Association between physical activity measured by accelerometry and cognitive function in older adults: a systematic review.

OBJECTIVE: To analyze studies that investigated the association between physical activity assessed by accelerometry and cognitive function in older people. METHODS: A systematic review was carried out in four electronic databases (PubMed, Web of Science, Scopus, and SportsDiscus). RESULTS: In total, 195 records were identified. Fifty-two studies were selected for a full evaluation; 23 were selected according to the inclusion criteria adopted and divided into four chapters (characteristics of the studies, the association between physical activity level and cognitive function decline, effects of physical activity in reducing the chances of cognitive function decline and effects of physical activity on brain plasticity. The cross-sectional studies had an average score of 7 points, and the cohort studies obtained 10 points, indicating the high quality of the selected studies. Seven studies indicated an association between Moderate to vigorous physical activities (MVPA) and cognitive function, two specifically indicated a reduction in the chances of cognitive function decline according to the interquartile of MVPA, and three studies indicated improvements in MVPA in brain plasticity. CONCLUSION: Measured by accelerometry, seems to be favorably associated with important outcomes in cognitive function assessed through questionnaires, imaging analyses, and biochemical markers with older adults.

Low-Level Photobiomodulation Therapy Modulates H2O2 Production, TRPC-6, and PGC-1α Levels in the Dystrophic Muscle.

Objective: This study evaluated photobiomodulation therapy (PBMT) effects on the factors involved in mitochondrial biogenesis, on the mitochondrial respiratory complexes, and on the transient receptor potential canonical channels (such as TRPC-1 and TRPC-6) in in vitro (mdx muscle cells) and in vivo studies (gastrocnemius muscle) from mdx mice, the dystrophin-deficient model of Duchenne muscular dystrophy (DMD). Background: There is no successful treatment for DMD, therefore demanding search for new therapies that can improve the muscle role, the quality of life, and the survival of dystrophic patients. Methods: The dystrophic primary muscle cells received PBMT at 0.6 J and 5 J, and the dystrophic gastrocnemius muscle received PBMT at 0.6 J. Results: The dystrophic muscle cells treated with PBMT (0.6 J and 5 J) showed no cytotoxicity and significantly lower levels in hydrogen peroxide (H2O2) production. We also demonstrated, for the first time, the capacity of PBMT, at a low dose (0.6 J), in reducing the TRPC-6 content and in raising the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) content in the dystrophic gastrocnemius muscle. Conclusions: PBMT modulates H2O2 production, TRPC-6, and PGC-1α content in the dystrophic muscle. These results suggest that laser therapy could act as an auxiliary therapy in the treatment of dystrophic patients.

Effectiveness of electrotherapy for the treatment of orofacial pain: A systematic review and meta-analysis.

OBJECTIVE: Summarize the evidence from randomized controlled trials and controlled trials that examined the effectiveness of electrotherapy in the treatment of patients with orofacial pain. DATA SOURCE: Medline, Embase, CINAHL PLUS with Full text, Cochrane Library Trials, Web of Science, and Scopus. REVIEW METHODS: A data search (last update, July 1, 2022) and a manual search were performed (October 5, 2022). Trials involving adults with orofacial pain receiving electrotherapy compared with any other type of treatment were included. The main outcome was pain intensity; secondary outcomes were mouth opening and tenderness. The reporting was based on the new PRISMA Guidelines. RESULTS: From the electronics databases and manual search 43 studies were included. Although this study was open to including any type of orofacial pain, only studies that investigated temporomandibular disorders were found. The overall quality of the evidence for pain intensity was very low. Although the results should be carefully used, transcutaneous electric nerve stimulation therapy showed to be clinically superior to placebo for reducing pain after treatment (2.63 [-0.48; 5.74]) and at follow-up (0.96 [-0.02; 1.95]) and reduce tenderness after treatment (1.99 [-0.33; 4.32]) and at follow-up (2.43 [-0.24; 5.10]) in subjects with mixed temporomandibular disorders. CONCLUSION: The results of this systematic review support the use of transcutaneous electric nerve stimulation therapy for patients with mixed temporomandibular disorders to improve pain intensity, and tenderness demonstrating that transcutaneous electric nerve stimulation is superior to placebo. There is inconsistent evidence supporting the superiority of transcutaneous electric nerve stimulation against other therapies.

Strength of scapular elevation in women with TMD and asymptomatic women - a cross-sectional study

Temporomandibular disorder (TMD) is recognized for its high prevalence, presenting characteristic signs and symptoms. Cervical spine pain is present in 70% of diagnosed TMD cases. Aim To verify if women with TMD present changes in isometric muscle strength in the scapula elevation. Methods This is an observational, cross-sectional study. Thirty-five women, aged 22.89±2.04 years, were divided into the TMD group (TMDG), diagnosed with TMD according to the DC/TMD, and control group (CG), with asymptomatic individuals. The volunteers accessed a online link by the smartphone in order to answer questions on personal data, the Fonseca Anamnestic Index (FAI), Neck Disability Index (NDI), and Masticatory preference. In all participants, evaluation of the force of the scapula elevation muscles was performed, using a load cell model MM-100 (Kratos® SP, Brazil). Data were analyzed descriptively using the maximum, mean, and standard deviation and a two-way ANCOVA test was applied for all variables. A significance level of 5% was considered. Results There were no statistically significant differences between the TMDG and CG for the maximal and mean muscle strength of scapular elevation. There were statistically significant differences in FAI (p <0.001*) between the CG and the TMDG. Conclusion Based on the results, it was not possible to confirm the hypothesis that women diagnosed with TMD present lower isometric strength during scapular elevation (right/left).

The effect of physical activity on total homocysteine concentrations and cardiovascular risk in older Brazilian adults with type 2 diabetes.

A low level of physical activity has a potential association with high levels of homocysteine, which implies an increased chance of older adults with type 2 diabetes mellitus developing cardiovascular disease (CVD). However, the effects of physical activity on homocysteine levels have been poorly explored in the literature. Therefore, this study compared homocysteine levels and cardiovascular risk among physically active and inactive older women with type 2 diabetes mellitus. Fifty-nine women with type 2 diabetes mellitus, between 60 and 91 years old, were evaluated. The level of physical activity was assessed using the International Physical Activity Questionnaire (IPAQ) long version to identify active and inactive older women. Blood samples were collected and anthropometric, body composition, and blood pressure measurements were performed to determine homocysteine levels and cardiovascular risk. The results demonstrated that active older women with type 2 diabetes mellitus have lower homocysteine values (F = 17.79, p < 0.001, ηp2 = 0.238), cardiovascular risk scores (F = 15.84, p = p < 0.001, ηp2 = 0.217), and waist circumferences (F = 2.95, p = 0.013, ηp2 = 0.049) when compared with inactive older women. It was concluded that there was a difference in the levels of homocysteine, cardiovascular risk, and waist circumference between active and inactive older women with type 2 diabetes. Active older women are less likely to have cardiovascular risk than inactive older women.

Photobiomodulation Therapy for Attenuating the Dystrophic Phenotype of Mdx Mice.

This study analyzed photobiomodulation therapy (PBMT) effects on regenerative, antioxidative, anti-inflammatory and angiogenic markers in the dystrophic skeletal muscle of mdx mice, the experimental model of Duchenne muscular dystrophy (DMD), during the acute phase of dystrophy disease. The following groups were set up: Ctrl (control group of normal wild-type mice; C57BL/10); mdx (untreated mdx mice); mdxPred (mdx mice treated with prednisolone) and mdxLA (mdx mice treated with PBMT). The PBMT was carried out using an Aluminum Gallium Arsenide (AIGaAs; IBRAMED® laserpulse) diode, 830 nm wavelength, applied on the dystrophic quadriceps muscle. The mdxLA group showed a degenerative and regenerative area reduction simultaneously with a MyoD level increase, ROS production and inflammatory marker reduction and up-regulation in the VEGF factor. In addition, PBMT presented similar effects to prednisolone treatment in most of the parameters analyzed. In conclusion, our results indicate that PBMT in the parameters selected attenuated the dystrophic phenotype of mdx mice, improving skeletal muscle regeneration; reducing the oxidative stress and inflammatory process; and up-regulating the angiogenic marker.

Effects of Creatine Supplementation on Renal Function: A Systematic Review and Meta-Analysis.

Creatine supplements are intended to improve performance, but there are indications that it can overwhelm liver and kidney functions, reduce the quality of life, and increase mortality. Therefore, this is the first systematic review and meta-analysis study that aimed to investigate creatine supplements and their possible renal function side effects. After evaluating 290 non-duplicated studies, 15 were included in the qualitative analysis and 6 in the quantitative analysis. The results of the meta-analysis suggest that creatine supplementation did not significantly alter serum creatinine levels (standardized mean difference = 0.48, 95% confidence interval 0.24-0.73, P = .001, I2 = 22%), and did not alter plasma urea values (standardized mean difference = 1.10, 95% confidence interval 0.34-1.85, P = .004, I2 = 28%). The findings indicate that creatine supplementation does not induce renal damage in the studied amounts and durations.

Translation of the short version of the Smartphone Addiction Scale into Brazilian Portuguese: cross-cultural adaptation and testing of measurement properties.

BACKGROUND: Smartphone use has been constantly increasing. Smartphone addiction can lead to changes in the emotional state and musculoskeletal system of users. To identify smartphone addicts, the Smartphone Addiction Scale-Short Version was developed; however, this scale has not been translated into Brazilian Portuguese and tested for its measurement properties. OBJECTIVE: To translate and cross-culturally adapt the Smartphone Addiction Scale-Short Version into Brazilian Portuguese; to assess the internal consistency, reliability and construct validity of the scale among university students. METHODS: The cross-cultural adaptation was performed following the guidelines for cross-cultural adaptation of self-report measures, and data were collected via online surveys administered to 59 university students over 18 years of age for test-retest. To test the measurement properties of the final version of the Smartphone Addiction Scale-Short Version, a convenience sample including 130 university students was used. RESULTS: The Smartphone Addiction Scale-Short Version showed good reliability for test-retest scores (ICC3,1=0.82; 95% CI=0.70-0.89) and good internal consistency considering all 10 items (Cronbach's alpha=0.95). The construct validity was calculated comparing the Smartphone Addiction Scale-Short Version score to data from a questionnaire prepared by the authors of this study, including frequency per day (r=0.35; p<0.001), leisure time on the smartphone (r=0.33; p<0.001), and time working on the smartphone (r=0.18; p=0.04) that were significantly positively associated with higher Smartphone Addiction Scale-Short Version scores. The results show a high prevalence of smartphone addiction among university students (33.1%). CONCLUSION: It can be concluded that the Brazilian Portuguese version of the Smartphone Addiction Scale-Short Version is a reliable and valid tool for screening smartphone addiction in university students.

Avaliações funcionais e morfométrica de modelo de lesão muscular por agulha de biópsia em gastrocnêmio de ratos / Functional and morphometric evaluations of model of muscle lesion with biopsy needle in gastrocnemius of rats

Introdução: Dentre os modelos experimentais, o uso de agulha de biópsia mostrou ser eficaz para reproduzir as lesões em atletas. Objetivo: Avaliar a força de preensão, a nocicepção e as alterações morfológicas do músculo gastrocnêmio de animais submetidos à lesão muscular. Métodos: Foram utilizados seis ratos Wistar. A lesão foi realizada na junção miotendínea do músculo gastrocnêmio direito, utilizando agulha de biópsia. Para avaliação funcional utilizou-se o teste de força de preensão e avaliação nociceptiva em três momentos: 24 horas antes da lesão (AV1); no segundo dia pós-lesão (AV2) e no sexto dia pós-lesão (AV3). Ao final do experimento o músculo foi retirado para análise morfológica. Resultados: Houve redução da força de preensão entre AV1 e AV2 (p=0,0031). Para a nocicepção os valores de AV2 (p<0,001) e AV3 (p=0,0109) foram maiores que AV1. Na região das fibras musculares observou-se desarranjo do padrão fascicular, aumento do calibre de vasos sanguíneos, da quantidade de tecido conjuntivo, de fibroblastos e de células inflamatórias. Conclusão: A lesão muscular por agulha de biópsia provocou redução da força de preensão e da nocicepção do membro lesado, como também evidenciou as etapas características do processo de degeneração muscular e início do processo de regeneração.

Introduction: Among the experimental models, the use of a biopsy needle was shown to be effective to reproduce lesions that occur with athletes. Objective: To evaluate the grip strength, nociception and morphological alterations of the gastrocnemius muscle of animals submitted to muscle injury. Methods: Six Wistar rats were used. The lesion was performed at the myotendinous junction of the right gastrocnemius muscle using a biopsy needle. For functional evaluation, the grip strength test and nociceptive evaluation were used at three moments: 24 hours before the injury (AV1); on the second postoperative day (AV2) and on the sixth postoperative day (AV3). At the end of the experiment the muscle was removed for morphological analysis. Results: There was a reduction in grip strength between AV1 and AV2 (p = 0.0031). For the nociception the values of AV2 (p < 0.001) and AV3 (p = 0.0109) were higher than AV1. In the muscle fibers region, there was disarrangement of the fascicular pattern, increased blood vessel size, the amount of connective tissue, fibroblasts and inflammatory cells. Conclusion: Muscle lesion by biopsy needle caused reduction of grip strength and nociception of the damaged limb, as well as the characteristic stages of the muscular degeneration process and the beginning of the regeneration process.

High-fat diet suppresses the positive effect of creatine supplementation on skeletal muscle function by reducing protein expression of IGF-PI3K-AKT-mTOR pathway.

High-fat (HF) diets in combination with sedentary lifestyle represent one of the major public health concerns predisposing to obesity and diabetes leading to skeletal muscle atrophy, decreased fiber diameter and muscle mass with accumulation of fat tissue resulting in loss of muscle strength. One strategy to overcome the maleficent effects of HF diet is resistance training, a strategy used to improve muscle mass, reverting the negative effects on obesity-related changes in skeletal muscle. Together with resistance training, supplementation with creatine monohydrate (CrM) in the diet has been used to improve muscle mass and strength. Creatine is a non-essential amino acid that is directly involved in the cross-bridge cycle providing a phosphate group to ADP during the initiation of muscle contraction. Besides its antioxidant and anti-inflammatory effects CrM also upregulates IGF-1 resulting in hyperthophy with an increase in muscle function. However, it is unknown whether CrM supplementation during resistance training would revert the negative effects of high-fat diet on the muscle performance. During 8 weeks we measured muscle performance to climb a 1.1m and 80° ladder with increasing load on trained rats that had received standard diet or high-fat diet, supplemented or not with CrM. We observed that the CrM supplementation up-regulated IGF-1 and phospho-AKT protein levels, suggesting an activation of the IGF1-PI3K-Akt/PKB-mTOR pathway. Moreover, despite the CrM supplementation, HF diet down-regulated several proteins of the IGF1-PI3K-Akt/PKB-mTOR pathway, suggesting that diet lipid content is crucial to maintain or improve muscle function during resistance training.

Laser de baixa intensidade favorece a regeneração muscular em modelo experimental desnutrido e recuperado / Láser de baja intensidad favorece la regeneración muscular en modelo experimental desnutrido y recuperado / Low-intensity laser favors muscle regeneration in a malnourished and recovered experimental model

RESUMO A terapia por laser de baixa intensidade (Low-Level Laser Therapy - LLLT) é utilizada com frequência nas lesões musculares, mas precisa ser investigada em modelo de desnutrição. O objetivo desse estudo foi analisar os efeitos da LLLT na regeneração muscular de ratos submetidos à desnutrição e recuperação proteica. Foram utilizados 40 ratos Wistar, recém-desmamados, divididos em grupo controle (C), que consumiu ração normoproteica (14% caseína), e grupo desnutrido (D), que consumiu ração hipoproteica (6% caseína) por 45 dias e ração normoproteica até o final do experimento. Posteriormente, o músculo tibial anterior direito foi criolesado e tratado com LLLT (AsGaAl 830nm, 30mW, 20J/cm²), três vezes por semana, por 7 e 21 dias. Houve redução da área de inflamação/regeneração no grupo C21 comparado ao D21 (p<0,05), sendo mais evidente com a LLLT (C21L e D21L). O conteúdo de TNF-α foi reduzido após 21 dias da lesão. A área de densidade de tecido conjuntivo (ADTC) foi menor nos grupos C21 e C21L comparados aos respectivos grupos desnutridos (p<0,05). A LLLT reduziu a ADTC no grupo D21L quando comparado do D21 (p<0,05), porém o conteúdo de TGF-β1 não foi influenciado. A área de secção transversa (AST) da fibra muscular aumentou nos grupos 21 dias. A m-TOR apresentou maior conteúdo no grupo C21L quando comparado ao D21L (p<0,05). Concluiu-se que a LLLT favoreceu a regeneração muscular na fase tardia no modelo experimental de desnutrição pós-natal e posterior recuperação proteica.

RESUMEN La terapia por láser de baja intensidad (Low-Level Laser Therapy - LLLT) es utilizada con frecuencia en las lesiones musculares, sin embargo, precisa ser investigada en modelo de desnutrición. El objetivo de ese estudio fue analizar los efectos de la LLLT en la regeneración muscular de ratones sometidos a la desnutrición y a la recuperación proteica. Fueron utilizados 40 ratones Wistar, recién-destetados, divididos en grupo control (C), que consumió ración normoproteica (el 14% caseína), y grupo desnutrido (D), que consumió ración hipoproteica (el 6% caseína) por 45 días y ración normoproteica hasta el final del experimento. Posteriormente, el músculo tibial anterior derecho que tuvo criolesión y fue tratado con LLLT (AsGaAl 830nm, 30mW, 20J/cm²), tres veces a la semana, por 7 y 21 días. Hubo reducción del área de inflamación/regeneración en el grupo C21 comparado al D21 (p<0,05), siendo más evidente con la LLLT (C21L y D21L). El contenido de TNF-α fue reducido después de 21 días de la lesión. El área de densidad de tejido conjuntivo (ADTC) fue más pequeña en los grupos C21 y C21L comparados a los respectivos grupos desnutridos (p<0,05). La LLLT redujo la ADTC en el grupo D21L cuando comparado del D21 (p<0,05), sin embargo, el contenido de TGF-β1 no fue influenciado. El área de sección transversa (AST) de la fibra muscular incrementó en los grupos 21 días. La m-TOR presentó contenido más grande en el grupo C21L cuando comparado al D21L (p<0,05). Se concluyó que la LLLT favoreció la regeneración muscular en la etapa tardía en el modelo experimental de desnutrición posnatal y posterior recuperación proteica.

ABSTRACT Low-Level Laser Therapy - LLLT is used frequently on muscle lesions, but needs to be investigated in a malnutrition model. The aim of this study was to analyze the effects of LLLT on muscle regeneration of rats subjected to malnutrition and protein recovery. Forty recently weaned Wistar rats were used, divided into control group (C), subjected to a normal-protein diet (14% casein), and the malnourished group (D), subjected to a low-protein diet (6% casein) for 45 days and to a normal-protein diet until the end of the experiment. Subsequently, the right tibialis anterior muscle was subjected to cryogenic cooling and treated with LLLT (830 nm AsGaAl, 30 mW, 20 J/cm²), three times a week, for 7 and 21 days. There was a reduction of the inflammation/regeneration area in the C21 group compared to D21 (p<0.05), which became more evident with the LLLT (C21L and D21L). The TNF-α contents were reduced after 21 days of the injury. The connective tissue density area (CTDA) was lower in the C21 and C21L groups compared to the respective malnourished groups (p<0.05). LLLT reduced the CTDA in group D21L in comparison to D21 (p<0.05), but the TGF-β1 contents were not influenced. The cross-sectional area (CSA) of the muscle fiber increased in the 21-day groups. Higher levels of m-TOR were found in the C21L group when compared to D21L (p<0.05). It was concluded that LLLT favored muscle regeneration in the late stage of the experimental model of postnatal malnutrition and subsequent protein recovery.

Comportamento social em ratos recuperados após desnutrição proteica: análise comparativa entre machos e fêmeas / Social behavior in rats recovered from protein malnutrition: comparative analysis between males and females

A maturação do sistema nervoso central depende, entre outros fatores, da ingestão adequada de nutrientes. Períodos de desnutrição podem afetar seu desenvolvimento, comprometendo a capacidade cognitiva. O objetivo do trabalho foi avaliar o comportamento social de ratos e ratas Wistar alimentados com dieta hipoproteica e posteriormente recuperados com dieta normoproteica. Foram utilizados ratos Wistar (machos e fêmeas) divididos em dois grupos: Controle (C), alimentado com dieta normoproteica (AIN 14% de proteína) durante 12 semanas e Recuperado (R), desnutrido com dieta hipoproteica (AIN 6% de proteína) por 6 semanas e posteriormente alimentado com dieta normoproteica da 7ª a 12ª semanas. A massa corporal foi verificada semanalmente e após o período experimental os animais foram submetidos aos testes de labirinto em cruz elevado e reconhecimento social. Foram avaliados os parâmetros sensoriais utilizados pelos ratos no reconhecimento de seus pares no lócus de convívio. Utilizou-se o paradigma intruso-residente na análise, sendo observado que a dieta hipoproteica comprometeu o ganho de massa corporal em machos e fêmeas, como também foi verificado redução na capacidade de reconhecer seus pares, após exposição consecutiva de curta duração, e ainda, houve uma intensa manifestação de agressividade nos machos do grupo recuperado, fato que não foi observado pelas fêmeas indicando que a intensidade de comprometimento no sistema nervoso central, gerado pela desnutrição pode ter relação com o dimorfismo sexual. (AU)

The maturation of the central nervous system depends, among other factors, proper intake of nutrients. Periods of malnutrition can affect your development, undermining the cognitive ability. The objective of this work was to evaluate the social behavior of mice and Wistar rats fed with hipoproteica diet and later recovered with present diet. Wistar rats were used (males and females) divided into two groups: control (C), fed up with the present diet (AIN 14% protein) for 12 weeks and recovered (R), malnourished with diet hipoproteica (AIN 6% protein) for 6 weeks and subsequently fed with the present diet of 7th to 12th weeks. Body mass was checked weekly and after the trial period the animals were subjected to the tests of high cross maze and social recognition. We evaluated the sensory parameters used by rats in the recognition of his peers in locus. The intruder-resident paradigm in the analysis, being observed that diet hipoproteica undertook the weight gain in males and females and verified reduction in ability to recognize their peers, after successive exposure of short duration, and yet, there was an intense manifestation of aggression in males of the group recovered, a fact that was not observed for females, indicating that the intensity of commitment in the central nervous system, generated by malnutrition may be related to sexual dimorphism. (AU)

Effects of beta-hydroxy-beta-methyl butyrate in muscle regeneration of rats / Efeitos do beta-hidroxi-beta-metil-butirato na regeneração muscular de ratos / Efectos de beta-hidroxi-beta-metilbutirato en la regeneración muscular de ratas

ABSTRACT Introduction: Studies have shown that beta-hydroxy-beta-methyl butyrate (HMB) supplementation increases muscle strength and mass. Objective: To evaluate the effect of HMB supplementation on the muscle regeneration process in young and sedentary rats. Methods: Twenty-four male Wistar rats two months old were divided into two groups: lesion (LE) and supplemented (S), and evaluated in two moments - seven days (LE7; S7, n=6) and 21 days (LE21; S21, n=6). The right tibialis anterior muscle was subjected to cryolesion in all animals. After the injury, the LE group remained in the vivarium without any intervention. Group S received HMB calcium supplementation diluted in water by gavage (320 mg/kg/weight per day). The injury tibialis anterior (ITA), the tibialis anterior (TA), and the left soleus (SOL) muscles were removed, weighted and divided transversally into two parts, one for the analysis of the cross-sectional area (CSA) and the area of inflammation/regeneration and the other part to measure the muscular glycogen concentration. Data were evaluated using the SAS program considering mean and standard deviation. For analysis of variance the ANOVA test was used followed by the Tukey-HSD test (p≤0.05). Results: The ITA muscle weight was higher in S21 compared to S7 (p<0.05). The groups LE21 and S21 presented greater CSA of muscle fibers area and smaller ITA regeneration/inflammation area (p<0.05) when compared with the LE7 and S7 groups. There was an increase in muscle glycogen levels in S7 group compared to LE7 and S21 groups for TA and SOL (p<0.01), as well as in S21 group compared to LE21 for SOL (p<0.05). Conclusion: HMB did not influence the muscle regeneration process and did not favor anabolic activity in the different muscular fibers of young sedentary rats. Level of Evidence II; Therapeutic studies - Investigation of treatment results.

RESUMO Introdução: Estudos demonstram que a suplementação de beta-hidroxi-beta-metil-butirato (HMB) aumenta a força e a massa muscular. Objetivo: Avaliar o efeito da suplementação com HMB no processo de regeneração muscular em ratos jovens e sedentários. Métodos: Foram utilizados 24 ratos Wistar machos com dois meses de idade, divididos nos grupos lesão (LE) e suplementado (S) e avaliados em dois momentos, em sete dias (LE7; S7, n = 6) e em 21 dias (LE21; S21, n = 6). O músculo tibial anterior direito foi submetido à criolesão em todos os animais. Após a lesão, o grupo LE permaneceu no biotério sem nenhum tipo de intervenção. O grupo S recebeu suplementação de cálcio HMB em pó diluído em água por meio de gavagem (320 mg/kg/peso por dia). Os músculos tibial anterior lesado (TAL), tibial anterior (TA) e sóleo (SOL) esquerdo foram retirados, pesados e divididos transversalmente em duas partes, sendo uma destinada à análise da área de corte transversal (ACT) e da área de inflamação/regeneração e a outra parte para medir a concentração de glicogênio muscular. A avaliação dos dados foi realizada por meio do programa SAS, considerando média e desvio padrão. Para análise de variância usou-se o teste ANOVA, seguido do teste de Tukey-HSD (p ≤ 0,05). Resultados: O peso do músculo TAL foi maior no S21 em comparação com o S7 (p < 0,05). Os grupos LE21 e S21 apresentaram maior ACT de fibras musculares e menor área de regeneração/inflamação do TAL (p < 0,05), quando comparados com os grupos LE7 e S7. Observou-se aumento nos níveis de glicogênio muscular no grupo S7 com relação a LE7 e S21 para TAE e SOL (p < 0,01), assim como no grupo S21 em comparação com LE21 no SOL (p < 0,05). Conclusão: O HMB não influenciou o processo de regeneração muscular e não favoreceu a atividade anabólica nos diferentes tipos de fibras musculares de ratos jovens e sedentários. Nível de Evidência II, Estudos terapêuticos - Investigação dos resultados do tratamento.

RESUMEN Introducción: Los estudios han demostrado que el beta-hidroxi-beta-metilbutirato (HMB) suplementario aumenta la fuerza y la masa muscular. Objetivo: Evaluar el efecto del HMB suplementario en el proceso de regeneración muscular en ratas jóvenes y sedentarias. Métodos: Se utilizaron 24 ratas Wistar machos con dos meses de edad, divididas en los grupos lesión (LE) y suplementario (S) y evaluados en dos momentos, en siete días (LE7; S7, n = 6) y en 21 días (LE21; S21, n = 6). El músculo tibial anterior derecho fue sometido a la criolesión en todos los animales. Después de la lesión, el grupo LE se mantuvo en el vivero sin ninguna intervención. El grupo S recibió calcio HMB suplementario diluido en agua por medio de alimentación forzada (320 mg/kg/peso al día). Los músculos tibial anterior lesión (TAL), tibial anterior (TA) y sóleo (SOL) izquierdo fueron retirados, pesados y divididos transversalmente en dos partes, siendo una destinada al análisis del área de corte transversal (ACT) y del área de inflamación/regeneración y otra parte para medir la concentración de glucógeno muscular. La evaluación de los datos se realizó a través del programa SAS, considerando media y desviación estándar. Para el análisis de varianza se utilizó la prueba ANOVA, seguida de la prueba de Tukey-HSD (p ≤ 0,05). Resultados: El peso del músculo TAL fue mayor en el grupo S21 en comparación con el S7 (p < 0,05). Los grupos LE21 y S21 tuvieron mayor ACT de fibras musculares y menor área de regeneración/inflamación del TAL (p < 0,05) en comparación con los grupos LE7 y S7. Se observó un aumento en los niveles de glucógeno muscular en el grupo S7 con relación a LE7 y S21 para TA y SOL (p < 0,01), así como en el grupo S21 en comparación con LE21 en el SOL (p < 0,05). Conclusión: HMB no influyó el proceso de regeneración muscular y no favoreció la actividad anabólica en los diferentes tipos de fibras musculares de ratas jóvenes y sedentarias. Nivel de Evidencia II, Estudios terapéuticos - Investigación de los resultados del tratamiento.

Treinamento de força/sobrecarga mecânica e sinalização do complexo 1 do alvo da rapamicina em mamíferos na hipertrofia muscular em diferentes modelos experimentais: revisão sistemátic / Resistance training/mechanical overload and mammalian target of rapamycin complex 1 signaling on muscle hypertrophy in different experimental

O objetivo deste artigo de revisão sistemática foi apresentar o envolvimento da sinalização de aminoácidos e mecanotransdução na ativação do alvo mamífero de rapamicina do complexo 1 (mTORC1) na musculatura esquelética de animais e a expressão e papel do mTORC1 em humanos submetidos ao treinamento de força/estímulo mecânico. Foi realizada uma busca na base de dados PubMed com as seguintes palavras-chave: mTORC1, mammalian target of rapamycin complex 1, resistance exercise, strength training, mechanical overload e skeletal muscle hypertrophy, amino acid sensing transporter e mechanotransduction. Evidências demonstram que a ativação do mTORC1 possui correlação positiva com a hipertrofia muscular induzida pelo treinamento de força/estímulo mecânico. O mTORC1 integra diversos sinais oriundos de aminoácidos (sinalização de transportadores e sensores) e estímulo mecânico/treinamento de força (mecanotransdução). Ademais, o emprego de modelos de camundongos mutantes, abordagens genéticas, farmacológicas, cultura de células, modelos experimentais de treinamento de força para animais, assim como estudos com humanos, vêm possibilitando a elucidação destes mecanismos moleculares...(AU)

The aim of this systematic review was to provide comprehensive review about mechanotransduction and amino acid signaling in the activation of the mammalian target of rapamycin complex 1 (mTORC1) in animal skeletal muscle and the expression and role of mTORC1 in humans in response to resistance training/mechanical stimulus. PubMed data base was used with the following keywords: mTORC1, mammalian target of rapamycin complex 1, resistance exercise, strength training, mechanical overload and skeletal muscle hypertrophy, amino acid sensing transporter and mechanotransduction. Evidence demonstrates that the activation of the mechanistic target of rapamycin complex 1 (mTORC1) is correlated positively with skeletal muscle hypertrophy induced by resistance training/mechanical stimulus. mTORC1 integrates a myriad of signals coming from amino acids (transporter and sensing mechanisms) and mechanical stimulus/resistance training (mechanotransduction). Moreover, the utilization of mutant mice models, genetic, cell culture and pharmacological tools, experimental resistance exercise rodent models, as well as human studies have been elucidating these molecular mechanisms...(AU)

Prior swimming exercise favors muscle recovery in adult female rats after joint immobilization.

[Purpose] To evaluate the efficacy of pre-exercise on immobilization and subsequent recovery of white gastrocnemius (WG) and soleus (SOL) muscles of female rats. [Subjects and Methods] Thirty, 8-month-old, female Wistar rats were randomly and evenly allocated to six groups: sedentary (S); immobilized sedentary (IS); immobilized/rehabilitated sedentary (IRS); trained (T); immobilized trained (IT); and immobilized/rehabilitated trained (IRT). For four months, T, IT and IRT group animals performed swimming exercise (three sessions per week, 60 minutes per session), while S, IS and IRS groups animals remained housed in cages. After this period, the left hindlimb of the animals from the IS, IRS, IT and IRT groups was immobilized for five days, with the ankle at 90°. After removal of the orthosis, animals from the IRS and IRT groups followed a rehabilitation program based on swimming (five sessions per week, 60 minutes per session) for two weeks. [Results] Immobilization significantly reduced the cross-sectional area of the white gastrocnemius muscle; no changes were observed in the soleus muscles of the trained animals. Transforming growth factor-ß1 protein levels were similar among the trained groups. [Conclusion] Prior swimming prevents hypotrophy of the soleus muscle after immobilization, and protein levels reflected the adaptive capacity of the skeletal muscle.

Treinamento aquático em longo prazo desencadeia alterações elétricas positivas e outros parâmetros em ratas adultas / El entrenamiento acuático en largo plazo produce alteraciones eléctricas positivas y otros parámetros en ratas adultas / Long-term aquatic training triggers positive electrical alterations and other parameters in adult female rats

RESUMO A proposta deste estudo foi avaliar as alterações elétricas cardíacas e os efeitos sobre a massa corporal, consumo hídrico e alimentar, além do peso relativo de órgãos de ratas adultas submetidas a um treinamento de natação em longo prazo. Utilizou-se ratas Wistar adultas, saudáveis e dividas em grupos de n=10, sendo S (sedentárias) e TR (treinadas), que realizaram treinamento aquático de sessenta minutos, três vezes na semana, por 16 semanas. Foram avaliados o peso corporal (P), o consumo hídrico e alimentar, a frequência cardíaca (FC), ângulo do miocárdio (SÂQRS), os intervalos QRS, QTc e PR e o peso relativo dos glândulas adrenais, coração, baço e rins. Para análise estatística, utilizou-se o pacote estatístico SPSS versão 17.0; a distribuição dos dados foi verificada pelo teste de normalidade Kolmogorov-Smirnov. Para os dados com distribuição paramétrica, foi utilizado o teste T de Student, para amostras independentes, e aos dados com distribuição não paramétrica, foi aplicado o teste Mann-Whitney (p<0,05). As ratas do grupo TR apresentaram maior consumo hídrico e alimentar, entretanto, a massa corporal foi semelhante entre os grupos TR e S. O grupo TR apresentou alterações elétricas na FC, ângulo do miocárdio (SÂQRS), onda S e T, demonstrando significativa bradicardia em repouso e possível hipertrofia cardíaca, além da diferença encontrada no peso relativo do baço e dos rins. O protocolo de treinamento utilizado para as ratas adultas favoreceu as alterações elétricas positivas do coração, resultando em bradicardia durante repouso e melhora no condicionamento cardiovascular.

RESUMEN Este estudio tuvo el propósito de evaluar las alteraciones eléctricas cardíacas y los resultados sobre la masa corporal, consumo de agua y alimentos, además del peso relacionado a los órganos de las ratas adultas sometidas a un entrenamiento de natación en largo plazo. Se utilizó de ratas Wistar, adultas, saludables, divididas en grupos de n=10, siendo S (sedentarias) y E (entrenadas), las que realizaron el entrenamiento acuático de 60 minutos, tres veces por semana, durante 16 semanas. Se evaluaron el peso corporal (P), el consumo de agua y alimentos, la frecuencia cardiaca (FC), el ángulo del miocardio (SAQRS), los intervalos QRS, QTc y PR y el peso relacionado a las glándulas adrenales, al corazón, al bazo y a los riñones. En el análisis estadístico se empleó el sistema estadístico SPSS versión 17.0; se evaluó la distribución de los datos a través del test de normalidad Kolmogorov-Smirnov. En los datos con distribución paramétrica se empleó el test t Student, en las muestras independientes y en los datos con distribución no paramétrica se aplicó el test Mann-Whitney (p<0,05). Las ratas del grupo E presentaron un mayor consumo de agua y de alimentos, no obstante, la masa corporal fue semejante entre los grupos E y S. El grupo E presentó alteraciones eléctricas en la FC, en el ángulo del miocardio (SAQRS), ondas S y T, lo que muestra una bradicardia en reposo y una posible hipertrofia cardiaca, además de la diferencia encontrada en el peso del bazo y de los riñones. El protocolo de entrenamiento empleado en las ratas adultas les favoreció las alteraciones eléctricas positivas del corazón, resultando en bradicardia durante reposo y en una mejora de su condición cardiovascular.

ABSTRACT The purpose of this study was to assess cardiac electrical alterations and effects on body weight, water and food consumption, and relative weight of organs of adult female rats submitted to long-term swimming training. We used adult Wistar female rats, healthy, divided into n=10 groups, groups S (sedentary) and TR (trained), which had aquatic training for sixty minutes, three times a week, for 16 weeks. We evaluated body weight (W), water and food consumption, heart rate (HR), myocardial angle (SAQRS), intervals QRS, QTc, and PR, and relative weight of adrenal glands, heart, spleen, and kidneys. For statistical analysis, we used the statistical package "SPSS version 17.0"; data distribution was verified by the Kolmogorov-Smirnov normality test. For data with parametric distribution, we used student's t test for independent samples, while for data with nonparametric distribution we applied Mann-Whitney test (p<0.05). Rats from group TR had higher water and food consumption; however, body weight was similar between groups TR and S. Group TR had electrical alterations in HR, myocardial angle (SAQRS), S and T wave, demonstrating significant bradycardia at rest and possible cardiac hypertrophy, in addition to the difference found for relative weight of spleen and kidney. Training protocol used for adult female rats favored positive electrical changes in the heart, resulting in bradycardia during rest and improvement in cardiovascular fitness.

Low-Level Laser Therapy (LLLT) in Dystrophin-Deficient Muscle Cells: Effects on Regeneration Capacity, Inflammation Response and Oxidative Stress.

The present study evaluated low-level laser therapy (LLLT) effects on some physiological pathways that may lead to muscle damage or regeneration capacity in dystrophin-deficient muscle cells of mdx mice, the experimental model of Duchenne muscular dystrophy (DMD). Primary cultures of mdx skeletal muscle cells were irradiated only one time with laser and analyzed after 24 and 48 hours. The LLLT parameter used was 830 nm wavelengths at 5 J/cm² fluence. The following groups were set up: Ctrl (untreated C57BL/10 primary muscle cells), mdx (untreated mdx primary muscle cells), mdx LA 24 (mdx primary muscle cells - LLLT irradiated and analyzed after 24 h), and mdx LA 48 (mdx primary muscle cells - LLLT irradiated and analyzed after 48 h). The mdx LA 24 and mdx LA 48 groups showed significant increase in cell proliferation, higher diameter in muscle cells and decreased MyoD levels compared to the mdx group. The mdx LA 48 group showed significant increase in Myosin Heavy Chain levels compared to the untreated mdx and mdx LA 24 groups. The mdx LA 24 and mdx LA 48 groups showed significant increase in [Ca2+]i. The mdx group showed significant increase in H2O2 production and 4-HNE levels compared to the Ctrl group and LLLT treatment reduced this increase. GSH levels and GPx, GR and SOD activities increased in the mdx group. Laser treatment reduced the GSH levels and GR and SOD activities in dystrophic muscle cells. The mdx group showed significant increase in the TNF-α and NF-κB levels, which in turn was reduced by the LLLT treatment. Together, these results suggest that the laser treatment improved regenerative capacity and decreased inflammatory response and oxidative stress in dystrophic muscle cells, indicating that LLLT could be a helpful alternative therapy to be associated with other treatment for dystrophinopathies.

Evaluation of muscle regeneration in aged animals after treatment with low-level laser therapy / Avaliação da regeneração muscular em animais idosos após tratamento com laser de baixa intensidade

BACKGROUND: The aging process and its associated morphophysiological changes trigger a reduction in the regenerative ability of the satellite cells, a reduction of vascular tissue and an increase in the production of fibroblasts, developing a cellular environment unfavorable for muscle regeneration. OBJECTIVE: The aim of this study was to evaluate the effect of low-level laser therapy on the muscle regeneration of old experimental rat models after contusion. METHOD: A total of 25 old rats,18 months old, were divided into three groups: control group (CT) without treatment; injury group (IN) with muscle contusion and without treatment and laser group (LA) with contusion and low-level laser therapy, 830 nm, 30 mW e 4 J/cm². The no invasive contusion was induced in the Tibialis Anterior muscle and the samples were collected after 7 and 21 treatment sessions. The muscle was evaluated by Light Microscopy and Immunoblotting. RESULTS: After 21 days of treatment there was a significant reduction in the areas of inflammation/regeneration of the LA 21 group compared to IN 21 group. The cross-sectional area of the fibers in regeneration was not statistically different between the groups. Molecular analysis showed that the content of MyoD was statistically reduced in the IN 21 group compared to the CT group. The Myogenin content was increased in the IN 21 group compared to the CT group. Ultimately, the content of TGF-β1 on the IN 21 group was higher when compared to the CT group. CONCLUSION: Considering the parameters used, the laser therapy demonstrated to be effective for muscle regeneration in old rats, however only through its anti-inflammatory effect.

CONTEXTUALIZAÇÃO: O processo de envelhecimento e suas consequentes alterações morfofisiológicas desencadeiam redução da habilidade regenerativa das células satélites, redução da vascularização tecidual e aumento da produção de fibroblastos, desenvolvendo-se um ambiente celular desfavorável para a regeneração muscular. OBJETIVO: Avaliar o efeito do tratamento com laser de baixa intensidade sobre a regeneração muscular de modelos experimentais idosos após contusão. MÉTODO: Foram utilizados 25 ratos machos, com 18 meses de idade, divididos em três grupos: grupo controle (CT), sem intervenção; grupo lesão (LE), com contusão muscular e sem tratamento e grupo laser (LA), com contusão muscular e tratado com laser de baixa intensidade, 830 nm, 30 mW e 4 J/cm². A contusão foi realizada no músculo tibial anterior, e as amostras coletadas após sete e 21 sessões de tratamento. O músculo foi designado às técnicas de Microscopia de Luz e Immunoblotting. RESULTADOS: Após 21 dias de tratamento, houve redução significativa na área de inflamação/regeneração no grupo LA 21 comparado ao grupo LE 21. Na área de secção transversal das fibras em processo de regeneração, não houve diferença estatística entre os grupos LA e LE. A análise molecular evidenciou que o conteúdo de MyoD apresentou redução significativa no grupo LE 21 em relação ao CT. O conteúdo de Miogenina exibiu aumento no LE 21 comparado ao CT e, por fim, o conteúdo de TGF-β1 do grupo LE 21 aumentou em relação ao grupo CT. CONCLUSÃO: Para os parâmetros utilizados, o laser demonstrou eficácia na regeneração muscular em animais idosos somente por meio do seu efeito anti-inflamatório.

Evaluation of muscle regeneration in aged animals after treatment with low-level laser therapy.

BACKGROUND: The aging process and its associated morphophysiological changes trigger a reduction in the regenerative ability of the satellite cells, a reduction of vascular tissue and an increase in the production of fibroblasts, developing a cellular environment unfavorable for muscle regeneration. OBJECTIVE: The aim of this study was to evaluate the effect of low-level laser therapy on the muscle regeneration of old experimental rat models after contusion. METHOD: A total of 25 old rats,18 months old, were divided into three groups: control group (CT) without treatment; injury group (IN) with muscle contusion and without treatment and laser group (LA) with contusion and low-level laser therapy, 830 nm, 30 mW e 4 J/cm². The no invasive contusion was induced in the Tibialis Anterior muscle and the samples were collected after 7 and 21 treatment sessions. The muscle was evaluated by Light Microscopy and Immunoblotting. RESULTS: After 21 days of treatment there was a significant reduction in the areas of inflammation/regeneration of the LA 21 group compared to IN 21 group. The cross-sectional area of the fibers in regeneration was not statistically different between the groups. Molecular analysis showed that the content of MyoD was statistically reduced in the IN 21 group compared to the CT group. The Myogenin content was increased in the IN 21 group compared to the CT group. Ultimately, the content of TGF-ß1 on the IN 21 group was higher when compared to the CT group. CONCLUSION: Considering the parameters used, the laser therapy demonstrated to be effective for muscle regeneration in old rats, however only through its anti-inflammatory effect.

Immediate effects of bilateral grade III mobilization of the talocrural joint on the balance of elderly women.

OBJECTIVE: The purpose of this study was to evaluate the immediate effects of a single treatment session of bilateral grade III mobilization of the talocrural joint on the balance of elderly women. METHODS: Thirty-two elderly women (age, 65-80 years) with low physical activity levels completed balance evaluation using baropodometry, the Functional Reach Test and the Timed Up and Go Test, and plantar flexion and dorsiflexion range of motion (ROM), before and immediately after the mobilization (n = 16) or sham (n = 16). Each subject was submitted to a total of twelve 30-second grade III mobilizations, 6 for each ankle, in a single treatment session. RESULTS: No significant difference was found for intragroup and intergroup comparisons in the balance of elderly women during the following evaluations: Functional Reach Test (P = .851), Timed Up and Go Test (P = .653), anteroposterior oscillation with eyes opened (P = .333) and with eyes closed (P = .652), and mediolateral oscillation with eyes opened (P = .486) and with eyes closed (P = .602). In addition, no significant difference was observed in right (P = .881) and left (P = .060) plantar flexion ROM and in right (P = .540) and left (P = .341) dorsiflexion ROM. CONCLUSION: The results of this study suggest that a single session of bilateral grade III mobilization of the talocrural joint does not immediately improve balance and ROM in elderly women with low physical activity levels.