ABSTRACT
The aim of the present study was to investigate the effects of different doses of oral creatine supplementation on tibial muscle resistance and fatigue in Wistar rats. The treatment protocols included swimming exercises, supplementation alone (different doses), and supplementation (different doses) + swimming exercises. Analysis of the effect of creatine supplementation on skeletal muscle fatigue was performed using the intensity of muscle contraction to electrical stimulation to evaluate the intensity of muscle contraction, decay time of muscle tetanic contraction to 50% of maximum tension (fatigue), and the area under the curve for the intensity x time ratio, besides AST, LDH, and urea plasmatic analysis. Our results suggest that creatine supplementation seems to be able to produce ergogenic effects on contractile metabolism in the group treated with the dose of 280 mg/kg + swim exercise. This creatine dose presented a statistically significant increase in decay time of muscle tetanic contraction (C280+swim (119±13.1), C500+swim (110±23.6) and C1000+swim (87±15.1)), area under the curve between tetanic contractions, and plasma LDH decrease, when compared to the other doses. These data clearly demonstrate that high doses do not lead to any additional ergogenic effects. We conclude that the dose of 280 mg/kg+swim exercise obtained the best ergogenic effects on tibial muscle resistance and fatigue in Wistar rats.
O objetivo do presente estudo foi investigar os efeitos de diferentes doses de suplementação oral de creatina sobre a resistência e fadiga do músculo tibial em ratos wistar. Os protocolos de tratamento incluíram exercícios de natação, suplementação isolada (doses diferentes) e suplementação (doses diferentes) + exercícios de natação. A análise do efeito da suplementação de creatina na fadiga do músculo esquelético foi realizada utilizando-se a intensidade da contração muscular à uma estimulação elétrica, aferindo a intensidade da contração muscular, tempo de decaimento da contração tetânica do músculo a 50% da tensão máxima (fadiga) e a área sob a curva para a razão de intensidade x tempo, além de análises plasmática de AST, LDH e ureia. Nossos resultados sugerem que a suplementação de creatina parece ser capaz de produzir efeitos ergogênicos no metabolismo contrátil no grupo tratado, com a dose de 280 mg/kg+natação. Esta dose de creatina teve um aumento estatisticamente significativo no tempo de decaimento da contracção tetânica muscular (C280+natação (119±13.1), C500+natação (110±23.6) e C1000+natação (87±15.1)), área sob a curva entre as contrações tetânicas e também diminuição da LDH plasmática quando comparada com as outras doses. Estes dados demonstraram claramente que doses elevadas não conduzem a qualquer aumento adicional de efeitos ergogênicos. Concluimos que a dose de 280 mg / kg + exercício de natação obteve os melhores efeitos ergogênicos sobre a resistência e fadiga do músculo tibial em ratos wistar.
Subject(s)
Food , Rats, Wistar , Muscle Fatigue , Dietary Supplements , CreatineABSTRACT
INTRODUCTION: Thrombosis is a complex disease that is often silent and is characterized by thrombus formation within the blood vessel. It can lead to a venous obstruction in the body, severe sequelae and even death. Thrombus formation occurs when there is reduced blood flow and/or the release of procoagulant substances caused by external factors. In Brazil, the data on this pathology are still underestimated, and its incidence is approximately 0.8 cases/1000 inhabitants per year according to the literature. The aim of this study was to develop and validate a predictive method for the risk of thrombosis or thromboembolism according to various risk factors. METHODS: This is an observational and retrospective study based on a convenience sample of records. It was approved by the Institutional Review Board (IRB) of the University Mogi das Cruzes and the Heart Hospital of the São Paulo. The sample was classified according to the risk, and the assessment of concordance was performed by determining the Kappa coefficient and accuracy. RESULTS: Of the observed patients, 23 (46%) were women, and 86% were over 45 years old. The mean age of the patients was 60.8 years. Forty-eight percent of the patients underwent surgery for more than 30 minutes. In this study, the method categorized 29 (58%) patients as moderate risk, 10 as low risk and 11 as high risk. Two cases of thrombotic disease were sufficient for validation. CONCLUSION: The use of this software as a predictive method was feasible, providing fast filling, immediate scoring, flexibility and an upgrade over previous systems. The software will not substitute for diagnosis, which is a medical competence, but it may help as a warning of risk.
ABSTRACT
OBJECTIVE: To analyze the results of isolated on-pump coronary artery bypass graft surgery (CABG) in patients > 65 years-old. METHODS: Patients undergoing isolated on-pump CABG from December 1st 2010 to July 31th 2012 were divided in two groups: GE (elderly > 65 years-old, n=103) and GA (adults < 65 years-old, n=150). Preoperative data, intraoperative (as cardiopulmonar bypass time, aortic clamping time, time length of stay in mechanical ventilation - MV - and number of grafts), and postoperative variable (as morbidity, mortality and time length of stay in hospital) were analyzed during hospitalization. RESULTS: In GE, the morbidity rate was greater than in GA (30% vs. 14%, P=0.004), but there was no difference in the mortality rate (5.8% vs. 2.0%, P=0.165). In GA, there was higher prevalence DM (39.6% vs. 27%, P=0.043) and smoking (32.2% versus 19.8%, P=0.042); and in GE, higher prevalence of stroke (17% vs. 6.7%, P=0.013). There was no difference between the groups regarding intraoperative variables. After multivariate analysis, age > 65-year-old was associated with greater morbidity, but it was not independent predictive factor for in-hospital mortality. Considering in-hospital mortality, stay in ward time length (P=0.006), cardiac (P=0.011) and respiratory complications (P=0.026) were independent predictive factors. CONCLUSION: This study suggests that patients > 65-year old were at increased risk of postoperative complications when submitted to isolated on-pump CABG in comparison to patients < 65-year-old, but not under increased risk of death.
OBJETIVO: Analisar os desfechos da cirurgia de revascularização do miocárdio (CRM) isolada com circulação extracorpórea em pacientes com idade > 65 anos em comparação àqueles com < 65 anos. MÉTODOS: foram analisados 253 pacientes submetidos consecutivamente à CRM isolada entre 1º de dezembro de 2010 a 31 de julho de 2012. Os pacientes foram separados em dois grupos: GI (idosos > 65 anos) e GA (adultos < 65 anos). Foram analisadas variáveis pré-operatórias, intraoperatórias (tempo de CEC, tempo de pinçamento aórtico, tempo de submissão à VM e número de enxertos) e pós-operatórias (morbidade, mortalidade e tempo de internação). RESULTADOS: Dos 253 pacientes, 103 pertenciam ao GI (40,7%) e 150 ao GA (59,3%). A taxa de morbidade foi significativamente maior no GI quando comparada ao GA (30% vs. 14%, P=0,004), porém não houve diferença na taxa de mortalidade (5,8% vs. 2,0%, P=0,165). No GA havia maior prevalência DM (39,6% vs. 27%, P=0,043) e tabagismo (32,2% vs. 19,8%, P=0,042); e no GI, maior prevalência de acidente vascular encefálico prévio (17% vs. 6,7%, P=0,013). Não houve diferença entre os grupos quanto às variáveis intraoperatórias. Na análise multivariada: tempo de internação na enfermaria (P=0,006), complicações cardíacas (P=0,011) e complicações respiratórias (P=0,026) foram variáveis preditoras de risco para maior mortalidade intra-hospitalar. No entanto, a idade > 65 anos não foi um fator preditor de risco associada a variável óbito. CONCLUSÃO: Este estudo sugere que pacientes com idade igual ou superior a 65 anos possuem um maior risco de complicações intra-hospitalares no pós-operatório de CRM isolada com CEC em comparação com pacientes mais jovens.