No abstract available.
Animals ; Mice*

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*

The interaction of radiation and 5-luorouracil (5-U) on mouse jejunal crypt cells was studied using the microcolony survival assay. 150mg/kg of 5-U was injected intraperitoneally 15 minutes before irradiation and 6 hours after irradiation. Jejunal crypt cells of mouse survived more when 5-U was given 15 minutes before irradiation than giving it 6 hours after irradiation. The mean lethal doses (Do) of each of irradiation alone group, 5-U injection group of 15 minutes preceding irradiation, and 5-U injection group of 6 hours post irradiation were. 135, 135, and 114 rad respectively. The dose effect factor (DEF) of each of 5-U injection groups of 15 minutes preceding irradiation and of 6 hours post irradiation were 1.13 and 1.27.
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

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

No abstract available.
Animals ; Mice*

PURPOSE: Oral mucositis induced by radiotherapy to the head and neck area, is a common acute complication and is considered as the most severe symptom for cancer patients in the early stages of treatment. This study was proposed to establish the oral mucositis mouse model induced by a single dose of radiation for the facility of testing therapeutic candidates which can be used for the oral mucositis treatments. MATERIALS AND METHODS: Fifty-five BALB/c mice were divided into four groups: control, 16 Gy, 18 Gy, and 20 Gy. Oral mucositis was induced by a single dose of radiation to the head and neck using 6 MV x-Ray from linear accelerator. After irradiation, body weight and physical abnormalities were checked daily. Tongue tissues from all groups were taken on days 1, 2, 3, 5, 7, 9, and 14, respectively and H&E staining was conducted to examine morphological changes. RESULTS: Body weight dramatically decreased after day 5 in all irradiated mice. In the 16 Gy treatment group, body weight was recovered on day 14. The histology data showed that the thickness of the epithelial cell layer was decreased by the accumulated time after radiation treatment, up to day 9. Severe ulceration was revealed on day 9. CONCLUSION: A single dose of 16 Gy is sufficient dose to induce oral mucositis in Balb/C mice. Significant changes were observed in the Balb/C mice on days 7 and 9 after radiation. It is suggested that this mouse model might be a useful standard tool for studying oral mucositis induced by radiation.
Mice ; Animals

No abstract available.
Animals ; Mice*

It has been thought that autoimmune diseases like systemic lupus erythematosus and rhumatoid athritis are closely associated with anti-DNA antibodies (Abs). In studies of the control for anti-DNA Ab generation, an understanding of the regulatory mechanisms by anti-idiotypic Abs that influence the production of anti- DNA Abs would be facillitated by the availability of the hybridomas producing the pairs of DNA-specific and anti-DNA's idiotope-specific monoclonal antibodies (mAbs). We have produced a series of anti-DNA mAbs and then monoclonal anti-idiotypic Ab directed against idiotypic determinant of the 3D8 mAb that has the highest affinity to dsDNA and ssDNA among the anti-DNA mABs that we had obtained. The spleen cells of the MRL-Ipr/Ipr, autoimmune prone, mice were fused with P3X63Ag8.653 myeioma cells to obtain anti-DNA Ab secreting hybridomas. Out of the fourteen clones that showed strong binding to ssDNA, four clones had cross-reactivity with dsDNA whereas none of these clones reacted with left-handed z-DNA. The binding activities of the anti-DNA mAbs to various synthetic polynucleotide sequences were different respectively. Anti-idiotypic mAbs were generated by the fusion of myeloma cells and spleen cells from the Balb/c mice immunized with 3DB-Fab. We have produced two anti-idiotypic mAbs, B7 (IgG2a/k) and 02F3 (IgM/k), which were specific to 3DB-Fab and cloned the variable region of the heavy chain from the 02F3 hybridoma.
Mice ; Animals