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Publication
Journal: Neuroscience Research
March/18/1997
Abstract
Somatosensory evoked magnetic fields (SEFs) following stimulation of the median nerves bilaterally ('bilateral' waveform) were examined in normal subjects to determine the interference effects of activation of sensory areas in bilateral hemispheres. SEFs following right median nerve stimulation and those following left median nerve stimulation were summated ('summated' waveform). A 'difference' waveform was induced by subtraction of the 'bilateral' waveform from 'summated' waveform. Short-latency deflections showed no consistent differences between the 'summated' and 'bilateral' waveforms, but the middle-latency deflection. N60m-P60m, in the 'bilateral' waveform was significantly (P < 0.01) smaller than that in the 'summated' waveform. The long-latency deflection, the N90m-P90m, in the 'bilateral' waveform was markedly (P < 0.001) reduced in amplitude as compared with the 'summated' waveform. The differences were clearly identified in the 'difference' waveform, in which the main deflections, U90m-D90m, were found in all subjects. Equivalent current dipoles (ECDs) of the short- and middle-latency deflections were located in the primary sensory cortex (SI) contralateral to the stimulated nerve, but ECDs of the N90m-P90m and U90m-D90m were located in bilateral second sensory cortices (SII) which are considered to receive ascending signals from bilateral sides of the body.
Publication
Journal: IEEE Transactions on Biomedical Engineering
December/18/1991
Abstract
A novel noninvasive and quasi-continuous method of transcutaneous blood glucose monitoring for use with the human 75 g oral glucose tolerance test (OGTT) has been developed. The effused fluid was obtained by applying suction on the skin surface and labeled suction effusion fluid (SEF). The system consists of two main parts: a suction apparatus and the glucose sensor system. The suction apparatus applies vacuum to the patient's skin at 400 mmHg absolute pressure to collect the SEF. The miniature ion sensitive field effect transistor (ISFET) based glucose sensor can measure glucose in small SEF quantities. The monitoring system is based on the association between the glucose concentration in the SEF and in the serum. During the 75 g OGTT, the glucose change in the SEF was measured every 10 min. Although a response delay of up to 20 min was observed in the SEF glucose change, it was possible to perform the 75 g OGTT by this noninvasive monitoring method.
Publication
Journal: Behavioural Neurology
July/8/2012
Abstract
The current paper describes a rare case of a patient who suffered from unilateral apraxia of eye closure as a result of a bilateral stroke. Interestingly, the patient's ability to voluntarily close both eyelids (i.e. blinking) was not affected, indicating that different neural mechanisms control each type of eye closure. The stroke caused damage to a large part of the right frontal cortex, including the motor cortex, pre-motor cortex and the frontal eye field (FEF). The lesion in the left hemisphere was restricted to the FEF. In order to further study the neural mechanisms of eye closure, we conducted an fMRI study in a group of neurological healthy subjects. We found that all areas of the oculomotor cortex were activated by both left and right winking, including the FEF, supplementary eye field (SEF), and posterior parietal cortex (PPC). Blinking activated FEF and SEF, but not PPC. Both FEF and PPC were significantly more active during winking than blinking. Together, these results provide evidence for a critical role of the FEF in voluntary unilateral eye closure.
Publication
Journal: Acta Dermato-Venereologica
March/13/1988
Abstract
The aetiology of the folliculitis associated with seborrhoeic eczema is unclear, though the yeast, Pityrosporum orbiculare has been implicated. P. orbiculare was applied under occlusion to normal forearm skin of patients with seborrhoeic eczema (SE), seborrhoeic eczema and folliculitis (SEF), and normal controls. There were significant differences in response to occlusion between the three groups. Those patients with previous clinical evidence of folliculitis (SEF) developed folliculitis at the site of occlusion more frequently than either of the other two groups (p less than 0.001), in whom only one patient developed skin changes. This difference was not explained by the response to occlusion alone, nor by natural carriage of yeasts. These results suggest that the yeast P. orbiculare is necessary for the development of folliculitis, but that the nature of the host response determines those patients prone to follicular inflammation.
Publication
Journal: Journal of Neurophysiology
March/12/2009
Abstract
When different stimuli indicate where and when to make an eye movement, the brain areas involved in oculomotor control must selectively plan an eye movement to the stimulus that encodes the target position and also encode the information available from the timing cue. This could pose a challenge to the oculomotor system since the representation of the timing stimulus location in one brain area might be interpreted by downstream neurons as a competing motor plan. Evidence from diverse sources has suggested that the supplementary eye fields (SEF) play an important role in behavioral timing, so we recorded single-unit activity from SEF to characterize how target and timing cues are encoded in this region. Two monkeys performed a variant of the memory-guided saccade task, in which a timing stimulus was presented at a randomly chosen eccentric location. Many spatially tuned SEF neurons encoded only the location of the target and not the timing stimulus, whereas several other SEF neurons encoded the location of the timing stimulus and not the target. The SEF population therefore encoded the location of each stimulus with largely distinct neuronal subpopulations. For comparison, we recorded a small population of lateral intraparietal (LIP) neurons in the same task. We found that most LIP neurons that encoded the location of the target also encoded the location of the timing stimulus after its presentation, but selectively encoded the intended eye movement plan in advance of saccade initiation. These results suggest that SEF, by conditionally encoding the location of instructional stimuli depending on their meaning, can help identify which movement plan represented in other oculomotor structures, such as LIP, should be selected for the next eye movement.
Publication
Journal: Electroencephalography and clinical neurophysiology
January/7/1998
Abstract
The objective of the present study was to evaluate the normal interhemispheric variability of the locations and activation strengths of the somatosensory cortices. Somatosensory evoked magnetic fields (SEFs) were recorded with a 122-channel magnetometer in 23 healthy subjects (mean age 57 years) to stimulation of left and right median nerves. Equivalent current dipole (ECD) strengths and locations were determined for the main SEF deflections at the contralateral primary sensorimotor (SMI) and secondary somatosensory (SIIc) cortices. In a Cartesian co-ordinate system, defined by the preauricular points and the nasion, the SMI sources were slightly but significantly more laterally and anteriorly located in the right than in the left hemisphere. No systematic co-ordinate asymmetries were found for the SIIc sources. In individual subjects, the interhemispheric differences in the ECD co-ordinates averaged less than 6 mm at both SMI and SIIc. The group means of the source strengths did not differ between the hemispheres, but individual differences were on average 20% for the SMI and 65% for the SIIc sources. We conclude that at the individual level, the median nerve SEFs from SMI can be used to detect abnormally large interhemispheric asymmetries of source locations in the centimetre scale.
Publication
Journal: Acta Anaesthesiologica Scandinavica
October/19/2004
Abstract
BACKGROUND
It has been shown that spinal reflexes such as the H-reflex predict motor responses to painful stimuli better than cortical parameters derived from the EEG. The precise concentration-dependence of H-reflex suppression by anaesthetics, however, is not known. Here we investigated this concentration-response relationship and the equilibration between the alveolar and the effect compartment for sevoflurane.
METHODS
In 26 patients, the H-reflex was recorded at a frequency of 0.1 Hz while anaesthesia was induced and maintained with sevoflurane at increasing and decreasing concentrations. Population pharmacodynamic modelling was performed using the NONMEM software package, yielding population mean parameters as well as indicators of interindividual variability.
RESULTS
Suppression of H-reflex amplitude occurred at lower concentrations (mean EC(50) 1.04 +/- 0.10 vol%, SE of NONMEM estimate) than the effect on either BIS or SEF(95) of the EEG (mean EC(50) 1.55 +/- 0.08 and 1.72 +/- 0.18 vol%, respectively), and exhibited a higher interindividual variability. The concentration-response function for the H-reflex was also steeper (mean ë 2.83 +/- 0.25). In addition, the equilibration between alveolar and effect compartment was slower for the H-reflex (mean k(e0) 0.15 +/- 0.01 min(-1)) than for BIS or SEF(95) (mean k(e0) 0.22 +/- 0.02 and 0.41 +/- 0.05 min(-1)).
CONCLUSIONS
The differences in EC(50) and slope of the concentration-response relationships for H-reflex suppression and the EEG parameters point to different underlying mechanisms. In addition, the differences in time constant for equilibration between alveolar and effect compartment confirm the notion that immobility is caused at a different anatomic site than suppression of the EEG.
Publication
Journal: Computer Methods in Biomechanics and Biomedical Engineering
April/25/2013
Abstract
There is a scarcity of data regarding the mechanical properties of the ureter, although this would facilitate our understanding of its physiology and pathophysiology, and the development of suitable biomaterials for replacement. There is hence an urgent need for multiaxial experimental data and methodical constitutive formulations, which we aim at presenting through this report. The zero-stress state of wall tissue, serving as the starting geometry for biomechanical analyses, was accordingly determined and the 3D passive behaviour of ureteral specimens, isolated from healthy rabbits, was studied under a physiologic range of finite inflation and longitudinal extension. Two most-commonly employed descriptors of soft tissue behaviour were chosen to fit the material response: the Fung-type strain-energy function (SEF) and its combination with a quadratic function. Both SEFs were tested in the thick-walled setting, with incompressibility enforced explicitly or via a Lagrange multiplier. The deformational response of the ureter exhibited an exponential and not the sigmoidal dependency on pressure that requests implementation of two-term SEFs. Indeed, the four-parameter Fung-type SEF resulted in reasonable fit of both the external radius and longitudinal force vs. lumen pressure data, and fitting accuracy was not improved when attempting the seven-parameter Fung-type or biphasic SEFs. There were also serious over-parameterisation problems with those models, favouring the implementation of the SEF with the smallest number of parameters. The material parameters optimised revealed significant mechanical anisotropy, with longitudinal properties being stiffer than circumferential ones under equibiaxial stress states. We conclude that ureter displays a nonlinear anisotropic mechanical response that is well-characterised by the four-parameter Fung-type SEF.
Publication
Journal: Avian Diseases
January/19/2000
Abstract
Salmonella pullorum is the cause of pullorum disease, which is characterized by white diarrhea and a high mortality rate in poultry. During the 1990s, the serologic "pullorum" test has occasionally failed to detect infected birds during the early stage of disease. To determine if any recent genetic changes have taken place in S. pullorum to account for poor seroconversion sometimes observed in infected flocks, S. pullorum from 1990s outbreaks and strains isolated prior to the 1980s were typed by random amplified polymorphic DNA (RAPD). Of 40 S. pullorum isolates typed by this method, eight distinct DNA patterns were identified with one of three RAPD polymerase chain reaction primers. Sixty-two percent of S. pullorum isolates shared the same RAPD DNA pattern, and a major proportion of these strains were from recent flock infections. The RAPD patterns for S. pullorum were clearly distinct from the avian Salmonella group B isolates included in this analysis. The distribution of Salmonella virulence genes among avian Salmonella isolates was also examined. Eighty-five percent of the S. pullorum isolates had both the virulence plasmid gene, spvB, and the invasion gene, invA, with the same percentage positive for the Salmonella enteriditis fimbrial gene, sef. However, significant variability was observed among S. pullorum in their ability to invade avian epithelial cells, despite the presence of the Salmonella invasion gene in these isolates.
Publication
Journal: Clinical Nuclear Medicine
February/21/2001
Abstract
OBJECTIVE
The stimulated salivary clearance of Tc-99m pertechnetate (SSCP) introduced in 1985 by Blue and Jackson is revisited here in patients with known or possible salivary disorders and correlated with most commonly cited and up-to-date quantitative indices obtained from standard dynamic salivary scintigraphy.
METHODS
An SSCP test was performed after dynamic salivary scintigraphy in 19 patients with oral or ocular dryness, among whom 7 had Sjögren's syndrome. Many scintigraphic indices were calculated: salivary to background ratio (S/B[t]), background-corrected uptake U[t]), maximal uptake (Umax), cumulative gland uptake (CGU), initial slope of the uptake curve (IS), stimulated excretion velocity (SEV), stimulated excretion fraction (SEF), and excreted activity (EA).
RESULTS
The SSCP test was well tolerated, except in two patients in whom it had to be interrupted. Clearance values ranged from 5 to 40 ml/minute, with a clear-cut bimodal distribution centered around 15 to 20 ml/ minute. Six of the seven patients with Sjögren's syndrome had values less than 15 ml/minute. SSCP was closely correlated with all uptake indices (S/B, U, Umax, CGU, and IS) and uptake-related indices (EA, ISxSEF) (P < 0.01). A poor correlation was found with the excretion index SEV (P = 0.06) and none with SEF.
CONCLUSIONS
SSCP is a quick and objective means to investigate the sicca syndrome that may be useful in most clinical situations. It reflects the parenchymatous salivary gland function and will provide a means to assess and predict salivary gland involvement. Dynamic salivary scintigraphy remains necessary in very early stages because of its high sensitivity rate and ability to locate the impaired gland, or in severe stages in which lemon juice could be deleterious.
Publication
Journal: Psychophysiology
June/20/2011
Abstract
Studies on attention to tactile stimuli have produced conflicting results concerning the possibility and/or direction of modulation of early somatosensory-evoked fields (SEFs). To evaluate sources of these conflicting results, the same subjects performed four different tasks in which the stimulation site, type, and intensity were kept constant. Twelve subjects performed an oddball-like tactile task, two different one-back tactile tasks, and a visual task, while two distal phalanges of the index and ring finger were stimulated. Task-dependent SEF modulations were found as early as 50 ms after stimulus onset (M50 component). Target/non-target ratios of M50 revealed enhanced values for the oddball-like tactile task, but decreased values for the tactile one-back task. This indicates that previously obtained conflicting results might be due to different central mechanisms induced by different task requirements.
Publication
Journal: Neuroscience Letters
June/14/1989
Abstract
Neuromagnetic measurements were carried out during median nerve stimulation at the wrist in complete relaxation (a) and during active contraction of the hand muscles (b). Firstly, activity of the generator source responsible for the major component of the sensory evoked magnetic fields (SEFs) was mapped and localized during condition (a) and (b). Then the subtraction maps ((a)-(b)) were obtained and the virtual 'dipole' responsible for the 'interference' (less than or equal to SEFs amplitude) between the afferent input and the motor output was tridimensionally localized in a position compatible with the knee and the convexity of the postcentral gyrus.
Publication
Journal: Genetics
August/5/2015
Abstract
During segmentation of vertebrate embryos, somites form in accordance with a periodic pattern established by the segmentation clock. In the zebrafish (Danio rerio), the segmentation clock includes six hairy/enhancer of split-related (her/hes) genes, five of which oscillate due to negative autofeedback. The nonoscillating gene hes6 forms the hub of a network of 10 Her/Hes protein dimers, which includes 7 DNA-binding dimers and 4 weak or non-DNA-binding dimers. The balance of dimer species is critical for segmentation clock function, and loss-of-function studies suggest that the her genes have both unique and redundant functions within the clock. However, the precise regulatory interactions underlying the negative feedback loop are unknown. Here, we combine quantitative experimental data, in silico modeling, and a global optimization algorithm to identify a gene regulatory network (GRN) designed to fit measured transcriptional responses to gene knockdown. Surprisingly, we find that hes6, the clock gene that does not oscillate, responds to negative feedback. Consistent with prior in silico analyses, we find that variation in transcription, translation, and degradation rates can mediate the gain and loss of oscillatory behavior for genes regulated by negative feedback. Extending our study, we found that transcription of the nonoscillating Fgf pathway gene sef responds to her/hes perturbation similarly to oscillating her genes. These observations suggest a more extensive underlying regulatory similarity between the zebrafish segmentation clock and the mouse and chick segmentation clocks, which exhibit oscillations of her/hes genes as well as numerous other Notch, Fgf, and Wnt pathway genes.
Publication
Journal: Annals of Biomedical Engineering
June/21/2015
Abstract
The push towards low-power and wearable sleep systems requires using minimum number of recording channels to enhance battery life, keep processing load small and be more comfortable for the user. Since most sleep stages can be identified using EEG traces, enormous power savings could be achieved by using a single channel of EEG. However, detection of REM sleep from one channel EEG is challenging due to its electroencephalographic similarities with N1 and Wake stages. In this paper we investigate a novel feature in sleep EEG that demonstrates high discriminatory ability for detecting REM phases. We then use this feature, that is based on spectral edge frequency (SEF) in the 8-16 Hz frequency band, together with the absolute power and the relative power of the signal, to develop a simple REM detection algorithm. We evaluate the performance of this proposed algorithm with overnight single channel EEG recordings of 5 training and 15 independent test subjects. Our algorithm achieved sensitivity of 83%, specificity of 89% and selectivity of 61% on a test database consisting of 2221 REM epochs. It also achieved sensitivity and selectivity of 81 and 75% on PhysioNet Sleep-EDF database consisting of 8 subjects. These results demonstrate that SEF can be a useful feature for automatic detection of REM stages of sleep from a single channel EEG.
Publication
Journal: Psychopharmacology
March/29/2004
Abstract
BACKGROUND
Serotonin is shown to regulate the activity of primary auditory cortex, but little is known about serotonin modulation of other sensory cortices.
METHODS
We investigated somatosensory evoked magnetic fields (SEF) to left median nerve stimulation in eight healthy subjects in a double-blind, controlled, cross-over design study after acute tryptophan depletion (ATD) and control mixture. SEFs were recorded with the whole-head magnetoencephalography 6 h after ingestion of mixtures. The SEF sources and strength were estimated by a least-squares fit of a single equivalent current dipole.
RESULTS
ATD decreased the total and free TPR levels by 75 and 48% and control mixture increased them by 98% and 44%. ATD had no effect on the amplitudes or latencies of SEF components. The source locations of the responses were not significantly affected by ATD.
CONCLUSIONS
Serotonin does not affect stimuli processing in the primary somatosensory cortex.
Publication
Journal: Nanomaterials
December/5/2018
Abstract
Gold nanocrystals have attracted considerable attention due to their excellent physical and chemical properties and their extensive applications in plasmonics, spectroscopy, biological detection, and nanoelectronics. Gold nanoparticles are able to be readily modified and arranged with DNA materials and protein molecules, as well as viruses. Particularly DNA materials with the advantages endowed by programmability, stability, specificity, and the capability to adapt to functionalization, have become the most promising candidates that are widely utilized for building plenty of discrete gold nanoarchitectures. This review highlights recent advances on the DNA-based assembly of gold nanostructures and especially emphasizes their resulted superior optical properties and principles, including plasmonic extinction, plasmonic chirality, surface enhanced fluorescence (SEF), and surface-enhanced Raman scattering (SERS).
Publication
Journal: Nutrition Research
November/24/2014
Abstract
Because socioeconomic factors (SEFs) may influence dietary quality and vitamin intakes, this study aimed to examine associations between socioeconomic factors and folate and vitamin B12 intakes as well as their related biomarkers in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. Vitamin intakes were obtained from two 24-hour recalls in 2253 participants (47% males). Vitamin B biomarkers were assessed in a subsample of 977 participants (46% males). Socioeconomic factors were assessed by questionnaire, and 1-way analysis of covariance and linear regression analysis were applied. For males and females, mean intakes of folate were 211.19 and 177.18 μg/d, and for vitamin B12, 5.98 and 4.54 μg/d, respectively. Levels of plasma folate, red blood cell folate, serum B12, and holotranscobalamin were 18.74, 807.19, 330.64, and 63.04 nmol/L in males, respectively, and 19.13, 770.16, 377.9, and 65.63 nmol/L in females, respectively. Lower folate intakes were associated with several SEFs, including maternal and paternal education in both sexes. Regarding folate biomarkers, lower plasma folate intakes were associated with single/shared care in males and with lower paternal occupation in females. Lower vitamin B12 intakes were associated with almost all the studied SEFs, except paternal occupation in both sexes. In females, when considering vitamin B12 biomarkers, lower plasma vitamin B12 was associated with lower maternal education and occupation, and lower holotranscobalamin was associated with lower maternal education and lower paternal occupation. In conclusion, from the set of socioeconomic determinants studied in a sample of European adolescents, maternal education and paternal occupation were more consistently associated with folate and vitamin B12 intakes and biomarkers concentrations.
Publication
Journal: Analytica Chimica Acta
October/26/2011
Abstract
A study of the interaction between paraquat (methyl viologen) and humic acids, extracted from a soil amended over 30 years with crop residues, cow slurries and cattle manure, was carried out by two emission spectroscopies based on plasmonic effects: surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF). To carry out this study Ag nanoparticles were used. The complex formation was tested by analyzing the effect of the herbicide on humic acids, and by varying experimental parameters such as the pH and the laser excitation wavelength. The study of the vibrational bands led to infer information about the interaction mechanism of paraquat with humic acids and to find a correlation between this interaction and the humic acids structural modification induced by the different amendments added to soil.
Publication
Journal: Journal of the American Society for Mass Spectrometry
November/10/2013
Abstract
Gas chromatography-mass spectrometry (GC-MS) analyses of thermally labile compounds have been studied by using a short column fast gas chromatograph, coupled with fly-through electron ionization in supersonic molecular beams. Thirty-two compounds, which include steroids, carbamate pesticides, antibiotic drugs, and other pharmaceutical compounds, have been analyzed and the details of their GC-MS analysis are provided. The ability to analyze thermally labile compounds is discussed in relation to the speed of analysis. A new term, "speed enhancement factor" (SEF), is defined as the product of column length reduction and the carrier gas linear velocity increase, as compared with normal GC-MS conditions. Fast, very fast, and ultra-fast GC-MS are defined with a SEF in the ranges of 5-30, 30-400, and 400-4000, respectively. Trade-offs in the degree of dissociation, speed, gas chromatograph resolution, and sensitivity were studied and examined with thermally labile molecules. The experimental factors that affect the dissociation are described with emphasis on its reduction. We claim that the use of supersonic molecular beams for sampling and ionization provides the ultimate capability in the GC-MS of thermally labile compounds. The obtained 70-eV electron ionization mass spectra are shown, and an enhanced relative abundance of the molecular ion is demonstrated together with library search capability of these mass spectra, which is better than that reported with particle beam liquid chromatography-mass spectrometry. The performance of fast GC-MS in supersonic molecular beams is compared with other methods of fast GC-MS and with particle beam liquid chromatography-mass spectrometry.
Publication
Journal: European Journal of Paediatric Neurology
October/31/2001
Abstract
Northern epilepsy syndrome (NES, EPMR, progressive epilepsy with mental retardation, CLN8), an inherited childhood-onset epilepsy with mental retardation, has been recently characterized to belong to the family of neuronal ceroid lipofuscinoses (NCLs). In this study, four patients (ages 26-44 years) with NES and eight healthy controls underwent magnetic resonance imaging (MRI) and electrophysiological evaluation with somatosensory evoked magnetic field (SEF) studies. The findings in NES were compared with the known findings in juvenile NCL (JNCL, CLN3) and Finnish variant late infantile NCL (vLINCLFIN, CLN5) that manifest around the same age as NES. Also postmortem MRI was performed on one brain. On the MRIs, slight to moderate cerebellar atrophy was seen in all patients, whereas only two patients had slightly enlarged cerebral sulci. None of the MRIs demonstrated signal intensity abnormalities that are commonly seen in JNCL and vLINCLFIN and are considered to reflect the Wallerian degeneration after neuronal death. Generally SEFs in NES were within normal limits, indicating that the disease had not impaired the function of the neurons on the somatosensory pathway. In conclusion, MRI imaging and SEF findings suggest that the cerebral neuronal death and dysfunction in NES are minimal compared with JNCL and vLINCLFIN.
Publication
Journal: Small
October/20/2015
Abstract
Nano-sculptured thin films (nSTFs) is a group of meterials prepared by the oblique or the glancing angle deposition technique. They take the form of rods having different shapes such as nanocolumns, nanoscrews, nanozigzags and many other nanoshapes. Their potential for biosensing is highlighted in this review particularly the metallic ones due to their remarkable plasmonic properties. The techniques that have been shown so far to be of high potential are: extended surface plasmon resonance (SPR), localised SPR, surface enhanced flourescence (SEF) and Raman scattering (SERS). The use of metal nSTFs in SPR biosensors with Kretschmann-Raether configuration enhances both the angular and the spectral sensitivities due to the porosity and adds more degrees of freedom in designing evanescent waves based techniques. The metallic nSTFs, exhibit remarkable localised plasmonic properties that make them a promising substrate for enhanced spectroscopies. Their long term stability in water environment makes them suitable candidates for biosensing in water as it is already demonstrated for several water pollutants. The influences of the nanostructures' size, topology, the substrate features, and the preparation conditions on the enhancement of SEF and SERS are highlighted with emphases on the unresolved issues and future trends.
Publication
Journal: Early Human Development
December/12/2007
Abstract
OBJECTIVE
Power spectral analysis combined with a two-channel EEG system may be useful in management of newborn term infants at risk of hypoxic-ischaemic encephalopathy (HIE). This pilot study aimed to determine differences in the EEG power spectrum between normal term infants, infants who were at risk of but had not developed HIE, and infants who had developed HIE.
METHODS
Observational.
METHODS
EEG recordings from normal term newborn infants and term infants at risk of HIE were analyzed using fast Fourier transforms. EEG total power (TP), TP variance, TP coefficient of variation (TP CV) and spectral edge frequency (SEF) were compared between three groups: control infants (n=15); at-risk infants who had not developed clinically diagnosed HIE (n=4); and at-risk infants who had developed HIE (n=7).
RESULTS
Total power was similar in all groups. Variation of TP (variance and CV) was higher (p<0.05) in control infants than in infants at risk of HIE, regardless of whether they had developed HIE. SEF values were similar across all three groups.
CONCLUSIONS
Reduced variation of EEG power is a feature of infants at risk of HIE.
Publication
Journal: Human Brain Mapping
July/13/2016
Abstract
Fast cancellation or switching of action plans is a critical cognitive function. Rapid signal transmission is key for quickly executing and inhibiting responses, and the structural integrity of connections between brain regions plays a crucial role in signal transmission speed. In this study, we used the search-step task, which has been used in nonhuman primates to measure dynamic alteration of saccade plans, in combination with functional and diffusion-weighted MRI. Functional MRI results were used to identify brain regions involved in the reactive control of gaze. Probabilistic tractography was used to identify white matter pathways connecting these structures, and the integrity of these connections, as indicated by fractional anisotropy (FA), was correlated with search-step task performance. Average FA from tracts between the right frontal eye field (FEF) and both right supplementary eye field (SEF) and the dorsal striatum were associated with faster saccade execution. Average FA of connections between the dorsal striatum and both right SEF and right inferior frontal cortex (IFC) as well as between SEF and IFC predicted the speed of inhibition. These relationships were largely behaviorally specific, despite the correlation between saccade execution and inhibition. Average FA of connections between the IFC and both SEF and the dorsal striatum specifically predicted the speed of inhibition, and connections between the FEF and SEF specifically predicted the speed of execution. In addition, these relationships were anatomically specific; correlations were observed after controlling for global FA. These data suggest that networks supporting saccade initiation and inhibition are at least partly dissociable. Hum Brain Mapp 37:2811-2822, 2016. © 2016 Wiley Periodicals, Inc.
Publication
Journal: AIDS Research and Therapy
June/13/2013
Abstract
BACKGROUND
CSIC (5-chloro-3-phenylsulfonylindole-2-carboxamide), a non-nucleoside reverse transcriptase inhibitor (NNRTI) has not been advanced as a therapeutic anti-HIV candidate drug due to its low aqueous solubility and poor bioavailability.
OBJECTIVE
The objective of this work was to formulate CSIC into self-emulsifying oil formulations for the purpose of improving its aqueous solubility and evaluating in vitro antiretroviral activity.
METHODS
CSIC self-emulsifying oil formulations (SEFs) were formulated and evaluated for droplet size, zeta potential, polydispersity index (PDI), viscosity, emulsification time, stability and bioactivity.
RESULTS
Results showed significantly improved solubility of CSIC in the SEFs.The concentration of co-surfactant affected the droplet size, zeta potential and polydispersity index. In vitro bioactivity studies showed that the CSIC SEFs retained full anti-HIV activity.
CONCLUSIONS
The in vitro data from this first attempt to formulate CSIC SEFs suggest that improvement on the aqueous solubility of CSIC through this delivery system may accentuate its antiretroviral effectiveness in vivo via bioavailability enhancement. The formulation is therefore intended as an oral anti-HIV agent for prophylactic and therapeutic uses.
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