• Journal of Marine Bioscience and Biotechnology
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• v.2 no.2
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• pp.77-80
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• 2007

Macroalgal tissues can be used as indicating materials for environmental assessment using several algal biotechnology techniques. As bioassay test organisms, macroalgal tissues are required as an axenic state for suitable biological indicators. Callus formation and blade regeneration under suitable culture conditions are also useful for the tests. Quantitative method using tetrazolium chloride or $alamarBlue^{TM}$ is devised on a rapid assessment of the seaweed viability. The use of RT-PCR especially differential display technique should provide the means for the detection and isolation of the responding genes induced by the environmental stress. Seaweed thriving in more environmental changes might contain more diverse biologically active substances.

• The Journal of Korean Medicine
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• v.21 no.2
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• pp.68-78
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• 2000

Objective : This research was performed to investigate protective effects of Sophora subprostrata, against ischemic brain damage after a middle cerebral artery(MCA) occlusion. The effect was estimated using histological test, neurobehavioural test, and biochemical test. Methods : Rats(Sprague-Dawley) were divided into four groups: Sham operated group, MCA occluded group, Sophora subprostrata administrated group after MCA occlusion, and Normal group. The MCA was occluded by intraluminal method. Sophora subprostrata was administrated orally twice(l and 4 hours) after middle cerebral artery occlusion. The neurobeavioural test was performed at 3 hours, 6 hours, 9 hours and 24 hours after the surgery by posture reflex test and swimming behavioural test. All groups were sacrificed at 24 hours after the surgery. The brain tissue was stained with 2% triphenyl tetrazolium chioride(TTC) or 1 % cresyl violet solution, to examine effect of Sophora subprostrata on ischemic brain tissue. The blood samples were obtained from the heart of rats. Tumor necrosis factor-a level was measured from sera using Enzyme-Linked Immunoabsorbent Assay(ELISA). Results : The results showed that (1) Sophora subprostrata reduced infarct size and total infarct volume by 54.8% compared to the control group, (2) that neuronal death, which was shown by decrease in cell number and size, was attenuated significantly in the boundary area of the infarction, (3) that serum $TNF-{\alpha}$ㆍlevel was reduced significantly, and finally, there was significant recovery of motor deficit at 3 hours after MCA occluded by Swimming behavioural test. Conclusions :In conclusion, Sophora subprostrata has protective effects against ischemic brain damage at the early stage of ischemia.

• Journal of Plant Biotechnology
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• v.40 no.1
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• pp.43-48
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• 2013

Oreorchis coreana Finet is threatened globally by over-collection from its natural habitats for horticultural purposes. Its rarity in nature makes this plant one of the most endangered species in Korea. In this study, we investigated the effects of sodium hypochlorite (NaOCl) on orchid seed viability and seed germination. An in vitro bioassay swelling test using immature seeds was compared with a standard chemical procedure using triphenyl tetrazolium chloride (TTC) to test seed viability. In general, the bioassay was more appropriate for estimating embryo viability after a prolonged pre-treatment (more than 1 h) in 1% NaOCl, a surface sterilant often used to enhance germination of seeds of terrestrial plants. Therefore, an efficient method for investigating in vitro swelling of immature seeds is urgently needed. We established a method for determining the viability and swelling of O. coreana seeds via in vitro examination of immature seeds. Treatment of immature seeds with 1% NaOCl for 10 min greatly enhanced the extent of swelling of immature zygote embryos when compared to untreated seeds. These data obtained here appear to be comparable to viability and swelling that occurs in O. coreana seeds via asymbiotic germination.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.397-401
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• 2011

Aspiration of lytic bone lesions is an excellent diagnostic test in the initial evaluation of primary bone tumor. However, cytologically, it can be difficult to differentiate osteosarcoma (OSA) from other bone neoplasms, including fibrosarcoma, chondrosarcoma, synovial cell sarcoma, malignant fibrous histiocytoma and malignant peripheral nerve sheath tumor. The purpose of this study is to introduce alkaline phosphatase (ALP) staining to differentiate OSA from other mesenchymal tumors. Tumors actively producing bone are specifically positive for ALP staining. Unstained, cytologic specimens were incubated for 10 minutes with nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indolyl phosphate toluidine salt-phosphatase substrate. Among 20 cases of cytology specimen, 14 were positive for ALP staining and histopathology, 6 were negative for ALP staining and histopathology. ALP staining was 100% sensitive and specificity for the diagnosis of OSA. Aspirate cytology with ALP staining was a simple, fast, safe and accurate diagnostic test for the evaluation of suspected OSA lesions in dogs.

• Biomedical Science Letters
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• v.2 no.1
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• pp.49-55
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• 1996

The objective of this study was to develop a paper strip which could determine E. coli qualitatively and quantitatively in water, wastewater, drinks, or food. This paper strip method was a simple and rapid test method that determine E. coli by visual identification. In this study, nutrient culture media were formulated and characterized for optimum conditions. Paper strips were then prepared by impregnating into the media and dried at $60^\circ$C. The test procedure is quite simple to use. The paper strip was dipped into a sample, and excess sample was removed. The strip was then incubated at $37^\circ$C for 16 to 20 hours and the number of colonies on the strip was counted. The color of the colony spots produced by microorganisms varied depending on the media formulation. Violet-red spots were produced by E. coli. The test method was simple, rapid and no special laboratory equipment was necessary for visual identification. Therefore, this test method is applicable to on-site tests such as field tests or home tests. The paper strip method was compared with the standard agar plate method and Japanese commercial product. The method of the economical preparation of test strips was studied for production on industrial scale.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.504-511
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• 1995

This study was conducted to investigate the superoxide dismutase (SOD) characteristics and antioxidant activity by nonenzymatic(Fe$^{2+}$/Ascorbate) and Fe$^{3+}$-ADP/NADPH method in perilla(Perilla frutescens var. japonica Hara.) and jaso(Perilla frutescens Briton var. acuta Kudo.) leaves. The characteristics were evaluated by the nitro blue tetrazolium reduction method. Perilla leaves contained three or four major SODs depending on the varieties. The inhibitor test indicated that the Perilla leaves contained two Cu /ZnSODs and one or two FeSODs, but Jaso leaves have only Cu/ZnSOD. However, no varietal differences were detected in the Cu /ZnSOD isozyme patterns. FeSODs, however, showed different varietal isozyme patterns through the different combinations of the two FeSOD isozymes. Among MeOH extractes, "mil yang 2" showed very strong antioxidant activity. Relatively large differences in the levels of SOD and antioxidant activity detected in the Perilla varietites. There was significantly different in the comparison between perilla leaves and red jaso leaves.s.etween perilla leaves and red jaso leaves.

• The Journal of Korean Medicine
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• v.22 no.1
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• pp.10-21
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• 2001

Objective : This study was performed to investigate the protective effect of Stephania tetrandra(ST) against ischemic brain damage after a middle cerebral artery(MCA) occlusion. The effect was evaluated using histological tests, neurobehavioral tests, and biochemical tests. Methods : Rats(Sprague-Dawley) were divided into four groups : sham operated group, MCA occluded group, post MCA occlusion Stephania tetrandra administrated (7.6mg/l00g) group, and normal group. The MCA was occluded by intraluminal method. Stephania tetrandra was administrated orally twice at 1 and 4 hours after MCA occlusion. The neurobehavioral test was performed at 3, 6, 9 and 24 hours after MCA occlusion by posture reflex test and swimming behavioral test. All groups were sacrificed then. The brain tissues were stained with 2% triphenyl tetrazolium chloride(TTC) or 1 % cresyl violet solution, to examine infarct size, volume and cell number. Tumor necrosis $factor-{\alpha}$ level was measured from sera using Enzyme-Linked Immunoabsorbent Assay(ELISA). The mRNA expression level of inflammatory cytokines and related receptor type I and II, $IL-1{\beta}$, IL-6, and IL-10 6hours after MCA occlusion were also studied by reverse transcriptase polymerase chain reaction(RTPCR). Results : The results showed that : Stephania tetrandra (1) reduced infarct size and total infarct volume by 52.2% compared to the control group; (2) attenuated significantly in neuronal death, which was shown by a decrease in cell number(P<0.01) and size(P<0.01) in the boundary area of the infarction; (3) significantly reduced serum $TNF-{\alpha}$ level, and increased the mRNA level of IL-10 in the cortex region(P<0.01). However, there was no significant effect on motor deficit in swimming behavioral test. Conclusions : In conclusion, Stephania tetrandra has protective effects against ischemic brain damage at the early stage of ischemia.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.163-170
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• 2001

Purpose : The measurement of radiation survival using a clonogenic assay, the established standard, can be difficult and time consuming. In this study, We have used the MTT assay, based on the reduction of a tetrazolium salt to a purple formazan precipitate by living cells, as a substitution for clonogenic assay and have examined the optimal condition for performing this assay in determination of radiation sensitivity. Materials and Methods : Four human cancer cell lines - PCI-1, SNU-1066, NCI-H630 and RKO cells have been used. For each cell line, a clonogenic assay and a MTT assay using Premix WST-1 solution, which is one of the tetrazolium salts and does not require washing or solubilization of the precipitate were carried out after irradiation of 0, 2, 4, 6, 8, 10 Gy. For clonogenic assay, cells in $25\;cm^2$ flasks were irradiated after overnight incubation and the resultant colonies containing more than 50 cells were scored after culturing the cells for $10\~14$ days. For MTT assay, the relationship between absorbance and cell number, optimal seeding cell number, and optimal timing of assay was determined. Then, MTT assay was performed when the irradiated cells had regained exponential growth or when the non-irradiated cells had undergone four or more doubling times. Results : There was minimal variation in the values gained from these two methods with the standard deviation generally less than $5\%$, and there were no statistically significant differences between two methods according to t-test in low radiation dose (below 6 Gy). The regression analyses showed high linear correlation with the $R^2$ value of $0.975\~0.992$ between data from the two different methods. The optimal cell numbers for MTT assay were found to be dependent on plating efficiency of used cell line. Less than 300 cells/well were appropriate for cells with high plating efficiency (more than $30\%$). For cells with low plating efficiency (less than $30\%$), 500 cells/well or more were appropriate for assay. The optimal time for MTT assay was after 6 doubling times for the results compatible with those of clonogenic assay, at least after 4 doubling times was required for valid results. In consideration of practical limits of assay (12 days, in this study) cells with doubling time more than 3 days were inappropriate for application. Conclusion : In conclusion, it is found that MTT assay can successfully replace clonogenic assay of tested cancer cell lines after irradiation only if MTT assay was undertaken with optimal assay conditions that included plating efficiency of each cell line and doubling time at least.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.409-428
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• 1994

Endodontic surgery is performed when conventional endodontic therapy fails or is contraindicated. In such cases, retrograde filling materials including amalgam, composite resin, and various cements have been used. Biocompatibilty and margin sealing ability of retrograde filling materials are important for the long term success of endodontic surgery. In vitro cell culture is frequently used as the method of measuring the biocompatibilty of dental materials. The purpose of this study was to evaluate the cytotoxicity of six kinds of retrograde filling materials including newly developed light curing glass ionomer cements. Each material was mixed according to. the manufacture's instruction and evaluated as : freshly mixed, 24-hour after mixing, and 168-hour after mixing respectively. The elution solution was extracted after 24-hour contact with materials using media. Cytotoxicity was evaluated by direct contact, or elution contact. Test results of radiochromium($^{51}Cr$) release, cell viability using tetrazolium dye (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl dimethyltetrazolium bromide(MTT) test and lactate dehydrogenase(LD) of damaged L929 cells were analyzed. In the $^{51}Cr$ release of direct contact, all experimental retrograde filling materials except amalgam and glass ionomer cement showed increased cytotoxicity compared to control. In the $^{51}Cr$ release of elution solution, the released $^{51}Cr$ was so minimal that it was impossible. to evlauate the cytotoxicity exactly. The elution solutions of glass ionomer cement and IRM showed marked cytotoxicity in MTT test. LD enzyme activity was highest in tests of direct contact with composite, light curing composite, and light curing glass ionomer cement and IRM. Amalgam revealed least cytotoxicity while IRM showed cytotoxicity using all three methods. Composite, light curing composite and light curing glass iomomer cement were cytotoxic in the tests of $^{51}Cr$ release and LD activity. Glass ionomer cement showed cytotoxic effect only in the MTT method. From these results it is suggested that the standardization and optimization of cytotoxicity testing, especially using elution solutions, should be strongly advised.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.47.1-47.11
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• 2020

Objectives: The aim of this study was to assess the physicochemical properties, cytotoxicity and penetration into dentinal tubules of ChlorCid^TM Surf (3% sodium hypochlorite [NaOCl] with surfactant) in comparison to ChlorCid^TM (3% NaOCl without surfactant). Materials and Methods: The physicochemical properties evaluated were pH, surface tension, free available chlorine (FAC) and contact angle. Cytotoxicity was evaluated in L929 fibroblasts exposed to the solutions by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red assays. Assessment of penetration into dentinal tubules was performed by staining single-rooted permanent human teeth with crystal violet (n = 9), which were irrigated with the solutions and analyzed in cervical, middle and apical segments. Data were analyzed by one-way analysis of variance (ANOVA) and Tukey's post-test, 2-way ANOVA and Bonferroni's post-test or t-test (α = 0.05). Results: ChlorCid^TM Surf and ChlorCid^TM FAC values were close to those indicated by the manufacturer. ChlorCid^TM Surf showed lower surface tension and contact angle on dentin, and higher pH than ChlorCid^TM (p < 0.05). The penetration of ChlorCid^TM Surf was higher in cervical and middle segments, compared with ChlorCid^TM (p < 0.05). There was no difference in irrigant cytotoxicity (p > 0.05). Conclusions: ChlorCid^TM Surf showed lower surface tension, lower contact angle on root canal dentin, higher penetration into dentinal tubules and more alkaline pH, compared with ChlorCid^TM. However, both solutions showed similar cytotoxicity and FAC content.