• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.295-308
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• 1992

In order to study on the Sertoli cell, we attempt have been made to measure the average number of each germ cells per Sertoli cell on the 12 stages of cycle in matured korean Jindo dog. The fine structure of Sertoli cell junctional specialization was studied with electron microscope. The results were summarized as follows; 1. The average number of various germ cells associated with Sertoli cell was 9.77 to 13. 80 through stages of cycle and the total average number was 11.62. 2. Sertoli-Sertoli cell junctional specialization was present in seminiferous epilthelium, and Sertoli-spermatid cell junctional specialization rose from stage 8 spermatid, persisted to step 13 spermatid and then disappeared. The structure of Sedoli-spermatid cell juncticnal specialization was not similar to that of Sertoli cxlls. 3. Just after spermiation, free-surface of Sertoli-spermatid cell junctional specialization was replaced by Sertoli cell cytoplasm with tubulobulbar complex at the neiglaboring region observed. 4. The Sertoli cell process was located within the cytoplasm of late stage spermatids. Some membranes of residual body and spermatid cytoplasm partly disappeared, resulting in opening of the cytoplasm of spermatid into that Sertoli cell. This fact suggested that spermatid cytoplasm was partly eliminated.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.99-103
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• 2013

An emzymatic bioanode for a glucose/oxygen biofuel cell was prepared by the sequential coating of carbon nanotube (CNT), charge transfer complex (CTC) based on tetracyanoquinodimethane (TCNQ) and tetrathiafulvalene (TTF), glucose oxidase (GOx), and polyion complex (mixture of poly-L-lysine hydrobromide and poly (sodium 4-styrenesulfonate)) on a glassy carbon electrode. A biocathode was also prepared by the sequential coating of CNT, bilirubin oxidase (BOD), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and polyion complex. The effect of CNT and CTC on the electrochemical performance was investigated. The biofuel cell exhibited a promising performance with maximum power densities of 3.6, 10.1, and $46.5{\mu}W/cm^2$ at 5, 20, and 200 mM of glucose concentration, respectively. The result indicates that the biofuel cell architecture prepared in this study can be used in the development of biofuel cells and biosensors.

• BMB Reports
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• v.55 no.12
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• pp.645-650
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• 2022

Epithelial-to-mesenchymal transition (EMT)-subtype gastric cancers have the worst prognosis due to their higher recurrence rate, higher probability of developing metastases and higher chemo-resistance compared to those of other molecular subtypes. Pharmacologically actionable somatic mutations are rarely found in EMT-subtype gastric cancers, limiting the utility of targeted therapies. Here, we conducted a high-throughput chemical screen using 37 gastric cancer cell lines and 48,467 synthetic small-molecule compounds. We identified YK-135, a small-molecule compound that showed higher cytotoxicity toward EMT-subtype gastric cancer cell lines than toward non-EMT-subtype gastric cancer cell lines. YK-135 exerts its cytotoxic effects by inhibiting mitochondrial complex I activity and inducing AMP-activated protein kinase (AMPK)-mediated apoptosis. We found that the lower glycolytic capacity of the EMT-subtype gastric cancer cells confers synthetic lethality to the inhibition of mitochondrial complex I, possibly by failing to maintain energy homeostasis. Other well-known mitochondrial complex I inhibitors (e.g., rotenone and phenformin) mimic the efficacy of YK-135, supporting our results. These findings highlight mitochondrial complex I inhibitors as promising therapeutic agents for EMT-subtype gastric cancers and YK-135 as a novel chemical scaffold for further drug development.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.303-310
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• 2002

Cell therapy applied to wound healing or tissue regeneration presents a revolutionary realm to which principles of gene engineering and delivery may be applied. One promising application is the transplantation of cells into the wounded tissue to help the tissue repair. However, when cells are transplanted from in vitro to in vivo, immune rejection occurs due to the immune response triggered by the activation of T-cell, and the transplanted cells are destroyed by the attack of activated T-cell and lose their function. Immune suppressant such as FK506 is commonly used to suppress immune rejection during transplantation. However, such kind of immune suppressants not only suppresses immune rejection in the periphery of transplanted cells but also suppresses whole immune response system against pathogenic infection. In order to solve this problem, we developed a method to protect the desired cells from immune rejection without impairing whole immune system during cell transplantation. Previously, we reported the success of constructing glomerular epithelial cells for removal of immune complex, in which complement receptor of type 1 (CR1) was over-expressed on the membrane of renal glomerular epithelial cells and could bind immune complex of DNA/anti-DNA-antibody to remove immune complex through phagocy-tosis [1]. Attempting to apply the CR1-expressing cells to cell therapy and evade immune rejection during cell transplantation, we constructed three plasmids containing genes encoding a soluble fusion protein of cytolytic T lymphocyte associated antigen-4 (CTLA4Ig) and an enhanced green fluorescent protein (EGFP). The plasmids were transfected to the above-mentioned glomerular epithelial cells to express both genes simultaneously. Using the clone cells for cell transplantation showed that mice with autoimmune disease prolonged their life significantly as compared with the control mice, and two injections of the cells at the beginning of two weeks resulted in remarkable survivability, whereas it requires half a year and 50 administrations of proteins purified from the same amount of cells to achieve the same effect.

• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.3
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• pp.150-156
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• 2018

Precision medicine stands for 4Ps - precise, preventive, participatory, and personal; in which "precision" is important because the current modern medicine starts from "trial and error," and "one does not fit all". Current targeted therapies for cancer have changed treatment approaches and led the precision medicine; however, clinical use of liquid biopsy, using blood or other liquid specimens to characterize circulating tumor cells (CTC) or tumor genes instead of biopsies of tumor tissues, still awaits availability of more information regarding non-invasive cancer detection and characterization, prediction of treatment response, monitoring the disease course and relapse possibilities, identification of mechanisms of drug resistance, and newer pathogenesis. In this review, we will introduce the basic concept of CTC, circulating cell free DNA, and exosomes and their possible application for gastric cancer relevant with Helicobacter pylori infection.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.77-86
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• 2018

Interest in renewable energy is increasing for eco-friendly use of energy, and fuel cells are being used in various ways such as houses and buildings as power generation methods that have low emissions such as $NO_X$ and $CO_2$. As the supply of fuel cells expands, more and more boilers are installed in the existing buildings, but safety management is not being performed properly. Therefore, in this study, a prior study was conducted on the status of fuel cell-boiler complex installation and related criteria, and the risk factors were analyzed according to the installation environment and structure. Based on these standards, the safety performance of the fuel cell-boiler combined installation is assessed by conducting a demonstration using the starting product of the simulated operation to derive the installation criteria (proposal) for the fuel cell-boiler combined installation. The installation criteria (proposal) include the construction and connection method of the piping according to the fuel cell-boiler complex installation.

• Applied Microscopy
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• v.21 no.2
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• pp.29-38
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• 1991

Ventral nephrocytes in the larva of the Lucilia illustris comprise ellipsoid cells situated onto the salivary glands. The cells are $60{\sim}100{\mu}m$ in diameter. Junctional complex beneath the basement membrane hold the plasma membrane in a even contour. Intracellular channels from the juntion complex are well developed at the cortex part of the cell. Coated vesicles pinched off from the channels seems to be connected with the ${\alpha}$-vacuoles via the tubular elements, which is regared as selective absorption system from the hemolymph. Two nuclei are sometimes observed in the medulla part of the cell. Ventral nephrocytes contain well-developed rough endoplasmic reticulum and Golgi complex, and numerous mitochondria. These cellular organelles synthesize lysosome. The lysosome not only digest some cell organells but also seems to be related with the ${\beta}$-vacuoles.

• Molecules and Cells
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• v.40 no.1
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• pp.24-36
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• 2017

The stability of peptide-MHC complex (pMHC) is an important factor to shape the fate of peptide-specific T cell immune response, but how it influences on T cell activation process is poorly understood. To better understand that, we investigated various T cell activation events driven by $L^d$ MHCI loaded with graded concentrations of P2Ca and QL9 peptides, respectively, with 2C TCR Tg T cells; the binding strength of P2Ca for $L^d$ is measurably weaker than that of QL9, but either peptides in the context of $L^d$ interact with 2C TCR with a similar strength. When their concentrations required for early T cell activation events, which occur within several minutes to an hour, were concerned, $EC_{50}s$ of QL9 were about 100 folds lower than those of P2Ca, which was expected from their association constants for $L^d$. When $EC_{50}s$ for late activation events, which takes over several hours to occur, were concerned, the differences grew even larger (> 300 folds), suggesting that, due to weak binding, $L^d/P2Ca$ dissociate from each other more easily to lose its antigenicity in a short time. Accordingly, fixation of $L^d/P2Ca$ with paraformaldehyde resulted in a significant improvement in its immunogenicity. These results imply that binding strength of a peptide for a MHC is a critical factor to determine the duration of pMHC-mediated T cell activation and thus the attainment of productive T cell activation. It is also suggested that paraformaldehyde fixation should be an effective tool to ameliorate the immunogenicity of pMHC with a poor stability.

• BMB Reports
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• v.43 no.11
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• pp.766-771
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• 2010

The biological evaluation of a new synthesized Pt(II)-complex, 2,2'-bipyridin Butylglycinato Pt(II) nitrate, an anti-tumor component, was studied at different temperatures by fluorescence and far UV circular dichroism (CD) spectroscopic methods. Human serum albumin (HSA) and human tumor cell line K562 were as targets. The Pt(II)-complex has a strong ability to quench the intrinsic fluorescence of HSA. Binding and thermodynamic parameters of the interaction were calculated by fluorescence quenching method. Far-UV-CD results showed that Pt(II)-complex induced increasing in content of $\alpha$ helical structure of the protein and stabilized it. The 50% cytotoxic concentration ($Cc_{50}$) of complex was determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay at different incubation times. Also, fluorescence staining with DAPI (4,6-diamidino-2-phenylindole) revealed some typical nuclear changes, which are characteristic of apoptosis. Above results suggest that Pt (II) complex is a promising anti-proliferative agent and should execute its biological effects by inducing apoptosis.

• Clinical and Experimental Pediatrics
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• v.54 no.6
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• pp.241-245
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• 2011

Tuberous sclerosis complex (TSC) is a genetic multisystem disorder that results from mutations in the TSC1 or TSC2 genes, and is associated with hamartomas in several organs, including subependymal giant cell tumors. The neurological manifestations of TSC are particularly challenging and include infantile spasms, intractable epilepsy, cognitive disabilities, and autism. The TSC1- and TSC2-encoded proteins modulate cell function via the mammalian target of rapamycin (mTOR) signaling cascade, and are key factors in the regulation of cell growth and proliferation. The mTOR pathway provides an intersection for an intricate network of protein cascades that respond to cellular nutrition, energy levels, and growth factor stimulation. In the brain, TSC1 and TSC2 have been implicated in cell body size, dendritic arborization, axonal outgrowth and targeting, neuronal migration, cortical lamination, and spine formation. The mTOR pathway represents a logical candidate for drug targeting, because mTOR regulates multiple cellular functions that may contribute to epileptogenesis, including protein synthesis, cell growth and proliferation, and synaptic plasticity. Antagonism of the mTOR pathway with rapamycin and related compounds may provide new therapeutic options for TSC patients.