Analyzing the advantages of subcutaneous over transcutaneous electrical stimulation for activating brainwaves

Transcranial electrical stimulation (TES) is a widely accepted neuromodulation modality for treating brain disorders. However, its clinical efficacy is fundamentally limited due to the current shunting effect of the scalp and safety issues. A newer electrical stimulation technique called subcutaneous electrical stimulation (SES) promises to overcome the limitations of TES by applying currents directly at the site of the disorder through the skull. While SES seems promising, the electrophysiological effect of SES compared to TES is still unknown, thus limiting its broader application. Here we comprehensively analyze the SES and TES to demonstrate the effectiveness and advantages of SES. Beagles were bilaterally implanted with subdural strips for intracranial electroencephalography and electric field recording. For the intracerebral electric field prediction, we designed a 3D electromagnetic simulation framework and simulated TES and SES. In the beagle model, SES induces three to four-fold larger cerebral electric fields compared to TES, and significant changes in power ratio of brainwaves were observed only in SES. Our prediction framework suggests that the field penetration of SES would be several-fold larger than TES in human brains. These results demonstrate that the SES would significantly enhance the neuromodulatory effects compared to conventional TES and overcome the TES limitations.11Ysciescopu

Cognitive improvement after long-term electrical stimulation of bilateral anterior thalamic nucleus in refractory epilepsy patients

AbstractIntroductionThe cognitive and behavioral effect of deep brain stimulation (DBS) administered to the deep cerebral nuclei for epilepsy treatment is unknown. We investigated the cognitive outcomes at least 12 months after DBS to the bilateral anterior thalamic nucleus (ATN) for controlling intractable epilepsy.MethodsNine patients with intractable epilepsy who were not candidates for resective surgery, but who were treated by bilateral ATN DBS underwent cognitive and behavioral assessments before implantation and more than 1 year after DBS surgery. Postoperative cognitive assessments were carried out under a continuous stimulation mode.ResultsThe mean seizure-reduction rate of these patients after ATN DBS was 57.9% (35.6–90.4%). Cognitive testing showed favorable results for verbal fluency tasks (letter and category, p<0.05), and a significant improvement in delayed verbal memory was observed (p=0.017). However, we did not observe any significant changes in general abilities (IQ, MMSE), information processing (digit forward and backward, Trail A, and Digit Symbol), or executive function (Trail B and WCST). Interestingly, we did not observe any significant cognitive decline approximately 1 year (mean, 15.9 months) after ATN DBS surgery.ConclusionsWe showed that ATN DBS not only resulted in promising clinical effects but was also associated with improvements in both verbal recall and oral information processing, which may be related to the bilateral activation of the fronto-limbic circuit following DBS surgery. Further controlled, long-term studies with larger populations are warranted for elucidating the clinical effects of ATN DBS

Comparison and analysis of the prevalence of hepatitis C virus infection by region in the Republic of Korea during 2005-2012

Background/AimsThis study compared the prevalence of hepatitis C virus (HCV) infection in the Republic of Korea and estimated the high-risk regions and towns.MethodsNational Health Insurance Service data for 8 years from 2005 to 2012 were used. The subjects of the study had visited medical facilities and been diagnosed with or received treatment for acute or chronic HCV as a primary or secondary disease according to ICD-10 codes of B17.1 or B18.2, respectively. Any patient who received treatment for the same disease multiple times during 1 year was counted as one patient in that year. To correct for the effect of the age structure of the population by year and region, the age-adjusted prevalence was calculated using the direct method based on the registered population in 2010.ResultsThe overall prevalence of HCV infection among Korean adults (>20 years old) increased from 0.14% in 2005 to 0.18% in 2012. The sex-, age-, and region-adjusted prevalence in 2012 was 0.18%. The prevalence was highest in Busan, Jeonnam, and Gyeongnam, and there were towns with noticeably higher prevalences within these regions: Jindo (0.97%) in Jeonnam, Namhae (0.90%) in Gyeongnam, and Seo-gu (0.86%) in Busan.ConclusionsThe prevalence of HCV infection differs by regions as well as towns in the Republic of Korea, and is highest in Busan, Jeonnam, and Gyeongnam. The reasons for the high prevalence in these specific regions should be identified, since this could help prevent HCV infections in the future. In addition, active surveillance and treatment policies should be introduced to stop any further spread of infection in these high-prevalence regions

Abnormal Integrity of Corticocortical Tracts in Mild Cognitive Impairment: A Diffusion Tensor Imaging Study

Mild cognitive impairment (MCI) has been defined as a transitional state between normal aging and Alzheimer disease. Diffusion tensor imaging (DTI) can estimate the microstructural integrity of white matter tracts in MCI. We evaluated the microstructural changes in the white matter of MCI patients with DTI. We recruited 11 patients with MCI who met the working criteria of MCI and 11 elderly normal controls. The mean diffusivity (MD) and fractional anisotropy (FA) were measured in 26 regions of the brain with the regions of interest (ROIs) method. In the MCI patients, FA values were significantly decreased in the hippocampus, the posterior limb of the internal capsule, the splenium of corpus callosum, and in the superior and inferior longitudinal fasciculus compared to the control group. MD values were significantly increased in the hippocampus, the anterior and posterior limbs of the internal capsules, the splenium of the corpus callosum, the right frontal lobe, and in the superior and the inferior longitudinal fasciculus. Microstructural changes of several corticocortical tracts associated with cognition were identified in patients with MCI. FA and MD values of DTI may be used as novel biomarkers for the evaluation of neurodegenerative disorders

Comparison of methods for proanthocyanidin extraction from pine (Pinus densiflora) needles and biological activities of the extracts

Flavonoids are known to be effective scavengers of free radicals. In particular, proanthocyanidins are flavonoids that possess cardiovascular protection, antioxidative activities, and immunomodulatory activities. Here, we evaluated proanthocyanidin contents in the total polyphenolic compounds of pine needle extracts prepared by hot water, ethanol, hexane, hot water-hexane (HWH), and hot water-ethanol (HWE). Analysis of each extract indicated that the ethanol extract contained the highest proanthocyanidin concentration. The HWH and hexane extracts also contained relatively high concentrations of proanthocyanidin. On the other hand, proanthocyanidin content analyses out of the total polyphenolic compounds indicated that the HWH extract contained the highest content. These results suggest that HWH extraction is a suitable method to obtain an extract with a high level of pure proanthocyanidins and a relatively high yield. The HWH extract possessed superior activity in diverse antioxidative analyses such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferrous ion chelating (FIC), and ferric-ion reducing power (FRAP) assays. In addition, upon assessing the effects of the pine needle extracts on macrophages (Raw 264.7 cell), the HWH extract exhibited the highest activity. In this study, we discerned an efficient extraction method to achieve relatively pure proanthocyanidins from pine needles and evaluated the biological functions of the resulting extract, which could potentially be used for its efficacious components in functional food products

Efficacy and Tolerability of Peginterferon Alpha Plus Ribavirin in the Routine Daily Treatment of Chronic Hepatitis C Patients in Korea: A Multi-Center, Retrospective Observational Study

Background/Aims: We aimed to evaluate the efficacy and safety of peginterferon plus ribavirin for chronic hepatitis C (CHC) patients under real life setting in Korea. Methods: We retrospectively analyzed the medical records of 758 CHC patients treated with peginterferon plus ribavirin between 2000 and 2008 from 14 university hospitals in the Gyeonggi-Incheon area in Korea. Results: Hepatitis C virus (HCV) genotype 1 was detected in 61.2% of patients, while genotype 2 was detected in 35.5%. Baseline HCV RNA level was &gt;= 6x10(5) IU/mL in 51.6% of patients. The sustained virological response (SVR) rate was 59.6% regardless of genotype; 53.6% in genotype 1 and 71.4% in genotype 2/3. On multivariate analysis, male gender (p=0.011), early virological response (p&lt;0.001), genotype 2/3 (p&lt;0.001), HCV RNA &lt;6x10(5) IU/mL (p=0.005) and adherence to the drug &gt;80% of the planned dose (p&lt;0.001) were associated with SVR. The rate of premature discontinuation was 35.7%. The main reason for withdrawal was intolerance to the drug due to common adverse events or cytopenia (48.2%). Conclusions: Our data suggest that the efficacy of peginterferon and ribavirin therapy in Koreans is better in Koreans than in Caucasians for the treatment of CHC, corroborating previous studies that have shown the superior therapeutic efficacy of this regimen in Asians.This study was supported by the Korean Association for the Study of the Liver in 2009

Focused clamping of a single neuronal SNARE complex by complexin under high mechanical tension

The SNARE complex enables the fusion of synaptic vesicles with presynaptic membrane via a zippering process that is modulated by the protein complexin, though the precise mechanism remains unclear. Here, the authors used magnetic tweezers to show how complexin prepares a SNARE complex for fusion under mechanical tension

Submicrometer elasticity of double-stranded DNA revealed by precision force-extension measurements with magnetic tweezers

Submicrometer elasticity of double-stranded DNA (dsDNA) governs nanoscale bending of DNA segments and their interactions with proteins. Single-molecule force spectroscopy, including magnetic tweezers (MTs), is an important tool for studying DNA mechanics. However, its application to short DNAs under 1 mm is limited. We developed an MT-based method for precise force-extension measurements in the 100-nm regime that enables in situ correction of the error in DNA extension measurement, and normalizes the force variability across beads by exploiting DNA hairpins. The method reduces the lower limit of tractable dsDNA length down to 198 base pairs (bp) (67 nm), an order-of-magnitude improvement compared to conventional tweezing experiments. Applying this method and the finite worm-like chain model we observed an essentially constant persistence length across the chain lengths studied (198 bp to 10 kbp), which steeply depended on GC content and methylation. This finding suggests a potential sequence-dependent mechanism for short-DNA elasticity.11Nsciescopu

Positive effects of E-beam irradiation in inorganic particle based separators for lithium-ion battery

An inorganic separator was prepared by coating inorganic submicrometer sized particles on a nonwoven matrix followed by an E-beam irradiation treatment. Its characteristics were investigated by scanning electron microscopy, tensile strength analysis, thermogravimetric analysis, ionic conductivity measurements, and charge-discharge analysis. The mechanical and thermal properties of the separator were greatly enhanced by the simple curing under E-beam irradiation. However, there was no significant change in the morphology or ionic conductivity of the E-beam treated separator. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3247825] All rights reserved.N