• 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.

• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.77-81
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• 1996

The present experiment was carried out to examine the mechanism of cytotoxicity of Chromium in CHO cells. Chromium induced chromosomal aberrations in a dose-dependent manner. The most frequent type of aberration was chromatid deletions and chromosome type exchanges were also observed. Ultrafiltrates of culture media from CHO cells treated with Chromium induced sister chromatid exchanges(SCE) in CHO cells and Chromium induced lipid peroxidation. It was suggested that indirect effect through formation of clastogenic factor(CF) as well as direct effect on DNA might contribute to the cytotoxicity of Chromium.

• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.369-376
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• 1993

To know the in vitro and the in vivo cytotoicity of resin solution, resin solution was applied to cultured fibroblast and was injected into the mouse. The cytotoxic effect of resin solution was measured by MIT assay and in vivo cytotoxicity was examined after Hematoxylin and Eosin staining. The cell activity of resin solution in the concentration of 50% was significantly decreased compared to control group and 5 % group. In histopathologic study of resin solution, there were severe inflammatory cell infiltration, mild interstitial edema, trace hemorrhage, and moderate or severe muscle destruction in resin injected group. These results suggested that there might be some differences between the cell viability of fibroblast and in vivo cell cytotoxicity. Further study is needed to clarify the cytotoxicity by direct implanting of resin mass.

• IMMUNE NETWORK
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• v.2 no.2
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• pp.115-124
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• 2002

Background: The chemical characteristics of the exo-secretion from Phellinus linteus (referred to as exo-secretion) including the compositions of amino acids and monosaccharides were investigated. In addition, cytotoxicity of the exo-secretion on 5 tumor cell lines derived from human cancers and its antitumor activity against ascitic sarcoma-180 cells were examined. Methods: The antitumor activity of exo-secretion from Phellinus linteus was determined by measuring parameters including tumor weight, life span of mice, chemotatic activity of leukocytes, counts of immune cells, and activity of cytokines. Results: The exo-secretion from Phellinus linteus showed no direct cytotoxicity to the five tumor cell lines tested, but it had a strong antitumor activity against sarcoma-180 cells in ICR mice as measured by tumor weight and life span of mice. The exo-secretion stimulated the chemotaxis of leukocytes and production of immune cells and cytokines. Conclusion: These results suggest that the exo-secretion from Phellinus linteus do not act as a direct cytotoxic substance to cancer cells but as an immunomodulator.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.235-240
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• 2000

Inhibitory effects of cockle extracts on carcinogen-induced cytotoxicity in C3H/10T1/2 cells were studied. Soup (62$\mu\textrm{g}$/mL), solubility (28$\mu\textrm{g}$/mL) and liposolubility (9 $\mu\textrm{g}$/mL) of the cockle inhibited 3-methyl-cholanthrene(MCA)-induced cytotoxicity in C3H/10T1/2 cells by 53 and 94%, respectively. These results suggest that the extracts cockle might have anticarcinogen-induced cytotoxicity of C3H/10T1/2 cells. The effects of cockle extracts on the immune response related to its antitumor activity in vitro and in vivo were investigated. The cockle extracts showed a direct cytotoxic effect on sarcoma-180 cells, tumor cells in vitro. Soup (0.49 mg/mL), solubility (0.11 mg/mL) and liposolubiliy (0.05 mg/mL) of the cockle markedly decreased the total numbers of sarcoma-180 cells, but not their viability. The phagocytic acitivity of peritoneal macrophage of mice was significantly augmented by these extracts of the cockle compared with that of control in vivo. These extracts also raised the phagocuytic index, indicating that the number of phagocytize dmicrobes per macrophage increased. Thus, cockle extracts might show a antitumor activity by enhancing the phagocytic cell activities.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.4
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• pp.309-322
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• 2002

The purpose of this study was to investigate the cytotoxicity and mutagenicity of denture base resins. According to manufacturer's instructions, resin specimens were made. Group 1 : heat-polymerizing acrylic resin (Luciton $199^{(R)}$) Group 2 : heat-polymerizing acrylic resin containing polyhedraloligosilsesquioxane(POSS resin) Group 3 : auto-polymerizing acrylic resin (Repair $Acrylic^{(R)}$) Group 4 : direct relining auto-polymerizing acrylic resin (Tokuso $Rebase^{(R)}$). Fresh specimens 24 hrs. and 72 hrs. soaked specimens in distil)ed water were made. Responses with metabolic assay and mutagenesis assay to eluates from resin specimens were measured. Cultures with medium alone provided controls. Cytotoxicity was assessed with agar overlay test. The results were as follows; 1. Group 4 showed higher cytotoxicity than Group 1, Group 2 and Group 3 in fresh, 24-an4 72-hour immersion caries (p<.05). Group 3 showed higher cytotoxicity than Group 2 in fresh cases and showed higher cytotoxicity than Group 1 and Group 2 in 24-and 72-hour immersion cases (p<.05) . Group 1 and Group 2 showed no significant difference. 2. All acrylic denture base resins skewed significant increase of cell activity as immersion time increased (p<.05). 3. Auto-polymerizing acrylic denture base resins skewed higher cytotoxicity than heat-polymerizing acrylic denture base resins (p<.05). 4. All acrylic denture base resins showed lower mutagenicity than controls (p<.05).

• IMMUNE NETWORK
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• v.2 no.2
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• pp.109-114
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• 2002

Background: To investigate the role of sympathetic nervous system (SNS) in moxibustion-induced immunomodulation, the effects of chemical sympathectomy on moxibustion-induced changes in splenic NK cell cytotoxicity, T and B cell proliferation were studied in Sprague-Dawley male rats. Methods: Chemical sympathectomy was achieved with intraperitoneal injection of 6-hydroxydopamine 50 mg/kg/day for 3 successive days. Direct moxibustion (6-minute interval, 9 moxa ball, each of which weighing 0.007 g and burning for 40 seconds) was applied on unilateral anterior tibial muscle region where Zusanli (ST36) acupoint is located, once a day for 7 successive days. NK cell cytotoxicity was measured by $4hr-^{51}Cr$ release assay. Mitogen-induced lymphocyte proliferation was analyzed by [$^3H$]-thymidine incorporation assay. Results: NK cell cytotoxicity was suppressed by moxibustion, more in sympathectomized rats than in vehicle-treated rats. T cell proliferation induced by concanavalin A was not affected by moxibustion. B cell proliferation induced by lipopolysaccharide showed no significant change in vehicle-treated rats, but an increase in sympathectomized rats by moxibustion. Sympathectomy alone induced augmentation of NK cell cytotoxicity and suppression of T cell proliferation. Conclusion: These results suggest that SNS has no direct relation with moxibution-induced immunomodulation but has an important role in the mechanism to keep the homeostasis of immune system by tonically inhibiting excessive changes of various immune components.

• Parasites, Hosts and Diseases
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• v.28 no.2
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• pp.85-90
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• 1990

This study was aimed to observe the direct and Iymphokine-activated cell mediated cytotoxic effects against Trichomenas waginalis by mouse peritoneal macrophages. Cytotoxicity was measured as release of 3H-thymidine from prelabeled protozoa, and tested in U-bottom microtiter plates. A 0.1 ml suspension of labeled protozoa (2{\times}10^5/ml$) was placed in each well, followed by 0.1 ml of a suspension containing increasing numbers of peritoneal cells. After a 24 hr incubation at $37^{\circ}C$, 0.1ml of the supernatant was collected and counted in liquid scintillation counter. Mouse peritoneal macrophages had appreciable level of spontaneous cytotoxicity against T. maginalis at the effector to target cell ratios from 5 : 1 to 50 : 1, Treatment of macrophages with Iymphokine, produced by PHA-stimulated spleen cells, increased the cytotoxicity in comparison with resident macrophages against T. vaginalis. The degree of macrophage activation for the killing was not dependent upon the Iymphokine concentration. Peritoneal cells adherent to plastic displayed significant levels of cytotoxicity against T. vaginalis. This study indicates that mouse peritoneal macrophages are spontaneously cytotoxic for T. waginalis and Iymphokine increases the cytotoxicity by activating macrophages to kill T. vaginalis.

• Journal of Korean Dental Science
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• v.7 no.2
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• pp.80-86
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• 2014

Purpose: Current common method of cytotoxicity evaluation for elastomeric impression materials use animal based cell lines, which the clinical relevance has been often questioned. Hence, the purpose of this study was to examine the difference in results with both human based and animal based fibroblast cell line. Materials and Methods: Three types of fibroblast cells were used in this study; conventional mouse fibroblasts of L929, human gingival fibroblasts (HGF-1), and immortalized human oral fibrobalsts (hTERT-hNOF). Test on extract and test by direct contact using different commercially available elastomeric impression materials were carried out according to the international standards. Result: There was significant difference in cell viability between types of fibroblasts cell used, where HGF-1 showed highest cell viability and L929 the lowest. Conclusion: Within the limitation of this study, careful consideration must be given when selecting the cells and interpreting the results for cytotoxicity evaluation of elastomeric impression materials, where use of human based cell lines such as hTERT-hNOF would be appropriate for both ease of cytotoxicity test and clinical relevance.

• Biomedical Science Letters
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• v.25 no.4
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• pp.293-301
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• 2019

Combination chemotherapy is more effective than mono-chemotherapy and is widely used in clinical practice for enhanced cancer treatment. In this study, we investigated the potential synergistic effects of acetaminophen, a common component in many cold medicines, and romidepsin, a histone deacetylase (HDAC) inhibitor, in the A549 non-small cell lung cancer (NSCLC) cell line. The combination of acetaminophen and romidepsin also exerted significant cytotoxicity and apoptosis induced by activation of caspase-3 on tumor cells in vitro. Moreover, combination therapy significantly induced increased production of chemokines that stimulate migration of activated T-cells into tumor cells. This mechanism can lead to active T-cell mediated anti-tumor immunity in addition to the direct cytotoxic chemotherapeutic effect. Activated T-cells led to enhanced cytotoxicity in drug-treated A549 cells through interaction with tumor cells. These results suggested that the interaction between the two drugs is synergistic and significant. In conclusion, our data showed that the use of romidepsin and low concentrations acetaminophen could induce effective anti-tumor effects via enhanced tumor immune and direct cytotoxic chemotherapeutic responses. The combination of acetaminophen with romidepsin should be considered as a promising strategy for the treatment of lung cancer.