• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.61-66
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• 2001

The aim of this study was to examine how plant terpenoids, as natural growth substrates or inducers, would affect the biodegradation of PCB congeners. Various PCB degraders that could grow on biphenyl and several terpenoids were tested for their PCB degradation capabilities. Degradation activities of the PCB congeners, 4,4-dichlorobiphenyl (4,4-DCBp) and 2,2-dichlorobiphenyl (2,2-DCBp), were initially monitored through a resting cell assay technique that could detect their degradation products. The PCB degraders, Pseudomonas ((S)-(-) limonene, p-cymene and $\alpha$-terpinene) whereas Arthrobacter sp. B1B could not grow on the terpenoids as a sole carbon source. The B1B strain grown on biphenyl exhibited good degradation activity for 4,4-DCBp and 2,2-DCBp, while the activity of strains P166 and T104 was about 25% that of the B1B strain, respectively. Concomitant GC analysis, however, demonstrated that strain T104, grown on (S)-(-) limonene, p-cymene and $\alpha$-terpinene, could degrade 4,4-DCBp up to 30%, equivalent to 50% of the biphenyl induction level. Moreover, strain T104 grown on (S)-(-) limonene, could also degrade 2,2-DCBp up to 30%. This indicates that terpenoids, widely distributed in nature, could be utilized as both growth and/or inducer substrate(s) for PCB biodegradation in the environment.

• The Korean Journal of Physiology
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• 제30권1호
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• pp.77-83
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• 1996

Platelet-activating factor(PAF) is a phospholipid mediator of pulmonary inflammation, and immunologic reaction. In this study, the role of PAF on tumor necrosis factor$(TNF_{-{\alpha}})$ production by rat alveolar macrophages(AM) was examined. When PAF $(10^{-12}{\sim}10{-16}\;M)$ alone was added to AM culture, $(TNF_{-{\alpha}})$ production was not significantly increased above the resting level. In contrast, the combined addition of PAF $(10^{-6}\;M)$ and muramyl dipeptide(MDP) $(1.0\;{\mu}g\ml)$ to AM cultures markedly enhanced $(TNF_{-{\alpha}})$ production with 8.2 fold increase compared with AM culture in resting state. This potentiative effect was 313% above the sum of the separate effects of PAF and MDP. To characterize MDP effects on $(TNF_{-{\alpha}})$ production, the dose-response of AM cultured with various concentrations of MDP was tested. High level of MDP $(10\;{\mu}g\ml)$ could not significantly enhance the potentiation effect on $(TNF_{-{\alpha}})$ production compared with AM cultures with low level of MDP $(0.1\;{\mu}g\ml)$, i.e. 112.5% vs 107.8%, respectively when $10^{-10}$ M of PAF was simultaneously added to the cell culture. These data support that the potentiation of TNF. g production in AM culture is mediated by PAF rather than MDf It was also evaluated whether the similar result was obtained in silica, respirable toxic particle-treated AM culture. $(TNF_{-{\alpha}})$ production was also significantly enhanced in the PAF $(10^{-6}\;M)$ and silica $(50\;{\mu}g\ml)$-added cell cultures with 4.7 fold above the value of silica alone-stimulated cells. These results indicate that PAF can potentiate $(TNF_{-{\alpha}})$ production by MDP-or silica- stimulated AM and suggest that PAF may play a potent role in lung inflammation and disease associated with microbe and occupational dust exposures.

• Journal of Periodontal and Implant Science
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• 제24권3호
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• pp.472-482
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• 1994

Cytokines expressed specifically in leukocytes subsets and in activated cells, which are involved in chemotaxis and activation of leukocytes, are recently defined as chemokines. Macrophage inflammatory $protein-1{\alpha}(MIP-1{\alpha})$ and $MIP-1{\beta}$ are members of C-C chemokine subfamily which produces wide immunomodulatory, proinflammatory, and hematopoietic modulatory actions. We have studied their gene expression by using Northern blot analysis in various blood cells such as cytolytic T lymphocyte(CTL), helper T lymphocyte(HTL), macrophage, and B lymphocyte. Resting CTL line CTLL-R8 expressed $MIP-1{\alpha}$ mRNA which was downregulated by ConA stimulation. Both of resting and ConA stimulated HTL line Hut78 and Jurkat did not express $MIP-1{\alpha}$ mRNA. There was detectable $MIP-1{\alpha}$ transcript in HTL hybridoma 2B4.11 which was a little upstimulated by ConA stimulation. B cell line 230, and macrophage cell line RAW264.7 and WR19M.1 showed distinct $MIP-1{\alpha}$ message which were induced after LPS stimulation. Expression pattern of $MIP-1{\beta}$ in all cell lines or cell were almost identical to that of $MIP-1{\alpha}$. Also strategies employed to identify and characterize the biological functions was preceded by receptor cloning to trace the shorcut to the final goal of cytokine research. For the cloning of $MIP-1{\alpha}$ receptor(R), we used synthetic oligonucleotides of transmembrane(T) conserved sequences of already cloned human(h) IL-8-R, and performed reverse transcription-polymerase chain reaction(RT-PCR) amplification using murine(m) macrophage cell line mRNA. Among 5RT-PCR products, we isolated a homologous cDNA with hIL-8-R which were shown to be putative mIL-8-R cDNA.

• 한국수소및신에너지학회논문집
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• 제21권1호
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• pp.35-41
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• 2010

Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoutic methods is presented. Piezo-actuators which are devices to generate the flexural wave are attached at the end of a cathode bipolar plate. Flexural wave is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

• Biomolecules & Therapeutics
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• 제2권1호
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• pp.16-22
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• 1994

Using 2 to 4 day-old postnatal rats, primary brain cell cultures were made from various brain regions (substantia nigra, hippocampus, striatum, and nucleus accumbens). Whole-cell patch clamp technique was used for electrophysiological studies. Neurons cultured from substantia nigra were characterized more in detail to test whether these cultured neurons were appropriate for physiological studies. Immunocytochemical and electrophysiological properties of these cultured neurons agreed with those from other in vivo or in vitro studies suggesting that cultured neurons maintained normal cytological and physiological conditions. Modulation of ionic channels through dopamine receptors were studied from brain areas where dopamine plays important roles on brain functions. When neurons were clamped near resting membrane potential (-74mV), R(+), R(+)-SKF 38393, a specific D$_1$receptor agonist, activated cultured striatal neurons, and dopamine itself produced biphasic responses. Responses of cultured hippocampal neurons to dopamine agonists were kinds of mirror images to those from striatal neurons; D$_1$receptor agonists inhibited hippocampal neurons but quinpirole, a D$_2$receptor agonist, activated them. Neurons cultured from nucleus accumbens were inhibited by dopamine.

• KSBB Journal
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• 제16권4호
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• pp.356-359
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• 2001

톨루엔을 분해하는 대표적인 미생물로 알려진 Pseudomonas putida를 이용하여 생분해 특성을 살펴보고자 하였다. 톨루엔은 물에 대한 용해도가 매우 낮기 때문에, 호기적 조건으로 배양하는데 어려움이 있다. 톨루엔을 포함하는 배지를 포함한 닫힌 계를 이용함으로써, 반응기 내에서의 톨루엔 분해와 미생물 성장에 관해 살펴보았다. 초기에 액상으로 접종하는 톨루엔의 농도를 변화시켰고, 이에 따른 headspace에서의 톨루엔의 농도와 미생물 균체 농도 변화를 측정하였다. 닫힌계에서의 톨루엔 생분해에 관한 물질 수지식을 세우고 이를 전산 모사함으로써, 실험 값과 비교 분석하였다. Pseudomonas putida의 resting cell을 이용하면 닫힌 계에서도 톨루엔을 분해할 수 있었고, 반응기 내에서 일어나는 현상을 매개 변수를 통해 고찰하였다.

• IMMUNE NETWORK
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• 제22권5호
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• pp.39.1-39.18
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• 2022

RNA metabolism plays a central role in regulating of T cell-mediated immunity. RNA processing, modifications, and regulations of RNA decay influence the tight and rapid regulation of gene expression during T cell phase transition. Thymic selection, quiescence maintenance, activation, differentiation, and effector functions of T cells are dependent on selective RNA modulations. Recent technical improvements have unveiled the complex crosstalk between RNAs and T cells. Moreover, resting T cells contain large amounts of untranslated mRNAs, implying that the regulation of RNA metabolism might be a key step in controlling gene expression. Considering the immunological significance of T cells for disease treatment, an understanding of RNA metabolism in T cells could provide new directions in harnessing T cells for therapeutic implications.

• 한국임상수의학회지
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• 제8권1호
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• pp.1-10
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• 1991

The B-lymphocyte differentiation from committed B-cell progenitors to antibody-secreting cells was discussed. B-cell progenitors derived from hematopoietic stem cells undergo the rearrangement of immunoglobulin(Ig) gene. The earliest cells as B-cell precursors have cytoplasmic Is(${\mu}$ chain). The entire Is molecule is expressed on the surface after synthesis of L chain. The resting B cells(Go stage) stimulated by binding antigen via Ig-receptors are activated(G$_1$ stage) and followed by proliferation(S stage), coupled with further selection(affinity maturation. class switch). The production of antibody against a particular antigen depends on the activation of B cells with surface Is capable of reacting with that antigen. This process does not occur in isolation but is controlled by helper and suppressor T cells and antigen presenting cells(APC). The mechanism of T cell-dependent B-cell response for production of antibody is largely explained by the cell to cell cooperation and soluble helper factors of T cells. 1) The antigen specific B cells and helper T cells are linked by Is-receptors, leading to the delivery of helper signals to the B cells. 2) Helper T cells recognize the processed antigen-derived peptides with the MHC class II molecules(la antigen) and is stimulated to secrete B-cell proliferation and differentiation factors which activate B cells of different antigenic specificity. The two models are shown currently 1) At low antigen concentration, only the antigen-specific B cell binds antigen and presents antigen-derived peptides with la molecules to helper T cells, which are stimulated to secrete cytokines(IL-4, IL-5, etc.) and 2) At high antigen concentration, antigen-derived peptides are presented by specific B cells, by B cells that endocytose the antigens, as well as by APC Cytokines secreted from helper T cells also lead to the activation of B cells and even bystander B cells in the on- vironmment and differentiate them into antibody-secreting plasma cells.

• 대한영양사협회학술지
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• 제14권1호
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• pp.64-76
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• 2008

The purpose of this study was to investigate the change of body composition, biochemical index level, resting metabolic rate and daily activities by the public health center's health-promoted program in overweight middle aged women. The workout program of 12 subjects constituted by exercise(aerobic exercise & resistance training) and nutritional education for 10 weeks. As the results, there was a significant decrease in all the weight(59.0$\pm$8.9 vs 57.2$\pm$8.3kg, p<0.05), body fat percentage(33.4$\pm$4.3 vs 30.5$\pm$4.5%, p<0.05) and body fat mass(19.8$\pm$5.4 vs 17.7$\pm$4.9kg, p<0.05) after program. Fat free mass and RMR which tend to be higher after than before program were found not to be significantly. In addition, the serum HDL-cholesterol(54.3$\pm$8.1 vs 59.7$\pm$13.9mg/dl, p<0.05) and TG level(65.2$\pm$418 vs 89.4$\pm$65.6mg/dl, p<0.05) of the subjects increased at the end of the study significantly and significant correlation found between total-cholesterol and TG before program. When the other laboratory parameter were compared before and after program, hematocrit(35.1$\pm$3.3 vs 39.7$\pm$3.3%, p<0.001), platelet(225.9$\pm$49.6 vs 244.3$\pm$49.7cell/ul, p<0.05) and fasting glucose(88.0$\pm$6.5 vs 76.6$\pm$9.7mg/dl, p<0.001) increased significantly but hemoglobin(13.3$\pm$1.3 vs 12.9$\pm$1.3mg/dl, p<0.01) decreased. And in activities analysis, 'moderate activity(18.8 vs 5.8minutes, p<0.05)' clearly showed a significant decrease but 'severe activity(17.7 vs 11.4minutes, p<0.05)' showed a increase. These results suggest that continuous health-promoted program involved exercise and nutritional education at the public health center are effective to reduce body fat and to improve resting metabolic rate(RMR). Further research is required to develop more effective public health program for the middle aged women in community.

• 생약학회지
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• 제25권4호통권99호
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• pp.348-355
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• 1994

An antitumor component, F-D-P, was purified from the hot water extract of the carpophores of Elfvingia applanata by precipitation with ethanol, dialysis, and passage through a column of DEAE-cellulose ion exchange. F-D-P inhibited the growth of Sarcoma 180 in mice showing the tumor inhibition ratio of 88.3% in doses of 20 mg/kg for ten days. Chemical analysis of F-D-P showed that it was composed of polysaccharide(65.3%) and protein(6.5%0, and that the monosaccharides consisting of the polysaccharide was glucose(89.1%) and mannose(10.9%). The immunomodulatory activities of F-D-P were explored by determining its effect on the proliferation of the whole and subpopulations of lymphocytes, and on the generation of natural killer(NK) cell activity in vitro. F-D-P was mitogenic to total lymphocytes and B cells, but not to purified T cells, even in the presence of accessory cells. F-D-P did not increase NK cell activity when added to cultures of resting lymphocytes. From these results, it is clear that F-D-P modulates primarily the humoral immune responeses.