• Clinical and Experimental Pediatrics
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• v.50 no.12
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• pp.1165-1172
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• 2007

Self/non-self discrimination and unresponsiveness to self is the fundamental properties of the immune system. Self-tolerance is a state in which the individual is incapable of developing an immune response to an individual's own antigens and it underlies the ability to remain tolerant of individual's own tissue components. Several mechanisms have been postulated to explain the tolerant state. They can be broadly classified into two groups: central tolerance and peripheral tolerance. Several mechanisms exist, some of which are shared between T cells and B cells. In central tolerance, the recognition of self-antigen by lymphocytes in bone marrow or thymus during development is required, resulting in receptor editing (revision), clonal deletion, anergy or generation of regulatory T cells. Not all self-reactive B or T cells are centrally purged from the repertoire. Additional mechanisms of peripheral tolerance are required, such as anergy, suppression, deletion or clonal ignorance. Tolerance is antigen specific. Generating and maintaining the self-tolerance for T cells and B cells are complex. Failure of self-tolerance results in immune responses against self-antigens. Such reactions are called autoimmunity and may give rise to autoimmune diseases. Development of autoimmune disease is affected by properties of the genes of the individual and the environment, both infectious and non-infectious. The host's genes affect its susceptibility to autoimmunity and the environmental factors promote the activation of self-reactive lymphocytes, developing the autoimmunity. The changes in participating antigens (epitope spreading), cells, cytokines or other inflammatory mediators contribute to the progress from initial activation to a chronic state of autoimmune diseases.

• Journal of the korean veterinary medical association
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• v.32 no.1
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• pp.43-51
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• 1996

경구적으로 투여된 항원에 대해서 특이적으로 T세포의 기능과 항체산생이 억제되는 현상이 경구면역관용(oral tolerance)인 것이다. 지금까지 해석이 곤란하였던 이 현상에 대해서 최근 분자생물학적인 기법이 적용되기 시작한 결과, 이 현상에 관여하는 세포가 주로 $CD8^+$ T세포에의한 억제 혹은 $CD4^+$T세포의 불응답(unresponsiveness)에 기인하다는 것이 명백해졌다. 또한 각종 cytokine중 IFN$\gamma$, TGF$\beta$, IL-10 등이 이 현상에 있어 중요한 역할을 담당한다는 것이 밝혀지고 있다. 사실 경구면역관용은 말초면역관용을 야기한다는 것이 오래전부터 알려진 한 방도이다. 경구적으로 투여된 항원이 관용을 야기하는 일차적인 기전은 능동적인 억제의 발생 혹은 clone성 anergy(과민증에 대한 무감증)에 의거하는 것이다. 낮은 량의 경구투여항원은 능동적인 억제를 야기하기 쉬우나 반대로 높은 양의 경구투여항원은 clone성 anergy를 야기하는 경향이 있다. 능동적인 억제를 매개하는 조절세포는 경구면역관용에 의해서 격발된 후 TGF$\beta$및 IL-4와 같은 억제성 cytokine의 분비에 의해서 능동적 억제작용을 한다. 더구나 GALT(gut-associated lymphoid tissue)를 선별적으로 자극하는 항원은 Th2형 세포반응을 발생한다. 또한 이와같은 유도기구의 해석과 동시에 사람에서 면역반응의 이상으로 야기되는 관절 rheumatism이나 다발성경화증(multiple sclerosis) 그리고 각종 allergy도 이 경구면역관용을 이용하여 치료하는 것이 가능하게 되었다는 것이다.

• Tuberculosis and Respiratory Diseases
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• v.39 no.4
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• pp.334-342
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• 1992

Background: The activated T lymphocyte by inhalaed mycobacterial antigen may evoke cell-mediated immunity in patients with active pulmonary tuberculosis. These activated lymphocyte may influence the response of tuberculin-purified protein derivative (PPD) in skin test. But occasionally, anergy to PPD appear in patients with pulmonary tuberculosis in spite of active stage. Thus we evaluated the effect of change of subtypes of lymphocyte in bronchoalveolar lavage fluid (BAL) and peripheral blood on anergy to PPD in patients with active pulmonary tuberculosis. Method: We performed tuberculin skin test and flow-cytometry analysis of lymphocytes obtained from BAL fluid and peripheral blood in 11 healthy normal volunteers and 20 patients with active pulmonary tuberculosis. Results: 1) The composition of lymphocyte significantly increased in patients with active pulmonary tuberculosis when compared with that in healthy control ($25.2{\pm}4.8$ vs $6.5{\pm}1.3%$, p<0.01), but composition of monocyte significantly decreased ($69.6{\pm}5.7$ vs $89.2{\pm}1.4%$, p<0.05) in analysis of BAL fluid. 2) There were no differences in compositions of cells in BAL fluid between responders and no-responders to PPD. 3) The compositions of CD3 (+), CD4 (+), CD3 (+) IL-2R (+), CD3 (+) HLA-DR (+) significantly increased in BAL fluid when compared with those in peripheral blood in patients with active pulmonary tuberculosis. But the composition of CDS (+), CD4/CDS were not different between BAL fluid and peripheral blood. 4) There were no correlations between response to PPD and compositions of cells and lymphocyte subtypes in BAL fluid and peripheral blood in all patients with tuberculosis, responders, and no-responders, respectively. Conclusion: From these results, we suggest no direct relationship between compositions of inflammatory cells in bronchoalveolar lavage fluid and we could not rule out the possibility of compartmentalization of activated lymphocyte involving in anergy to PPD in skin test in patients with active pulmonary tuberculosis.

• Environmental and Resource Economics Review
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• v.14 no.4
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• pp.839-866
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• 2005

This study addresses the effects on the economy of atomic sector's R&D by considering how much KAERI's R&D expenditures in 2000 affect on the production and value-added of each industry and the whole economy. This study answers to the question using competitive import input-output tables and both supply driven and demand driven IO models, which are frequently employed in evaluating economic impacts of R&D in both domestic and foreign academic areas.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.10a
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• pp.271-274
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• 1997

This paper presents an adaptive quantization of image sequences using the Radial Basis Function Network(RBFN) which classifies interframe image blocks. The clssification algorithm consists of two steps. Blocks are classified into NA(No Activity), SA(Small Activity), VA(Verical Activity), and HA(Horizontal Activity) classes according to edges, image activity and AC anergy distribution. RBFN is trained using the classification results of the above algorithm, which are nonlinear classification features are acquired from the complexity and variability of difference blocks. Simulation result shows that the the adaptive quantization using the RBFN method produced better results better results than that of the sorting and MLP methods.

• Journal of the Korean Society for Heat Treatment
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• v.6 no.3
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• pp.159-165
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• 1993

Creep tests of the TiC particulate reinforced Al composite have been conducted in the temperature ranges from 200 to $500^{\circ}C$. The steady-state cree rate of the composite depended strongly on the temperature and ap' plied stress. The stress exponent for the steady state creep rate of the composites was approximately 17.5 and the activation anergy was calculated to be 390KJ/mol. The steady-state creep equation could be written as $\acute{\varepsilon}_{ss}$ $$(s^{-1})=1.5{\times}10^{-9}\;{\sigma}^{17.5}\exp(-390000/RT)$$. Fracture surface examination showed that the fracture mode of the particulate reinforced composite was ductile by plastic tearing of the aluminum matrix and TiC particle interfaces were offered as sites for crack.

• Journal of Life Science
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• v.25 no.12
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• pp.1425-1431
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• 2015

The lymphocyte component of the immune system is divided into B lymphocytes and T lymphocytes. B lymphocytes produce antibodies (humoral immunity) via maturation into plasma cells, and T lymphocytes kill other cells or organisms (cellular immunity). A traditional immunological paradigm is that B lymphocyte and T lymphocyte interactions are a one-way phenomenon, with T lymphocytes helping to induce the terminal differentiation of B lymphocytes into immunoglobulin class-switched plasma cells. A deficiency of T lymphocytes was reported to result in defective B lymphocyte function. However, evidence for a reciprocal interaction between B and T lymphocytes is emerging, with B lymphocytes influencing the differentiation and effector function of T lymphocytes. For example, B lymphocytes have been shown to induce direct tolerance of antigen-specific CD8⁺ T lymphocytes and induce T lymphocytes anergy via transforming growth factor-beta (TGF-β) production. The present study showed that LPS-stimulated B lymphocytes inhibited the differentiation of Th1 lymphocytes by inhibiting the production of interleukin-12 (IL-12) from dendritic cells. An interaction between the B lymphocytes and dendritic cells was not needed for this inhibition, and the B lymphocytes did not alter dendritic cell maturation. B lymphocyte-derived soluble factor (BDSF) suppressed the LPS-induced IL-12p35 transcription in the dendritic cells. Overall, these results point to a novel B lymphocyte- mediated immune suppressive mechanism. The findings cast doubt on the traditional paradigm of immunological interactions involving B lymphocyte and T lymphocyte interactions.

• Journal of Chest Surgery
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• v.12 no.1
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• pp.16-22
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• 1979

Clinical evaluation of contact sensitization to 2, 4-dinitro-chlorobenzene [DNCB] was performed in 2 groups: group A [30 patients with non-malignant disease] and group B [30 patients with bronchogenic carcinoma]. Initial sensitization was elicited out by applying 2, 000 ug of DNCB to skin surface of the both group A and B. Subsequently a relatively weak challenge dose, 200 ug of DNCB, was applied 14 days later, showing the satisfactory results of sensitization with minimizing non-specific irritative inflammatory skin response. Delayed cutaneous hypersensitivity reactions shown by spontaneous flare phenomena appeared at the challenge site, and they were assessed 48 hours later. The reaction were graded from +1 to +4 according to the degree of flare or vesicular reaction. The results were as follows: 1. 28 cases [93%] of group A, however, only 18 cases [67%] of group B exhibited delayed cutaneous hypersensitivity reaction to DNCB contact sensitization [P<0.02]. 2. Of group A, the delayed cutaneous hypersensitivity reactions above +2 of DNCB score were 25 cases [83%], meanwhile 11 cases [37%] in group B [P<0.001]. 3. Undifferentiated carcinomas showed highest incidence of anergy to DNCB contact sensitization in the all histologic types of group B. 4. In group B, 8 [42%] of 19 cases who react to DNCB were resectable, whereas only 2 [18 %] of 11 cases who failed to react to DNCB were resectable for curative cancer surgery. These study suggests that cellular immune reaction of group B was depressed remarkably comparing with that of group A.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.1
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• pp.65-72
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• 2012

Rankine cycle using ammonia-water mixture as a working fluid has attracted much attention, since it may be a very useful device to extract power from low-temperature heat source. In this work, the thermodynamic performance of regenerative ammonia-water Rankine cycle is thoroughly investigated based on the second law of thermodynamics and exergy analysis, when the energy source is low-temperature heat source in the form of sensible energy. In analyzing the power cycle, several key system parameters such as ammonia mass concentration in the mixture and turbine inlet pressure are studied to examine their effects on the system performance including exergy destructions or anergies of system components, efficiencies based on the first and second laws of thermodynamics. The results show that as the ammonia concentration increases, exergy exhaust increases but exergy destruction at the heat exchanger increases. The second-law efficiency has an optimum value with respect to the ammonia concentration.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1534-1540
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• 2005

In order to testify the urate lowering effects of Daihwangmudan-tang(DMT), ICR mice were injected monosodium urate into the abdominal cavity and then DMT was administered on 2 and 4 days after Injection. Uric acid and triglyceride were measured as hematological indices of gout, and some genes related with this change were identified by ACP based GeneFishing PCR method and direct sequencing. From this experiment, DMT highly decreased the blood levels of uric acid and significantly suppressed and lowered the acute increment of triglyceride level. There were 11 differentially expressed genes(DEG) having relations with positive actions of DMT, and 4 major genes in the middle of DEGs were sequenced; Mfap 2, jagged 2, Hsd17b7, DkkI-1, These genes were supposed that several mechanisms through interleukin 1 and T-cell anergy, LDL cholesterol metabolism, wnt pathway would be related with the anti-inflammation effect against gout.