• Proceedings of the Korean Society of Applied Pharmacology
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• 2006.04a
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• pp.95-105
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• 2006

Alzheimer's disease (AD) is an irreversible, progressive brain disorder that is characterized by dementia. Amounts of p25 and cdk5 kinase activity are specifically upregulated in AD patient's brain samples. Considerable evidence now points importance of p25/cdk5 in generation of A$\beta$ peptides and hyperphosphorylation of tau linking amyloid plaques and neurofibrillary tangles, two major pathological hallmarks of AD. We demonstrated that P25/CDK5 phosphorylates BACE1, the first step protease to produce A$\beta$. P25/CDK5 inhibitors to reduce BACE1 phosphorylation and the secretion of A$\beta$ are screened through in silica, in vitro, and cell-based assays. Out of 4.3 million chemicals we finally selected two compounds to have IC50 of 10 microM in cell-based assays. The inhibitors block Tau phosphrorylation as well as BACE1 phosphorylation. In conclusion P25 should be one of the best targets for AD therapeutics.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.873-879
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• 2011

5-Fluorouracil (5-FU), an anticancer agent was covalently attached to the recently developed sorbitol-based G8 transporter, and the conjugate (7) with FITC was found to have an affinity toward mitochondria and to readily cross BBB to gain an entry into mouse brain. Measured by $IC_{50}$, the conjugate (9) without the fluorophore showed enhanced cytotoxic activity toward two types of multidrug-resistant cell lines. These results strongly suggest that the sorbitol-based G8 transporter can be utilized as a good CNS delivery vector.

• Journal of Biomedical Engineering Research
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• v.15 no.2
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• pp.129-134
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• 1994

In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Transformation from temporal summation to two-dimensional mappings is formed by 4 nearest point interpolaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality.

• International Journal of Computer Science & Network Security
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• v.24 no.6
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• pp.59-66
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• 2024

Measurable electrophysiological changes in the scalp are frequently linked to brain activities. These progressions are called related evoked potentials (ERP), which are transient electrical responses recorded by electroencephalography (EEG) in light of tactile, mental, or motor enhancements. This painless strategy is gradually being used as a conclusion and clinical help. In this article, we will talk about the main ways to monitor brain activities in people with neurological diseases like Alzheimer's disease by analyzing EEG signals using ERP. We will also talk about how this method helps to detect the disease at an early stage.

• Korean Journal of Radiology
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• v.2 no.4
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• pp.239-242
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• 2001

Nonketotic hyperglycinemia (NKH) is a rare metabolic brain disease caused by deficient activity of the glycine cleveage system. Localized proton MR spectroscopy (echo-time 166 msec), performed in an infant with the typical clinical and biochemical features of neonatal NKH, showed a markedly increased peak intensity at 3.55 ppm, which was assigned to glycine. Serial proton MR spectrosocpic studies indicated that glycine/choline and glycine/total creatine ratios correlated closely with the patient's clinical course. Proton MR spectroscopy was useful for the non-invasive detection and monitoring of cerebral glycine levels in this infant with NKH.

• The Journal of Korean Medicine
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• v.25 no.4
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• pp.1-7
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• 2004

Objective : This study was designed to examine the effects of orally administered Prunus persica water extract (PPE), which is used as herbal medicine, for treatment of Yu Xue (stasis of blood) and tacrine on the basal concentration of extracellular acetylcholine in the hippocampus of rats. Methods: To investigate the effects of PPE and tacrine on concentration of extracellular acetylcholine in the hippocampus of rats, the microdialysis technique, under the same experimental conditions, was used. And we used male Wistar rats which were 7 weeks of age and 210-290 g. PPE was extracted with boiling water, and the rats were anesthetized with pentobarbital Na. Their skulls were exposed and a hole was drilled for implantation of a microdialysis probe. In order to increase the recovery of acetylcholine, a probe with a long membrane was used. One day after surgery, the microdialysis probe was perfused with Ringer's solution at a flow rate of 1.5 l/min. The acetylcholine concentration in dialysis samples was measured by high-performance liquid chromatography (HPLC) with electrochemical detection. AChE activity was measured using the radiometric method, as described by Sherman. Results : The comparative effects of PPE and tacrine on hippocampal extracellular acetylcholine concentration was that these cholinesterase inhibitors produced dose-dependent increases in the extracellular acetylcholine concentration. And the effect of PPE and tacrine on rat brain AChE activity was that PPE produced maximal inhibition at 1 h after administration, when AChE activity was 44% of the intact level. AChE activity gradually recovered thereafter, and reached 78% of the intact level at 12 h after administration. Conclusion : In this study, PPE has a potent activity and a long-lasting effect on the central cholinergic system, in terms of the basal concentration of extracellular acetylcholine in the hippocampus and the AChE activity in the brain of rats. And oral administration of PPE increased dose-dependently the basal concentration of extracellular acetylcholine in the hippocampus of rats. PPE may be one of the more useful cholinesterase inhibitors for the treatment of Alzheimer's disease.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.111-111
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• 2003

Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomeres and telomerase have been studied extensively, very little is known about telomere dynamics in embryonic cells. This study was carried out to analyze the telomeres distribution and telomerase activity of chicken cells during embryonic and developmental stages. The target cells for analysing were sperms, ovulated ova, early embryonic cells and the cells from brain, heart, liver, kidney and germinal tissue in fetus. Telomeres distribution on target cells was analyzed by Q-FISH (Quantitation-Fluorescence in situ Hybridization) techniques using a chicken telomere repeat probe. Telomerase activity was performed by TRAP assay (Telomeric repeat Amplification Protocol) with target DNA. In results, the telomeres of chicken were found at the ends of all chromosomes. In addition, chicken had interstitial telomeres on chromosomes 1, 2 and 3. Telomerase activity was highly detectable in early embryonic cells, germinal tissues and kidney cells. Whereas telomerase activity was gradually down-regulated when the organs, including brain, heart, and liver, were developed from embryos. In the distribution of telomeric DNA on the embryonic and developmental stages, most of the cells was gradually decreased in telomere quantity during ontogenesis.

• Journal of Acupuncture Research
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• v.26 no.1
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• pp.39-47
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• 2009

Objectives : The mesolimbic dopamine system is believed to play a major role in the reinforcing effect and behavioral hyperactivity of abused drugs including methamphetamine. In the present study, the effect of acupuncture on methamphetamine-induced locomotor activity and c-Fos expression in the striatum and nucleus accumbens of rats were examined. Methods : Male Sprague-Dawley rats received acupuncture at bilateral Yanggu($SI_5$) point for 30seconds immediately before the subcutaneous injection of saline or methamphetamine(0.5mg/kg). The total amount of locomotor activity for 90min were measured just before brain samples were taken for immunohistochemistry. Results : Results showed that acupuncture at the specific point $SI_5$, but not control point(Kunlun, $BL_{60}$) significantly reduced locomotor activity and c-Fos expression in the striatum and nucleus accumbens induced by acute administration of methamphetamine. Conclusions : These results suggest that acupuncture may be effective in suppressing the reinforcing effect of methamphetamine by regulating neuronal activity.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.41-46
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• 1999

Purpose : To investigate the difference of total activation in visual area, motor area, and cerebellum according to the stimulation paradigm. Materials and Methods : Functional MR imaging was performed in 5 healthy volunteers with visual and motor activity using EPI technique. LED and Checker-Board stimulation were performed for visual activity. Thumb motion and Finger Tapping were performed for motor and cerebellum activity. Stimulus timing was 60sec. off, 120sec. on, 60sec. off. Data processing was carried out by using the cross-correlation method for each pixel. Each pixel was then selected and assumed activated if the correlation coefficient was equal or larger than a threshold value. Time course data was obtained by calculating the total activation which was defined as the number of activated pixel x averaged pixel intensity. Results : In the case of visual activity with LED stimulation, we found increased total activity of more than 100% compared with Checker-Board stimulation. In the case of motor area and cerebellum with Finger tapping stimulation, we found increased total activity of more than 10% and 150%, respectively compared with Thumb motion stimulation.

• Food Quality and Culture
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• v.2 no.2
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• pp.61-66
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• 2008

The principal objective of this study was to assess the anti oxidative activities of Petasites japonicus against oxidative stress in bovine brain tissue. Petasites japonicus is found with a relatively widespread distribution, and is cultivated as a culinary vegetable in Korea. Petasites japonicus samples were dried either by freeze-drying or by hot air-convection drying ($80^{\circ}C$), then evaluated for their anti oxidative activity by measuring 1-dipheny-1,2-picrylhydrazyl (DPPH) radical scavenging, and by measuring thiobarbituric acid-reactive substances (TBARS) in brain homogenates subjected to $Fe^{2+}$-mediated lipids with or without the addition of botanical extract. Hot air convection-drying resulted in a slight increase in the extraction yield as compared with freeze-drying. However, total phenol and flavonoid contents in freeze-dried Petasites japonicas were significantly higher than those of hot air convection-drying. Freeze-drying increased the free radical scavenging activity of Petasites japonicas, leaves, and stems by 52.6, 28.6, and 248.0%, as compared with hot air convection-drying. Additionally, the $IC_{50}$ values measured by TBARS in hot air convection-dried Petasites japonicas, leaves, and stems were increased by 36.0, 31.6, and 15.9%, as compared to those of freeze-drying. Although anti oxidative activity was reduced slightly by heat processing in Petasites japonicas, freeze-drying for each portion of Petasites japonicus was the most appropriate for use as a functional food and pharmaceutical material.