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1.
J Virol Methods ; 293: 114131, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33798606

RESUMO

The World Health Organization (WHO) has declared a pandemic of COVID-19, the disease caused by the recently described SARS-CoV-2. The relevance and importance of mass diagnosis in order to find the asymptomatic individuals is widely recognized as a mandatory tool to reinforce the control measures for monitoring virus circulation and reduce the spreading of SARS-CoV-2. Here, we described quickness and cheaper strategies of direct RT-qPCR (in the absence of RNA isolation) and compared the results to those obtained using standard RNA isolation procedure. The tests varied using pure, diluted samples, combined with Proteinase K (PK) or Lysis Buffer. Our findings showed consistently that PK pre-treated samples in the absence of RNA extraction procedures presents similar results to those obtained by standard RNA isolation procedures. On average, 16 samples extracted with the MagMAX™ CORE Kit, take around 2 h, costing an average of USD 5, the pre-treatment of samples using PK, on the other hand, would cut the value to less than USD 0.30 and reduce the time of procedure in more than 1 ½ hours. The present study suggests the use of PK treatment instead of RNA isolation in order to reduce costs and time in processing samples for molecular diagnosis of SARS-CoV-2.


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , Endopeptidase K/farmacologia , RNA Viral/análise , SARS-CoV-2/isolamento & purificação , Teste de Ácido Nucleico para COVID-19/economia , Humanos , SARS-CoV-2/genética
2.
Braz. j. biol ; Braz. j. biol;79(4): 712-712, Nov. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1001480

RESUMO

Abstract Bisphenol A (BPA) is an emerging contaminant, regularly detected in aquatic ecosystems, considered as an endocrine disrupting compound (EDC). Caffeine is another chemical related to human activity, often found in surface waters. The objective of this study was to evaluate the ecotoxicological risk due to BPA and caffeine in water samples from the Sinos River basin, Rio Grande do Sul, Brazil. Water samples were collected at three sites monthly from May 9 th, 2016 to April 11th, 2017 (n = 36). BPA concentrations in water samples collected were in the range of not detected to 517 ng L-1 and caffeine concentrations in the range of 41.7 to 28,439.6 ng L-1. The concentration of BPA in the analyzed samples had a moderate correlation with caffeine (rs = 0.402). High ecotoxicological risk for BPA was characterized in 77.77% of samples, with 11.11% presenting medium and 11.1% presenting low risk. For caffeine 13.9%, 50% and 36.11% of the samples presented high, medium and low risk, respectively. Caffeine concentrations in water can be used as predictors of BPA concentrations above 10 ng L-1, the lower concentration of ecotoxicological risk, with specificity of 66.7% and sensitivity of 70.4%. The assessment of aquatic risks has shown that both investigated compounds pose risks to organisms in the studied surface waters, mouth of the Pampa stream, mouth of the Luiz Rau stream and catchment point for public supply in Lomba Grande.


Resumo Bisfenol A (BPA) é um contaminante emergente regularmente detectado em ecossistemas aquáticos, é considerado um agente modificador endócrino (EDC). Além disso, outro produto químico relacionado com atividade humana, encontrado com frequência nas águas superficiais, é a cafeína. O objetivo deste estudo foi avaliar a ocorrência de risco ecotoxicológico devido a BPA e cafeína em amostras de água da Bacia Hidrográfica do Rio Sinos, Rio Grande do Sul, Brasil. Foram coletadas amostras de água em três locais mensalmente no período de 9 de maio de 2016 a 11 de abril de 2017 (n = 36). As concentrações de BPA em amostras de água coletadas estavam na faixa de não detectada a 517 ng L-1 e concentrações de cafeína na faixa de 41,7 a 28,439,6 ng L-1. A concentração de BPA nas amostras analisadas apresentou correlação moderada com a cafeína (rs = 0,402). Alto risco ecotoxicológico para BPA foi caracterizado em 77,77% das amostras, com 11,11% apresentando médio e 11,1% apresentando baixo risco. Para cafeína 13,9%, 50% e 36,11% das amostras apresentaram risco alto, médio e baixo, respectivamente. Concentrações de cafeína em água podem ser utilizadas como preditoras de concentrações de BPA acima de 10 ng L-1, menor concentração de risco ecotoxicológico, com especificidade de 66,7% e sensibilidade de 70,4%. A avaliação dos riscos aquáticos revelou que ambos os compostos investigados representam risco para os organismos nas águas superficiais estudadas, foz do arroio Pampa, foz do arroio Luiz Rau e ponto de captação para abastecimento público em Lomba Grande.


Assuntos
Humanos , Fenóis/análise , Poluentes Químicos da Água/análise , Compostos Benzidrílicos/análise , Cafeína/análise , Rios/química , Brasil/epidemiologia , Monitoramento Ambiental/métodos , Medição de Risco/métodos , Disruptores Endócrinos/análise
3.
Braz J Biol ; 79(4): 712, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30427383

RESUMO

Bisphenol A (BPA) is an emerging contaminant, regularly detected in aquatic ecosystems, considered as an endocrine disrupting compound (EDC). Caffeine is another chemical related to human activity, often found in surface waters. The objective of this study was to evaluate the ecotoxicological risk due to BPA and caffeine in water samples from the Sinos River basin, Rio Grande do Sul, Brazil. Water samples were collected at three sites monthly from May 9 th, 2016 to April 11th, 2017 (n = 36). BPA concentrations in water samples collected were in the range of not detected to 517 ng L-1 and caffeine concentrations in the range of 41.7 to 28,439.6 ng L-1. The concentration of BPA in the analyzed samples had a moderate correlation with caffeine (rs = 0.402). High ecotoxicological risk for BPA was characterized in 77.77% of samples, with 11.11% presenting medium and 11.1% presenting low risk. For caffeine 13.9%, 50% and 36.11% of the samples presented high, medium and low risk, respectively. Caffeine concentrations in water can be used as predictors of BPA concentrations above 10 ng L-1, the lower concentration of ecotoxicological risk, with specificity of 66.7% and sensitivity of 70.4%. The assessment of aquatic risks has shown that both investigated compounds pose risks to organisms in the studied surface waters, mouth of the Pampa stream, mouth of the Luiz Rau stream and catchment point for public supply in Lomba Grande.


Assuntos
Compostos Benzidrílicos/análise , Cafeína/análise , Fenóis/análise , Rios/química , Poluentes Químicos da Água/análise , Brasil/epidemiologia , Disruptores Endócrinos/análise , Monitoramento Ambiental/métodos , Humanos , Medição de Risco/métodos
4.
J Am Heart Assoc ; 7(16): e008841, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-30369321

RESUMO

Background Obstructive sleep apnea ( OSA ) is common among patients with acute ischemic stroke and transient ischemic attack. We evaluated whether continuous positive airway pressure for OSA among patients with recent ischemic stroke or transient ischemic attack improved clinical outcomes. Methods and Results This randomized controlled trial among patients with ischemic stroke/transient ischemic attack compared 2 strategies (standard or enhanced) for the diagnosis and treatment of OSA versus usual care over 1 year. Primary outcomes were National Institutes of Health Stroke Scale and modified Rankin Scale scores. Among 252 patients (84, control; 86, standard; 82, enhanced), OSA prevalence was as follows: control, 69%; standard, 74%; and enhanced, 80%. Continuous positive airway pressure use occurred on average 50% of nights and was similar among standard (3.9±2.1 mean hours/nights used) and enhanced (4.3±2.4 hours/nights used; P=0.46) patients. In intention-to-treat analyses, changes in National Institutes of Health Stroke Scale and modified Rankin Scale scores were similar across groups. In as-treated analyses among patients with OSA, increasing continuous positive airway pressure use was associated with improved National Institutes of Health Stroke Scale score (no/poor, -0.6±2.9; some, -0.9±1.4; good, -0.3±1.0; P=0.0064) and improved modified Rankin Scale score (no/poor, -0.3±1.5; some, -0.4±1.0; good, -0.9±1.2; P=0.0237). In shift analyses among patients with OSA, 59% of intervention patients had best neurological symptom severity (National Institutes of Health Stroke Scale score, 0-1) versus 38% of controls ( P=0.038); absolute risk reduction was 21% (number needed to treat, 4.8). Conclusions Although changes in neurological functioning and functional status were similar across the groups in the intention-to-treat analyses, continuous positive airway pressure use was associated with improved neurological functioning among patients with acute ischemic stroke/transient ischemic attack with OSA . Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT 01446913.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Ataque Isquêmico Transitório/fisiopatologia , Apneia Obstrutiva do Sono/terapia , Acidente Vascular Cerebral/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Humanos , Ataque Isquêmico Transitório/epidemiologia , Masculino , Pessoa de Meia-Idade , Polissonografia , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Resultado do Tratamento
5.
Nat Commun ; 9(1): 71, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29302028

RESUMO

Segregation of the iron core from rocky silicates is a massive evolutionary event in planetary accretion, yet the process of metal segregation remains obscure, due to obstacles in simulating the extreme physical properties of liquid iron and silicates at finite length scales. We present new experimental results studying gravitational instability of an emulsified liquid gallium layer, initially at rest at the interface between two glucose solutions. Metal settling coats liquid metal drops with a film of low density material. The emulsified metal pond descends as a coherent Rayleigh-Taylor instability with a trailing fluid-filled conduit. Scaling to planetary interiors and high pressure mineral experiments indicates that molten silicates and volatiles are entrained toward the iron core and initiate buoyant thermochemical plumes that later oxidize and hydrate the upper mantle. Surface volcanism from thermochemical plumes releases oxygen and volatiles linking atmospheric growth to the Earth's mantle and core processes.

6.
Braz. j. biol ; Braz. j. biol;2017.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467239

RESUMO

Abstract Bisphenol A (BPA) is an emerging contaminant, regularly detected in aquatic ecosystems, considered as an endocrine disrupting compound (EDC). Caffeine is another chemical related to human activity, often found in surface waters. The objective of this study was to evaluate the ecotoxicological risk due to BPA and caffeine in water samples from the Sinos River basin, Rio Grande do Sul, Brazil. Water samples were collected at three sites monthly from May 9 th, 2016 to April 11th, 2017 (n = 36). BPA concentrations in water samples collected were in the range of not detected to 517 ng L-1 and caffeine concentrations in the range of 41.7 to 28,439.6 ng L-1. The concentration of BPA in the analyzed samples had a moderate correlation with caffeine (rs = 0.402). High ecotoxicological risk for BPA was characterized in 77.77% of samples, with 11.11% presenting medium and 11.1% presenting low risk. For caffeine 13.9%, 50% and 36.11% of the samples presented high, medium and low risk, respectively. Caffeine concentrations in water can be used as predictors of BPA concentrations above 10 ng L-1, the lower concentration of ecotoxicological risk, with specificity of 66.7% and sensitivity of 70.4%. The assessment of aquatic risks has shown that both investigated compounds pose risks to organisms in the studied surface waters, mouth of the Pampa stream, mouth of the Luiz Rau stream and catchment point for public supply in Lomba Grande.


Resumo Bisfenol A (BPA) é um contaminante emergente regularmente detectado em ecossistemas aquáticos, é considerado um agente modificador endócrino (EDC). Além disso, outro produto químico relacionado com atividade humana, encontrado com frequência nas águas superficiais, é a cafeína. O objetivo deste estudo foi avaliar a ocorrência de risco ecotoxicológico devido a BPA e cafeína em amostras de água da Bacia Hidrográfica do Rio Sinos, Rio Grande do Sul, Brasil. Foram coletadas amostras de água em três locais mensalmente no período de 9 de maio de 2016 a 11 de abril de 2017 (n = 36). As concentrações de BPA em amostras de água coletadas estavam na faixa de não detectada a 517 ng L-1 e concentrações de cafeína na faixa de 41,7 a 28,439,6 ng L-1. A concentração de BPA nas amostras analisadas apresentou correlação moderada com a cafeína (rs = 0,402). Alto risco ecotoxicológico para BPA foi caracterizado em 77,77% das amostras, com 11,11% apresentando médio e 11,1% apresentando baixo risco. Para cafeína 13,9%, 50% e 36,11% das amostras apresentaram risco alto, médio e baixo, respectivamente. Concentrações de cafeína em água podem ser utilizadas como preditoras de concentrações de BPA acima de 10 ng L-1, menor concentração de risco ecotoxicológico, com especificidade de 66,7% e sensibilidade de 70,4%. A avaliação dos riscos aquáticos revelou que ambos os compostos investigados representam risco para os organismos nas águas superficiais estudadas, foz do arroio Pampa, foz do arroio Luiz Rau e ponto de captação para abastecimento público em Lomba Grande.

7.
Braz J Med Biol Res ; 49(4): e5031, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26909785

RESUMO

Cysteinyl leukotrienes (CysLTs) have been implicated in seizures and kindling; however, the effect of CysLT receptor antagonists on seizure frequency in kindled animals and changes in CysLT receptor expression after pentylenetetrazol (PTZ)-induced kindling have not been investigated. In this study, we evaluated whether the CysLT1 inverse agonist montelukast, and a classical anticonvulsant, phenobarbital, were able to reduce seizures in PTZ-kindled mice and alter CysLT receptor expression. Montelukast (10 mg/kg, sc) and phenobarbital (20 mg/kg, sc) increased the latency to generalized seizures in kindled mice. Montelukast increased CysLT1 immunoreactivity only in non-kindled, PTZ-challenged mice. Interestingly, PTZ challenge decreased CysLT2 immunoreactivity only in kindled mice. CysLT1 antagonists appear to emerge as a promising adjunctive treatment for refractory seizures. Nevertheless, additional studies are necessary to evaluate the clinical implications of this research.


Assuntos
Acetatos/farmacologia , Anticonvulsivantes/farmacologia , Antagonistas de Leucotrienos/farmacologia , Quinolinas/farmacologia , Convulsões/tratamento farmacológico , Acetatos/uso terapêutico , Animais , Anticonvulsivantes/uso terapêutico , Western Blotting , Convulsivantes , Ciclopropanos , Excitação Neurológica/efeitos dos fármacos , Antagonistas de Leucotrienos/uso terapêutico , Masculino , Camundongos , Pentilenotetrazol , Fenobarbital/farmacologia , Fenobarbital/uso terapêutico , Quinolinas/uso terapêutico , Receptores de Leucotrienos/efeitos dos fármacos , Convulsões/induzido quimicamente , Sulfetos , Fatores de Tempo , Resultado do Tratamento
8.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;49(4): e5031, 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-774523

RESUMO

Cysteinyl leukotrienes (CysLTs) have been implicated in seizures and kindling; however, the effect of CysLT receptor antagonists on seizure frequency in kindled animals and changes in CysLT receptor expression after pentylenetetrazol (PTZ)-induced kindling have not been investigated. In this study, we evaluated whether the CysLT1 inverse agonist montelukast, and a classical anticonvulsant, phenobarbital, were able to reduce seizures in PTZ-kindled mice and alter CysLT receptor expression. Montelukast (10 mg/kg, sc) and phenobarbital (20 mg/kg, sc) increased the latency to generalized seizures in kindled mice. Montelukast increased CysLT1 immunoreactivity only in non-kindled, PTZ-challenged mice. Interestingly, PTZ challenge decreased CysLT2 immunoreactivity only in kindled mice. CysLT1 antagonists appear to emerge as a promising adjunctive treatment for refractory seizures. Nevertheless, additional studies are necessary to evaluate the clinical implications of this research.


Assuntos
Animais , Masculino , Camundongos , Acetatos/farmacologia , Anticonvulsivantes/farmacologia , Antagonistas de Leucotrienos/farmacologia , Quinolinas/farmacologia , Convulsões/tratamento farmacológico , Acetatos/uso terapêutico , Anticonvulsivantes/uso terapêutico , Western Blotting , Convulsivantes , Excitação Neurológica/efeitos dos fármacos , Antagonistas de Leucotrienos/uso terapêutico , Pentilenotetrazol , Fenobarbital/farmacologia , Fenobarbital/uso terapêutico , Quinolinas/uso terapêutico , Receptores de Leucotrienos/efeitos dos fármacos , Convulsões/induzido quimicamente , Fatores de Tempo , Resultado do Tratamento
9.
Braz J Biol ; 75(2 Suppl): 11-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26270208

RESUMO

The spread of enteric viruses of domestic animals and human beings to wild species can be facilitated by the resistance of these viruses on the environment and their ability to be transmitted by water and contaminated food. The health status of the populations of pampas foxes Lycalopex gymnocercus) and crab-eating foxes (Cerdocyon thous) is largely unknown and the landscapes occupied by these animals in southern Brazil have been threatened by human occupation and expansion of agriculture. In this work, the search of genomes of human and canine adenoviruses in feces from these wild carnivores was used to track the dissemination of domestic animals and human pathogens to the free-living populations in a wildlife reserve located in southern Brazil. This was performed by virus-specific differential real-time polymerase chain reactions (qPCR) on stool specimens, avoiding capture and additional stress to the animals. Genus-specific conventional reverse-transcriptase PCR (RT-PCR) was complementarily performed aiming the detection of enteroviruses (EV) and rotaviruses (RV) on these same samples. HAdV genomes were found on 14 out of the 17 (82.35%) stool samples analysed, whereas CAV was found co-infecting 5 of these samples. RV genomes were detected on 7 of the 17 samples (41.18%) and all samples were negative for EV. The results point to the dispersion of HAdV and RV at a high rate to these species of South American wild carnivores, which can be an effect of growing anthropisation of the habitat of these animals.


Assuntos
Infecções por Adenoviridae/veterinária , Adenoviridae/isolamento & purificação , Raposas , Adenoviridae/genética , Infecções por Adenoviridae/virologia , Animais , Brasil , Cães , Enterovirus/isolamento & purificação , Infecções por Enterovirus/genética , Infecções por Enterovirus/veterinária , Infecções por Enterovirus/virologia , Fezes/virologia , Humanos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Rotavirus/isolamento & purificação , Infecções por Rotavirus/genética , Infecções por Rotavirus/veterinária , Infecções por Rotavirus/virologia , Especificidade da Espécie
10.
Braz J Biol ; 75(2 Suppl): 50-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26270213

RESUMO

Unplanned use and occupation of the land without respecting its capacity of assimilation and environmental purification leads to the degradation of the environment and of water used for human consumption. Agricultural areas, industrial plants and urban centres developed without planning and the control of effluent discharges are the main causes of water pollution in river basins that receive all the liquid effluents produced in those places. Over the last decades, environmental management has become part of governmental agendas in search of solutions for the preservation of water quality and the restoration of already degraded resources. This study evaluated the conditions of the main watercourse of the Sinos River basin by monitoring the main physical, chemical and microbiological parameters described in the CONAMA Resolution no. 357/2005.The set of parameters evaluated at five catchment points of water human consumption revealed a river that has different characteristics in each reach, as the upper reach was class 1, whereas the middle and lower reaches of the basin were class 4. Monitoring pointed to households as the main sources of pollutants in those reaches, although metals used in the industrial production of the region were found in the samples analyzed.


Assuntos
Enterobacteriaceae/isolamento & purificação , Metais/análise , Compostos Orgânicos/análise , Rios/química , Rios/microbiologia , Poluentes Químicos da Água/análise , Brasil , Monitoramento Ambiental
11.
Braz J Biol ; 75(2 Suppl): 63-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26270215

RESUMO

It is well recognized that the classical biological and chemical markers of environmental pollution do not necessarily indicate the presence or absence of emerging threats to public health, such as waterborne viruses and genotoxicants. The purpose of this preliminary study was to evaluate the presence of material of enteroviruses (EV), rotavirus (RV) and adenovirus (AdV) and genotoxicity in water samples from points of routine monitoring of water quality in the main course of the Sinos River. The points are classified into different levels of pollution in accordance to the Brazilian federal regulations. Viral genomes from EV, AdV were detected in two of the 4 collection points regardless of the level of urbanisation of the surrounding areas. In contrast, genotoxicity was not observed in piava (Leporinus obtusidens) fingerlings cultivated on these same water samples. Results were compared with classical physical, chemical and microbiological parameters. There was no clear evidence of association between any of the classical markers and the presence of viral genomes in the water samples tested.


Assuntos
Monitoramento Ambiental/métodos , Rios/química , Rios/virologia , Qualidade da Água , Animais , Brasil , Caraciformes/metabolismo , Enterovirus/genética , Enterovirus/isolamento & purificação , Mastadenovirus/genética , Mastadenovirus/isolamento & purificação , Mutagênicos/análise , Rotavirus/genética , Rotavirus/isolamento & purificação , Poluentes Químicos da Água/análise
12.
Braz J Biol ; 75(2 Suppl): 81-4, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26270218

RESUMO

The preservation of hydric resources is directly related to fecal contamination monitoring, in order to allow the development of strategies for the management of polluting sources. In the present study, twenty-five water samples from six water public supply collection sites were used for the evaluation of the presence of caffeine, total and fecal coliforms. Caffeine was detected in all samples, with concentrations ranging from 0.15 ng mL-1 to 16.72 ng mL-1. Total coliforms were detected in all samples, with concentrations in the range of 52 NMP/100 mL to higher than 24196 NMP/100 mL, whether the concentration range for fecal coliforms was in the range of below 1 NMP/100 mL to 7800 NMP/100 mL. No significant correlation was found between total coliforms and caffeine concentrations (rs = 0.35, p = 0.09). However, a moderate correlation between fecal coliforms and caffeine concentrations was found (rs = 0.412, p <0.05), probably indicating a human source for these bacteria. Caffeine determination in water may be a useful strategy to evaluate water contamination by human fecal waste.


Assuntos
Cafeína/análise , Rios/química , Poluentes Químicos da Água/análise , Qualidade da Água , Brasil , Enterobacteriaceae/isolamento & purificação , Monitoramento Ambiental , Fezes/química , Fezes/microbiologia , Abastecimento de Água
13.
J Water Health ; 12(3): 526-32, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25252356

RESUMO

The effects of viral gastroenteritis are more devastating in children than in any other age category. Thus, children exposed to the consumption of low quality water are at an increased risk of infection, especially in regions where sanitation is inadequate. The present study aimed to provide a survey of the occurrence of representative enteric viruses: human adenovirus (HAdV), human enteroviruses (hEV), and genogroup A rotavirus (GARV) in tap water samples collected in public schools located at six municipalities of Rio Grande do Sul, southern Brazil. Seventy-three schools were included in the study and tap water samples were analyzed by conventional PCR for the presence of HAdV, hEV, and GARV genomes. hEV showed the highest detection rate (27.4%), followed by HAdV (23.3%), and GARV (16.4%). New approaches to water monitoring should be considered to promote a better water quality and reduce the risk of waterborne diseases, especially considering drinking water to be served to vulnerable individuals.


Assuntos
Adenovírus Humanos/isolamento & purificação , Água Potável/virologia , Enterovirus/isolamento & purificação , Adenovírus Humanos/genética , Brasil , DNA Viral/genética , Enterovirus/genética , Reação em Cadeia da Polimerase , Rotavirus/genética , Rotavirus/isolamento & purificação , Instituições Acadêmicas
14.
Sci Total Environ ; 484: 249-62, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24666634

RESUMO

Concentration and mass balance analyses were used to quantify methylmercury (MeHg) loads from conventional (white) rice, wild rice, and fallowed fields in northern California's Yolo Bypass. These analyses were standardized against chloride to distinguish transport pathways and net ecosystem production (NEP). During summer, chloride loads were both exported with surface water and moved into the root zone at a 2:1 ratio. MeHg and dissolved organic carbon (DOC) behaved similarly with surface water and root zone exports at ~3:1 ratio. These trends reversed in winter with DOC, MeHg, and chloride moving from the root zone to surface waters at rates opposite and exceeding summertime root zone fluxes. These trends suggest that summer transpiration advectively moves constituents from surface water into the root zone, and winter diffusion, driven by concentration gradients, subsequently releases those constituents into surface waters. The results challenge a number of paradigms regarding MeHg. Specifically, biogeochemical conditions favoring microbial MeHg production do not necessarily translate to synchronous surface water exports; MeHg may be preserved in the soils allowing for release at a later time; and plants play a role in both biogeochemistry and transport. Our calculations show that NEP of MeHg occurred during both summer irrigation and winter flooding. Wild rice wet harvesting and winter flooding of white rice fields were specific practices that increased MeHg export, both presumably related to increased labile organic carbon and disturbance. Outflow management during these times could reduce MeHg exports. Standardizing MeHg outflow:inflow concentration ratios against natural tracers (e.g. chloride, EC) provides a simple tool to identify NEP periods. Summer MeHg exports averaged 0.2 to 1µgm(-2) for the different agricultural wetland fields, depending upon flood duration. Average winter MeHg exports were estimated at 0.3µgm(-2). These exports are within the range reported for other shallow aquatic systems.

15.
Sci Total Environ ; 472: 957-70, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24345859

RESUMO

Concentration and mass balance analyses were used to quantify methylmercury (MeHg) loads from conventional (white) rice, wild rice, and fallowed fields in northern California's Yolo Bypass. These analyses were standardized against chloride to distinguish transport pathways and net ecosystem production (NEP). During summer, chloride loads were both exported with surface water and moved into the root zone at a 2:1 ratio. MeHg and dissolved organic carbon (DOC) behaved similarly with surface water and root zone exports at ~3:1 ratio. These trends reversed in winter with DOC, MeHg, and chloride moving from the root zone to surface waters at rates opposite and exceeding summertime root zone fluxes. These trends suggest that summer transpiration advectively moves constituents from surface water into the root zone, and winter diffusion, driven by concentration gradients, subsequently releases those constituents into surface waters. The results challenge a number of paradigms regarding MeHg. Specifically, biogeochemical conditions favoring microbial MeHg production do not necessarily translate to synchronous surface water exports; MeHg may be preserved in the soils allowing for release at a later time; and plants play a role in both biogeochemistry and transport. Our calculations show that NEP of MeHg occurred during both summer irrigation and winter flooding. Wild rice wet harvesting and winter flooding of white rice fields were specific practices that increased MeHg export, both presumably related to increased labile organic carbon and disturbance. Outflow management during these times could reduce MeHg exports. Standardizing MeHg outflow:inflow concentration ratios against natural tracers (e.g. chloride, EC) provides a simple tool to identify NEP periods. Summer MeHg exports averaged 0.2 to 1 µg m(-2) for the different agricultural wetland fields, depending upon flood duration. Average winter MeHg exports were estimated at 0.3 µg m(-2). These exports are within the range reported for other shallow aquatic systems.


Assuntos
Agricultura , Monitoramento Ambiental , Compostos de Metilmercúrio/análise , Solo/química , Poluentes Químicos da Água/análise , Áreas Alagadas , California , Inundações , Modelos Químicos , Rizosfera , Estações do Ano
16.
Sci Total Environ ; 484: 232-48, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24296049

RESUMO

The current state of science and engineering related to analyzing wetlands overlooks the importance of transpiration and risks data misinterpretation. In response, we developed hydrologic and mass budgets for agricultural wetlands using electrical conductivity (EC) as a natural conservative tracer. We developed simple differential equations that quantify evaporation and transpiration rates using flow rates and tracer concentrations at wetland inflows and outflows. We used two ideal reactor model solutions, a continuous flow stirred tank reactor (CFSTR) and a plug flow reactor (PFR), to bracket real non-ideal systems. From those models, estimated transpiration ranged from 55% (CFSTR) to 74% (PFR) of total evapotranspiration (ET) rates, consistent with published values using standard methods and direct measurements. The PFR model more appropriately represents these non-ideal agricultural wetlands in which check ponds are in series. Using a flux model, we also developed an equation delineating the root zone depth at which diffusive dominated fluxes transition to advective dominated fluxes. This relationship is similar to the Peclet number that identifies the dominance of advective or diffusive fluxes in surface and groundwater transport. Using diffusion coefficients for inorganic mercury (Hg) and methylmercury (MeHg) we calculated that during high ET periods typical of summer, advective fluxes dominate root zone transport except in the top millimeters below the sediment-water interface. The transition depth has diel and seasonal trends, tracking those of ET. Neglecting this pathway has profound implications: misallocating loads along different hydrologic pathways; misinterpreting seasonal and diel water quality trends; confounding Fick's First Law calculations when determining diffusion fluxes using pore water concentration data; and misinterpreting biogeochemical mechanisms affecting dissolved constituent cycling in the root zone. In addition, our understanding of internal root zone cycling of Hg and other dissolved constituents, benthic fluxes, and biological irrigation may be greatly affected.


Assuntos
Agricultura , Monitoramento Ambiental , Transpiração Vegetal/fisiologia , Rizosfera , Áreas Alagadas , Água Subterrânea/química , Estações do Ano
17.
Braz J Biol ; 72(2): 323-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22735140

RESUMO

Adenovirus (AdV), enterovirus (EV), genogroup A rotaviruses (GARV) and Torque teno virus (TTV) are non-enveloped viral agents excreted in feces and so may contaminate water bodies. In the present study, the molecular detection of these viruses was performed in samples of surface water collected from the Arroio Dilúvio, a waterstream that crosses the city of Porto Alegre, RS, Brazil, receiving great volumes of non-treated sewage from a large urban area. Sampling was performed during 2009, in three different occasions (January, April and September). The highest detection rate was observed for EV (64.28%), followed by TTV (28.57%) and AdV (21.43%). Rotaviruses were not detected. More than on kind of tested virus was detected in five (35. 71%) of 14 samples. January was the month with the highest viral detection rate, being all samples, collected in this month, positive for at least one group of tested virus. The correlation between the detection of these different viral agents and environmental factors is discussed. To the knowledge of the authors, this is the first description of viral genomes in water samples taken from the Arroio Dilúvio, Porto Alegre (Brazil).


Assuntos
Adenoviridae/isolamento & purificação , Enterovirus/isolamento & purificação , Rotavirus/isolamento & purificação , Torque teno virus/isolamento & purificação , Microbiologia da Água , Adenoviridae/genética , Brasil , DNA Viral/genética , Enterovirus/genética , Reação em Cadeia da Polimerase , Rios , Rotavirus/genética , Torque teno virus/genética
18.
Braz J Biol ; 72(4): 839-46, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23295512

RESUMO

In order to verify the microbial quality of the influents and effluents of one STP from southern Brazil, an eight-month survey was conducted to examine the presence of total and fecal coliforms and of adenovirus (HAdV), enterovirus (EV), genogroup A rotaviruses (GARV) and Torque teno virus (TTV), in treated effluent samples from São João/Navegantes STP, Porto Alegre (Brazil). A total of 16 samples were collected, eight of influent (raw sewage, prior to treatment), and the other eight of the effluent (post-treatment sewage). Total and fecal coliform levels ranging from 3.6 × 10(4) to 4.4 × 10(7) MPN/100 mL and 2.9 × 10(3) to 1.7 × 10(7) MPN/100 mL, were detected in all samples. In raw sewage, HAdV (25%) and GARV (28.6%) viral genomes were detected. The analysis of effluent samples revealed the presence of HAdV (50%), EV (37.5%), and TTV (12.5%) genomic fragments. All samples, regardless of the month analysed, presented detection of a least one virus genus, except for in April. Higher virus detection rates were observed in treated sewage samples (62.5%), and in 80% of them (effluent positive samples) HAdV was detected. Results showed that improvements in sewage monitoring and treatment processes are necessary to reduce the viral and bacterial load on the environment in southern Brazil. To the knowledge of the authors, this is the first study showing the monitoring of viral genomes in influent and effluent samples from a STP located in Porto Alegre (Rio Grande do Sul, Brazil), southern Brazil.


Assuntos
Vírus de DNA/classificação , Vírus de RNA/classificação , Esgotos/virologia , Microbiologia da Água , Adenoviridae/isolamento & purificação , Brasil , Vírus de DNA/isolamento & purificação , DNA Viral , Enterovirus/isolamento & purificação , Reação em Cadeia da Polimerase , Vírus de RNA/isolamento & purificação , Rotavirus/isolamento & purificação , Torque teno virus/isolamento & purificação , Eliminação de Resíduos Líquidos , Purificação da Água
19.
Mini Rev Med Chem ; 11(10): 857-80, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21762102

RESUMO

Saponins can be classified as triterpenoid (C30) or steroidal (C27), based on their carbon nucleus (aglycone). Sugar residues are linked to the aglycone, conferring an amphiphilic nature on these molecules, which is relevant for their biological activities. Saponins include a large variety of molecules that find several applications in pharmacology. Saponins have been shown to display immunoadjuvant, anti-inflammatory, antiplatelet, hypocholesterolemic, antitumoral, anti-HIV, antibacterial, insecticide, fungicide and anti-leishmanial activities. Anti-inflammatory medicines are increasingly demanded to treat various forms of arthritis in aging and obese populations and to help reduce the doses and duration of conventional corticotherapy with less side effects and without immunosuppression. The vaccine market for both human and veterinary uses is close to US$ 15 billion, progressively inflated by the recurrent threat of global pandemics.This paper provides an overview of recent advances (main focus on the last five years) on plant saponins that show anti-inflammatory and/or immunoadjuvant activities: source plants, isolation procedures, mechanism of action and biotechnological approaches towards sustainable production of bioactive saponins. Special attention is given to ginseng and Quillaja saponins. Strategies based on plant cultivation, cell and tissue culture, elicitation, and metabolic engineering for improved production of saponins are described. Future directions for research in the field and strategies to overcome bottlenecks are also discussed.


Assuntos
Adjuvantes Imunológicos/química , Anti-Inflamatórios/química , Plantas Medicinais/química , Saponinas/biossíntese , Adjuvantes Imunológicos/isolamento & purificação , Animais , Anti-Inflamatórios/isolamento & purificação , Biotecnologia , Humanos , Células Vegetais/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/metabolismo , Saponinas/química , Saponinas/farmacologia
20.
Dev Biol (Basel) ; 131: 367-75, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18634498

RESUMO

In 2004, a teenager survived bat-associated rabies through the Milwaukee protocol (MP). This survivor and another patient with dog-associated rabies were found to have developed deficiencies of tetrahydrobiopterin (BH4) and associated neurotransmitters. BH4 is also essential for neuronal nitric oxide synthase (nNOS), so rabies is predicted to cause constriction of cerebral arteries. We assume that rabies virus, which almost exclusively targets neurons, would disproportionately affect cerebral over systemic perfusion by disrupting nNOS and lead to generalised cerebral artery spasm. Cranial artery vasospasm, therefore, was actively sought in two rabies patients, with the intention to specifically treat with BH4 and L-arginine when necessary. Flow velocities and resistive (RI) or pulsatility indices (PI) of middle cerebral arteries (MCA) were obtained by transcranial doppler ultrasound (TCD). A survival analysis of 8 attempts at the MP is presented. Of these, two cases are reported here. The first case is one child with bat-associated rabies who developed severe bilateral MCAspasm on hospital day (HD)-10 that responded to very low dose (0.2 mcg/kg/min) nitroprusside. The second case, a child with dog-associated rabies, developed spasm of MCA on HD-6 that responded to 6 mg/kg/day BH4. A second spasm with high RI (without cerebral oedema or increased intracranial pressure) responded to 20 mg/kg/day BH4 and 0.5 g/kg/dose L-arginine. Review of the TCD of the first child showed a similar second spasm seven days after first episode. Cerebral artery vasospasm occurred in the two children with rabies, but was clinically silent by standard monitoring. Spasm responded to drugs directed at the NOS pathway. Animal models for treatment of rabies are sorely needed to evaluate therapy.


Assuntos
Artérias Cerebrais/patologia , Quirópteros/virologia , Óxido Nítrico Sintase/metabolismo , Raiva/patologia , Vasoespasmo Intracraniano/patologia , Animais , Arginina/uso terapêutico , Biopterinas/análogos & derivados , Biopterinas/uso terapêutico , Velocidade do Fluxo Sanguíneo , Artérias Cerebrais/efeitos dos fármacos , Circulação Cerebrovascular , Criança , Doenças do Cão/transmissão , Cães , Humanos , Nitroprussiato/uso terapêutico , Raiva/tratamento farmacológico , Raiva/transmissão , Raiva/veterinária , Resultado do Tratamento , Ultrassonografia Doppler Transcraniana/métodos , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/virologia , Zoonoses
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