The social impact of liver disease

Expression of liver-specific functions by rat hepatocytes seeded in treated poly(lactic-co-glycolic) acid biodegradable foams

Techniques of liver replacement would benefit patients awaiting donor livers and may be a substitute for transplantation in patients whose livers can regenerate. Poly(lactic-co-glycolic acid) (PLGA) copolymers are biodegradable and have been shown to be useful as scaffolds for seeding and culturing various types of cells. In this study, foam disks were prepared from PLGA (lactic-to-glycolic mole ratio of 85:15) by lyophilization of benzene (5% w/v) solutions. These disks were then used as scaffolds for rat hepatocyte culture. Foams were coated with either a type I collagen gel (0.1% w/v), coated with gelatin (5% w/v), or treated with oxygen plasma (25 W, 90 s) to modify their surface chemistry and wettability. The disks were then seeded with rat hepatocytes (10(6)/mL) and cultured for a period of 2 weeks. All surface treatments resulted in increased hydrophilicity, the greatest being obtained by collagen treatment (contact angle < 10 degrees ), and a minimal decrease in void fraction (5%). DNA content after a 2-week culture period increased proportionally with the wettability of the treated foam surface. Urea synthesis in untreated foams averaged 15.3 +/- 2.3 microg/h/microg DNA, which was significantly higher than that for controls, whereas gelatin and collagen treated foams exhibited urea synthetic rates below the control levels at all times. The DNA content decreased significantly by about 50% between days 1 and 12. PLGA foams, treated and untreated, represent a promising scaffold for scaling up hepatocyte cultures.

Pharmacological aspects of pentoxifylline with emphasis on its inhibitory actions on hepatic fibrogenesis

1. Pentoxifylline (PTX), a derivative of the methylxanthine theobromine, has been used for many years in the treatment of peripheral vascular diseases. Increased red blood cell flexibility, reduction of blood viscosity, and decreased potential of platelet aggregation are the basic actions of PTX, resulting in therapeutic benefits due to improved microcirculation and tissue oxygenation. 2. PTX's generally accepted mechanism of action is the inhibition of phosphodiesterases, leading to increased intracellular levels of cyclic adenosine monophosphate (cAMP). 3. A number of studies have shown PTX's effects on the cytokine network. The most relevant clinical results are the therapeutic benefits of PTX in attenuating the effects of tumor necrosis factor-alpha (TNF-alpha) in conditions such as septic shock. 4. PTX also has been found to exert antifibrogenic actions, using cultured fibroblasts or animal models of fibrosis, including liver fibrosis. 5. In hepatic stellate cell culture PTX has been shown to inhibit the basic reactions of liver fibrogenesis, being effective on cytokines and growth factors relevant in fibrogenesis of the liver, too. 6. Therefore, PTX might be an effective drug with few side effects in the treatment of liver fibrosis. Further clinical studies have to be done to establish the real therapeutic benefits of PTX in liver fibrosis and cirrhosis.

A histological semiquantitative scoring system for evaluation of hepatic fibrosis in needle liver biopsy specimens: comparison with morphometric studies

The evaluation of hepatic fibrosis on histological sections is of great interest for the staging and follow-up of chronic liver disease. Because no reliable scoring system is yet available, we have designed a semiquantitative scoring system in which the four main sites of fibrotic deposit--centrilobular vein, portal tract and perisinusoidal space, together with width and number of septa when present--are analyzed. These different items have been previously settled from comparison with morphometric measurements to evaluate surface density of total collagen performed on the same liver needle biopsy specimens stained with picro-sirius. The score has been tested on samples from 200 consecutive patients with various liver diseases and compared with the surface density of total collagen and Knodell scoring system. For observer variation study, the features by three independent pathologists were coded on 20 cases. There was a good interobserver (Kendall's tau-b = 0.75) and intraobserver (tau-B = 0.73) reproducibility. Each component of the fibrosis scoring system and total collagen surface density were significantly linearly related (one-way polynomial analysis, p < 10(-4); the correlation between semiquantitative scoring system and surface density of total collagen was 0.73 (p < 10(-5). Our semiquantitative scoring system, simple and reproducible, describes both liver architecture and fibrotic deposit. It is better related to morphometric measurement of fibrosis than each of its constituents or than the fibrosis item of the Knodell scoring system. It represents a reliable and convenient method for fibrosis evaluation, which is mandatory for clinical use.

Studies in alcoholic liver disease in Britain. I. Clinical and pathological patterns related to natural history

A group of 258 patients with various forms of alcoholic liver disease-steatosis, mild and severe hepatitis, and cirrhosis-has been studied. Severity of disease as judged histologically did not correlate very well with clinical presentation although signs of hepatocellular failure were certainly commoner in severe hepatitis and cirrhosis. Fever, pigmentation, and clubbing were also pointers to these two conditions. Alcoholic hepatitis is probably precirrhotic and carries a poor prognosis and the best laboratory indicators of this are moderate elevation of white cell count and bilirubin. Prognosis in alcoholic liver disease is significantly improved by abstinence from alcohol.