No abstract available.
Animals ; Mice*

Alveolar bone destruction is a characteristic of periodontal disease. Treponema denticola are found in significantly increased numbers in the sites affected with periodontal disease. In order to clarify the role of T. denticola in destruction of alveolar bone in periodontal disease, this study was undertaken to determine the effect of sonicated extract of T. denticola on osteoclast differentiation in co-culture system of mouse bone marrow cells and calvaria cells. The ability of osteoclast formation was estimated by counting the number of tartrate resistant acid phosphatase(TRAP) positive cells. Sonicated extract of this bacteria stimulated osteoclast formation in a dose dependent manner(p<0.05). Indomathacin, an inhibitor of prostaglandin synthesis, decreased osteoclast formation induced by sonicated extract of this bacteria(p<0.05). Extract-induced osteoclast formation was decreased, when sonicated extract of bacteria was heated(p<0.05). These findings suggest that T. denticola induces osteoclast differentiation, and protein component of this bacteria and PGE2 may play an important role in this process.
Mice ; Animals

The mechanism of cytolysis by complement attack of nucleated cells(NC) is of special interest in comparison to that of red blood cells. It is known that NC death by membrane attack comples, C5b-9, is caused by many factors, i.e., efficiency of complex assembly, activation of intrinsic metabolic pathway by signal transduction, cytotoxic effect of the channel itself and natural repair ability. These factors suggest that colloid osmotic lysis, known in red blood cells, does not fully explain the complement-mediated cell death of NC. In this study, the authors investigated correlation between biochemical and morphological changes to prove "Ca2+-mediated metabolic death"8~13) representing a mechanism of NC death caused by C5b-9 attack. The L1210 cells, mouse leukemic cell line carrying small complement channel(TAC5b-91) were used in the experiments. The amounts of intracellular adenine nucleotides to extracellular Ca2+, ouabain, KC1 and dextran were analyzed by bioluminescence method using luminometer. Cell viability was checked by 0.4% trypan blue dye and LDH release. Morphological observation of TAC5b-91 was done by immunocytochemical staining and electron microscope. The results were as follows: 1) The release of ATP, ADP and AMP followed by cell death was rapid and progressive along the incubation time at 37 degrees C and it was accelerated in 1.5 mM of [Ca2+]0. 2) There was no evidence of ATP repairment in the TAC5b-91. 3) Extracellular KC1(150 mM), dextran(0.66 mM) and ATP supplement(0.2 microM) could not effectively inhibit ATP depletion and cell death. Ouabain(27 and 100 microM) enhanced cell death and could not completely prevent ATP loss. 4) Most of the mitochondria showed swelling, loss of cristae and Ca2+ deposit in matrix in the electron microscopic observation. Rapid, sustained and irreversible depletion of adenine nucleotides was due to Ca2+ deposit with destruction of mitochondria and also the leakage through transmembrane channels. Moreover this energy depletion was accelerated by high extracellular Ca2+ concentration. These results indicate that Ca2+-mediated, energy exhaustion is one of the mechanisms of the metabolic cell death by C5b-9 attack of NC.
Mice ; Animals

No abstract available.
Animals ; Mice*

No abstract available.
Animals ; Mice*

Viral myocarditis is considered an important cause of dilated cardiomyopathy. At preseent, two mechanisms are known to be involved in the pathogenesis of viral myocarditis and subse-quent cardiomyopathy: viral direct toxicity and immune mediated toxicity. Some authors have reported that IL-6 influences the immunologic mechanism and the virus-induced tissue damage in myocarditis. We injected encephalomyocarditis(EMC) virus to induce viral myocarditis in ICR mice. In order to study the lymphocyte subset and IL-6 expression to clarify the immune mechanism and to demonstrate the role of IL-6 in viral induced myocardial damage. The following results were obtained: 1) In virus inoculated mice, inflammation was severest at 10 days, and some serious complications developed, indicating a possible transition to dilated cardiomyopathy. 2) On analysis of the lymphocyte subset, CD4 cells were most prevalent at 5 days and CD8 cells were most prevalent at 10 and 20 days. 3) IL-6 was significantly increased and expression of IL-6 was constant, but its intensity was strongest at 5 days. In conclusion, IL-6, produced by inflammatory cells, fibroblasts, and endothelial cells, might play an important role in myocardial damage in experimentally induced EMC viral myocarditis by its direct cytotoxicity or cytokine mediated activation of cytotoxic cells.
Mice ; Animals

PURPOSE: To investigate synergistic effect of local cryoablation with systemic immunotherapy, the tumor control ability and immunologic responses of combining these two modalities was compared with that of cryoablation, surgical excision, and immunotherapy only group in a tumor re-challenge model. MATERIALS AND METHODS: Preliminary experiments were performed in two stages. The first stage consisted of 36 Balb/c mice with Renca bearing tumors imbedded in the right thigh, and was treated with interleukin-2 (IL-2) and interferon-alpha(IFN-alpha) to evaluate the efficacy of immunotherapy and to determine the adequate dosage. The second stage was performed on 10 mice, to evaluate histological changes and efficacy after cryoablation. The main experiment was performed on 48 mice, divided into 6 groups of control with tumor implantation, excision of tumor, excision combined with immunotherapy, cryoablation of tumor, cryoablation with immunotherapy and control without tumor. After treatment, tumor re-challenge was performed with Renca cell, then the growth pattern was evaluated with physical measurements, and immune response was investigated with fluorescent activated cell sorter and cytotoxicity assay. RESULTS: Preliminary studies on immunologic efficacy revealed that IL-2 and IFN-alpha have a dose dependent inhibition of tumor growth. The main experiment evaluating the efficacy of combination treatment revealed that cryoablation with immunotherapy proved to be most effective in terms of tumor recurrence and tumor growth inhibition, yet the difference was not statistically significant from monotherapy with cryoablation. However, cytotoxicity was significantly increased cryoablation with immunotherapy compared with other groups. CONCLUSIONS: Cryoablation on tumor re-challenge mice model showed advantages with immunotherapy most prominently in cytotoxicity.
Mice ; Animals

OBJECTIVE: To determine the effects of leukemia inhibitory factor (LIF) on embryonal development in in vitro culture. METHODS: This is designed in vitro model using eggs from mouse. The eggs from mouse were assigned 29 for control group, 53 for 20 ng/ml of LIF, 88 for 40 ng/ml of LIF, 68 for 80 ng/ml of LIF respectively for in vitro fertilization. And 26 fertilized eggs at 2 cell stage from mouse also were assigned. The mouse embryos of all groups were cultured in medium supplemented with LIF in different concentrations, whereas the eggs in control group was cultured in medium without supplement of LIF. RESULTS: At 72 hours culture of eggs from in vitro fertilization, there was a slight increas in rate of embryonal development to morula in both LIF-20 and LIF-40 as results of 64.15% and 75% respectively, while 42.65% in inferior rate of LIF-80, compare with 51.72% in control group. But the difference between these each groups were not significant in statistically (p< or =0.05). And after 96 hours culture of eggs, the rates blastocyst formation was significantly higher in both LIF-20 and LIF-40 as 56.6% and 63.63% than those in control and LIF-80 as 44.83% and 35.29% respectively. On culturing eggs from in vivo fertilization, the rates of blastocyst formation was significantly not only higher as 85% and 81.81% respectively in medium supplemented with LIF-40 and LIF-80 than 42.3% in LIF-20 but also embryonal cell viability were remakedly improved at 96 hours after culture. CONCLUSION: The LIF in low dose is embryotrophic, but LIF in high dose is embryotoxic on eggs from in vitro fertilization. Whereas on culturing eggs from in vivo fertilization, LIF is more beneficial with dose dependent in high concentration.
Mice ; Animals

OBJECTIVE: In muscle and neuronal cells, calcium channels have been classified by electrophysiological and pharmacological properties into (1) voltage-dependent Ca2+-channel(1) P/Q-type Ca2+-channel (2) N-type Ca2+-channel R(3) L-type Ca2+-channel (4) T-type Ca2+-channel (5)R-type Ca2+-channel. The present study was done in order to investigate whether there is any difference in Ca2+-channel distribution between activated and normally fertilized embryos. METHODS: The immunocytochemical method was used to identify the existence of voltage-dependent Ca2+-channels in parthenogenetically activated 2-cell embryos by ethanol and SrCl2 treatment. These 2-cell embryos were obtained by exposure to 6% ethanol for 6 min and to 10 mM SrCl2 for 2h. RESULTS: P/Q-type Ca2+ channels and L-type Ca2+-channels have been identified. Whereas, three type of Ca2+-channel P/Q-type, N-type, L-type have been identified in 2-cell embryos fertilized in vivo. CONCLUSION: Activation by ethanol was faster than those by SrCl2. However, there was difference in DAB staining of the embryos between ethanol and SrCl2 treatment (87.7% and 54.1%). Intensity of staining was also different between ethanol- and SrCl2-treated group. However, it has not been known why there was some difference in DAB staining and staining intensity in the present study.
Mice ; Animals

No abstract available.
Animals ; Mice*