• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.3
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• pp.261-270
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• 2006

The success of an implant is determined by its integration into the tissue surrounding the biomaterial. Surface roughness is considered to influence the behavior of adherent cells. The aim of this in vitro study was to determine the effect of surface roughness on Saos-2 osteoblast-like cells. Titanium disks, blasted with $75{\mu}m$ aluminum oxide particles and anodic oxidized and machined titanium disks were prepared. Saos-2 were plated on the disks at a density of 50,000 cells per well in 48-well dishes. After 1 hour, 1 day, 6 days cell numbers were counted. One day, 6 days after plating, alkaline phosphatase(ALPase) activity was determined. Compared to experimental groups, the number of cells was significantly higher on control group. The stimulatory effect of surface roughness on ALPase was more pronounced on the experimental groups than on control group. These results demonstrate that surface roughness alters proliferation and differentiation of osteoblasts. The results also suggest that implant surface roughness may play a role in determining phenotypic expression of cells.

• Korean Journal of Veterinary Service
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• v.18 no.1
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• pp.1-21
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• 1995

To elucidate pathogenesis of bovine leukemia virus(BLV) in Korean native goats, the goats experimentally infected with BLV were studied especially for the aspects of infectivity and hematological changes. The experimental goats were examined for 27 months by agar-gel immunodiffusion(AGID) test and syncytium formation assay. During this period, changes of total leucocyte, absolute Iymphocyte and atypical Iymphocyte were examined, and the distribution of surface immunoglobulin ( sIg ) -bearing cells and rosette forming cell (RFC) in the peripheral Iymphocyte were also investigated. By indirect immunofluorescence (IFA) and complement dependent antibody cytotoxicity (CDAC) assay using monoclonal antibody(Mab) against bovine leukosis tumor-associated anti-gen(BL-TAA), changes of BL-TAA positive Iymphocyte in peripheral blood were measured. The results obtained through the experiment were summarized as follows. 1. Antibody titers were measured by AGID using gP51 and P24 antigens. The animals were serologically converted at 2 months post-inoculation(pi) in gP51 antigen, whereas sero-converted at 4 months pi in P24 antigen. In comparison with antibody titers for gP51, P24 antigen showed lower titers throughout the trial period. 2. The peripheral lymphocytes from all of the infected goats, as co-cultivated with F8l cells manifested syncytial formation at 4 months pi. 3. On counting total leucocyte, Iymphocyte and atypical Iymphocyte, two out of four infected goats showed normal distribution, while No 2 of the remaining two revealed temporal and No 3, Persistant increasing number of the cells. 4. The optimal condition of rosette formation of the peripheral Iymphocyte of normal Korean native goats was shown in the sheep erythrocyte treated with 0.1M AET for 30 nun at $37^{\circ}C$. When the Iymphocytes were treated in nylon wool column, the number of sIg-bear-ing cell were increased in the nylon wool adherent cells, but RFC was increased in the non-adherent cells. Of the infected goats, No 2 and No 3 showed significantly increasing number of sIg-bearing cells at 18 months pi. 5. The Iymphocytes of No 2 and No 3 goats reacted positively in IFA using Mab against BL-TAA at 12 months pi and 18 months pi, respectively. In CDAC test, all of four infected goats revealed positive reaction at 24 months pi. The higher positive rates were observed in No 2 and No 3 as compared with the remainders.

• Journal of Life Science
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• v.10 no.1
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• pp.57-63
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• 2000

${\beta}$-catenin, which plays a critical role in both the cytoskeleton and in transcriptional regulation in variousadherent cell types, undergoes degradation during adherent cell apoptosis. Although ${\beta}$-catenin has been reported to be present in Jurkat T-acute lymphoblastic leukemia cells, the regulation of ${\beta}$-catenin in hematologic malignancies have not been examined. The data presented here demonstrate that treatment of the T cell leukemia Jurkat iwht the apoptosis inducer anti-Fas induced proteolytic cleavage of ${\beta}$-catenin. ${\beta}$-catenin was cleaved at both the N- and C-terminus after anti-Fas treatment. Cleavage of intact ${\beta}$-catenin was completely inhibited by caspase selective protease inhibitors. These data demonstrate that ${\beta}$ -catenin proteolysis is triggered by the cross-linking of the Fas receptor on Jurkat cells and subsequent activation of caspase protease. There was a clear accumulatio of the large proteolytic fragment in Jurkat cells treated with lactacystin of ALLM. These are potent inhibitors of proteasome and calpain. these results suggest that both the proteasome and clapain may recognize the large ${\beta}$-catenin fragment as a substrate fot further degradation and that these pathewasy may act downstream of scapase in response to Fas receptor activation. Therefore, we suggest that ${\beta}$-catenin may play a role in promoting Jurkat survival.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.482-490
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• 2018

Candida albicans infections are often problematic to treat owing to antifungal resistance, as such infections are mostly associated with biofilms. The ability of C. albicans to switch from a budding yeast to filamentous hyphae and to adhere to host cells or various surfaces supports biofilm formation. Previously, the ethanol extract from Paeonia lactiflora was reported to inhibit cell wall synthesis and cause depolarization and permeabilization of the cell membrane in C. albicans. In this study, the P. lactiflora extract was found to significantly reduce the initial stage of C. albicans biofilms from 12 clinical isolates by 38.4%. Thus, to assess the action mechanism, the effect of the P. lactiflora extract on the adhesion of C. albicans cells to polystyrene and germ tube formation was investigated using a microscopic analysis. The density of the adherent cells was diminished following incubation with the P. lactiflora extract in an acidic medium. Additionally, the P. lactiflora-treated C. albicans cells were mostly composed of less virulent pseudohyphae, and ruptured debris was found in the serum-containing medium. A quantitative real-time PCR analysis indicated that P. lactiflora downregulated the expression of C. albicans hypha-specific genes: ALS3 by 65% (p = 0.004), ECE1 by 34.9% (p = 0.001), HWP1 by 29.2% (p = 0.002), and SAP1 by 37.5% (p = 0.001), matching the microscopic analysis of the P. lactiflora action on biofilm formation. Therefore, the current findings demonstrate that the P. lactiflora ethanol extract is effective in inhibiting C. albicans biofilms in vitro, suggesting its therapeutic potential for the treatment of biofilm-associated infections.

• Analytical Science and Technology
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• v.34 no.6
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• pp.275-283
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• 2021

This study presents the development of cell-based microfluidic chips for the performance of acute eye irritation tests due to chemicals and examined some of their applications. Microfluidic chips were fabricated by photolithography and soft lithography, and they had three compartments with different areas for cell culture. Rabbit corneal epithelial cells were used for the eye irritation test. The death of cells cultured inside the chip was monitored at regular time intervals after treatment with an aqueous solution of chemicals, and the cell death rate constants were calculated based on the viability curve. The performance of the microfluidic chip was verified by examining the effects of cell-cell junctions, cell-substrate adhesion, and initial cell numbers compared to cell death rates. Eye irritation tests were performed at various concentrations of an aqueous solution of sodium dodecyl sulfate (SDS), a standard substance for the eye irritant test. The cells were exposed to the SDS aqueous solution for 300 s, and the resulting eye irritation was assessed by cell viability. Finally, the equation for calculating the toxicity score (TS) was derived based on the weighting factor for each compartment in the chip. The cell-based microfluidic chip developed in this study may be used for eye irritation tests from chemicals used in cosmetics and pharmaceuticals.

• Molecules and Cells
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• v.24 no.3
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• pp.343-350
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• 2007

Mesenchymal stem/progenitor cells (MPCs) were isolated from porcine umbilical cord blood (UCB) and their morphology, proliferation, cell cycle status, cell-surface antigen profile and expression of hematopoietic cytokines were characterized. Their capacity to differentiate in vitro into osteocytes, adipocytes and chondrocytes was also evaluated. Primary cultures of adherent porcine MPCs (pMPCs) exhibited a typical fibroblast-like morphology with significant renewal capacity and proliferative ability. Subsequent robust cell growth was indicated by the high percentage of quiescent (G0/G1) cells. The cells expressed the mesenchymal surface markers, CD29, CD49b and CD105, but not the hematopoietic markers, CD45 and CD133 and synthesized hematopoietic cytokines. Over 21 days of induction, the cells differentiated into osteocytes adipocytes and chondrocytes. The expression of lineage specific genes was gradually upregulated during osteogenesis, adipogenesis and chondrogenesis. We conclude that porcine umbilical cord blood contains a population of MPCs capable of self-renewal and of differentiating in vitro into three classical mesenchymal lineages.

• IMMUNE NETWORK
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• v.2 no.3
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• pp.166-174
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• 2002

Background: Human umbilical cord bloods, which could be taken during the delivery are utilized as a source of hematopoietic stem cells. Also in cord blood, there are several kinds of stem cells such as endothelial and mesenchymal stem cells. Methods: We isolated the mesenchymal stem cells from human umbilical cord bloods and confirmed the differentiation of these cells into osteoblast progenitor cells. The mesenchymal stem cells derived from umbilical cord blood have the ability to differentiate into specific tissue cells, which is one of characteristics of stem cells. These cells were originated from the multipolar shaped cells out of adherent cells of the umbilical cord blood mononuclear cell culture. Results: The mesenchymal stem cells expressed cell surface antigen CD13, CD90, CD102, CD105, ${\alpha}$-smooth muscle actin and cytoplasmic antigen vimentine. Having cultrued these cells in bone formation media, we observed the formation of extracellular matrix and the expression of alkaline phosphatase and of mRNA of cbfa-1, ostoecalcin and type I collagen. Conclusion: From these results we concluded that the cells isolated from the umbilical cord blood were mesenchymal stem cells, which we could differentiate into osteoblast when cultured in bone formation media. In short, it is suggested that these cells could be used as a new source of stem cells, which has the probability to alternate the embryonic stem cells.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1370-1372
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• 1998

Boron doped CdS films were prepared by CBD(Chemical Bath Deposition) method using boric acid ($B_3HO_3$) as donor dopant source, and their properties were investigated. As-grown CdS films were highly adherent and specularly reflective. Boron doped CdS film which was fabricated under the condition of 0.01 $B_3HO_3/Cd(Ac)_2$ mole ratio, exhibited the lowest resistivity of $2{\Omega}cm$ and the highest optical bandgap of 2.41eV. Also, CdS/CdTe solar cells were fabricated with various doping concentration of CdS films. Using optimized CdS film as the window layer of CdS/CdTe solar cell, the characteristics of the cell were improved. ( $V_{oc}$=610mV, $J_{sc}$=37.5mA/cm, FF=0.4, $\eta$=9.1% )

• Korean Journal of Pharmacognosy
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• v.32 no.3 s.126
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• pp.226-232
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• 2001

To explore the possible cancer therapeutic application of "Bo-yang-hwan-oh-tang" (BH), a herbal medicinal recipe used for improvement of blood stasis, we have examined its direct cytotoxicity against tumor cell, and induction of cytotoxic activity of lymphocytes. Water extract of BH alone did not exhibit direct cytotoxicity to Yac-1 target cells even with high concentrations (10 mg/ml). By exposure for 3 days, BH did not induce any nonspecific cytotoxic activity of mouse spleen cells, either, when assessed in a 4 hr $^{51}Cr-release$ assay. However, when BH was added during CD3 stimulation of non-adherent spleen cells, non-specific CTL activity was markedly promoted in a dose dependent manner. In contrast, BH did not alter activated NK cell activity following IL-2 stimulation. These data suggest that BH does not induce but upregulates non-specific CTL effecter function and that activated NK cell does not respond to BH. For elucidation of the mechanism underlying this function of BH, time kinetic study for IL-2 production using ELISA was undertaken. IL-2 production following CD3 stimulation was significantly augmented and higher level of IL-2 is sustained over 3 days in the culture medium by BH treatment. Moreover, addition of exogenous IL-2 during CD3 stimulation resulted in a similar level of cytotoxicity between control and BH-treated culture. These data indicate that the BH-mediated upregulation of non-specific CTL activity is contributed by augmentation of IL-2 production. Our data imply the possible application of BH for combination therapy of cancer with non-specific activator.

• Journal of Ginseng Research
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• v.36 no.1
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• pp.78-85
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• 2012

Endothelial progenitor cells (EPC) are a population of cells that circulate in the blood stream. They play a role in angiogenesis and, therefore, can be prognostic markers of vascular repair. Ginsenoside $Rg_3$ prevents endothelial cell apoptosis through the inhibition of the mitochondrial caspase pathway. It also affects estrogen activity, which reduces EPC senescence. Sun ginseng (SG), which is heat-processed ginseng, has a high content of ginsenosides. The purpose of this study was to investigate the protective effects of SG on senescence-associated apoptosis in EPCs. In order to isolate EPCs, mononuclear cells of human blood buffy coats were cultured and characterized by their uptake of acetylated low-density lipoprotein (acLDL) and their binding of Ulex europaeus agglutinin I (ulex-lectin). Flow cytometry with annexin-V staining was performed in order to assess early and late apoptosis. Senescence was determined by ${\beta}$-galactosidase (${\beta}$-gal) staining. Staining with 4'-6-Diamidino-2-phenylindole verified that most adherent cells (93${\pm}$2.7%) were acLDL-positive and ulex-lectin-positive. The percentage of ${\beta}$-gal-positive EPCs was decreased from 93.8${\pm}$2.0% to 62.5${\pm}$3.6% by SG treatment. A fluorescence-activated cell sorter (FACS) analysis showed that 4.9% of EPCs were late apoptotic in controls. Sun ginseng decreased the apoptotic cell population by 39% in the late stage of apoptosis from control baseline levels. In conclusion, these results show antisenescent and antiapoptotic effects of SG in human-derived EPCs, indicating that SG can enhance EPC-mediated repair mechanisms.