Publications by authors named "Minkyung Park"

38 Publications

Neuromodulatory Effect of Transcranial Direct Current Stimulation on Resting-State EEG Activity in Internet Gaming Disorder: A Randomized, Double-Blind, Sham-Controlled Parallel Group Trial.

Cereb Cortex Commun 2021 4;2(1):tgaa095. Epub 2021 Jan 4.

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul 07061, Republic of Korea.

Transcranial direct current stimulation (tDCS) has been used as an adjunct therapy for psychiatric disorders; however, little is known about the underlying neurophysiological effects of tDCS in Internet gaming disorder (IGD). We investigated the effects of tDCS on cortical activity using resting-state electroencephalography (EEG) in patients with IGD. This randomized, double-blind, sham-controlled parallel group study of tDCS (ClinicalTrials.gov NCT03347643) included 31 IGD patients. Participants received 10 sessions (2 sessions per day for 5 consecutive days) of active repetitive tDCS (2 mA for 20 min per session) or sham stimulation. Anode/cathode electrodes were placed over the left and right dorsolateral prefrontal cortex, respectively. In total, 26 participants (active group  = 14; sham group  = 12) completed the trial. Resting-state EEG spectral activity (absolute power) and functional connectivity (coherence) were used to assess the effects of tDCS on cortical activity before stimulation and 1 month after the intervention. Active stimulation of tDCS suppressed increase of intra-hemispheric beta coherence after 1 month, which was observed in the sham group. The 1-month follow-up assessment revealed that absolute gamma power in the left parietal region was decreased in the active group relative to the sham group. Our findings suggest that repetitive tDCS stabilizes fast-wave activity in IGD.
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http://dx.doi.org/10.1093/texcom/tgaa095DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8152877PMC
January 2021

Problematic Use of Alcohol and Online Gaming as Coping Strategies During the COVID-19 Pandemic: A Mini Review.

Front Psychiatry 2021 14;12:685964. Epub 2021 Jun 14.

Emotion, Cognition and Behavior Research Group, Korea Brain Research Institute, Daegu, South Korea.

The COVID-19 (coronavirus disease 2019) pandemic has dramatically changed our daily lives and activities, including those originally intended to serve for leisure and pleasure. Drinking and online gaming became coping behaviors used to rescue ourselves from the stress and restricted lifestyle during the COVID-19 pandemic. However, frequent drinking and gaming can result in the pathological consequences of addiction. Those affected use the stimuli not to obtain pleasure, but rather to avoid the displeasure induced by stress and previous use, often unsuccessfully. This review aims to provide an overview of recent longitudinal cohort studies on alcohol and gaming use during the COVID-19 pandemic, as well as to analyze how the pandemic has affected alcohol and gaming use. There was a substantial risk of alcohol and online gaming overuse during the lockdown, which may depend on the pandemic's duration or overuse patterns. Previous studies have shown that increased alcohol consumption and online gaming are associated with heightened stress and anxiety levels caused by social isolation/quarantine. Over time, frequent or excessive alcohol consumption and gaming could lead to an increased risk of more serious mental health problems. Every effort should be made to mitigate mental health problems and ensure adequate adaptation to these exceptional circumstances. Therefore, it would be helpful to encourage physical activity, social interaction, and collaboration to facilitate psychological and physical health.
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http://dx.doi.org/10.3389/fpsyt.2021.685964DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8236582PMC
June 2021

Transcutaneous Measurement of Essential Vitamins Using Near-Infrared Fluorescent Single-Walled Carbon Nanotube Sensors.

Small 2021 Jun 27:e2100540. Epub 2021 Jun 27.

Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA.

Vitamins such as riboflavin and ascorbic acid are frequently utilized in a range of biomedical applications as drug delivery targets, fluidic tracers, and pharmaceutical excipients. Sensing these biochemicals in the human body has the potential to significantly advance medical research and clinical applications. In this work, a nanosensor platform consisting of single-walled carbon nanotubes (SWCNTs) with nanoparticle corona phases engineered to allow for the selective molecular recognition of ascorbic acid and riboflavin, is developed. The study provides a methodological framework for the implementation of colloidal SWCNT nanosensors in an intraperitoneal SKH1-E murine model by addressing complications arising from tissue absorption and scattering, mechanical perturbations, as well as sensor diffusion and interactions with the biological environment. Nanosensors are encapsulated in a polyethylene glycol diacrylate hydrogel and a diffusion model is utilized to validate analyte transport and sensor responses to local concentrations at the boundary. Results are found to be reproducible and stable after exposure to 10% mouse serum even after three days of in vivo implantation. A geometrical encoding scheme is used to reference sensor pairs, correcting for in vivo optical and mechanical artifacts, resulting in an order of magnitude improvement of p-value from 0.084 to 0.003 during analyte sensing.
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http://dx.doi.org/10.1002/smll.202100540DOI Listing
June 2021

Identification of brevinin-1EMa-derived stapled peptides as broad-spectrum virus entry blockers.

Virology 2021 Sep 24;561:6-16. Epub 2021 May 24.

College of Pharmacy, Dongguk University, Goyang, Republic of Korea. Electronic address:

Based on the previously reported 13-residue antibacterial peptide analog, brevinin-1EMa (FLGWLFKVASKVL, peptide B), we attempted to design a novel class of antiviral peptides. For this goal, we synthesized three peptides with different stapling positions (B-2S, B-8S, and B-5S). The most active antiviral peptide with the specific stapling position (B-5S) was further modified in combination with either cysteine (B-5S3C, B-5S7C, and B-5S10C) or hydrophilic amino acid substitution (Bsub and Bsub-5S). Overall, B, B-5S, and Bsub-5S peptides showed superior antiviral activities against enveloped viruses such as retrovirus, lentivirus, hepatitis C virus, and herpes simplex virus with EC values of 1-5 μM. Murine norovirus, a non-enveloped virus, was not susceptible to the virucidal actions of these peptides, suggesting the virus membrane disruption as their main antiviral mechanisms of action. We believe that these three novel peptides could serve as promising candidates for further development of membrane-targeting antiviral drugs in the future.
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http://dx.doi.org/10.1016/j.virol.2021.05.004DOI Listing
September 2021

Association of General Cognitive Functions with Gaming Use in Young Adults: A Comparison among Excessive Gamers, Regular Gamers and Non-Gamers.

J Clin Med 2021 May 25;10(11). Epub 2021 May 25.

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul 07061, Korea.

This study aimed to examine the relationship of general cognitive function with gaming use, and to identify elements of intelligence predicting increased gaming use. In total, 160 young adults participated in this study. Two clinical groups ( = 97) were defined: excessive gaming users diagnosed with internet gaming disorder (IGD) ( = 64) and the high-risk users ( = 33). The control group ( = 63) was also divided into regular gamers ( = 14) and non-gamers ( = 49). Participants completed the Wechsler Adult Intelligence Scale-IV and self-reported questionnaires regarding IGD severity and gaming hours. The IGD group had significantly lower Full Scale Intelligence Quotient (FSIQ), Verbal Comprehension Index (VCI), and Processing Speed Index (PSI) scores, compared with regular gamers and non-gamers. The IGD group also exhibited lower Working Memory Index (WMI) scores, compared with non-gamers. The high-risk group demonstrated significantly lower PSI score, compared with non-gamers. Furthermore FSIQ, VCI, WMI, and PSI scores were significant predictors of gaming hours in the IGD group. For the high-risk group, FSIQ, WMI, and VCI scores were negatively associated with gaming hours. Our study demonstrates the need to address the importance of enhancing working memory and verbal ability, thus, preventing the development of gaming addiction among individuals at high-risk gamers.
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http://dx.doi.org/10.3390/jcm10112293DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8197560PMC
May 2021

Factors influencing the perceived health status of older adults living alone based on the Korean National Health and Nutrition Examination Survey (2016-2018).

Arch Gerontol Geriatr 2021 May 14;96:104433. Epub 2021 May 14.

Professor, Mo-Im Kim Nursing Research Institute, College of Nursing, Yonsei University, 50-1 Yonsei-ro Seodaemun-gu, Seoul, 03722, Republic of Korea. Electronic address:

Purpose: Older adults living alone have a lower level of health due to functional degradation and social isolation, and hence, it is important to assess their health condition and health-related factors. In this study we intended to evaluate the factors influencing the perceived health status of older adults living alone in Korea.

Materials And Methods: Data from the 7th (2016-2018) Korean National Health and Nutrition Examination Survey (KNHANES) were used. Perceived health status and health-related and demographic characteristics of 1,074 older adults (age≥65 years) living alone were included in this study. A complex sample design analysis method was used to consider the characteristics of the raw data of the KNHANES, and a complex sample ordinal logistic regression analysis was performed to identify factors that affect perceived health status.

Results: Female sex, low economic status, not consuming alcohol, perceived stress, high number of chronic diseases, underweight, and limitation of activity were risk factors of low perceived health status of older adults living alone.

Conclusions: Interventions to improve the identified health-related factors, such as stress, underweight, and activity limitation of older adults need to be devised. In addition, differences in risk factors according to sex should be considered when providing interventions. Furthermore, policies supporting the promotion of health status among older adults with low-income and living alone are warranted to improve health equity in Korea.
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http://dx.doi.org/10.1016/j.archger.2021.104433DOI Listing
May 2021

Event-related brain response to visual cues in individuals with Internet gaming disorder: relevance to attentional bias and decision-making.

Transl Psychiatry 2021 05 1;11(1):258. Epub 2021 May 1.

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul, 07061, Republic of Korea.

This study investigated attentional bias toward game-related cues in Internet gaming disorder (IGD) using electrophysiological markers of late positive potential (LPP) and identifying the sources of LPP. In addition, the association between LPP and decision-making ability was investigated. The IGD (n = 40) and healthy control (HC; n = 39) participants viewed a series of game-related and neutral pictures, while their event-related potentials (ERPs) were recorded. LPPs were calculated as the mean amplitudes between 400 and 700 ms at the centro-parietal (CP3, CP1, Cpz, CP2, and CP4) and parietal (P3, P1, Pz, P2, and P4) electrode sites. The source activations of LPP were estimated using standardized low-resolution brain electromagnetic tomography (sLORETA). In addition, decision-making ability was evaluated by the Cambridge Gambling Task. Higher LPP amplitudes were found for game-related cues in the IGD group than in the HC group. sLORETA showed that the IGD group was more active in the superior and middle temporal gyri, which are involved in social perception, than in the HC group, whereas it was less active in the frontal area. Individuals with IGD have deficits in decision-making ability. In addition, in the HC group, the lower the LPP when looking at the game-related stimuli, the better the quality of decision-making, but not in the IGD group. Enhanced LPP amplitudes are associated with emotional arousal to gaming cues and decision-making deficits in IGD. In addition, source activities suggest that patients with IGD perceive game-related cues as social stimuli. LPP can be used as a neurophysiological marker of IGD.
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http://dx.doi.org/10.1038/s41398-021-01375-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8088436PMC
May 2021

Plant Nanobionic Sensors for Arsenic Detection.

Adv Mater 2021 Jan 26;33(1):e2005683. Epub 2020 Nov 26.

Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.

Arsenic is a highly toxic heavy-metal pollutant which poses a significant health risk to humans and other ecosystems. In this work, the natural ability of wild-type plants to pre-concentrate and extract arsenic from the belowground environment is exploited to engineer plant nanobionic sensors for real-time arsenic detection. Near-infrared fluorescent nanosensors are specifically designed for sensitive and selective detection of arsenite. These optical nanosensors are embedded in plant tissues to non-destructively access and monitor the internal dynamics of arsenic taken up by the plants via the roots. The integration of optical nanosensors with living plants enables the conversion of plants into self-powered autosamplers of arsenic from their environment. Arsenite detection is demonstrated with three different plant species as nanobionic sensors. Based on an experimentally validated kinetic model, the nanobionic sensor could detect 0.6 and 0.2 ppb levels of arsenic after 7 and 14 days respectively by exploiting the natural ability of Pteris cretica ferns to hyperaccumulate and tolerate exceptionally high level of arsenic. The sensor readout could also be interfaced with portable electronics at a standoff distance, potentially enabling applications in environmental monitoring and agronomic research.
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http://dx.doi.org/10.1002/adma.202005683DOI Listing
January 2021

A synthetic mimic of phosphodiesterase type 5 based on corona phase molecular recognition of single-walled carbon nanotubes.

Proc Natl Acad Sci U S A 2020 10 14;117(43):26616-26625. Epub 2020 Oct 14.

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139

Molecular recognition binding sites that specifically identify a target molecule are essential for life science research, clinical diagnoses, and therapeutic development. Corona phase molecular recognition is a technique introduced to generate synthetic recognition at the surface of a nanoparticle corona, but it remains an important question whether such entities can achieve the specificity of natural enzymes and receptors. In this work, we generate and screen a library of 24 amphiphilic polymers, preselected for molecular recognition and based on functional monomers including methacrylic acid, acrylic acid, and styrene, iterating upon a poly(methacrylic acid-co-styrene) motif. When complexed to a single-walled carbon nanotube, some of the resulting corona phases demonstrate binding specificity remarkably similar to that of phosphodiesterase type 5 (PDE5), an enzyme that catalyzes the hydrolysis of secondary messenger. The corona phase binds selectively to a PDE5 inhibitor, Vardenafil, as well as its molecular variant, but not to other potential off-target inhibitors. Our work herein examines the specificity and sensitivity of polymer "mutations" to the corona phase, as well as direct competitions with the native binding PDE5. Using structure perturbation, corona surface characterization, and molecular dynamics simulations, we show that the molecular recognition is associated with the unique three-dimensional configuration of the corona phase formed at the nanotube surface. This work conclusively shows that corona phase molecular recognition can mimic key aspects of biological recognition sites and drug targets, opening up possibilities for pharmaceutical and biological applications.
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http://dx.doi.org/10.1073/pnas.1920352117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7604511PMC
October 2020

Maladaptive Alterations of Defensive Response Following Developmental Complex Stress in Rats.

Clin Psychopharmacol Neurosci 2020 Aug;18(3):412-422

Department of Psychiatry, Yonsei University, Seoul, Korea.

Objective: Despite the etiological significance of complex developmental trauma in adult personality disorders and treatment-resistant depression, neurobiological studies have been rare due to the lack of useful animal models. As a first step, we devised an animal model to investigate the effects of multiple trauma-like stress during different developmental periods.

Methods: Twenty-one male Sprague-Dawley rats were classified into 3 groups based on the stress protocol: fear conditioning control (FCC, n = 6), complex stress (ComS, n = 9), and control (n = 6). While the ComS experienced three types of stress (maternal separation, juvenile isolation, electric foot shock), the FCC only experienced an electric foot shock stress and the control never experienced any. We compared fear responses at postnatal day (PND) 29 and PND 56 through freezing time per episode (FTpE), total freezing time (TFT), total freezing episodes (TFE), and ultrasonic vocalization (USV).

Results: ComS showed the longest FTpE in the conditioned fear response test. ComS and FCC exhibited the longer TFT and these two groups only displayed USV. ComS show difference TFE between PND 29 and PND 56.

Conclusion: The results of this investigation show that complex stress may affect not quantity of fear response but characteristics of fear response. Longer FTpE may be associated with tonic immobility which could be considered as a failed self-protective reaction and might be analogous to a sign of inappropriate coping strategy and self-dysregulation in complex trauma patients.
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http://dx.doi.org/10.9758/cpn.2020.18.3.412DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7383007PMC
August 2020

A novel rat robot controlled by electrical stimulation of the nigrostriatal pathway.

Neurosurg Focus 2020 07;49(1):E11

2Department of Physiology, College of Medicine, Hallym University, Chuncheon.

Objective: Artificial manipulation of animal movement could offer interesting advantages and potential applications using the animal's inherited superior sensation and mobility. Although several behavior control models have been introduced, they generally epitomize virtual reward-based training models. In this model, rats are trained multiple times so they can recall the relationship between cues and rewards. It is well known that activation of one side of the nigrostriatal pathway (NSP) in the rat induces immediate turning toward the contralateral side. However, this NSP stimulation-induced directional movement has not been used for the purpose of animal-robot navigation. In this study, the authors aimed to electrically stimulate the NSP of conscious rats to build a command-prompt rat robot.

Methods: Repetitive NSP stimulation at 1-second intervals was applied via implanted electrodes to induce immediate contraversive turning movements in 7 rats in open field tests in the absence of any sensory cues or rewards. The rats were manipulated to navigate from the start arm to a target zone in either the left or right arm of a T-maze. A leftward trial was followed by a rightward trial, and each rat completed a total of 10 trials. In the control group, 7 rats were tested in the same way without NSP stimulation. The time taken to navigate the maze was compared between experimental and control groups.

Results: All rats in the experimental group successfully reached the target area for all 70 trials in a short period of time with a short interstimulus interval (< 0.7 seconds), but only 41% of rats in the control group reached the target area and required a longer period of time to do so. The experimental group made correct directional turning movements at the intersection zone of the T-maze, taking significantly less time than the control group. No significant difference in navigation duration for the forward movements on the start and goal arms was observed between the two groups. However, the experimental group showed quick and accurate movement at the intersection zone, which made the difference in the success rate and elapsed time of tasks.

Conclusions: The results of this study clearly indicate that a rat-robot model based on NSP stimulation can be a practical alternative to previously reported models controlled by virtual sensory cues and rewards.
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http://dx.doi.org/10.3171/2020.4.FOCUS20150DOI Listing
July 2020

Neurophysiological and Cognitive Correlates of Error Processing Deficits in Internet Gaming Disorder.

Cereb Cortex 2020 07;30(9):4914-4921

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul 07061, Republic of Korea.

The ability to detect and correct errors is a critical aspect of human cognition. Neuronal dysfunction in error processing has been reported in addictive disorders. The aim of this study was to investigate neural systems underlying error processing using event-related potentials (ERPs) and current source localization as well as neurocognitive executive function tests in patients with Internet gaming disorder (IGD). A total of 68 individuals (34 patients with IGD and 34 healthy controls [HCs]) were included, and two ERP components, error-related negativity (ERN) and error positivity (Pe), were extracted during a GoNogo task. Patients with IGD exhibited significantly reduced ERN and Pe amplitudes compared with HCs. Standardized low-resolution brain electromagnetic tomography (sLORETA) in between-group comparisons revealed that patients with IGD had decreased source activations of the Pe component in the anterior cingulate cortex (ACC) under the Nogo condition. These ERP changes were associated with deficits in decision-making and response inhibition in IGD patients. The results suggest that IGD may be associated with functional abnormalities in the ACC and alterations in neural activity related to both the early unconscious and the later conscious stages of error processing, as well as deficits in area of decision-making.
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http://dx.doi.org/10.1093/cercor/bhaa083DOI Listing
July 2020

Real-time detection of wound-induced HO signalling waves in plants with optical nanosensors.

Nat Plants 2020 04 15;6(4):404-415. Epub 2020 Apr 15.

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.

Decoding wound signalling in plants is critical for understanding various aspects of plant sciences, from pest resistance to secondary metabolite and phytohormone biosynthesis. The plant defence responses are known to primarily involve NADPH-oxidase-mediated HO and Ca signalling pathways, which propagate across long distances through the plant vasculature and tissues. Using non-destructive optical nanosensors, we find that the HO concentration profile post-wounding follows a logistic waveform for six plant species: lettuce (Lactuca sativa), arugula (Eruca sativa), spinach (Spinacia oleracea), strawberry blite (Blitum capitatum), sorrel (Rumex acetosa) and Arabidopsis thaliana, ranked in order of wave speed from 0.44 to 3.10 cm min. The HO wave tracks the concomitant surface potential wave measured electrochemically. We show that the plant RbohD glutamate-receptor-like channels (GLR3.3 and GLR3.6) are all critical to the propagation of the wound-induced HO wave. Our findings highlight the utility of a new type of nanosensor probe that is species-independent and capable of real-time, spatial and temporal biochemical measurements in plants.
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http://dx.doi.org/10.1038/s41477-020-0632-4DOI Listing
April 2020

Focused ultrasound-induced blood-brain barrier opening improves adult hippocampal neurogenesis and cognitive function in a cholinergic degeneration dementia rat model.

Alzheimers Res Ther 2019 12 27;11(1):110. Epub 2019 Dec 27.

Department of Neurosurgery, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea.

Background: The persistence of adult hippocampal neurogenesis (AHN) is sharply decreased in Alzheimer's disease (AD). The neuropathologies of AD include the presence of amyloid-β deposition in plaques, tau hyperphosphorylation in neurofibrillary tangles, and cholinergic system degeneration. The focused ultrasound (FUS)-mediated blood-brain barrier opening modulates tau hyperphosphorylation, the accumulation of amyloid-β proteins, and increases in AHN. However, it remains unclear whether FUS can modulate AHN in cholinergic-deficient conditions. In this study, we investigated the effect of FUS on AHN in a cholinergic degeneration rat model of dementia.

Methods: Adult male Sprague-Dawley rats (n = 48; 200-250 g) were divided into control (phosphate-buffered saline injection), 192 IgG-saporin (SAP), and SAP+FUS groups; in the two latter groups, SAP was injected bilaterally into the lateral ventricle. We applied FUS to the bilateral hippocampus with microbubbles. Immunohistochemistry, enzyme-linked immunosorbent assay, immunoblotting, 5-bromo-2'-deoxyuridine labeling, an acetylcholinesterase assay, and the Morris water maze test were performed to assess choline acetyltransferase, acetylcholinesterase activity, brain-derived neurotrophic factor expression, neural proliferation, and spatial memory, respectively. Statistical significance of differences in between groups was calculated using one-way and two-way analyses of variance followed by Tukey's multiple comparison test to determine the individual and interactive effects of FUS on immunochemistry and behavioral analysis. P < 0.05 was considered significant.

Results: Cholinergic degeneration in rats significantly decreased the number of choline acetyltransferase neurons (P < 0.05) in the basal forebrain, as well as AHN and spatial memory function. Rats that underwent FUS-mediated brain-blood barrier opening exhibited significant increases in brain-derived neurotrophic factor (BDNF; P < 0.05), early growth response protein 1 (EGR1) (P < 0.01), AHN (P < 0.01), and acetylcholinesterase activity in the frontal cortex (P < 0.05) and hippocampus (P < 0.01) and crossing over (P < 0.01) the platform in the Morris water maze relative to the SAP group after sonication.

Conclusions: FUS treatment increased AHN and improved spatial memory. This improvement was mediated by increased hippocampal BDNF and EGR1. FUS treatment may also restore AHN and protect against neurodegeneration, providing a potentially powerful therapeutic strategy for AD.
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http://dx.doi.org/10.1186/s13195-019-0569-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6933667PMC
December 2019

Identification of novel non-nucleoside vinyl-stilbene analogs as potent norovirus replication inhibitors with a potential host-targeting mechanism.

Eur J Med Chem 2019 Dec 26;184:111733. Epub 2019 Sep 26.

College of Pharmacy, Dongguk University-Seoul, Goyang, 10326, Republic of Korea. Electronic address:

Norovirus (NV), is the most common cause of acute gastroenteritis worldwide. To date, there is no specific anti-NV drug or vaccine to treat NV infections. In this study, we evaluated the inhibitory effect of different stilbene-based analogs on RNA genome replication of human NV (HNV) using a virus replicon-bearing cell line (HG23). Initial screening of our in-house chemical library against NV led to the identification of a hit containing stilbene scaffold 5 which on initial optimization gave us a vinyl stilbene compound 16c (EC = 4.4 μM). Herein we report our structure-activity relationship study of the novel series of vinyl stilbene analogs that inhibits viral RNA genome replication in a human NV-specific manner. Among these newly synthesized compounds, several amide derivatives of vinyl stilbenes exhibited potent anti-NV activity with EC values ranging from 1 to 2 μM. A trans-vinyl stilbenoid with an appended substituted piperazine amide (18k), exhibited potent anti-NV activity and also displayed favorable metabolic stability. Compound 18k demonstrated an excellent safety profile, the highest suppressive effect, and was selective for HNV replication via a viral RNA polymerase-independent manner. Its potential host-targeting antiviral mechanism was further supported by specific activation of heat shock factor 1-dependent stress-inducible pathway by 18k. These results suggest that 18k might be a promising lead compound for developing novel NV inhibitors with the novel antiviral mechanism.
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http://dx.doi.org/10.1016/j.ejmech.2019.111733DOI Listing
December 2019

Measuring the Accessible Surface Area within the Nanoparticle Corona Using Molecular Probe Adsorption.

Nano Lett 2019 11 4;19(11):7712-7724. Epub 2019 Nov 4.

Department of Chemical Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States.

The corona phase-the adsorbed layer of polymer, surfactant, or stabilizer molecules around a nanoparticle-is typically utilized to disperse nanoparticles into a solution or solid phase. However, this phase also controls molecular access to the nanoparticle surface, a property important for catalytic activity and sensor applications. Unfortunately, few methods can directly probe the structure of this corona phase, which is subcategorized as either a hard, immobile corona or a soft, transient corona in exchange with components in the bulk solution. In this work, we introduce a molecular probe adsorption (MPA) method for measuring the accessible nanoparticle surface area using a titration of a quenchable fluorescent molecule. For example, riboflavin is utilized to measure the surface area of gold nanoparticle standards, as well as corona phases on dispersed single-walled carbon nanotubes and graphene sheets. A material balance on the titration yields certain surface coverage parameters, including the ratio of the surface area to dissociation constant of the fluorophore, /, as well as itself. Uncertainty, precision, and the correlation of these parameters across different experimental systems, preparations, and modalities are all discussed. Using MPA across a series of corona phases, we find that the Gibbs free energy of probe binding scales inversely with the cube root of surface area, . In this way, MPA is the only technique to date capable of discerning critical structure-property relationships for such nanoparticle surface phases. Hence, MPA is a rapid quantitative technique that should prove useful for elucidating corona structure for nanoparticles across different systems.
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http://dx.doi.org/10.1021/acs.nanolett.9b02647DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7206615PMC
November 2019

Plant-Derived Purification, Chemical Synthesis, and In Vitro/In Vivo Evaluation of a Resveratrol Dimer, Viniferin, as an HCV Replication Inhibitor.

Viruses 2019 09 23;11(10). Epub 2019 Sep 23.

College of Pharmacy, Dongguk University, Goyang 10326, Korea.

Oligostilbenoid compounds, a group of resveratrol multimers, display several anti-microbial activities through the neutralization of cytotoxic oxidants, and by inhibiting essential host and viral enzymes. In our previous study, we identified a series of oligostilbenoid compounds as potent hepatitis C virus (HCV) replication inhibitors. In particular, vitisin B, a resveratrol tetramer, exhibited the most dramatic anti-HCV activity (EC = 6 nM and CC > 10 μM) via the disruption of the viral helicase NS3 (IC = 3 nM). However, its further development as an HCV drug candidate was halted due to its intrinsic drawbacks, such as poor stability, low water solubility, and restricted in vivo absorption. In order to overcome these limitations, we focused on (+)-ε-viniferin, a resveratrol dimer, as an alternative. We prepared three different versions of (+)-ε-viniferin, including one which was extracted from the grapevine root (EVF) and two which were chemically synthesized with either penta-acetylation (SVF-5Ac) or no acetylation (SVF) using a newly established synthesis method. We confirmed their anti-HCV replication activities and minimal cytotoxicity by using genotype 1b and 2a HCV replicon cells. Their anti-HCV replication action also translated into a significant reduction of viral protein expression. Anti-HCV NS3 helicase activity by EVF was also verified in vitro. Finally, we demonstrated that SVF has improved pharmacokinetic properties over vitisin B. Overall, the favorable antiviral and pharmacokinetic properties of these three versions of viniferin warrant their further study as members of a promising new class of anti-HCV therapeutics.
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http://dx.doi.org/10.3390/v11100890DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6832221PMC
September 2019

The Mediating Effects of Affect on Associations between Impulsivity or Resilience and Internet Gaming Disorder.

J Clin Med 2019 Jul 25;8(8). Epub 2019 Jul 25.

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul 07061, Korea.

Internet gaming disorder (IGD) is a new disease proposed by the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5), and has been studied extensively in relation to depression and impulsivity. The relationship between resilience and disease has been found in a variety of addictive disorders, but studies on IGD are lacking. In this study, 71 IGD patients and 78 healthy controls (HCs) were recruited. Impulsivity, resilience, affects, and the degree of internet game addiction were measured using formal tools. The measured values were analyzed by mediation analysis to evaluate the mediating role of affects on resilience and impulsivity related to IGD symptoms. The IGD group showed higher impulsivity, lower resilience, lower positive affect, and higher negative affect than the HC group. The mediation analysis showed that a positive affect was a mediator between impulsivity and the severity of addiction in both groups. Negative affect mediated impulsivity/resilience and the severity of addiction only in the IGD group. Although the results of this study are based on a narrow category of subjects, who are young male adults around 25 years of age, the results suggest that positive affect can be strengthened to prevent the IGD illness, and that illness symptoms may be alleviated by reducing negative affect.
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http://dx.doi.org/10.3390/jcm8081102DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723401PMC
July 2019

Single-Particle Tracking for Understanding Polydisperse Nanoparticle Dispersions.

Small 2019 09 24;15(37):e1901468. Epub 2019 Jul 24.

Department of Chemical Engineering Massachusetts Institute of Technology, 77 Massachusetts Avenue 66-570b, Cambridge, MA, 02139, USA.

Colloidal dispersions of nanomaterials are often polydisperse in size, significantly complicating their characterization. This is particularly true for materials early in their historical development due to synthetic control, dispersion efficiency, and instability during storage. Because a wide range of system properties and technological applications depend on particle dimensions, it remains an important problem in nanotechnology to identify a method for the routine characterization of polydispersity in nanoparticle samples, especially changes over time. Commonly employed methods such as dynamic light scattering or analytical ultracentrifugation (AUC) accurately estimate only the first moment of the distribution or are not routine. In this work, the use of single-particle tracking (SPT) to probe size distributions of common nanoparticle dispersions, including polystyrene nanoparticles, single-walled carbon nanotubes, graphene oxide, chitosan-tripolyphosphate, acrylate, hexagonal boron nitride, and poly(lactic-co-glycolic acid), is proposed and explored. The analysis of particle tracks is conducted using a newly developed Bayesian algorithm that is called Maximum A posteriori Nanoparticle Tracking Analysis. By combining SPT and AUC techniques, it is shown that it is possible to independently estimate the mean aspect ratio of anisotropic particles, an important characterization property. It is concluded that SPT provides a facile, rapid analytical method for routine nanomaterials characterization.
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http://dx.doi.org/10.1002/smll.201901468DOI Listing
September 2019

Establishment of Nrf2-deficient HaCaT and immortalized primary human foreskin keratinocytes and characterization of their responses to ROS-induced cytotoxicity.

Toxicol In Vitro 2019 Dec 15;61:104602. Epub 2019 Jul 15.

College of Pharmacy, Dongguk University, Goyang 10326, Republic of Korea. Electronic address:

Nuclear factor erythroid 2-like 2 (Nrf2) is a key transcription factor responsible for the induction of cytoprotective genes when a cell is exposed to reactive oxygen species (ROS). Insufficient ROS neutralization has been associated with undesirable changes in the skin caused by age and disease. In order to mimic the pathological conditions of these oxidative stress-induced skin disorders, we established Nrf2-deficient HaCaT and immortalized human foreskin keratinocyte (iHFK) cell lines via lentiviral transduction of Nrf2-targeting short-hairpin RNAs. Their transcriptional, as well as translational blockage of Nrf2 expression, was verified by using a proteasomal inhibitor (MG132) and well-known Nrf2 activator (α-lipoic acid (ALA)). Reduced expression of NADPH dehydrogenase quinone 1 (NQO-1) and heme oxygenase 1 (HO-1) genes, which are well-characterized downstream targets of Nrf2-mediated transactivation, was also confirmed by using ALA and another Nrf2 activator, marliolide. In general, iHFK cells displayed more enhanced cytotoxicity to menadione, a ROS-generating reference compound, than HaCaT cells. In addition, the Nrf2 deficiency highly potentiated the cytotoxic effects of menadione in both HaCaT and iHFK cells. Interestingly, pretreatment of either ALA or marliolide conferred protection against the ROS induction and the subsequent development of cytotoxicity by menadione in both HaCaT and iHFK cells regardless of the Nrf2 status. These data suggest a possibility for activation of Nrf2-independent ROS detoxification pathways by either ALA or marliolide. These newly established Nrf2-deficient HaCaT and iHFK cell lines should be useful as a highly ROS-sensitive damaged skin model for the study of age-dependent cellular changes in an in vitro setting.
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http://dx.doi.org/10.1016/j.tiv.2019.104602DOI Listing
December 2019

Maladaptive neurovisceral interactions in patients with Internet gaming disorder: A study of heart rate variability and functional neural connectivity using the graph theory approach.

Addict Biol 2020 07 12;25(4):e12805. Epub 2019 Jul 12.

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul, South Korea.

Heart rate variability (HRV) can be used to represent the regulatory adaptive system and is a proxy for neurovisceral integration. Consistent with the view that, like other addictions, Internet gaming disorder (IGD) involves disrupted regulatory function, the present study hypothesized that IGD patients would show (a) decreased HRV, (b) ineffective functional neural connectivity, and (c) differential patterns of association between HRV and functional neural connectivity relative to healthy controls (HCs). The present study included 111 young adults (53 IGD patients and 58 age- and sex-matched HCs) who underwent simultaneous recordings with an electrocardiogram and electroencephalogram during a resting state. Heart rate (HR), HRV, and functional neural connectivity were calculated using the graph theory approach. Compared with the HCs, the IGD patients exhibited elevated HR and decreased HRV based on the high frequency (HF), which reflects suppression of parasympathetic and/or vagal tone. The IGD patients also exhibited a heightened theta band characteristic path length (CPL) compared with HCs, indicating decreased efficacy of the functional network. Furthermore, IGD patients exhibited negative correlations between the standard deviation of the normal-to-normal interval index (SDNNi) and theta and delta CPL values, which were not observed in HCs. In conclusion, the present findings suggest that IGD patients might have maladaptive brain-body integration features involving disruptions of the autonomic nervous system and brain function.
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http://dx.doi.org/10.1111/adb.12805DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7317587PMC
July 2020

Application of Diagnostic Interview for Internet Addiction (DIA) in Clinical Practice for Korean Adolescents.

J Clin Med 2019 Feb 6;8(2). Epub 2019 Feb 6.

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul 07061, Korea.

The increased prevalence of Internet Gaming Disorder (IGD) and the inclusion of IGD in DSM-5 and ICD-11 emphasizes the importance of measuring and describing the IGD symptoms. We examined the psychometric properties of the Diagnostic Interview for Internet Addiction (DIA), a semi-structured diagnostic interview tool for IGD, and verified the application of DIA in clinical practice for Korean adolescents. The DIA is conducted in a manner that interviews both adolescents and their caregivers, and each item has a standardized representative question and various examples. It consists of 10 items based on the DSM-5 IGD diagnostic criteria, which is cognitive salience, withdrawal, tolerance, difficulty in regulating use, loss of interest in other activities, persistent use despite negative results, deception regarding Internet/games/SNS use, use of Internet/games/SNS to avoid negative feelings, interference with role performance, and craving. The study included 103 adolescents divided into three subgroups (mild risk, moderate risk, and addicted group) based on the total score of DIA. Demographic and clinical characteristics were compared among the DIA subgroups using the chi-square test and analysis of variance (ANOVA), and correlation analysis was used to examine the associations of IGD symptoms with clinical variables (e.g., impulsivity, aggression, depression, anxiety, self-esteem). The DIA total score was significantly correlated with Internet and smartphone addiction, depression, state anxiety, self-esteem, impulsivity, aggression, and stress. Furthermore, the moderate risk and addicted group showed significantly higher levels of Internet and smartphone addiction, anxiety, depression, impulsivity, aggression, stress, and lower self-esteem compared with the mild risk group. The Junior Temperament and Character Inventory (JTCI), which measures temperament and character traits, revealed that the mild risk group had higher levels of persistence and self-directedness than did the addicted group. Our findings confirmed the psychometric properties of DIA and the application of the DIA classifications in Korean adolescents.
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http://dx.doi.org/10.3390/jcm8020202DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6406814PMC
February 2019

Increased Attentional Bias Toward Visual Cues in Internet Gaming Disorder and Obsessive-Compulsive Disorder: An Event-Related Potential Study.

Front Psychiatry 2018 13;9:315. Epub 2018 Jul 13.

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul, South Korea.

Internet gaming disorder (IGD) is a newly identified potential addiction disorder associated with compulsive internet-game playing behavior and attentional bias toward online gaming- related cues. Attentional bias toward addiction-related cues is the core feature of addiction that is associated with craving, but the pathophysiology of attentional bias in IGD is not well-understood, such as its relationship to compulsivity. In this study, we used the electrophysiological marker of late positive potential (LPP) to compare attentional bias in IGD and obsessive compulsive disorder (OCD). Twenty patients with IGD, 20 patients with OCD, and 23 healthy control (HC) subjects viewed a series of game-related, OCD-related, and neutral pictures while their event-related potentials (ERPs) were recorded. The game-related cues included in-game screen captures of popular internet games. The OCD-related cues included pictures which provokes obsessive and compulsive symptoms of contamination/washing or checking. LPPs were calculated as the mean value of amplitudes between 350 and 750 ms at the centro-parietal (CP1, CPz, CP2) and parietal (P1, Pz, P2) electrode sites. Higher LPP amplitudes were found for game-related cues in the IGD group than in the HCs, and higher LPP amplitudes were observed in the OCD group for OCD-related cues. The IGD group did not exhibit LPP changes in response to OCD-related cues. Subjective scales demonstrated increased arousal to game-related cues and OCD-related cues in both the IGD and OCD groups compared with the HC group. Increased LPPs in response to disorder-specific cues (game-related and OCD-related) were found in both IGD and OCD groups respectively, although the groups showed overlapping arousal on subjective scales. Our results indicate that LPP is a candidate neurophysiological marker for cue-related craving in IGD.
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http://dx.doi.org/10.3389/fpsyt.2018.00315DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6053507PMC
July 2018

Dysfunctional information processing in individuals with acute exposure to sexual abuse: An ERP study.

Medicine (Baltimore) 2018 Jun;97(22):e10880

Department of Psychiatry, Eulji University Gangnam Eulji Hospital, Seoul Department of Addiction Rehabilitation Social Welfare, Eulji University, Kyunggi Department of Psychiatry, SMG-SNU Boramae Medical Center Department of Psychiatry and Behavioral Science Department of Clinical Medical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea.

Acute stress disorder (ASD) and posttraumatic stress disorder (PTSD) may occur after traumatic event and also cause significant life time impairment. P300 event-related potential (ERP) is a potential biological marker for PTSD and can reflect cognitive impairment in information processing and attention. Despite the usefulness of ERP, there are few attempts to reveal relationships between ASD and P300. In the present study, we aimed to determine if the P300 of the patients who were the victims of sexual abuse reflected the quantitative trait of ASD or if P300 is applicable as a state marker for predicting the risk of PTSD.Fifteen female victims of sexual abuse diagnosed with ASD and 18 healthy controls (HCs) without trauma exposure participated in this study. We investigated the P300 ERPs in patients with ASD to compare them with those of HCs. ERPs were acquired from female adults during an auditory oddball task. Between-group differences in amplitudes or latencies of P300 were investigated using repeated-measures analysis of variance.The ASD groups showed reduced P300 amplitudes at the midline centroparietal site as well as reduced accuracy rates during an auditory oddball task compared with the HCs.These results indicate that ASD have abnormalities in the P300 compared to those in HCs. Moreover, the reduction in P300 could be considered a candidate neurophysiological marker for ASD.
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http://dx.doi.org/10.1097/MD.0000000000010880DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6392618PMC
June 2018

Clinical Trial of the Potassium Channel Activator Diazoxide for Major Depressive Disorder Halted Due to Intolerability.

J Clin Psychopharmacol 2018 Jun;38(3):243-246

Background: Some glutamatergic modulators have demonstrated rapid and relatively sustained antidepressant properties in patients with major depressive disorder. Because the potassium channel activator diazoxide increases glutamate uptake via potassium channel activation, we hypothesized that it might exert antidepressant effects by increasing the removal of glutamate from the synaptic cleft, thereby reducing excessive glutamate transmission.

Methods: This randomized, double-blind, placebo-controlled, crossover, single-site inpatient clinical study was conducted at the National Institute of Mental Health to assess the efficacy and safety of a 3-week course of diazoxide (200-400 mg daily, twice a day) versus a 3-week course of placebo in 6 participants with treatment-refractory major depressive disorder. The primary clinical outcome measure was change in Montgomery-Asberg Depression Rating Scale score from baseline to posttreatment. Quantitative insulin sensitivity check index, as well as concomitant imaging measures (electroencephalography, proton magnetic resonance spectroscopy, magnetoencephalography), were used as potential surrogate markers of target (KATP channel) engagement.

Results: The study was halted due to severe adverse effects. Given the small sample size, statistical evaluation of the effect of diazoxide on Montgomery-Asberg Depression Rating Scale scores or the imaging measures was not pursued. Visual inspection of the quantitative insulin sensitivity check index test revealed no evidence of target engagement.

Conclusions: Although the results are negative, they are an important addition to the literature in this rapidly changing field.
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http://dx.doi.org/10.1097/JCP.0000000000000866DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5903962PMC
June 2018

Insulin Detection Using a Corona Phase Molecular Recognition Site on Single-Walled Carbon Nanotubes.

ACS Sens 2018 02 7;3(2):367-377. Epub 2018 Feb 7.

Department of Biological Systems Engineering, University of Nebraska-Lincoln , 223 L.W. Chase Hall, Lincoln, Nebraska 68583, United States.

Corona phase molecular recognition (CoPhMoRe) is a technique whereby an external, adsorbed phase around a colloidal nanoparticle is selected such that its molecular conformation or interaction recognizes a specific target analyte. In this work, we employ a high-throughput screening of a library of poly(ethylene glycol) (PEG)-conjugated lipids adsorbed onto near-infrared fluorescent single-walled carbon nanotubes to discover a corona phase selective for insulin. We find that a C-PEG(2000 Da)-ceramide causes a 62% fluorescent intensity decrease of the (10,2) chirality nanotube in the presence of 20 μg/mL insulin. The insulin protein has no prior affinity toward the C-PEG(2000 Da)-ceramide molecules in free solution, verified by isothermal titration calorimetry, and the interaction occurs only upon their adsorption onto the single-walled carbon nanotube scaffolds. Testing a panel of proteins originating from human blood as well as short 7 amino acid fragments of the insulin peptide rules out nonselective recognition mechanisms such as molecular weight, isoelectric point, and hydrophobicity-based detection. Interestingly, longer fragments of isolated α- and β-peptide chains of insulin are detected by the construct, albeit with lower affinity compared to that of the intact insulin protein, suggesting that the construct recognizes insulin in its native form and conformation. Finally, the insulin recognition and the quantification of its solution concentration were demonstrated both in buffer and in blood serum, showing that the CoPhMoRe construct works in this complex environment despite the presence of potential nonspecific adsorption. Our results further motivate the search for nonbiological synthetic recognition sites and open up a new path for continuous insulin monitoring in vivo with the hope of improving glycemic control in closed-loop artificial pancreas systems.
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http://dx.doi.org/10.1021/acssensors.7b00788DOI Listing
February 2018

The antidepressant efficacy of subanesthetic-dose ketamine does not correlate with baseline subcortical volumes in a replication sample with major depressive disorder.

J Psychopharmacol 2017 12 17;31(12):1570-1577. Epub 2017 Oct 17.

1 Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, USA.

Background: This study sought to reproduce, in a larger sample, previous findings of a correlation between smaller raw 3-Tesla (3T) hippocampal volumes and improved antidepressant efficacy of ketamine in individuals with major depressive disorder (MDD). A secondary analysis stratified subjects according to functional BDNF rs6265 (val66met) genotype.

Methods: Unmedicated subjects with treatment-resistant MDD ( n=55) underwent baseline structural 3T MRI. Data processing was conducted with FSL/FIRST and Freesurfer software. The amygdala, hippocampus, and thalamus were selected a priori for analysis. All subjects received a single 0.5mg/kg × 40-minute ketamine infusion. Pearson correlations were performed with subcortical volumes and percent change in MADRS score (from baseline to 230 minutes, 1 day, and 1 week post-infusion).

Results: Raw and corrected subcortical volumes did not correlate with antidepressant response at any timepoint. In val/val subjects ( n=23), corrected left and right thalamic volume positively correlated with antidepressant response to ketamine at 230 minutes post-infusion but did not reach statistical significance. In met carriers ( n=14), corrected left and right thalamic volume negatively correlated with antidepressant response to ketamine.

Conclusion: Baseline subcortical volumes implicated in MDD did not correlate with ketamine's antidepressant efficacy. Baseline thalamic volume and BDNF genotype may be a combinatorial rapid antidepressant response biomarker.
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http://dx.doi.org/10.1177/0269881117732514DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5863225PMC
December 2017

Sustained dysfunctional information processing in patients with Internet gaming disorder: 6-month follow-up ERP study.

Medicine (Baltimore) 2017 Sep;96(36):e7995

Department of Psychiatry, SMG-SNU Boramae Medical Center Department of Psychiatry, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine Department of Psychiatry and Behavioral Science, Seoul National University College of Medicine, Seoul, Republic of Korea.

Internet gaming disorder (IGD), defined as an inability to control Internet-based game play, leads to serious impairment in psychological and social functioning, but few studies have identified the neurophysiological characteristics of patients with IGD. The aim of this study was to determine neurophysiological markers of P300 components associated with changes in symptoms after outpatient management with pharmacotherapy in patients with IGD. The present prospective longitudinal study included 18 patients with IGD and 29 healthy controls. The patients with IGD completed a 6-month outpatient management program including selective serotonin reuptake inhibitor-based pharmacotherapy. Event-related potentials (ERPs) were acquired during the auditory oddball task. ERPs of the patients with IGD were recorded before and after treatment. Between-group differences and the pre-to-post treatment differences in P300 components were investigated using repeated-measures analysis of variance. The primary treatment outcome was a change in score on Young Internet Addiction Test between before and after treatment. At baseline assessments, the IGD group showed significantly reduced P300 amplitudes and delayed latencies at the midline centro-parietal site compared with those in the healthy controls. No significant changes in the P300 indices were observed between pre and post-treatment in the patients with IGD after 6 months of treatment, even though the patients with IGD exhibited significant improvements in their IGD symptoms. Furthermore, no significant difference in ERPs was observed between responders and nonresponders to a 6-month treatment in patients with IGD. These results suggest that reduced P300 amplitudes and delayed latencies are candidate endophenotypes in the pathophysiology of IGD.
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http://dx.doi.org/10.1097/MD.0000000000007995DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6392623PMC
September 2017

Differential neurophysiological correlates of information processing in Internet gaming disorder and alcohol use disorder measured by event-related potentials.

Sci Rep 2017 08 22;7(1):9062. Epub 2017 Aug 22.

Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul, Republic of Korea.

Internet gaming disorder (IGD) shares clinical and neuropsychological features with alcohol use disorder (AUD), but few studies have identified the neurophysiological characteristics of IGD. We investigated the N100 and P300 event-related potentials (ERPs) in patients with IGD to compare them with those of patients with AUD and healthy controls (HCs). Twenty-six patients with IGD, 22 patients with AUD, and 29 HCs participated in this study. ERPs were acquired from young male adults during an auditory oddball task. Between-group differences in N100 and P300 were investigated separately using repeated-measures analysis of variance. Correlations between the ERP values and neurocognitive functioning of each group were examined. Both the IGD and AUD groups showed reduced P300 amplitudes at the midline central and parietal area compared with the HCs. The IGD exhibited reduced N100 amplitudes at the midline frontal area compared with the HCs. The reduced P300 were correlated with a higher spatial span error rate in the IGD. The reduced N100 and P300 were not correlated with Internet addiction severity scores in the IGD. These results indicate that IGD have abnormalities in the P300 comparable to those in AUD. Moreover, the reduction in N100 could be considered a candidate trait marker for IGD.
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http://dx.doi.org/10.1038/s41598-017-09679-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5567258PMC
August 2017
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