Linking stable isotopes and biochemical responses in Balanus glandula under sewage influence.

In the present study, we analyzed the influence of untreated sewage exposure on carbon (δ13C) and nitrogen (δ15N) isotopic composition and several biochemical responses in the barnacle Balanus glandula. The main objective was to evaluate whether changes in stable isotopes signature do reflect biochemical sub-lethal effects in a sewage influence gradient. Stable isotopes analysis showed differences in isotope signatures between close sewage influence and distant sites, being δ13C signatures stronger than that of δ15N. Regarding biochemical effects, although organisms close to the effluent would be clearly exposed to contaminants (increased GST activity) the oxidative stress would not be too evident (peroxidases and ACAP not affected). The most affected physiological aspect was the digestive one, reflected in increased alkaline proteases and lipases activities. A clear relation between δ15N and GST activity was found, showing to δ15N as an indicator of potential exposure to chemical contaminants.

Plasma ribavirin concentrations during treatment of recurrent hepatitis C with peginterferon alpha-2b and ribavirin combination after liver transplantation.

After liver transplantation (LT) for hepatitis C virus (HCV)-related cirrhosis, recurrence of HCV infection is universal. The efficacy of antiviral therapy in this indication is usually reduced because of its poor tolerability. We present herein the results of plasma measurement of ribavirin levels in transplanted patients when using increasing dosage of ribavirin, in comparison with a control cohort of nontransplanted patients. Seventeen control patients (nine women and eight men, median age 51.5 years) were compared with 12 liver transplant patients (2 women and 10 men, median age 55 years). In 76% of patients, HCV infection was genotype 1. All patients were treated by a combination of ribavirin and pegylated-interferon alpha-2b. A total of 54 blood samples were taken (1.8 per patient) for ribavirin level measurement. A virological response was obtained in 8/17 patients in the control group and in 6/12 LT patients. Ribavirin dose was lower in the LT group (8.79 vs 12.98 mg/kg/day), but plasma levels were the same in both groups (2.23 vs 2.43 mg/L for LT and non-LT groups, respectively). This was probably related to impaired renal function in the LT group (serum creatinine: 112.6 vs 73.6 micromol/L). No discontinuation of ribavirin therapy was observed and haemoglobin level was the same in both groups (109.5 g/L in LT patients vs 119.5 g/L in the control group). These results strongly support the interest in plasma measurement of ribavirin concentration during antiviral therapy in LT patients. Ribavirin dosage might be adapted without compromising its efficacy.

The male sterile G cytoplasm of wild beet displays modified mitochondrial respiratory complexes.

Cytoplasmic male sterility (CMS) in higher plants has been mainly studied in cultivated species. In most cases, pollen abortion is linked to the presence of an additional mitochondrial polypeptide leading to organelle dysfunction in reproductive tissues. In wild beet, both CMS and hermaphrodite plants coexist in natural populations. The G cytoplasm is widely distributed along the Western European coast, and previous genetic studies have demonstrated that this cytoplasm confers male sterility in beet. In the present study, we have identified two mutations of G mitochondrial genes, each of which results in the production of a respiratory chain complex subunit with an altered molecular weight; the NAD9 subunit has a C-terminal extension while the COX2 subunit has a truncated C-terminus. NADH dehydrogenase activity was unchanged in leaves, but cytochrome c oxidase activity was reduced by 50%. Moreover, Western blot analyses revealed that alternative oxidase was more abundant in male sterile G plants than in a fertile control (Nv), suggesting that this alternative pathway might compensate for the cytochrome c oxidase deficiency. Implications of respiratory chain changes and a putative link with CMS are discussed.