Activity modulation of microbial enzymes by llama (Lama glama) heavy-chain polyclonal antibodies during in vivo immune responses.

Since they were first described in 1993, it was found that recombinant variable fragments (rVHHs) of heavy-chain antibodies (HCAbs) from Camelidae have unusual biophysical properties, as well as a special ability to interact with epitopes that are cryptic for conventional Abs. It has been assumed that in vivo raised polyclonal HCAbs (pHCAbs) should behave in a similar manner than rVHHs; however, this assumption has not been tested sufficiently. Furthermore, our own preliminary work on a single serum sample from a llama immunized with a ß-lactamase, has suggested that pHCAbs have no special ability to down-modulate catalytic activity. In this work, we further explored the interaction of pHCAbs from four llamas raised against two microbial enzymes and analyzed it within a short and a long immunization plan. The relative contribution of pHCAbs to serum titer was found to be low compared with that of the most abundant conventional subisotype (IgG(1)), during the whole immunization schedule. Furthermore, pHCAbs not only failed to inhibit the enzymes, but also activated one of them. Altogether, these results suggest that raising high titer inhibitory HCAbs is not a straightforward strategy - neither as a biotechnological strategy nor in the biological context of an immune response against infection - as raising inhibitory rVHHs.

[Radiofrequency ablation: a new approach in the treatment of hepatocellular carcinoma]. / Termoablazione mediante radiofrequenza: nuovo approccio nella terapia locoregionale dell'HCC.

HCC is a tumor with increasing incidence that usually develops on cirrhotic liver; therefore the prognosis depends on both tumor size and liver function. HCC generally shows a slow growth and (not very important) symptoms; so, the periodic surveillance of cirrhotic patients, by using US examination and alpha-fetoprotein level, allows an early diagnosis of the tumor. Several techniques have proved useful in the treatment of HCC but, in comparison with other currently available percutaneous therapies, RF ablation appears to have several advantages. Authors' results suggest that RF ablation is an effective and safe procedure for the therapy of local hepatic neoplasms. However, further studies will be required to demonstrate that RF ablation is more effective than percutaneous ethanol injection (PEI) in the treatment of HCC.

Efficacy of high dose of recombinant alpha 2b interferon on long term response in chronic hepatitis C and cirrhosis: prospective randomized multicentre study.

BACKGROUND/AIMS: The long-term response to alpha-Interferon in HCV-related chronic liver diseases is disappointing. A randomized controlled trial was conducted to investigate: 1) if doubling the standard regimen of 3 MU recombinant alpha 2b-interferon thrice weekly for one year could improve the long-term response, and 2) the efficacy of these two schedules in cirrhotic patients. PATIENTS AND METHODS: A series of 80 anti-HCV positive patients with biopsy proven liver disease (52 chronic hepatitis and 28 cirrhosis) were randomized to receive either 3 MU or 6 MU alpha 2b-interferon. RESULTS: Based on "intention-to-treat analysis", 38% in the 3 MU group and 53% in the 6 MU group had end-of-treatment response. After 24 months, 18% had long-term response: 5% in 3 MU group and 30% in 6 MU group (p < 0.008). HCV genotype had no influence on the response rate. Thirty-eight percent of the cirrhotics treated with 6 MU had long-term response, while none of those treated with 3 MU had long-term response (difference 38%; 95% confidence internal 10%-67%; p = 0.03). At the end of treatment, 38% of patients lost HCV-RNA. After 24 months only 19% remained HCV-RNA negative: 12 patients (31%) in the 6 MU group and 2 (6%) in the 3 MU group (p < 0.05). CONCLUSIONS: 6 MU of alpha 2b-interferon thrice weekly for 12 months is significantly better than 3 MU in inducing a long-term response and permanent loss of HCV-RNA. This result is particularly striking in the subgroup of cirrhotics.