The nephroprotective action of Passiflora edulis in streptozotocin-induced diabetes.

In the present study, we aimed to evaluate the therapeutic effect of Passiflora edulis fruit peel aqueous (AFA) extract as an adjuvant to insulin to confer nephroprotection against streptozotocin-induced diabetes. Male Wistar rats were divided into four groups based on treatment received for 60 days: diabetic (DB), control (CTL), insulin (INS), and insulin + AFA extract (INS + AFA). mRNA and protein expression levels of podocyte (nephrin, podocin, and WT1) and tubular (megalin) proteins were measured in kidney tissue specimens and urine. Biochemical parameters and kidney histopathology were also examined. Herein, the INS + AFA group showed superior glycemic control, which resulted in the reduction of urinary albumin/creatinine ratio, maintenance of baseline levels of Nphs1, Nphs2, Wt1, and Lrp2 mRNA expression, prevention of protein loss from the kidney tissue into the urinary space, along with the maintenance of glomerular basement membrane thickness, hyalinization, glomerular and tubulointerstitial fibrosis at values approximating those of the CTL group and significantly lower than those in the DB group. Therefore, these results suggest that, as an anti-diabetic agent, the AFA extract adjuvant to insulin could reduce and potentially prevent diabetic kidney disease.

Effects of Creatine Supplementation on Histopathological and Biochemical Parameters in the Kidney and Pancreas of Streptozotocin-Induced Diabetic Rats.

Diabetes mellitus (DM) is a worldwide health concern, and projections state that cases will reach 578 million by 2030. Adjuvant therapies that can help the standard treatment and mitigate DM effects are necessary, especially those using nutritional supplements to improve glycemic control. Previous studies suggest creatine supplementation as a possible adjuvant therapy for DM, but they lack the evaluation of potential morphological parameters alterations and tissue injury caused by this compound. The present study aimed to elucidate clinical, histomorphometric, and histopathological consequences and the cellular oxidative alterations of creatine supplementation in streptozotocin (STZ)-induced type 1 DM rats. We could estimate whether the findings are due to DM or the supplementation from a factorial experimental design. Although creatine supplementation attenuated some biochemical parameters, the morphological analyses of pancreatic and renal tissues made clear that the supplementation did not improve the STZ-induced DM1 injuries. Moreover, creatine-supplemented non-diabetic animals were diagnosed with pancreatitis and showed renal tubular necrosis. Therefore, even in the absence of clinical symptoms and unaltered biochemical parameters, creatine supplementation as adjuvant therapy for DM should be carefully evaluated.

Hyperbaric oxygen therapy mitigates left ventricular remodeling, upregulates MMP-2 and VEGF, and inhibits the induction of MMP-9, TGF-ß1, and TNF-α in streptozotocin-induced diabetic rat heart.

AIMS: Hyperbaric oxygen (HBO) therapy has been widely used for the adjunctive treatment of diabetic wounds, and is currently known to influence left ventricular (LV) function. However, morphological and molecular repercussions of the HBO in the diabetic myocardium remain to be described. We aimed to investigate whether HBO therapy would mitigate adverse LV remodeling caused by streptozotocin (STZ)-induced diabetes. MAIN METHODS: Sixty-day-old Male Wistar rats were divided into four groups: Control (n = 8), HBO (n = 7), STZ (n = 10), and STZ + HBO (n = 8). Diabetes was induced by a single STZ injection (60 mg/kg, i.p.). HBO treatment (100% oxygen at 2.5 atmospheres absolute, 60 min/day, 5 days/week) lasted for 5 weeks. LV morphology was evaluated using histomorphometry. Gene expression analyzes were performed for LV collagens I (Col1a1) and III (Col3a1), matrix metalloproteinases 2 (Mmp2) and 9 (Mmp9), and transforming growth factor-ß1 (Tgfb1). The Immunoexpression of cardiac tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) were also quantified. KEY FINDINGS: HBO therapy prevented LV concentric remodeling, heterogeneous myocyte hypertrophy, and fibrosis in diabetic rats associated with attenuation of leukocyte infiltration. HBO therapy also increased Mmp2 gene expression, and inhibited the induction of Tgfb1 and Mmp9 mRNAs caused by diabetes, and normalized TNF-α and VEGF protein expression. SIGNIFICANCE: HBO therapy had protective effects for the LV structure in STZ-diabetic rats and ameliorated expression levels of genes involved in cardiac collagen turnover, as well as pro-inflammatory and pro-angiogenic signaling.

CmyoSize: An ImageJ macro for automated analysis of cardiomyocyte size in images of routine histology staining.

BACKGROUND: Cardiomyocyte size histomorphometry is widely required in myocardial remodeling research, but it relies on subjective, time-consuming manual tracing. We aimed to present the CmyoSize, a Fiji/ImageJ macro that reproducibly measures the transnuclear cross-sectional size of cardiomyocytes in multiple H&E images. METHODS: CmyoSize output per image are: mean cross-sectional area (CSA), CSA's local standard deviation (LSD), mean width, and width's LSD. CmyoSize was validated against measurements of an expert examiner, using myocardium micrographs (400-fold magnification) from rats treated with hyperbaric oxygen (HBO), streptozotocin (STZ), as well as control rats (five images/heart, five rats/group). RESULTS: CmyoSize achieved high cardiomyocyte detection precision (95.17 ± 1.11%) and it analyzed each image at least 30-times faster than expert examiner (8.44 ± 0.17 s vs. 266.70 ± 25.15 s). Bland-Altman analyses showed no meaningful bias ( ± 95% confidence interval) between both methods: mean CSA = 1.88 ± 6.83 µm2, CSA's LSD = -4.55 ± 5.07 µm2; mean width = -0.02 ± 0.22 µm; width's LSD = -0.16 ± 0.17 µm. Pearson's r ranged from 0.85 to 0.94 (P < 0.0001). CmyoSize revealed homogenous cardiomyocyte hypertrophy in HBO-treated animals and STZ-induced heterogeneous hypertrophy. CONCLUSION: Fully automated, standardized cardiomyocyte size quantification in H&E images using CmyoSize is feasible, accurate, and time-efficient.

S-methyl cysteine sulfoxide mitigates histopathological damage, alleviate oxidative stress and promotes immunomodulation in diabetic rats.

OBJECTIVES: S-methyl cysteine sulfoxide (SMCS) is a hydrophilic cysteine-containing natural compound found in plants and is known to possess antidiabetic and antioxidant properties. We investigated the antioxidant and immunomodulatory properties of SMCS, as well as histopathological changes in the liver and pancreas in streptozotocin (STZ)-induced diabetic rats. METHODS: The rats were divided into the following groups: control (CG), comprising non-diabetic rats; STZ-DB, comprising STZ-induced diabetic rats; and STZ-SMCS, comprising STZ-induced diabetic rats treated with SMCS. SMCS (200 mg/kg) was administered by gavage daily for 30 days. Biochemical and cytokine analyses, catalase (CAT) and superoxide dismutase (SOD) activities assays and histopathological analysis of liver and pancreas tissues were performed. RESULTS: SMCS treatment reduced glycemia (p<0.05), decreased triglyceride (p<0.01) and very-low-density lipoprotein (VLDL) levels (p<0.01), and increased SOD and CAT activity in the liver (both p<0.01) compared with STZ-DB group. Higher activity values of IL-10 were observed in the STZ-SMCS group than in the other groups (p<0.001). Liver glycogen was significantly improved in the STZ-SMCS group compared with the STZ-DB group. SMCS also ameliorated damage to pancreatic islets, which resulted in restoration of their morphology. CONCLUSIONS: Oral treatment of SMCS showed improvement of the morphological alterations in liver and pancreatic islet in diabetic rats. These beneficial morphological effects of SMCS can be partially explained by IL-10 modulation associated with antioxidant action.

S-methyl cysteine sulfoxide ameliorates duodenal morphological alterations in streptozotocin-induced diabetic rats.

Diabetes mellitus (DM) is a metabolic disease associated with several intestinal disorders. S-methyl cysteine sulfoxide (SMCS) ​​is an amino acid present in Allium cepa L with hypoglycemic effects. However, the effects of SMCS on diabetic intestinal changes are unknown. Thus, we aimed to investigate the effects of SMCS on duodenal morphology and immunomodulatory markers in diabetic rats. Twenty-six rats were divided into three groups: control (C), diabetic (D) and diabetic +200 mg/kg SMCS (DSM). DM was induced by intraperitoneal injection of streptozotocin (50 mg/kg). After 30 days, duodenum samples were processed to assess histopathological and stereological alterations in volume, villus length, and immunohistochemical expression of NF-kB, IL-10, BCL-2, and caspase-3. SMCS reduced hyperglycemia and mitigated the increase in total reference volume of the duodenum, the absolute volume of the mucosa, and the length of the intestinal crypts in the DMS group when compared to D. IL-10 immunostaining was reduced in D when compared to C, while NF-kB was increased in D in comparison to the other groups. SMCS ​​supplementation could decrease the NF-kB immunostaining observed in D. Positive staining for BCL-2 and caspase-3 were not statistically different between groups. In summary, SMCS decreased hyperglycemia and mitigated the morphological changes of the duodenum in diabetic animals, and these beneficial effects can be partially explained by NF-kB modulation.

Complete mid-portion rupture of the rat achilles tendon leads to remote and time-mismatched changes in uninjured regions.

PURPOSE: To examine healing adaptations over 17 weeks post Achilles tendon (AT) rupture in the injured region (IR) compared to an uninjured region (UIR) of the AT. METHODS: Twenty-four rats were subjected to a complete right-sided AT rupture, while the left side served as a control. ATs were harvested at 1, 2, 8 and 17 weeks post-rupture and stained with antibodies specific to Collagen type I (Col I) and II (Col II) as well as Alcian Blue and Picrosirius Red staining techniques. Histopathological changes, proteoglycan content, collagen alignment and immunoexpression were assessed. RESULTS: Both regions examined, IR and UIR, exhibited over weeks 1-17 similar healing adaptations of increasing collagen alignment, decreasing Col I immunoexpression, as well as increasing proteoglycan content and Col II occurrence. Increased proteoglycan content was found already at week 2 in the UIR, while it first increased at week 8 in the IR. The area positive to Col II was increased compared to controls at week 8 in the UIR, whereas it first raised at week 17 in the IR. Collagen disorganization successively declined to reach control levels at week 17 in the UIR, but was still higher in the IR. CONCLUSION: This study demonstrated that uninjured areas of the AT remote from the rupture site also undergo pronounced remodeling, although with time-span differences relative to injured AT portions. These changes including the pathologic heterotopic mineralization and chondrogenic differentiation observed in both regions may have implications in the choice of rehabilitation regimes in order to prevent secondary rupture.

Thirty-day experimental diabetes impairs contractility and increases fatigue resistance in rat diaphragm muscle associated with increased anti-oxidative activity.

Diabetes mellitus is a metabolic disorder that can generate tissue damage through several pathways. Alteration and dysfunction of skeletal muscle are reported including respiratory muscles, which may compromise respiratory parameters in diabetic patients. We have aimed to evaluate the diaphragm muscle contractility, tissue remodeling, oxidative stress, and inflammatory parameters from 30 day streptozotocin-treated rats. The diaphragm contractility was assessed using isolated muscle, tissue remodeling using histology and zymography techniques, and tissue oxidative stress and inflammatory parameters by enzyme activity assay. Our data revealed in the diabetes mellitus group an increase in maximum tetanic force (4.82 ± 0.13 versus 4.24 ± 0.18 N/cm2 (p = 0.015)) and fatigue resistance (139.16 ± 10.78 versus 62.25 ± 4.45 s (p < 0.001)), reduction of 35.4% in muscle trophism (p < 0.001), increase of 32.6% of collagen deposition (p = 0.007), reduction of 21.3% in N-acetylglucosaminidase activity (p < 0.001), and increase of 246.7% of catalase activity (p = 0.002) without changes in reactive oxygen species (p = 0.518) and tissue lipid peroxidation (p = 0.664). All observed changes are attributed to the poor glycemic control (471.20 ± 16.91 versus 80.00 ± 3.42 mg/dL (p < 0.001)), which caused defective tissue regeneration and increased catalase activity as a compensatory mechanism.

Efeito do aquecimento sobre a flexibilidade e o desempenho funcional: ensaio clínico randomizado / Effect of warm-up on flexibility and functional performance: randomized clinical trial / Efecto del calentamiento sobre la flexibilidad y el rendimiento funcional: ensayo clínico aleatorizado

RESUMO Introdução: A atividade física deve ser parte fundamental de programas de promoção da saúde. No entanto, sua realização pode expor o indivíduo a riscos de lesão, o que torna necessária a adoção de medidas preventivas como o aquecimento, com o intuito de minimizar os riscos e/ou contribuir para o melhor desempenho funcional. Objetivo: O propósito deste estudo foi analisar o efeito agudo de diferentes tempos de aquecimento sobre flexibilidade, equilíbrio e desempenho funcional em indivíduos fisicamente ativos. Método: Trinta e dois homens saudáveis que realizavam exercício regularmente pelo menos três vezes por semana foram aleatoriamente incluídos em um de quatro grupos (n = 8): G0 (sem aquecimento), G5 (aquecimento por cinco min.), G10 (aquecimento por dez min.) e G15 (aquecimento por quinze min.). Os indivíduos foram avaliados antes e depois da intervenção nas seguintes variáveis: flexibilidade do reto femoral (RF) e dos isquiotibiais (IT), equilíbrio corporal com olhos abertos e fechados e desempenho funcional por meio dos testes de salto triplo horizontal (STH) e shuttle run (SR). O aquecimento foi realizado numa esteira ergométrica entre 70% e 80% da frequência cardíaca máxima estimada para idade. Resultado: Não houve diferenças significativas na flexibilidade e no equilíbrio nas comparações intra e intergrupos (p > 0,05). Contudo, houve melhora significativa do desempenho funcional somente no G10 na comparação intragrupo para as variáveis STH (de 5,88 ± 0,55 para 6,23 ± 0,66; p = 0,0051) e SR (de 4,72 ± 0,13 para 4,61 ± 0,13; p= 0,0194). Conclusão: O aquecimento durante 10 minutos parece melhorar o desempenho funcional em indivíduos ativos, podendo também ser uma alternativa viável para a prevenção de lesão.

ABSTRACT Introduction: Physical activity should be a fundamental part of health promotion programs. However, its performance can expose the individual to risk of injury, which makes it necessary to adopt preventive measures such as warm-up (WU) in order to minimize risks and/or contribute to better functional performance. Objective: The purpose of this study was to analyze the acute effect of different warm-up times on flexibility, balance, and functional performance in physically active individuals. Method: Thirty two healthy men, who exercise regularly at least three times a week, were randomly assigned to one of four groups (n=8): G0 (without WU), G5 (WU for 5 min), G10 (WU for 10 min), and G15 (WU for 15 min). The subjects were assessed before and after the intervention on the following variables: flexibility of the rectus femoris (RF) and hamstrings (HM) muscles, body balance with open and close eyes and functional performance through triple horizontal jump (THJ) and shuttle run (SR) tests. The WU was carried out on a treadmill between 70% and 80% estimated maximum heart rate for age. Results: There were no significant differences in flexibility and balance in intra and intergroup comparisons (p>0.05). However, there was a significant improvement in functional performance only in G10 in the intragroup comparison for THJ variables (5.88±0.55 to 6.23±0.66; p=0.0051) and SR variables (4.72±0.13 to 4.61±0.13; p=0.0194) variables. Conclusion: Warm-up for 10 minutes seems to improve functional performance in active individuals, and may be a viable alternative for injury preventions.

RESUMEN Introducción: La actividad física debe ser parte fundamental de los programas de promoción de la salud. Sin embargo, su realización puede exponer al individuo a riesgos de lesión, lo que hace necesaria la adopción de medidas preventivas como el calentamiento con el fin de minimizar los riesgos y/o contribuir para el mejor desempeño funcional. Objetivo: El propósito de este estudio fue analizar el efecto agudo de diferentes tiempos de calentamiento sobre flexibilidad, equilibrio y desempeño funcional en individuos físicamente activos. Método: Treinta y dos hombres sanos que hacen ejercicio regularmente por lo menos tres veces por semana fueron incluidos aleatoriamente en uno de cuatro grupos (n = 8): G0 (sin calentamiento), G5 (calentamiento por cinco minutos), G10 (calentamiento por diez minutos) y G15 (calentamiento por quince minutos). Los individuos fueron evaluados antes y después de la intervención en las siguientes variables: flexibilidad del recto femoral (RF) y de los isquiotibiales (IT), equilibrio corporal con ojos abiertos y cerrados y desempeño funcional por medio de las pruebas de salto triple horizontal (STH) y shuttle run (SR). El calentamiento se realizó en una cinta rodante entre el 70% y el 80% de la frecuencia cardiaca máxima estimada para la edad. Resultado: No hubo diferencias significativas en la flexibilidad y el equilibrio en las comparaciones intra e intergrupos (p > 0,05). Sin embargo, hubo una mejora significativa en el desempeño funcional sólo en el G10 en la comparación intragrupo para las variables STH (de 5,88 ± 0,55 a 6,23 ± 0,66, p = 0,0051) y SR (de 4,72 ± 0,13 a 4,61 ± 0,13, p = 0,0194). Conclusión : El calentamiento durante 10 minutos parece mejorar el desempeño funcional en individuos activos, pudiendo también ser una alternativa viable para la prevención de lesión.

Anabolic Effect of Insulin Therapy on the Bone: Osteoprotegerin and Osteocalcin Up-Regulation in Streptozotocin-Induced Diabetic Rats.

Type 1 diabetes mellitus (T1DM) is associated with several skeletal alterations, particularly in conditions of poor glycaemic control. Insulin therapy is the major conservative treatment for T1DM; however, the effects of this hormone on bone markers of T1DM rats are limited, and the regulatory mechanisms remain elusive. Therefore, the evaluation of molecular and non-molecular parameters in a chronic animal model of T1DM-induced bone loss, treated with and without insulin, may help in elucidating the insulin mechanisms. Male Wistar rats were assigned into three groups: control, T1DM (T1DM rats induced with streptozotocin [STZ] at 40 mg/kg intravenously) and T1DM plus insulin therapy (T1DMI). After 8 weeks, we evaluated the serum biochemical, tibia histomorphometric and biomechanical parameters, as well as the gene expression of the receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG) and osteocalcin (OC) of femur mRNA. Compared with T1DM, the T1DMI group showed less bone loss, which was revealed by the increased trabecular width (TbWi, p < 0.001) and trabecular bone area (BAr, p < 0.01), reduced trabecular separation (TbSp, p < 0.01) and increased Young's modulus (p < 0.05). Moreover, molecular analyses indicated that the expression of OPG and OC was up-regulated (p < 0.001 and p < 0.05, respectively). In summary, the up-regulation of OPG and OC in the T1DMI group supports an anabolic effect of insulin, which was demonstrated by the maintenance of bone architecture and flexibility. These results suggest that insulin therapy may prevent T1DM-induced bone loss via the effects on the bone formation.

Validity analysis of one-repetition maximum strength test for determining the hamstrings-to-quadriceps ratio

One of the approaches to evaluate injury prediction is the hamstrings-to-quadriceps peak torque conventional ratio (H:Q ratio). The gold standard for assessment of muscle strength in vivo is by isokinetic dynamometry; however, the one-repetition maximum strength test (1-RM) presents high correlation with isokinetic data. This study aimed to compare measures of H:Q ratio in young adults obtained by dynamometry and 1-RM testing. No significant differences were observed in the H:Q ratio when comparing 1-RM and dynamometry testing. However, there was a significant and strong correlation between the measurements obtained in the two tests. Despite this correlation, data from both tests are not equal as the H:Q ratio obtained from 1-RM test presents a systematic error. Nonetheless, the results can enhance the applicability of 1-RM test in clinical settings

Metalloproteinase Changes in Diabetes.

Matrix metalloproteinases (MMPs) constitute a group of over 20 structurally-related proteins which include a Zn(++) ion binding site that is essential for their proteolytic activities. These enzymes play important role in extracellular matrix turnover in order to maintain a proper balance in its synthesis and degradation. MMPs are associated to several physiological and pathophysiological processes, including diabetes mellitus (DM). The mechanisms of DM and its complications is subject of intense research and evidence suggests that MMPs are implicated with the development and progression of diabetic microvascular complications such as nephropathy, cardiomyopathy, retinopathy and peripheral neuropathy. Recent data has associated DM to changes in the tendon structure, including abnormalities in fiber structure and organization, increased tendon thickness, volume and disorganization obtained by image and a tendency of impairing biomechanical properties. Although not fully elucidated, it is believed that DM-induced MMP dysregulation may contribute to structural and biomechanical alterations and impaired process of tendon healing.

Protection against T1DM-Induced Bone Loss by Zinc Supplementation: Biomechanical, Histomorphometric, and Molecular Analyses in STZ-Induced Diabetic Rats.

Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days) type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS). Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young's modulus), and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic and protective effect of zinc under chronic diabetic conditions. Furthermore, these results indicate that zinc supplementation could act as a complementary therapy in chronic T1DM.

Efeito do ultrassom terapêutico sobre as propriedades mecânicas do gastrocnêmio em ratos / Effect of therapeutic ultrasound on mecnanical properties of gastrocnemius in rats / Efecto del ultrasounido terapéutico sobre las propiedades mecánicas del gastrocnemio en ratones

INTRODUÇÃO: Apesar de algumas controvérsias quanto à sua utilização, o ultrassom terapêutico (UST) é um recurso comumente aplicado na reabilitação desportiva para aceleração do reparo tecidual de lesões musculares. Sabe-se que lesões musculares influenciam negativamente as propriedades mecânicas da musculatura estriada esquelética e algumas evidências demonstram que o UST poderia ter efeitos benéficos sobre o reparo muscular e, consequentemente, sobre suas propriedades mecânicas. OBJETIVO: Analisar o efeito do UST no reparo tecidual por meio das propriedades mecânicas musculares de ratos após trauma por criolesão. MÉTODOS: Foram utilizados no estudo 30 ratos da linhagem Wistar, os quais foram divididos em três grupos: grupo controle intacto (GC), grupo lesionado sem tratamento (GL), e grupo lesionado e estimulado com UST (frequência de 1 MHz; intensidade de 0,5 W/cm2; ciclo de trabalho de 50%; por quatro minutos diários), durante sete dias consecutivos (GLUST). As propriedades mecânicas obtidas através de ensaio mecânico de tração foram avaliadas em uma máquina universal de ensaios. RESULTADOS: Foram analisados estatisticamente, com nível de significância de 95% (P<0,05). Após sete sessões de tratamento, houve melhora estatisticamente significativa nas propriedades mecânicas de carga no limite de proporcionalidade, carga no limite máximo e resiliência para o GLUST em relação ao GL (p<0,05). CONCLUSÃO: O UST foi eficaz no processo de reparo tecidual, conferindo ao tecido muscular maior resistência à tração e absorção de energia. .

INTRODUCTION: Despite controversial, ultrasonic therapy (UST) is commonly applied in sports rehabilitation practice to accelerate tissue repair after muscle damage. Muscle injuries have a negative influence on the mechanical properties of skeletal striated muscles and some scientific evidence shows that UST could have a positive effects on tissue repair and, therefore, on its mechanical properties. OBJECTIVE: To analyze the effect of UST on muscle repair by evaluation of the mechanical properties of rat muscles after cryolesion. METHODS: We used 30 adult Wistar rats which were divided into three groups: CG (control group), IG (injured group) and IGUST (injured plus UST) - (frequency of 1 MHz; intensity of 0.5 W/cm2; pulsed to 50%; four minutes daily) for seven consecutive days. The mechanical properties obtained through mechanical tests were evaluated in a universal testing machine. RESULTS: Data were statistically analyzed with a significance level of 95% (p<0.05). After seven treatment sessions, we found significant improvement in the mechanical properties of load at the proportionality limit, load at maximum limit and resilience in IGUST compared to IG (p<0.05). CONCLUSION: The UST was effective in the tissue repair process, giving higher tensile strength and energy absorption to the muscle tissue. .

INTRODUCCIÓN: A pesar de algunas controversias cuanto a su utilización, el ultrasonido terapéutico (UST) es un recurso aplicado comúnmente en la rehabilitación deportiva para aceleración de la reparación tecidual de lesiones musculares. Se sabe que las lesiones musculares influyen negativamente en las propiedades mecánicas de la musculatura estriada esquelética y algunas evidencias demuestran que el UST podría tener efectos sobre la reparación muscular y, en consecuencia, con respecto a sus propiedades mecánicas. OBJETIVO: Analizar el efecto del UST en la reparación tecidual por medio de las propiedades mecánicas musculares de ratones después de traumatismo por criolesión. MÉTODOS: Se utilizaron, en el estudio, 30 ratones de la raza Wistar, los cuales fueron divididos en tres grupos: grupo de control intacto (GC), grupo lesionado sin tratamiento (GL) y grupo lesionado y estimulado con UST (frecuencia de 1 MHz; intensidad de 0,5 W/cm2; ciclo de trabajo de 50%, durante cuatro minutos diarios) a lo largo de siete días consecutivos (GLUST). Las propiedades mecánicas obtenidas, mediante el ensayo mecánico de tracción, fueron evaluadas en una máquina universal de ensayos. RESULTADOS: Se analizaron estadísticamente, con nivel de significancia de 95% (P<0,05). Después de siete sesiones de entrenamiento, hubo mejora estadísticamente significativa en las propiedades mecánicas de carga en el límite de proporcionalidad, carga en el límite máximo y resiliencia para el GLUST en relación con el GL (p<0,05). CONCLUSIÓN: El UST fue eficaz en el proceso de reparación tecidual, dando al tejido muscular más resistencia cuanto a la tracción y la absorción de energía. .

Overview of ultrasound usage trends in orthopedic and sports physiotherapy.

BACKGROUND: The purpose of this study is to examine current beliefs about the use, the clinical importance, the theoretical fundamentals and the utilization criteria of therapeutic ultrasound (TUS) among physical therapists on the clinical practice in orthopedic and sports physiotherapy in Brazil. METHODS: A brief survey was developed based on previous studies and was sent to 55 physical therapists with advanced competency in orthopedics and sports physiotherapy. The questions addressed general topics about the professional profile and ultrasound usage and dosage. RESULTS: Our data show the wide availability and frequent use of TUS in this sample of physical therapists. TUS is used in distinct musculoskeletal injuries and/or disorders in both acute and chronic conditions. Muscles, tendons and ligaments represented the major structures where TUS is used. Questions on the basic theory of TUS demonstrated a lack of knowledge of the ultrasound physiological effects as well as its interaction with biological tissues and TUS absolute contraindication. CONCLUSION: A Brazilian profile about the US usage and dosage in orthopedic and sports physiotherapy is presented and highlights the need for a continuous upgrading process and further research into its effects.

Synaptic vesicle cycling is not impaired in a glutamatergic and a cholinergic synapse that exhibit deficits in acidification and filling

The purpose of the present work was to investigate synaptic vesicle trafficking when vesicles exhibit alterations in filling and acidification in two different synapses: a cholinergic frog neuromuscular junction and a glutamatergic ribbon-type nerve terminal in the retina. These synapses display remarkable structural and functional differences, and the mechanisms regulating synaptic vesicle cycling might also differ between them. The lipophilic styryl dye FM1-43 was used to monitor vesicle trafficking. Both preparations were exposed to pharmacological agents that collapse ΔpH (NH4Cl and methylamine) or the whole ΔµH+ (bafilomycin), a necessary situation to provide the driving force for neurotransmitter accumulation into synaptic vesicles. The results showed that FM1-43 loading and unloading in neuromuscular junctions did not differ statistically between control and experimental conditions (P > 0.05). Also, FM1-43 labeling in bipolar cell terminals proved highly similar under all conditions tested. Despite remarkable differences in both experimental models, the present findings show that acidification and filling are not required for normal vesicle trafficking in either synapse.

O objetivo do presente trabalho foi investigar o tráfego de vesículas sinápticas quando estas apresentam alterações no armazenamento de neurotransmissores e acidificação em duas distintas sinapses: a junção neuromuscular colinérgica de rãs versus o terminal nervoso glutamatérgico do tipo ribbon em céulas bipolares da retina. Essas sinapses exibem notáveis diferenças estruturais e funcionais e os mecanismos de regulação de ciclo das vesículas sinápticas podem ser diferentes entre eles. Para monitorar o tráfego de vesícula, foi utilizado o marcador lipofílico FM1-43. Ambas as preparações foram expostas a agentes farmacológicos que provocam o colapso de ΔpH (NH4Cl e metilamina) ou de todo ΔµH+ (bafilomicina), gradientes necessários para o acúmulo de neurotransmissores em vesículas sinápticas. Nossos resultados demonstram que a marcação e desmarcação de FM1-43 nas junções neuromusculares não foi estatisticamente diferente entre as diversas condições experimentais (P > 0,05). Além disso, a marcação de FM1-43 em terminais sinápticos de células bipolares foram bastante semelhantes em todas as condições testadas. Apesar das diferenças marcantes em ambos os modelos experimentais, nossos achados demonstram que a acidificação e o preenchimento de vesículas sinápticas não são necessários para o tráfico normal da vesícula nas sinapses estudadas.