• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.897-905
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• 2003

Phospholipase D (PLD) and ADP-ribosylation factor (ARF) were partially purified on a series of column chromatography, and their biochemical properties were characterized to understand the regulatory mechanism of PLD activation by ARF protein in the antigen-induced immune responses in guinea pigs. Heparin Sepharose and high-Q Sepharose column chromatographies were used for the purification of PLD, and Sephadex G-25, DEAE Sephacel, Source 15 PHE (HIC), Superdex-75, and Uno-Q column chromatographies were used for the purification of ARF. The purified PLD and ARF proteins were identified with anti-rabbit PLD- or ARF-specific antibodies, showing about 64 or 85 kDa for the molecular mass of PLD and 29 or 35 kDa for the sizes of ARF. Partial cDNA of ARF3 was cloned by RT-PCR in guinea pig lung tissue and its nucleotides and amino acids were sequenced. Guinea pig ARF3 showed 92% of nucleotides sequence identity and 100% of amino acid sequence homology with human ARF3. The ARF-regulated PLD activity was measured in the oleate or ARFs-containing mixed lipid vesicles. The purified and recombinant ARF (rARF) activities were assessed with the $GTP{\gamma}S$ binding assay. The PLD activity was induced by oleate in a dose-dependent manner. The purified ARF and recombinant ARF3 increased PLD activity in guinea pig lung tissues. These data show that the activity of membrane-bound PLD can be regulated by the cytosolic ARF proteins, suggesting that ARF proteins in guinea pig lung can act as a regulatory factor in controlling the PLD activity in allergic reaction.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.325-332
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• 1998

In vitro phosphorylation experiments with a cell extract of Streptomyces coelicolor A3(2) M130 in the presence of ${\gamma}-[^32P]$]ATP revealed the presence of multiple phosphorylated proteins, including the AfsR/AfsK kinases which control the biosynthesis of A-factor, actinorhodin, and undecylprodigiosin. Phosphorylation of AfsR by a cell extract as an AfsK source was significantly inhibited by Ser/Thr protein kinase inhibitors, staurosporine and K-252a, at concentrations giving 50% inhibition ($IC_50$) of $1{\mu}M\;and\;0.1{\mu}M$, respectively. Further in vitro experiments with the cell extracts showed that phosphorylation of multiple proteins was inhibited by various protein kinase inhibitors with different inhibitory profiles. Manganese and calcium ions in the reaction mixture also modulate phosphorylation of multiple proteins. Manganese at 10 mM greatly enhanced the phosphorylation and partially circumvented the inhibition caused by staurosporine and K-252a. A calcium-activated protein kinase(s) was little affected by these inhibitors. Herbimycin and radicicol, which are known as tyrosine kinase inhibitors, did not show any significant inhibition of AfsR phosphorylation. Consistent with the in vitro effect of the kinase inhibitors, they inhibited aerial mycelium formation and pigmented antibiotic production on solid media. On the contrary, when assayed in liquid culture, the amount of actinorhodin produced was increased by staurosporine and K-252a and greatly decreased by manganese. All of these data clearly show that the genus Streptomyces possesses several protein kinases of eukaryotic types which are involved in the regulatory network for morphogenesis and secondary metabolism.

• Journal of Ginseng Research
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• v.14 no.3
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• pp.357-363
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• 1990

When mice irradiated by neutron (Be) are fed with ginseng concentrate, ginseng powder, and adaptagen of which the major ingredient is ginseng alkaloid to neutron (Be source) irradiated mouse, the following results are obtained. 1. The 50% lethal dose (LD50) for the neutron irradiation were 4 days at 600 rad, 7 days at 500 rad, 16 days at 400 rad, 33 days at 375 rad, and 55 days at 350 rad. In thistest, the standard amollntofirradiation was set at 375 rad/8 min. 2. Some spots appeared in the tail of the neutron-irradiated mouse because of blood congestion, and some had its tip tails cut. But the group administered with adaptagen did not show any of these symptoms. 3. The neutron irradiated mouse showed darkening the color of their lung-chloasmas while none of the adaptagen group had this symptom. 4. The lung tissue of the neutron irradiated mouse showed an increase of the karyolysis and cytoplasmic vacuole. 5. When both neutron irradiation and the ginseng sllbstances were given to the mouse at the same day, the 50% lethal days were increased to 29-33 days for the group administered with ginseng extract. 67 days for the group given with the ginseng powder. and 80 days for the groilp arith the adaptagen. 6. The survival rate of those fed with adaptagen for 33 days before the neutron-irradiation was 100%, while the 50% lethal daysofthe group fed with ginsengextract were 39 days and that of the group fed with ginseng powder were 69 days. 7. The serum valued of ${\gamma}$-globulin, IgG, and albumin were returned to normal condition in the group fed with adaptagen for 33 days before the neutron-irradiation. But those of the group which were given the irradiation and the ginseng substances at the same day did not show such a recovery.

• The Korean Journal of Zoology
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• v.7 no.2
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• pp.25-36
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• 1964

The present paper deals with the comparative study on phylogenic difference in the patterns of energy metabolism of brain slices of several vertebrate species by measuring oxygen consumptionwith glucose-6-phosphate, glucose-1-phosphate, glyceraldehyde-3-phosphate or glutamate as respiratory substrate employing Warburg's manometric method, by determination of the utilization rate of glucose using glucose-1-C14 by analyzing patterns of free amino acid distribution , and by histochemical determination using glucose-1-C14 by analyzing patterns of free amino acid distribution acid distribution , and by histochemical determination of glycogen contents. 1. Glucose enhances the oxygen consumption of brain slices of animals belinging to reptile, aves and mammalia while it shows a tendency to decrease that of animals belonging to pisces and amphibia. 2. Glucose-6--phosphate increase oxygen consumption more than glucose in every species examined, while glucose-1-phosphate and glyceraldehyde-3-phosphate increase that of Rana nigromaculata only . In general m, it appears that phosphosugars are more effective as a respiratory substrate to those species which have less endogenous respiration than to those having larger endogenous respiration. 3. Similar patterns of free amino acid distribution and the relative amount are found among the species and in every species examined glutamic acid is detected in the larges amount . ${\gamma}$-Amino butyric acid, glycine, alanine and aspartic acid are found in every species. 4. Ophicephalus showed less oxygen consumption than endogenous respiration when glutamate was added to the medium. When sodium fluoride was added, the oxygen consumption was some what increased . Such phenomenon wasnot found in the frog. 5. The result of histochemcial analysis of the brain showed that glycogen was abundantly present in the fish , amphibia , and especially in the reptile and that no distinctive grains of glycogen were found in the bird and mammal . From these facts, it may be supposed that anaerobic glycolysis as energy source dominates in fish and amphibia and aerobic respiration through the oxidation of glucose dominates in bird and mamal , the reptile occupying transitional position between these two categories. The way of obtaining energy for brain activity by the oxidation of glucose supplied from the circulating blood is seemed to be first acquired by reptile and the function is completed both in aves and mammal.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.147-152
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• 2013

The fibrinolytic activity of aqueous extracts from Korean indigenous insects were studied. Fibrinolytic activity of aqueous extract from 5 insects (larva and adult parts of Meloimorpha japonica, Allomyrina dichotoma, Cetonia pilifera, Apis mellifera) showed 2.7-fold potent than that of plasmin used as a positive control. In addition, the fibrinolytic activity was observed through the degradation products by SDS-PAGE. The extracts efficiently hydrolyzed ${\alpha}-$, ${\beta}-$ and ${\gamma}$ chains of human fibrinogen. This study suggested that aqueous extracts from Korean indigenous insects have potential in developing a useful source of antithrombosis agent(s).

• Progress in Medical Physics
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• v.30 no.4
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• pp.128-138
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• 2019

Purpose: Segmental analysis of volumetric modulated arc therapy (VMAT) is not clinically used for compositional error source evaluation. Instead, dose verification is routinely used for plan-specific quality assurance (QA). While this approach identifies the resultant error, it does not specify which machine parameter was responsible for the error. In this research study, we adopted an approach for the segmental analysis of VMAT as a part of machine QA of linear accelerator (LINAC). Methods: Two portal dose QA plans were generated for VMAT QA: a) for full arc and b) for the arc, which was segmented in 12 subsegments. We investigated the multileaf collimator (MLC) position and dosimetric accuracy in the full and segmented arc delivery schemes. A MATLAB program was used to calculate the MLC position error from the data in the dynalog file. The Gamma passing rate (GPR) and the measured to planned dose difference (DD) in each pixel of the electronic portal imaging device was the measurement for dosimetric accuracy. The eclipse treatment planning system and a MATLAB program were used to calculate the dosimetric accuracy. Results: The maximum root-mean-square error of the MLC positions were <1 mm. The GPR was within the range of 98%-99.7% and was similar in both types of VMAT delivery. In general, the DD was <5 calibration units in both full arcs. A similar DD distribution was found for continuous arc and segmented arcs sums. Exceedingly high DD were not observed in any of the arc segment delivery schemes. The LINAC performance was acceptable regarding the execution of the VMAT QA plan. Conclusions: The segmental analysis proposed in this study is expected to be useful for the prediction of the delivery of the VMAT in relation to the gantry angle. We thus recommend the use of segmental analysis of VMAT as part of the regular QA.

• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.558-565
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• 2002

Coal fly ash, produced from a power plant in Korea was used for the production of glass-ceramics and the physical properties of glass-ceramics were evaluated. CaO and TiO$_2$ were added into the fly ash during the melting process to reduce the viscosity of molten glass and to induce internal crystallization of glass, respectively. Glass-ceramic was produced through a single stage heat treatment (at 950∼1050$\^{C}$ for 37∼240 min) after preparing glass (iota fly ash powder. As a result, a new tiny rod type crystals (a=7.4480, b=10.7381, c=4.3940 A, $\alpha$=94.9, $\beta$=98.6, γ=108.5°) was found in the glass-ceramics, which showed attractive mechanical properties, high hardness (7.1∼7.6 GPa) and wear resistance (by erosion test). Thus a glass-ceramic produced from thermal power plant fly ash and cell as a source for CaO exhibits a suitable treatment for the recycling and exploitation of waste materials and would be acceptable for a new application far building materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.226-229
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• 2004

A stoichiometric mixture of evaporating materials for $CuAlSe_2$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $CuAlSe_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $680^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CuAlSe_2$ single crystal thin films measured with Hall effect by van der Pauw method are $9.24{\times}10^{16}\;cm^{-3}$ and $295\;cm^2/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $CuAlSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)\;=\;2.8382\;eV\;-\;(8.68{\times}10^{-4}\;eV/K)T^2/(T+155K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $CuAlSe_2$ have been estimated to be 0.2026 eV and 0.2165 eV at 10K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $CuAlSe_2$. The three photocurrent peaks observed at 10K are ascribed to the $A_1-$, $B_1-$, and $C_1$-exciton peaks for n = 1.

• Journal of Radiation Protection and Research
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• v.27 no.1
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• pp.51-57
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• 2002

An electronic personal dosimeter(EPD) with hybrid type preamplifier adopting a semiconductor detector as a radiation detector has been developed, manufactured and test-evaluated. The radiation detection characteristics of this EPD has been performance-tested by using a reference photon radiation field. After several test-irradiations to a $^{137}Cs$ gamma radiation source the radiation detection sensitivity of this EPD appeared to be $3.8\;cps/Gy{\cdot}h^{-1}$. The linearity of radiation response was kept within 8% of the dose equivalent ranges of $10{\mu}Sv{\sim}4Sv$ and the angular dependence was under less than 4% in angles of ${\pm}60^{\circ}$. It was confirmed that the energy response range was in $60{\sim}1,250keV$ given in the ISO standard. This EPD satisfied the international criteria for the EPD in the mechanical and the environmental performance test for 9 test categories according to IEC 61526.

• Preventive Nutrition and Food Science
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• v.16 no.1
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• pp.18-23
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• 2011

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by neuronal loss and extracellular senile plaques containing $\beta$-amyloid peptide (A$\beta$). The deposition of the A$\beta$ peptide following proteolytic processing of amyloid precursor protein (APP) by $\beta$-secretase (BACE1) and $\gamma$-secretase is a critical feature in the progression of AD. Among the plant extracts tested, the ethanol extract of Petasites japonicus leaves showed novel protective effect on B103 neuroblastoma cells against neurotoxicity induced by A$\beta$, as well as a strong suppressive effect on BACE1 activity. Ethanol extracts of P. japonicus leaves were sequentially extracted with methylene chloride, ethyl acetate and butanol and evaluated for potential to inhibit BACE1, as well as to suppress A$\beta$-induced neurotoxicity. Exposure to A$\beta$ significantly reduced cell viability and increased apoptotic cell death. However, pretreatment with ethyl acetate fraction of P. japonicus leaves prior to A$\beta$ (50 ${\mu}M$) significantly increased cell viability (p<0.01). In parallel, cell apoptosis triggered by A$\beta$ was also dramatically inhibited by ethyl acetate fraction of P. japonicus leaves. Moreover, the ethyl acetate fraction suppressed caspase-3 activity to the basal level at 30 ppm. Taken together, these results demonstrated that P. japonicus leaves appear to be a useful source for the inhibition and/or prevention of AD by suppression of BACE1 activity and attenuation of A$\beta$ induced neurocytotoxicity.