Doo Ho Park

A Case of Pancreatic Endometrial Cyst

Pancreatic endometrial cyst is an extremely rare instance of ectopic endometriosis that was first described by Marchevsky in 19841). A 21-yr-old woman with a history of epigastric pain and weight loss was found to have a cystic lesion in the pancreas on CT-scan. Under the tentative diagnosis of a pancreatic cystic neoplasm, partial pancreatectomy was performed. Histopathological examination of the specimen revealed cystic endometriosis. The clinicopathological features of the lesion are discussed and literature concerning this extremely rare lesion is reviewed.

Effects of Selective Cyclooxygenase‐2 Inhibitor and Non‐Selective NSAIDs on Helicobacter pylori‐Induced Gastritis in Mongolian Gerbils

Background. It is still a point of controversy whether Helicobacter pylori‐infected patients are more likely to develop mucosal damage while taking NSADIs. Selective cyclooxygenase (COX‐2) inhibitors may be associated with less severe gastric mucosal damage than conventional NSAIDs, but this association is undefined in H. pylori‐induced gastritis. The aim of this study was to evaluate the effects of selective COX‐2 and nonselective NSAIDs on H. pylori‐induced gastritis.

PCNA Expression and Electron Microscopic Study of Acinus-Forming Hepatocytes in Chronic Hepatitis B

Background One of the major morphologic characteristics of hepatitis B is a hepatocellular regeneration which is induced by massive hepatocyte necrosis and associated with proliferative activity of hepatocytes. The purpose of this study is to document the proliferative activity of hepatocytes in various types of hepatitis B by immunohistochemical staining for proliferative cell nuclear antigen-labelling index (PCNA-LI) and electron microscopy. Methods We studied 83 patients with hepatitis B; 11 cases of acute viral hepatitis, 24 cases of mild chronic hepatitis, 34 cases of severe chronic hepatitis with early cirrhosis and 14 cases of severe chronic hepatitis. The PCNA was tested by immunohistochemical staining using anti-PCNA antibody. Furthermore we evaluated the ultrastructure of acinus-forming hepatocytes (AFH) by electron microscopy. Results The expression rate and labelling index of PCNA were 27.3% and 5.3±0.9% in acute viral hepatitis, 62.5% and 22.9±31.7% in mild chronic hepatits, and then 47.1% and 14.7±24.2% in severe chronic hepatitis with early cirrhosis, respectively (Figure 1). By contrast, no detectable PCNA expression was noted in AFH. Electron microscopic findings showed that hepatocytes forming a rosette underwent marked degenerative changes with sinusoidal capillarization and increased fine strands of collagen fiber in portal area. Conclusion The proliferative acitivity of hepatitis B was significantly decreased in severe chronic hepatitis containing AFH. This result suggested that differences in proliferative activity was associated with hepatic cell necrosis and AFH.

p53 mutations and microsatellite instabilities in the subtype of intestinal metaplasia of the stomach and its role as a precancerous lesion

To investigate the potential implication of the subtype of intestinal metaplasia in the progression to the gastric carcinoma, we analyzed the mutations of the p53 gene and microsatellite instability (MSI) both in the complete type (type I) and in the sulphomucin-secreting incomplete type (type III) intestinal metaplasia located adjacent to the gastric carcinoma. p53 mutations were observed in 13.3% of type I, in 6.6% of type III intestinal metaplasia, and in 40% of gastric carcinoma. The difference between p53 mutations observed in type I and type III intestinal metaplasia was not statistically significant. No identical mutation of the p53 gene was found in the intestinal metaplasia and carcinoma specimens from the patients. There was no case of intestinal metaplasia showing MSI. In gastric carcinomas, MSI was observed in six cases (40%). The cases harboring BAT-26 instability did not have the mutation of the p53 gene. These data suggest that intestinal metaplasia adjacent to gastric carcinoma, irrespective of its subtype, do not have the genetic alterations as showing in their carcinoma tissues.