Cardiac response in tambaqui Colossoma macropomum anaesthetised with Piper divaricatum essential oil.

The aim of this study was to evaluate the electrocardiographic responses of Colossoma macropomum exposed to short-term baths using the essential oil of Piper divaricatum (EOPD) as an anaesthetic-like agent in different doses (40, 60, and 80 µL L-1). Cardiac responses throughout and after exposure to EOPD were monitored and evaluated through mean heart rate (HR), duration and amplitude of the QRS complex (ventricular depolarization), and Q-T (ventricular contraction) and R-R (time between two successive QRS complexes) wave intervals. Across all doses, there was a marked depression of the HR, mainly at 80 µL L-1 EOPD. Mean amplitudes recorded for the QRS complex and Q-T interval at 40 µL L-1 EOPD were indistinguishable from the control, which could reinforce this concentration as sufficient and safe to promote fast anaesthesia without affecting cardiac function. Recovery from bradycardia, duration of the R-R interval, and QRS complex were similar at 60 and 80 µL L-1 EOPD; however, the Q-T interval at 80 µL L-1 EOPD revealed a more pronounced cardiac depression in relation to the controls and fish exposed to 60 µL L-1 EOPD. Thus, we conclude that 40 µL L-1 EOPD should suffice to induce fast, deep, and safe anaesthesia in tambaqui juveniles, whereas the concentration of 80 µL L-1 led to a greater depression of the cardiac function, albeit showing effect reversibility.

Cunaniol-elicited seizures: Behavior characterization and electroencephalographic analyses.

This study aimed at describing the characteristics and properties of seizures induced by cunaniol, a polyacetylenic alcohol isolated from the Clibadium genus, which is ubiquitous in the Amazon biodiversity and its potential use as a convulsant model. Wistar rat behavior was assessed upon cunaniol administration and animals were evaluated for neural activity through electroencephalographic records whereby epidural electrodes were positioned over the motor cortex under cunaniol-elicited seizures and seizure's control using three anticonvulsant agents, namely phenytoin, phenobarbital and diazepam. Cunaniol-induced seizures displayed a cyclic development of electrocorticographic seizures, presenting interictal-like spike and ictal period, which correlates to the behavioral observations and is in line with acute seizures induced by pentylenetetrazole. Cunaniol-elicited seizures were intractable by phenytoin treatment and controlled under the GABAergic activities of phenobarbital and diazepam. The results indicate that the cunaniol-induced changes show characteristics of seizure activity, making this plant compound a suitable animal convulsant model for seizure-related studies that could be used to assist in the development of novel anticonvulsant agents.

Clove oil induces anaesthesia and blunts muscle contraction power in three Amazon fish species.

Clove oil is used as an anaesthetic for many species of fish worldwide; however, relatively few studies have assessed its effectiveness on Amazon fish species and no compelling evidence has ever been reported on the relaxant properties of this oil for skeletal muscle of fish. Thus, the objective of this study was to evaluate the latencies to deep anaesthesia and recovery, along with the myorelaxant effect of clove oil on three Amazon fish species: cardinal tetra, Paracheirodon axelrodi, banded cichlid, Heros severus and angelfish, Pterophyllum scalare, submitted to short-term anaesthetic baths. Fish were assayed in three groups of 60 fish each and individually anaesthetized in a completely randomized design with six clove oil concentrations using 10 fish/species/concentration. Electromyographic recordings from dorsal muscle were performed during stages of induction and recovery in which nine fish/species/stage were used. Deep anaesthesia was attained for all concentrations tested, and no mortalities were observed throughout the experiments and after a 48-h observation period. Concentration of 90 µL L-1 and above promoted fast deep anaesthesia (< 3 min) and calm recovery in angelfish and cardinal tetra, whereas the concentration of 60 µL L-1 sufficed to quickly anaesthetize banded cichlid. Times to full recovery were not significantly contrasting among species and occurred within appropriate time threshold (< 5 min). Clove oil exerted a conspicuous depression of muscle contraction power, and therefore can be effectively used as a muscle relaxant agent for P. scalare, P. axelrodi, H. severus and potentially, for other fish species.

Hypoglycemic and hypolipidemic effects of Lippia origanoides Kunth in diabetic rats.

Diabetes mellitus is a metabolic disorder commonly associated with atherosclerosis. Plants with therapeutic potential, such as Lippia origanoides Kunth, emerge as effective alternatives for treating these diseases. Therefore, this work aims to analyze the antihyperglycemic and antidyslipidemic potential of the hydroalcoholic extract of Lippia origanoides Kunth (ELo) in alloxan-diabetic rats. Animals were treated orally: normal control, hyperglycemic control, positive control glibenclamide (5 mg/kg), and groups treated with ELo (75, 150, and 250 mg/kg). Preclinical evaluation of ELo showed hypoglycemic, hypolipidemic, hepatic, and renal protective effects. At all doses, ELo significantly reduced hyperglycemia, triglycerides, total cholesterol, low-density lipoprotein, atherogenic index, atherogenic coefficient, and cardiovascular risk index (p < .05). Elo at different doses promoted an increase in insulin release compared to untreated animals (p < .05) and showed α-glucosidase inhibitory activity (p < .05). Also, ELo (250 mg/kg group) showed maximum reduction of hyperglycemia, alanine transaminase, aspartate aminotransferase, malonaldehyde, and urea compared to the hyperglycemic and glibenclamide groups, and creatinine only compared to the hyperglycemic groups (p < .05). The promising action of ELo in the context of diabetes may be related to the synergistic action of flavonoid compounds identified in liquid chromatography, whose pharmacological capabilities have already been documented in previous studies. The mechanisms may be the stimulation of insulin release; the inhibitory activity of α-glucosidase; improving general clinical conditions; and the antioxidant effects of the extract. These findings pave the way for the future development of an herbal presentation of L. origanoides Kunth as a hypoglycemic and cardiovascular protector with a lipid-lowering effect.

Unmasking hidden risks: The surprising link between PDE5 inhibitors and seizure susceptibility.

BACKGROUND: Phosphodiesterase 5 inhibitors (PDE5i) are the first line treatment for erectile dysfunction; however, several articles and case reports have shown central nervous system effects, that can cause seizures in susceptible patients. This study aims to describe the changes caused by the use of Sildenafil and Tadalafil through the analysis of abnormalities expressed in the electrocorticogram (ECoG) of rats and evaluate the seizure threshold response and treatment of seizures with anticonvulsants. MATERIALS AND METHODS: The study used 108 rats (Wistar). Before surgery for electrode placement in dura mater, the animals were randomly separated into 3 experiments for electrocorticogram analysis. Experiment 1: ECoG response to using PD5i (Sildenafil 20mg/kg and Tadalafil 2.6mg/kg p.o.). Experiment 2: ECoG response to the use of PD5i in association with Pentylenetetrazole (PTZ-30 mg/kg i.p.), a convulsive model. Experiment 3: ECoG response to anticonvulsant treatment (Phenytoin, Phenobarbital and Diazepam) of seizures induced by association IPDE5 + PTZ. All recordings were made thirty minutes after administration of the medication and analyzed for ten minutes, only once. We considered statistical significance level of *p<0.05, **p<0.01 and ***p < 0.001. RESULTS: After administration of Sildenafil and Tadalafil, there were increases in the power of recordings in the frequency bands in oscillations in alpha (p = 0.0920) and beta (p = 0.602) when compared to the control group (p<0.001). After the use of Sildenafil and Tadalafil associated with PTZ, greater potency was observed in the recordings during seizures (p<0.001), however, the Sildenafil group showed greater potency when compared to Tadalafil (p<0.05). Phenobarbital and Diazepam showed a better response in controlling discharges triggered by the association between proconvulsant drugs. CONCLUSIONS: PDE5i altered the ECoG recordings in the rats' motor cortexes, demonstrating cerebral asynchrony and potentiating the action of PTZ. These findings demonstrate that PDE5i can lower the seizure threshold.

Extract of Euterpe oleracea Martius Stone Presents Anticonvulsive Activity via the GABAA Receptor.

Epilepsy is one of the most common neurological diseases globally, resulting from a disorder in brain activity. This condition can be triggered by birth trauma, traumatic brain injury (TBI), infections of the brain and stroke. More than 70 million people suffer seizures caused by neurological abnormalities. Approximately 80% of all epileptic patients reside in low-income conditions or in developing countries, and over 75% of patients do not receive proper treatment. Our previous study found an anticonvulsant property of an extract of Euterpe oleracea stone (EEOS) that caused myorelaxation, sedation, and cardiac and respiratory depression after intraperitoneal administration. The present study investigated through electroencephalographic (EEG) profiling the anticonvulsant protective properties of EEOS in induced convulsing rats. Male Wistar rats were treated with EEOS (300 mg/kg), diazepam (DZP) (5 mg/kg), pentylenetetrazol (PTZ) (60 mg/kg) and flumazenil (FMZ) (0.1 mg/kg) by intraperitoneal (i.p.). Electrodes implanted on the dura mater provided EEG data in which EEOS suppressed seizure deflagration caused by PTZ. In addition, EEOS presented no significant difference in comparison to DZP, which has the same mechanism of action. After FMZ injection, a GABAA receptor antagonist blocked the anticonvulsive effect in both the DZP and EEOS groups, suggesting that EEOS exerts it action on the GABAA receptor at the benzodiazepine (BDZ) subunit.

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.

Myorelaxation, respiratory depression and electrocardiographic changes caused by the administration of extract of açai (Euterpe oleracea Mart.) stone in rats.

The biological and pharmacological properties of natural polyphenols of the extract of Euterpe oleracea stone (EEOS) are associated with the central nervous system (CNS). To investigate the sedative and myorelaxant activity of EEOS in vivo, this study aimed to present the myorelaxant and sedative effects of EEOS in Wistar rats using spontaneous locomotor activity and motor electrophysiology. A total of 108 animals were used in the following experiments: a) behavioral tests (n = 27); b) electromyographic recordings of skeletal muscle (n = 27); c) respiratory muscle activity recordings (n = 27); d) cardiac muscle activity recordings (n = 27). The behavioral characteristics were measured according to the latency time of onset, the transient loss of posture reflex and maximum muscle relaxation. Electrodes were implanted in the gastrocnemius muscle and in the tenth intercostal space for electromyographic (EMG) signal capture to record muscle contraction, and in the D2 lead for electrocardiogram acquisition. After using the 300 mg/kg dose of EEOS intraperitoneally, a myorelaxant activity exhibited a lower frequency of contractility with an amplitude pattern of low and short duration at gastrocnemius muscle and intercostal muscle, which clearly describes a myorelaxant activity and changes in cardiac activity. The present report is so far the first study to demonstrate the myorelaxant activity of this extract, indicating an alternative route for açai stone valorization and its application in pharmaceutical fields.

Electrocorticographic patterns dominated by low-frequency waves in camphor-induced seizures.

Camphor is an aromatic terpene compound found in the essential oils of many plants, which has been used for centuries as a herbal medicine, especially in children. However, many studies have shown that camphor may have major side effects, including neurological manifestation, such as seizures. In the present study, we investigated the electrocorticographic patterns of seizures induced by camphor in male adult Wistar rats. Each rat received 400 mg/kg (i.p.) of camphor prior to monitoring by electrocorticography. The application of camphor resulted a rapid evolution to seizure and marked changes in the electrocorticographic readings, which presented characteristics of epileptiform activity, with an increase in the total power wave. The decomposition of the cerebral waves revealed an increase in the delta and theta waves. The analysis of the camphor traces revealed severe ictal activity marked by an increase in the polyspike wave. Our data thus indicate that camphor may cause seizures, leading to tonic-clonic seizures. Clearly, further studies are necessary to better elucidate the mechanisms through which camphor acts on the brain, and to propose potential treatments with anticonvulsant drugs that are effective for the control of the seizures.

New nanocarried phenobarbital formulation: Maintains better control of pentylenetetrazole-Induced seizures.

This study aims to evaluate the efficacy of slow release phenobarbital in the control of convulsions triggered by pentylenetetrazole (PTZ), verifying the time of permanence in the anticonvulsant effect through behavior and electroencephalographic records. A total of 162 male Wistar rats weighing between 100 and 120 g were divided into two groups, one for behavior analysis (n = 90) and biochemistry, and another for the acquisition of electrocorticographic record (n = 72). Hepatic enzymes were measured by obtaining a blood sample from the animals studied by means of a biochemical analysis. The procedures for electrode implant and electrocorticographic recordings were performed. The intercalation of phenobarbital in layered double hydroxide (LDH) nanocarrier allowed us to evaluate a new slow release pharmaceutical formulation based on methodologies that have proven longer residence time and lower side effects. This study demonstrates that phenobarbital can be a new perspective pharmaceutical formulation.

Behavioural, electrocorticographic, and electromyographic alterations induced by Nerium oleander ethanolic extract: Anticonvulsant therapeutics assessment.

Nerium oleander Linn. is an Apocynaceae shrub which is among the most toxic ornamental plants. Although seizures are one of the symptoms associated with N. Oleander poisoning in humans, only a few studies are available on the behavioural and electrophysiological alterations caused by this plant poisoning. This study aimed at providing a thorough description of the electroencephalographic (EEG) and electromyographic (EMG) profiles throughout the experimental poisoning of Wistar rats (200-250 g) using ethanolic extract of N. oleander (EENO). Further, seizure control was assessed using different anticonvulsants. Male Wistar rat's behaviour was assessed upon EENO (150 mg/kg) administration and the animals were evaluated for muscle and neural activities through EMG and EEG recordings, respectively. The behavioural test showed two distinct phases of CNS activity: Phase I - myorelaxation and depression, and Phase II - excitability (agitated behaviour and seizures). Such phases were consistent with the EEG and EMG tracing patterns attained. Within the first 400 s of the recordings, during Phase I, the EMG showed no tracing amplitude variation. Later, the tracing pattern was changed and an intensification of the muscle contraction power in higher frequencies was observed during Phase II. The EEG showed initially a slight flattening in the tracings with a reduction in the intensity of the signal as per spectrogram of frequency attained. Thereafter, during Phase II, much higher amplitude tracings could be noted with an intensification of the signal, compatible with seizures. Seizure control was evaluated using four agents: phenytoin, phenobarbital, diazepam and scopolamine (at 10 mg/kg in all cases). While scopolamine was not effective in the seizure control, diazepam was the most efficient drug for the attenuation of the poisoning. Our results indicate the possibility of including phenytoin, phenobarbital and diazepam, mainly the latter, in the poisoning therapeutic protocol, including for those individuals who could be more susceptible to the poisoning by Nerium oleander as in the case of epileptic 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.

Central nervous system tumours profile at a referral center in the Brazilian Amazon region, 1997-2014.

Tumours of the Central Nervous System (CNS) are an important cause of mortality from cancer. Epidemiological data on neoplams affecting the CNS are scarce in Brazil, especially in the Amazon region. The study aims at describing the histopathological profile of CNS tumours cases at a high-complexity referral cancer center. This study has described a 17-year-series profile of CNS tumours, registered at a high-complexity referral cancer center in Pará state, from January 1997 until July 2014 in the Brazilian Amazon Region. Data was gathered from histopathology reports kept in the hospital's cancer registry and 949 cases of CNS tumours were analyzed. The most common histopathology were neuroepithelial tumours (approx. 40%) and meningioma was the most frequent especific tumor histologic subtype (22.2%). Neuroepithelial tumours were more frequent in patients with ages ranging from less than a year to 19 years, whereas metastatic tumours were prevalent in patients over 40 years of age. It was not found temporal trends during the studied period. The knowledge of these tumours profile is valuable for the understanding of cancer epidemiology in the region, since its prevalence is currently underreported and more awareness on the disease is needed.

Depletion of enteroendocrine and mucus-secreting cells is associated with colorectal carcinogenesis severity and impaired intestinal motility in rats.

This study investigated the relationship between enteroendocrine and mucus-secreting cells distribution, the severity of colonic mucosal injury and intestinal motility in experimental colorectal carcinogenesis. Using a standardized murine model of colorectal carcinogenesis, eight-weeks-old female Wistar rats weighting 147.30 ± 29.15g were randomized into two groups receiving a subcutaneous injection of 0.9% saline (control) or the chemical carcinogen 1,2-dimethylhydrazine (DMH) at 20 mg/kg per week during 10 weeks. Aberrant crypt foci (ACF) were more frequent in DMH group compared to control group (P < 0.001). The number of enteroendocrine and mucus-secreting cells, and intestinal motility was reduced in DMH animals (P < 0.05). The distribution of enteric neurons was similar in both groups. In DMH animals there was a direct correlation between colonic motility and distribution of enteroendocrine (R(2) = 0.68, P < 0.05) and mucus-secreting cells (R(2) = 0.77, P < 0.05). Inverse correlation between the number of ACF, mucus-secreting cells (R(2) = -0.57, P < 0.05), and enteroendocrine cells (R(2) = -0.74, P < 0.05) was also observed. There was inverse correlation between the severity of the mucosal lesion, the number of mucus-secreting cells (R(2) = -0.83, P < 0.05) and enteroendocrine cells (R(2) = -0.96, P < 0.05). There was a direct correlation between nucleolar organizer regions (AgNOR) and ACF number (R(2) = 0.62; P < 0.01). Inverse correlation was also found between AgNOR, the number of mucus-secreting cells (R(2) = -0.76; P < 0.001), and enteroendocrine cells (R(2) = -0.86; P < 0.001). Taken together, the results indicated that colonic malignant transformation is related to depletion of mucus-secreting and enteroendocrine cells, which was a useful indicator of the evolutionary status of intestinal neoplasm, partially explaining the intestinal motility disorders in the early stages of colorectal carcinogenesis.

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.