• Journal of Technologic Dentistry
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• v.31 no.3
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• pp.21-26
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• 2009

Purpose: Standards of alloy for porcelain fused to metal crown be classified by metallic factor and biological factor. Metallic factors consist of stability of alloy composition and mechanical strength and surface characteristics for chemical bond. Biological factors be considered properties of metallic elements and problems originated by toxicity and hypersensitive reaction. Alloys considered such controversial points are the most suitable alloy for dental instrument. Method: Alloys added Be and Nb using Ni-Cr alloy which has been widely used for dental instrument be selected and classified experimental group. Non-addition Be and Nb to Ni-Cr alloy classify control group and addition Be alloy is Be-experimental group, addition Nb alloy is Nb-experimental group. Specimens for cytotoxicity analysis gave effect to washing and sterilization. and then made an experiment on elution with cell medium after disinfection. It conducted specimens within cell medium with 24hours, 48hours, 72hours, respectively. It cultured human dermal fibroblast(HDF) using cell medium for cytotoxicity test and then investigated elution rate through spectroscopic analysis by MTT-assay. Result: As results of cytotoxicity test by MTT-assay, cultured cell rate of VII measured more low numerical value within elution medium for 24hours focused on control group. Also, cultured cell rate of K3 alloys observed low value for 48hours, 72hours than value of control group. Conclusion: According to final result that synthesize above results, Ni-Cr alloy added Be and Ni has little difference in Cytotoxicity by MTT-assay.

• Korean Journal of Medicinal Crop Science
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• v.7 no.1
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• pp.37-44
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• 1999

This study was conducted to screen antitumoral activity by in vitro bioassay method using 60 Korean medicinal and food plants extracted by 80% EtOH. Antitumor activity test was applied by the PKC(protein kinase C) and antibleb formation, PLC (Phospholipase C), and colorimetric tetrazolium assay (MTT assay) methods. Chenopodjum album and black Glycine max showed high antitumoral activity by 73.5% and 81.0%, respectively, against PKC by bleb-forming assay and PKC enzyme assay on human chronic leukemia K562 cell. Black Glycine max also showed 91.2% antitumoral activity in the PLC method and the lowest $IC_{50}$ $value(4.7{\mu}g/ml)$ by MTT method against P-338 cell line. In the effect of the concentration treatment on antitumoral test, the more concentration indicated the more activity value.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.581-584
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• 2002

Individual surface(hydrophilic/hydrophobic) were prepared and mammalian cells were cultured on the hydrophilic region. For drug test, cancer and normal cells were treated with Taxol, as an example. Our system was compared with MTT assay. CHO cells were resistant to Taxol up to 100 nM in both Methods. However, A549 cells was sensitive at 100 nM Taxol in the 2 day-treatment. Cervical carcinoma cell, HeLa, was very sensitive to Taxol. In our system, the cells were not shown from above 20 nM Taxol treatment. Our system was competitive to MTT assay in animal cells for drug test.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.98-98
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• 1995

독사 또는 곤충의 독 30여종을 대상으로 SNU-1 위암세포에 대하여 MTT test를 실시한 결과 세포 독성 활성이 제일 높은 킹코브라(Ophiophagus hannah)의 venom을 가지고 세포 독성 물질을 정제하였다. Gel Filtration Chromatography와 Anion Exchange Chromatography로 정제한 4번째 peak만이 MTT/SRB test결과 IC$_{50}$ value 0.947$\mu\textrm{g}$/ml이었다. 음이온 교환 크로마토그라피로 정제한 단백질을 PRO-RPC로 더 분리하여 순수한 단일성분을 얻었으며 맹장암, 대장암, melanoma, fibrosarcoma 세포에 대해 독성을 확인하였고, 광학 및 전자 현미경에 의해 암세포의 분화와 성장이 억제됨을 재확인하였다. 또한 thymidine uptake asaay에서 암세포의 증식이 억제되었고, 또한 EDTA, $Zn^{++}$, $Ba^{++}$ 첨가로 세포 독성 활성이 증가되었다. (중략)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.303-303
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• 2015

In order to investigate ion release and biocompatibility of Ti-6Al-4V dental alloy by electrochemical corrosion test and MTT assay, commercial Ti-6Al-4V alloy rod (99.99% Ti, USA, Co) were used in the study. The microstructure of the alloys was examined by optical microscopy (OM), Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), MTT assay, and corrosion test. From the polarization curves, very low current densities were obtained for Ti-6Al-4V alloys, indicating a formation of stable passive layer.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.107-107
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• 2015

In order to investigate electrochemical behavior and biocompatibility of Co-Cr dental alloy by electrochemical corrosion test and MTT assay, the xCo-25Cr-yW-zNi alloys were used in this study. Samples of Co-Cr-W-Ni alloys were manufactured using arc melting furnace. The microstructure of the alloys was examined by optical microscopy (OM), Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), MTT assay, and corrosion test. Corrosion resistance increased slightly as cobalt (Co) content increased. And bioactivity was concerned with nickel (Ni) and tungsten (W). Biocompatibility of Co-Cr alloy depended on Ni and W contents.

• Toxicological Research
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• v.25 no.1
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• pp.47-50
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• 2009

To investigate the mutation inducibility of surfactin C, we performed the chromosome aberration assay with Chinese hamster lung cells in vitro. The colorimetric MTT screening assay was carried out to determine the cytotoxicity index ($IC_{50}$) of surfactin C. The $IC_{50}$ value was $125{\mu}g/ml$. For the chromosome aberration test of surfactin C, the maximum concentration was employed as $125{\mu}g/ml$, followed by 62.5 and $31.25{\mu}g/ml$ for the lower concentrations, with or without metabolic activation (S9). Cyclophosphamide and mitomycin C were used as positive controls in the presence and absence of S9 metabolic activation, respectively. These results showed that surfactin C was not capable of inducing chromosome aberration, as measured by the chromosome aberration test using Chinese hamster lung cell line. There is no evidence for surfactin C to have a genotoxic potential.

• Physical Therapy Korea
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• v.23 no.4
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• pp.1-8
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• 2016

Background: Various methods are used for recovery of knee flexion range of motion (ROM) due to a tightened rectus femoris muscle (RFM) or limited inferior glide of the patella. Stretching methods are common interventions for restoring the tightened RFM length. Also patellar inferior gliding (PIG) technique can recover tightened RFM length too. However, effect of applying the PIG to passive knee flexion (PKF) has not been studied. Objects: The purpose of this study was to investigate the effect of combining PIG with RFM stretching for improving knee flexion ROM in subjects with RFM tightness. Methods: Twenty-six subjects with RFM tightness were recruited. Two different methods of knee stretching were tested: 1) PKF during modified Thomas test (MTT) and 2) PKF with PIG during MTT. The passive stretching forces was controlled by hand-held dynamometer. The knee flexion ROM angle was measured by a MTT with ImageJ software. Differences between the conditions with and without PIG were identified with a paired t-test. Results: The knee flexion ROM was significantly greater for PKF with PIG ($114.44{\pm}9.33$) than for PKF alone ($108.97{\pm}9.42$) (p<.001). Conclusion: A combination of passive knee flexion exercise and PIG can be more effective than PKF in increasing knee flexion ROM in individuals with RFM tightness.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.61-72
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• 1995

The author performed radionuclide esophageal transit studies(RETS) with liquid and solid boluses using the same day protocol in 90 normal controls and 164 patients with various primary esophageal motility disorders who were diagnosed by manometric criteria and clinical courses. The authors calculated mean esophageal transit time(MTT) and mean residual retention(MRR) in each of the liquid and solid studies, and classified time-activity curve(TAC) patterns. The normal criteria of RETS with liquid bolus were MTT<24 sec, MRR<9%, and the TAC pattern that showed rapid declining slope and flat low residual(Type 1). The normal criteria of RETS with solid bolus were MTT<35 sec, MRR<9% and TAC of type 1. With these normal criteria, the sensitivity and the specificity of the liquid study were 62.2 % and 97.8%, respectively. The sensitivity increased to 75.4% with the solid study. The author also found that the RETS was highly reproducible. The achalasia typically showed no effective emptying of both liquid and solid boluses during the whole study period, and was well differentiated by its extremely long transit time and high retention from the other motility disorders. The diffuse esophageal spasm (DES) and nonspecific esophageal motility disorder(NEMD) showed intermediate delay in transit time and increased retention. In the groups of hypertensive lower esophageal sphincter(LES), hypotensive LES and nutcracker, there noted no significant difference with the normal control group in terms of MTT and MRR. The DES and NEMD could be more easily identified by solid studies that showed more marked delay in MTT and increased MRR as compared with the liquid study. In conclusion, esophageal scintigraphy is a safe, noninvasive and physiologic method for the evaluation of esophageal emptying.

• Journal of Oriental Neuropsychiatry
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• v.21 no.2
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• pp.61-73
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• 2010

Objectives : The purpose of this study was to assess anti-depressive effects of Bee Venom(BV) on an Animal Model of Depression induced immobility stress. Methods : There was 2 pre-experiments MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and Western blot test and 3 main experiments ; forced swimming test, tail suspension test and Y-maze task. Male rats were used for main experiment. The subject was divided into 4 groups(1. control group injected only saline, without immobility stress 2. Negative group injected saline after 2 hours immobility stress 3. Positive group injected Amitriptyline after 2 hours immobility stress 4. BV group injected Bee Venom after 2 hours immobility stress). Each group consisted of 6 rats. Forced swimming test, tail suspension test, Y-maze task were used to evaluate anti-depressive effect of Bee Venom. Results : In MTT assay, as the density of BV increased, the existence rate of primary neuronal cell increased. In Western blot test, the density of CREB and AKT was increasing as time went by. In forced swimming test, BV group showed immobility decreased more than Normal group and Positive group. In tail suspension test, Normal group and Positive group showed immobility decreased more than BV group. In Y-maze task, BV group showed immobility decreased more than Normal group, but Positive group showed immobility decreased more than BV group. Conclusions : These results suggest that Bee Venom may have anti-depressive effect on depression.