BACKGROUND The pathogenesis of transition from viral myocarditis to dilated cardiomyopathy is elusive, although the incidence of dilated cardiomyopathy in human is increasing. METHODS To clarify the role of the tissue inhibitor of matrix metaloproteinase-2 (TIMP-2) in this event, we performed immunohistochemistry, immunoblotting and immunoassay of matrix metalloproteinase-9 (MMP-9) and TIMP-2 in the serum and heart tissue of mice, which were inoculated with 4000 plaque-forming units of coxsackie B virus. RESULTS The MMP-9 was expressed in damaged cardiomyocytes, and the TIMP-2 was expressed in mainly interstitial connective tissue between cardiac muscle bundles by immunohistochemistry. The level of serum MMP-9 was higher in the complicated than non-complicated group (p<0.001), but the level of TIMP-2 was much lower in complicated than non-complicated group (p<0.05). These findings were similar to the results of immunohistochemistry and immunoblotting in tissues. CONCLUSIONS These results suggest that an imbalance in the level of MMP-9 and its inhibitor might activate cardiac complication in viral myocarditis.
BACKGROUND CD24, also referred to as the heat stable antigen in mice, is a glycosyl phosphatidylinositol- linked glycoprotein expressed by thymocytes, B cells, neutrophils and immature neuronal cells. It has been recently observed in a variety of human malignancy. Here, we demonstrated the expression of CD24 in gastric adenocarcinomas. METHODS A total of 40 gastric adenocarcinomas and 20 tubular adenomas were immunohistochemically examined for the expression of CD24 and matrix metalloproteinase-2 (MMP-2) proteins. The immunoreactivity of CD24 was semiquantitatively scored (0, 1+, 2+) and compared with clinicopathologic variables and MMP-2 expression in tumor cells. RESULTS CD24 was rarely expressed in normal gastric tissue and not expressed in tubular adenoma. In contrast, a moderate/strong expression (2+) of CD24 was observed in 25% of gastric adenocarcinomas, and 30% cases showed a weak CD24 staining (1+). Moreover, CD24 expression was significantly correlated with the depth of tumor invasion and MMP-2 expression. CONCLUSION These results suggest that the aberrant expression of CD24 in gastric adenocarcinomas might be associated with tumor progression and invasiveness.