• IMMUNE NETWORK
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• 제15권3호
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• pp.111-120
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• 2015

Dendritic cells (DCs) play a significant role in establishing self-tolerance through their ability to present self-antigens to developing T cells in the thymus. DCs are predominantly localized in the medullary region of thymus and present a broad range of self-antigens, which include tissue-restricted antigens expressed and transferred from medullary thymic epithelial cells, circulating antigens directly captured by thymic DCs through coticomedullary junction blood vessels, and peripheral tissue antigens captured and transported by peripheral tissue DCs homing to the thymus. When antigen-presenting DCs make a high affinity interaction with antigen-specific thymocytes, this interaction drives the interacting thymocytes to death, a process often referred to as negative selection, which fundamentally blocks the self-reactive thymocytes from differentiating into mature T cells. Alternatively, the interacting thymocytes differentiate into the regulatory T (Treg) cells, a distinct T cell subset with potent immune suppressive activities. The specific mechanisms by which thymic DCs differentiate Treg cells have been proposed by several laboratories. Here, we review the literatures that elucidate the contribution of thymic DCs to negative selection and Treg cell differentiation, and discusses its potential mechanisms and future directions.

• Toxicological Research
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• 제20권4호
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• pp.315-320
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• 2004

In this study we assessed the influences of ultraviolet (UV) light B radiation on epidermal ATPase-positive dendritic cell (DC) and the effect of green tea treatment in ICR mouse. The extent of changes following 200 mJ/$cm^2$ (0.5 mW/sec) was studied at 0, 6, 12, 18, 24, 30 or 36 hours after exposure. SBCs were decreased by 6 hours after irradiation. There was tendency to decrease from 6 hours to 24 hours and had little further change from then to 36 hours after irradiation. The mice that received 0, 50, 100, 200, 300 or 400 mJ/$cm^2$ of UVB were examined 24 hours after irradiation. The DCs were decreased as the radiation dose increases from 100 to 400 mJ/$cm^2$. The frequency of UVB (200 mJ/$cm^2$)-induced DC decrease was reduced by treatment of green tea (i.p. and topical application, p<0.01).

• Applied Microscopy
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• 제27권1호
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• pp.57-70
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• 1997

개의 교핵내 glutamate를 함유한 연접 구조의 분포를 fixative-modified glutamate에 대한 monoclonal antibody를 사용하여 미세구조적 차원에서 조사하였다. 반응산물은 신경세포체의 핵주위 영역에 위치하였으며, 가지돌기내의 미세소관을 따라서 존재하였다. 반응산물을 함유하지 않은 한 개이상의 신경종말이 glutamate에 면역반응을 나타낸 가지돌기와 비대칭형 연접을 형성하였다. 그 외에도 수초로 둘러싸인 축삭돌기나 신경종말내에서도 반응산물이 관찰되었다. 이들 신경종말은 표지된 또는 표지되지않은 가지돌기와 비대칭형 연접을 형성하였다. 이상의 관찰은 glutamate에 면역반응을 나타내는 흥분성 교핵 신경원이, glutamate를 함유한 교핵으로의 여러 수입계나, 교핵으로부터 소뇌로의 투사 신경세포, 그리고 소뇌피질내의 glutamate성 과립세포를 포괄하는 다연접 신경경로에서 어떤 역할을 수행하는지에 관한 형태학적 근거를 제시한다.

• Applied Microscopy
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• 제25권1호
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• pp.65-74
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• 1995

개의 교핵내의 GABA를 함유한 억제성 신경세포의 연접부위를 전자현미경을 이용한 면역세포화학적 방법으로 조사하였다. 반응산물은 신경원의 핵부위나 가지돌기에서 관찰되었으며, 반응산물을 포함하고 있지 않은 신경종말이 이들과 비대칭형 연접을 형성하였다. 그 외에도 많은 수의 GABA성 신경종말이 관찰되었으며, 이들은 반응산물을 함유하지 않은 가지돌기와 대칭형 또는 비대칭형 연접을 형성하였다. 한편 축삭돌기-축삭돌기 연접에서는 연접후 유축사돌기 (axon-like processes)가 GABA-양성이었다. 이와 같은 관찰은 개의 교핵에 존재하는 억제성 개재신경원이 여러 수입계로부터의 정보를 통합하고, 이를 소뇌피질이나 소뇌핵에 전달함으로써, 대뇌-교핵-소뇌계의 신경경로에서 조절기능을 담당함을 뒷받침하는 것이다.

• Journal of Korean Society for Atmospheric Environment
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• 제17권E2호
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• pp.53-59
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• 2001

A hybrid dust-collector combining electrostatic charging with fabric filtration method was developed, and its performance characteristics were evaluated in this study. Charged particles build porous dendritic structure on the surfaces of filter by electrostatic attraction, increasing the collection efficiency of dust particles and reducing the pressure drop through the deposited dust layer and filter media. The cleaning performance of the dust layer is improved because the dendritic structured dust layer can be removed more easily by pulse jet cleaning flow. The results of the experiment showed a reduction of fine particle emission of 37% and the energy saving of 13% by precharging dust particles before filtration.

• 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.

• IMMUNE NETWORK
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• 제11권6호
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• pp.364-367
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• 2011

Background: Prostaglandins (PGs) play pathogenic and protective roles in inflammatory diseases. The novel concept of PGs as immune modulators is being documented by several investigators. By establishing an in vitro experimental model containing human follicular dendritic cell-like cells, HK cells, we reported that HK cells produce prostaglandin $E_2$ ($PGE_2$) and prostaglandin $I_2$ ($PGI_2$) and that these PGs regulate biological functions of T and B cells. Methods: To investigate the respective contribution of cyclooxygenase-1 (COX-1) and COX-2 to $PGE_2$ and $PGI_2$ production in HK cells, we performed siRNA technology to knock down COX enzymes and examined the effect on PG production. Results: Both $PGE_2$ and $PGI_2$ productions were almost completely inhibited by the depletion of COX-2. In contrast, COX-1 knockdown did not significantly affect PG production induced by lipopolysaccharide (LPS). Conclusion: The current results suggest that mPGES-1 and PGIS are coupled with COX-2 but not with COX-1 in human follicular dendritic cell (FDC) and may help understand the potential effects of selective COX inhibitors on the humoral immunity.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.422-426
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• 2018

The lithium-ion battery pack of an electric vehicle (EV) deserves to be considered for an alternative use within smart-grid infrastructure. Despite the long automotive service life, EV batteries retain over 70~80% of their initial capacity. These battery packs must be managed for their reliability and safety. Therefore, a battery management system (BMS) should use specific algorithms to measure and estimate the status of the battery. Most importantly, the BMS of a grid-connected energy storage system (ESS) must ensure that the lithium-ion battery does not catch fire or explode due to an internal short from uncontrolled dendrite growth. In other words, the BMS of a lithium-ion battery pack should be capable of detecting the battery's status based on the electrochemical reaction continuously until the end of the battery's lifespan. In this paper, we propose a new protection algorithm for a dendritic lithium battery. The proposed algorithm has applied a parameter from battery pack aging results and has control power managing.

• Molecules and Cells
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• 제37권3호
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• pp.248-256
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• 2014

N-acetylglucosamine kinase (GlcNAc kinase or NAGK; EC 2.7.1.59) is a N-acetylhexosamine kinase that belong to the sugar kinase/heat shock protein 70/actin superfamily. In this study, we investigated both the expression and function of NAGK in neurons. Immunohistochemistry of rat brain sections showed that NAGK was expressed at high levels in neurons but at low levels in astrocytes. Immunocytochemistry of rat hippocampal dissociate cultures confirmed these findings and showed that NAGK was also expressed at low levels in oligodendrocytes. Furthermore, several NAGK clusters were observed in the nucleoplasm of both neuron and glia. The overexpression of EGFP- or RFP (DsRed2)-tagged NAGK in rat hippocampal neurons (DIV 5-9) increased the complexity of dendritic architecture by increasing the numbers of primary dendrites and dendritic branches. In contrast, knockdown of NAGK by shRNA resulted in dendrite degeneration, and this was prevented by the co-expression of RFP-tagged NAGK. These results suggest that the upregulation of dendritic complexity is a non-canonical function of NAGK.

• 한국표면공학회지
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• 제36권6호
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• pp.480-490
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• 2003

Effects of plasma-nitriding on the pitting corrosion of Fe-30at%Al-5at%Cr alloy containing Ti, Hf, and Zr were investigated using potentiostat in 0.1M HCl. The specimen was casted by the vacuum arc melting. The subsequent homogenization was carried out in Ar gas atmosphere at $1000^{\circ}C$ for 7days and phase stabilizing heat treatment was carried out in Ar gas atmosphere at $500^{\circ}C$ for 5 days. The specimen was nitrided in the $N_2$, and $H_2$, (1:1) mixed gas of $10^{-4}$ torr at $480^{\circ}C$ for 10 hrs. After the corrosion tests, the surface of the tested specimens were observed by the optical microscopy and scanning electron microscopy(SEM). For Fe-30at%Al-5Cr alloy, the addition of Hf has equi-axied structure and addition of Zr showed dendritic structure. For Fe-30at%Al-5Cr alloy containing Ti, plasma nitriding proved beneficial to decrease the pitting corrosion attack by increasing pitting potential due to formation of TiN film. Addition of Hf and Zr resulted in a higher activation current density and also a lower pitting potential. These results indicated the role of dendritic structure in decreasing the pitting corrosion resistance of Fe-30Al-5Cr alloy. Ti addition to Fe-30Al-5Cr decreased the number and size of pits. In the case of Zr and Hf addition, the pits nucleated remarkably at dendritic branches.