Hepatic fibrosis—Current concepts of pathogenesis and therapy

Biotransformation of theophylline in cirrhotic rats induced by biliary obstruction

The object of this work was to study the pharmacokinetic differences and the cause of these differences in cirrhotic rats induced by biliary obstruction when aminophylline (8 mg/kg as theophylline, i.v.) was administered. The concentrations of theophylline and its major metabolite (1,3-dimethyluric acid) in plasma were determined by HPLC. In addition, formation of 1,3-dimethyluric acid from theophylline in microsomes and the changes in the activity of drug metabolizing enzymes, which are suggested to be involved in theophylline metabolism, were determined. In cirrhotic rats, the systemic clearance of theophylline was reduced to 30% of the control value while AUC (area under the plasma concentration-time curve) and (t1/2)beta were increased 1.3 fold and 3.5 fold, respectively. The formation of 1,3-dimethyluric acid was decreased to 30% of the control value in microsomes of cirrhotic rat liver. In cirrhotic rat liver, activities of aniline hydroxylase (CYP2E1 related), erythromycin-N-demethylase (CYP3A related), and methoxyresorufin-O-demethylase (CYP1A2 related), which were reported to be related with theophylline metabolism, were decreased to 67%, 53%, and 76% that of normal rat liver, respectively. From the results, it can be concluded that in cirrhotic rats induced by biliary obstruction, the total body clearance of theophylline is markedly reduced and it may be due to decreased activity of drug metabolizing enzymes in liver.

Expression of biglycan, decorin and proteoglycan-100/CSF-1 in normal and fibrotic human liver

The immunohistochemical expression of the three small chondroitin/dermatan sulphate proteoglycans biglycan, decorin and proteoglycan-100 (PG-100), the proteoglycan form of colony-stimulating factor-1 (CSF-1), was studied in normal and fibrotic human liver. In normal liver tissue biglycan and decorin were clearly seen in the space of Disse, which was in contrast to a faint staining of PG-100. Biglycan and decorin were additionally detected around small bile ducts and in vessel walls. In patients with HBs-Ag positive, chronic active hepatitis decorin as well as biglycan showed strong immunoreactivity in fibrotic areas. In contrast to normal liver, PG-100 was visualized in bile duct epithelia. Therefore, PG-100 could serve as an immunohistochemical marker of the involvement of the bile duct system in chronic active hepatitis and progressive liver fibrosis.

N-terminal peptide of type III procollagen: a possible predictor of colorectal carcinoma recurrence

BACKGROUND

The first step of colorectal carcinoma spread depends on the ability of the tumor cells to degrade and invade the extracellular matrix (ECM). The objectives of the current study were to evaluate the serum pattern of laminin, C-terminal peptide of Type I (PIP), and N-terminal peptide of Type III (PIIIP) procollagens, markers of ECM synthesis, in the follow-up of patients after resection for colorectal carcinoma and to evaluate their role in predicting local recurrence or metastases.

METHODS

A total of 32 patients who had undergone resection for colorectal carcinoma were followed for a median period of 24 months (range, 6-36 months). Every 3 months, laminin, PIP, and PIIIP were measured in the sera together with the tumor markers carcinoembryonic antigen (CEA), CA 19-9, and tissue plasminogen activator (TPA). Twenty-one patients (Group 1) had no signs of recurrence, whereas the remaining 11 (Group 2) developed hepatic (n = 7) or pulmonary (n = 4) metastases.

RESULTS

No variations were observed in either group for laminin, CEA, CA 19-9, or TPA, whereas significant increases in PIP and PIIIP were observed in both groups 3 months after surgery. The increase in PIP and PIIIP at the 3-month follow-up was significantly greater in Group 1 than in Group 2. The difference between values at 3 months and basal values enabled a discrimination between Group 1 and Group 2, with a sensitivity of 36% and 91% and a specificity of 71% and 71% for PIP and PIIIP, respectively.

CONCLUSIONS

The authors believe PIIIP is useful as an early prognostic indicator of recurrence in the follow-up of patients who have undergone radical resection for colorectal carcinoma.

Changes in serum levels of metalloproteinases and their inhibitors by treatment of chronic hepatitis C with interferon

We treated 18 patients with chronic hepatitis C by recombinant interferon-alpha (6 MIU for 24 weeks). In seven patients, serum aminotransferase levels declined to normal (responders). To evaluate the effect of interferon on matrix metalloproteinases (MMPs) and their inhibitors, namely tissue inhibitors of metalloproteinases (TIMPs), the serum levels of these enzymes were determined by enzyme immunoassay (EIA) using a specific monoclonal antibody. In responders, there was a tendency, but not a significant one, towards either an increase in serum MMP 1 levels or a decrease in serum TIMP 1 levels. In contrast, in nonresponders, both a significant decrease in MMP 1 and MMP 3 and a significant increase in TIMP 1 were observed. The number of cases of either increase in serum MMP levels or decreased in serum TIMP levels was significantly larger in responders than in nonresponders. Furthermore, the ratio of MMP 1 to TIMP 1 significantly increased in responders, suggesting that the balance between matrix formation and degradation in hepatic fibrosis tended to move toward degradation. These data indicate that interferon may exert a beneficial effect on hepatic fibrosis in parallel with improvement of aminotransferase activity.