• 약학회지
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• 제30권6호
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• pp.317-322
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• 1986

To clarify resistance mechanisms of lincosamide antibiotics, it was examined whether lincosamide antibiotics was able to induce high resistance to macrolide and lincosamide antibiotics against EMR-1 strain of Bacillus species. And it was also examined whether the inducible resistance was plasmid-mediated or chromosome-mediated. This strain was identified as Bacillus licheniformis by its morphological and physiological characteristics. The subinhibitory concentrations of lincomycin and clindamycin induced high resistance in the strain to lincosamide antibiotics, but not to macrolide antibiotics. The inducible resistance was not eliminated by treating the strain with ethidium bromide, and plasmid was not identified by the alkaline lysis method of plasmid preparation. These results indicate, therefore, that the inducible resistance to macrolide and lincosamide antibiotics in the strain may be chromosome-mediated, not plasmid-mediated.

• 미생물학회지
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• 제29권4호
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• pp.215-220
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• 1991

MudJ(Km.lac) operon fusions were used in the identification of osmotic-inducible genetic(osi) loci in Salmonella typhimurium. Expression of osi::lacZ(osi5001, 5027) genes were dramatically induced 39-189 fold when the osmolarity was increased. Seven osm::lacZ genes were constituvely expressed under both low and high osmotic strength. The osi5001::lacZ fusion strains showed the enhanced osmotolerance and the reduced expression of the osi5001::lacZ in the presence of 1mM proline or betaine as osmoprotectants. Four osmotic inducible genetic loci were mapped into 36 (YK531), 44 (YK504), 57 (YK501) and 84 (YK528) map unit by testing the cotransduction frequency.

• 한국해양바이오학회지
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• 제7권2호
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• pp.35-41
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• 2015

Whales are marine mammals that are fully adapted to aquatic environment. Whales breathe by lungs so they require adaptive system to low oxygen concentration (hypoxia) while deep and prolonged diving. However, the study for the molecular mechanism underlying cetacean adaptation to hypoxia has been limited. Hypoxia-inducible factor (HIF) is the central transcription factor that regulates hypoxia-related gene expression. Here we identified HIF-binding sites in whale genome by phylogenetic footprinting and analyzed HIF-target genes to understand how whales cope with hypoxia. By comparison with the HIF-target genes of terrestrial mammals, it was suggested that whales may retain unique adaptation mechanisms to hypoxia.

• Archives of Pharmacal Research
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• 제12권3호
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• pp.176-180
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• 1989

Four bacterial strains having inducible resistance to erythromycin were isolated from soil samples in Korea and characterized. MLS inducibility was checked in each strain. Cloning of inducible resistance gene(s) has been tried. Four isolates were identified as B. anthracis, Micrococcus luteus, Streptococcus faecium and B. licheniformis, in which erythromycin, oleandomycin, cirramycin and carbomycin acted as resistance inducers respectively. The resistance gene cloned from B, licheniformis 597 strain using pBS 42 vector was found to have a 3.2 kb insert.

• 생명과학회지
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• 제16권1호
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• pp.126-130
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• 2006

본 연구는 DNA상해유도기작을 규명하기 위하여 하등 진핵생물인 분열형 효모 Schizosaccharomyces pombe로부터 subtraction hybridization방법을 이용하여 자외선 유도 유전자인 UVI-155을 분리하고 그 유전자 구조와 발현양상을 조사하였다. UVI-155 유전자의 발현양상을 Northern hybridization 방법으로 살펴본 결과 자외선(ultraviolet-light) 조사 1시간 후에 최대의 발현 증가를 나타내었다. 반면 알킬화제 인 MMS (methyl methanesulfonate) 처리에 의해서도 발현이 증가되었다. 이 결과 다른 UV-inducible 유전자와는 다르게 UVI-l55 유전자는 UV와 MMS 등의 DNA 상해에 모두 발현이 증가됨을 알 수 있었다. 또 한 유전자의 기능을 알기 위하여 null-mutant세포 주를 제조하여 그 특성을 살펴본 결과 이 유전자는 세포의 성장에 필수적인 유전자임을 알 수 있었다.

• 생명과학회지
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• 제16권4호
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• pp.704-709
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• 2006

본 연구는 DNA 상해유도기작을 규명하기 위하여 꼬마선충 (Caenorhabditis elegans) 으로 부터 subtraction hybridization 방법을 이용하여 자외선 유도 유전자인 UV100과 UV150을 분리하고 그 유전자 구조와 발현양상을 조사하였다. 분리한 유전자의 발현양상을 Northern hybridization 방법으로 살펴본 결과 자외선 조사 후에 최대 2배 이상의 발현 증가를 나타내었다. 이 결과 이미 밝혀진 다른 UV-inducible 유전자와 유사하게 UV100과 UV150 유전자는 자외선에 의해서만 발현이 증가됨을 알 수 있었다. 또한 분리한 유전자의 기능을 알기 위하여 RNAi 실험을 한 결과 분리한 자외선 유도유전자는 발생단계에 따라 다양한 DNA 회복기작을 나타냄을 알 수 있었다.

• Journal of Microbiology
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• 제41권4호
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• pp.295-299
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• 2003

Adenovirus (Ad) precursor to the terminal protein (pTP) plays an essential roles in the viral DNA replication. Ad pTP serves as a primer for the synthesis of a new DNA strand during the initiation step of replication. In addition, Ad pTP forms organized spherical replication foci on the nuclear matrix (NM) and anchors the viral genome to the NM. Here we identified the interferon inducible gene product 1-8D (Inid) as a pTP binding protein by using a two-hybrid screen of a HeLa cDNA library. Of the clones obtained in this assay, nine were identical to the Inid, a 13-kDa polypeptide that shares homology with genes 1-8U and Leu-13/9-27, most of which have little known functions. The entire open reading frame (ORF) of Inid was cloned into the tetracycline inducible expression vector in order to determine the biological functions related with adenoviral infection. When Inid was introduced to the cells along with adenoviruses, fifty to sixty percent of Ad-infected cells expressing Inid had rounded morphology, which was suggestive of apoptosis. Results from the terminal deoxynucleotidyl transferase (TdT) and DNA fragmentation assays confirmed that Inid induces apoptosis in Ad-infected or in uninfected cells. The Inid binding to pTP may target the cell for apoptotic destruction as a host defense mechanism against the viral infection.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1124-1131
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• 2020

Techniques used for the regulation of gene expression facilitate studies of gene function and treatment of diseases via gene therapy. Many tools have been developed for the regulation of gene expression in mammalian cells. The Lac operon system induced with isopropyl β-D-1-thiogalactopyranoside (IPTG) is one of the employed inducible systems. IPTG mimics the molecular structure of allolactose and has a strong affinity for the corresponding repressor. IPTG is known to rapidly penetrate into mammalian cells and exhibits low toxicity. In the present study, we developed a new inducible expression system that could regulate the expression of genes in mammalian cells using IPTG. Here we confirm that unlike other vector systems based on the Lac operon, this expression system allows regulation of gene expression with lactose in the mammalian cells upon transfection. The co-treatment with IPTG and lactose could improve the regulatory efficiency of the specific target gene expression. The regulation of gene expression with lactose has several benefits. Lactose is safe in humans as compared to other chemical substances and is easily available, making this technique very cost-effective.

• 약학회지
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• 제48권6호
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• pp.309-316
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• 2004

The present investigation was undertaken to find out the anticancer activity of monoterpene compounds. Monoterpenes showed generally the inhibitory effect on the proliferation o f L1210 cancer cells (cytotoxicity). Geraniol was found to exibit the most potent cytotoxic effect on L1210 cells with an IC50 values of $0.67{\mu}g/ml$. On the other hand, geraniol proved to be capable of stimulating the macrophage proliferation (135% of control). When the life prolonging activity of geraniol by daily oral administration of 0.1~10${\mu}g/10{\mu}l/20$ g body weight to Sarcoma 180 bearing ICR mouse was examined, there was also a significant elevation of survival (best result of 134% of control). The contradictory effects of geraniol on the proliferation of L1210 cells and macrophages proved to be accompanied by the coincident alterations of RNS (reactive nitrogen species) related enzymes activities such as inducible nitric oxide synthase (Inos) in macrophages and ROS (reactive oxygen species) related enzymes activities such as superoxide dismutase (SOD) in L1210 cells, respectively.

• 대한의생명과학회지
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• 제19권3호
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• pp.180-187
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• 2013

Hypoxia is an integral part of the environment during luteolysis. In this study we examined whether hypoxia could directly stimulate endothelial cells to produce nitric oxide (NO). Endothelial cells were cultured in hypoxic (5% $O_2$) or normoxic (20% $O_2$) conditions and the levels of total NO, inducible NO and endothelial NO was measured. We found that hypoxia but not normoxia upregulated NO production. The increased NO levels correlated with increased inducible NO synthase (iNOS) expression whereas expression of endothelial NOS (eNOS) expression remained constant. Addition of the iNOS specific inhibitor 1400W to hypoxic cultures prevented NO production suggesting that hypoxia-induced NO production in endothelial cells was due mainly to upregulation of iNOS. We also found that prostaglandin $F_{2{\alpha}}$ (PGF) production was unaffected by hypoxia suggesting that upregulation of NO was not due to increased synthesis of PGF. In summary, we report that endothelial cells cultured under hypoxic conditions produce NO via the iNOS pathway. This study provides the importance of the relation between the hypoxic environment and the induction of NO by endothelial cells during regression of the corpus luteum in the ovary.