DDT and Other Organohalogen Pesticides in Aquatic Organisms

Organohalogen (OH) compounds are persistent hydrocarbon compounds containing a halogen group, often chlorine or bromine, that substitutes for hydrogen atoms in different positions in the hydrocarbon. They may occur naturally, but this chapter\u27s focus is on synthetically produced compounds, mainly organochlorines, that were produced for use as pesticides. Nine OH compounds (aldrin, chlordane, dichlorodiphenyltrichloroethane [DDT], dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, and toxaphene) are in the top 12 list of particularly toxic and persistent organic pollutants (POPs) identified by the Stockholm Convention treaty implemented in 2004 under the United Nations Environment Program (UNEP). More than 90 countries have signed on to this treaty as Parties. These chemicals became classified as POPs because they may remain in the environment for decades following their use, they accumulate in fatty tissues of exposed organisms, they have a variety of toxic endpoints, and they travel long distances from source areas through atmospheric or aqueous transport

DDT and Other Organohalogen Pesticides in Aquatic Organisms

Organohalogen (OH) compounds are persistent hydrocarbon compounds containing a halogen group, often chlorine or bromine, that substitutes for hydrogen atoms in different positions in the hydrocarbon. They may occur naturally, but this chapter\u27s focus is on synthetically produced compounds, mainly organochlorines, that were produced for use as pesticides. Nine OH compounds (aldrin, chlordane, dichlorodiphenyltrichloroethane [DDT], dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, and toxaphene) are in the top 12 list of particularly toxic and persistent organic pollutants (POPs) identified by the Stockholm Convention treaty implemented in 2004 under the United Nations Environment Program (UNEP). More than 90 countries have signed on to this treaty as Parties. These chemicals became classified as POPs because they may remain in the environment for decades following their use, they accumulate in fatty tissues of exposed organisms, they have a variety of toxic endpoints, and they travel long distances from source areas through atmospheric or aqueous transport

Toxicity of Polycyclic Aromatic Hydrocarbons to Benthic Invertebrates.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in aquatic environments. Because of their hydrophobicity, PAHs accumulate in bed sediments and pose a risk to the benthos. Information on the toxicity of sediment-associated PAHs is, however, limited and more information is needed to improve sediment quality-criteria and ecological-risk assessments. My research focused on improving our current knowledge of the acute and, especially, the sublethal effects of sediment-associated PAHs to aquatic invertebrates. Representatives of two phylogenetically distinct benthic invertebrate groups, freshwater tubificid oligochaetes and estuarine meiobenthic harpacticoid copepods, were used. Organisms were exposed to a range of concentrations of sediment-amended contaminants in laboratory bioassays. Individual PAH congeners (pyrene, fluoranthene, and phenanthrene) and a complex mixture (diesel fuel) were employed. The tubificid oligochaete Limnodrilus hoffmeisferi was tolerant to PAH effects on survival in 10-d exposures. Because of its feeding mode (head-down, bulk-deposit feeder), egestion rates were used as surrogates for ingestion rates. PAHs significantly reduced sediment ingestion at concentrations much lower than lethal. This impact had direct effects on the flux of contaminants from sediments to the water column. Offspring production was also decreased at relatively low PAH concentrations, whereas burrowing avoidance did not occur. Harpacticoid copepods display many traits desirable for sediment-toxicity testing. The estuarine species Schizopera knatreni, Nirocra locustris and Coullana sp. were used. Adult harpacticoids were relatively tolerant to PAHs in 10-d exposures. Species-specific differences in sensitivity were detected. Early life stages were much more sensitive than adults in some species, but not others. Low concentrations of PAHs decreased copepod-offspring production, egg hatching-success, and embryonic and early-stage-development rate, demonstrating the high sensitivity of life-history related endpoints. In addition, grazing on microalgae was significantly impaired at low concentrations after short exposures ($\u3c$30 h). Finally, it was demonstrated that harpacticoids can actively avoid contaminated sediments. Harpacticoids were shown to uptake and eliminate PAHs efficiently. Lethal and sublethal effects were related to the tissue concentration of PAH. Lethal doses were within the range predicted to cause death by narcosis in animals. Low tissue concentrations were associated with significant reductions in reproduction and feeding

Toxicity and bioaccumulation of TNT in marine fish in sediment exposures

The bioaccumulation potential and toxicity of 2, 4, 6-trinitrotoluene (TNT) spiked to sediment was evaluated in juvenile sheeps head minnows (JSHM, Cyprinodon variegatus) and adult freckled blennies (FB, Hypsoblennius ionthas). The JSHM were exposed for 4 days in the presence or absence of a mesh separating fish from sediment. FB were exposed to sediment for 7 days. During the 24-day storage period(4 °C), extensive transformation of spiked TNT occurred and concentrations are expressed as the sum of TNT, aminodinitrotoluenes and diaminonitrotoluenes (Sum TNT), on a dry weight basis. Sum TNT in the overlying water, not exchanged during exposure, increased gradually. Survival was high( ≥ 90%) for JSHM exposed to 7 mgkg-1 and FB exposed to up to 260 mgkg-1. All SHM died after 24-h exposure to 340 mgkg-1. Isolation from sediment did not significantly affect water concentrations or decrease bioaccumulation. Uptake from contact to sediment was likely negligible and bioaccumulation was from the overlying water. The feeding rate of FB exposed to 1700 μmol kg-1 sediment suspended in water for 24-h was significantly reduced by 50%

Resultados de oito aplicações do Teste do Progresso na Faculdade de Medicina da Universidade de São Paulo

BACKGROUND: Progress testing is a longitudinal tool for evaluating knowledge gains during the medical school years. OBJECTIVES: (1) To implement progress testing as a form of routine evaluation; (2) to verify whether cognitive gain is a continuous variable or not; and (3) to evaluate whether there is loss of knowledge relating to basic sciences in the final years of medical school. METHODS: A progress test was applied twice a year to all students from 2001 to 2004. The mean percentage score was calculated for each school year, employing ANOVA with post hoc Bonferroni test evaluation for each test. RESULTS: Progress testing was implemented as a routine procedure over these 4 years. The results suggest a cognitive gain from first to sixth year in all eight tests, as a continuum (P for trend < .0001). Gain was found to be continuous for basic sciences (taught during the first 2 years), clinical sciences (P < .0001), and clerkship rotation (P < .0001). There was no difference between the performance of men and women. CONCLUSION: Progress testing was implemented as a routine, applied twice a year. Data suggest that cognitive gain during medical training appears to be a continuum, even for basic science issues.O Teste do Progresso foi introduzido na Faculdade de Medicina da Universidade de São Paulo em 2001. OBJETIVO: (1) Testar a viabilidade da aplicação rotineira do teste; (2) verificar se o ganho de conhecimentos era progressivo e contínuo durante a graduação; (3) determinar se esse ganho de conhecimento inclui também as disciplinas do curso básico. MÉTODOS: O teste foi aplicado duas vezes por ano entre 2001-2004. Em cada teste, calculou-se o escore médio de acertos por ano letivo usando-se ANOVA com correção de Bonferroni para múltiplas comparações. RESULTADOS: O Teste do Progresso foi implementado como rotina entre 2001-2004. Os resultados sugerem um ganho cognitivo contínuo e progressivo ao longo da graduação (P < 0,0001) nos oito testes aplicados até o momento. Esse ganho seria significativo mesmo para as disciplinas do curso básico (P < 0,05), curso clínico (P < 0.0001) e internato (P < 0.0001). Não houve diferença de performance em função do gênero. CONCLUSÃO: O Teste do Progresso foi implementado como rotina, sendo aplicado semestralmente. Os resultados sugerem que o ganho cognitivo parece ser contínuo e progressivo mesmo para as disciplinas do básico ao longo dos seis anos

An open, multi-vendor, multi-field-strength brain MR dataset and analysis of publicly available skull stripping methods agreement

This paper presents an open, multi-vendor, multi-field strength magnetic resonance (MR) T1-weighted volumetric brain imaging dataset, named Calgary-Campinas-359 (CC-359). The dataset is composed of images of older healthy adults (29-80 years) acquired on scanners from three vendors (Siemens, Philips and General Electric) at both 1.5 T and 3 T. CC-359 is comprised of 359 datasets, approximately 60 subjects per vendor and magnetic field strength. The dataset is approximately age and gender balanced, subject to the constraints of the available images. It provides consensus brain extraction masks for all volumes generated using supervised classification. Manual segmentation results for twelve randomly selected subjects performed by an expert are also provided. The CC-359 dataset allows investigation of 1) the influences of both vendor and magnetic field strength on quantitative analysis of brain MR; 2) parameter optimization for automatic segmentation methods; and potentially 3) machine learning classifiers with big data, specifically those based on deep learning methods, as these approaches require a large amount of data. To illustrate the utility of this dataset, we compared to the results of a supervised classifier, the results of eight publicly available skull stripping methods and one publicly available consensus algorithm. A linear mixed effects model analysis indicated that vendor (p - value < 0.001) and magnetic field strength (p - value < 0.001) have statistically significant impacts on skull stripping results170482494CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP311228/2014-3; 157534/2015-488881.062158/2014-012013/07559-3; 2013/23514-0; 2016/18332-

The Acute-Phase Proteins Serum Amyloid A and C Reactive Protein in Transudates and Exudates

The distinction between exudates and transudates is very important in the patient management. Here we evaluate whether the acute-phase protein serum amyloid A (SAA), in comparison with C reactive protein (CRP) and total protein (TP), can be useful in this discrimination. CRP, SAA, and TP were determined in 36 exudate samples (27 pleural and 9 ascitic) and in 12 transudates (9 pleural and 3 ascitic). CRP, SAA, and TP were measured. SAA present in the exudate corresponded to 10% of the amount found in serum, that is, the exudate/serum ratio (E/S) was 0.10 ± 0.13. For comparison, the exudate/serum ratio for CRP and TP was 0.39 ± 0.37 and 0.68 ± 0.15, respectively. There was a strong positive correlation between serum and exudate SAA concentration (r = 0.764;p < 0.0001). The concentration of SAA in transudates was low and did not overlap with that found in exudates (0.02-0.21 versus 0.8–360.5 g/mL). SAA in pleural and ascitic exudates results mainly from leakage of the serum protein via the inflamed membrane. A comparison of the E/S ratio of SAA and CRP points SAA as a very good marker in discriminating between exudates and transudates

Nível de escolaridade e dependência funcional em sobreviventes de acidente vascular cerebral isquêmico

We evaluated the functional dependence of stroke survivors from the Study of Stroke Mortality and Morbidity, using the Rankin Scale. Out of 355 ischemic stroke survivors (with a mean age of 67.9 years), 40% had some functional dependence at 28 days and 34.4% had some functional dependence at 6 months. Most predictors of physical dependence were identified at 28 days. These predictors were: low levels of education [illiterate vs. &gt;= 8 years of education, multivariate odds ratio (OR) = 3.7; 95% confidence interval (95%CI): 1.60-8.54] and anatomical stroke location (total anterior circulation infarct, OR = 16.9; 95%CI: 2.93-97.49). Low levels of education and ischemic brain injury influenced functional dependence in these stroke survivors. Our findings reinforce the necessity of developing strategies for the rehabilitation of stroke patients, more especially in formulating specific strategies for care and treatment of stroke survivors with low socioeconomic status.Foi avaliada a dependência funcional em sobreviventes de acidente vascular cerebral (AVC) do Estudo da Mortalidade e Morbidade do Acidente Vascular Cerebral, utilizando a Escala de Rankin. De 355 sobreviventes com AVC isquêmico (idade média de 67,9 anos), 40% tinham dependência funcional em 28 dias e 34,4% em 6 meses. Os principais indicadores de dependência física foram identificados em 28 dias, e eram: baixa escolaridade (analfabetos vs. > 8 anos de educação, RC = 3,7; IC95%: 1,60-8,54) e localização do AVC (infarto circulação total anterior, RC = 16,9; IC95%: 2,93-97,49). Baixo nível educacional e insulto cerebral isquêmico influenciaram o grau de dependência funcional nesses sobreviventes de AVC. Nossos achados reforçam a necessidade de desenvolvimento de estratégias para reabilitação de pacientes com AVC e formulação de estratégias específicas de atenção e tratamento para essas pessoas, especialmente na população com baixo nível socioeconômico.CNPqFAPES