RESUMO
Access to detailed comparisons in air quality variations encountered when commuting through a city offers the urban traveller more informed choice on how to minimise personal exposure to inhalable pollutants. In this study we report on an experiment designed to compare atmospheric contaminants inhaled during bus, subway train, tram and walking journeys through the city of Barcelona. Average number concentrations of particles 10-300 nm in size, N, are lowest in the commute using subway trains (N<2.5×10(4) part. cm(-3)), higher during tram travel and suburban walking (2.5×10(4) cm(-3)
Assuntos
Poluentes Atmosféricos/análise , Ar , Exposição por Inalação/análise , Material Particulado/análise , Meios de Transporte , Emissões de Veículos/análise , Ar/análise , Ar/normas , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Espanha , Meios de Transporte/normas , Urbanização , CaminhadaRESUMO
It was almost 150 years ago that Golgi revolutionised histology with silver-based stains. Major advances in knowledge of the nervous system became possible because of silver impregnations. Silver staining combined with classical histological staining, cytochemistry methods, and electron microscopy is useful for studying mechanisms and components at subcellular, cellular, and tissue levels. Despite the advantages of silver staining, its use has decreased over time. The aim of this work was to use argentic staining to study the cerebellar effects of controversial prenatal glucocorticoid (GC) therapy. At postnatal day 12 (P12), the cerebellum of corticosterone (CC)-treated rats impregnated with AgNOR staining exhibited diminished thickness of the external granule layer (EGL) and irregular Purkinje cell arrangement. There was a greater number of nucleoli and nucleolar organiser regions (NORs) in 24% of Purkinje cells. Cerebellar granule neuron progenitor (CGNP) cells of the EGL showed a decrease in cellular density (confirmed by proliferating cell nuclear antigen [PCNA] immunolocalization) and NORs. At postnatal day 6 (P6), the Golgi-Kopsch technique allowed us to observe disturbances in the distribution pattern of CGNP cells (during proliferation, migration, and differentiation) and premature growth of the Bergmann glia. Our findings reveal disturbances in the cerebellar development program with early cellular and tissue changes.
Assuntos
Corticosteroides/metabolismo , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Glucocorticoides/farmacologia , Animais , Diferenciação Celular , Movimento Celular , Nucléolo Celular/metabolismo , Proliferação de Células , Feminino , Humanos , Neurônios/patologia , Região Organizadora do Nucléolo/metabolismo , Gravidez , Prenhez , Efeitos Tardios da Exposição Pré-Natal , Antígeno Nuclear de Célula em Proliferação/biossíntese , Células de Purkinje/metabolismo , Ratos , Ratos Wistar , Coloração pela PrataRESUMO
The purpose of this work was to study if chronic low-dose ozone exposure could per se induce oxidative damage to neurons of striatum and substantia nigra. Thirty male Wistar rats were divided into three groups--Group 1: exposed to an air stream free of ozone; Group 2: exposed for 15 days to ozone; Group 3: exposed for 30 days to ozone. Ozone exposure was carried out daily for 4 h at a 0.25 ppm dose. Each group was then tested for (1) motor activity, (2) quantification of lipid peroxidation levels, (3) Klüver-Barrera staining, and (4) immunohistochemistry for tyrosine hydroxylase (TH), dopamine and adenosine 3',5'-monophosphate-regulated phosphoprotein of 32 kD (DARPP-32), inducible nitric oxide synthase (iNOS), and superoxide dismutase (SOD), to study neuronal alterations in striatum and substantia nigra. Results indicate that ozone exposure causes a significant decrease in motor activity. Ozone produced lipid peroxidation, morphological alterations, loss of fibers and cell death of the dopaminergic neurons. The DARPP-32, iNOS and SOD expression increased with repetitive ozone exposure. These alterations suggest that ozone causes oxidative stress which induces oxidative damage to substantia nigra and striatum of the rat.
Assuntos
Neostriado/patologia , Oxidantes Fotoquímicos/toxicidade , Estresse Oxidativo/fisiologia , Ozônio/toxicidade , Substância Negra/patologia , Algoritmos , Animais , Contagem de Células , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Imuno-Histoquímica , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Atividade Motora/efeitos dos fármacos , Neostriado/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Substância Negra/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
The aim of this study was to determine GH-effects on Cyclooxygenase-2 (COX-2) expression on hippocampus alterations caused by ozone exposure. Seventy male rats were divided into: (1) control; (2) exposed to ozone for 7, 15, and 30 days; (3) exposed to ozone and treated with GH, for 7, 15, and 30 days. Results showed that lipoperoxidation levels and number of COX-2-positive cells increased in all groups exposed to ozone compared to control. In the groups treated with GH, COX-2 immunoreactive cell number decreased with respect to the ozone group. Therefore, GH could provide protection against damage induced by oxidative stress.
Assuntos
Ciclo-Oxigenase 2 , Hormônio do Crescimento/farmacologia , Hipocampo/metabolismo , Ozônio/farmacologia , Animais , Ciclo-Oxigenase 2/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Hormônio do Crescimento/administração & dosagem , Masculino , Ozônio/administração & dosagem , Distribuição Aleatória , Ratos , Ratos WistarRESUMO
The administration of 3-nitropropionic acid increases reactive oxygen species (ROS). Antioxidant defense mechanisms buffer these ROS converting them into non-damaging compounds. Taurine and vitamins C and E are antioxidants that play a role in the defense against cellular damage. This study examines the antioxidant effect of taurine, vitamin C, and vitamin E on acute hippocampal damage caused by 3-NP. Animals treated with 3-NP increased lipid peroxidation levels and astrocytic damage in the hippocampus. Administration of taurine, vitamin C, and vitamin E partially protected from oxidative damage, indicate that while all substances had antioxidant effects, only taurine showed morphological protection in surviving cells.