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Publication
Journal: Physiology and Behavior
July/10/2003
Abstract
Neuronal activity in macaque supplementary eye field (SEF) is enhanced during performance of the antisaccade task. This could be related to the selection of targets by a difficult rule (move to a location diametrically opposite the cue) or to conflict between the automatic tendency to look at the cue and the voluntary intention to look away. To distinguish between rule- and conflict-based mechanisms of enhancement, we monitored neuronal activity in the SEF during performance of a delayed response task in which monkeys selected saccade targets in response to peripheral visual cues. In spatial trials, the monkey had to select as target the location marked by the cue. In color trials, the monkey had to select as target the location associated with the color of the cue. 'Color-congruent' trials resembled spatial trials in that saccades were directed to the location occupied by the cue. Nevertheless, many SEF neurons were sensitive to the rule being used, with the majority firing more strongly under the color-rule condition. 'Color-incongruent' trials resembled 'color-congruent' trials in that a color rule guided target selection. Nevertheless, many SEF neurons were sensitive to the spatial relation between cue and saccade, with the majority firing more strongly on trials in which they were incongruent. We conclude that neuronal activity in the SEF is enhanced in connection both with the use of a more difficult rule and with conflict.
Publication
Journal: Journal of Neurology
April/23/1997
Abstract
Eye movement disturbances resulting from cerebral lesions are reviewed and the specific roles of the different ocular motor areas are summarized. Three cortical areas may trigger saccades: the frontal eye field (FEF), the supplementary eye field (SEF) and the parietal eye field (PEF). The FEF could be involved mainly in intentional visual exploration (intentional saccades), the PEF mainly in reflexive visual exploration (reflexive saccades) and the SEF in the preparation of motor programs (sequences of saccades). Only bilateral lesions affecting these areas result in visible saccade disturbances (at bedside examination), as manifested in Balint's syndrome after parietal lesions, and ocular motor apraxia after fronto-parietal lesions. Other cortical areas prepare saccades: the posterior parietal cortex (near the PEF) controls visuomotor integration; the prefrontal cortex (i.e. area 46 of Brodmann) is involved in inhibition of unwanted reflexive saccades, prediction (predictive saccades) and spatial memory. Smooth pursuit is controlled by the FEF and the medial superior temporal area, located in the posterior part of the cerebral hemisphere. Eye movement disorders resulting from basal ganglia lesions are also reviewed. Lastly, the contribution of eye movement recordings in early diagnosis of some cerebral degenerative diseases (such as progressive supranuclear palsy or corticobasal degeneration) is emphasized.
Publication
Journal: ACS Nano
August/26/2012
Abstract
Silicon nanowire and nanopillar structures have drawn increased attention in recent years due in part to their unique optical properties. Herein, electron beam lithography combined with reactive-ion etching is used to reproducibly create individual silicon nanopillars of various sizes, shapes, and heights. Finite difference time domain analysis predicts local field intensity enhancements in the vicinity of appropriately sized and coaxially illuminated silicon nanopillars of approximately 2 orders of magnitude. While this level of enhancement is modest when compared to plasmonic systems, the unique advantage of the silicon nanopillar resonators is that they enhance optical fields in substantially larger volumes. By analyzing experimentally measured strength of the silicon Raman phonon line (500 cm(-1)), it was determined that nanopillars produced local field enhancements that are consistent with these predictions. Additionally, we demonstrate that a thin layer of Zn phthalocyanine on the nanopillar surface with a total amount of <30 attomoles produced prominent Raman spectra, yielding enhancement factors (EFs) better than 2 orders of magnitude. Finally, silicon nanopillars of cylindrical and elliptical shapes were labeled with different fluorophors and evaluated for their surface-enhanced fluorescence (SEF) capability. The EFs derived from analysis of the acquired fluorescence microscopy images indicate that silicon nanopillar structures can provide enhancements comparable or even stronger than those typically achieved using plasmonic SEF structures without the limitations of the metal-based substrates, such as fluorescence quenching and an insufficiently large probe volume. It is anticipated that dense arrays of silicon nanopillars will enable SEF assays with extremely high sensitivity, while a broader impact of the reported phenomena is anticipated in photovoltaics, subwavelength light focusing, and fundamental nanophotonics.
Publication
Journal: British Journal of General Practice
December/25/2002
Abstract
BACKGROUND
Ear syringing is a common procedure performed for a variety of symptoms in primary care. Reports of its effectiveness vary considerably and no randomised controlled trials (RCTs) have been performed.
OBJECTIVE
To estimate the effect of ear syringing on hearing thresholds and on symptoms leading to ear syringing in general practice.
METHODS
Randomised single-blind controlled trial. Before-and-after self-assessments of symptoms.
METHODS
Patients from three general practices in the Bristol area attending twice-weekly clinics dedicated to ear syringing over a 12-week period.
METHODS
Patients were randomly assigned to have their hearing tested before and after ear syringing, or twice before ear syringing. Changes in hearing threshold were measured by pure tone audiometry (PTA). All patients completed sef-assessment forms of symptoms using Likert scales before, and one week after, ear syringing.
RESULTS
Hearing threshold improved by 10 dB or more in 34% (95% confidence interval [CI] = 21% to 47%) of the intervention group and 1.6% of control group (number needed to treat = 3.1, 95% CI = 2.2 to 5.2, P<0.001). The levels of improvement in the intervention group ranged between 15 dB and 36 dB. The symptoms that most commonly improved included hearing on the phone, pain, a feeling of blocked ears, and hearing one-to-one. There was a strong relationship between the change thresholds, as measure using PTA, and self-reports of hearing improvement. Secondary analysis was unable to identify predictors of objectively measured improvement.
CONCLUSIONS
Ear syringing improved hearing threshold in a substantial proportion of patients. An even larger proportion reported an improvement in symptoms. It was not possible to predict which patients would benefit.
Publication
Journal: NeuroImage
July/14/2008
Abstract
The purpose of the present study was to shed light on the physiology underlying somatosensory evoked magnetic fields (SEFs) by means of pharmacological manipulation with the GABA A agonist lorazepam and paired-pulse stimulation. SEFs were recorded from the primary (SI) and secondary (SII) somatosensory cortices following median nerve stimulation. Responses were obtained to single stimuli every 2 s and to paired stimuli with interpulse intervals (IPIs) of 20 ms and 100 ms. Recordings were performed in 2 sessions, once after the intravenous injection of lorazepam and once after the injection of placebo. The underlying neural generators of the response components were modelled with single equivalent current dipoles (ECDs). In the single-stimulus condition, lorazepam slightly increased the ECD strength of the 1st excitatory deflection (N20m) from the contralateral SI and reduced the strengths of the following P35m, P60m and N140m deflections from the contralateral SI and the response from the ipsilateral SII. Under placebo, paired-pulse stimulation with the IPI of 20 ms diminished all SEF components compared with single-pulse stimulation. At the IPI of 100 ms, the N20m and the P60m deflections from SI had recovered to nearly baseline levels, being consistent with recovery cycles of excitatory postsynaptic potentials (EPSPs). In contrast, the P35m and N140m, as well as the SII deflections, did not recover at 100 ms. Lorazepam had no effect on the paired-pulse depression (PPD) or recovery thereof for the N20m deflection. The attenuation of the P35m deflection by lorazepam and its lack of recovery in the 100-ms paired-pulse condition are expected behaviours of inhibitory postsynaptic potentials (IPSPs) in intracellular recordings, thus lending further support to our previous suggestion that P35m largely represents IPSPs. The lack of PPD modulation of N20m by lorazepam suggests that paired-pulse depression of the first cortical excitatory response (N20m) may be caused by mechanisms other than GABA A receptor-mediated inhibition.
Publication
Journal: Oral Oncology
May/29/2013
Abstract
OBJECTIVE
We investigated salivary function using quantitative scintigraphy and sought to identify functional correlations between parotid dose and quality of life (QoL) for head and neck cancer (HNC) patients receiving intensity-modulated radiotherapy (IMRT).
METHODS
Between August, 2007 and June, 2008, 31 patients treated IMRT for HNC were enrolled in this prospective study. Salivary excretion function (SEF) was previously measured by salivary scintigraphy at annual intervals for 2 years after IMRT. A dose-volume histogram of each parotid gland was calculated, and the normal tissue complication probability (NTCP) was used to determine the tolerance dose. QoL was longitudinally assessed by the EORTC QLQ-C30 and H&N35 questionnaires prior to RT, and at one, three, 12 and 24 months after RT.
RESULTS
A significant correlation was found between the reduction of SEF and the mean parotid dose measured at 1 year (correlation coefficient, R(2)=0.651) and 2 years (R(2)=0.310) after IMRT (p<0.001). The TD(50) of the parotid gland at 1 year after IMRT is 43.6 Gy, comparable to results from western countries. We further found that contralateral parotid and submandibular gland function preservation was correlated with reduced sticky saliva and a better QoL compared to the functional preservation of both parotid glands, as determined by the EORTC QLQ-H&N35 questionnaire.
CONCLUSIONS
A significant correlation was found between the reduction of SEF and the mean parotid dose. Preservation of contralateral parotid and submandibular gland function predicts a better QoL compared to preservation of the function of both parotid glands.
Publication
Journal: Developmental Cell
January/7/2013
Abstract
The NF-κB transcription factor controls diverse biological processes. According to the classical model, NF-κB is retained in the cytoplasm of resting cells via binding to inhibitory, IκB proteins and translocates into the nucleus upon their ligand-induced degradation. Here we reveal that Sef, a known tumor suppressor and inhibitor of growth factor signaling, is a spatial regulator of NF-κB. Sef expression is regulated by the proinflammatory cytokines tumor necrosis factor and interleukin-1, and Sef specifically inhibits "classical" NF-κB (p50:p65) activation by these ligands. Like IκBs, Sef sequesters NF-κB in the cytoplasm of resting cells. However, contrary to IκBs, Sef continues to constrain NF-κB nuclear entry upon ligand stimulation. Accordingly, endogenous Sef knockdown markedly enhances stimulus-induced NF-κB nuclear translocation and consequent activity. This study establishes Sef as a feedback antagonist of proinflammatory cytokines and highlights its potential to regulate the crosstalk between proinflammatory cytokine receptors and receptor tyrosine kinases.
Publication
Journal: Journal of Biological Chemistry
October/18/2004
Abstract
Sef was recently identified as a negative regulator of fibroblast growth factor (FGF) signaling in a genetic screen of zebrafish and subsequently in mouse and humans. By inhibiting FGFR1 tyrosine phosphorylation and/or Ras downstream events, Sef inhibits FGF-mediated ERK activation and cell proliferation as well as PC12 cell differentiation. Here we show that Sef and a deletion mutant of Sef lacking the extracellular domain (SefIC) physically interact with TAK1 (transforming growth factor-beta-associated kinase) and activate JNK through a TAK1-MKK4-JNK pathway. Sef and SefIC overexpression also resulted in apoptotic cell death, while dominant negative forms of MKK4 and TAK1 blocked Sef-mediated JNK activation and attendant 293T cell apoptosis. These investigations reveal a novel activating function of Sef that is distinct from its inhibitory effect on FGF receptor signaling and ERK activation.
Publication
Journal: British Journal of Cancer
December/22/2009
Abstract
BACKGROUND
The fibroblast growth factor (FGF) axis is an important mitogenic stimulus in prostate carcinogenesis. We have previously reported that transcript level of human similar expression to FGF (hSef), a key regulator of this pathway, is downregulated in clinical prostate cancer. In this study we further analysed the role of hSef in prostate cancer.
METHODS
hSef function was studied in in vitro and in vivo prostate cancer models using stable over-expression clones. Protein expression of hSef was studied in a comprehensive tissue microarray.
RESULTS
Stable over-expression of hSef resulted in reduced in vitro cancer cell proliferation, migration and invasive potential. In an in vivo xenograft model, the expression of hSef significantly retarded prostate tumour growth as compared with empty vector (P=0.03) and non-transfected (P=0.0001) controls. Histological examination further showed a less invasive tumour phenotype and reduced numbers of proliferating cells (P=0.0002). In signalling studies, hSef inhibited FGF-induced ERK phosphorylation, migration to the nucleus and activation of a reporter gene. Constitutively active Ras, however, was able to reverse these effects, suggesting that hSef exerts an effect either above or at the level of Ras in prostate cancer cells. In a large tissue microarray, we observed a significant loss of hSef protein in high-grade (P<0.0001) and metastatic (P<0.0001) prostate cancer.
CONCLUSIONS
Considered together, the role of hSef in attenuating FGF signalling and evidence of downregulation in advanced tumours argue strongly for a tumour suppressor function in human prostate cancer.
Publication
Journal: Virchows Archiv
December/8/2004
Abstract
Recently, low-grade fibromyxoid sarcoma/hyalinizing spindle cell tumor with giant rosettes (LGMFS/HSCT) and sclerosing epithelioid fibrosarcoma (SEFS) have come to be recognized as distinctive types of fibrosarcoma. Because their pathological features seem to sometimes overlap, it may be that these tumors belong to a similar entity. We report an aggressive sarcoma with unusual histology arising from the right ovary of a 44-year-old woman. The tumor was 12 cm in size, and there were multiple distant metastases to lung, kidney, stomach and bones. Microscopically, the tumor was composed of broad sheets or variously sized nodules of polygonal epithelioid cells accompanied by hyalinous stroma, resembling SEFS. The hyalinous nodules surrounded by the palisading epithelioid cells, as seen in a rosette of HSCT, were scattered. Between these nodules, spindle cells arranged in fascicles or whorled bundles, mimicking LGMFS, proliferated. Immunohistochemical and ultrastructural analyses revealed fibroblastic differentiation of epithelioid cells and the myofibroblastic nature of the spindle tumor cells. We think the present tumor is a distinctive epithelioid fibrosarcoma with the combined features of SEFS and LGFMS/HSCT, suggesting their intimate relationship.
Publication
Journal: Biochemical and Biophysical Research Communications
April/18/2007
Abstract
Sef (similar expression to fgf genes) was identified as an inhibitor of FGF signaling. The regulation of this inhibitory effect was largely unknown. In this report we demonstrated that tyrosine 330 in hSef protein plays a critical role in the control of the protein localization and thereby in the regulation of Ras/MAPK signaling pathway. We found that the tyrosine 330 is in the form of the YXXcapital EF, Cyrillic signal context and mutation of this residue resulted in preferred plasma membrane localization of hSef. We also observed that both Sef and SefY330F (where tyrosine is substituted by phenylalanine) interacted and co-localized with FGFR in the co-immunoprecipitation assay, and immunostaining assay respectively. We further revealed that the increased amount of Sef localization in the plasma membrane was coupled with the enhanced inhibitory effect on the FGF signaling pathway, indicating that Sef might exert its inhibitory function on the plasma membrane. This paper revealed that tyrosine 330 is critical for the inhibitory function of Sef on FGF signaling.
Publication
Journal: Investigative Ophthalmology and Visual Science
June/23/2008
Abstract
OBJECTIVE
To compare the cortical networks that underlie oculomotor function in patients with age-related macular degeneration (AMD) with those in normally sighted control subjects, using functional magnetic resonance imaging (fMRI).
METHODS
Six patients with bilateral geographic retinal atrophy due to AMD (age range, 55-83 years) were recruited for the study. The visual acuities of the patients ranged from 20/76 (0.58 logMAR) to 20/360 (1.26 logMAR). An additional six younger (age range, 22-31 years) and six older (age range, 54-78 years) normally sighted individuals were recruited as control subjects. fMRI data were acquired on a 3.0-Tesla, scanner while subjects performed visually guided saccade (VGS) and smooth-pursuit (SmP) tasks.
RESULTS
Contrasts between VGS and fixation on a stationary target identified a network of activation that included the frontal eye fields (FEFs), supplementary eye fields (SMA/SEFs), prefrontal cortex (PFC), intraparietal sulci (IPS), and the areas of the visual cortex (MT/V5, V2/V3, and V1) in control subjects and patients. A similar network was identified for comparisons between SmP and periods of fixation. Marked variability was observed in the performance of both tasks across all patients. For both tasks, the patients generally showed increased PFC and IPS activation, with decreased activation in visual cortex compared with the control subjects. The patients showed significantly increased activation of the FEFs and SMA/SEFs in the SmP task, compared with the control subjects.
CONCLUSIONS
These data suggest that performance of both eye movement tasks required greater involvement of the cortical regions generally implicated in attention and effort in patients with AMD.
Publication
Journal: Human Brain Mapping
August/2/2011
Abstract
Demyelination and axonal damage are pathologic hallmarks of multiple sclerosis (MS), leading to loss of neuronal synchronization, functional disconnection amongst brain relays, and clinical sequelae. To investigate these properties, the primary component of the sensorimotor network was analyzed in mildly disabled Relapsing-Remitting MS patients without sensory symptoms at the time of the investigation. By magnetoencephalography (MEG), the recruitment pattern within the primary sensory (S1) and motor (M1) areas was estimated through the morphology of the early components of somatosensory evoked magnetic fields (SEFs), after evaluating the S1 responsiveness to sensory inputs from the contralateral arm. In each hemisphere, network recruitment properties were correlated with ispilateral thalamus volume, estimated by morphometric techniques upon high-resolution 3D structural magnetic resonance images (MRI). S1 activation was preserved, whereas SEF morphology was strikingly distorted in MS patients, marking a disruption of primary somatosensory network patterning. An unbalance of S1-M1 dynamic recruitment was documented and correlated with the thalamic volume reduction in the left hemisphere. These findings support the model of MS as a disconnection syndrome, with major susceptibility to damage experienced by nodes belonging to more frequently recruited and highly specialized networks.
Publication
Journal: Neuropsychological Rehabilitation
January/9/2006
Abstract
The aim of this study was to investigate the accuracy of bispectral index (BIS), spectral edge frequency (SEF 95%), total power (TOTPOW) and frontal spontaneous electromyography (F-EMG) in monitoring consciousness in severely brain damaged patients. In 29 patients a total of 106 sedation-free and good quality EEG epochs were correlated with the level of consciousness as assessed by means of the Glasgow Liège Scale (GLS) and the Wessex Head Injury Matrix (WHIM). The strongest correlation with behavioural measures of consciousness was observed with BIS recordings. An empirically defined BIS cut-off value of 50 differentiated unconscious patients (coma or vegetative state) from conscious patients (minimally conscious state or emergence from minimally conscious state) with a sensitivity of 75% and specificity of 75%. These preliminary findings are encouraging in the search for electrophysiological correlates of consciousness in severe acute brain damage.
Publication
Journal: PLoS ONE
May/31/2015
Abstract
To increase the reliability for the non-invasive determination of the irritative zone in presurgical epilepsy diagnosis, we introduce here a new experimental and methodological source analysis pipeline that combines the complementary information in EEG and MEG, and apply it to data from a patient, suffering from refractory focal epilepsy. Skull conductivity parameters in a six compartment finite element head model with brain anisotropy, constructed from individual MRI data, are estimated in a calibration procedure using somatosensory evoked potential (SEP) and field (SEF) data. These data are measured in a single run before acquisition of further runs of spontaneous epileptic activity. Our results show that even for single interictal spikes, volume conduction effects dominate over noise and need to be taken into account for accurate source analysis. While cerebrospinal fluid and brain anisotropy influence both modalities, only EEG is sensitive to skull conductivity and conductivity calibration significantly reduces the difference in especially depth localization of both modalities, emphasizing its importance for combining EEG and MEG source analysis. On the other hand, localization differences which are due to the distinct sensitivity profiles of EEG and MEG persist. In case of a moderate error in skull conductivity, combined source analysis results can still profit from the different sensitivity profiles of EEG and MEG to accurately determine location, orientation and strength of the underlying sources. On the other side, significant errors in skull modeling are reflected in EEG reconstruction errors and could reduce the goodness of fit to combined datasets. For combined EEG and MEG source analysis, we therefore recommend calibrating skull conductivity using additionally acquired SEP/SEF data.
Publication
Journal: Journal of Neuroscience
April/7/2009
Abstract
When a monkey executes a learned series of eye movements (for example, rightward followed by upward followed by leftward), neurons in the supplementary eye field (SEF) fire differentially in conjunction with the first, second, and third movements. It has not been clear whether such ordinal position signals are truly general, accompanying all forms of sequential behavior, or accompany only learned sequences of movements. To resolve this issue, we trained monkeys to perform both a serial action task (making saccades in a fixed sequence of directions) and a serial object task (making saccades to a fixed sequence of objects). We found concordant ordinal position selectivity in the two tasks. Neuronal selectivity for the passage of time and expectation of reward could not explain such concordance. We conclude that SEF neurons signal ordinal position consistently across different task contexts. These signals presumably underlie the ability of primates including humans to perform a broad range of serial order tasks.
Publication
Journal: Developmental Dynamics
September/19/2005
Abstract
The signaling pathways leading to growth and patterning of various organs are tightly controlled during the development of any organism. These control mechanisms usually involve the utilization of feedback- and pathway-specific antagonists where the pathway induces the expression of its own antagonist. Sef is a feedback antagonist of fibroblast growth factor (FGF) signaling, which has been identified recently in zebrafish and mammals. Here, we report the isolation of chicken Sef (cSef) and demonstrate the conserved nature of the regulatory relationship with FGF signaling. In chick embryos, Sef is expressed in a pattern that coincides with many known sites of FGF signaling. In the developing limb, cSef is expressed in the mesoderm underlying the apical ectodermal ridge (AER) in the region known as the progress zone. cSef message first appeared after limb budding and AER formation. Expression was intense at stages of rapid limb outgrowth, and gradually decreased to almost undetectable levels when differentiation was clearly apparent. Gain- and loss-of-function experiments showed that FGFs differentially regulate the expression of cSef in various tissues. Thus, removal of the AER down-regulated cSef expression, and FGF2 but not FGF4 or FGF8 beads substituted for the AER in maintaining cSef expression. At sites where cSef is not normally expressed, FGF4 and FGF2, but not FGF8 beads, induced cSef expression. Our results demonstrate the complexity of cSef regulation by FGFs and point to FGF2 as a prime candidate in regulating cSef expression during normal limb development. The spatiotemporal pattern of cSef expression during limb development suggests a role for cSef in regulating limb outgrowth but not limb initiation.
Publication
Journal: Experimental Brain Research
April/29/2008
Abstract
It is essential to sense anticipated and elapsed time in our daily life. Several areas of the brain including parietal cortex, prefrontal cortex, basal ganglia and olivo-cerebellar system are known to be related to this temporal processing. We now describe a number of cells in the supplementary eye field (SEF) with phasic, delay activity and postdelay activity modulation that varied with the length of the delay period. This variation occurred in two manners. First, cells became active with the shorter delay periods (GO signal presented earlier). We call these cells "short-delay cells". Second, cells became active with the longer delay periods (GO signal presented later). We call these cells "long-delay cells". However, such changed neuronal activity did not correlate with reaction time. These results suggest that the delay-dependent activity may reflect anticipated and elapsed time during performance of a delayed saccadic eye movement.
Publication
Journal: NeuroImage
November/4/1999
Abstract
We studied the interaction between responses to contra- and ipsilateral stimuli in the human second somatosensory cortex SII by recording somatosensory evoked magnetic fields (SEFs) from 8 healthy subjects with a 122-channel whole-scalp SQUID magnetometer. Right (R) and left (L) median nerves were electrically stimulated at the wrists at intensities exceeding the motor threshold. In each stimulus sequence, the four equiprobable pairs (L-L, R-R, L-R, R-L) were presented in a random order once every 2 s, with a 300-ms interstimulus interval within the pair. The responses were modelled with a four-dipole model, with current dipoles located in the SI and SII cortices of both hemispheres. The SII responses peaked around 85-120 ms and responses to the 1st (2nd) stimulus on the pair were on average 2 (12) ms earlier and about 3 (2.5) times stronger for contralateral than ipsilateral stimuli. Independently of the condition, the 2nd response always peaked later than the 1st; the mean delay was 16 ms. The responses to the 2nd stimulus depended only slightly on the type of the 1st: the latency increased more and the amplitude decreased less after different than identical 1st stimuli. These results suggest that neuronal activations due to contra- and ipsilateral stimuli overlap strongly in the human SII cortex.
Publication
Journal: Journal of Neurophysiology
June/13/1999
Abstract
Macaque SEF neurons encode object-centered directions of eye movements regardless of the visual attributes of instructional cues. Neurons in the supplementary eye field (SEF) of the macaque monkey exhibit object-centered direction selectivity in the context of a task in which a spot flashed on the right or left end of a sample bar instructs a monkey to make an eye movement to the right or left end of a target bar. To determine whether SEF neurons are selective for the location of the cue, as defined relative to the sample bar, or, alternatively, for the location of the target, as defined relative to the target bar, we carried out recording while monkeys performed a new task. In this task, the color of a cue-spot instructed the monkey to which end of the target bar an eye movement should be made (blue for the left end and yellow for the right end). Object-centered direction selectivity persisted under this condition, indicating that neurons are selective for the location of the target relative to the target bar. However, object-centered signals developed at a longer latency (by approximately 200 ms) when the instruction was conveyed by color than when it was conveyed by the location of a spot on a sample bar.
Publication
Journal: Journal of Cellular Biochemistry
August/11/2010
Abstract
Repetitive deformation like that engendered by peristalsis or villous motility stimulates intestinal epithelial proliferation on collagenous substrates and motility across fibronectin, each requiring ERK. We hypothesized that ERK acts differently at different intracellular sites. We stably transfected Caco-2 cells with ERK decoy expression vectors that permit ERK activation but interfere with its downstream signaling. Targeting sequences constrained the decoy inside or outside the nucleus. We assayed proliferation by cell counting and migration by circular wound closure with or without 10% repetitive deformation at 10 cycles/min. Confocal microscopy confirmed localization of the fusion proteins. Inhibition of phosphorylation of cytoplasmic RSK or nuclear Elk confirmed functionality. Both the nuclear-localized and cytosolic-localized ERK decoys prevented deformation-induced proliferation on collagen. Deformation-induced migration on fibronectin was prevented by constraining the decoy in the nucleus but not in the cytosol. Like the nuclear-localized ERK decoy, a Sef-overexpressing adenovirus that sequesters ERK in the cytoplasm also blocked the motogenic and mitogenic effects of strain. Inhibiting RSK or reducing Elk ablated both the mitogenic and motogenic effects of strain. RSK isoform reduction revealed isoform specificity. These results suggest that ERK must translocate to the nucleus to stimulate cell motility while ERK must act in both the cytosol and the nucleus to stimulate proliferation in response to strain. Selectively targeting ERK within different subcellular compartments may modulate or replace physical force effects on the intestinal mucosa to maintain the intestinal mucosal barrier in settings when peristalsis or villous motility are altered and fibronectin is deposited into injured tissue.
Publication
Journal: Brain Research
November/8/1995
Abstract
Neuromagnetic fields from the left cerebral hemisphere of five healthy, right-handed subjects were investigated under two different experimental conditions: (1) electrical stimulation of the right index finger (task somatosensory evoked fields, task SEF's), and (2) voluntary movement of the same finger referred to as movement-related fields, (MRFs). The two conditions were, performed in random order every 5-8 s. In addition, the task SEF's were compared to control SEF's recorded at the beginning of the experiment in order to find the optimal dewar position for localizing the central sulcus. The magnetic signals of the sources corresponding to the main components of the somatosensory evoked fields (early ones at 24 ms and at 34 ms, and late ones after 50 ms) and movement-related fields (motor field, MF and movement-evoked field I-MEF I) were mapped and localized by means of a moving dipole model. In four out of five subjects the MEF I dipoles were found to be located deeper than the early task SEF dipoles. In addition, all of the task SEF's components were found to exhibit larger amplitudes than the control SEF's components. The results are discussed in respect to the ability to selectively analyze contributions of mainly proprioceptive (area 3a) and cutaneous (area 3b) areas in the primary somatosensory cortex using magnetoencephalography. An additional finding of the study was that all of the task SEF's components were found to exhibit larger amplitudes than the control SEF's components.
Publication
Journal: Cognitive and Behavioral Practice
February/19/2017
Abstract
Rates of depression are reported to be between 22-33% in adults with HIV, which is double that of the general population. Depression negatively affects treatment adherence and health outcomes of those with medical illnesses. Further, it has been shown in adults that reducing depression may improve both adherence and health outcomes. To address the issues of depression and non-adherence, Health and Wellness (H&W) Cognitive Behavioral Therapy (CBT) and medication management (MM) treatment strategies have been developed specifically for youth living with both HIV and depression. H&W CBT is based on other studies with uninfected youth and upon research on adults with HIV. H&W CBT uses problem-solving, motivational interviewing, and cognitive-behavioral strategies to decrease adherence obstacles and increase wellness. The intervention is delivered in 14 planned sessions over a 6-month period, with three different stages of CBT. This paper summarizes the feasibility and acceptability data from an open depression trial with 8 participants, 16-24 years of age, diagnosed with HIV and with a Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) diagnosis of depression, conducted at two treatment sites in the Adolescent Trials Network (ATN). Both therapists and subjects completed a Session Evaluation Form (SEF) after each session, and results were strongly favorable. Results from The Quick Inventory of Depressive Symptomatology-Clinician (QIDS-C) also showed noteworthy improvement in depression severity. A clinical case vignette illustrates treatment response. Further research will examine the use of H&W CBT in a larger trial of youth diagnosed with both HIV and depression.
Publication
Journal: Antonie van Leeuwenhoek
April/6/1983
Abstract
Staphyloccoccus aureus enterotoxin F (SEF), which is associated with S. aureus strains isolated from toxic-shock-syndrome patients, was purified by successive chromatography on CM sephadex C-25 and gelfiltration on sephadex G-75. When tested by disc-polyacrylamide gel-electrophoresis the toxin migrated as a homogeneous protein. In SDS-polyacrylamide gel-electrophoresis three protein bands were observed. The main component had a mol wt of 23 000 and the two minor components had a mol wt less than 13 000. By iso-electric focussing a main protein band with an iso-electric point of 7.2 was obtained. The LD50 for rabbits (3-3.5 kg) by subcutaneous and intravenous application of SEF was 6 micrograms and 180 micrograms, respectively. Antibodies to SEF prepared in a sheep did not react with other staphylococcal enterotoxins (A to E).
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