Neuromuscular Activity Of Bothrops Fonsecai Snake Venom In Vertebrate Preparations.

The neuromuscular activity of venom from Bothrops fonsecai, a lancehead endemic to southeastern Brazil, was investigated. Chick biventer cervicis (CBC) and mouse phrenic nerve-diaphragm (PND) preparations were used for myographic recordings and mouse diaphragm muscle was used for membrane resting potential (RP) and miniature end-plate potential (MEPP) recordings. Creatine kinase release and muscle damage were also assessed. In CBC, venom (40, 80 and 160μg/ml) produced concentration- and time-dependent neuromuscular blockade (50% blockade in 85±9 min and 73±8 min with 80 and 160μg/ml, respectively) and attenuated the contractures to 110μM ACh (78-100% inhibition) and 40mM KCl (45-90% inhibition). The venom-induced decrease in twitch-tension in curarized, directly-stimulated preparations was similar to that in indirectly stimulated preparations. Venom (100 and 200μg/ml) also caused blockade in PND preparations (50% blockade in 94±13 min and 49±8 min with 100 and 200μg/ml, respectively) but did not alter the RP or MEPP amplitude. In CBC, venom caused creatine kinase release and myonecrosis. The venom-induced decrease in twitch-tension and in the contractures to ACh and K(+) were abolished by preincubating venom with commercial antivenom. These findings indicate that Bothrops fonsecai venom interferes with neuromuscular transmission essentially through postsynaptic muscle damage that affects responses to ACh and KCl. These actions are effectively prevented by commercial antivenom.

A Metabolomic Protocol For Plant Systematics By Matrix-assisted Laser-desorption/ionization Time-of Flight Mass Spectrometry.

Matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS) has been widely used for the identification and classification of microorganisms based on their proteomic fingerprints. However, the use of MALDI-TOF MS in plant research has been very limited. In the present study, a first protocol is proposed for metabolic fingerprinting by MALDI-TOF MS using three different MALDI matrices with subsequent multivariate data analysis by in-house algorithms implemented in the R environment for the taxonomic classification of plants from different genera, families and orders. By merging the data acquired with different matrices, different ionization modes and using careful algorithms and parameter selection, we demonstrate that a close taxonomic classification can be achieved based on plant metabolic fingerprints, with 92% similarity to the taxonomic classifications found in literature. The present work therefore highlights the great potential of applying MALDI-TOF MS for the taxonomic classification of plants and, furthermore, provides a preliminary foundation for future research.

Ressonância magnética e características clínicas em adultos com doenças desmielinizantes monofásicas: encefalomielite aguda disseminada ou uma variante da esclerose múltipla?

Acute disseminated encephalomyelitis (ADEM) is a widespread monophasic inflamatory disease affecting the central nervous system, that usually follows an infection or vaccination. In this study, we present an analysis of magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) and clinical aspects in four patients with clinical diagnosis of ADEM. The presence of MRI demyelinating lesions was crucial, but not in itself sufficient for definitive diagnosis. Clinical and MRI follow up, in order to exclude new lesions and to reevaluate the former ones, as well as CSF, were important for the differential diagnosis with other demyelinating diseases, particularly multiple sclerosis. In addition, we have shown that early treatment with methylprednisolone after the initial symptoms was effective for improving clinical manifestations as well as for reducing MRI lesions.

Analise da variabilidade da frequencia cardiaca em mulheres na pos-menopausa sedentarias e treinadas

Universidade Estadual de Campinas . Faculdade de Educação Física