• Journal of Gastric Cancer
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• v.10 no.3
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• pp.99-105
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• 2010

Purpose: Currently, the two most influential gastric stem cell marker candidates are CD44 and CD133. The aim of this study was to make a comparison and determine the appropriate marker for use in gastric cancer stem cell research. Materials and Methods: We analyzed the expressions of CD44, CD133, and CD24 from the gastric cancer cell lines MKN45, MKN74, KATO-III, NCI-N87, SNU-1, SNU-216, SNU-601, SNU-638, and SNU-688 using flow cytometry. In addition, we measured the change in viability after applying 5 fluorouracil (5-FU) to the MKN45, MKN74, KATO-III, and NCI-N87 cell lines using a Cell Counting Kit 8. Results: CD133 expression was above moderate in the KATO-III, SNU-216, SNU-601 cell lines, whereas it was below 1% in the remaining cell lines. CD44 was expressed at levels above 5% in all gastric cancer cell lines. The effect of 5-FU on viability and CD133 or CD44 expression in the cell lines were not related. Conclusions: Expression of CD133 positive cells was insufficient in the gastric cancer cell lines. Therefore, of the cell lines tested, CD44 was the most appropriate tumor maker for research on gastric cancer stem cells.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1023-1035
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• 2016

The purpose of this study was to investigate the role of colon cancer stem cells (CSCs) during chemically-induced rat multi-step colon carcinogenesis with or without the treatment with a specific cyclooxygenase-2 inhibitor drug (celecoxib). Two experiments were performed, the first, a short term 12 week colon carcinogenesis bioassay in which only surrogate markers for colon cancer, aberrant crypt foci (ACF) lesions, were formed. The other experiment was a medium term colon cancer rat assay in which tumors had developed after 32 weeks. Treatment with celecoxib lowered the numbers of ACF, as well as the tumor volumes and multiplicities after 32 weeks. Immunohistochemical proliferating cell nuclear antigen (PCNA) labeling indexes LI (%) were downregulated after treatment by celecoxib. Also different cell surface antigens known to associate with CSCs such as the epithelial cell adhesion molecule (EpCAM), CD44 and CD133 were compared between the two experiments and showed differential expression patterns depending on the stage of carcinogenesis and treatment with celecoxib. Flow cytometric analysis demonstrated that the numbers of CD133 cells were increased in the colonic epithelium after 12 weeks while those of CD44 but not CD133 cells were increased after 32 weeks. Moreover, aldehyde dehydrogenase-1 activity levels in the colonic epithelium (a known CSC marker) detected by ELISA assay were found down-regulated after 12 weeks, but were up-regulated after 32 weeks. The data have also shown that the protective effect of celecoxib on these specific markers and populations of CSCs and on other molecular processes such as apoptosis targeted by this drug may vary depending on the genetic and phenotypic stages of carcinogenesis. Therefore, uncovering these distinction roles of CSCs during different phases of carcinogenesis and during specific treatment could be useful for targeted therapy.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.156-162
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• 1994

To better understand the exact nature of the major toxic compound responsible for phytotoxicity of sorghum stem, the most toxic compound from the stem extract was isolated by rapid chromatography and subsequently purified by thin-layer chromatography(TLC) and high pressure liquid chromatography(HPLC). Of the eight fractions isolated by rapid chromatography, the fraction with solvent combinations of butanol (8) : acetic acid (1) : water (1) had the highest toxicity. Further separation of the fraction by TLC in a solvent mixture of butanol (24) : acetic acid (16.4) : water (7) : propanol (1) showed that the spot with an $R_f$ 0.71 had one major peak with retention time of 20.40 minutes. Upon subjecting gas chromatography and the HPLC fraction to the mass spectrometry, the toxic compound is probably one of the four compounds ; 1-methyl-1-(2-propynyl)-hydrazine, 1-aziridineethanol, 5-chloro-2-pentanone, and 2-(methylseleno)-ethanamine.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6191-6196
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• 2012

Aims and Background: Traditional chemotherapy strategies for human leukemia commonly use drugs based on cytotoxicity to eradicate cancer cells. One predicament is that substantial damage to normal tissues is likely to occur in the course of standard treatments. Obviously, it is urgent to explore therapies that can effectively eliminate malignant cells without affecting normal cells. Our previous studies indicated that ginsenoside $Rg_1$ ($Rg_1$), a major active pharmacological ingredient of ginseng, could delay normal hematopoietic stem cell senescence. However, whether $Rg_1$ can induce cancer cell senescence is still unclear. Methods: In the current study, human leukemia K562 cells were subjected to $Rg_1$ exposure. The optimal drug concentration and duration with K562 cells was obtained by MTT colorimetric test. Effects of $Rg_1$ on cell cycle were analyzed using flow cytometry and by SA-${\beta}$-Gal staining. Colony-forming ability was measured by colony-assay. Telomere lengths were assessed by Southern blotting and expression of senescence-associated proteins P21, P16 and RB by Western blotting. Ultrastructural morphology changes were observed by transmission electron microscopy. Results: K562 cells demonstrated a maximum proliferation inhibition rate with an $Rg_1$ concentration of $20{\mu}\;mol{\cdot}L^{-1}$ for 48h, the cells exhibiting dramatic morphological alterations including an enlarged and flat cellular morphology, larger mitochondria and increased number of lysosomes. Senescence associated-${\beta}$-galactosidase (SA-${\beta}$-Gal) activity was increased. K562 cells also had decreased ability for colony formation, and shortened telomere length as well as reduction of proliferating potential and arrestin $G_2$/M phase after $Rg_1$ interaction. The senescence associated proteins P21, P16 and RB were significantly up-regulated. Conclusion: Ginsenoside $Rg_1$ can induce a state of senescence in human leukemia K562 cells, which is associated with p21-Rb and p16-Rb pathways.

• Ocean and Polar Research
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• v.23 no.4
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• pp.323-335
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• 2001

Distribution features of foulers attached on 28 ships of 6 main shipping routes (SR) of the Far East Sea Basin were analyzed using various statistical methods. Collections obtained during 1976-1990 in the expeditions by the Institute of Marine Biology were used for the analyses. Samples were taken from the ships during anchorage by SCUBA diving and from dry-docks of Vladivostok ship-repairing yard. In all cases, the distribution patterns of most animals and algal species showed clear contagious patterns. Total biomass of fouling organisms and biomass of attached animals frequently increased along the horizontal direction of ship hulls, from the stem to the sternpost. Animal and algal species were usually located at different sites of the hulls. According to the increasing floating speed, there was, a clear tendency of the displacement in main fouling biomass from the stem to the stem. Any generalizations and deductions concerning the distribution patterns of the foulers from the same SR ships are not always substantiated, but one may see some similarities of the fouler distributions in many cases. Micro-scale turbulence generated by water flow around a ship hull for the distribution of fouling organisms is discussed.

• Journal of Veterinary Science
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• v.23 no.2
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• pp.35.1-35.13
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• 2022

Background: The testis has been reported to be a naturally O2-deprived organ, dimethyloxaloylglycine (DMOG) can inhibit hypoxia inducible factor-1alpha (HIF-1α) subject to degradation under normal oxygen condition in cells. Objectives: The objective of this study is to detect the effects of DMOG on the proliferation and differentiation of spermatogonial stem cells (SSCs) in Bama minipigs. Methods: Gradient concentrations of DMOG were added into the culture medium, HIF-1α protein in SSCs was detected by western blot analysis, the relative transcription levels of the SSC-specific genes were analyzed using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Six days post-induction, the genes related to spermatogenesis were detected by qRT-PCR, and the DNA content was determined by flow cytometry. Results: Results revealed that the levels of HIF-1α protein increased in SSCs with the DMOG treatment in a dose-dependent manner. The relative transcription levels of SSC-specific genes were significantly upregulated (p < 0.05) by activating HIF-1α expression. The induction results showed that DMOG significantly increased (p < 0.05) the spermatogenesis capability of SSCs, and the populations of haploid cells significantly increased (p < 0.05) in DMOG-treated SSCs when compared to those in DMOG-untreated SSCs. Conclusion: We demonstrate that DMOG can promote the spermatogenesis activity of SSCs.

• Journal of Microbiology
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• v.45 no.6
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• pp.547-552
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• 2007

Previously, we generated monoclonal antibodies (MAbs) that bound to the surface of human embryonic stem cells (hESCs) in an attempt to discover new hESC-specific surface markers. In this study, MAb 47-235 (IgG1, ${\kappa}$) was selected for further characterization. The MAb bound to the surface of undifferentiated hESCs but did not bind to mouse ESCs or mouse embryonic fibroblast cells in flow cytometric analysis. The antibody immunoprecipitated a 47 kDa protein from the lysates of cell surface-biotinylated hESCs. Identification of the protein by quadrupole time of flight tandem mass spectrometry revealed that 47-235 binds to Ag 243-5 protein of Mycoplasma arginini. BM-Cyclin treatment of the hESCs that reacted with 47-235 resulted in loss of mycoplasma DNA and the reactivity to 47-235. Nevertheless, the hESCs that were reactive to 47-235 maintained self-renewal and pluripotency and thus could be differentiated into three embryonic germ layers.

• 한국가시화정보학회:학술대회논문집
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• 2004.11a
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• pp.72-75
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• 2004

The present study describes a computational work to investigate detailed behaviors of the twin shock waves discharged from the exits of two-parallel ducts. In computations, the Yee-Roe-Davis's TVD scheme was used to solve the unsteady, three-dimensional, inviscid, compressible, Euler equations. The distance between two ducts is varied and the Mach number of the incident shock wave is changed below 2.0. The results obtained show that on the symmetric axis between two-parallel ducts, the maximum pressure achieved by the merge of twin shock waves and its location strongly depend upon the distance between two-parallel ducts and the Mach number of the incident shock wave. It is also found that the twin shock waves discharged from the exits of two-parallel ducts leads to the complicated flow fields, such as Mach stem, spherical waves, and vertical structures.

• Journal of the Korean Society of Tobacco Science
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• v.5 no.2
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• pp.9-15
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• 1983

The effect of leaf dehydration process and air flow capacity of bulk curing on physical properties and composition of cured leaves was studied, respectively, during flue- curing. Cured leaves from excessive moisture during yellowing stage and those from rapid dehydration Process inevitably during later stages, tend towards lower equilibrium moisture contents, higher shatter index, hither protein nitrogen, and leaf scalding or deterioration of Beaves with redish cast. Early dehydration at the yellowing stage re suited in increasing of p Bamitic, stearic, linoleic, and linolenic acid contents, but showed reduction of brightness difference between upper and lower surface of the cured leaves, Leaf surface lipid decreased with the progress of curing stages, more conspicuously during later stage. Lowering air flow capacity of fan by 50oye during stem drying stage resulted in increasing of leaf surface lipid and 25oye decreasing of electric power consumption , but curing period and kerosene consumption were not affected.

• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.21-29
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• 2009

A rapeseed reaping equipment attachable to a conventional combine was developed in order to harvest rapeseed for bio-diesel materials. This study was carried out to measure the harvest feasibility of a prototype combine in rapeseed fields. Grain, stem and pod flow rate, grain qualities (whole kernel, damaged kernel, unhulled kernel, material-other-than-grain) and grain loss rates (header, threshing, separation) were investigated in each field test. As the result of the fold test, the average grain flow rates of SUNMANG and MS varieties showed 1,430 kg/h and 2,038 kg/h, respectively. The average stem and pod flow rates showed 3,443 kg/h and 6,596 kg/h, respectively. In each working speed, the average whole kernel rate and the material-other-than-grain showed 99.9% and below 0.08%, respectively. In the average grain loss, the rates showed 5.66% in case of SUNMANG and 5.94% in MS. Header loss was higher than other parts for SUNMANG. However, threshing loss was relatively higher than other parts for MS. Header loss rate due to side cutter knifes, however, was not so high when compared with a grain loss due to the cutter bar. Effective field capacity and field efficiency of the prototype combine showed 0.389 ha/h and 44%, respectively. Comparison of customary combine with the prototype combine through field test demonstrated that the header loss was reduced by 69.3% when the prototype combine was used.