• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.230-234
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• 2003

The Bacillus subtilis YvaE protein, the small multidrug resistance (SMR) family (TC #2.A. 7.1), is shown to catalyze efflux of multiple cationic drugs including many disinfectants, when it was cloned and expressed in Escherichia coli. When the yvaD gene was coexpressed with yvaE gene, the yvaD protein, encoded within a single operon with the yvaE gene, is shown to counteract the action ofYvaE. By ethidium efflux analysis, the cells harvoring a vector with yvaE gene showed a rapid ethidium efflux, compared with the control cells. These results clearly suggest that YvaE mediates drug export from the cell cytoplasm.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.346-354
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• 1992

Cancer cells have several tumor-associated antigens on the cell surfaces, and antibodies against these antigens have been developed by many investigators. Radiolabeled antibodies have been used as new methods to diagnose and treat malignant tumors. Especially anti-carcinoembryonic antigen (CEA) is the most popular antibody for these purposes. In this investigation, we tried to label $^{131}I$ and $^{99m}Tc $ to anti-CEA monoclonal antibodies which were developed in the Seoul National University College of Medicine. We found CEA-79 and CEA-92 antibodies had the better immunological characteristics among 8 anti-CEA monoclonal antibodies. And radioiodination of CEA-79 could be performed by chloramine-T method, while radioiodination of CEA-92 by iodogen method. To label these antibodies with $^{99m}Tc $, we used pretargeting transchelation as direct labeling method. At first, $^{99m}Tc $ was bound to glucaric acid, and monoclonal antibody was reduced by $\beta-mercaptoethanol$. When these were incubated together. $^{99m}Tc $ bound to glucarate was switched to monoclonal antibody because of higher affinity. We established conditions of several steps in this method. Anti-CEA monoclonal antibodies labeled with $^{131}I$ and $^{99m}Tc $ are expected to be used valuably in the detection and treatment of malignant tumors.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2410-2412
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• 2011

Using a single step chemical synthesis, we synthesized the potential tumor imaging agent $^{99m}Tc$-diglucose-diethylenetriamine (DGTA) from diethylenetriamine and natural D-glucose. 10 min Incubation of 10 mg of precursor with 50 ${\mu}g$ of $SnCl_2{\cdot}2H_2O$ at room temperature yielded over 95% of $^{99m}Tc$ labeling. The stability for 6 hours in saline or human plasma was over 90%. In vitro tumor cell uptake assays using the SNU-C5 and 9 L cell lines showed that, in 0-400 mg/dL glucose medium, cell uptake of $^{99m}Tc$-DGTA was 1.5-8 times higher than that of [$^{18}F$]FDG. Moreover, [$^{18}F$]FDG uptake was dependent on glucose concentration in the medium, whereas cellular uptake of $^{99m}Tc$-DGTA was not dependent on glucose concentration, suggesting that the two compounds have different uptake mechanisms by tumor cells.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.3
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• pp.140-147
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• 2002

We investigated the temporal variations in the heterotrophic dinoflagellates (hereafter HTD), tintinnid ciliates(TC), and naked ciliates(NC) from August to November 1999 in the coastal waters off the southern Saemankeum areas where a huge red tide dominated by Cochlodinium polykrikoides/Gymnodinium impudicum was first observed in 1998. We took water samples from 2-5 depths of 4 stations in each of the 5 cruises and then measured the species composition and abundances of HTD, TC, and NC The maximum species numbers and densities of HTD, TC, and NC(11, 12, and 10 cells $m\ell$$^{-1}$ , respectively) were observed when the density of diatoms was highest (August 10), while the lowest values (1.0, 0.5, and 2.4 cells $m\ell$$^{-1}$ , respectively) were found when the red tide dominated by C. polykrikoides/G. impudicum took placed (October 18). On August 10 and November 11 when diatoms dominated the abundance of phytoplankton, the correlation coefficients between TC, NC and diatoms were relatively high. However, On September 16 and October 18 when autotrophic+mixotrophic dinoflagellates(ATD+MTD) were abundant, the correlation coefficients between HTD and ATD+MTD were relatively high. The large HTD Noctiluca scintillans was the most dominant heterotrophic protists during the C. polykrikoides/G. impudicum red tide on October 18. N. scintillans has been known to feed on the prey cells when the swimming speeds of C. polykrikikoides/G. impudicum markedly reduced at the decline stage of the red tide. Therefore, N. scintillans could be effective grazers on C. polykrikoides/G. impudicum. The maximum densities of HTD, TC, and NC in the study area were fairly lower than those obtained in the waters off Kohung-Yeosu areas in the summer-fall, 1997. The results of the present study provide the basis of understanding predator-prey relationships between dominant phytoplankton and heterotrophic protists and the roles of the protist grazers in bloom dynamics in the waters off the western Korea.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.5
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• pp.372-377
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• 2003

To realize a high integrated flash memory utilizing SONOS memory devices, the NOR type ITC(one Transistor Cell) SONOS flash arrays are fabricated and characterized. This SONOS flash arrays with the common source lines are designed and fabricated by conventional 0.35$\mu\textrm{m}$ CMOS process. The thickness of ONO for memory cells is tunnel oxide of 34${\AA}$, nitride of 73${\AA}$ and blocking oxide of 34${\AA}$ . To investigate operating characteristics, CHEI(Channel Hot Electron Injection) method and bit line method are selected as the program and 4he erase operation, respectively. The disturbance characteristics ,according to the program/erase/read cycling are also examined. The degradation characteristics are investigated and then the reliability of SONOS flash memory is guaranteed.

• Archives of Pharmacal Research
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• v.2 no.1
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• pp.25-33
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• 1979

In order to find out nutritional effects of Korean edible mushrooms on the multiplication of tissue cells, the alcohol extracts and acid bydrolysates of eleven species of mushrooms were added to Earle's ESS. A comparison of the respective multiplications of HeLa cells in this solution and in control solution of TC=199. Yielded the following result: The alcohol extracts and acid hydrolysates of a Coprinus comatur, Agaricus campestris, Agaricus bisporus, Lentinus edodes, Tricholoma matsutake, Pleurotus ostretus, Ramaria botrytis and Pholiota nameko influenced favorably the maintenance of the normal form and monolayer of HeLa cells. The growth curves of HeLa cells in the cultures containing, respectively, the alcohol extracts and acid hydrolysates of these eight mushrooms showed that five species, i.e., Coprinus comatus, Agaricus compestris, Agaricus bisporus, Lentinus edodes and Tricholoma matsutake effected an excellent multiplication and that the other three species were less effective than those five species. As to the effects on the cell multiplication, no marked difference was observed between the alcohol extracts and the acid hydrolysates of the mushrooms tested.

• Biomedical Science Letters
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• v.11 no.3
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• pp.327-332
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• 2005

Sf21 cells become popular as the host permissive cell line to support the baculovirus AcNPV replication and protein synthesis. The cells grow well on TC-100 medium that contains $0.1\%$ D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transporters. However, unlike human glucose transporters, very little is known about the characteristics of the endogenoussugar transporter(s) in Sf21 cells. Thus, some kinetic properties of the sugar transport system were investigated, involving the uptake of 2-deoxy-D-glucose (2dG1c). In order to obtain a true measure of the initial rate of uptake, the uptake of $[^3H]2dGlc$ from both low $(100{\mu}M)$ and high (10 mM) extracellular concentrations was measured over periods ranging from 30 sec to30 min. The data obtained indicated that the uptake was linear for at least 2 min at both concentrations, suggesting that measurements made over a 1min time course would reflect initial rates of the jexpse uptake. To determine $K_m\;and\;V_{max}$ of the endogenous glucose transporter(s) in Sf21 cells, the uptake of 2dG1c was measured over a range of substrate concentrations $(50{\mu}M\~10mM)$ 2dG1c uptake by the Sf21 cells appeared to involve both saturable and non-saturable (or very low affinity) components. A saturable transport system for 2dG1c was relatively high, the $K_m$ value for uptake being < 0.45 mM. The $V_{max}$ value obtained for 2dG1c transport in the Sf21 cells was about 9.7-folds higher than that reported for Chinese hamster ovary cells, which contain a GLUT1 homologue. Thus, it appeared that the transport activity of the Sf21 cells was very high. In addition, the Sf21 glucose transporter was found to have very low affinity for cytochalasin B, a potent inhibitor of human erythrocyte glucose transporter

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.111-116
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• 1998

To construct transformed Bm5 cells, Autographa californica nuclear polyhedrosis virus (AcNPV)IE1 gene, an immediate early viral gene was firstly used in this study. AcNPV IE1 gene, which shares on 95.3% uncleotide sequence homology with Bombyx mori nuclear polyhedrosis virus (BmNPV) IE1 gene, was isolated and cloned into pBluescript. Neomycin gene from pKO-neo was inserted under the control of the IE1 promoter to yield pAcIE1-neo. The plasmid pAcIE1-neo was transfected into Bm5 or Sf9 cells, and neomycin-resistant cells were selected in TC100 medium containing 10% fetal bovine serum (FBS) and 1 mg/$m\ell$ G418 for two weeks. Individual clones were picked and each was amplified for further characterization. The genomic DNA from neomycin-resistnt cells was isolated and characterized by PCR using AcNPV IE1 gene-specific primers and by Southern blot analysis using neomycin gene probe. We concluded that AcNPV IE1 gene was functional in B. moridrived Bm5 cells as well as Spodaptera frugiperda-derived Sf9 cells to produce stably-transformed insect cells.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.4
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• pp.1-16
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• 2006

Purpose : The purpose of this research was to investigate the effects of Kamibojoongikkitang (KBT) on the immune cells in C57BL/6 mice. Methods : KBT (500mg/kg) was administerd p.o. once a day for 7 days. Results : KBT decreased the cell viability of thymocytes in vivo and in vitro system and decreased the cell viability of splenocytes in vivo, but increased the viability of splenocytes in vitro system. In addition, KBT did not affect the population of helper T (Th) cells and cytotoxic T (Tc) cells in thymocytes and decreased the population of T- and B-lymphocytes and the population of Th and Tc cells in splenocytes. Furthermore, KBT did not affect the production of ${\gamma}%-interferon and interleukin-4 in splenocytes. KBT increased the production of nitric oxide in vivo but decreased the production of nitric oxide in vitro system. KBT enhanced the phagocytic activity of peritoneal macrophages in vivo, but decreased the phagocytic activity in vitro. Conclusion : KBT has an inhibitory action on the specific immune response via decrease of the cell viability of thymocytes and splenocytes and has a potent action on the non-specific immunity via increase of phagocytic activity of peritoneal macrophages.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.516-524
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• 1998

Purpose: Radiolabeled CEA79.4 antibody has a possibility to be used in radioimmunoscintigraphy or radioimmunotherapy of cancer. We investigated the in vitro properties and biodistribution of CEA79.4 antibody labeled with Re-188 or Tc-99m. Materials and Methods: CEA79.4 was reduced by 2-mercaptoethanol to produce-SH residue, and was labeled with Re-188 or Tc-99m. For direct labeling of Tc-99m, methylene-diphosphonate was used as transchelating agent. CEA79.4 in 50 mM Acetate Buffered Saline (ABS, pH 5.3) was labeled with Re-188, using stannous tartrate as reducing agent. In order to measure immunoreactivity and the affinity constant of radiolabeled antibody, cell binding assay and Scatchard analysis using human colon cancer cells SNU-C4, were performed. Biodistribution study of labeled CEA79.4 was carried out at 1, 14 and 24 hr in ICR mice. Results: Labeling efficiencies of Tc-99m and Re-188 labeled antibodies were $92.4{\pm}5.9%$ and $84.7{\pm}4.6%$, respectively, In vitro stability of Tc-99m-CEA79.4 in human serum was higher than Re-188-CEA79.4. Immunoreactivity and affinity constant of Tc-99m-CEA79.4 were 59.2% and $6.59{\times}10^9\;M^{-1}$, respectively, while those of Re-188-CEA79.4 were 41.6% and $4.2{\times}10^9\;M^{-1}$, respectively. After 24 hr of administrations of Re-188 and Tc-99m labeled antibody, the remaining antibodies in blood were 6.32 and 9.35% ID/g respectively. The biodistribution of each labeled antibody in other organs was similar because they did not accumulate in non-targeted organs. Conclusion: In vitro properties and biodistribution of Re-188-CEA79.4 were similar to those of Tc-99m-CEA79.4. It appears that Re-188-CEA79.4 can be used as a suitable agent for radioimmunotheraphy.