RESUMEN

Tryptophan is an essential amino acid precursor of neurotransmitter serotonin and triptamine. During its metabolism, indole-3-acetic acid (IAA) is generated; this substance presents both antioxidant and prooxidant effects in different biological systems in addition to hipoglicemic effects. To date, electroencephalography (EEG) has been used to evaluate the temporal effect of several substances in neurotransmission. The goal of this study was to characterize the effect of IAA in the brain by analysing the EEG signal and evaluate the oxidative status by means of biochemical parameters. The EEG was acquired by using a noninvasive method, and the brain electric signal was analysed by advanced digital signal processing techniques to determinate the energy signal filtered in different band frequencies. Furthermore, the oxidative status of the brain was investigated by measuring the activity of antioxidant enzymes and lipid peroxidation as well as blood glucose rates of the animals treated with different doses of IAA. Our results showed the relationship of IAA administration with changes in EEG signals. The oxidative status of the brain was modified by IAA after 14 days of treatment.

Asunto(s)

RESUMEN

This research presents a noninvasive method for the acquisition of brain electrical signal in rat. Was used an electroencephalography (EEG) system developed for bovine and adapted to rats. The bipolar electrode system (needle electrodes) was glued on the surface of the head of the animal without surgical procedures and the other electrode was glued to the tail, as ground. The EEG activity was sampled at 120Hz for an hour. The accuracy and precision of the EEG measurement was performed using Fourier analysis and signal energy. For this, the digital signal was divided into sections successive of 3 seconds and was decomposed into four frequency bands: delta (0.3 to 4Hz), theta (4-8Hz), alpha (8-12Hz) and beta (12-30Hz) and energy (µV²) of the series of time filtered were calculated. The method allowed the acquisition of non-invasive electrical brain signals in conscious rats and their frequency patterns were in agreement with previous studies that used surgical procedures to acquire EEG in rats. This system showed accuracy and precision and will allow further studies on behavior and to investigate the action of drugs on the central nervous system in rats without surgical procedures.

Este trabalho apresenta um método não invasivo para a aquisição de sinal elétrico cerebral em ratos. Utilizou-se um sistema de eletroencefalografia EEG desenvolvido para bovino e adaptado para ratos. O sistema bipolar de eléctrodos (eléctrodos de agulha) foi colado na superfície da cabeça do animal, sem procedimentos cirúrgicos e outro eletrodo foi colado na cauda, como terra. A atividade do EEG foi amostrada em 120Hz durante uma hora. Foi calculada a exatidão e a precisão da medida de EEG usando análise de Fourier e energia do sinal. Para isso, o sinal digital foi dividido em trechos sucessivos de 3 segundos, decomposto em quatro faixas de frequência: delta (0,3-4Hz), teta (4-8Hz), alfa (8-12Hz) e beta (12-30Hz) e a energia (µV²) das séries de tempo filtradas foram calculadas. O método não invasivo permitiu adquirir sinais elétricos cerebrais em ratos conscientes e seus padrões de frequências foram de acordo com trabalhos anteriores, que utilizaram procedimentos cirúrgicos para adquirir EEG em ratos. Esse sistema apresentou exatidão e precisão e permitirá novos estudos sobre comportamento e para investigar a ação de drogas no sistema nervoso central sem procedimentos cirúrgicos em ratos.

RESUMEN

This research presents a noninvasive method for the acquisition of brain electrical signal in rat. Was used an electroencephalography (EEG) system developed for bovine and adapted to rats. The bipolar electrode system (needle electrodes) was glued on the surface of the head of the animal without surgical procedures and the other electrode was glued to the tail, as ground. The EEG activity was sampled at 120Hz for an hour. The accuracy and precision of the EEG measurement was performed using Fourier analysis and signal energy. For this, the digital signal was divided into sections successive of 3 seconds and was decomposed into four frequency bands: delta (0.3 to 4Hz), theta (4-8Hz), alpha (8-12Hz) and beta (12-30Hz) and energy (µV²) of the series of time filtered were calculated. The method allowed the acquisition of non-invasive electrical brain signals in conscious rats and their frequency patterns were in agreement with previous studies that used surgical procedures to acquire EEG in rats. This system showed accuracy and precision and will allow further studies on behavior and to investigate the action of drugs on the central nervous system in rats without surgical procedures.

Este trabalho apresenta um método não invasivo para a aquisição de sinal elétrico cerebral em ratos. Utilizou-se um sistema de eletroencefalografia EEG desenvolvido para bovino e adaptado para ratos. O sistema bipolar de eléctrodos (eléctrodos de agulha) foi colado na superfície da cabeça do animal, sem procedimentos cirúrgicos e outro eletrodo foi colado na cauda, como terra. A atividade do EEG foi amostrada em 120Hz durante uma hora. Foi calculada a exatidão e a precisão da medida de EEG usando análise de Fourier e energia do sinal. Para isso, o sinal digital foi dividido em trechos sucessivos de 3 segundos, decomposto em quatro faixas de frequência: delta (0,3-4Hz), teta (4-8Hz), alfa (8-12Hz) e beta (12-30Hz) e a energia (µV²) das séries de tempo filtradas foram calculadas. O método não invasivo permitiu adquirir sinais elétricos cerebrais em ratos conscientes e seus padrões de frequências foram de acordo com trabalhos anteriores, que utilizaram procedimentos cirúrgicos para adquirir EEG em ratos. Esse sistema apresentou exatidão e precisão e permitirá novos estudos sobre comportamento e para investigar a ação de drogas no sistema nervoso central sem procedimentos cirúrgicos em ratos.

RESUMEN

This research presents a noninvasive method for the acquisition of brain electrical signal in rat. Was used an electroencephalography (EEG) system developed for bovine and adapted to rats. The bipolar electrode system (needle electrodes) was glued on the surface of the head of the animal without surgical procedures and the other electrode was glued to the tail, as ground. The EEG activity was sampled at 120Hz for an hour. The accuracy and precision of the EEG measurement was performed using Fourier analysis and signal energy. For this, the digital signal was divided into sections successive of 3 seconds and was decomposed into four frequency bands: delta (0.3 to 4Hz), theta (4-8Hz), alpha (8-12Hz) and beta (12-30Hz) and energy (µV²) of the series of time filtered were calculated. The method allowed the acquisition of non-invasive electrical brain signals in conscious rats and their frequency patterns were in agreement with previous studies that used surgical procedures to acquire EEG in rats. This system showed accuracy and precision and will allow further studies on behavior and to investigate the action of drugs on the central nervous system in rats without surgical procedures.

Este trabalho apresenta um método não invasivo para a aquisição de sinal elétrico cerebral em ratos. Utilizou-se um sistema de eletroencefalografia EEG desenvolvido para bovino e adaptado para ratos. O sistema bipolar de eléctrodos (eléctrodos de agulha) foi colado na superfície da cabeça do animal, sem procedimentos cirúrgicos e outro eletrodo foi colado na cauda, como terra. A atividade do EEG foi amostrada em 120Hz durante uma hora. Foi calculada a exatidão e a precisão da medida de EEG usando análise de Fourier e energia do sinal. Para isso, o sinal digital foi dividido em trechos sucessivos de 3 segundos, decomposto em quatro faixas de frequência: delta (0,3-4Hz), teta (4-8Hz), alfa (8-12Hz) e beta (12-30Hz) e a energia (µV²) das séries de tempo filtradas foram calculadas. O método não invasivo permitiu adquirir sinais elétricos cerebrais em ratos conscientes e seus padrões de frequências foram de acordo com trabalhos anteriores, que utilizaram procedimentos cirúrgicos para adquirir EEG em ratos. Esse sistema apresentou exatidão e precisão e permitirá novos estudos sobre comportamento e para investigar a ação de drogas no sistema nervoso central sem procedimentos cirúrgicos em ratos.

RESUMEN

This research presents a noninvasive method for the acquisition of brain electrical signal in rat. Was used an electroencephalography (EEG) system developed for bovine and adapted to rats. The bipolar electrode system (needle electrodes) was glued on the surface of the head of the animal without surgical procedures and the other electrode was glued to the tail, as ground. The EEG activity was sampled at 120Hz for an hour. The accuracy and precision of the EEG measurement was performed using Fourier analysis and signal energy. For this, the digital signal was divided into sections successive of 3 seconds and was decomposed into four frequency bands: delta (0.3 to 4Hz), theta (4-8Hz), alpha (8-12Hz) and beta (12-30Hz) and energy (µV²) of the series of time filtered were calculated. The method allowed the acquisition of non-invasive electrical brain signals in conscious rats and their frequency patterns were in agreement with previous studies that used surgical procedures to acquire EEG in rats. This system showed accuracy and precision and will allow further studies on behavior and to investigate the action of drugs on the central nervous system in rats without surgical procedures.

Este trabalho apresenta um método não invasivo para a aquisição de sinal elétrico cerebral em ratos. Utilizou-se um sistema de eletroencefalografia EEG desenvolvido para bovino e adaptado para ratos. O sistema bipolar de eléctrodos (eléctrodos de agulha) foi colado na superfície da cabeça do animal, sem procedimentos cirúrgicos e outro eletrodo foi colado na cauda, como terra. A atividade do EEG foi amostrada em 120Hz durante uma hora. Foi calculada a exatidão e a precisão da medida de EEG usando análise de Fourier e energia do sinal. Para isso, o sinal digital foi dividido em trechos sucessivos de 3 segundos, decomposto em quatro faixas de frequência: delta (0,3-4Hz), teta (4-8Hz), alfa (8-12Hz) e beta (12-30Hz) e a energia (µV²) das séries de tempo filtradas foram calculadas. O método não invasivo permitiu adquirir sinais elétricos cerebrais em ratos conscientes e seus padrões de frequências foram de acordo com trabalhos anteriores, que utilizaram procedimentos cirúrgicos para adquirir EEG em ratos. Esse sistema apresentou exatidão e precisão e permitirá novos estudos sobre comportamento e para investigar a ação de drogas no sistema nervoso central sem procedimentos cirúrgicos em ratos.

RESUMEN

Guanidine has been used with some success to treat myasthenia gravis and myasthenic syndrome because it increases acetylcholine release at nerve terminals through K⁺, Na⁺ and Ca²âº channels-involving mechanisms. Currently, guanidine derivatives have been proposed for treatment of several diseases. Studies aimed at providing new insights to the drug are relevant. Experimentally, guanidine (10 mM) induces on mouse phrenic nerve-diaphragm (PND) preparations neurotransmission facilitation followed by blockade and a greatest secondary facilitation after its removal from bath. Herein, we hypothesized that this peculiar triphasic response may differ in muscles with distinct twitch/metabolic characteristics. Morphological alterations and contractile response of PND, extensor digitorum longus (EDL) and soleus (SOL) preparations incubated with guanidine (10 mM) for 15, 30, 60 min were analyzed. Guanidine concentrations of 5 mM (for PND and EDL) and 1 mM (for EDL) were also tested. Guanidine triphasic effect was only observed on PND regardless the concentration. The morphological alterations in muscle tissue varied along time but did not impede the PND post-wash facilitation. Higher doses (20-25 mM) did not increase EDL or SOL neurotransmission. The data suggest a complex mechanism likely dependent on the metabolic/contractile muscle phenotype; muscle fiber types and density/type of ion channels, sarcoplasmic reticulum and mitochondria organization may have profound impact on the levels and isoform expression pattern of Ca²âº regulatory membrane proteins so reflecting regulation of calcium handling and contractile response in different types of muscle.

Asunto(s)

RESUMEN

PURPOSE--To search for the existence and degree of correlation between total 12 lead ECG amplitude and the sum of RaVL + SV3 > 28 mm (for men) or > 20mm (for women) and left ventricular hypertrophy (LV mass calculated by echocardiography > 215g for both sexes). METHODS--ECG and echocardiograms of 227 consecutive patients were examined and submitted to statistical analysis searching for correlation between total 12 lead ECG amplitude and Cornell criteria and LV mass (ASE formula modified by Devereux). RESULTS--Patients had ischemic heart disease, hypertension, valvular disease, cardiomyopathy or other less common heart diseases, or had no cardiac illness at all. There was statistically significant association of total 12 lead amplitude > 120mm and Cornell criteria with LV mass > 215g (p = 0.02 and p = 0.01 respectively). Total ECG amplitude showed 74.3//sensitivity, 42.6//specificity, and 52.4//accuracy. Cornell criteria showed values of 37.8//, 82.7//and 68.7//respectively. CONCLUSION--Total 12-lead amplitude presented limited diagnostic performance for detecting LV hypertrophy, as well as did ECG Cornell criteria, although the latter was more specific and more accurate

Asunto(s)

RESUMEN

A transfusäo de sangué é reconhecida como o segundo mais importante modo de transmissäo da doença de Chagas. Este estudo faz um levantamento dos métodos empregados em diversos bancos de sangue para detectar doadores infectados e prevenir esta iatrogenia e compara as áreas controladas por órgäos oficiais com aquelas de maior prevalência da doença

Asunto(s)

RESUMEN

A transfusäo de sangue é reconhecida como o segundo mais importante modo de transmissäo da Doença de Chagas. Este estudo faz um levantamento dos métodos empregados em diversos Bancos de Sangue para detectar doadores infectados e prevenir esta iatrogenia e compara as áreas controladas por órgäos oficiais com aquelas de maior prevalência da Doençça

Asunto(s)