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Pancreatic rat islets are encapsulated by a siliceous layer deposited on the surface of single islets upon reaction with gaseous siliceous precursors. The process preserves original islet dimensions and does not suppress viability or function. The encapsulated material is homogeneously distributed on the islet surface, and layer thickness can be controlled in the 0.1–2.0 μm interval. Dynamic perfusion experiments with glucose stimulation were carried out in both encapsulated and non-encapsulated islets. Results were treated according to a kinetic model presented here for the analysis of perfusion data; the model tested by literature data, was used to substantiate the diffusion features of the siliceous layer, which does not affect mass transfer of insulin but which modifies the texture of the islet surface tissue. The clinical potential of silica encapsulation was demonstrated by in vivo experiments using encapsulated islets transplanted into diabetic rats. Transplantation was carried out in both inbred and outbred rats and indicated prolonged restoration of normal glycaemia levels and protection from immunological attack. [Copyright &y& Elsevier]

Abstract: Background and aim: Hepatitis C virus (HCV)-related cirrhosis is one of the leading indication for liver transplantation (LT) and a major risk factor for the development of hepatocellular carcinoma (HCC). HCV recurrence after LT is universal. This study evaluated HCV recurrence and survival in patients transplanted for HCV and HCC. Methods: We evaluated all adults transplanted for HCV cirrhosis between January 1999 and December 2006, HCC was diagnosed on the explant and HCV recurrence confirmed on protocol liver biopsies performed at 6 months and yearly after LT. The sustained viral response (SVR) was defined as HCV-RNA undetectable at 6 months after therapy discontinuation. The patient survival rates were assessed with Kaplan-Meier curves and the chi-square test was used when appropriate. Results: Two hundred sixteen patients underwent LT for HCV including 153 men and 63 women of mean age 54 years with a mean follow-up of 35 months. There were 71 (33%) HCC+ patients. At 1, 3, and 5 years from LT severe fibrosis (Scheuer 3–4) due to the HCV recurrence was reported in 18%, 14%, and 11% for HCC+ and 14%, 16%, and 28% for HCC− patients respectively (P = NS). HCC recurred only in 3 (4%) patients at a mean follow-up of 3 years. Patients who received antiviral treatment after LT were 10% HCC+ and 12% HCC− patients (P = NS). SVR was seen in 3/7 (43%) of HCC+ and in 10/18 (55%) of HCC− patients (P = NS). At 1, 3, and 5 years the patient survivals was 91%, 86%, and 86% for HCC+ and 94%, 86%, and 83% for HCC− patients, respectively (P = NS). Conclusions: Severe fibrosis due to HCV recurrence, which increases over time, involves one third of transplanted patients at 5 years after LT. The long-term survival was identical among HCC+ compared to HCC− recipients. The recurrence of HCC was negligible and did not affect patient survival. [Copyright &y& Elsevier]

Abstract: Background: Hepatitis C virus (HCV) reinfection after liver transplantation is a virtually constant finding and leads to chronic hepatitis and cirrhosis in variable proportions. This study aimed to assess the safety and efficacy of α-interferon (IFN) plus ribavirin for recurrent HCV following liver transplantation. Patients and Methods: Thirty of 55 patients (54.5%) with histologically proven HCV recurrence after liver transplantation were given antiviral therapy (α-IFN at a dose of 6 MU × 3 × week IM associated with oral ribavirin 1 g/d for 12 months) and followed up for a further 12 months after the end of the treatment. Liver and renal function tests, hemocytometric values, and HCV-RNA were assessed every 3 months throughout the therapy and follow-up. Liver biopsy was performed before and after the treatment and after another 12 months of follow-up. Results: Eight patients (26.7%) were withdrawn from the treatment due to adverse events and another 8 (26.7%) needed a dosage reduction. Eleven patients (36.7%) had a biochemical and virological response, becoming aminotransferase and HCV-RNA negative at the end of the treatment; 6 patients (20%) still had a sustained response after 12 months of follow-up. All 6 patients are clinically stable at 6 years after completing the antiviral therapy. A low viral load before therapy was a positive predictor of sustained response. No histologically significant improvement was seen at the end of the therapy or after the follow-up. Conclusions: The combination of α-IFN plus ribavirin induced a sustained virologic response in 20% of liver transplant recipients with recurrent HCV, but intolerance of the therapy prompted its discontinuation or a dosage reduction in a large proportion of patients. However, we have observed a long-term efficacy of the antiviral therapy in the sustained responders. [Copyright &y& Elsevier]