108 resultados para Musculos


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Muscle atrophy is always associated with Dexamethasone (Dexa) treatment, however the mechanisms are not completely understood. This study investigated the effects of Dexa on myostatin and p70S6K protein expression and if previous exercise training (T) can attenuate these effects. Eighty rats were distributed into 4 groups: sedentary control (SC), sedentary treated with Dexa (SD; 0,5 mg/kg per day, i.p., 10 days), trained control (TC) and trained treated with Dexa (TD) and underwent a training period where they were either submitted to a running protocol (60% of physical capacity, 5 days/week for 8 weeks) or kept sedentary. After T period, animals underwent Dexa treatment concomitant with training. Western Blot was performed to identify myostatin and p70S6k protein expression in the tibialis anterior (TA) and soleus (SOL) muscle. Ten days of Dexa treatment increased fasting glucose (SD=+62%), however previous T attenuated this increase (TD=+20%, p<0.05). Dexa determined significant decrease in body weight in TD (-22%) and SD (-25%), followed by TA weight reduction in SD (-23%) and TD (-20%). Previous training could not avoid these decreases. Myostatin protein expression was not altered by dexa treatment or training in TA muscle but in SOL muscle it was significantly modified after T, regardless of treatment (TC=+%23 and TD=+25) compared with their respective controls. The protein p70S6K was not modified neither by dexa nor training in any of the analyzed muscle or condition. The results of this study allowed us to conclude that previous training attenuates the hyperglycemia induced by Dexa, however it did not prevent the body or muscle weight reductions. Even in the presence of muscle atrophy, the expression of myostatin and p70S6K do not justify the mechanisms of muscle loss induced by Dexa, which suggests that other catabolic or anabolic proteins could be involved in the process of muscle atrophy after 10 days of treatment with Dexa

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The present study aimed to analyze the performance of 'boost' among water polo athletes. Twelve athletes (13,9  1,08 years, 169,0  6,0 cm and 59,5  13,5 kg of bodyweight) were under went to anthropometric assessment, body composition and maximum concentric strength of lower limbs. The jump test in the water was done by 'boost' and scaled to jump height. According to the results of strength (Leg Press 45: 157,08  43,30 kg Leg Extension: 72,08  12,86 kg), anthropometry (arm circumf.: 26,04  3,25 cm, thigh circumf.: 50,47  7,65 cm, sholder circumf.: 95,97  8,00 cm, elbow diam.: 4,74  0,51 cm, wrist diam.: 3,21  0,34 cm, knee diam.: 7,89  0,58 cm, biacromial diam.: 37,49  3,81 cm and bi-iliac diam.: 25,43  4,34 cm) and body composition (BMI: 20,74  4,00 kg / m² and% fat: 8,45  4,28), only stature showed a linear correlation (r= 0,595) to the values of vertical jump (height: 47,80  4,35 cm) performance. This anthropometric variable was one able to influence the height of performance by modifying it self, perhaps by maturity. However maturity may be an implicity feature of performance, since force is a concerned effect of the growth. Otherwise technique could play a mains role to the performance of the 'boost'. It can be conclude that possibly is advantageous for water polo athlete be higher and more mature for the realization of 'boost', and the training directed for the technique, but is necessary muscle fitness for the holder

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The control of stances such as the upright stance seems not to have a purpose in itself; this control could facilitate the execution of other simultaneous tasks, the so-called suprapostural tasks. The goal of this study was to determine the effects of saccadic eye movements on the control of posture. Twelve adult participants had their body oscillations analyzed while standing upright, for 70 s, in the postural conditions of feet apart and feet together, performing fixation in the central target or horizontal saccadic movements, in the conditions slow (0,5 Hz) and fast (1,1 Hz). The results showed that saccadic movements, independently of their frequency, strongly reduced trunk and head oscillations in the anterior-posterior (AP) axis. In this axis, there was an effect of feet position only in head oscillation. In the medio-lateral (ML) axis, the results showed a strong effect of feet position with body oscillation decreased in the condition of feet apart. The effect of the visual task in the ML axis occurred only for trunk oscillation, not reaching significance level in the pairewise comparisons. In the AP axis, the data corroborate a facilitatory explanation of the control of posture: the reduction in body oscillation limited the variations of the stimulus image projected on the retina, facilitating the execution of saccadic movements as compared to fixation. In the ML axis, the effect of reducing the basis of support was more evident than the effect of saccadic movements, suggesting that the available resources were used primarily for the postural task in detriment of the visual task. Additionally, aspects like attentional focus and sensory information pick up are discussed as mechanisms involved in this task

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The purpose of the present study was to analyze the visual control of braking a bicycle when the cyclist is surprised by an obstacle in his way. According to Lee (1976), visually controlled braking based on time to collision information utilizes the optic variables tau and its first derivative in time, tau-dot, to initiating the braking action and regulating its intensity. Seven young adults performed a bicycle braking task in curvilinear trajectory under distinct velocity (high, medium, and low) and uncertainty (certainty and uncertainty) conditions. Results showed that, independently of velocity and uncertainty levels, participants utilized tau and tau-dot to initiating and regulating the braking action, avoiding collision with the obstacle. Cognitive, attentional, and other psychological factors resulting from both increased velocity and uncertainty were not capable of altering the use of time to collision information, corroborating the tested hypothesis

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The goal of the present study was to investigate possible differences towards strenght recovery measured by different methods and running economy (RE), after one session of downhill running (DR), in order to induce muscle damage (MD). Our hypothesis is that the strenght recovery measured by jumps is more alike RE markers, due to the measures' specificity. Ten male subjects, ages 18 to 30, apparently healthy, without any experience with strenght training at least 6 months before the tests took place in this study. After going to the lab twice (to familiarize themselves with the protocols, and determine their maximum oxygen consumption/running speeds), they went to the lab five times in the following week, in order to collect all the variables before, immediately after, and 24, 48, 72 and 96 hours in. The variables obtained were: stride frequency (SF), stride lenght (SL), oxygen volume (VO2), carbon dioxide volume (VCO2), ventilation (VE), lactate blood concentration ([Lac]), isometric peak torque (IPT), subjective pain perception (SPP), effort perception (EP), medial-portion circumference (CIR), knee movement extent (EXT), torque development rate (TDR), counter movement jump and squat jump height (HCM and HS), strenght development rate of both jumps (SDCM and SDS), and maximum soil strenght reaction (SRCM and SRS). Changes over time in all variables were verified by one way variancy analysis. Differences between the strenght measures were verified by two way variancy analysis. When significant effects were verified, Tuckey's post-hoc were applied. The significancy level taken on this study was p < 0,05. Of all indirect muscle damage markers, IPT, SPP and TDR were the only ones in which ocurred significant changes. We couldn't find the moments where this happened for TDR with the post-hoc used. On RE markers, VO2, [Lac] and VE suffered significant effects over time. About the jumps variables, only SDCM and HCM presented significant...

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Several methods are used towards delayed onset muscle soreness appraisal. This study's goal was to investigate, amongst three commonly adopted methods, which one would be the most effective (the one that shows higher values) in the quantification of this phenomenon. 10 male subjects, of age 22.8 ± 3.1 years old, weight 80 ± 12.4 kg, height 174 ± 0.07 cm, without recent experience with strength training (lower limbs) and/or running took place in this study. All subjects carried out a muscle damage induction protocol, which consisted of 30 minute downhill running (-16% or -9.09º) at 80% speed compared to their maximum oxygen consumption. Muscle damage determinants such as isometric peak torque, knee joint range of motion and circumference of the medial portion of the thight were measured before, during, 24, 48, 72 and 96 hours after downhill running. The subjective pain perception was measured simultaneously with the other determinants through three different tests: sitting on and getting up of a chair; climbing and descending from a 45cm step; and self thigh palpation. After going through all subjective pain perception tests, the subjects filled out a visual analog scale with their perception of pain. Muscle damage changes over time were compared through variance analysis (ANOVA) one way for repeated measures. Subjective pain perception values obtained in all three different tests were compared through two way ANOVAs for repeated numbers. The significance level adopted in this study was z ≤ 0.05. The results showed that the step test was the on which better evaluated the delayed onset muscle soreness. No significant differences were found through the ADM and CIR recovery markers. Downhil running determined reduced of PTI (~22.4%). Significant links between pain were obtained for both subjective pain perception tests starting at 24 and 48 hours, where the highest registered average happened in the step test after 48h, with high...

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Muscle activity has been studied indirectly through analyses of temperature variation in skin surface temperature on the masticatory muscles. These procedure may be an important tool for clinical evaluation and assessment of the evolution of temporomandibular disorders, as well as monitoring the adopted protocol. Thus, its utilization for identified pathological alterations on blood circulation and/or on metabolic activity in subcutaneous tissues, such as the masticatory muscles, is justified. The aim of this study was to investigate the effect of occlusal splints’ thickness on the variation of surface temperature of the anterior temporal and masseter muscles during rest and clenching. It were analyzed 20 symptomatic subjects (10 males and 10 females) selected through the Research Diagnostic Criteria (RDC) questionnaire. Temperature expressed in degrees Celsius (ºC) was measured on the surface of both muscles measured with the aid of a digital thermometer with an infrared radiation reading system. The surface temperature of the anterior temporal and masseter muscles presented significant reduction during teeth clenching in relation to the mandibular rest position. However, there were no significant differences between conditions with and without occlusal splint or between the different thicknesses of splints analyzed. Masticatory muscles showed a considerable similar behavior for both sides, and no significant distinctions were observed between male and female patients.

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Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

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Pós-graduação em Medicina Veterinária - FCAV

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Pieri N.C.G., Alicia M. Flamini A.M., Barbeito C.G., Casals J.B., Roque K.B., Favaron P.O., Miglino M.A. & Martins D.S. 2012. [Shape and function of the perineal muscles of viscacha (Lagostomus maximus).] Forma e funcao dos musculos perineais da viscacha (Lagostomus maximus). Pesquisa Veterinaria Brasileira 32(2):183-187. Departamento de Zootecnia, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de Sao Paulo, Av. Duque de Caxias Norte 225, Pirassununga, SP 13635-900, Brazil. E-mail: daniele@usp.br. Among the rodent species studied we can highlight the wide variation in the morphology of the male reproductive system. Thus, considering the ecological importance of rodents, and the large number and geographical representation of this animal, as well as shortages regarding the reproductive anatomy, we developed this study with viscacha, a South American histricomorph rodent. As this species has some very peculiar reproductive features, we described the gross anatomy of the perineal muscles and the role of copulatory behavior. The perineal region of viscacha is composed of five muscles, three of which are arranged in the superficial genitourinary diaphragm, as Musculus ischiocavernosus, M. bulbocavernosus and M. bulbospongiosus, and the muscles that lie at the pelvic diaphragm, M. levator ani and M. retractor penis. Therefore, we emphasize that the study of the pelvic floor in wild animals is of great value, then contribute to a better understanding of the mechanisms related to erection and ejaculation or collaborate with studies on the reproduction of animals.

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Las aleaciones metálicas que exhiben una propiedad conocida como efecto de memoria de forma, pertenecen a la clase de materiales inteligentes cuya aplicación más notable en el campo de la robótica se refleja en el uso de actuadores musculares artificiales, ó músculos inteligentes. Estos materiales tienen una estructura cristalina uniforme que cambia radicalmente en función de su temperatura de transición, causando su deformación. Se les denomina materiales inteligentes por la capacidad de recordar su configuración inicial después de recibir dicho estímulo térmico. Este artículo presenta la implementación de un actuador muscular inteligente aplicado en un micro-robot aéreo bio-inspirado tipo murciélago. Esto mamíferos voladores desarrollaron poderosos músculos que se extienden a lo largo de la estructura ósea de las alas, adquiriendo una asombrosa capacidad de maniobra gracias a la capacidad de cambiar la forma del ala durante el vuelo. Replicar este tipo de alas mórficas en un prototipo robótico requiere el análisis de nuevas tecnologías de actuación, abordando los problemas de modelado y control que garanticen la aplicabilidad de este actuador compuesto por fibras musculares de SMAs

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Du génie allégorique et symbolique de l'antiquité, con portadilla propia.

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Compendio anatómico : segunda parte : Myotomologia ó Discurso teórico-práctico de la naturaleza y circunstancias de los musculos, llamado por otro nombre la myologia, con portadilla propia, en segunda secuencia de pag.