• The Korean Journal of Physiology and Pharmacology
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• 제2권6호
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• pp.671-676
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• 1998

In the present study, we first examined whether the changes in the DNA binding activities of the transcription factors, cAMP response element binding protein (CREB) and activator protein-1 (AP-1) mediate the long-term effects of morphine in differentiated SH-SY5Y human neuroblastoma cells. The increases in CREB and AP-1 DNA binding activities were time-dependent up to 6 days of morphine treatment (1, 4, and 6 days). However, the significant reduction in the DNA binding activities of CREB and AP-1 was observed after 10 days of chronic morphine $(10\;{\mu}M)$ administration. Secondly, we examined whether the changes of CREB and AP-1 DNA binding activities could be modulated by dopamine and haloperidol. Dopamine cotreatment moderately increased the levels of the CREB and AP-1 DNA binding activities induced by 10 days of chronic morphine treatment, and haloperidol cotreatment also resulted in a moderate increase of the CREB and AP-1 DNA binding activities. However, dopamine or haloperidol only treatment showed a significant increase or decrease of the CREB and AP-1 DNA binding activities, respectively. In the case of acute morphine treatment, the CREB and AP-1 DNA binding activities were shown to decrease in a time-dependent manner (30, 60, 90, and 120 min). Taken these together, in differentiated SH-SY5Y cells, morphine tolerance seems to involve simultaneous changes of the CREB and AP-1 DNA binding activities. Our data also suggest the possible involvement of haloperidol in prevention or reversal of morphine tolerance at the transcriptional level.

• Journal of Microbiology
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• 제44권5호
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• pp.508-514
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• 2006

In this study, the double-stranded DNA-dependent activities of Deinococcus radiodurans RecA protein (Dr RecA) were characterized. The interactions of the Dr RecA protein with double-stranded DNA were determined, especially dsDNA-dependent ATP hydrolysis by the Dr RecA protein and the DNA strand exchange reaction, in which multiple branch points exist on a single RecA protein-DNA complex. A nucleotide cofactor (ATP or dATP ) was required for the Dr RecA protein binding to duplex DNA. In the presence of dATP, the nucleation step in the binding process occurred more rapidly than in the presence of ATP. Salts inhibited the binding of the Dr RecA protein to double-stranded DNA. Double-stranded DNA-dependent ATPase activities showed a different sensitivity to anion species. Glutamate had only a minimal effect on the double-stranded DNA-dependent ATPase activities, up to a concentration of 0.7 M. In the competition experiment for Dr RecA protein binding, the Dr RecA protein manifested a higher affinity to double-stranded DNA than was observed for single-stranded DNA.

• Preventive Nutrition and Food Science
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• 제4권3호
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• pp.209-214
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• 1999

In this study, the effectof ethanol and acetaldehyde on DNA binding activities of NF-$textsc{k}$B and AP-1 were evaluated in C6 rat glial cells. Both NF-$textsc{k}$B and AP-1 are important transcription factors for the expression of various cytokines in glial cells. Our data showed that neither ethanol nor acetaldehyde induced conspicuous cell death of C6 cells at clinically realistic concentrations. When the DNA binding activities of nuclear NF-$textsc{k}$B and AP-1 were estimated using electrophoretic mobility shift assay (EMSA), ethanol(0.3%) or acetaldehyde(1mM) induced transient activation of these transcription factors, which attained peak levels at 4~8 hours and declined to basal levels at 12 hours after treatement . The supershift analysis showed that the increased activities of NF-$textsc{k}$B in ethanol/acetaldehyde-treated C6 cells were due to the preferential induction of p65/p50 heterodimer complex. The DNA binding activities of these transcriptional factors decreased below basal levels when cells were cultured with either ethanol or acetaldehyde for 24 hours, and showed the inhibitory effect of chronic ehtanol /acetaldehyde treatment on the activities of these transsriptional factors. Our data indicate that either ethanol or acetaldehyde can induce functional changes of glial cells throught bi-directional modulation of NF-$textsc{k}$B and AP-1 DNA binding activities.

• Archives of Pharmacal Research
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• 제20권1호
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• pp.80-84
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• 1997

Substituted cinnamoyl-tyramine derivatives were synthesized by DCC-coupling of substituted cinnamic acid with tyramine or tyramine methyl-1-ether to evaluate PAF-receptor binding antagonistic activities and inhibitory activities on PAF-induced platelet aggregation with interest on structure-activity relations. The results show that 3,4-dimethoxy-cinnamoyl tyramine-amide or its methyl ether have significant PAF-receptor binding antagonistic activity and platelet anti-aggregatory activities.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 제3회 추계심포지움
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• pp.107-113
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• 1995

Basement membrane laminin is a multidomain glycoprotein that interacts with itself, heparin and cells. The distal long arm plays major cell and heparin interactive roles. The long arm consists of three subunits (A, B1, B2) joined in a coiled-coil rod attached to a terminal A chain globule (G). The globule is in turn subdivided into five subdomains (Gl-5). In order to analyze the functions of this region, recombinant G domains (rG, rAiG, rG5, rGΔ2980-3028) were expressed in Sf9 insect cells using a baculovirus expression vector. A hybrid molecule (B-rAiG), consisting of recombinant A chain(rAiG) and the authentic B chains (E8-B)was assembled in vitro. The intercalation of rAiG into E8-B chains suppressed a heparin binding activity identified in subdomain Gl-2. By the peptide napping and ligand blotting, the relative affinity of each subeomain to heparin was assigned as Gl> G2= G4> G5> G3, such that G1 bound strongly and G3 not at all. The active heparin binding site of G domain in intact laminin appears to be located in G4 and proximal G5. Cell binding was examined using fibrosarcoma Cells. Cells adhered to E8, B-rAiG, rAiG and rG, did not bind on denatured substrates, poorly bound to the mixture of E8-B and rG. Anti-${\alpha}$6 and anti-${\beta}$1 integrin subunit separately blocked cell adhesion on E8 and B-rAiG, but not on rAiG. Heparin inhibited cell adhesion on rAiG, partially on B-rAiG, and not on E8. In conclusion, 1) There are active and cryptic cell and heparin binding activities in G domain. 2) Triple-helix assembly inactivates cell and heparin binding activities and restores u6131 dependent cell binding activities.

• Toxicological Research
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• 제16권2호
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• pp.141-146
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• 2000

Phthalate esters are used extensively as a plasticizer in the manufacture of plastic products such as PVC bags and medical devices. Recently, phthalate esters have been shown to induce endocrine system mediated responses. However. only a Jew studies have been conducted for estrogenic activity of phthalate esters. In this study estrogenic activities of seven phthalate esters. butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), di-n-butylphthalate (DBP), diethylphthalate (DEP), di-n-pentylphthalate (DPP), di-n-propylphthalate (DPrP) and dicyclohexylphthalate (DCHP), were examined in vitro using E-screen assay and competitive binding assay. From the E-screen assay, BBP. DEHP. DBP and DEP showed weak estrogenic activity at the concentration of 5 $\mu\textrm{M}$. The relative proliferative effect (RPE) and the relative proliferative potency (RPP) were 50~70% and 0.01%. respectively, when compared with 500 pM of 17$\beta$-estradiol (E2). In competitive binding assay with the rat uterine estrogen receptor (ER), BBP and DEP showed weak binding potency ［(l/$10^4$~1/$10^5$ of E2］ while DEHP and DBP scarcely bound to ER. These results suggest that some phthalate esters have weak estrogenic activities in vitro.

• Journal of Microbiology and Biotechnology
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• 제9권1호
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• pp.62-69
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• 1999

In order to investigate the critical amino acid residues involved in the catalytic activities of $\beta$-cyclodextrin glucanotransferase ($\beta$-CGTase) excreted by Bacillus firmus var. alkalophilus, the amino acid residues in $\beta$-CGTase were modified by various site-specific amino acid modifying reagents. The cyclizing and amylolytic activities of $\beta$-CGTase were all seriously reduced after treatment with Woodward's reagent K (WRK) modifying aspartic/glutamic acid, N-bromosuccinimde (NBS) modifying tryptophan, and diethylpyrocarbonate (DEPC) modifying histidine residues. The roles of tryptophan and histidine residues in $\beta$-CGTase were further investigated by measuring the protection effect of various substrates during chemical modification, comparing protein mobility in native and affinity polyacrylamide gel electrophoresis containing soluble starch, and comparing the $K_m$ and $V_{max}$ values of native and modified enzymes. Tryptophan residues were identified as affecting substrate-binding ability rather than influencing catalytic activities. On the other hand, histidine residues influenced catalytic ability rather than substrate-binding ability, plus histidine modification had an effect on shifting the optimum pH and pH stability.

• 생명과학회지
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• 제10권4호
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• pp.374-379
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• 2000

This study was attempted to evaluate an agonistic activity to benzodiazepine receptor of several medicinal pants, which have been used as sedatives in oriental medicine. The activities of the methanol extracts of composite preparation of oriental drugs were compared with those of the simple drugs, furthermore, the active fraction was found out from the simple preparation. Inhibitory effects of composite preparations, Cyperus rotundus/Acorus gramineus, Thuja orientalis/Euphoria longan, Thuja orientalis/Albizzia julibrissin, on the binding of ${[^3H]}$Ro15-1788, a selective benszodiazepine receptor antagonist to benzodiazepine receptor of rat cortices, were observed to be lower than those of corresponding simple preparations. These unexpected results suggest that some components of the composite druge may rather act as an obstacle, not to show the sinergistic effect. The methanol extracts of Cyperus rotundus having the highest activity were fractionated using polar and nonpolar solvents to give ethylacetate and hexane fractions, respectively. The ethylacetate fraction containing relatively polar components exhibited much higher activity than the hexane fraction, which consiste of nonpolar agonist, binding to benzodiazepine receptor. However, in the presence of GABA, this fraction inhibited ${[^3H]}$flunitrazepan binding, and these positive GABA shift supported the strong possibility of agonistic activity to benzodiazepine receptro. As a result, it may be concluded that the substance or substances with neurochemical properties as a benzodiazepine receptor agonist may contribute to the sedative property of Cyperus rotundus.

• 항공우주시스템공학회지
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• 제8권2호
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• pp.1-6
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• 2014

Currently outer space become more and more congested and contested, according to the increase of satellites, nations and government consortia that operate satellites, and commercial and academic satellite operators. Therefore, international community, including the United Nations has been making a greater effort to adopt non-legally binding international documents capable of regulating space activities for the purpose of the security, safety and long-term sustainability of space activities. These are a draft International Code of Conduct for Outer Space Activities(ICoC) and UN Group of Governmental Experts on Transparency and Confidence-Building Measures in Outer Space Activities(UNGGE).

• Archives of Pharmacal Research
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• 제20권1호
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• pp.39-45
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• 1997

Changes in glutamatergic nervous activities following intracerebroventricular (icv) administration of ethylcholine aziridinium (AF64A) were studied in rats. The levels of total glutamate, those of glutamate in cerebrospinal fluid (CSF) and in extracellular fluid (ECF) of striatum, the activities of glutamine synthetase (GS), glutaminase and glutamate dehydrogenase (GDH) and the specific binding sites of $[^3H]$MK801 in striatum, hippocampus and frontal cortex were assessed a week after the infusion of AF64A (3 nmol) into lateral ventricle. The levels of total glutamate were significantly decreased in striatum, hippocampus and frontal cortex after AF64A treatment. Although the levels of glutamate in CSF weren't changed after AF64A treatment, the levels of glutamate in ECF of striatum were significantly decreased (62.6%). GS activities in striatum were significantly decreased. But, glutaminase activities in striatum were significantly increased. However, the activities of GS and glutaminase in frontal cortex and hippocampus weren't changed. Although GDH activities in frontal cortex were significantly decreased, those in striatum and hippocampus weren't altered. The striatal densities of $[^3H]$MK 801 binding sites were increased without changes in its affinity. Also, the specific binding sites of $[^3H]$MK801 were increased in frontal cortex but not in hippocampus. These results indicate that the glutamatergic nervous activities were altered with the infusion of AF64A into lateral ventricle. Furthermore, it suggest that the decreased levels of glutamate after AF64A treatment may affect the change in the other parameters of glutamatergic neuronal activities.