• Toxicological Research
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• 제30권4호
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• pp.267-276
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• 2014

Exposures to lead (Pb) are associated with neurological problems including psychiatric disorders and impaired learning and memory. Pb can be absorbed by iron transporters, which are up-regulated in hereditary hemochromatosis, an iron overload disorder in which increased iron deposition in various parenchymal organs promote metal-induced oxidative damage. While dysfunction in HFE (High Fe) gene is the major cause of hemochromatosis, the transport and toxicity of Pb in Hfe-related hemochromatosis are largely unknown. To elucidate the relationship between HFE gene dysfunction and Pb absorption, H67D knock-in Hfe-mutant and wild-type mice were given drinking water containing Pb 1.6 mg/ml ad libitum for 6 weeks and examined for behavioral phenotypes using the nestlet-shredding and marble-burying tests. Latency to nestlet-shredding in Pb-treated wild-type mice was prolonged compared with non-exposed wild-types (p < 0.001), whereas Pb exposure did not alter shredding latency in Hfe-mutant mice. In the marble-burying test, Hfe-mutant mice showed an increased number of marbles buried compared with wild-type mice (p = 0.002), indicating more repetitive behavior upon Hfe mutation. Importantly, Pb-exposed wild-type mice buried more marbles than non-exposed wild-types, whereas the number of marbles buried by Hfe-mutant mice did not change whether or not exposed to Pb. These results suggest that Hfe mutation could normalize Pb-induced behavioral alteration. To explore the mechanism of repetitive behavior caused by Pb, western blot analysis was conducted for proteins involved in brain dopamine metabolism. The levels of tyrosine hydroxylase and dopamine transporter increased upon Pb exposure in both genotypes, whereas Hfe-mutant mice displayed down-regulation of the dopamine transporter and dopamine D1 receptor with D2 receptor elevated. Taken together, our data support the idea that both Pb exposure and Hfe mutation increase repetitive behavior in mice and further suggest that these behavioral changes could be associated with altered dopaminergic neurotransmission, providing a therapeutic basis for psychiatric disorders caused by Pb toxicity.

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.176-183
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• 2014

Cognitive impairment is a result of dementia of diverse causes, such as cholinergic dysfunction and Alzheimer's disease (AD). Houttuynia cordata Thunb. (Saururaceae) has long been used as a traditional herbal medicine. It has biological activities including protective effects against amyloid beta ($A{\beta}$) toxicity, via regulation of calcium homeostasis, in rat hippocampal cells. To extend previous reports, we investigated the effects of water extracts of H. cordata herb (HCW) on tauopathies, also involving calcium influx. We then confirmed the effects of HCW in improving memory impairment and neuronal damage in mice with Ab-induced neurotoxicity. We also investigated the effects of HCW against scopolamine-induced cholinergic dysfunction in mice. In primary neuronal cells, HCW inhibited the phosphorylation of tau by regulating p25/p35 expression in $A{\beta}$-induced neurotoxicity. In mice with $A{\beta}$-induced neurotoxicity, HCW improved cognitive impairment, as assessed with behavioral tasks, such as novel object recognition, Y-maze, and passive avoidance tasks. HCW also inhibited the degeneration of neurons in the CA3 region of the hippocampus in Ab-induced neurotoxicity. Moreover, HCW, which had an $IC_{50}$ value of $79.7{\mu}g/ml$ for acetylcholinesterase inhibition, ameliorated scopolamine-induced cognitive impairment significantly in Y-maze and passive avoidance tasks. These results indicate that HCW improved cognitive impairment, due to cholinergic dysfunction, with inhibitory effects against tauopathies and cholinergic antagonists, suggesting that HCW may be an interesting candidate to investigate for the treatment of AD.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권2호
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• pp.87-98
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• 2020

The aim of this study was to determine the efficacy of oral splints in reducing the intensity of pain in patients with temporomandibular joint dysfunction in both short and long-term treatment durations. Electronic databases, Cochrane Library, MEDLINE via PubMed, Web of Science, Egyptian Knowledge Bank, and EMBASE were searched for randomized controlled trials comparing different types of splints to non-occluding splints, behavioral therapy, pharmacotherapy, counseling, and no treatment. The risk of bias was assessed by using Cochrane risk of bias recommendations. Fixed and random effects were used to summarize the outcomes. The effect estimates were expressed as standardized mean differences (SMD) or risk ratios with a 95% confidence interval (CI). Subgroup analyses were carried out according to the treatment duration. Twenty-two studies met the inclusion criteria. A meta-analysis of short-term studies up to three months revealed no significant difference between the study groups. However, long-term studies exhibited a significant difference in pain reduction in favor of the control group. Total analysis revealed that the control group resulted in significant pain reduction (SMD 0.14, 95% CI 0.05-0.23, P=0.002, I²=0%). Oral splints are not effective in reducing pain intensity or improving function in patients with temporomandibular joint dysfunction.

• Childhood Kidney Diseases
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• 제2권1호
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• pp.90-94
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• 1998

Hinman syndrome is a condition representing urinary voiding dysfunction in the neurologically intact child. The syndrome is probably caused by acquired behavioral and psychosocial disorders manifested by bladder and/or bowel dysfunction mimicking neurologic disease. Clinically, the symptom complex may include day and night time enuresis, encopresis, constipation, and recurrent urinary tract infections. Cystoscopy frequently demonstrates normal vesicourethral anatomy. Voiding films usually demonstarate a carrot-shaped proximal urethra with a persistent narrowing at the external sphincter. The bladder is large and often appears trabeculated with a thickened wall and significant postvoid residual. A 13-year-old male child was admitted due to fever, urinary tract infection, enuresis and flank pain. His neurologic examination was normal. Renal sonograms showed moderate hydronephrosis. Voiding cystourethrograms showed a huge, trabeculated bladder without vesicourethral reflux and urethral valves. No abnormal findings was found in spinal MRI.

• 대한간호학회지
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• 제52권2호
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• pp.121-133
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• 2022

Purpose: This study examined the impact of a virtual reality intervention program based on psychological needs on behavioral and psychological symptoms, apathy, and quality of life (QOL) in patients with dementia or mild cognitive impairment living in nursing facilities. Methods: This study is nonequivalent control group pretest-posttest design of quasi-experimental study. The study collected data from November 18, 2020 to July 24, 2021 from patients with dementia or mild cognitive impairment (30 in the experimental group and 30 in the control group) at three nursing facilities in G city using self-reporting and caregiver-informant reporting methods. The analysis employed the chi-square test, Fisher's exact test, paired t-test, independent t-test, Wilcoxon signed rank test, Mann-Whitney U, repeated measures ANOVA, GEE, using SPSS/WIN 27.0. Results: The severity of behavioral and psychological symptoms (Wald 𝛘² = 2.68, p = .102) and the care burden of caregivers (Wald 𝛘² = 1.72, p = .190) were not significant and was no significant time and group interaction effect (Wald 𝛘² = 0.63, p = .426, Wald 𝛘² = 0.52, p =. 471). The difference in apathy and QOL score were statistically significant for the group-time interaction (F = 43.65, p < .001; F = 4.35, p = .041). Conclusion: The virtual reality intervention program of this study shows a positive effect on the apathy reduction and QOL of patients with dementia or mild cognitive impairment residing in nursing facilities.

• Journal of Oral Medicine and Pain
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• 제20권2호
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• pp.257-267
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• 1995

An Epidemiologic study was carried out on 77 TMD patients with degenerative joint disease who had visited the Orofacial Pain Clinic in Pusan National University Hospital. Al subjects were interviewed and examined clinically and radiologically using a standardized examination form. As related to gender and duration, subjective and objective sysmptoms in DJD patients were studied. The obtained results were as follows : 1. There were much more patients in the twenties or thirties, women and histories such as chronic duration and microtrauma. 2. Most patients responded positively more often to the questions of jaw function, unilateral chewing in habits, poot appetite and depression in behavioral response and shoulder pain in worsening prognosis 3. While the most common reasons for treatment were pain, noise, and limitation of opening, the associated symptoms such as headache, neckache, earache, jaw dysfunction, neck dysfunction, acute bite change and dizziness, ringing or fullness in the ears as secondary CNS excitatory effects were complained. 4. Opening the mouth in 25 to 40mm, soft end feel and deflective incisal pathway were seen and more tenderness to lateral or dorsal capsule of joint than intra or extra oral muscles were complained. 5. While there appeared no click, crepitus and single click in acute group, in chronic group, crepitus, single click and no click appeared in order of sequence. 6. Tomogram or bone scan revealed more bony changes than panorama and transcranial view.

• Journal of Information Technology Applications and Management
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• 제26권2호
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• pp.27-40
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• 2019

As reliance on information and communication becomes widespread, a variety of information dysfunctions such as hacking, viruses, and the infringement of personal information are also occurring. Korean adolescents are especially exposed to an environment in which they are experiencing information dysfunction. In addition, youth cybercrimes are steadily occurring. To prevent cybercrime and the damage caused by information dysfunction, information security practices are essential. Accordingly, the purpose of this study is to discuss the factors affecting the information security practices of Korean youths, considering information security education, perceived severity, and perceived vulnerability as leading factors of the theory of planned behavior. A questionnaire survey was administered to 118 middle and high school students. Results of the hypothesis test show that information security education affects perceived behavior control, and perceived severity affects attitude. Subjective norms, information security attitudes, and perceived behavioral control were found to influence adolescents' practices of information security. However, perceived vulnerabilities did not affect youths' information security attitudes. This study confirms that information security education can help youths to practice information security. In other words, information security education is important, and it is a necessary element in the information curriculum of contemporary youth. However, perceived vulnerability to youth information security threats did not affect information security attitudes. Consequently, we suggest that it is necessary to strengthen the contents of the information security education for Korean youths.

• 동의신경정신과학회지
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• 제24권3호
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• pp.281-292
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• 2013

Objectives : A growing body of evidence has suggested that the dysfunction of glutamatergic systems plays a pivotal role in major depressive disorder (MDD). This study was performed to investigate the antidepressant-like effects of the ethanolic extract of Gastrodia elata Bl (GE) in mouse models and to investigate the role of ${\alpha}$-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors in producing these antidepressant-like effects. Methods : The forced swim test (FST) and tail suspension test (TST) were used to investigate GE's behavioral effects in mice. Additional biochemical and behavioral experiments with NBQX, an AMPA receptor antagonist, were undertaken to determine whether the antidepressant-like properties of GE are involved in AMPA receptor throughput. Results : Oral administration of GE extract (1,600 mg/kg) 1h prior to testing significantly reduced the immobility times in the FST and TST. These antidepressant-like effects of GE extract were increased dose-dependently. Pre-treatment with NBQX significantly attenuated the reduction in immobility time induced by the GE extract in the FST and TST. Conclusions : The ethanolic extract of GE may exert antidepressant-like effects with involvement of AMPA receptor.

• Biomolecules & Therapeutics
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• 제31권2호
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• pp.148-160
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• 2023

Depression is a neuropsychiatric disorder associated with persistent stress and disruption of neuronal function. Persistent stress causes neuronal atrophy, including loss of synapses and reduced size of the hippocampus and prefrontal cortex. These alterations are associated with neural dysfunction, including mood disturbances, cognitive impairment, and behavioral changes. Synaptic plasticity is the fundamental function of neural networks in response to various stimuli and acts by reorganizing neuronal structure, function, and connections from the molecular to the behavioral level. In this review, we describe the alterations in synaptic plasticity as underlying pathological mechanisms for depression in animal models and humans. We further elaborate on the significance of phytochemicals as bioactive agents that can positively modulate stress-induced, aberrant synaptic activity. Bioactive agents, including flavonoids, terpenes, saponins, and lignans, have been reported to upregulate brain-derived neurotrophic factor expression and release, suppress neuronal loss, and activate the relevant signaling pathways, including TrkB, ERK, Akt, and mTOR pathways, resulting in increased spine maturation and synaptic numbers in the neuronal cells and in the brains of stressed animals. In clinical trials, phytochemical usage is regarded as safe and well-tolerated for suppressing stress-related parameters in patients with depression. Thus, intake of phytochemicals with safe and active effects on synaptic plasticity may be a strategy for preventing neuronal damage and alleviating depression in a stressful life.

• BMB Reports
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• 제55권12호
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• pp.621-626
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• 2022

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease characterized by the degeneration of motor neurons in the spinal cord. Main symptoms are manifested as weakness, muscle loss, and muscle atrophy. Some studies have reported that alterations in sphingolipid metabolism may be intimately related to neurodegenerative diseases, including ALS. Acid sphingomyelinase (ASM), a sphingolipid-metabolizing enzyme, is considered an important mediator of neurodegenerative diseases. Herein, we show that ASM activity increases in samples from patients with ALS and in a mouse model. Moreover, genetic inhibition of ASM improves motor function impairment and spinal neuronal loss in an ALS mouse model. Therefore, these results suggest the role of ASM as a potentially effective target and ASM inhibition may be a possible therapeutic approach for ALS.