Caffeine intoxication: Behavioral and electrocorticographic patterns in Wistar rats.

Caffeine is a psychoactive substance used worldwide. The present study analyzes the seizure-related behavior and electrocorticographic (ECoG) patterns observed in rats following of a toxic dose of caffeine (150 mg/kg; intraperitoneal). Sixty-three rats were divided into three experiments: 1-Behavior's Description associated with caffeine-induced convulsion; 2- Comparison of the electrocorticographic patterns induced by caffeine and pentylenetetrazole, and 3- Assessment of the electrocorticographic response to antiepileptic drugs (diazepam, phenytoin, and phenobarbital). The behavioral analysis demonstrated tonic-clonic seizures with a loss of postural reflex and a latency of 365.8 s after the caffeine's administration. Caffeine-induced changes in the ECoG were consistent with the development of seizures with rapid evolution and burst potential consistent with the behavioral patterns observed during the caffeine-induced seizure. The ECoG of the brainwaves varied significantly between the seizures caused by caffeine and pentylenetetrazole. The predominant brain forces observed during the seizures were beta-band oscillations. The caffeine-induced seizures were resistant to attempted control with phenytoin and phenobarbital, but responded well to diazepam, which is consistent with a study of Pilocarpine, which showed that diazepam has anticonvulsant effects. These findings are important for the development of effective treatments for caffeine intoxication, in particular for individuals with a low seizure threshold.

Characterization of electrocorticographic, electromyographic and electrocardiographic recordings after the use of caffeine in Wistar rats.

OBJECTIVE: To describe electrocorticographic, electromyographic and electrocardiographic profiles to report the electrophysiological effects of caffeine in Wistar rats. METHODS: Male adult Wistar rats weighing 230g to 250g were used. Rats were allocated to one of two groups, as follows: Group 1, Control, intraperitoneal injection of 0.9% saline solution (n=27); and Group 2, treated with intraperitoneal injection of caffeine (50mg/kg; n=27). The rats were submitted to electrocorticographic, electromyographic and electrocardiographic assessment. RESULTS: Brain oscillations (delta, theta, alpha, beta and gamma) in the frequency range up to 40Hz varied after caffeine administration to rats. Powers in delta and theta oscillations ranges were preponderant. The contractile force of the skeletal striated and cardiac muscles increased. Electrocardiogram analysis revealed shorter RR, QRS and QT intervals under the effect of caffeine. CONCLUSION: In the central nervous system, there was an increase in the delta, theta and alpha amplitude spectrum, which are related to memory encoding and enhanced learning. With regard to skeletal muscle, increased contraction of the gastrocnemius muscle was demonstrated, a clear indication of how caffeine can be used to enhance performance of some physical activities. Electrocardiographic changes observed after caffeine administration are primarily related to increased heart rate and energy consumption.

Validação dos intervalos de referência hematológicos e bioquímicos estabelecidos para cães domiciliados na Amazônia Oriental, Pará, Brasil / Validation of hematological and biochemical reference intervals established for dogs housed in the Eastern Amazon, Pará, Brazil

O objetivo do presente estudo foi validar intervalos de referências (IRs) para hematologia e bioquímica sanguínea de cães domiciliados da Amazônia Oriental e estabelecer novos IRs para os parâmetros não validados. Foram utilizadas amostras de 44 cães adultos clinicamente saudáveis de diferentes raças e sexos. Na validação, foi utilizada a metodologia proposta pelo Clinical and Laboratory Standards Institute (CLSI) e na determinação dos IRs dos parâmetros não validados foi utilizada a metodologia estatística proposta pela American Society for Clinical Veterinary Pathology (ASCPV). Os IRs foram determinados por meio do programa Excel com o suplemento Reference Value Advisor (versão 2.1). O software realiza os cálculos de acordo com as recomendações CLSI, conforme sugerido pelas diretrizes da ASCVP. Um total de 25 parâmetros (13 hematológicos e 12 bioquímicos) foram submetidos ao processo de validação. Desse total, seis (24%) parâmetros não foram validados (Hemoglobina, CHGM, eosinófilos, linfócitos, albumina e GGT) e para estes foram estabelecidos novos intervalos. Para a maioria dos parâmetros hematológicos e bioquímicos (76%), os IRs estabelecidos previamente na literatura ainda são válidos para utilização em cães criados na Amazônia Oriental. Para os parâmetros não validados, apenas para eosinófilos e linfócitos recomendamos que outros trabalhos, com um número maior de animais, sejam realizados para confirmar os nossos resultados ou estabelecer novos IRs. Os IRs estabelecidos para hemoglobina, CHGM, albumina e GGT podem ser utilizados em substituição aos intervalos antigos.

The aim of the present study was to validate reference intervals (RIs) for hematology and blood biochemistry of dogs domiciled in the Eastern Amazon and to establish new RIs for parameters not yet validated. Samples from 44 clinically healthy adult dogs of different breeds and sexes were used. The methodology proposed by the Clinical and Laboratory Standards Institute (CLSI) was used for validation, and the statistical methodology proposed by the American Society for Clinical Veterinary Pathology (ASCPV) was used to determine the RIs of the non-validated parameters. The IRs were determined using the Excel program with the Reference Value Advisor add-in (version 2.1). The software performs calculations according to CLSI recommendations as suggested by the ASCVP guidelines. A total of 25 parameters (13 hematological and 12 biochemical) were submitted to the validation process. Of this total, six (24%) parameters were not validated (Hemoglobin, CHGM, eosinophils, lymphocytes, albumin and GGT) and new intervals were established for these. For most hematological and biochemical parameters (76%), the RIs previously established in the literature are still valid for use in dogs raised in the Eastern Amazon. For non-validated parameters, just for eosinophils and lymphocytes, we recommend that other studies, with a larger number of animals, be carried out to confirm our results or establish new IRs. The established IRs for hemoglobin, CHGM, albumin and GGT can be used in place of the old ranges.

Characterization of electrocorticographic, electromyographic and electrocardiographic recordings after the use of caffeine in Wistar rats / Caracterização dos registros eletrocorticográficos, eletromiográficos e eletrocardiográficos após uso de cafeína em ratos Wistar

ABSTRACT Objective: To describe electrocorticographic, electromyographic and electrocardiographic profiles to report the electrophysiological effects of caffeine in Wistar rats. Methods: Male adult Wistar rats weighing 230g to 250g were used. Rats were allocated to one of two groups, as follows: Group 1, Control, intraperitoneal injection of 0.9% saline solution (n=27); and Group 2, treated with intraperitoneal injection of caffeine (50mg/kg; n=27). The rats were submitted to electrocorticographic, electromyographic and electrocardiographic assessment. Results: Brain oscillations (delta, theta, alpha, beta and gamma) in the frequency range up to 40Hz varied after caffeine administration to rats. Powers in delta and theta oscillations ranges were preponderant. The contractile force of the skeletal striated and cardiac muscles increased. Electrocardiogram analysis revealed shorter RR, QRS and QT intervals under the effect of caffeine. Conclusion: In the central nervous system, there was an increase in the delta, theta and alpha amplitude spectrum, which are related to memory encoding and enhanced learning. With regard to skeletal muscle, increased contraction of the gastrocnemius muscle was demonstrated, a clear indication of how caffeine can be used to enhance performance of some physical activities. Electrocardiographic changes observed after caffeine administration are primarily related to increased heart rate and energy consumption.

RESUMO Objetivo: Descrever os perfis eletrocorticográficos, eletromiográficos e eletrocardiográficos para relatar os efeitos eletrofisiológicos da cafeína em ratos Wistar. Métodos: Foram utilizados ratos Wistar, machos, adultos, pesando de 230g a 250g. Os animais foram divididos nos seguintes grupos: Grupo 1, Controle com solução fisiológica 0,9% por via intraperitoneal (n=27), e Grupo 2, Tratado com Cafeína (50mg/kg intraperitoneal; n=27). Foram realizadas avaliações por eletrocorticograma, eletromiograma e eletrocardiograma. Resultados: Houve variações nas oscilações cerebrais (delta, teta, alfa, beta e gama) na faixa de frequência de até 40Hz após a aplicação de cafeína em ratos. Observou-se que as potências nas faixas das oscilações delta e teta foram preponderantes. A força de contração nos músculos estriado esquelético e cardíaco aumentou. A avaliação do eletrocardiograma demonstrou que a duração dos intervalos RR, QRS e QT foram menores na presença da cafeína. Conclusão: No sistema nervoso central, houve aumento dos espectros de amplitude delta, teta e alfa, que auxiliam na codificação das memórias e estão relacionados à melhora do aprendizado. Em relação à musculatura esquelética, demonstrou-se aumento da contração do músculo gastrocnêmio, uma clara indicação de como a cafeína pode ser usada para aumentar o desempenho em algumas atividades físicas. As alterações eletrocardiográficas observadas após a administração de cafeína estiveram relacionadas principalmente ao aumento da frequência cardíaca e do consumo de energia.

Analysis of imatinib adherence in chronic myeloid leukemia: a retrospective study in a referral hospital in the Brazilian Amazon

ABSTRACT Background: There has been a revolution in the treatment of Chronic Myeloid Leukemia since imatinib's introduction. However, patient adherence has a great impact on the response obtained with medical treatment. This study's objective was to analyze the drug adherence and the factors that influenced it in patients with Chronic Myeloid Leukemia in a referral hospital in the Brazilian Amazon. Method: This was a retrospective study including 120 patients with Chronic Myeloid Leukemia from January 2002 to December 2014. The adherence was estimated by the Proportion of Days Covered and the persistence by Kaplan-Meier analysis. The data was analyzed in Epi Info 7® software and the relationship between the variables was analyzed by Fisher's exact test. A p-value lower than 0.05 was considered significant. Results: Twenty-seven patients (22.5%) were considered non-adherent. There has been irregular medication use and disinterest in the treatment in 20.83% (n = 25), of which 13 were considered non-adherent (p < 0.001). A total of 26.67% (n = 32) abandoned the treatment for a period. Of those, 56.25% (n = 18) were non-adherent (p < 0.001). Distance to the hospital, lack of medication and side-effects were all non-significant to low adherence. At the end of a 360-day follow-up, 44.16% (n = 53) of patients presented a break in persistence, whose average was 255 days. Conclusion: The adherence found in this study was similar to that found in others of its kind. The only factors that negatively influenced the adherence were disinterest and abandonment of treatment, which can reflect the need to individually educate Chronic Myeloid Leukemia patients.

Analysis of imatinib adherence in chronic myeloid leukemia: a retrospective study in a referral hospital in the Brazilian Amazon.

BACKGROUND: There has been a revolution in the treatment of Chronic Myeloid Leukemia since imatinib's introduction. However, patient adherence has a great impact on the response obtained with medical treatment. This study's objective was to analyze the drug adherence and the factors that influenced it in patients with Chronic Myeloid Leukemia in a referral hospital in the Brazilian Amazon. METHOD: This was a retrospective study including 120 patients with Chronic Myeloid Leukemia from January 2002 to December 2014. The adherence was estimated by the Proportion of Days Covered and the persistence by Kaplan-Meier analysis. The data was analyzed in Epi Info 7® software and the relationship between the variables was analyzed by Fisher's exact test. A p-value lower than 0.05 was considered significant. RESULTS: Twenty-seven patients (22.5%) were considered non-adherent. There has been irregular medication use and disinterest in the treatment in 20.83% (n=25), of which 13 were considered non-adherent (p<0.001). A total of 26.67% (n=32) abandoned the treatment for a period. Of those, 56.25% (n=18) were non-adherent (p<0.001). Distance to the hospital, lack of medication and side-effects were all non-significant to low adherence. At the end of a 360-day follow-up, 44.16% (n=53) of patients presented a break in persistence, whose average was 255 days. CONCLUSION: The adherence found in this study was similar to that found in others of its kind. The only factors that negatively influenced the adherence were disinterest and abandonment of treatment, which can reflect the need to individually educate Chronic Myeloid Leukemia patients.