• Toxicological Research
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• v.31 no.4
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• pp.347-354
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• 2015

Excess manganese (Mn) is neurotoxic. Increased manganese stores in the brain are associated with a number of behavioral problems, including motor dysfunction, memory loss and psychiatric disorders. We previously showed that the transport and neurotoxicity of manganese after intranasal instillation of the metal are altered in Hfe-deficient mice, a mouse model of the iron overload disorder hereditary hemochromatosis (HH). However, it is not fully understood whether loss of Hfe function modifies Mn neurotoxicity after ingestion. To investigate the role of Hfe in oral Mn toxicity, we exposed Hfe-knockout ($Hfe^{-/-}$) and their control wild-type ($Hfe^{+/+}$) mice to $MnCl_2$ in drinking water (5 mg/mL) for 5 weeks. Motor coordination and spatial memory capacity were determined by the rotarod test and the Barnes maze test, respectively. Brain and liver metal levels were analyzed by inductively coupled plasma mass spectrometry. Compared with the water-drinking group, mice drinking Mn significantly increased Mn concentrations in the liver and brain of both genotypes. Mn exposure decreased iron levels in the liver, but not in the brain. Neither Mn nor Hfe deficiency altered tissue concentrations of copper or zinc. The rotarod test showed that Mn exposure decreased motor skills in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice (p = 0.023). In the Barns maze test, latency to find the target hole was not altered in Mn-exposed $Hfe^{+/+}$ compared with water-drinking $Hfe^{+/+}$ mice. However, Mn-exposed $Hfe^{-/-}$ mice spent more time to find the target hole than Mn-drinking $Hfe^{+/+}$ mice (p = 0.028). These data indicate that loss of Hfe function impairs spatial memory upon Mn exposure in drinking water. Our results suggest that individuals with hemochromatosis could be more vulnerable to memory deficits induced by Mn ingestion from our environment. The pathophysiological role of HFE in manganese neurotoxicity should be carefully examined in patients with HFE-associated hemochromatosis and other iron overload disorders.

• Journal of Yeungnam Medical Science
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• v.27 no.1
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• pp.27-36
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• 2010

Purpose : The purpose of this study was to find out cognitive function of the patients with subjective memory complaint. Material and Methods : From March 1st 2005 to May 31st 2009, 155 normal individuals without any medical illness who visited Yeungnam University Hospital to undergo medical checkup with neurocognitive test was enrolled, and checked by using Cognitive Assessment & Reference Diagnostic System. Results : 107 of the patients had normal cognitive function, 21 patients (about 15%) were diagnosed with dementia, and 10 patients (about 7%) were diagnosed with considerable psychiatric illness, such as depression, anxiety disorder, adjustment disorder. In amnesia, agnosia, aphasia, attention, calculation, dysexecution, Dementia group and Psychiatric illness group has worse score than Normal individuals group. But, in apraxia, Dementia group has worse score than Psychiatric illness group and Normal individual group. Conclusion : Because the patients with subjective memory complaint can be diagnosed as any psychiatric illness as well as dementia, sensitive screening test and early psychiatric approach is needed.

• Journal of Sensor Science and Technology
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• v.6 no.6
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• pp.500-507
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• 1997

For fine control of operating temperature of shape memory alloy, we investigated the effect of thermal teratment of shape memory alloy with the impurity kind. The martensitic transformation temperature in a Cu-17.25Zn-15Al and Cu-17.25Zn-15Al-1Ag/Fe was measured using electrical resistivity as a function of quenching temperature. Order-disorder phase transition temperatures in parent phase were measured and kind of transition were distinguised by DSC(differential scanning calorimeter) with heating rate variation. And structual changes were studied with XRD. For the Cu-17.25Zn-15Al shape memory alloy, the order-disorder phase transition temperature, $T_{B2}$ and $T_{L21}$ was 809K and 610K and for the Cu-17.25Zn-15Al-1Ag and Cu-17.25Zn-15Al-1Fe specimen $T_{B2}$ and $T_{L21}$ was 794K and 610K, and 803K and 613K, respectively. In all the specimens, quenching from near $T_{B2}$ leads to an increase in martensitic temperature, whereas quenching from near $T_{L21}$ leads to an decrease in martensitic temperature.

• Clinical and Experimental Pediatrics
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• v.60 no.11
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• pp.337-343
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• 2017

Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in childhood. This disorder, in addition to its main symptoms, creates significant difficulties in education, social performance, and personal relationships. Given the importance of rehabilitation for these patients to combat the above issues, the use of virtual reality (VR) technology is helpful. The aim of this study was to highlight the opportunities for VR in the rehabilitation of children with ADHD. This narrative review was conducted by searching for articles in scientific databases and e-Journals, using keywords including VR, children, and ADHD. Various studies have shown that VR capabilities in the rehabilitation of children with ADHD include providing flexibility in accordance with the patients' requirements; removing distractions and creating an effective and safe environment away from real-life dangers; saving time and money; increasing patients' incentives based on their interests; providing suitable tools to perform different behavioral tests and increase ecological validity; facilitating better understanding of individuals' cognitive deficits and improving them; helping therapists with accurate diagnosis, assessment, and rehabilitation; and improving working memory, executive function, and cognitive processes such as attention in these children. Rehabilitation of children with ADHD is based on behavior and physical patterns and is thus suitable for VR interventions. This technology, by simulating and providing a virtual environment for diagnosis, training, monitoring, assessment and treatment, is effective in providing optimal rehabilitation of children with ADHD.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.3
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• pp.192-197
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• 2011

Objectives: This study was conducted to examine the prevalence and characteristics of savant skills and the relationship between the savant skills and autistic symptoms in Korean ASD children. Methods: 141 ASD subjects participated in this study and they were divided in to two groups based on the presence or lack of savant skills. The domain scores and total scores of the K-ADI-R, K-ASDS and SRS were used for evaluating the ASD symptoms between the groups. Results: Memory (N=47) was the most prevalent savant skill in the savant ASD group (N=60). The savant ASD group had a statistically higher mean age and IQ score than did the nonsavant ASD group. Despite their high IQ profile, the savant ASD group showed a higher restricted, repetitive and stereotype behavior score on the K-ADI-R and higher language and cognitive scores on the K-ASDS than did the nonsavant ASD group. Conclusions: These results suggest savant syndrome in ASD might be related to the severity of some subdomain of autistic symptoms even though their IQ scores were higher than nonsavant ASD patients.

• Tuberculosis and Respiratory Diseases
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• v.63 no.4
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• pp.382-386
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• 2007

Paraneoplastic limbic encephalitis is a rare disorder that is characterized by personality changes, irritability, depression, seizures, memory loss and dementia, and is commonly associated with small cell lung cancer. The cause is unknown but it is believed to be an autoimmune disorder that develops secondary to a carcinomatous process. We report a patient with the clinical feature consistent with limbic encephalitis. A 64-year-old women developed disorientation, memory loss and general weakness. She was diagnosed with NSCLC (adenocarcinoma) with a brain metastasis 1 year earlier and was treated with radiation and chemotherapy. Although the lung mass and brain metastatic lesions had improved, the brain T2-weighted MRI showed high signal intensity in the right temporal region. This lesion consisted of with limbic encephalitis and was negative to the other viral and immune markers. The patient's symptoms did not improve after steroid treatment. Our case demonstrated that a NSCLC (adenocarcinoma) also can be associated with paraneoplastic limbic encephalitis.

• Biomolecules & Therapeutics
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• v.28 no.1
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• pp.74-82
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• 2020

Alzheimer's disease (AD) is a progressive and most frequently diagnosed neurodegenerative disorder. However, there is still no drug preventing the progress of this disorder. β-Amyrin, an ingredient of the surface wax of tomato fruit and dandelion coffee, is previously reported to ameliorate memory impairment induced by cholinergic dysfunction. Therefore, we tested whether β-amyrin can prevent AD-like pathology. β-Amyrin blocked amyloid β (Aβ)-induced long-term potentiation (LTP) impairment in the hippocampal slices. Moreover, β-amyrin improved Aβ-induced suppression of phosphatidylinositol-3-kinase (PI3K)/Akt signaling. LY294002, a PI3K inhibitor, blocked the effect of β-amyrin on Aβ-induced LTP impairment. In in vivo experiments, we observed that β-amyrin ameliorated object recognition memory deficit in Aβ-injected AD mice model. Moreover, neurogenesis impairments induced by Aβ was improved by β-amyrin treatment. Taken together, β-amyrin might be a good candidate of treatment or supplement for AD patients.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.34 no.4
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• pp.275-282
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• 2023

Objectives: This study aimed to identify the psychiatric comorbidity status of adult patients diagnosed with attention-deficit hyperactivity disorder (ADHD) and determine the impact of comorbidities on neuropsychological outcomes in ADHD. Methods: The study participants were 124 adult patients with ADHD. Clinical psychiatric assessments were performed by two board-certified psychiatrists in accordance with the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. All participants were assessed using the Mini-International Neuropsychiatric Interview Plus version 5.0.0 to evaluate comorbidities. After screening, neuropsychological outcomes were assessed using the Comprehensive Attention Test (CAT) and the Korean version of the Wechsler Adult Intelligence Scale, Fourth Edition (K-WAIS-IV). Results: Mood disorders (38.7%) were the most common comorbidity of ADHD, followed by anxiety (18.5%) and substance use disorders (13.7%). The ADHD with comorbidities group showed worse results on the Perceptual Organization Index and Working Memory Index sections of the K-WAIS than the ADHD-alone group (p=0.015 and p=0.024, respectively). In addition, the presence of comorbidities was associated with worse performance on simple visual commission errors in the CAT tests (p=0.024). Conclusion: These findings suggest that psychiatric comorbidities are associated with poor neuropsychological outcomes in adult patients with ADHD, highlighting the need to identify comorbidities in these patients.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.1
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• pp.39-46
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• 2020

Alzheimer's disease (AD) is the most common neurodegenerative disorder causing dementia worldwide, and is mainly characterized by aggregated β-amyloid (Aβ). Increasing evidence has shown that plant extracts have the potential to delay AD development. The plant sterol β-Sitosterol has a potential role in inhibiting the production of platelet Aβ, suggesting that it may be useful for AD prevention. In the present study, we aimed to investigate the effect and mechanism of β-Sitosterol on deficits in learning and memory in amyloid protein precursor/presenilin 1 (APP/PS1) double transgenic mice. APP/PS1 mice were treated with β-Sitosterol for four weeks, from the age of seven months. Brain Aβ metabolism was evaluated using ELISA and Western blotting. We found that β-Sitosterol treatment can improve spatial learning and recognition memory ability, and reduce plaque load in APP/PS1 mice. β-Sitosterol treatment helped reverse dendritic spine loss in APP/PS1 mice and reversed the decreased hippocampal neuron miniature excitatory postsynaptic current frequency. Our research helps to explain and support the neuroprotective effect of β-Sitosterol, which may offer a novel pharmaceutical agent for the treatment of AD. Taken together, these findings suggest that β-Sitosterol ameliorates memory and learning impairment in APP/PS1 mice and possibly decreases Aβ deposition.

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.243-249
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• 2015

Myrrh, Angelicae Radix, and Schisandrae Fructus have been used to treat diverse diseases including neurological disorder in the traditional Korean medicine. In the present study, we investigated the ameliorating effects of HPM-1, a combined extract of Myrrh, Angelicae Radix and Schisandrae Fructus, on scopolamine-induced memory impairments in mice. First, we assessed HPM-1, HPM-2 and HPM-3, in which Myrrh was extracted with water, 30% ethanol, and 30% ethanol/3% vinegar, respectively. The oral administration of HPM-1, HPM-2, or HPM-3 significantly reversed scopolamine-induced reduction of spontaneous alternation in the Y-maze task. In the passive avoidance task, HPM-1 or HPM-3 restored the decreased latency time of the retention trial by scopolamine treatment, but in terms of efficacy, HPM-1 showed more beneficial effects than HPM-3. In addition, HPM-1 administration reversed scopolamine-induced reduction of spontaneous alternation in the Y-maze task and scopolamine-decreased latency time in the passive avoidance in a dose-dependent manner. These results suggest that HPM-1 has the therapeutic potential in memory impairments.