432 research outputs found

    Evaluation of phosphorous removals by biochar supported nano-scale zero-valent iron

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    This study evaluated the effectiveness of biochar-supported nano-scale zero-valent iron (nZVI/BC) in removing phosphorus (P) from water. Samples of nZVI/BC were prepared using aqueous nanoparticles synthesis techniques, and were mixed with a stock phosphorus solution. To determine P reductions water samples were tested for P content using the ascorbic acid method. This procedure was repeated for samples of stock P solution, zero-valent iron (ZVI), biochar, and ZVI/BC. nZVI/BC reduced P content by 86% whereas ZVI, biochar, and ZVI/BC removed 6%, -23%, and 17% respectively. This suggests that nZVI/BC has the potential to be an effective method of stormwater remediation

    The potential release of phosphorus in floodplains

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    In the Illinois River Watershed, there has been growing concern over elevated phosphorus concentrations in the water column. This study evaluated how much phosphorus is contributed from floodplain soils into surface waters, examining the relationship between the flux of phosphorus released and the amount of phosphorus stored in the soil. This was investigated by artificially inundating soil cores from four sites and determining the soluble reactive phosphorus concentrations of the overlying water and the levels of Water and Mehlich-3 extractable phosphorus in the soil. The flux of phosphorus to the overlying water ranged from 0.43 to 6.61 mg m-2 hr-1 within the short-term (16.5-hr incubation) and 0.06 to 1.26 mg m-2 hr-1 over the long term (282.5-hr incubation). Phosphorus flux to the overlying water was significantly correlated with the amount of phosphorus stored in the soil. This study showed that riparian soils with elevated phosphorus content have the potential to release phosphorus when flooded

    Fatal Naegleria fowleri Meningoencephalitis, Italy

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    We report the first case of primary amebic meningoencephalitis in Italy, in a 9-year-old boy. Clinical course was fulminant, and diagnosis was made by identifying amebas in stained brain sections and by indirect immunofluorescence analysis. Naegleria fowleri was characterized as genotype I on the basis of polymerase chain reaction test results

    Prior exercise training and experimental myocardial infarction: A systematic review and meta-analysis

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    Exercising prior to experimental infarction may have beneficial effects on the heart. The objective of this study was to analyze studies on animals that had exercised prior to myocardial infarction and to examine any benefits through a systematic review and meta-analysis. The databases MEDLINE, Google Scholar, and Cochrane were consulted. We analyzed articles published between January 1978 and November 2018. From a total of 858 articles, 13 manuscripts were selected in this review. When animals exercised before experimental infarction, there was a reduction in mortality, a reduction in infarct size, improvements in cardiac function, and a better molecular balance between genes and proteins that exhibit cardiac protective effects. Analyzing heart weight/body weight, we observed the following results - Mean difference 95% CI - -0.02 [-0.61,0.57]. Metaanalysis of the infarct size (% of the left ventricle) revealed a statistically significant decrease in the size of the infarction in animals that exercised before myocardial infarction, in comparison with the sedentary animals -5.05 [-7.68, -2.40]. Analysis of the ejection fraction, measured by echo (%), revealed that animals that exercised before myocardial infarction exhibited higher and statistically significant measures, compared with sedentary animals 8.77 [3.87,13.66]. We conclude that exercise performed prior to experimental myocardial infarction confers cardiac benefits to animals

    Correlations of mutations in katG, oxyR-ahpC and inhA genes and in vitro susceptibility in Mycobacterium tuberculosis clinical strains segregated by spoligotype families from tuberculosis prevalent countries in South America

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    Background Mutations associated with resistance to rifampin or streptomycin have been reported for W/Beijing and Latin American Mediterranean (LAM) strain families of Mycobacterium tuberculosis. A few studies with limited sample sizes have separately evaluated mutations in katG, ahpC and inhA genes that are associated with isoniazid (INH) resistance. Increasing prevalence of INH resistance, especially in high tuberculosis (TB) prevalent countries is worsening the burden of TB control programs, since similar transmission rates are noted for INH susceptible and resistant M. tuberculosis strains. Results We, therefore, conducted a comprehensive evaluation of INH resistant M. tuberculosis strains (n = 224) from three South American countries with high burden of drug resistant TB to characterize mutations in katG, ahpC and inhA gene loci and correlate with minimal inhibitory concentrations (MIC) levels and spoligotype strain family. Mutations in katG were observed in 181 (80.8%) of the isolates of which 178 (98.3%) was contributed by the katG S315T mutation. Additional mutations seen included oxyR-ahpC; inhA regulatory region and inhA structural gene. The S315T katG mutation was significantly more likely to be associated with MIC for INH ≥2 μg/mL. The S315T katG mutation was also more frequent in Haarlem family strains than LAM (n = 81) and T strain families. Conclusion Our data suggests that genetic screening for the S315T katG mutation may provide rapid information for anti-TB regimen selection, epidemiological monitoring of INH resistance and, possibly, to track transmission of INH resistant strains.Fil: Dalla Costa, Elis R. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Ribeiro, Marta O. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Silva, Márcia S. N. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Arnold, Liane S. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Rostirolla, Diana C. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Cafrune, Patricia I. State Foundation for Production and Research in Health (FEPPS); Brasil.Fil: Espinoza, Roger C. Blufstein Clinic Laboratory; Perú.Fil: Palaci, Moises. Federal University of Espírito Santo; Brasil.Fil: Telles, Maria A. Adolfo Lutz Institute; Brasil.Fil: Ritacco, Viviana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Servicio de Micobacterias; Argentina.Fil: Suffys, Philip N. Oswaldo Cruz Institute; Brasil.Fil: Lopes, Maria L. Evandro Chagas Institute; Brasil.Fil: Campelo, Creuza L. LACEN Ceará; BrasilFil: Miranda, Silvana S. Federal University of Minas Gerais; Brasil.Fil: Kremer, Kristin. National Institute for Public Healthand the Environment (RIVM). Mycobacteria Reference Unit (CIb-LIS); Países Bajos.Fil: Almeida da Silva, Pedro E. Federal Foundation of Rio Grande; Brasil.Fil: de Souza Fonseca, Leila. Federal University of Rio de Janeiro. Tuberculosis Academic Program; Brasil.Fil: Ho, John L. Cornell University; Estados Unidos.Fil: Kritski, Afrânio L. Federal University of Rio de Janeiro. Tuberculosis Academic Program; Brasil.Fil: Rossetti, María L. R. State Foundation for Production and Research in Health (FEPPS); Brasil

    Cost-effectiveness analysis of PCR for the rapid diagnosis of pulmonary tuberculosis

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    <p>Abstract</p> <p>Background</p> <p>Tuberculosis is one of the most prominent health problems in the world, causing 1.75 million deaths each year. Rapid clinical diagnosis is important in patients who have co-morbidities such as Human Immunodeficiency Virus (HIV) infection. Direct microscopy has low sensitivity and culture takes 3 to 6 weeks <abbrgrp><abbr bid="B1">1</abbr><abbr bid="B2">2</abbr><abbr bid="B3">3</abbr></abbrgrp>. Therefore, new tools for TB diagnosis are necessary, especially in health settings with a high prevalence of HIV/TB co-infection.</p> <p>Methods</p> <p>In a public reference TB/HIV hospital in Brazil, we compared the cost-effectiveness of diagnostic strategies for diagnosis of pulmonary TB: Acid fast bacilli smear microscopy by Ziehl-Neelsen staining (AFB smear) plus culture and AFB smear plus colorimetric test (PCR dot-blot).</p> <p>From May 2003 to May 2004, sputum was collected consecutively from PTB suspects attending the Parthenon Reference Hospital. Sputum samples were examined by AFB smear, culture, and PCR dot-blot. The gold standard was a positive culture combined with the definition of clinical PTB. Cost analysis included health services and patient costs.</p> <p>Results</p> <p>The AFB smear plus PCR dot-blot require the lowest laboratory investment for equipment (US20,000).Thetotalscreeningcostsare3.8timesforAFBsmearpluscultureversusforAFBsmearplusPCRdotblotcosts(US 20,000). The total screening costs are 3.8 times for AFB smear plus culture versus for AFB smear plus PCR dot blot costs (US 5,635,760 versus US1,498,660).CostspercorrectlydiagnosedcasewereUS 1,498, 660). Costs per correctly diagnosed case were US 50,773 and US13,749forAFBsmearpluscultureandAFBsmearplusPCRdotblot,respectively.AFBsmearplusPCRdotblotwasmorecosteffectivethanAFBsmearplusculture,whenthecostoftreatingallcorrectlydiagnosedcaseswasconsidered.Thecostofreturningpatients,whicharenottreatedduetoanegativeresult,tothehealthservice,washigherinAFBsmearplusculturethanforAFBsmearplusPCRdotblot,US 13,749 for AFB smear plus culture and AFB smear plus PCR dot-blot, respectively. AFB smear plus PCR dot-blot was more cost-effective than AFB smear plus culture, when the cost of treating all correctly diagnosed cases was considered. The cost of returning patients, which are not treated due to a negative result, to the health service, was higher in AFB smear plus culture than for AFB smear plus PCR dot-blot, US 374,778,045 and US$ 110,849,055, respectively.</p> <p>Conclusion</p> <p>AFB smear associated with PCR dot-blot associated has the potential to be a cost-effective tool in the fight against PTB for patients attended in the TB/HIV reference hospital.</p

    PCR colorimetric dot-blot assay and clinical pretest probability for diagnosis of Pulmonary Tuberculosis in Smear-Negative patients

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    <p>Abstract</p> <p>Background</p> <p>Smear-negative pulmonary tuberculosis (SNPTB) accounts for 30% of Pulmonary Tuberculosis (PTB) cases reported annually in developing nations. Polymerase chain reaction (PCR) may provide an alternative for the rapid detection of <it>Mycobacterium tuberculosis </it>(MTB); however little data are available regarding the clinical utility of PCR in SNPTB, in a setting with a high burden of TB/HIV co-infection.</p> <p>Methods</p> <p>To evaluate the performance of the PCR dot-blot in parallel with pretest probability (Clinical Suspicion) in patients suspected of having SNPTB, a prospective study of 213 individuals with clinical and radiological suspicion of SNPTB was carried out from May 2003 to May 2004, in a TB/HIV reference hospital. Respiratory specialists estimated the pretest probability of active disease into high, intermediate, low categories. Expectorated sputum was examined by direct microscopy (Ziehl-Neelsen staining), culture (Lowenstein Jensen) and PCR dot-blot. Gold standard was based on culture positivity combined with the clinical definition of PTB.</p> <p>Results</p> <p>In smear-negative and HIV subjects, active PTB was diagnosed in 28.4% (43/151) and 42.2% (19/45), respectively. In the high, intermediate and low pretest probability categories active PTB was diagnosed in 67.4% (31/46), 24% (6/25), 7.5% (6/80), respectively. PCR had sensitivity of 65% (CI 95%: 50%–78%) and specificity of 83% (CI 95%: 75%–89%). There was no difference in the sensitivity of PCR in relation to HIV status. PCR sensitivity and specificity among non-previously TB treated and those treated in the past were, respectively: 69%, 43%, 85% and 80%. The high pretest probability, when used as a diagnostic test, had sensitivity of 72% (CI 95%:57%–84%) and specificity of 86% (CI 95%:78%–92%). Using the PCR dot-blot in parallel with high pretest probability as a diagnostic test, sensitivity, specificity, positive and negative predictive values were: 90%, 71%, 75%, and 88%, respectively. Among non-previously TB treated and HIV subjects, this approach had sensitivity, specificity, positive and negative predictive values of 91%, 79%, 81%, 90%, and 90%, 65%, 72%, 88%, respectively.</p> <p>Conclusion</p> <p>PCR dot-blot associated with a high clinical suspicion may provide an important contribution to the diagnosis of SNPTB mainly in patients that have not been previously treated attended at a TB/HIV reference hospital.</p

    Dynamic Diagnosis of Familial Prion Diseases Supports the β2-α2 Loop as a Universal Interference Target

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    [Background] Mutations in the cellular prion protein associated to familial prion disorders severely increase the likelihood of its misfolding into pathogenic conformers. Despite their postulation as incompatible elements with the native fold, these mutations rarely modify the native state structure. However they variably have impact on the thermodynamic stability and metabolism of PrPC and on the properties of PrPSc aggregates. To investigate whether the pathogenic mutations affect the dynamic properties of the HuPrP(125-229) α-fold and find possible common patterns of effects that could help in prophylaxis we performed a dynamic diagnosis of ten point substitutions.[Methodology/Principal Findings] Using all-atom molecular dynamics simulations and novel analytical tools we have explored the effect of D178N, V180I, T183A, T188K, E196K, F198S, E200K, R208H, V210I and E211Q mutations on the dynamics of HuPrP(125-228) α-fold. We have found that while preserving the native state, all mutations produce dynamic changes which perturb the coordination of the α2-α3 hairpin to the rest of the molecule and cause the reorganization of the patches for intermolecular recognition, as the disappearance of those for conversion inhibitors and the emergence of an interaction site at the β2-α2 loop region.[Conclusions/Significance] Our results suggest that pathogenic mutations share a common pattern of dynamical alterations that converge to the conversion of the β2-α2 loop into an interacting region that can be used as target for interference treatments in genetic diseases.This work was supported in parts by grants BFU2009-07971 from the MICINN (MG), FundaciÃ3n Cien (MG); Fondazione Cariplo (GC) and AIRC (GC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding received for this study.Peer reviewe
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