• 한국식물학회:학술대회논문집
• /
• 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
• /
• pp.157-167
• /
• 1987

The have been many reports that phenoloxidase are correlated with development in many fungi. C. congregatus, one of nushroom-forming basidiomycetes, which requires light for its development also has phenoloxidases. In C. congragatus, there are two sets of membrane-associated phenoloxidase (PHO I and PHO II) which are differentiated by their isozyme patterns, and each enzyme set consists of two different subtrate specific enzyme protein; o-tolidine reacting enzyme, and DOPA reacting enzyme. PHO I which is localized by a protoplast-concanavalin A technique by using a new solidifying agent, Pluronic Polyol F 127, instead of agar appears in the vegetative hyphae, and PHO II appears at the early primordial stage on agar and at the sclerotial stage of liquid shake cultures. Inhibition of PHO I with the enzyme inhibitors inhibits mushroom formation as well as melanization of the vegetative hyphae at concentrations which do not inhibit the vegetative growth. PHO I deficient mutants do not form mushrooms or melanins, and the mutants show abnormal nuclear migration patterns. PHO II has roles; possibly cementing the adjacent hyphae during the actual three dimensonal structure formation, and melanizing mushrooms and sclerotia. The possible roles of PHO I in the light reception complex and in melanin formation, the function of malanin, and possible roles of postulated post translational modifying enzymes which regulate the phenoloxidases, nuclear migration pattern, and self-nonself recognition mechanism are discussed.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권6호
• /
• pp.3751-3755
• /
• 2013

Backgroud and Aims: MicroRNA-206 has proven to be down-regulated in many human malignancies in correlation with tumour progression. Our study aimed to characterize miR-206 contributions to initiation and malignant progression of human osteosarcoma. Methods: MiR-206 expression was detected in human osteosarcoma cell 1ine MG63, human normal osteoblastic cell line hFOB 1.19, and paired osteosarcoma and normal adjacent tissues from 65 patients using quantitative RT-PCR. Relationships of miR-206 levels to clinicopathological characteristics were also investigated. Moreover, miR-206 mimics and negative control siRNA were transfected into MG63 cells to observe effects on cell viability, apoptosis, invasion and migration. Results: We found that miR-206 was down-regulated in the osteosarcoma cell line MG63 and primary tumor samples, and decreased miR-206 expression was significantly associated with advanced clinical stage, T classification, metastasis and poor histological differentiation. Additionally, transfection of miR-206 mimics could reduce MG-63 cell viability, promote cell apoptosis, and inhibit cell invasion and migration. Conclusions: These findings indicate that miR-206 may have a key role in osteosarcoma pathogenesis and development. It could serve as a useful biomarker for prediction of osteosarcoma progression, and provide a potential target for gene therapy.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권7호
• /
• pp.2719-2724
• /
• 2015

Objective: The aim of this study was to investigate the clinical significance of annexin a1 (ANXA1) and provide molecular evidence to support that decreased ANXA1 expression could enhance cancer migration and invasion in pancreatic ductal adenocarcinoma (PDAC). Materials and Methods: Immunohistochemistry of a tissue microarray with 162 surgically resected PDAC specimens was performed to examine the expression of ANXA1. We also investigated the relationship between ANXA1 expression and clinicopathological factors and prognosis of PDAC patients. We further studied the role of ANXA1 in PDAC cell proliferation, migration and invasion by cell proliferation assay, migration assay and matrigel invasion assay with reduced ANXA1 expression by RNAi. Western blotting was used to detect matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) expression. We also detected MMP-9 enzyme activity by gelatin zymography. Results: Decreased expression of ANXA1 was significantly associated with poor differentiation, lymph node metastasis and advanced TNM stage of PDAC patients (p<0.05). Moreover, decreased expression of ANXA1 was correlated with poor survival (p<0.05). Furthermore, we found that ANXA1 knockdown inhibited cell proliferation, induced G1 phase cell cycle arrest, increased PDAC cell migration and invasion capacity compared with controls. In addition, Western blotting showed that ANXA1 knockdown increased the MMP-9 protein level and decreased TIMP-1 expression. Gelatin zymography showed that MMP-9 enzyme activity was also elevated. Conclusions: Negative ANXA1 expression is a most unfavorable prognostic factor for PDAC patients. ANXA1 knockdown inhibits cell proliferation by inducing G1 phase cell cycle arrest and increases migration and invasion of PDAC cells through up-regulating MMP-9 expression and activity, implying that ANXA1 may serve as a promising prognostic biomarker and therapeutic target for PDAC.

• Bulletin of the Korean Chemical Society
• /
• 제34권12호
• /
• pp.3715-3721
• /
• 2013

In this study, the behavior of cells on the modified surface, and the correlation between the modified substrates and the response of cells is described. A close-packed layer of nano-sized silica beads was prepared on a coverslip, and the adhesion, proliferation, and migration of BALB/3T3 fibroblast cells on the silica layer was monitered. The 550 nm silica beads were synthesized by the hydrolysis and condensation reaction of tetraethylorthosilicate in basic solution. The amine groups were introduced onto the surfaces of silica particles by treatment with 3-aminopropyltrimethoxysilane. The close-packed layer of silica beads on the coverslip was obtained by the reaction of the amine-functionalized silica beads and the (3-triethoxysilyl)propylsuccinic anhydride treated coverslip. BALB/3T3 fibroblast cells were loaded on bare glass, APTMS coated glass, and silica bead coated glass with the same initial cell density, and the migration and proliferation of cells on the substrates was investigated. The cells were fixed and stained with antibodies in order to analyze the changes in the actin filaments and nuclei after culture on the different surfaces. The motility of cells on the silica bead coated glass was greater than that of the cells cultured on the control substrate. The growth rate of cells on the silica bead coated glass was slower than that of the control. Because the close-packed layer of silica beads gave an embossed surface, the adhesion of cells was very weak compared to the smooth surfaces. These results indicate that the adhesion of cells on the substrates is very important, and the actin filaments might play key roles in the migration and proliferation of cells. The nuclei of the cells were shrunk on the weakly adhered surfaces, and the S1 stage in which DNA is duplicated in the cell dividing processes might be retarded. As a result, the rate of proliferation of cells was decreased compared to the smooth surface of the control. In conclusion, the results described here are very important in the understanding of the interaction between implanted materials and biosystems.

• Journal of Biomedical and Translational Research
• /
• 제19권4호
• /
• pp.125-129
• /
• 2018

Dopaminergic neurons are one of the major neuronal components in the brain. Mesencephalon dopamine (DA) neurogenesis takes place in the ventricular zone of the floor plate, when DA progenitors divide to generate postmitotic cells. These cells migrate through the intermediate zone while they differentiate and become DA neurons on reaching the mantle zone. However, neurogenesis and neuronal migration on dopaminergic neurons remain largely unexplored in the mesencephalon development. This study presents neurogenesis and neuronal migration patterns of dopaminergic neurons during mesencephalic development of the mouse. Neurons from embryonic day (E) 10-14 were labelled by a single injection of 5-bromodeoxyuridine and immunohistochemistry was performed. The neurogenesis occurred mainly at the E10 and E11, which was uniformly distributed in the mesencephalic region, but neurons after E13 were observed only in the dorsal mesencephalon. At the postnatal day 0 (P0), E10 generated neurons were spread out uniformly in the whole mesencephalon whereas E11-originated neurons were clearly depleted in the red nucleus region. DA neurons mainly originated in the ventromedial mesencephalon at the early embryonic stage especially E10 to E11. DA neurons after E12 were only observed in the ventral mesencephalon. At E17, E10 labelled neurons were only observed in the substantia nigra (SN) region. Our study demonstrated that major neurogenesis occurred at E10 and E11. However, neuronal migration continued until neonatal period during mesencephalic development.

• 터널과지하공간
• /
• 제29권4호
• /
• pp.262-279
• /
• 2019

고준위방사성폐기물처분장의 공학적 방벽에서는 다양한 원인으로 인해 기체가 발생한다. 만약 기체 생성 속도가 기체 확산 속도보다 빠를 경우 기체의 압력이 증가하게 되고, 기체 유입 압력(gas entry pressure)을 넘어서게 되면 기체가 급격히 벤토나이트 완충재를 통과하는 기체 이동 현상(gas migration)이 발생하게 되며 이는 사람과 주변 환경을 방사능에 노출시킬 수 있기 때문에, 공학적 방벽의 장기 건전성 확보 측면에서 기체 이동 현상을 명확히 규명하는 것이 매우 중요하다. 특히 벤토나이트 완충재와 같이 점토 물질을 다량 함유한 매질에서만 나타나는 매우 중요한 기체 흐름 현상인 팽창 흐름에 대한 수리-역학적 메커니즘을 규명하고, 기체 이동 현상의 정량적 평가를 위한 새로운 수치 해석 기법 개발 및 검증이 필수적이다. 따라서 본 연구에서는 공학적 방벽에서의 기체 이동 현상을 모사하고자 역학 손상 모델 및 손상도를 고려한 2상 유동 모델을 개발하였으며, 일정 체적 경계 조건 하에서의 1차원 기체 주입 시험 모사를 통해 개발된 모델의 적용성을 검토하였다. 수치 해석 결과 공극 수압 및 응력, 기체 유출량이 팽창 흐름 발생 시 급격히 증가하는 현상을 모사할 수 있었다.

• 대한수의학회지
• /
• 제59권4호
• /
• pp.201-205
• /
• 2019

This study presents neurogenesis and neuronal migration patterns of gamma-aminobutyric acid-ergic (GABAergic) neurons during mesencephalic development of mouse. After neurons from embryonic day (E) 10-16 were labelled by a single injection of 5-bromo-2'-deoxyuridine (BrdU), immunohistochemistry was performed. Neurogenesis were mainly generated in the mesencephalic region at E10 to E13. After E14, BrdU positive cells were observed only in the dorsal mesencephalon. GABAergic neurons were mainly originated in the ventrolateral region of the mesencephalon at the early embryonic stage, especially at E11 to E13. E10-labeled cells showed positive for GABAergic neuron in the basal plate of the mesencephalon at E13. At E15, GABAergic neurons were observed in the entire basal plate and some regions of the ventral and dorsal mesencephalon. They were present in the whole basal plate, the ventral and dorsal mesencephalon of E17, spreading more outward of the mesencephalon at P0. Our study demonstrates that major neurogenesis of GABAergic neurons occurs at E11 to E13. However, neuronal migration continues until neonatal period during mesencephalic development.

• 대한수의학회지
• /
• 제60권4호
• /
• pp.203-207
• /
• 2020

This study presents neuronal migration pattern of dopamine (DA) neurons generated in separate regions occupying the ventral mesencephalic territory. A single pulse 5-bromodeoxyuridine (BrdU) was administered at embryonic day (E)10-E15. Distribution of tyrosine hydroxylase (TH) positive cells was determined at E13-postnatal day 0 (P0) by immunohistochemistry. BrdU positive cells labeled at E10 were spread out uniformly in the mesencephalon from E13 to E15, migrating through dorsal and ventral routes at E17 and P0. TH expression labeled at E10 was observed at E13 in the ventromedial region and clearly formed in the ventral tegmental area (VTA) at E15. At E17, TH expression in the substantia nigra (SN) was observed in the ventrolateral region, spreading more outward of the mesencephalon at P0. Generation of TH-positive cells labeled at E13 was also observed in VTA and SN of the mesencephalon at E17 and P0. The expression of these cells labeled after E15 was markedly decreased. These results demonstrated that an almost complete primary structure of DA neuron was formed at the early embryonic stage in the ventral mesencephalon, showing the most active neuronal migration was occurred at E13-E17.

• Nuclear Engineering and Technology
• /
• 제56권4호
• /
• pp.1385-1397
• /
• 2024

Bentonite is a recommended material for the multiple barriers in the final disposal of low-level radioactive waste (LLW) to prevent groundwater intrusion and nuclear species migration. However, after drying-wetting cycling during the repository construction stage and ion exchange with the concrete barrier in the long-term repository, the bentonite mechanical behaviors, including swelling capacity and hydraulic conductivity, would be further influenced by the groundwater intrusion, resulting in radioactive leakage. To comprehensively examine the factors on the mechanical characteristics of bentonite, this study presented scenarios involving MX-80 and KV-1 bentonites subjected to drying-wetting cycling and accelerated ion migration. The experiments subsequently measured free swelling, swelling pressure, and hydraulic conductivity of bentonites with intrusions of seawater, high pH, and low pH solutions. The results indicated that the solutions caused a reduction in swelling volume and pressure, and an increase in hydraulic conductivity. Specifically, the swelling capability of bentonite with drying-wetting cycling in the seawater decreased significantly by 60%, while hydraulic conductivity increased by more than three times. Therefore, the study suggested minimizing drying-wetting cycling and preventing seawater intrusion, ensuring a long service life of the multiple barriers in the LLW repository.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권6호
• /
• pp.2437-2444
• /
• 2012

Tumor metastasis remains the principal cause of treatment failure and poor prognosis in patients with colorectal cancer. It is a multistage process which includes proteolysis, motility and migration of cells, proliferation in a new site, and neoangiogenesis. A crucial step in the process of intra- and extra-vasation is the activation of proteolytic enzymes capable of degrading the extracellular matrix (ECM). In this stage, urokinase plasminogen activator receptor (uPAR) and matrix metalloproteinases (MMPs) are necessary. Micrometastases need the presence of growth factor and vascular growth factor so that they can form macrometastasis. In addition, cell adhesion molecules (CAMs) and guanine nucleotide exchange factors (GEFs) play important roles in the progression of colorectal cancer and metastatic migration. Further elucidation of the mechanisms of how these molecules contribute will aid in the identification of diagnostic and prognostic markers as well as therapeutic targets for patients with colorectal metastasis.