Application of SS-CS-HR-AAS measurements for the detection of Ag nanoparticles in marine invertebrates.

The present study describes the development of a fit-for-purpose analytical procedure for the detection of Ag NPs in different marine organisms by Solid Sampling Continuous Source High Resolution Atomic Absorption Spectrometry (SS-CS-HR-AAS). The detection is based on the observation of the Ag absorption peak and its atomization delay tad which is different for ionic Ag and Ag NPs. The temperature program was optimized in order to achieve the maximum difference between the t ad (Δtad ). The method was first developed using biota CRMs spiked with different Ag NPs standard solutions or Ag+ , at the same concentration. Then, laboratory exposure experiments were performed on mussels and marine sponges. The results showed that the developed methodology is suitable for the detection of Ag NPs for both groups of organisms, showing Δtad up to 3.1 s. The developed method is therefore a promising tool to assess the presence of AgNPs in marine invertebrates.

Scavenging of select radionuclides and trace elements by pelagic Sargassum in the Caribbean Sea.

In recent years, the North Atlantic and the Caribbean Sea have experienced unusual and unprecedented pelagic Sargassum blooms, which may adversely affect coastal ecosystems and productive ocean. Sargassum has the potential to scavenge trace elements and radionuclides from seawater, and when bioaccumulated and thus concentrated, can pose a potential threat to higher trophic organisms, including humans that consume impacted seafood. In this study, trace elements and naturally-occurring U/Th-series radionuclides were measured in Sargassum that were collected in the coastal waters of the Caribbean Sea (Antigua/Barbuda, Belize, and Barbados) to better define baseline concentrations and activities, and to assess the scavenging potential for these trace elements and radionuclides. The mean concentration of trace elements observed in Sargassum collected across these three Caribbean Sea are ranked accordingly to the following descending order: Sr > As>Fe > Mn > Zn > Ni > V > C > Cd > Se > Co > Cr > Pb > Ag > Hg. 210-Po and 210Pb activities in Sargassum were observed to be more elevated than previously reported values.

Marine sponges as coastal bioindicators of rare earth elements bioaccumulation in the French Mediterranean Sea.

In recent years, the widespread use of rare earth elements (REEs) has raised the issue of their harmful effects on the aquatic environment. REEs are now considered as contaminants of emerging concern. Despite the increasing interest of REEs in modern industry, there is still a lack of knowledge on their potential impact on the environment and especially in the marine environment. In this context, the need for monitoring tools to assess REEs pollution status in marine ecosystems is considered as the first step towards their risk assessment. Similar to mussels, filter-feeder sponges have emerged as a key bio-monitor species for marine chemical pollution. Their key position at a low level of the trophic chain makes them suitable model organisms for the study of REEs potential transfer through the aquatic food web. We therefore undertook a comparative study on seven marine sponge species, assessing their capability to bioaccumulate REEs and to potentially transfer these contaminants to higher positions in the trophic chain. A spike experiment under controlled conditions was carried out and the intra- and inter-species variability of REEs was monitored in the sponge bodies by ICP-MS. Concentrations were found to be up to 170 times higher than the corresponding control specimens. The tubular species Aplysina cavernicola showed the highest concentrations among the studied species. This study shows, for the first time, the potential of marine sponges as bio-monitor of REEs as well as their possible application in the bioremediation of polluted sites.

Comparative study on Hg bioaccumulation and biotransformation in Mediterranean and Atlantic sponge species.

In this work we present an assessment of mercury (Hg) and methyl mercury (MeHg) bioaccumulation in different species of marine sponges collected off the Northwestern Mediterranean and Northeastern Atlantic coasts. Overall the results showed significant accumulation of Hg in sponges, with the Mediterranean sponge Chondrilla nucula exhibiting the highest total Hg content (up to 0.5 mg kg-1) and bio-concentration factor (BCF) up to 23. A significant inter-species variability of Hg bioaccumulation was observed among species collected at the same site. The sponges, collected in marine environment contaminated with Hg show consistently higher Hg accumulation, meaning that the bioaccumulation is proportional to the Hg availability in the surrounding environment. Different extraction protocols were tested for MeHg analysis and, generally, a low MeHg ratio in Hg species (4% and 17% average for Mediterranean and Irish sponges respectively) was detected suggesting a possible demethylation process and therefore a promising role of sponges for Hg bioremediation Additionally, the Hg isotopic composition in these organisms was determined and it showed that MDF (mass dependent fractionation) is the main process in sponges, with the absence of significant MIF. This result suggests a dominant role of associated microbial population in the methylation and/or demethylation processes.

Trace elements contamination assessment in marine sediments from different regions of the Caribbean Sea.

Trace elements (TEs), rare earth elements (REEs), and methylmercury (MeHg) concentrations as well as mercury (Hg) and lead (Pb) isotope compositions in sediment samples collected from strategic locations along the Caribbean Sea were determined. The analyzed sediment samples were collected at different core depths from localities in Colombia, Cuba, Haiti, and the Dominican Republic. The evaluation of pollution assessment indices i.e. enrichment factors and geoaccumulation index revealed significant enrichment of several priority substances, such as Pb, Cd and Hg, in most of the sampling sites. Hg was found in extremely high concentrations (up to 22 ± 3 mg kg-1) in bottom samples of Colombian core, which led the authors to further investigate this area with respect to the source for Hg contamination. The analysis of Hg isotope ratios in Colombian sediments and the Pb isotope ratios in all studied cores, helped in the identification of likely pollution sources and represents a critically important record of anthropogenic influence in the region. Finally, the REEs patterns determined in all samples, also provide a needed baseline for these contaminants in the Caribbean region.

Tracing source and mobility of arsenic and trace elements in a hydrosystem impacted by past mining activities (Morelos state, Mexico).

The Sierra Huautla (Morelos State, Mexico) is a biological reserve with historical mines of Ag and Pb. In this area, waters used by inhabitants are contaminated by arsenic (As). An integrated environmental survey was realized both in waters and sediments to better constrain the source and the mobility of As and other trace elements. Two areas of interest were selected: (1) the Nexpa River ecosystem to determine the local geochemical background, and (2) the Huautla area, affected by past mining activities. This study allowed the definition of the local geochemical baseline in sediments or in waters, demonstrated uncontaminated by TE in the Nexpa area, except for As in the dissolved phase or for Cd in Suspended Particulate Matters (SPM). In the Huautla area, TE contents in water were higher than the World Health Organization (WHO) limits for Al, As and Mn in unfiltered waters, and only for As in the dissolved phase. Speciation analyses revealed arsenic to be present only as the toxic-inorganic arsenate species, As(+V). In SPM, Ag, As, Cd and Zn concentrations were higher than Sediment Quality Guidelines (SQG). The different geochemical indice (EF: 5, PLI: 3, EF: Igeo: 5-3) demonstrated that SPM were significantly contaminated and consistute an health risk for Huautla inhabitants exposed to As-contaminated waters and TE-rich SPM. The combination of mineralogy, chemistry, C and S stable isotopes with thermodynamic modeling indicate dissolutions of minerals from local geological formations, sorption-desorption phenomena from clays and oxy-hydroxides, and the weathering responsible for the transport of the TE-rich SPM (1.8 wt% for 17% of the total TE concentration). Moreover, the past mining activity would be a source of the contamination only for As in waters from flooded mines.

First assessment on trace elements in sediment cores from Namibian coast and pollution sources evaluation.

Trace elements (TEs), Rare Earth Elements (REEs) and Pb isotope ratios were determined in six small cores sampled along the Namibian coast and different indices, such as Enrichment Factor, Geo-accumulation Index and Pollution load index, were calculated to evaluate possible metal contamination in the area. Concentrations of Pb, Cu, As and Cd were strongly enhanced at the upper 7 cm of core C5, which is located at Walvis Bay, at the major harbor and urban/industrial center of Namibia, indicating the impact from the recent anthropogenic activities. Principal Component Analysis was applied to the data set indicating possible common sources of the contaminants. Pb stable isotope ratios, combined with the dating of core C5 at Walvis Bay, further confirmed the anthropogenic provenance of Pb sources in the recent sediment deposits, which occurred after 1945, when the anthropogenic activities in the area began to increase. REEs profiles were also determined, showing enrichment in REEs for some of the samples, typical for the minerals present in the area. Ce anomaly was detected in one of the cores but the REEs profile did not reveal anomalies ascribable to anthropogenic influence.

Baseline study on trace and rare earth elements in marine sediments collected along the Namibian coast.

Namibia is a fast-growing country with extensive mineral extraction activities used in diamond, fluorspar, uranium, and metals production. To assess the impact of land based human activities on the Namibian coastal marine environment, 25 elements were analyzed in 22 surface sediments samples collected along the coast. After applying a variety of pollution assessment indices (Enrichment Factor, Igeo and Pollution Load Indexes) was concluded that As, Cd and Sb were considerably enriched in the sediments from several sites, while Cu, Pb and Zn showed very high enrichment near the Walvis Bay harbor. Pearson's correlation and Principal Component Analysis were used to investigate common metal sources. Additionally, the determination of Pb isotope ratios confirmed the contribution of land based human activities at Walvis Bay and Lüderitz as sources of pollution. The analysis of REEs did not reveal any important enrichment due to anthropogenic activities, but provides a needed baseline for further investigations.

Marine sponges as a powerful tool for trace elements biomonitoring studies in coastal environment.

In this work, we performed a comparative study on six marine sponge species collected along the French Mediterranean and Irish coasts for their TEs accumulation. Intra and inter-species variabilities were examined. Among the Mediterranean species, Cymbaxinella damicornis accumulates significantly more As and Cu than others sponge species; Chondrilla nucula more Ni and Mo and Acanthella acuta more Ag. Among Irish samples, Hymeniacidon perlevis showed higher accumulation properties for most of TEs in comparison to Halichondria panicea. Bioconcentration Factors were > 1 in all species for most of TEs. This study suggests that TEs bioaccumulation is most likely associated to differences in morphological features and/or to specific bacterial communities associated to different species. The determination of Pb isotope ratios revealed mainly natural Pb sources for Mediterranean and Kilkieran Bay's samples, and rather anthropogenic influence for Belfast samples. This study confirms that sponges represent a powerful tool for biomonitoring studies.

Comparative study on the bioaccumulation and biotransformation of arsenic by some northeastern Atlantic and northwestern Mediterranean sponges.

The bioaccumulation and biotransformation of arsenic (As) were studied in six representative marine sponges from the French Mediterranean and Irish Atlantic coasts. Methodologies were carefully optimized in one of the species on Haliclona fulva sponges for two critical steps: the sample mineralization for total As analysis by ICP-MS and the extraction of As species for HPLC-ICP-MS analysis. During the optimization, extractions performed with 0.6 mol L-1 H3PO4 were shown to be the most efficient. Extraction recovery of 81% was obtained which represents the best results obtained until now in sponge samples. Total As analyses and As speciation were performed on certified reference materials and allow confirming the measurement quality both during the sample preparation and analysis. Additionally, this study represents an environmental survey demonstrating a high variability of total As concentrations among the different species, probably related to different physiological or microbial features. As speciation results showed the predominance of arsenobetaine (AsB) regardless of the sponge species, as well as the occurrence of low amounts of dimethylarsinic acid (DMA), arsenate (As(+V)), and unknown As species in some samples. The process responsible for As transformation in sponges is most likely related to sponges metabolism itself or the action of symbiont organisms. AsB is supposed to be implied in the protection against osmolytic stress. This study demonstrates the ability of sponges to accumulate and bio-transform As, proving that sponges are relevant bio-monitors for As contamination in the marine environment, and potential tools in environmental bio-remediation.

Access to treatment for HBV infection and its consistency with 2008 European guidelines in a multicentre cross-sectional study of HIV/HBV co-infected patients in Italy.

BACKGROUND: A survey was performed in 2008 to evaluate the profiles of patients with chronic hepatitis B cared for by Italian Infectious Diseases Centers (IDCs). This analysis describes: i) factors associated with access to the anti-HBV treatment in a cohort of HIV/HBV co-infected patients cared for in tertiary centers of a developed country with comprehensive coverage under the National Health System (NHS); ii) consistency of current anti-HBV regimens with specific European guidelines in force at the time of the study and factors associated with the receipt of sub-optimal regimens. METHODS: The study focuses on 374 (87.6%) treated patients at some point in their life out of the 427 tested HIV/HBV positive. It is multicentre, cross-sectional in the design. To account for missing values, a Multiple Imputation method is used. RESULTS: Three hundred and thirty-four (89.3%) patients were currently treated. The most common current regimen was combination therapy of tenofovir (TDF) plus LAM/FTC (lamivudine/emtricitabine) (n = 235, 70.4%), as part of antiretroviral treatment. In the multivariate analysis, an increased chance of getting treated was independently associated with increasing years since HBV diagnosis (2-10 years, p <0.001; >10 years, p <0.001). Patients consistently treated with European AIDS Clinical Society (EACS) 2008 guidelines were 255 (76.6%), of whom 202 (79.2%) with an indication to an anti-HIV treatment, 30 (11.8%)without an indication, and 21 (8.2%) with cirrhosis. Among the 78 not-consistent patients, LAM mono-therapy (n = 60, 76.9%) was the most common regimen, 34 (56.7%) of them showing HBV DNA load below 1x10(3) IU/mL. Previous anti-HBV treatment (p = 0.01) and a triple HDV co-infection (p = 0.03) reduced the chance of not-consistent regimens. Conversely, HCV co-infection was independently associated with an increased odds ratio of being inconsistently treated (p = 0.004). CONCLUSION: Our study shows that Italian IDCs treat for HBV infection the vast majority of HIV/HBV co-infected patients with no disparities limiting access to antiviral therapy. In approximately two-thirds of the patients on treatment, anti-HBV regimens are consistent with 2008 EACS guidelines. Finally, our study identifies scenarios in which clinical practice deviates from recommendations, as in case of sub-optimal regimens with effective anti-HBV response.

Nevirapine-based regimens in routine clinical settings: results from a large Italian cohort of HIV-1 infected adults.

UNLABELLED: We assessed the safety and efficacy of different nevirapine-based regimens in patients starting this drug in a large cohort of Caucasian subjects during the 1999-2007 periods. METHODS: A retrospective database review of all patients receiving nevirapine was performed; clinical, biochemical (hepatic and metabolic profiles), immuno-virological parameters were evaluated in the overall population and in different subgroups (according to gender, therapy-experience and HBV/HCV co-infection). We determined risk factors related to dyslipidemia development and to nevirapine interruption within 1 year. RESULTS: We evaluated 277 patients; 58 (20.9%) were naïve, 180 (65%) females and 137 (49.5%) HBV/HCV co-infected. After 48 weeks, 73.6% patients continued antiretroviral regimens. Among these, nevirapine showed little hepatic and metabolic impact, as well as good immuno-virological outcome despite sex, drug experience and co-infection. Factors related to development of dyslipidemia were higher in total cholesterol, female gender with high CD4 count and male gender with low CD4 count (p<0.05). Factors related to discontinue nevirapine were age and HBV/HCV co-infection (p<0.05). CONCLUSIONS: We observed a high rate of discontinuation probably because of the special composition of our population (huge proportion of women and co-infected individuals). Nevertheless, nevirapine was a well-tolerated drug with a favorable impact on hepatic, metabolic and immuno-virological parameters in all the analyzed subgroups.

A cluster of patients with recombinant B/F HIV-1 infection: epidemiological, clinical, and virological aspects.

Migratory processes have caused changes in human immunodeficiency virus (HIV) epidemiology and non-B subtypes are now playing an increasing role. In a cohort of 553 HIV-infected outpatients tested to identify non-B isolates, the largest group consisted of 13 subjects with a recombinant B/F form (prevalence 2.4%). Sequencing and phylogenetic analyses described a B/F recombinant clade with anomalous breakpoints that did not allow it to be classified as CRF12_BF. Viral load was not quantified efficiently because of a mismatch in the primers and probes used by commercial assays. An assessment of the clinical management, and epidemiological, immunological, and virological characteristics of these patients, who were receiving non-nucleoside reverse transcriptase inhibitor (NNRTI)- or protease inhibitor (PI)-based regimens, showed that the immunological and virological mismatch delayed the start of treatment by a mean of 6.8 months. Therapy was started in nine patients. Both NNRTI- and PI-based regimens led to full virological suppression after a mean 36 weeks of treatment; the PI-based regimens proved to be more effective in terms of immunological recovery (1,341 vs. 544 CD4+ cells/mm(3) ). The spread of non-B subtypes is increasing throughout the world but their response to treatment is still unclear. PIs and NNRTIs are effective but further tests are needed to allow the more efficient recognition of these viral strains and establish how they should be treated.

Once-a-day (QD) vs. twice-daily (BID) nevirapine as simplification in PI-treated patients after 2 mos. of BID induction.

To assess the efficacy and the tolerability of once-daily (QD) versus twice-daily (BID) nevirapine (NVP)-based highly active antiretroviral therapy (HAART) in virologically suppressed, HIV-positive patients switched from protease inhibitor (PI)-based HAART. Eligible patients were enrolled in the multicenter trial if HIV RNA levels were <50 copies/mL for ³6 months prior. Patients were switched from a PI to NVP 200 mg BID for 2 months, and then randomized to continue with that regimen (group A) or NVP 400 mg QD (group B) for a further 10 months. Virological efficacy (primary endpoint) and tolerability/toxicity were evaluated according to an intention-to-treat analysis. A total of 126 patients (63 per group) were enrolled. Withdrawals from the study (any reason) numbered 15 in group A and 14 in B, virological failures numbered 5 and 2, respectively, and there were 4 cases of adverse events in each group (all p = NS). Mean alanine aminotransaminase (ALT) and gamma-glutamyl transpeptidase (γ-GT) level increases were significant for the whole cohort (33.2±22.9 to 43.3±29.1, p < 0.001; 57.3±72 to 109±131 U/L, p < 0.0002, respectively), but there were no differences between the two groups. Apparently, no significant differences between the QD and BID NVP groups were found, in terms of virological failures or tolerability/toxicity. The switch to NVP may be safely pursued with a QD schedule.

A cluster of human immunodeficiency virus Type 1 recombinant form escaping detection by commercial genomic amplification assays.

BACKGROUND: Nucleic acid testing (NAT)-based methods for the detection and quantification of human immunodeficiency virus Type 1 (HIV-1) RNA are used to increase transfusion safety and to diagnose and manage HIV-1-infected patients. We describe a novel HIV-1 recombinant form associated with lack of reactivity or substantial underestimation of viral load by commercial NAT assays. STUDY DESIGN AND METHODS: We observed a repeat blood donor seroconverting to anti-HIV in whom HIV RNA was initially undetectable with routine NAT was observed. During donor follow-up, HIV RNA became detectable, but the viral load was 2 to 3 log lower than measured with other NATs targeting different genome regions. Genome sequencing revealed a novel B/F recombinant with mutations affecting primers and probe annealing accounting for the poor performance of routine NAT. A total of 553 HIV-1-infected patients attending the hospital clinic were subsequently tested prospectively using the routine assay and an in-house assay specifically designed to detect the B/F strains. RESULTS: The routine assay substantially underestimated viremia (1-5 log) in 19 cases (3.5%), 11 (58%) of which were infected with the same B/F strain observed in the index donor samples. Two other non-B circulating recombinant forms of HIV-1 (A/G, B/G subtypes) were identified as poorly detected. Newly introduced NATs targeting two HIV-1 regions improved assay performance. CONCLUSION: HIV-1 increasing heterogeneity affects the efficiency of NATs and consequently the safety of the blood supply as well as diagnosis and patient management.

Viral interference between hepatitis B, C, and D viruses in dual and triple infections in HIV-positive patients.

OBJECTIVE: To investigate the reciprocal inhibitory effects of hepatitis B virus (HBV)/hepatitis C virus (HCV)/hepatitis D virus (HDV) infections in naive and previously antiretroviral-experienced HIV-positive patients. DESIGN: This retrospective study involved 72 consecutive patients of the Italian Cohort Naive Antiretroviral cohort: 21 coinfected with HBV/HCV (group 1BC), 18 infected with HBV (group 2B), and 33 infected with HCV (group 3C). METHODS: Viral interference between HBV and HCV was assessed by means of the qualitative detection, quantification, and genotyping of each virus; HDV infection was assessed by means of genomic amplification. RESULTS: Univariate analysis showed that HBV DNA was less frequently detected in group 1BC than in group 2B (16 of 21 vs 18 of 18; P = 0.02), their HBV load was significantly lower (median 3.9 vs 5.4 log10 HBV DNA copies/mL; P = 0.002), and they more frequently carried HBV genotype D (12 of 13 vs 4 of 11; P = 0.0071). HCV RNA was less frequently detected in group 1BC than in group 3C (12 of 21 vs 33 of 33; P < 0.0001), and HDV RNA was more frequently detected in group 1BC than in group 2B (9 of 21 vs 2 of 18; P = 0.028). Multivariate analysis of the HBV-infected subjects showed that the risk of HCV coinfection was associated with older age [relative risk 0.28, 95% confidence interval (CI): 0.09 to 0.90; P = 0.033 for every 10 years older] and intravenous drug use (relative risk 73, 95% CI: 2.4 to >999.999; P = 0.013). The only predictor of HBV coinfection in HCV-infected individuals was a lower HCV load (relative risk 0.30, 95% CI: 0.11 to 0.79 for every additional log10 HCV RNA; P = 0.015). CONCLUSION: HBV and HCV showed alternative dominant replication in the I.Co.N.A. cohort, with HBV having a more unfavorable effect on HCV replication.

Multidrug-experienced HIV-1-infected women demonstrated similar virological and immunological responses to tipranavir/ritonavir compared with men.

Gender-related differences in the efficacy and safety of ritonavir-boosted tipranavir [tipranavir/ritonavir (TPV/r) 500/200 mg twice daily (b.i.d.)] were evaluated in a subanalysis of the Randomized Evaluation of Strategic Intervention in Multidrug Resistant Patients with Tipranavir (RESIST) trials. Data from HIV-1-infected women (203; TPV/r = 117) and men (1280; TPV/r = 629) showed no significant gender-related differences in HIV RNA response rates (at 48 weeks) and safety (at 96 weeks) despite higher mean steady-state plasma TPV trough concentrations in women. Significantly greater increases in CD4 cell count (+81.2 vs. +48.6; P = 0.0012) were observed in women at week 48.

Influence of viral chronic hepatitis co-infection on plasma drug concentrations and liver transaminase elevations upon therapy switch in HIV-positive patients.

It is still controversial whether viral hepatitis co-infection can influence antiretroviral plasma drug concentrations and whether drug concentrations are correlated with liver enzyme elevations during highly active antiretroviral therapy. An analysis of data from a cohort of 220 human immunodeficiency virus (HIV)-infected patients was conducted. Univariate and multivariate logistic analyses were performed to identify predictors of plasma drug concentrations. The association of transaminase elevation with higher plasma drug concentrations was explored following stratification of patients into HIV monoinfected and hepatitis C virus (HCV) and/or hepatitis B virus (HBV) co-infected groups. Hepatitis co-infections were independently correlated with drug concentrations above the therapeutic cut-offs at Week 1 (P=0.06), Week 4 (P=0.04) and Week 12 (P=0.005). The apparent effect was independent of the possible impact exerted by other variables such as demographics and medication adherence. The incidence of relevant hypertransaminasaemia was low. Patients with hepatitis co-infections had higher rates of transaminase elevation than monoinfected HIV patients; however, risk of transaminase elevation was not associated with drug concentrations. The presence of HCV and/or HBV co-infections correlated with higher plasma drug concentrations, although it did not appear to influence hepatotoxicity risk.

Antiretroviral therapy in chronic liver disease: focus on HIV/HCV coinfection--statements of the First Italian Consensus Workshop.

Hepatitis C virus common transmission routes and HCV coinfection is frequent in persons living with HIV. Liver enzyme elevation following the initiation of antiretroviral therapy is frequently seen in HIV-infected patients with chronic liver disease, particularly those with chronic hepatitis C. This complication may lead to treatment discontinuation, complicating HIV therapeutic management. Multiple factors influence the risk of liver toxicity under antiretroviral therapy, including the specific drug in use (e.g. use of full doses of ritonavir), and environmental factors (e.g. alcohol abuse). However a beneficial effect of antiretroviral therapy on liver disease has been supported by some studies. Despite increasing knowledge of HCV/HIV coinfection, there is no clear consensus on how to treat HIV in HCV-coinfected patients An Italian group of experts were invited to discuss in detail the current risks and implications of antiretroviral treatment in HIV-infected persons with chronic hepatitis C, and their main conclusions are summarized in this consensus document.