• YAKHAK HOEJI
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• v.58 no.5
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• pp.287-293
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• 2014

Alzheimer's disease (AD), most common form of dementia is characterized that memory deficit and loss of cognitive function. This study was evaluated cognitive enhancing effect of water and ethanol extracts of Codonopsis lanceolata and compared using Morris water maze and passive avoidance test. The water and 70% ethanol extracts (100, 300 and 500 mg/kg) were administered to mice. The neuroprotective effect on glutamate-induced cell death in HT22 cells was additionally investigated using MTT assay. Results showed 70% ethanol extract of Codonopsis lanceolata enhanced cognitive function than water extract, as shown by decrease in escape latency time in Morris water maze test. In passive avoidance test, 70% ethanol extract also increased the latency time compared to the water extract. Furthermore, 70% ethanol extract significantly protected neuronal cell against glutamate cytotoxicity and showed higher than neuroprotective effect of water extract. These results indicate that 70% ethanol extract more improve spatial cognitive ability and protected neuronal cells than water extract.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.703-721
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• 1998

In order to observe the effects of Nicotine and NNK on cultured human gingival fibroblast, several factors were examined including mutagenicity, the number of cells attached culture plate surface through MTT test, the abundance of collagen & collagenase in mRNA level and collagenolytic activity in extracellular matrix. The results were as follows; 1. Regardless of the co-existence of S9, Nicotine did not show the mutagenicity by itself and NNK by itself showd the same result; However, dose related mutagenicity was shown in NNK with S9. 2. The number of fibroblasts attached cultured plate surface was measured by MTT procedure. The number of cells in Non-smokers increased at all time periods as compared to those of smoker. 3. Non-smoker's fibroblast treated by NNK or Nicotine was dosedependently dosedependently decreased in the number of cells when compared to untreated control. In higher dose, Nicotine showed the cellular toxicity, but NNK did not. 4. No change in the abundance of mRNA for pro${\alpha}1$ and pro${\alpha}2$ was shown in Nicotine treated group but in gingival fibroblasts following treatment with NNK, the abundance of mRNA for pro${\alpha}1$, but not pro${\alpha}2$ collagen was decreased. 5. The abundance of mRNA for collagenase was decreased when NNK was treated but no change occurred in Nicotine treated group. 6. The effect of NNK and Nicotine in collagenolytic activity showed that, collagenase activity exclusively react to type I collagen, was increased in both group, but gelatinase exclusively react to type IV collagen was not influenced at all. Collagenase activity of smoker's fibroblast was also increased as much as Nicotine and NNK group. The findings suggest that both of Nicotine and NNK lead gingival fibroblast to decrease in the abundance of collagen. And it seems to be that Nicotine and NNK have independent pathway toward the gingival fibroblast.

• Journal of radiological science and technology
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• v.34 no.4
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• pp.323-331
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• 2011

We evaluated clinical usefulness of Arterial spin labeling perfusion MR imaging on the acute ischemic cerebral infarction patients through this study. We compared 22 patients who were done with DSC imaging and ASL imaging in admitted emergency room with acute ischemic cerebral infarction, with 36 normal comparison persons (DSC image on 21persons, ASL images on 15persons). Siemens Magnetom Verio 3.0T with 12 channel head coil was used for this study. DSC image obtained 4 maps(rCBV, rCBF, rMTT, TTP) through post-processing. For qualitative analysis we compared the area of lesion macro-diagonal with the size of diffusion weighted MR image for rMTT, TTP, rCBF, rCBV, ASL maps. For Quantitative analysis we analyzed significant correlations between less than 3 cm infarction group and normal comparison group using mean relative value of flowing image with Mann-Whitney U test. TTP(95.5%) and rCBF(95.5%) maps showed high recognition rate in qualitative analysis for >3cm infarction group. The rCBF and rCBV map tests were highly related with final stage stroke areas. Mean relative value of infarction group showed a significant correlations in quantitative analysis(p<0.05). As a conclusion, arterial spin labeling image showed high lesion recognition rate in the >3cm infarction group. Mean relative values in quantitative evaluation were used for reference data. If we do more sustainable researches, ASL image will be useful for an early diagnosis of cerebral infarction, determination of the range of ischemic pneumbra and effective treatments.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.84-95
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• 2001

Titanium is widely used in dentistry for its low density, high strength, fatigue resistance, corrosion resistance, and biocompatibility. But it has a tendency of surface damage under circumstance of friction and impact for its low hardness of the surface. Coating is one of methods fir increasing surface hardness. Its effect is to improve surface physical characteristics without change of titanium. Diamond-like carbon and titanium nitride are known for its high hardness of the surface. So that this study was aimed at the wear test and the cytotoxicity test of the commercially pure titanium and Ti-6Al-4V alloy which were deposited by diamond-like carbon film or titanium nitride film to acertain improvement of the surface hardness and the biocompatibility. A disk (25mm diameter, 2mm thickness) was made of commercially pure titanium and Ti-6Al-4V alloy and these substrates were deposited by diamond-like carbon film or titanium nitride film. Diamond-like carbon film was deposited by the method of radiofrequency plasma assisted chemical vapor deposition and titanium nitride film was deposited by the method of reactive arc ion plating. Then these substrates were tested about wear characteristics by the pin-on-disk type wear tester in which ruby ball was used as a wear causer under the load of 32N, The fracture cycles were measured by rotating the substrates until their films were fractured. The wear volume was measured after 150 cycles and 3,000 cycles using surface profiler. The cytotoxicity test was peformed by the method of the MTT assay. The results were as follows : 1. In the results of the wear volume test, commercially pure titanium and titanium alloy which were coated by diamond-like carbon film or titanium nitride aim had higher resistance against wear than the substrates which were not coated by any films (P<0.05). 2. In the results of the fracture cycle test and the wear volume test, diamond-like carbon film had higher resistance against wear than titanium nitride film (P<0.05). 3. In both coatings of diamond-like carbon aim and titanium nitride film, Ti-6Al-4V alloy had higher resistance against wear than commercially pure titanium (P<0.05) 4. In the results of the cytotoxicity test, diamond-like carbon film and titanium nitride film had little cytotoxicity as like commercially pure titanium or Ti-6Al-4V alloy (P>0.05).

• Transactions on Electrical and Electronic Materials
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• v.15 no.5
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• pp.275-278
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• 2014

We deposited TiAgN and ZrAgN nanocomposite coatings on pure Titanium specimens, by using arc ion plating (AIP) with single alloy targets. TiAg ZrAg alloy targets of 5 wt.%, 10 wt.% silver content by vacuum arc remelting (VAR), followed by homogenization for 2 hours at $1,100^{\circ}C$ in non-active Ar gas atmosphere and characterized these samples for morphology and chemical composition. We investigated the biocompatibility of TiAg and ZrAg alloys by examining the proliferation of L929 fibroblast cells by MTT test assay, after culturing the cells ($4{\times}10^4cells/cm^2$) for 24 hours; and exploring the antibacterial properties of thin films by culturing Streptococus Mutans (KCTC3065), using paper disk techniques. Our results showed no cytotoxic effects in any of the specimens, but the antibacterial effects against Streptococus Mutans appeared only in the 10 wt.% silver content specimens.

• Journal of Sericultural and Entomological Science
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• v.51 no.1
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• pp.41-47
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• 2013

In this study, silkgland powder of silkworm were investigated to see possibility for cosmetic powder materials. To test possibility as a baby powder cosmetics, total content rate of amino acids, DPPH free radical scavenging assay, MTT assay, and clinical trial were done. According to the result of the analysis of the amino acids of silkgland powder, serin (26.77%) content was the highest and asparatic acid (15.47%), and glycine (9.62%) were followed. DPPH free radical scavenging activity of silkgland powder was lower than vitamin C by 82.3% and 97%, respectively, which is relatively good. And the moisture and elasticity effect were increased in silkgland powder compared to control cosmetics by 210% and 185%, relatively. Thus, these results suggest that silkgland powder of silkworm may have beneficial properties as a material for cosmeceuticals.

• Journal of Nutrition and Health
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• v.36 no.4
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• pp.382-388
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• 2003

(-)-Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound found in peen tea leaves, and has been known to be one of the most potent catechin species which inhibits cell growth most possibly through an apoptotic cell death. We investigated the apoptotic activity of (-)-EGCG on the human myeloid leukemia cell line, HL-60. Our results of MTT test indicated that (-)-EGCG had a significant antiproliferation effect in HL-60 cells with $IC_{50}$/ (50% inhibition concentration) value of 65 $\mu$M. Giemsa statining of HL-60 cells treated with (-)-EGCG (100 $\mu$M) for 6hrs showed a typical apoptosis-specific morphological change including shrinkage of the cytoplasm, membrane blobbing and compaction of the nuclear chromatin. The DNA fragmentation was observed from the agarose gel electrophoresis of cells treated with (-)-EGCG for 3hrs or longer, and was progressed to a greater degree as treatment time increases. Treatment of the cells with (-)-EGCG (100 $\mu$M) resulted in a rapid release of mitochondrial cytochrome c into the cytosol, and a subsequent cleavage of caspase-3 to an active form in a treatment-time dependent manner. (-)-EGCG (100 $\mu$M) also stimulated proteolytic cleavage of poly-(ADP-ribose) polymerase (PARP) to an active form in HL-60 cells. Tlken together, (-)-EGCG appears to induce the apoptosis in human myeloid leukemia cells via a caspase-dependent pathway. These results suggest the possible application of (-)-EGCG, the major active compound in green tea, as an antiproliferative agent for cancer prevention.

• Journal of Nutrition and Health
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• v.32 no.7
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• pp.838-843
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• 1999

Antitumor effects of various teas have been studied for a long time. Among them, green tea is one of the most popular test and very close to our lives in Korea. However, precise effect and mechanism about antitumor effects of green tea were not estabilished. The present study investigated the antitumor effect of catechin, which is main component of green tea, which was produced in Korea, was used. In each group, morphological changes were observed induced severe cell damage and growth inhibition gradually until 24hours. Then catechin effect was found to be concentration-and time-dependent. EATC was injured abruptly at 100ug/ml catechin treatment for 6 hours and the effect lasted constantly until 24 hours. But in both of cell lines, cell damage and inhibition of proliferation did not show up apparently at concentration of 10 and 1ug/ml. In contrast, catechin led to little or no effect against HepG2 in all of concentrations and periods. These results suggest that catechin extracted from green tea had different effect on cancer cells as cell type, concentration and period. Therefore green tea would be helpful to cancer treatment as well as cancer prevention and this study would be the basic source for further research of green tea.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.2
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• pp.111-117
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• 2003

Cisplatin is often effective in cancer treatment, but its clinical use is limited because of its nephrotoxicity. We have synthesized new platinum(II) coordination complexes (PC-1 & PC-2) containing trans-${\iota}$ and cis-1,2-diaminocyclohexane (DACH) as carrier ligands and L-3 -phenyllactic acid (PLA) as a leaving group with the aim of reducing nephrotoxicity but maintaining its anticancer activity. In this study, new platinum(II) complex compounds were evaluated for selective cytotoxicity on cancer cell-lines and normal kidney cells. The new platinum complexes have demonstrated high efficacy in the cytotoxicity against human bladder carcinoma cell-lines (T-24/HT-1376). The cytotoxicity of these compounds against rabbit proximal renal tubular cells and human renal cortical tissues, was determined by MTT assay, the [3H]-thymidine uptake and glucose consumption test, and found to be quite less than those of cisplatin. Based on our results, these novel platinum compounds appear to be valuable lead compounds with high efficacy and low nephrotoxicity.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.51.2-51.2
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• 2011

A novel electrospun nanofiber membrane was fabricated using combined poly (vinylphosphonic acid) (PVPA) and polyvinyl alcohol (PVA) intended for bone tissue engineering applications. PVPA is a proton-conducting polymer used as primer for bone implants and dental cements to prevent corrosion and brush abrasion. The phosphonate groups of PVPA have the ability to crosslink and attach itself to the hydroxyapatite surface facilitating faster integration of the biomaterial to the bone matrix. PVA was combined with PVPA to provide hydrophilicity, biocompatibility and improve its spinnability. To improve its mechanical strength, PVPA/PVA and neat PVA mixtures were combined to produce a multilayer scaffold. The physical and chemical properties of the of the fabricated matrix was investigated by SEM and TEM morphological analyses, tensile strength test, XRD, FT-IR spectra, swelling behavior and biodegradation rates, porosity and contact angle measurements. Biocompatibility was also examined in vitro by cytotoxicity and cell proliferation studies with MTT assay and cell adhesion behavior by SEM and confocal microscopy.