system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Animals, Celecoxib, Cell Growth Processes, Cyclooxygenase 2, Cyclooxygenase 2 Inhibitors, Dinoprostone, Liver, Liver Neoplasms, Experimental, Male, Organ Size, Precancerous Conditions, Pyrazoles, Rats, Rats, Sprague-Dawley, Sulfonamides.
user
Does celecoxib induce regression of putative preneoplastic lesions in rat liver? Context: Celecoxib, a cyclooxygenase-2 (COX-2) inhibitor, may reduce the risk and mortality of certain types of human cancer. The chemopreventive effect of celecoxib on preneoplastic lesions induced by chemical hepatocarcinogenesis was investigated. Male Sprague Dawley rats were fed a celecoxib-supplemented diet between days 18 and 26 post-initiation (1500 ppm) and sacrificed on day 26. The effects of celecoxib on proliferation, apoptosis, COX-2 activity and liver function were evaluated by immunohistochemistry, TUNEL assay, enzyme-immunoassay and spectrophotometry, respectively. Celecoxib decreased, in area and number, gamma-glutamyltranspeptidase and glutathione S-transferase placental-positive lesions, below levels found after 18 days, by 55.2% and 62.2%, and by 50.5% and 71.1%, respectively, (p < 0.05). Celecoxib neither induced apoptosis nor altered the levels of prostaglandin E2, bilirubin or alanine aminotransferase in the plasma; however, proliferating cell nuclear antigen and cyclin D1 decreased by 77.7% and 94.9%, respectively, (p < 0.05).
assistant
Celecoxib regresses existing preneoplastic liver lesions through antiproliferative processes, without altering liver function. Final Decision: yes