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Background/aims: Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) plays a critical role in adipocytes differentiation and insulin sensitivity and is also related to regulation of inflammation and cell proliferation. The aim of this study was to investigate the PPAR-gamma agonist-induced apoptosis and effects of PPAR-gamma agonist on Fas-mediated apoptosis in a human colon cancer cell line., Methods: Cell survival and apoptosis of HT-29 cells were measured by trypan blue exclusion method and FACScan after treatment with 15d-PGJ2, ciglitazone and IgM anti-Fas antibody (CH11), respectively or simultaneously. Also, activation of caspase-3 and caspase-8 was analyzed to assess the effects of PPAR-gamma and Fas on apoptosis signaling pathways., Results: CH11 induced apoptosis of HT-29 cells. 15d-PGJ2 or ciglitazone alone did not induce apoptosis, but combined stimulation with CH11 synergistically induced apoptosis. Also, 15d-PGJ2 alone did not activate caspase-3, but CH11 and 15d-PGJ2 synergistically activated caspase-3. CH11 activated procaspase-8, but 15d-PGJ2 did not., Conclusions: PPAR-gamma was not an enough condition to induce apoptosis of HT-29 cells. Apoptosis was induced by high dose Fas, and was enhanced with PPAR-gamma agonist. PPAR-gamma agonist seems to enhance Fas-mediated apoptosis by affecting the way between caspase-8 and caspase-3. Further research is needed to use PPAR-gamma agonists as chemopreventive and therapeutic agent for colon cancer and to find the pathways of PPAR-gamma on apoptotic cascade of colon cancer cells.

Background/aims: Obscure gastrointestinal bleeding (OGIB) is defined as recurrent acute or chronic bleeding for which no sources have been identified by routine endoscopic and contrast studies. The patients with OGIB are frequently difficult to manage and often undergo extensive investigation and even laparatomy without diagnosis. The aim of this study was to review our overall experiences of the investigation and treatment of OGIB., Methods: We reviewed, retrospectively, medical records of 41 cases with OGIB from June 1996 to July 2002., Results: Of the 41 patients with OGIB, there were 21 men and 20 women and their mean age was 47.8 years (range, 18 to 81 years). Diagnosis was possible in 13 patients (31.7%) and no specific causes were identified in the remaining 28 patients (68.3%). The principal etiologies were gastrointestinal stromal tumor of the small bowel in 3 cases, duodenal diverticulum in 2 cases. Other causes are as follows: adenocarcinoma of the duodenal 3rd portion, duodenal varix at the 4th portion, splenic artery pseudoaneurysm, Crohn's disease, jejunal ulcer, ileal ulcer, ileal angiodysplasia, and anastomosis site bleeding after hemicolectomy., Conclusions: We conclude that further and logical diagnostic investigations such as small bowel enteroscopy and wireless capsule endoscopy will promise better results.

Background/aims: This study was designed to determine the relationship of propranolol pharmacokinetic parameters with portosystemic shunt in CCl4-induced cirrhotic rats., Methods: Cirrhotic rats(n=6) were induced by intramuscular injection of CCl4 in olive oil(two time per weeks) for 12 weeks. Controls (n=6) were injected intramuscularly with the same dose of olive oil for 12 weeks. We evaluated the amount of portosystemic shunt by thallium-201 per rectal scintigraphy. After intravenous bolus injection of propranolol (2mg/kg) to rats, the serum propranolol concentrations were analyzed by a HPLC-fluorimetric detector system. Pharmacokinetic parameters such as C0, AUC, t1/2(beta), and CLp were determined in each group. Then, a small amount of heptic tissue was obtained and subjected to determination of the hepatic collagen content by quantitating 4-hydroxyproline and were inspected by microscope after hematoxylin and eosin stain., Results: In liver biopsy, liver fibrosis progressed in CCl4-induced cirrhotic rats. The serum concentrations of propranolol were significantly (p < 0.01) elevated in CCl4-induced cirrhotic rats. Mean amount of 4-hydroxyproline, mean H/L ratio, and mean AUC in CCl4-induced cirrhotic rats was significantly (p < 0.01) higher than that in control rats. There was a relationship between AUC, H/L ratio, and amount of 4-hydroxyproline., Conclusion: H/L ratio may help in the selection of drug dosage (especially blood flow dependent drug) in pre-clinical studies for chronic liver disease during the drug development process.

Background/aims: It is important to evaluate the general status of the liver including the structural and inflammatory aspects, as well as the functional aspects, in order to determine a patient's treatment modality and prognosis., Methods: 55 Child-Pugh class A liver cirrhosis patients confirmed by liver biopsy have been categorized into 4 groups based on the shunt index and p-value(Y= 3.3431-0.8160 ALT/AST ratio-0.0343 X prothrombin time+2.6963 X shunt index, p = e(y)/(e(y)+1)), which was obtained by Thallium- 201 scan; group I - shunt index less than 0.3 and p-value less than 0.7; group II - shunt index less than 0.3 and p-value more than 0.7; group III - shunt index more than 0.3 and p-value less than 0.7; and group IV - shunt index more than 0.3 and p-value more than 0.7. Statistical analyses used were ANOVA, paired t-test, and Chi-square test., Results: 1. The laboratory data after a 5-year follow-up also showed a significant difference between four groups. 2. In group IV, the Child-Pugh class after 5 years worsened, and complications of liver cirrhosis such as esophageal varix, ascites, and hepatic encephalopathy occurred more frequently. 3. In group II, the laboratory data after a 5-year follow-up indicated some improvement., Conclusion: It can be seen that even early in patients with initially the same cirrhosis, the course of the illness can progress to a variety of different situations. The measurement of shunt index and the p-value of cirrhosis will be more helpful in the follow-up evaluation and predicting its prognostic index in liver cirrhosis patients.