Digital quantification is more precise than traditional semiquantitation of hepatic steatosis: correlation with fibrosis in 220 treatment-naïve patients with chronic hepatitis C.

BACKGROUND: Steatosis, as associated with chronic hepatitis C (CHC) and non-alcoholic fatty liver disease (NAFLD), has been considered a risk factor for development of fibrosis. AIMS: Our aims were to determine if correlations existed between the degree of steatosis and fibrosis in treatment-naïve CHC patients, and to compare the accuracy of digital image analysis with semiquantification (manual assessment) to quantify hepatic steatosis. METHODS: We studied 220 treatment-naïve, liver biopsy-proven CHC patients, including a serial biopsy sub-cohort of 37 patients with a mean interval of 3.82 years. Steatosis and fibrosis % were evaluated using digital quantification of steatosis (DQS) and fibrosis contrasted with manual assessment. RESULTS: Most patients had <6% steatosis measured manually and digitally. Overall, manual assessment of steatosis was 3.78 times greater than DQS. Increasing steatosis % was associated with advancing fibrosis stage, both manually and digitally. Intraobserver reliability for DQS showed higher intraclass correlation reproducibility (r = 0.98, P < 0.001) than the manual method (r = 0.81, P < 0.01). Interobserver concordance for DQS had an average measure intraclass correlation of r = 0.99. Cirrhotics were more likely than non-cirrhotics to have grade 2 steatosis. CONCLUSIONS: Increased steatosis was associated with increased fibrosis. DQS was consistently more precise and reproducible than manual assessment of steatosis in grades 1 (1 to <6%) and 2 (6 to <34%), and may prove to be especially preferable in clinical trials of pharmacotherapeutic agents.

Gastric acid is the key modulator in the pathogenesis of non-steroidal anti-inflammatory drug-induced ulceration in rats.

1. In the present study, we investigated the role of gastric acid (GA) secretion on non-steroidal anti-inflammatory drug (NSAID)-induced ulcerogenesis in vivo. Rats were administered single oral doses of selective cyclo-oxygenase (COX)-1 (SC-560; 2.5 mg/kg), COX-2 (DFU; 25 mg/kg) or non-selective COX (indomethacin; 25 mg/kg) inhibitors. Three groups (basal, histamine-stimulated and histamine with lansoprazole) were pylorus ligated 2 h after inhibitor administration and killed 2 h later. Another group without pylorus ligation received only inhibitors and was killed after 18 h. 2. At 4 h, indomethacin increased the ulcer index (UI) and myeloperoxidase (MPO) activity in basal and histamine-stimulated states, whereas SC-560 only increased MPO activity. Histamine-stimulated, but not basal, GA was further enhanced by indomethacin and SC-560 via increased proton pump expression. Lansoprazole (10 mg/kg) reduced the UI, MPO activity and GA to basal levels with SC-560 and DFU and to near basal with indomethacin. Indomethacin and SC-560 significantly inhibited prostaglandin (PG) E(2), without significantly affecting COX-1 and COX-2 expression. Although DFU inhibited PGE(2) by one-third, it did not affect COX expression. 3. At 18 h, indomethacin significantly increased the UI and MPO activity, whereas PGE(2) synthesis was less inhibited, indicating a return to control levels. In contrast, PGE(2) synthesis was higher than control with SC-560. Furthermore, COX-2 expression was significantly elevated with indomethacin and SC-560, explaining the source of augmented PGE(2) synthesis. Proton pump expression remained elevated, comparable with 4 h levels, with indomethacin and SC-560. However, DFU had no significant effect on the aforementioned parameters. 4. The data suggest that NSAID-induced ulcerogenesis is dependent on the amount of GA secretion derived from increased proton pump expression and requires inhibition of both COX-1 and COX-2.

TNF-alpha modulates iNOS expression in an experimental rat model of indomethacin-induced jejunoileitis.

Multiple mucosal immune factors, such as TNF-alpha and IL-1beta, are thought to be key mediators involved in inflammatory bowel disease. We evaluated the role of the pro-inflammatory cytokine TNF-alpha on nitric oxide synthase (NOS) expression in indomethacin-induced jejunoileitis in rats. Jejunoileitis was induced in rats with subcutaneous injections of indomethacin (7.5 mg/kg) 24 h apart for two consecutive days, and animals were randomized into four groups. Group 1 received only indomethacin. Group 2 was treated with a daily dose of phosphodiesterase (PDE) inhibitor (theophylline or pentoxifylline) by oral gavage for 2 days before and 4 days after indomethacin. Group 3 received a single dose of anti-TNF-alpha monoclonal antibody (TNF-Ab, IP) 30 min before indomethacin. Group 4 was treated with 1 h hyperbaric oxygenation (HBO(2)) for 5 days after indomethacin. Rats were sacrificed at 12 h or 4 days after final indomethacin injection. PDE inhibitor, TNF-Ab, or HBO(2) treatment significantly decreased indomethacin-induced ulceration, myeloperoxidase activity, and disease activity index. Although indomethacin significantly increased serum TNF-alpha and nitrate/nitrite (NOx) concentrations above control values at 12 h, inducible NOS (iNOS) expression was detected only at day 4. Serum IL-1beta levels did not change at 12 h but increased 4-fold after 4 days. Indomethacin had no effect on constitutive NOS. Treatment with PDE inhibitor, TNF-Ab, or HBO(2) significantly reduced serum/tissue TNF-alpha, IL-1beta, NOx, and iNOS expression. Our data show TNF-alpha plays an early pro-inflammatory role in indomethacin-induced jejunoileitis. Additionally, down-regulation of NOx by PDE inhibitors, TNF-Ab, or HBO(2) suggests that TNF-alpha modulates iNOS expression.

Cyclo-oxygenase-1 inhibition increases acid secretion by modulating H+,K+-ATPase expression and activation in rabbit parietal cells.

1. In the present study, we evaluated the role of cyclo-oxygenase (COX)-1 and COX-2 on gastric acid secretion in rabbit isolated parietal cells and gastric glands by examining [(14)C]-aminopyrine uptake, prostaglandin (PG) E(2) synthesis and COX-1, COX-2 and proton pump expression at baseline and after treatment with various concentrations of specific COX-1 (SC-560), COX-2 (5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methyl-sulphonyl)phenyl-2 (5H)-furanone; DFU) and non-specific COX (indomethacin) inhibitors. 2. In parietal cells, SC-560 and indomethacin, over the concentration range 10(-8) to 10(-4) mol/L, dose-dependently increased basal and 10(-4) mol/L histamine-stimulated aminopyrine uptake and inhibited PGE(2) synthesis, whereas DFU (10(-8) to 10(-5) mol/L) had no effect. However, at 10(-4) mol/L, DFU augmented histamine-stimulated aminopyrine uptake by 135% and inhibited PGE(2) synthesis by 39%, indicating an inhibition of COX-1 at this higher concentration. 3. The SC-560-, DFU- and indomethacin-induced augmentation of histamine-stimulated aminopyrine uptake was reduced to basal levels after 10(-5) mol/L lansoprazole treatment in parietal cells and gastric glands, whereas 10(-4) mol/L ranitidine only partially inhibited such augmentation. 4. Only COX-1 was detected in parietal cells. However, both COX-1 and COX-2 were expressed in gastric glands, with relative protein density of COX-1 being sixfold higher than that of COX-2. Protein levels of COX-1 in parietal cells and those of COX-1 and COX-2 in gastric glands remained unchanged, regardless of inhibitor treatment, either alone or with histamine. 5. Parietal cell proton pump expression was significantly enhanced by 10(-5) mol/L SC-560 and 10(-4) mol/L indomethacin (by 29 and 31%, respectively) and pump activity was enhanced by 61 and 65%, respectively. In contrast, 10(-5) mol/L DFU had no effect. 6. In conclusion, the data indicate that inhibition of COX-1- but not COX-2-derived PGE(2) synthesis is involved in augmentation of non-steroidal anti-inflammatory drug-induced gastric acid secretion in parietal cells by enhancing expression and activation of the proton pump.

5-aminosalicylic acid improves indomethacin-induced enteropathy by inhibiting iNOS transcription in rats.

Nitric oxide has been implicated in the pathogenic mechanism of inflammatory bowel disease states. We evaluated indomethacin-induced enteropathy in rats, in relation to the expression of the inducible isoform of NO synthase (iNOS) using aminosalicylic acid (5-ASA), its isomer 4-ASA (10 or 50 mg/kg/day, po), and dexamethasone, an iNOS transcription inhibitor (3 mg/kg/day, sc). Enteropathy was induced by indomethacin (7.5 mg/kg/day, sc) for two days and the small intestine was examined for lesions over the next 14 days. Indomethacin-induced small-intestinal ulcer size, mucosal myeloperoxidase activity, iNOS expression and serum nitrite/nitrate levels were maximally increased by day 4 and gradually decreased by day 14. Treatment with 5-ASA, but not 4-ASA, decreased indomethacin-induced ulcer length, myeloperoxidase activity, serum nitrite/nitrate levels and iNOS expression at day 4. Dexamethasone had a greater effect than 5-ASA in reducing myeloperoxidase activity and ulcer length by 26 and 32%, respectively. Dexamethasone also reduced serum nitrate/nitrite and iNOS expression to their basal levels. In conclusion, inhibition of iNOS expression by 5-ASA appears to be associated with diminished intestinal ulceration in indomethacin-induced enteropathy.