• Proceedings of the Botanical Society of Korea Conference
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• 1995.06a
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• pp.40-56
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• 1995

During the past two decades, China has seen her great progress in plant biotechnology. Since the Chinese market of herb medicine is huge, while the plant resources are shrinking, particular emphasis has been placed in plant tissue and cell cultures of medicinal plants, this includes fast propagation, protoplast isolation and regeneration, cell suspension cultures and large scale fermentation. To optimize culture conditions for producing secondary compounds in vitro, various media, additives and elicitors have been tested. Successful examples of large scale culture for the secondary metabolite biosynthesis are quite limited : Lithospermum ery throrhizon and Arnebia euchroma for shikonin derivatives, Panax ginseng, P. notoginseng, P. quinquefolium for saponins, and a few other medicinal plants. Recent development of genetic transformation systems of plant cells offered a new approach to in vitro production of secondary compounds. Hairy root induction and cultures, by using Ri-plasmid, have been reported from a number of medicinal plant species, such as Artemisia annua that produces little artemisinin in normal cultured cells, and from Glycyrrhiza uralensis. In the coming five years, Chinese scientists will continue their work on large scale cell cultures of a few of selected plant species, including Taxus spp. and A. annua, for the production of secondary metabolites with medicinal interests, one or two groups of scientists will be engaged in molecular cloning of the key enzymes in plant secondary metabolism.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.933-943
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• 1994

The present study was undertaken to determine the effect of tensile force on DNA and protein biosynthesis in bone cells, and to identify the cell type(s) which primarily respond to external physical force among the heterogenous bone cell populations. As a prerequisite for this study, two bone cell populations which retain fibroblastic and osteoblastic feature were isolated from fetal rat calvaria with sequential enzyme digestion scheme. Tensile force was delivered to each bone cell population by two acrylic resin plates connected with a orthodontic expansion screw during culture period. Rate of DNA and protein synthesis in each bone cell population were assessed by the incorporated radioactivity of $[^3H]-thymidine$ into DNA and $[^3H]-proline$ into fraction of collagenase-digestible protein and noncollagenous protein, respectively. DNA synthesis of osteoblast-like calvarial cell populations was increased significantly by the application of tensile force for 24 hours. In contrast, no alteration in DNA synthesis of fibroblast-like populations could be observed in response to applied force. Tensile force induced the change in protein synthesis of bone cell populations with the same pattern. Total protein and collagen synthesis were increased whithin 24 hours in osteoblast-like populations, but not in fibroblast-like populations by tensile force application. These findings indicate that physical force can affect cellullar activity of the particular cell population, not all cell Populations residing in bone and osteoblasts respond more sensitively than fibroblasts. So osteoblasts can modulate the behavior of other bone cells including osteoclasts by producing several local regulating factors of bone metabolism. In this context, preferential responsiveness of osteoblasts to applied tensile force observed in this study suggests that osteoblasts may play an important role in regulation of physical force-induced remodelling process.

• BMB Reports
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• v.38 no.4
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• pp.391-398
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• 2005

3-hydrogenwadaphnin (3-HK) is a new daphnane-type diterpene ester isolated from Dendrostellera lessertii with strong anti-tumoral activity in animal models and in cultures. Here, prolonged effects of this new agent on proliferation and viability of several different cancerous cell lines were evaluated. Using [$^3H$]thymidine incorporation, it was found that the drug inhibited cell proliferation and induced G1/S cell cycle arrest in leukemic cells 24 h after a single dose treatment. The cell viability of Jurkat cells was also decreased by almost 10%, 31% and 40% after a single dose treatment (7.5 nM) at 24, 48 and 72 h, respectively. The drug-treated cells were stained with acridine orange/ethidium bromide to document the chromatin condensation and DNA fragmentation. These observations were further confirmed by detection of DNA laddering pattern in the agarose gel electrophoresis of the extracted DNA from the treated cells. Treatment of K562 cells with the drug at 7.5, 15 and 30 nM caused apoptosis in 25%, 45% and 65% of the cells, respectively. Exogenous addition of $25-50\;{\mu}M$ guanosine and/or deoxyguanosine to the cell culture of the drug-treated cells restored DNA synthesis, released cell arrest at G1/S checkpoint and decreased the apoptotic cell death caused by the drug. These observations were not made using adenosine. However, the drug effects on K562 cells were potentiated by hypoxanthine. Based on these observations, perturbation of GTP metabolism is considered as one of the main reasons for apoptotic cell death by 3-HK.

• The Korean Journal of Zoology
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• v.16 no.1
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• pp.13-23
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• 1973

The changes in the quantitative distribution and in cytoplasmic granules of tongue mast cells and duodenal enterochromaffin cells in male albino rats were observed following oral administration of 40mg/kg body wt. isonicotinic acid hydraside (INH) and 20mg/kg body wt. pyridoxine. The results obtained are summarized as follows: 1. INH administered-rat showed a marked decrease in the number of mast cells, caused by leakage of cytoplasmic granules, while pyridoxine-rat showed increased the number of mast cells. 2. Similarly, INH-rat showed a marked decrease in the number of enterochromaffin cells. In the case of pyridoxine-rat, however, the number of enterochromaffin cells increased compared with that of the controls. 3. In view of the fact that a large dose of INH was harmful to the formation of mast cells and enterochromaffin cells. And considering that a moderate dose of pyridoxine stimulated the formation of the two kinds of cells and the amounts of cytoplasmic granules, it was concluded that pyridoxine might be concerned with the metabolism of secretory products, 5-Hydroxytryptamine.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1200-1210
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• 2004

Metabolic flux analysis was established by adapting previous stoichiometric model developed during growth with cellulose to cell grown with cellobiose for further direct comparison of the bacterial metabolism. In carbon limitation with cellobiose, a shift from acetate-ethanol fermentation to ethanol-lactate fermentation is observed and the pyruvate overflow is much higher than with cellulose. In nitrogen limitation with cellobiose, the cellodextrin and exopolysaccharide overflows are much higher than on cellulose. In carbon and nitrogen saturation with cellobiose, the cellodextrin, exopolysaccharide, and free amino acids overflows reach the highest levels observed but all remain limited on cellulose. By completely shunting the cellulosome, the use of cellobiose allows to reach much higher carbon consumption rates which, in return, highlights the metabolic limitation of C. cellulolyticum. Therefore, the physical nature of the carbon source has a profound impact on the metabolism of C. cellulolyticum and most probably of other cellulolytic bacteria. For cellulolytic bacteria, the use of soluble carbon substrate must carefully be taken into consideration for the interpretation of results. Direct comparison of metabolic flux analysis from cellobiose and cellulose revealed the importance of cellulosome, phosphoglucomutase and pyruvate-ferredoxin oxidoreductase in the distribution of carbon flow in the central metabolism. In the light of these findings, future directions for improvement of cellulose catabolism by this bacterium are discussed.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.45-54
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• 2017

Our study aims to determine the metabolism and excretion of novel pulmonary-targeting docetaxel liposome (DTX-LP) using the in vitro and in vivo animal experimental models. The metabolism and excretion of DTX-LP and intravenous DTX (DTX-IN) in New Zealand rabbits were determined with ultra-performance liquid chromatography tandem mass spectrometry. We found DTX-LP and DTX-IN were similarly degraded in vitro by liver homogenates and microsomes, but not metabolized by lung homogenates. Ultra-performance liquid chromatography tandem mass spectrometry identified two shared DTX metabolites. The unconfirmed metabolite $M_{un}$ differed structurally from all DTX metabolites identified to date. DTX-LP likewise had a similar in vivo metabolism to DTX-IN. Conversely, DTX-LP showed significantly diminished excretion in rabbit feces or urine, approximately halving the cumulative excretion rates compared to DTX-IN. Liposomal delivery of DTX did not alter the in vitro or in vivo drug metabolism. Delayed excretion of pulmonary-targeting DTX-LP may greatly enhance the therapeutic efficacy and reduce the systemic toxicity in the chemotherapy of non-small cell lung cancer. The identification of $M_{un}$ may further suggest an alternative species-specific metabolic pathway.

• Proceedings of the Ginseng society Conference
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• 1987.06a
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• pp.47-58
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• 1987

Ethanol exerts different effects on hepatic cellular metabolism, depending mainly on the duration of its intake. In the presence of ethanol following an acute load, a number of hepatic functions are inhibited, including lipid oxidation and microsomal drug metabolism. In its early stages, chronic ethanol consumption produces adaptive metabolic changes in the endoplasmic reticulum which result in increased metabolism of ethanol and drugs and accelerated lipoprotein production. Prolongation of ethanol intake may result in injurious hepatic lesions such as alcoholic hepatitis and cirrhosis A number of such metabolic effects of ethanol are directly linked to the two major products of its oxidation; hydrogen and acetaldehyde. The excess hydrogen from ethanol unbalances the liver cell's chemistry. In the presence of excess hydrogen ions the process is turned in a different direction. In this study, it was attempted to observe the effect of ginseng saponins on alcohol Oehydrogenase(ADH), aldehyde dehydrogenase(ALDH) and microsomal ethanol oxidizing system(MEOS) in vivo as well as in vitro. Furthermore, the effect of ginseng saponin on the hydrogen balance in the liver and the hepatic cellular distribution of (1-14C) ethanol, its incorporation into acetaldehyde and lipids was also investigated. It seemed that ginseng saponin stimulated the above enzymes and other related enzymes in ethanol metabolism, resulting in a rapid removal of acetaldehyde and excess hydrogen from the animal body,

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.485-492
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• 1996

myo-Inositol, a growth factor for Saccharomyces cerevisiae (S. cerevisiae), has been known to be incorporated into phosphatidylinositol (PI), which is a kind of phospholipid in the cell membrane, by a membrane-associated PI-synthesizing enzyme. The deficiency of myo-inositol in S. cerevisiae adversely affected the membrane structure and function. On the basis of biochemical functions of myo-inositol, the effect of deficiency of myo-inositol on the aerobic glucose metabolism was investigated by measuring specific oxygen uptake rate (Q$_{O2}$) used as an indicator representing the respiratory capacity of S. cerevisiae in batch and continuous cultures. The respiratory capacity of aerobic glucose metabolism in S. cerevisiae was also monitored after glucose pulse-addition in a continuous culture (D=0.2, 1/hr), in which glucose was utilized through respiratory metabolism. The deficiency of myo-inositol was found to lead to both the decrease of the maximum specific oxygen uptake rate (Q$_{O2max}$) observed from the batch as well as in the continuous culture experiment and the decrease of the respiratory capacity of aerobic glucose metabolism of S. cerevisiae determined from the glucose pulse-addition experiment, in which the glucose flux into respiratory and fermen- tative metabolism was quantitatively analyzed.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.372-373
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• 2003

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.518-521
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• 2000

Aspergillus niger is capable of metabolizing dimethyphthalate. The maximum weight of mycelium wa observed afterabout 6-8 dys of incubation. A TLC analysis revealed the accumulation of metabolites in the resting cell culture. Monomethylphthalate, phthalate, and protocatechuate were shown to be the intermediates by thin layer chromatographic and spectrophotometric analyses. The fungus metabolized dimethylphthalate through monomethylphthalate, phthalate, and protocatechuate as evidenced by the oxygen uptake and an enzymatic analysis. The terminal aromatic metabolite, protocatechuate, is metabolized via the ortho-cleavage pathway.