Undetectable HCV-RNA at treatment-week 8 results in high-sustained virological response in HCV G1 treatment-experienced patients with advanced liver disease: the International Italian/Spanish Boceprevir/Peginterferon/Ribavirin Name Patients Program.

In many countries, first-generation protease inhibitors (PIs)/peginterferon/ribavirin (P/R) still represent the only treatment option for HCV-infected patients. Subjects with advanced disease and previous failure to P/R urgently need therapy, but they are under-represented in clinical trials. All treatment-experienced F3/4 Metavir patients who received boceprevir (BOC)+P/R in the Italian-Spanish Name Patient Program have been included in this study. Multivariate logistic regression analysis (MLR) was used to identify baseline and on-treatment predictors of SVR and adverse events (AEs). Four hundred and sixteen patients, mean age 57.7 (range 25-78 years), 70% males, 69.5% (289/416) F4, 14% (41/289) Child-Pugh class A6, 24% (70/289) with varices and 42% (173/416) prior null responders to P/R, were analysed. Overall, SVR rate (all 381 patients who received one dose of BOC) was 49%, (58% in F3, 45% in F4, 61% in relapsers, 51% in partial, 38% in null responders, and 72% in subjects with undetectable HCV-RNA at treatment-week (TW)8. Among patients with TW8 HCV-RNA ≥ 1000 IU/L, SVR was 8% (negative predictive value = 92%). Death occurred in 3 (0.8%) patients, while decompensation and infections were observed in 2.9% and 11%, respectively. At MLR, SVR predictors were TW4 HCV-RNA ≥ 1log10 -decline from baseline, undetectable TW8 HCV-RNA, prior relapse, albumin levels ≥3.5 g/dL and platelet counts ≥100 000/µL. Metavir F4, Child-Pugh A6, albumin, platelets, age and female gender were associated with serious and haematological AEs. Among treatment-experienced patients with advanced liver disease eligible for IFN-based therapy, TW8 HCV-RNA characterised the subset with either high or poor likelihood of achieving SVR. Using TW8 HCV-RNA as a futility rule, BOC/P/R appears to have a favourable benefit-risk profile.

Understanding the insulating nature of alkali-metal/Si(111):B interfaces.

We have recently revisited the phase diagram of alkali-metal/Si(111):B semiconducting interfaces previously suggested as the possible realization of a Mott-Hubbard insulator on a triangular lattice. The insulating character of the 2√[3] × 2√[3]R30 surface reconstruction observed at the saturation coverage, i.e. 0.5 ML, has been shown to find its origin in a giant alkali-metal-induced vertical distortion. Low energy electron diffraction, photoemission spectroscopy and scanning tunneling microscopy and spectroscopy experiments coupled with linear augmented plane-wave density functional theory calculations allow a full understanding of the k-resolved band structure, explaining both the inhomogeneous charge transfers into an Si-B hybridized surface state and the opening of a band gap larger than 1 eV. Moreover, √[3] × âˆš[3]R30, 3 × 3 and 2√[3] × 2√[3]R30 surface reconstructions observed as a function of coverage may reveal a filling-controlled transition from a half-filled correlated magnetic material to a strongly distorted band insulator at saturation.

Electronic instability in a zero-gap semiconductor: the charge-density wave in (TaSe4)2I.

We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe(4))(2)I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below T(CDW)=263 K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at T(CDW).

Giant ambipolar Rashba effect in the semiconductor BiTeI.

We observe a giant spin-orbit splitting in the bulk and surface states of the noncentrosymmetric semiconductor BiTeI. We show that the Fermi level can be placed in the valence or in the conduction band by controlling the surface termination. In both cases, it intersects spin-polarized bands, in the corresponding surface depletion and accumulation layers. The momentum splitting of these bands is not affected by adsorbate-induced changes in the surface potential. These findings demonstrate that two properties crucial for enabling semiconductor-based spin electronics-a large, robust spin splitting and ambipolar conduction-are present in this material.

Giant alkali-metal-induced lattice relaxation as the driving force of the insulating phase of alkali-metal/Si(111):B.

Ab initio density-functional theory calculations, photoemission spectroscopy (PES), scanning tunneling microscopy, and spectroscopy (STM, STS) have been used to solve the 2sqrt[3]×2sqrt[3]R30 surface reconstruction observed previously by LEED on 0.5 ML K/Si:B. A large K-induced vertical lattice relaxation occurring only for 3/4 of Si adatoms is shown to quantitatively explain both the chemical shift of 1.14 eV and the ratio 1/3 measured on the two distinct B 1s core levels. A gap is observed between valence and conduction surface bands by ARPES and STS which is shown to have mainly a Si-B character. Finally, the calculated STM images agree with our experimental results. This work solves the controversy about the origin of the insulating ground state of alkali-metal/Si(111):B semiconducting interfaces which were believed previously to be related to many-body effects.

Phonon contribution to the lifetime of surface state quasiparticles confined in nanopyramids.

We present a scanning tunneling microscopy investigation of the dynamics of hot electrons and holes in Ag pyramidal nanostructures. The geometry of the nanostructure leads to a strong reduction of the decay mechanism into the bulk states and then to a large reflection coefficient of the surface electronic waves. Therefore, in contrast to quantum corrals and adatom islands which show a dominant lossy scattering contribution to the linewidth, the narrow observed structures in the differential conductivity spectra reveal the expected linewidth minimum at the Fermi energy. The electron-phonon contribution to the lifetime is shown to be dominant, in agreement with previous photoemission measurements.

A randomized 4-arm multicenter study of interferon alfa-2b plus ribavirin in the treatment of patients with chronic hepatitis C not responding to interferon alone.

To determine whether a higher dosage of interferon (IFN) associated with ribavirin and/or prolonged time of administration may improve therapeutic efficacy, we conducted a 4-arm randomized trial on patients with chronic hepatitis C not responding to one or more previous treatment courses with IFN monotherapy. Group 1 (n = 139) received 3 million units (MU) IFN-alpha2b 3 times a week (t.i.w.) plus ribavirin 1,000 mg/d for 12 months; group 2 (n = 162) received 5 MU t.i.w. plus ribavirin for 12 months; group 3 (n = 142) received 3 MU t.i.w. plus ribavirin for 6 months; and group 4 (n = 151) received 5 MU t.i.w. plus ribavirin for 6 months. The primary end point was hepatitis C virus (HCV)-RNA clearance at the end of 6-month follow-up. HCV-RNA was negative in 15% of group 1, 23% of group 2, 11% of group 3, 16% of group 4 (group 2 vs. group 3, P =.04). Among patients with genotypes 1 and 4, sustained response was significantly higher in group 2 vs. group 3 (18% vs. 7%, P =.03; group 1 = 9%, group 4 = 12%, P = not significant [NS]). In patients with genotypes 2 and 3, sustained virologic response was not affected by the different regimens (group 1 = 32%, group 2 = 30%, group 3 = 30%, group 4 = 35%, P = NS). In conclusion, about 23% of nonresponders to IFN monotherapy may achieve a sustained response if re-treated by 5 MU t.i.w. IFN plus ribavirin 1,000 mg/d for 1 year. Patients with genotype 1 should receive a high dosage of IFN plus ribavirin for 12 months, whereas therapy for patients with genotype 2 or 3 should be less aggressive.

Hepatitis B virus binds to peripheral blood mononuclear cells via the pre S1 protein.

The hepatitis B virus has been documented in hepatic and extrahepatic compartments, including bone marrow and peripheral blood cells. The viral protein involved in the attachment to human hepatocytes has been identified within the N-terminus of the pre S1 envelope protein. Using recombinant particles containing the pre S1, pre S2 and S encoded sequences, we studied which virus envelope protein is involved in binding to peripheral blood cells. Mononuclear cells of 20 healthy subjects bound 125I-labelled particles, with a S/N ratio higher than 2.5 (range 2.69-7.77). Binding was abolished by trypsinization. B lymphocytes and monocytes were found to bind viral particles much more efficiently compared to T cells and granulocytes. A monoclonal antibody (MA 18/7), recognizing the (27-49) pre S1 sequence, completely inhibited viral particle attachment to PBMC, while anti-pre S2 (Q 19/10) and anti-S (20/2) monoclonal antibodies had no effect. We conclude that the pre S1 sequence is involved in HBV attachment to PBMC and to hepatocytes. The nature of the cellular attachment site is unknown, but it might be a receptor for physiologic ligands, as occurs with other viruses.

Serum levels of soluble interleukin-2 receptors in acute and chronic viral hepatitis.

To analyze interleukin-2-dependent immunoregulatory function in hepatitis B virus infection and in other forms of viral hepatitis, levels of soluble interleukin-2 receptors (sIL-2R) were measured by an enzyme-linked assay in sera from patients with acute and chronic viral hepatitis of different etiology. Increased sIL-2R levels were detected in the early phase of acute hepatitis type A and type B, but not during acute non-A, non-B hepatitis. Among 46 patients with chronic hepatitis B virus infection, levels of sIL-2R were significantly increased only in cases with chronic active hepatitis, while they were about normal in chronic persistent hepatitis or in healthy carriers of the infection. These differences were independent of virus replication, being maintained when patients were stratified according to HBeAg/anti-HBe status and to serum HBV-DNA. Nine patients with chronic active hepatitis type B and high sIL-2R levels at presentation were followed prospectively for two to eight years, and in HBeAg-positive patients, the behavior of receptor levels closely paralleled disease activity. These results, which may reflect increased shedding of IL-2R by activated T lymphocytes in patients with active destruction of HBV infected hepatocytes, indicate the usefulness and potential prognostic importance of serum sIL-2R determination in patients with chronic viral hepatitis. Patients with chronic non-A, non-B hepatitis had much lower sIL-2R levels, although their liver disease was similar to hepatitis B cases, suggesting that different pathogenetic mechanisms operate in these patients.