Publications by authors named "Anna Korzeniewska"

36 Publications

LCA and economic study on the local oxygen supply in Central Europe during the COVID-19 pandemic.

Sci Total Environ 2021 Sep 29;786:147401. Epub 2021 Apr 29.

AGH University of Science and Technology, Faculty of Energy and Fuels, Department of Coal Chemistry and Environmental Sciences, Al. Mickiewicza 30, 30-059 Kraków, Poland. Electronic address:

Medical oxygen is the key to survival for COVID-19 patients. To meet the pandemic-driven oxygen demand spike, local hospitals began searching for a suitable medical oxygen delivery system. Among the studies published on the impact of COVID-19 on a range of aspects, including the global economy and the environment, no study has been conducted on the environmental impact of medical oxygen supply to hospitals under epidemic conditions. In this paper the authors perform a comparative Life Cycle Assessment (LCA) to evaluate the environmental and economic impact of three scenarios (oxygen cylinders, liquid oxygen in tanks and on-site oxygen production) of local oxygen supply to hospitals in Poland. The LCA was performed according to ISO 14040 -14044 standards requirements, using the SimaPro 9.0 software. Results from the analysis showed that the Global Warming Potential (GWP) and Fine Particulate Matter Formation Potential (FPMFP) indicators for the liquid oxygen in tank scenario are the lowest and equal 265 kg CO eq and 0.309 kg PM eq. respectively. The greatest terrestrial acidification reductions (-1.38 kg SO eq) can be achieved when applying the on-site oxygen production scenario. Our findings revealed that the oxygen in cylinders scenario has the most harmful impact on the environment. The economic analysis was performed in order to compare the monthly and annual operational costs of analysed scenarios. The results show that hospitals sustain the lowest annual costs when using the on-site oxygen production scenario.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147401DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8081744PMC
September 2021

Spatial-Temporal Functional Mapping Combined With Cortico-Cortical Evoked Potentials in Predicting Cortical Stimulation Results.

Front Hum Neurosci 2021 14;15:661976. Epub 2021 Apr 14.

Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.

Functional human brain mapping is commonly performed during invasive monitoring with intracranial electroencephalographic (iEEG) electrodes prior to resective surgery for drug- resistant epilepsy. The current gold standard, electrocortical stimulation mapping (ESM), is time -consuming, sometimes elicits pain, and often induces after discharges or seizures. Moreover, there is a risk of overestimating eloquent areas due to propagation of the effects of stimulation to a broader network of language cortex. Passive iEEG spatial-temporal functional mapping (STFM) has recently emerged as a potential alternative to ESM. However, investigators have observed less correspondence between STFM and ESM maps of language than between their maps of motor function. We hypothesized that incongruities between ESM and STFM of language function may arise due to propagation of the effects of ESM to cortical areas having strong effective connectivity with the site of stimulation. We evaluated five patients who underwent invasive monitoring for seizure localization, whose language areas were identified using ESM. All patients performed a battery of language tasks during passive iEEG recordings. To estimate the effective connectivity of stimulation sites with a broader network of task-activated cortical sites, we measured cortico-cortical evoked potentials (CCEPs) elicited across all recording sites by single-pulse electrical stimulation at sites where ESM was performed at other times. With the combination of high gamma power as well as CCEPs results, we trained a logistic regression model to predict ESM results at individual electrode pairs. The average accuracy of the classifier using both STFM and CCEPs results combined was 87.7%, significantly higher than the one using STFM alone (71.8%), indicating that the correspondence between STFM and ESM results is greater when effective connectivity between ESM stimulation sites and task-activated sites is taken into consideration. These findings, though based on a small number of subjects to date, provide preliminary support for the hypothesis that incongruities between ESM and STFM may arise in part from propagation of stimulation effects to a broader network of cortical language sites activated by language tasks, and suggest that more studies, with larger numbers of patients, are needed to understand the utility of both mapping techniques in clinical practice.
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http://dx.doi.org/10.3389/fnhum.2021.661976DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8079642PMC
April 2021

During vigilance to painful stimuli: slower response rate is related to high trait anxiety, whereas faster response rate is related to high state anxiety.

J Neurophysiol 2021 01 16;125(1):305-319. Epub 2020 Dec 16.

Department of Neurosurgery, Johns Hopkins University, Baltimore, Maryland.

A pathological increase in vigilance, or hypervigilance, may be related to pain intensity in some clinical pain syndromes and may result from attention bias to salient stimuli mediated by anxiety. During a continuous performance task where subjects discriminated painful target stimuli from painful nontargets, we measured detected targets (hits), nondetected targets (misses), nondetected nontargets (correct rejections), and detected nontargets (false alarms). Using signal detection theory, we calculated response bias, the tendency to endorse a stimulus as a target, and discriminability, the ability to discriminate a target from nontarget. Owing to the relatively slow rate of stimulus presentation, our primary hypothesis was that sustained performance would result in a more conservative response bias reflecting a lower response rate over time on task. We found a more conservative response bias with time on task and no change in discriminability. We predicted that greater state and trait anxiety would lead to a more liberal response bias. A multivariable model provided partial support for our prediction; high trait anxiety related to a more conservative response bias (lower response rate), whereas high state anxiety related to a more liberal bias. This inverse relationship of state and trait anxiety is consistent with reports of effects of state and trait anxiety on reaction times to threatening stimuli. In sum, we report that sustained attention to painful stimuli was associated with a decrease in the tendency of the subject to respond to any stimulus over time on task, whereas the ability to discriminate target from nontarget remains unchanged. During a series of painful stimuli requiring subjects to respond to targets, we separated response willingness from ability to discriminate targets from nontargets. Response willingness declined during the task, with no change in subjects' ability to discriminate, consistent with previous vigilance studies. High trait anxious subjects were less willing to respond and showed slower reaction times to hits than low anxious subjects. This study reveals an important role of trait anxiety in pain vigilance.
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http://dx.doi.org/10.1152/jn.00492.2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087378PMC
January 2021

The Dynamics of Language Network Interactions in Lexical Selection: An Intracranial EEG Study.

Cereb Cortex 2021 Mar;31(4):2058-2070

Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.

Speaking in sentences requires selection from contextually determined lexical representations. Although posterior temporal cortex (PTC) and Broca's areas play important roles in storage and selection, respectively, of lexical representations, there has been no direct evidence for physiological interactions between these areas on time scales typical of lexical selection. Using intracranial recordings of cortical population activity indexed by high-gamma power (70-150 Hz) modulations, we studied the causal dynamics of cortical language networks while epilepsy surgery patients performed a sentence completion task in which the number of potential lexical responses was systematically varied. Prior to completion of sentences with more response possibilities, Broca's area was not only more active, but also exhibited more local network interactions with and greater top-down influences on PTC, consistent with activation of, and competition between, more lexical representations. These findings provide the most direct experimental support yet for network dynamics playing a role in lexical selection among competing alternatives during speech production.
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http://dx.doi.org/10.1093/cercor/bhaa344DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7945024PMC
March 2021

Behavioral, Physiological and EEG Activities Associated with Conditioned Fear as Sensors for Fear and Anxiety.

Sensors (Basel) 2020 Nov 26;20(23). Epub 2020 Nov 26.

Department of Neurosurgery, Johns Hopkins University, Baltimore, MD 21287-7713, USA.

Anxiety disorders impose substantial costs upon public health and productivity in the USA and worldwide. At present, these conditions are quantified by self-report questionnaires that only apply to behaviors that are accessible to consciousness, or by the timing of responses to fear- and anxiety-related words that are indirect since they do not produce fear, e.g., Dot Probe Test and emotional Stroop. We now review the conditioned responses (CRs) to fear produced by a neutral stimulus (conditioned stimulus CS+) when it cues a painful laser unconditioned stimulus (US). These CRs include autonomic (Skin Conductance Response) and ratings of the CS+ unpleasantness, ability to command attention, and the recognition of the association of CS+ with US (expectancy). These CRs are directly related to fear, and some measure behaviors that are minimally accessible to consciousness e.g., economic scales. Fear-related CRs include non-phase-locked phase changes in oscillatory EEG power defined by frequency and time post-stimulus over baseline, and changes in phase-locked visual and laser evoked responses both of which include late potentials reflecting attention or expectancy, like the P300, or contingent negative variation. Increases (ERS) and decreases (ERD) in oscillatory power post-stimulus may be generalizable given their consistency across healthy subjects. ERS and ERD are related to the ratings above as well as to anxious personalities and clinical anxiety and can resolve activity over short time intervals like those for some moods and emotions. These results could be incorporated into an objective instrumented test that measures EEG and CRs of autonomic activity and psychological ratings related to conditioned fear, some of which are subliminal. As in the case of instrumented tests of vigilance, these results could be useful for the direct, objective measurement of multiple aspects of the risk, diagnosis, and monitoring of therapies for anxiety disorders and anxious personalities.
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http://dx.doi.org/10.3390/s20236751DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7728331PMC
November 2020

Changes in human brain dynamics during behavioral priming and repetition suppression.

Prog Neurobiol 2020 06 18;189:101788. Epub 2020 Mar 18.

Department of Neurology, Johns Hopkins University, Baltimore, Maryland, 21287, USA.

Behavioral responses to a perceptual stimulus are typically faster with repeated exposure to the stimulus (behavioral priming). This implicit learning mechanism is critical for survival but impaired in a variety of neurological disorders, including Alzheimer's disease. Many studies of the neural bases for behavioral priming have encountered an interesting paradox: in spite of faster behavioral responses, repeated stimuli usually elicit weaker neural responses (repetition suppression). Several neurophysiological models have been proposed to resolve this paradox, but noninvasive techniques for human studies have had insufficient spatial-temporal precision for testing their predictions. Here, we used the unparalleled precision of electrocorticography (ECoG) to analyze the timing and magnitude of task-related changes in neural activation and propagation while patients named novel vs repeated visual objects. Stimulus repetition was associated with faster verbal responses and decreased neural activation (repetition suppression) in ventral occipito-temporal cortex (VOTC) and left prefrontal cortex (LPFC). Interestingly, we also observed increased neural activation (repetition enhancement) in LPFC and other recording sites. Moreover, with analysis of high gamma propagation we observed increased top-down propagation from LPFC into VOTC, preceding repetition suppression. The latter results indicate that repetition suppression and behavioral priming are associated with strengthening of top-down network influences on perceptual processing, consistent with predictive coding models of repetition suppression, and they support a central role for changes in large-scale cortical dynamics in achieving more efficient and rapid behavioral responses.
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http://dx.doi.org/10.1016/j.pneurobio.2020.101788DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7198339PMC
June 2020

Subthalamic Nucleus Activity Influences Sensory and Motor Cortex during Force Transduction.

Cereb Cortex 2020 04;30(4):2615-2626

Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA.

The subthalamic nucleus (STN) is proposed to participate in pausing, or alternately, in dynamic scaling of behavioral responses, roles that have conflicting implications for understanding STN function in the context of deep brain stimulation (DBS) therapy. To examine the nature of event-related STN activity and subthalamic-cortical dynamics, we performed primary motor and somatosensory electrocorticography while subjects (n = 10) performed a grip force task during DBS implantation surgery. Phase-locking analyses demonstrated periods of STN-cortical coherence that bracketed force transduction, in both beta and gamma ranges. Event-related causality measures demonstrated that both STN beta and gamma activity predicted motor cortical beta and gamma activity not only during force generation but also prior to movement onset. These findings are consistent with the idea that the STN participates in motor planning, in addition to the modulation of ongoing movement. We also demonstrated bidirectional information flow between the STN and somatosensory cortex in both beta and gamma range frequencies, suggesting robust STN participation in somatosensory integration. In fact, interactions in beta activity between the STN and somatosensory cortex, and not between STN and motor cortex, predicted PD symptom severity. Thus, the STN contributes to multiple aspects of sensorimotor behavior dynamically across time.
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http://dx.doi.org/10.1093/cercor/bhz264DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7174991PMC
April 2020

Missed targets, reaction times, and arousal are related to trait anxiety and attention to pain during an experimental vigilance task with a painful target.

J Neurophysiol 2020 02 9;123(2):462-472. Epub 2019 Oct 9.

Department of Neurosurgery, Johns Hopkins University, Baltimore, Maryland.

Although hypervigilance may play a role in some clinical pain syndromes, experimental vigilance toward painful stimuli has been studied infrequently. We evaluated vigilance toward pain by using a continuous performance task (CPT), in which subjects responded to moderately intense painful target stimuli, occurring in a train of mildly painful nontargets. We assessed nondetected targets (misses), reaction times (RTs), and psychological activation (tense arousal). During time on task in CPTs of other sensory modalities, there is an increase in misses and RTs (vigilance decrement). We hypothesized that our CPT would influence vigilance performance related to pain, anxiety, and limitation of attentional resources. The results showed a decrement in vigilance over time as misses increased, although RTs were unchanged. While mind-wandering did not influence vigilance performance, intrinsic attention to pain drove both hit RTs and number of misses. This resulted in pain-focused subjects performing worse on the CPT pain task with slower RTs and more misses per block. During the CPT, the change in stimulus salience was related to the change in pain intensity, while pain unpleasantness correlated with tense arousal. CPT performance during experimental vigilance to pain and psychological activation were related to trait anxiety, as measured by the Spielberger State-Trait Anxiety Inventory and neuroticism, as measured by the NEO five factor inventory. Trait anxiety and neuroticism may play important roles in an individual's predisposition to dwell on pain and interpret pain as threatening. Subjects detected moderately painful target stimuli in a train of mildly painful nontarget stimuli, which resulted in vigilance performance metrics including missed targets, reaction times, and psychological activation. These performance metrics were related to intrinsic attention to pain and trait anxiety. Subjects with high trait anxiety and neuroticism scores, with a predisposition to attend to pain, had greater tense arousal and poorer vigilance performance, which may be important psychological aspects of vigilance to pain.
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http://dx.doi.org/10.1152/jn.00331.2019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7052634PMC
February 2020

The neural tides of sleep and consciousness revealed by single-pulse electrical brain stimulation.

Sleep 2019 06;42(6)

Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD.

Wakefulness and sleep arise from global changes in brain physiology that may also govern the flow of neural activity between cortical regions responsible for perceptual processing versus planning and action. To test whether and how the sleep/wake cycle affects the overall propagation of neural activity in large-scale brain networks, we applied single-pulse electrical stimulation (SPES) in patients implanted with intracranial EEG electrodes for epilepsy surgery. SPES elicited cortico-cortical spectral responses at high-gamma frequencies (CCSRHG, 80-150 Hz), which indexes changes in neuronal population firing rates. Using event-related causality (ERC) analysis, we found that the overall patterns of neural propagation among sites with CCSRHG were different during wakefulness and different sleep stages. For example, stimulation of frontal lobe elicited greater propagation toward parietal lobe during slow-wave sleep than during wakefulness. During REM sleep, we observed a decrease in propagation within frontal lobe, and an increase in propagation within parietal lobe, elicited by frontal and parietal stimulation, respectively. These biases in the directionality of large-scale cortical network dynamics during REM sleep could potentially account for some of the unique experiential aspects of this sleep stage. Together these findings suggest that the regulation of conscious awareness and sleep is associated with differences in the balance of neural propagation across large-scale frontal-parietal networks.
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http://dx.doi.org/10.1093/sleep/zsz050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6559171PMC
June 2019

Coexistence of asthma and the obesity-hypoventilation syndrome.

Wiad Lek 2018;71(5):949-953

Department Of Pulmonology And Lung Cancer, Medical University In Wroclaw, Wroclaw, Poland.

Objective: Introduction: With the increasing problem of obesity in the world, high prevalence of asthma in obese persons and high prevalence of sleep breathing disorders related to obesity, the number of patients with coexisting asthma and obesity hypoventilation syndrome is likely to increase. The aim: To evaluate long-term effects of obesity hypoventilation syndrome treatment in the patients with concomitant asthma.

Patients And Methods: Materials and methods: Obesity hypoventilation syndrome was diagnosed in six adult patients with asthma (body mass index 43.2±5.84 kg/m2, diurnal PaCO2 53.8±8.9 mmHg, apnea/hypopnea index 82±12.8/hour, mean SaO2 during sleep 77.7±6.6%). Four patients were treated with continuous positive airway pressure (CPAP) and two patients - with non-invasive ventilation (NIV). The patients were followed-up for 36±19 months.

Results: Results: During the follow-up period daytime PaCO2 decreased to normal values, mean SaO2 during sleep increased to 93±3.1%, p<0.001. No asthma exacerbations were observed. In two patients significant reduction of anti-asthmatic treatment was observed, including withdrawal of chronic oral corticosteroid treatment.

Conclusion: Conclusions: Obese asthmatic patients with chronic respiratory insufficiency should be checked for concomitant obesity hypoventilation syndrome. Positive airway pressure treatment during sleep (CPAP or NIV) in asthmatic patients with obesity hypoventilation syndrome is well tolerated, leads to reversal of chronic respiratory insufficiency and in some patients may contribute to the improvement of asthma control.
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March 2019

Cortical Responses to Input From Distant Areas are Modulated by Local Spontaneous Alpha/Beta Oscillations.

Cereb Cortex 2019 02;29(2):777-787

Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Any given area in human cortex may receive input from multiple, functionally heterogeneous areas, potentially representing different processing threads. Alpha (8-13 Hz) and beta oscillations (13-20 Hz) have been hypothesized by other investigators to gate local cortical processing, but their influence on cortical responses to input from other cortical areas is unknown. To study this, we measured the effect of local oscillatory power and phase on cortical responses elicited by single-pulse electrical stimulation (SPES) at distant cortical sites, in awake human subjects implanted with intracranial electrodes for epilepsy surgery. In 4 out of 5 subjects, the amplitudes of corticocortical evoked potentials (CCEPs) elicited by distant SPES were reproducibly modulated by the power, but not the phase, of local oscillations in alpha and beta frequencies. Specifically, CCEP amplitudes were higher when average oscillatory power just before distant SPES (-110 to -10 ms) was high. This effect was observed in only a subset (0-33%) of sites with CCEPs and, like the CCEPs themselves, varied with stimulation at different distant sites. Our results suggest that although alpha and beta oscillations may gate local processing, they may also enhance the responsiveness of cortex to input from distant cortical sites.
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http://dx.doi.org/10.1093/cercor/bhx361DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6319171PMC
February 2019

Brain network dynamics in the human articulatory loop.

Clin Neurophysiol 2017 08 17;128(8):1473-1487. Epub 2017 May 17.

Department of Pediatrics, Children's Hospital of Michigan, Wayne State University, Detroit Medical Center, Detroit, MI 48201, USA; Department of Neurology, Children's Hospital of Michigan, Wayne State University, Detroit Medical Center, Detroit, MI 48201, USA. Electronic address:

Objective: The articulatory loop is a fundamental component of language function, involved in the short-term buffer of auditory information followed by its vocal reproduction. We characterized the network dynamics of the human articulatory loop, using invasive recording and stimulation.

Methods: We measured high-gamma activity recorded intracranially when patients with epilepsy either only listened to, or listened to and then reproduced two successive tones by humming. We also conducted network analyses, and analyzed behavioral responses to cortical stimulation.

Results: Presentation of the initial tone elicited high-gamma augmentation bilaterally in the superior-temporal gyrus (STG) within 40ms, and in the precentral and inferior-frontal gyri (PCG and IFG) within 160ms after sound onset. During presentation of the second tone, high-gamma augmentation was reduced in STG but enhanced in IFG. The task requiring tone reproduction further enhanced high-gamma augmentation in PCG during and after sound presentation. Event-related causality (ERC) analysis revealed dominant flows within STG immediately after sound onset, followed by reciprocal interactions involving PCG and IFG. Measurement of cortico-cortical evoked-potentials (CCEPs) confirmed connectivity between distant high-gamma sites in the articulatory loop. High-frequency stimulation of precentral high-gamma sites in either hemisphere induced speech arrest, inability to control vocalization, or forced vocalization. Vocalization of tones was accompanied by high-gamma augmentation over larger extents of PCG.

Conclusions: Bilateral PCG rapidly and directly receives feed-forward signals from STG, and may promptly initiate motor planning including sub-vocal rehearsal for short-term buffering of auditory stimuli. Enhanced high-gamma augmentation in IFG during presentation of the second tone may reflect high-order processing of the tone sequence.

Significance: The articulatory loop employs sustained reciprocal propagation of neural activity across a network of cortical sites with strong neurophysiological connectivity.
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http://dx.doi.org/10.1016/j.clinph.2017.05.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5512585PMC
August 2017

Human Thalamic Somatosensory Nucleus (Ventral Caudal, Vc) as a Locus for Stimulation by INPUTS from Tactile, Noxious and Thermal Sensors on an Active Prosthesis.

Sensors (Basel) 2017 May 24;17(6). Epub 2017 May 24.

Department of Neurosurgery, Johns Hopkins University, Baltimore, MD 21287, USA.

The forebrain somatic sensory locus for input from sensors on the surface of an active prosthesis is an important component of the Brain Machine Interface. We now review the neuronal responses to controlled cutaneous stimuli and the sensations produced by Threshold Stimulation at Microampere current levels (TMIS) in such a locus, the human thalamic Ventral Caudal nucleus (Vc). The responses of these neurons to tactile stimuli mirror those for the corresponding class of tactile mechanoreceptor fiber in the peripheral nerve, and TMIS can evoke sensations like those produced by the stimuli that optimally activate each class. These neuronal responses show a somatotopic arrangement from lateral to medial in the sequence: leg, arm, face and intraoral structures. TMIS evoked sensations show a much more detailed organization into anterior posteriorly oriented rods, approximately 300 microns diameter, that represent smaller parts of the body, such as parts of individual digits. Neurons responding to painful and thermal stimuli are most dense around the posterior inferior border of Vc, and TMIS evoked pain sensations occur in one of two patterns: (i) pain evoked regardless of the frequency or number of spikes in a burst of TMIS; and (ii) the description and intensity of the sensation changes with increasing frequencies and numbers. In patients with major injuries leading to loss of somatic sensory input, TMIS often evokes sensations in the representation of parts of the body with loss of sensory input, e.g., the phantom after amputation. Some patients with these injuries have ongoing pain and pain evoked by TMIS of the representation in those parts of the body. Therefore, thalamic TMIS may produce useful patterned somatotopic feedback to the CNS from sensors on an active prosthesis that is sometimes complicated by TMIS evoked pain in the representation of those parts of the body.
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http://dx.doi.org/10.3390/s17061197DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5492124PMC
May 2017

Cortical subnetwork dynamics during human language tasks.

Neuroimage 2016 07 2;135:261-72. Epub 2016 Apr 2.

Department of Neurology, Johns Hopkins University, 600 N. Wolfe St., Meyer 2-161, Baltimore, MD 21287, USA.

Language tasks require the coordinated activation of multiple subnetworks-groups of related cortical interactions involved in specific components of task processing. Although electrocorticography (ECoG) has sufficient temporal and spatial resolution to capture the dynamics of event-related interactions between cortical sites, it is difficult to decompose these complex spatiotemporal patterns into functionally discrete subnetworks without explicit knowledge of each subnetwork's timing. We hypothesized that subnetworks corresponding to distinct components of task-related processing could be identified as groups of interactions with co-varying strengths. In this study, five subjects implanted with ECoG grids over language areas performed word repetition and picture naming. We estimated the interaction strength between each pair of electrodes during each task using a time-varying dynamic Bayesian network (tvDBN) model constructed from the power of high gamma (70-110Hz) activity, a surrogate for population firing rates. We then reduced the dimensionality of this model using principal component analysis (PCA) to identify groups of interactions with co-varying strengths, which we term functional network components (FNCs). This data-driven technique estimates both the weight of each interaction's contribution to a particular subnetwork, and the temporal profile of each subnetwork's activation during the task. We found FNCs with temporal and anatomical features consistent with articulatory preparation in both tasks, and with auditory and visual processing in the word repetition and picture naming tasks, respectively. These FNCs were highly consistent between subjects with similar electrode placement, and were robust enough to be characterized in single trials. Furthermore, the interaction patterns uncovered by FNC analysis correlated well with recent literature suggesting important functional-anatomical distinctions between processing external and self-produced speech. Our results demonstrate that subnetwork decomposition of event-related cortical interactions is a powerful paradigm for interpreting the rich dynamics of large-scale, distributed cortical networks during human cognitive tasks.
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http://dx.doi.org/10.1016/j.neuroimage.2016.03.072DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4985237PMC
July 2016

Spatial-temporal functional mapping of language at the bedside with electrocorticography.

Neurology 2016 Mar 2;86(13):1181-9. Epub 2016 Mar 2.

From the Departments of Neurology (Y.W., A.K., M.C.C., D.F.B.-R., N.E.C.), Biomedical Engineering (M.S.F.), and Neurosurgery (W.S.A.), Johns Hopkins University, Baltimore, MD; Fischell Department of Bioengineering (Y.W.), University of Maryland College Park; and Department of Psychology (A.F.), New York University, New York.

Objective: To investigate the feasibility and clinical utility of using passive electrocorticography (ECoG) for online spatial-temporal functional mapping (STFM) of language cortex in patients being monitored for epilepsy surgery.

Methods: We developed and tested an online system that exploits ECoG's temporal resolution to display the evolution of statistically significant high gamma (70-110 Hz) responses across all recording sites activated by a discrete cognitive task. We illustrate how this spatial-temporal evolution can be used to study the function of individual recording sites engaged during different language tasks, and how this approach can be particularly useful for mapping eloquent cortex.

Results: Using electrocortical stimulation mapping (ESM) as the clinical gold standard for localizing language cortex, the average sensitivity and specificity of online STFM across 7 patients were 69.9% and 83.5%, respectively. Moreover, relative to regions of interest where discrete cortical lesions have most reliably caused language impairments in the literature, the sensitivity of STFM was significantly greater than that of ESM, while its specificity was also greater than that of ESM, though not significantly so.

Conclusions: This study supports the feasibility and clinical utility of online STFM for mapping human language function, particularly under clinical circumstances in which time is limited and comprehensive ESM is impractical.
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http://dx.doi.org/10.1212/WNL.0000000000002525DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818563PMC
March 2016

Serum levels of apoptosis-related markers (sFasL, TNF-a, p53 and bcl-2) in COPD patients.

Pneumonol Alergol Pol 2016 21;84(1):11-5. Epub 2015 Dec 21.

Chair and Department of Pulmonology and Lung Cancer, Wroclaw Medical University, Poland.

Introduction: Taking into account important role of apoptosis in COPD pathogenesis, we wanted to asses the serum levels of markers involved in apoptosis regulation, including apoptosis inducers such as TNF-a, sFasL or p53 protein and apoptosis inhibitor bcl-2 and, in addition, to compare these markers with selected COPD parameters.

Material And Methods: In 181 patients (60 women) with COPD (age was 62.2+ 9.37 years; FEV1% 55.2 + 19.98 %) and in 29 controls (11 women), serum levels of TNF-a, sFasL, p53 and bcl-2 were evaluated by the enzyme-linked immunosorbent assay (ELISA) method.

Results: In COPD patients the mean sFasL level was 0.092 ± 0.077 ng/ml and mean TNF-a level was 2.911 ± 3.239 pg/ml. There were no differences in serum sFasL and TNF-a in COPD patients and control group. TNF-a and sFasL did not correlate with COPD parameters such as FEV₁%, BMI, RV% (percentage of predicted value of residual volume) or BODE. Although we tried to evaluate bcl-2 and p53 protein serum levels with two different tests, measurable levels of bcl-2 were only detected in 15 patients and p53 in only 3 patients. Bcl-2 values were from 0.418 to 11.423 ng/ml and p53 from 90.772 to 994.749 pg/ml.

Conclusions: We didn't observe any differences in serum levels of pro- and antiapoptotic markers in COPD patients and the control group or correlations between the markers studied and COPD parameters.
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http://dx.doi.org/10.5603/PiAP.a2015.0080DOI Listing
January 2017

Fusion of the H NMR data of serum, urine and exhaled breath condensate in order to discriminate chronic obstructive pulmonary disease and obstructive sleep apnea syndrome.

Metabolomics 2015;11(6):1563-1574. Epub 2015 May 22.

Department of Bioorganic Chemistry, Wroclaw University of Technology, 27 Wybrzeze Wyspianskiego Str., 50-370 Wroclaw, Poland.

Chronic obstructive pulmonary disease, COPD, affects the condition of the entire human organism and causes multiple comorbidities. Pathological lung changes lead to quantitative changes in the composition of the metabolites in different body fluids. The obstructive sleep apnea syndrome, OSAS, occurs in conjunction with chronic obstructive pulmonary disease in about 10-20 % of individuals who have COPD. Both conditions share the same comorbidities and this makes differentiating them difficult. The aim of this study was to investigate whether it is possible to diagnose a patient with either COPD or the OSA syndrome using a set of selected metabolites and to determine whether the metabolites that are present in one type of biofluid (serum, exhaled breath condensate or urine) or whether a combination of metabolites that are present in two biofluids or whether a set of metabolites that are present in all three biofluids are necessary to correctly diagnose a patient. A quantitative analysis of the metabolites in all three biofluid samples was performed using H NMR spectroscopy. A multivariate bootstrap approach that combines partial least squares regression with the variable importance in projection score (VIP-score) and selectivity ratio (SR) was adopted in order to construct discriminant diagnostic models for the groups of individuals with COPD and OSAS. A comparison study of all of the discriminant models that were constructed and validated showed that the discriminant partial least squares model using only ten urine metabolites (selected with the SR approach) has a specificity of 100 % and a sensitivity of 86.67 %. This model (AUC = 0.95) presented the best prediction performance. The main conclusion of this study is that urine metabolites, among the others, present the highest probability for correctly identifying patents with COPD and the lowest probability for an incorrect identification of the OSA syndrome as developed COPD. Another important conclusion is that the changes in the metabolite levels of exhaled breath condensates do not appear to be specific enough to differentiate between patients with COPD and OSAS.
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http://dx.doi.org/10.1007/s11306-015-0808-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4605976PMC
May 2015

A study of the dynamics of seizure propagation across micro domains in the vicinity of the seizure onset zone.

J Neural Eng 2015 Aug 10;12(4):046016. Epub 2015 Jun 10.

Department of Neurosurgery, Johns Hopkins University, MD, USA.

Objective: The use of micro-electrode arrays to measure electrical activity from the surface of the brain is increasingly being investigated as a means to improve seizure onset zone (SOZ) localization. In this work, we used a multivariate autoregressive model to determine the evolution of seizure dynamics in the [Formula: see text] Hz high frequency band across micro-domains sampled by such micro-electrode arrays. We showed that a directed transfer function (DTF) can be used to estimate the flow of seizure activity in a set of simulated micro-electrode data with known propagation pattern.

Approach: We used seven complex partial seizures recorded from four patients undergoing intracranial monitoring for surgical evaluation to reconstruct the seizure propagation pattern over sliding windows using a DTF measure.

Main Results: We showed that a DTF can be used to estimate the flow of seizure activity in a set of simulated micro-electrode data with a known propagation pattern. In general, depending on the location of the micro-electrode grid with respect to the clinical SOZ and the time from seizure onset, ictal propagation changed in directional characteristics over a 2-10 s time scale, with gross directionality limited to spatial dimensions of approximately [Formula: see text]. It was also seen that the strongest seizure patterns in the high frequency band and their sources over such micro-domains are more stable over time and across seizures bordering the clinically determined SOZ than inside.

Significance: This type of propagation analysis might in future provide an additional tool to epileptologists for characterizing epileptogenic tissue. This will potentially help narrowing down resection zones without compromising essential brain functions as well as provide important information about targeting anti-epileptic stimulation devices.
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http://dx.doi.org/10.1088/1741-2560/12/4/046016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4531844PMC
August 2015

Redefining the role of Broca's area in speech.

Proc Natl Acad Sci U S A 2015 Mar 17;112(9):2871-5. Epub 2015 Feb 17.

Department of Neurology, Cognitive Neurophysiology and Brain-Machine Interface Laboratory, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;

For over a century neuroscientists have debated the dynamics by which human cortical language networks allow words to be spoken. Although it is widely accepted that Broca's area in the left inferior frontal gyrus plays an important role in this process, it was not possible, until recently, to detail the timing of its recruitment relative to other language areas, nor how it interacts with these areas during word production. Using direct cortical surface recordings in neurosurgical patients, we studied the evolution of activity in cortical neuronal populations, as well as the Granger causal interactions between them. We found that, during the cued production of words, a temporal cascade of neural activity proceeds from sensory representations of words in temporal cortex to their corresponding articulatory gestures in motor cortex. Broca's area mediates this cascade through reciprocal interactions with temporal and frontal motor regions. Contrary to classic notions of the role of Broca's area in speech, while motor cortex is activated during spoken responses, Broca's area is surprisingly silent. Moreover, when novel strings of articulatory gestures must be produced in response to nonword stimuli, neural activity is enhanced in Broca's area, but not in motor cortex. These unique data provide evidence that Broca's area coordinates the transformation of information across large-scale cortical networks involved in spoken word production. In this role, Broca's area formulates an appropriate articulatory code to be implemented by motor cortex.
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http://dx.doi.org/10.1073/pnas.1414491112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4352780PMC
March 2015

Dynamics of functional and effective connectivity within human cortical motor control networks.

Clin Neurophysiol 2015 May 18;126(5):987-96. Epub 2014 Sep 18.

Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA. Electronic address:

Objective: Praxis, the performance of complex motor gestures, is crucial to the development of motor and social/communicative capacities. Praxis relies on a network consisting of inferior parietal and premotor regions, particularly on the left, and is thought to require transformation of spatio-temporal representations (parietal) into movement sequences (premotor).

Method: We examined praxis network dynamics by measuring EEG effective connectivity while healthy subjects performed a praxis task.

Results: Propagation from parietal to frontal regions was not statistically greater on the left than the right. However, propagation from left parietal regions to all other regions was significantly greater during gesture preparation than execution. Moreover, during gesture preparation only, propagation from the left parietal region to bilateral frontal regions was greater than reciprocal propagations to the left parietal region. This directional specificity was not observed for the right parietal region.

Conclusions: These findings represent direct electrophysiological evidence for directionally predominant propagation in left frontal-parietal networks during praxis behavior, which may reflect neural mechanisms by which representations in the human brain select appropriate motor sequences for subsequent execution.

Significance: In addition to bolstering the classic view of praxis network function, these results also demonstrate the relevance of additional information provided by directed connectivity measures.
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http://dx.doi.org/10.1016/j.clinph.2014.09.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4364936PMC
May 2015

Metabolomics provide new insights on lung cancer staging and discrimination from chronic obstructive pulmonary disease.

J Pharm Biomed Anal 2014 Nov 21;100:369-380. Epub 2014 Aug 21.

Department of Bioorganic Chemistry Wrocław University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland. Electronic address:

Chronic obstructive pulmonary disease (COPD) and lung cancer are widespread lung diseases. Cigarette smoking is a high risk factor for both the diseases. COPD may increase the risk of developing lung cancer. Thus, it is crucial to be able to distinguish between these two pathological states, especially considering the early stages of lung cancer. Novel diagnostic and monitoring tools are required to properly determine lung cancer progression because this information directly impacts the type of the treatment prescribed. In this study, serum samples collected from 22 COPD and 77 lung cancer (TNM stages I, II, III, and IV) patients were analyzed. Then, a collection of NMR metabolic fingerprints was modeled using discriminant orthogonal partial least squares regression (OPLS-DA) and further interpreted by univariate statistics. The constructed discriminant models helped to successfully distinguish between the metabolic fingerprints of COPD and lung cancer patients (AUC training=0.972, AUC test=0.993), COPD and early lung cancer patients (AUC training=1.000, AUC test=1.000), and COPD and advanced lung cancer patients (AUC training=0.983, AUC test=1.000). Decreased acetate, citrate, and methanol levels together with the increased N-acetylated glycoproteins, leucine, lysine, mannose, choline, and lipid (CH3-(CH2)n-) levels were observed in all lung cancer patients compared with the COPD group. The evaluation of lung cancer progression was also successful using OPLS-DA (AUC training=0.811, AUC test=0.904). Based on the results, the following metabolite biomarkers may prove useful in distinguishing lung cancer states: isoleucine, acetoacetate, and creatine as well as the two NMR signals of N-acetylated glycoproteins and glycerol.
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http://dx.doi.org/10.1016/j.jpba.2014.08.020DOI Listing
November 2014

The evaluation of body composition, adiponectin, C-reactive protein and cholesterol levels in patients with obstructive sleep apnea syndrome.

Adv Clin Exp Med 2013 Nov-Dec;22(6):817-24

Chair and Department of Pulmonology and Lung Cancer, Wroclaw Medical University, Poland.

Background: Obstructive sleep apnea syndrome (OSAS) is a frequent disease, characterized by repetitive episodes of upper airway obstruction during sleep, leading to many pathological events. Adiponectin is an adipocyte-specific secreted protein that plays a role in glucose and lipid homeostasis, in addition to antiatherogenic and anti-diabetic effects. Bioelectrical impedance analysis (BIA) is a reliable, non-invasive, safe and effective technique to measure body composition.

Objectives: The aim of the study was the evaluation of body composition and adiponectin serum levels in OSAS patients and their comparison with OSAS parameters as well as with C-reactive protein (CRP) and cholesterol levels.

Material And Methods: In this study, 137 patients with OSAS and 42 persons for the control group were enrolled. In the examined group with OSAS, there were 100 males (73%) and 37 females (27%). The average age was 54.37 + 9.8 years. All subjects underwent polysomnography with Grass Aura PSG Lite and bioelectrical impedance analysis (BIA) with a single-frequency bioimpedance analyzer (Model BIA 101, AKERN-RJL, Italy). The adiponectin serum level was measured using a sandwich ELISA kit.

Results: In OSAS patients we demonstrated a higher body mass index (BMI) and percentage of extracellular water (ECW%) and lower percentage of intracellular water (ICW%) and phase angle. Moreover, severe OSAS and control comparison revealed a lower percentage of muscle mass (MM%) in severe OSAS. Positive correlations were found between the apnea-hypopnea index (AHI) and BMI, CRP and ECW%. Negative correlations were observed between AHI and ICW%, MM% and phase angle. We found neither differences in adiponectin levels between the control group and OSAS patients nor correlations between adiponectin and body composition parameters. But we showed that adiponectin levels were significantly lower in OSAS patients with diabetes than in OSAS patients without diabetes (2.64 vs. 13.46 µg/mL, p = 0.003). In OSAS patients without diabetes, we revealed many negative correlations between adiponectin levels and the body composition parameters (including phase angle, percentage of total body water - TBW%, ICW%, percentage of fat free mass - FFM% and MM%) and triglycerides. The positive relationships were between adiponectin and CRP, ECW% and percentage of fat mass (FM%).

Conclusions: Our results indicate that in OSAS patients there are many changes in body composition. The most interesting are higher BMI, TBW% and ECW% and lower BCM%, IW%, MM% and phase angle. Our results suggest that OSAS does not influence adiponectin level, but adiponectin levels are lower in patients with diabetes. Adiponectin levels correlate with many body composition parameters in OSAS patients without diabetes.
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May 2014

Antibiotic resistant Escherichia coli in hospital and municipal sewage and their emission to the environment.

Ecotoxicol Environ Saf 2013 May 20;91:96-102. Epub 2013 Feb 20.

Department of Environmental Microbiology, Faculty of Environmental Sciences, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1 Str., Olsztyn 10-720, Poland.

The spreading of antibiotic resistant bacteria in the environment is a threat to human health but little is known about the transmission of extended-spectrum beta-lactamases (ESBL)-producing Escherichia coli from the hospital and municipal sewage to the water basin and to the air at the WWTPs (Waste Water Treatment Plants) area and their surroundings. Accordingly, it seems particularly interesting to trace the fate of these bacteria and their genes encoding antibiotic resistance in both untreated sewage from hospitals, and in sewage after different stages of purification, and finally to examine the degree of their emissions to environment. Although wastewater treatment processes reduce number of bacteria in sewage up to 99%, in the presented study it was reported that more than 2.7×10(3) CFU/mL E. coli reached the receiving water and contributed to dissemination of resistant bacteria into the environment. We received 395 E. coli strains from sewage and environmental samples and we investigated their antibiotic susceptibility and the presence of bla gene encoding TEM, CTX, OXA and SHV. From among 167 and 147 E. coli strains isolated from hospital effluents and municipal sewage in Olsztyn, Poland, up to 37.1% and 17.7%, respectively, were ESBL-positive. From among 38 and 43 strains isolated from river water and the air up to 18.4% and 27.9%, respectively, were ESBL-producers. The blaCTX-M (blaCTX-M-1, blaCTX-M-3, blaCTX-M-5, blaCTX-M-15) genes were the predominant group of the plasmid-coded ESBLs. More than 38% out of ESBL-producing isolates carried several bla genes. The multiple-antibiotic-resistant (MAR) indexes for ESBL-positive were higher than for ESBL-negative isolates and ranged from 0.45 to 0.63. The MAR indexes for E. coli from hospital effluents and air samples were greater than the indexes calculated for strains isolated from other samples. Presumably, the preliminary disinfection of hospital sewage before its inflow into the sewage system might minimize the spreading of antibiotic-resistant bacteria to the environment.
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http://dx.doi.org/10.1016/j.ecoenv.2013.01.014DOI Listing
May 2013

Proceedings of the Second International Workshop on Advances in Electrocorticography.

Epilepsy Behav 2011 Dec 28;22(4):641-50. Epub 2011 Oct 28.

Albany Medical College, Albany, NY, USA.

The Second International Workshop on Advances in Electrocorticography (ECoG) was convened in San Diego, CA, USA, on November 11-12, 2010. Between this meeting and the inaugural 2009 event, a much clearer picture has been emerging of cortical ECoG physiology and its relationship to local field potentials and single-cell recordings. Innovations in material engineering are advancing the goal of a stable long-term recording interface. Continued evolution of ECoG-driven brain-computer interface technology is determining innovation in neuroprosthetics. Improvements in instrumentation and statistical methodologies continue to elucidate ECoG correlates of normal human function as well as the ictal state. This proceedings document summarizes the current status of this rapidly evolving field.
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http://dx.doi.org/10.1016/j.yebeh.2011.09.028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3847909PMC
December 2011

[The cyclin A, B1, D1 and E expression in advanced non-small cell lung cancer--stages IIIB-IV (preliminary report)].

Pol Merkur Lekarski 2011 Apr;30(178):253-8

Akademia Medyczna we Wrocławiu, Katedra i Klinika Pulmonologii i Nowotworów Płuc.

Unlabelled: Lung cancer is the leading cause of cancer death in the majority of developed countries. Uncontrolled cell proliferation is the hallmark of malignant tumours. Cyclins play an important role in cell cycle regulation. The aim of this study was to evaluate the expression of cyclins A, B1, D1 and E in advanced non-small cell lung cancer (stages IIIB-IV) with its prognostic significance.

Material And Method: An immunohistochemical assessment of cyclins A, B1, D1 and E expression was performed in the paraffin-embedded tumor tissues of 19 patients (9 men and 10 women). The mean was age 59 +/- 6.64 years. 9 patients were in IIIB and 10 in IV. The 2-years survival rate was evaluated.

Results: We showed positive cyclin A expression in 13 tumor tissue specimens (68%), cyclin B1 in 3 (16%), cyclin D1 in 9 (47%) and cyclin E in 7 (37%). We analyzed the prognostic value of examinated cyclins in all NSCLC patients and separately in patients with squamous cell lung cancer and adenocarcinoma and in patients in stage IIIB and IV, but we have no found any correlations. We did not find also any differences in examinated cyclins expression depending on stages nor different histopathological types.

Conclusion: We did not observe prognostic value of cyclins A, B1, D1 or E expression in advanced non-small cell lung cancer.
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April 2011

Dynamics of large-scale cortical interactions at high gamma frequencies during word production: event related causality (ERC) analysis of human electrocorticography (ECoG).

Neuroimage 2011 Jun 16;56(4):2218-37. Epub 2011 Mar 16.

Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Meyer 2-147, Baltimore, MD 21287, USA.

Intracranial EEG studies in humans have shown that functional brain activation in a variety of functional-anatomic domains of human cortex is associated with an increase in power at a broad range of high gamma (>60Hz) frequencies. Although these electrophysiological responses are highly specific for the location and timing of cortical processing and in animal recordings are highly correlated with increased population firing rates, there has been little direct empirical evidence for causal interactions between different recording sites at high gamma frequencies. Such causal interactions are hypothesized to occur during cognitive tasks that activate multiple brain regions. To determine whether such causal interactions occur at high gamma frequencies and to investigate their functional significance, we used event-related causality (ERC) analysis to estimate the dynamics, directionality, and magnitude of event-related causal interactions using subdural electrocorticography (ECoG) recorded during two word production tasks: picture naming and auditory word repetition. A clinical subject who had normal hearing but was skilled in American Signed Language (ASL) provided a unique opportunity to test our hypothesis with reference to a predictable pattern of causal interactions, i.e. that language cortex interacts with different areas of sensorimotor cortex during spoken vs. signed responses. Our ERC analyses confirmed this prediction. During word production with spoken responses, perisylvian language sites had prominent causal interactions with mouth/tongue areas of motor cortex, and when responses were gestured in sign language, the most prominent interactions involved hand and arm areas of motor cortex. Furthermore, we found that the sites from which the most numerous and prominent causal interactions originated, i.e. sites with a pattern of ERC "divergence", were also sites where high gamma power increases were most prominent and where electrocortical stimulation mapping interfered with word production. These findings suggest that the number, strength and directionality of event-related causal interactions may help identify network nodes that are not only activated by a task but are critical to its performance.
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http://dx.doi.org/10.1016/j.neuroimage.2011.03.030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3105123PMC
June 2011

Cortical γ responses: searching high and low.

Int J Psychophysiol 2011 Jan 23;79(1):9-15. Epub 2010 Nov 23.

Department of Neurology, The Johns Hopkins University School of Medicine, 600 N. Wolfe St., Meyer 2-147, Baltimore, Maryland 21287, United States.

In this paper, a brief, preliminary attempt is made to frame a scientific debate about how functional responses at gamma frequencies in electrophysiological recordings (EEG, MEG, ECoG, and LFP) should be classified and interpreted. In general, are all gamma responses the same, or should they be divided into different classes according to criteria such as their spectral characteristics (frequency range and/or shape), their spatial-temporal patterns of occurrence, and/or their responsiveness under different task conditions? In particular, are the responses observed in intracranial EEG at a broad range of "high gamma" frequencies (~60-200Hz) different from gamma responses observed at lower frequencies (~30-80Hz), typically in narrower bands? And if they are different, how should they be interpreted? Does the broad spectral shape of high gamma responses arise from the summation of many different narrow-band oscillations, or does it reflect something completely different? If we are not sure, should we refer to high gamma activity as oscillations? A variety of theories have posited a mechanistic role for gamma activity in cortical function, often assuming narrow-band oscillations. These theories continue to influence the design of experiments and the interpretation of their results. Do these theories apply to all electrophysiological responses at gamma frequencies? Although no definitive answers to these questions are immediately anticipated, this paper will attempt to review the rationale for why they are worth asking and to point to some of the possible answers that have been proposed.
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http://dx.doi.org/10.1016/j.ijpsycho.2010.10.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3958992PMC
January 2011

Quantifying auditory event-related responses in multichannel human intracranial recordings.

Front Comput Neurosci 2010 19;4. Epub 2010 Mar 19.

Department of Neurology, Johns Hopkins School of Medicine Baltimore, MD, USA.

Multichannel intracranial recordings are used increasingly to study the functional organization of human cortex. Intracranial recordings of event-related activity, or electrocorticography (ECoG), are based on high density electrode arrays implanted directly over cortex, combining good temporal and spatial resolution. Developing appropriate statistical methods for analyzing event-related responses in these high dimensional ECoG datasets remains a major challenge for clinical and systems neuroscience. We present a novel methodological framework that combines complementary, existing methods adapted for statistical analysis of auditory event-related responses in multichannel ECoG recordings. This analytic framework integrates single-channel (time-domain, time-frequency) and multichannel analyses of event-related ECoG activity to determine statistically significant evoked responses, induced spectral responses, and effective (causal) connectivity. Implementation of this quantitative approach is illustrated using multichannel ECoG data from recent studies of auditory processing in patients with epilepsy. Methods described include a time-frequency matching pursuit algorithm adapted for modeling brief, transient cortical spectral responses to sound, and a recently developed method for estimating effective connectivity using multivariate autoregressive modeling to measure brief event-related changes in multichannel functional interactions. A semi-automated spatial normalization method for comparing intracranial electrode locations across patients is also described. The individual methods presented are published and readily accessible. We discuss the benefits of integrating multiple complementary methods in a unified and comprehensive quantitative approach. Methodological considerations in the analysis of multichannel ECoG data, including corrections for multiple comparisons are discussed, as well as remaining challenges in the development of new statistical approaches.
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http://dx.doi.org/10.3389/fncom.2010.00004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2859880PMC
July 2011

[The evaluation of prognostic value of cyclin B1 expression in patients with resected non-small-cell lung cancer stage I-IIIA--preliminary report].

Pol Merkur Lekarski 2010 Feb;28(164):117-21

Akademia Medyczna we Wrocławiu, Katedra i Klinika Pulmonologii i Nowotworów Płuc.

Unlabelled: Lung cancer is a leading cause of cancer death in the majority of developed countries and in Poland. THE AIM of this study was to evaluate the prognostic significance of cyclin B1 expression in primary, resected stage I-IIIA non-small cell lung cancer.

Material And Method: The expression of cyclin BI was investigated in the paraffin-embedded tumor tissues of 71 patients (53 male and 18 female, aged 59.27 + 8.50 years), using a mouse monoclonal antibody to cyclin B1. In all patients the 24 month survival was determined. Thirty eight (54%) patients survived and 33 (46%) died.

Results: Positive expression of cyclin B1 was documented in 6 (8.5%) tumor tissue specimens. Only cytoplasmatic staining was revealed. The prognostic values of cyclin B1 expression were presented in all examined patients and in patients with squamous cell lung cancer, adenocarcinoma and separately in every stage of disease. Any correlations between cyclin B1 expression and survival of patients were not confirmed in all examined groups.

Conclusion: In examined groups we did not reveal neither the prognostic value of cyclin B1 expression in patients with resected nonsmall cell lung cancer nor the correlations between cyclin B1 expression and neoadjuvant chemotherapy. More studies are expected in the future.
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February 2010
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