Bioavailability studies of a new iron source by means of the prophylactic-preventive method in rats

The bioavailability of iron from a new commercial source containing ferric gluconate stabilized with glycine sold under the trade name Bioferrico™ was studied in this work by means of the prophylactic-preventive test in rats. NaFeEDTA was also studied by the same methodology for comparative purposes and ferrous sulfate was used as the reference standard. The test was conducted for 4 wk with male weaned rats, which were randomized into four groups of at least eight animals each. A control group received a basal diet of low-iron content, whereas the other groups received the same diet with iron added at a dose of 20 mg/kg as FeSO₄·7H₂O, NaFeEDTA, and Bioferrico, respectively. Individual hemoglobin concentrations (HbC) and weights were determined at the beginning and at the end of the study and food intake was daily registered. The iron bioavailability (BioFe) of each source was calculated as the ratio between the amount of iron incorporated into hemoglobin during the treatment (HbFe) and the total iron intake per animal (ToFeIn). A relative biological value (RBV) was obtained for each iron source under study as the ratio between the BioFe of the tested compound and that of the reference standard. The RBVs were 98% and 86% for Bioferrico and NaFeEDTA, respectively. Bioferrico showed a high bioavailability and behaved inertly in relation to the sensorial properties of the fortified food when it was added to flour. These qualities emphasize Bioferrico as a promising source for iron fortification.     

Evaluating treatment of hepatitis C for hemolytic anemia management

The combination therapy of antiviral peg-interferon and ribavirin has evolved as one of the better treatments for hepatitis C. In spite of its success in controlling hepatitis C infection, it has also been associated with treatment-related adverse side effects. The most common and life threatening among them is hemolytic anemia, necessitating dose reduction or therapy cessation. The presence of this side effect leads to a trade-off between continuing the treatment and exacerbating the side effects versus decreasing dosage to relieve severe side effects while allowing the disease to progress. The drug epoietin (epoetin) is often administered to stimulate the production of red blood cells (RBC) in the bone marrow, in order to allow treatment without anemia. This paper uses mathematical models to study the effect of combination therapy in light of anemia. In order to achieve this we introduce RBC concentration and amount of drug in the body as state variables in the usual immunological virus infection model. Analysis of this model provides a quantification of the amount of drug a body can tolerate without succumbing to hemolytic anemia. Indirect estimation of parameters allow us to calculate the necessary increment in RBC production to be ?2.3 times the patient’s original RBC production rate to sustain the entire course of treatment without encountering anemia in a sensitive patient.     

Oncostatin M synergistically inhibits HCV RNA replication in combination with interferon-α

Oncostatin M (OSM), a member of the interleukin-6 family, possesses various functions, including hepatocyte differentiation and suppression of melanoma cell growth. Here, we report anti-hepatitis C virus (HCV) activity of OSM as a new function of this cytokine. OSM possessed marked anti-HCV activity (50% effective concentration: 0.71 ng/ml) in an HCV RNA replication cell culture system. The most striking finding is that OSM exhibited synergistic inhibitory activity on interferon (IFN)-α even at a low concentration with weak anti-HCV activity, such as 25 pg/ml. OSM is a candidate anti-HCV reagent and may improve the current IFN therapy for patients with chronic hepatitis C.     

Association study of IL28B: rs12979860 and rs8099917 polymorphisms with SVR in patients infected with chronic HCV genotype 1 to PEG-INF/RBV therapy using systematic meta-analysis

Recently, genome-wide associated studies (GWAS) have identified that host genetics IL28B SNPs rs12979860 and rs8099917 were significantly associated with SVR in patients infected with chronic HCV genotype 1 to PEG-INF/RBV therapy. Results from these studies remain conflicting. We conducted this meta-analysis to estimate the overall association of SVR with rs12979860 and rs8099917. We searched the PubMed, Embase, Scholar Google, ISI Web of Knowledge, and Chinese National Knowledge Infrastructure (CNKI) databases for all articles before July 30, 2012. The odds ratio (OR) corresponding to the 95% confidence interval (CI) was used to assess the association. The statistical heterogeneity among studies was assessed with the I² statistics. Begg's test and Egger's test were performed to evaluate the publication bias. Eventually, twenty studies were selected for the meta-analysis. The IL-28B SNPs rs12979860 genotype CC and rs8099917 genotype TT significantly positive associated with SVR in patients infected chronic HCV genotype 1 to PEG-INF/RBV therapy (OR = 4.473, 95% CI = 3.814–5.246, OR = 5.171, 95% CI = 4.372–6.117 respectively). The results suggested that rs12979860 genotype CC and rs8099917 genotype TT could be used as independent predictors of the HCV-1 infected patients.     

Prediction of efficient virological response to pegylated interferon/ribavirin combination therapy by NS5A sequences of hepatitis C virus and anti-NS5A antibodies in pre-treatment sera

A considerable number of patients infected with Hepatitis C virus subtype 1b (HCV-1b) do not respond to pegylated interferon/ribavirin combination therapy. In this study we explored a useful factor(s) to predict treatment outcome. A total of 47 HCV-1b-infected patients were treated with pegylated interferon/ ribavirin for 48 weeks. Sera of the patients were examined for the entire NS5A sequence of the HCV genome, HCV RNA titers and anti-NS5A antibodies. According to their responses, the patients were divided into two groups, early viral responders who cleared the virus by week 16 (EVR[16w]) and those who did not (Non-EVR[16w]). The mean number of mutations in the V3 region (aa 2356 to 2379) or that in the V3 region plus its N-terminally flanking region, which we refer to as interferon/ribavirin resistancedetermining region (IRRDR; aa 2334 to 2379), of NS5A obtained from the pretreatment sera was signifi-cantly larger for EVR(16w) compared with Non-EVR(16w). Moreover, HCV-1b isolates with > or =5 mutations in V3 or those with > or =6 mutations in IRRDR were almost exclusively found in EVR(16w). Also, the presence of detectable levels of anti-NS5A antibodies in the pretreatment sera was closely associated with EVR(16w). In conclusion, a high degree of sequence variation in V3 (> or =5) or IRRDR (> or =6) and the presence of detectable levels of anti-NS5A antibodies in the pretreatment sera would be useful factors to predict EVR(16w). On the other hand, a less diverse sequence in V3 (< or =4) or IRRDR (< or =5) together with the absence of detectable anti-NS5A antibodies could be a predictive factor for Non-EVR(16w).     

Anti-interferon-α neutralizing antibody induced telaprevir resistance under the interferon-α plus telaprevir treatment in vitro

Although the development of anti-interferon (IFN)-α neutralizing antibodies (NAbs) is likely to be a common clinical problem for patients with various diseases treated with IFN, anti-IFN-α NAb has been exceptionally considered to have no clinical significance in the treatment of chronic hepatitis C with pegylated IFN-α (Peg-IFN-α). However, we recently clarified that the presence of NAb was associated with a non-response to the Peg-IFN plus ribavirin (RBV) therapy. In this study, we used the HCV-replicon system with genotype 1b, and investigated the role of anti-IFN-α NAb in the response to telaprevir (TVR)-containing new antiviral therapy for hepatitis C virus (HCV). Anti-IFN-α NAb-positive sera specifically inhibited the anti-HCV effects of IFN-α, without any effect on the activity of IFN-β in vitro. The NAb-positive sera also inhibited the IFN-α-dependent induction of interferon-stimulated genes, MxA and OAS-1, in a dose-dependent manner. Although TVR monotherapy decreased the HCV-RNA in vitro, the HCV-RNA was increased again with the development of TVR-resistant mutations. When IFN-α was administrated with TVR, the replication of HCV was continuously suppressed for more than a month. However, in the presence of anti-IFN-α NAb-positive sera, even when IFN-α was combined with TVR, the levels of HCV-RNA exhibited a time-course similar to that with TVR monotherapy, and HCV with TVR-resistant mutations emerged. In conclusion, our findings suggest that the presence of IFN-α NAb decreases the antiviral effects of IFN-α and may be related to the development of TVR-resistant mutated viruses.     

Structural and functional characterization of the single-chain Fv fragment from a unique HCV E1E2-specific monoclonal antibody

The nucleotide sequence of the unique neutralizing monoclonal antibody D32.10 raised against a conserved conformational epitope shared between E1 and E2 on the serum-derived hepatitis C virus (HCV) envelope was determined. Subsequently, the recombinant single-chain Fv fragment (scFv) was cloned and expressed in Escherichia coli, and its molecular characterization was assessed using multi-angle laser light scattering. The scFv mimicked the antibody in binding to the native serum-derived HCV particles from patients, as well as to envelope E1E2 complexes and E1, E2 glycoproteins carrying the viral epitope. The scFv D32.10 competed with the parental IgG for binding to antigen, and therefore could be a promising candidate for therapeutics and diagnostics.     

Bioavailability Studies of Stabilized Iron (II) Sulfate by Means of the Prophylactic-preventive Method

The bioavailability of stabilized ferrous sulfate was studied by means of the prophylactic-preventive test in rats. For comparative purposes, ferrous sulfate was used as reference standard. The test was performed in male weaned rats during 3 weeks, which were randomized into three groups of ten animals each. A control group received a basal diet of low iron content while the other groups received the same diet added with iron at a dose of 15 mg/kg as FeSO₄ 7H₂O and stabilized ferrous sulfate, respectively. Individual hemoglobin concentrations and weights were determined at the beginning and at the end of the study, and food intake was daily registered. Iron bioavailability (BioFe) of each source was calculated as the ratio between the amount of iron incorporated into hemoglobin during the treatment and the total iron intake per animal. A relative biological value was obtained as the ratio between the BioFe of stabilized ferrous sulfate and the reference standard given a value of 96%. Stabilized ferrous sulfate showed a high bioavailability, and when it is used to fortify dairy products as cheese and fluid milk in a dose of 15–20 mg of iron per kilogram, it behaved inertly in relation to the sensorial properties of the fortified food. These results suggest that this iron compound is a promising source to be use in food fortification.