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SUMMARY: The existence of "transitional muscular structures" between subendocardial branches (Purkinje fibers) and ventricular working muscle fibers (WF) was first described by the German anatomist, Kurt Goerttler, in 1964. He designated them as "subendocardial nucleus organs." He supposed such fibers functioned as mechanoreceptors, controlling of the intensity of contraction of the ventricular musculature. Brazilian anatomist Ferraz de Carvalho described similar structures in 1993. A thorough literature search failed to identify any other research articles confirming or denying their existence. The objective of this work was to find such structures in subendocardial ventricular walls in human hearts. We collected fifteen formalin-preserved hearts from the Anatomy Department of São Paulo University and sectioned the apical portions on the right and left ventricles according to method used by Goerttler. We utilized conventional histology (light microscopy- LM), scanning electron microscopy (SEM), and a new preservation method called micro- plastination (MP). At the anterior wall of the right ventricle in the subendocardial region between the interventricular septum and moderator band, we found several bundles of fusiform and helicoidal fibers of similar histology to the WF. The bundles measured between 400 and 1150 µm in length and were separated from adjacent muscular fibers by thin collagen fiber, thus acting as a "pseudo capsule." Some structures seemed to be linked to PF and were appeared to be lymphatic and blood vessels and nerves. We called those structures "cardiac corpuscles" (CC). The observation of the previously "unknown" CC in this initial study confirmed the previous descriptions and its discovery may contribute to new perspectives in the study of cardiac muscle structure and function.

La existencia de "estructuras musculares de transición" entre los ramos subendocárdicos (fibras de Purkinje) y las fibras musculares ventriculares activas(FMV) fue descrita por primera vez por el anatomista alemán Kurt Goerttler en 1964, quien las denominó "órganos del núcleo subendocárdico". Supuso que tales fibras funcionaban como mecanoreceptores, controlando la intensidad de la contracción de la musculatura ventricular. El anatomista brasileño Ferraz de Carvalho describió estructuras similares en 1993. Una búsqueda bibliográfica exhaustiva no logró identificar ningún otro artículo de investigación que confirmara o negara su existencia. El objetivo de este trabajo fue encontrar dichas estructuras en las paredes ventriculares subendocárdicas de corazones humanos. Recolectamos 15 corazones conservados en formalina del Departamento de Anatomía de la Universidad de São Paulo y seccionamos las porciones apicales de los ventrículos derecho e izquierdo según el método utilizado por Goerttler. Utilizamos histología convencional (microscopía de luz-LM), microscopía electrónica de barrido (SEM) y un nuevo método de conservación llamado microplastinación (MP). En la pared anterior del ventrículo derecho en la región subendocárdica entre el tabique interventricular y la banda moderadora, encontramos varios haces de fibras fusiformes y helicoidales de histología similar a la FMV. Los haces medían entre 400 y 1150 µm de longitud y estaban separados de las fibras musculares adyacentes por una fina fibra de colágeno, actuando así como una "pseudocápsula". Algunas estructuras parecían estar vinculadas a la fibras de purkinje y parecían ser vasos linfáticos, sanguíneos y nerviosos. Llamamos a esas estructuras "corpúsculos cardíacos" (CC). La observación del CC previamente "desconocido" en este estudio inicial confirmó las descripciones anteriores y su descubrimiento puede contribuir a nuevas perspectivas en el estudio de la estructura y función del músculo cardíaco.

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Creatine has been used to maximize resistance training effects on skeletal muscles, including muscle hypertrophy and fiber type changes. This study aimed to evaluate the impact of creatine supplementation on the myostatin pathway and myosin heavy chain (MyHC) isoforms in the slow- and fast-twitch muscles of resistance-trained rats. Twenty-eight male Wistar rats were divided into four groups: a sedentary control (Cc), sedentary creatine supplementation (Cr), resistance training (Tc), and resistance training combined with creatine supplementation (Tcr). Cc and Tc received standard commercial chow; Cr and Tcr received a 2% creatine-supplemented diet. Tc and Tcr performed a resistance training protocol on a ladder for 12 weeks. Morphology, MyHC isoforms, myostatin, follistatin, and ActRIIB protein expressions were analyzed in soleus and white gastrocnemius portion samples. The results were analyzed using two-way ANOVA and Tukey's test. Tc and Tcr exhibited higher performance than their control counterparts. Resistance training increased the ratio between muscle and body weight, the cross-sectional area, as well as the interstitial collagen fraction. Resistance training alone increased MyHC IIx and follistatin while reducing myostatin (p < 0.001) and ActRIIB (p = 0.040) expressions in the gastrocnemius. Resistance training induced skeletal muscle hypertrophy and interstitial remodeling, which are more evident in the gastrocnemius muscle. The effects were not impacted by creatine supplementation.

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he existence of “transitional muscular structures” between subendocardial branches (Purkinje fibers) and ventricular working muscle fibers (WF) was first described by the German anatomist, Kurt Goerttler, in 1964. He designated them as “subendocardial nucleus organs.” He supposed such fibers functioned as mechanoreceptors, controlling of the intensity of contraction of the ventricular musculature. Brazilian anatomist Ferraz de Carvalho described similar structures in 1993. A thorough literature search failed to identify any other research articles confirming or denying their existence. The objective of this work was to find such structures in subendocardial ventricular walls in human hearts. We collected fifteen formalin-preserved hearts from the Anatomy Department of São Paulo University and sectioned the apical portions on the right and left ventricles according to method used by Goerttler. We utilized conventional histology (light microscopy- LM), scanning electron microscopy (SEM), and a new preservation method called micro- plastination (MP). At the anterior wall of the right ventricle in the subendocardial region between the interventricular septum and moderator band, we found several bundles of fusiform and helicoidal fibers of similar histology to the WF. The bundles measured between 400 and 1150 µm in length and were separated from adjacent muscular fibers by thin collagen fiber, thus acting as a “pseudo capsule.” Some structures seemed to be linked to PF and were appeared to be lymphatic and blood vessels and nerves. We called those structures “cardiac corpuscles” (CC). The observation of the previously “unknown” CC in this initial study confirmed the previous descriptions and its discovery may contribute to new perspectives in the study of cardiac muscle structure and function.

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Insulin resistance onset in skeletal muscle is characterized by the impairment of insulin signaling, which reduces the internalization of glucose, known as glucose uptake, into the cell. Therefore, there is a deficit of intracellular glucose, which is the main source for energy production in the cell. This may compromise cellular viability and functions, leading to pathological dysfunction. Skeletal muscle fibers continuously generate reactive oxygen and nitrogen species (RONS). An excess of RONS produces oxidative distress, which may evoke cellular damage and dysfunction. However, a moderate level of RONS, which is called oxidative eustress, is critical to maintain, modulate and regulate cellular functions through reversible interactions between RONS and the components of cellular signaling pathways that control those functions, such as the facilitation of glucose uptake. The skeletal muscle releases peptides called myokines that may have endocrine and paracrine effects. Some myokines bind to specific receptors in skeletal muscle fibers and might interact with cellular signaling pathways, such as PI3K/Akt and AMPK, and facilitate glucose uptake. In addition, there are cytokines, which are peptides produced by non-skeletal muscle cells, that bind to receptors at the plasma membrane of skeletal muscle cells and interact with the cellular signaling pathways, facilitating glucose uptake. RONS, myokines and cytokines might be acting on the same signaling pathways that facilitate glucose uptake in skeletal muscle. However, the experimental studies are limited and scarce. The aim of this review is to highlight the current knowledge regarding the role of RONS, myokines and cytokines as potential signals that facilitate glucose uptake in skeletal muscle. In addition, we encourage researchers in the field to lead and undertake investigations to uncover the fundamentals of glucose uptake evoked by RONS, myokines, and cytokines.

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Objective: Analyze the effects of aerobic and anaerobic training on different ergometers on muscle and cardiac hypertrophy in rats. Methods: The animals were separated into the following groups: Control (C), Aerobic Training in Water (ATW), Resistance Training in Water (RTW), Aerobic Training on Treadmill (ATT), and Resistance Training in Climbing (RTC). All training protocols were carried out for 4 weeks, 3 times/week. The cross-sectional area (CSA) of the gastrocnemius muscle cells and the areas of the cardiomyocytes were measured. Results: In the fast-twitch fibers, there was an increase in CSA in the RTW and RTC groups compared to the ATW (p<0.01 and p<0.01) and ATT groups (p<0.01 and p<0.01). In the slow-twitch fibers, the ATW and ATT groups demonstrated a lower CSA compared to the RTW (p=0.03 and p<0.00) and RTC groups (p<0.01 and p<0.01). In the cardiomyocytes, there was an increase in the area of the RTW and RTC groups compared to groups C (p<0.01; p<0.01), ATW (p=0.02; p<0.01), and ATT (p<0.01; p<0.01). Conclusion: The anaerobic training effectively promotes hypertrophy in the fast-twitch fibers and the cardiomyocytes. Level of Evidence V; Animal experimental study .

Objetivo: Analisar os efeitos dos treinamentos aeróbios e anaeróbios em diferentes ergômetros na hipertrofia muscular e cardíaca de ratos. Métodos: Os animais foram separados nos grupos controle (C), treinamento aeróbio em natação (ATW), treinamento resistido em meio aquático (RTW), treinamento aeróbio em esteira rolante (ATT) e treinamento resistido em escalada (RTC). Os protocolos de treinamento foram realizados por 4 semanas, 3 x/semana. Foram mensurados a área de secção transversa (CSA) das células do músculo gastrocnêmio e as áreas dos cardiomiócitos. Resultados: Nas fibras de contração rápida houve aumento da CSA dos grupos RTW e RTC em relação aos grupos ATW (p<0,01 e p<0,01) e ATT (p<0,01 e p<0,01). Nas fibras de contração lenta os grupos ATW e ATT demonstraram menor CSA comparado aos grupos RTW (p=0,03 e p<0,00) e RTC (p<0,01 e p<0,01). Nos cardiomiócitos houve aumento da área dos grupos RTW e RTC em comparação com os grupos C (p<0,01 e p<0,01), ATW (p=0,02 e p<0,01) e ATT (p<0,01 e p<0,01). Conclusão: Os treinamentos anaeróbios promoveram hipertrofia nas fibras de contração rápida e nos cardiomiócitos. Nível de Evidência V; Estudo experimental em animais .

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ABSTRACT Objective Analyze the effects of aerobic and anaerobic training on different ergometers on muscle and cardiac hypertrophy in rats. Methods The animals were separated into the following groups: Control (C), Aerobic Training in Water (ATW), Resistance Training in Water (RTW), Aerobic Training on Treadmill (ATT), and Resistance Training in Climbing (RTC). All training protocols were carried out for 4 weeks, 3 times/week. The cross-sectional area (CSA) of the gastrocnemius muscle cells and the areas of the cardiomyocytes were measured. Results In the fast-twitch fibers, there was an increase in CSA in the RTW and RTC groups compared to the ATW (p<0.01 and p<0.01) and ATT groups (p<0.01 and p<0.01). In the slow-twitch fibers, the ATW and ATT groups demonstrated a lower CSA compared to the RTW (p=0.03 and p<0.00) and RTC groups (p<0.01 and p<0.01). In the cardiomyocytes, there was an increase in the area of the RTW and RTC groups compared to groups C (p<0.01; p<0.01), ATW (p=0.02; p<0.01), and ATT (p<0.01; p<0.01). Conclusion The anaerobic training effectively promotes hypertrophy in the fast-twitch fibers and the cardiomyocytes. Level of Evidence V; Animal experimental study.

RESUMO Objetivo Analisar os efeitos dos treinamentos aeróbios e anaeróbios em diferentes ergômetros na hipertrofia muscular e cardíaca de ratos. Métodos Os animais foram separados nos grupos controle (C), treinamento aeróbio em natação (ATW), treinamento resistido em meio aquático (RTW), treinamento aeróbio em esteira rolante (ATT) e treinamento resistido em escalada (RTC). Os protocolos de treinamento foram realizados por 4 semanas, 3 x/semana. Foram mensurados a área de secção transversa (CSA) das células do músculo gastrocnêmio e as áreas dos cardiomiócitos. Resultados Nas fibras de contração rápida houve aumento da CSA dos grupos RTW e RTC em relação aos grupos ATW (p<0,01 e p<0,01) e ATT (p<0,01 e p<0,01). Nas fibras de contração lenta os grupos ATW e ATT demonstraram menor CSA comparado aos grupos RTW (p=0,03 e p<0,00) e RTC (p<0,01 e p<0,01). Nos cardiomiócitos houve aumento da área dos grupos RTW e RTC em comparação com os grupos C (p<0,01 e p<0,01), ATW (p=0,02 e p<0,01) e ATT (p<0,01 e p<0,01). Conclusão Os treinamentos anaeróbios promoveram hipertrofia nas fibras de contração rápida e nos cardiomiócitos. Nível de Evidência V; Estudo experimental em animais.

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Static stretching provides benefits to the range of motion, modulates intramuscular connective tissue, and is incorporated into warm-up exercises. In this study, we present the effects in the motor endplate and belly muscle resulting from previous static stretching to climbing training. Twenty-four adult male Wistar rats were divided into four groups (n = 6 each): Sedentary (Sed), Climbing (Clb), Static stretching (Ss), and Static stretching prior to climbing (Ssc). The animals (Clb, Ss, and Ssc groups) were subjected to a training protocol 3×/week for 8 weeks, and the Ssc group was subjected to the Ss and Clb protocols in the same session. Samples from the animals were processed for immunostaining, histochemistry, and light microscopy. The Clb group presented a higher motor endplate; the Ss group presented no changes in the motor endplate; and the Ssc group demonstrated a higher compactness. We concluded that static stretching prior to the climbing protocol maintained the density of the motor endplate and increased the compactness of the neuromuscular junction structure. Also, there was a reduction in the myofibers' diameter (Type I and IIa), an increase in myofibrillar densities (Type I and IIx, and total), and the reorganization of the myonuclei and the interstitium.

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The objective was to investigate gene and protein expression of myosin heavy chain (MyHC) in Nellore cattle slaughtered at different weights (BW) or degrees of meat tenderness. Ninety animals with initial BW 370 ± 37 kg, 24 months of age, were slaughtered after 95 days on feed. We evaluated shear force (SF), myofibrillar fragmentation index, ribeye area, backfat thickness, marbling, color, and cooking losses. Subsequently, 24 animals were selected and divided into four contrasting groups, in which light (BW = 504.58 ± 32.36 kg) versus heavy animals (BW = 604.83 ± 42.97 kg) and animals with tender (SF = 3.88 ± 0.57 kg) versus tough meat (SF = 7.95 ± 1.04 kg) were compared. The MYH7, MYH2 and MYH1 genes were analyzed by real-time PCR. The MyHC isoforms (MyHC-I, MyHC-IIa, and MyHC-IIx) were quantified by SDS-PAGE electrophoresis. We found lower expression of MYH2 and MYH1 genes in heavy compared to light animals and a higher amount of MyHC-I isoform in the tough meat group compared to the tender meat group. Protein expression of MyHC-IIa was higher in the tender meat group. A negative correlation was found of this protein and SF (tenderness), suggesting MyHC-IIa as a biomarker of meat quality.

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ABSTRACT Objective To evaluate the morphology and morphometry of the muscles extensor digitorium longus and soleus of C57BL/6 females, who were exposed to glyphosate during pregnancy and lactation. Methods Twelve female mice from the C57BL/6 lineage were used. After detection of pregnancy, they were divided into a Control Group, which received only water, and a Glyphosate Group, which received water with 0.5% glyphosate during pregnancy and lactation. Both groups received ad libitum standard diet. After weaning, the females were euthanized and weighed; naso-anal length was measured, and fats were collected and weighed. The muscles extensor digitorium longus and soleus were collected, and their length and weight were measured. Then, the muscles were fixed in Methacarn to perform the histological study of muscle fibers. Results Glyphosate Group presented lower weight gain during pregnancy and also lower final body weight and naso-anal length; however, the other body parameters evaluated did not present a significant difference in relation to the Control Group. Significant differences were also not observed in the analysis of muscle fibers and connective tissue. Conclusion Exposure to 0.5% glyphosate during pregnancy and lactation resulted in lower weight gain during pregnancy, final weight, and naso-anal length. Despite not directly altering the morphology of muscle tissue, these results may indicate enough exposure to interfere with animal metabolism.

RESUMO Objetivo Avaliar a morfologia e a morfometria dos músculos extensor longo dos dedos e sóleo de fêmeas C57BL/6 expostas ao glifosato durante a prenhez e lactação. Métodos Foram utilizados 12 camundongos fêmeas da linhagem C57BL/6. Após detecção da prenhez, foram separadas em Grupo Controle, que recebeu somente água, e Grupo Glifosato, que recebeu água com 0,5% de glifosato durante a prenhez e lactação. Ambos os grupos receberam dieta padrão ad libitum. Após o desmame, as fêmeas foram eutanasiadas e pesadas; o comprimento nasoanal foi mensurado, e as gorduras foram coletadas e pesadas. Os músculos extensor longo dos dedos e sóleo foram coletados, e seu comprimento e peso foram mensurados. Em seguida, os músculos foram fixados em Methacarn para a realização do estudo histológico das fibras musculares. Resultados O Grupo Glifosato apresentou menor ganho de peso durante a prenhez e também menor peso corporal final e comprimento nasoanal, entretanto os demais parâmetros corporais avaliados não apresentaram diferença significativa em relação ao Grupo Controle. Na análise das fibras musculares e do tecido conjuntivo, também não foram observadas diferenças significativas. Conclusão A exposição a 0,5% de glifosato durante a prenhez e lactação resultou em menor ganho de peso na gestação, peso final e comprimento nasoanal, o que pode indicar que, apesar de não alterar a morfologia do tecido muscular diretamente, a exposição foi suficiente para interferir no metabolismo dos animais.

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La respiración es un proceso continuo donde los músculos respiratorios tienen un rol central e imprescindible para la vida. Su óptimo funcionamiento involucra diversas estructuras que deben funcionar de forma armónica y coordinada, para que el gasto energético asociado a sus demandas permita aumentos considerables de carga sin afectar mayormente la función esencial de intercambio gaseoso. Comprender la fisiología muscular, desde la base anatómica hasta su comportamiento en el ejercicio y la enfermedad, es fundamental para detectar con anticipación las diversas disfunciones que se producen cuando este equilibrio se descompensa. El objetivo de esta revisión es entregar las bases fisiológicas del comportamiento de la musculatura respiratoria que permitan comprender y aplicar las mejores estrategias de evaluación y tratamiento, cuando la función normal se ve alterada, ya sea por enfermedad, desuso o altas cargas asociadas al ejercicio físico.

Breathing is a continuous process where the respiratory muscles have a central and essential role for life. Its optimal operation involves various structures that must work in a harmonious and coordinated way, so that the energy expenditure associated with their demands allows considerable increases in load without significantly affecting the essential function of gas exchange. Understanding muscle physiology, from the anatomical basis to its behavior in exercise and disease, is essential to anticipate the various dysfunctions that can occur when this balance is decompensated. The objective of this review is to provide physiological bases for the behavior of the respiratory muscles that allow understanding and applying the best evaluation and treatment strategies, when its correct functioning is altered, either due to illness, disuse or high loads associated with physical exercise.

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Resumen ANTECEDENTES: Los leiomiomas son tumores benignos que se originan en las fibras musculares lisas. La mayor parte de los leiomiomas del aparato genital femenino se localizan en el útero. La localización extrauterina es excepcional, la incidencia del leiomioma vulvar es del 0.07%. Estos tumores del músculo liso suelen ser indoloros, de crecimiento lento y pueden aparecer en mujeres de cualquier edad. OBJETIVO: Reportar un caso de leiomioma vulvar que, por su baja incidencia y similitud clínica con otras lesiones, como el quiste de la glándula de Bartolino, pueden conducir a un diagnóstico erróneo inicial. Además, efectuar una revisión bibliográfica que aporte conocimiento a su diagnóstico y tratamiento. CASO CLÍNICO: Paciente de 52 años, con una masa vulvar de años de evolución y un diagnóstico equívoco inicial de quiste de la glándula de Bartolino. La paciente fue intervenida mediante escisión quirúrgica y estudio histopatológico posterior. El diagnóstico definitivo fue de leiomioma vulvar con diferenciación simplástica. CONCLUSIONES: En contraposición con sus homólogos uterinos, la localización vaginal del leiomioma es excepcional. Si bien hasta ahora no ha podido demostrarse la efectividad de la biopsia preoperatoria se aconseja su toma porque podría tratarse de una masa de características malignas, lo que modificaría el tratamiento y su urgencia. La actitud quirúrgica es, quizá, la más acertada porque permite, además de un diagnóstico anatomopatológico definitivo, un tratamiento curativo. Se propone la escisión completa, mediante una incisión elipsoidal en la piel y asegurar la extirpación completa de la pseudocápsula.

Abstract BACKGROUND: Leiomyomas are benign tumors that originate in smooth muscle fibers. Most leiomyomas of the female genital tract are located in the uterus. Extrauterine localization is exceptional; the incidence of vulvar leiomyoma is 0.07%. These smooth muscle tumors are usually painless, slow growing and can occur in women of any age. OBJECTIVE: To report a case of vulvar leiomyoma that because of its low incidence and clinical similarity to other lesions, such as Bartholin's gland cyst, may lead to an initial misdiagnosis. In addition, a review of the literature should be carried out in order to contribute to its diagnosis and treatment. CLINICAL CASE: A 52-year-old patient with a vulvar mass of years of evolution and an initial misdiagnosis of Bartholin's gland cyst. The patient was operated by surgical excision and subsequent histopathological study. The definitive diagnosis was vulvar leiomyoma with symplastic differentiation. CONCLUSIONS: In contrast to its uterine counterparts, the vaginal location of leiomyoma is exceptional. Although the effectiveness of a preoperative biopsy has not been demonstrated so far, it is advisable to take a biopsy because it could be a mass with malignant characteristics, which would change the treatment and its urgency. The surgical approach is perhaps the most appropriate because it allows, in addition to a definitive anatomopathological diagnosis, a curative treatment. Complete excision is proposed, by means of an ellipsoidal incision in the skin and ensuring complete excision of the pseudocapsule.

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La musculatura masticatoria se caracteriza por presentar fibras híbridas que en los últimos años se han relacionado con el fenómeno de plasticidad muscular. El objetivo del estudio fue describir la relación entre la plasticidad muscular y las fibras musculares híbridas presentes en la musculatura masticatoria, mediante una revisión narrativa de literatura. Para esto, se realizó una búsqueda electrónica en PUBMED, ScienceDirect y BIREME, utilizando las palabras claves: "Muscle Plasticity", "Hybrid Muscle Fibers" y "Hybrid Fibers". Fueron seleccionados documentos que reportan las isoformas de cadena pesada de miosina (MHC) presentes en los músculos masticatorios de humanos y otros mamíferos, junto a los cambios vinculados a demandas funcionales. Se describe la presencia de fibras puras tipo I y tipo II, además de otras isoformas como la MHC-la, MHC-IIM, MHC-fetal y MHC-cardíaca. Sin embargo, un porcentaje considerable de fibras en la musculatura masticatoria son híbridas, es decir, expresan a más de una isoforma de MHC, las cuales también son diferentes a nivel intermuscular e intramuscular. Las influencias locales pueden contribuir a la variación de la expresión del tipo de fibra. En la musculatura masticatoria, el destete, la dureza de los alimentos, el bruxismo, la morfología craneofacial y el uso de prótesis dentales genera cambios a nivel de los músculos masticatorios, donde es común la presencia de fibras híbridas. Se concluye la presencia importante de fibras híbridas en la musculatura masticatoria y su relación con la plasticidad muscular a lo largo del ciclo vital, debido a cambios funcionales y patológicos. Es importante que los terapeutas de habla y motricidad orofacial profundicen en el conocimiento de la fisiología del comportamiento oromiofuncional.

The masticatory musculature is characterized by presenting hybrid fibers that in recent years have been related to the phenomenon of muscle plasticity. The objective of the study was to describe the relationship between muscle plasticity and the hybrid muscle fibers present in the masticatory muscles, through a narrative review. For this, an electronic search was conducted in PUBMED, ScienceDirect and BIREME, using the keywords: "Muscle Plasticity", "Hybrid Muscle Fibers" and "Hybrid Fibers". Documents that report the myosin heavy chain (MHC) isoforms present in the masticatory muscles of humans and other mammals were selected, along with the changes linked to functional demands. The presence of type I and type II pure fibers were described, in addition to other isoforms such as MHC-la, MHC-IIM, MHC-fetal and MHC-cardiac. However, a significant percentage of fibers in the masticatory muscles are hybrids, that is, they express more than one MHC isoform, which are also different at the intermuscular and intramuscular level. Local influences can contribute to the variation of fiber type expression. In the chewing muscles, weaning, the hardness of food, bruxism, craniofacial morphology and the use of dental prostheses generate changes at the level of the chewing muscles, where the presence of hybrid fibers is common. The important presence of hybrid fibers in the masticatory muscles and their relationship with muscle plasticity throughout the life cycle, due to functional and pathological changes, is concluded. It is important for Speech Therapy andMyofunctional Therapy to deepen their understanding of the physiology of oromyofunctional behavior.

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Joint immobilization is commonly used as a conservative treatment for osteoarticular and musculotendinous traumas. However, joint immobilization might elicit degenerative effects on the neuromuscular system and muscle atrophy. For this reason, the choice of strategies that mitigate these effects is essential in the post-immobilization period. Therefore, this study aimed to investigate the impact of aquatic training on the morphology of muscle fibers and motor endplates of the gastrocnemius muscle in the post-immobilization period. Male Wistar rats (90 days old) were divided into groups: Sedentary: no procedure; Immobilization: joint immobilization protocol (10 days); Immobilization/non-training: joint immobilization protocol (10 days) followed by four weeks without exercise intervention; Immobilization/training: joint immobilization protocol (10 days) and post-immobilization aquatic training (4 weeks). After the procedures, we quantified the cross-sectional area (CSA), volume and numerical density of different myofibers types, and total and stained area and perimeter of the motor endplate. We demonstrate the following main results: (a) short-term joint immobilization resulted in myofibers atrophy; however, we verified a small change in the postsynaptic component; (b) the period of inactivity after immobilization caused severe changes in the motor endplate (lower stained area, stained perimeter, total area, and total perimeter) and maintenance of muscle atrophy due to immobilization; (c) the prescription of post-immobilization exercise proved to be effective in restoring muscle morphology and inducing plasticity in the motor endplate. We conclude that short-term joint immobilization (10 days) results in atrophy type I and II myofibers, in addition to a decline in the total perimeter of the motor endplate. Besides, the post-immobilization period appears to be decisive in muscle and postsynaptic remodeling. Thus, aquatic training is effective in stimulating adjustments associated with muscle hypertrophy and plasticity of the motor endplate during the post-immobilization period.

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The aim of this study was to describe the first occurrence ofKudoasp. inGobioides grahamae, contributing to the understanding of this group of parasites in the Amazonian ichthyofauna. Forty specimens ofG. grahamaecollected from the natural environment were analyzed. Cysts ofKudoasp. were diffusely distributed through the striated skeletal muscle fibers with severe edema and inflammatory infiltrate composed of lymphocytes were observed in 30% of the specimens. Edema and marked coagulation necrosis of the muscle fibers was associated with infection byKudoasp. spores, which had accumulated inside the skeletal muscle fibers. Although there are no records of foodborne outbreaks caused by Kudoa spp. in Brazil, it is of paramount importance that we evaluate its occurrence, since the consumption of fish, especially raw fish, has increased because of the adoption of Japanese cuisine. To minimize the economic impacts on the fisheries market and the risk of this parasite to public health, it is necessary to initiate a program to monitor the presence of this likely underdiagnosed, emerging parasite.(AU)

O objetivo deste estudo foi descrever a primeira ocorrência de Kudoa sp. em Gobioides grahamae, contribuindo, assim, para a compreensão desse grupo de parasitas na ictiofauna amazônica. Foram analisados 40 espécimes de G. grahamae coletados de ambiente natural. Cistos de Kudoa sp. foram distribuídos difusamente através das fibras musculares esqueléticas estriadas com presença de edema grave e infiltrado inflamatório composto de linfócitos, que foram observados em 30% dos espécimes. Edema e necrose de coagulação acentuada das fibras musculares foram associados com a infecção por esporos de Kudoa sp., acumulados no interior das fibras musculares da faringe. Apesar de não haver registros de surtos de origem alimentar causada por Kudoa spp. no Brasil, é de suma importância a avaliação de sua ocorrência, uma vez que o consumo de peixe, especialmente peixe cru, aumentou por causa da adoção da culinária japonesa. Para minimizar os impactos econômicos no mercado da pesca e o risco desse parasita para a saúde pública, é necessário iniciar um programa para monitorar a presença desse parasita emergente, possivelmente subdiagnosticada.(AU)

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The aim of this study was to describe the first occurrence ofKudoasp. inGobioides grahamae, contributing to the understanding of this group of parasites in the Amazonian ichthyofauna. Forty specimens ofG. grahamaecollected from the natural environment were analyzed. Cysts ofKudoasp. were diffusely distributed through the striated skeletal muscle fibers with severe edema and inflammatory infiltrate composed of lymphocytes were observed in 30% of the specimens. Edema and marked coagulation necrosis of the muscle fibers was associated with infection byKudoasp. spores, which had accumulated inside the skeletal muscle fibers. Although there are no records of foodborne outbreaks caused by Kudoa spp. in Brazil, it is of paramount importance that we evaluate its occurrence, since the consumption of fish, especially raw fish, has increased because of the adoption of Japanese cuisine. To minimize the economic impacts on the fisheries market and the risk of this parasite to public health, it is necessary to initiate a program to monitor the presence of this likely underdiagnosed, emerging parasite.(AU)

O objetivo deste estudo foi descrever a primeira ocorrência de Kudoa sp. em Gobioides grahamae, contribuindo, assim, para a compreensão desse grupo de parasitas na ictiofauna amazônica. Foram analisados 40 espécimes de G. grahamae coletados de ambiente natural. Cistos de Kudoa sp. foram distribuídos difusamente através das fibras musculares esqueléticas estriadas com presença de edema grave e infiltrado inflamatório composto de linfócitos, que foram observados em 30% dos espécimes. Edema e necrose de coagulação acentuada das fibras musculares foram associados com a infecção por esporos de Kudoa sp., acumulados no interior das fibras musculares da faringe. Apesar de não haver registros de surtos de origem alimentar causada por Kudoa spp. no Brasil, é de suma importância a avaliação de sua ocorrência, uma vez que o consumo de peixe, especialmente peixe cru, aumentou por causa da adoção da culinária japonesa. Para minimizar os impactos econômicos no mercado da pesca e o risco desse parasita para a saúde pública, é necessário iniciar um programa para monitorar a presença desse parasita emergente, possivelmente subdiagnosticada.(AU)

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The enzymatic complex Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase (NOx) may be the principal source of reactive oxygen species (ROS). The NOX2 and NOX4 isoforms are tissue-dependent and are differentially expressed in slow-twitch fibers (type I fibers) and fast-twitch fibers (type II fibers) of skeletal muscle, making them different markers of ROS metabolism induced by physical exercise. The aim of this study was to investigate NOx signaling, as a non-adaptive and non-cumulative response, in the predominant fiber types of rat skeletal muscles 24 h after one strenuous treadmill exercise session. The levels of mRNA, reduced glycogen, thiol content, NOx, superoxide dismutase, catalase, glutathione peroxidase activity, and PPARGC1α and SLC2A4 gene expression were measured in the white gastrocnemius (WG) portion, the red gastrocnemius (RG) portion, and the soleus muscle (SOL). NOx activity showed higher values in the SOL muscle compared to the RG and WG portions. The same was true of the NOX2 and NOX4 mRNA levels, antioxidant enzymatic activities, glycogen content. Twenty-four hours after the strenuous exercise session, NOx expression increased in slow-twitch oxidative fibers. The acute strenuous exercise condition showed an attenuation of oxidative stress and an upregulation of antioxidant activity through PPARGC1α gene activity, antioxidant defense adaptations, and differential gene expression according to the predominant fiber type. The most prominent location of detoxification (indicated by NOX4 activation) in the slow-twitch oxidative SOL muscle was the mitochondria, while the fast-twitch oxidative RG portion showed a more cytosolic location. Glycolytic metabolism in the WG portion suggested possible NOX2/NOX4 non-regulation, indicating other possible ROS regulation pathways.

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The current study was conducted to develop the correlations between muscle fiber characteristics and meat quality attributes in the biceps femoris muscle of Arbor Acres (AA) and Yellow-feathered chicken (YFC). A total of fourty pure breed birds of AA (n=20) and YFC (n=20) were used in the experiment. After slaughtering at their respective market age of slaughtering: AA 40 d and YFC 120 d, samples were collected for meat quality attributes and myosin ATPase staining for fiber types analyses. Meat quality attributes and muscle fiber characteristics i-e; diameter, cross-sectional area (CSA) and density of AA were significantly different from the YFC (p 0.05). Type I fibers number percentage was significantly higher in YFC than AA, whereas CSA and fiber diameter were higher in AA (p 0.05). Negative correlations were obtained between lightness (L*) and type I fiber number percentage in AA (p 0.05). In YFC fiber number percentage, CSA and diameter of type IIA were negatively correlated with Warner-Bratzler Shear Force. Taken together, muscle fibers characteristics of AA and YFC differ in both breeds and have influenced the meat quality attributes.

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The current study was conducted to develop the correlations between muscle fiber characteristics and meat quality attributes in the biceps femoris muscle of Arbor Acres (AA) and Yellow-feathered chicken (YFC). A total of fourty pure breed birds of AA (n=20) and YFC (n=20) were used in the experiment. After slaughtering at their respective market age of slaughtering: AA 40 d and YFC 120 d, samples were collected for meat quality attributes and myosin ATPase staining for fiber types analyses. Meat quality attributes and muscle fiber characteristics i-e; diameter, cross-sectional area (CSA) and density of AA were significantly different from the YFC (p 0.05). Type I fibers number percentage was significantly higher in YFC than AA, whereas CSA and fiber diameter were higher in AA (p 0.05). Negative correlations were obtained between lightness (L*) and type I fiber number percentage in AA (p 0.05). In YFC fiber number percentage, CSA and diameter of type IIA were negatively correlated with Warner-Bratzler Shear Force. Taken together, muscle fibers characteristics of AA and YFC differ in both breeds and have influenced the meat quality attributes.(AU)

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This study aimed to evaluate the effects of antioxidant supplementation in diets of breeding roosters during the post-peak phase on reproduction characteristics and muscle performance of offspring in two similar breeder houses from a local company. Treatments consisted of a control diet and a diet supplemented with antioxidants (8 ppm canthaxanthin + 40 ppm lycopene + 150 ppm vitamin C). During the 66th week of age, eggs were incubated, and offspring were housed. Dietary supplementation of the blend of antioxidant resulted in higher (p<0.05) weights of testicles, crests, dewlaps, dewlap thickness, and number of perforations (53.35 x 25.30) in relation to non-supplemented roosters. There was no significant effect (p>0.05) of supplementation of the antioxidant blend on weight gain and breast weight and count and diameter of muscle fibers of offspring at 7 days of age. Feed conversion and weight gain from 14 to 35 days were better (p<0.05) in offspring from supplemented roosters. The supplementation of an antioxidant blend in roosters improved reproductive characteristics assessed and feed conversion and weight gain of offspring.(AU)

O objetivo foi avaliar o efeito da suplementação de antioxidantes em dietas para reprodutores machos de frangos de corte na fase pós-pico sobre características reprodutivas e muscular da progênie. O experimento foi conduzido no matrizeiro de uma agroindústria local. Os tratamentos consistiram em uma dieta controle e uma dieta suplementada com blend de antioxidantes (8 ppm de cantaxantina + 40 ppm de licopeno + 150 ppm de vitamina C). Na 66ª semana de idade, os ovos foram incubados e a progênie foi alojada. A suplementação de antioxidantes na dieta resultou em maior (p<0,05) peso de testículos, cristas, peso e espessura de barbelas e maior número de perfurações (53,35 x 25,30) em relação aos não suplementados. Não houve efeito significativo (p>0,05) dos antioxidantes na dieta dos reprodutores sobre o ganho de peso e o peso de peito e a contagem e diâmetro da fibra muscular da progênie aos 7 dias de idade. A conversão alimentar e ganho de peso na fase de 14 a 35 dias foram melhores (p<0,05) para a progênie dos reprodutores suplementados. A suplementação de antioxidantes na dieta dos reprodutores melhorou as características reprodutivas avaliadas e o ganho de peso e a conversão alimentar da progênie.(AU)

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SUMMARY OBJECTIVE: With high-resolution real-time ultrasonography we investigated the muscle architectural parameters of vastus lateralis in healthy volunteers. PURPOSES: We determined the reproducibility and validity of ultrasonography and the role of the ultrasonographer in assessing muscle architecture. We proposed the most appropriate clinical parameters for objective measurements and an ultrasound protocol of muscle architecture. METHODS: We conducted an intraobserver and interobserver study. We investigated 21 healthy male volunteers. The subjects were independently evaluated by four different operators using high-resolution real-time ultrasonography. To assess the reproducibility of ultrasound examinations, four operators repeated measurements using the same ultrasound device. Muscle thickness, muscle volume, muscle fiber pennation angle, and subcutaneous adiposity of the vastus lateralis muscle were measured. RESULTS: Intra-observer (ICC 0.92-0.97), interobserver (ICC 0.78-0.92) reproducibility was good to excellent for all measurements. CONCLUSION: Simple, reproducible, non-invasive ultrasound measurements of muscle structure easily demonstrated differences in muscle morphology. With a protocol and with objective and repeatable measurements, sonographers from different backgrounds could obtain an objective measurement of ultrasound images with little differences and low variability in results, thanks to the upgrading of diagnostic ultrasound imaging and their clinical skills.

RESUMO OBJETIVO: Nós utilizamos ultrassonografia de alta resolução em tempo real para investigar os parâmetros da arquitetura muscular do vasto lateral em voluntários saudáveis. PROPÓSITO: Nós determinamos da reproduzibilidade e validade da ultrassonografia e o papel do ultrassonografista na avaliação da arquitetura muscular. Nós propomos os parâmetros clínicos mais apropriados para uma medição objetiva e um protocolo de ultrassonografia para arquitetura muscular. MÉTODOS: Nós conduzimos um estudo intra-observador e inter-observador. Investigamos 21 voluntários saudáveis do sexo masculino. Os participantes foram avaliados de forma independente por quatro operadores diferentes usando ultrassonografia de alta-resolução em tempo real. Para avaliar a reprodutibilidade dos exames de ultrassonografia, quatro operadores repetiram as medições usando o mesmo equipamento de ultrassonografia. A espessura e o volume do músculo, o ângulo de penação da fibra muscular, adiposidade subcutânea do músculo vasto lateral foram medidos. RESULTADOS: A reprodutibilidade intra-observador (ICC 0,92-0,97) e inter-observador (ICC 0,78-0,92) foi boa a excelente para todas as medições. CONCLUSÃO: Medições de ultrassonografia simples, reprodutíveis e não-invasivas da estrutura muscular demostraram facilmente as diferenças na morfologia muscular. Seguindo um protocolo e com medições objetivas e reproduzíveis, ultrassonografistas com diferentes formações e experiências podem conseguir uma medição objetiva de imagens de ultrassonografia com poucas diferenças e pouca variação nos resultados graças à melhoria da qualidade nos exames de diagnóstico por imagem de ultrassonografia e das habilidades clínicas.

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