• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.773-788
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• 2017

This study was carried out to investigate the damage patterns, the occurrence and migration time of Pseudococcus comstocki and in order to improve the control effect of organic agricultural materials (OAMs). The experiment was carried out at Okcheon's organic vineyard ($2,500m^2$, sandy loam, manure) where planted 8~9 year old 'Muscat of Alexandria' vines. The comstock mealybug's migration to grape clusters occurred from the middle of July, and produced eggs in the grape clusters from the end of July, and the density of the comstock mealybug was highest at $0.6cm^2$ in late August. The number and fruit damage of comstock mealybug in eco-friendly vineyards were higher than in conventional culture vineyard. And the marketability of green variety grape was more damaged from comstock mealybug than the black variety grape. Toxicities of 8 OAMs were evaluated to comstock mealybug at the recommended concentration. As a results, Lightyellow sophora and Derris extracts exhibited strong insecticidal activity with 100% mortality. When the Lightyellow sophora extract was uniformly distributed on the vine from early-July to mid-July, fruit damage reduction rate was 96.2% and 84.6%, respectively. So commercial grapes could be harvested. Therefore, it was considered to be effective to reduce fruit damage by controlling in early - late July (the green stage) when the comstock mealybug migrated to grape clusters in the vine greenhouse. In the future, it will be necessary to study the effect of external exposure time and momentum on the control of OAMs.

• Journal of Life Science
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• v.29 no.8
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• pp.904-915
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• 2019

Prostate cancer (PCa) is one of the most metastatic tumor. Although hormone therapy or surgical castration is mostly conducted to treat PCa, it has a lot of side effects. Recently, many researchers have been exploring the tumor microenvironment to remedy these circumstances. Immune cells, especially macrophages, are an important composition of the tumor microenvironment. Under normal conditions, macrophages exhibit mild tumoricidal activity against tumors. However, once activated by interferon gamma or lipopolysaccharides, macrophages can kill cancer cells directly or indirectly by secreting cytokines and chemokines. In this study, murine macrophage RAW 264.7 cells were treated with Phellinus linteus extract. To analyze their pro-inflammatory phenotype, we were used several assays such as a real-time polymerase chain reaction, an enzyme-linked immunosorbent and nitric oxide assay. Prostate cancer cells were treated with the RAW 264.7-conditioned media, which was identified as a pro-inflammatory nature, for 48 h, and the expression of epithelial-mesenchymal transition (EMT)-related genes was determined. Not only N-cadherin, Snail, Twist, Slug, and Cadherin 11, which are mechenchymal-related proteins, were decrease, but epithelial marker of E-cadherin was increased. In addition, the mRNA level of vimentin, ccl2, and vegfa were decreased, as the EMT is closely related to the migration and invasion of cancer cells. In conclusion, the RAW 264.7-conditioned media stimulated with P. linteus extract inhibited migration and invasion and regulated the EMT pathway in human prostate cancer cells.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.847-870
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• 2023

The safe disposal of high-level radioactive waste requires accurate predictions of the long-term geochemical behavior of radionuclides. To achieve this, the present study was conducted to model geochemical behaviors of uranium (U), plutonium (Pu), and palladium (Pd) under different hydrogeochemical conditions that represent deep groundwater in Korea. Geochemical modeling was performed for five types of South Korean deep groundwater environment: high-TDS saline groundwater (G1), low-pH CO₂-rich groundwater (G2), high-pH alkaline groundwater (G3), sulfate-rich groundwater (G4), and dilute (fresh) groundwater (G5). Under the pH and Eh (redox potential) ranges of 3 to 12 and ±0.2 V, respectively, the solubility and speciation of U, Pu, and Pd in deep groundwater were predicted. The result reveals that U(IV) exhibits high solubility within the neutral to alkaline pH range, even in reducing environment with Eh down to -0.2 V. Such high solubility of U is primarily attributed to the formation of Ca-U-CO₃ complexes, which is important in both G2 located along fault zones and G3 occurring in granitic bedrocks. On the other hand, the solubility of Pu is found to be highly dependent on pH, with the lowest solubility in neutral to alkaline conditions. The predominant species are Pu(IV) and Pu(III) and their removal is predicted to occur by sorption. Considering the migration by colloids, however, the role of colloid formation and migration are expected to promote the Pu mobility, especially in deep groundwater of G3 and G5 which have low ionic strengths. Palladium (Pd) exhibits the low solubility due to the precipitation as sulfides in reducing conditions. In oxidizing condition, anionic complexes such as Pd(OH)₃^-, PdCl₃(OH)₂^-, PdCl₄^2-, and Pd(CO₃)₂^2- would be removed by sorption onto metal (hydro)oxides. This study will improve the understanding of the fate and transport of radionuclides in deep groundwater conditions of South Korea and therefore contributes to develop strategies for safe high-level radioactive waste disposal.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.263-271
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• 2001

Objective : Glioblastomas, the most common type of primary brain tumors, are highly invasive and cause massive tissue destruction at both the tumor invading edges and in areas that are not in direct contact with glioma cells. As a result, patients with high-grade gliomas are faced with a poor prognosis. Such grim statistics emphasize the need to better understand the mechanisms that underlie glioma invasion, as these may lead to the identification of novel targets in the therapy of high grade gliomas. Protein kinase C(PKC) is a family of serine/threonine kinases and an important signal transduction enzyme that conveys signals generated by ligand-receptor interaction at the cell surface to the nucleus. PKC appears to be critical in regulating many aspects of glioma biology. The purpose of this study was to assess accurately the role of PKC in the invasion regulation of human gliomas based on hypothesis that protein kinase C(PKC) is functional in the process of glial tumor cell invasion. Method : To test this hypothesis, U-87 malignant glioma cell line intracellular PKC levels were up and down regulated and their invasiveness was tested. Intracellular PKC level was characterized using PKC activity assays. Invasion assays including barrier migration and spheroid confrontation were used to study the relationship between PKC concentration and invasiveness. Result : The cell line which were treated by PKC inhibitor tamoxifen and hypericin exhibited decreased PKC activity and decreased invasive abilities dose dependently both in matrigel invasion assay and tumor spheroid fetal rat brain aggregates(FRBA) confrontation assay. However, the cell line that was treated by PKC activator 12-O-tetradecanylphorbol-13acetate(TPA) did not exhibit increases in either PKC activity or invasive ability. Conclusion : These studies suggest that PKC may be a useful molecular target for the chemotherapy of glioblastoma and other malignancies and that a therapeutic approach based on the ability of PKC inhibitors may be helpful in preventing invasion.

• Journal of Life Science
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• v.25 no.4
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• pp.416-424
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• 2015

Pinosylvin is a stilbenoid found in the Pinus species. Pinosylvin at ~pM to ~nM concentrations induces cell proliferation, cell migration and anti-inflammatory activity in endothelial cells. However, it was recently reported that pinosylvin at high concentrations (50 to 100 μM) induces cell death in bovine aortic endothelial cells. In this study, we conducted a series of experiments to discover how pinosylvin at a high concentration (50 μM) induces endothelial cell death. Pinosylvin at the high concentration was shown to induce endothelial cell apoptosis through enhancing caspase-3 activity, flip-flop of phosphatidyl serine, and nuclear fragmentation. We found that pinosylvin at the high concentration additively increased caspase-3 activity enhanced by serum-starvation or treatment with 100 μM etoposide. We also determined that pinosylvin at the high concentration promoted activations of c-Jun N-terminal kinase (JNK) and endothelial nitric oxide synthetase (eNOS). We further ran a series of experiments to find out which signaling molecule plays a critical role in the pinosylvin-induced apoptosis. We finally found that SP-600125, a JNK inhibitor, had an inhibitory effect on the pinosylvin-induced endothelial cell death, but L-NAME, an eNOS inhibitor, had no effect. These data indicate that JNK is involved in the pinosylvin-induced apoptosis. Collectively, pinosylvin at high doses induces cell apoptosis via JNK activation.

• Journal of Life Science
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• v.30 no.9
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• pp.826-833
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• 2020

Phospholipase C gamma (PLCγ) has critical roles in receptor tyrosine kinase- and non-receptor tyrosine kinase-mediated cellular signaling relating to the hydrolysis of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P₂] to produce inositol 1,4,5 trisphosphate (IP₃) and diacylglycerol (DAG), which promote protein kinase C (PKC) and Ca²⁺ signaling to their downstream cellular targets. PLCγ has two isozymes called PLCγ1 and PLCγ2, which control cell growth and differentiation. In addition to catalytically active X- and Y-domains, both isotypes contain two Src homology 2 (SH2) domains and an SH3 domain for protein-protein interaction when the cells are activated by ligand stimulation. PLCγ also contains two pleckstrin homology (PH) domains for membrane-associated phosphoinositide binding and protein-protein interactions. While PLCγ1 is widely expressed and appears to regulate intracellular signaling in many tissues, PLCγ2 expression is restricted to cells of hematopoietic systems and seems to play a role in the regulation of immune response. A distinct mechanism for PLCγ activation is linked to an increase in phosphorylation of specific tyrosine residue, Y783. Recent studies have demonstrated that PLCγ mutations are closely related to cancer, immune disease, and brain disorders. Our review focused on the physiological roles of PLCγ by means of its structure and enzyme activity and the pathological functions of PLCγ via mutational analysis obtained from various human diseases and PLCγ knockout mice.

• Journal of Life Science
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• v.27 no.1
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• pp.78-88
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• 2017

Angiogenesis, the formation of new blood vessels, plays an important role in tumor growth and metastasis; therefore, it has become an important target in cancer therapy. Novel anticancer pharmaceutical products that have relatively few side effects or are non-cytotoxic must be developed, and such products may be obtained from traditional herbal medicines. Coptis chinensis Franch. is an herb used in traditional medicine for the treatment of inflammatory diseases and diabetes. However, potential antiangiogenic effects of C. chinensis water extract (CCFWE) have not yet been studied. The purpose of this study was to determine the antiangiogenic effect of CCFWE in order to evaluate its potential for an anticancer drug. We found that the treatment with CCFWE inhibited the major steps of the angiogenesis process, such as the endothelial cell proliferation, migration, invasion, and capillary-like tube formation in response to vascular endothelial growth factor (VEGF), and also resulted in the growth inhibition of new blood vessels in an ex vivo rat aortic ring assay. We also observed that CCFWE treatment arrested the cell cycle at the G0/G1 phase, preventing the G0/G1 to S phase cell cycle progression in response to VEGF. In addition, the treatment reduced the VEGF-induced activation of matrix metalloproteinases 2 and 9. Taken together, these findings indicate that CCFWE should be considered a potential anticancer therapy against pathological conditions where angiogenesis is stimulated during tumor development.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.77-85
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• 2018

There would be a possibility of uranium contamination around the nuclear power plants and the underground waste disposal sites, where the uranium could further migrate and diffuse to some distant places by groundwater. It is necessary to understand the biogeochemical behaviors of uranium in underground environments to effectively control the migration and diffusion of uranium. In general, various kinds of microbes are living in soils and geological media where the activity of microbes may be closely connected with the redox reaction of nuclides resulting in the changes of their solubility. We investigated the adsorption and precipitation behaviors of dissolved uranium on some solid materials using hydrogen gas as an electron donor instead of organic matters. Although the effect of hydrogen gas did not appear in a batch experiment that used granite as a solid material, there occurred a reduction of uranium concentration by 5~8% due to hydrogen in an experiment using bentonite. This result indicates that some indigenous bacteria in the bentonite that have utilized hydrogen as the electron donor affected the behavior (reduction) of uranium. In addition, the bentonite bacteria have showed their strong tolerance against a given high temperature and radioactivity of a specific waste environment, suggesting that the nuclear-biogeochemical reaction may be one of main mechanisms if the natural bentonite is used as a buffer material for the disposal site in the future.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.47-58
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• 1996

Histopathological vascular changes in hemorrhagic fever with renal syndrome (HFRS) caused by Hantaan virus include increased vascular permeability, disseminated intravascular coagulation, thrombocytopenia and changes in coagulation activity. Although vascular endothelial cells of main target organs such as kidney infected with Hantaan virus are not damaged but swelling of endothelial cells, perivascular exudates and infiltration of mononuclear cells and fresh interstitial hemorrhages are common. However, the pathogenesis of cell infiltration and hemorrhages around vascular endothelial cells are not well understood. Some endothelial cell molecules or vascular adhesins that acts as adhesion moleulces for leukocyte are expressed on endothelial cells close to site of inflammation. However, whether the expression of endothelial adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule (ICAM-1) and endothelial leukocyte adhesion molecule (ELAM) on vascular endothelial cells are increased by infection with Hantaan virus has not been studied. In this study, the relationship between the expression of VCAM-1, ICAM-1 and ELAM and adhesion of mononuclear cells on endothelial cells of human blood vessels infected with Hantaan virus was investigated. The endothelial cells of umbilical vein was passaged three times in culture medium and the monolayered cells were infected with $10^5\;pfu/ml$ of Hantaan virus grown in Vera E6 cell cultures. The multiplication of virus in cultured endothelial cells was monitored by immunohistochemistry and the expression of adhesion molecules was demonstrated by immunohistochemistry using monoclonal antibodies against VCAM-1, ICAM-1 and ELAM. And in situ hybriditation against ICAM-1 was also performed. The endothelial adhesion molecules, VCAM and ICAM, were expressed after 6 hours postinfection, respectively, and their expressions lasted for 72 hours. Similar expression of VCAM and ICAM appeared on endothelial cells by infection with virus, but the expression of ELAM was not recognized up to 72 hours postinfection. Microscopically, it was noted that many monocuclear cells adhered on endothelial cells infected with viruses. In an electronmicroscopic study, the transendothelial migration of mononuclear cells was observed on monolayered endothelial cells infected with virus. This results suggested that the endothelial adhesion molecules, particulary VCAM and ICAM, might be expressed on endothelial cells by infection with Hantaan virus and these molecules play a key role in the adhesion and extravasation of inflammatory cells around blood vessels.

• Journal of Veterinary Clinics
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• v.29 no.4
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• pp.334-338
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• 2012

A 3-year-old, intact male Pungsan dog was presented for a 2-week history of a non-weight-bearing lameness of left hindlimb with anorexia. The dog had no history of trauma, and never been routinely vaccinated or treated with heartworm preventatives. The complete blood count showed severe leukocytosis and neutrophilia with left shift. Serum biochemistry showed hypoalbuminemia, azotemia, and increased hepatobilliary enzyme activity. A canine heartworm antigen test was positive. Thoracic radiographs were consistent with heartworm disease as evidences by main pulmonary artery enlargement, right-sided cardiomegaly, and interstitial lung pattern. Echocardiography revealed pulmonary valvular regurgitation and pulmonary hypertension. Selective femoral arterial angiogram was performed, and bilateral femoral arterial occlusion was identified. The dog died after angiogram, and necropsy was performed. At necropsy, adult heartworm and a large blood clot were found within the lumen of left and right femoral artery. This case report describes an unusual migration of heartworm to femoral artery that caused hindlimb lameness.