RESUMO
Pediatric stroke is an important cause of mortality and morbidity in children. There is a paucity of clinical trials pertaining to pediatric stroke management, and solidified universal guidelines are not established for children the way they are for the adult population. Diagnosis of pediatric stroke can be challenging, and it is often delayed or mischaracterized, which can result in worse outcomes. Understanding risks and appropriate therapy is paramount to improving care.
RESUMO
This report is the outcome of the meeting "Environmental and Human Health Consequences of Arsenic" held at the MDI Biological Laboratory in Salisbury Cove, Maine, August 13-15, 2014. Human exposure to arsenic represents a significant health problem worldwide that requires immediate attention according to the World Health Organization (WHO). One billion people are exposed to arsenic in food, and more than 200 million people ingest arsenic via drinking water at concentrations greater than international standards. Although the US Environmental Protection Agency (EPA) has set a limit of 10 µg/L in public water supplies and the WHO has recommended an upper limit of 10 µg/L, recent studies indicate that these limits are not protective enough. In addition, there are currently few standards for arsenic in food. Those who participated in the Summit support citizens, scientists, policymakers, industry, and educators at the local, state, national, and international levels to (1) establish science-based evidence for setting standards at the local, state, national, and global levels for arsenic in water and food; (2) work with government agencies to set regulations for arsenic in water and food, to establish and strengthen non-regulatory programs, and to strengthen collaboration among government agencies, NGOs, academia, the private sector, industry, and others; (3) develop novel and cost-effective technologies for identification and reduction of exposure to arsenic in water; (4) develop novel and cost-effective approaches to reduce arsenic exposure in juice, rice, and other relevant foods; and (5) develop an Arsenic Education Plan to guide the development of science curricula as well as community outreach and education programs that serve to inform students and consumers about arsenic exposure and engage them in well water testing and development of remediation strategies.
Assuntos
Arsênio/toxicidade , Água Potável/normas , Exposição Ambiental/efeitos adversos , Abastecimento de Água/legislação & jurisprudência , Arsênio/efeitos adversos , Relações Comunidade-Instituição , Contaminação de Alimentos/análise , Regulamentação Governamental , Humanos , Concentração Máxima Permitida , Saúde Pública , Medição de Risco , Estados Unidos , Poluentes Químicos da Água/efeitos adversos , Abastecimento de Água/normasRESUMO
Mitochondrial DNA (mtDNA) copy number is a critical component of overall mitochondrial health. In this chapter, we describe methods for isolation of both mtDNA and nuclear DNA (nucDNA) and measurement of their respective copy numbers using quantitative PCR. Methods differ depending on the species and cell type of the starting material and availability of specific PCR reagents.
Assuntos
DNA Mitocondrial/genética , Dosagem de Genes , Reação em Cadeia da Polimerase/métodos , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Calibragem , Núcleo Celular/genética , DNA Mitocondrial/isolamento & purificação , Humanos , Camundongos , RatosRESUMO
To understand the ecotoxicological impacts of the Deepwater Horizon oil spill, field studies provide a context for ecological realism but laboratory-based studies offer power for connecting biological effects with specific causes. As a complement to field studies, we characterized genome-wide gene expression responses of Gulf killifish (Fundulus grandis) to oil-contaminated waters in controlled laboratory exposures. Transcriptional responses to the highest concentrations of oiled water in the laboratory were predictive of field-observed responses that coincided with the timing and location of major oiling. The transcriptional response to the low concentration (â¼ 10-fold lower than the high concentration) was distinct from the high concentration and was not predictive of major oiling in the field. The high concentration response was characterized by activation of the molecular signaling pathway that facilitates oil metabolism and oil toxicity. The high concentration also induced DNA damage. The low concentration invoked expression of genes that may support a compensatory response, including genes associated with regulation of transcription, cell cycle progression, RNA processing, DNA damage, and apoptosis. We conclude that the gene expression response detected in the field was a robust indicator of exposure to the toxic components of contaminating oil, that animals in the field were exposed to relatively high concentrations that are especially damaging to early life stages, and that such exposures can damage DNA.
Assuntos
Desastres , Ecotoxicologia , Fundulidae/genética , Genômica , Poluição por Petróleo/efeitos adversos , Petróleo/toxicidade , Animais , Dano ao DNA , Relação Dose-Resposta a Droga , Testes de Mutagenicidade , Especificidade de Órgãos , Poluição por Petróleo/análise , Transcriptoma/efeitos dos fármacosRESUMO
Fullerene (C(60)), with its unique physical properties and nanometer size, has been mass-produced for many applications in recent decades. The increased likelihood of direct release into the environment has raised interest in understanding both the environmental fate and corresponding biological effects of fullerenes to living organisms. Because few studies have emphasized fullerene uptake and resulting biochemical responses by living organisms, a toxicity screening test and a 28-d bioaccumulation test for Lumbriculus variegatus were performed. No mortality was observed in the range of 0.05 mg C(60) /kg dry sediment to 11.33 mg C(60) /kg dry sediment. A biota-sediment accumulation factor of micron-sized fullerene agglomerates (µ-C(60)) was 0.032 ± 0.008 at day 28, which is relatively low compared with pyrene (1.62 ± 0.22). Catalase (CAT) activity, an oxidative stress indicator, was elevated significantly on day 14 for L. variegatus exposed to µ-C(60) (p = 0.034). This peak CAT activity corresponded to the highest body residues observed in the present study, 199 ± 80 µg C(60) /kg dry weight sediment. Additionally, smaller C(60) agglomerate size increased bioaccumulation potential in L. variegatus. The relationship between C(60) body residue and the increased CAT activity followed a linear regression. All results suggest that C(60) has a lower bioaccumulation potential than pyrene but a higher potential to induce oxidative stress in L. variegatus.
Assuntos
Catalase/metabolismo , Poluentes Ambientais/farmacocinética , Fulerenos/farmacocinética , Oligoquetos/metabolismo , Animais , Poluentes Ambientais/análise , Poluentes Ambientais/química , Poluentes Ambientais/toxicidade , Fulerenos/análise , Fulerenos/química , Fulerenos/toxicidade , Sedimentos Geológicos/química , Oligoquetos/efeitos dos fármacos , Oligoquetos/enzimologia , Pirenos/análise , Pirenos/farmacocinéticaRESUMO
Juvenile rainbow trout (Oncorhynchus mykiss) were subjected to a 2-day radioactive pulse of 110mAg at 11.9 microg/l (as AgNO3), followed by a 19-day post-tracer exposure to non-radioactive Ag(I) (3.8 microg/l). The distribution of 110mAg in the gills, liver, intestine, kidney, brain and remaining carcass was investigated over a 19-day post-tracer period. Initially, the intestine contained the highest proportion of the 110mAg burden (34%), however, by day 8, less than 5% of the total radioactivity remained in this tissue. The majority of the 110mAg eliminated from the intestine appeared to distribute to the liver. Eventually, the 110mAg content in the liver accounted for as much as 65% of the total radioactivity in the fish. Apart from the liver and intestine, only the gills and carcass contained any appreciable amount (>5%) of the total body 110mAg content. Liver and gill samples were fractionated using differential centrifugation techniques to discern the subcellular distribution of 110mAg in these tissues. In the liver, the 110mAg levels in the cytosolic fraction increased from 35% to 72% of the total cellular burden between days 8 and 19, respectively. The radioactive pulse in the gills was predominantly found in a membrane compartment termed the nuclear fraction ( approximately 60% of the total). Little change was observed over time (day 8 to day 19) to the subcellular distribution of Ag in the gills. Using size-exclusion chromatography, most ( approximately 70%) of the 110mAg content in the liver cytosol eluted at a molecular weight characteristic of metallothionein. The cytosolic distribution of 110mAg in gills was quite diffuse, occurring primarily in the heavy molecular weight fractions.