• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.88-94
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• 2005

Plant tissue culture studies have been done for the preservation of medicinal plant resources and efficient production of pharmaceutically important secondary metabolites. Micropropagation methods for Cephaelis ipecacuanha have been established and these methods enabled much more efficient propagation of the plants than the conventional methods using seedling or layering. The C. ipecacuanha plants derived from tissue culture grew uniformly in the field and they showed higher alkaloid contents compared to the plants grown from seedlings. Hairy root cultures of C. ipecacuanha and Panax ginseng have been established by infection with Agrobacterium rhizogenes, and the production of important pharmaceuticals by these cultures have been successfully demonstrated. In the case of C. ipecacuanha, the highest alkaloid yields from the hairy roots cultured for 8 weeks were 2.75-fold cephaeline (5.5 mg) and one third emetine (0.7 mg) compared with those from the roots of one-year old plant propagated through shoot-tip culture and cultivated in a greenhouse (2.0 mg cephaeline and 2.0 mg emetine). In the case of P. ginseng, ginsenoside contents in the hairy roots optimally cultured for 4 weeks were much higher than those in the roots of 4-year old field-grown plant. Thus our medicinal plant tissue cultures demonstrate desirable properties. However, they are always exposed to danger of microbial contamination or unexpected trouble of culture facilities. Cryopreservation of plant tissue cultures is a reliable method for long-term preservation. Cryopreservation studies on these cultures are also presented.

• BMB Reports
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• v.30 no.1
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• pp.55-59
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• 1997

The heat shock response is a universal stress response observed in all organisms and cultured cells. The response is regulated at both the transcriptional and translational level. Heat shocked Drosophila melanogaster Kc cells are used as the system for the study of translational regulation. In this system non-heat shock messages are associated with polysome but are not translated in a heat shocked condition. To figure out the change in the translation machinery. the effects of translation elongation inhibitors were tested on Kc cells. The result showed that the sensitivity of translation to these drugs changed in heat shocked cells. The significant changes were the decreased inhibition of heat shock protein synthesis by cycloheximide, emetine. and puromycin. and the increased inhibition of heat shock protein synthesis by verrucarin A. implying that the translation elongation mechanism in heat shocked cells changed.

• BMB Reports
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• v.52 no.8
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• pp.502-507
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• 2019

Translation is a costly, but inevitable, cell maintenance process. To reduce unnecessary ATP consumption in cells, a fine-tuning mechanism is needed for both ribosome biogenesis and translation. Previous studies have suggested that the ribosome functions as a hub for many cellular signals such as ribotoxic stress response, mammalian target of rapamycin (mTOR), and ribosomal S6 kinase (RSK) signaling. Therefore, we investigated the relationship between ribosomes and mitogen-activated protein kinase (MAPK) activation under ribotoxic stress conditions and found that the activation of c-Jun N-terminal kinases (JNKs) was suppressed by ribosomal protein knockdown but that of p38 was not. In addition, we found that JNK activation is driven by the association of inactive JNK in the 80S monosomes rather than the polysomes. Overall, these data suggest that the activation of JNKs by ribotoxic stress is attributable to 80S monosomes. These 80S monosomes are active ribosomes that are ready to initiate protein translation, rather than polysomes that are already acting ribosomes involved in translation elongation.

• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.165-171
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• 1990

Human Fasciola hepatica infection is a rare entity involving infestation of the liver and biliary tree with adult flukes. which can result in hepatitis. cirrhos is and biliary tract inflammation. obstruction and lithiasis. The patient had the typical diagnostic tetrad of fever. eosinophilic leukocytos is. tender hepatomegaly and fluke ova in the stools. Theatment consistes of Emetine hydrochloride administration for hepatic involvement and common bile duct exploration for removal of flukes. with cholecystectomy for associated cholelithiasis. The combination of medical and surgical therapy cal be expected to produce an arrest of this infection. The removed liver revealed eggs of the fasciols species in the intrahepatic bile duct. The clinical history. pathological findings and treatment of this case were described.