How green can Amazon hydropower be? Net carbon emission from the largest hydropower plant in Amazonia

The current resurgence of hydropower expansion toward tropical areas has been largely based on run-of-the-river (ROR) dams, which are claimed to have lower environmental impacts due to their smaller reservoirs. The Belo Monte dam was built in Eastern Amazonia and holds the largest installed capacity among ROR power plants worldwide. Here, we show that postdamming greenhouse gas (GHG) emissions in the Belo Monte area are up to three times higher than preimpoundment fluxes and equivalent to about 15 to 55 kg CO₂eq MWh^-1 Since per-area emissions in Amazonian reservoirs are significantly higher than global averages, reducing flooded areas and prioritizing the power density of hydropower plants seem to effectively reduce their carbon footprints. Nevertheless, total GHG emissions are substantial even from this leading-edge ROR power plant. This argues in favor of avoiding hydropower expansion in Amazonia regardless of the reservoir type.

Rhabdomyolysis as a clinical manifestation of association with ciprofibrate, sirolimus, cyclosporine, and pegylated interferon-α in liver-transplanted patients: a case report and literature review

BACKGROUND

Rhabdomyolysis is a syndrome characterized by impaired metabolic integrity of myocytes, causing the release of intracellular constituents into the circulation, and can be a serious side effect of drug intake.

CASE REPORT

This report describes a unique case of rabdomyolysis secondary in which ciprofibrate, sirolimus, cyclosporine, and pegylated interferon-α in a liver transplant patient was used. A 47-year-old male liver transplant recipient in 2009, who had hepatitis C and incidental hepatocellular carcinoma, underwent immunosuppressive therapy (cyclosporine and sirolimus). The patient is currently in treatment for viral recurrence with pegylated interferon-α and ribavirin; he had a history of hypertriglyceridemia treated with ciprofibrate. He had development of severe and generalized myalgia and fever after the eighth application of pegylated interferon-α and increasing doses of cyclosporine. Laboratorial tests showed acute renal failure and significant increase in creatine kinase. Rhabdomyolysis secondary to interaction of fibrate-cyclosporine-pegylated interferon-α was postulated.

CONCLUSIONS

Medical professionals should be aware of possible drug interactions and should monitor patients receiving these drugs.

Taxonomic and functional profiles of soil samples from Atlantic forest and Caatinga biomes in northeastern Brazil

Although microorganisms play crucial roles in ecosystems, metagenomic analyses of soil samples are quite scarce, especially in the Southern Hemisphere. In this work, the microbial diversity of soil samples from an Atlantic Forest and Caatinga was analyzed using a metagenomic approach. Proteobacteria and Actinobacteria were the dominant phyla in both samples. Among which, a significant proportion of stress-resistant bacteria associated to organic matter degradation was found. Sequences related to metabolism of amino acids, nitrogen, and DNA and stress resistance were more frequent in Caatinga soil, while the forest sample showed the highest occurrence of hits annotated in phosphorous metabolism, defense mechanisms, and aromatic compound degradation subsystems. The principal component analysis (PCA) showed that our samples are close to the desert metagenomes in relation to taxonomy, but are more similar to rhizosphere microbiota in relation to the functional profiles. The data indicate that soil characteristics affect the taxonomic and functional distribution; these characteristics include low nutrient content, high drainage (both are sandy soils), vegetation, and exposure to stress. In both samples, a rapid turnover of organic matter with low greenhouse gas emission was suggested by the functional profiles obtained, reinforcing the importance of preserving natural areas.

Liver failure and the need for transplantation in 6 patients with hepatoportal sclerosis

Hepatoportal sclerosis (HPS), first reported by Mikkelsen et al in 1965, is a pathologic condition that does not cause cirrhotic portal hypertension. The primary hepatic lesion in HPS is found in portal vein branches with preserved synthetic function. Rarely do patients with HPS need liver transplantation. The aim of this study was to describe the clinical and pathologic features of 6 HPS cases who underwent liver transplantation (OLT). From 2000 to 2008, 6 OLT candidates were diagnosed with HPS: 3 displayed bleeding varices and 4 ascites. Child-Pugh evaluation was class B (n = 4) or C (n = 2). The Model for End-stage Liver Disease scores were 18 (n = 2), 20 (n = 3), and 22 (n = 1). Cirrhosis resulted from presumed diagnoses of alcohol n = (1), autoimmune n = (2) or cryptogenic cirrhosis n = (3). On histologic examination, there was marked phlebosclerosis in all cases, including nonocclusive portal vein thrombosis (n = 3), intense portal fibrosis (n = 1), moderate portal fibrosis (n = 5), and uniform moderate sinusoidal dilatation without megasinusoid formation, but with ductal biliary proliferation and ductal biliary fibrosis in all cases. Cholestasis was observed in 1 and incomplete septal cirrhosis in 4 cases. None of the subjects showed histological features of the presumed underlying liver disease. The overall survival of this group was no different from that of other OLT patients. HPS causing hepatic failure may require liver transplantation. Fhlebosclerosis andportal fibrosis may contribute to the loss of hepatic synthesis leading to the need for hepatic transplant. Significant portal fibrosis and phlebosclerosis can contribute to hepatic parenchymal and posterior synthetic loss.

Toxicogenetic monitoring in urban cities exposed to different airborne contaminants

Microparticles found in the air may be associated with organic matter that contains several compounds, such as Polycyclic Aromatic Hydrocarbons (PAHs) and nitro-PAHs, and may pose a significant risk to human health, possibly leading to DNA mutations and cancers. This study associated genotoxicity assays for evaluating human exposure with the atmospheric air of two urban areas in southern Brazil, that received different atmospheric contributions. Site 1 was under urban-industrial influence and the other was a non-industrial reference, Site 2. Organic extracts from the airborne particulate matter were tested for mutagenicity via the Salmonella/microsome assay and analyzed for PAH composition. Cells samples of people residing in these two cities were evaluated using the comet and micronucleus assay (MN).Concentrations of the individual PAHs ranged from 0.01 ng/m(3) (benzo[a]anthracene) to 5.08 ng/m(3) (benzo[ghi]perylene). As to mutagenicity analysis of airborne, Site 1 presented all the mutagenic responses, which varied from 3.2±1.22 rev/m(3) (TA98 no S9) to 32.6±2.05 rev/m(3) (TA98, S9), while Site 2 ranged from negative to minimal responses. Site 1 presented a high quantity of nitro and amino derivatives of PAHs, and peaked at 56.0±3.68 rev/μg (YG1024 strain). The two groups presented very low DNA damage levels without intergroup difference. Although Site 1 presented high mutagenic responses in the air samples, high PAH levels, healthy people exposed to this environment did not show significative damage in their genetic material. However, the evaluation of different environmental and genetic damage in such population is necessary to monitor possible damages.

Genetic biomonitoring of an urban population exposed to mutagenic airborne pollutants

Biomonitoring studies have increased as a consequence of risks and effects to human health on exposure to environmental contaminants, mainly air pollutants. Genetic biomarkers are useful tools for the early assessment of exposure to occupational and environmental pollution. The objective of the present study was to investigate genotoxic effects on people residing and/or working downwind from an oil refinery in southern Brazil and the mutagenic activity of airborne particulate matter (PM10). Samples of peripheral blood and buccal mucosa cells were evaluated using the single-cell gel electrophoresis assay (comet assay) and the micronucleus (MN) assay, respectively. PM10 samples were collected in the target site and the organic matter extraced with dichloromethane was assessed for mutagenic activity in the Salmonella/microsome assay. The exposed group (n=37) was compared to a reference group (n=37) of subjects living in an urban area with limited traffic and industrial influence, located far from the main industrial areas. All PM10 organic extracts showed mutagenic positive responses and the effect decreased in the presence of S9 mix indicating that the predominant compounds present were direct-acting mutagens. The responses of YGs strains are consistent with aromatic amines and nitroarenes being present in the PM10 extracts. The group in the area under the influence of the oil refinery (exposed group) showed significantly higher DNA damage in lymphocytes than the reference group. The MN frequencies in buccal mucosa were very low for both groups and no difference between groups was observed. No association was found between age and tobacco smoking habit and level of DNA damages measured by the comet assay. The results indicate that the comet assay was a sensitive tool to detect DNA damage in subjects under the influence of an oil refinery, with marked genotoxic activity in the atmospheric environment.