• Journal of Aquaculture
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• v.15 no.4
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• pp.253-260
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• 2002

To find the optimal rearing conditions for Saxidomus purpuratus juvenile, filtering activity was estimated as functions of algal concentration and temperature by measuring the rates of clearance (CR) and ingestion (IR), when S. purpuratus was feeding. The clams were fed on unialgal diet of Isochrysis galbana at 6 algal concentrations (4.6$\times$$10^4$~2.6$\times$$10^6$ cells/ml) and at 6 temperatures (5, 10, 15, 20, 25, and 30^{\circ}C ). Algal concentration significantly affected the CR and the IR at all temperatures. At lower algal concentrations, CR increased, but decreased beyond a particular concentration. The maximum CR ($CR_{max}$) at 5, 10, 15, 20, 25, and 30^{\circ}C were 0.30, 1.73, 5.95, 15.17, 21.12, and 0.33 $l/g/h$, respectively. Below the level of 5.6$\times$10$^{5}$ cells/ml, IR increased as algal concentration increased, but was saturated at higher concentrations. To maintain high growth rate of S. purpuratus, I. galbana should be supplied with more than 5.6$\times$10$^{5}$ cells/ml. The maximum IR ($IR_{max}$) at 5, 10, 15, 20, 25 and30^{\circ}C were $2.2$\times$10^8, $1.5\times$10^9, 3.4$\times$10^9, 4.9$\times$10^9, 5.3$\times$10^9, and 1.0$\times$10^8$ cells/g/h, respectively. As for temperature, both $CR_max$ and $IR_max$ increased remarkably with raising temperature from 5 to 25^{\circ}C, but rapidly decreased at 30^{\circ}C. Between 15 and 25^{\circ}C $CR_{max} and IR_{max}$ were higher and most stable, At this temperature range, the $Q_{10}/s for CR_{max} and IR_{max}$ were 3.5 and 1.6, respectively. Therefore the optimal thermal range for the juvenile is 15~$25^{\circ}C$. The annual variation in IR$_{max}$ predicted by natural seawater temperature shows that inactive period (with lower $IR_max$) lasts for 5 months (from December to April). To ensure higher growth of juvenile during this inactive period at hatcheries, rearing temperature should be elevated to $15^{\circ}C$.>.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.143-160
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• 1996

The purpose of this study was to evaluate the response in aspect of attachment and growth rate of osteoblasts and growth rate of osteoblasts and human gingival fibroblasts to the commercially pure titanium(CP titanium)and titanium alloy(Ti-6AI-4V) that are used widely as implant materials, and to obtain the basic information to ideal implant materials. In the studly, commercially pure titanium in first test group, titanium alloy(Ti-6AI-4V) in second test group, cobalt-chrome-molybdenum alloy(Co-Cr-Mo alloy) in positive control group, and tissue culture polystyrene plate in negative control group were used. The results of this study were as follows. 1. Bone marrow cells cultured on CP titanium and Ti-6Al-4V showed significantly greater attachment and growth rate(p(0.05) compared to Co-Cr-Mo alloy in each time. 2. There were no significant differences(p>0.05) in attachment and growth rate of bone marrow cells cultured on CP titanium and Ti-6AI-4V or tissue culture plate. 3. Most bone marrow cells cultured on CP titanium, Ti-6Al-4V and tissue culture plate were attached well to each substratum in first 2days, and then, grew at higher growth rate. On the other hand, some cells cultured on Co-Cr-Mo alloy failed to attach in first 2 days, and then, attached cells grew at lower growth rate than other groups. 4. Attachment and growth rates of gingival fibroblasts cultured on CP titanium and Ti-6Al-4V showed no significant differences(p>0.05) compared to Co-Cr-Mo alloy in 2 days, but significantly greater increase(p<0.05) in 5 and 9 days. 5. There were no significantly differences(p>0.05) between growth rates on gingival fibroblasts cultured on CP titanium, Ti-6Al-4V and tissue culture plate in 2 and 5days, but a significant lower growth rate(p<0.05) on CP titanium and Ti-6Al-4V versus tissue culture plate. 6. Some gingival fibroblasts cultured on all specimen groups failed to attach, but attached cells grew well, especially on CP titanium, Ti-GAl-4V and tissue culture plate. 7. There were no significant differences(P>0.05) between growth rates of both bone marrow cells and gingival fibroblasts cultured on CP titanium and Ti-6AI-4V. As a result of this study, both commercially pure titanium and Ti-6AI-4V showed excellent biocompatibility and there was no significant difference in the cellular response to the both metals. Bone marrow cells cultured on each substratum showed significantly greater growth rate and responded sensitively to cytotoxic effects of metal surfaces compared to gingival fibroblasts. Considering cell response to the substrate, it was likely that the composition itself of titanium metals have no significant effect on the biocompatibility. Further study need to be done to evaluate the influence of surface characteristics on cellular responses.

• Journal of Life Science
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• v.18 no.3
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• pp.311-317
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• 2008

Pathophysiological oxidative stress results in neuronal cell death mainly due to the generation reactive oxygen species (ROS). In low oxygen situation such as hypoxia and ischemia, excessive ROS is generated. Coptidis Rhizoma (CR) is a traditional medicine used for the incipient stroke. In this report we show that CR water extracts $(1\;{\mu}g/ml)$ exhibited protective effects of neuronal cell death in a hypoxic model (2% $O_2/5%\;CO_2,\;37^{\circ}C,$ 3 hr) of cultured rat cortical cells. We further show that CR water extracts significantly reduced the intensity of green fluorescence after staining with $H_2DCF-DA$ on one hour and three days after hypoxic shock and in normoxia as well. Our results indicate that CR water extracts prevent neuronal death by suppressing ROS generation.

• The Journal of Korean Medicine
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• v.24 no.2
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• pp.159-165
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• 2003

Objectives : Coptidis rhizoma (CR) is an oriental medicine that has been used in many traditional prescriptions against diabetes mellitus in Korea for centuries. Our purpose was to determine the protective effect and its action mechanism of CR on the cytotoxicity of pancreatic -cell line (RINm5F cell). Methods : In this experiment, we used methods such as MTT assay for detection of cytotoxicity, DNA fragmentation assay for detection of apoptotic cell death, LDH activity assay for detection of necrotic cell death, and measurement of $DiOC_{6}$ (3) retention for detection of mitochondrial membrane potential (MMP). Background : Nitric oxide (NO) is believed to playa key role in the process of pancreatic -cell destruction leading to insulin-dependent diabetes mellitus (IDDM). Results : Exposure of RINm5F cells to chemical NO donor such as S-nitroso-N-acetylpenicillamine (SNAP) induced cytotoxic events such as DNA fragmentation and lactate dehydrogenase (LDH) release into medium. However, pretreatment of RINm5F cells with CR extract ($10~50{\mu\textrm{g}}/ml$) for 3 hours prevented SNAP-induced DNA fragmentation and LDH release into medium through the inhibition of MMP disruption. Conclusions : These results suggest that CR may be a candidate for a therapeutic or preventing agent against IDDM.

• Reproductive and Developmental Biology
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• v.32 no.3
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• pp.175-181
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• 2008

This study was conducted to investigate an effective recipient oocyte and culture system for producing of Hanwoo (Korean native cattle) somatic cell nuclear transfer (SCNT) embryos. Hanwoo ear skin fibroblasts were used as donor cells. In vitro matured Hanwoo or Holstein oocytes were enucleated, and single donor cells were transferred into the perivitelline space of the enucleated oocytes. The couplets were subsequently fused and activated. The reconstructed embryos were cultured in a conventional or sequential culture system. In the former, embryos were cultured in CR2aa medium for eight days; in the latter, embryos were cultured in modified CR2aa-A (mCR2-A) for three days and then further cultured in modified CR2aa-B (mCR2-B) for five days. In the experiment with the recipient oocyte, the rate of embryo development to the blastocyst stage was significantly (p<0.05) higher in Hanwoo recipient oocytes than in Holstein ones (48.8% vs 38.9%). BIastocysts derived from Hanwoo recipient oocytes contained significantly (p<0.05) higher numbers of total cells than those derived from Holstein recipient oocytes ($156.0{\pm}68.2$ vs $134.7{\pm}54.8$). There was no difference in the mean proportion of apoptotic cells in blastocysts between the sources of recipient oocytes. In the experiment with the embryo culture system, the blastocyst rate was somewhat higher in sequential system than in conventional system (50.0% vs 43.5%), though there was no significant difference. The numbers of total ($160.0{\pm}69.0$ vs $156.7{\pm}68.4$) and apoptotic cells ($14.0{\pm}10.4$ vs $11.8{\pm}6.4$) were not different between the culture systems. In conclusion, the present study demonstrated that Hanwoo recipient oocytes and the sequential culture system were more effective in supporting the production of Hanwoo SCNT embryos.

• Journal of Microbiology and Biotechnology
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• v.22 no.5
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• pp.690-698
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• 2012

Cr-B2, a Gram-negative hexavalent chromium [Cr(VI)] reducing bacteria, was isolated from the aerator water of an activated sludge process in the wastewater treatment facility of a dye and pigment based chemical industry. Cr-B2 exhibited a resistance for 1,100 mg/l Cr(VI) and, similarly, resistance against other heavy metal ions such as $Ni^{2+}$ (800 mg/l), $Cu^{2+}$ (600 mg/l), $Pb^{2+}$ (1,100 mg/l), $Cd^{2+}$ (350 mg/l), $ZN^{2+}$ (700 mg/l), and $Fe^{3+}$ (1,000 mg/l), and against selected antibiotics. Cr-B2 was observed to efficiently reduce 200 mg/l Cr(VI) completely in both nutrient and LB media, and could convert Cr(VI) to Cr(III) aerobically. Cr(VI) reduction kinetics followed allosteric enzyme kinetics. The $K_m$ values were found to be 43.11 mg/l for nutrient media and 38.05 mg/l for LB media. $V_{max}$ values of 13.17 mg/l/h and 12.53 mg/l/h were obtained for nutrient media and LB media, respectively, and the cooperativity coefficients (n) were found to be 8.47 and 3.49, respectively, indicating positive cooperativity in both cases. SEM analysis showed the formation of wrinkles and depressions in the cells when exposed to 800 mg/l Cr(VI) concentration. The organism was seen to exhibit pleomorphic behavior. Cr-B2 was identified on the basis of morphological, biochemical, and partial 16S rRNA gene sequencing chracterizations and found to be Acinetobacter sp.

• Applied Microscopy
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• v.28 no.1
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• pp.49-62
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• 1998

To investigate the morphological changes of epithelial cells of ductus epididymides by sperm entrance, the Korean striped field mouse, Apodemus agrarius coreae was studied with light and transmission electron microscopy. 1. The diameters of the caput epididymis (Cp) and its lumen were $135\sim145{\mu}(140{\pm}0.5{\mu})$ and $115\sim120{\mu}m(117{\pm}0.1{\mu}m)$. The length and width of the epithelium were $27.0\sim28.5{\mu}m(28.0{\pm}0.1{\mu}m)$ and $4.8\sim5.4{\mu}m(5.1{\pm}0.2{\mu}m)$. 2. The diameters of the corpus epididymis (Cr) and its lumen were $160\sim170{\mu}m(166{\pm}0.2{\mu}m)$ and $140\sim150{\mu}m(145{\pm}0.3{\mu}m)$. The length and width of the epithelium were $17.4\sim18.0{\mu}m(17.6{\pm}0.5{\mu}m)$ and $8.8\sim10.4{\mu}m(9.5{\pm}0.2{\mu}m)$. 3. The diameters of the cauda epididymis (Cu) and its lumen were $270\sim280{\mu}m(275{\pm}0.2{\mu}m)$ and $265\sim275{\mu}m(268{\pm}0.3{\mu}m)$. The length and width of the epithelium were $11.2\sim13.4{\mu}m(12.3{\pm}0.3{\mu}m)$ and $9.2\sim11.2{\mu}m(10.0{\pm}0.2{\mu}m)$. Therefore, the size of diameter and lumen of the ductus epididymides and the width of the epithelium increased from Cp and Cr to Cu, but the length of epithelial cells decreased from Ca and Cr to Cu. These data suggest that the morphological changes of epithelial cells of the ductus epididymides may be the results of the sperm entrance.

• Journal of Acupuncture Research
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• v.26 no.6
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• pp.1-9
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• 2009

Objectives : For evaluation of preventive and anti-diabetic activities of Cinnamomi ramulus(CR) herbal acupuncture on pancreatic islet damage in streptozotocin(STZ)-induced diabetic rat. Methods : CR herbal acupuncture was performed at Bisu($BL_{20}$) for 3 weeks subcutaneously starting1 week before STZ i.p. injection. SD rats were divided into four groups(n=10 for each group); 1) NC group, non-treated normal control group, 2) STZ group, STZ administered control group, 3) CR125 group, CR(125mg/kg) + STZ administered group, and 4) CR250 group, CR(250mg/kg) + STZ administered group. Results : Both of CR250 and CR125 groups showed increase in insulin secretion and decrease in the level of serum triglyceride and non-esterified fatty acid in a dose-dependent manner compared to the STZ group. Only CR250 group showed decrease in the levels of glucose and total cholesterol compared to the STZ group. CR herbal acupuncture prevents $\beta$-cell damage of pancreatic islet, showing round figure on the sections of the pancreas. In the pancreatic cells, expressions of iNOS, JNK-2, P-JNK-1/2 and ERK-1/2 were decreased compared to the STZ group. CR herbal acupuncture solution did not show any cytotoxicity by MTS assay and inhibited expressions of iNOS and COX-2 in the STZ-induced diabetic rats. Conclusions : Therefore, we suggest that CR herbal acupuncture may act as a prophylactic as well as a therapeutic modality for diabetes mellitus.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.331-336
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• 1995

A composite material was produced as an artificial bone substitute which is gradually degrAded and replaced by the regenerated natural bones after implantation. To detect the effect of the material on the cell's activity, the composite specimens were placed in MEMs and incubated at $37^{\circ}C$ for one week. Human uterus cervical cancer origin HeLa 3 cells and mouse subcutaneous origin L929 cells were cul- tured in the specimen dissolved MEMs for 5 days to investigate cytotoxicity via cell growth rates. ${Na_2}^{51}CrO_4$ solution was added to the media, to label the HeLa 53 cells, and the released amount of $^{51}Cr$ was measured by a $\gamma$-counter. On the cell growth investigation, no significant cytotoxic phenomena were revealed in both HeLa S3 and L929 cell cultures. On the released 51CR from the incubated HeLa 53 cells, no significant cell degeneration was observed from the composite embedded MEMs.

• Journal of the Korean Electrochemical Society
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• v.18 no.2
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• pp.68-74
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• 2015

To compare the microstructure and electrochemical properties between two binary alloys (Cr-Si, Ni-Si), two composition of binary alloys with the same capacity were selected using phase-diagram and prepared by matrix-stabilization method to suppress the volume expansion of Si by inactive-matrix. Master alloys were made by Arc-melting followed by fine structured ribbon sample preparation by Rapid Solidification Process (RSP, Melt-spinning method) under the same conditions. Also powder samples were produced by wet grinding for X-Ray Diffraction (XRD) and electrochemical measurements. As predicted from the phase diagram, only active-Si and inactive-matrix ($CrSi_2$, $NiSi_2$) were detected. The results of Scanning Electron Microscope (SEM) and Transmission Electron Microscopy - Energy Dispersive X-ray Spectroscopy (TEM-EDS) show that Cr-Si alloy has finer microstructure than Ni-Si alloy, which was also predictable through phase diagram. The electrochemical properties related to microstructure were evaluated by coin type full- and half-cells. Separately, self-designed test-cells were used to measure the volume expansion of Si during reaction. Volume expansion of Cr-Si alloy electrode with finer microstructure was suppressed significantly and improved in cycle capability, in comparison Ni-Si alloy with coarse microstructure. From these, we could infer the correlation of microstructure, volume expansion and electrochemical degradation and these properties might be predicted by phase diagram.