Targeting α-synuclein post-translational modifications in Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disease characterized by the progressive loss of dopaminergic neurons in the nigrostriatal pathway. Although the exact mechanisms underlying PD are still not completely understood, it is well accepted that α-synuclein plays key pathophysiological roles as the main constituent of the cytoplasmic inclusions known as Lewy bodies. Several post-translational modifications (PTMs), such as the best-known phosphorylation, target α-synuclein and are thus implicated in its physiological and pathological functions. In this review, we present (1) an overview of the pathophysiological roles of α-synuclein, (2) a descriptive analysis of α-synuclein PTMs, including phosphorylation, ubiquitination, SUMOylation, acetylation, glycation, truncation, and O-GlcNAcylation, as well as (3) a brief summary on α-synuclein PTMs as potential biomarkers for PD. A better understanding of α-synuclein PTMs is of paramount importance for elucidating the mechanisms underlying PD and can thus be expected to improve early detection and monitoring disease progression, as well as identify promising new therapeutic targets.

POTENTIAL EFFECTS OF WHOLE-BODY VIBRATION EXERCISES ON BLOOD FLOW KINETICS OF DIFFERENT POPULATIONS: A SYSTEMATIC REVIEW WITH A SUITABLE APPROACH.

BACKGROUND: The ability to control skin blood flow decreases with advancing age and some clinical disorders, as in diabetes and in rheumatologic diseases. Feasible clinical strategies such as whole-body vibration exercise (WBVE) are being used without a clear understanding of its effects. The aim of the present study is to review the effects of the WBVE on blood flow kinetics and its feasibility in different populations. MATERIAL AND METHODS: The level of evidence (LE) of selected papers in PubMed and/or PEDRo databases was determined. We selected randomized, controlled trials in English to be evaluated. RESULTS: Six studies had LE II, one had LE III-2 and one III-3 according to the NHMRC. A great variability among the protocols was observed but also in the assessment devices; therefore, more research about this topic is warranted. CONCLUSION: Despite the limitations, it is can be concluded that the use of WBVE has proven to be a safe and useful strategy to improve blood flow. However, more studies with greater methodological quality are needed to clearly define the more suitable protocols.

Comparison between whole-body vibration, light-emitting diode, and cycling warm-up on high-intensity physical performance during sprint bicycle exercise.

The purpose of this study was to compare the effects of light-emitting diode (LED) irradiation and whole-body vibration (WBV) delivered either in isolation or combination (LED + WBV), warm-up (WU), and a control (C) treatment on performance during a sprint bicycle exercise. Ten cyclists performed a 30-second sprint cycle test under these conditions. The LED light was applied at 4 points bilaterally. Whole-body vibration consisted of 5 minutes of squats associated with WBV. LED + WBV consisted of WBV followed by LED therapy. Warm-up consisted of 17 minutes of moderate-intensity bicycle exercise. Control consisted of 10 minutes at rest. Blood lactate (BL) and ammonia (BA) levels and skin temperature (ST) were determined. Peak power (842 ± 117 vs. 800 ± 106 vs. 809 ± 128 W [p = 0.02 and p = 0.01]), relative power (12.1 ± 1.0 vs. 11.5 ± 0.9 vs. 11.6 ± 1.0 W·kg [p = 0.02 and p = 0.02]), and relative work (277 ± 23 vs. 263 ± 24 vs. 260 ± 23 J·kg [p = 0.02 and p = 0.003]) were higher in the WU group compared with the control and LED groups. In the LED + WBV group, peak (833 ± 115 vs. 800 ± 106 W [p = 0.02]) and relative (11.9 ± 0.9 vs. 11.5 ± 0.9 W·kg [p = 0.02]) power were higher than those in the control group, and relative work (272 ± 22 vs. 260 ± 23 J·kg [p = 0.02]) were improved compared with the LED group. There were no differences for BL, BA, and ST. The findings of this study confirmed the effectiveness of a warm-up as a preparatory activity and demonstrated that LED + WBV and WBV were as effective as WU in improving cyclist performance during a sprint bicycle exercise.

Cardiorespiratory responses and prediction of peak oxygen uptake during the shuttle walking test in healthy sedentary adult men.

BACKGROUND: The application of the Shuttle Walking Test (SWT) to assess cardiorespiratory fitness and the intensity of this test in healthy participants has rarely been studied. This study aimed to assess and correlate the cardiorespiratory responses of the SWT with the cardiopulmonary exercise testing (CEPT) and to develop a regression equation for the prediction of peak oxygen uptake (VO2 peak) in healthy sedentary adult men. METHODS: In the first stage of this study, 12 participants underwent the SWT and the CEPT on a treadmill. In the second stage, 53 participants underwent the SWT twice. In both phases, the VO2 peak, respiratory exchange ratio (R), and heart rate (HR) were evaluated. RESULTS: Similar results in VO2 peak (P>0.05), R peak (P>0.05) and predicted maximum HR (P>0.05) were obtained between the SWT and CEPT. Both tests showed strong and significant correlations of VO2 peak (r = 0.704, P = 0.01) and R peak (r = 0.737, P<0.01), as well as the agreement of these measurements by Bland-Altman analysis. Body mass index and gait speed were the variables that explained 40.6% (R2 = 0.406, P = 0.001) of the variance in VO2 peak. The results obtained by the equation were compared with the values obtained by the gas analyzer and no significant difference between them (P>0.05) was found. CONCLUSIONS: The SWT produced maximal cardiorespiratory responses comparable to the CEPT, and the developed equation showed viability for the prediction of VO2 peak in healthy sedentary men.

Influence of the knee flexion on muscle activation and transmissibility during whole body vibration.

The influence of the knee flexion on muscle activation and transmissibility during whole body vibration is controversially discussed in the literature. In this study, 34 individuals had electromyography activity (EMG) of the vastus lateralis and the acceleration assessed while squatting with 60° and 90° of knee flexion either with or without whole-body vibration (WBV). The conditions were maintained for 10s with 1min of rest between each condition. The main findings were (1) the larger the angle of knee flexion (90° vs. 60°), the greater the EMG (p<0.001), with no difference on acceleration transmissibility; (2) for both angles of knee flexion, the addition of WBV produced no significant difference in EMG and higher acceleration compared to without WBV (p<0.001). These results suggest that the larger the knee flexion angle (60° vs. 90°), the greater the muscle activation without acceleration modification. However, the addition of WBV increases the transmissibility of acceleration in the lower limbs without modification in EMG of vastus lateralis.

Influence of aerobic training on cardiovascular and metabolic parameters in ederly hypertensive women.

BACKGROUND: Treatment of hypertension includes pharmacological and nonpharmacological interventions. Among the nonpharmacological interventions emphasizes the practice of regular physical exercise. However, the effects of aerobic exercise training on cardiovascular and metabolic parameters in elderly hypertensive women are still controversial. OBJECTIVES: The purpose of this study was to assess the effects of a walking program on metabolic and cardiovascular parameters at rest and during the recovery period following maximal exercise by hypertensive elderly women. METHODS: Twelve elderly women with hypertension started a 2-week walking program. Rest blood cholesterol and anthropometric data, as well as blood pressure and heart rate at rest and after progressive maximal exercise were measured before and after training. RESULTS: There were significant differences between the pre- and posttraining periods in VO(2)max, systolic blood pressure, diastolic blood pressure, and mean blood pressure. There were no changes in serum cholesterol levels after the training. During the recovery period following the progressive test, the fall in heart rate and mean blood pressure after 10 minutes of recovery was significantly higher after training. CONCLUSION: The proposed walking program did not alter serum cholesterol, but it did reduce resting blood pressure, improve aerobic performance and accelerate the fall in heart rate and mean blood pressure during the postprogressive maximal aerobic exercise recovery period in elderly hypertensive women.

The effects of passive warm-up vs. whole-body vibration on high-intensity performance during sprint cycle exercise.

The purpose of this study was to compare the effects of passive warm-up (PW), whole-body vibration (WBV), and control (C) on high-intensity performance during sprint cycle exercise. Six recreationally trained men performed a 30-second sprint cycle test after the 3 aforementioned conditions; each test was carried out on a different day after balanced-order experimental tests. The WBV consisted of 5 minutes of squats associated with WBV (45 Hz, 2 mm). The PW consisted of 30 minutes of PW using a thermal blanket on the thighs and legs (35 W). The C consisted of 30 minutes of no warm-up with the subject lying down. Motor neuron excitability from the vastus lateralis muscle, evaluated by electromyography (EMG), was determined before exercise at rest and during sprint cycle exercise. Blood lactate levels (BLs), evaluated by spectroscopy, and muscle temperature (MT) of the thigh, estimated indirectly by measuring skin temperature, were determined at following time points: before exercise at rest (before and after experimental conditions), immediately, and 3 minutes after the 30-second sprint cycle test. Peak power, relative power, relative work, time of peak power, and pedaling cadence were significantly higher in the WBV compared with that for C (p < 0.05). Although MT was significantly greater in PW compared with that in WBV and C before exercise (p < 0.01), no significant differences were observed between the experimental conditions for BL immediately after sprint cycle exercise (p = 0.35) and in EMG during sprint cycle exercise (p = 0.16). Thus, it is plausible to suggest WBV as a method for an acute increase in high-intensity performance during sprint cycle exercise for athletes immediately before competition or training.

Effectiveness of aquatic and non-aquatic lower limb muscle endurance training in the static and dynamic balance of elderly people.

BACKGROUND: Aging compromises the ability of the central nervous system to maintain body balance and reduces the capacity for adaptive reactions. To prevent falls, the reception conditions for sensory information need to be improved. OBJECTIVES: To evaluate the impact of a structured aquatic and a non-aquatic exercise program for lower-limb muscle endurance on the static and dynamic balance of elderly people. METHODS: This was a prospective randomized clinical study in which the variables were assessed before and after the training program. Thirty-six elderly people were evaluated using four tests: the Berg Balance Scale, Dynamic Gait Index, gait speed and tandem gait. The participants were randomized into three groups: aquatic exercise group, non-aquatic exercise group and control group. The exercise groups underwent a program for lower-limb muscle endurance that consisted of 40-minute sessions twice a week for six weeks. The participants were reevaluated after six weeks. The data were analyzed statistically using the univariate ANOVA test for comparisons between the groups before and after the intervention. RESULTS: The program for lower-limb muscle endurance significantly increased balance (p<0.05) in the evaluation tests after the training program. CONCLUSION: The muscle endurance program provided a significant improvement in static and dynamic balance among community-dwelling elderly people. It was also possible to infer that this improvement occurred regardless of the environment, i.e. aquatic or non-aquatic. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number ACTRN 12609000780257.

Efetividade do treinamento de resistência à fadiga dos músculos dos membros inferiores dentro e fora d'água no equilíbrio estático e dinâmico de idosos / Effectiveness of aquatic and non-aquatic lower limb muscle endurance training in the static and dynamic balance of elderly people

CONTEXTUALIZAÇÃO: O envelhecimento compromete a habilidade do sistema nervoso central (SNC) de realizar a manutenção do equilíbrio corporal bem como diminui a capacidade das reações adaptativas. Para prevenir as quedas, é necessário aprimorar as condições de recepção de informações sensoriais. OBJETIVOS: Comparar o impacto de um programa estruturado de exercícios de resistência muscular dos membros inferiores dentro e fora d'água no equilíbrio estático e dinâmico em idosos. MÉTODOS: Trata-se de um estudo clínico, prospectivo, aleatório, em que as variáveis utilizadas foram avaliadas antes e após o programa de treinamento. Foram avaliados 36 idosos por meio de quatro testes: Escala de Equilíbrio de Berg, Dynamic Gait Index, velocidade da marcha, Marcha Tandem. Posteriormente, houve a alocação dos voluntários em três grupos: grupo de exercício na piscina terapêutica, grupo de exercício no solo e grupo controle. Os grupos de exercícios foram submetidos a um programa de resistência muscular dos membros inferiores aplicado durante seis semanas, duas sessões semanais com 40 minutos de duração. Os voluntários foram reavaliados após seis semanas. Os dados foram analisados estatisticamente pelo teste ANOVA univariada para comparação entre os três grupos antes e após a intervenção. RESULTADOS: O programa de resistência muscular dos membros inferiores promoveu aumento significativo do equilíbrio dos idosos (p<0,05) nos testes avaliados após o programa de treinamento. CONCLUSÃO: O programa de resistência muscular proporcionou uma melhora significativa no equilíbrio estático e dinâmico de idosos comunitários. Foi possível inferir também que essa melhora ocorreu independentemente do meio em que o programa foi realizado, ou seja, se dentro ou fora d'água.

BACKGROUND: Aging compromises the ability of the central nervous system to maintain body balance and reduces the capacity for adaptive reactions. To prevent falls, the reception conditions for sensory information need to be improved. OBJECTIVES: To evaluate the impact of a structured aquatic and a non-aquatic exercise program for lower-limb muscle endurance on the static and dynamic balance of elderly people. METHODS: This was a prospective randomized clinical study in which the variables were assessed before and after the training program. Thirty-six elderly people were evaluated using four tests: the Berg Balance Scale, Dynamic Gait Index, gait speed and tandem gait. The participants were randomized into three groups: aquatic exercise group, non-aquatic exercise group and control group. The exercise groups underwent a program for lower-limb muscle endurance that consisted of 40-minute sessions twice a week for six weeks. The participants were reevaluated after six weeks. The data were analyzed statistically using the univariate ANOVA test for comparisons between the groups before and after the intervention. RESULTS: The program for lower-limb muscle endurance significantly increased balance (p<0.05) in the evaluation tests after the training program. CONCLUSION: The muscle endurance program provided a significant improvement in static and dynamic balance among community-dwelling elderly people. It was also possible to infer that this improvement occurred regardless of the environment, i.e. aquatic or non-aquatic.