Spatial distribution of contaminants in sediments of two rivers crossing Tangier (northern Morocco)

The distribution and accumulation of heavy metals in the sediments of two rivers which cross various agglomerations of Tangier city, Morocco, were investigated. Surficial sediment samples were collected during 2005 and characterized for metal content (Zn, Pb, Cd, Cu, Cr and Ni), organic matter, total nitrogen, and n-hexane extractable material (HEM). The organic components (organic carbon, total nitrogen and HEM) show a slightly increasing enrichment from the upstream to the downstream of the emissary. An evaluation of the heavy metal pollution status of both tributaries was carried out using the metal pollution index (MPI). The results revealed the importance of anthropic pressure and the zones influenced by industrial discharges, which keep the metals Pb, Cr and Ni at high levels. Comparison with international regulatory guidelines for sediments revealed serious contamination of Cr, Zn and Ni.

Hepatic profile analyses of tipranavir in Phase II and III clinical trials

Background

The risk and course of serum transaminase elevations (TEs) and clinical hepatic serious adverse event (SAE) development in ritonavir-boosted tipranavir (TPV/r) 500/200 mg BID recipients, who also received additional combination antiretroviral treatment agents in clinical trials (TPV/r-based cART), was determined.

Methods

Aggregated transaminase and hepatic SAE data through 96 weeks of TPV/r-based cART from five Phase IIb/III trials were analyzed. Patients were categorized by the presence or absence of underlying liver disease (+LD or -LD). Kaplan-Meier (K-M) probability estimates for time-to-first US National Institutes of Health, Division of AIDS (DAIDS) Grade 3/4 TE and clinical hepatic SAE were determined and clinical actions/outcomes evaluated. Risk factors for DAIDS Grade 3/4 TE were identified through multivariate Cox regression statistical modeling.

Results

Grade 3/4 TEs occurred in 144/1299 (11.1%) patients; 123/144 (85%) of these were asymptomatic; 84% of these patients only temporarily interrupted treatment or continued, with transaminase levels returning to Grade ≤ 2. At 96 weeks of study treatment, the incidence of Grade 3/4 TEs was higher among the +LD (16.8%) than among the -LD (10.1%) patients. K-M analysis revealed an incremental risk for developing DAIDS Grade 3/4 TEs; risk was greatest through 24 weeks (6.1%), and decreasing thereafter (>24-48 weeks: 3.4%, >48 weeks-72 weeks: 2.0%, >72-96 weeks: 2.2%), and higher in +LD than -LD patients at each 24-week interval. Treatment with TPV/r, co-infection with hepatitis B and/or C, DAIDS grade >1 TE and CD4⁺ > 200 cells/mm³ at baseline were found to be independent risk factors for development of DAIDS Grade 3/4 TE; the hazard ratios (HR) were 2.8, 2.0, 2.1 and 1.5, respectively. Four of the 144 (2.7%) patients with Grade 3/4 TEs developed hepatic SAEs; overall, 14/1299 (1.1%) patients had hepatic SAEs including six with hepatic failure (0.5%). The K-M risk of developing hepatic SAEs through 96 weeks was 1.4%; highest risk was observed during the first 24 weeks and decreased thereafter; the risk was similar between +LD and -LD patients for the first 24 weeks (0.6% and 0.5%, respectively) and was higher for +LD patients, thereafter.

Conclusion

Through 96 weeks of TPV/r-based cART, DAIDS Grade 3/4 TEs and hepatic SAEs occurred in approximately 11% and 1% of TPV/r patients, respectively; most (84%) had no significant clinical implications and were managed without permanent treatment discontinuation. Among the 14 patients with hepatic SAE, 6 experienced hepatic failure (0.5%); these patients had profound immunosuppression and the rate appears higher among hepatitis co-infected patients. The overall probability of experiencing a hepatic SAE in this patient cohort was 1.4% through 96 weeks of treatment. Independent risk factors for DAIDS Grade 3/4 TEs include TPV/r treatment, co-infection with hepatitis B and/or C, DAIDS grade >1 TE and CD4⁺ > 200 cells/mm³ at baseline.

Trial registration

US-NIH Trial registration number: NCT00144170

Assessment of liver fibrosis: noninvasive means

Liver biopsy, owing to its limitations and risks, is an imperfect gold standard for assessing the severity of the most frequent chronic liver diseases chronic hepatitis C (HCV), B (HBV) non alcoholic (NAFLD) and alcoholic (ALD) fatty liver diseases. This review summarizes the advantages and the limits of the available biomarkers of liver fibrosis. Among a total of 2,237 references, a total of 14 validated serum biomarkers have been identified between 1991 and 2008. Nine were not patented and five were patented. Two alternatives to liver biopsy were the most evaluated FibroTest and Fibroscan. For FibroTest, there was a total of 38 different populations including 7,985 subjects with both FibroTest and biopsy (4,600 HCV, 1,580 HBV, 267 NAFLD, 524 ALD, and 1014 mixed). For Fibroscan, there was a total of 11 published studies including 2,260 subjects (1,466 HCV, 95 cholestatic liver disease, and 699 mixed). For FibroTest, the mean diagnostic value for the diagnosis of advanced fibrosis assessed using standardized area under the ROC curves was 0.84 (95% confidence interval 0.83-0.86), without a significant difference between the causes of liver disease, hepatitis C, hepatitis B, and alcoholic or non alcoholic fatty liver disease. High-risk profiles of false negative/false positive of FibroTest, mainly Gilbert syndrome, hemolysis and acute inflammation, are present in 3% of the populations. In case of discordance between biopsy and FibroTest, half of the failures can be due to biopsy; the prognostic value of FibroTest is at least similar to that of biopsy in HCV, HBV and ALD. In conclusion this overview of evidence-based data suggests that biomarkers could be used as an alternative to liver biopsy for the first line assessment of fibrosis stage in the four most common chronic liver diseases, namely HCV, HBV, NAFLD and ALD. Neither biomarkers nor biopsy alone is sufficient for taking a definite decision in a given patient; all the clinical and biological data must be taken into account. There is no evidence based data justifying biopsy as a first line estimate of liver fibrosis. Health authorities in some countries have already approved validated biomarkers as the first line procedure for the staging of liver fibrosis.

Evaluation of metal contamination in sediments from north of Morocco: geochemical and statistical approaches

Concentrations of Fe, Mn, Cr, Cu, Ni, Pb, Zn, Cd and Hg were evaluated in surface sediments of two rivers from north of Morocco, known as Souani and Mghogha rivers. Significantly higher concentrations in mg kg(-1) dry weight (dw) of Mn (747.6 vs. 392.9), Cr (86.4 vs. 56.3), Zn (299.5 vs. 138.5) were found in sediment samples from Mghogha when compared with Souani river. Average concentrations of Cd and Hg in several sediment samples from both rivers were above the effect range median that predicts toxic effects to aquatic organisms. The calculation of enrichment factors showed that Mn, Cr, Cu and Ni were depleted, whereas Pb and Hg were enriched. The results of geoaccumulation index revealed that sediments of both rivers were unpolluted with most of the metals and moderately contaminated with Fe and Hg. Some of elevated concentrations of Hg, principally in Mghogha River, were due to anthropogenic sources including the direct discharges of industrial zone.

Prospective randomized study of doxorubicin-eluting-bead embolization in the treatment of hepatocellular carcinoma: results of the PRECISION V study

Transcatheter arterial chemoembolization (TACE) offers a survival benefit to patients with intermediate hepatocellular carcinoma (HCC). A widely accepted TACE regimen includes administration of doxorubicin-oil emulsion followed by gelatine sponge-conventional TACE. Recently, a drug-eluting bead (DC Bead) has been developed to enhance tumor drug delivery and reduce systemic availability. This randomized trial compares conventional TACE (cTACE) with TACE with DC Bead for the treatment of cirrhotic patients with HCC. Two hundred twelve patients with Child-Pugh A/B cirrhosis and large and/or multinodular, unresectable, N0, M0 HCCs were randomized to receive TACE with DC Bead loaded with doxorubicin or cTACE with doxorubicin. Randomization was stratified according to Child-Pugh status (A/B), performance status (ECOG 0/1), bilobar disease (yes/no), and prior curative treatment (yes/no). The primary endpoint was tumor response (EASL) at 6 months following independent, blinded review of MRI studies. The drug-eluting bead group showed higher rates of complete response, objective response, and disease control compared with the cTACE group (27% vs. 22%, 52% vs. 44%, and 63% vs. 52%, respectively). The hypothesis of superiority was not met (one-sided P = 0.11). However, patients with Child-Pugh B, ECOG 1, bilobar disease, and recurrent disease showed a significant increase in objective response (P = 0.038) compared to cTACE. DC Bead was associated with improved tolerability, with a significant reduction in serious liver toxicity (P < 0.001) and a significantly lower rate of doxorubicin-related side effects (P = 0.0001). TACE with DC Bead and doxorubicin is safe and effective in the treatment of HCC and offers a benefit to patients with more advanced disease.

Prospective randomized study of doxorubicin-eluting-bead embolization in the treatment of hepatocellular carcinoma: results of the PRECISION V study

Transcatheter arterial chemoembolization (TACE) offers a survival benefit to patients with intermediate hepatocellular carcinoma (HCC). A widely accepted TACE regimen includes administration of doxorubicin-oil emulsion followed by gelatine sponge-conventional TACE. Recently, a drug-eluting bead (DC Bead) has been developed to enhance tumor drug delivery and reduce systemic availability. This randomized trial compares conventional TACE (cTACE) with TACE with DC Bead for the treatment of cirrhotic patients with HCC. Two hundred twelve patients with Child-Pugh A/B cirrhosis and large and/or multinodular, unresectable, N0, M0 HCCs were randomized to receive TACE with DC Bead loaded with doxorubicin or cTACE with doxorubicin. Randomization was stratified according to Child-Pugh status (A/B), performance status (ECOG 0/1), bilobar disease (yes/no), and prior curative treatment (yes/no). The primary endpoint was tumor response (EASL) at 6 months following independent, blinded review of MRI studies. The drug-eluting bead group showed higher rates of complete response, objective response, and disease control compared with the cTACE group (27% vs. 22%, 52% vs. 44%, and 63% vs. 52%, respectively). The hypothesis of superiority was not met (one-sided P = 0.11). However, patients with Child-Pugh B, ECOG 1, bilobar disease, and recurrent disease showed a significant increase in objective response (P = 0.038) compared to cTACE. DC Bead was associated with improved tolerability, with a significant reduction in serious liver toxicity (P < 0.001) and a significantly lower rate of doxorubicin-related side effects (P = 0.0001). TACE with DC Bead and doxorubicin is safe and effective in the treatment of HCC and offers a benefit to patients with more advanced disease.

Methodological aspects of the interpretation of non-invasive biomarkers of liver fibrosis: a 2008 update

This review summarizes the methodological aspects of the interpretation of non-invasive biomarkers in liver fibrosis. A scoring system has been updated to better compare the quality of fibrosis biomarkers. Several methodological issues are related to the classical methodology using biopsy, as this is considered the gold standard. However, from evidence-based data, it appears that the methodology needs to change to prevent flawed conclusions among key opinion leaders as well as in obsolete guidelines. As waiting for the perfect biomarker for the diagnosis of advanced fibrosis to come along is probably a waste of time, in the meantime, methods can be improved. The main proposals for improving the methodology are, to take into account the spectrum bias, to assess accuracy between adjacent stages, to compare biomarkers in the same patient, to assess the cause of failure among discordant cases and to use specific statistical methods adapted for imperfect gold standards.

A phase III study of the safety and efficacy of viramidine versus ribavirin in treatment-naïve patients with chronic hepatitis C: ViSER1 results

Pegylated interferon (peg-IFN) and ribavirin (RBV) are effective in eradicating the hepatitis C virus in more than half of patients. However, anemia arising from RBV-induced hemolysis can prompt dose reductions and lower sustained virologic response (SVR) rates. In early clinical trials, Viramidine (VRD, renamed taribavirin), an RBV prodrug, was associated with less anemia and VRD given at 600 mg twice daily (BID) appeared to provide the best safety with comparable efficacy to RBV. The phase III Viramidine's Safety and Efficacy versus Ribavirin 1 (ViSER1) study randomized 972 treatment-naïve patients with chronic hepatitis C to fixed-dose VRD (600 mg BID) or weight-based RBV (1000 or 1200 mg/day), each given with peg-IFN alfa-2b at 1.5 microg/kg/week. The primary efficacy endpoint was SVR rate, and the primary safety endpoint was hemoglobin (Hb) event rate (percent of patients with Hb < 10 g/dL or at least a 2.5-g/dL decrease from baseline). SVR rates were 37.7% with VRD (244/647) and 52.3% with RBV (170/325). Thus, the ViSER1 study failed to demonstrate the primary noninferiority efficacy endpoint. Significantly fewer patients had Hb events with VRD (353/647; 54.6%) compared to those with RBV (272/325; 83.7%) (P < 0.001), and significantly fewer developed anemia (Hb < 10 g/dL) with VRD (34/647; 5.3%) compared to those with RBV (76/325; 23.5%) (P < 0.001).

CONCLUSION

Fixed doses of VRD failed to demonstrate noninferiority to RBV in producing SVR rates. The incidence of anemia was approximately four-fold significantly lower with VRD than with RBV. These results suggest fixed-dose VRD given 600 mg BID is insufficient to treat patients with chronic hepatitis C; a weight-based dosing trial of viramidine is currently under way.

Natural variability of NS3 protease in patients infected with genotype 4 hepatitis C virus (HCV): implications for antiviral treatment using specifically targeted antiviral therapy for HCV

To analyze the genetic diversity of the NS3 gene in patients infected with hepatitis C virus (HCV) genotype 4 (HCV-4) and to assess the possible effects of the gene polymorphism (or variability) on drug susceptibility, 43 NS3 gene sequences were determined for 53 selected patients with HCV-4 infection. NS3 sequencing, like NS5B sequencing, allowed correct subtype determination. Most residues that were located within the catalytic triad or the NS4-binding region or that were involved in metal binding were highly conserved and identical to those found in HCV genotype 1. Compared with HCV genotype 1, all HCV-4 NS3 protein presented V36L and C16T residue changes that could potentially reduce antiprotease activity. The efficacy of antiprotease in HCV-4-infected patients remains to be proven in large clinical trials.

Applicability and variability of liver stiffness measurements according to probe position

AIM

To investigate the liver stiffness measurement (LSM) applicability and variability with reference to three probe positions according to the region of liver biopsy.

METHODS

The applicability for LSM was defined as at least 10 valid measurements with a success rate greater than 60% and an interquartile range/median LSM < 30%. The LSM variability compared the inter-position concordance and the concordance with FibroTest.

RESULTS

Four hundred and forty two consecutive patients were included. The applicability of the anterior position (81%) was significantly higher than that of the reference (69%) and lower positions (68%), (both P = 0.0001). There was a significant difference (0.5 kPa, 95% CI 0.13-0.89; P < 0.0001) between mean LSM estimated at the reference position (9.3 kPa) vs the anterior position (8.8 kPa). Discordance between positions was associated with thoracic fold (P = 0.008). The discordance rate between the reference position result and FibroTest was higher when the 7.1 kPa cutoff was used to define advanced fibrosis instead of 8.8 kPa (33.6% vs 23.5%, P = 0.03).

CONCLUSION

The anterior position of the probe should be the first choice for LSM using Fibroscan, as it has a higher applicability without higher variability compared to the usual liver biopsy position.

Positive and negative prediction of sustained virologic response at weeks 2 and 4 of treatment with albinterferon alfa-2b or peginterferon alfa-2a in treatment-naïve patients with genotype 1, chronic hepatitis C

BACKGROUND/AIMS

Albinterferon alfa-2b is a novel, long-acting, fusion polypeptide that is dosed q2wk or q4wk. The predictive value of early virologic response during albinterferon alfa-2b or peginterferon alfa-2a treatment was investigated in interferon-naïve patients with genotype 1, chronic hepatitis C.

METHODS

Four hundred and fifty-eight patients were randomized to: albinterferon 900 or 1200 microg q2wk, or 1200 microg q4wk, or peginterferon 180 microg qwk. HCV RNA was measured by real-time PCR. A linear exhaustive search algorithm was used to determine the best SVR prediction algorithm in the per-protocol population (n=368), with inclusion of key ITT analyses to assess impact.

RESULTS

SVR rate: 54-67% (P=NS between arms). Rapid initial virologic response rate at week 2 (RIVR; viral decline >2 log(10)IU/mL) was 32-50% and gave rise to positive predictive value of 88-97% for SVR. No initial virologic response at week 4 (NIVR; viral decline <2 log(10)IU/mL; viral load >5.5 log(10)IU/mL) demonstrated a 100% negative predictive value for SVR. A sequential prediction algorithm based on viral kinetics at weeks 2 and 4 identified four prediction groups that reliably predicted SVR, positively or negatively, in 65-72% of patients.

CONCLUSIONS

Improved SVR prediction was obtained by integrating absolute levels and reduction of HCV RNA at treatment week 2 and 4. Patients with RIVR had a high likelihood of achieving SVR.

Impact of adefovir dipivoxil on liver fibrosis and activity assessed with biochemical markers (FibroTest-ActiTest) in patients infected by hepatitis B virus

The aim was to assess the utility of FibroTest-ActiTest (FT-AT) as noninvasive markers of histological changes in patients with chronic hepatitis. Patients with chronic hepatitis B (HBeAg+ and HBeAg-) randomized in two trials of adefovir (ADV) vs placebo, with available paired liver biopsies and FT-AT at baseline and after 48 weeks of treatment were included. The predictive value of FT-AT was assessed using the area under the receiver operating characteristics curves (AUROCs) for the diagnosis of bridging fibrosis, cirrhosis and moderate-severe necroinflammatory activity. The impact of treatment with ADV vs placebo was assessed on liver injury according to baseline stage and virological response at 48 weeks. The analysis of 924 estimates for the diagnosis of bridging fibrosis, cirrhosis and moderate or severe necroinflammatory activity yielded FT-AT AUROCs: 0.76 +/- 0.02 (standardized 0.81 +/- 0.02), 0.81 +/- 0.02 and 0.80 +/- 0.01, respectively. Similar impacts of ADV on liver fibrosis and activity were observed both with paired biopsy (fibrosis stage from 1.6 to 1.4, activity grade from 2.5 to 1.3) and paired biomarkers (FT from 0.44 to 0.40, AT from 0.62 to 0.25) (P < 0.0001). FibroTest-ActiTest provides a quantitative estimate of liver fibrosis and necroinflammatory activity in patients with chronic hepatitis B and may be an alternative to reduce the need for liver biopsy.

An independent and prospective comparison of two commercial fibrosis marker panels (HCV FibroSURE and FIBROSpect II) during albinterferon alfa-2b combination therapy for chronic hepatitis C

Noninvasive markers that accurately follow changes in fibrosis may provide alternatives to liver biopsy for assessment of histological endpoints of antiviral therapy in chronic hepatitis C (CHC). This study compared two commercially available serum marker panels (HCV FibroSURE and FIBROSpect II) during interferon-based therapy. Ninety-five interferon-naïve patients with genotype 1 CHC were enrolled in a phase 2b, active-controlled study of albinterferon alfa-2b/ribavirin for 48 weeks. Proprietary and simple biochemical marker panels were independently evaluated in serum before and during the study. Baseline liver biopsies were evaluated for METAVIR fibrosis by a single pathologist. Index scores were obtained for HCV FibroSURE (n = 84) and FIBROSpect II (n = 95); mean biopsy length: 17.8 +/- 8.0 mm. For detecting fibrosis stages 2-4 (prevalence 23% [22/95] and 21% [18/84]), HCV FibroSURE and FIBROSpect II indicated high sensitivity (1.00 and 0.95, respectively), lower but comparable specificity (0.61 and 0.66, respectively), and a good area under the receiver operating characteristic curve (0.89 and 0.90, respectively). Simple indices had high indeterminate rates (31-40%) at baseline. Patients with a sustained virological response had lower baseline scores than nonresponders, and reduced median percent changes in index scores for HCV FibroSURE (-20.0%vs 2.9%; P = 0.14) and FIBROS Spect II (-6.8%vs 18.4%; P = 0.05). The panels demonstrated comparable performance characteristics for differentiating mild from moderate-severe stage disease in CHC. Lower index scores at baseline that continue to decline likely reflect reduced fibrogenesis activity in patients with successful antiviral responses to therapy.