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

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

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*

Dendritic cell (DC)s are protessional antigen presenting cells and they have been used for antitumor immunotherapy or cell vaccines. However therapy using DC is restricted because the number of DC available from tissue is very low. Flt3 ligand (FL) has been known as a hematopoietic growth factor that increases proliferation of hematopoietic stem cells and progenitor cells, and recently it showed inducibility of dendritic cell (DC)s and signiticant antitumor effects in vivo. Thus FL will be frequently used for DC induction and antitumor immunotherapy in future. Here we constructed FL plasmid and studied its in vivo effect. FL plasmids were made by cloning of partial FL cDNA into pcDNA3 plasmid, and gene expression and protein producibility of FL plasmid were confirmed in Renca cells transfected with FL plasmid. Mice were injected with FL plasmid (100ug/mouse) three times and 20 days later mouse spleens were harvested for staining and RT-PCR. There were lots of blastogenic cells in the spleen of mice treated with FL plasmid. FL plasmid also induced DEC205, IL-12 and GM-CSF gene expression in mouse splenocyte. All these data suggest FL plasmid may be used for induction of DC and antitumor therapy as DNA adjuvant.
Mice ; Animals

Regarding numerical changes of leukocytes involved in immune defects following thermal injury, a lot of controversial results have been reported. In this study, the changes of leukocyte number and distribution were examined and compared in spleen and lymph nodes of thermally injured mice. Mice (Balb/c) were anesthetized by intraqeritoneal injection of 2,2,2-tribromoethanol and thermally injured by immersion of hair-removed dorsal skin (15% total body surface) in a boiling water bath (96`C) for 7 seconds. Both of lymph node cell (LNC) and spleen cell (SPC) numbers decreased significantly at day 2 of injury and thereafter rebounded, but in a distinct pattern; 1) LNC numer returned to over normal level at day 6 and normalized again, whereas SPC number increased gradually over normal level and sustained until day 24 of injury. 2) Such increase of LNC and SPC number coincided with higher proportion of PMN and relative decline of lymphacytes, particularly CD3 T cells rather than slg' B cells, but such alteration was more significant in spleen. The changes of peripheral blood leukocyte (PBL) number was comparable to those of SPC. These data suggest that the cause of immune modulation in thermally injured mice acts systemically. In addition, it is noteworthy that reduction of lymphocyte and CD3 T cell proportions was due to relative increase of PMN number, not the decrease of absolute number of lymphocytes. Spontaneous recovery of injured mice in this study also implicates that increase of PMN number may be responsible for recovery from injury without infection. Finally, the CD4'/CD8' ratio of injured mice was lower only at day 2 ot injury, but not significantly, than that of control group. It is likely that contribution of Th/Ts ratio to immune defect after thermal injury should be determined together with other factors, such as injured body surface % and severity of injury.
Mice ; Animals

We have used BALB/c mice as an animal model for the study of anaphylactic hypersensitivity to the house dust mite. For the sensitization, BALB/c mice were injected with a single dose of extracts of Oermatophagoides farinae (D. pa) or Dermatophagoides pteronyssinus (D. pt) mixed with adjuvants (aluminum hydroxide and Bordetella pertussis) intraperitonealy. On days of 15, 30, and 60 after the sensitization, the mice received a challenge dose of the same allergen intravenously to induce anaphylactic shock. The hypersensitivity reactions were scored by anaphylactic shock. And various immunological parameters, including cytokines and immunoglobulin isotypes, were studied in relation with the shock. A high level of anaphylactic shock was produced in the mice by both of the allergens, D, fa and D, pt, at 15 and 30 days after sensitization. In vitro Ag specific proliferative reponses of spleen cells from D. pt treated mice (D. pt mice) was six times higher than those from O. fa treated mice (O. fa mice). Regardless the differences in antigens, the production of IFN-r by spleen cells from D. pt mice or O. fa mice was equally high at 15 days after sensitization. However, the ability to produce IFN-r by the spleen cells from D, pt mice was three times higher compared to that from D. fa mice. The production of IL-4 by the spleen cells was enhanced slightly but not significant in both groups. In studies of the allergen-specific immunoglobulin isotypes in the sera of the mice, the level of IgE in both groups was enhanced slightly but not significant. In contrast, the level of IgG subtypes were increased in both groups. When the levels of IgG were compared by subtypes, the level of IgG1 increased significantly on day 15 when the anaphylactic shock score was maximized in both groups. Increase in IgG2a level at the day was not significant, instead, asignificant increase in IgG2 levels was observed on day 60 after sensitization when the anaphylaxis was almost discontinued. Although a higher level of IgG3 was examined on day 15 and 30 in D. pt mice and on day 60 in D, fa mice, anaphylaxis was not appeared to be associated with the levels of IgG3 in this study. The IgG1, rather than IgE, was assumed to the major factor involved in the anaphylactic response observed in this experiment. In conclusion, BALB/c mice would be an animal model for the study of anaphylactic hypersensitivity to D. fa or D, pt., which might be an essential tool for the future development of immuno-therapeutic agents.
Mice ; Animals

No abstract available.
Animals ; Mice*

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