Peginterferon plus Ribavirin for chronic hepatitis C in opiate addicts on methadone/buprenorphine maintenance therapy.

BACKGROUND: In developed countries hepatitis C is prevalently transmitted by intravenous drug users (IDUs). The problems associated with management of HCV hepatitis in these patients have, in the past, discouraged treatment. AIM: To evaluate efficacy, safety and tolerability of a standard Peginterferon (Peg-IFN) alpha-2b or alpha-2a plus Ribavirin treatment in IDUs who were receiving methadone or buprenorphine. METHODS: A multi-centre prospective observational study performed from September 2003 to September 2006 in Central Italy (Umbria and Marches regions). A shared care model of HCV management was used which integrated a multidimensional, multidisciplinary approach. RESULTS: Sixty-five subjects were evaluated and 52 satisfied inclusion criteria. Forty-five completed treatment (25 with Peg-IFN alpha-2b, 20 with Peg-IFN alpha-2a), a total of 37 showed a biochemical/virological response at the end of treatment (ITT 71.1%), 26 had a sustained virological response (ITT 50%; 38.4% of cases genotype 1-4, 61.6% genotype 3-2). CONCLUSIONS: The results indicate that patients on maintenance treatment with methadone/buprenorphine can be treated for HCV. The success rate was fairly good; tolerability and side effects were similar to those reported in non-IDU patients. Close cooperation with specialists in drug addiction and psychiatrists is however essential for success.

A test of the nature of cosmic acceleration using galaxy redshift distortions.

Observations of distant supernovae indicate that the Universe is now in a phase of accelerated expansion the physical cause of which is a mystery. Formally, this requires the inclusion of a term acting as a negative pressure in the equations of cosmic expansion, accounting for about 75 per cent of the total energy density in the Universe. The simplest option for this 'dark energy' corresponds to a 'cosmological constant', perhaps related to the quantum vacuum energy. Physically viable alternatives invoke either the presence of a scalar field with an evolving equation of state, or extensions of general relativity involving higher-order curvature terms or extra dimensions. Although they produce similar expansion rates, different models predict measurable differences in the growth rate of large-scale structure with cosmic time. A fingerprint of this growth is provided by coherent galaxy motions, which introduce a radial anisotropy in the clustering pattern reconstructed by galaxy redshift surveys. Here we report a measurement of this effect at a redshift of 0.8. Using a new survey of more than 10,000 faint galaxies, we measure the anisotropy parameter beta = 0.70 +/- 0.26, which corresponds to a growth rate of structure at that time of f = 0.91 +/- 0.36. This is consistent with the standard cosmological-constant model with low matter density and flat geometry, although the error bars are still too large to distinguish among alternative origins for the accelerated expansion. The correct origin could be determined with a further factor-of-ten increase in the sampled volume at similar redshift.

A large population of galaxies 9 to 12 billion years back in the history of the Universe.

To understand the evolution of galaxies, we need to know as accurately as possible how many galaxies were present in the Universe at different epochs. Galaxies in the young Universe have hitherto mainly been identified using their expected optical colours, but this leaves open the possibility that a significant population remains undetected because their colours are the result of a complex mix of stars, gas, dust or active galactic nuclei. Here we report the results of a flux-limited I-band survey of galaxies at look-back times of 9 to 12 billion years. We find 970 galaxies with spectroscopic redshifts between 1.4 and 5. This population is 1.6 to 6.2 times larger than previous estimates, with the difference increasing towards brighter magnitudes. Strong ultraviolet continua (in the rest frame of the galaxies) indicate vigorous star formation rates of more than 10-100 solar masses per year. As a consequence, the cosmic star formation rate representing the volume-averaged production of stars is higher than previously measured at redshifts of 3 to 4.