period (deltaFRP = 11.3 +/- 2.1 vs 1.25 +/- 6.8 ms, P = 0.02) compared to the ovariectomized mice. These results were not altered by the time of ovariectomy (PRE vs POST groups). Our results suggest that estrogen modulates the autonomic inputs into the murine sinus and AV nodes. These findings, if replicated in humans, might underlie the observed clustering of certain arrhythmias around menstruation and explain the higher incidence of arrhythmias in men and postmenopausal women.

Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology.

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Shankarjee Krishnamoorthi

Full Text Available We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology.

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Krishnamoorthi, Shankarjee; Perotti, Luigi E; Borgstrom, Nils P; Ajijola, Olujimi A; Frid, Anna; Ponnaluri, Aditya V; Weiss, James N; Qu, Zhilin; Klug, William S; Ennis, Daniel B; Garfinkel, Alan

2014-01-01

We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG) and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

Effects of Prolonged Spaceflight on Atrial Size, Atrial Electrophysiology, and Risk of Atrial Fibrillation.

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Khine, Htet W; Steding-Ehrenborg, Katarina; Hastings, Jeffrey L; Kowal, Jamie; Daniels, James D; Page, Richard L; Goldberger, Jeffery J; Ng, Jason; Adams-Huet, Beverley; Bungo, Michael W; Levine, Benjamin D

2018-05-01

The prevalence of atrial fibrillation (AF) in active astronauts is ≈5%, similar to the general population but at a younger age. Risk factors for AF include left atrial enlargement, increased number of premature atrial complexes, and certain parameters on signal-averaged electrocardiography, such as P-wave duration, root mean square voltage for the terminal 20 ms of the signal-averaged P wave, and P-wave amplitude. We aimed to evaluate changes in atrial structure, supraventricular beats, and atrial electrophysiology to determine whether spaceflight could increase the risk of AF. Thirteen astronauts underwent cardiac magnetic resonance imaging to assess atrial structure and function before and after 6 months in space and high-resolution Holter monitoring for multiple 48-hour time periods before flight, during flight, and on landing day. Left atrial volume transiently increased after 6 months in space (12±18 mL; P =0.03) without changing atrial function. Right atrial size remained unchanged. No changes in supraventricular beats were noted. One astronaut had a large increase in supraventricular ectopic beats but none developed AF. Filtered P-wave duration did not change over time, but root mean square voltage for the terminal 20 ms decreased on all fight days except landing day. No changes in P-wave amplitude were seen in leads II or V 1 except landing day for lead V 1 . Six months of spaceflight may be sufficient to cause transient changes in left atrial structure and atrial electrophysiology that increase the risk of AF. However, there was no definite evidence of increased supraventricular arrhythmias and no identified episodes of AF. © 2018 American Heart Association, Inc.

Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study

Energy Technology Data Exchange (ETDEWEB)

Rakovec, P.; Kranjec, I.; Fettich, J.J.; Jakopin, J.; Fidler, V.; Turk, J.

1985-01-01

Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combined electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates.

Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study

International Nuclear Information System (INIS)

Rakovec, P.; Kranjec, I.; Fettich, J.J.; Jakopin, J.; Fidler, V.; Turk, J.

1985-01-01

Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combined electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates

Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives

DEFF Research Database (Denmark)

Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa

2016-01-01

Non-invasive transcranial brain stimulation (NTBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (TCS) are important tools in human systems and cognitive neuroscience because they are able to reveal the relevance of certain brain structures...... are technically demanding. We argue that the benefit from this combination is twofold. Firstly, neuroimaging and electrophysiology can inform subsequent NTBS, providing the required information to optimize where, when, and how to stimulate the brain. Information can be achieved both before and during the NTBS...... experiment, requiring consecutive and concurrent applications, respectively. Secondly, neuroimaging and electrophysiology can provide the readout for neural changes induced by NTBS. Again, using either concurrent or consecutive applications, both "online" NTBS effects immediately following the stimulation...

Electrophysiological Correlates of Reading the Single- and Interactive-Mind

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Wang, Yi-Wen; Zheng, Yu-Wei; Lin, Chong-De; Wu, Jie; Shen, De-Li

2011-01-01

Understanding minds is the cognitive basis of successful social interaction. In everyday life, human mental activity often happens at the moment of social interaction among two or multiple persons instead of only one-person. Understanding the interactive mind of two- or multi-person is more complex and higher than understanding the single-person mind in the hierarchical structure of theory of mind. Understanding the interactive mind maybe differentiate from understanding the single mind. In order to examine the dissociative electrophysiological correlates of reading the single mind and reading the interactive mind, the 64 channels event-related potentials were recorded while 16 normal adults were observing three kinds of Chinese idioms depicted physical scenes, one-person with mental activity, and two- or multi-person with mental interaction. After the equivalent N400, in the 500- to 700-ms epoch, the mean amplitudes of late positive component (LPC) over frontal for reading the single mind and reading the interactive mind were significantly more positive than for physical representation, while there was no difference between the former two. In the 700- to 800-ms epoch, the mean amplitudes of LPC over frontal–central for reading the interactive mind were more positive than for reading the single mind and physical representation, while there was no difference between the latter two. The present study provides electrophysiological signature of the dissociations between reading the single mind and reading the interactive mind. PMID:21845178

Electrophysiological correlates of reading the single- and interactive-mind

Directory of Open Access Journals (Sweden)

Yi-Wen eWang

2011-07-01

Full Text Available Understanding minds is the cognitive basis of successful social interaction. In everyday life, human mental activity often happens at the moment of social interaction among two or multiple persons instead of only one person. Understanding the interactive mind of two- or multi-person is more complex and higher than understanding the single-person mind in the hierarchical structure of theory-of-mind. Understanding the interactive mind maybe differentiate from understanding the single mind. In order to examine the dissociative electrophysiological correlates of reading the single mind and reading the interactive mind, the 64 channels event-related potentials (ERP were recorded while 16 normal adults were observing three kinds of Chinese idioms depicted physical scenes, one-person with mental activity and two- or multi-person with mental interaction. After the equivalent N400, in the 500- to 700-ms epoch, the mean amplitudes of late positive component (LPC over frontal for reading the single mind and reading the interactive mind were significantly more positive than for physical representation, while there was no difference between the former two. In the 700-to 800-ms epoch, the mean amplitudes of LPC over frontal-central for reading the interactive mind were more positive than for reading the single mind and physical representation, while there was no difference between the latter two. The present study provides electrophysiological signature of the dissociations between reading the single mind and reading the interactive mind.

Conduction disturbances after TAVR: Electrophysiological studies and pacemaker dependency.

Science.gov (United States)

Makki, Nader; Dollery, Jenn; Jones, Danielle; Crestanello, Juan; Lilly, Scott

Permanent pacemaker (PPM) placement occurs in 5-20% of patients after transcatheter aortic valve replacement (TAVR). Although predictors of pacemaker implantation have been established, features that predispose patients to pacemaker utilization on follow up have not been widely reported. We performed a retrospective review of patients undergoing commercial TAVR between 2011 and 2016. We collated patients that underwent in-hospital PPM implantation and had a follow up of at least 3months. Data abstraction was performed for electrophysiological studies (EPS), pacemaker indication, timing, and device interrogation for pacemaker dependency on follow up. A total of 24 patients received in-hospital PPM post-TAVR (14% of total cohort), and mean follow up was 22months. Indications for PPM included resting complete heart block (CHB; 15/24, 63%), left bundle branch block and abnormal electrophysiological study (EPS; 7/24, 29%), alternating bundle branch block (1/24, 4%) and tachy-brady syndrome (1/24, 4%). Pacemaker dependency (underlying ventricular asystole, complete heart block, or >50% pacing) occurred in 8/24 patients (33%) during follow-up, 7 of whom had resting CHB, and one with CHB invoked during EPS. Pacemaker dependency after TAVR is common among those that exhibited CHB, but not among those with a prolonged HV delay during EPS. Although preliminary, these observations are relevant to management of rhythm disturbances after TAVR, and may inform the practice of EPS-based PPM implantation. Copyright © 2017 Elsevier Inc. All rights reserved.

Attachment affects social information processing: Specific electrophysiological effects of maternal stimuli.

Science.gov (United States)

Wu, Lili; Gu, Ruolei; Zhang, Jianxin

2016-01-01

Attachment is critical to each individual. It affects the cognitive-affective processing of social information. The present study examines how attachment affects the processing of social information, specifically maternal information. We assessed the behavioral and electrophysiological responses to maternal information (compared to non-specific others) in a Go/No-go Association Task (GNAT) with 22 participants. The results illustrated that attachment affected maternal information processing during three sequential stages of information processing. First, attachment affected visual perception, reflected by enhanced P100 and N170 elicited by maternal information as compared to others information. Second, compared to others, mother obtained more attentional resources, reflected by faster behavioral response to maternal information and larger P200 and P300. Finally, mother was evaluated positively, reflected by shorter P300 latency in a mother + good condition as compared to a mother + bad condition. These findings indicated that the processing of attachment-relevant information is neurologically differentiated from other types of social information from an early stage of perceptual processing to late high-level processing.

Electrical Stimulation of Artificial Heart Muscle: a look into the electrophysiological and genetic implications

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Mohamed, Mohamed A; Islas, Jose F; Schwartz, Robert J; Birla, Ravi K

2016-01-01

Development of tissue-engineered hearts for treatment of myocardial infarction or biological pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. In order to further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously. In this study, we examined the effect of an intermittent biphasic square wave on our artificial heart muscle (AHM) composed of neonatal rat cardiac cells and fibrin gel. Twitch forces, spontaneous contraction rates, biopotentials, gene expression profiles, and histological observations were examined for the ES protocol over a 12 day culture period. We demonstrate improved consistency between samples for twitch force and contraction rate, and higher normalized twitch force amplitudes for electrically stimulated AHM. Improvements in electrophysiology within the AHM was noted by higher conduction velocities and lower latency in electrical response for electrically stimulated AHM. Genes expressing key electrophysiological and structural markers peaked at days 6 and 8 of culture, only a few days after the initiation of ES. These results may be used for optimization strategies to establish protocols for producing AHM capable of replacing damaged heart tissue in either a contractile or electrophysiological capacity. Optimized AHM can lead to alternative treatments to heart failure and alleviate the limited donor supply crisis. PMID:28459744

Electrical Stimulation of Artificial Heart Muscle: A Look Into the Electrophysiologic and Genetic Implications.

Science.gov (United States)

Mohamed, Mohamed A; Islas, Jose F; Schwartz, Robert J; Birla, Ravi K

Development of tissue-engineered hearts for treatment of myocardial infarction or biologic pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. To further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously. In this study, we examined the effect of an intermittent biphasic square wave on our artificial heart muscle (AHM) composed of neonatal rat cardiac cells and fibrin gel. Twitch forces, spontaneous contraction rates, biopotentials, gene expression profiles, and histologic observations were examined for the ES protocol over a 12 day culture period. We demonstrate improved consistency between samples for twitch force and contraction rate, and higher normalized twitch force amplitudes for electrically stimulated AHMs. Improvements in electrophysiology within the AHM were noted by higher conduction velocities and lower latency in electrical response for electrically stimulated AHMs. Genes expressing key electrophysiologic and structural markers peaked at days 6 and 8 of culture, only a few days after the initiation of ES. These results may be used for optimization strategies to establish protocols for producing AHMs capable of replacing damaged heart tissue in either a contractile or electrophysiologic capacity. Optimized AHMs can lead to alternative treatments to heart failure and alleviate the limited donor supply crisis.

Scalable Electrophysiology in Intact Small Animals with Nanoscale Suspended Electrode Arrays

OpenAIRE

Gonzales, Daniel L.; Badhiwala, Krishna N.; Vercosa, Daniel G.; Avants, Ben W.; Liu, Zheng; Zhong, Weiwei; Robinson, Jacob T.

2017-01-01

Electrical measurements from large populations of animals would help reveal fundamental properties of the nervous system and neurological diseases. Small invertebrates are ideal for these large-scale studies; however, patch-clamp electrophysiology in microscopic animals typically requires low-throughput and invasive dissections. To overcome these limitations, we present nano-SPEARs: suspended electrodes integrated into a scalable microfluidic device. Using this technology, we have made the fi...

Neural ensemble communities: Open-source approaches to hardware for large-scale electrophysiology

Science.gov (United States)

Siegle, Joshua H.; Hale, Gregory J.; Newman, Jonathan P.; Voigts, Jakob

2014-01-01

One often-overlooked factor when selecting a platform for large-scale electrophysiology is whether or not a particular data acquisition system is “open” or “closed”: that is, whether or not the system’s schematics and source code are available to end users. Open systems have a reputation for being difficult to acquire, poorly documented, and hard to maintain. With the arrival of more powerful and compact integrated circuits, rapid prototyping services, and web-based tools for collaborative development, these stereotypes must be reconsidered. We discuss some of the reasons why multichannel extracellular electrophysiology could benefit from open-source approaches and describe examples of successful community-driven tool development within this field. In order to promote the adoption of open-source hardware and to reduce the need for redundant development efforts, we advocate a move toward standardized interfaces that connect each element of the data processing pipeline. This will give researchers the flexibility to modify their tools when necessary, while allowing them to continue to benefit from the high-quality products and expertise provided by commercial vendors. PMID:25528614

Groin hematoma after electrophysiological procedures-incidence and predisposing factors.

Science.gov (United States)

Dalsgaard, Anja Borgen; Jakobsen, Christina Spåbæk; Riahi, Sam; Hjortshøj, Søren

2014-10-01

We evaluated the incidence and predisposing factors of groin hematomas after electrophysiological (EP) procedures. Prospective, observational study, enrolling consecutive patients after EP procedures (Atrial fibrillation: n = 151; Supraventricular tachycardia/Diagnostic EP: n = 82; Ventricular tachycardia: n = 18). Patients underwent manual compression for 10 min and 3 h post procedural bed rest. AF ablations were performed with INR 2-3, ACT > 300, and no protamine sulfate. Adhesive pressure dressings (APDs) were used if sheath size ≥ 10F; procedural time > 120 min; and BMI > 30. Patient-reported hematomas were recorded by a telephone follow-up after 2 weeks. Hematoma developed immediately in 26 patients (10%) and after 14 days significant hematoma was reported in 68 patients (27%). Regression analysis on sex, age, BMI 25, ACT 300, use of APD, sheath size and number, and complicated venous access was not associated with hematoma, either immediately after the procedure or after 14 days. Any hematoma presenting immediately after procedures was associated with patient-reported hematomas after 14 days, odds ratio 18.7 (CI 95%: 5.00-69.8; P hematoma immediately after EP procedures was the sole predictor of patient-reported hematoma after 2 weeks. Initiatives to prevent groin hematoma should focus on the procedure itself as well as post-procedural care.

Use Case Evaluation (UCE): A Method for Early Usability Evaluation in Software Development

DEFF Research Database (Denmark)

Stage, Jan; Høegh, Rune Thaarup; Hornbæk, K.

2007-01-01

t is often argued that usability problems should be identified as early as possible during software development, but many usability evaluation methods do not fit well in early development activities. We propose a method for usability evaluation of use cases, a widely used representation of design...... ideas produced early in software development processes. The method proceeds by systematic inspection of use cases with reference to a set of guidelines for usable design. To validate the method, four evaluators inspected a set of use cases for a health care application....

Relationships Among Peripheral and Central Electrophysiological Measures of Spatial and Spectral Selectivity and Speech Perception in Cochlear Implant Users.

Science.gov (United States)

Scheperle, Rachel A; Abbas, Paul J

2015-01-01

The ability to perceive speech is related to the listener's ability to differentiate among frequencies (i.e., spectral resolution). Cochlear implant (CI) users exhibit variable speech-perception and spectral-resolution abilities, which can be attributed in part to the extent of electrode interactions at the periphery (i.e., spatial selectivity). However, electrophysiological measures of peripheral spatial selectivity have not been found to correlate with speech perception. The purpose of this study was to evaluate auditory processing at the periphery and cortex using both simple and spectrally complex stimuli to better understand the stages of neural processing underlying speech perception. The hypotheses were that (1) by more completely characterizing peripheral excitation patterns than in previous studies, significant correlations with measures of spectral selectivity and speech perception would be observed, (2) adding information about processing at a level central to the auditory nerve would account for additional variability in speech perception, and (3) responses elicited with spectrally complex stimuli would be more strongly correlated with speech perception than responses elicited with spectrally simple stimuli. Eleven adult CI users participated. Three experimental processor programs (MAPs) were created to vary the likelihood of electrode interactions within each participant. For each MAP, a subset of 7 of 22 intracochlear electrodes was activated: adjacent (MAP 1), every other (MAP 2), or every third (MAP 3). Peripheral spatial selectivity was assessed using the electrically evoked compound action potential (ECAP) to obtain channel-interaction functions for all activated electrodes (13 functions total). Central processing was assessed by eliciting the auditory change complex with both spatial (electrode pairs) and spectral (rippled noise) stimulus changes. Speech-perception measures included vowel discrimination and the Bamford-Kowal-Bench Speech

Cognitive training and selective attention in the aging brain: an electrophysiological study.

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O'Brien, Jennifer L; Edwards, Jerri D; Maxfield, Nathan D; Peronto, Carol L; Williams, Victoria A; Lister, Jennifer J

2013-11-01

Age-related deficits in selective attention are hypothesized to result from decrements in inhibition of task-irrelevant information. Speed of processing (SOP) training is an adaptive cognitive intervention designed to enhance processing speed for attention tasks. The effectiveness of SOP training to improve cognitive and everyday functional performance is well documented. However, underlying mechanisms of these training benefits are unknown. Participants completed a visual search task evaluated using event-related potentials (ERPs) before and after 10 weeks of SOP training or no contact. N2pc and P3b components were evaluated to determine SOP training effects on attentional resource allocation and capacity. Selective attention to a target was enhanced after SOP training compared to no training. N2pc and P3b amplitudes increased after training, reflecting attentional allocation and capacity enhancement, consistent with previous studies demonstrating behavioral improvements in selective attention following SOP training. Changes in ERPs related to attention allocation and capacity following SOP training support the idea that training leads to cognitive enhancement. Specifically, we provide electrophysiological evidence that SOP training may be successful in counteracting age-related declines in selective attention. This study provides important evidence of the underlying mechanisms by which SOP training improves cognitive function in older adults. Published by Elsevier Ireland Ltd.

OptoDyCE: Automated system for high-throughput all-optical dynamic cardiac electrophysiology

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Klimas, Aleksandra; Yu, Jinzhu; Ambrosi, Christina M.; Williams, John C.; Bien, Harold; Entcheva, Emilia

2016-02-01

In the last two decades, market were due to cardiac toxicity, where unintended interactions with ion channels disrupt the heart's normal electrical function. Consequently, all new drugs must undergo preclinical testing for cardiac liability, adding to an already expensive and lengthy process. Recognition that proarrhythmic effects often result from drug action on multiple ion channels demonstrates a need for integrative and comprehensive measurements. Additionally, patient-specific therapies relying on emerging technologies employing stem-cell derived cardiomyocytes (e.g. induced pluripotent stem-cell-derived cardiomyocytes, iPSC-CMs) require better screening methods to become practical. However, a high-throughput, cost-effective approach for cellular cardiac electrophysiology has not been feasible. Optical techniques for manipulation and recording provide a contactless means of dynamic, high-throughput testing of cells and tissues. Here, we consider the requirements for all-optical electrophysiology for drug testing, and we implement and validate OptoDyCE, a fully automated system for all-optical cardiac electrophysiology. We demonstrate the high-throughput capabilities using multicellular samples in 96-well format by combining optogenetic actuation with simultaneous fast high-resolution optical sensing of voltage or intracellular calcium. The system can also be implemented using iPSC-CMs and other cell-types by delivery of optogenetic drivers, or through the modular use of dedicated light-sensitive somatic cells in conjunction with non-modified cells. OptoDyCE provides a truly modular and dynamic screening system, capable of fully-automated acquisition of high-content information integral for improved discovery and development of new drugs and biologics, as well as providing a means of better understanding of electrical disturbances in the heart.

Right brain, left brain in depressive disorders: Clinical and theoretical implications of behavioral, electrophysiological and neuroimaging findings.

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Bruder, Gerard E; Stewart, Jonathan W; McGrath, Patrick J

2017-07-01

The right and left side of the brain are asymmetric in anatomy and function. We review electrophysiological (EEG and event-related potential), behavioral (dichotic and visual perceptual asymmetry), and neuroimaging (PET, MRI, NIRS) evidence of right-left asymmetry in depressive disorders. Recent electrophysiological and fMRI studies of emotional processing have provided new evidence of altered laterality in depressive disorders. EEG alpha asymmetry and neuroimaging findings at rest and during cognitive or emotional tasks are consistent with reduced left prefrontal activity in depressed patients, which may impair downregulation of amygdala response to negative emotional information. Dichotic listening and visual hemifield findings for non-verbal or emotional processing have revealed abnormal perceptual asymmetry in depressive disorders, and electrophysiological findings have shown reduced right-lateralized responsivity to emotional stimuli in occipitotemporal or parietotemporal cortex. We discuss models of neural networks underlying these alterations. Of clinical relevance, individual differences among depressed patients on measures of right-left brain function are related to diagnostic subtype of depression, comorbidity with anxiety disorders, and clinical response to antidepressants or cognitive behavioral therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Biofeedback in psychomotor training. Electrophysiological bases].

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Bazanova, O M; Mernaia, E M; Shtark, M B

2008-05-01

Comparison of influence of usual musical practice and the same trainings but using biofeedback on electrophysiological and psychological markers of optimal psychomotor functioning in 39 students-musicians revealed that the obvious musical practice caused psychomotor pressure in most students (with initially low individual alpha peak frequency), whereas similar practice combined with an individualized session of alpha-EEG/EMG biofeedback was accompanied by increase of alpha-activity in all examinees and a decrease (reduction) of integrated EMG that indicated reaching of optimal psychomotor functioning. It appears that the psychomotor learning ability depends on the baseline individual alpha-activity. Individual alpha peak frequency was associated with fluency and efficiency of psychomotor performance, individual alpha band width--with plasticity and creativity, individual amount of alpha suppression in response to opening eyes--with the level of selfactualization. These alpha activity EEG indices correlated with efficiency of the biofeedback training.

PINP: a new method of tagging neuronal populations for identification during in vivo electrophysiological recording.

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Susana Q Lima

Full Text Available Neural circuits are exquisitely organized, consisting of many different neuronal subpopulations. However, it is difficult to assess the functional roles of these subpopulations using conventional extracellular recording techniques because these techniques do not easily distinguish spikes from different neuronal populations. To overcome this limitation, we have developed PINP (Photostimulation-assisted Identification of Neuronal Populations, a method of tagging neuronal populations for identification during in vivo electrophysiological recording. The method is based on expressing the light-activated channel channelrhodopsin-2 (ChR2 to restricted neuronal subpopulations. ChR2-tagged neurons can be detected electrophysiologically in vivo since illumination of these neurons with a brief flash of blue light triggers a short latency reliable action potential. We demonstrate the feasibility of this technique by expressing ChR2 in distinct populations of cortical neurons using two different strategies. First, we labeled a subpopulation of cortical neurons-mainly fast-spiking interneurons-by using adeno-associated virus (AAV to deliver ChR2 in a transgenic mouse line in which the expression of Cre recombinase was driven by the parvalbumin promoter. Second, we labeled subpopulations of excitatory neurons in the rat auditory cortex with ChR2 based on projection target by using herpes simplex virus 1 (HSV1, which is efficiently taken up by axons and transported retrogradely; we find that this latter population responds to acoustic stimulation differently from unlabeled neurons. Tagging neurons is a novel application of ChR2, used in this case to monitor activity instead of manipulating it. PINP can be readily extended to other populations of genetically identifiable neurons, and will provide a useful method for probing the functional role of different neuronal populations in vivo.

Electrophysiological and olfactometer responses of two histerid predators to three pine bark beetle pheromones

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William P. Shepherd; Brian T. Sullivan; Richard A. Goyer; Kier D. Klepzig

2005-01-01

We measured electrophysiological responses in the antennae of two predaceous hister beetles, Platysoma parallelum and Plegaderus transversus, exposes to racemic mixtures of primary aggregation pheromones of scolytid bark beetle prey, ipsenol, ipsdienol, and frontalin. No significant differences were found for either histerid...

Electrophysiological Evidence of Heterogeneity in Visual Statistical Learning in Young Children with ASD

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Jeste, Shafali S.; Kirkham, Natasha; Senturk, Damla; Hasenstab, Kyle; Sugar, Catherine; Kupelian, Chloe; Baker, Elizabeth; Sanders, Andrew J.; Shimizu, Christina; Norona, Amanda; Paparella, Tanya; Freeman, Stephanny F. N.; Johnson, Scott P.

2015-01-01

Statistical learning is characterized by detection of regularities in one's environment without an awareness or intention to learn, and it may play a critical role in language and social behavior. Accordingly, in this study we investigated the electrophysiological correlates of visual statistical learning in young children with autism…

Electrophysiologic alterations in the excitability of the sciatic and vagus nerves during early stages of sepsis.

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Diniz, Lúcio Ricardo Leite; Portella, Viviane Gomes; da Silva Alves, Kerly Shamira; Araújo, Pâmella Cristina da Costa; de Albuquerque Júnior, Ricardo Luiz Cavalcanti; Cavalcante de Albuquerque, Aline Alice; Coelho-de-Souza, Andrelina Noronha; Leal-Cardoso, José Henrique

2018-01-01

Nonspecific and delayed diagnosis of neurologic damage contributes to the development of neuropathies in patients with severe sepsis. The present study assessed the electrophysiologic parameters related to the excitability and conductibility of sciatic and vagus nerves during early stages of sepsis. Twenty-four hours after sepsis induced by cecal ligation and puncture (CLP) model, sciatic and vagus nerves of septic (CLP group) and control (sham group) rats were removed, and selected electric stimulations were applied to measure the parameters of the first and second components of the compound action potential. The first component originated from fibers with motor and sensory functions (Types A α and A β fibers) with a large conduction velocity (70-120 m/s), and the second component originated from fibers (Type A γ ) with sensorial function. To evaluate the presence of sensorial alterations, the sensitivity to non-noxious mechanical stimuli was measured by using the von Frey test. Hematoxylin and eosin staining of the nerves was performed. We observed an increase of rheobase followed by a decrease in the first component amplitude and a higher paw withdrawal threshold in response to the application of von Frey filaments in sciatic nerves from the CLP group compared to the sham group. Differently, a decrease in rheobase and an increase in the first component amplitude of vagal C fibers from CLP group were registered. No significant morphologic alteration was observed. Our data showed that the electrophysiologic alterations in peripheral nerves vary with the fiber type and might be identified in the first 24 h of sepsis, before clinical signs of neuromuscular disorders.

Electrophysiological mechanisms of sophocarpine as a potential antiarrhythmic agent.

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Yang, Zhi-fang; Li, Ci-zhen; Wang, Wei; Chen, Ying-min; Zhang, Ying; Liu, Yuan-mou; Wang, Hong-wei

2011-03-01

To examine the electrophysiological effects of sophocarpine on action potentials (AP) and ionic currents of cardiac myocytes and to compare some of these effects with those of amiodarone. Langendorff perfusion set-up was used in isolated guinea pig heart, and responses to sophocarpine were monitored using electrocardiograph. Conventional microelectrode, voltage clamp technique and perforated patch were employed to record fast response AP (fAP), slow response AP (sAP) and ionic currents in guinea pig papillary muscle or rabbit sinus node cells. Tachyarrhythmia produced by isoprenaline (15 μmol/L) could be reversed by sophocarpine (300 μmol/L). Sophocarpine (10 μmol/L) decreased the amplitude by 4.0%, maximal depolarization velocity (V(max)) of the fAP by 24.4%, and Na(+) current (I(Na)) by 18.0%, while it prolonged the effective refractory period (ERP) by 21.1%. The same concentration of sophocarpine could also decrease the amplitude and V(max) of the sAP, by 26.8% and 25.7%, respectively, and attenuated the Ca(2+) current (I(CaL)) and the K(+) tail current substantially. Comparison of sophocarpine with amiodarone demonstrated that both prolonged the duration and the ERP of fAP and sAP, both decreased the amplitude and V(max) of the fAP and sAP, and both slowed the automatic heart rate. Sophocarpine could reverse isoprenaline-induced arrhythmia and inhibit I(Na), I(CaL), and I(Kr) currents. The electrophysiological effects of sophocarpine are similar to those of amiodarone, which might be regarded as a prospective antiarrhythmic agent.

Novel electrophysiological approaches to clinical epilepsy. Diagnosis and treatment

International Nuclear Information System (INIS)

Kanazawa, Kyoko; Matsumoto, Riki; Ikeda, Akio; Kinoshita, Masako

2011-01-01

Seizure onset zone (SOZ) is currently defined by ictal epileptiform discharges, which are most commonly recorded as regional low-voltage fast waves or repetitive spikes. Interictal epileptiform discharges, on the other hand, are not specific enough for SOZ as they are recorded at zones other than the SOZ; they are also recorded from areas that do not generate the ictal pattern and from areas to which ictal discharges propagate. Besides spikes and sharp waves, a novel index of human epileptogenicity has been investigated in association with wide-band electroencephalography (EEG) analysis. We primarily noted the following during clinical neurophysiological analysis for clinical epilepsy. Recent development of digital EEG technology enabled us to record wide-band EEG in a clinical setting. Thus, high frequency (>200 Hz) and low frequency (<1 Hz) components can be reliably recorded using subdural electrodes. Direct current shift, slow shift, ripple, and fast ripple can be well delineated, and they will be potentially useful in the diagnosis and management of epileptic patients. Fiber tractography (morphological parameter) and cortico-cortical-evoked potentials with single cortical stimulation (electrophysiological parameter) elucidated cortico-cortical connections in human brain. The data thus obtained can help us understand the mechanism of seizure propagation and normal cortical functional connectivity. Non-invasive simultaneous recording of EEG and functional magnetic resonance imaging (fMRI) provided information on the roles of deep brain structures associated with scalp-recorded epileptiform discharges. Interventional neurophysiology can shed light on the non-pharmacological treatment of epilepsy. In this report, we discuss these novel electrophysiological approaches to the diagnosis and treatment of clinical epilepsy. (author)

The development of future-oriented control: an electrophysiological investigation.

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Waxer, Matthew; Morton, J Bruce

2011-06-01

Cognitive control, or the ability to focus attention and select task-appropriate responses, is not static but can be dynamically adjusted in the face of changing environmental circumstances. Several models suggest a role for conflict-monitoring in triggering these adjustments, whereby instances of response uncertainty are detected by the anterior cingulate cortex and strengthen attention-guiding rules actively maintained by lateral prefrontal cortex. Given the continued development of active maintenance mechanisms into adolescence, these models predict that the capacity to dynamically modulate control should be protracted in its development. The present study tested this prediction by examining age-related differences in behavioral and electrophysiological adaptations to prior conflict. Children, adolescents, and adults were administered the Dimensional Change Card Sort (DCCS; Zelazo, 2006) - a developmentally-appropriate task modified so that response conflict varied from trial to trial - as cortical activity was measured by means of event-related potentials (ERPs). Although all groups showed a robust conflict effect, there were pronounced age-related differences in behavioral and electrophysiological adaptations to prior conflict. First, responses to incongruent trials were faster following incongruent trials than following congruent trials, but only for adults and adolescents. Second, ERP components that indexed response conflict, and the cortical source of these components, were modulated by preceding conflict for adults and adolescents, but not children. Taken together, the findings suggest that adults and adolescents take advantage of prior conflict to prepare for the future, whereas children respond to cognitive challenges as they occur. Theoretical implications are discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

Reentrant Information Flow in Electrophysiological Rat Default Mode Network.

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Jing, Wei; Guo, Daqing; Zhang, Yunxiang; Guo, Fengru; Valdés-Sosa, Pedro A; Xia, Yang; Yao, Dezhong

2017-01-01

Functional MRI (fMRI) studies have demonstrated that the rodent brain shows a default mode network (DMN) activity similar to that in humans, offering a potential preclinical model both for physiological and pathophysiological studies. However, the neuronal mechanism underlying rodent DMN remains poorly understood. Here, we used electrophysiological data to analyze the power spectrum and estimate the directed phase transfer entropy (dPTE) within rat DMN across three vigilance states: wakeful rest (WR), slow-wave sleep (SWS), and rapid-eye-movement sleep (REMS). We observed decreased gamma powers during SWS compared with WR in most of the DMN regions. Increased gamma powers were found in prelimbic cortex, cingulate cortex, and hippocampus during REMS compared with WR, whereas retrosplenial cortex showed a reverse trend. These changed gamma powers are in line with the local metabolic variation of homologous brain regions in humans. In the analysis of directional interactions, we observed well-organized anterior-to-posterior patterns of information flow in the delta band, while opposite patterns of posterior-to-anterior flow were found in the theta band. These frequency-specific opposite patterns were only observed in WR and REMS. Additionally, most of the information senders in the delta band were also the receivers in the theta band, and vice versa. Our results provide electrophysiological evidence that rat DMN is similar to its human counterpart, and there is a frequency-dependent reentry loop of anterior-posterior information flow within rat DMN, which may offer a mechanism for functional integration, supporting conscious awareness.

Effect of olanzapine combined with modified electroconvulsive therapy on cytokines, sTNFRs and neural electrophysiological characteristics in patients with schizophrenia

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Wei Cheng

2016-12-01

Full Text Available Objective: To analyze the effect of olanzapine combined with modified electroconvulsive therapy on cytokines, sTNFRs and neural electrophysiological characteristics in patients with schizophrenia. Methods: Patients with schizophrenia treated in our hospital between March 2013 and March 2016 were selected and randomly divided into two groups, the observation group received olanzapine combined with modified electroconvulsive therapy, and the control group received olanzapine therapy. After 6 weeks of treatment, serum levels of soluble tumor necrosis factor receptor (sTNFR, acute phase reaction proteins and brain function indexes as well as the neural electrophysiological characteristics were compared between the two groups. Results: After 6 weeks of treatment, serum sTNFRs, CRP, CER and AAG content of observation group were lower than those of control group while TRF content was higher than that of control group; serum brain function indexes NGF and BDNF content were higher than those of control group while GFAP, S100B, NSE and Hcy content were lower than those of control group; nerve electrophysiology indexes P300, LPP and ERN amplitude were higher than those of control group while LPP amplitude was lower than that of control group. Conclusions: Olanzapine combined with modified electroconvulsive therapy can optimize the condition of schizophrenia, reduce the abnormal degree of nerve electrophysiology and help to improve treatment outcome.

Electrophysiology for biomedical engineering students: a practical and theoretical course in animal electrocorticography.

Science.gov (United States)

Albarracín, Ana L; Farfán, Fernando D; Coletti, Marcos A; Teruya, Pablo Y; Felice, Carmelo J

2016-09-01

The major challenge in laboratory teaching is the application of abstract concepts in simple and direct practical lessons. However, students rarely have the opportunity to participate in a laboratory that combines practical learning with a realistic research experience. In the Biomedical Engineering career, we offer short and optional courses to complement studies for students as they initiate their Graduation Project. The objective of these theoretical and practical courses is to introduce students to the topics of their projects. The present work describes an experience in electrophysiology to teach undergraduate students how to extract cortical information using electrocorticographic techniques. Students actively participate in some parts of the experience and then process and analyze the data obtained with different signal processing tools. In postlaboratory evaluations, students described the course as an exceptional opportunity for students interested in following a postgraduate science program and fully appreciated their contents. Copyright © 2016 The American Physiological Society.

Impact of KChIP2 on Cardiac Electrophysiology and the Progression of Heart Failure

DEFF Research Database (Denmark)

Grubb, Søren; Callø, Kirstine; Thomsen, Morten B

2012-01-01

Electrophysiological remodeling of cardiac potassium ion channels is important in the progression of heart failure. A reduction of the transient outward potassium current (I(to)) in mammalian heart failure is consistent with a reduced expression of potassium channel interacting protein 2 (KChIP2...

Brain mapping in a patient with congenital blindness – a case for multimodal approaches

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Jarod L Roland

2013-07-01

Full Text Available Recent advances in basic neuroscience research across a wide range of methodologies have contributed significantly to our understanding of human cortical electrophysiology and functional brain imaging. Translation of this research into clinical neurosurgery has opened doors for advanced mapping of functionality that previously was prohibitively difficult, if not impossible. Here we present the case of a unique individual with congenital blindness and medically refractory epilepsy who underwent neurosurgical treatment of her seizures. Pre-operative evaluation presented the challenge of accurately and robustly mapping the cerebral cortex for an individual with a high probability of significant cortical re-organization. Additionally, a blind individual has unique priorities in one’s ability to read Braille by touch and sense the environment primarily by sound than the non-vision impaired person. For these reasons we employed additional measures to map sensory, motor, speech, language, and auditory perception by employing a number of cortical electrophysiologic mapping and functional magnetic resonance imaging methods. Our data show promising results in the application of these adjunctive methods in the pre-operative mapping of otherwise difficult to localize, and highly variable, functional cortical areas.

Electrophysiology of blunted emotional bias in psychopathic personality.

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Carolan, Patrick L; Jaspers-Fayer, Fern; Asmaro, Deyar T; Douglas, Kevin S; Liotti, Mario

2014-01-01

Diminished emotional capacity is a core characteristic of psychopathic personality. We examined behavioral and electrophysiological differences in attentional bias to emotional material in 34 healthy individuals rated high or low in psychopathic traits using the short form of the Psychopathic Personality Inventory-Revised (18 high-trait, 16 low-trait). While performing an emotional Stroop task, high-trait participants displayed reduced emotional modulation of the late positive potential (LPP, 400-600 ms), and early anterior positivity (EAP, 200-300 ms) amplitudes. Results suggest blunted bias to affective content in psychopathic personality, characterized by diminished early capture to emotional salience (EAP) and dampened cognitive emotional processing (LPP). Copyright © 2013 Society for Psychophysiological Research.

A strategy to measure electrophysiological changes with photoacoustic imaging (Conference Presentation)

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Sepela, Rebecka J.; Sherlock, Benjamin E.; Tian, Lin; Marcu, Laura; Sack, Jon

2017-03-01

Photoacoustic imaging is an emerging technology capable of both functional and structural biological imaging. Absorption and scattering in tissue limit the penetration depth of conventional microscopy techniques to live cell imaging. This technology could permit photoacoustic imaging of electrophysiological dynamics in deep tissue, such as the brain. Further optimization of this technology could lead to concurrent imaging of neural activity and hemodynamic responses, a crucial step towards understanding neurovascular coupling in the brain.

Electrophysiological, histochemical, and hormonal adaptation of rat muscle after prolonged hindlimb suspension

Science.gov (United States)

Kourtidou-Papadeli, Chrysoula; Kyparos, Antonios; Albani, Maria; Frossinis, Athanasios; Papadelis, Christos L.; Bamidis, Panagiotis; Vivas, Ana; Guiba-Tziampiri, Olympia

2004-05-01

The perspective of long-duration flights for future exploration, imply more research in the field of human adaptation. Previous studies in rat muscles hindlimb suspension (HLS), indicated muscle atrophy and a change of fibre composition from slow-to-fast twitch types. However, the contractile responses to long-term unloading is still unclear. Fifteen adult Wistar rats were studied in 45 and 70 days of muscle unweighting and soleus (SOL) muscle as well as extensor digitorum longus (EDL) were prepared for electrophysiological recordings (single, twitch, tetanic contraction and fatigue) and histochemical stainings. The loss of muscle mass observed was greater in the soleus muscle. The analysis of electrophysiological properties of both EDL and SOL showed significant main effects of group, of number of unweighting days and fatigue properties. Single contraction for soleus muscle remained unchanged but there was statistically significant difference for tetanic contraction and fatigue. Fatigue index showed a decrease for the control rats, but increase for the HLS rats. According to the histochemical findings there was a shift from oxidative to glycolytic metabolism during HLS. The data suggested that muscles atrophied, but they presented an adaptation pattern, while their endurance in fatigue was decreased.

Electrophysiology Catheter-Facilitated coronary sinus cannulation and implantation of cardiac resynchronization therapy systems

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Antonis S. Manolis, MD, FESC, FACC, FHRS

2018-01-01

Full Text Available Background: Cardiac resynchronization therapy (CRT device implantation is hampered by difficult placement of the left ventricular (LV lead. We have routinely used a steerable electrophysiology catheter to guide coronary sinus (CS cannulation and facilitate LV lead positioning. The aim of this prospective study is to present our results with this approach in 138 consecutive patients receiving a CRT device over 10 years. Methods: The study included 120 men and 18 women, aged 64.8±11.4 years, with coronary disease (n=63, cardiomyopathy (n=72, or other disease (n=3, and mean ejection fraction of 24.5±4.5%. Devices were implanted for refractory heart failure and dyssynchrony, all but 2 in the presence of left bundle branch block. Implanted devices included biventricular pacemakers (CRT-P (n=33 and cardioverter defibrillators (CRT-D (n=105. Results: Using the electrophysiology catheter, the CS could be engaged in 134 (97.1% patients. In 4 patients failing CS cannulation, a dual-chamber device was implanted in 2, and bifocal right ventricular pacing was effected in 2. Bifocal (n=2 or conventional (n=1 systems were implanted in another 3 patients, in whom the LV lead got dislodged (n=2 or removed because of local dissection (n=1. Thus, finally, a CRT system was successfully established in 131 (94.9% patients. There were 3 patients with CS dissection, of whom 1 was complicated by cardiac tamponade managed with pericardiocentesis. There were no perioperative deaths. During follow-up (31.0±21.2 months, clinical improvement was reported by 108 (82.4% patients. Conclusion: Routine use of an electrophysiology catheter greatly facilitated CS cannulation and successful LV lead placement in ∼95% of patients undergoing CRT system implantation. Keywords: heart failure, cardiac resynchronization therapy, implantable cardioverter defibrillator, coronary sinus, left ventricular lead

Electrophysiological response of chicken's jejunal epithelium to increasing levels of T-2 toxin.

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Yunus, Agha Waqar; Kröger, Susan; Tichy, Alexander; Zentek, Jürgen; Böhm, Josef

2013-02-01

The present investigations were conducted to test the effects of T-2 toxin on electrophysiological variables of jejunal epithelium of chicken. Jejunal segments of broilers were monitored in Ussing chambers in the presence of T-2 toxin at the levels of 0 (negative control), 0 (methanol/vehicle control), 0.1, 1, 5, and 10 μg/ml of buffer. T-2 toxin did not affect basal values of short circuit current (I(sc)), transmural potential difference, or tissue conductivity in the jejunal epithelium. T-2 toxin also did not statistically affect glucose-induced electrophysiological variables during the first 3 min of glucose induction. Compared to the vehicle control, the ouabain-sensitive I(sc) was negatively affected (P = 0.008) only under 5 μg of T-2 toxin/ml. Increasing levels of T-2 toxin negatively affected the ouabain-sensitive I(sc) in a cubic (P = 0.007) fashion. These data indicate that acute exposure to moderate levels of T-2 toxin may progressively impair the cation gradient across the jejunal epithelium.

An Association between Auditory-Visual Synchrony Processing and Reading Comprehension: Behavioral and Electrophysiological Evidence.

Science.gov (United States)

Mossbridge, Julia; Zweig, Jacob; Grabowecky, Marcia; Suzuki, Satoru

2017-03-01

The perceptual system integrates synchronized auditory-visual signals in part to promote individuation of objects in cluttered environments. The processing of auditory-visual synchrony may more generally contribute to cognition by synchronizing internally generated multimodal signals. Reading is a prime example because the ability to synchronize internal phonological and/or lexical processing with visual orthographic processing may facilitate encoding of words and meanings. Consistent with this possibility, developmental and clinical research has suggested a link between reading performance and the ability to compare visual spatial/temporal patterns with auditory temporal patterns. Here, we provide converging behavioral and electrophysiological evidence suggesting that greater behavioral ability to judge auditory-visual synchrony (Experiment 1) and greater sensitivity of an electrophysiological marker of auditory-visual synchrony processing (Experiment 2) both predict superior reading comprehension performance, accounting for 16% and 25% of the variance, respectively. These results support the idea that the mechanisms that detect auditory-visual synchrony contribute to reading comprehension.

Crescent Evaluation : appendix B : state case study evaluation report

Science.gov (United States)

1994-02-01

The state case study evaluation approach uniquely captured an understanding of the potential of such a system by documenting the experiences, issues, and opportunities of selected key state government personnel from a cross-section of involved agenci...

Luigi Galvani and animal electricity: two centuries after the foundation of electrophysiology.

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Piccolino, M

1997-10-01

Luigi Galvani and his famous experiments on frogs carried out in the second half of the 18th century belong more to legend than to the history of science. Galvani not only laid the foundations of a new science, electrophysiology, but also opened the way for the invention of the electric battery, and thus for the development of the physical investigations of electricity. However, in spite of the widespread celebration of his work, Galvani's scientific endeavours have been largely misrepresented in the history of science. The scholar of Bologna has a stereotyped image as an 'occasional' scientist, who started his studies by chance, largely ignored the scientific theories of his time and wandered aimlessly in mental elaborations until the physicist of Pavia, Alessandro Volta, entered the field, correctly interpreted Galvani's results and eventually developed the electric battery. With the present understanding of electrical phenomena in excitable membranes, it is now time to reconsider the real matter raised by Galvani's discoveries and by his hypothesis of an intrinsic 'animal electricity', and to make a clearer evaluation of a revolutionary phase of scientific progress.

EXAMINATION OF ELECTROPHYSIOLOGICAL PARAMETERS OF THE ATRIUMS IN PATIENTS WITH LONG-TERM PERSISTENT FORM OF ATRIAL FIBRILLATION AND VALVULAR HEART DISEASE

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A. A. Kulikov

2017-01-01

-term mitral valve incompetence and persistent AF lead to anatomical and electrophysiological remodeling of the atriums, which manifests through increased volume of the left atrium, as well as increased duration of intra-atrial conduction and heterogeneity  of refractory periods. EES allows to evaluate these functions of the atrioventricular conduction system and atrial electrophysiological parameters: detect aberrations in conduction through atrial myocardium, dispersion of its refractoriness, and the area of atrial vulnerability. These factors can serve as predictors of AF recurrence. 

Electrophysiological correlates of mental navigation in blind and sighted people.

Science.gov (United States)

Kober, Silvia Erika; Wood, Guilherme; Kampl, Christiane; Neuper, Christa; Ischebeck, Anja

2014-10-15

The aim of the present study was to investigate functional reorganization of the occipital cortex for a mental navigation task in blind people. Eight completely blind adults and eight sighted matched controls performed a mental navigation task, in which they mentally imagined to walk along familiar routes of their hometown during a multi-channel EEG measurement. A motor imagery task was used as control condition. Furthermore, electrophysiological activation patterns during a resting measurement with open and closed eyes were compared between blind and sighted participants. During the resting measurement with open eyes, no differences in EEG power were observed between groups, whereas sighted participants showed higher alpha (8-12Hz) activity at occipital sites compared to blind participants during an eyes-closed resting condition. During the mental navigation task, blind participants showed a stronger event-related desynchronization in the alpha band over the visual cortex compared to sighted controls indicating a stronger activation in this brain region in the blind. Furthermore, groups showed differences in functional brain connectivity between fronto-central and parietal-occipital brain networks during mental navigation indicating stronger visuo-spatial processing in sighted than in blind people during mental navigation. Differences in electrophysiological parameters between groups were specific for mental navigation since no group differences were observed during motor imagery. These results indicate that in the absence of vision the visual cortex takes over other functions such as spatial navigation. Copyright © 2014 Elsevier B.V. All rights reserved.

An open-source hardware and software system for acquisition and real-time processing of electrophysiology during high field MRI.

Science.gov (United States)

Purdon, Patrick L; Millan, Hernan; Fuller, Peter L; Bonmassar, Giorgio

2008-11-15

Simultaneous recording of electrophysiology and functional magnetic resonance imaging (fMRI) is a technique of growing importance in neuroscience. Rapidly evolving clinical and scientific requirements have created a need for hardware and software that can be customized for specific applications. Hardware may require customization to enable a variety of recording types (e.g., electroencephalogram, local field potentials, or multi-unit activity) while meeting the stringent and costly requirements of MRI safety and compatibility. Real-time signal processing tools are an enabling technology for studies of learning, attention, sleep, epilepsy, neurofeedback, and neuropharmacology, yet real-time signal processing tools are difficult to develop. We describe an open-source system for simultaneous electrophysiology and fMRI featuring low-noise (tested up to 7T), and user-programmable real-time signal processing. The hardware distribution provides the complete specifications required to build an MRI-compatible electrophysiological data acquisition system, including circuit schematics, print circuit board (PCB) layouts, Gerber files for PCB fabrication and robotic assembly, a bill of materials with part numbers, data sheets, and vendor information, and test procedures. The software facilitates rapid implementation of real-time signal processing algorithms. This system has been used in human EEG/fMRI studies at 3 and 7T examining the auditory system, visual system, sleep physiology, and anesthesia, as well as in intracranial electrophysiological studies of the non-human primate visual system during 3T fMRI, and in human hyperbaric physiology studies at depths of up to 300 feet below sea level.

Biophysical characterisation of electrofused giant HEK293-cells as a novel electrophysiological expression system

International Nuclear Information System (INIS)

Zimmermann, D.; Terpitz, U.; Zhou, A.; Reuss, R.; Mueller, K.; Sukhorukov, V.L.; Gessner, P.; Nagel, G.; Zimmermann, U.; Bamberg, E.

2006-01-01

Giant HEK293 cells of 30-65 μm in diameter were produced by three-dimensional multi-cell electrofusion in 75 mOsm sorbitol media. These strong hypotonic conditions facilitated fusion because of the spherical shape and smooth membrane surface of the swollen cells. A regulatory volume decrease (RVD), as observed at higher osmolalities, did not occur at 75 mOsm. In contrast to field-treated, but unfused cells, the increase in volume induced by hypotonic shock was only partly reversible in the case of fused giant cells after their transfer into isotonic medium. The large size of the electrofused cells allowed the study of their electrophysiological properties by application of both whole-cell and giant excised patch-clamp techniques. Recordings on giant cells yielded a value of 1.1 ± 0.1 μF/cm 2 for the area-specific membrane capacitance. This value was consistent with that of the parental cells. The area-specific conductivity of giant cells (diameter > 50 μm) was found to be between 12.8 and 16.1 μS/cm 2 , which is in the range of that of the parental cells. Measurements with patch-pipettes containing fluorescein showed uniform dye uptake in the whole-cell configuration, but not in the cell-attached configuration. The diffusion-controlled uniform uptake of the dye into the cell interior excludes internal compartmentalisation. The finding of a homogeneous fusion was also supported by expression of the yellow fluorescent protein YFP (as part of the fusion-protein ChR2-YFP) in giant cells since no plasma-membrane bound YFP-mediated fluorescence was detected in the interior of the electrofused cells. Functional expression and the electrophysiological characterisation of the light-activated cation channel Channelrhodopsin 2 (ChR2) yielded similar results as for parental cells. Most importantly, the giant cells exhibited a comparable expression density of the channel protein in the plasma membrane as observed in parental cells. This demonstrates that electrofused cells

Carpal tunnel syndrome assessed with diffusion tensor imaging: Comparison with electrophysiological studies of patients and healthy volunteers

International Nuclear Information System (INIS)

Wang, Chien-Kuo; Jou, I-Ming; Huang, Han-Wei; Chen, Pei-Yin; Tsai, Hong-Ming; Liu, Yi-Sheng; Lin, Chou-Ching K.

2012-01-01

The main goal of this study was to investigate the applicability of parameters derived from diffusion tension imaging (DTI) in diagnosing carpal tunnel syndrome (CTS). Forty subjects were recruited, of which 19 were normal controls and 21 belonged to the CTS group. DTI of median nerves evaluated at 4 levels of the wrist (distal radius, pisiform bone, middle portion of the carpal tunnel, and hamate bone) and conventional MRI of the wrist was performed in normal and CTS subjects in two finger postures (extension and flexion). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were derived from DTI, and parameters related to abnormal hyperintensity of the median nerve were derived from conventional MRI. Electrophysiological tests, including nerve conduction velocity and F wave were also performed for comparison. The results of FA and ADC measurements did not depend on the measuring location and finger posture. Mean FA was decreased while mean ADC was increased by CTS. FA and ADC at the middle portion of the carpal tunnel was 0.47 ± 0.05 and 1.37 ± 0.12 (×10 −3 mm 2 /s) for the control group and 0.42 ± 0.04 and 1.50 ± 0.15 (×10 −3 mm 2 /s) for the CTS group, respectively. The linear correlations of FA and ADC versus electrophysiological indicators of CTS were significant (R 2 ranged from 0.09 to 0.36), indicating FA and ADC from DTI had significant correlation with the existence and severity of CTS.

Open Ephys: an open-source, plugin-based platform for multichannel electrophysiology.

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Siegle, Joshua H; López, Aarón Cuevas; Patel, Yogi A; Abramov, Kirill; Ohayon, Shay; Voigts, Jakob

2017-08-01

Closed-loop experiments, in which causal interventions are conditioned on the state of the system under investigation, have become increasingly common in neuroscience. Such experiments can have a high degree of explanatory power, but they require a precise implementation that can be difficult to replicate across laboratories. We sought to overcome this limitation by building open-source software that makes it easier to develop and share algorithms for closed-loop control. We created the Open Ephys GUI, an open-source platform for multichannel electrophysiology experiments. In addition to the standard 'open-loop' visualization and recording functionality, the GUI also includes modules for delivering feedback in response to events detected in the incoming data stream. Importantly, these modules can be built and shared as plugins, which makes it possible for users to extend the functionality of the GUI through a simple API, without having to understand the inner workings of the entire application. In combination with low-cost, open-source hardware for amplifying and digitizing neural signals, the GUI has been used for closed-loop experiments that perturb the hippocampal theta rhythm in a phase-specific manner. The Open Ephys GUI is the first widely used application for multichannel electrophysiology that leverages a plugin-based workflow. We hope that it will lower the barrier to entry for electrophysiologists who wish to incorporate real-time feedback into their research.

Churg-Strauss Syndrome as an Unusual Cause of Dysphagia: Case Report.

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Park, Jihye; Im, Sun; Moon, Su-Jin; Park, Geun-Young; Jang, Yongjun; Kim, Yeonjin

2015-06-01

Systemic vasculitis is a rare disease, and the diagnosis is very difficult when patient shows atypical symptoms. We experienced an unusual case of dysphagia caused by Churg-Strauss syndrome with lower cranial nerve involvement. A 74-year-old man, with a past history of sinusitis, asthma, and hearing deficiency, was admitted to our department for evaluation of dysphagia. He also complained of recurrent bleeding of nasal cavities and esophagus. Brain magnetic resonance imaging did not show definite abnormality, and electrophysiologic findings were suggestive of mononeuritis multiplex. Dysphagia had not improved after conventional therapy. Biopsy of the nasal cavity showed extravascular eosinophilic infiltration. All these findings suggested a rare form of Churg-Strauss syndrome involving multiple lower cranial nerves. Dysphagia improved after steroid therapy.

Electrophysiological and neurochemical changes in the rat hippocampus after in vitro and in vivo treatments with cocaine

International Nuclear Information System (INIS)

Yasuda, R.P.

1986-01-01

The in vitro and in vivo effects of cocaine in the noradrenergic pathway in the rat hippocampus were examined. Although the blockade of [ 3 H]-norepinephrine-uptake by cocaine has been well-characterized in both the central and peripheral nervous systems, investigations characterizing the electrophysiological effects of cocaine in the central nervous system have been limited. The first part of this thesis examines the relationship between the ability of cocaine to potentiate the electrophysiological response to norepinephrine (NE) and the ability of cocaine to block noradrenergic high affinity uptake in rat hippocampal slices. The second part of this thesis examines the effects of the repeated administration of cocaine on noradrenergic pre- and postsynaptic function and receptors of the rat hippocampus. These studies demonstrate that after repeated administration of cocaine (10 mg/kg/day) for 8 and 14 days there is a 50% decrease in NE high affinity uptake in the rat hippocampus. This was accompanied by a 40% increase in a binding site for NE uptake inhibitors at 14 days. In contrast to these effects, there was no effect on β-adrenergic receptor number or the isoproterenol induced electrophysiological responsiveness in the rat hippocampus. The conclusion of these studies is that the repeated administration of cocaine has a greater effect on presynaptic targets in the noradrenergic system than on postsynaptic neurons

Central vs. peripheral neuraxial sympathetic control of porcine ventricular electrophysiology

Science.gov (United States)

Yamakawa, Kentaro; Howard-Quijano, Kimberly; Zhou, Wei; Rajendran, Pradeep; Yagishita, Daigo; Vaseghi, Marmar; Ajijola, Olujimi A.; Armour, J. Andrew; Shivkumar, Kalyanam; Ardell, Jeffrey L.

2015-01-01

Sympathoexcitation is associated with ventricular arrhythmogenesis. The aim of this study was to determine the role of thoracic dorsal root afferent neural inputs to the spinal cord in modulating ventricular sympathetic control of normal heart electrophysiology. We hypothesize that dorsal root afferent input tonically modulates basal and evoked efferent sympathetic control of the heart. A 56-electrode sock placed on the epicardial ventricle in anesthetized Yorkshire pigs (n = 17) recorded electrophysiological function, as well as activation recovery interval (ARI) and dispersion in ARI, at baseline conditions and during stellate ganglion electrical stimulation. Measures were compared between intact states and sequential unilateral T1–T4 dorsal root transection (DRTx), ipsilateral ventral root transection (VRTx), and contralateral dorsal and ventral root transections (DVRTx). Left or right DRTx decreased global basal ARI [Lt.DRTx: 369 ± 12 to 319 ± 13 ms (P < 0.01) and Rt.DRTx: 388 ± 19 to 356 ± 15 ms (P < 0.01)]. Subsequent unilateral VRTx followed by contralateral DRx+VRTx induced no further change. In intact states, left and right stellate ganglion stimulation shortened ARIs (6 ± 2% vs. 17 ± 3%), while increasing dispersion (+139% vs. +88%). There was no difference in magnitude of ARI or dispersion change with stellate stimulation following spinal root transections. Interruption of thoracic spinal afferent signaling results in enhanced basal cardiac sympathoexcitability without diminishing the sympathetic response to stellate ganglion stimulation. This suggests spinal dorsal root transection releases spinal cord-mediated tonic inhibitory control of efferent sympathetic tone, while maintaining intrathoracic cardiocentric neural networks. PMID:26661096

FieldTrip: Open source software for advanced analysis of MEG, EEG, and invasive electrophysiological data

NARCIS (Netherlands)

Oostenveld, R.; Fries, P.; Maris, E.G.G.; Schoffelen, J.M.

2011-01-01

This paper describes FieldTrip, an open source software package that we developed for the analysis of MEG, EEG, and other electrophysiological data. The software is implemented as a MATLAB toolbox and includes a complete set of consistent and user-friendly high-level functions that allow

Mapping of electrophysiological response to transcranial infrared laser stimulation on the human brain in vivo measured by electroencephalography (Conference Presentation)

Science.gov (United States)

Wang, Xinlong; Reddy, Divya Dhandapani; Gonzalez-Lima, F.; Liu, Hanli

2017-02-01

Transcranial infrared laser stimulation (TILS) is a non-destructive and non-thermal photobiomodulation therapy or process on the human brain; TILS uses infrared light from lasers or LEDs and has gained increased recognition for its beneficial effects on a variety of neurological and psychological conditions. While the mechanism of TILS has been assumed to stem from cytochrome-c-oxidase (CCO), which is the last enzyme in the electron transportation chain and is the primary photoacceptor, no literature is found to report electrophysiological response to TILS. In this study, a 64-channel electroencephalography (EEG) system was employed to monitor electrophysiological activities from 15 healthy human participants before, during and after TILS. A placebo experimental protocol was also applied for rigorous comparison. After recording a 3-minute baseline, we applied a 1064-nm laser with a power of 3.5W on the right forehead of each human participant for 8 minutes, followed by a 5-minute recovery period. In 64-channel EEG data analysis, we utilized several methods (root mean square, principal component analysis followed by independent component analysis, permutation conditional mutual information, and time-frequency wavelet analysis) to reveal differences in electrophysiological response to TILS between the stimulated versus placebo group. The analyzed results were further investigated using general linear model and paired t-test to reveal statistically meaningful responses induced by TILS. Moreover, this study will provide spatial mapping of human electrophysiological and possibly neural network responses to TILS for first time, indicating the potential of EEG to be an effective method for monitoring neurological improvement induced by TILS.

Electrophysiological study in neuromuscular junction disorders

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Ajith Cherian

2013-01-01

Full Text Available This review is on ultrastructure and subcellular physiology at normal and abnormal neuromuscular junctions. The clinical and electrophysiological findings in myasthenia gravis, Lambert-Eaton myasthenic syndrome (LEMS, congenital myasthenic syndromes, and botulinum intoxication are discussed. Single fiber electromyography (SFEMG helps to explain the basis of testing neuromuscular junction function by repetitive nerve stimulation (RNS. SFEMG requires skill and patience and its availability is limited to a few centers. For RNS supramaximal stimulation is essential and so is display of the whole waveform of each muscle response at maximum amplitude. The amplitudes of the negative phase of the first and fourth responses are measured from baseline to negative peak, and the percent change of the fourth response compared with the first represents the decrement or increment. A decrement greater than 10% is accepted as abnormal and smooth progression of response amplitude train and reproducibility form the crux. In suspected LEMS the effect of fast rates of stimulation should be determined after RNS response to slow rates of stimulation. Caution is required to avoid misinterpretation of potentiation and pseudofacilitation.

Pitch Discrimination Learning: Specificity for Pitch and Harmonic Resolvability, and Electrophysiological Correlates

OpenAIRE

Carcagno, Samuele; Plack, Christopher J.

2011-01-01

Multiple-hour training on a pitch discrimination task dramatically decreases the threshold for detecting a pitch difference between two harmonic complexes. Here, we investigated the specificity of this perceptual learning with respect to the pitch and the resolvability of the trained harmonic complex, as well as its cortical electrophysiological correlates. We trained 24 participants for 12 h on a pitch discrimination task using one of four different harmonic complexes. The complexes differed...

A non-linear regression analysis program for describing electrophysiological data with multiple functions using Microsoft Excel.

Science.gov (United States)

Brown, Angus M

2006-04-01

The objective of this present study was to demonstrate a method for fitting complex electrophysiological data with multiple functions using the SOLVER add-in of the ubiquitous spreadsheet Microsoft Excel. SOLVER minimizes the difference between the sum of the squares of the data to be fit and the function(s) describing the data using an iterative generalized reduced gradient method. While it is a straightforward procedure to fit data with linear functions, and we have previously demonstrated a method of non-linear regression analysis of experimental data based upon a single function, it is more complex to fit data with multiple functions, usually requiring specialized expensive computer software. In this paper we describe an easily understood program for fitting experimentally acquired data, in this case the stimulus-evoked compound action potential from the mouse optic nerve, with multiple Gaussian functions. The program is flexible and can be applied to describe data with a wide variety of user-input functions.

Human Embryonic Kidney 293 Cells: A Vehicle for Biopharmaceutical Manufacturing, Structural Biology, and Electrophysiology.

Science.gov (United States)

Hu, Jianwen; Han, Jizhong; Li, Haoran; Zhang, Xian; Liu, Lan Lan; Chen, Fei; Zeng, Bin

2018-01-01

Mammalian cells, e.g., CHO, BHK, HEK293, HT-1080, and NS0 cells, represent important manufacturing platforms in bioengineering. They are widely used for the production of recombinant therapeutic proteins, vaccines, anticancer agents, and other clinically relevant drugs. HEK293 (human embryonic kidney 293) cells and their derived cell lines provide an attractive heterologous system for the development of recombinant proteins or adenovirus productions, not least due to their human-like posttranslational modification of protein molecules to provide the desired biological activity. Secondly, they also exhibit high transfection efficiency yielding high-quality recombinant proteins. They are easy to maintain and express with high fidelity membrane proteins, such as ion channels and transporters, and thus are attractive for structural biology and electrophysiology studies. In this article, we review the literature on HEK293 cells regarding their origins but also stress their advancements into the different cell lines engineered and discuss some significant aspects which make them versatile systems for biopharmaceutical manufacturing, drug screening, structural biology research, and electrophysiology applications. © 2018 S. Karger AG, Basel.

Acute Flaccid Paralysis by Enterovirus D68 Infection: First Italian Description in Adult Patient and Role of Electrophysiology

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Marco Ceccanti

2017-11-01

Full Text Available A Peruvian woman was admitted to the Emergency Department, due to an acute flaccid paralysis (AFP of the upper limbs that progressively involved also lower limbs and respiratory muscles. She previously suffered from non-Hodgkin’s lymphoma and had to undergo hematopoietic stem cell transplantation. A magnetic resonance imaging showed a T2 hyperintensity in the anterior and central region of the cervical segment with an elective involvement of gray matter. This finding, combined with other clinical, laboratory, and electrophysiological data, led to a diagnosis of AFP. Enterovirus D68 was isolated in the patient’s cerebrospinal fluid, plasma, and throat swab. To our knowledge, this is the first Italian case of AFP by Enterovirus D68 infection in an adult. The diagnostic assessment and management of AFP by Enterovirus D68 are discussed.

Simple Ion Channels: From Structure to Electrophysiology and Back

Science.gov (United States)

Pohorille, Andrzej

2018-01-01

A reliable way to establish whether our understanding of a channel is satisfactory is to reproduce its measured ionic conductance over a broad range of applied voltages in computer simulations. In molecular dynamics (MD), this can be done by way of applying an external electric field to the system and counting the number of ions that traverse the channel per unit time. Since this approach is computationally very expensive, we have developed a markedly more efficient alternative in which MD is combined with the electrodiffusion (ED) equation. In this approach, the assumptions of the ED equation can be rigorously tested, and the precision and consistency of the calculated conductance can be determined. We have demonstrated that the full current/voltage dependence and the underlying free energy profile for a simple channel can be reliably calculated from equilibrium or non-equilibrium MD simulations at a single voltage. To carry out MD simulations, a structural model of a channel has to be assumed, which is an important constraint, considering that high-resolution structures are available for only very few simple channels. If the comparison of calculated ionic conductance with electrophysiological data is satisfactory, it greatly increases our confidence that the structure and the function are described sufficiently accurately. We examined the validity of the ED for several channels embedded in phospholipid membranes - four naturally occurring channels: trichotoxin, alamethicin, p7 from hepatitis C virus (HCV) and Vpu from the HIV-1 virus, and a synthetic, hexameric channel, formed by a 21-residue peptide that contains only leucine and serine. All these channels mediate transport of potassium and chloride ions. It was found that the ED equation is satisfactory for these systems. In some of them experimental and calculated electrophysiological properties are in good agreement, whereas in others there are strong indications that the structural models are incorrect.

Frontal negativity: An electrophysiological index of interpersonal guilt.

Science.gov (United States)

Leng, Bingbing; Wang, Xiangling; Cao, Bihua; Li, Fuhong

2017-12-01

The present study aimed to reveal the temporal course and electrophysiological correlates of interpersonal guilt. Human participants were asked to perform multiple rounds of a dot-estimation task with their partners, while event-related potential being recorded. The paired participants were informed that they would win money if both responded correctly; otherwise, both of them would lose money. The feeling of guilt in Self-Wrong condition (SW) was significantly higher than that in Both-Wrong and Partner-Wrong conditions. At approximately 350 ms after the onset of feedback presentation, greater negativities were observed in the frontal regions in the guilt condition (i.e., SW) than those in the non-guilt condition. The guilt-modulated frontal negativity might reflect the interactions of self-reflection, condemnation, and negative emotion.

Dopaminergic modulation of mitral cell activity in the frog olfactory bulb: a combined radioligand binding-electrophysiological study

International Nuclear Information System (INIS)

Duchamp, A.; Moyse, E.; Delaleu, J.-C.; Coronas, V.; Duchamp-Viret, P.

1997-01-01

Dopamine content in the amphibian olfactory bulb is supplied by interneurons scattered among mitral cells in the external plexiform/mitral cell layer. In mammals, dopamine has been found to be involved in various aspects of bulbar information processing by influencing mitral cell odour responsiveness. Dopamine action in the bulb depends directly on the localization of its receptor targets, found to be mainly of the D 2 type in mammals. The present study assessed, in the frog, both the anatomical localization of D 2 -like, radioligand-labelled receptors of dopamine and the in vivo action of dopamine on unitary mitral cell activity in response to odours delivered over a wide range of concentrations. The [ 125 I]iodosulpride-labelled D 2 binding sites were visualized on frozen sagittal sections of frog brains by film radioautography. The sites were found to be restricted to the external plexiform/mitral cell layer; other layers of the olfactory bulb were devoid of specific labelling. Electrophysiological recordings of mitral unit activity revealed that dopamine or its agonist apomorphine induced a drastic reduction of spontaneous firing rate of mitral cells in most cases without altering odour intensity coding properties of these cells. Moreover, pre-treatment with the D 2 antagonist eticlopride blocked the dopamine-induced reduction of mitral cell spontaneous activity.In the frog olfactory bulb, both anatomical localization of D 2 -like receptors and functional data on dopamine involvement in information processing differ from those reported in mammals. This suggests a phylogenetic evolution of dopamine action in the olfactory bulb. In the frog, anatomical data perfectly corroborate electrophysiological results, together strongly suggesting a direct action of dopamine on mitral cells. In a physiologically operating system, such an action would result in a global improvement of signal-to-noise ratio. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights

A behavioural and electrophysiological investigation of the effect of bilingualism on aging and cognitive control.

Science.gov (United States)

Kousaie, Shanna; Phillips, Natalie A

2017-01-08

Given previous, but inconsistent, findings of language group differences on cognitive control tasks the current investigation examined whether such differences could be demonstrated in a sample of older bilingual adults. Monolingual and bilingual older adults performed three cognitive control tasks that have previously been used in the literature (i.e., Stroop, Simon and flanker tasks) while brain electrophysiological recordings took place. Both behavioural (response time and accuracy) and event-related brain potentials (ERPs; N2 and P3 amplitude and latency) were compared across the two language groups. Processing differences between monolinguals and bilinguals were identified for each task, although the locus differed across the tasks. Language group differences were most clear in the Stroop task, with bilinguals showing superior performance both behaviourally and electrophysiologically. In contrast, for the Simon and flanker tasks there were electrophysiological differences indicating language group processing differences at the level of conflict monitoring (Simon task only) and stimulus categorization (Simon and flanker tasks), but no behavioural differences. These findings support suggestions that these three tasks that are often used to examine executive control processes show little convergent validity; however, there are clear language group differences for each task that are suggestive of superior performance for bilinguals, with behavioural differences emerging only in the linguistic Stroop task. Furthermore, it is clear that behavioural measures alone do not capture the language group effects in their entirety, and perhaps processing differences between language groups are more marked in a sample of older adults who are experiencing age-related cognitive changes than in younger adults who are at the peak of their cognitive capacity. Copyright © 2016 Elsevier Ltd. All rights reserved.

MR evaluation of brachial plexus injuries

International Nuclear Information System (INIS)

Gupta, R.K.; Jain, R.K.; Mehta, V.S.; Banerji, A.K.

1989-01-01

Ten cases of brachial plexus injury were subjected to magnetic resonance (MR) to demonstrate the roots, trunks, divisions or cord abnormalities. Both normal and abnormal brachial plexuses were imaged in sagittal, axial, coronal and axial oblique planes. Myelography, using water soluble contrast agents, was performed in seven cases. MR demonstrated one traumatic meningocele, one extradural cerebrospinal fluid (CSF) collection, trunk and/or root neuromas in four, focal root fibrosis in two and diffuse fibrosis in the remaining two cases. Results of MR were confirmed at surgery in four cases with neuromas, while myelography was normal in two and was not carried out in the remaining two. In two cases, where MR demonstrated diffuse fibrosis of the brachial plexus, myelography showed C7 and T1 traumatic meningocele in one and was normal in the other. Both these patients showed excellent clinical and electrophysiological correlation with MR findings and in one of them surgical confirmation was also obtained. In the other two cases with focal nerve root fibrosis, myelography was normal in one and showed a traumatic meningocele in another. Operative findings in these cases confirmed focal root fibrosis but no root avulsion was observed although seen on one myelogram. Focal fibrosis, however, was noted at operation in more roots than was observed with MR. Initial experience suggests that MR may be the diagnostic procedure of choice for complete evaluation of brachial plexus injuries. (orig.)

Prism Adaptation Alters Electrophysiological Markers of Attentional Processes in the Healthy Brain.

Science.gov (United States)

Martín-Arévalo, Elisa; Laube, Inga; Koun, Eric; Farnè, Alessandro; Reilly, Karen T; Pisella, Laure

2016-01-20

Neglect patients typically show a rightward attentional orienting bias and a strong disengagement deficit, such that they are especially slow in responding to left-sided targets after right-sided cues (Posner et al., 1984). Prism adaptation (PA) can reduce diverse debilitating neglect symptoms and it has been hypothesized that PA's effects are so generalized that they might be mediated by attentional mechanisms (Pisella et al., 2006; Redding and Wallace, 2006). In neglect patients, performance on spatial attention tasks improves after rightward-deviating PA (Jacquin-Courtois et al., 2013). In contrast, in healthy subjects, although there is evidence that leftward-deviating PA induces neglect-like performance on some visuospatial tasks, behavioral studies of spatial attention tasks have mostly yielded negative results (Morris et al., 2004; Bultitude et al., 2013). We hypothesized that these negative behavioral findings might reflect the limitations of behavioral measures in healthy subjects. Here we exploited the sensitivity of event-related potentials to test the hypothesis that electrophysiological markers of attentional processes in the healthy human brain are affected by PA. Leftward-deviating PA generated asymmetries in attentional orienting (reflected in the cue-locked N1) and in attentional disengagement for invalidly cued left targets (reflected in the target-locked P1). This is the first electrophysiological demonstration that leftward-deviating PA in healthy subjects mimics attentional patterns typically seen in neglect patients. Significance statement: Prism adaptation (PA) is a promising tool for ameliorating many deficits in neglect patients and inducing neglect-like behavior in healthy subjects. The mechanisms underlying PA's effects are poorly understood but one hypothesis suggests that it acts by modulating attention. To date, however, there has been no successful demonstration of attentional modulation in healthy subjects. We provide the first

Generation of electrophysiologically functional cardiomyocytes from mouse induced pluripotent stem cells

Directory of Open Access Journals (Sweden)

Hongran Wang

2016-03-01

Full Text Available Induced pluripotent stem (iPS cells can efficiently differentiate into the three germ layers similar to those formed by differentiated embryonic stem (ES cells. This provides a new source of cells in which to establish preclinical allogeneic transplantation models. Our iPS cells were generated from mouse embryonic fibroblasts (MEFs transfected with the Yamanaka factors, the four transcription factors (Oct4, Sox2, Klf4 and c-Myc, without antibiotic selection or MEF feeders. After the formation of embryoid bodies (EBs, iPS cells spontaneously differentiated into Flk1-positive cardiac progenitors and cardiomyocytes expressing cardiac-specific markers such as alpha sarcomeric actinin (α-actinin, cardiac alpha myosin heavy chain (α-MHC, cardiac troponin T (cTnT, and connexin 43 (CX43, as well as cardiac transcription factors Nk2 homebox 5 (Nkx2.5 and gata binding protein 4 (gata4. The electrophysiological activity of iPS cell-derived cardiomyocytes (iPS-CMs was detected in beating cell clusters with optical mapping and RH237 a voltage-sensitive dye, and in single contracting cells with patch-clamp technology. Incompletely differentiated iPS cells formed teratomas when transplanted into a severe combined immunodeficiency (SCID mouse model of myocardial infarction. Our results show that somatic cells can be reprogrammed into pluripotent stem cells, which in turn spontaneously differentiate into electrophysiologically functional mature cardiomyocytes expressing cardiac-specific makers, and that these cells can potentially be used to repair myocardial infarction (MI in the future.

A simplified protocol for differentiation of electrophysiologically mature neuronal networks from human induced pluripotent stem cells.

Science.gov (United States)

Gunhanlar, N; Shpak, G; van der Kroeg, M; Gouty-Colomer, L A; Munshi, S T; Lendemeijer, B; Ghazvini, M; Dupont, C; Hoogendijk, W J G; Gribnau, J; de Vrij, F M S; Kushner, S A

2017-04-18

Progress in elucidating the molecular and cellular pathophysiology of neuropsychiatric disorders has been hindered by the limited availability of living human brain tissue. The emergence of induced pluripotent stem cells (iPSCs) has offered a unique alternative strategy using patient-derived functional neuronal networks. However, methods for reliably generating iPSC-derived neurons with mature electrophysiological characteristics have been difficult to develop. Here, we report a simplified differentiation protocol that yields electrophysiologically mature iPSC-derived cortical lineage neuronal networks without the need for astrocyte co-culture or specialized media. This protocol generates a consistent 60:40 ratio of neurons and astrocytes that arise from a common forebrain neural progenitor. Whole-cell patch-clamp recordings of 114 neurons derived from three independent iPSC lines confirmed their electrophysiological maturity, including resting membrane potential (-58.2±1.0 mV), capacitance (49.1±2.9 pF), action potential (AP) threshold (-50.9±0.5 mV) and AP amplitude (66.5±1.3 mV). Nearly 100% of neurons were capable of firing APs, of which 79% had sustained trains of mature APs with minimal accommodation (peak AP frequency: 11.9±0.5 Hz) and 74% exhibited spontaneous synaptic activity (amplitude, 16.03±0.82 pA; frequency, 1.09±0.17 Hz). We expect this protocol to be of broad applicability for implementing iPSC-based neuronal network models of neuropsychiatric disorders.Molecular Psychiatry advance online publication, 18 April 2017; doi:10.1038/mp.2017.56.

Electrophysiological measurements of spectral sensitivities: a review

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R.D. DeVoe

1997-02-01

Full Text Available Spectral sensitivities of visual systems are specified as the reciprocals of the intensities of light (quantum fluxes needed at each wavelength to elicit the same criterion amplitude of responses. This review primarily considers the methods that have been developed for electrophysiological determinations of criterion amplitudes of slow-wave responses from single retinal cells. Traditional flash methods can require tedious dark adaptations and may yield erroneous spectral sensitivity curves which are not seen in such modifications as ramp methods. Linear response methods involve interferometry, while constant response methods involve manual or automatic adjustments of continuous illumination to keep response amplitudes constant during spectral scans. In DC or AC computerized constant response methods, feedback to determine intensities at each wavelength is derived from the response amplitudes themselves. Although all but traditional flash methods have greater or lesser abilities to provide on-line determinations of spectral sensitivities, computerized constant response methods are the most satisfactory due to flexibility, speed and maintenance of a constant adaptation level

Electrophysiological Characteristics of Human iPSC-Derived Cardiomyocytes for the Assessment of Drug-Induced Proarrhythmic Potential.

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Wataru Yamamoto

Full Text Available The aims of this study were to (1 characterize basic electrophysiological elements of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs that correspond to clinical properties such as QT-RR relationship, (2 determine the applicability of QT correction and analysis methods, and (3 determine if and how these in-vitro parameters could be used in risk assessment for adverse drug-induced effects such as Torsades de pointes (TdP. Field potential recordings were obtained from commercially available hiPSC-CMs using multi-electrode array (MEA platform with and without ion channel antagonists in the recording solution. Under control conditions, MEA-measured interspike interval and field potential duration (FPD ranged widely from 1049 to 1635 ms and from 334 to 527 ms, respectively and provided positive linear regression coefficients similar to native QT-RR plots obtained from human electrocardiogram (ECG analyses in the ongoing cardiovascular-based Framingham Heart Study. Similar to minimizing the effect of heart rate on the QT interval, Fridericia's and Bazett's corrections reduced the influence of beat rate on hiPSC-CM FPD. In the presence of E-4031 and cisapride, inhibitors of the rapid delayed rectifier potassium current, hiPSC-CMs showed reverse use-dependent FPD prolongation. Categorical analysis, which is usually applied to clinical QT studies, was applicable to hiPSC-CMs for evaluating torsadogenic risks with FPD and/or corrected FPD. Together, this results of this study links hiPSC-CM electrophysiological endpoints to native ECG endpoints, demonstrates the appropriateness of clinical analytical practices as applied to hiPSC-CMs, and suggests that hiPSC-CMs are a reliable models for assessing the arrhythmogenic potential of drug candidates in human.

Moderate injury in motor-sensory cortex causes behavioral deficits accompanied by electrophysiological changes in mice adulthood.

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Wei Ouyang

Full Text Available Moderate traumatic brain injury (TBI in children often happen when there's a sudden blow to the frontal bone, end with long unconscious which can last for hours and progressive cognitive deficits. However, with regard to the influences of moderate TBI during children adulthood, injury-induced alterations of locomotive ability, long-term memory performance, and hippocampal electrophysiological firing changes have not yet been fully identified. In this study, lateral fluid percussion (LFP method was used to fabricate moderate TBI in motor and somatosensory cortex of the 6-weeks-old mice. The motor function, learning and memory function, extracellular CA1 neural spikes were assessed during acute and subacute phase. Moreover, histopathology was performed on day post injury (DPI 16 to evaluate the effect of TBI on tissue and cell morphological changes in cortical and hippocampal CA1 subregions. After moderate LFP injury, the 6-weeks-old mice showed severe motor deficits at the early stage in acute phase but gradually recovered later during adulthood. At the time points in acute and subacute phase after TBI, novel object recognition (NOR ability and spatial memory functions were consistently impaired in TBI mice; hippocampal firing frequency and burst probability were hampered. Analysis of the altered burst firing shows a clear hippocampal theta rhythm drop. These electrophysiological impacts were associated with substantially lowered NOR preference as compared to the sham group during adulthood. These results suggest that moderate TBI introduced at motorsenory cortex in 6-weeks-old mice causes obvious motor and cognitive deficits during their adulthood. While the locomotive ability progressively recovers, the cognitive deficits persisted while the mice mature as adult mice. The cognitive deficits may be attributed to the general suppressing of whole neural network, which could be labeled by marked reduction of excitability in hippocampal CA1

Moderate injury in motor-sensory cortex causes behavioral deficits accompanied by electrophysiological changes in mice adulthood.

Science.gov (United States)

Ouyang, Wei; Yan, Qichao; Zhang, Yu; Fan, Zhiheng

2017-01-01

Moderate traumatic brain injury (TBI) in children often happen when there's a sudden blow to the frontal bone, end with long unconscious which can last for hours and progressive cognitive deficits. However, with regard to the influences of moderate TBI during children adulthood, injury-induced alterations of locomotive ability, long-term memory performance, and hippocampal electrophysiological firing changes have not yet been fully identified. In this study, lateral fluid percussion (LFP) method was used to fabricate moderate TBI in motor and somatosensory cortex of the 6-weeks-old mice. The motor function, learning and memory function, extracellular CA1 neural spikes were assessed during acute and subacute phase. Moreover, histopathology was performed on day post injury (DPI) 16 to evaluate the effect of TBI on tissue and cell morphological changes in cortical and hippocampal CA1 subregions. After moderate LFP injury, the 6-weeks-old mice showed severe motor deficits at the early stage in acute phase but gradually recovered later during adulthood. At the time points in acute and subacute phase after TBI, novel object recognition (NOR) ability and spatial memory functions were consistently impaired in TBI mice; hippocampal firing frequency and burst probability were hampered. Analysis of the altered burst firing shows a clear hippocampal theta rhythm drop. These electrophysiological impacts were associated with substantially lowered NOR preference as compared to the sham group during adulthood. These results suggest that moderate TBI introduced at motorsenory cortex in 6-weeks-old mice causes obvious motor and cognitive deficits during their adulthood. While the locomotive ability progressively recovers, the cognitive deficits persisted while the mice mature as adult mice. The cognitive deficits may be attributed to the general suppressing of whole neural network, which could be labeled by marked reduction of excitability in hippocampal CA1 subregion.

Spyke Viewer: a flexible and extensible platform for electrophysiological data analysis

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Robert ePröpper

2013-11-01

Full Text Available Spyke Viewer is an open source application designed to help researchers analyze data from electrophysiological recordings or neural simulations. It provides a graphical data browser and supports finding and selecting relevant subsets of the data. Users can interact with the selected data using an integrated Python console or plugins. Spyke Viewer includes plugins for several common visualizations and allows users to easily extend the program by writing their own plugins. New plugins are automatically integrated with the graphical interface. Additional plugins can be downloaded and shared on a dedicated website.

Evaluation and selection of CASE tool for SMART OTS development

International Nuclear Information System (INIS)

Park, K. O; Seo, S. M.; Seo, Y. S.; Koo, I. S.; Jang, M. H.

1999-01-01

CASE(Computer-Aided Software Engineering) tool is a software that aids in software engineering activities such as requirement analysis, design, testing, configuration management, and project management. The evaluation and selection of commercial CASE tools for the specific software development project is not a easy work because the technical ability of an evaluator and the maturity of a software development organization are required. In this paper, we discuss selection strategies, characteristic survey, evaluation criteria, and the result of CASE tool selection for the development of SMART(System-integrated Modular Advanced ReacTor) OTS(Operator Training Simulator)

The diagnostic efficacy of clinical findings and electrophysiological studies in carpal tunnel syndrome

OpenAIRE

Buyukkoyuncu Pekel, Nilufer; Nar Senol, Pelin; Yildiz, Demet; Kilic, Ahmet Kasim; Kamaci Sener, Deniz; Seferoglu, Meral; Gunes, Aygul

2017-01-01

Objective. The aim of the study was to examine the relation between clinical findings, neurological examination and electrophysiological studies in diagnosing carpal tunnel syndrome (CTS) and share our institutional experience in patients with CTS. Methods. Patients presenting with complaints of pain, paresthesia, and weakness in hands who diagnosed CTS between 2014 and 2015 were examined retrospectively. Demographic characteristics, clinical and neurological examination findings and electrod...

Image-based reconstruction of three-dimensional myocardial infarct geometry for patient-specific modeling of cardiac electrophysiology

Energy Technology Data Exchange (ETDEWEB)

Ukwatta, Eranga, E-mail: eukwatt1@jhu.edu; Arevalo, Hermenegild; Pashakhanloo, Farhad; Prakosa, Adityo; Vadakkumpadan, Fijoy [Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland 21205 and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Rajchl, Martin [Department of Computing, Imperial College London, London SW7 2AZ (United Kingdom); White, James [Stephenson Cardiovascular MR Centre, University of Calgary, Calgary, Alberta T2N 2T9 (Canada); Herzka, Daniel A.; McVeigh, Elliot [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Lardo, Albert C. [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 and Division of Cardiology, Johns Hopkins Institute of Medicine, Baltimore, Maryland 21224 (United States); Trayanova, Natalia A. [Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Department of Biomedical Engineering, Johns Hopkins Institute of Medicine, Baltimore, Maryland 21205 (United States)

2015-08-15

Purpose: Accurate three-dimensional (3D) reconstruction of myocardial infarct geometry is crucial to patient-specific modeling of the heart aimed at providing therapeutic guidance in ischemic cardiomyopathy. However, myocardial infarct imaging is clinically performed using two-dimensional (2D) late-gadolinium enhanced cardiac magnetic resonance (LGE-CMR) techniques, and a method to build accurate 3D infarct reconstructions from the 2D LGE-CMR images has been lacking. The purpose of this study was to address this need. Methods: The authors developed a novel methodology to reconstruct 3D infarct geometry from segmented low-resolution (Lo-res) clinical LGE-CMR images. Their methodology employed the so-called logarithm of odds (LogOdds) function to implicitly represent the shape of the infarct in segmented image slices as LogOdds maps. These 2D maps were then interpolated into a 3D image, and the result transformed via the inverse of LogOdds to a binary image representing the 3D infarct geometry. To assess the efficacy of this method, the authors utilized 39 high-resolution (Hi-res) LGE-CMR images, including 36 in vivo acquisitions of human subjects with prior myocardial infarction and 3 ex vivo scans of canine hearts following coronary ligation to induce infarction. The infarct was manually segmented by trained experts in each slice of the Hi-res images, and the segmented data were downsampled to typical clinical resolution. The proposed method was then used to reconstruct 3D infarct geometry from the downsampled images, and the resulting reconstructions were compared with the manually segmented data. The method was extensively evaluated using metrics based on geometry as well as results of electrophysiological simulations of cardiac sinus rhythm and ventricular tachycardia in individual hearts. Several alternative reconstruction techniques were also implemented and compared with the proposed method. Results: The accuracy of the LogOdds method in reconstructing 3D

Flexible Conductive Composite Integrated with Personal Earphone for Wireless, Real-Time Monitoring of Electrophysiological Signs.

Science.gov (United States)

Lee, Joong Hoon; Hwang, Ji-Young; Zhu, Jia; Hwang, Ha Ryeon; Lee, Seung Min; Cheng, Huanyu; Lee, Sang-Hoon; Hwang, Suk-Won

2018-06-14

We introduce optimized elastomeric conductive electrodes using a mixture of silver nanowires (AgNWs) with carbon nanotubes/polydimethylsiloxane (CNTs/PDMS), to build a portable earphone type of wearable system that is designed to enable recording electrophysiological activities as well as listening to music at the same time. A custom-built, plastic frame integrated with soft, deformable fabric-based memory foam of earmuffs facilitates essential electronic components, such as conductive elastomers, metal strips, signal transducers and a speaker. Such platform incorporates with accessory cables to attain wireless, real-time monitoring of electrical potentials whose information can be displayed on a cell phone during outdoor activities and music appreciation. Careful evaluations on experimental results reveal that the performance of fabricated dry electrodes are comparable to that of commercial wet electrodes, and position-dependent signal behaviors provide a route toward accomplishing maximized signal quality. This research offers a facile approach for a wearable healthcare monitor via integration of soft electronic constituents with personal belongings.

Evaluation of a Marketing Campaign: A Case Study of Company X

OpenAIRE

Moisio, Ada

2015-01-01

This thesis concentrates on evaluating a marketing campaign for the case Company X in Finland. The thesis will present the importance of thoroughly understanding different stages of the process of implementing a public communication campaign. Systematic evaluation of marketing campaigns can provide the case company with invaluable information. The reason for elaborating this research was the authors aspiration in cooperation with case companies management to evaluate campaign data from a ...

Electrophysiological Basis of Fecal Incontinence and Its Implications for Treatment

Science.gov (United States)

2017-01-01

The majority of patients with neuropathic incontinence and other pelvic floor conditions associated with straining at stool have damage to the pudendal nerves distal to the ischial spine. Sacral nerve stimulation appears to be a promising innovation and has been widely adopted and currently considered the standard of care for adults with moderate to severe fecal incontinence and following failed sphincter repair. From a decision-to-treat perspective, the short-term efficacy is good (70%–80%), but the long-term efficacy of sacral nerve stimulation is around 50%. Newer electrophysiological tests and improved anal endosonography would more effectively guide clinical decision making. PMID:29159162

A multi-site array for combined local electrochemistry and electrophysiology in the non-human primate brain.

Science.gov (United States)

Disney, Anita A; McKinney, Collin; Grissom, Larry; Lu, Xuekun; Reynolds, John H

2015-11-30

Currently, the primary technique employed in circuit-level study of the brain is electrophysiology, recording local field or action potentials (LFPs or APs). However most communication between neurons is chemical and the relationship between electrical activity within neurons and chemical signaling between them is not well understood in vivo, particularly for molecules that signal at least in part by non-synaptic transmission. We describe a multi-contact array and accompanying head stage circuit that together enable concurrent electrophysiological and electrochemical recording. The array is small (electrochemistry) recording. This system is designed for concurrent, dual-mode recording. It is also the only system designed explicitly to meet the challenges of recording in non-human primates. Our system offers the possibility for conducting in vivo studies in a range of species that examine the relationship between the electrical activity of neurons and their chemical environment, with exquisite spatial and temporal precision. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Barley yellow dwarf virus Infection Leads to Higher Chemical Defense Signals and Lower Electrophysiological Reactions in Susceptible Compared to Tolerant Barley Genotypes.

Science.gov (United States)

Paulmann, Maria K; Kunert, Grit; Zimmermann, Matthias R; Theis, Nina; Ludwig, Anatoli; Meichsner, Doreen; Oelmüller, Ralf; Gershenzon, Jonathan; Habekuss, Antje; Ordon, Frank; Furch, Alexandra C U; Will, Torsten

2018-01-01

Barley yellow dwarf virus (BYDV) is a phloem limited virus that is persistently transmitted by aphids. Due to huge yield losses in agriculture, the virus is of high economic relevance. Since the control of the virus itself is not possible, tolerant barley genotypes are considered as the most effective approach to avoid yield losses. Although several genes and quantitative trait loci are known and used in barley breeding for virus tolerance, little is known about molecular and physiological backgrounds of this trait. Therefore, we compared the anatomy and early defense responses of a virus susceptible to those of a virus-tolerant cultivar. One of the very early defense responses is the transmission of electrophysiological reactions. Electrophysiological reactions to BYDV infection might differ between susceptible and tolerant cultivars, since BYDV causes disintegration of sieve elements in susceptible cultivars. The structure of vascular bundles, xylem vessels and sieve elements was examined using microscopy. All three were significantly decreased in size in infected susceptible plants where the virus causes disintegration of sieve elements. This could be associated with an uncontrolled ion exchange between the sieve-element lumen and apoplast. Further, a reduced electrophysiological isolation would negatively affect the propagation of electrophysiological reactions. To test the influence of BYDV infection on electrophysiological reactions, electropotential waves (EPWs) induced by leaf-tip burning were recorded using aphids as bioelectrodes. EPWs in infected susceptible plants disappeared already after 10 cm in contrast to those in healthy susceptible or infected tolerant or healthy tolerant plants. Another early plant defense reaction is an increase in reactive oxygen species (ROS). Using a fluorescent dye, we found a significant increase in ROS content in infected susceptible plants but not in infected tolerant plants. Similar results were found for the

OpenElectrophy: an electrophysiological data- and analysis-sharing framework

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Samuel Garcia

2009-05-01

Full Text Available Progress in experimental tools and design is allowing the acquisition of increasingly large datasets. Storage, manipulation and efficient analyses of such large amounts of data is now a primary issue. We present OpenElectrophy, an electrophysiological data and analysis sharing framework developed to fill this niche. It stores all experiment data and meta-data in a single central MySQL database, and provides a graphic user interface to visualize and explore the data, and a library of functions for user analysis scripting in Python. It implements multiple spike sorting methods, and oscillation detection based on the ridge extraction methods due to Roux et. al., 2007. OpenElectrophy is open-source and is freely available for download at http://neuralensemble.org/trac/OpenElectrophy.

Right Atrial Dual-loop Reentry Tachycardia after Cardiac Surgery: Prevalence, Electrophysiologic Characteristics and Ablation Outcomes.

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Yang, Jian-du; Sun, Qi; Guo, Xiao-Gang; Zhou, Gong-Bu; Liu, Xu; Luo, Bin; Wei, Hui-Qiang; Santangeli, Pasquale; Liang, Jackson J; Ma, Jian

2018-04-03

Right atrial dual-loop reentry tachycardia has been described in patients with open-heart surgery. However, the prevalence, electrophysiologic substrate and ablation outcomes have been poorly characterized. We aimed to investigate the prevalence, electrophysiologic substrate and ablation outcomes for RA dual-loop reentry tachycardia following cardiac surgery. We identified all patients with atrial tachycardia after cardiac surgery. We compared electrophysiologic findings and outcomes of those with RA dual-loop reentry tachycardia versus a control group of patients with RA macro-reentrant arrhythmias in the setting of linear RA free wall (FW) scar. Out of 127 patients with 152 post-surgical atrial tachycardias (ATs), 28 (18.4%) had diagnosis of RA dual-loop reentry and 24/28 (85.7%) had tricuspid annular (TA) reentry combined with FW incisional reentry. An incision length > 51.5mm along the FW predicted the substrate for a second loop. In 22/23 patients (95.7%) with initial ablation in the cavo-tricuspid isthmus, a change in the interval between Halo d to CS p could be recorded, while 15/23 patients (65.2%) had CS activation pattern change. Complete success was achieved in 25/28 (89.3%) and 64/69 (92.8%) in the dual-loop reentry and control groups, respectively. After mean follow-up of 33.9±24.2 months, 24/28 (85.7%) and 60/69 (86.95%) were free of arrhythmias after initial procedure in two groups. The prevalence of RA dual-loop reentry is 18.4% among ATs with prior atriotomy scar. A long incision should alert physician the possibility of the second loop at the FW. Halo and CS activation pattern are important clues for circuit transformation. Copyright © 2018. Published by Elsevier Inc.

Electrophysiological changes in patients with liver cirrhosis in a tertiary care hospital in karachi, pakistan

International Nuclear Information System (INIS)

Parkash, O.; Mohyuddin, G.R.; Ayub, A.; Nazir, I.

2017-01-01

Electrophysiological changes in cirrhosis are well known but least investigated especially in our country hence we wanted to see electrophysiological changes especially QT interval in cirrhotic patients. Methods: A cross-sectional study was conducted at Aga Khan University Hospital Karachi (AKUH) in which medical records (duration 2008-2010) of cirrhotic patients were reviewed. Results: Three hundred and eighty cirrhotic patients' charts were studied, 227 (59.7 percent) were male and mean age of this cohort was 52.8+-12.6 years. The most common cause for CLD was Hepatitis C (CHC) in 260 (68.4 percent), NBNC in 56(14.7 percent) and HBV in 51 (13.4 percent). Only 225 had complete ECG workup, the mean corrected QT interval was 0.44+-0.067 sec. Among the electrophysiological abnormalities, 79 (35 percent) had a prolonged corrected QT interval, 7 (3.1 percent) had a prolonged PR interval (>0.22s) and prolonged QRS duration was seen in 23 (10.4 percent) patients. QT prolongation was seen in 1 of the 5 patients with Child Class A (20 percent), 22 of the 73 patients with Child Class B (30.1 percent), and 25 of the 61 patients with Child Class C (41 percent). However, this difference however was not statistically significant. (p value=.331). Conclusion: We conclude that QT prolongation is more frequent in patients with liver cirrhosis especially when the disease is more advanced like in Child C hence these patients are more prone to sudden cardiac death. Moreover, this study shows that the risk associated with QT prolongation is present through all classes of liver cirrhosis. We recommend that routine cardiac screening with ECG of all cirrhotic patients be performed. (author)

Evaluation of Radiographic Instability of the Trapeziometacarpal Joint in Women With Carpal Tunnel Syndrome.

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Kim, Jeong Hwan; Gong, Hyun Sik; Kim, Youn Ho; Rhee, Seung Hwan; Kim, Jihyoung; Baek, Goo Hyun

2015-07-01

To determine whether median nerve dysfunction measured by electrophysiologic studies in carpal tunnel syndrome (CTS) is associated with thumb trapeziometacarpal (TMC) joint instability. We evaluated 71 women with CTS and 31 asymptomatic control women. Patients with generalized laxity or TMC joint osteoarthritis were excluded. We classified the electrophysiologic severity of CTS based on nerve conduction time and amplitude and assessed radiographic instability of the TMC joint based on TMC joint stress radiographs. We compared subluxation ratio between patients with CTS and controls and performed correlation analysis of the relationship between the electrophysiologic grade and subluxation ratio. Thirty-one patients were categorized into the mild CTS subgroup and 41 into the severe CTS subgroup. There was no significant difference in subluxation ratio between the control group and CTS patients or between the control group and CTS subgroup patients. Furthermore, there was no significant correlation between electrophysiologic grade and subluxation ratio. This study demonstrated that patients with CTS did not have greater radiographic TMC joint instability compared with controls, and suggests that TMC joint stability is not affected by impaired median nerve function. Further studies could investigate how to better evaluate proprioceptive function of TMC joint and whether other nerves have effects on TMC joint motor/proprioceptive function, to elucidate the relationship between neuromuscular control of the TMC joint, its stability, and its progression to osteoarthritis. Diagnostic II. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Heterogeneity of Monosymptomatic Resting Tremor in a Prospective Study: Clinical Features, Electrophysiological Test, and Dopamine Transporter Positron Emission Tomography

Institute of Scientific and Technical Information of China (English)

Hua-Guang Zheng; Rong Zhang; Xin Li; Fang-Fei Li; Ya-Chen Wang; Xue-Mei Wang; Ling-Long Lu

2015-01-01

Background:The relationship between monosymptomatic resting tremor (mRT) and Parkinson's disease (PD) remains controversial.In this study,we aimed to assess the function ofpresynaptic dopaminergic neurons in patients with mRT by dopamine transporter positron emission tomography (DAT-PET) and to evaluate the utility of clinical features or electrophysiological studies in differential diagnosis.Methods:Thirty-three consecutive patients with mRT were enrolled prospectively.The Unified Parkinson's Disease Rating Scale and electromyography were tested before DAT-PET.Striatal asymmetry index (SAI) was calculated,and a normal DAT-PET was defined as a SAI of ＜15％.Scans without evidence of dopaminergic deficits (SWEDDs) were diagnosed in patients with a subsequent normal DAT-PET and structural magnetic resonance imaging.Results:Twenty-eight mRT patients with a significant reduction in uptake of DAT binding in the striatum were diagnosed with PD,while the remained 5 with a normal DAT-PET scan were SWEDDs.As for UPRDS,the dressing and hygiene score,walking in motor experiences of daily living (Part Ⅱ) and motor examination (Part Ⅲ) were significant different between two groups (P ＜ 0.05 andP＜ 0.01,respectively).Bilateral tremor was more frequent in the SWEDDs group (P ＜ 0.05).The frequency of resting tremor and the amplitude of postural tremor tend to be higher in the SWEDDs group (P =0.08 and P =0.05,respectively).Conclusions:mRT is heterogeneous in presynaptic nigrostriatal dopaminergic degeneration,which can be determined by DAT-PET brain imaging.Clinical and electrophysiological features may provide clues to distinguish PD from SWEDDs.

Electrophysiological effects of Chinese medicine Shen song Yang xin (SSYX) on Chinese miniature swine heart and isolated guinea pig ventricular myocytes.

Science.gov (United States)

Feng, Li; Gong, Jing; Jin, Zhen-yi; Li, Ning; Sun, Li-ping; Wu, Yi-ling; Pu, Jie-lin

2009-07-05

Shen song Yang xin (SSYX) is a compound of Chinese medicine with the effect of increasing heart rate (HR). This study aimed to evaluate its electrophysiological properties at heart and cellular levels. The Chinese miniature swines were randomly assigned to two groups, administered with SSYX or placebo for 4 weeks (n = 8 per group). Cardiac electrophysiological study (EPS) was performed before and after drug administration. The guinea pig ventricular myocytes were enzymatically isolated and whole cell voltage-clamp technique was used to evaluate the effect of SSYX on cardiac action potential (AP). SSYX treatment accelerated the HR from (141.8 +/- 36.0) beats per minute to (163.0 +/- 38.0) beats per minute (P = 0.013) without changing the other parameters in surface electrocardiogram. After blockage of the autonomic nervous system with metoprolol and atropin, SSYX had no effect on intrinsic HR (IHR), but decreased corrected sinus node recovery time (CSNRT) and sinus atrium conducting time (SACT). Intra cardiac EPS showed that SSYX significantly decreased the A-H and A-V intervals as well as shortened the atrial (A), atrioventricular node (AVN) and ventricular (V) effective refractory period (ERP). In isolated guinea pig ventricular myocytes, the most obvious effect of SSYX on action potential was a shortening of the action potential duration (APD) without change in shape of action potential. The shortening rates of APD(30), APD(50) and APD(90) were 19.5%, 17.8% and 15.3%, respectively. The resting potential (Em) and the interval between the end of APD(30) and APD(90) did not significantly change. The present study demonstrates that SSYX increases the HR and enhances the conducting capacity of the heart in the condition of the intact autonomic nervous system. SSYX homogenously decreases the ERP of the heart and shortens the APD of the myocytes, suggesting its antiarrhythmic effect without proarrhythmia.

Encouraging Stakeholder Engagement: A Case Study of Evaluator Behavior

Science.gov (United States)

Poth, Cheryl-Anne; Shulha, Lyn

2008-01-01

This chapter describes evaluator behaviors revealed by the case analysis of a participatory and developmental evaluation. The analysis revealed that the evaluator paid specific attention to individual stakeholder cues. These cues were related to three elements of the evaluation: negotiating the design, monitoring individual stakeholder needs, and…

Closed-loop, open-source electrophysiology

Directory of Open Access Journals (Sweden)

John D Rolston

2010-09-01

Full Text Available Multiple extracellular microelectrodes (multi-electrode arrays, or MEAs effectively record rapidly varying neural signals, and can also be used for electrical stimulation. Multi-electrode recording can serve as artificial output (efferents from a neural system, while complex spatially and temporally targeted stimulation can serve as artificial input (afferents to the neuronal network. Multi-unit or local field potential recordings can not only be used to control real world artifacts, such as prostheses, computers or robots, but can also trigger or alter subsequent stimulation. Real-time feedback stimulation may serve to modulate or normalize aberrant neural activity, to induce plasticity, or to serve as artificial sensory input. Despite promising closed-loop applications, commercial electrophysiology systems do not yet take advantage of the bidirectional capabilities of multi-electrodes, especially for use in freely moving animals. We addressed this lack of tools for closing the loop with NeuroRighter, an open-source system including recording hardware, stimulation hardware, and control software with a graphical user interface. The integrated system is capable of multi-electrode recording and simultaneous patterned microstimulation triggered by recordings with minimal stimulation artifact. The potential applications of closed-loop systems as research tools and clinical treatments are broad; we provide one example where epileptic activity recorded by a multi-electrode probe is used to trigger targeted stimulation, via that probe, to freely moving rodents.

Fluent conceptual processing and explicit memory for faces are electrophysiologically distinct.

Science.gov (United States)

Voss, Joel L; Paller, Ken A

2006-01-18

Implicit memory and explicit memory are fundamentally different manifestations of memory storage in the brain. Yet, conceptual fluency driven by previous experience could theoretically be responsible for both conceptual implicit memory and aspects of explicit memory. For example, contemplating the meaning of a word might serve to speed subsequent processing of that word and also make it seem familiar. We examined electrophysiological correlates of conceptual priming with 180 celebrity faces to determine whether or not they resemble electrophysiological correlates of explicit memory. Celebrity faces are ideal for this purpose because they carry with them preexisting conceptual information (i.e., biographical facts) that can selectively be brought to mind such that conceptual processing can be manipulated systematically. In our experiment, exposure to biographical information associated with only one-half of the celebrities yielded conceptual priming for those faces, whereas all faces were perceptually primed. Conceptual priming was indexed by positive brain potentials over frontal regions from approximately 250 to 500 ms. Explicit memory retrieval was associated with later brain potentials over posterior regions that were strikingly similar to potentials previously associated with pure familiarity for faces (when a face seems familiar in the absence of retrieval of any specific information about previous occurrence). Furthermore, the magnitude of conceptual priming was correlated across subjects with the amplitude of frontal but not posterior potentials, whereas the opposite was true for explicit memory. Distinct brain processes were thus associated with conceptual priming and conscious recognition of faces, thus providing a sharper focus on the border between implicit and explicit memory.

Behavioral and electrophysiological studies of radiation detection in a freshwater crustacean

International Nuclear Information System (INIS)

Rodriguez, A.; Kimeldorf, D.J.

1976-01-01

Behavioral and electrophysiological studies were done on the crayfish (Pacifastacus trowbridgii Stimpson) to determine its ability to detect exposure to 300 kVp x rays. Behavioral arousal responses were observed at exposure rates of 10 to 30 R/sec. Wholebody and partial-body exposures of eye-stalkless (blinded) animals also induced similar responses and indicated a radiation-sensitive receptor in the abdomen. Prolonged exposure under free choice of residence conditions induced an avoidance of the x-ray field. X-ray exposure of the dark-adapted compound eye evoked an electroretinogram (ERG) that was similar to the light-evoked ERG. The ERG amplitude was directly proportional to the total exposure with exposures less than 300 msec duration and related to the logarithm of the exposure rate with exposures greater than 300 msec. X-ray exposure of receptor sites on the medial branch of the antennule and the cheliped of the first walking-leg did not yield any significant chemoreceptor responses as judged by electrophysiological tests. X-irradiation of the sixth abdominal ganglion in both isolated and in vivo preparations elicited significant increases in neural impulse activity. The latency varied inversely with exposure rate. Spike potentials evoked by x rays were similar to those evoked by light; however, a supplemental increase in spikes of lower amplitude occurred that did not occur during light stimulation. It appears likely that the behavioral response in the crayfish, subjected to abdomen-only exposure, may be instigated by x-ray excitation of the sixth ganglion

Heterogeneity of Monosymptomatic Resting Tremor in a Prospective Study: Clinical Features, Electrophysiological Test, and Dopamine Transporter Positron Emission Tomography

Directory of Open Access Journals (Sweden)

Hua-Guang Zheng

2015-01-01

Conclusions: mRT is heterogeneous in presynaptic nigrostriatal dopaminergic degeneration, which can be determined by DAT-PET brain imaging. Clinical and electrophysiological features may provide clues to distinguish PD from SWEDDs.

Electrophysiological and biochemical studies of slow responses to serotonin and dopamine of snail identified neurons. Mediating role of the cyclic AMP

International Nuclear Information System (INIS)

Deterre, Philippe

1983-01-01

In this research thesis, the electrophysiological study of slow incoming currents induced in some identified neurons of the Helix aspersa snail by serotonin and dopamine shows that they are associated with a decrease of a potassium conductance involved in the modulation of the action potential duration. By means of enzymatic tests performed on a single cell, and of electrophysiological experiments, the author shows that the cyclic AMP is an intracellular mediator involved in the genesis of these slow responses. Moreover, the obtained results show that serotonin and dopamine act by binding to specific receptors, and that these receptors activate the adenylate-cyclase through a GTP binding protein [fr

Electrophysiological and Pharmacological Analyses of Nav1.9 Voltage-Gated Sodium Channel by Establishing a Heterologous Expression System

Directory of Open Access Journals (Sweden)

Xi Zhou

2017-11-01

Full Text Available Nav1. 9 voltage-gated sodium channel is preferentially expressed in peripheral nociceptive neurons. Recent progresses have proved its role in pain sensation, but our understanding of Nav1.9, in general, has lagged behind because of limitations in heterologous expression in mammal cells. In this work, functional expression of human Nav1.9 (hNav1.9 was achieved by fusing GFP to the C-terminal of hNav1.9 in ND7/23 cells, which has been proved to be a reliable method to the electrophysiological and pharmacological studies of hNav1.9. By using the hNav1.9 expression system, we investigated the electrophysiological properties of four mutations of hNav1.9 (K419N, A582T, A842P, and F1689L, whose electrophysiological functions have not been determined yet. The four mutations significantly caused positive shift of the steady-state fast inactivation and therefore increased hNav1.9 activity, consistent with the phenotype of painful peripheral neuropathy. Meanwhile, the effects of inflammatory mediators on hNav1.9 were also investigated. Impressively, histamine was found for the first time to enhance hNav1.9 activity, indicating its vital role in hNav1.9 modulating inflammatory pain. Taken together, our research provided a useful platform for hNav1.9 studies and new insight into mechanism of hNav1.9 linking to pain.

Association of Atrial Fibrillation with Morphological and Electrophysiological Changes of the Atrial Myocardium.

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Matějková, Adéla; Šteiner, Ivo

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. For long time it was considered as pure functional disorder, but in recent years, there were identified atrial locations, which are involved in the initiation and maintenance of this arrhythmia. These structural changes, so called remodelation, start at electric level and later they affect contractility and morphology. In this study we attempted to find a possible relation between morphological (scarring, amyloidosis, left atrial (LA) enlargement) and electrophysiological (ECG features) changes in patients with AF. We examined grossly and histologically 100 hearts of necropsy patients - 54 with a history of AF and 46 without AF. Premortem ECGs were evaluated. The patients with AF had significantly heavier heart, larger LA, more severely scarred myocardium of the LA and atrial septum, and more severe amyloidosis in both atria. Severity of amyloidosis was higher in LAs vs. right atria (RAs). Distribution of both fibrosis and amyloidosis was irregular. The most affected area was in the LA anterior wall. Patients with a history of AF and with most severe amyloidosis have more often abnormally long P waves. Finding of long P wave may contribute to diagnosis of a hitherto undisclosed atrial fibrillation.

Closed-loop, multichannel experimentation using the open-source NeuroRighter electrophysiology platform

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Jonathan Paul Newman

2013-01-01

Full Text Available Single neuron feedback control techniques, such as voltage clamp and dynamic clamp, have enabled numerous advances in our understanding of ion channels, electrochemical signaling, and neural dynamics. Although commercially available multichannel recording and stimulation systems are commonly used for studying neural processing at the network level, they provide little native support for real-time feedback. We developed the open-source NeuroRighter multichannel electrophysiology hardware and software platform for closed-loop multichannel control with a focus on accessibility and low cost. NeuroRighter allows 64 channels of stimulation and recording for around US $10,000, along with the ability to integrate with other software and hardware. Here, we present substantial enhancements to the NeuroRighter platform, including a redesigned desktop application, a new stimulation subsystem allowing arbitrary stimulation patterns, low-latency data servers for accessing data streams, and a new application programming interface (API for creating closed-loop protocols that can be inserted into NeuroRighter as plugin programs. This greatly simplifies the design of sophisticated real-time experiments without sacrificing the power and speed of a compiled programming language. Here we present a detailed description of NeuroRighter as a stand alone application, its plugin API, and an extensive set of case studies that highlight the system's abilities for conducting closed-loop, multichannel interfacing experiments.

Rare association of thymoma, myasthenia gravis and sarcoidosis : a case report

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Kurukumbi Mohankumar

2008-07-01

Full Text Available Abstract Introduction The association of thymoma with myasthenia gravis (MG is well known. Thymoma with sarcoidosis however, is very rare. We presented an interesting case with coexisting thymoma, MG and sarcoidosis. Case presentation A 59-year-old female patient with a history of sarcoidosis was admitted to the hospital with a one-day history of sudden onset of right-sided partial ptosis and diplopia. Neurosarcoidosis with cranial nerve involvement was considered, but was ruled out by the clinical findings, and MG was confirmed by the positive tensilon test, electrophysiological findings and positive acetylcholine receptor binding antibodies. On further evaluation, a CT chest scan showed a left anterior mediastinal mass and bilateral lymphadenopathy. Post surgical diagnosis confirmed the thymoma and sarcoidosis in the lymph nodes. Conclusion When two or more diseases of undetermined origin are found together, several interesting questions are raised. It is important to first confirm the diagnoses individually. Immunologic mechanisms triggering the occurrence of these diagnoses together, are difficult to address. Although the coexistence of thymoma, MG and sarcoidosis may be coincidental, it is noteworthy to report this case because of the multiple interesting features observed as well as the rarity of occurrence.

Electrophysiological indices of response inhibition in a Go/NoGo task predict self-control in a social context.

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Kyle Nash

Full Text Available Recent research demonstrates that response inhibition-a core executive function-may subserve self-regulation and self-control. However, it is unclear whether response inhibition also predicts self-control in the multifaceted, high-level phenomena of social decision-making. Here we examined whether electrophysiological indices of response inhibition would predict self-control in a social context. Electroencephalography was recorded as participants completed a widely used Go/NoGo task (the cued Continuous Performance Test. Participants then interacted with a partner in an economic exchange game that requires self-control. Results demonstrated that greater NoGo-Anteriorization and larger NoGo-P300 peak amplitudes-two established electrophysiological indices of response inhibition-both predicted more self-control in this social game. These findings support continued integration of executive function and self-regulation and help extend prior research into social decision-making processes.

Processing graded feedback: electrophysiological correlates of learning from small and large errors.

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Luft, Caroline Di Bernardi; Takase, Emilio; Bhattacharya, Joydeep

2014-05-01

Feedback processing is important for learning and therefore may affect the consolidation of skills. Considerable research demonstrates electrophysiological differences between correct and incorrect feedback, but how we learn from small versus large errors is usually overlooked. This study investigated electrophysiological differences when processing small or large error feedback during a time estimation task. Data from high-learners and low-learners were analyzed separately. In both high- and low-learners, large error feedback was associated with higher feedback-related negativity (FRN) and small error feedback was associated with a larger P300 and increased amplitude over the motor related areas of the left hemisphere. In addition, small error feedback induced larger desynchronization in the alpha and beta bands with distinctly different topographies between the two learning groups: The high-learners showed a more localized decrease in beta power over the left frontocentral areas, and the low-learners showed a widespread reduction in the alpha power following small error feedback. Furthermore, only the high-learners showed an increase in phase synchronization between the midfrontal and left central areas. Importantly, this synchronization was correlated to how well the participants consolidated the estimation of the time interval. Thus, although large errors were associated with higher FRN, small errors were associated with larger oscillatory responses, which was more evident in the high-learners. Altogether, our results suggest an important role of the motor areas in the processing of error feedback for skill consolidation.

Neuroprotective effects of riluzole: an electrophysiological and histological analysis in an in vitro model of ischemia.

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Siniscalchi, A; Zona, C; Sancesario, G; D'Angelo, E; Zeng, Y C; Mercuri, N B; Bernardi, G

1999-06-01

The protective effects of riluzole against the neuronal damage caused by O2 and glucose deprivation (ischemia) was investigated in rat cortical slices by recording electrophysiologically the cortico-cortical field potential and by evaluating histologically the severity of neuronal death. Five minutes of ischemia determined an irreversible depression of the amplitude of the field potential. In addition, this insult caused a clear enhancement of the number of death cells that were specifically colored with trypan blue (a vital colorant which stains altered cells). We found that riluzole, which by itself depressed the synaptic transmission, neuroprotected when perfused 15-20 min before and during ischemia. In fact, due to the treatment with riluzole, the ischemia-induced irreversible depression of the field potential recovered and less cells were stained with trypan blue. These findings demonstrate that riluzole prevents neuronal death in an in vitro model of ischemia and suggest a therapeutic use of this drug in order to reduce the pathophysiological outcomes of stroke.

Introduction to solid supported membrane based electrophysiology.

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Bazzone, Andre; Costa, Wagner Steuer; Braner, Markus; Călinescu, Octavian; Hatahet, Lina; Fendler, Klaus

2013-05-11

The electrophysiological method we present is based on a solid supported membrane (SSM) composed of an octadecanethiol layer chemisorbed on a gold coated sensor chip and a phosphatidylcholine monolayer on top. This assembly is mounted into a cuvette system containing the reference electrode, a chlorinated silver wire. After adsorption of membrane fragments or proteoliposomes containing the membrane protein of interest, a fast solution exchange is used to induce the transport activity of the membrane protein. In the single solution exchange protocol two solutions, one non-activating and one activating solution, are needed. The flow is controlled by pressurized air and a valve and tubing system within a faraday cage. The kinetics of the electrogenic transport activity is obtained via capacitive coupling between the SSM and the proteoliposomes or membrane fragments. The method, therefore, yields only transient currents. The peak current represents the stationary transport activity. The time dependent transporter currents can be reconstructed by circuit analysis. This method is especially suited for prokaryotic transporters or eukaryotic transporters from intracellular membranes, which cannot be investigated by patch clamp or voltage clamp methods.

Risk of malignant arrhythmias in initially symptomatic patients with Wolff-Parkinson-White syndrome: results of a prospective long-term electrophysiological follow-up study.

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Pappone, Carlo; Vicedomini, Gabriele; Manguso, Francesco; Baldi, Mario; Pappone, Alessia; Petretta, Andrea; Vitale, Raffaele; Saviano, Massimo; Ciaccio, Cristiano; Giannelli, Luigi; Calovic, Zarko; Tavazzi, Luigi; Santinelli, Vincenzo

2012-02-07

The available amount of detailed long-term data in patients with Wolff-Parkinson-White syndrome is limited, and no prospective electrophysiological studies looking at predictors of malignant arrhythmia are available. Among 8575 symptomatic Wolff-Parkinson-White patients with atrioventricular reentrant tachycardia referred for electrophysiological test, 369 (mean age, 23±12.5 years) declined catheter ablation and were followed up. The primary end point of the study was to evaluate over a 5-year follow-up the predictors and characteristics of patients who develop malignant arrhythmias. After a mean follow-up of 42.1±10 months, malignant arrhythmias developed in 29 patients (mean age, 13.9±5.6 years; 26 male), resulting in presyncope/syncope (25 patients), hemodynamic collapse (3 patients), or cardiac arrest caused by ventricular fibrillation (1 patient). Of the remaining 340 patients, 168 (mean age, 34.2±9.0 years) remained asymptomatic up to 5 years, and 172 (mean age, 13.6±5.1 years) had benign recurrence, including sustained atrioventricular reentrant tachycardia (132 patients) or atrial fibrillation (40 patients). Compared with the group with no malignant arrhythmias, the group with malignant arrhythmias showed shorter accessory-pathway effective refractory period (PWolff-Parkinson-White syndrome generally have a good outcome, and predictors of malignant arrhythmias are similar to those reported for asymptomatic patients with ventricular pre-excitation.

Haloacetate analogs of pheromones: effects on catabolism and electrophysiology in Plutella xylostella

International Nuclear Information System (INIS)

Prestwich, G.D.; Streinz, L.

1988-01-01

A series of mono, di-, and trihalogenated acetate analogs of Z11-16:Ac were prepared and examined for electrophysiological activity in antennae of males of the diamondback moth, Plutella xylostella. In addition, two potential affinity labels, a diazoacetate (Dza) and a trifluoromethyl ketone (Tfp), were evaluated for EAG activity. The Z11-16:Ac showed the highest activity in EAG assays, followed by the fluorinated acetates, but other haloacetates were essentially inactive. The effects of these analogs on the hydrolysis of [ 3 H]Z11-16:Ac to [ 3 H]Z11-16:OH by antennal esterases was also examined. The three fluorinated acetates showed the greatest activity as inhibitors in competition assays, with rank order F 2 Ac > F 3 Ac > FAc > AC > Cl 2 Ac > ClAc > Dza > Br 2 Ac > BrAc > Tfp > I > Cl 3 Ac > Br 3 Ac > OH. The relative polarities of the haloacetates, as determined by TLC mobility, are in the order mono- > di- > trihalo, but F, Cl, Br, and I all confer similar polarities within a substitution group. Thus, the steric size appears to be the predominant parameter affecting the interactions of the haloacetate analogs with both receptor and catabolic proteins in P. xylostella males

The assessment of macular electrophysiology and macular morphology in patients with vitiligo.

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Aydin, Rukiye; Ozsutcu, Mustafa; Erdur, Sevil Karaman; Dikkaya, Funda; Balevi, Ali; Ozbek, Merve; Senturk, Fevzi

2018-02-01

We aimed to analyze the electrophysiologic function and morphology of macula in vitiligo patients. Seventeen patients with vitiligo and 11 healthy subjects were studied. All participants underwent multifocal electroretinography (mfERG) and spectral domain optical coherence tomography (SD-OCT) evaluations. The mfERG (P1 mfERG responses central and peripheral) and retinal layer segmentation parameters (nine ETDRS subfields) were compared in vitiligo and control groups. The mean P1 response amplitudes were significantly decreased in central and peripheral rings of the fovea in patients with vitiligo compared with controls (p = 0.002 and p = 0.006, respectively). There was a tendency toward a prolonged mean implicit time for both central and peripheral in patients with vitiligo compared to controls, however, with no statistical significance (p = 0.453 and p = 0.05, respectively). There was no statistically significant difference in all retinal layers thickness between two groups. In patients with vitiligo, while photoreceptor segment preserved in SD-OCT, mfERG reduced showing potential decline in central retinal function. This study showed a potential decline in central retinal function in patients with vitiligo even if they have normal fundus appearance and SD-OCT findings.

High-Content Electrophysiological Analysis of Human Pluripotent Stem Cell-Derived Cardiomyocytes (hPSC-CMs).

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Kong, Chi-Wing; Geng, Lin; Li, Ronald A

2018-01-01

Considerable interest has been raised to develop human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) as a model for drug discovery and cardiotoxicity screening. High-content electrophysiological analysis of currents generated by transmembrane cell surface ion channels has been pursued to complement such emerging applications. Here we describe practical procedures and considerations for accomplishing successful assays of hPSC-CMs using an automated planar patch-clamp system.

Slow and fast fatigable frog muscle fibres: electrophysiological and histochemical characteristics.

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Vydevska-Chichova, M; Mileva, K; Todorova, R; Dimitrova, M; Radicheva, N

2005-12-01

Continuous activity of isolated frog gastrocnemius muscle fibres provoked by repetitive stimulation of 5 Hz was used as an experimental model for fatigue development in different fibre types. Parameter changes of the elicited intracellular action potentials and mechanical twitches during the period of uninterrupted activity were used as criteria for fatigue evaluation. Slow fatigable muscle fibre (SMF) and fast fatigable muscle fibre (FMF) types were distinguished depending on the duration of their uninterrupted activity, which was significantly longer in SMFs than in FMFs. The normalized changes of action potential amplitude and duration were significantly smaller in FMFs than in SMFs. The average twitch force and velocity of contraction and relaxation were significantly higher in FMFs than in SMFs. Myosin ATPase (mATPase) and succinate dehydrogenase activity were studied by histochemical assessment in order to validate the fibre type classification based on their electrophysiological characteristics. Based on the relative mATPase reactivity, the fibres of the studied muscle were classified as one of five different types (1-2, 2, 2-3, 3 and tonic). Smaller sized fibres (tonic and type 3) expressed higher succinate dehydrogenase activity than larger sized fibres (type 1-2, 2), which is related to the fatigue resistance. The differences between fatigue development in SMFs and FMFs during continuous activity were associated with fibre-type specific mATPase and succinate dehydrogenase activity.

Electrophysiological assessment of the effects of obstructive sleep apnea on cognition.

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Ethem Gelir

Full Text Available We used electrophysiological measures to investigate the effects of obstructive sleep apnea on attention, learning, and memory. Thirty subjects (OSA group, n = 15, control group n = 15 participated in n-back tests, accompanied by P300 recordings, to investigate working memory and attention. The mirror-drawing test was used to study procedural memory, and the trail-making test (TMT was used to evaluate divided attention and executive function. No significant group difference in reaction time was found in the 0-back and 1-back tests. In the 2-back test, reaction times of patients were longer than those of the control group. No P300 wave was obtained in the OSA group in any (0-, 1-, or 2-back n-back test. In contrast, in the control group, significant P300 waves were recorded except for the 2-back test. The mirror-drawing scores were unaffected by sleep apnea. There was no difference between groups in the TMT-A test on any of the trials. Although no group difference was found in the first or second trials of the TMT-B test, OSA patients were less successful in learning on the third trial. According to our study results, OSA affects attention and executive function adversely however, we could not detect a significant effect on working or procedural memory.

Effects of radiographic contrast media on cellular electrophysiology in the beating heart

Energy Technology Data Exchange (ETDEWEB)

Wolpers, H.G.; Baller, D.; Ensink, F.B.M.; Hoeft, A.; Korb, H.; Hellige, G.

1982-01-01

Electrophysiological effects of intracoronarily administered contrast media have been documented in 12 thoracotomized dogs at the cellular level by use of a modified microelectrode technique. Injections (n = 63) of 4 different contrast media uniformly led to a temporary cellular hyperpolarisation of the resting potential and prolongation of the action potential. Additional experiments with intracoronary injections of several electrolyte concentrations, mainly by a local deficiency of potassium ions and an excess of sodium ions. The significance of the findings for mechanisms underlying ECG-changes and ventricular arrhythmia by radiographic contrasts media will be discussed.

Two subgroups of antipsychotic-naive, first-episode schizophrenia patients identified with a Gaussian mixture model on cognition and electrophysiology

DEFF Research Database (Denmark)

Bak, N.; Ebdrup, B.H.; Oranje, B

2017-01-01

Deficits in information processing and cognition are among the most robust findings in schizophrenia patients. Previous efforts to translate group-level deficits into clinically relevant and individualized information have, however, been non-successful, which is possibly explained by biologically...... and sixty-five healthy controls underwent extensive electrophysiological and neurocognitive test batteries. Patients were assessed on the Positive and Negative Syndrome Scale (PANSS) before and after 6 weeks of monotherapy with the relatively selective D2 receptor antagonist, amisulpride (280.3±159 mg per...... day). A reduced principal component space based on 19 electrophysiological variables and 26 cognitive variables was used as input for a Gaussian mixture model to identify subgroups of patients. With support vector machines, we explored the relation between PANSS subscores and the identified subgroups...

A behavioural and electrophysiological investigation of the effect of bilingualism on lexical ambiguity resolution in young adults

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Shanna eKousaie

2015-12-01

Full Text Available Previous research suggests that bilinguals demonstrate superior cognitive control processes than monolinguals. The goal of the current investigation was to examine whether this bilingual advantage is observed in a language processing task that requires inhibition, i.e., lexical ambiguity processing. Monolingual and bilingual participants read sentences that biased the reading of a terminal homonym toward the subordinate or dominant reading (e.g., The doctor asked her to step onto the scale.. A relatedness judgement was made on target words that were related to the contextually appropriate (e.g., balance or inappropriate meaning (e.g., skin, or unrelated to either meaning (e.g., shoe while electrophysiological recording took place. The results revealed subtle processing differences between monolinguals and bilinguals that were evident in electrophysiological measures, but not in behavioural measures. These findings suggest that monolinguals rely on context to access the contextually appropriate meaning of a homonym to a greater extent than bilinguals, while bilinguals demonstrate simultaneous activation of both meanings.

Scopolamine Reduces Electrophysiological Indices of Distractor Suppression: Evidence from a Contingent Capture Task

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Inga Laube

2017-12-01

Full Text Available Limited resources for the in-depth processing of external stimuli make it necessary to select only relevant information from our surroundings and to ignore irrelevant stimuli. Attentional mechanisms facilitate this selection via top-down modulation of stimulus representations in the brain. Previous research has indicated that acetylcholine (ACh modulates this influence of attention on stimulus processing. However, the role of muscarinic receptors as well as the specific mechanism of cholinergic modulation remains unclear. Here we investigated the influence of ACh on feature-based, top-down control of stimulus processing via muscarinic receptors by using a contingent capture paradigm which specifically tests attentional shifts toward uninformative cue stimuli which display one of the target defining features In a double-blind, placebo controlled study we measured the impact of the muscarinic receptor antagonist scopolamine on behavioral and electrophysiological measures of contingent attentional capture. The results demonstrated all the signs of functional contingent capture, i.e., attentional shifts toward cued locations reflected in increased amplitudes of N1 and N2Pc components, under placebo conditions. However, scopolamine did not affect behavioral or electrophysiological measures of contingent capture. Instead, scopolamine reduced the amplitude of the distractor-evoked Pd component which has recently been associated with active suppression of irrelevant distractor information. The findings suggest a general cholinergic modulation of top-down control during distractor processing.

Evaluation of a case-based urology learning program.

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Mishra, Kirtishri; Snow-Lisy, Devon C; Ross, Jonathan; Goldfarb, David A; Goldman, Howard; Campbell, Steven C

2013-12-01

To address the challenges that today's trainees encounter, such as information overload and reduced immersion in the field, and recognizing their preference for novel educational resources, an electronic case-based urology learning program was developed. Each case was designed to illustrate the basic principles of the disease process and the fundamentals of evaluation and management using the Socratic method, recapitulating a prototypical patient encounter. A 21-question survey was developed after review of published reports of classroom and clinical learning environment surveys. The target group was 2 pilot urology training programs (the Cleveland Clinic and University Hospitals-Case Medical Center). The responses were entirely anonymous. A total of 32 trainees participated (8 fellows and 24 residents), representing a 53% response rate. Most trainees (79%) were able to process cases within an average of ≤ 10 minutes. Of the trainees, 91% reported referring back to particular cases for patient care, to review for examinations, or for studying. Most trainees believed a case-based urology learning program would be a potentially important resource for clinical practice (69%) and for preparing for the in-service (63%) or board (69%) examinations. Most trainees believed the program met its goals of illustrating the basics principles of the disease process (88%), outlining the fundamentals of evaluation and management (94%), and improving the trainees' knowledge base (91%). An electronic case-based urology learning program is feasible and useful and stimulates learning at all trainee levels. Copyright © 2013 Elsevier Inc. All rights reserved.

Inheritance of electrophysiological responses to leaf saps of host- and nonhost plants in two helicoverpa species and their hybrids

NARCIS (Netherlands)

Tang, Q.B.; Huang, L.Q.; Wang, C.Z.; Tang, Q.B.T.; Zhan, H.; Loon, van J.J.A.

2014-01-01

The polyphagous cotton bollworm Helicoverpa armigera (Hubner) and the oligophagous oriental tobacco budworm Helicoverpa assulta (Guenee) (Lepidoptera: Noctuidae) display contrasting heritable feeding preferences for cotton and pepper leaves. In this study, electrophysiological response patterns to

Electrophysiological assessment of auditory processing disorder in children with non-syndromic cleft lip and/or palate.

Science.gov (United States)

Ma, Xiaoran; McPherson, Bradley; Ma, Lian

2016-01-01

Cleft lip and/or palate is a common congenital craniofacial malformation found worldwide. A frequently associated disorder is conductive hearing loss, and this disorder has been thoroughly investigated in children with non-syndromic cleft lip and/or palate (NSCL/P). However, analysis of auditory processing function is rarely reported for this population, although this issue should not be ignored since abnormal auditory cortical structures have been found in populations with cleft disorders. The present study utilized electrophysiological tests to assess the auditory status of a large group of children with NSCL/P, and investigated whether this group had less robust central auditory processing abilities compared to craniofacially normal children. 146 children with NSCL/P who had normal peripheral hearing thresholds, and 60 craniofacially normal children aged from 6 to 15 years, were recruited. Electrophysiological tests, including auditory brainstem response (ABR), P1-N1-P2 complex, and P300 component recording, were conducted. ABR and N1 wave latencies were significantly prolonged in children with NSCL/P. An atypical developmental trend was found for long latency potentials in children with cleft compared to control group children. Children with unilateral cleft lip and palate showed a greater level of abnormal results compared with other cleft subgroups, whereas the cleft lip subgroup had the most robust responses for all tests. Children with NSCL/P may have slower than normal neural transmission times between the peripheral auditory nerve and brainstem. Possible delayed development of myelination and synaptogenesis may also influence auditory processing function in this population. Present research outcomes were consistent with previous, smaller sample size, electrophysiological studies on infants and children with cleft lip/palate disorders. In view of the these findings, and reports of educational disadvantage associated with cleft disorders, further research

Anatomical and electrophysiological characterization of presumed dopamine-containing neurons within the supramammillary region of the rat.

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Shepard, P D; Mihailoff, G A; German, D C

1988-03-01

A combination of immunocytochemical, electrophysiological and pharmacological techniques were employed to study the properties of neurons within the supramammillary (SUM) complex of the rat. The SUM region contains a small, but dense, population of tyrosine hydroxylase immunoreactive neurons. Following injection of the orthograde neuroanatomical tracer, Phaseolus Vulgaris leucoagglutinin, into the SUM region, heavy terminal labeling was observed in the lateral septal nucleus, diagonal band of Broca and bed nucleus of the stria terminalis. The electrophysiological and pharmacological properties of antidromically-activated SUM neurons revealed evidence of two neuronal populations. Both groups of neurons exhibited long duration action potentials (greater than 2 msec) and slow conduction velocities (less than 0.5 m/sec). However, cells in one group were characterized by slow and erratic firing rates and insensitivity to dopamine (DA) autoreceptor agonists. Cells in the other group typically exhibited no spontaneous activity but could be induced to discharge by iontophoretic application of glutamate. These latter cells were sensitive to DA autoreceptor stimulation. Of the two populations of mammilloseptal SUM neurons, the silent population exhibited several properties similar to those of midbrain DA neurons.

Castration modulates singing patterns and electrophysiological properties of RA projection neurons in adult male zebra finches

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Songhua Wang

2014-04-01

Full Text Available Castration can change levels of plasma testosterone. Androgens such as testosterone play an important role in stabilizing birdsong. The robust nucleus of the arcopallium (RA is an important premotor nucleus critical for singing. In this study, we investigated the effect of castration on singing patterns and electrophysiological properties of projection neurons (PNs in the RA of adult male zebra finches. Adult male zebra finches were castrated and the changes in bird song assessed. We also recorded the electrophysiological changes from RA PNs using patch clamp recording. We found that the plasma levels of testosterone were significantly decreased, song syllable’s entropy was increased and the similarity of motif was decreased after castration. Spontaneous and evoked firing rates, membrane time constants, and membrane capacitance of RA PNs in the castration group were lower than those of the control and the sham groups. Afterhyperpolarization AHP time to peak of spontaneous action potential (AP was prolonged after castration.These findings suggest that castration decreases song stereotypy and excitability of RA PNs in male zebra finches.

Scalable Electrophysiological Investigation of iPS Cell-Derived Cardiomyocytes Obtained by a Lentiviral Purification Strategy

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Stephanie Friedrichs

2015-01-01

Full Text Available Disease-specific induced pluripotent stem (iPS cells can be generated from patients and differentiated into functional cardiomyocytes for characterization of the disease and for drug screening. In order to obtain pure cardiomyocytes for automated electrophysiological investigation, we here report a novel non-clonal purification strategy by using lentiviral gene transfer of a puromycin resistance gene under the control of a cardiac-specific promoter. We have applied this method to our previous reported wild-type and long QT syndrome 3 (LQTS 3-specific mouse iPS cells and obtained a pure cardiomyocyte population. These cells were investigated by action potential analysis with manual and automatic planar patch clamp technologies, as well as by recording extracellular field potentials using a microelectrode array system. Action potentials and field potentials showed the characteristic prolongation at low heart rates in LQTS 3-specific, but not in wild-type iPS cell-derived cardiomyocytes. Hence, LQTS 3-specific cardiomyocytes can be purified from iPS cells with a lentiviral strategy, maintain the hallmarks of the LQTS 3 disease and can be used for automated electrophysiological characterization and drug screening.

Subthalamic nucleus high-frequency stimulation restores altered electrophysiological properties of cortical neurons in parkinsonian rat.

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Bertrand Degos

Full Text Available Electrophysiological recordings performed in parkinsonian patients and animal models have confirmed the occurrence of alterations in firing rate and pattern of basal ganglia neurons, but the outcome of these changes in thalamo-cortical networks remains unclear. Using rats rendered parkinsonian, we investigated, at a cellular level in vivo, the electrophysiological changes induced in the pyramidal cells of the motor cortex by the dopaminergic transmission interruption and further characterized the impact of high-frequency electrical stimulation of the subthalamic nucleus, a procedure alleviating parkinsonian symptoms. We provided evidence that a lesion restricted to the substantia nigra pars compacta resulted in a marked increase in the mean firing rate and bursting pattern of pyramidal neurons of the motor cortex. These alterations were underlain by changes of the electrical membranes properties of pyramidal cells including depolarized resting membrane potential and increased input resistance. The modifications induced by the dopaminergic loss were more pronounced in cortico-striatal than in cortico-subthalamic neurons. Furthermore, subthalamic nucleus high-frequency stimulation applied at parameters alleviating parkinsonian signs regularized the firing pattern of pyramidal cells and restored their electrical membrane properties.

Microfluidic platform for electrophysiological recordings from host-stage hookworm Ascaris suum larvae: a new tool for anthelmenthic research

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The screening of candidate compounds and natural products for anthelmintic activity is a key component of discovering new drugs against human and animal parasites. We previously validated in Caenorhabditis elegans a microfluidic device (‘chip’) that records non-invasively the tiny electrophysiologic...

Multiplexed, high density electrophysiology with nanofabricated neural probes.

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Jiangang Du

Full Text Available Extracellular electrode arrays can reveal the neuronal network correlates of behavior with single-cell, single-spike, and sub-millisecond resolution. However, implantable electrodes are inherently invasive, and efforts to scale up the number and density of recording sites must compromise on device size in order to connect the electrodes. Here, we report on silicon-based neural probes employing nanofabricated, high-density electrical leads. Furthermore, we address the challenge of reading out multichannel data with an application-specific integrated circuit (ASIC performing signal amplification, band-pass filtering, and multiplexing functions. We demonstrate high spatial resolution extracellular measurements with a fully integrated, low noise 64-channel system weighing just 330 mg. The on-chip multiplexers make possible recordings with substantially fewer external wires than the number of input channels. By combining nanofabricated probes with ASICs we have implemented a system for performing large-scale, high-density electrophysiology in small, freely behaving animals that is both minimally invasive and highly scalable.

Electrophysiological and psychophysical correlates of spatial summation to noxious heat: the possible role of A-delta fibers.

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Granovsky, Y; Raz, N; Defrin, R

2017-02-01

Although spatial summation of pain (SSP) is central to the processing of pain intensity and quality, its mechanism is not fully understood. We previously found greater heat SSP in hairy than in glabrous skin, suggesting that perhaps A-mechano-heat II (AMH-II) nociceptors are the dominant subserving system. In order to further explore the role of A-delta fibers in heat-induced SSP, we analyzed the electrophysiological correlates of SSP under conditions that minimize the influence of skin thicknesses. Among 17 subjects, fast rate of rise (70 °C/sec) heat stimuli that induced a pre-fixed, similar, SSP magnitude for hairy and glabrous skin were repeatedly administered using large and small probes, during which time the contact heat-evoked potentials (CHEPs) and pain ratings were recorded. Both N2 and P2 amplitudes were larger in hairy than in glabrous skin, but a differential effect of SSP was found on the CHEPs. Despite similar psychophysical SSP in hairy and glabrous skin, the electrophysiological SSP reflected in N2 but not P2 amplitude was larger in hairy skin. Nevertheless, regardless of skin type, SSP was manifested by an increase in P2 amplitudes. Considering the uniform psychophysical SSP for the two skin types, the fast stimulation rate and lower activity of AMH-II in glabrous skin, a greater electrophysiological SSP in hairy than in glabrous skin may suggest that SSP is mainly subserved by AMH nociceptors. The overall SSP effect, manifested in greater P2 amplitude, may reflect specific brain responses aimed to prepare the individual to an increased potential tissue damage.

Electrophysiological and Morphological Properties of α and γ Motoneurons in the Rat Trigeminal Motor Nucleus

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Kayo Nishimura

2018-01-01

Full Text Available The muscle contraction during voluntary movement is regulated by activities of α- and γ-motoneurons (αMNs and γMNs, respectively. The tension of jaw-closing muscles can be finely tuned over a wide range. This excellent function is likely to be achieved by the specific populations of αMNs innervating jaw-closing muscles. Indeed, we have recently demonstrated that in the rat dorsolateral trigeminal motor nucleus (dl-TMN, the size distribution of αMNs was bimodal and the population of smaller αMNs showed a size distribution similar to that of γMNs, by immunohistochemically identifying αMNs and γMNs based on the expressions of estrogen-related receptor gamma (Err3 and neuronal DNA binding protein NeuN together with ChAT. This finding suggests the presence of αMNs as small as γMNs. However, differences in the electrophysiological membrane properties between αMNs and γMNs remain unknown also in the dl-TMN. Therefore, in the present study, we studied the electrophysiological membrane properties of MNs in the dl-TMN of infant rats at postnatal days 7–12 together with their morphological properties using whole-cell current-clamp recordings followed by immunohistochemical staining with an anti-NeuN and anti-ChAT antibodies. We found that the ChAT-positive and NeuN-positive αMNs were divided into two subclasses: the first one had a larger cell body and displayed a 4-aminopyridine (4-AP-sensitive current while the second one had a smaller cell body and displayed a less prominent 4-AP-sensitive current and a low-threshold spike, suitable for their orderly recruitment. We finally found that γMNs showing ChAT-positive and NeuN-negative immunoreactivities had smaller cell bodies and displayed an afterdepolarization mediated by flufenamate-sensitive cation current. It is suggested that these electrophysiological and morphological features of MNs in the dl-TMN are well correlated with the precise control of occlusion.

Radiologic Monitoring of Faculty and Staff in an Electrophysiology Lab Using a Real-Time Dose Monitoring System

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Chardenet, Kathleen A.

2016-01-01

Purpose: A real-time dose management system was used to determine if radiation exposure levels would decrease when providers were privy to their real-time radiation exposure levels. Six aggregate categories of providers were first blinded (phase 1) and subsequently made aware of their radiation exposure levels during electrophysiology procedures…

Developing Oral Case Presentation Skills: Peer and Self-Evaluations as Instructional Tools.

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Williams, Dustyn E; Surakanti, Shravani

2016-01-01

Oral case presentation is an essential skill in clinical practice that is decidedly varied and understudied in teaching curricula. We developed a curriculum to improve oral case presentation skills in medical students. As part of an internal medicine clerkship, students receive instruction in the elements of a good oral case presentation and then present a real-world case in front of a video camera. Each student self-evaluates his/her presentation and receives evaluations from his/her peers. We expect peer and self-evaluation to be meaningful tools for developing skills in oral presentation. We hope to not only improve the quality of oral case presentations by students but also to reduce the time burden on faculty.

Evaluation of cases with Fasciola hepatica infection: experience in 6 children

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Hasan Tezer

2013-06-01

Full Text Available Objective: To evaluate 6 pediatric cases diagnosed as fascioliasis. Methods: Patients diagnosed as fascioliasis are retrospectively interpreted. Results: Herein 6 pediatric cases having a mean age of (12.7±3.1 years with different complaints including fever, weakness, paleness, sweating, cough, headache, rectal bleeding, abdominal pain, and abdominal distension admitting to our hospital are evaluated. Conclusions: Diagnosis of fascioliasis needs a high index of suspicion supported by stool microscopy, serology, imaging procedures, and in difficult cases even liver biopsy. Triclabendazole resistance should be kept in mind in unresponsive cases.

Animal electricity and the birth of electrophysiology: the legacy of Luigi Galvani.

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Piccolino, M

1998-07-15

Preceded by a companion paper on Galvani's life, this article is written on the occasion of the bicentenary of the death of Luigi Galvani. From his studies on the effects of electricity on frogs, the scientist of Bologna derived the hypothesis that animal tissues are endowed with an intrinsic electricity that is involved in fundamental physiological processes such as nerve conduction and muscle contraction. Galvani's work swept away from life sciences mysterious fluids and elusive entities like "animal spirits" and led to the foundation of a new science, electrophysiology. Two centuries of research work have demonstrated how insightful was Galvani's conception of animal electricity. Nevertheless, the scholar of Bologna is still largely misrepresented in the history of science, because the importance of his researches seems to be limited to the fact that they opened the paths to the studies of the physicist Alessandro Volta, which culminated in 1800 with the invention of the electric battery. Volta strongly opposed Galvani's theories on animal electricity. The matter of the scientific controversy between Galvani and Volta is examined here in the light of two centuries of electrophysiological studies leading to the modern understanding of electrical excitability in nerve and muscle. By surveying the work of scientists such as Nobili, Matteucci, du Bois-Reymond, von Helmholtz, Bernstein, Hermann, Lucas, Adrian, Hodgkin, Huxley, and Katz, the real matter of the debate raised by Galvani's discoveries is here reconsidered. In addition, a revolutionary phase of the 18th century science that opened the way for the development of modern neurosciences is reevaluated.

The evaluation of forensic cases reported due to food poisoning

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Beyza Urazel

2014-03-01

Full Text Available Objective: In this study it is aimed to examine forensic food poisoning cases and to evaluate the clinical presentation of food poisoning in people within the context of forensic medicine. Methods: In the study, 215 food poisoning cases are evaluated, which applied to the forensic medicine branch office in our city between 01.01.2007 and 31.12.2011. The forensic reports and forensic investigations of these cases are analyzed retrospectively. The cases are examined in terms of gender, age, the type of food consumed, the treatment applied and the result of the forensic report. Results: It is determined that in 83 cases (38.6% food poisoning was caused by chicken products, and in 178 cases (82.8% the poisoned people were students. In 3 cases (1.4% the poisoning was life threatening. For 75 cases (34.9% no forensic report was prepared in emergency service and among the 140 cases for which a forensic report was prepared, only 3 of the reports were prepared in a correct manner. Conclusions: It is determined that the demographic data of the cases complies with the city where the study was conducted. It is found out that in emergency services the food poisoning cases are usually misevaluated.

Diagnostic investigation of patients with chronic polyneuropathy: evaluation of a clinical guideline

NARCIS (Netherlands)

Rosenberg, N. R.; Portegies, P.; de Visser, M.; Vermeulen, M.

2001-01-01

OBJECTIVE: (1) To evaluate a clinical guideline for the diagnostic investigation of patients presenting with signs and symptoms (present for longer than 6 weeks) suggesting a chronic polyneuropathy. (2) To investigate the contribution of electrophysiological studies to a focused search for aetiology

Characterization of the in vitro propagation of epileptiform electrophysiological activity in organotypic hippocampal slice cultures coupled to 3D microelectrode arrays

DEFF Research Database (Denmark)

Pisciotta, Marzia; Morgavi, Giovanna; Jahnsen, Henrik

2010-01-01

Dynamic aspects of the propagation of epileptiform activity have so far received little attention. With the aim of providing new insights about the spatial features of the propagation of epileptic seizures in the nervous system, we studied in vitro the initiation and propagation of traveling...... activity are completely coherent with respect to the activity originating in the CA3, while components at higher frequencies lose the coherence, possibly suggesting that the cellular mechanism mediating propagation of electrophysiological activity becomes ineffective for those firing rates exceeding...... epileptiform waves of electrophysiological activity in the hippocampus by means of substrate three-dimensional microelectrode arrays (MEAs) for extracellular measurements. Pharmacologically disinhibited hippocampal slices spontaneously generate epileptiform bursts mostly originating in CA3 and propagating...

Collaboration, communication and categorical complexity: A case study in collaboratory evaluation

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Cleal, B.R.; Andersen, H.H.K.; Albrechtsen, H.

2004-01-01

This article presents findings from an empirical evaluation of a collaboratory supporting film research. Few collaboratories have been formally evaluated. The article makes a case for looking at wider work-based contexts users engage in. Focussing on key features of the prototype system, it is sh......This article presents findings from an empirical evaluation of a collaboratory supporting film research. Few collaboratories have been formally evaluated. The article makes a case for looking at wider work-based contexts users engage in. Focussing on key features of the prototype system...

Electrophysiology and optical coherence tomography to evaluate Parkinson disease severity.

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Garcia-Martin, Elena; Rodriguez-Mena, Diego; Satue, Maria; Almarcegui, Carmen; Dolz, Isabel; Alarcia, Raquel; Seral, Maria; Polo, Vicente; Larrosa, Jose M; Pablo, Luis E

2014-02-04

To evaluate correlations between visual evoked potentials (VEP), pattern electroretinogram (PERG), and macular and retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) and the severity of Parkinson disease (PD). Forty-six PD patients and 33 age and sex-matched healthy controls were enrolled, and underwent VEP, PERG, and OCT measurements of macular and RNFL thicknesses, and evaluation of PD severity using the Hoehn and Yahr scale to measure PD symptom progression, the Schwab and England Activities of Daily Living Scale (SE-ADL) to evaluate patient quality of life (QOL), and disease duration. Logistical regression was performed to analyze which measures, if any, could predict PD symptom progression or effect on QOL. Visual functional parameters (best corrected visual acuity, mean deviation of visual field, PERG positive (P) component at 50 ms -P50- and negative (N) component at 95 ms -N95- component amplitude, and PERG P50 component latency) and structural parameters (OCT measurements of RNFL and retinal thickness) were decreased in PD patients compared with healthy controls. OCT measurements were significantly negatively correlated with the Hoehn and Yahr scale, and significantly positively correlated with the SE-ADL scale. Based on logistical regression analysis, fovea thickness provided by OCT equipment predicted PD severity, and QOL and amplitude of the PERG N95 component predicted a lower SE-ADL score. Patients with greater damage in the RNFL tend to have lower QOL and more severe PD symptoms. Foveal thicknesses and the PERG N95 component provide good biomarkers for predicting QOL and disease severity.

The Electrophysiological Signature of Remember-Know Is Confounded with Memory Strength and Cannot Be Interpreted as Evidence for Dual-process Theory of Recognition.

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Brezis, Noam; Bronfman, Zohar Z; Yovel, Galit; Goshen-Gottstein, Yonatan

2017-02-01

The quantity and nature of the processes underlying recognition memory remains an open question. A majority of behavioral, neuropsychological, and brain studies have suggested that recognition memory is supported by two dissociable processes: recollection and familiarity. It has been conversely argued, however, that recollection and familiarity map onto a single continuum of mnemonic strength and hence that recognition memory is mediated by a single process. Previous electrophysiological studies found marked dissociations between recollection and familiarity, which have been widely held as corroborating the dual-process account. However, it remains unknown whether a strength interpretation can likewise apply for these findings. Here we describe an ERP study, using a modified remember-know (RK) procedure, which allowed us to control for mnemonic strength. We find that ERPs of high and low mnemonic strength mimicked the electrophysiological distinction between R and K responses, in a lateral positive component (LPC), 500-1000 msec poststimulus onset. Critically, when contrasting strength with RK experience, by comparing weak R to strong K responses, the electrophysiological signal mapped onto strength, not onto subjective RK experience. Invoking the LPC as support for dual-process accounts may, therefore, be amiss.

Electrophysiological resting-state biomarker for diagnosing mesial temporal lobe epilepsy with hippocampal sclerosis.

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Jin, Seung-Hyun; Chung, Chun Kee

2017-01-01

The main aim of the present study was to evaluate whether resting-state functional connectivity of magnetoencephalography (MEG) signals can differentiate patients with mesial temporal lobe epilepsy (MTLE) from healthy controls (HC) and can differentiate between right and left MTLE as a diagnostic biomarker. To this end, a support vector machine (SVM) method among various machine learning algorithms was employed. We compared resting-state functional networks between 46 MTLE (right MTLE=23; left MTLE=23) patients with histologically proven HS who were free of seizure after surgery, and 46 HC. The optimal SVM group classifier distinguished MTLE patients with a mean accuracy of 95.1% (sensitivity=95.8%; specificity=94.3%). Increased connectivity including the right posterior cingulate gyrus and decreased connectivity including at least one sensory-related resting-state network were key features reflecting the differences between MTLE patients and HC. The optimal SVM model distinguished between right and left MTLE patients with a mean accuracy of 76.2% (sensitivity=76.0%; specificity=76.5%). We showed the potential of electrophysiological resting-state functional connectivity, which reflects brain network reorganization in MTLE patients, as a possible diagnostic biomarker to differentiate MTLE patients from HC and differentiate between right and left MTLE patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrophysiological explorations of the bilingual advantage: evidence from a Stroop task.

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Coderre, Emily L; van Heuven, Walter J B

2014-01-01

Bilinguals have been shown to exhibit a performance advantage on executive control tasks, outperforming their monolingual counterparts. Although a wealth of research has investigated this 'bilingual advantage' behaviourally, electrophysiological correlates are lacking. Using EEG with a Stroop task that manipulated the stimulus onset asynchrony (SOA) of word and colour presentation, the current study addressed two facets of the bilingual advantage. The possibility that bilinguals experience superior conflict processing relative to monolinguals (a 'conflict-specific advantage') was investigated by comparing behavioural interference effects as well as the amplitude of the Ninc, a conflict-related ERP component occurring from approximately 300-500 ms after the onset of conflict. In contrast, the hypothesis that bilinguals experience domain-general, conflict-independent enhancements in executive processing (a 'non-conflict-specific advantage') was evaluated by comparing the control condition (symbol strings) between groups. There was some significant, but inconsistent, evidence for a conflict-specific bilingual advantage. In contrast, strong evidence emerged for a non-conflict-specific advantage, with bilinguals demonstrating faster RTs and reduced ERP amplitudes on control trials compared to monolinguals. Importantly, when the control stimulus was presented before the colour, ERPs to control trials revealed group differences before the onset of conflict, suggesting differences in the ability to ignore or suppress distracting irrelevant information. This indicates that bilinguals experience superior executive processing even in the absence of conflict and semantic salience, and suggests that the advantage extends to more efficient proactive management of the environment.

Electrophysiological explorations of the bilingual advantage: evidence from a Stroop task.

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Emily L Coderre

Full Text Available Bilinguals have been shown to exhibit a performance advantage on executive control tasks, outperforming their monolingual counterparts. Although a wealth of research has investigated this 'bilingual advantage' behaviourally, electrophysiological correlates are lacking. Using EEG with a Stroop task that manipulated the stimulus onset asynchrony (SOA of word and colour presentation, the current study addressed two facets of the bilingual advantage. The possibility that bilinguals experience superior conflict processing relative to monolinguals (a 'conflict-specific advantage' was investigated by comparing behavioural interference effects as well as the amplitude of the Ninc, a conflict-related ERP component occurring from approximately 300-500 ms after the onset of conflict. In contrast, the hypothesis that bilinguals experience domain-general, conflict-independent enhancements in executive processing (a 'non-conflict-specific advantage' was evaluated by comparing the control condition (symbol strings between groups. There was some significant, but inconsistent, evidence for a conflict-specific bilingual advantage. In contrast, strong evidence emerged for a non-conflict-specific advantage, with bilinguals demonstrating faster RTs and reduced ERP amplitudes on control trials compared to monolinguals. Importantly, when the control stimulus was presented before the colour, ERPs to control trials revealed group differences before the onset of conflict, suggesting differences in the ability to ignore or suppress distracting irrelevant information. This indicates that bilinguals experience superior executive processing even in the absence of conflict and semantic salience, and suggests that the advantage extends to more efficient proactive management of the environment.

A Wireless Headstage for Combined Optogenetics and Multichannel Electrophysiological Recording.

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Gagnon-Turcotte, Gabriel; LeChasseur, Yoan; Bories, Cyril; Messaddeq, Younes; De Koninck, Yves; Gosselin, Benoit

2017-02-01

This paper presents a wireless headstage with real-time spike detection and data compression for combined optogenetics and multichannel electrophysiological recording. The proposed headstage, which is intended to perform both optical stimulation and electrophysiological recordings simultaneously in freely moving transgenic rodents, is entirely built with commercial off-the-shelf components, and includes 32 recording channels and 32 optical stimulation channels. It can detect, compress and transmit full action potential waveforms over 32 channels in parallel and in real time using an embedded digital signal processor based on a low-power field programmable gate array and a Microblaze microprocessor softcore. Such a processor implements a complete digital spike detector featuring a novel adaptive threshold based on a Sigma-delta control loop, and a wavelet data compression module using a new dynamic coefficient re-quantization technique achieving large compression ratios with higher signal quality. Simultaneous optical stimulation and recording have been performed in-vivo using an optrode featuring 8 microelectrodes and 1 implantable fiber coupled to a 465-nm LED, in the somatosensory cortex and the Hippocampus of a transgenic mouse expressing ChannelRhodospin (Thy1::ChR2-YFP line 4) under anesthetized conditions. Experimental results show that the proposed headstage can trigger neuron activity while collecting, detecting and compressing single cell microvolt amplitude activity from multiple channels in parallel while achieving overall compression ratios above 500. This is the first reported high-channel count wireless optogenetic device providing simultaneous optical stimulation and recording. Measured characteristics show that the proposed headstage can achieve up to 100% of true positive detection rate for signal-to-noise ratio (SNR) down to 15 dB, while achieving up to 97.28% at SNR as low as 5 dB. The implemented prototype features a lifespan of up to 105

Electrophysiological Monitoring of Injury ProgressionIn the Rat Cerebellar Cortex

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Gokhan eOrdek

2014-10-01

Full Text Available The changes of excitability in affected neural networks can be used as a marker to study the temporal course of traumatic brain injury (TBI. The cerebellum is an ideal platform to study brain injury mechanisms at the network level using the electrophysiological methods. Within its crystalline morphology, the cerebellar cortex contains highly organized topographical subunits that are defined by two main inputs, the climbing and mossy fibers. Here we demonstrate the use of cerebellar evoked potentials (EPs mediated through these afferent systems for monitoring the injury progression in a rat model of fluid percussion injury (FPI. A mechanical tap on the dorsal hand was used as a stimulus, and EPs were recorded from the paramedian lobule (PML of the posterior cerebellum via multi-electrode arrays (MEA. Post-injury evoked response amplitudes (EPAs were analyzed on a daily basis for one week and compared with pre-injury values. We found a trend of consistently decreasing EPAs in all nine animals, losing as much as 72±4% of baseline amplitudes measured before the injury. Notably, our results highlighted two particular time windows; the first 24 hours of injury in the acute period and day-3 to day-7 in the delayed period where the largest drops (~50% and 24% were observed in the EPAs. In addition, cross-correlations of spontaneous signals between electrode pairs declined (from 0.47±0.1 to 0.35±0.04, p<0.001 along with the EPAs throughout the week of injury. In support of the electrophysiological findings, immunohistochemical analysis at day-7 post-injury showed detectable Purkinje cell loss at low FPI pressures and more with the largest pressures used. Our results suggest that sensory evoked potentials recorded from the cerebellar surface can be a useful technique to monitor the course of cerebellar injury and identify the phases of injury progression even at mild levels.

Electrophysiological and pharmacological evidence for the existence of distinct subpopulations of nigrostriatal dopaminergic neuron in the rat.

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Shepard, P D; German, D C

1988-11-01

The electrophysiological and pharmacological properties of dopaminergic neurons were systematically examined throughout the anterior-posterior extent of the substantia nigra zona compacta in the rat. Cells were characterized in terms of their (1) firing pattern, (2) firing rate, (3) antidromic response properties, and (4) inhibition in firing rate following dopaminergic agonist administration. These properties were then related to the cell's position within one of four anterior-posterior segments of the nucleus. There were three types of neuronal discharge pattern encountered; irregular, burst and regular. Cells which exhibited different firing patterns exhibited different firing rates and anatomical locations within the substantia nigra zona compacta. All neurons were antidromically activated from the striatum, however, the burst- and regular-firing cells exhibited significantly faster estimated conduction velocities than irregular-firing cells. The irregular-firing cells were most sensitive to dopaminergic autoreceptor agonists whereas the burst-firing cells were most sensitive to an indirect-acting dopaminergic agonist. These experiments provide both electrophysiological and pharmacological evidence to indicate that nigrostriatal dopaminergic neurons are composed of distinct subpopulations which are characterized by their firing pattern.

Radiation exposure of an anaesthesiologist in catheterisation and electrophysiological cardiac procedures

International Nuclear Information System (INIS)

Andreoli, Stefano; Moretti, Renzo; Lorini, Ferdinando Luca; Lagrotta, Mariavittoria

2016-01-01

Sometimes, cardiac catheterisation and electrophysiological procedures, diagnostic and interventional, require an anaesthesiological support. The anaesthesiologist receives radiation doses depending on various factors, such as type of procedure and exposure modality, anaesthesiological technique, individual protective devices and operator experience. The aim of this study was to investigate the dose per procedure, the exposure inhomogeneity and the effective dose, E, of a senior anaesthesiologist in the haemodynamic laboratory of Ospedali Riuniti, Bergamo. The dose monitoring was routinely performed with sets of several thermoluminescent dosemeters and an electronic personal dosemeter. The study covered 300 consecutive procedures over 1 y. The anaesthesiologist wore a protective apron, a thyroid collar and glasses (0.5 mm lead-equivalent). (authors)

Chronic cranial window with access port for repeated cellular manipulations, drug application, and electrophysiology

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Christopher Joel Roome

2014-11-01

Full Text Available Chronic cranial windows have been instrumental in advancing optical studies in vivo, permitting long-term, high-resolution imaging in various brain regions. However, once a window is attached it is difficult to regain access to the brain under the window for cellular manipulations. Here we describe a simple device that combines long term in vivo optical imaging with direct brain access via glass or quartz pipettes and metal, glass, or quartz electrodes for cellular manipulations like dye or drug injections and electrophysiological stimulations or recordings while keeping the craniotomy sterile. Our device comprises a regular cranial window glass coverslip with a drilled access hole later sealed with biocompatible silicone. This chronic cranial window with access port is cheap, easy to manufacture, can be mounted just as the regular chronic cranial window, and is self-sealing after retraction of the pipette or electrode. We demonstrate that multiple injections can be performed through the silicone port by repetitively bolus loading calcium sensitive dye into mouse barrel cortex and recording spontaneous cellular activity over a period of weeks. As an example to the extent of its utility for electrophysiological recording, we describe how simple removal of the silicone seal can permit patch pipette access for whole-cell patch clamp recordings in vivo. During these chronic experiments we do not observe any infections under the window or impairment of animal health.

BRUGADA SYNDROME-A CASE REPORT

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Kuževska-Maneva Konstandina

2016-03-01

Full Text Available Brugada syndrome is a type of arrhythmia disorder, which is characterised by abnormal electrocardiogram (ECG findings and an increased risk of sudden cardiac death. The most frequent sign is a persistent ST elevation in the electrocardiographic leads V1-V3 with a right bundle branch block (RBBB.We present a case of 12 years old healthy child, without any complains until then. He had 2 episodes of collapse/syncope, which lasted long and spontaneously disappeared. The collapses were provoked by physical activity. On ECG we found sinus rhythm 62 bpm, RBBB (right bundle brunch block and Brugada signs in V2 and V3 channel-ST elevation ≥ 2mm. The child was sent in electrophysiological centre abroad where the electrophysiological study was performed. They did not found any accessory pathway. The atrioventricular (AV conduction was normal. Long lasting polymorphic ventricular tachycardia/fibrillation was induced with programed stimulation with 3 extrastimuli in right ventricular outflow tract. Performing one defibrillation the rhythm turned in sinus way. Then they performed ECG with translocation of electrodes V1-3 in 2nd intercostal space and the Brugada I type findings was discovered. After confirming of presence of Brugada type -1 syndrome the implantable cardioverter- defibrillator (ICD was applied on child heart.

Haloacetate analogs of pheromones: Effects on catabolism and electrophysiology inPlutella xylostella.

Science.gov (United States)

Prestwich, G D; Streinz, L

1988-03-01

A series of mono-, di-, and trihalogenated acetate analogs of Zl 1-16: Ac were prepared and examined for electrophysiological activity in antennae of males of the diamondback moth,Plutella xylostella. In addition, two potential affinity labels, a diazoacetate (Dza) and a trifluoromethyl ketone (Tfp), were evaluated for EAG activity. The Z11-16∶Ac showed the highest activity in EAG assays, followed by the fluorinated acetates, but other halo-acetates were essentially inactive. The polar diazoacetate and the trifluoromethyl ketone were also very weak EAG stimulants. The effects of these analogs on the hydrolysis of [(3)H]Z11-16∶Ac to [(3)H]Z11-16∶OH by antennal esterases was also examined. The three fluorinated acetates showed the greatest activity as inhibitors in competition assays, with rank order F2Ac > F(3)Ac > FAc > Ac > Cl2Ac > ClAc > Dza > Br2Ac > BrAc > Tfp > I > Cl3Ac > Br3Ac > OH. The relative polarities of the haloacetates, as determined by TLC mobility, are in the order mono- > di- > trihalo, but F, Cl, Br, and I all confer similar polarities within a substitution group. Thus, the steric size appears to be the predominant parameter affecting the interactions of the haloacetate analogs with both receptor and catabolic proteins inP. xylostella males.

Electrophysiologic studies of the thoracic limb of the horse.

Science.gov (United States)

Blythe, L L; Kitchell, R L

1982-09-01

The cutaneous innervation of the thoracic limb was investigated in 18 barbiturate-anesthetized horses, using electrophysiologic techniques. The cutaneous area (CA) innervated by each cutaneous nerve was delineated in at least 4 horses by stroking the hairs with a small watercolor brush while recording from the nerve. Mapping of adjacent CA revealed areas of considerable overlap. The part of a CA of a given nerve supplied only by that nerve is referred to as its autonomous zone (AZ). In contrast to the standard textbook illustrations cutaneous branches of the axillary, radial, musculocutaneous, and ulnar nerves overlapped extensively in the antebrachium. Clinically testable AZ were found in the antebrachium for the caudal cutaneous antebrachial nerve of the ulnar nerve and in the carpus and manus for the cutaneous branches of the median, ulnar, and musculocutaneous nerves; AZ were not found for the cutaneous branches of the radial and axillary nerves.

Extracellular Electrophysiological Measurements of Cooperative Signals in Astrocytes Populations

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Mestre, Ana L. G.; Inácio, Pedro M. C.; Elamine, Youssef; Asgarifar, Sanaz; Lourenço, Ana S.; Cristiano, Maria L. S.; Aguiar, Paulo; Medeiros, Maria C. R.; Araújo, Inês M.; Ventura, João; Gomes, Henrique L.

2017-01-01

Astrocytes are neuroglial cells that exhibit functional electrical properties sensitive to neuronal activity and capable of modulating neurotransmission. Thus, electrophysiological recordings of astroglial activity are very attractive to study the dynamics of glial signaling. This contribution reports on the use of ultra-sensitive planar electrodes combined with low noise and low frequency amplifiers that enable the detection of extracellular signals produced by primary cultures of astrocytes isolated from mouse cerebral cortex. Recorded activity is characterized by spontaneous bursts comprised of discrete signals with pronounced changes on the signal rate and amplitude. Weak and sporadic signals become synchronized and evolve with time to higher amplitude signals with a quasi-periodic behavior, revealing a cooperative signaling process. The methodology presented herewith enables the study of ionic fluctuations of population of cells, complementing the single cells observation by calcium imaging as well as by patch-clamp techniques. PMID:29109679

Closed Loop Experiment Manager (CLEM—An Open and Inexpensive Solution for Multichannel Electrophysiological Recordings and Closed Loop Experiments

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Hananel Hazan

2017-10-01

Full Text Available There is growing need for multichannel electrophysiological systems that record from and interact with neuronal systems in near real-time. Such systems are needed, for example, for closed loop, multichannel electrophysiological/optogenetic experimentation in vivo and in a variety of other neuronal preparations, or for developing and testing neuro-prosthetic devices, to name a few. Furthermore, there is a need for such systems to be inexpensive, reliable, user friendly, easy to set-up, open and expandable, and possess long life cycles in face of rapidly changing computing environments. Finally, they should provide powerful, yet reasonably easy to implement facilities for developing closed-loop protocols for interacting with neuronal systems. Here, we survey commercial and open source systems that address these needs to varying degrees. We then present our own solution, which we refer to as Closed Loop Experiments Manager (CLEM. CLEM is an open source, soft real-time, Microsoft Windows desktop application that is based on a single generic personal computer (PC and an inexpensive, general-purpose data acquisition board. CLEM provides a fully functional, user-friendly graphical interface, possesses facilities for recording, presenting and logging electrophysiological data from up to 64 analog channels, and facilities for controlling external devices, such as stimulators, through digital and analog interfaces. Importantly, it includes facilities for running closed-loop protocols written in any programming language that can generate dynamic link libraries (DLLs. We describe the application, its architecture and facilities. We then demonstrate, using networks of cortical neurons growing on multielectrode arrays (MEA that despite its reliance on generic hardware, its performance is appropriate for flexible, closed-loop experimentation at the neuronal network level.

NeuroChip: a microfluidic electrophysiological device for genetic and chemical biology screening of Caenorhabditis elegans adult and larvae.

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Chunxiao Hu

Full Text Available Genetic and chemical biology screens of C. elegans have been of enormous benefit in providing fundamental insight into neural function and neuroactive drugs. Recently the exploitation of microfluidic devices has added greater power to this experimental approach providing more discrete and higher throughput phenotypic analysis of neural systems. Here we make a significant addition to this repertoire through the design of a semi-automated microfluidic device, NeuroChip, which has been optimised for selecting worms based on the electrophysiological features of the pharyngeal neural network. We demonstrate this device has the capability to sort mutant from wild-type worms based on high definition extracellular electrophysiological recordings. NeuroChip resolves discrete differences in excitatory, inhibitory and neuromodulatory components of the neural network from individual animals. Worms may be fed into the device consecutively from a reservoir and recovered unharmed. It combines microfluidics with integrated electrode recording for sequential trapping, restraining, recording, releasing and recovering of C. elegans. Thus mutant worms may be selected, recovered and propagated enabling mutagenesis screens based on an electrophysiological phenotype. Drugs may be rapidly applied during the recording thus permitting compound screening. For toxicology, this analysis can provide a precise description of sub-lethal effects on neural function. The chamber has been modified to accommodate L2 larval stages showing applicability for small size nematodes including parasitic species which otherwise are not tractable to this experimental approach. We also combine NeuroChip with optogenetics for targeted interrogation of the function of the neural circuit. NeuroChip thus adds a new tool for exploitation of C. elegans and has applications in neurogenetics, drug discovery and neurotoxicology.

Retrospective evaluation of childhood alopecia areata cases

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Munise Daye

2013-09-01

Full Text Available Background and design: Approximately 20% of alopecia areata (AA cases are children. There is limited information about childhood AA.We aimed to examine demographic features,treatments and diseases prognosis of child cases of AA that were followed in our clinic. Material and methods: Datas of 110 AA patients who are 16 and under 16 years old were examined retrospectively.The age,gender,disease onset age,duration of disease,types of AA and onset area,nail involvement, accompanying systemic and dermatological diseases,laboratory tests,treatments and the prognosis were evaluated in their follow-up time.Results: Female cases were 46,4%, male cases were 53,6%.The mean age was 10,35 years.The age of disease onset was 8,65 years.Primary onset areas of AA cases were scalp in 83,6%, eyebrows in 5,4%, body hair in 5,4%, eyelashes in 2,7%, eyebrows and eyelashes in 2,7%.Types of disease were AA in 73,4% cases,alopecia totalis in 19% cases, alopecia universalis in 5,4% cases,ophiaisis in 1,8% cases.Nail involvement was established in 36,3% cases. Nevus flammeus was established in 2,7% cases.Mean disease duration was 17,02 months.Accompaying dermatosis were vitiligo in 2,7% cases,atopic dermatitis in 6,3% cases. The accompaying systemic diseases were autoimmune thyroiditis in 1,8% cases and Down's Syndrome in 2,7% cases.Thyroid autoantibodies were high in 0,9% cases.We have treated 24,5% of cases with topical corticosteroid lotion, 30,9% of cases with anthralin, 0,9%of cases with 2% minoxidil lotion, 0,9% of cases with calcipotriol lotion, 1,8% of cases with topical calcineurin inhibitors, 10% of cases with intralesional corticosteroids.We have treated 15,4% of cases with systemic corticosteroids and PUVA therapy who were resistant to topical treatment.We have treated 14,5% of cases with different combinations of topical treatments.Remission was observed in 34,5% of cases.The mean remission duration was 12.2 months.Relapse was observed at a average of two

Clinical, neuropsychological, and pre-stimulus dorsomedial thalamic nucleus electrophysiological data in deep brain stimulation patients

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Catherine M. Sweeney-Reed

2016-09-01

Full Text Available The data presented here comprise clinical, neuropsychological, and intrathalamic electrophysiological data from 7 patients with pharmacoresistant focal epilepsy and are related to the article “Pre-stimulus thalamic theta power predicts human memory formation” C.M. Sweeney-Reed, T. Zaehle, J. Voges, F.C. Schmitt, L. Buentjen, K. Kopitzki, et al. (2016 [1]. The patients participated in a memory paradigm after receiving electrodes implanted in the DMTN due to the surgical approach taken in electrode insertion for deep brain stimulation of the anterior thalamic nucleus. Epilepsy duration and pre-operative neuropsychological tests provide an indication of the profile of patients receiving intrathalamic electrode implantation and the memory capabilities in such a patient group. The electrophysiological data were recorded from the right DMTN preceding stimulus presentation during intentional memory encoding. The patients viewed a series of photographic scenes, which they judged as indoors or outdoors. The 900 ms epochs prior to stimulus presentation were labeled as preceding successful or unsuccessful subsequent memory formation according to a subsequent memory test for the items. The difference between theta power preceding successful versus unsuccessful subsequent memory formation is shown against time for each patient individually. Keywords: Memory encoding, Dorsomedial thalamic nucleus, Pre-stimulus theta

A Case Of Infectious Mononucleosis With Acute Inflammatory Demyelinating Polyradiculoneuropathy

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Somani S K

2003-01-01

Full Text Available We report a case of Acute inflammatory demyelinating polyradiculo neuropathy (AIDP, following infectious mononucleosis. A 12 year old girl presented with acute flaccid quadriplegia with bilateral cervical lymphadenopathy and enlarged tonsils six weeks after a febrile illness. Cerebrospinal fluid revealed albuminocytological dissociation and electrophysiology showed evidence of axonal-demyelinating polyradiculoneuropathy. Heterophile antibody test was positive and lymph node biopsy showed non -specific reactive hyperplasia. She was managed conservatively with good outcome.

Student Evaluation of Teaching: A Case Study from School of ...

African Journals Online (AJOL)

Purpose: This paper presents a case study of an academic department's experience with evaluation. The purpose is to review the impact of student evaluation of teaching. The paper also introduces a new evaluation scoring method: the University of Zambia Staff Appraisal System (UNZASAS) method. Method: Anonymous ...

Characterization and Evaluation of Neuronal Trans-Differentiation with Electrophysiological Properties of Mesenchymal Stem Cells Isolated from Porcine Endometrium

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Raghavendra Baregundi Subbarao

2015-05-01

Full Text Available Endometrial stromal cells (EMSCs obtained from porcine uterus (n = 6 were positive for mesenchymal stem cell markers (CD29, CD44 and CD90, and negative for epithelial marker CD9 and hematopoietic markers CD34, CD45 analyzed by flow cytometry. Further the cells were positive for expression of mesenchymal markers, CD105, CD140b, and CD144 by PCR. Pluripotent markers OCT4, SOX2, and NANOG were positively expressed in EMSCs analyzed by Western blotting and PCR. Further, differentiation into adipocytes and osteocytes was confirmed by cytochemical staining and lineage specific gene expression by quantitative realtime-PCR. Adipocyte (FABP, LPL, AP2 and osteocyte specific genes (ON, BG, RUNX2 in differentiated EMSCs showed significant (p < 0.05 increase in expression compared to undifferentiated control cells. Neurogenic transdifferentiation of EMSCs exhibited distinctive dendritic morphology with axon projections and neuronal specific genes, NFM, NGF, MBP, NES, B3T and MAP2 and proteins, B3T, NFM, NGF, and TRKA were positively expressed in neuronal differentiated cells. Functional analysis of neuronal differentiated EMSCs displayed voltage-dependence and kinetics for transient outward K+ currents (Ito, at holding potential of −80 mV, Na+ currents and during current clamp, neuronal differentiated EMSCs was more negative than that of control EMSCs. Porcine EMSCs is a suitable model for studying molecular mechanism of transdifferentiation, assessment of electrophysiological properties and their efficiency during in vivo transplantation.

Distribution of extracellular potassium and electrophysiologic changes during two-stage coronary ligation in the isolated, perfused canine heart

NARCIS (Netherlands)

Coronel, R.; Fiolet, J. W.; Wilms-Schopman, J. G.; Opthof, T.; Schaapherder, A. F.; Janse, M. J.

1989-01-01

We studied the relation between [K+]o and the electrophysiologic changes during a "Harris two-stage ligation," which is an occlusion of a coronary artery, preceded by a 30-minute period of 50% reduction of flow through the artery. This two-stage ligation has been reported to be antiarrhythmic. Local

Electrophysiological Correlates of Semantic Dissimilarity Reflect the Comprehension of Natural, Narrative Speech.

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Broderick, Michael P; Anderson, Andrew J; Di Liberto, Giovanni M; Crosse, Michael J; Lalor, Edmund C

2018-03-05

People routinely hear and understand speech at rates of 120-200 words per minute [1, 2]. Thus, speech comprehension must involve rapid, online neural mechanisms that process words' meanings in an approximately time-locked fashion. However, electrophysiological evidence for such time-locked processing has been lacking for continuous speech. Although valuable insights into semantic processing have been provided by the "N400 component" of the event-related potential [3-6], this literature has been dominated by paradigms using incongruous words within specially constructed sentences, with less emphasis on natural, narrative speech comprehension. Building on the discovery that cortical activity "tracks" the dynamics of running speech [7-9] and psycholinguistic work demonstrating [10-12] and modeling [13-15] how context impacts on word processing, we describe a new approach for deriving an electrophysiological correlate of natural speech comprehension. We used a computational model [16] to quantify the meaning carried by words based on how semantically dissimilar they were to their preceding context and then regressed this measure against electroencephalographic (EEG) data recorded from subjects as they listened to narrative speech. This produced a prominent negativity at a time lag of 200-600 ms on centro-parietal EEG channels, characteristics common to the N400. Applying this approach to EEG datasets involving time-reversed speech, cocktail party attention, and audiovisual speech-in-noise demonstrated that this response was very sensitive to whether or not subjects understood the speech they heard. These findings demonstrate that, when successfully comprehending natural speech, the human brain responds to the contextual semantic content of each word in a relatively time-locked fashion. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation and perceived results of moral case deliberation: A mixed methods study.

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Janssens, Rien M J P A; van Zadelhoff, Ezra; van Loo, Ger; Widdershoven, Guy A M; Molewijk, Bert A C

2015-12-01

Moral case deliberation is increasingly becoming part of various Dutch healthcare organizations. Although some evaluation studies of moral case deliberation have been carried out, research into the results of moral case deliberation within aged care is scarce. How did participants evaluate moral case deliberation? What has moral case deliberation brought to them? What has moral case deliberation contributed to care practice? Should moral case deliberation be further implemented and, if so, how? Quantitative analysis of a questionnaire study among participants of moral case deliberation, both caregivers and team leaders. Qualitative analysis of written answers to open questions, interview study and focus group meetings among caregivers and team leaders. Caregivers and team leaders in a large organization for aged care in the Netherlands. A total of 61 moral case deliberation sessions, carried out on 16 care locations belonging to the organization, were evaluated and perceived results were assessed. Participants gave informed consent and anonymity was guaranteed. In the Netherlands, the law does not prescribe independent ethical review by an Institutional Review Board for this kind of research among healthcare professionals. Moral case deliberation was evaluated positively by the participants. Content and atmosphere of moral case deliberation received high scores, while organizational issues regarding the moral case deliberation sessions scored lower and merit further attention. Respondents indicated that moral case deliberation has the potential to contribute to care practice as relationships among team members improve, more openness is experienced and more understanding for different perspectives is fostered. If moral case deliberation is to be successfully implemented, top-down approaches should go hand in hand with bottom-up approaches. The relevance of moral case deliberation for care practice received wide acknowledgement from the respondents. It can contribute

[Evaluation by case managers dementia : An explorative practice based study on types and content].

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Ketelaar, Nicole A B M; Jukema, Jan S; van Bemmel, Marlies; Adriaansen, Marian J M; Smits, Carolien H M

2017-06-01

This practice based explorative study aims to provide insight into the ways in which case managers shape and fill up the evaluation phase of their support of the informal care network of persons with dementia. A combination of quantitative and qualitative research methods were used. A group of 57 case managers of persons with dementia in three different organisational networks took part in this study. Results from the quantitative and qualitative data are organized into four themes: (1) attitude towards evaluation, (2) forms of evaluation, (3) implementation of evaluation and (4) content of evaluation. There are different ways in shaping evaluation and the content of it. The importance of interim and final evaluation is recognized, but is difficult to realize in a methodical way. Barriers experienced by the case managers include various factors associated both with clients as professionals. Case managers evaluate continuously and in an informal way to assess whether the extent of their assistance is meeting the needs of the client and informal network. Case managers do not use systematic evaluation to measure the quality of care they offer to persons with dementia and their caregivers. The findings demand a discussion on the level of clients, as well as on the professional and societal level about the way case managers should evaluate their support.

Clinical neurological examination vs electrophysiological studies: Reflections from experiences in occupational medicine

DEFF Research Database (Denmark)

Jepsen, Jørgen Riis

2015-01-01

a diagnosis requires the identification of the responsible pathology and the involved tissues and structures. Consequently, improved diagnostic approaches are needed. This editorial discusses the potentials of using the clinical neurologic examination in patients with upper limb complaints related to work....... It is argued that a simple but systematic physical approach permits the examiner to frequently identify patterns of neurological findings that suggest nerve afflictions and their locations, and that electrophysiological studies are less likely to identify pathology. A diagnostic algorithm for the physical...... assessment is provided to assist the clinician. Failure to include representative neurological items in the physical examination may result in patients being misinterpreted, misdiagnosed and mistreated....

A Rubric for Evaluating Student Analyses of Business Cases

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Riddle, Emma Jane; Smith, Marilyn; Frankforter, Steven A.

2016-01-01

This article presents a rubric for evaluating student performance on written case assignments that require qualitative analysis. This rubric is designed for three purposes. First, it informs students of the criteria on which their work will be evaluated. Second, it provides instructors with a reliable instrument for accurately measuring and…

The Role of mf-ERG in the Diagnosis and Treatment of Age-Related Macular Degeneration: Electrophysiological Features of AMD.

Science.gov (United States)

Moschos, Marilita M; Nitoda, Eirini

2018-01-01

Age-related macular cegeneration (AMD) is the leading cause of visual dysfunction worldwide, affecting 9-25% of individuals between 65 and 75 years old. We have reviewed the published articles investigating the role of multifocal electroretinogram (mf-ERG) in the diagnosis and treatment of AMD. Visual evoked potentials have revealed decreased amplitudes and higher latencies in patients with AMD, while the degeneration of photoreceptors and abnormalities of retinal pigment epithelium can be identified by electro-oculogram recordings. Moreover, ERG can detect the functional abnormalities observed in AMD and evaluate each therapeutic approach. The record of local electrophysiological responses coming from different retinal areas can be accurately performed by mfERG. The accuracy of mfERG in detecting the degeneration of photoreceptors, as well the disturbances of macular function, could be useful both in the early diagnosis of AMD and the assessment of treatment efficacy.

Continuous Evaluation in Ethics Education: A Case Study.

Science.gov (United States)

McIntosh, Tristan; Higgs, Cory; Mumford, Michael; Connelly, Shane; DuBois, James

2018-04-01

A great need for systematic evaluation of ethics training programs exists. Those tasked with developing an ethics training program may be quick to dismiss the value of training evaluation in continuous process improvement. In the present effort, we use a case study approach to delineate how to leverage formative and summative evaluation measures to create a high-quality ethics education program. With regard to formative evaluation, information bearing on trainee reactions, qualitative data from the comments of trainees, in addition to empirical findings, can ensure that the training program operates smoothly. Regarding summative evaluation, measures examining trainee cognition, behavior, and organization-level results provide information about how much trainees have changed as a result of taking the ethics training. The implications of effective training program evaluation are discussed.

An electrophysiological analysis of altered cognitive functions in Huntington disease.

Science.gov (United States)

Münte, T F; Ridao-Alonso, M E; Preinfalk, J; Jung, A; Wieringa, B M; Matzke, M; Dengler, R; Johannes, S

1997-09-01

Neuropsychological deficits are a main feature of Huntington disease (HD) with previous data suggesting involvement of memory functions and visual processing. To increase the knowledge about cognitive malfunction in HD in the domains of visual processing and memory by the use of modern electrophysiological techniques (event-related potentials [ERPs]). A case-control design was used. Three ERP paradigms were used; a parallel visual search paradigm allowed for the simultaneous processing of a multi-element visual array in search of a target stimulus, while a serial search paradigm with varied numbers of distractor items necessitated a serial one by one scanning of the arrays. The third experiment was a word-recognition memory task. The measurements were obtained in a neurophysiological laboratory of a university hospital. Nine patients with HD and 9 control subjects matched for age, sex, and education were studied. Components of averaged ERPs were quantified by latency and amplitude measures and subjected to statistical analysis. Behavioral measures (search time, hit rate, and recognition accuracy) were assessed as well. The early visual components showed a significant latency shift (delay of about 50 milliseconds) in HD. In the search paradigms the P3 components differentiating target and standard stimuli were virtually absent in HD as was the ERP effect indexing word recognition. This was accompanied by a marked delay in search times and lower hit rates in the search tasks and a grossly reduced recognition accuracy in the memory task. The results suggest marked impairments of patients with HD in early visual sensory processing (early components). Deficits in visual search might be attributed to an impairment to deploy attentional resources across the visual field and/or an inability to control eye movements. The ERPs in the memory task differed grossly from similar data obtained by others in patients with Alzheimer disease, suggesting a different neural basis for

Functional Na(V)1.8 Channels in Intracardiac Neurons The Link Between SCN10A and Cardiac Electrophysiology

NARCIS (Netherlands)

Verkerk, Arie O.; Remme, Carol Ann; Schumacher, Cees A.; Scicluna, Brendon P.; Wolswinkel, Rianne; de Jonge, Berend; Bezzina, Connie R.; Veldkamp, Marieke W.

2012-01-01

Rationale: The SCN10A gene encodes the neuronal sodium channel isoform Na(V)1.8. Several recent genome-wide association studies have linked SCN10A to PR interval and QRS duration, strongly suggesting an as-yet unknown role for Na(V)1.8 in cardiac electrophysiology. Objective: To demonstrate the

Atriofascicular Mahaim with Ebstein anomaly: A case report

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Kazushi Ueshima, MD

2017-10-01

Full Text Available We report a case of a 7-year-old girl with atriofascicular Mahaim (AFM pathway concomitant with Ebstein's anomaly. The QRS wave showed left bundle branch block pattern on electrocardiogram. Holter electrocardiogram showed prolongation of the PR interval and QRS morphological change during sinus tachycardia. An electrophysiological study demonstrated that the distal His potential appeared earlier than the proximal His potential, which suggested retrograde His conduction toward the atrioventricular node. Conduction from the Mahaim fiber to the His bundle was faster than that from the atrioventricular node towards the His bundle. The findings of this important case allowed a differential diagnosis between AFM and Wolff-Parkinson-White (WPW syndrome.

Case-oriented computer-based-training in radiology: concept, implementation and evaluation

Science.gov (United States)

Dugas, Martin; Trumm, Christoph; Stäbler, Axel; Pander, Ernst; Hundt, Walter; Scheidler, Jurgen; Brüning, Roland; Helmberger, Thomas; Waggershauser, Tobias; Matzko, Matthias; Reiser, Maximillian

2001-01-01

Background Providing high-quality clinical cases is important for teaching radiology. We developed, implemented and evaluated a program for a university hospital to support this task. Methods The system was built with Intranet technology and connected to the Picture Archiving and Communications System (PACS). It contains cases for every user group from students to attendants and is structured according to the ACR-code (American College of Radiology) [2]. Each department member was given an individual account, could gather his teaching cases and put the completed cases into the common database. Results During 18 months 583 cases containing 4136 images involving all radiological techniques were compiled and 350 cases put into the common case repository. Workflow integration as well as individual interest influenced the personal efforts to participate but an increasing number of cases and minor modifications of the program improved user acceptance continuously. 101 students went through an evaluation which showed a high level of acceptance and a special interest in elaborate documentation. Conclusion Electronic access to reference cases for all department members anytime anywhere is feasible. Critical success factors are workflow integration, reliability, efficient retrieval strategies and incentives for case authoring. PMID:11686856

Case-oriented computer-based-training in radiology: concept, implementation and evaluation

Directory of Open Access Journals (Sweden)

Helmberger Thomas

2001-10-01

Full Text Available Abstract Background Providing high-quality clinical cases is important for teaching radiology. We developed, implemented and evaluated a program for a university hospital to support this task. Methods The system was built with Intranet technology and connected to the Picture Archiving and Communications System (PACS. It contains cases for every user group from students to attendants and is structured according to the ACR-code (American College of Radiology 2. Each department member was given an individual account, could gather his teaching cases and put the completed cases into the common database. Results During 18 months 583 cases containing 4136 images involving all radiological techniques were compiled and 350 cases put into the common case repository. Workflow integration as well as individual interest influenced the personal efforts to participate but an increasing number of cases and minor modifications of the program improved user acceptance continuously. 101 students went through an evaluation which showed a high level of acceptance and a special interest in elaborate documentation. Conclusion Electronic access to reference cases for all department members anytime anywhere is feasible. Critical success factors are workflow integration, reliability, efficient retrieval strategies and incentives for case authoring.

Electrophysiological correlates of social information processing for detecting agents in social interaction scenes: P200 and N250 components

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Crivelli Davide

2016-04-01

Full Text Available According to interaction theories, the detection of situated agents and the understanding of their intentions and mental states are mediated by smart perceptual and embodied mechanisms. While the network supporting agency-attribution, action understanding, and grasping of others’ mental state is quite known, the actual mental chronometry of such social perception processes is still not clear. We then designed an exploratory study to investigate electrophysiological correlates (ERPs and source localization of information-processing for the detection of potential agents in realistic interaction scenes. Morphological and statistical analyses of electrophysiological data highlighted that the manipulation the nature of a potential agent, the gesture it executed and the relative position of an interagent was differently associated to the modulation of specific relevant middle-latency ERP components, labelled as P200 and N250, and of their relative intra-cortical current density distribution within the first 300 ms from the appearance of the stimulus.

Electrophysiological correlates of melodic processing in congenital amusia.

Science.gov (United States)

Omigie, Diana; Pearce, Marcus T; Williamson, Victoria J; Stewart, Lauren

2013-08-01

Music listening involves using previously internalized regularities to process incoming musical structures. A condition known as congenital amusia is characterized by musical difficulties, notably in the detection of gross musical violations. However, there has been increasing evidence that individuals with the disorder show preserved musical ability when probed using implicit methods. To further characterize the degree to which amusic individuals show evidence of latent sensitivity to musical structure, particularly in the context of stimuli that are ecologically valid, electrophysiological recordings were taken from a sample of amusic and control participants as they listened to real melodies. To encourage them to pay attention to the music, participants were asked to detect occasional notes in a different timbre. Using a computational model of auditory expectation to identify points of varying levels of expectedness in these melodies (in units of information content (IC), a measure which has an inverse relationship with probability), ERP analysis investigated the extent to which the amusic brain differs from that of controls when processing notes of high IC (low probability) as compared to low IC ones (high probability). The data revealed a novel effect that was highly comparable in both groups: Notes with high IC reliably elicited a delayed P2 component relative to notes with low IC, suggesting that amusic individuals, like controls, found these notes more difficult to evaluate. However, notes with high IC were also characterized by an early frontal negativity in controls that was attenuated in amusic individuals. A correlation of this early negative effect with the ability to make accurate note expectedness judgments (previous data collected from a subset of the current sample) was shown to be present in typical individuals but compromised in individuals with amusia: a finding in line with evidence of a close relationship between the amplitude of such a

Electrophysiological correlates of error processing in borderline personality disorder.

Science.gov (United States)

Ruchsow, Martin; Walter, Henrik; Buchheim, Anna; Martius, Philipp; Spitzer, Manfred; Kächele, Horst; Grön, Georg; Kiefer, Markus

2006-05-01

The electrophysiological correlates of error processing were investigated in patients with borderline personality disorder (BPD) using event-related potentials (ERP). Twelve patients with BPD and 12 healthy controls were additionally rated with the Barratt impulsiveness scale (BIS-10). Participants performed a Go/Nogo task while a 64 channel EEG was recorded. Three ERP components were of special interest: error-related negativity (ERN)/error negativity (Ne), early error positivity (early Pe) reflecting automatic error processing, and the late Pe component which is thought to mirror the awareness of erroneous responses. We found smaller amplitudes of the ERN/Ne in patients with BPD compared to controls. Moreover, significant correlations with the BIS-10 non-planning sub-score could be demonstrated for both the entire group and the patient group. No between-group differences were observed for the early and late Pe components. ERP measures appear to be a suitable tool to study clinical time courses in BPD.

Severity of Carpal Tunnel Syndrome and Diagnostic Accuracy of Hand and Body Anthropometric Measures.

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Mauro Mondelli

Full Text Available To study the diagnostic properties of hand/wrist and body measures according to validated clinical and electrophysiological carpal tunnel syndrome (CTS severity scales.We performed a prospective case-control study. For each case, two controls were enrolled. Two five-stage clinical and electrophysiological scales were used to evaluate CTS severity. Anthropometric measurements were collected and obesity indicators and hand/wrist ratios were calculated. Area under the receiver operating characteristic curves (AUC, sensitivity, specificity, and likelihood ratios were calculated separately by gender.We consecutively enrolled 370 cases and 747 controls. The wrist-palm ratio, waist-hip-height ratio and waist-stature ratio showed the highest proportion of cases with abnormal values in the severe stages of CTS for clinical and electrophysiological severity scales in both genders. Accuracy tended to increase with CTS severity for females and males. In severe stage, most of the indexes presented moderate accuracy in both genders. Among subjects with severe CTS, the wrist-palm ratio presented the highest AUC for hand measures in the clinical and electrophysiological severity scales both in females (AUC 0.83 and 0.76, respectively and males (AUC 0.91 and 0.82, respectively. Among subjects with severe CTS, the waist-stature ratio showed the highest AUC for body measures in the clinical and electrophysiological severity scales both in females (AUC 0.78 and 0.77, respectively and males (AUC 0.84 and 0.76, respectively. The results of waist-hip-height ratio AUC were similar.Wrist-palm ratio, waist-hip-height ratio and waist-stature ratio could contribute to support the diagnostic hypothesis of severe CTS that however has to be confirmed by nerve conduction study.

Effects of intraoperative irradiation and intraoperative hyperthermia on canine sciatic nerve: neurologic and electrophysiologic study

International Nuclear Information System (INIS)

Vujaskovic, Zeljko; Gillette, Sharon M.; Powers, Barbara E.; Stukel, Therese A.; LaRue, Susan M.; Gillette, Edward L.; Borak, Thomas B.; Scott, Robert J.; Weiss, Julia; Colacchio, Thomas A.

1996-01-01

Purpose: Late radiation injury to peripheral nerve may be the limiting factor in the clinical application of intraoperative radiation therapy (IORT). The combination of IORT with intraoperative hyperthermia (IOHT) raises specific concerns regarding the effects on certain normal tissues such as peripheral nerve, which might be included in the treatment field. The objective of this study was to compare the effect of IORT alone to the effect of IORT combined with IOHT on peripheral nerve in normal beagle dogs. Methods and Materials: Young adult beagle dogs were randomized into five groups of three to five dogs each to receive IORT doses of 16, 20, 24, 28, or 32 Gy to 5 cm of surgically exposed right sciatic nerve using 6 MeV electrons and six groups of four to five dogs each received IORT doses of 0, 12, 16, 20, 24, or 28 Gy simultaneously with 44 deg. C of IOHT for 60 min. IOHT was performed using a water circulating hyperthermia device with a multichannel thermometry system on the surgically exposed sciatic nerve. Neurologic and electrophysiologic examinations were done before and monthly after treatment for 24 months. Electrophysiologic studies included electromyographic (EMG) examinations of motor function, as well as motor nerve conduction velocities studies. Results: Two years after treatment, the effective dose for 50% complication (ED 50 ) for limb paresis in dogs exposed to IORT only was 22 Gy. The ED 50 for paresis in dogs exposed to IORT combined with IOHT was 15 Gy. The thermal enhancement ratio (TER) was 1.5. Electrophysiologic studies showed more prominent changes such as EMG abnormalities, decrease in conduction velocity and amplitude of the action potential, and complete conduction block in dogs that received the combination of IORT and IOHT. The latency to development of peripheral neuropathies was shorter for dogs exposed to the combined treatment. Conclusion: The probability of developing peripheral neuropathies in a large animal model was higher

Individual Differences in Behavioral and Electrophysiological Measures of Binaural Processing Across the Adult Life Span.

Science.gov (United States)

Roup, Christina M; Leigh, Elizabeth D

2015-06-01

The purpose of the present study was to examine individual differences in binaural processing across the adult life span. Sixty listeners (aged 23-80 years) with symmetrical hearing were tested. Binaural behavioral processing was measured by the Words-in-Noise Test, the 500-Hz masking level difference, and the Dichotic Digit Test. Electrophysiologic responses were assessed by the auditory middle latency response binaural interaction component. No correlations among binaural measures were found. Age accounted for the greatest amount of variability in speech-in-noise performance. Age was significantly correlated with the Words-in-Noise Test binaural advantage and dichotic ear advantage. Partial correlations, however, revealed that this was an effect of hearing status rather than age per se. Inspection of individual results revealed that 20% of listeners demonstrated reduced binaural performance for at least 2 of the binaural measures. The lack of significant correlations among variables suggests that each is an important measurement of binaural abilities. For some listeners, binaural processing was abnormal, reflecting a binaural processing deficit not identified by monaural audiologic tests. The inclusion of a binaural test battery in the audiologic evaluation is supported given that these listeners may benefit from alternative forms of audiologic rehabilitation.

Computerized tomographic evaluations of 37 cases of craniopharyngiomas

International Nuclear Information System (INIS)

Nagasawa, Shiro; Yamashita, Junkoh; Handa, Hajime; Takeuchi, Juji.

1983-01-01

Although craniopharyngiomas are well known to exhibit three basic CT characteristics: Calcification, cysts, and contrast enhancement (CE), several cases with atypical CT manifestations have been reported lately. These atypical manifestations can be classified into three groups: Unusual extensions of the tumors, high-density cysts, and marked homogeneous CE. The CT scans obtained in our recent series of 37 craniopharyngiomas were evaluated in an attempt to analyze the tumoral extensions, the cyst densities, and the CE, and were compared with those of other, rarer parasellar lesions. Cystic tumors were much more frequent than solid tumors (Table 1); 14 cases (38%) were exclusively cystic; 17 cases (46%), equally cystic and solid, and 6 cases (16%), solid. Calcifications were present in 86% of the children and 43% of the adults. Unusual extensions were noted in 7 cases (Fig. 1, 2): Anteriorly to the frontal fossa (5 cases, 14%), laterally to the temporal fossa (1 case, 3%), or posteriorly to the posterior fossa (1 case, 3%). All these tumors were either purely cystic or equally cystic and solid. Cystic portions were detected in the tumors of 31 cases (Table 2). Although the majority of the cystic portions (25 cases, 81%) were low in density, isodense cysts were observed in 6 cases (19%). Out of 23 cases exhibiting solid portions in the tumors, high-density areas (calcified masses) were detected in 3 cases and mixed-density areas in 20 cases. While these 20 cases all showed CE, marked homogeneous CE were noted in 5 cases (25%). (J.P.N.)

First implantation of selective his bundle pacing in Colombia. Report of two cases

International Nuclear Information System (INIS)

Velasquez, Jorge E; Duque, Mauricio; Marin V, Jorge E; Aristizabal, Julian M; Medina, Luis E; Gonzalez, Edgardo; Duque, Laura; Uribe, William

2010-01-01

Pacing in the right ventricular apex is known to produce ventricular dysynchrony and patients often develop dilated cardiomyopathy. For this reason, a more physiological stimulation has been performed. With the recent technological development of electrodes for selective stimulation of the His bundle, we want to show the experience of this type of implantation in the first two cases made in the electrophysiology laboratory in Medellin.

Electrophysiological correlates of emotional face processing in typically developing adults and adults with high functioning Autism

OpenAIRE

Barrie, Jennifer Nicole

2012-01-01

Emotional expressions have been found to affect various event-related potentials (ERPs). Furthermore, socio-emotional functioning is altered in individuals with autism, and a growing body of neuroimaging and electrophysiological evidence substantiates underlying neural differences for face processing in this population. However, relatively few studies have examined the time-course of emotional face processing in autism. This study examined how implicit (not the intended focus of attention) ve...

Electrophysiology of Extraocular Cranial Nerves: Oculomotor, Trochlear, and Abducens Nerve.

Science.gov (United States)

Hariharan, Praveen; Balzer, Jeffery R; Anetakis, Katherine; Crammond, Donald J; Thirumala, Parthasarathy D

2018-01-01

The utility of extraocular cranial nerve electrophysiologic recordings lies primarily in the operating room during skull base surgeries. Surgical manipulation during skull base surgeries poses a risk of injury to multiple cranial nerves, including those innervating extraocular muscles. Because tumors distort normal anatomic relationships, it becomes particularly challenging to identify cranial nerve structures. Studies have reported the benefits of using intraoperative spontaneous electromyographic recordings and compound muscle action potentials evoked by electrical stimulation in preventing postoperative neurologic deficits. Apart from surgical applications, electromyography of extraocular muscles has also been used to guide botulinum toxin injections in patients with strabismus and as an adjuvant diagnostic test in myasthenia gravis. In this article, we briefly review the rationale, current available techniques to monitor extraocular cranial nerves, technical difficulties, clinical and surgical applications, as well as future directions for research.

[Electrophysiological bases of semantic processing of objects].

Science.gov (United States)

Kahlaoui, Karima; Baccino, Thierry; Joanette, Yves; Magnié, Marie-Noële

2007-02-01

How pictures and words are stored and processed in the human brain constitute a long-standing question in cognitive psychology. Behavioral studies have yielded a large amount of data addressing this issue. Generally speaking, these data show that there are some interactions between the semantic processing of pictures and words. However, behavioral methods can provide only limited insight into certain findings. Fortunately, Event-Related Potential (ERP) provides on-line cues about the temporal nature of cognitive processes and contributes to the exploration of their neural substrates. ERPs have been used in order to better understand semantic processing of words and pictures. The main objective of this article is to offer an overview of the electrophysiologic bases of semantic processing of words and pictures. Studies presented in this article showed that the processing of words is associated with an N 400 component, whereas pictures elicited both N 300 and N 400 components. Topographical analysis of the N 400 distribution over the scalp is compatible with the idea that both image-mediated concrete words and pictures access an amodal semantic system. However, given the distinctive N 300 patterns, observed only during picture processing, it appears that picture and word processing rely upon distinct neuronal networks, even if they end up activating more or less similar semantic representations.

An integrated domain specific language for post-processing and visualizing electrophysiological signals in Java.

Science.gov (United States)

Strasser, T; Peters, T; Jagle, H; Zrenner, E; Wilke, R

2010-01-01

Electrophysiology of vision - especially the electroretinogram (ERG) - is used as a non-invasive way for functional testing of the visual system. The ERG is a combined electrical response generated by neural and non-neuronal cells in the retina in response to light stimulation. This response can be recorded and used for diagnosis of numerous disorders. For both clinical practice and clinical trials it is important to process those signals in an accurate and fast way and to provide the results as structured, consistent reports. Therefore, we developed a freely available and open-source framework in Java (http://www.eye.uni-tuebingen.de/project/idsI4sigproc). The framework is focused on an easy integration with existing applications. By leveraging well-established software patterns like pipes-and-filters and fluent interfaces as well as by designing the application programming interfaces (API) as an integrated domain specific language (DSL) the overall framework provides a smooth learning curve. Additionally, it already contains several processing methods and visualization features and can be extended easily by implementing the provided interfaces. In this way, not only can new processing methods be added but the framework can also be adopted for other areas of signal processing. This article describes in detail the structure and implementation of the framework and demonstrate its application through the software package used in clinical practice and clinical trials at the University Eye Hospital Tuebingen one of the largest departments in the field of visual electrophysiology in Europe.

A Framework for the Evaluation of CASE Tool Learnability in Educational Environments

Science.gov (United States)

Senapathi, Mali

2005-01-01

The aim of the research is to derive a framework for the evaluation of Computer Aided Software Engineering (CASE) tool learnability in educational environments. Drawing from the literature of Human Computer Interaction and educational research, a framework for evaluating CASE tool learnability in educational environments is derived. The two main…

[On the first studies of electrophysiology].

Science.gov (United States)

de Micheli, Alfredo

2011-01-01

A historical outline of the evolution of electrophysiology from the eighteenth century is shortly presented. Topics concerning the so called animal electricity starting from the observations on descharges of Torpedo fish until Bolognese Galvani's researches on the frogs are exposed. The points of view of their oppositionists also are examined. These ones, leaded by the physicist Alessandro Volta, professor in the University of Pavia, believed that electricity detected by galvanists was not inherent to animal but was due to the action of the metallic conductors present in the circuit: contact electricity. Only towards the middle of the nineteenth century the physicist Carlo Matteucci attained to demonstrate the existente of the real animal electricity in form of injury current. It was possible to determine that quantitatively thanks to the capillary electrometer built in 1872 by the French physicist Gabriel Lippmann. This instrument was used by the English physiologist Waller in order to obtain the primitive electrocardiographic tracings in humans (1887). At beginnings of the twentieth century, the Dutch professor Willem Einthoven, of the University of Leiden, introduced his string galvanometer which permitted to allow the modern electrocardiography. So it was possible to record the electrical potentials of myocardial cells, first in vitro, later in isolated and perfused heart, son after in dog's heart in situ and finally in human heart. Therefore now it is possible to effectuate endocardial and epicardial mappings, indispensable in order to diagnose and treat the cardiac arrhythmias.

Familial atrioventricular nodal re-entrant tachycardia: A case seriers and a systematic review

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Muthiah Subramanian

2017-11-01

Full Text Available Multiple reports of familial clustering suggest that genetic factors may contribute in the pathogenesis of atrioventricular nodal re-entrant tachycardia (AVNRT. We report three cases of AVNRT in a father and his two sons along with a review of literature of other similar cases. Electrophysiological studies induced typical AVNRT, which was successfully eliminated by radiofrequency ablation in all of them. Of the 22 reported cases, 96% had typical (slow-fast variant of AVNRT. The predominant pattern of inheritance appears to be autosomal dominant, though other patterns may exist. Further research is needed to understand the genetic influence of AVNRT and its pathophysiology. Keywords: Familial, AVNRT, Tachycardia

Electrophysiological correlates of word recognition memory process in patients with ischemic left ventricular dysfunction.

Science.gov (United States)

Giovannelli, Fabio; Simoni, David; Gavazzi, Gioele; Giganti, Fiorenza; Olivotto, Iacopo; Cincotta, Massimo; Pratesi, Alessandra; Baldasseroni, Samuele; Viggiano, Maria Pia

2016-09-01

The relationship between left ventricular ejection fraction (LVEF) and cognitive performance in patients with coronary artery disease without overt heart failure is still under debate. In this study we combine behavioral measures and event-related potentials (ERPs) to verify whether electrophysiological correlates of recognition memory (old/new effect) are modulated differently as a function of LVEF. Twenty-three male patients (12 without [LVEF>55%] and 11 with [LVEF25 were enrolled. ERPs were recorded while participants performed an old/new visual word recognition task. A late positive ERP component between 350 and 550ms was differentially modulated in the two groups: a clear old/new effect (enhanced mean amplitude for old respect to new items) was observed in patients without LVEF dysfunction; whereas patients with overt LVEF dysfunction did not show such effect. In contrast, no significant differences emerged for behavioral performance and neuropsychological evaluations. These data suggest that ERPs may reveal functional brain abnormalities that are not observed at behavioral level. Detecting sub-clinical measures of cognitive decline may contribute to set appropriate treatments and to monitor asymptomatic or mildly symptomatic patients with LVEF dysfunction. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Functional, electrophysiological recoveries of rats with sciatic nerve lesions following transplantation of elongated DRG cells.

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Dayawansa, Samantha; Zhang, Jun; Shih, Chung-Hsuan; Tharakan, Binu; Huang, Jason H

2016-04-01

Functional data are essential when confirming the efficacy of elongated dorsal root ganglia (DRG) cells as a substitute for autografting. We present the quantitative functional motor, electrophysiological findings of engineered DRG recipients for the first time. Elongated DRG neurons and autografts were transplanted to bridge 1-cm sciatic nerve lesions of Sprague Dawley (SD) rats. Motor recoveries of elongated DRG recipients (n=9), autograft recipients (n=9), unrepaired rats (n=9) and intact rats (n=6) were investigated using the angle board challenge test following 16 weeks of recovery. Electrophysiology studies were conducted to assess the functional recovery at 16 weeks. In addition, elongated DRGs were subjected to histology assessments. At threshold levels (35° angle) of the angle board challenge test, the autograft recipients', DRG recipients' and unrepaired group's performances were equal to each other and were less than the intact group (pDRG recipients' performance was similar to both the intact group and the autograft nerve recipients, and was better (pDRG constructs had intact signal transmission when recorded over the lesion, while the unrepaired rats did not. It was observed that elongated DRG neurons closely resembled an autograft during histological assessments. Performances of autograft and elongated DRG construct recipients were similar. Elongated DRG neurons should be further investigated as a substitute for autografting.

Etiological evaluation of primary congenital hypothyroidism cases.

Science.gov (United States)

Bezen, Diğdem; Dilek, Emine; Torun, Neşe; Tütüncüler, Filiz

2017-06-01

Primary congenital hypothyroidism is frequently seen endocrine disorder and one of the preventable cause of mental retardation. Aim of study was to evaluate the frequency of permanent/transient hypothyrodism, and to detect underlying reason to identfy any marker which carries potential to discriminate permanent/transient form. Forty eight cases older than 3 years of age, diagnosed as primary congenital hypothyroidism and started thyroxin therapy in newborn-period, and followed up between January 2007-June 2013 were included in the study. Thyroid hormon levels were evaluated and thyroid ultrasonography was performed in cases who are at the end of their 3 years of age, after 6 weeks of thyroxine free period. Thyroid sintigraphy was performed if serum thyroid-stimulating hormone was high (≥ 5 mIU/mL) and perchlorate discharge test was performed if uptake was normal or increased on sintigraphy. Cases with thyroid-stimulating hormone levels ≥ 5 mIU/mL were defined as permanent primary congenital hypothyroidism group and as transient primary congenital hypothyroidism group with normal thyroid hormones during 6 months. The mean age was 3.8±0.7 years. Mean diagnosis age was 16.6±6.5 days and 14 cases (29.2%) were diagnosed by screening program of Ministry of Health. There were 23 cases (14F, 9M) in permanent primary congenital hypothyroidism group and 12 (52.2%) of them were dysgenesis (8 hypoplasia, 4 ectopia), and 11 (47.8%) dyshormonogenesis. In transient primary congenital hypothyroidism group, there were 25 cases (17M, 8F). The mean thyroid-stimulating hormone levels at diagnosis were similar in two groups. The mean thyroxin dose in permanent primary congenital hypothyroidism group was significantly higher than transient group at the time of thyroxin cessation (2.1±0.7, 1.5±0.5 mg/kg/d, respectively, p=0.004). Thyroxin dose ≥1.6 mcg/kg/d was 72% sensitive and 69.6% specific for predicting permenant primary congenital hypothyroidism. Transient primary

Electrophysiological Characteristics of Embryonic Stem Cell-Derived Cardiomyocytes are Cell Line-Dependent

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Tobias Hannes

2015-01-01

Full Text Available Background: Modelling of cardiac development, physiology and pharmacology by differentiation of embryonic stem cells (ESCs requires comparability of cardiac differentiation between different ESC lines. To investigate whether the outcome of cardiac differentiation is consistent between different ESC lines, we compared electrophysiological properties of ESC-derived cardiomyocytes (ESC-CMs of different murine ESC lines. Methods: Two wild-type (D3 and R1 and two transgenic ESC lines (D3/aPIG44 and CGR8/AMPIGX-7 were differentiated under identical culture conditions. The transgenic cell lines expressed enhanced green fluorescent protein (eGFP and puromycin-N-acetyltransferase under control of the cardiac specific α-myosin heavy chain (αMHC promoter. Action potentials (APs were recorded using sharp electrodes and multielectrode arrays in beating clusters of ESC-CMs. Results: Spontaneous AP frequency and AP duration (APD as well as maximal upstroke velocity differed markedly between unpurified CMs of the four ESC lines. APD heterogeneity was negligible in D3/aPIG44, moderate in D3 and R1 and extensive in CGR8/AMPIGX-7. Interspike intervals calculated from long-term recordings showed a high degree of variability within and between recordings in CGR8/AMPIGX-7, but not in D3/aPIG44. Purification of the αMHC+ population by puromycin treatment posed only minor changes to APD in D3/aPIG44, but significantly shortened APD in CGR8/AMPIGX-7. Conclusion: Electrophysiological properties of ESC-CMs are strongly cell line-dependent and can be influenced by purification of cardiomyocytes by antibiotic selection. Thus, conclusions on cardiac development, physiology and pharmacology derived from single stem cell lines have to be interpreted carefully.

Effects of selective attention on the electrophysiological representation of concurrent sounds in the human auditory cortex.

Science.gov (United States)

Bidet-Caulet, Aurélie; Fischer, Catherine; Besle, Julien; Aguera, Pierre-Emmanuel; Giard, Marie-Helene; Bertrand, Olivier

2007-08-29

In noisy environments, we use auditory selective attention to actively ignore distracting sounds and select relevant information, as during a cocktail party to follow one particular conversation. The present electrophysiological study aims at deciphering the spatiotemporal organization of the effect of selective attention on the representation of concurrent sounds in the human auditory cortex. Sound onset asynchrony was manipulated to induce the segregation of two concurrent auditory streams. Each stream consisted of amplitude modulated tones at different carrier and modulation frequencies. Electrophysiological recordings were performed in epileptic patients with pharmacologically resistant partial epilepsy, implanted with depth electrodes in the temporal cortex. Patients were presented with the stimuli while they either performed an auditory distracting task or actively selected one of the two concurrent streams. Selective attention was found to affect steady-state responses in the primary auditory cortex, and transient and sustained evoked responses in secondary auditory areas. The results provide new insights on the neural mechanisms of auditory selective attention: stream selection during sound rivalry would be facilitated not only by enhancing the neural representation of relevant sounds, but also by reducing the representation of irrelevant information in the auditory cortex. Finally, they suggest a specialization of the left hemisphere in the attentional selection of fine-grained acoustic information.

How does "not left" become "right"? Electrophysiological evidence for a dynamic conflict-bound negation processing account.

Science.gov (United States)

Dudschig, Carolin; Kaup, Barbara

2018-05-01

Human thought and language is traditionally considered as abstract, amodal, and symbolic. However, recent theories propose that high-level human cognition is directly linked to basic, modal biological systems such as sensorimotor areas. Despite this influential representational debate very little is known regarding whether the mechanisms involved in sensorimotor control are also shared with higher-level cognitive processes, such as language comprehension. We investigated negation as a universal of human language, addressing two key questions: (a) Does negation result in a conflict-like representation? (b) Does negation trigger executive control adjustments in a similar manner as standard information processing conflicts do (e.g., Simon, Flanker)? Electrophysiological data indicated that phrases such as "not left/not right" result in initial activation of the to-be-negated information and subsequently the outcome of the negation process. More importantly, our findings also suggest that negation triggers conflict-related adjustments in information processing in line with traditional conflict tasks. Trial-by-trial conflict adaptation patterns in both behavioral and electrophysiological data indicated that negation processing dynamically changes depending on the current cognitive state. In summary, negation processing results in cognitive conflict, and dynamic influences of the cognitive state determine conflict resolution, that is, negation implementation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Review of GIF PR and PP Evaluation Case Study for Application to Pyroprocessing

Energy Technology Data Exchange (ETDEWEB)

Kim, H. M.; Ahn, S. K.; Kwon, E. H.; Kim, H. D. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

This paper has summarized and reviewed the ESFR case study, as it relates to the application of the evaluation methods to pyroprocessing facilities as well as the sodium fast reactor fuel cycle in the future as a self-assessment study. The GIF PR and PP evaluation methodology and the case study both addressed physical protection, but this paper focuses only on proliferation resistance. It does not consider physical protection. The Generation IV International Forum (GIF) emphasizes proliferation resistance and physical protection (PR and PP) as one of the main aspects to be considered regarding future nuclear energy systems (NESs). As such, the PR and PP Working Group developed an evaluation methodology and applied it to the Example Sodium Fast Reactor (ESFR) as a case study. This paper has summarized and reviewed the ESFR case study, as it relates to the application of the evaluation methods to pyroprocessing facilities as well as the sodium fast reactor fuel cycle in the future as a self-assessment study. The GIF PR and PP evaluation methodology and the case study both addressed physical protection, but this paper focuses only on proliferation resistance. It does not consider physical protection.

Review of GIF PR and PP Evaluation Case Study for Application to Pyroprocessing

International Nuclear Information System (INIS)

Kim, H. M.; Ahn, S. K.; Kwon, E. H.; Kim, H. D.

2014-01-01

This paper has summarized and reviewed the ESFR case study, as it relates to the application of the evaluation methods to pyroprocessing facilities as well as the sodium fast reactor fuel cycle in the future as a self-assessment study. The GIF PR and PP evaluation methodology and the case study both addressed physical protection, but this paper focuses only on proliferation resistance. It does not consider physical protection. The Generation IV International Forum (GIF) emphasizes proliferation resistance and physical protection (PR and PP) as one of the main aspects to be considered regarding future nuclear energy systems (NESs). As such, the PR and PP Working Group developed an evaluation methodology and applied it to the Example Sodium Fast Reactor (ESFR) as a case study. This paper has summarized and reviewed the ESFR case study, as it relates to the application of the evaluation methods to pyroprocessing facilities as well as the sodium fast reactor fuel cycle in the future as a self-assessment study. The GIF PR and PP evaluation methodology and the case study both addressed physical protection, but this paper focuses only on proliferation resistance. It does not consider physical protection

Two-stage categorization in brand extension evaluation: electrophysiological time course evidence.

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Qingguo Ma

Full Text Available A brand name can be considered a mental category. Similarity-based categorization theory has been used to explain how consumers judge a new product as a member of a known brand, a process called brand extension evaluation. This study was an event-related potential study conducted in two experiments. The study found a two-stage categorization process reflected by the P2 and N400 components in brand extension evaluation. In experiment 1, a prime-probe paradigm was presented in a pair consisting of a brand name and a product name in three conditions, i.e., in-category extension, similar-category extension, and out-of-category extension. Although the task was unrelated to brand extension evaluation, P2 distinguished out-of-category extensions from similar-category and in-category ones, and N400 distinguished similar-category extensions from in-category ones. In experiment 2, a prime-probe paradigm with a related task was used, in which product names included subcategory and major-category product names. The N400 elicited by subcategory products was more significantly negative than that elicited by major-category products, with no salient difference in P2. We speculated that P2 could reflect the early low-level and similarity-based processing in the first stage, whereas N400 could reflect the late analytic and category-based processing in the second stage.

The Co-Existence of Myasthenia Gravis in Patients with Myositis: A Case Series

Science.gov (United States)

Paik, Julie J.; Corse, Andrea M.; Mammen, Andrew L.

2014-01-01

Objective Myositis and myasthenia gravis (MG) are both autoimmune disorders presenting with muscle weakness. Rarely, they occur simultaneously in the same patient. Since the management of myasthenia gravis differs from that of myositis, it is important to recognize when patients have both diseases. We reviewed the cases of 6 patients with both myositis and MG to identify clinical features that suggest the possibility of co-existing MG in myositis patients. Methods We identified 6 patients with dermatomyositis or polymyositis and MG. We reviewed their medical records to assess their clinical presentations, laboratory findings, and electrophysiological features. Results All 6 patients had definite dermatomyositis or polymyositis by the criteria of Bohan and Peter as well as electrophysiologic and/or serologic confirmation of MG. Among overlap patients, 5/6 (83%) had bulbar weakness, 2/6 (33%) had ptosis, and 1/6 (17%) had diplopia. Fatigable weakness was noted by 5/6 (83%) patients. Treatment with pyridostigmine improved symptoms in 5/6 (83%). High dose steroids were associated with worsening weakness in 2/6 (33%) patients. Conclusions Prominent bulbar symptoms, ptosis, diplopia, and fatigable weakness should suggest the possibility of MG in patients with myositis. A suspicion of MG may be confirmed through appropriate electrophysiologic and laboratory testing. In those with myositis-MG overlap, high dose steroids may exacerbate symptoms and pryidostigmine may play an important therapeutic role. PMID:24412588

Forensic evaluation of medical liability cases in general surgery.

Science.gov (United States)

Moreira, H; Magalhães, T; Dinis-Oliveira, Rj; Taveira-Gomes, A

2014-10-01

Although medical liability (disciplinary, civil and criminal) is increasingly becoming an issue, few studies exist, particularly from the perspective of forensic science, which demonstrate the extent to which medical malpractice occurs, or when it does, the reasons for it. Our aims were to evaluate the current situation concerning medical liability in general surgery (GS) in Portugal, the reasons for claims, and the forensic evaluations and conclusions, as well as the association between these issues and the judicial outcomes. We analysed the Medico-Legal Council (CML) reports of the National Institute of Legal Medicine and Forensic Sciences of Portugal related to GS during 2001-2010. The judicial outcomes of each case were requested from the Public Prosecutor Office (PPO) and the court. Alleged cases of medical liability in GS represented 11.2% of the total cases analysed by the CML. We estimated that in Portugal, 4:100,000 surgeries are subject to litigation. The majority of complaints were due to the patient's death (75.4%), with laparoscopic cholecystectomy surgeries representing 55.2% of cases. In 76.1% of the cases, the CML believed that there was no violation of legesartis and in 55.2% of cases, no causal nexus was found between the medical practice and the alleged harm. The PPO prosecuted physicians in 6.4% of the cases and resulted in one conviction. Finally, the importance of the CML reports as a relevant technical-scientific tool for judicial decision was evident because these reports significantly (p < 0.05) influenced the prosecutor's decision, whether to prosecute or not. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Evaluation of TB Case Finding through Systematic Contact Investigation, Chhattisgarh, India

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Kshitij Khaparde

2015-01-01

Full Text Available Rationale. Contact investigation is an established tool for early case detection of tuberculosis (TB. In India, contact investigation is not often conducted, despite national policy, and the yield of contact investigation is not well described. Objective. To determine the yield of evaluating household contacts of sputum smear-positive TB cases in Rajnandgaon district, Chhattisgarh, India. Methods. Among 14 public health care facilities with sputum smear microscopy services, home visits were conducted to identify household contacts of all registered sputum smear-positive TB cases. We used a standardized protocol to screen for clinical symptoms suggestive of active TB with additional referral for chest radiograph and sputa collection. Results. From December 2010 to May 2011, 1,556 household contacts of 312 sputum smear-positive TB cases were identified, of which 148 (9.5% were symptomatic. Among these, 109 (73.6% were evaluated by sputum examination resulting in 11 cases (10.1% of sputum smear-positive TB and 4 cases (3.6% of smear-negative TB. Household visits contributed additional 63% TB cases compared to passive case detection alone. Conclusion. A standard procedure for conducting household contact investigation identified additional TB cases in the community and offered an opportunity to initiate isoniazid chemoprophylaxis among children.

The up and down of sleep: From molecules to electrophysiology.

Science.gov (United States)

Navarro-Lobato, Irene; Genzel, Lisa

2018-03-12

Alternations of up and down can be seen across many different levels during sleep. Neural firing-rates, synaptic markers, molecular pathways, and gene expression all show differential up and down regulation across brain areas and sleep stages. And also the hallmarks of sleep - sleep stage specific oscillations - are characterized themselves by up and down as seen within the slow oscillation or theta cycles. In this review, we summarize the up and down of sleep covering molecules to electrophysiology and present different theories how this up and down could be regulated by the up and down of sleep oscillations. Further, we propose a tentative theory how this differential up and down could contribute to various outcomes of sleep related memory consolidation: enhancement of hippocampal representations of very novel memories and cortical consolidation of memories congruent with previous knowledge-networks. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Bacteriological And Clinical Evaluation Of Twelve Cases Of Post ...

African Journals Online (AJOL)

Bacteriological And Clinical Evaluation Of Twelve Cases Of Post-Surgical Sepsis Of Odontogenic Tumours At A ... East African Medical Journal ... Intervention: Adequate review of patient\\'s medical history, bacteriological investigations and

Frontal cortex electrophysiology in reward- and punishment-related feedback processing during advice-guided decision making: An interleaved EEG-DC stimulation study

NARCIS (Netherlands)

Wischnewski, M.; Bekkering, H.; Schutter, D.J.L.G.

2018-01-01

During decision making, individuals are prone to rely on external cues such as expert advice when the outcome is not known. However, the electrophysiological correlates associated with outcome uncertainty and the use of expert advice are not completely understood. The feedback-related negativity

Case study of evaluations that go beyond clinical outcomes to assess quality improvement diabetes programmes using the Diabetes Evaluation Framework for Innovative National Evaluations (DEFINE).

Science.gov (United States)

Paquette-Warren, Jann; Harris, Stewart B; Naqshbandi Hayward, Mariam; Tompkins, Jordan W

2016-10-01

Investments in efforts to reduce the burden of diabetes on patients and health care are critical; however, more evaluation is needed to provide evidence that informs and supports future policies and programmes. The newly developed Diabetes Evaluation Framework for Innovative National Evaluations (DEFINE) incorporates the theoretical concepts needed to facilitate the capture of critical information to guide investments, policy and programmatic decision making. The aim of the study is to assess the applicability and value of DEFINE in comprehensive real-world evaluation. Using a critical and positivist approach, this intrinsic and collective case study retrospectively examines two naturalistic evaluations to demonstrate how DEFINE could be used when conducting real-world comprehensive evaluations in health care settings. The variability between the cases and the evaluation designs are described and aligned to the DEFINE goals, steps and sub-steps. The majority of the theoretical steps of DEFINE were exemplified in both cases, although limited for knowledge translation efforts. Application of DEFINE to evaluate diverse programmes that target various chronic diseases is needed to further test the inclusivity and built-in flexibility of DEFINE and its role in encouraging more comprehensive knowledge translation. This case study shows how DEFINE could be used to structure or guide comprehensive evaluations of programmes and initiatives implemented in health care settings and support scale-up of successful innovations. Future use of the framework will continue to strengthen its value in guiding programme evaluation and informing health policy to reduce the burden of diabetes and other chronic diseases. © 2016 The Authors. Journal of Evaluation in Clinical Practice published by John Wiley & Sons, Ltd.

A case for evaluating sensor network protocols concurrently

KAUST Repository

Gnawali, Omprakash; Guibas, Leonidas; Levis, Philip

2010-01-01

Researchers typically evaluate and compare protocols on the testbeds by running them one at a time. This methodology ignores the variation in link qualities and wireless environment across these experiments. These variations can introduce significant noise in the results. Evaluating two protocols concurrently, however, suffers from inter-protocol interactions. These interactions can perturb performance even under very light load, especially timing and timing sensitive protocols. We argue that the benefits of running protocols concurrently greatly outweigh the disadvantages. Protocols rarely run in isolation in real networks, and so considering such interactions is valuable. Although the wireless environment is still uncontrolled, concurrent evaluations make comparisons fair and more statistically sound. Through experiments on two testbeds, we make the case for evaluating and comparing low data-rate sensor network protocols by running them concurrently. Copyright 2010 ACM.

The value of scintigraphy in the evaluation of oropharyngeal dysphagia

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Argon, Murat; Duygun, Uelkem; Kocacelebi, Kenan; Ozkilic, Hayal [Department of Nuclear Medicine, Ege University Medical School Hospital, 35100, Bornova, Izmir (Turkey); Secil, Yaprak; Aydogdu, Ibrahim; Ertekin, Cumhur [Department of Clinical Neurophysiology, Ege University Medical School Hospital, Izmir (Turkey)

2004-01-01

Healthy adults can swallow boluses of 20 ml water in a single swallow. Individuals with impaired swallowing, however, may be unable to do so, instead requiring two or more swallows; this phenomenon is called ''piecemeal deglutition''. The term ''dysphagia limit'' refers to the volume at which piecemeal deglutition occurs. The aim of our study was to investigate the potential value of scintigraphic evaluation of piecemeal deglutition and dysphagia limit in patients with dysphagia, based on correlation with the results of submental electromyography (SM-EMG) and laryngeal sensor monitoring (LS). The study population comprised 24 patients with dysphagia secondary to neurological disorders and ten normal adults, who formed a control group. In the scintigraphic evaluation, subjects underwent four separate dynamic studies using 5, 10, 15 and 20 ml of water containing 0.5 mCi technetium-99m labelled sulphur colloid, and time-activity curves (TACs) were created for each study. Static thoracic images were also recorded in order to detect airway aspiration Observation of two or more peaks on TACs within the 10-s acquisition period was considered a sign of piecemeal deglutition. If piecemeal deglutition occurred at or below 20 ml, this volume was regarded as the dysphagia limit. Piecemeal deglutition was not found in any normal subjects; by contrast, it was observed in 14 of the 24 (58%) patients on scintigraphy and in 17 (71%) patients on EMG and LS. In three patients, signs of the airway aspiration were observed on static thoracic images. Scintigraphic and electrophysiological findings were in agreement in 19 patients (79%), and the correlation between scintigraphy and the electrophysiological methods for the evaluation of dysphagia was statistically significant (r=0.57, P=0.003). The novel finding of this study is the demonstration of piecemeal deglutition and dysphagia limit on scintigraphic studies in patients with neurogenic

The value of scintigraphy in the evaluation of oropharyngeal dysphagia

International Nuclear Information System (INIS)

Argon, Murat; Duygun, Uelkem; Kocacelebi, Kenan; Ozkilic, Hayal; Secil, Yaprak; Aydogdu, Ibrahim; Ertekin, Cumhur

2004-01-01

Healthy adults can swallow boluses of 20 ml water in a single swallow. Individuals with impaired swallowing, however, may be unable to do so, instead requiring two or more swallows; this phenomenon is called ''piecemeal deglutition''. The term ''dysphagia limit'' refers to the volume at which piecemeal deglutition occurs. The aim of our study was to investigate the potential value of scintigraphic evaluation of piecemeal deglutition and dysphagia limit in patients with dysphagia, based on correlation with the results of submental electromyography (SM-EMG) and laryngeal sensor monitoring (LS). The study population comprised 24 patients with dysphagia secondary to neurological disorders and ten normal adults, who formed a control group. In the scintigraphic evaluation, subjects underwent four separate dynamic studies using 5, 10, 15 and 20 ml of water containing 0.5 mCi technetium-99m labelled sulphur colloid, and time-activity curves (TACs) were created for each study. Static thoracic images were also recorded in order to detect airway aspiration Observation of two or more peaks on TACs within the 10-s acquisition period was considered a sign of piecemeal deglutition. If piecemeal deglutition occurred at or below 20 ml, this volume was regarded as the dysphagia limit. Piecemeal deglutition was not found in any normal subjects; by contrast, it was observed in 14 of the 24 (58%) patients on scintigraphy and in 17 (71%) patients on EMG and LS. In three patients, signs of the airway aspiration were observed on static thoracic images. Scintigraphic and electrophysiological findings were in agreement in 19 patients (79%), and the correlation between scintigraphy and the electrophysiological methods for the evaluation of dysphagia was statistically significant (r=0.57, P=0.003). The novel finding of this study is the demonstration of piecemeal deglutition and dysphagia limit on scintigraphic studies in patients with neurogenic dysphagia. Based on this finding we consider

Severity of Carpal Tunnel Syndrome and Diagnostic Accuracy of Hand and Body Anthropometric Measures

Science.gov (United States)

Mondelli, Mauro; Farioli, Andrea; Mattioli, Stefano; Aretini, Alessandro; Ginanneschi, Federica; Greco, Giuseppe; Curti, Stefania

2016-01-01

Objective To study the diagnostic properties of hand/wrist and body measures according to validated clinical and electrophysiological carpal tunnel syndrome (CTS) severity scales. Methods We performed a prospective case-control study. For each case, two controls were enrolled. Two five-stage clinical and electrophysiological scales were used to evaluate CTS severity. Anthropometric measurements were collected and obesity indicators and hand/wrist ratios were calculated. Area under the receiver operating characteristic curves (AUC), sensitivity, specificity, and likelihood ratios were calculated separately by gender. Results We consecutively enrolled 370 cases and 747 controls. The wrist-palm ratio, waist-hip-height ratio and waist-stature ratio showed the highest proportion of cases with abnormal values in the severe stages of CTS for clinical and electrophysiological severity scales in both genders. Accuracy tended to increase with CTS severity for females and males. In severe stage, most of the indexes presented moderate accuracy in both genders. Among subjects with severe CTS, the wrist-palm ratio presented the highest AUC for hand measures in the clinical and electrophysiological severity scales both in females (AUC 0.83 and 0.76, respectively) and males (AUC 0.91 and 0.82, respectively). Among subjects with severe CTS, the waist-stature ratio showed the highest AUC for body measures in the clinical and electrophysiological severity scales both in females (AUC 0.78 and 0.77, respectively) and males (AUC 0.84 and 0.76, respectively). The results of waist-hip-height ratio AUC were similar. Conclusions Wrist-palm ratio, waist-hip-height ratio and waist-stature ratio could contribute to support the diagnostic hypothesis of severe CTS that however has to be confirmed by nerve conduction study. PMID:27768728

Language effects in second-language learners: A longitudinal electrophysiological study of spanish classroom learning.

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Soskey, Laura; Holcomb, Phillip J; Midgley, Katherine J

2016-09-01

How do the neural mechanisms involved in word recognition evolve over the course of word learning in adult learners of a new second language? The current study sought to closely track language effects, which are differences in electrophysiological indices of word processing between one's native and second languages, in beginning university learners over the course of a single semester of learning. Monolingual L1 English-speakers enrolled in introductory Spanish were first trained on a list of 228 Spanish words chosen from the vocabulary to be learned in class. Behavioral data from the training session and the following experimental sessions spaced over the course of the semester showed expected learning effects. In the three laboratory sessions participants read words in three lists (English, Spanish and mixed) while performing a go/no-go lexical decision task in which event-related potentials (ERPs) were recorded. As observed in previous studies there were ERP language effects with larger N400s to native than second language words. Importantly, this difference declined over the course of L2 learning with N400 amplitude increasing for new second language words. These results suggest that even over a single semester of learning that new second language words are rapidly incorporated into the word recognition system and begin to take on lexical and semantic properties similar to native language words. Moreover, the results suggest that electrophysiological measures can be used as sensitive measures for tracking the acquisition of new linguistic knowledge. Copyright © 2016 Elsevier B.V. All rights reserved.

[Mirizzi's syndrome. Evaluation of 3 cases].

Science.gov (United States)

Garavello, A; Manfroni, S; Bellanova, G; Antonellis, D

2004-01-01

Evaluation of three cases of Mirizzi's syndrome (MS), a rare condition of non neoplastic biliary tree obstruction. We reviewed three cases of MS, operated from July 1998 to December 2000 in our institution. All patients were preoperatively evaluated by clinical examination, Ultrasound (US) and Endoscopic retrograde colangiopancreatography (CPRE) for jaundice. Computed Tomography (TC) was also performed in two. Abdominal pain was the main symptom in two patients, jaundice in one (17 mg/dl); Courvoisier-Terrier sign, suggestive for a biliopancreatic neoplasm, was present in two patients. US was sensitive for gallbladder stones and biliary tree dilatation but not specific for MS; TC only excluded a malignancy in the biliopancreatic area but wasn't useful for diagnosis. CPRE visualized a gallbladder stone obstructing the biliary tree in two cases, but failed to show the fistula between gallbladder and hepatic duct in one. Operations were performed with an "open" approach; in two patients colecystectomy was sufficient to relieve the obstruction, in one patient the biliary fistula was closed with a gallbladder tissue flap over a T tube. Mirizzi's syndrome is a rare condition, but surgeons must be aware of it, particularly in the laparoscopic era were dissection of the Calot triangle may lead to a damage of the hepatic duct. Suspect of MS is mandatory in all cases of jaundice with non neoplastic biliary obstruction. Preoperative diagnosis of MS is not easy; US is sensitive for gallbladder stone and biliary tree dilatation, but not specific for choledochal stone compression and biliobiliary fistula. TC is useful for exclusion of pancreatic or liver neoplasms but is non specific for MS. CPRE represents the "gold" standard for MS, showing the hepatic duct compression caused by the stone impacted in gallbladder neck. CPRE is not only diagnostic but also operative; sphyncterotomy and stones extraction give a temporary relief of hyerbilirubinemia waiting for operation. When

Evaluation and perceived results of moral case deliberation: A mixed methods study

NARCIS (Netherlands)

Janssens, R.; van Zadelhoff, E.; van Loo, G.; Widdershoven, G.A.; Molewijk, A.C.

2015-01-01

Background: Moral case deliberation is increasingly becoming part of various Dutch healthcare organizations. Although some evaluation studies of moral case deliberation have been carried out, research into the results of moral case deliberation within aged care is scarce. Research questions: How did

Avaliação audiológica e eletrofisiológica em crianças com transtornos psiquiátricos Audiologic and electrophysiologic evaluation in children with psychiatric disorders

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Carla Gentile Matas

2009-02-01

and Asperger syndrome and 20 individuals without psychiatric disorders from eight to 19 years of age, were submitted to audiological and electrophysiological evaluation. RESULTS: No alterations were observed on the audiological evaluation in all the individuals. In ABR, 50% of individuals with autism and 30% with Asperger syndrome presented alterations. Significant statistical differences were observed between the groups in the quantitative analysis. All groups presented alterations in AMLR and P300. In AMLR, no significant statistical differences were observed between the groups in the qualitative and quantitative analyses. In the P300, we noticed significant statistical differences between Asperger and control groups in the quantitative analysis. CONCLUSIONS: A high occurrence of alterations in auditory evoked potentials was seen in children with psychiatric disorders, although in some analysis it was observed a non-statistically significant difference when comparing study and control groups. We stress the need for a more careful investigation of the auditory function in this population.

Electrophysiology of pumpkin seeds: Memristors in vivo.

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Volkov, Alexander G; Nyasani, Eunice K; Tuckett, Clayton; Greeman, Esther A; Markin, Vladislav S

2016-01-01

Leon Chua, the discoverer of a memristor, theoretically predicted that voltage gated ion channels can be memristors. We recently found memristors in different plants such as the Venus flytrap, Mimosa pudica, Aloe vera, apple fruits, and in potato tubers. There are no publications in literature about the existence of memristors in seeds. The goal of this work was to discover if pumpkin seeds might have memristors. We selected Cucurbita pepo L., cv. Cinderella, Cucurbita maxima L. cv Warty Goblin, and Cucurbita maxima L., cv. Jarrahdale seeds for this analysis. In these seeds, we found the presence of resistors with memory. The analysis was based on cyclic voltammetry where a memristor should manifest itself as a nonlinear two-terminal electrical element, which exhibits a pinched hysteresis loop on a current-voltage plane for any bipolar cyclic voltage input signal. Dry dormant pumpkin seeds have very high electrical resistance without memristive properties. The electrostimulation by bipolar sinusoidal or triangular periodic waves induces electrical responses in imbibed pumpkin seeds with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, transforms a memristor to a resistor in pumpkin seeds. NPPB (5-Nitro-2-(3-phenylpropylamino)benzoic acid) inhibits the memristive properties of imbibed pumpkin seeds. The discovery of memristors in pumpkin seeds creates a new direction in the understanding of electrophysiological phenomena in seeds.

Integrated platform and API for electrophysiological data.

Science.gov (United States)

Sobolev, Andrey; Stoewer, Adrian; Leonhardt, Aljoscha; Rautenberg, Philipp L; Kellner, Christian J; Garbers, Christian; Wachtler, Thomas

2014-01-01

Recent advancements in technology and methodology have led to growing amounts of increasingly complex neuroscience data recorded from various species, modalities, and levels of study. The rapid data growth has made efficient data access and flexible, machine-readable data annotation a crucial requisite for neuroscientists. Clear and consistent annotation and organization of data is not only an important ingredient for reproducibility of results and re-use of data, but also essential for collaborative research and data sharing. In particular, efficient data management and interoperability requires a unified approach that integrates data and metadata and provides a common way of accessing this information. In this paper we describe GNData, a data management platform for neurophysiological data. GNData provides a storage system based on a data representation that is suitable to organize data and metadata from any electrophysiological experiment, with a functionality exposed via a common application programming interface (API). Data representation and API structure are compatible with existing approaches for data and metadata representation in neurophysiology. The API implementation is based on the Representational State Transfer (REST) pattern, which enables data access integration in software applications and facilitates the development of tools that communicate with the service. Client libraries that interact with the API provide direct data access from computing environments like Matlab or Python, enabling integration of data management into the scientist's experimental or analysis routines.

Electrophysiological mapping of novel prefrontal - cerebellar pathways

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Thomas C Watson

2009-08-01

Full Text Available Whilst the cerebellum is predominantly considered a sensorimotor control structure, accumulating evidence suggests that it may also subserve non motor functions during cognition. However, this possibility is not universally accepted, not least because the nature and pattern of links between higher cortical structures and the cerebellum are poorly characterized. We have therefore used in vivo electrophysiological methods in anaesthetized rats to directly investigate connectivity between the medial prefrontal cortex (prelimbic subdivision, PrL and the cerebellum. Stimulation of deep layers of PrL evoked distinct field potentials in the cerebellar cortex with a mean latency to peak of approximately 35ms. These responses showed a well-defined topography, and were maximal in lobule VII of the contralateral vermis (a known oculomotor centre; they were not attenuated by local anesthesia of the overlying M2 motor cortex, though M2 stimulation did evoke field potentials in lobule VII with a shorter latency. Single-unit recordings showed that prelimbic cortical stimulation elicits complex spikes in lobule VII Purkinje cells, indicating transmission via a previously undescribed cerebro-olivocerebellar pathway. Our results therefore establish a physiological basis for communication between PrL and the cerebellum. The role(s of this pathway remain to be resolved, but presumably relate to control of eye movements and/or distributed networks associated with integrated prefrontal cortical functions.

Computerized tomographic evaluations of 33 consecutive cases of craniopharyngiomas

International Nuclear Information System (INIS)

Nagasawa, Shiro; Takeuchi, Juji; Yamashita, Junkoh; Handa, Hajime

1983-01-01

Although craniopharyngiomas are widely known to exhibit three basic CT characteristics; calcification, cyst(s) and contrast enhancement (CE), several cases with atypical CT manifestations have been reported lately. These atypical manifestations can be classified into unusual extensions of the tumors, high dense cyst and marked homogeneous CE. The CT scans obtained in our recent series of 33 craniopharyngiomas were evaluated to analyze tumoral extensions, cyst density and CE. Cystic tumors were much more frequent than solid tumors (Table 1); 13 cases (39%) were exclusively cystic, 15 cases (45%) equally cystic and solid, and 5 case (15%) solid. Calcifications were present in 80 % in children and 39% in adults. Unusual extensions were noted in 7 cases (Fig. 2,3,4); anteriorly to the frontal fossa (5 cases, 15 %), laterally to the temporal fossa (1 case, 3%) and posteriorly to the posterior fossa (1 case, 3%). All these tumors were either pure cystic or equally cystic and solid. Cystic portions were detected in the tumors of 28 cases (Table 2). Although the majority of the cystic portions (22 cases, 79%) were low density, iso-dense cysts were observed in 6 cases (21%). Out of 20 cases exhibiting solid portions in the tumors, high density areas (calcified masses) were detected in 3 cases and mixed density areas in 17 cases (Table 3). While these 17 cases showed CE, marked homogeneous CE were noted in 5 cases (29%)

Evaluation of Cases Consulted to Forensic Toxicology Laboratory between 2008 and 2012

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Ismail Ethem Goren

2013-08-01

Full Text Available Purpose: In this study, we aimed to determine annual and seasonal distribution of cases and affecting factors of the distribution in Cukurova University Hospital, Forensic Toxicology Laboratory. Method: Five-year (up to 2012 from 2008 archives of cases consulted to our forensic toxicology laboratory was investigated and classified according to gender, situation of case, type of poisoning, seasonal distribution, findings were statistically evaluated by SPSS v20.0 software Results: After screening five-year archives using laboratory registration book, we determined that of 608 cases 49.5 % were from emergency medicine, 19.6 % from pediatric, 7.4 % from psychiatry, 4.4 % 4.4 from neurology, 2.3 % from other units of the hospital, 7.9 % from judicial authorities, 4.8 % from special requests and 6.1 % from circumjacent hospitals. 57.9 % of the cases are male and 42.1 % are female. 87.3 % of 608 cases were clinical cases, 7.9 % were forensic cases, 4.8 % special requests. 95.8 % of judicial cases were male and 85.4 % were drugs of abuse cases. 28.1 % of clinical cases were the carbon monoxide poisoning and 64.3 % of the carbon monoxide poisoning cases were female. Conclusion: When five-year data were evaluated, we determine that numbers of case are increasing every year. Males are more than in females. Forensic cases which were mostly drugs of abuse were most commonly have seen in male. When our data were investigated together with TUBIM’s data belong to 2009, 2010, 2011 and 2012 (Turkey Monitoring Centre for Drugs and Drugs Addiction, the use of drug abuse were seen most commonly in male. Also carbon monoxide poisoning in clinical cases were evaluated and we see that Carbon monoxide intoxication in winter was more than in summer due to heating. Women who exposed to carbon monoxide were more than men to be much more at home according to men. [Cukurova Med J 2013; 38(4.000: 675-680

Inhibitory effects of Urtica dioica L. root on electrophysiological properties of isolated rabbit atrioventricular node

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A. Enayati

2017-11-01

Full Text Available Background and objectives: The ideal drug for treatment of a wide range of supraventricular arrhythmia hasn't yet been developed. Previous studies have shown antihypertensive and negative inotropic effects of the Urtica dioica L. (nettle. Therefore, the aim of present study is to determine the rate dependent inhibitory effects of ethanol extract of nettle root and investigate the role of adrenoceptors in the anti-arrhythmic mechanism of nettle on the isolated rabbit atrio-ventricular node. Methods: Urtica dioica roots were collected from Gorgan (Golestan, Iran. Male New Zealand rabbits (n=7 were used in all of the experiments. Experimental stimulation protocols (WBCL; Recovery, Facilitation, Fatigue were applied to assess electrophysiological properties of Node. All protocols were repeated in the presence and absence (control of different concentration (0.25-0.5 w/v % of nettle and 1 μM nadolol. Data were shown as Mean±SE, difference between groups statistically were assessed by SPSS software. Results: Nettle (0.5 w/v significantly decreased basic and functional properties of node as WBCL, ERP, FRP, AVCT and magnitude of fatigue (∆AH significantly increased but ∆FRP significantly decreased. In the presence of nadolol (1μM as a nonselective β-blocker, nettle (0.3 mg/L could not repeat its effects on electrophysiological properties of AV-node. Conclusion: The results showed the modifying properties of Urtica dioica root extract. It may be considered as a candidate for the treatment of supraventicular arrhythmias.

A protocol for preparation and transfection of rat entorhinal cortex organotypic cultures for electrophysiological whole-cell recordings

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Nicholas I. Cilz

2017-01-01

Full Text Available Understanding how neuromodulators influence synaptic transmission and intrinsic excitability within the entorhinal cortex (EC is critical to furthering our understanding of the molecular and cellular aspects of this region. Organotypic cultures can provide a cost-effective means to employ selective molecular biological strategies in elucidating cellular mechanisms of neuromodulation in the EC. We therefore adapted our acute slice model for organotypic culture applications and optimized a protocol for the preparation and biolistic transfection of cultured horizontal EC slices. Here, we present our detailed protocol for culturing EC slices. Using an n-methyl-d-glucamine (NMDG-containing cutting solution, we obtain healthy EC slice cultures for electrophysiological recordings. We also present our protocol for the preparation of “bullets” carrying one or more constructs and demonstrate successful transfection of EC slices. We build upon previous methods and highlight specific aspects in our method that greatly improved the quality of our results. We validate our methods using immunohistochemical, imaging, and electrophysiological techniques. The novelty of this method is that it provides a description of culturing and transfection of EC neurons for specifically addressing their functionality. This method will enable researchers interested in entorhinal function to quickly adopt a similar slice culture transfection system for their own investigations.

Maternal mobile phone exposure alters intrinsic electrophysiological properties of CA1 pyramidal neurons in rat offspring.

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Razavinasab, Moazamehosadat; Moazzami, Kasra; Shabani, Mohammad

2016-06-01

Some studies have shown that exposure to electromagnetic field (EMF) may result in structural damage to neurons. In this study, we have elucidated the alteration in the hippocampal function of offspring Wistar rats (n = 8 rats in each group) that were chronically exposed to mobile phones during their gestational period by applying behavioral, histological, and electrophysiological tests. Rats in the EMF group were exposed to 900 MHz pulsed-EMF irradiation for 6 h/day. Whole cell recordings in hippocampal pyramidal cells in the mobile phone groups did show a decrease in neuronal excitability. Mobile phone exposure was mostly associated with a decrease in the number of action potentials fired in spontaneous activity and in response to current injection in both male and female groups. There was an increase in the amplitude of the afterhyperpolarization (AHP) in mobile phone rats compared with the control. The results of the passive avoidance and Morris water maze assessment of learning and memory performance showed that phone exposure significantly altered learning acquisition and memory retention in male and female rats compared with the control rats. Light microscopy study of brain sections of the control and mobile phone-exposed rats showed normal morphology.Our results suggest that exposure to mobile phones adversely affects the cognitive performance of both female and male offspring rats using behavioral and electrophysiological techniques. © The Author(s) 2014.

Awake craniotomy, electrophysiologic mapping, and tumor resection with high-field intraoperative MRI.

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Parney, Ian F; Goerss, Stephan J; McGee, Kiaran; Huston, John; Perkins, William J; Meyer, Frederic B

2010-05-01

Awake craniotomy and electrophysiologic mapping (EPM) is an established technique to facilitate the resection of near eloquent cortex. Intraoperative magnetic resonance imaging (iMRI) is increasingly used to aid in the resection of intracranial lesions. Standard draping protocols in high-field iMRI units make awake craniotomies challenging, and only two groups have previously reported combined EPM and high-field iMRI. We present an illustrative case describing a simple technique for combining awake craniotomy and EPM with high-field iMRI. A movable platter is used to transfer the patient from the operating table to a transport trolley and into the adjacent MRI and still maintaining the patient's surgical position. This system allows excess drapes to be removed, facilitating awake craniotomy. A 57-year-old right-handed man presented with new onset seizures. Magnetic resonance imaging demonstrated a large left temporal mass. The patient underwent an awake, left frontotemporal craniotomy. The EPM demonstrated a single critical area for speech in his inferior frontal gyrus. After an initial tumor debulking, the scalp flap was loosely approximated, the wound was covered with additional drapes, and the excess surrounding drapes were trimmed. An iMRI was obtained. The image-guidance system was re-registered and the patient was redraped. Additional resection was performed, allowing extensive removal of what proved to be an anaplastic astrocytoma. The patient tolerated this well without any new neurological deficits. Standard protocols for positioning and draping in high-field iMRI units make awake craniotomies problematic. This straightforward technique for combined awake EPM and iMRI may facilitate safe removal of large lesions in eloquent cortex. Copyright © 2010 Elsevier Inc. All rights reserved.

Auditory Cortical Maturation in a Child with Cochlear Implant: Analysis of Electrophysiological and Behavioral Measures

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Liliane Aparecida Fagundes Silva

2015-01-01

Full Text Available The purpose of this study was to longitudinally assess the behavioral and electrophysiological hearing changes of a girl inserted in a CI program, who had bilateral profound sensorineural hearing loss and underwent surgery of cochlear implantation with electrode activation at 21 months of age. She was evaluated using the P1 component of Long Latency Auditory Evoked Potential (LLAEP; speech perception tests of the Glendonald Auditory Screening Procedure (GASP; Infant Toddler Meaningful Auditory Integration Scale (IT-MAIS; and Meaningful Use of Speech Scales (MUSS. The study was conducted prior to activation and after three, nine, and 18 months of cochlear implant activation. The results of the LLAEP were compared with data from a hearing child matched by gender and chronological age. The results of the LLAEP of the child with cochlear implant showed gradual decrease in latency of the P1 component after auditory stimulation (172 ms–134 ms. In the GASP, IT-MAIS, and MUSS, gradual development of listening skills and oral language was observed. The values of the LLAEP of the hearing child were expected for chronological age (132 ms–128 ms. The use of different clinical instruments allow a better understanding of the auditory habilitation and rehabilitation process via CI.

Auditory Cortical Maturation in a Child with Cochlear Implant: Analysis of Electrophysiological and Behavioral Measures

Science.gov (United States)

Silva, Liliane Aparecida Fagundes; Couto, Maria Inês Vieira; Tsuji, Robinson Koji; Bento, Ricardo Ferreira; de Carvalho, Ana Claudia Martinho; Matas, Carla Gentile

2015-01-01

The purpose of this study was to longitudinally assess the behavioral and electrophysiological hearing changes of a girl inserted in a CI program, who had bilateral profound sensorineural hearing loss and underwent surgery of cochlear implantation with electrode activation at 21 months of age. She was evaluated using the P1 component of Long Latency Auditory Evoked Potential (LLAEP); speech perception tests of the Glendonald Auditory Screening Procedure (GASP); Infant Toddler Meaningful Auditory Integration Scale (IT-MAIS); and Meaningful Use of Speech Scales (MUSS). The study was conducted prior to activation and after three, nine, and 18 months of cochlear implant activation. The results of the LLAEP were compared with data from a hearing child matched by gender and chronological age. The results of the LLAEP of the child with cochlear implant showed gradual decrease in latency of the P1 component after auditory stimulation (172 ms–134 ms). In the GASP, IT-MAIS, and MUSS, gradual development of listening skills and oral language was observed. The values of the LLAEP of the hearing child were expected for chronological age (132 ms–128 ms). The use of different clinical instruments allow a better understanding of the auditory habilitation and rehabilitation process via CI. PMID:26881163

Alternans promotion in cardiac electrophysiology models by delay differential equations.

Science.gov (United States)

Gomes, Johnny M; Dos Santos, Rodrigo Weber; Cherry, Elizabeth M

2017-09-01

Cardiac electrical alternans is a state of alternation between long and short action potentials and is frequently associated with harmful cardiac conditions. Different dynamic mechanisms can give rise to alternans; however, many cardiac models based on ordinary differential equations are not able to reproduce this phenomenon. A previous study showed that alternans can be induced by the introduction of delay differential equations (DDEs) in the formulations of the ion channel gating variables of a canine myocyte model. The present work demonstrates that this technique is not model-specific by successfully promoting alternans using DDEs for five cardiac electrophysiology models that describe different types of myocytes, with varying degrees of complexity. By analyzing results across the different models, we observe two potential requirements for alternans promotion via DDEs for ionic gates: (i) the gate must have a significant influence on the action potential duration and (ii) a delay must significantly impair the gate's recovery between consecutive action potentials.

Alternans promotion in cardiac electrophysiology models by delay differential equations

Science.gov (United States)

Gomes, Johnny M.; dos Santos, Rodrigo Weber; Cherry, Elizabeth M.

2017-09-01

Cardiac electrical alternans is a state of alternation between long and short action potentials and is frequently associated with harmful cardiac conditions. Different dynamic mechanisms can give rise to alternans; however, many cardiac models based on ordinary differential equations are not able to reproduce this phenomenon. A previous study showed that alternans can be induced by the introduction of delay differential equations (DDEs) in the formulations of the ion channel gating variables of a canine myocyte model. The present work demonstrates that this technique is not model-specific by successfully promoting alternans using DDEs for five cardiac electrophysiology models that describe different types of myocytes, with varying degrees of complexity. By analyzing results across the different models, we observe two potential requirements for alternans promotion via DDEs for ionic gates: (i) the gate must have a significant influence on the action potential duration and (ii) a delay must significantly impair the gate's recovery between consecutive action potentials.

Anatomical localization of electrophysiological recording sites by co-ordinate transformation.

Science.gov (United States)

Sinex, D G

1997-07-18

A method for estimating the anatomical locations of the units recorded in electrophysiological mapping experiments is described. A total of three locations must be marked by dye injections or electrolytic lesions and identified in tissue sections. From those locations, equations are derived to translate, scale, and rotate the three-dimensional co-ordinates of the recording sites, so that they are correct for a second, three-dimensional co-ordinate system based on the anatomy of the mapped structure. There is no limit to the number of recording sites that can be localized. This differs from methods that require a dye injection or lesion to be made at the exact location at which a particular unit was recorded. The accuracy of the transformed co-ordinates is limited by the accuracy with which the co-ordinates can be measured: in test measurements and in the experiments for which this algorithm was developed, the computed co-ordinates were typically accurate to within 100 microns or less.

Effects of Motivation and Medication on Electrophysiological Markers of Response Inhibition in Children with Attention-Deficit/Hyperactivity Disorder

OpenAIRE

Groom, Madeleine J.; Scerif, Gaia; Liddle, Peter F.; Batty, Martin J.; Liddle, Elizabeth B.; Roberts, Katherine L.; Cahill, John D.; Liotti, Mario; Hollis, Chris

2010-01-01

Background Theories of attention-deficit/hyperactivity disorder (ADHD) posit either executive deficits and/or alterations in motivational style and reward processing as core to the disorder. Effects of motivational incentives on electrophysiological correlates of inhibitory control and relationships between motivation and stimulant medication have not been explicitly tested. Methods Children (9?15 years) with combined-type ADHD (n = 28) and matched typically developing children (CTRL) (n = 28...

A SUBSTRATE AND A METHOD FOR DETERMINING AND/OR MONITORING ELECTROPHYSIOLOGICAL PROPERTIES OF ION CHANNELS

DEFF Research Database (Denmark)

2001-01-01

The present invention relates to a substrate and a method for obtaining an electrophysiological measuring configuration in which a cell forms a high resistive seal (giga-seal) around a measuring electrode making it suitable for determining and monitoring a current flow through the cell membrane...... and reference electrodes formed by wafer processing technology. The electrodes are adapted to conduct a current between them by delivery of ions by one electrode and receipt of ions by the other electrode and are typically silver/silver halide electrodes. This allows for effective and fast measuring of cells...

Interesting asian plants: their compounds and effects on electrophysiology and behaviour.

Science.gov (United States)

Abdullah, Jafri Malin

2011-10-01

There have been numerous non-scientific reports on the behavioural effects of Asian plants in humans who consumed these plants wholly or part thereof. Knowledge passed from generation to generation informs us of plants that increase effort and stamina, such as during paddy planting after the ingestion of Mitragyna speciosa Korth (ketum) as a tea supplement. Centella asiatica and Myristica fragrans are used as herbs to improve memory and to treat epilepsy, respectively. Zizyphus mauritiana is used to treat headache and burn pain, acts as an antitussive, and reduces rigor mortis immediately after death. These plants, which have been identified to exhibit analgaesic, muscle-relaxing, and nootropic effects, may contain important bio-compounds for medicinal chemistry and pharmaceutical research in Malaysia. The electrophysiology properties of these plants and their effects on epilepsy, behaviour, and pain will lead Malaysia to future new drug discoveries.

Stability results for the parameter identification inverse problem in cardiac electrophysiology

Science.gov (United States)

Lassoued, Jamila; Mahjoub, Moncef; Zemzemi, Néjib

2016-11-01

In this paper we prove a stability estimate of the parameter identification problem in cardiac electrophysiology modeling. We use the monodomain model which is a reaction diffusion parabolic equation where the reaction term is obtained by solving an ordinary differential equation (ODE). We are interested in proving the stability of the identification of the parameter {τ }{in}, which is the parameter that multiplies the cubic term in the reaction term. The proof of the result is based on a new Carleman-type estimate for both partial differential equation (PDE) and ODE problems. As a consequence of the stability result we prove the uniqueness of the parameter {τ }{in} giving some observations of both state variables at a given time t 0 in the whole domain and in the PDE variable in a non empty open subset w 0 of the domain.

External Evaluation of Education and Teacher Work: The Brazilian Case

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Rothen, José Carlos; da Cunha Malheiros Santana, Andréia

2015-01-01

This article aims to discuss whether external evaluations are instruments to ensure increased quality of public school education. It is part of a research that investigated how evaluation results and the resulting indices were used in two schools in the state of São Paulo (Brazil). The methodology adopted was the case study, using different…

Using Case Studies to Promote Student Engagement in Primary Literature Data Analysis and Evaluation

Science.gov (United States)

Cook-Snyder, Denise R.

2017-01-01

Analyzing and evaluating primary literature data is a common learning objective in undergraduate neuroscience courses. However, students with more clinically focused career goals often dismiss the relevance of evaluating basic neuroscience literature. Here, we describe using case studies to promote student engagement in primary literature in a cellular and molecular neuroscience course. Two example literature-based case studies are provided: Untwisting Pretzel Syndrome, a neurodevelopment case exploring synapse formation in a pretzel syndrome patient, and The Trials of ALS, a neurodegeneration case exploring axon degeneration and repair in an amyotrophic lateral sclerosis patient. These cases were assigned after neurodevelopment and neurodegeneration lectures covering key concepts. Both cases begin by introducing the patient and hypothesizing symptoms and diagnoses, followed by scenes incorporating primary data to illustrate disease pathogenesis and treatments. Students complete questions embedded in these cases as homework, and class time is used to discuss their answers. Discussion emphasizes that there can be multiple “correct” answers, and the best answers are accurate and well-supported. Accordingly, students edit their answers in class, and these annotations are factored into a pass/fail grade on the case. Additional scenes and questions from the same case studies are used on the course’s take-home exams, thereby allowing students to practice primary data analysis and evaluation before a graded assignment. Student evaluations support literature-based case studies as an effective learning tool, with students identifying cases as the most valuable aspect of the course, and reporting increased confidence in understanding cellular and molecular neuroscience. PMID:29371850

Using Case Studies to Promote Student Engagement in Primary Literature Data Analysis and Evaluation.

Science.gov (United States)

Cook-Snyder, Denise R

2017-01-01

Analyzing and evaluating primary literature data is a common learning objective in undergraduate neuroscience courses. However, students with more clinically focused career goals often dismiss the relevance of evaluating basic neuroscience literature. Here, we describe using case studies to promote student engagement in primary literature in a cellular and molecular neuroscience course. Two example literature-based case studies are provided: Untwisting Pretzel Syndrome, a neurodevelopment case exploring synapse formation in a pretzel syndrome patient, and The Trials of ALS, a neurodegeneration case exploring axon degeneration and repair in an amyotrophic lateral sclerosis patient. These cases were assigned after neurodevelopment and neurodegeneration lectures covering key concepts. Both cases begin by introducing the patient and hypothesizing symptoms and diagnoses, followed by scenes incorporating primary data to illustrate disease pathogenesis and treatments. Students complete questions embedded in these cases as homework, and class time is used to discuss their answers. Discussion emphasizes that there can be multiple "correct" answers, and the best answers are accurate and well-supported. Accordingly, students edit their answers in class, and these annotations are factored into a pass/fail grade on the case. Additional scenes and questions from the same case studies are used on the course's take-home exams, thereby allowing students to practice primary data analysis and evaluation before a graded assignment. Student evaluations support literature-based case studies as an effective learning tool, with students identifying cases as the most valuable aspect of the course, and reporting increased confidence in understanding cellular and molecular neuroscience.

Case report

African Journals Online (AJOL)

ebutamanya

2015-01-22

Jan 22, 2015 ... at rest, including while in bed and while driving her car. The episodes of ... another country where advanced technology electrophysiological study confirmed the ... instability [12,13]. Exceptionally the implantable automatic.

Evaluating performance of local case-mix system by international comparison: a case study in Beijing, China.

Science.gov (United States)

Jian, Wei-Yan; Lu, Ming; Cui, Tao; Hu, Mu

2011-01-01

Case-mix is an important tool for health planning and management in many countries. As a major developing country, China is considering the introduction of the case-mix system in the health reform. Beijing, the capital of China, developed a local case-mix version whose performance needs to be evaluated before utilization. The objective of this study was to evaluate the performance of the case-mix system developed in Beijing by comparing it with those used in Australia and the U.S.A. A total of 1.3 million inpatient records from 154 hospitals in Beijing in 2008 were grouped respectively using three case-mix systems: (i) Beijing Diagnosis Related Groups (BJ-DRGs); (ii) US-based All Patient DRGs; and (iii) Australian Refined DRGs. Coefficient of variation (CV) and reduction in variance (RIV) were used to measure the performance of DRGs system. The BJ-DRGs produced the best CV and RIV results for expenditure. However, at the level of Major Diagnostic Category (MDC), three MDCs of BJ-DRGs gave the poorest RIVs for both expenditure and length of stay. Although the performance of BJ-DRGs was acceptable, further revision and improvement is needed. Comparisons with other mature DRGs versions can assist in identifying the improvement priorities of the local version. Copyright © 2011 John Wiley & Sons, Ltd.

Toxicity of marine pollutants on the ascidian oocyte physiology: an electrophysiological approach.

Science.gov (United States)

Gallo, Alessandra

2018-02-01

In marine animals with external fertilization, gametes are released into seawater where fertilization and embryo development occur. Consequently, pollutants introduced into the marine environment by human activities may affect gametes and embryos. These xenobiotics can alter cell physiology with consequent reduction of fertilization success. Here the adverse effects on the reproductive processes of the marine invertebrate Ciona intestinalis (ascidian) of different xenobiotics: lead, zinc, an organic tin compound and a phenylurea herbicide were evaluated. By using the electrophysiological technique of whole-cell voltage clamping, the effects of these compounds on the mature oocyte plasma membrane electrical properties and the electrical events of fertilization were tested by calculating the concentration that induced 50% normal larval formation (EC50). The results demonstrated that sodium currents in mature oocytes were reduced in a concentration-dependent manner by all tested xenobiotics, with the lowest EC50 value for lead. In contrast, fertilization current frequencies were differently affected by zinc and organic tin compound. Toxicity tests on gametes demonstrated that sperm fertilizing capability and fertilization oocyte competence were not altered by xenobiotics, whereas fertilization was inhibited in zinc solution and underwent a reduction in organic tin compound solution (EC50 value of 1.7 µM). Furthermore, fertilized oocytes resulted in a low percentage of normal larvae with an EC50 value of 0.90 µM. This study shows that reproductive processes of ascidians are highly sensitive to xenobiotics suggesting that they may be considered a reliable biomarker and that ascidians are suitable model organisms to assess marine environmental quality.

Permanent pacemaker implantation in octogenarians with unexplained syncope and positive electrophysiologic testing.

Science.gov (United States)

Giannopoulos, Georgios; Kossyvakis, Charalampos; Panagopoulou, Vasiliki; Tsiachris, Dimitrios; Doudoumis, Konstantinos; Mavri, Maria; Vrachatis, Dimitrios; Letsas, Konstantinos; Efremidis, Michael; Katsivas, Apostolos; Lekakis, John; Deftereos, Spyridon

2017-05-01

Syncope is a common problem in the elderly, and a permanent pacemaker is a therapeutic option when a bradycardic etiology is revealed. However, the benefit of pacing when no association of symptoms to bradycardia has been shown is not clear, especially in the elderly. The aim of this study was to evaluate the effect of pacing on syncope-free mortality in patients aged 80 years or older with unexplained syncope and "positive" invasive electrophysiologic testing (EPT). This was an observational study. A positive EPT for the purposes of this study was defined by at least 1 of the following: a corrected sinus node recovery time of >525 ms, a basic HV interval of >55 ms, detection of infra-Hisian block, or appearance of second-degree atrioventricular block on atrial decremental pacing at a paced cycle length of >400 ms. Among the 2435 screened patients, 228 eligible patients were identified, 145 of whom were implanted with a pacemaker. Kaplan-Meier analysis determined that time to event (syncope or death) was 50.1 months (95% confidence interval 45.4-54.8 months) with a pacemaker vs 37.8 months (95% confidence interval 31.3-44.4 months) without a pacemaker (log-rank test, P = .001). The 4-year time-dependent estimate of the rate of syncope was 12% vs 44% (P pacemaker implantation was independently associated with longer syncope-free survival. Significant differences were also shown in the individual components of the primary outcome measure (syncope and death from any cause). Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Familial adult spinal muscular atrophy associated with the VAPB gene: report of 42 cases in Brazil

Directory of Open Access Journals (Sweden)

Victor Kosac

2013-10-01

Full Text Available Familial spinal muscular atrophy (FSMA associated with the vesicle-associated membrane protein-associated protein B (VAPB gene is a rare autosomal dominant disease with late onset and slow progression. We studied 10 of 42 patients from 5 families by taking clinical histories and performing physical exams, electrophysiological studies, and genetic tests. All patients presented late onset disease with slow progression characterized by fasciculations, proximal weakness, amyotrophy, and hypoactive deep tendon reflex, except two who exhibited brisk reflex. Two patients showed tongue fasciculations and respiratory insufficiency. Electrophysiological studies revealed patterns of lower motor neuron disease, and genetic testing identified a P56S mutation of the VAPB gene. Although it is a rare motor neuron disease, FSMA with this mutation might be much more prevalent in Brazil than expected, and many cases may be undiagnosed. Genetic exams should be performed whenever it is suspected in Brazil.

Myokit: A simple interface to cardiac cellular electrophysiology.

Science.gov (United States)

Clerx, Michael; Collins, Pieter; de Lange, Enno; Volders, Paul G A

2016-01-01

Myokit is a new powerful and versatile software tool for modeling and simulation of cardiac cellular electrophysiology. Myokit consists of an easy-to-read modeling language, a graphical user interface, single and multi-cell simulation engines and a library of advanced analysis tools accessible through a Python interface. Models can be loaded from Myokit's native file format or imported from CellML. Model export is provided to C, MATLAB, CellML, CUDA and OpenCL. Patch-clamp data can be imported and used to estimate model parameters. In this paper, we review existing tools to simulate the cardiac cellular action potential to find that current tools do not cater specifically to model development and that there is a gap between easy-to-use but limited software and powerful tools that require strong programming skills from their users. We then describe Myokit's capabilities, focusing on its model description language, simulation engines and import/export facilities in detail. Using three examples, we show how Myokit can be used for clinically relevant investigations, multi-model testing and parameter estimation in Markov models, all with minimal programming effort from the user. This way, Myokit bridges a gap between performance, versatility and user-friendliness. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance evaluation of PCA-based spike sorting algorithms.

Science.gov (United States)

Adamos, Dimitrios A; Kosmidis, Efstratios K; Theophilidis, George

2008-09-01

Deciphering the electrical activity of individual neurons from multi-unit noisy recordings is critical for understanding complex neural systems. A widely used spike sorting algorithm is being evaluated for single-electrode nerve trunk recordings. The algorithm is based on principal component analysis (PCA) for spike feature extraction. In the neuroscience literature it is generally assumed that the use of the first two or most commonly three principal components is sufficient. We estimate the optimum PCA-based feature space by evaluating the algorithm's performance on simulated series of action potentials. A number of modifications are made to the open source nev2lkit software to enable systematic investigation of the parameter space. We introduce a new metric to define clustering error considering over-clustering more favorable than under-clustering as proposed by experimentalists for our data. Both the program patch and the metric are available online. Correlated and white Gaussian noise processes are superimposed to account for biological and artificial jitter in the recordings. We report that the employment of more than three principal components is in general beneficial for all noise cases considered. Finally, we apply our results to experimental data and verify that the sorting process with four principal components is in agreement with a panel of electrophysiology experts.

A suspended act: increased reflectivity and gender-dependent electrophysiological change following Quadrato Motor Training.

Science.gov (United States)

Ben-Soussan, Tal Dotan; Berkovich-Ohana, Aviva; Glicksohn, Joseph; Goldstein, Abraham

2014-01-01

Quadrato Motor Training (QMT) is a specifically-structured walking meditation, aimed at improving reflectivity and lowering habitual thought and movement. Here we set out to examine the possible effect of QMT on reflectivity, employing the Hidden Figures Test (HFT), which assesses both spatial performance (measured by correct answers) as well as reflectivity (interpolated from correct answers and reaction time). In the first study (n = 24, only females), we showed that QMT significantly improves HFT performance, compared to two groups, controlling for cognitive or motor aspects of the QMT: Verbal Training (identical cognitive training with verbal response) and Simple Motor Training (similar motor training with reduced choice requirements). These results show that QMT improves HFT performance above the pre-post expected learning. In the second study, building on previous literature showing gender-dependent effects on cognitive performance, we conducted a preliminary pilot examining gender-dependent effect of training on reflectivity and its electrophysiological counterparts. EEG analyses focused on theta, alpha and gamma coherence. HFT performance and resting-state EEG were measured in 37 participants (20 males), using a within-subject pre-post design. Following training, HFT performance improved in both genders. However, we found a gender-dependent difference in functional connectivity: while theta and alpha intra-hemispheric coherence was enhanced in females, the opposite pattern was found in males. These results are discussed in relation to neuronal efficiency theory. Together, the results demonstrate that QMT improves spatial performance, and may involve a gender-dependent electrophysiological effect. This study emphasizes both the importance of studying gender-related training effects within the contemplative neuroscience endeavor, as well as the need to widen its scope toward including "contemplation in action."

Case of Unilateral Peripheral Cone Dysfunction

Directory of Open Access Journals (Sweden)

Yujin Mochizuki

2012-05-01

Full Text Available Purpose: Peripheral cone dystrophy is a subgroup of cone dystrophy, and only 4 cases have been reported. We present a patient with unilateral peripheral cone dysfunction and report the functional changes determined by electrophysiological tests and ultrastructural changes determined by spectral domain optical coherence tomography (SD-OCT. Case: A 34-year-old woman complained of blurred vision in both eyes. Our examination showed that her visual acuity was 0.05 OD and 0.2 OS. A relative afferent pupillary defect was present in her right eye. The results of slit-lamp examination, ophthalmoscopy, and fluorescein angiography were normal except for pallor of the right optic disc. SD-OCT showed a diffuse thinning of the retina in the posterior pole of the right eye. A severe constriction of the visual fields was found in both eyes but more in the right eye. The photopic full-field electroretinograms (ERGs were reduced in the right eye but normal in the left eye. The multifocal ERGs were severely reduced throughout the visual field except in the central area of the right eye. The multifocal ERGs from the left eye were normal. The pattern visual evoked responses were within the normal range in both eyes. She had a 5-year history of sniffing paint thinner. Results: Although the visual dysfunction was initially suspected to be due to psychological problems from the results of subjective tests, objective tests indicated a peripheral cone dysfunction in the right eye. The pathophysiological mechanism and the relationship with thinner sniffing were not determined. Conclusions: Our findings indicate that peripheral cone dysfunction can occur unilaterally. Electrophysiology and SD-OCT are valuable tests to perform to determine the pathogenesis of unusual ocular findings objectively.

Emotional Availability Modulates Electrophysiological Correlates of Executive Functions in Preschool Children.

Science.gov (United States)

Schneider-Hassloff, Henriette; Zwönitzer, Annabel; Künster, Anne K; Mayer, Carmen; Ziegenhain, Ute; Kiefer, Markus

2016-01-01

Executive functions (EFs) - a set of cognitive control abilities - mediate resilience to stress and are associated with academic achievement and health throughout life. They are crucially linked to prefrontal cortex function as well as to other cortical and subcortical brain functions, which are maturing throughout childhood at different rates. Recent behavioral research suggested that children's EFs were related to parenting quality and child attachment security, but the neural correlates of these associations are unknown. With this study we tested in 4- to 6-year-old healthy children (N = 27) how emotional availability (EA) of the mother-child-interaction was associated with behavioral and electrophysiological correlates of response inhibition (a core EF) in a Go/Nogo task, using event-related potential recordings (ERPs), and with behavioral performance in a Delay of Gratification (DoG) and a Head-Toes-Knees-Shoulders task (HTKS). Our data showed that the Go/Nogo task modulated children's ERP components resembling adult electrophysiological indices of response inhibition - the N2 and P3/LPC ERPs-, but the children's N2 and P3/LPC ERPs showed longer latencies. Higher maternal autonomy-fostering behavior and greater child responsiveness were significantly associated with smaller children's N2 Go/Nogo effects at fronto-central and parietal sites and with greater Go/Nogo effects in the N2 time window at occipital sites, over and above children's age and intelligence. Additionally, greater maternal sensitivity and a higher dyadic EA quality of the mother-child-interaction went along with greater occipital Go/Nogo effects in the N2 time window, but this effect clearly diminished when we controlled for children's age and intelligence. Higher maternal autonomy-support was also positively associated with better HTKS performance, and higher dyadic EA quality went along with higher HTKS and DoG scores. However, no significant associations were found between EA variables and

Programme evaluation – Case work with families and children in Riga

Directory of Open Access Journals (Sweden)

Filipova M.

2014-01-01

The aim of the study is to evaluate the quality of the case work system in providing social assistance. The research involved the unity of all the activities undertaken by a social worker when focusing on case work. Quality assessment criteria were defined for the sake of carrying out the research.

A brain electrophysiological correlate of depth perception

International Nuclear Information System (INIS)

Akay, Ahmet; Celebi, Gurbuz

2009-01-01

To investigate brain electrical activity accompanying depth perception using random-dot stereograms. Additional experiments were conducted to ascertain the specificity of this potential to depth perception. In the present study, we performed 3 different and independent experiments on 34 subjects to establish the relationship between depth perception and its cortical electrophysiological correlate. Visual evoked potentials in response to visual stimulation by random-dot stereograms were recorded. To achieve this goal, a data acquisition and analysis system, different from common visual evoked potential recording systems, consisting of 2 personal computers, was used. One of the computers was used to generate the visual stimulus patterns and the other to record and digitally average the potentials evoked by the stimuli. This study was carried out at the Department of Biophysics of Ege University Medical School, Izmir, Turkey, from April to December, 2006. A negative potential component, which is thought to arise in association with depth perception, was recorded from the occipital region from 30 of the 34 subjects. Typically, it had a mean latency of 211.46 ms and 6.40 micron V amplitude. The negative potential is related to depth perception, as this component is present in the responses to stimulus, which carries disparity information but is absent when the stimulus is switched to no disparity information. Additional experiments also showed that the specificity of this component to depth perception becomes evident beyond doubt. (author)

Recent advances in recording electrophysiological data simultaneously with magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Laufs, H. [Univ Frankfurt, Zentrum Neurol and Neurochirurg, Neurol Klin, D-60590 Frankfurt (Germany); Laufs, H. [Univ Frankfurt, Dept Neurol, D-60590 Frankfurt (Germany); Laufs, H. [Univ Frankfurt, Brain Imaging Ctr, D-60590 Frankfurt (Germany); Laufs, H.; Carmichael, D.W. [UCL, Inst Neurol, Dept Clin and Expt Epilepsy, London (United Kingdom); Daunizeau, J. [Wellcome Trust Ctr Neuroimaging, London (United Kingdom); Kleinschmidt, A. [INSERM, Unite 562, F-91191 Gif SurYvette (France); Kleinschmidt, A. [CEA, DSV, I2BM, NeuroSpin, F-91191 Gif Sur Yvette (France); Kleinschmidt, A. [Univ Paris 11, F-91405 Orsay (France)

2008-07-01

Simultaneous recording of brain activity by different neuro-physiological modalities can yield insights that reach beyond those obtained by each technique individually, even when compared to those from the post-hoc integration of results from each technique recorded sequentially. Success in the endeavour of real-time multimodal experiments requires special hardware and software as well as purpose-tailored experimental design and analysis strategies. Here,we review the key methodological issues in recording electrophysiological data in humans simultaneously with magnetic resonance imaging (MRI), focusing on recent technical and analytical advances in the field. Examples are derived from simultaneous electro-encephalography (EEG) and electromyography (EMG) during functional MRI in cognitive and systems neuroscience as well as in clinical neurology, in particular in epilepsy and movement disorders. We conclude with an outlook on current and future efforts to achieve true integration of electrical and haemodynamic measures of neuronal activity using data fusion models. (authors)

The Evaluation and Application Plan Report for the Development of Nuclear Power Plant DCS Using CASE Tools

Energy Technology Data Exchange (ETDEWEB)

Lee, B.Y.; Moon, H.J.; Yoon, M.H.; Lee, Y.K. [Korea Electric Power Research Institute, Taejon (Korea)

2000-06-01

This report contains the evaluation and application plan report for the development of nuclear power plant DCS using CASE tools. In this report, the necessity of using CASE tools is considered and a available CASE environment is suggested. And, also according to the IEEE Std 1209 Recommended Practice for Evaluation and Selection of CASE Tools, their functional and economical evaluation about available commercial CASE tools is performed and described. (author). 6 figs., 3 tabs.

In vivo characterization of the electrophysiological and astrocytic responses to a silicon neuroprobe implanted in the mouse neocortex.

Science.gov (United States)

Mols, Katrien; Musa, Silke; Nuttin, Bart; Lagae, Liesbet; Bonin, Vincent

2017-11-15

Silicon neuroprobes hold great potential for studies of large-scale neural activity and brain computer interfaces, but data on brain response in chronic implants is limited. Here we explored with in vivo cellular imaging the response to multisite silicon probes for neural recordings. We tested a chronic implant for mice consisting of a CMOS-compatible silicon probe rigidly implanted in the cortex under a cranial imaging window. Multiunit recordings of cortical neurons with the implant showed no degradation of electrophysiological signals weeks after implantation (mean spike and noise amplitudes of 186 ± 42 µV pp and 16 ± 3.2 µV rms , respectively, n = 5 mice). Two-photon imaging through the cranial window allowed longitudinal monitoring of fluorescently-labeled astrocytes from the second week post implantation for 8 weeks (n = 3 mice). The imaging showed a local increase in astrocyte-related fluorescence that remained stable from the second to the tenth week post implantation. These results demonstrate that, in a standard electrophysiology protocol in mice, rigidly implanted silicon probes can provide good short to medium term chronic recording performance with a limited astrocyte inflammatory response. The precise factors influencing the response to silicon probe implants remain to be elucidated.

Contributions of neuroimaging, balance testing, electrophysiology and blood markers to the assessment of sport-related concussion.

Science.gov (United States)

Davis, G A; Iverson, G L; Guskiewicz, K M; Ptito, A; Johnston, K M

2009-05-01

To review the diagnostic tests and investigations used in the management of sports concussion, in the adult and paediatric populations, to (a) monitor the severity of symptoms and deficits, (b) track recovery and (c) advance knowledge relating to the natural history and neurobiology of the injury. Qualitative literature review of the neuroimaging, balance testing, electrophysiology, blood marker and concussion literature. PubMed and Medline databases were reviewed for investigations used in the management of adult and paediatric concussion, including structural imaging (computerised tomography, magnetic resonance imaging, diffusion tensor imaging), functional imaging (single photon emission computerised tomography, positron emission tomography, functional magnetic resonance imaging), spectroscopy (magnetic resonance spectroscopy, near infrared spectroscopy), balance testing (Balance Error Scoring System, Sensory Organization Test, gait testing, virtual reality), electrophysiological tests (electroencephalography, evoked potentials, event related potentials, magnetoencephalography, heart rate variability), genetics (apolipoprotein E4, channelopathies) and blood markers (S100, neuron-specific enolase, cleaved Tau protein, glutamate). For the adult and paediatric populations, each test has been classified as being: (1) clinically useful, (2) a research tool only or (3) not useful in sports-related concussion. The current status of the diagnostic tests and investigations is analysed, and potential directions for future research are provided. Currently, all tests and investigations, with the exception of clinical balance testing, remain experimental. There is accumulating research, however, that shows promise for the future clinical application of functional magnetic resonance imaging in sport concussion assessment and management.

A High Density Electrophysiological Data Analysis System for a Peripheral Nerve Interface Communicating with Individual Neurons in the Brain

Science.gov (United States)

2016-11-14

of-the-art instrumentation to communicate with individual neurons in the brain and the peripheral nervous system. The major theme of the research is...Nerve Interface Communicating with Individual Neurons in the Brain The views, opinions and/or findings contained in this report are those of the author... Communicating with Individual Neurons in the Brain Report Title The high density electrophysiological data acquisition system obtained through this

Endoscopic ultrasound-guided evaluation of the pleura and cases of pleural effusion.

Science.gov (United States)

Sharma, Malay; Rameshbabu, Chittapuram Srinivasan

2017-01-01

The most efficient and cost-effective approach for the diagnosis of pleural exudates remains uncertain and is a subject of controversy. Essential factors to be considered include the respective diagnostic yields of thoracocentesis, closed pleural biopsy, and thoracoscopy. The role of endoscopic ultrasound (EUS) of the esophagus as a modality for the evaluation of pleural exudates has not yet been evaluated. The applied anatomy of the pleura has been discussed. The techniques involved in the EUS imaging of different aspects of the pleura in normal cases and in cases with pleural effusion are elaborated. The practical application of this knowledge can be useful in EUS-guided sampling of the pleural wall, pleural nodules, and in cases of pleural effusion.

Single-case synthesis tools I: Comparing tools to evaluate SCD quality and rigor.

Science.gov (United States)

Zimmerman, Kathleen N; Ledford, Jennifer R; Severini, Katherine E; Pustejovsky, James E; Barton, Erin E; Lloyd, Blair P

2018-03-03

Tools for evaluating the quality and rigor of single case research designs (SCD) are often used when conducting SCD syntheses. Preferred components include evaluations of design features related to the internal validity of SCD to obtain quality and/or rigor ratings. Three tools for evaluating the quality and rigor of SCD (Council for Exceptional Children, What Works Clearinghouse, and Single-Case Analysis and Design Framework) were compared to determine if conclusions regarding the effectiveness of antecedent sensory-based interventions for young children changed based on choice of quality evaluation tool. Evaluation of SCD quality differed across tools, suggesting selection of quality evaluation tools impacts evaluation findings. Suggestions for selecting an appropriate quality and rigor assessment tool are provided and across-tool conclusions are drawn regarding the quality and rigor of studies. Finally, authors provide guidance for using quality evaluations in conjunction with outcome analyses when conducting syntheses of interventions evaluated in the context of SCD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mechanism of Restoration of Forelimb Motor Function after Cervical Spinal Cord Hemisection in Rats: Electrophysiological Verification

Directory of Open Access Journals (Sweden)

Takumi Takeuchi

2017-01-01

Full Text Available The objective of this study was to electrophysiologically assess the corticospinal tracts of adult rats and the recovery of motor function of their forelimbs after cervical cord hemisection. Of 39 adult rats used, compound muscle action potentials (CMAPs of the forelimbs of 15 rats were evaluated, before they received left C5 segmental hemisection of the spinal cord, by stimulating the pyramid of the medulla oblongata on one side using an exciting microelectrode. All 15 rats exhibited contralateral electrical activity, but their CMAPs disappeared after hemisection. The remaining 24 rats received hemisection first, and CMAPs of 12 rats were assessed over time to study their recovery time. All of them exhibited electrical activity of the forelimbs in 4 weeks after surgery. The remaining 12 rats received additional right C2 segmental hemisection, and variation of CMAPs between before and after surgery was examined. The right side of the 12 rats that received the additional hemisection exhibited no electrical activity in response to the stimulation of the pyramids on both sides. These results suggest that changes in path between the resected and healthy sides, activation of the ventral corticospinal tracts, and propriospinal neurons were involved in the recovery of motor function after cervical cord injury.

Vdrive Evaluation of Remote Steering and Testing in Lasso Electrophysiology Procedures Study: The VERSATILE Study in Atrial Fibrillation Ablation.

Science.gov (United States)

Nölker, Georg; Schwagten, Bruno; Deville, J Brian; Burkhardt, J David; Horton, Rodney P; Sha, Qun; Tomassoni, Gery

2016-03-01

Circular mapping catheters (CMC) are an essential tool in most atrial fibrillation ablation procedures. The Vdrive™ with V-Loop™ system enables a physician to remotely manipulate a CMC during electrophysiology studies. Our aim was to compare the clinical performance of the system to conventional CMC navigation according to efficiency and safety endpoints. A total of 120 patients scheduled to undergo a CMC study followed by pulmonary vein isolation (PVI) were included. Treatment allocation was randomized 2:1, remote navigation:manual navigation. The primary effectiveness endpoint was assessed based on both successful navigation to the targeted pulmonary vein (PV) and successful recording of PV electrograms. All PVs were treated independently within and between patients. The primary safety endpoint was assessed based on the occurrence of major adverse events (MAEs) through seven days after the study procedure. Primary effectiveness endpoints were achieved in 295/302 PVs in the Vdrive arm (97.7%) and 167/167 PVs in the manual arm (100%). Effectiveness analysis indicates Vdrive non-inferiority (pnon-inferiority = 0.0405; δ = -0.05) per the Cochran-Mantel-Haenszel test adjusted for PV correlation. Five MAEs related to the ablation procedure occurred (three in the Vdrive arm-3.9%; two in the manual arm-2.33%). No device-related MAEs were observed; safety analysis indicates Vdrive non-inferiority (pnon-inferiority = 0.0441; δ = 0.07) per the normal Z test. Remote navigation of a CMC is equivalent to manual in PVI in terms of safety and effectiveness. This allows for single-operator procedures in conjunction with a magnetically guided ablation catheter. © 2016 Wiley Periodicals, Inc.

In vivo electrophysiological measurement of the rat ulnar nerve with axonal excitability testing

DEFF Research Database (Denmark)

Wild, Brandon M.; Morris, Renée; Moldovan, Mihai

2018-01-01

Electrophysiology enables the objective assessment of peripheral nerve function in vivo. Traditional nerve conduction measures such as amplitude and latency detect chronic axon loss and demyelination, respectively. Axonal excitability techniques "by threshold tracking" expand upon these measures...... by providing information regarding the activity of ion channels, pumps and exchangers that relate to acute function and may precede degenerative events. As such, the use of axonal excitability in animal models of neurological disorders may provide a useful in vivo measure to assess novel therapeutic...... interventions. Here we describe an experimental setup for multiple measures of motor axonal excitability techniques in the rat ulnar nerve. The animals are anesthetized with isoflurane and carefully monitored to ensure constant and adequate depth of anesthesia. Body temperature, respiration rate, heart rate...

Evaluation of coexistence of cancer and active tuberculosis; 16 case series

Directory of Open Access Journals (Sweden)

Beyhan Çakar

Full Text Available Introduction: Tuberculosis is an important risk factor for cancer. Pulmonary TB and lung cancer(LC may mimic each other especially in the aspect of the clinical and radiological features. The aim of the study was to evaluate the features and risk factors of cases with coexistence cancer and active TB. Methodology: We retrospectively reviewed the medical records of patients with coexisting TB and cancer a period from 2009 to 2014. We evaluated demographic data, the ways diagnosis of TB cases, the location of TB and cancer, TB treatment results of the cases. Results: We recorded 374 TB cases in our dyspensary at this study period. In 16 (4% of these cases, a coexistence of cancer and TB was detected. The male/female ratio was 12/4. The mean age was 62,12 ± 15,13 years. There were TST results except three cases. There were ten pulmonary TB and six extra-pulmonary TB (four peripheral lymphadenopathy TB, one abdominal TB lymphadenopathy and one salivary gland TB. Cancer types were as follows; eight lung cancer, two breast cancer, one base of tongue, one endometrium cancer, one hypopharyngeal cancer, one stomach cancer, one bladder cancer and one maxillary cancer. Diagnosis of all cases was confirmed by bacteriologic and/or histopathological examination. Squamous cell carcinoma was the most common type of cancers. This rate was 9/16. All TB cases were new. There were risk factors out of two case in the cases. Five cases were died during TB treatment. Others completed TB treatment without any complication. Conclusions: In our study, the coexistence of LC and pulmonary TB was more common. The local immunity is deteriorated in cancer cases. If there is pulmonary infiltrates in lung or peripheral lymphadenopathy, we must search tuberculosis too out of metastatic lesion and other infectious diseases. We should not make delay in the diagnosis of active TB in cancer cases. Keywords: Coexistent, Cancer, Tuberculosis, Tuberculosis treatment

Electrophysiological Assessment of Serotonin and GABA Neuron Function in the Dorsal Raphe during the Third Trimester Equivalent Developmental Period in Mice.

Science.gov (United States)

Morton, Russell A; Yanagawa, Yuchio; Valenzuela, C Fernando

2015-01-01

Alterations in the development of the serotonin system can have prolonged effects, including depression and anxiety disorders later in life. Serotonin axonal projections from the dorsal raphe undergo extensive refinement during the first 2 weeks of postnatal life in rodents (equivalent to the third trimester of human pregnancy). However, little is known about the functional properties of serotonin and GABA neurons in the dorsal raphe during this critical developmental period. We assessed the functional properties and synaptic connectivity of putative serotoninergic neurons and GABAergic neurons in the dorsal raphe during early [postnatal day (P) P5-P7] and late (P15-P17) stages of the third trimester equivalent period using electrophysiology. Our studies demonstrate that GABAergic neurons are hyperexcitable at P5-P7 relative to P15-P17. Furthermore, putative serotonin neurons exhibit an increase in both excitatory and GABAA receptor-mediated spontaneous postsynaptic currents during this developmental period. Our data suggest that GABAergic neurons and putative serotonin neurons undergo significant electrophysiological changes during neonatal development.

Microelectrode Array-evaluation of Neurotoxic Effects of Magnesium as an Implantable Biomaterial.

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Huang, Ting; Wang, Zhonghai; Wei, Lina; Kindy, Mark; Zheng, Yufeng; Xi, Tingfei; Gao, Bruce Z

2016-01-01

Magnesium (Mg)-based biomaterials have shown great potential in clinical applications. However, the cytotoxic effects of excessive Mg 2+ and the corrosion products from Mg-based biomaterials, particularly their effects on neurons, have been little studied. Although viability tests are most commonly used, a functional evaluation is critically needed. Here, both methyl thiazolyl tetrazolium (MTT) and lactate dehydrogenase (LDH) assays were used to test the effect of Mg 2+ and Mg-extract solution on neuronal viability. Microelectrode arrays (MEAs), which provide long-term, real-time recording of extracellular electrophysiological signals of in vitro neuronal networks, were used to test for toxic effects. The minimum effective concentrations (EC min ) of Mg 2+ from the MTT and LDH assays were 3 mmol/L and 100 mmol/L, respectively, while the EC min obtained from the MEA assay was 0.1 mmol/L. MEA data revealed significant loss of neuronal network activity when the culture was exposed to 25% Mg-extract solution, a concentration that did not affect neuronal viability. For evaluating the biocompatibility of Mg-based biomaterials with neurons, MEA electrophysiological testing is a more precise method than basic cell-viability testing.

Ultrasonographic findings in hereditary neuropathy with liability to pressure palsies.

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Bayrak, Ayse O; Bayrak, Ilkay Koray; Battaloglu, Esra; Ozes, Burcak; Yildiz, Onur; Onar, Musa Kazim

2015-02-01

The aims of this study were to evaluate the sonographic findings of patients with hereditary neuropathy with liability to pressure palsies (HNPP) and to examine the correlation between sonographic and electrophysiological findings. Nine patients whose electrophysiological findings indicated HNPP and whose diagnosis was confirmed by genetic analysis were enrolled in the study. The median, ulnar, peroneal, and tibial nerves were evaluated by ultrasonography. We ultrasonographically evaluated 18 median, ulnar, peroneal, and tibial nerves. Nerve enlargement was identified in the median, ulnar, and peroneal nerves at the typical sites of compression. None of the patients had nerve enlargement at a site of noncompression. None of the tibial nerves had increased cross-sectional area (CSA) values. There were no significant differences in median, ulnar, and peroneal nerve distal motor latencies (DMLs) between the patients with an increased CSA and those with a normal CSA. In most cases, there was no correlation between electrophysiological abnormalities and clinical or sonographic findings. Although multiple nerve enlargements at typical entrapment sites on sonographic evaluation can suggest HNPP, ultrasonography cannot be used as a diagnostic tool for HNPP. Ultrasonography may contribute to the differential diagnosis of HNPP and other demyelinating polyneuropathies or compression neuropathies; however, further studies are required.

A framework and case studies for evaluation of enzyme ontogeny in children's health risk evaluation.

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Ginsberg, Gary; Vulimiri, Suryanarayana V; Lin, Yu-Sheng; Kancherla, Jayaram; Foos, Brenda; Sonawane, Babasaheb

2017-01-01

Knowledge of the ontogeny of Phase I and Phase II metabolizing enzymes may be used to inform children's vulnerability based upon likely differences in internal dose from xenobiotic exposure. This might provide a qualitative assessment of toxicokinetic (TK) variability and uncertainty pertinent to early lifestages and help scope a more quantitative physiologically based toxicokinetic (PBTK) assessment. Although much is known regarding the ontogeny of metabolizing systems, this is not commonly utilized in scoping and problem formulation stage of human health risk evaluation. A framework is proposed for introducing this information into problem formulation which combines data on enzyme ontogeny and chemical-specific TK to explore potential child/adult differences in internal dose and whether such metabolic differences may be important factors in risk evaluation. The framework is illustrated with five case study chemicals, including some which are data rich and provide proof of concept, while others are data poor. Case studies for toluene and chlorpyrifos indicate potentially important child/adult TK differences while scoping for acetaminophen suggests enzyme ontogeny is unlikely to increase early-life risks. Scoping for trichloroethylene and aromatic amines indicates numerous ways that enzyme ontogeny may affect internal dose which necessitates further evaluation. PBTK modeling is a critical and feasible next step to further evaluate child-adult differences in internal dose for a number of these chemicals.

Evaluating the Patient With Diarrhea: A Case-Based Approach

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Sweetser, Seth

2012-01-01

The evaluation of the patient with diarrhea can be complex and the treatment challenging. In this article, the definition of diarrhea and the pathophysiologic mechanisms that lead to diarrhea are reviewed. A simplified 5-step approach to the patient with diarrhea is provided and applied in a case-oriented manner applicable to everyday clinical practice. On completion of this article, you should be able to (1) define diarrhea, (2) outline various pathophysiologic mechanisms of diarrhea, and (3) describe a simplified 5-step approach to facilitate the evaluation of diarrhea. PMID:22677080

Churg-Strauss Syndrome Following Vaccination Against 2010 Influenza A (H1N1): A Case Report.

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Fu, Mu-Hui; Tsai, Wan-Chen; Lan, Jui; Lu, Cheng-Hsien; Lee, Lian-Hui; Huang, Chih-Cheng

2014-09-01

Churg-Strauss syndrome (CSS) is a systemic inflammatory disorder characterized by asthma, transient pulmonary infiltration, hyper-eosinophilia, and systemic vasculitis. Reported triggering factors include infections, drugs, allergic desensitization, and vaccinations, although cases involving the latter two are extremely rare. Herein, we describe a patient who developed CSS after receiving an H1N1 vaccination. A 55-year-old woman presented with fever, skin eruptions, and sensory impairment of her feet within one week after an H1N1 vaccine injection. A chest X-ray showed pulmonary infiltrations in both lower lung fields. Eosinophilia was noted in a hematological test, and an electrophysiological study revealed a pattern of mononeuritis multiplex. A skin biopsy was performed which revealed palisading necrotizing granuloma around a degenerated dermis and eosinophilic infiltration of the blood vessel walls. These findings combined with the hematological and electrophysiological findings met the criteria of CSS according to the American College of Rheumatology. The patient recovered well after steroid treatment. This case highlights the possibility that the H1N1 vaccination can trigger CSS. Due to the rarity of reported autoimmune events after vaccine administration and the obscure causal association between autoimmunity and a vaccine, further post-marketing surveillance and research are necessary to clarify the relationship and identify risk factors.

Clinical characteristics of patients with tinnitus evaluated with the Tinnitus Sample Case History Questionnaire in Japan: A case series.

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Takashi Kojima

Full Text Available The Tinnitus Sample Case History Questionnaire was determined as a standardized questionnaire for obtaining patient case histories and for characterizing patients into subgroups at the Tinnitus Research Initiative in 2006. In this study, we developed a Japanese version of this questionnaire for evaluating the clinical characteristics of patients with tinnitus. The Japanese version of the questionnaire will be available for evaluating treatments for tinnitus and for comparing data on tinnitus in research centers.To evaluate the clinical characteristics of patients with tinnitus in Japan using a newly developed Japanese version of Tinnitus Sample Case History Questionnaire.This was a prospective study based on patient records.University hospitals, general hospitals, and clinics.We collected patient data using a Japanese translated version of the Tinnitus Sample Case History Questionnaire. In total, 584 patients who visited our institutions in Japan between August 2012 and March 2014 were included (280 males and 304 females; age 13-92 years; mean age, 60.8. We examined patients after dividing them into two groups according to the presence or absence of hyperacusis. The collected results were compared with those from the Tinnitus Research Initiative database.Compared with the TRI database, there were significantly more elderly female patients and fewer patients with trauma-associated tinnitus. There was a statistically lower ratio of patients with hyperacusis. We found that patients with tinnitus in addition to hyperacusis had greater tinnitus severity and exhibited higher rates of various complications.The Japanese version of the Tinnitus Sample Case History Questionnaire developed in this study can be a useful tool for evaluating patients with tinnitus in Japan. The results of this multicenter study reflect the characteristics of patients with tinnitus who require medical care in Japan. Our data provides a preliminary basis for an international

Is there a prognostic relevance of electrophysiological studies in bundle branch block patients?

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Bogossian, Harilaos; Frommeyer, Gerrit; Göbbert, Kornelius; Hasan, Fuad; Nguyen, Quy Suu; Ninios, Ilias; Mijic, Dejan; Bandorski, Dirk; Hoeltgen, Reinhard; Seyfarth, Melchior; Lemke, Bernd; Eckardt, Lars; Zarse, Markus

2017-08-01

The present European guidelines suggest a diagnostic electrophysiological (EP) study to determine indication for cardiac pacing in patients with bundle branch block and unexplained syncope. We evaluated the prognostic relevance of an EP study for mortality and the development of permanent complete atrioventricular (AV) block in patients with symptomatic bifascicular block and first-degree AV block. The HV interval is a poor prognostic marker to predict the development of permanent AV block in patients with symptomatic bifascicular block (BFB) and AV block I°. Thirty consecutive patients (mean age, 74.8 ± 8.6 years; 25 males) with symptomatic BFB and first-degree AV block underwent an EP study before device implantation, according to current guidelines. For 53 ± 31 months, patients underwent yearly follow-up screening for syncope or higher-degree AV block. Thirty patients presented with prolonged HV interval during the EP study (mean, 82.2 ± 20.1 ms; range, 57-142 ms), classified into 3 groups: group 1, 70 to ≤100 ms (mean, 80 ± 8 ms; range, 70-97 ms; n = 18), and group 3, >100 ms (mean, 119 ± 14 ms; range, 107-142 ms; n = 5). According to the guidelines, patients in groups 2 and 3 received a pacemaker. The length of the HV interval was not associated with the later development of third-degree AV block or with increased mortality. Our present study suggests that an indication for pacemaker implantation based solely on a diagnostic EP study with prolongation of the HV interval is not justified. © 2017 Wiley Periodicals, Inc.

The amygdala as a neurobiological target for ghrelin in rats: neuroanatomical, electrophysiological and behavioral evidence.

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Mayte Alvarez-Crespo

Full Text Available Here, we sought to demonstrate that the orexigenic circulating hormone, ghrelin, is able to exert neurobiological effects (including those linked to feeding control at the level of the amygdala, involving neuroanatomical, electrophysiological and behavioural studies. We found that ghrelin receptors (GHS-R are densely expressed in several subnuclei of the amygdala, notably in ventrolateral (LaVL and ventromedial (LaVM parts of the lateral amygdaloid nucleus. Using whole-cell patch clamp electrophysiology to record from cells in the lateral amygdaloid nucleus, we found that ghrelin reduced the frequency of mEPSCs recorded from large pyramidal-like neurons, an effect that could be blocked by co-application of a ghrelin receptor antagonist. In ad libitum fed rats, intra-amygdala administration of ghrelin produced a large orexigenic response that lasted throughout the 4 hr of testing. Conversely, in hungry, fasted rats ghrelin receptor blockade in the amygdala significantly reduced food intake. Finally, we investigated a possible interaction between ghrelin's effects on feeding control and emotional reactivity exerted at the level of the amygdala. In rats allowed to feed during a 1-hour period between ghrelin injection and anxiety testing (elevated plus maze and open field, intra-amygdala ghrelin had no effect on anxiety-like behavior. By contrast, if the rats were not given access to food during this 1-hour period, a decrease in anxiety-like behavior was observed in both tests. Collectively, these data indicate that the amygdala is a valid target brain area for ghrelin where its neurobiological effects are important for food intake and for the suppression of emotional (anxiety-like behaviors if food is not available.

Laparoscopic evaluation of tubal pathology in cases of infertility

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Maherunnessa

2013-07-01

Full Text Available Infertility is a public health problem in developed and developing countries. Diagnostic laparoscopy is a generally accepted procedure to detect pelvic organ pathologies affecting fertility. This study was undertaken to find out the tubal pathology contributing to primary and secondary infertility by laparoscopic examination. The study was carried out in the department of Gynaecology and Obstetrics, BIRDEM during the period of January 2001 to December 2001. The study group comprised of 100 cases of infertile patients of age between 20 to 40 years. Sixty seven percent patients had primary infertility and 33% patients had secondary infertility. Size and shape of the uterus was normal in 69% cases and bicornuate uterus was found in 2% cases. Out of total cases, 71% and 69% had normal right and left fallopian tubes respectively. Patency of right and left fallopian tube was normal in 90% and 89% cases respectively while 11% and 10% had peritubal adhesions. Laparoscopy examination is an important tool for evaluation of tubal pathology contributing to infertility and might play a major role in infertility management. Ibrahim Med. Coll. J. 2013; 7(2: 38-40

Project management in practice : Evaluating a case project through project management theories

OpenAIRE

Uusitalo, Jenni

2013-01-01

The purpose of this thesis was to evaluate a case project and to study whether it was carried out in a correct manner; meaning that did the case project follow the project management models. In addition, part of the study was to determine what could have been improved in the management of the case project. The case project was about creating and launching a communication channel based on a social media service, on a blog platform called Tumblr, for Team Finland in Spain network. The network p...

Effect of the small-world structure on encoding performance in the primary visual cortex: an electrophysiological and modeling analysis.

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Shi, Li; Niu, Xiaoke; Wan, Hong

2015-05-01

The biological networks have been widely reported to present small-world properties. However, the effects of small-world network structure on population's encoding performance remain poorly understood. To address this issue, we applied a small world-based framework to quantify and analyze the response dynamics of cell assemblies recorded from rat primary visual cortex, and further established a population encoding model based on small world-based generalized linear model (SW-GLM). The electrophysiological experimental results show that the small world-based population responses to different topological shapes present significant variation (t test, p 0.8), while no significant variation was found for control networks without considering their spatial connectivity (t test, p > 0.05; effect size: Hedge's g < 0.5). Furthermore, the numerical experimental results show that the predicted response under SW-GLM is more accurate and reliable compared to the control model without small-world structure, and the decoding performance is also improved about 10 % by taking the small-world structure into account. The above results suggest the important role of the small-world neural structure in encoding visual information for the neural population by providing electrophysiological and theoretical evidence, respectively. The study helps greatly to well understand the population encoding mechanisms of visual cortex.

2010 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Training Standards and Maintenance of Competency in Adult Clinical Cardiac Electrophysiology.

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Green, Martin S; Guerra, Peter G; Krahn, Andrew D

2011-01-01

The last guidelines on training for adult cardiac electrophysiology (EP) were published by the Canadian Cardiovascular Society in 1996. Since then, substantial changes in the knowledge and practice of EP have mandated a review of the previous guidelines by the Canadian Heart Rhythm Society, an affiliate of the Canadian Cardiovascular Society. Novel tools and techniques also now allow electrophysiologists to map and ablate increasingly complex arrhythmias previously managed with pharmacologic or device therapy. Furthermore, no formal attempt had previously been made to standardize EP training across the country. The 2010 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Training Standards and Maintenance of Competency in Adult Clinical Cardiac Electrophysiology represent a consensus arrived at by panel members from both societies, as well as EP program directors across Canada and other select contributors. In describing program requirements, the technical and cognitive skills that must be acquired to meet training standards, as well as the minimum number of procedures needed in order to acquire these skills, the new guidelines provide EP program directors and committee members with a template to develop an appropriate curriculum for EP training for cardiology fellows here in Canada. Copyright © 2011 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Extracellular Matrix-Mediated Maturation of Human Pluripotent Stem Cell-Derived Cardiac Monolayer Structure and Electrophysiological Function.

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Herron, Todd J; Rocha, Andre Monteiro Da; Campbell, Katherine F; Ponce-Balbuena, Daniela; Willis, B Cicero; Guerrero-Serna, Guadalupe; Liu, Qinghua; Klos, Matt; Musa, Hassan; Zarzoso, Manuel; Bizy, Alexandra; Furness, Jamie; Anumonwo, Justus; Mironov, Sergey; Jalife, José

2016-04-01

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) monolayers generated to date display an immature embryonic-like functional and structural phenotype that limits their utility for research and cardiac regeneration. In particular, the electrophysiological function of hPSC-CM monolayers and bioengineered constructs used to date are characterized by slow electric impulse propagation velocity and immature action potential profiles. Here, we have identified an optimal extracellular matrix for significant electrophysiological and structural maturation of hPSC-CM monolayers. hPSC-CM plated in the optimal extracellular matrix combination have impulse propagation velocities ≈2× faster than previously reported (43.6±7.0 cm/s; n=9) and have mature cardiomyocyte action potential profiles, including hyperpolarized diastolic potential and rapid action potential upstroke velocity (146.5±17.7 V/s; n=5 monolayers). In addition, the optimal extracellular matrix promoted hypertrophic growth of cardiomyocytes and the expression of key mature sarcolemmal (SCN5A, Kir2.1, and connexin43) and myofilament markers (cardiac troponin I). The maturation process reported here relies on activation of integrin signaling pathways: neutralization of β1 integrin receptors via blocking antibodies and pharmacological blockade of focal adhesion kinase activation prevented structural maturation. Maturation of human stem cell-derived cardiomyocyte monolayers is achieved in a 1-week period by plating cardiomyocytes on PDMS (polydimethylsiloxane) coverslips rather than on conventional 2-dimensional cell culture formats, such as glass coverslips or plastic dishes. Activation of integrin signaling and focal adhesion kinase is essential for significant maturation of human cardiac monolayers. © 2016 American Heart Association, Inc.

Bio-electrochemical microelectrode arrays for glutamate and electrophysiology detection in hippocampus of temporal lobe epileptic rats.

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Li, Ziyue; Song, Yilin; Xiao, Guihua; Gao, Fei; Xu, Shengwei; Wang, Mixia; Zhang, Yu; Guo, Fengru; Liu, Jie; Xia, Yang; Cai, Xinxia

2018-06-01

Temporal Lobe Epilepsy (TLE) is a chronic neurological disorder, characterized by sudden, repeated and transient central nervous system dysfunction. For better understanding of TLE, bio-nanomodified microelectrode arrays (MEA) are designed, for the achievement of high-quality simultaneous detection of glutamate signals (Glu) and multi-channel electrophysiological signals including action potentials (spikes) and local field potentials (LFPs). The MEA was fabricated by Micro-Electro-Mechanical System fabrication technology and all recording sites were modified with platinum black nano-particles, the average impedance decreased by nearly 90 times. Additionally, glutamate oxidase was also modified for the detection of Glu. The average sensitivity of the electrode in Glu solution was 1.999 ± 0.032 × 10 -2 pA/μM·μm 2 (n = 3) and linearity was R = 0.9986, with a good selectivity of 97.82% for glutamate and effective blocking of other interferents. In the in-vivo experiments, the MEA was subjected in hippocampus to electrophysiology and Glu concentration detection. During seizures, the fire rate of spikes increases, and the interspike interval is concentrated within 30 ms. The amplitude of LFPs increases by 3 times and the power increases. The Glu level (4.22 μM, n = 4) was obviously higher than normal rats (2.24 μM, n = 4). The MEA probe provides an advanced tool for the detection of dual-mode signals in the research of neurological diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

Axonal electrovisiogram as an electrophysiological test to evaluate optic nerve and inner retina electrical potentials: findings in normal subjects

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Wener Passarinho Cella

2011-02-01

Full Text Available PURPOSES: To standardize and validate the technique of axonal electrovisiogram (AxEvg, defining its normative values and parameters and characterizing its findings in normal individuals. METHODS: We enrolled 140 normal individuals (280 eyes divided into seven groups according to age, each one with 10 males and 10 females. The technique was based on monocular visual stimulation by a 0 dB intensity bright flash on Ganzfeld bowl at a presentation rate of 1.4 Hz. Golden cup electrodes were used and electrical waves were acquired after artifact rejection. For each amplitude and implicit time peak we calculated the mean, median, pattern deviation, minimum and maximum values and 95% confidence interval. RESULTS: Monocular visual stimulation with bright flash under mesopic conditions was the standard technical procedure established. The normal AxEvg waveform consists of an initial positive wave (named P1, with mean amplitude of 2.0 mV and mean implicit time peak of 23.1 ms followed by a negative wave (named N1, with mean amplitude of -3.9 mV and mean implicit time peak of 41.4 ms. No significant differences were observed between males and females or between right and left eyes, but there was an increased P1 and N1 implicit time peaks according to age. Implicit time characteristics suggest that P1 wave represents an optic nerve electrical potential and N1 wave represents an inner retinal layers potential. CONCLUSIONS: AxEvg can be considered a pre-chiasmatic visual evoked potential capable to reliably record the electrical activity of optic nerve and inner retina. The findings suggest that AxEvg may be useful as an electrophysiological test in the diagnosis of neuroretinal diseases.

The acute effects of MDMA and ethanol administration on electrophysiological correlates of performance monitoring in healthy volunteers.

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Spronk, D B; Dumont, G J H; Verkes, R J; De Bruijn, E R A

2014-07-01

Knowing how commonly used drugs affect performance monitoring is of great importance, because drug use is often associated with compromised behavioral control. Two of the most commonly used recreational drugs in the western world, 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") and ethanol (alcohol), are also often used in combination. The error-related negativity (ERN), correct-related negativity (CRN), and N2 are electrophysiological indices of performance monitoring. The present study aimed to investigate how ethanol, MDMA, and their co-administration affect performance monitoring as indexed by the electrophysiological correlates. Behavioral and EEG data were obtained from 14 healthy volunteers during execution of a speeded choice-reaction-time task after administration of ethanol, MDMA, and combined ethanol and MDMA, in a double-blind, placebo-controlled, randomized crossover design. Ethanol significantly reduced ERN amplitudes, while administration of MDMA did not affect the ERN. Co-administration of MDMA and ethanol did not further impair nor ameliorate the effect of ethanol alone. No drug effects on CRN nor N2 were observed. A decreased ERN following ethanol administration is in line with previous work and offers further support for the impairing effects of alcohol intoxication on performance monitoring. This impairment may underlie maladaptive behavior in people who are under influence. Moreover, these data demonstrate for the first time that MDMA does not affect performance monitoring nor does it interact with ethanol in this process. These findings corroborate the notion that MDMA leaves central executive functions relatively unaffected.

Hybrid automata models of cardiac ventricular electrophysiology for real-time computational applications.

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Andalam, Sidharta; Ramanna, Harshavardhan; Malik, Avinash; Roop, Parthasarathi; Patel, Nitish; Trew, Mark L

2016-08-01

Virtual heart models have been proposed for closed loop validation of safety-critical embedded medical devices, such as pacemakers. These models must react in real-time to off-the-shelf medical devices. Real-time performance can be obtained by implementing models in computer hardware, and methods of compiling classes of Hybrid Automata (HA) onto FPGA have been developed. Models of ventricular cardiac cell electrophysiology have been described using HA which capture the complex nonlinear behavior of biological systems. However, many models that have been used for closed-loop validation of pacemakers are highly abstract and do not capture important characteristics of the dynamic rate response. We developed a new HA model of cardiac cells which captures dynamic behavior and we implemented the model in hardware. This potentially enables modeling the heart with over 1 million dynamic cells, making the approach ideal for closed loop testing of medical devices.

Piloting a programme tool to evaluate malaria case investigation and reactive case detection activities: results from 3 settings in the Asia Pacific.

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Cotter, Chris; Sudathip, Prayuth; Herdiana, Herdiana; Cao, Yuanyuan; Liu, Yaobao; Luo, Alex; Ranasinghe, Neil; Bennett, Adam; Cao, Jun; Gosling, Roly D

2017-08-22

Case investigation and reactive case detection (RACD) activities are widely-used in low transmission settings to determine the suspected origin of infection and identify and treat malaria infections nearby to the index patient household. Case investigation and RACD activities are time and resource intensive, include methodologies that vary across eliminating settings, and have no standardized metrics or tools available to monitor and evaluate them. In response to this gap, a simple programme tool was developed for monitoring and evaluating (M&E) RACD activities and piloted by national malaria programmes. During the development phase, four modules of the RACD M&E tool were created to assess and evaluate key case investigation and RACD activities and costs. A pilot phase was then carried out by programme implementers between 2013 and 2015, during which malaria surveillance teams in three different settings (China, Indonesia, Thailand) piloted the tool over a period of 3 months each. This study describes summary results of the pilots and feasibility and impact of the tool on programmes. All three study areas implemented the RACD M&E tool modules, and pilot users reported the tool and evaluation process were helpful to identify gaps in RACD programme activities. In the 45 health facilities evaluated, 71.8% (97/135; min 35.3-max 100.0%) of the proper notification and reporting forms and 20.0% (27/135; min 0.0-max 100.0%) of standard operating procedures (SOPs) were available to support malaria elimination activities. The tool highlighted gaps in reporting key data indicators on the completeness for malaria case reporting (98.8%; min 93.3-max 100.0%), case investigations (65.6%; min 61.8-max 78.4%) and RACD activities (70.0%; min 64.7-max 100.0%). Evaluation of the SOPs showed that knowledge and practices of malaria personnel varied within and between study areas. Average monthly costs for conducting case investigation and RACD activities showed variation between study

The "wins" of change: evaluating the impact of predicted changes on case management practice.

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Stanton, Marietta P; Barnett Lammon, Carol Ann

2008-01-01

A variety of strategies were employed to identify current and future trends that would impact the practice of case management. Historical review, consultation with case management experts, literature review, and environmental scanning by practicing case managers were strategies employed to determine the impact of current and future trends on case management. The trends identified in this article have implications for case managers in a variety of settings. Case managers participating in the environmental scanning process to evaluate the impact of the identified trends on their organization included representation from acute care, home care, behavioral health, workers' compensation, and private insurance settings. The top 7 trends identified by experts in the field of case management included pay for performance, recovery audit contractors, Medicare demonstration projects, transitions of care, informatics in healthcare and case management, metrics for case management, and the impact of an aging population in case management. Practicing case managers were asked to react to these trends in terms of likelihood of occurrence in their organization and impact of these trends on their case management practice. Case management will ultimately have a higher degree of accountability for its practice if metrics to evaluate and reimbursement for case management become a reality. A multitude of performance measures exist that will be monitored and be tied to reimbursement. To ensure that agencies are accomplishing these performance measures, case management will potentially have a growing importance. Case managers perceive that these trends have a predominantly positive impact on case management.

An Evaluative Case Study on Professional Competency of Preservice Information Technology Teachers

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Kabakci Yurdakul, Isil

2011-01-01

The purpose of this study is to evaluate preservice Information Technology (IT) teachers' professional competency in the teaching process. The study was designed on the basis of evaluative case study. The participants of the study consisted of seven preservice IT teachers attending the department of Computer Education and Instructional…

Dual Atrioventricular Nodal Pathways Physiology: A Review of Relevant Anatomy, Electrophysiology, and Electrocardiographic Manifestations

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Bhalaghuru Chokkalingam Mani, MD

2014-01-01

Full Text Available More than half a century has passed since the concept of dual atrioventricular (AV nodal pathways physiology was conceived. Dual AV nodal pathways have been shown to be responsible for many clinical arrhythmia syndromes, most notably AV nodal reentrant tachycardia. Although there has been a considerable amount of research on this topic, the subject of dual AV nodal pathways physiology remains heavily debated and discussed. Despite advances in understanding arrhythmia mechanisms and the widespread use of invasive electrophysiologic studies, there is still disagreement on the anatomy and physiology of the AV node that is the basis of discontinuous antegrade AV conduction. The purpose of this paper is to review the concept of dual AV nodal pathways physiology and its varied electrocardiographic manifestations.

Multi-master profibus dp modelling and worst case analysis-based evaluation

OpenAIRE

Salvatore Monforte; Eduardo Tovar; Francisco Vasques; Salvatore Cavalieri

2002-01-01

This paper provides an analysis of the real-time behaviour of the multi-master Profibus DP network. The analysis is based on the evaluation of the worst-case message response time and the results obtained are compared with those present in literature, pointing out its capability to perform a more accurate evaluation of the performance of the Profibus network. Copyright © 2002 IFAC.

Spiral wave classification using normalized compression distance: Towards atrial tissue spatiotemporal electrophysiological behavior characterization.

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Alagoz, Celal; Guez, Allon; Cohen, Andrew; Bullinga, John R

2015-08-01

Analysis of electrical activation patterns such as re-entries during atrial fibrillation (Afib) is crucial in understanding arrhythmic mechanisms and assessment of diagnostic measures. Spiral waves are a phenomena that provide intuitive basis for re-entries occurring in cardiac tissue. Distinct spiral wave behaviors such as stable spiral waves, meandering spiral waves, and spiral wave break-up may have distinct electrogram manifestations on a mapping catheter. Hence, it is desirable to have an automated classification of spiral wave behavior based on catheter recordings for a qualitative characterization of spatiotemporal electrophysiological activity on atrial tissue. In this study, we propose a method for classification of spatiotemporal characteristics of simulated atrial activation patterns in terms of distinct spiral wave behaviors during Afib using two different techniques: normalized compressed distance (NCD) and normalized FFT (NFFTD). We use a phenomenological model for cardiac electrical propagation to produce various simulated spiral wave behaviors on a 2D grid and labeled them as stable, meandering, or breakup. By mimicking commonly used catheter types, a star shaped and a circular shaped both of which do the local readings from atrial wall, monopolar and bipolar intracardiac electrograms are simulated. Virtual catheters are positioned at different locations on the grid. The classification performance for different catheter locations, types and for monopolar or bipolar readings were also compared. We observed that the performance for each case differed slightly. However, we found that NCD performance is superior to NFFTD. Through the simulation study, we showed the theoretical validation of the proposed method. Our findings suggest that a qualitative wavefront activation pattern can be assessed during Afib without the need for highly invasive mapping techniques such as multisite simultaneous electrogram recordings.

Visual search elicits the electrophysiological marker of visual working memory.

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Stephen M Emrich

Full Text Available BACKGROUND: Although limited in capacity, visual working memory (VWM plays an important role in many aspects of visually-guided behavior. Recent experiments have demonstrated an electrophysiological marker of VWM encoding and maintenance, the contralateral delay activity (CDA, which has been shown in multiple tasks that have both explicit and implicit memory demands. Here, we investigate whether the CDA is evident during visual search, a thoroughly-researched task that is a hallmark of visual attention but has no explicit memory requirements. METHODOLOGY/PRINCIPAL FINDINGS: The results demonstrate that the CDA is present during a lateralized search task, and that it is similar in amplitude to the CDA observed in a change-detection task, but peaks slightly later. The changes in CDA amplitude during search were strongly correlated with VWM capacity, as well as with search efficiency. These results were paralleled by behavioral findings showing a strong correlation between VWM capacity and search efficiency. CONCLUSIONS/SIGNIFICANCE: We conclude that the activity observed during visual search was generated by the same neural resources that subserve VWM, and that this activity reflects the maintenance of previously searched distractors.

Auditing and Evaluating University-Community Engagement: Lessons from a UK Case Study

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Hart, Angie; Northmore, Simon

2011-01-01

The growing importance of community and public engagement activities in universities has led to an increasing emphasis on auditing and evaluating university-community partnerships. However, the development of effective audit and evaluation tools is still at a formative stage. This article presents a case study of the University of Brighton's…

Overexpression of Dyrk1A is implicated in several cognitive, electrophysiological and neuromorphological alterations found in a mouse model of Down syndrome.

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Susana García-Cerro

Full Text Available Down syndrome (DS phenotypes result from the overexpression of several dosage-sensitive genes. The DYRK1A (dual-specificity tyrosine-(Y-phosphorylation regulated kinase 1A gene, which has been implicated in the behavioral and neuronal alterations that are characteristic of DS, plays a role in neuronal progenitor proliferation, neuronal differentiation and long-term potentiation (LTP mechanisms that contribute to the cognitive deficits found in DS. The purpose of this study was to evaluate the effect of Dyrk1A overexpression on the behavioral and cognitive alterations in the Ts65Dn (TS mouse model, which is the most commonly utilized mouse model of DS, as well as on several neuromorphological and electrophysiological properties proposed to underlie these deficits. In this study, we analyzed the phenotypic differences in the progeny obtained from crosses of TS females and heterozygous Dyrk1A (+/- male mice. Our results revealed that normalization of the Dyrk1A copy number in TS mice improved working and reference memory based on the Morris water maze and contextual conditioning based on the fear conditioning test and rescued hippocampal LTP. Concomitant with these functional improvements, normalization of the Dyrk1A expression level in TS mice restored the proliferation and differentiation of hippocampal cells in the adult dentate gyrus (DG and the density of GABAergic and glutamatergic synapse markers in the molecular layer of the hippocampus. However, normalization of the Dyrk1A gene dosage did not affect other structural (e.g., the density of mature hippocampal granule cells, the DG volume and the subgranular zone area or behavioral (i.e., hyperactivity/attention alterations found in the TS mouse. These results suggest that Dyrk1A overexpression is involved in some of the cognitive, electrophysiological and neuromorphological alterations, but not in the structural alterations found in DS, and suggest that pharmacological strategies targeting

A comprehensive grid to evaluate case management's expected effectiveness for community-dwelling frail older people: results from a multiple, embedded case study.

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Van Durme, Thérèse; Schmitz, Olivier; Cès, Sophie; Anthierens, Sibyl; Maggi, Patrick; Delye, Sam; De Almeida Mello, Johanna; Declercq, Anja; Macq, Jean; Remmen, Roy; Aujoulat, Isabelle

2015-06-18

Case management is a type of intervention expected to improve the quality of care and therefore the quality of life of frail, community-dwelling older people while delaying institutionalisation in nursing homes. However, the heterogeneity, multidimensionality and complexity of these interventions make their evaluation by the means of classical approaches inadequate. Our objective was twofold: (i) to propose a tool allowing for the identification of the key components that explain the success of case management for this population and (ii) to propose a typology based on the results of this tool. The process started with a multiple embedded case study design in order to identify the key components of case management. Based on the results of this first step, data were collected among 22 case management interventions, in order to evaluate their expected effectiveness. Finally, multiple correspondence analyses was conducted to propose a typology of case management. The overall approach was informed by Wagner's Chronic Care Model and the theory of complexity. The study identified a total of 23 interacting key components. Based on the clustering of response patterns of the 22 case management projects included in our study, three types of case management programmes were evidenced, situated on a continuum from a more "socially-oriented" type towards a more "clinically-oriented" type of case management. The type of feedback provided to the general practitioner about both the global geriatric assessment and the result of the intervention turned out to be the most discriminant component between the types. The study design allowed to produce a tool that can be used to distinguish between different types of case management interventions and further evaluate their effect on frail older people in terms of the delaying institutionalisation, functional and cognitive status, quality of life and societal costs.

Evaluation of Active Case Finding (ACF of Tuberculosis in Slums Population in North of Iran

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Reza Hoseinpoor

2017-05-01

Full Text Available Background At present of the limitation of the current case finding strategies and the global urgency to improve tuberculosis (TB case finding, a renewed interest in active case finding (ACF has risen. World Health Organization (WHO calls for research on TB screening among low-income countries because of the limitation of the passive case finding strategies. We aimed to evaluated Active Case Finding strategy for TB among the slums population in North of Iran (Gorgan city and comprise this procedure to Passive Case Finding. Materials and Methods We conducted a house-to-house survey from April 2016 to July 2016 by trained health volunteers for TB in ten urban slums of Gorgan. Individuals with TB symptoms were identified through targeted screening using a standardized questionnaire and investigated further for TB. Descriptive analyses were performed using Stata-12. Results During study period, of 22,741 individuals screened for TB, 112 (0.49% were identified as TB suspects; 95 suspects were evaluated for TB. TB was diagnosed in four individuals, representing 4.2% of those evaluated for TB as suspected cases. The incidence rate of tuberculosis was 17.5 in 100.000 people in slums population of Gorgan. Of the four detected cases, three individuals had pulmonary TB that among them two cases had new smear-positive TB. Conclusion ACF could supplement current strategies to yield additional TB cases, lead to early diagnosis and better treatment.

Evaluating Fall Risk in People with Low Vision: A Case Series

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Kierstyn Napier-Dovorany, OD; Victoria Graham, DPT

2013-01-01

Background: People with low vision have increased risk for falls and preventable health conditions due to sedentary lifestyle and reduced participation in social activities. This case series describes an interprofessional low vision, balance, and mobility evaluation of two patients referred to our low vision optometric clinic. Case Report: RM, an 82-year-old white female with diabetic retinopathy, and PC, a 55-year-old white female with retinopathy of prematurity, completed a comprehensive lo...

The application of method supplier’s complex evaluation. Case study

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Ekaterina Chytilová

2012-01-01

Full Text Available The main goal of this article includes the illustration of selecting bidders evaluation with help Method of complex evaluation of suppliers (MCE. Nowadays the evaluation of suppliers has more importance is in the supply chain management. For SMEs with discontinuous custom manufacturing supplier evaluation at first stage becomes a priority to maintain and enhance the competitiveness of farm output and overall competitiveness. This article presents results of control MCE. The results of this article are results of suppliers’ evaluation conditions and eliminations of MCE application on the base of real enterprise data. MCE is oriented to small and medium-sized enterprises with discontinue manufacturing to order. Research is oriented to selecting procedure of existing suppliers at the first stage of supply chain. Nationality and geographic location haven’t importance to MCE application. Illustrative case study presents the evaluation process to the specific conditions and subsequently demonstrated viability of MCE.

Lexical Decision with Left, Right and Center Visual Field Presentation: A Comparison between Dyslexic and Regular Readers by Means of Electrophysiological and Behavioral Measures

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Shaul, Shelley

2012-01-01

This study examined the differences in processing between regular and dyslexic readers in a lexical decision task in different visual field presentations (left, right, and center). The research utilized behavioral measures that provide information on accuracy and reaction time and electro-physiological measures that permit the examination of brain…

Postictal psychosis and its electrophysiological correlates in invasive EEG: a case report study and literature review.

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Kuba, Robert; Brázdil, Milan; Rektor, Ivan

2012-04-01

We identified two patients with medically refractory temporal lobe epilepsy, from whom intracranial EEG recordings were obtained at the time of postictal psychosis. Both patients had mesial temporal epilepsy associated with hippocampal sclerosis. In both patients, the postictal psychosis was associated with a continual "epileptiform" EEG pattern that differed from their interictal and ictal EEG findings (rhythmical slow wave and "abortive" spike-slow wave complex activity in the right hippocampus and lateral temporal cortex in case 1 and a periodic pattern of triphasic waves in the contacts recording activity from the left anterior cingulate gyrus). Some cases of postictal psychosis might be caused by the transient impairment of several limbic system structures due to the "continual epileptiform discharge" in some brain regions. Case 2 is the first report of a patient with TLE in whom psychotic symptoms were associated with the epileptiform impairment of the anterior cingulate gyrus. Copyright © 2012 Elsevier Inc. All rights reserved.

Convergence of circuit dysfunction in ASD: a common bridge between diverse genetic and environmental risk factors and common clinical electrophysiology.

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Port, Russell G; Gandal, Michael J; Roberts, Timothy P L; Siegel, Steven J; Carlson, Gregory C

2014-01-01

Most recent estimates indicate that 1 in 68 children are affected by an autism spectrum disorder (ASD). Though decades of research have uncovered much about these disorders, the pathological mechanism remains unknown. Hampering efforts is the seeming inability to integrate findings over the micro to macro scales of study, from changes in molecular, synaptic and cellular function to large-scale brain dysfunction impacting sensory, communicative, motor and cognitive activity. In this review, we describe how studies focusing on neuronal circuit function provide unique context for identifying common neurobiological disease mechanisms of ASD. We discuss how recent EEG and MEG studies in subjects with ASD have repeatedly shown alterations in ensemble population recordings (both in simple evoked related potential latencies and specific frequency subcomponents). Because these disease-associated electrophysiological abnormalities have been recapitulated in rodent models, studying circuit differences in these models may provide access to abnormal circuit function found in ASD. We then identify emerging in vivo and ex vivo techniques, focusing on how these assays can characterize circuit level dysfunction and determine if these abnormalities underlie abnormal clinical electrophysiology. Such circuit level study in animal models may help us understand how diverse genetic and environmental risks can produce a common set of EEG, MEG and anatomical abnormalities found in ASD.

Convergence of circuit dysfunction in ASD: a common bridge between diverse genetic and environmental risk factors and common clinical electrophysiology

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Port, Russell G.; Gandal, Michael J.; Roberts, Timothy P. L.; Siegel, Steven J.; Carlson, Gregory C.

2014-01-01

Most recent estimates indicate that 1 in 68 children are affected by an autism spectrum disorder (ASD). Though decades of research have uncovered much about these disorders, the pathological mechanism remains unknown. Hampering efforts is the seeming inability to integrate findings over the micro to macro scales of study, from changes in molecular, synaptic and cellular function to large-scale brain dysfunction impacting sensory, communicative, motor and cognitive activity. In this review, we describe how studies focusing on neuronal circuit function provide unique context for identifying common neurobiological disease mechanisms of ASD. We discuss how recent EEG and MEG studies in subjects with ASD have repeatedly shown alterations in ensemble population recordings (both in simple evoked related potential latencies and specific frequency subcomponents). Because these disease-associated electrophysiological abnormalities have been recapitulated in rodent models, studying circuit differences in these models may provide access to abnormal circuit function found in ASD. We then identify emerging in vivo and ex vivo techniques, focusing on how these assays can characterize circuit level dysfunction and determine if these abnormalities underlie abnormal clinical electrophysiology. Such circuit level study in animal models may help us understand how diverse genetic and environmental risks can produce a common set of EEG, MEG and anatomical abnormalities found in ASD. PMID:25538564

Early diagnosis of amyotrophic lateral sclerosis mimic syndromes: pros and cons of current clinical diagnostic criteria.

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Cortés-Vicente, Elena; Pradas, Jesús; Marín-Lahoz, Juan; De Luna, Noemi; Clarimón, Jordi; Turon-Sans, Janina; Gelpí, Ellen; Díaz-Manera, Jordi; Illa, Isabel; Rojas-Garcia, Ricard

2017-08-01

To describe the frequency and clinical characteristics of patients referred to a tertiary neuromuscular clinic as having amyotrophic lateral sclerosis (ALS) but who were re-diagnosed as having an ALS mimic syndrome, and to identify the reasons that led to the revision of the diagnosis. We reviewed the final diagnosis of all patients prospectively registered in the Sant Pau-MND register from 1 January 2004 to 31 December 2015. A detailed clinical evaluation and a clinically-guided electrophysiological study were performed at first evaluation. Twenty of 314 (6.4%) patients included were re-diagnosed as having a condition other than ALS, in 18 cases already at first evaluation. An alternative specific diagnosis was identified in 17 of those 20, consisting of a wide range of conditions. The main finding leading to an alternative diagnosis was the result of the electrophysiological study. Fifty per cent did not fulfil the El Escorial revised criteria (EECr) for ALS. The most common clinical phenotype at onset in patients with ALS mimic syndromes was progressive muscular atrophy (PMA). Misdiagnosing ALS is still a common problem. Early identification of ALS mimic syndromes is possible based on atypical clinical features and a clinically-guided electrophysiological study. Patients should be attended in specialised centres. The application of EECr helps to identify ALS misdiagnoses.

Tics and Tourette syndrome: clinical evaluation of 44 cases

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Teive Hélio A.G.

2001-01-01

Full Text Available We evaluated 44 patients with tics and Tourette's syndrome (TS emphasising the age of onset of symptoms, sex, classification and localization of tics, associated symptoms and signs and comorbidities. Thirty-three patients (75.2% had TS defined criteria whereas 10 (22.7% had chronic motor and/or vocal tics. Simple motor tics were found in 43 cases (97.7%, mainly affecting the eyes (43.2%, mouth (43.2%, face (34.1%. Simple vocal tics occurred in 33 (75%. Coprolalia was found in just 6 cases (13.6% and copropraxia in just 2 (4.5%. Obsessive compulsive disorder and/or symptoms were found in 26 cases (59.1% and attention deficit in 17 (38.6%. Eighteen patients (40.9% had other disorders, such as alcoholism, tabagism, drug abuse, affective disorders, anxiety, sleep and learning disorders. The data obtained are similar to those found by other authors. We highlight the low frequency of coprolalia, as well as the associated neuropsychiatric disorders.

The evaluation of complex interventions in palliative care: an exploration of the potential of case study research strategies.

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Walshe, Catherine

2011-12-01

Complex, incrementally changing, context dependent and variable palliative care services are difficult to evaluate. Case study research strategies may have potential to contribute to evaluating such complex interventions, and to develop this field of evaluation research. This paper explores definitions of case study (as a unit of study, a process, and a product) and examines the features of case study research strategies which are thought to confer benefits for the evaluation of complex interventions in palliative care settings. Ten features of case study that are thought to be beneficial in evaluating complex interventions in palliative care are discussed, drawing from exemplars of research in this field. Important features are related to a longitudinal approach, triangulation, purposive instance selection, comprehensive approach, multiple data sources, flexibility, concurrent data collection and analysis, search for proving-disproving evidence, pattern matching techniques and an engaging narrative. The limitations of case study approaches are discussed including the potential for subjectivity and their complex, time consuming and potentially expensive nature. Case study research strategies have great potential in evaluating complex interventions in palliative care settings. Three key features need to be exploited to develop this field: case selection, longitudinal designs, and the use of rival hypotheses. In particular, case study should be used in situations where there is interplay and interdependency between the intervention and its context, such that it is difficult to define or find relevant comparisons.

Clinical evaluation of multiple exostoses (17 cases) on bonescintigraphy

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Yamada, Takayuki; Nakamura, Mamoru; Sugita, Reiji; Satou, Akihiro; Sakamoto, Kiyohiko (Tohoku Univ., Sendai (Japan). School of Medicine)

1991-03-01

Seventeen patients with multiple exostoses were examined on bone scintigraphy. Inheritance was recognized on seven patients (41%). Onset age of 15 patients was under 20 years old and 10 patients were under 10. The number of lesions was 211 and they were usually recognized at metaphyses of long bones. The degree of accumulation was classified into four grades: 0 (non increased), 1 (slightly-mild), 2 (moderate), and 3 (strong). One hundred and fifty-three lesions (73%) did not show definite increased activity (Grade 0, 1). Grade 3 included 14 lesions and they tended to be strongly calcified on X-P. This disease was said to transform into chondrosarcoma in 10 to 20%. Transformation was said to occur preferably in adults at heavily calcified lesion or one which showed irregularly thick hyaline cartilage. Such lesions showed more increased accumulation than normal bones. In our cases three cases were resected for this reason but turned out to be benign histologically. One case showed malignant transformation. In this case, a large malignant tumor replaced the parent bone and bone scan showed the cold lesion. Bone scintigraphy was considered useful to evaluate the biological activity of multiple exostoses. (author).

Paying attention to attention in recognition memory: insights from models and electrophysiology.

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Dubé, Chad; Payne, Lisa; Sekuler, Robert; Rotello, Caren M

2013-12-01

Reliance on remembered facts or events requires memory for their sources, that is, the contexts in which those facts or events were embedded. Understanding of source retrieval has been stymied by the fact that uncontrolled fluctuations of attention during encoding can cloud results of key importance to theoretical development. To address this issue, we combined electrophysiology (high-density electroencephalogram, EEG, recordings) with computational modeling of behavioral results. We manipulated subjects' attention to an auditory attribute, whether the source of individual study words was a male or female speaker. Posterior alpha-band (8-14 Hz) power in subjects' EEG increased after a cue to ignore the voice of the person who was about to speak. Receiver-operating-characteristic analysis validated our interpretation of oscillatory dynamics as a marker of attention to source information. With attention under experimental control, computational modeling showed unequivocally that memory for source (male or female speaker) reflected a continuous signal detection process rather than a threshold recollection process.

A comparison of electrophysiologically determined spectral responses in six subspecies of Lymantria.

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Crook, Damon J; Hull-Sanders, Helen M; Hibbard, Emily L; Mastro, Victor C

2014-04-01

The spectral sensitivity of the compound eye in three gypsy moth species from six different geographical regions (Lymantria dispar asiatica Vnukovskij [Asian gypsy moth], Lymantria dispar japonica Motschulsky [Japanese gypsy moth], and Lymantria dispar dispar L. [North American gypsy moth]) was tested electrophysiologically in the wavelength region 300-700 nm. For all moths examined, a maximum response occurred in the 480-520-nm range (blue-green region) with a shoulder peak occurring at 460 nm. A smaller, secondary peak was observed for both sexes at the 340-380-nm range, which is in the region considered behaviorally maximal in night-flying insects. No peaks in sensitivity were observed between 520 and 700 nm (red region) for any of the moths tested. Based on our retinal recording data, a short wavelength blocking filter with a transition wavelength near 500 nm should reduce gypsy moth attraction to artificial lighting sources. This would help reduce the number of Lymantria-infested ships traveling to and from foreign ports.

Successful Treatment with Microvascular Decompression Surgery of a Patient with Hemiparesis Caused by Vertebral Artery Compression of the Medulla Oblongata: Case Report and Review of the Literature.

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Ren, Jibin; Sun, Hongtao; Diao, Yunfeng; Niu, Xuegang; Wang, Hang; Wei, Zhengjun; Yuan, Fei

2017-12-01

There are few reports on hemiparesis caused by vascular medullary compression, which can occur because of dolichoectasia of the vertebrobasilar arterial system. In this article, we report a case of vertebral artery compression of the medulla oblongata in a 67-year-old woman. The patient was hypertensive, and she developed hemiparesis and intermittent spasms over 5 years. These spasms had worsened during the last year. Cranial nerve magnetic resonance imaging showed compression of the medulla oblongata by the left vertebral artery. A motor evoked potential (MEP) examination showed abnormal conduction of MEPs of bilateral toe abductors. The patient underwent microvascular decompression surgery under general anesthesia through a retrosigmoid keyhole approach. This operation led to relief of vascular compression and symptomatic improvement. Our case suggests that detailed history, imaging studies, and electrophysiologic studies help lead to a correct and early diagnosis of hemiparesis caused by vascular compression of the rostral ventrolateral medulla. Microvascular decompression surgery improves patient symptoms, and intraoperative electrophysiologic monitoring helps to avoid injury to important adjacent nerves. Copyright © 2017 Elsevier Inc. All rights reserved.

Development and evaluation of standardized narrative cases depicting the general surgery professionalism milestones.

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Rawlings, Arthur; Knox, Aaron D C; Park, Yoon Soo; Reddy, Shalini; Williams, Sarah R; Issa, Nabil; Jameel, Abid; Tekian, Ara

2015-08-01

Residency programs now are required to use educational milestones, which has led to the need for new methods of assessment. The literature suggests that narrative cases are a promising tool to track residents' progress. This study demonstrates the process for developing and evaluating narrative cases representing the five levels of the professionalism milestones. In 2013, the authors identified 28 behaviors in the Accreditation Council for Graduate Medical Education general surgery professionalism milestones. They modified previously published narrative cases to fit these behaviors. To evaluate the quality of these cases, the authors developed a 28-item, five-point scale instrument, which 29 interdisciplinary faculty completed. The authors compared the faculty ratings by narrative case and specialty with the authors' initial rankings of the cases by milestone level. They used t tests and analysis of variance to compare mean scores across specialties. The authors developed 10 narrative cases, 2 for each of the 5 milestone levels. Each case contained at least 20 of the 28 behaviors identified in the milestones. Mean faculty ratings matched the milestone levels. Reliability was good (G coefficient = 0.86, phi coefficient = 0.85), indicating consistency in raters' ability to determine the proper milestone level for each case. The authors demonstrate a process for using specialty-specific milestones to develop narrative cases that map to a spectrum of professionalism behaviors. This process can be applied to other competencies and specialties to facilitate faculty awareness of resident performance descriptors and provide a frame of reference for milestones assessment.

Evaluation of Viral Meningoencephalitis Cases

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Handan Ilhan

2012-08-01

Full Text Available AIM: To evaluate retrospectively adult cases of viral encephalitis. METHOD: Fifteen patients described viral encephalitis hospitalized between the years 2006-2011 follow-up and treatment at the infectious diseases clinic were analyzed retrospectively. RESULTS: Most of the patients (%60 had applied in the spring. Fever (87%, confusion (73%, neck stiffness (73%, headache (73%, nausea-vomiting (33%, loss of consciousness (33%, amnesia (33%, agitation (20%, convulsion (%20, focal neurological signs (13%, Brudzinski-sign (13% were most frequently encountered findings. Electroencephalography test was applied to 13 of 14 patients, and pathological findings compatible with encephalitis have been found. Radiological imaging methods such as CT and MRI were performed in 9 of the 14 patients, and findings consistent with encephalitis were reported. All of initial cerebrospinal fluid (CSF samples were abnormal. The domination of the first examples was lymphocytes in 14 patients; only one patient had an increase in neutrophilic cells have been found. CSF protein level was high in nine patients, and low glucose level was detected in two patients. Herpes simplex virus polymerized chain reaction (PCR analyze was performed to fourteen patients CSF. Only two of them (14% were found positive. One of the patients sample selectively examined was found to be Parvovirus B19 (+, the other patient urine sample Jacobs-creutzfeld virus PCR was found to be positively. Empiric acyclovir therapy was given to all patients. Neuropsychiatric squeal developed at the one patient. CONCLUSION: The cases in the forefront of change in mental status viral meningoencephalitis should be considered and empirical treatment with acyclovir should be started. [TAF Prev Med Bull 2012; 11(4.000: 447-452

Audiological and electrophysiological alterations in HIV-infected individuals subjected or not to antiretroviral therapy.

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Matas, Carla Gentile; Samelli, Alessandra Giannella; Magliaro, Fernanda Cristina Leite; Segurado, Aluisio

2017-08-02

The Human Immunodeficiency Virus (HIV) and infections related to it can affect multiple sites in the hearing system. The use of High-Activity Anti-Retroviral Therapy (HAART) can cause side effects such as ototoxicity. Thus, no consistent patterns of hearing impairment in adults with Human Immunodeficiency Virus / Acquired Immune Deficiency Syndrome have been established, and the problems that affect the hearing system of this population warrant further research. This study aimed to compare the audiological and electrophysiological data of Human Immunodeficiency Virus-positive patients with and without Acquired Immune Deficiency Syndrome, who were receiving High-Activity Anti-Retroviral Therapy, to healthy individuals. It was a cross-sectional study conducted with 71 subjects (30-48 years old), divided into groups: Research Group I: 16 Human Immunodeficiency Virus-positive individuals without Acquired Immunodeficiency Syndrome (not receiving antiretroviral treatment); Research Group II: 25 Human Immunodeficiency Virus-positive individuals with Acquired Immunodeficiency Syndrome (receiving antiretroviral treatment); Control Group: 30 healthy subjects. All individuals were tested by pure-tone air conduction thresholds at 0.25-8kHz, extended high frequencies at 9-20kHz, electrophysiological tests (Auditory Brainstem Response - ABR, Middle Latency Responses - MLR, Cognitive Potential - P300). Research Group I and Research Group II had higher hearing thresholds in both conventional and high frequency audiometry when compared to the control group, prolonged latency of waves I, III, V and interpeak I-V in Auditory Brainstem Response and prolonged latency of P300 Cognitive Potential. Regarding Middle Latency Responses, there was a decrease in the amplitude of the Pa wave of Research Group II compared to the Research Group I. Both groups with Human Immunodeficiency Virus had higher hearing thresholds when compared to healthy individuals (group exposed to antiretroviral

A Case with Cramp-Fasciculation Syndrome

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Pinar Yalinay Dikmen

2014-12-01

Full Text Available Cramp-fasciculation syndrome is one of the peripheral nerve hyperexcitability disorders and presents muscle aching, cramps, stiffness and exercise intolerance. Fasciculation and cramps can be seen both in healthy individuals and in those with fatal diseases, such as Amyotrophic Lateral Sclerosis. We present a 27-year-old male patient, professional soccer player with fasciculations and cramps in  bilateral gastrocnemius-soleus complex. The patient complained about having to stop playing soccer because of muscle cramps and twitches in both calves, which had started 3 years earlier. After completing all laboratory and electrophysiological examinations, the patient was diagnosed as cramp-fasciculation syndrome. The aim of this paper was to present a rare case of cramp-fasiculation syndrome and discuss if the syndrome is benign or pioneer of a severe pathological process.

Synthetic Antimalarial Maculopathy: A Case Report

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Aziz El Ouaf

2017-04-01

Full Text Available Antimalarial drug-induced retinopathy was first described in the 1950s. Screening for preclinical poisoning prevents evolution to irreversible maculopathy. We discuss, through the case of maculopathy with antimalarial (AM revealed by progressive bilateral decrease in vision in a patient with lupus, the modalities of monitoring patients treated with AM and the management of a potential intoxication. All authors stress the need for clinical and paraclinical ophthalmological monitoring regularly to detect early signs of impaired retinal function at a reversible stage. Indeed, at a more severe retinal intoxication, impaired visual function remains irreversible and can lead to blindness. A full ophthalmologic assessment is necessary before starting long course treatment with AM, possibly coupled with additional tests (central visual field, colour vision and/or electrophysiological examinations.