ABSTRACT
Introduction: Sepsis is defined as a multifactorial debilitating condition with high risks of death. The intense inflammatory response causes deleterious effects on the brain, a condition called sepsis-associated encephalopathy. Neuroinflammation or pathogen recognition are able to stress cells, resulting in ATP (Adenosine Triphosphate) release and P2X7 receptor activation, which is abundantly expressed in the brain. The P2X7 receptor contributes to chronic neurodegenerative and neuroinflammatory diseases; however, its function in long-term neurological impairment caused by sepsis remains unclear. Therefore, we sought to evaluate the effects of P2X7 receptor activation in neuroinflammatory and behavioral changes in sepsis-surviving mice. Methods: Sepsis was induced in wild-type (WT), P2X7-/-, and BBG (Brilliant Blue G)-treated mice by cecal ligation and perforation (CLP). On the thirteenth day after the surgery, the cognitive function of mice was assessed using the novel recognition object and Water T-maze tests. Acetylcholinesterase (AChE) activity, microglial and astrocytic activation markers, and cytokine production were also evaluated. Results: Initially, we observed that both WT and P2X7-/- sepsis-surviving mice showed memory impairment 13 days after surgery, once they did not differentiate between novel and familiar objects. Both groups of animals presented increased AChE activity in the hippocampus and cerebral cortex. However, the absence of P2X7 prevented partly this increase in the cerebral cortex. Likewise, P2X7 absence decreased ionized calcium-binding protein 1 (Iba-1) and glial fibrillary acidic protein (GFAP) upregulation in the cerebral cortex of sepsis-surviving animals. There was an increase in GFAP protein levels in the cerebral cortex but not in the hippocampus of both WT and P2X7-/- sepsis-surviving animals. Pharmacological inhibition or genetic deletion of P2X7 receptor attenuated the production of Interleukin-1ß (IL-1ß), Tumor necrosis factor-α (TNF-α), and Interleukin-10 (IL-10). Conclusion: The modulation of the P2X7 receptor in sepsis-surviving animals may reduce neuroinflammation and prevent cognitive impairment due to sepsis-associated encephalopathy, being considered an important therapeutic target.
ABSTRACT
The purpose of this meta-analytic review was to examine the extent and quality of research on the post-activation potentiation acute effect of rest interval manipulation on jumping performance. This manuscript adopted the recommendations from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. Criteria eligibility included crossover, randomised, non-randomised and counterbalanced studies that observed the voluntary muscle action-induced post-activation potentiation on jumping performance. Fourteen studies selected by two independent raters were included in the analysis. The rest intervals involved ranges including 0-3, 4-7, 8-12 and ≥16 min. The results demonstrated medium effect sizes for rest intervals 0-3 and 8-12 min (-0.25, confidence interval (CI): -0.51 to 0.01 for 0-3 min; 0.24, CI: -0.02 to 0.49 for 8-12 min) and a small effect for other ranges (0.15, CI: -0.08 to 0.38 for 4-7 min; 0.07, CI: -0.21 to 0.24 for ≥16 min). There was no evidence of heterogeneity for sub-groups (I2 = 0%; P < 0.001) and no indication of publication bias (Egger's test, P = 0.179). While a rest interval of 0-3 min induced a detrimental effect on jump performance, the range including 8-12 min had a beneficial impact on jump height. Findings suggest that the rest interval manipulation seems to affect post-activation potentiation magnitude and jump height.
Subject(s)
Athletic Performance/physiology , Exercise/physiology , Movement/physiology , Muscle, Skeletal/physiology , Rest/physiology , HumansABSTRACT
FUNDAMENTO: No passado, os exercícios isométricos foram proscritos para cardiopatas. Contudo, evidências recentes sugerem que um protocolo de treinamento isométrico de preensão manual (PTIM) - quatro séries de dois minutos a 30 por cento da força máxima - provoca efeitos favoráveis sobre a modulação autonômica e reduz os níveis de pressão arterial sistólica (PAS) e diastólica (PAD) de repouso. OBJETIVO: Visando obter subsídios para uma ampla aplicabilidade clínica, quantificamos as principais respostas hemodinâmicas durante uma sessão de PTIM em pacientes de um programa de exercício supervisionado. MÉTODOS: Quarenta e um pacientes (36 homens) realizaram o PTIM com medidas da frequência cardíaca (FC) e da PA antes, durante cada uma das duas séries feitas com o braço esquerdo e um minuto após a finalização. As medidas foram colhidas mediante um sinal de eletrocardiograma em um tensiômetro oscilométrico digital Tango+, previamente validado para condições de exercício físico. RESULTADOS: PTIM foi adequadamente realizado e sem a ocorrência de reações clínicas adversas. Observou-se um pequeno aumento dos níveis de PAS e de PAD, respectivamente, 16 e 7 mm Hg (p < 0,05) e um incremento ainda menor da FC - 3 bpm - (p < 0,05), quando compararam-se os dados obtidos aos 80 segundos da última série com os de pré-exercício. Um minuto pós-esforço, os valores de FC, de PAS e PAD já haviam praticamente retornado aos níveis iniciais. CONCLUSÃO: PTIM foi bem tolerado por pacientes em programas de exercício, gerando uma repercussão hemodinâmica transiente e modesta, sem induzir a rápida inativação vagal cardíaca característica dos exercícios dinâmicos e curtos.
BACKGROUND: In the past, isometric exercises were proscribed for heart disease. However, recent evidence suggests that an isometric handgrip training (IHT) protocol - four sets of two minutes at 30 percent of maximum strength - produces favorable effects on the autonomic modulation and reduces resting systolic (SBP) and diastolic (DBP) blood pressure. OBJECTIVE: Aiming at obtaining support for broad clinical applicability, we quantified the main hemodynamic responses during an IHT session in patients from a supervised physical exercise program. METHODS: Forty-one patients (36 men) underwent the IHT with measurements of heart rate (HR) and BP before, during each of the two series performed with the left arm and one minute after completion. Measurements were obtained by an electrocardiogram signal in a digital Tango + oscillometric tensiometer, previously validated for physical exercise conditions. RESULTS: The IHT was appropriately carried out, with no clinical adverse reactions. There was a small increase in SBP and DBP levels, respectively, of 16 and 7 mmHg (p <0.05) and an even smaller increase in HR - 3 bpm - (p <0.05) when we compared the data obtained at 80 seconds of the last series with the pre-exercise CONCLUSION: IHT was well tolerated by patients undergoing exercise programs, resulting in a transient and modest hemodynamic effect, without inducing rapid cardiac vagal inactivation, characteristic of dynamic and short exercises.
Subject(s)
Female , Humans , Male , Middle Aged , Clinical Protocols , Cardiovascular Diseases/rehabilitation , Exercise Test/methods , Hand Strength/physiology , Hemodynamics/physiology , Isometric Contraction/physiology , Analysis of VarianceABSTRACT
BACKGROUND: In the past, isometric exercises were proscribed for heart disease. However, recent evidence suggests that an isometric handgrip training (IHT) protocol - four sets of two minutes at 30% of maximum strength - produces favorable effects on the autonomic modulation and reduces resting systolic (SBP) and diastolic (DBP) blood pressure. OBJECTIVE: Aiming at obtaining support for broad clinical applicability, we quantified the main hemodynamic responses during an IHT session in patients from a supervised physical exercise program. METHODS: Forty-one patients (36 men) underwent the IHT with measurements of heart rate (HR) and BP before, during each of the two series performed with the left arm and one minute after completion. Measurements were obtained by an electrocardiogram signal in a digital Tango + oscillometric tensiometer, previously validated for physical exercise conditions. RESULTS: The IHT was appropriately carried out, with no clinical adverse reactions. There was a small increase in SBP and DBP levels, respectively, of 16 and 7 mmHg (p <0.05) and an even smaller increase in HR - 3 bpm - (p <0.05) when we compared the data obtained at 80 seconds of the last series with the pre-exercise CONCLUSION: IHT was well tolerated by patients undergoing exercise programs, resulting in a transient and modest hemodynamic effect, without inducing rapid cardiac vagal inactivation, characteristic of dynamic and short exercises.
