• 생명과학회지
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• 제30권12호
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• pp.1118-1127
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• 2020

알츠하이머병은 점진적인 신경세포의 손상과 이로 인해 인지기능 장애를 유발하는 질병이다. 이 질환은 현재로서는 치료할 수 있는 질환이 아니고 진행을 멈추게 할 수 있는 방법이 없다. 그러나 초기에 알츠하이머병을 치료하는 것이 가장 효과적이므로 초기 진단은 증상을 관리할 수 있는 가장 좋은 기회를 제공할 수 있다. 알츠하이머병을 진단하기 위한 바이오마커로는 아밀로이드 베타(Aβ), 병적인 타우, 그리고 신경퇴화가 있고, Aβ의 축적, 인산화 타우는 뇌척수액이나 양전자 방출 단층촬영술을 통해 분석할 수 있다. 그러나 뇌척수액의 채취는 매우 침습적이고 양전자 방출 단층촬영술은 전문적인 고가의 장비가 필요하다. 지난 수십년 동안 빠르고 최소한의 침습성을 가진 바이오마커 분석법을 개발하기 위하여 혈액에 기반한 바이오마커 분석 기술이 연구되어 왔다. 그 중 주목할 만 한 발견이 혈장에서 Aβ의 주요 원천으로 혈소판과의 관련성이다. 아밀로이드 베타는 혈액-뇌 장벽을 통과 할 수 있고 정상 상태에서는 뇌와 혈액 간 평형을 이루게 된다. 흥미롭게도, 여러 임상시험 결과 혈장에서 Aβ42/Aβ40 비율이 가벼운 인지장애 질환과 알츠하이머병에서 감소되어 있는 것을 증명하였다. 종합하면, 이러한 최근의 발견들은 침습성을 최소화한 알츠하이머병의 초기 진단 기술을 개발하는 데 이용될 수 있다. 본 총설에서, 저자들은 알츠하이머병의 바이오마커에 대한 최근 연구결과들, 특히 말초에서 Aβ를 생산하는 혈소판의 역할과 혈액 기반 바이오마커로서의 개발 가능성에 대해 고찰하였다.

• 대한치과교정학회지
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• 제44권5호
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• pp.246-253
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• 2014

Objective: To evaluate the bioactivity, and the biomechanical and bone-regenerative properties of Ti6Al4V miniscrews subjected to anodization, cyclic precalcification, and heat treatment (APH treatment) and their potential clinical use. Methods: The surfaces of Ti6Al4V alloys were modified by APH treatment. Bioactivity was assessed after immersion in simulated body fluid for 3 days. The hydrophilicity and the roughness of APH-treated surfaces were compared with those of untreated (UT) and anodized and heat-treated (AH) samples. For in vivo tests, 32 miniscrews (16 UT and 16 APH) were inserted into 16 Wistar rats, one UT and one APH-treated miniscrew in either tibia. The miniscrews were extracted after 3 and 6 weeks and their osseointegration (n = 8 for each time point and group) was investigated by surface and histological analyses and removal torque measurements. Results: APH treatment formed a dense surface array of nanotubular TiO2 layer covered with a compact apatite-like film. APH-treated samples showed better bioactivity and biocompatibility compared with UT and AH samples. In vivo, APH-treated miniscrews showed higher removal torque and bone-to-implant contact than did UT miniscrews, after both 3 and 6 weeks (p < 0.05). Also, early deposition of densely mineralized bone around APH-treated miniscrews was observed, implying good bonding to the treated surface. Conclusions: APH treatment enhanced the bioactivity, and the biomechanical and bone regenerative properties of the Ti6Al4V alloy miniscrews. The enhanced initial stability afforded should be valuable in orthodontic applications.

• KSBB Journal
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• 제28권4호
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• pp.230-237
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• 2013

Amyloid ${\beta}$ peptide (A${\beta}$) still best known as a molecule to cause Alzheimer's disease (AD). AD is characterized by the accumulation and deposition of A${\beta}$ within the brain, leading to neuronal cell loss and perturbation of synaptic function by causing free radical formation, inflammation and apoptosis. We investigated the inflammatory action of A${\beta}$ on two types of brain cells, neuronal cells (SH-SY5Y) and neuroglia cells (C6), and its mechanism. We measured the production of NO-iNOS, TNF-${\alpha}$, and ICAM-1 using RT-PCR and Western blot analysis less than the concentration of cytotoxic effects (> 70% survivability). A${\beta}$ had no effect on the production of NO and TNF-${\alpha}$, but significantly increases of iNOS and ICAM-1. Based on this, we suggest that the inflammatory effect of A${\beta}$ results from the action of ICAM-1 in neuronal cells, rather than the release of inflammatory mediators such as NO and TNF-${\alpha}$ in neuroglia cells. In addition, we confirmed whether p53 was related to the action of A${\beta}$ by using SH-SY5Y ($p53^{-/-}$) dominant cells. Neither the expression of p53 nor the cytotoxicity of SH-SY5Y ($p53^{-/-}$) cells were directly affected by A${\beta}$. However, ICAM-1 was not expressed in SH-SY5Y ($p53^{-/-}$) cells. This means that p53- independent pathway exists in the expression of ICAM-1 by A${\beta}$ while p53 plays a role as an on-and-off switch.

• BMB Reports
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• 제56권9호
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• pp.520-525
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• 2023

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by cognitive decline. Several recent studies demonstrated that impaired adult neurogenesis could contribute to AD-related cognitive impairment. Adult subventricular zone (SVZ) neurogenesis, which occurs in the lateral ventricles, plays a crucial role in structural plasticity and neural circuit maintenance. Alterations in adult SVZ neurogenesis are early events in AD, and impaired adult neurogenesis is influenced by the accumulation of intracellular Aβ. Although Aβ-overexpressing transgenic 5XFAD mice are an AD animal model well representative of Aβ-related pathologies in the brain, the characterization of altered adult SVZ neurogenesis following AD progression in 5XFAD mice has not been thoroughly examined. Therefore, we validated the characterization of adult SVZ neurogenesis changes with AD progression in 2-, 4-, 8-, and 11-monthold male 5XFAD mice. We first investigated the Aβ accumulation in the SVZ using the 4G8 antibody. We observed intracellular Aβ accumulation in the SVZ of 2-month-old 5XFAD mice. In addition, 5XFAD mice exhibited significantly increased Aβ deposition in the SVZ with age. Next, we performed a histological analysis to investigate changes in various phases of adult neurogenesis, such as quiescence, proliferation, and differentiation, in SVZ. Compared to age-matched wild-type (WT) mice, quiescent neural stem cells were reduced in 5XFAD mice from 2-11 months of age. Moreover, proliferative neural stem cells were decreased in 5XFAD mice from 2 to 8 months of age. Furthermore, differentiations of neuroblasts were diminished in 5XFAD mice from 2-11 months of age. Intriguingly, we found that adult SVZ neurogenesis was reduced with aging in healthy mice. Taken together, our results revealed that impairment of adult SVZ neurogenesis appears with aging or AD progression.

• Journal of Yeungnam Medical Science
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• 제40권2호
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• pp.136-145
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• 2023

Hepatic encephalopathy (HE) is a severe neuropsychiatric abnormality in patients with either acute or chronic liver failure. Typical brain magnetic resonance imaging findings of HE are bilateral basal ganglia high signal intensities due to manganese deposition in chronic liver disease and hyperintensity in T2, fluid-attenuated inversion recovery, or diffusion-weighted imaging (DWI) with hemispheric white matter changes including the corticospinal tract. Low values on apparent diffusion coefficient mapping of the affected area on DWI, indicating cytotoxic edema, can be observed in acute HE. However, neuropsychological impairment in HE ranges from mild deficits in psychomotor abilities affecting quality of life to stupor or coma with higher grades of hepatic dysfunction. In particular, the long-lasting compensatory mechanisms for the altered metabolism in chronic liver disease make HE imaging results variable. Therefore, the clinical relevance of imaging findings is uncertain and differentiating HE from other metabolic diseases can be difficult. The recent introduction of concepts such as "acute-on-chronic liver failure (ACLF)," a new clinical entity, has led to a change in the clinical view of HE. Accordingly, there is a need to establish a corresponding concept in the field of neuroimaging diagnosis. Herein, we review HE from a historical and etiological perspective to increase understanding of brain imaging and help establish an imaging approach for advanced new concepts such as ACLF. The purpose of this manuscript is to provide an understanding of HE by reviewing neuroimaging findings based on pathological and clinical concepts of HE, thereby assisting in neuroimaging interpretation.

• 대한영상의학회지
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• 제84권5호
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• pp.1140-1145
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• 2023

대뇌 아밀로이드 혈관병증 관련 염증은 베타 아밀로이드가 혈관에 침착되어 혈관 주위의 급성 염증성 반응으로 발생하는 뇌병증이다. 이 질환은 주로 고령자에게서 발생하는 드문 질환으로, 급격히 진행하는 치매, 두통, 발작, 국소 신경학적 결손을 동반한 증상으로 나타나며 특징적인 뇌자기공명영상 소견을 보인다. 또한 스테로이드 또는 기타 면역억제요법에 반응하는 가역적인 질병이다. 대뇌 아밀로이드 혈관병증 관련 염증을 처음에는 아급성 경색으로 오진하였다가 추적 관찰 중 뇌 자기공명영상 소견을 분석하면서 대뇌 아밀로이드 혈관병증 관련 염증이 진단되었고, 자연 관해가 이뤄진 대뇌 아밀로이드 혈관병증 관련 염증 증례를 보고한다.

• The Korean Journal of Physiology and Pharmacology
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• 제24권1호
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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.

• 동의신경정신과학회지
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• 제19권2호
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• pp.151-163
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• 2008

Objective : Recent studies indicate that the deposition of beta-amyloid ($A{\beta}$) is related in the pathogenesis of Alzheimer's disease (AD), but the underlying mechanism is still not clear. Method : To investigate the potential cellular functions of APP and LMK02, we use transgenic drosophila as a model was treated with either LMK02, and the effect in APP expression was determined by climbing assay. LMK02 have been shown to be neuroprotective in fly model systems. We asked whether dietary supplementation with LMK02 would influence behavior and AD-like pathology in a transgenic fly model. Result LMK02 water extract have attenuated fly death in vivo. LMK02-treated fly increased percentage of flight ability more longly and survival ratio more than controls. APP-GRIM drosophila treated with LMK02 had significantly less accumulation of APP deposition in the eye and brain as compared to control drosophila. Conclusion : These results suggest that LMK02 prevent APP-induced neurotoxicity through attenuating flies death induced by APP, and may be useful as potential therapeutic agents for AD.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.167-167
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• 2010

Indium tin oxide (ITO) has been widely used as transparent conductive oxides (TCOs) for transparent electrodes of various optoelectronic devices, such as liquid crystal displays (LCD) and organic light emitting diodes (OLED). However, indium has become increasingly expensive and rare because of its limited resources. In addition, ITO thin films have some problems for OLED and flexible displays, such as imperfect work function, chemical instability, and high deposition temperature. Therefore, multi-component TCO materials have been reported as anode materials. Among the various materials, IZTO thin films have been gained much attention as anode materials due to their high work function, good conductivity, high transparency and low deposition temperature. IZTO thin films with a thickness of 200nm were deposited on Corning glass substrate at different substrate temperature by pulsed DC magnetron sputtering with a sintered ceramic target of IZTO (In2O3 70 wt%, ZnO 15 wt%, SnO2 15 wt%). We investigated the electrical, optical, structural properties of IZTO thin films. As the substrate temperature is increased, the electrical properties of IZTO are improved. All IZTO thin films have good optical properties, which showed an average of transmittance over 80%. These IZTO thin films were used to fabricate organic light emitting diodes (OLEDs) as anode and the device performances studied. As a result, IZTO has utility value of TCO electrode although it reduced indium and we expect it is possible for the IZTO to apply to flexible display due to the low processing temperature.

• Nutrition Research and Practice
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• 제13권1호
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• pp.64-69
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• 2019

BACKGROUND/OBJECTIVES: Alzheimer's disease is a neurodegenerative disease that induces symptoms such as a decrease in motor function and cognitive impairment. Increases in the aggregation and deposition of amyloid beta protein ($A{\beta}$) in the brain may be closely correlated with the development of Alzheimer's disease. In this study, the effects of an adzuki bean extract on the aggregation of $A{\beta}$ were examined; moreover, the anti-Alzheimer's activity of the adzuki extract was examined. MATERIALS/METHODS: First, we undertook thioflavin T (ThT) fluorescence analysis and transmission electron microscopy (TEM) to evaluate the effect of an adzuki bean extract on $A{\beta}_{42}$ aggregation. To evaluate the effects of the adzuki extract on the symptoms of Alzheimer's disease in vivo, $A{\beta}_{42}$-overexpressing Drosophila were used. In these flies, overexpression of $A{\beta}_{42}$ induced the formation of $A{\beta}_{42}$ aggregates in the brain, decreased motor function, and resulted in cognitive impairment. RESULTS: Based on the results obtained by ThT fluorescence assays and TEM, the adzuki bean extract inhibited the formation of $A{\beta}_{42}$ aggregates in a concentration-dependent manner. When $A{\beta}_{42}$-overexpressing flies were fed regular medium containing adzuki extract, the $A{\beta}_{42}$ level in the brain was significantly lower than that in the group fed regular medium only. Furthermore, suppression of the decrease in motor function, suppression of cognitive impairment, and improvement in lifespan were observed in $A{\beta}_{42}$-overexpressing flies fed regular medium with adzuki extract. CONCLUSIONS: The results reveal the delaying effects of an adzuki bean extract on the progression of Alzheimer's disease and provide useful information for identifying novel prevention treatments for Alzheimer's disease.