• BMB Reports
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• v.49 no.8
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• pp.405-413
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• 2016

Tau proteins, which stabilize the structure and regulate the dynamics of microtubules, also play important roles in axonal transport and signal transduction. Tau proteins are missorted, aggregated, and found as tau inclusions under many pathological conditions associated with neurodegenerative disorders, which are collectively known as tauopathies. In the adult human brain, tau protein can be expressed in six isoforms due to alternative splicing. The aberrant splicing of tau pre-mRNA has been consistently identified in a variety of tauopathies but is not restricted to these types of disorders as it is also present in patients with non-tau proteinopathies and RNAopathies. Tau mis-splicing results in isoform-specific impairments in normal physiological function and enhanced recruitment of excessive tau isoforms into the pathological process. A variety of factors are involved in the complex set of mechanisms underlying tau mis-splicing, but variation in the cis-element, methylation of the MAPT gene, genetic polymorphisms, the quantity and activity of spliceosomal proteins, and the patency of other RNA-binding proteins, are related to aberrant splicing. Currently, there is a lack of appropriate therapeutic strategies aimed at correcting the tau mis-splicing process in patients with neurodegenerative disorders. Thus, a more comprehensive understanding of the relationship between tau mis-splicing and neurodegenerative disorders will aid in the development of efficient therapeutic strategies for patients with a tauopathy or other, related neurodegenerative disorders.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.84-84
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• 2003

Lead has long been considered as a toxic environmental pollutant, which severely damages central nervous system. Lead can cause hypo- and de-myelination, and glial cells are closely related with myelination or demyelination. Matrix metalloproteinases (MMPs) are proteolytic enzymes that are involved in the remodelling of the extracellular matrix in a variety of physiological and pathological processes. MMPs also seem to be important in the pathogenesis of inflammatory demyelinating diseases of the central and peripheral nervous system. In this study, we investigated whether lead affects MMP-9 expression in rat primary glial cells. Treatment of 0.1-5 ${\mu}$M lead dose- and time-dependently increased MMP-9 expression in rat primary glial cells. The activity of MMPs was determined using zymography. Lead activated Erk(1/2) but neither of the other endogenous MAP kinases, p38 or JNK. Inhibition of Erk(1/2) activation by PD98059, a MEK inihibitor, prevented lead-induced expression of MMP-9. The results of the present study suggest that lead intoxication may adversely affect brain function at least in part by inducing MMP-9 expression through Erk(1/2) activation in primary glial cells.

• Journal of Dairy Science and Biotechnology
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• v.27 no.1
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• pp.53-57
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• 2009

Lactic acid bacteria (LAB) Play an important role in the human diet and are used in the production of edible fermented products such as kimchi and yoghurt. LAB are regarded as safe food additives used to enhance the nutritive value of foods. Plant-origin lactic acid bacteria (PLAB) cultured in vegetal media are now widely used in food industries. PLAB have been found to activate intestinal immunity, modulate the balance of the intestinal bacterial from, and enhance intestinal function. They are known for their strong resistance to acid; this enables them to persist for a longer duration in the human intestine. PLAB can also survive in the intestinal environment under conditions of poor nutrition. They have stronger vitality as compared to LAB of animal origin. Due to the unique characteristics of PLAB, they are being widely used in Japan for processing foods such as yoghurt and beverages. Recently, PLAB has also been used as the culture for processing yoghurt in Korea. We expect further research on the functional effects of PLAB.

• Journal of Biomedical Engineering Research
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• v.15 no.4
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• pp.481-488
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• 1994

In this paper a study of neuro-pathway estimation based on visual and somatosensory evoked potential is given. The evoked potentials which are caused by visual and somatosensory stimulation are detected by an average method. The forward problem that is estimating a scalp potential from a given electrical source in the brain is solved by using a triple concentric spherical shell model of the head and a single current dipole model of the neuron activity. The inverse problem which calculates a source position is solved by a least square fit between the model predicted potential and a given evoked potential measurement. The similarities between estimated sensory neuro-pathways and physiological brain function regions are verified.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.1
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• pp.118-123
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• 2010

Piper nigrum Linne has been used spice as well as herbal medicine in worldwide and has function of anti-oxidant, anti-inflammation, anti-cancer, bioavailability of drugs and etc. In this study, anti-adipogenic activity of Piper nigrum Linne extract and its constituent piperine were investigated in 3T3-L1 differentiation. Adipogenic effects and lipid accumulation in 3T3-L1 was measured by RT-PCR and Oil Red O staining assays respectively in stimulation of Piper nigrum Linne extract and piperine. Piper nigrum Linne and piperine reduced lipid accumulation in 3T3-L1 differentiation and expression of genes associated with adipogenesis such as PPAR${\gamma}$, adipsin, SERBP-1c and LPL. All of taken, anti-adipogenic mechanism of Piper nigrum Linne and piperine were related with regulation of SREBP-1c and PPAR${\gamma}$ expression.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.479-484
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• 1999

In this study, the effects of ursodeoxycholic acid (UDCA) on ischemia/reperfusion injury were investigated on isolated heart perfusion model. Hearts were perfused with oxygenated Krebs-Henseleit solution (pH 7.4, $37^{\circ}C$) on a Langendroff apparatus. After equilibration, isolated hearts were treated with UDCA 20 to 160 $\mu$M or vehicle (0.04% DMSO) for 10 min before the onset of ischemia. After global ischemia (30 min), ischemic hearts were reperfused and allowed to recover for 30 min. The physiological (i.e. heart rate, left ventricular developed pressure, coronary flow, double product and time to contracture formation) and biochemical (lactate dehydrogenase; LDH) parameters were evaluated. In vehicle-treated group, time to contracture formation was 21.4 min during ischemia, LVDP was 18.5 mmHg at the endpoint or reperfusion and LDH activity in total reperfusion effluent was 54.0 U/L. Cardioprotective effects of UDCA against ischemia/reperfusion consisted of a reduced TTC $(EC_{25}=97.3{\mu}M)$, reduced LDH release and enhanced recovery of cardiac contractile function during reperfusion. Especially, the treatments of UDCA 80 and $160 {\mu}M $ significantly increased LVDP and reduced LDH release. Our findings suggest that UDCA ameliorates ischemia/reperfusion-induced myocardial damage.

• BMB Reports
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• v.50 no.5
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• pp.235-236
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• 2017

The circadian clock is an internal system that is synchronized by external stimuli, such as light and temperature, and influences various physiological and developmental processes in living organisms. In the model plant Arabidopsis, transcriptional, translational and post-translational processes are interlocked by feedback loops among morning- and evening-phased genes. In a post-translational loop, plant-specific single-gene encoded GIGANTEA (GI) stabilize the F-box protein ZEITLUPE (ZTL), driving the targeted-proteasomal degradation of TIMING OF CAB EXPRESSION 1 (TOC1) and PSEUDO-RESPONSE REGULATOR 5 (PRR5). Inherent to this, we demonstrate the novel biochemical function of GI as a chaperone and/or co-chaperone of Heat-Shock Protein 90 (HSP90). GI prevents ZTL degradation as a chaperone and facilitates ZTL maturation together with HSP90/HSP70, enhancing ZTL activity in vitro and in planta. GI is known to be involved in a wide range of physiology and development as well as abiotic stress responses in plants, but it could also interact with diverse client proteins to increase protein maturation. Our results provide evidence that GI helps proteostasis of ZTL by acting as a chaperone and a co-chaperone of HSP90 for proper functioning of the Arabidopsis circadian clock.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.641-649
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• 2012

To investigate scientific evidence for the use of a Korean Medicine (KM), the papers regarding Sipjeondabo-tang (Shiquandabu-tang) frequently used in Korean medical clinics and hospitals were collected and analyzed. The papers were classified as being from domestic or international journals and by the year of publication. The mechanisms of immuno-activity Sipjeondabo-tang (Shiquandabu-tang) were researched. Among 41 papers, 4 were published as Korean papers whereas 7 were as Chinese papers and 40 were as Japanese papers. Sipjeondabo-tang (Shiquandabu-tang) regulated the productions of Th1 cytokines such as interleukin-2 (IL-2) and interferon-${\gamma}$ (IFN-${\gamma}$), and Th2 cytokines such as IL-4, IL-5, IL-6, IL-12 improving the function of immune organ including bone marrow, spleen, liver, thymus and peyer's patch. It also modulated the releases of immunoglobulin-G (IgG) and IgM. Thus, Sipjeondabo-tang (Shiquandabu-tang) balanced the Th1/Th2 immune responses as well as T/B cell. The regulation of immunoactivity could be speculated as an objective and scientific evidence of Sipjeondabo-tang (Shiquandabu-tang).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.799-804
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• 2015

This study aims at the new analysis of heart beat fluctuations by applying physiological Heart Rate Variability Model with representing the cardiac control system in sympathetic and parasympathetic-coupling oscillator constants, C_s and C_p. To find the effects of coupling constants on the beat-to-beat fluctuations, Integral Pulse Frequency Modulation (IPFM) model is adopted to generate the time series data of ECG R-peaks and represent them by poincaré scattergram plot in the time domain and HRV in the frequency domain, respectively. The actual poincaré plots and HRV spectrum are also analyzed by acquiring the experimental data from the subjects exposed to the emotional-stress invoking environment and the function of the coupling constants are verified in terms of antagonism in sympathetic and parasympathetic activity.

• Korean Journal of Microbiology
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• v.34 no.4
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• pp.243-247
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• 1998

Comparative analyses of intracellular biopterin contents and its biosynthetic enzymes were performed in Allomyces macrogynus. Biopterin content in fresh weight was 14-fold higher in mycelium than in zoospore. Enzyme activities of GTP cyclohydrolase I and 6-pyruvoyltetrahydropterin synthase in ammonium sulfate fractions were approximately 2-fold higher in mycelium. On the other hand, sepiapterin reductase (SR) activity was 10 fold higher in zoospore. Northern blot assay also demonstrated that SR transcript was abundant in zoospore. These results suggest a possible involvement of tetrahydrobiopterin in cellular differentiation of Allomyces macrogyllus as well as provide an experimental basis to elucidate the physiological function of SR in this organism.