The effect of taurine treatment on oxidative stress in experimental liver fibrosis.

Oxidative stress is important in pathogenesis of liver fibrosis, which is the result of deposition of excessive ECM proteins produced by activated hepatic stellate cells (HSCs). Reducing reactive oxygen species (ROS) production decreases collagen accumulation in liver. We investigated the benefits of antioxidant therapy in liver fibrosis and its association with HSC apoptosis. Forty-five male Spraque-Dawley rats were subdivided into three groups. Group I was treated with CCl(4) plus taurine, Group II with CCl(4) plus saline, and Group III with saline for 12 weeks. Erythrocyte and liver malondialdehyde (MDA) levels, superoxide dismutase (SOD) activities, Glutathione peroxidase (GSHpx) activities, and serum and liver TIMP-1 and MMP-13 levels were measured. Histopathological examinations were performed. Activated and total HSCs were quantified immunohistochemically. Apoptotic HSCs were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining. Taurine decreased histopathological injury scores and oxidative stress parameters significantly. The number of activated HSCs was significantly higher in taurine untreated group ( [Formula: see text] ). Serum and tissue MMP-13 levels were significantly higher and TIMP-1 levels were significantly lower in taurine-treated group ( [Formula: see text] and [Formula: see text], respectively). The number of apoptotic activated hepatic stellate cells was significantly higher with taurine treatment ( [Formula: see text] ). Preventing the production of reactive oxygen species is effective in inhibiting fibrogenesis in experimental rat model. Inhibitory activity of this agent on HSCs' activation, apoptosis, and further fibrogenic events should be clearly identified.

Is late antibiotic prophylaxis effective in the prevention of secondary pancreatic infection?

BACKGROUND: Secondary infection of the inflamed pancreas is the principal cause of death after severe acute pancreatitis (AP). Although patients are not always managed early in the course of AP in clinical practice, prophylactic antibiotics that were used in experimental studies in rats were always initiated early after induction of pancreatitis. The effectiveness of antibiotics initiated later is unknown. AIM: The aim of this study was to compare the effectiveness of ciprofloxacin and meropenem initiated early versus later in the course of acute necrotizing pancreatitis (ANP) in rats. METHODS: 100 Sprague-Dawley rats were studied. ANP was induced in rats by intraductal injection of 3% taurocholate. Rats were divided randomly into five groups: group I rats received normal saline as a placebo, group II and IV rats received three times daily meropenem 60 mg/kg i.p. at 2 and 24 h, respectively and group III and V rats received twice daily ciprofloxacin 50 mg/kg i.p. at 2 and 24 h, respectively, after induction. At 96 h, all rats were killed for quantitative bacteriologic study. A point-scoring system of histological features was used to evaluate the severity of pancreatitis. RESULTS: Meropenem and ciprofloxacin initiated 2 h after induction of pancreatitis significantly reduced the prevalence of pancreatic infection (p < 0.001 and p < 0.04, respectively) as compared to controls. Neither of the antibiotics initiated later during the course of AP caused a significant decrease in pancreatic infection in rats (p > 0.05). Although the rats treated early infected less frequently than the rats treated later, the comparison reached statistical significance only in the meropenem group (p < 0.02). CONCLUSION: Early antibiotic treatment reduces pancreatic infection more efficiently than late antibiotic treatment in ANP in rats.