• Journal of Microbiology and Biotechnology
• /
• v.34 no.7
• /
• pp.1425-1432
• /
• 2024

This study analyzed the effects of Ca²⁺ metal ions among culture medium components on the Chlorella sorokiniana strain DSCG150 strain cell growth. The C. sorokiniana strain DSCG150 grew based on a multiple fission cell cycle and growth became stagnant in the absence of metal ions in the medium, particularly Ca²⁺. Flow cytometry and confocal microscopic image analysis results showed that in the absence of Ca²⁺, cell growth became stagnant as the cells accumulated into four autospores and could not transform into daughter cells. Genetic analysis showed that the absence of Ca²⁺ caused upregulation of calmodulin (calA) and cell division control protein 2 (CDC2_1) genes, and downregulation of origin of replication complex subunit 6 (ORC6) and dual specificity protein phosphatase CDC14A (CDC14A) genes. Analysis of gene expression patterns by qRT-PCR showed that the absence of Ca²⁺ did not affect cell cycle progression up to 4n autospore, but it inhibited Chlorella cell fission (liberation of autospores). The addition of Ca²⁺ to cells cultivated in the absence of Ca²⁺ resulted in an increase in n cell population, leading to the resumption of C. sorokiniana growth. These findings suggest that Ca²⁺ plays a crucial role in the fission process in Chlorella.

• The Korean Journal of Physiology and Pharmacology
• /
• v.5 no.4
• /
• pp.359-366
• /
• 2001

We have synthesized a novel platinum(II) coordination complex containing cis-1,2-diaminocyclohexane (DACH) as a carrier ligand and 1,3-dichloropropane (DCP) as a leaving group. A new series of [Pt(cis- DACH)(DCP)](PC) was evaluated for its cytotoxic activity on MKN-45 human gastric adenocarcinoma cells and normal primary cultured kidney cells. The new platinum complex has demonstrated high efficacy in the cytotoxicity against MKN-45/P, MKN-45/ADM and MKN-45/CDDP cell-lines. The cytotoxicity of PC against rabbit proximal renal tubular cells, human renal cortical cells and human renal cortical tissues, determined by MTT assay, the $[^3H]-thymidine$ uptake and glucose consumption tests, was found to be quite less than those of cisplatin. Based on these results, this novel platinum(II) coordination complex appears to be better for improving antitumor activities with low nephrotoxicity and is a valuable lead in the development of new, clinically available anticancer chemotherapeutic agents.

• Biomolecules & Therapeutics
• /
• v.8 no.3
• /
• pp.228-234
• /
• 2000

We have synthesized a novel platinum(II) coordination complex containing trans-ι-1,2-diaminocy-clohexane (DACH) as a carrier ligand and 1,2-dichloroethane (DCE) as a leaving group. A new series of [Pt(trans-ι-DACH)(DCE)](PC) was evaluated for its cytotoxic activity on MKN-45 human gastric adenocar-cinoma cells and normal primary cultured kidney cells. The new platinum complex has demonstrated high efficacy in the cytotoxicity against MKN-45/P, MKN-45/ADM and MKN-45/CDDP cell-lines. The cytotoxicity of PC against rabbit proximal renal tubular cells, human renal cortical cells and human renal cortical tissues, determined by MTT assay, the [$^3H$]-thymidine uptake arid glucose consumption tests, was found to be quite less than those of cisplatin. Based on these results, this novel platinum(II) coordination complex appears to be better for improving antitumor activities with low nephrotoxicity and is a valuable lead in the development of new, clinically available anticancer chemotherapeutic agents.

• Bulletin of the Korean Chemical Society
• /
• v.13 no.5
• /
• pp.498-503
• /
• 1992

The protonation of RuH(NO)(Cyttp) resulted in the formation of $[RuH_2(NO)(Cyttp)]^+$ which is characterized as a classical cis-dihydried complex. This complex is fluxional and the intramolecular process involving a molecular hydrogen complex is proposed. This mechanism was further supported by the reactivity of this complex toward neutral 2-electron ligands. On the other hand, it failed to detect the existence of $[RuH_2(NO)(etp)]^+$ probably due to instability of the complex but the crystal structure of $[Ru(PMe_3)(NO)(etp)]^+$ formed by the protonation of RuH(NO)(etp) followed by the addition of $PMe_3$ was determined to have a trigonal bipyramidal structure with a linear NO in the equatorial plane and a facial etp ligand. The crystals are monoclinic, space group P21/n, with unit cell dimensions a = 14.130(2), b = 21.026 (3), c = 14.760 (1) ${\AA}$, ${\beta}$ = 97.88 $(l)^{\circ}$ V = 4344 ${\AA}^3$, Z = 4, R = 0.046 and $R_w$ = 0.056 for the 4779 intensities with $F_o^2 > 3{\sigma}(F_0^2)$ and the 440 variables.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.8 no.4
• /
• pp.91-100
• /
• 2008

Numerical implementation with a Cartesian cut-cell method is conducted in this study. A Cartesian cut-cell method is an easy and efficient mesh generation methodology for complex geometries. In this method, a background Cartesian grid is employed for most of computational domain and a cut-cell grid is applied for the peculiar grids where the flow characteristics are changed such as solid boundary to enhance the accuracy, applicability and efficiency. Accurate representation of complex geometries can be obtained by using the cut-cell method. The cut-cell grids are constructed with irregular meshes which have various shape and size. Therefore, the finite volume method is applied to numerical discretization on a irregular domain. The HLLC approximate Riemann solver, a Godunov-type finite volume method, is employed to discretize the advection terms in the governing equations. The weighted average flux method applied on the Cartesian cut cell grid for stabilization of the numerical results. To validate the numerical model using the Cartesian cut-cell grids, the model is applied to the rectangular tank problem of which the exact solutions exist. As a comparison of numerical results with the analytical solutions, the numerical scheme well represents flow characteristics such as free surface elevation and velocities in x-and y-directions in a rectangular tank with the Cartesian and cut-cell grids.

• KSBB Journal
• /
• v.30 no.4
• /
• pp.175-181
• /
• 2015

Cells proliferate via repeating process that growth and division. This process is G1, S, G2 and M four phases consists. Monitoring the progression of the cell cycle is a specific step that to be a continuous process is repeated to adjust the start of the next step. At this time, this process is called a Checkpoint. Currently, there are three known checkpoints that G1-S phase, G2-M phase, and the M phase. In this study, we confirmed that cell cycle arrest effects by ethanol extracts of Artemisia annua Linne (AAE) in Hep3B liver cancer cells. AAE was regulated proteins which involved in cell cycle such as pAkt, pMDM2, p53, p21, pCDK2 (T14/Y15). AAE induced cell cycle arrest in G1 checkpoint through phosphorylation of CDK2. Akt and p53 upstream is inhibited by AAE and p53 activated by non-activated pMDM2, p53 inhibitor. Thereby, activated p53 is transcript to p21 and activated p21 protein is combined with Cyclin E-pCDK2 complex. Therefore, we confirmed that AAE-induced cell cycle arrest was occurred by p21-Cyclin E-pCDK2 complex by inhibition of pAkt signal. Because of this cell cycle can't pass to S phase from G1 phase.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10b
• /
• pp.1627-1632
• /
• 1991

A compact type LDPE autoclave reactor is analyzed with respect to the effects of the initiator feed concentration and the rate of heat transfer by employing the mixing-cell model with backflow. Singularity theory is applied for the single-cell model so that one can construct all the possible bifurcation diagrams. Since the single-cell model may not be adequate for the actual reactor, a two-cell model is also treated to predict the dynamic behavior of the reactor. As the rate of heat transfer increases, various multiplicity patterns and oscillatory motions are found. Apparently, the monomer conversion can be substantially increased with proper he-at removal and initiator supplement scheme. For this, however, the complex dynamic features accompanied must be taken into consideration in the reactor design.

• IMMUNE NETWORK
• /
• v.1 no.3
• /
• pp.179-186
• /
• 2001

Bone marrow stroma is a complex tissue encompassing a number of cell types and supports hematopiesis, differentiation of erythreid, nyel and lymphoid lineages, and also maintains undifferentiated hematopoietic stem cells. Marrow-derived stem cells were composed of two populations, namely, hematopoietic stem cells that can differentiate into blood elements and mesenchymal stem cells that can give rise to connective tissues such as bone, cartilage, muscle, tendon, adipose and stroma. Differentiation requires environmental factors and unique intracellular signaling. For example, $TGF-{\beta}$ or BMP2 induces osteoblastic differentiation of mesenchymal stem are very exciting. However, the intrinsic controls involved in differentiation of stem cells are yet to be understood properly in order to exploit the same. This review presents an overview of the recent developments made in mesenchymal stem cell research with respect to osteogenesis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3695-3700
• /
• 2012

Mammalian mediator (MED) is a multi-protein coactivator that has been identified by several research goups. The involvement of the MED complex subunit 19 (MED 19) in the metastasis of lung adenocarcinoma cell line (H1299), which expresses the MED 19 subunit, was here investigated. When MED 19 expression was decreased by RNA interference H1299 cells demonstrated reduced clone formation, arrest in the S phase of the cell cycle, and lowered metastatic capacity. Thus, MED 19 appears to play important roles in the biological behavior of non-small cell lung carcinoma cells. These findings may be important for the development of novel lung carcinoma treatments.

• BMB Reports
• /
• v.34 no.5
• /
• pp.391-394
• /
• 2001

The balance between life and death of a cell regulates essential developmental processes in multicellular organisms. Apoptotic cell death is a complex, stepwise program involving multiple protein components that trigger and execute the demise of the cell. Of the many triggers of apoptosis, most are not well understood, but some key components have been identified, such as those of the Bcl-2 family, which function as anti-apoptotic or proapoptotic factors. Bax, a pro-apoptotic member of this family, has been shown to serve as a component of many apoptotic triggering cascades and its mechanism of action is the focus of intense study. Herein we discuss current, differing ideas on the function of Bax and its structure, and suggest novel mechanisms for how this death protein targets mitochondria, triggering apoptosis.