• The Journal of the Acoustical Society of Korea
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• v.18 no.5
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• pp.35-43
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• 1999

In this paper, a new robust adaptive algorithm and a post-processing method are proposed to improve the performance of AEC without computational burden. Its step-size is normalized by the sum of the powers of the reference input signal and the desired signal. When the near-end speaker's speech and noise are applied into the microphone, the step-size becomes small and the misalignment of coefficients are reduced. To reduce the residual echoes, a new post-processing method, which is co-operated with the proposed noise-robust adaptive algorithm, is proposed in this paper. The method is based on the correlation of the desired signal and the estimation error signal. The residual echoes are attenuated as proportional to the correlation normalized with the power of desired signals. The normalized correlation plays a role as Wiener filter for residual echoes. In the double-talk situation, the estimation error signals, that are residual echoes, dominantly include the near-end speaker's speech and the normalized correlation closes to 1. Therefore, the near-end speaker's speech can be transmitted without being attenuated. When the desired signals consists of only the acoustic echoes, the residual echoes are mostly attenuated and canceled by the proposed post-processor. The computation of AEC using the proposed post-processor is comparable to NLMS algorithm.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1090-1097
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• 2017

Rhus verniciflua Stokes (RVS), an herbal medicine found in East Asia, was extracted and further fractionated to investigate its antioxidant capacity and neuroprotective effects. The RVS ethyl acetate (EtOAc) fraction had the highest level of total phenolics and antioxidant capacity among all solvent fractions tested. Pretreatment of PC-12 cells with the EtOAc fraction effectively attenuated $H_2O_2$-induced oxidative damage. Furthermore, the EtOAc fraction significantly attenuated caspase-3 activity, resulting in inhibition of $H_2O_2$-induced apoptosis. We identified and quantified fustin, sulfuretin, and butein in the EtOAc fraction using accurate mass quadrupole time-of-flight mass spectrometry and reversed-phase high-performance liquid chromatography. The intracellular antioxidant capacity and superoxide dismutase (SOD) activity were significantly increased in PC-12 cells treated with the EtOAc fraction and with individual flavonoids. When cells were pretreated with the EtOAc fraction or individual flavonoids and then co-incubated with diethyldithiocarbamic acid (an inhibitor of SOD activity), cell viability against $H_2O_2$-induced oxidative stress was attenuated. These results suggest that the RVS EtOAc fraction and its flavonoid constituents protect PC-12 cells against $H_2O_2$-induced neurotoxicity through their antioxidant properties.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.6
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• pp.549-555
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• 2015

We attempted to investigate molecular mechanisms underlying phenotypic change of vascular smooth muscle cells (VSMCs) by determining signaling molecules involved in chemokine production. Treatment of human aortic smooth muscle cells (HAoSMCs) with thrombin resulted not only in elevated transcription of the (C-C motif) ligand 11 (CCL11) gene but also in enhanced secretion of CCL11 protein. Co-treatment of HAoSMCs with GF109230X, an inhibitor of protein kinase C, or GW5074, an inhibitor of Raf-1 kinase, caused inhibition of ERK1/2 phosphorylation and significantly attenuated expression of CCL11 at transcriptional and protein levels induced by thrombin. Both Akt phosphorylation and CCL11 expression induced by thrombin were attenuated in the presence of pertussis toxin (PTX), an inhibitor of Gi protein-coupled receptor, or LY294002, a PI3K inhibitor. In addition, thrombin-induced production of CCL11 was significantly attenuated by pharmacological inhibition of Akt or MEK which phosphorylates ERK1/2. These results indicate that thrombin is likely to promote expression of CCL11 via PKC/Raf-1/ERK1/2 and PTX-sensitive protease-activated receptors /PI3K/Akt pathways in HAoSMCs. We propose that multiple signaling pathways are involved in change of VSMCs to a secretory phenotype.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.367-373
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• 2013

Contribution of the vestibular end organ to regulation of arterial pressure was quantitatively compared with the role of baroreceptors in terms of baroreflex sensitivity and c-Fos protein expression in the rostral ventrolateral medulla (RVLM). Baroreflex sensitivity and c-Fos protein expression in the RVLM were measured in conscious rats that had undergone bilateral labyrinthectomy (BL) and/or baroreceptor unloading. BL attenuated baroreflex sensitivity during intravenous infusion of sodium nitroprusside (SNP), but did not significantly affect the sensitivity following infusion of phenylephrine (PE). Baroreflex sensitivity became positive following sinoaortic denervation (SAD) during infusion of PE and attenuated sensitivity during infusion of SNP. Baroreflex sensitivity also became positive following double ablation (BL+SAD) during infusion of PE, and attenuated sensitivity during infusion of SNP. c-Fos protein expression increased significantly in the RVLM in the sham group after SNP administration. However, the BL, SAD, and SAD+BL groups showed significant decreases in c-Fos protein expression compared with that in the sham group. The SAD group showed more reduced c-Fos protein expression than that in the BL group, and the SAD+BL group showed less expression than that in the SAD group. These results suggest that the vestibular system cooperates with baroreceptors to maintain arterial pressure during hypotension but that baroreceptors regulate arterial pressure during both hypotension and hypertension. Additionally, afferent signals for maintaining blood pressure from the vestibular end organs and the baroreceptors may be integrated in the RVLM.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.791-797
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• 2003

This study investigated the effect of Yanggyuksanhwa-tang on cerebral ischemia of the rats. Considering age-related impact on cerebral ischemia, aged rats (18 months old) were used for this study. Ischemic damage was induced by the transient occlusion of bilateral common carotid arteries (BCAO) under the hypotension. Yanggyuksanhwa-tang was administered twice orally. Then changes of pyramidal neurons and heat shock protein 72 (HSP72) expressions in ischemic damaged hippocampus were of observed. The BCAO in aged rats led significant decrease of pyramidal neurons in CA1 hippocampus. While the treatment of Yanggyuksanhwa-tang significantly attenuated the reduction of pyramidal neurons in CA1 hippocampus following BCAO ischemia. The BCAO in aged rats led significant increase of HSP72 expression in CA1 and mild in CA3 hippocampus. While the treatment of Yanggyuksanhwa-tang significantly attenuated the increase of HSP72 expression in CA1 hippocampus following BCAO ischemia. The extent of HSP72 expression in CA2 and DG of hippocampus was not different between the sham operated group, the BCAO ischemia control group, and the group of Yanggyuksanhwa-tang administration after BCAO ischemia. The treatment of Yanggyuksanhwa-tang significantly attenuated the increase of normalized optical density depending on HSP72 expression in CA1 hippocampus following BCAO ischemia.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1025-1034
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• 2009

This study was carried out to examine the protective effect of Cultured Wild Ginseng(CWG) on the acute and subacute toxicities induced by doxorubicin(Doxo) in mice. Heart and liver weight was decreased following Doxo administration. In contrast, such a decrease was significantly attenuated by CWG administration. The value of serum CPK in Doxo group was increased compared with normal group. But the value of CWG group were decreased significantly compared with the values of Doxo group in the liver of the Doxo group, cloudy swelling of hepatic cells and narrowing of sinusoids were observed. Whereas in the CWG group, well oriented hepatic cell cords and sinusoids were observed. In the testis of the Doxo group, necrotic and degenerative changes of the seminiferous tubules, especially beneath testicular membrane were observed. But those lesions were alleviated in CWG group. Cross sectional area of testis and diameter of semineferous tubule were significantly increased in CWG group compared with Doxo group. Body weight was reduced in Doxo group compared with normal group. In contrast, such a decrease was significantly attenuated by CWG administration atwa5th day. Spermatogenetic cells in seminiferous tubules were necrotic and desquamated and the cellularity of seminiferous epithelia was reduced in Doxo group. But those lesions were attenuated by CWG administration. Cross sectional area of testis and diameter of seminiferous tubule were significantly increased in CWG group compared with Doxo group. In addition, the increase in lipid peroxidation(LPO) in testis was inaddition, the, iout such a increased was significantly inhibited in CWG group. BrdU labelled cells in the seminiferous tubules were remarkably decreased in Doxo group. Whereas the number of seminiferous tubules labelled with BrdU in spermatogonia was increased by CWG administration. The obtained results suggest that CWG has protective effect on doxorubicin-induced toxicity. This effect might be mediated through the supplementation of vital energy.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.2
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• pp.405-411
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• 2009

This study evaluated the effects of Puerariae Radix on the skeletal muscle atrophy, Muscle atrophy was induced by the sciatic nerve transection in Sprague-Dawley rats, then aqueous-extract of Puerariae Radix was administered for 12 days, Muscle wet weight was measured in soleus, plantaris, and medial gastrocnemius. Muscle fiber type was classified by MHCf immunohistochemistry. Muscle fiber type proportion and cross section area of muscle fiber also was observed in medial gastrocnemius. Bax and Bcl-2 expressions in medial gastrocnemius of the damaged hind limb were evaluated with immunohistochemistry. The results are as follows; Puerariae Radix attenuated muscle atrophy in soleus of the sciatic nerve transectioned rats, but there was statistic significance. Puerariae Radix attenuated significantly atrophy in plantaris at 12 days and in medial gastrocnemius at 8 days and 12 days. Puerariae Radix improved histology of the atrophic changes and increased significantly cross section areas of type-I and type-II muscle fibers in medial gastrocnemius of the sciatic nerve transectioned rats. Puerariae Radix did not affect to muscle fiber type proportion in medial gastrocnemius of the sciatic nerve transectioned rats. Puerariae Radix attenuated significantly Bax positive nuclei but did not affect to Bcl-2 positive muscle fibers in medial gastrocnemius of the sciatic nerve transectioned rats.According to above results, Puerariae Radix may have an anti-atrophy effect on the denervated skeletal muscle through anti-apoptotic effects on muscle fibers.

• Korean Journal of Poultry Science
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• v.26 no.3
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• pp.149-170
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• 1999

Protozoa of the genus Eimeria are the etiologic agents of avian coccidiosis, the most economically important Parasitic disease for the poultry industry. Coccidia multiply in intestinal epithelial cells of a wide range of hosts, including livestock in addition to poultry. Chemotherapy is extensively used to control coccidiosis. However, development of drug resistance by Eimeria parasites, the intensive cost and labor involved in the identification of new anticoccidial compounds and public awareness of drug residues in foods warrant alternative methods to prevent coccidiocic in the fast growing poultry industry. For these reasons, there is a great interest in developing vaccines against avian coccidiosis. Live Eimeria vaccines confer protective immunity, however a significant disadvantage of using these types of vaccines is their pathogenicity. Live parasites with attenuated pathogenicity also usually produce immunity but may revert back to a pathogenic form and may be contaminated with other pathogenic organisms. Killed Eimeria vaccines are safer but, unlike live attenuated vaccines, are not able to generate cytotoxic T lymphocyte responses. Recombinant vaccines are biochemically purified proteins produced by genetic engineering that consist of particular epitopes or metabolites of Eimeria. Unlike live attenuated organisms, recombinant vaccines do not possess as much risk and generally are able to induce both humoral and cell mediated immunity. DNA vaccines consist of genes encoding immunogenic proteins of pathogens that are directly administered into the host in a manner that the gene is expressed and the resulting protein generates a protective immune response. Although all of these different types of vaccines have been applied to coccidiosis, this disease continues to cause substantial morbidity and mortality in the poultry industry. Future development of an effective vaccine against coccidiosis will depend on further investigation of protective immunity to Eimeria infection and identification of important immundgenic parasite molecules.

• Biomedical Science Letters
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• v.11 no.3
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• pp.365-373
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• 2005

The aim of this study was to investigate the alterations in meningeal blood flow by stimulation of trigeminovascular system. An open cranial window was prepared on the right parietal bone of male Sprague-Dawley rats. Trigeminovascular system was stimulated by electrical stimulation of trigeminal ganglion (ETS), somatosensory (whisker) stimulation, or topical applications of capsaicin and neuropeptides including substance P and calcitonin gene-related peptide (CGRP). Neonatal capsaicin pretreatment was performed with subcutaneous administration of capsaicin (50 mg/kg) within the first 24 hours after birth. Changes in regional blood flow of dural artery (rDBF) and pial artery (rPBF) were continuously measured through the cranial window by laser-Doppler flowmetry. Both ETS and capsaicin caused a chain of alterations in rPBF and rDBF responses, i.e., an immediate transient decrease followed by rapid and marked increase in rPBF, which were significantly attenuated not only by pretreatments with L-733,060, a $NK_1$ receptor blocker, $CGRP_{8-37}$, a $CGRP_1$ receptor blocker, and 7-nitroindazole monosodium salt (7-NINA), a neuronal nitric oxide synthase inhibitor but also by neonatal capsaicin treatment. Exogenous neuropeptides including substance P and CGRP increased the meningeal blood flow, which was significantly attenuated not only by pretreatment with L-733,060 and $CGRP_{8-37}$, respectively, but also by pretreatment with 7-NINA. The rPBF response to whisker stimulation was significantly attenuated not only by trigeminovascular system injuries including nasociliary nerve denervation and neonatal capsaicin treatment but also by pretreatments with L-733,060, $CGRP_{8-37}$ and 7-NINA. These results suggest that the stimulation of trigeminovascular system causes prominent alterations in meningeal blood flow, and that neuropeptides as well as nitric oxide in the trigeminovascular system are importantly implicated in the regulation of meningeal blood flow.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5101-5104
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• 2012

Background: Genetic mutation is a significant factor in colon CA pathogenesis. Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary disease characterized by multiple colorectal adenomatous polyps affecting a number of cases in the family. This report focuses on a family with attenuated familial adenomatous polyposis (AFAP) with exon 4 mutation, c.481C>T p.Q161X of the APC gene. Methods: We analyzed 20 members of a family with AFAP. Clinical and endoscopic data were collected for phenotype determination. Genetic analysis was also performed by direct sequencing of the APC gene. Result: Five patients with a phenotype of AFAP were found. Endoscopic polyposis was demonstrated among the second generation with genotype mutation of the disease (age > 50 years) consistent with delayed phenotypic adenomatous polyposis in AFAP. APC gene mutation was identified in exon 4 of the APC gene, with mutation points of c.481C>T p.Q161X. Laparoscopic subtotal colectomy was performed to prevent carcinogenesis. Conclusion: A family with attenuated familial adenomatous polyposis of APC related to exon 4 mutation, c.481C>T p.Q161X, was reported and the phenotypic finding was confirmed by endoscopic examination. Genetic mutation analysis might be advantageous in AFAP for long term colon cancer prevention and management due to subtle or asymptomatic phenotype presentation in early adulthood.