• 한국운동역학회지
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• 제32권3호
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• pp.94-102
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• 2022

Objective: The purpose of this study was to investigate the effect of acute transcranial direct current stimulation (tDCS) on the isokinetic muscular endurance of the lower extremity for young adults. Method: Thirteen young adults performed isokinetic fatigue tasks for two experimental conditions including real tDCS and sham stimulation protocols. Before and after the task, the tensiomyography was used for evaluating muscle contraction characteristics of vastus medialis and semitendinosus. Paired t-test was performed to compare the fatigue index, changes in maximum radial displacement (∆Dm), delay time (∆Tc), and velocity of contraction (∆Vc) between tDCS conditions. Results: We found no significant differences in the fatigue index between real and sham conditions. In addition, the analyses identified no significant different values of ∆Dm, ∆Tc, and ∆Vc in the vastus medialis and semitendinosus between real and sham conditions. Conclusion: These findings suggest that the tDCS protocols may have no acute effect on lower limb muscle endurance for young adults. Future studies should consider the long-term effects of repetitive tDCS sessions, various stimulation positions, exercise tasks, and participant characteristics to more clearly understand the effect of tDCS on muscle endurance of lower extremities.

• Archives of Pharmacal Research
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• 제22권4호
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• pp.340-347
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• 1999

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with none marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocutured DCs was able to induce complete protectiv immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DC s induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be used for designing tumor vaccines using DCs when the information about tumor antigens is limited.

• IMMUNE NETWORK
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• 제10권3호
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• pp.92-98
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• 2010

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to relieve pain, reduce fever and inhibit inflammation. NSAIDs function mainly through inhibition of cyclooxygenase (COX). Growing evidence suggests that NSAIDs also have immunomodulatory effects on T and B cells. Here we examined the effects of NSAIDs on the antigen presenting function of dendritic cells (DCs). Methods: DCs were cultured in the presence of aspirin or ibuprofen, and then allowed to phagocytose biodegradable microspheres containing ovalbumin (OVA). After washing and fixing, the efficacy of OVA peptide presentation by DCs was evaluated using OVA-specific CD8 and CD4 T cells. Results: Aspirin and ibuprofen at high concentrations inhibited both MHC class I and class II-restricted presentation of OVA in DCs. In addition, the DCs generated in the presence of low concentrations of the drugs exhibit a profoundly suppressed capability to present MHC-restricted antigens. Aspirin and ibuprofen did not inhibit the phagocytic activity of DCs, the expression level of total MHC molecules and co-stimulatory molecules on DCs. Ibuprofen rather increased the expression level of total MHC molecules and co-stimulatory molecules on DCs. Conclusion: These results demonstrate that aspirin and ibuprofen inhibit the intracellular processing event of the phagocytosed antigen, and further suggest that prolonged administration of NSAIDs in high doses may impair the capability of DCs to present antigens in asiociation with MHC molecules.

• The Korean Journal of Physiology and Pharmacology
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• 제7권5호
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• pp.255-259
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• 2003

Dendritic cells (DCs) play a critical role in various immune responses involving $CD4^+$ T cells and have been used to generate anti-tumor immunity. Chemotherapy induces severe side effects including immunosuppression in patients with cancer. Although immunosuppression has been studied, the effects of anticancer drugs on DCs are not fully determined. In this study, we demonstrated that CD40 activation strongly protected DCs from 5-fluorouracil (5-FU) or mitomycin C-induced apoptosis. DCspecific surface markers, including CD11c and major histocompatibility complex (MHC) class II, were used for identifying DCs. CD 40 activation with anti-CD40 mAb significantly enhanced the viability of DCs treated with 5-FU or mitomycin C, assayed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). Fluorescence staining and analysis clearly confirmed the enhancing effect of anti-CD40 mAb on the viability of DCs, suggesting that CD40 activation may transduce critical signals for the viability of DCs. Annexin V staining assay showed that CD40 significantly protected DCs from 5-FU or mitomycin C-induced apoptosis. Taken together, this study shows that CD40 activation with anti-CD40 mAb has strong anti-apoptosis effect on DCs, suggesting that CD40 activation may overcome the immunosuppression, especially downregulation of number and function of DCs in chemotherapy-treated cancer patients.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2665-2669
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• 2015

CD4+CD25+regulatory T cells (Tregs) play a key role in regulation of immnue response and maintenance of self-tolerance. Studies have found Tregs could suppress tumor-specific T cell-mediated immune response and promote cancer progression. Depletion of Tregs can enhance antitumor immunity. Dendritic cells (DCs) are professional antigen-presenting cells and capable of activating antigen-specific immune responses, which make them ideal candidate for cancer immunotherapy. Now various DC vaccines are considered as effective treatment for cancers. The aim of this study was to evaluate variation of Tregs in BALB/C mice with hepatocellular carcinoma and investigate the interaction between tumor-derived Tregs, effector T cells (Teff) and splenic DCs. We found the percentages of Tregs/CD4+ in the peripheral blood of tumor-bearing mice were higher than in normal mice. Tumor-derived Tregs diminished the up-regulation of costimulatory molecule expression on splenic DCs, even in the presence of Teff cells and simultaneously inhibited IL-12 and $TNF-{\alpha}$ secretion by DCs.

• IMMUNE NETWORK
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• 제10권6호
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• pp.206-211
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• 2010

Background: Dendritic cell (DC)-based tumor vaccine is an attractive modality for the treatment of colon cancer because it has been recurred and produced few side effects in patients. Secretory glycoprotein 90K has been found at elevated level in various cancer tissues and sera. We investigated to establish a more effective DC vaccine for the treatment of colon cancer in which the levels of 90K are elevated. Methods: We obtained the concentrated 90K from 293T cells stably expressing 90K. DCs were cultured from peripheral blood monocytes, and a DC vaccine pulsed with tumor lysate was compared with a DC vaccine pulsed with 90K. We measured the functional activity for CTLs by using IFN-${\gamma}$-enzyme linked immunoabsorbent spot (ELISPOT) assay. Results: DCs pulsed with tumor lysate+90K exhibited the enhanced T cell stimulation, polarization of $\ddot{i}$ T cell toward Th1. The CTLs generated by DCs pulsed with 90K efficiently lysed HCT116 cells. The results indicate that 90K-speicifc-CTLs can recognize 90K proteins naturally presented by colon cancer cells. Conclusion: Our study suggests that 90K-specific CTLs generated by 90K-pulsed DCs could be useful effector cells for immunotherapy in colon cancer.

• The Journal of Korean Physical Therapy
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• 제21권4호
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• pp.73-79
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• 2009

Purpose: Recently, neurostimulation studies involving manipulation of cortical excitability of the human brain have been increasingly attempted. We investigated whether transcranial direct current stimulation (tDCS) applied to the underlying cerebral cortex, directly induces cortical activation during fMRI scanning. Methods: We recently recruited five healthy subjects without a neurological or psychiatric history and who were right-handed, as verified by the modified Edinburg Handedness Inventory. fMRI was done while constant anodal tDCS was delivered to the underlying SM1 area?? immediately after the pre-stimulation for eighteen minutes. Results: Group analysis yielded an averaged map that showed that the SM1 area and the superior parietal cortex in the ipsilateral hemisphere were activated. The voxel size and peak intensity were, respectively, 82 and 5.22 in the SM1, and 85 and 5.77 in the superior parietal cortex. Conclusion: Cortical activation can be induced by constant anodal tDCS of the underlying motor cortex. This suggests that tDCS may be an effective therapeutic device for enhancing? physical motor function by modulating neural excitability of the motor cortex.

• IMMUNE NETWORK
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• 제3권3호
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• pp.188-200
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• 2003

Background: Immunization of dendritic cells (DCs) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL) that are responsible for protection and regression. In this study, we examined whether the uptake of necrotic tumor cells could modulate DC phenotypes and whether the immunization of necrotic tumor cell-loaded DCs could elicit efficient tumor specific immune responses followed by a regression of established tumor burdens. Methods: We prepared necrotic tumor cell-pulsed DCs for the therapeutic vaccination and investigated their phenotypic characteristics, the immune responses induced by these DCs, and therapeutic vaccine efficacy against colon carcinoma in vivo. Several parameters including phagocytosis of tumor cells, surface antigen expression, chemokine receptor expression, IL-12 production, and NK as well as CTL activation were assessed to characterize the immune response. Results: DCs derived from mouse bone marrow efficiently phagocytosed necrotic tumor cells and after the uptake, they produced remarkably increased levels of IL-12. A decreased CCR1 and increased CCR7 expression on DCs was also observed after the tumor uptake, suggesting that antigen uptake could induce DC maturation. Furthermore, co-culturing of DCs with NK cells in vitro enhanced IL-12 production in DCs and IFN-${\gamma}$ production in NK cells, which was significantly dependent on IL-12 production and cell-to-cell contact. Immunization of necrotic tumor cell-loaded DCs induced cytotoxic T lymphocytes as well as NK activation, and protected mice against subsequent tumor challenge. In addition, intratumoral or contra-lateral immunization of these DCs not only inhibited the growth of established tumors, but also eradicated tumors in more than 60% of tumor-bearing mice. Conclusion: Our data indicate that production of IL-12, chemokine receptor expression and NK as well as CTL activation may serve as major parameters in assessing the effect of tumor cell-pulsed DC vaccine. Therefore, DCs loaded with necrotic tumor cells offer a rational strategy to treat tumors and eventually lead to prolonged survival.

• IMMUNE NETWORK
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• 제14권3호
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• pp.128-137
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• 2014

Respiratory viruses can induce acute respiratory disease. Clinical symptoms and manifestations are dependent on interactions between the virus and host immune system. Dendritic cells (DCs), along with alveolar macrophages, constitute the first line of sentinel cells in the innate immune response against respiratory viral infection. DCs play an essential role in regulating the immune response by bridging innate and adaptive immunity. In the steady state, lung DCs can be subdivided into $CD103^+$ conventional DCs (cDCs), $CD11b^+$ cDCs, and plasmacytoid DCs (pDCs). In the inflammatory state, like a respiratory viral infection, monocyte-derived DCs (moDCs) are recruited to the lung. In inflammatory lung, discrimination between moDCs and $CD11b^+$ DCs in the inflamed lung has been a critical challenge in understanding their role in the antiviral response. In particular, $CD103^+$ cDCs migrate from the intraepithelial base to the draining mediastinal lymph nodes to primarily induce the $CD8^+$ T cell response against the invading virus. Lymphoid $CD8{\alpha}^+$ cDCs, which have a developmental relationship with $CD103^+$ cDCs, also play an important role in viral antigen presentation. Moreover, pDCs have been reported to promote an antiviral response by inducing type I interferon production rather than adaptive immunity. However, the role of these cells in respiratory infections remains unclear. These different DC subsets have functional specialization against respiratory viral infection. Under certain viral infection, contextually controlling the balance of these specialized DC subsets is important for an effective immune response and maintenance of homeostasis.

• The Journal of Korean Physical Therapy
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• 제27권1호
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• pp.38-42
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• 2015

Purpose: Accuracy and variability of movement in daily life require synchronization of muscular activities through a specific chronological order of motor performance, which is controlled by higher neural substrates and/or lower motor centers. We attempted to investigate whether transcranial direct current stimulation (tDCS) over primary sensorimotor areas (SM1) could influence movement variability in healthy subjects, using a tapping task. Methods: Twenty six right-handed healthy subjects with no neurological or psychiatric disorders participated in this study. They were randomly and equally assigned to the real tDCS group or sham control group. Direct current with intensity of 1 mA was delivered over their right SM1 for 15 minutes. For estimation of movement variability before and after tDCS, tapping task was measured, and variability was calculated as standard deviation of the inter-tap interval (SD-ITI). Results: At the baseline test, there was no significant difference in SD-ITI between the two groups. In two-way ANOVA with repeated measurement no significant differences were found in a large main effect of group and interaction effect between two main factors (i.e., group factor and time factor (pre-post test)). However, significant findings were observed in a large main effect of the pre-post test. Conclusion: Our findings showed that the anodal tDCS over SM1 for 15 minutes with intensity of 1 mA could enhance consistency of motor execution in a repetitive-simple tapping task. We suggest that tDCS has potential as an adjuvant brain facilitator for improving rhythm and consistency of movement in healthy individuals.