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

Recently there is increasing tendency of the nosocomial infection, and Pseudomonas aeruginosa is one of the most important and common pathogens causing hospital opportunistic infections with rapid emergence of resistant strain especially in immunologically compromised patients. An experimental study for the effects of polyvalent Pseudomonas vaccine was performed in an animal model of Pseudomonas sepsis on a survival rates and histopathological points of view-using ICR inbred mice. The vaccine was prepared with heat killed whole cells of the 10 representative serotypes of Pseudomonas aeruginosa, which were isolated from the Department of Microbiology, College of Medicine, Kyung Hee University and Seoul National University, and they were devided into two polyvalent vaccine groups. The animal model of the Pseudomonas sepsis was deveoped by intravenous inoculation of Pseudomonas aeruginosa (serotype F, inoculum size 100 microliter, 109 cells/ml), immediately after cutaneous burns. The results were as follows. 1) The survival rate of the immune mice was 100% and that of non-immune mice was 60%. 2) The histologic findings of lung of the non-immune mice were severe congestion (18/18 mice), hemorrhage (18/18 mice), emphysematous change (18/18 mice), thrombosis (9/18 mice), infarction (9/18 mice) and inflammation (6/18 mice) and those of the immune mice were only congestion (6/20 mice) and focal emphysematous change (2/20) from the 3 day experimental group. 3) The histologic findings of the liver in the non-immune mice were severe congestion, Kupffer cell mobilization, focal necrosis, & portal inflammation in most of them, and from 7 day experimental group there were noted infiltrations of lagre histiocytic cells in sinusoids, and those in the immune mice were only reactive change of varying degree. 4) The histologic findings of the spleen in the non-immune mice were severe reactive hyperplasia in all and ischemic necrosis in about half of them, and those in the immune mice were only reactive change. 5) The histologic findings of the heart in the non-immune mice were severe congestion and inflammation in most and in the immune mice were only occasional nonspecific congestion. 6) The histologic findings of the kidney in the non-immune mice were severe congestion in all, interstitial inflammation, acute tubular necrosis and cortical necrosis in about half of them, and those in the immune mice were only mild congestion. With the above results, we can suspect there is a significant protective effects of the polyvalent pseudomonas vaccine on the pseudomonas sepsis in ICR mice.
Mice ; Animals

No abstract available.
Animals ; Mice*

Studying the effectiveness of irradiation on bone-marrow, the numbers of leukocyte, erythrocyte, hemoglobin of mice (25 normal mice and 35 mice treated by gamma irradiation with the dose of 600 rad/(100rad/day) (60 Co) showed that: Gamma irradiation reduced total of leucocytes, the number of different leucocytic (lymphocyte, granulocyte, mono and natural killer cells), the ratio of reticulocyte, number of mature erythrocyte and hemoglobin: Total of leucocytes (3,14 ± 1,58 in comparison with 13,45 ± 4,6); monocytes (0,05 ± 0,03 in comparison with 0,26 ± 0,13), lymphocytes (1,66 ± 0,36 in comparison with 6,34 ± 2,84). After gamma irradiation, the number of reticulocyte was 55%, mature erythrocyte was 73% and hemoglobin was 82%
Therapeutics ; Mice

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

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

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*

Bone resorption involves sequential stages of osteoclast precursor migration and differen-tiation of osteoclast precursors into multinucleated osteoclasts. Stromal cell derived factor (SDF)-1 is a chemotactic factor for osteoclast precursor migration. Matrix metalloproteinase (MMP)-9 is involved in migration of osteoclast precursors and activation of interleukin(IL)-1beta. Alveolar bone destruction is a characteristic feature of periodontal disease. Treponema lecithinolyticum is a oral spirochete isolated from the periodontal lesions. The effect of lipopolysaccharide(LPS) from T. lecithinolyticum on expression of SDF-1 and MMP-9 was examined in cocultures of bone marrow cells and osteblasts derived from mouse calvariae. T. lecithinolyticum LPS increased expression of MMP-9 in the coculture. Polymyxin B, an inhibitor of LPS, abolished the increase of MMP-9 mRNA expression by LPS. LPS did not increase the expression of SDF-1, IL-1beta and tumor necrosis factor(TNF)-alpha mRNA in cocultures. Prostaglandin E2(PGE2) up-regulated the expression of MMP-9 and NS398, an inhibitor of PGE2 synthesis, down-regulated the induction of MMP-9 expression by T. lecithinolyticm LPS. These results suggest that T. lecithinolytium LPS increases MMP-9 expression in bone cells via PGE2 and that the induction of MMP-9 expression by T. lecithinolyticum LPS is involved in alveolar bone destruction of periodontitis patients by the increase of osteoclast precursor migration and the activation of bone resorption-inducing cytokine.
Mice ; Animals