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1.
Rio de Janeiro; s.n; 2021. 135 f p. ilus.
Thesis in Portuguese | LILACS | ID: biblio-1353763

ABSTRACT

O músculo esquelético é responsável pelo movimento e manutenção da postura, e é um órgão produtor de miocinas e altamente metabólico, onde alterações em sua fisiologia podem ter consequências sistêmicas. Esse tecido é alvo para diferentes arboviroses, e mialgia é um sintoma frequentemente relatado. O músculo esquelético é composto majoritariamente por fibras musculares, e uma pequena população de células progenitoras denominadas células satélites (SC), que em caso de lesão podem ser ativadas, proliferam e se diferenciam, sendo capazes de regenerar o tecido muscular. Recentemente nosso grupo demonstrou que SC em proliferação (mioblastos) são infectadas pelo vírus ZIKA (ZIKV), enquanto células diferenciadas e fusionadas (miotubos) não apresentam proteínas virais. O presente trabalho avaliou alterações miogênicas e o perfil transcricional de mioblastos e miotubos humanos após tratamento com ZIKV, com o objetivo de identificar fatores e mecanismos envolvidos na susceptibilidade e resistência destas células à infecção. Confirmamos infecção produtiva do ZIKV nos mioblastos, que apresentaram uma redução no número de células expressando a molécula KI67 em altas concentrações (característico de células em mitose). A análise de sequenciamento mostrou perturbação das vias do ciclo celular em mioblastos infectados, que ainda apresentaram enriquecimento de vias relacionadas à morte celular. Também confirmamos a ausência de infecção produtiva nos miotubos. Interessantemente, verificamos que o ZIKV entra nas células diferenciadas, mas não consegue replicar o RNA viral, e a análise do transcriptoma identificou um enriquecimento de vias e modulação de genes antivirais maior ou exclusivamente nas células diferenciadas em comparação aos mioblastos infectados. Além disso, miotubos expostos ao ZIKV aparentam ter aumento de fusão/hipertrofia. Ao contrário dos mioblastos, miotubos apresentaram enriquecimento de vias relacionadas a organização da matriz extracelular. Dados preliminares do nosso grupo mostraram que o cultivo de mioblastos sobre a isoforma de laminina 511 levou à redução da infecção pelo ZIKV. Contudo, em nossos ensaios, a infecção pelo ZIKV não modulou a expressão de receptores para LM e o bloqueio do receptor de LM, a integrina α6, não reduziu a infecção pelo ZIKV em mioblastos. Nosso trabalho mostrou que a infecção pelo ZIKV induz resposta imune e antiviral, que foram enriquecidos em mioblastos e miotubos, sendo que estes apresentaram uma assinatura única de vias e genes antivirais, que poderiam explicar a resistência frente ao ZIKV.


Subject(s)
Arbovirus Infections , Muscle Fibers, Skeletal , Myoblasts , Extracellular Matrix , Zika Virus
2.
Einstein (Säo Paulo) ; 19: eAO5657, 2021. tab, graf
Article in English | LILACS | ID: biblio-1286305

ABSTRACT

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.


Subject(s)
Animals , Female , Pregnancy , Mice , Muscle, Skeletal , Muscle Fibers, Skeletal , Lactation , Glycine/analogs & derivatives , Mice, Inbred C57BL
3.
Rev. chil. fonoaudiol. (En línea) ; 19: 1-7, nov. 2020. tab
Article in Spanish | LILACS | ID: biblio-1148408

ABSTRACT

Los actuales protocolos de intervención en deglución no especifican parámetros de los ejercicios tales como la cantidad de series, duración, tiempos de repetición, entre otros. Lo anterior, es un desafío para la intervención fonoaudiológica en los trastornos de la deglución. El objetivo de este trabajo es acercar al profesional fonoaudiólogo al conocimiento de las fibras musculares, ya que es un conocimiento que se debe considerar antes de indicar ejercicios musculares cráneo-cérvico-orales. Por ello, se describen las principales fibras musculares con sus respectivas características fundamentales, como lo son: la resistencia a la fatiga y la velocidad de contracción. Se revisa la literatura sobre la dispersión de las fibras musculares, de algunos de los principales músculos que participan en el proceso deglutorio. También, se analizan diversas particularidades de los músculos de la zona cráneo-cérvico-oral. Se describen además las diferentes dificultades para evaluar esta musculatura. Finalmente, se expone la relevancia práctica de conocer estos tipos de fibras musculares y las perspectivas futuras de este enfoque basado en parámetros del ejercicio y la medición de variables objetivas.


Swallowing intervention protocols in dysphagia do not specify the parameters of the exercises, namely the duration, frequencyand number of series, all of which present a challenge in speech therapy intervention in swallowing disorders. The purpose of this review is to provide Speech and Language Pathologists with background information concerning crucial muscle fibres used in swallowing therapy and to subsequently indicate appropriate skull-cervical-oral muscle exercises. We describe the primary muscle and its characteristics such as fatigue resistance and contraction speed, review the types of fibres of some of the main muscles that participate in the swallowing process, and present the particularities of the muscles of the cranio-cervical-oral area in comparison with the rest of the skeletal muscles. We also provide information regarding the difficulties in evaluating the musculature involvedin the swallowing process before finally highlighting the relevance of understanding the roles and characteristics of these muscles for clinical practice


Subject(s)
Humans , Deglutition Disorders/rehabilitation , Muscle Fibers, Skeletal/physiology , Exercise Therapy , Muscle Fibers, Skeletal/classification , Speech, Language and Hearing Sciences
4.
Int. j. med. surg. sci. (Print) ; 7(3): 1-11, sept. 2020. ilus
Article in Spanish | LILACS | ID: biblio-1178941

ABSTRACT

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.


Subject(s)
Humans , Muscle Fibers, Skeletal , Speech, Language and Hearing Sciences , Masticatory Muscles
5.
Rev. Asoc. Méd. Argent ; 133(1): 12-20, mar. 2020. graf, tab
Article in Spanish | LILACS | ID: biblio-1097697

ABSTRACT

La rigidez cadavérica (rigor mortis) es un proceso no muy bien comprendido por la mayoría de los médicos. El conocimiento de la intimidad del proceso de la rigidez cadavérica es de vital importancia ya que es una de las variables que junto con las livideces (livor mortis) y la temperatura (algor mortis) del cadáver ayudan a determinar el cronotanatodiagnóstico, tanatocronodiagnóstico o intervalo postmortal del período inmediato de la muerte. Para entender el mecanismo de la rigidez y el espasmo cadavérico es preciso hacer un repaso de la contracción muscular fisiológica en el vivo. Hay que tener presente que el tipo de fibra muscular predominante modificará las características de la contracción muscular fisiológica en el vivo, y también la rigidez y el espasmo cadavérico. (AU)


The cadaveric rigidity (rigor mortis) is a process which is not very well understood by the majority of the doctors. The knowledge of the intimacy of the cadaveric stiffness process is of vital importance since it is one of the variables that, as well as the postmortem lividity (livor mortis) and the body temperature post mortem (algor mortis) help determine the chronotanatodiagnostic, tanatochronodiagnostic or postmortal interval of the immediate period of death. In order to understand the mechanism of stiffness and cadaveric spasm, it is necessary to review the physiological muscle contraction in vivo. We should keep in mind that the predominant type of muscle fiber will modify the characteristics of physiological muscle contraction in vivo, as well as stiffness and cadaveric spasm. (AU)


Subject(s)
Humans , Rigor Mortis/physiopathology , Spasm/physiopathology , Muscle Fibers, Skeletal/classification , Muscle Fibers, Skeletal/physiology , Time Factors , Muscle Contraction/physiology , Muscle Relaxation/physiology
6.
Fisioter. Pesqui. (Online) ; 26(1): 31-36, Jan.-Mar. 2019. tab
Article in Portuguese | LILACS | ID: biblio-1002014

ABSTRACT

RESUMO O Acidente Vascular Encefálico (AVE) é uma patologia que frequentemente causa limitações motoras nos Membros Superiores (MMSS) gerando prejuízos funcionais nos movimentos de alcance. O objetivo do estudo foi analisar o recrutamento muscular do membro superior parético durante três condições de alcance: ativo, ativo-assistido e autoassistido, através de dados eletromiográficos das fibras anteriores do Músculo Deltoide (MD), Bíceps Braquial (BB) e Tríceps Braquial (TB). Estudo do tipo transversal que utilizou como testes clínicos o miniexame do estado mental, escala de equilíbrio de Berg, medida de independência funcional, escala modificada de Ashworth e escala de Fugl-Meyer - seção MMSS. A coleta dos dados eletromiográficos de superfície foi realizada utilizando-se o eletromiógrafo e eletrodos de configuração bipolar da EMG System do Brasil com três canais posicionados nos pontos motores do MD (fibras anteriores), BB e TB de ambos os membros superiores. As variáveis clínicas apresentaram resultados de comprometimento motor, cognitivo e funcional leves. Os dados eletromiográficos mostraram que o MD e TB durante o alcance ativo-assistido contraíram mais que no alcance autoassistido (p<0.05). Os MD e TB apresentaram diferenças significativas durante os movimentos de alcance, enquanto que o músculo BB não mostrou alterações. Entre os diversos tipos de alcance, o ativo-assistido foi o que proporcionou maior ativação muscular. Sugere-se que sejam feitos ensaios clínicos para verificar a eficácia dos treinamentos.


RESUMEN El Accidente Vascular Encefálico (AVE) es una patología que frecuentemente causa limitaciones motoras en los Miembros Superiores (MMSS) generando perjuicios funcionales en los movimientos de alcance. El objetivo del estudio fue analizar el reclutamiento muscular del miembro superior parético durante tres condiciones de alcance: activo, activo-asistido y auto-asistido, a través de datos electromiográficos de las fibras anteriores del Músculo Deltóide (MD), Bíceps Braquial (BB) y Tríceps Braquial (TB). Estudio del tipo transversal que utilizó como pruebas clínicas el mini-examen del estado mental, escala de equilibrio de Berg, medida de independencia funcional, escala modificada de Ashworth y escala de Fugl-Meyer - sección MMSS. La recolección de los datos electromiográficos de superficie fue realizada utilizando el electromiografo y electrodos de configuración bipolar de la EMG System de Brasil con tres canales colocados en los puntos motores del MD (fibras anteriores), BB y TB de ambos miembros superiores. Las variables clínicas presentaron resultados de compromiso motor, cognitivo y funcional leves. Los datos electromiográficos mostraron que el MD y el TB durante el alcance activo-asistido contrajeron más que en el alcance auto-asistido (p<0.05). Los MD y TB presentaron diferencias significativas durante los movimientos de alcance, mientras que el músculo BB no mostró alteraciones. Entre los diversos tipos de alcance, el activo asistido fue el que proporcionó mayor activación muscular. Se sugiere que se realicen ensayos clínicos para verificar la eficacia de los entrenamientos.


ABSTRACT A cerebrovascular accident (CVA) is a disease that often causes upper limb motor limitations and functional losses in reaching movements. The objective of this study was to analyze the muscle recruitment of the paretic upper limb during three reaching conditions: active, active-assisted and self-assisted, through electromyographic data of anterior fibers of Deltoid Muscle (DM), Biceps Brachii (BB) and Triceps Brachii (TB). Cross-sectional study that used as clinical trials the Mini-Mental State Examination, Berg balance scale, functional independence measure, the modified Ashworth scale, and the Fugl-Meyer assessment - upper limbs section. Surface electromyographic data were collected using the electromyograph and bipolar electrode configuration of the EMG System do Brasil with three channels positioned in the motor points of DM (anterior fibers), BB and TB of both upper limbs. Clinical variables showed mild motor, cognitive, and functional impairment. Electromyographic data showed that DM and TB contracted more during active-assisted than during self-assisted exercise (p<0.05). DM and TB presented significant differences during reaching movements, while the BB muscle showed no changes. Among the different reaching exercises, the active-assisted was the one that provided greater muscle activation. Clinical trials are suggested to verify the effectiveness of the training.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Stroke/therapy , Electromyography , Exercise Therapy , Cross-Sectional Studies , Physical Therapy Modalities , Muscle Fibers, Skeletal/physiology , Deltoid Muscle/physiopathology , Hamstring Muscles/physiopathology
7.
Article in English | WPRIM | ID: wpr-761809

ABSTRACT

Anoctamin 5 (ANO5)/TMEM16E belongs to a member of the ANO/TMEM16 family member of anion channels. However, it is a matter of debate whether ANO5 functions as a genuine plasma membrane chloride channel. It has been recognized that mutations in the ANO5 gene cause many skeletal muscle diseases such as limb girdle muscular dystrophy type 2L (LGMD2L) and Miyoshi muscular dystrophy type 3 (MMD3) in human. However, the molecular mechanisms of the skeletal myopathies caused by ANO5 defects are poorly understood. To understand the role of ANO5 in skeletal muscle development and function, we silenced the ANO5 gene in C2C12 myoblasts and evaluated whether it impairs myogenesis and myotube function. ANO5 knockdown (ANO5-KD) by shRNA resulted in clustered or aggregated nuclei at the body of myotubes without affecting differentiation or myotube formation. Nuclear positioning defect of ANO5-KD myotubes was accompanied with reduced expression of Kif5b protein, a kinesin-related motor protein that controls nuclear transport during myogenesis. ANO5-KD impaired depolarization-induced [Ca²⁺]i transient and reduced sarcoplasmic reticulum (SR) Ca²⁺ storage. ANO5-KD resulted in reduced protein expression of the dihydropyridine receptor (DHPR) and SR Ca²⁺-ATPase subtype 1. In addition, ANO5-KD compromised co-localization between DHPR and ryanodine receptor subtype 1. It is concluded that ANO5-KD causes nuclear positioning defect by reduction of Kif5b expression, and compromises Ca²⁺ signaling by downregulating the expression of DHPR and SERCA proteins.


Subject(s)
Active Transport, Cell Nucleus , Calcium Channels, L-Type , Cell Membrane , Chloride Channels , Humans , Muscle Development , Muscle Fibers, Skeletal , Muscle, Skeletal , Muscular Diseases , Muscular Dystrophies , Muscular Dystrophies, Limb-Girdle , Myoblasts , RNA, Small Interfering , Ryanodine Receptor Calcium Release Channel , Sarcoplasmic Reticulum
8.
Article in Chinese | WPRIM | ID: wpr-776569

ABSTRACT

OBJECTIVE@#To investigate the expression of EGR1 gene and the localization of EGR1 protein in bovine skeletal muscle-derived satellite cells (MDSCs), as well as to investigate the mechanism that EGR1 protein enters the nucleus.@*METHODS@#Bovine MDSCs were cultured in differentiation medium for 1 day, 3 days and 5 days, respectively, and each group was triplicate. The expression of EGR1 gene and the localization of EGR1 protein were studied at different differentiation period in MDSCs by qRT-PC and Western blot. Moreover, the changes on the expression of endogenous EGR1 gene and EGR1 proteins were explored by CRISPRi, site-directed mutagenesis and laser confocal method.@*RESULTS@#The results from the qRT-PCR and Western blot showed that the expressions of EGR1 gene on transcription level and translation level were significantly higher in differentiated cells than those in undifferentiated cells. The highest expression was found on the third day after the differentiation, and then began to decline. Immunofluorescence assays showed that EGR1 proteins were preferentially expressed in differentiated MDSCs, and increased along with the increase of number of myotubes. Confocal observation revealed that some EGR1 proteins were transferred into the nucleus in the differentiation of cells, however, the EGR1 proteins would not be detected in the differentiated MDSCs nuclei if a site directed mutagenesis (serine) on EGR1 protein occurred.@*CONCLUSION@#During the differentiation of bovine skeletal muscle satellite cells, the transcriptional level of EGR1 gene is increased, and some EGR1 proteins are transferred into the nucleus. The serine phosphorylation at position 533 of the C terminal of EGR1 protein is necessary for the nucleus transfer.


Subject(s)
Animals , Cattle , Cell Differentiation , Cell Nucleus , Cells, Cultured , Early Growth Response Protein 1 , Genetics , Metabolism , Muscle Fibers, Skeletal , Satellite Cells, Skeletal Muscle , Metabolism
9.
Article in Chinese | WPRIM | ID: wpr-776525

ABSTRACT

OBJECTIVE@#To investigate the therapeutic effects of massage on denervated skeletal muscle atrophy in rats and its mechanism.@*METHODS@#Forty-eight male SD rats were randomly divided into model group (n=24) and massage group (n=24). Gastrocnemius muscle atrophy model was established by transecting the right tibial nerve of rat. On the second day after operation, the gastrocnemius muscle of the rats in the massage group was given manual intervention and the model group was not intervened. Six rats were sacrificed at the four time points of 0 d, 7 d, 14 d and 21 d. The gastrocnemius of the rats were obtained and measured the wet mass ratio after weighing. Cross-sectional area and diameter of the muscle fiber were measured after HE staining. The relative expressions of miR-23a, Akt, MuRF1 and MAFbx mRNA were tested with qPCR.@*RESULTS@#Compared with 0 d, the wet weight ratio, cross-sectional area and diameter of gastrocnemius muscle showed a progressive decline in the model group and massage group. The wet weight ratio, cross-sectional area and diameter of gastrocnemius muscle in the massage group were higher than those in the model group on 7 d, 14 d and 21 d (P<0.05, P<0.01). Compared with 0 d, the expressions of MuRF1, MAFbx and Akt mRNA were increased first and then were decreased in the model group and massage group. The expression of MuRF1 mRNA in massage group was lower than that in model group on 7 d and 21 d (P<0.05, P<0.01). The expression of MAFbx mRNA in massage group was lower than that in model group on 7 d, 14 d and 21 d (P<0.01, P<0.05, P<0.01). The expression of Akt mRNA in massage group was higher than that in model group on 7 d, 14 d and 21 d (P<0.05, P<0.01). Compared with 0 d, the expression of miR-23a mRNA was increased in the model group and massage group on 21 d, and the expression of miR-23a mRNA in massage group was higher than that in model group (P< 0.05).@*CONCLUSION@#Massage can delay the atrophy of denervated skeletal muscle. The mechanism may be related to up-regulation of the expression of miR-23a and Akt mRNA, down-regulation of the expressions of MuRF1 and MAFbx mRNA, inhibition of protein degradation rate, and reduction of skeletal muscle protein degradation.


Subject(s)
Animals , Male , Massage , MicroRNAs , Metabolism , Muscle Fibers, Skeletal , Muscle Proteins , Metabolism , Muscle, Skeletal , Muscular Atrophy , Therapeutics , Proto-Oncogene Proteins c-akt , Metabolism , Rats , Rats, Sprague-Dawley , SKP Cullin F-Box Protein Ligases , Metabolism , Tripartite Motif Proteins , Metabolism , Ubiquitin-Protein Ligases , Metabolism
10.
Article in Chinese | WPRIM | ID: wpr-773881

ABSTRACT

OBJECTIVE@#To detect the core muscle group in the patients with myofascial pain syndromes(MPS) by using the surface electromyography; to detect the distribution of muscle fiber type by the analysis of the median frequency and the slope of the median frequency.@*METHODS@#From October 2017 to March 2018, there were 100 patients with the MPS, including 45 males and 55 females; the average age was 48.5 years old, ranging from 29 to 76 years old. There were 40 cases of left back pain and 60 cases of right back pain. The course of illness was more than 6 months. Another 40 healthy patients without pain in the waist were included in the control group, 20 males and 20 females; the average age was 47.3 years old, ranging from 29 to 76 years old. All the patients had different degrees of back pain and muscle stiffness, which were diagnosed as lumbar fasciitis by clinical and imaging examination. Surface electromyography was used to measure the characteristics of the lumbar core muscles (multifissions, iliocostal muscles, and longest muscle) of the three groups in the Biering-Sorensen testing, such as median frequency(MF) and absolute slope of median frequency (MFs).@*RESULTS@#The MF values of the multifidus muscle in the three groups were as follows:the left side of the non-pain group was 133.88±26.61, and the right side was 131.39±29.81; left side of lift side pain group 117.29±10.93, right side 133.70±17.81; in the right pain group, the left side was 131.36±17.37, and the right side was 118.28±13.57. The MF values of the iliocostal muscle in the three groups were:106.94±28.01 on the left side of the non-pain group, 114.68±18.96 on the right side; left side of lift side pain group 93.95±11.17, right side 107.60±27.86; in the right pain group, the left side was 105.93±15.52, and the right side was 97.27±19.27. The MF values of the longest muscle in the three groups were:109.24±26.20 on the left side of the non-pain group, 112.58±17.70 on the right side. Left side of left side pain group 95.58±10.83, right side 108.79±26.39; in the right pain group, the left side was 106.50±17.98, and the right side was 98.20±11.16. The MFs values of the multifidus muscle in the three groups were:0.221±0.109 on the left side of the non-pain group, and 0.259±0.169 on the right side; left side of left side pain group 0.318±0.184, right side 0.210±0.159; in the right pain group, the left side was 0.258±0.169, and the right side was 0.386±0.166. The MFs values of the iliocostal muscles in the three groups were:0.241±0.158 for the left side of the non-pain group, and 0.238±0.128 for the right side. Left side of left side pain group 0.330±0.208, right side 0.252±0.171; in the right side pain group, left side 0.249±0.150, right side 0.343± 0.144. The MFs values of the longest muscle of the three groups were:0.244±0.252 on the left side of the non-pain group, and 0.210±0.128 on the right side; left side of left side pain group 0.348±0.255, right side 0.241±0.224; in the right pain group, the left side was 0.239±0.155, and the right side was 0.334±0.233. There were no statistically significant differences in MF and MFs values of the left and right lumbar multifidus muscle, iliocostal muscle and longest muscle in the non-pain group(>0.05). MF values of the pain side multifidus muscle, iliocostal muscle and longest muscle in the lumbago group were lower than those in the non-pain group(<0.05). MFs values of the painful side multifidus muscle, iliocostal muscle and longest muscle in the low back pain group were higher than those in the non-pain group(<0.05).@*CONCLUSIONS@#The muscle fatigue degree of the back muscle in the pain side of patients with MPs is decreased, and the muscle fiber type is dominated by II muscle fiber.


Subject(s)
Adult , Aged , Electromyography , Female , Humans , Low Back Pain , Male , Middle Aged , Muscle Fatigue , Muscle Fibers, Skeletal , Muscle, Skeletal , Myofascial Pain Syndromes
11.
Acta cir. bras ; 34(5): e201900503, 2019. tab, graf
Article in English | LILACS | ID: biblio-1010873

ABSTRACT

Abstract Purpose: To analyze the muscle changes with high-intensity aerobic training (HIAT) in an animal model of renal disease (RD). Methods: Twenty one adult Wistar rats were divided into 3 groups: healthy sedentary (HS), RD sedentary (RDS), RD aerobic training (RDAT). RDS and RDAT were subjected to unilateral renal ischemia-reperfusion (10 min) and 21days after that, RDAT was subjected to 6 weeks HIAT (swimming). Serum creatinine (Cr) and muscle morphometry (cross-sectional area = CSA) of gastrocnemius were analyzed. Results: Cr was higher (p = 0.0053) in RDS (0.82 ± 0.04) than in the others (RDAT 0.55 ± 0.04; HS 0.55 ± 0.04). Morphometric analysis (class interval of CSA in μm2/absolute frequency of muscle fibers in each class) indicated that 50th percentile occurred in: HS 7th class (3000.00-3499.00/515), RDS, 8th class (3500.00-3999.00/484), RDAT 5th class (2000.00-2499.00/856). CSA of largest fibers in RDS, RDAT, HS was 9953.00 μm2, 9969.00 μm2,11228.00 μm2, respectively. High frequency of fibers with lower CSA occurred in 4th, 5th, 6th and 7th class in RDA, absence of fibers into 22nd, 23rd classes (RDS and RDAT). Conclusion: HIAT in an animal model of RD resulted in increased the number of muscle fibers with smaller CSA.


Subject(s)
Animals , Physical Conditioning, Animal/physiology , Muscle, Skeletal/physiopathology , Renal Insufficiency/physiopathology , Reference Values , Swimming/physiology , Body Weight/physiology , Reperfusion Injury/physiopathology , Reproducibility of Results , Rats, Wistar , Muscle Fibers, Skeletal/physiology , Creatinine/blood , Disease Models, Animal , Sedentary Behavior , Kidney/physiopathology , Kidney/blood supply
12.
Int. j. morphol ; 36(3): 859-863, Sept. 2018. graf
Article in English | LILACS | ID: biblio-954198

ABSTRACT

The articularis genus, which lies under the vastus intermedius, has been regarded as part of the quadriceps femoris. However, they are well known to have different function because their respective origins and insertions are mutually distinct. These muscles are considered to work almost simultaneously when the knee is extended. The electromyogram has been used to demonstrate muscle co-contraction. However, the articularis genus is deeper than other muscles. Moreover, it is difficult to analyze it by surface electromyogram. The relative proportions of muscle fiber types and the characteristics of these fiber types are important determinants of the surface electromyogram. Furthermore, biomechanical analysis of AG has remained unclear. This study investigated the ratio of muscle fiber types in these muscles. Muscle samples from seven human cadaveric specimens were used with application of immunofluorescence double staining. Results show that in the vastus intermedius and articularis genus, the percentage of Type I fibers was significantly higher than that of Type II fibers. No significant difference was found in the mean percentages of Type I and Type II fiber types. The percentages of Type I and Type II fibers in articularis genus muscle were correlated positively to the percentage in the vastus intermedius. These results suggest that similar muscle fiber compositions of these muscles might reflect their contraction during the same active phase of knee extension, despite their different functions.


El músculo articular de la rodilla, que se encuentra cubierto por el músculo vasto intermedio, se ha considerado como parte del músculo cuádriceps femoral. Sin embargo, es sabido que tienen diferentes funciones debido a que sus respectivos orígenes e inserciones son mutuamente distintas. Se considera que estos músculos trabajan de forma casi simultánea cuando la rodilla está extendida. El electromiograma se ha usado para demostrar la contracción muscular. Sin embargo, el músculo articular de la rodillas es más profundo que otros músculos. Además, es difícil analizarlo por electromiograma de superficie. Las proporciones relativas de los tipos de fibras musculares y las características de estos tipos de fibras son importantes determinantes del electromiograma de superficie. Además, el análisis biomecánico de músculo articular de la rodilla no ha sido claro. Este estudio investigó la proporción de tipos de fibras musculares en estos músculos. Se usaron muestras musculares de siete cadáveres humanos con la aplicación de doble tinción de inmunofluorescencia. Los resultados muestran que en los músculos articular de la rodilla y vasto intermedio, el porcentaje de fibras de Tipo I fue significativamente mayor que el de las fibras de Tipo II. No se encontraron diferencias significativas en los porcentajes medios de los Tipo I y Tipo II. Los porcentajes de fibras Tipo I y Tipo II en el músculo articular de la rodilla se correlacionaron positivamente con el porcentaje en el músculo vasto intermediario. Estos resultados sugieren que las composiciones de las fibras musculares similares de estos músculos podrían reflejar su contracción durante la misma fase activa de la extensión de la rodilla, a pesar de sus diferentes funciones.


Subject(s)
Humans , Male , Female , Aged , Aged, 80 and over , Muscle, Skeletal/anatomy & histology , Muscle Fibers, Skeletal , Knee/anatomy & histology , Cadaver , Fluorescent Antibody Technique , Quadriceps Muscle/anatomy & histology
13.
An. acad. bras. ciênc ; 90(1): 169-178, Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-886912

ABSTRACT

ABSTRACT The wall of the diaphragm can be affected by congenital or acquired alterations which allow the passage of viscera between the abdominal and chest cavities, allowing the formation of a diaphragmatic hernia. We characterized morphology and performed biometrics of the diaphragm in the common squirrel monkey Saimiri sciureus. After fixation, muscle fragments were collected and processed for optical microscopy. In this species the diaphragm muscle is attached to the lung by phrenopericardial ligament. It is also connected to the liver via the coronary and falciform ligaments. The muscle is composed of three segments in total: 1) sternal; 2) costal, and 3) a segment consisting of right and left diaphragmatic pillars. The anatomical structures analyzed were similar to those reported for other mammals. Histological analysis revealed stable, organized muscle fibers with alternation of light and dark streaks, indicating transverse striation.


Subject(s)
Animals , Male , Saimiri/anatomy & histology , Diaphragm/anatomy & histology , Organ Size , Reference Values , Muscle Fibers, Skeletal , Hernias, Diaphragmatic, Congenital/pathology , Hernias, Diaphragmatic, Congenital/veterinary , Monkey Diseases/pathology
14.
Article in English | WPRIM | ID: wpr-727855

ABSTRACT

Myoblast fusion depends on mitochondrial integrity and intracellular Ca²⁺ signaling regulated by various ion channels. In this study, we investigated the ionic currents associated with [Ca²⁺]i regulation in normal and mitochondrial DNA-depleted (ρ0) L6 myoblasts. The ρ0 myoblasts showed impaired myotube formation. The inwardly rectifying K⁺ current (I(Kir)) was largely decreased with reduced expression of KIR2.1, whereas the voltage-operated Ca²⁺ channel and Ca²⁺-activated K⁺ channel currents were intact. Sustained inhibition of mitochondrial electron transport by antimycin A treatment (24 h) also decreased the I(Kir). The ρ0 myoblasts showed depolarized resting membrane potential and higher basal [Ca²⁺]ᵢ. Our results demonstrated the specific downregulation of I(Kir) by dysfunctional mitochondria. The resultant depolarization and altered Ca²⁺ signaling might be associated with impaired myoblast fusion in ρ0 myoblasts.


Subject(s)
Antimycin A , Down-Regulation , Electron Transport , Ion Channels , Membrane Potentials , Mitochondria , Muscle Development , Muscle Fibers, Skeletal , Myoblasts , Oxidative Phosphorylation
15.
Braz. j. med. biol. res ; 51(4): e7035, 2018. graf
Article in English | LILACS | ID: biblio-889054

ABSTRACT

The urethral muscle of diabetic pregnant rats is affected by long-term mild diabetes and short-term severe diabetes, which plays a crucial role in the pathogenesis of pelvic floor disorders. We hypothesized that muscles outside the pelvis are subject to similar changes. The current study aimed at analyzing the effects of long-term mild and short-term severe diabetes on the structure and ultrastructure of fiber muscles and collagen in rats' rectus abdominis (RA) muscle. Therefore, the RA muscle of virgin, pregnant, long-term mild diabetic, short-term severe diabetic, long-term mild diabetic pregnant and short-term severe diabetic pregnant 3-month-old Wistar rats were collected. The structure was analyzed by picrosirius red staining, immunohistochemistry for fast and slow muscle fibers and transmission electron microscopy. We investigated two levels of STZ- induced diabetes: long-term mild diabetes (blood glucose level: 120-200 mg/dL) and short-term severe diabetes (blood glucose level >300 mg/dL). Long-term mild diabetic pregnant and short-term severe diabetic pregnant rats had decreased fast fibers and increased slow fibers, disrupted areas of sarcomere, intermyofibrillar mitochondria and myelin figures in the RA muscle. Both groups enabled us to analyze the specific influence of pregnancy, separately from diabetes. The current study demonstrated that diabetes and pregnancy induced intramuscular transformation and reorganization of RA muscle with a switch of fiber type adjusting their architecture according to intensity and duration of hyperglycemic insult within pregnancy.


Subject(s)
Animals , Female , Pregnancy , Rats , Pregnancy in Diabetics/pathology , Collagen/ultrastructure , Rectus Abdominis/ultrastructure , Muscle Fibers, Skeletal/ultrastructure , Diabetes Mellitus, Experimental/pathology , Severity of Illness Index , Immunohistochemistry , Rats, Wistar
16.
Einstein (Säo Paulo) ; 15(2): 186-191, Apr.-June 2017. tab, graf
Article in English | LILACS | ID: biblio-891383

ABSTRACT

ABSTRACT Objective To evaluate the action of vanillin (Vanilla planifolia) on the morphology of tibialis anterior and soleus muscles after peripheral nerve injury. Methods Wistar rats were divided into four groups, with seven animals each: Control Group, Vanillin Group, Injury Group, and Injury + Vanillin Group. The Injury Group and the Injury + Vanillin Group animals were submitted to nerve injury by compression of the sciatic nerve; the Vanillin Group and Injury + Vanillin Group, were treated daily with oral doses of vanillin (150mg/kg) from the 3rd to the 21st day after induction of nerve injury. At the end of the experiment, the tibialis anterior and soleus muscles were dissected and processed for light microscopy and submitted to morphological analysis. Results The nerve compression promoted morphological changes, typical of denervation, and the treatment with vanillin was responsible for different responses in the studied muscles. For the tibialis anterior, there was an increase in the number of satellite cells, central nuclei and fiber atrophy, as well as fascicular disorganization. In the soleus, only increased vascularization was observed, with no exacerbation of the morphological alterations in the fibers. Conclusion The treatment with vanillin promoted increase in intramuscular vascularization for the muscles studied, with pro-inflammatory potential for tibialis anterior, but not for soleus muscle.


RESUMO Objetivo Avaliar a ação da vanilina (Vanilla planifolia) sobre a morfologia dos músculos tibial anterior e sóleo após lesão nervosa periférica. Métodos Ratos Wistar foram divididos em quatro grupos, com sete animais cada, sendo Grupo Controle, Grupo Vanilina, Grupo Lesão e Grupo Lesão + Vanilina. Os animais dos Grupos Lesão e Grupo Lesão + Vanilina foram submetidos à lesão nervosa por meio da compressão do nervo isquiático, e os Grupos Vanilina e Grupo Lesão + Vanilina foram tratados diariamente com doses orais de vanilina (150mg/kg) do 3o ao 21o dia após a indução da lesão nervosa. Ao término do experimento, os músculos tibial anterior e sóleo foram dissecados e seguiram o processamento de rotina em microscopia de luz, para posterior análise morfológica. Resultados A compressão nervosa promoveu alterações morfológicas características de denervação, sendo que o tratamento com vanilina foi responsável por respostas distintas nos músculos estudados. Para o tibial anterior, houve aumento do número de células satélites, núcleos centrais e atrofia das fibras, bem como desorganização fascicular. Já no sóleo, houve apenas aumento da vascularização, sem exacerbação das alterações morfológicas nas fibras. Conclusão O tratamento com vanilina promoveu o aumento da vascularização intramuscular para os músculos estudados, com potencial pró-inflamatório para o tibial anterior, o que não ocorreu no músculo sóleo.


Subject(s)
Humans , Animals , Male , Benzaldehydes/pharmacology , Muscle, Skeletal/drug effects , Connective Tissue/drug effects , Sciatic Neuropathy/pathology , Anti-Inflammatory Agents/pharmacology , Random Allocation , Rats, Wistar , Muscle, Skeletal/pathology , Muscle Fibers, Skeletal/drug effects , Connective Tissue/pathology , Sciatic Neuropathy/rehabilitation , Models, Animal
17.
Rev. Assoc. Med. Bras. (1992) ; 63(2): 148-155, Feb. 2017. graf
Article in English | LILACS | ID: biblio-842539

ABSTRACT

Summary The skeletal muscle tissue has a remarkable ability to alter its plastic structural and functional properties after a harmful stimulus, regulating the expression of proteins in complex events such as muscle regeneration. In this context, considering that potential therapeutic agents have been widely studied, nutritional strategies have been investigated in order to improve the regenerative capacity of skeletal muscle. There is evidence of the modulatory action of fatty acids, such that oleic and linoleic acids, that are abundant in Western diets, on muscle function and trophism. Thus, fatty acids appear to be potential candidates to promote or impair the recovery of muscle mass and function during regeneration, since they modulate intracellular pathways that regulate myogenesis. This study is the first to describe and discuss the effect of fatty acids on muscle plasticity and trophism, with emphasis on skeletal muscle regeneration and in vitro differentiation of muscle cells.


Resumo O tecido muscular esquelético possui a notável capacidade plástica de alterar suas propriedades estruturais e funcionais após um estímulo lesivo, regulando a expressão de proteínas durante eventos complexos como a regeneração muscular. Nesse contexto, considerando que possíveis agentes terapêuticos vêm sendo amplamente estudados, estratégias nutricionais têm sido investigadas na perspectiva de melhorar a capacidade regenerativa do músculo esquelético. Há evidências da ação modulatória dos ácidos graxos, como os ácidos oleico e linoleico, que são abundantes nas dietas ocidentais, sobre a função muscular e o trofismo. Nesse sentido, os ácidos graxos parecem ser potenciais candidatos para promover ou prejudicar a recuperação da massa e a função muscular durante a regeneração, uma vez que modulam vias intracelulares reguladoras da miogênese. Este trabalho é o primeiro a descrever e discutir o efeito dos ácidos graxos sobre a plasticidade e o trofismo muscular, com ênfase na regeneração do músculo esquelético e na diferenciação de células musculares in vitro.


Subject(s)
Humans , Regeneration/physiology , Muscle, Skeletal/physiology , Fatty Acids/metabolism , Cell Differentiation/drug effects , Muscle, Skeletal/cytology , Muscle, Skeletal/metabolism , Muscle Fibers, Skeletal/cytology , Muscle Fibers, Skeletal/metabolism , Myoblasts, Skeletal/cytology
18.
Acta cir. bras ; 32(1): 1-13, Jan. 2017. graf
Article in English | LILACS | ID: biblio-837674

ABSTRACT

Abstract Purpose: To evaluate the effects of duodenal-jejunal bypass (DJB) on the diaphragm muscle of obese rats fed on a western diet (WD) . Methods: Eighteen male Wistar rats were fed a standard rodent chow diet (CTL group) or WD ad libitum. After 10 weeks, WD rats were submitted to sham (WD SHAM) or duodenal-jejunal bypass (WD DJB). The structure, ultrastructure, collagen content and the morphometry of the neuromuscular junctions (NMJs) were analyzed two months after surgery. Results: WD SHAM rats displayed an increase in body weight, the Lee index and retroperitoneal and peri-epididymal fat pads compared to the CTL group. DJB did not alter these parameters. The muscle fiber structure and NMJs were similar in the WD SHAM and CTL groups. However, the WD SHAM group showed alterations in the fiber ultrastructure, such as loosely arranged myofibrils and Z line disorganization. In addition, WD SHAM animals presented a considerable amount of lipid droplets and a reduction in the percentage of collagen compared to the CTL group. DJB did not affect the structure or ultrastructure of the muscle fibers or the NMJs in the diaphragm of the WD DJB animals. Conclusion: Duodenal-jejunal bypass did not improve the alterations observed in the diaphragm of western diet obese-rats.


Subject(s)
Animals , Male , Rats , Diaphragm/ultrastructure , Duodenum/surgery , Diet, Western , Jejunum/surgery , Neuromuscular Junction/ultrastructure , Obesity/surgery , Anastomosis, Surgical , Random Allocation , Rats, Wistar , Muscle Fibers, Skeletal/ultrastructure , Obesity/metabolism
19.
Article in English | WPRIM | ID: wpr-85458

ABSTRACT

Proteasomes are the primary degradation machinery for oxidatively damaged proteins that compose a class of misfolded protein substrates. Cellular levels of reactive oxygen species increase with age and this cellular propensity is particularly harmful when combined with the age-associated development of various human disorders including cancer, neurodegenerative disease and muscle atrophy. Proteasome activity is reportedly downregulated in these disease conditions. Herein, we report that docosahexaenoic acid (DHA), a major dietary omega-3 polyunsaturated fatty acid, mediates intermolecular protein cross-linkages through oxidation, and the resulting protein aggregates potently reduce proteasomal activity both in vitro and in cultured cells. Cellular models overexpressing aggregation-prone proteins such as tau showed significantly elevated levels of tau aggregates and total ubiquitin conjugates in the presence of DHA, thereby reflecting suppressed proteasome activity. Strong synergetic cytotoxicity was observed when the cells overexpressing tau were simultaneously treated with DHA. Antioxidant N-acetyl cysteine significantly desensitized the cells to DHA-induced oxidative stress. DHA significantly delayed the proteasomal degradation of muscle proteins in a cellular atrophy model. Thus, the results of our study identified DHA as a potent inducer of cellular protein aggregates that inhibit proteasome activity and potentially delay systemic muscle protein degradation in certain pathologic conditions.


Subject(s)
Atrophy , Cells, Cultured , Cysteine , Humans , In Vitro Techniques , Muscle Fibers, Skeletal , Muscle Proteins , Muscular Atrophy , Neurodegenerative Diseases , Oxidative Stress , Proteasome Endopeptidase Complex , Protein Aggregates , Reactive Oxygen Species , Ubiquitin
20.
Braz. j. med. biol. res ; 50(12): e6733, 2017. graf
Article in English | LILACS | ID: biblio-888967

ABSTRACT

Myostatin is a novel negative regulator of skeletal muscle mass. Myostatin expression is also found in heart in a much less extent, but it can be upregulated in pathological conditions, such as heart failure. Myostatin may be involved in inhibiting protein synthesis and/or increasing protein degradation in skeletal and cardiac muscles. Herein, we used cell cultures and isolated muscles from rats to determine protein degradation and synthesis. Muscles incubated with myostatin exhibited an increase in proteolysis with an increase of Atrogin-1, MuRF1 and LC3 genes. Extensor digitorum longus muscles and C2C12 myotubes exhibited a reduction in protein turnover. Cardiomyocytes showed an increase in proteolysis by activating autophagy and the ubiquitin proteasome system, and a decrease in protein synthesis by decreasing P70S6K. The effect of myostatin on protein metabolism is related to fiber type composition, which may be associated to the extent of atrophy mediated effect of myostatin on muscle.


Subject(s)
Animals , Male , Muscle Fibers, Skeletal/drug effects , Muscle Fibers, Skeletal/metabolism , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Myostatin/pharmacology , Muscle Proteins/drug effects , Muscle Proteins/metabolism , Phosphorylation/drug effects , Phosphorylation/physiology , Time Factors , Tyrosine/drug effects , Tyrosine/metabolism , Gene Expression , Cells, Cultured , Blotting, Western , Reproducibility of Results , Rats, Wistar , Real-Time Polymerase Chain Reaction , Proteolysis/drug effects
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