• 한국미생물·생명공학회지
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• 제16권5호
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• pp.358-362
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• 1988

세포외 효소를 효율적으로 생산하기 위한 새로운 발효시스템으로서 수성 2상계를 시험하였다. 실험대상으로는 Bacillus amyloliquefaciens 균주에 의하여 $\alpha$-amylase를 생산하는 시스템을 선정하였다. Polyethylene glycol 5%, dextran 7%, 그리고 발효액이 88% 포함된 수성 2상계 발효시스템에 의하여 $\alpha$-amylase의 생합성은 25% 정도 증가하였으며 효소의 비활성화는 관찰되지 않았다. 또한 Polyethylene glycol 이 효소의 생합성을 증진시키는 것으로 관찰되었다. 효소의 생합성을 증가시키며 동시에 효소를 발효액으로부터 분리하기 위하여는 polyethylene glycol을 성장도중에, dextran은 효소의 활성이 최고에 달한 후에 발효액에 가하는 발효방법이 바람직하다.

• 인지과학
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• 제21권3호
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• pp.409-427
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• 2010

창의성과 지식의 관계를 설명하는 심리학적인 연구는 크게 긴장적 관점과 토대적 관점의 두 관점이 적용되어 오고 있으나, 기존의 연구들은 대부분 창의적 수행 결과를 토대로 한 창의적 산물 중심의 연구로서 창의적 사고 과정에 관한 정보를 제공해주는 데에는 한계점을 지니고 있다. 본 연구에서는 사고 과정에 관한 정보를 제공해줄 수 있는 뇌과학적 기법을 이용하여 지식과 창의성의 관계를 규명하고자 10명의 컴퓨터 전문가를 선정하여 언어적 창의성 과제인 소설쓰기 과제를 제시 한 후 전문 영역과 비전문 영역의 창의적 사고 과정 시 뇌파(EEG) 알파파의 과제 관련 파워값(Task Related Power, TRP)을 비교하였다. 실험은 기준 상태로 눈 감고 안정 상태, 일반적 사고 과정, 전문 분야의 창의적 사고 과정, 비전문 분야의 창의적 사고 과정 시의 EEG를 측정한 후 각각 비교 분석하는 순서로 진행되었다. 연구 결과 전문 영역의 창의적 사고 과정 시 알파파의 활성이 유의하게 감소함을 알 수 있었으며 이러한 현상이 주로 측두엽에서 나타났고, 특히 좌측 측두엽에서 뚜렷하게 관찰됨을 알 수 있었다. 이러한 관찰 결과는 지식이 창의적 사고를 방해할 수 있다는 긴장적 관점을 지지하는 것으로 창의적 사고 과정에 관한 연구를 뇌과학적으로 접근할 수 있음을 시사한다.

• 대한본초학회지
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• 제34권1호
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• pp.51-57
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• 2019

Objectives : Nypa fruticans Wurmb. (NF) have been used as a traditional medicine to treat inflammatory diseases in East-South Asia. However, it is largely undiscovered whether NF water extract could exhibit anti-inflammatory activities against tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-induced inflammatory responses on human keratinocytes, HaCaT cells. Therefore, this study was aimed to investigate the anti-inflammatory activity of NF water extract on TNF-${\alpha}$-induced inflammatory responses in HaCaT cells. Methods : To investigate the anti-inflammatory activites of NF water extract in HaCaT cells, the inflammatory model of HaCaT cells was established under a suitable concentration (10 ng/ml) of human TNF-${\alpha}$ (hTNF-${\alpha}$). HaCaT keratinocyte cells were pre-treated with NF water extract for 1 h, and then stimulated with hTNF-${\alpha}$. Then, the cells were harvested to measure the inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and prostaglandin $E_2$ ($PGE_2$), and pro-inflammatory cytokine including TNF-${\alpha}$ and interleukin (IL)-6. In addition, we examined the inhibitory mechanisms of NF, mitogen activated protein kinases (MAPKs) and inhibitory kappa B alpha ($I{\kappa}-B{\alpha}$) Results : The treatment of NF inhibited the hTNF-${\alpha}$-induced elevation of iNOS, COX-2, and $PGE_2$ in HaCaT cells. In addition, NF treatment inhibited the hTNF-${\alpha}$-induced elevation of TNF-${\alpha}$ and IL-6. Furthermore, NF treatment inhibited the activation of MAPKs but not degradation of $I{\kappa}-B{\alpha}$. Conclusions : Taken together, our result suggest that treatment of NF could inhibit the hTNF-${\alpha}$-induced inflammatory responses via deactivation of MAPKs in HaCaT cells. This study could suggest that NF could be a beneficial agent to prevent skin damage or inflammation.

• 대한한의학회지
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• 제43권1호
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• pp.99-111
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• 2022

Objectives: Rehmanniae Radix Preparata (RRP) has been used as a traditional remedy to treat gynecology and endocrine diseases. Recently, studies on antioxidant and anti-inflammatory effects of RRP have been reported, so it was judged that RRP extracts would have an anti-depressive effect. Methods: We investigated the anti-neuroinflammatory and anti-depressive effect of RRP on lipopolysaccharide (LPS)-induced depression and LPS-stimulated BV2 microglia. RRP inhibited the LPS-stimulated excessive release of nitrite in the BV2 cells. RRP also significantly inhibited the inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 in LPS-stimulated BV2 microglial cells. Results: RRP significantly suppressed the LPS-induced mitogen-activated protein kinase (MAPKs) and nuclear factor (NF)-𝜅B activation. In addition, administration of RRP not only inhibited the immobility time in the forced swimming test (FST) but also increased the total travel distance in the open field test (OFT). Also, RRP inhibited the elevation of TNF-alpha, IL-1beta, and IL-6 in brain of LPS-injected mice. Conclusions: Considering the overall results, our study showed that RRP exhibited the anti-neuroinflammatory and anti-depressive activities via deactivation of MAPKs and NF-𝜅B.

• Journal of Ginseng Research
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• 제37권2호
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• pp.187-193
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• 2013

The effect of Korean red ginseng (KRG) on diabetic renal damage was investigated using streptozotocin (STZ)-induced diabetic rats. The diabetic rats showed loss of body weight gain, and increases in kidney weight and urine volume, whereas the oral administration of KRG at a dose of 100 or 250 mg/kg of body weight per day for 28 d prevented these diabetes-induced physiological abnormalities. Among the kidney function parameters, elevated plasma levels of urea nitrogen and creatinine in diabetic control rats tended to be lowered in KRG-treated rats. In addition, administration of KRG at a dose of 100 mg/kg body weight in the diabetic rats showed significant decreases in serum glucose and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), implying that KRG might prevent the pathogenesis of diabetic complications caused by impaired glucose metabolism and oxidative stress. KRG also significantly reduced advanced glycation end product (AGE) formation and secretion from kidney of diabetic rats. Furthermore, KRG decreased the levels of N-(carboxymethyl) lysine and expression of AGE receptor. KRG also reduced the overexpression of cyclooxygenase-2 and inducible nitric oxide synthase in the kidney via deactivation of nuclear factor-kappa B. We also found that KRG prevented STZ-induced destruction of glomerular structure and significantly suppressed high glucose-induced fibronectin production. Taken together, KRG ameliorates abnormalities associated with diabetic nephropathy through suppression of inflammatory pathways activated by TNF-${\alpha}$ and AGEs. These findings indicate that KRG has a beneficial effect on pathological conditions associated with diabetic nephropathy.

• KSBB Journal
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• 제11권2호
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• pp.151-158
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• 1996

섬유소는 효소에 의한 가수분해에 의하여 유용한 화학물질이냐 연료 등으로 전환될 수 있다. 그러나 효소가 온도나 전단응력에 의해 쉽게 비활성화 되고 생성물인 당에 의한 억제 효과가 심각하기 때문에 효과적인 당화공정이 이루어지지 못하는 실정이다. 본 실험에서는 섬유소 가수분해에서의 두 효소, 즉 셀룰라아제 와 ${\beta}$-glucosidase의 통력학적 특정틀 을 이해하고, 생성물 억제영향 빛 효소의 비활성화 를 관찰하여, 섬유소의 고농도 당화 공정에 적용가 능한 통력학적 이론을 규명하고자 하였다. 셀룰라아제 벚 ${\beta}$-glucosidase는 다양한 통력학적 특정들을 보였으며, 반응기내에 5gN 의 포도당이 존재하여도 $\beta$glucosidase의 역가가 70% 이상 감소하는 것으로 나타나, 포도탕에 의한 ${\beta}$-glucosi­d dase의 억 제 영향이 가장 심각한 것으로 나타났다. 또한 셀로바이오스의 농도가 109/p 일때 역시 셀롤 라야제의 역가가 약 70% 감소하였다. ${\beta}$-glucosi dase의 경우 셀룰라아제와 비교하여 약 1.6배 정도 비활성화에 더 민강한 것으로 밝혀졌다. 당화 공정 모사 결과는 대체척으로 신뢰할 수 있는 범위의 결 과를 얻었으며, 가수분해가 진행되는동안 실험결과 와 모사에 의한 계산값은 잘 일치하였다.

• Journal of Life Science
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• 제11권1호
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• pp.14-21
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• 2001

To investigate the changes of carbohydrate metabolism in the senescing leaves of Zea mays during dark-induced senescence, the changes in the contents of reducing sugar, sucrose and starch as well as the activities of sucrose synthase, three isozymes of invertase, and ${\alpha}$-amylase were measured. In the senescing leaves, the content of reducing sugars temporarily increased at 4 d and rapidly decreased thereafter, whereas sucrose contents gradually decreased thereafter, whereas sucrose contents gradually decreased until 3 d of senscence and significantly decreased thereafter. The activities of intracellular invertases such as soluble acid and alkaline formed gradually enhanced until 4 d of leaf senescence and significantly declined thereafter. The extracellular invertase activity showed no significant changes during leaf senescence. The deactivation of sucrose synthase was observed within 3 d of leaf senscence. On the other hand, the starch contents gradually declined during 2 d of leaf senescence, and showed a temporary increase at 3 d, which is similar to the pattern of sucrose synthase activity., These results imply that sucrose in the senescing leaves. The major enzymes which correlated to the breakdown of sucrose during dark-induced senescence were soluble acid and alkaline invertases, not sucrose and ABA accelerated leaf senescence by inducing the accumulation of reducing sugar. These result, therefore, that leaf senescence may be mediated by the temporary quantitative changes of reducing sugar induced by the activation of intracellualr inveertases.

• Animal cells and systems
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• 제9권2호
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• pp.101-105
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• 2005

[ ${\beta}ig-h3$ ] is a secretory protein that is induced by $TGF-{\beta}$ and implicated in various disease conditions including fibrosis. We have previously reported that ${\beta}ig-h3$ expression is implicated in astrocyte response to brain injury. In this study, we further investigated potential roles of ${\beta}ig-h3$ protein in the injured central nervous system (CNS). We specifically assessed whether the treatment of microglial cells with ${\beta}ig-h3$ can regulate microglial activity. Microglial cells are the prime effector cells in CNS immune and inflammatory responses. When activated, they produce a number of inflammatory mediators, which can promote neuronal injury. We prepared conditioned medium from the stable CHO cell line transfected with human ${\beta}ig-h3$ cDNA. We then examined the effects of the conditioned medium on the LPS- or $IFN-{\gamma}-mediated$ induction of proinflammatory molecules in microglial cells. Preincubation with the conditioned medium significantly attenuated LPS-mediated upregulation of $TNF-{\alpha},\;IL-1{\beta}$, iNOS and COX-2 mRNA expression in BV2 murine microglial cells. It also reduced $IFN-{\gamma}-mediated$ upregulation of $TNF-{\alpha}$ and COX-2 mRNA expression but not iNOS mRNA expression. Assays of nitric oxide release correlated with the mRNA data, which showed selective inhibition of LPS-mediated nitric oxide production. Although the regulatory mechanisms need to be further investigated, these results suggest that astrocyte-derived ${\beta}ig-h3$ may contribute to protection of the CNS from immune-mediated damage via controlling microglial inflammatory responses.

• 한국수소및신에너지학회논문집
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• 제1권1호
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• pp.15-23
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• 1989

The selective separation of hydrogen from gas mixture containing hydrogen was experimentally studied using $LaNi_5$. The capacity and the rate of hydrogen separation, the purity of recovered hydrogen and the optimum condition of the regeneration of deactivated $LaNi_5$ were investigated. The separation rate and the recovery ratio of hydrogen were slowly decreased with the increase of the number of hydrogen absorption cycle. It was found that this result comes from the deactivation of $LaNi_5$ partly because of the blocking of hydrocarbon compounds in the $LaNi_5$ lattice and partly because of the poisoning of $LaNi_5$ surface by carbon monoxide contained in the gas mixture. The optimum condition for the regeneration of deactivated $LaNi_5$ was obtained by heating in a vacuum to about 637 K. The recovery ratio of hydrogen at the optimum condition was observed to be about 80%. The rates of hydrogen separation were measured in the ${\alpha}$-phase and two phase regions. The rate equations could be expressed as follows ; ${\alpha}$ - phase : $$-\frac{dP{_{H_2}}}{dt}=9.836{\times}10^{-3}(P{_{H_2}}_{-P_{eq}})$$ two phase region : $$-\frac{dP_{H{_2}}}{dt}=1.6909{\times}10^2\exp(-17560/RT)(P{_{H_2}}_{-P_{eq}})$$.

• 대한본초학회지
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• 제37권3호
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• pp.41-47
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• 2022

Objectives : Terminalia chebula (TC) has been used as a traditional remedy to treat gastrointestinal infectious and inflammatory diseases. However, its protective effects and mechanisms against skin inflammation have not been well-elucidated. Thus, the aim of this study is to evaluate the protective effects of the TC water extract and also to suggest a putative mechanism of TC against skin injury on human keratinocytes, HaCaT cells. Methods : HaCaT cells were pre-treated with TC for 1 h and then stimulated with tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) (10 ng/mL each) to induce skin inflammation and injury. After 24 h, the cells were harvested to evaluate the expression of Th2 chemokines, such as C-C motif chemokine ligand 5 (CCL5, also known as RANTES), C-C chemokine ligand 17 (CCL17, also known as TARC) and C-C chemokine ligand 22 (CCL22, also known as MDC). To investigate the regulatory mechanisms of TC, we also assessed the phosphorylation of signal transducer and activator of transcription 1 (STAT1) signaling pathways in HaCaT cells. Results : Treatment of TC decreased the mRNA levels of RANTES, TARC and MDC with a concentration dependent manner against co-stimulation of TNF-α and IFN-γ. In addition, TC significantly reduced TNF-α and IFN-γ induced phosphorylation of STAT1. Conclusions : In summary, we propose that TC may be a promising candidate for anti-inflammatory skin protector through the inhibition of chemokines via STAT1 deactivation.