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1.
Am J Physiol Gastrointest Liver Physiol ; 321(1): G87-G97, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34075793

RESUMO

Aging can lead to rectoanal incontinence due to internal anal sphincter (IAS) dysfunction, which is characterized by a decrease in IAS tone and contractility and an increase in nonadrenergic noncholinergic (NANC) relaxation. We aimed to determine whether brain-derived neurotropic factor (BDNF) rescues this aging-associated IAS dysfunction (AAID). To do so, we studied the effects of BDNF on the basal and G protein-coupled receptors (GPCR)-stimulated IAS smooth muscle tone and on NANC relaxation in Fischer 344 rats representing different age groups [26-mo-old (aging) vs. 6-mo-old (young)], before and after tyrosine kinase receptor B (TrkB) antagonist K252a. We also used isolated smooth muscle cells (SMCs) to determine the effects of BDNF before and after different agonists. For some studies, we monitored NO release using smooth muscle perfusates. BDNF reversed AAID by rescuing the basal IAS tone and agonists [thromboxane A2 analog (U46619) and angiotensin II (ANG II)]-induced contractility, and NANC relaxation. These rescue effects of BDNF were selective as K252a attenuated the changes in the IAS without modifying the effects of K+depolarization. Because of the direct association between the basal and GPCR-stimulated IAS tone and RhoA/ROCK activation, we speculate that this pathway in the rescue effects of BDNF. Conversely, our data suggest that aging-associated increased NANC relaxation is reversed by decreased release of NO and decrease in the sensitivity of the released inhibitory neurotransmitter. In summary, BDNF rescue of AAID involves RhoA/ROCK and inhibitory neurotransmission. These data have direct implications for the role of BDNF in the pathophysiology and therapeutic targeting of aging-associated rectoanal motility disorders.NEW & NOTEWORTHY These studies demonstrate that brain-derived neurotropic factor (BDNF) rescues the aging-associated internal anal sphincter (IAS) dysfunction, characterized by a decrease in IAS tone, and increase in non-adrenergic noncholinergic relaxation. We determined the effects of BDNF on the basal and GPCR (TXA2 and ANG II)-stimulated IAS tone, and on NANC relaxation, before and after TrkB inhibitor K252a. BDNF may have an important role in the pathophysiology and therapeutic targeting of certain rectoanal motility disorders.


Assuntos
Envelhecimento/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Masculino , Relaxamento Muscular/efeitos dos fármacos , Tono Muscular/fisiologia , Músculo Liso/metabolismo , Miócitos de Músculo Liso/metabolismo , Ratos , Ratos Endogâmicos F344 , Transdução de Sinais/fisiologia , Quinases Associadas a rho/metabolismo
2.
J Sports Sci Med ; 20(1): 17-25, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33707982

RESUMO

Increased muscle stiffness of the pectoralis minor (PMi) could deteriorate shoulder function. Stretching is useful for maintaining and improving muscle stiffness in rehabilitation and sport practice. However, the acute and prolonged effect of stretching on the PMi muscle stiffness is unclear due to limited methodology for assessing individual muscle stiffness. Using shear wave elastography, we explored the responses of shear modulus to stretching in the PMi over time. The first experiment (n = 20) aimed to clarify the acute change in the shear modulus during stretching. The shear modulus was measured at intervals of 30 s × 10 sets. The second experiment (n = 16) aimed to observe and compare the prolonged effect of different durations of stretching on the shear modulus. Short and long stretching duration groups underwent 30s × 1 set and 30s × 10 sets, respectively. The assessments of shear modulus were conducted before, immediately after, and at 5, 10, and 15 min post-stretching. In experiment I, the shear modulus decreased immediately after a bout (30 s) of stretching (p < 0.001, change: -2.3 kPa, effect size: r = 0.72) and further decreased after 3 repetitions (i.e., 90 s) of stretching (p = 0.03, change: -1.0 kPa, effect size: r = 0.53). In experiment II, the change in the shear modulus after stretching was greater in the long duration group than in the short duration group (p = 0.013, group mean difference: -2.5 kPa, partial η 2 = 0.36). The shear modulus of PMi decreased immediately after stretching, and stretching for a long duration was promising to maintain the decreased shear modulus. The acute and prolonged effects on the PMi shear modulus provide information relevant to minimum and persistent stretching time in rehabilitation and sport practice.


Assuntos
Módulo de Elasticidade/fisiologia , Exercícios de Alongamento Muscular/fisiologia , Músculos Peitorais/fisiologia , Adulto , Análise de Variância , Fenômenos Biomecânicos/fisiologia , Técnicas de Imagem por Elasticidade , Humanos , Masculino , Tono Muscular/fisiologia , Músculos Peitorais/diagnóstico por imagem , Fatores de Tempo
3.
J Sports Sci Med ; 20(1): 62-68, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33707988

RESUMO

"Foam Rolling" has been used in sports settings to increase range of motion and decrease muscle stiffness without decreasing muscle strength and athletic performance. However, there has been no study investigating the acute and prolonged effect of different durations of foam rolling intervention on muscle stiffness, and the minimum foam rolling intervention duration required to decrease muscle stiffness is unclear. Therefore, the purpose of this study was to investigate the acute and prolonged effect of different durations of foam rolling intervention on ROM, muscle stiffness, and muscle strength. The 45 participants were randomly allocated to 1 of 3 groups (30 s × 1 times group vs 30 s × 3 times group vs 30 s× 10 times group). The outcome measures were dorsiflexion range of motion, shear elastic modulus of medial gastrocnemius, and muscle strength before, 2 min and 30 min after foam rolling intervention. There were no significant differences before and 2 min after foam rolling intervention in 30 s×1 time group, whereas dorsiflexion range of motion was increased in both 30 s×3 times group (p = 0.042, d = 0.26) and 30 s× 10 times group (p < 0.01, d = 0.33). However, the increase in dorsiflexion range of motion was returned to baseline value after 30 minutes in both 30 s × 3 times group and 30 s × 10 times group. In addition, there were no significant changes in shear elastic modulus and muscle strength in all groups. This study suggested that foam rolling for more than 90 s or more of foam rolling was effective in order to increase the range of motion immediately without changing muscle stiffness and muscle strength.


Assuntos
Massagem/métodos , Força Muscular/fisiologia , Tono Muscular/fisiologia , Músculo Esquelético/fisiologia , Amplitude de Movimento Articular/fisiologia , Módulo de Elasticidade/fisiologia , Feminino , Humanos , Masculino , Massagem/instrumentação , Fatores de Tempo , Adulto Jovem
4.
J Sport Rehabil ; 30(5): 725-730, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33618331

RESUMO

CONTEXT: Fast and adequate recovery after exercise and activity is important for increasing performance and preventing injuries. Inadequate recovery usually causes changes in the biomechanical and viscoelastic properties of the muscle. OBJECTIVE: To compare the immediate effect of petrissage massage (PM) and manual lymph drainage (MLD) following submaximal exercise on the biomechanical and viscoelastic properties of the rectus femoris muscle in healthy women. DESIGN: Cross-sectional, repeated-measures. SETTING: Marmara University. PARTICIPANTS: 18 healthy female students. INTERVENTION(S): Following the submaximal quadriceps strengthening exercise performed in 3 sets of 8 repetitions with intensity of 75% of 1 maximum repetition, participants' right leg received a 5-minute PM (PM group) and the contralateral leg received a 5-minute MLD application (MLD group). MAIN OUTCOME MEASURES: Skin temperature was measured using P45 thermographic thermal camera (Flir System; ThermaCAM, Danderyd, Sweden), and muscle tone, biomechanical, and viscoelastic features were measured with a myometer (Myoton AS, Tallinn, Estonia) at baseline, immediately postexercise, post-PM/MLD application, and 10 minutes postexercise. RESULTS: In the PM group, the tonus (P = .002) and stiffness (P < .001) values measured after the massage and at the end of the 10-minute resting period were found to be statistically different than those measured right after the exercise (P < .05). Relaxation time and creep values at all measurement times were significantly different (P < .05). In the MLD group, it was observed the tonus (P < .001), stiffness (P = .025), and relaxation time (P < .01) values decreased significantly after the MLD compared with the values measured after the exercise; however, the creep value was found to be significantly different in all measurements (P < .05). CONCLUSION: PM and MLD reduce passive tissue stiffness and improve the extent of muscle extensibility over time against the muscle tensile strength. PM and MLD are therapeutic methods that can be used to support tissue recovery after exercise and prevent injuries.


Assuntos
Fenômenos Biomecânicos/fisiologia , Elasticidade/fisiologia , Exercício Físico/fisiologia , Drenagem Linfática Manual , Massagem/métodos , Músculo Quadríceps/fisiologia , Estudos Transversais , Feminino , Humanos , Tono Muscular/fisiologia , Treinamento de Força/métodos , Temperatura Cutânea/fisiologia , Pregas Cutâneas , Estudantes , Adulto Jovem
5.
Sci Rep ; 11(1): 378, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33432089

RESUMO

Quantitative assessment of soft tissue elasticity is crucial to a broad range of applications, such as biomechanical modeling, physiological monitoring, and tissue diseases diagnosing. However, the modulus measurement of soft tissues, particularly in vivo, has proved challenging since the instrument has to reach the site of soft tissue and be able to measure in a very short time. Here, we present a simple method to measure the elastic modulus of soft tissues on site by exploiting buckling of a long slender bar to quantify the applied force and a spherical indentation to extract the elastic modulus. The method is realized by developing a portable pen-sized instrument (EPen: Elastic modulus pen). The measurement accuracies are verified by independent modulus measures using commercial nanoindenter. Quantitative measurements of the elastic modulus of mouse pancreas, healthy and cancerous, surgically exposed but attached to the body further confirm the potential clinical utility of the EPen.


Assuntos
Estruturas Animais/fisiologia , Fenômenos Biomecânicos/fisiologia , Elasticidade/fisiologia , Tecnologia de Fibra Óptica/instrumentação , Animais , Biofísica/instrumentação , Módulo de Elasticidade , Feminino , Tecnologia de Fibra Óptica/métodos , Teste de Materiais , Camundongos , Camundongos Transgênicos , Microtecnologia/instrumentação , Aplicativos Móveis , Tono Muscular/fisiologia , Fenômenos Fisiológicos Musculoesqueléticos , Agulhas , Estresse Mecânico
6.
Dis Colon Rectum ; 64(6): 706-713, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33496487

RESUMO

BACKGROUND: External anal sphincter contractility significantly contributes to control the passage of stool. An artificial anal sphincter placed into the intersphincteric space is a safe and effective procedure to treat fecal incontinence, even if its mechanism of action has not been fully elucidated. OBJECTIVE: The aim of this study was to evaluate external anal sphincter contractility changes after a self-expandable hyexpan prostheses was implanted into the intersphincteric space of the anal canal and clinical outcomes compared. DESIGN: This was a prospective clinical study. SETTINGS: The study was conducted at a university teaching hospital. PATIENTS: Consecutive patients affected by fecal incontinence for at least 6 months after failure of conservative treatment were included. INTERVENTIONS: All of the patients underwent 10-prostheses implantation and were examined preoperatively and postoperatively by endoanal ultrasound and anorectal manometry. MAIN OUTCOME MEASURES: Fecal incontinence symptoms were assessed by severity scores. The external anal sphincter muscle tension was calculated using a specific equation. RESULTS: Thirty-nine patients (34 women; median age = 68 y) were included in the study; no morbidity was registered. After a median follow-up period of 14 months, both the median maximum voluntary squeeze pressure and the median inner radius of the external anal sphincter significantly increased. A statistically significant increase of external anal sphincter muscle tension was detected. A decrease of any fecal incontinence symptom and an improvement in severity scores were observed at the last follow-up examination. The external anal sphincter contractility was significantly higher in patients reducing incontinence episodes to solid stool by >50% and improving their ability to defer defecation for >15 minutes. LIMITATIONS: This was a single-center experience with a relatively small and heterogeneous sample size, patients with a potentially more severe disease because our institution is a referral center, and an absence of quality-of-life evaluation. CONCLUSIONS: Artificial anal sphincter implantation improved the external anal sphincter muscle tension; there was a positive correlation between its increase and the clinical outcome. See Video Abstract at http://links.lww.com/DCR/B468. IMPLANTE DE ESFNTER ANAL ARTIFICIAL AUTOEXPANDIBLE EN PACIENTES CON INCONTINENCIA FECAL MEJORA LA CONTRACTILIDAD DEL ESFNTER ANAL EXTERNO: ANTECEDENTES:La contractilidad del esfínter anal externo contribuye significativamente al control del paso de las heces. Un esfínter anal artificial colocado en el espacio interesfinteriano es un procedimiento seguro y eficaz para tratar la incontinencia fecal, incluso si su mecanismo de acción no se ha definido por completo.OBJETIVO:El objetivo de este estudio fue evaluar los cambios en la contractilidad del esfínter anal externo después de la implantación de una prótesis de hyexpan autoexpandible en el espacio interesfinteriano del canal anal y comparar los resultados clínicos.DISEÑO:Estudio clínico prospectivo.ENTORNO CLINICO:El estudio se realizó en un hospital universitario.PACIENTES:Pacientes consecutivos afectados por incontinencia fecal durante al menos 6 meses, tras fracaso de tratamiento conservador.INTERVENCIONES:Todos los pacientes fueron sometidos a la implantación de 10 prótesis, y fueron examinados pre y postoperatoriamente mediante ecografía endoanal y manometría anorrectal.PRINCIPALES MEDIDAS DE VALORACION:Los síntomas de incontinencia fecal se evaluaron mediante puntuaciones de gravedad. La tensión del músculo del esfínter anal externo se calculó mediante una formula específica.RESULTADOS:Treinta y nueve pacientes (34 mujeres; mediana de edad 68 años) fueron incluidos en el estudio; no se registró morbilidad. Después de un período de seguimiento medio de 14 meses, tanto la presión de compresión voluntaria máxima media como el radio interior medio del esfínter anal externo aumentaron significativamente. Se detectó un aumento estadísticamente significativo de la tensión del músculo del esfínter anal externo. En el último examen de seguimiento se observó una disminución de cualquier síntoma de incontinencia fecal y una mejora en las puntuaciones de gravedad. La contractilidad del esfínter anal externo fue significativamente mayor en los pacientes que redujeron los episodios de incontinencia a heces sólidas en más del 50% y mejoraron la capacidad para diferir la defecación durante más de 15 minutos.LIMITACIONES:Experiencia de un solo centro; tamaño de muestra relativamente pequeño y heterogéneo; pacientes con una enfermedad potencialmente más grave porque nuestra institución es un centro de referencia; ausencia de evaluación de la calidad de vida.CONCLUSIONES:La implantación del esfínter anal artificial mejoró la tensión muscular del esfínter anal externo; hubo una correlación positiva entre su aumento y el resultado clínico. Consulte Video Resumen en http://links.lww.com/DCR/B468.


Assuntos
Canal Anal/cirurgia , Incontinência Fecal/prevenção & controle , Tono Muscular/fisiologia , Próteses e Implantes/efeitos adversos , Implantação de Prótese/instrumentação , Idoso , Canal Anal/fisiopatologia , Defecação/fisiologia , Endossonografia/métodos , Incontinência Fecal/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Manometria/métodos , Pessoa de Meia-Idade , Estudos Prospectivos , Desenho de Prótese/tendências , Implantação de Prótese/métodos , Segurança , Índice de Gravidade de Doença , Resultado do Tratamento
7.
Physiother Theory Pract ; 37(1): 242-251, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30983479

RESUMO

Background and Purpose: The purpose of this case report is to describe the benefits of manual therapy techniques, including mobilization and stretching, in the management of a patient with chronic constipation. Case Description: A 17-year-old male with an 8-month history of constipation and complaint of incomplete evacuation after defecation was referred for therapy. The patient was diagnosed with a spastic perineal syndrome. Isolated puborectalis relaxation exercise was not successful in alleviating constipation. Physical examination showed tightness of left side piriformis, thoracic kyphosis, apparent limb shortening on the left side, and a right-on-right sacrum forward torsion. The patient was treated with stretching of left piriformis and mobilization of thoracic and lumbar vertebrae and sacroiliac joints along with puborectalis relaxation exercises. Outcomes: After 4 weeks of treatment, there was a reduction in Bowel Function Index (BFI) from 74.6 to 27.2. The patient also reported spending less time (<3 minutes) during defecation. The patient maintained his improvement at 7 months. Discussion: A detailed neuromuscular examination assisted in identifying the pathophysiology related to obstructive defecation for this patient. Controlled studies regarding the effectiveness of various physiotherapy interventions in the treatment of obstructive constipation are warranted.


Assuntos
Constipação Intestinal/fisiopatologia , Constipação Intestinal/terapia , Defecação/fisiologia , Tono Muscular/fisiologia , Manipulações Musculoesqueléticas , Diafragma da Pelve/fisiopatologia , Adolescente , Humanos , Masculino
8.
Laryngoscope ; 131(5): E1573-E1579, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33135806

RESUMO

OBJECTIVE: To analyze the Reflux Symptom Index (RSI) and the Voice-Related Quality of Life (V-RQOL) scores based on the perceptual and analytical parameters in primary MTD patients with no reflux. STUDY DESIGN: Cross-sectional study. METHODS: One hundred and eighteen participants, that is, sixty patients with normal voices and fifty-eight patients with primary MTD were recruited in this study. The diagnosis of primary MTD was made by perceptual voice analysis, neck palpation, video-laryngoscopic examination, and exclusion of other etiologies. Acoustic analysis and the GRBAS (Grade, Roughness, Breathiness, Asthenia, and Strain) scale were evaluated for all participants. The V-RQOL and RSI questionnaires were then given to all participants. RESULTS: This study included 118 participants of 29 males (48.3%) and 31 females (51.7%) in the normal group. MTD group also included 27 males (46.6%) and 31 (53.4%) female patients. Mean (SD) RSI and V-RQOL scores were 12.35 (3.84) and 11.09 (2.20) for the normal group, and 22.87 (6.97) and 22.89 (7.94) for the MTD group (P = .000). In the MTD group, V-RQOL had a positive correlation with jitter for /i/ and /u/, Noise to Harmonic Ratio (NHR) for /i/, /a/, and /u/, and Grade, Roughness, and Strain of GRBAS scale (P < .05). In addition, RSI had a positive correlation with Strain in the MTD group (P < .05). CONCLUSION: MTD patients in the absence of laryngopharyngeal reflux findings may have high RSI scores. Hence, patients with high RSI scores and disproportionate acoustic and perceptual analysis would require a thorough evaluation of MTD. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1573-E1579, 2021.


Assuntos
Disfonia/complicações , Refluxo Laringofaríngeo/diagnóstico , Laringe/fisiopatologia , Tono Muscular/fisiologia , Qualidade da Voz/fisiologia , Acústica , Adulto , Estudos Transversais , Disfonia/fisiopatologia , Feminino , Humanos , Refluxo Laringofaríngeo/etiologia , Refluxo Laringofaríngeo/fisiopatologia , Laringoscopia , Laringe/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Inquéritos e Questionários/estatística & dados numéricos
9.
J Electromyogr Kinesiol ; 56: 102493, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33227524

RESUMO

This study examined the effect of hip flexion angle on the stiffness of the adductor longus (AL) muscle during isometric hip flexion. Seventeen men were recruited. Ten participants performed submaximal voluntary contraction at 0%, 25%, 50%, and 75% of maximal voluntary contraction (MVC) during isometric hip flexion after performing MVC at 0°, 40°, and 80° of hip flexion. Seven participants performed submaximal voluntary tasks during isometric hip extension in addition to hip flexion task. The shear modulus of the AL muscle was used as the index of muscle stiffness, and was measured using ultrasound shear-wave elastography during the tasks at each contraction intensity for each hip flexion angle. During hip flexion, the shear modulus of the AL muscle was higher at 0° than at 40° and 80° of hip flexion at each contraction intensity (p < 0.016). Conversely, a significant effect was not found among hip flexion angle during hip extension at 75% of MVC (p = 0.867). These results suggest that mechanical stress of the AL muscle may be higher at 0° of hip flexion during isometric hip flexion.


Assuntos
Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/fisiologia , Contração Isométrica/fisiologia , Tono Muscular/fisiologia , Músculo Esquelético/fisiologia , Estresse Mecânico , Técnicas de Imagem por Elasticidade/métodos , Humanos , Masculino , Ultrassonografia/métodos , Adulto Jovem
10.
Scand J Med Sci Sports ; 31(2): 371-379, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33084051

RESUMO

This study investigated the effects of hamstring training methods on the passive viscoelastic properties of hamstring and quadriceps muscles and the relationship of these properties to lower extremity power, hamstring flexibility, and agility. A total of forty healthy individuals were recruited for this study. Participants performed Nordic hamstring exercises (n = 14), hamstring curl exercises (n = 14), or received neuromuscular electrical stimulation (NMES; n = 13) for eight weeks. Measurements were taken both before and one week after the interventions of the viscoelastic properties of hamstring and quadriceps muscles, strength, flexibility, agility, and lower extremity power. Nordic hamstring exercises increased hamstring muscle elasticity while decreasing quadriceps and hamstring muscle stiffness; whereas leg curl exercises increased quadriceps and hamstring muscle stiffness while decreasing quadriceps muscle tone (P < .05). Both strengthening methods increased agility, hamstring flexibility, and vertical jump. NMES produced no noticeable effects. Eccentric and concentric training methods had inverse effects on both hamstring and quadriceps muscles' viscoelastic parameters, but had similar improvements on performance parameters. Since changes in viscoelastic parameters of muscle could affect musculotendinous systems' compliance, clinicians should consider viscoelastic properties over performance parameters, when prescribing concentric or eccentric exercises.


Assuntos
Exercício Físico/fisiologia , Músculos Isquiossurais/fisiologia , Força Muscular/fisiologia , Músculo Quadríceps/fisiologia , Fenômenos Biomecânicos/fisiologia , Elasticidade , Estimulação Elétrica/métodos , Lateralidade Funcional/fisiologia , Humanos , Extremidade Inferior/fisiologia , Masculino , Contração Muscular/fisiologia , Tono Muscular/fisiologia , Distribuição Aleatória , Fatores de Tempo , Viscosidade , Adulto Jovem
11.
J Neurosci ; 41(7): 1582-1596, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33372061

RESUMO

During rapid eye movement (REM) sleep, anti-gravity muscle tone and bodily movements are mostly absent, because somatic motoneurons are inhibited by descending inhibitory pathways. Recent studies showed that glycine/GABA neurons in the ventromedial medulla (VMM; GlyVMM neurons) play an important role in generating muscle atonia during REM sleep (REM-atonia). However, how these REM-atonia-inducing neurons interconnect with other neuronal populations has been unknown. In the present study, we first identified a specific subpopulation of GlyVMM neurons that play an important role in induction of REM-atonia by virus vector-mediated tracing in male mice in which glycinergic neurons expressed Cre recombinase. We found these neurons receive direct synaptic input from neurons in several brain stem regions, including glutamatergic neurons in the sublaterodorsal tegmental nucleus (SLD; GluSLD neurons). Silencing this circuit by specifically expressing tetanus toxin light chain (TeTNLC) resulted in REM sleep without atonia. This manipulation also caused a marked decrease in time spent in cataplexy-like episodes (CLEs) when applied to narcoleptic orexin-ataxin-3 mice. We also showed that GlyVMM neurons play an important role in maintenance of sleep. This present study identified a population of glycinergic neurons in the VMM that are commonly involved in REM-atonia and cataplexy.SIGNIFICANCE STATEMENT We identified a population of glycinergic neurons in the ventral medulla that plays an important role in inducing muscle atonia during rapid eye movement (REM) sleep. It sends axonal projections almost exclusively to motoneurons in the spinal cord and brain stem except to those that innervate extraocular muscles, while other glycinergic neurons in the same region also send projections to other regions including monoaminergic nuclei. Furthermore, these neurons receive direct inputs from several brainstem regions including glutamatergic neurons in the sublaterodorsal tegmental nucleus (SLD). Genetic silencing of this pathway resulted in REM sleep without atonia and a decrease of cataplexy when applied to narcoleptic mice. This work identified a neural population involved in generating muscle atonia during REM sleep and cataplexy.


Assuntos
Cataplexia/fisiopatologia , Glicina/fisiologia , Bulbo/fisiologia , Músculo Esquelético/fisiologia , Neurônios/fisiologia , Sono REM/fisiologia , Animais , Ataxina-3/genética , Axônios/fisiologia , Cataplexia/genética , Eletroencefalografia , Masculino , Bulbo/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Tono Muscular/fisiologia , Músculo Esquelético/fisiopatologia , Narcolepsia/genética , Narcolepsia/fisiopatologia , Orexinas/genética , Toxina Tetânica/farmacologia
12.
Pain Res Manag ; 2020: 4184268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33273992

RESUMO

The study aimed to evaluate masseter muscle stiffness in adult healthy volunteers referred to a massage treatment and also to investigate whether shear-wave elastography can be used to monitor the effect of massage on the masseter muscle. The study included 21 healthy volunteers, who were subjected to a 30-minute massage of the masseter muscle. Muscle stiffness was measured by shear-wave elastography before and directly after the massage. Pain during the massage was assessed using the visual analogue scale (VAS). The data of 20 patients (one excluded due to severe pain) with a median age of 34.5 years were analysed. The stiffness values were 11.46 ± 1.55 kPa before and 8.97 ± 0.96 kPa after the massage (p < 0.0001). The mean drop was 2.49 ± 1.09 kPa. The greatest decrease was observed in people with higher elasticity values before the massage (r = 0.79; p < 0.0001). The median intensity of pain was 7.2 (range: 6-9.5). We concluded that shear-wave elastography is a sensitive tool to monitor changes in the stiffness of the masseter muscle.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Músculo Masseter/diagnóstico por imagem , Músculo Masseter/fisiologia , Tono Muscular/fisiologia , Medição da Dor/métodos , Adolescente , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Massagem/métodos , Pessoa de Meia-Idade , Adulto Jovem
13.
Med Sci Monit ; 26: e922544, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32745076

RESUMO

BACKGROUND The aim of this research was to compare the effects of contrast bath therapy (CBT) and contrast therapy (CT) using infrared (IR) and cryotherapy (CR) on blood flow, muscle tone, and pain in the forearm. MATERIAL AND METHODS Twenty healthy individuals participated in this study. Each participant received 2 kinds of CT separated by a week. CBT involved immersion in hot water (38-40°C) for 4 minutes, followed by 1 minute of immersion in cold water (12-14°C) for four rotations. CT using IR and CR was performed in the same manner as CBT. RESULTS The variables measured were blood flow, muscle tone, and pain before and after intervention. Both types of CT produced fluctuations in the blood flow (P<0.05). The pain threshold increased on both therapies; a significant increase was noted with IR and CR (P<0.05) therapies. Muscle elasticity was induced and stiffness was reduced with all therapies (P<0.05). IR and CR resulted in significant changes (P<0.05) in blood flow as compared with the CBT. CONCLUSIONS The results of this study suggest that CT using IR and CR is more effective in improving blood flow than CBT and has the same effect on muscle tone and pain. Nonetheless, using IR and CR is efficient with regard to mobility and maintaining temperature; therefore, it would be convenient to use these in clinical settings. Further studies involving CT should be carried out to determine whether our findings are clinically relevant.


Assuntos
Crioterapia/métodos , Temperatura Alta/uso terapêutico , Hidroterapia/métodos , Raios Infravermelhos/uso terapêutico , Tono Muscular/fisiologia , Limiar da Dor/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Adulto , Elasticidade/fisiologia , Feminino , Antebraço/fisiologia , Voluntários Saudáveis , Humanos , Fluxometria por Laser-Doppler , Masculino , Músculo Esquelético/fisiologia , Manejo da Dor/métodos , Temperatura Cutânea/fisiologia , Temperatura Cutânea/efeitos da radiação , Adulto Jovem
14.
Physiotherapy ; 108: 37-44, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32707289

RESUMO

OBJECTIVES: To test the effect of a structured abdominal hypopressive technique (AHT) programme on pelvic floor muscle (PFM) tone and urinary incontinence (UI) in women. DESIGN: Crossover trial with random assignment of women to one of two groups: Group 1 (AHT followed by rest) and Group 2 (rest followed by AHT). SETTING: Two cultural centres in Madrid, Spain. PARTICIPANTS: Women aged 20-65 years. INTERVENTIONS: Two months of supervised AHT exercises compared with 2 months of rest. MAIN OUTCOME MEASURES: Variation in PFM tone and score on the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF)]. RESULTS: Forty-two women were randomised to two groups (both n=21). No sequence or period effect was noted. The mean difference in PFM tone after the 2-month AHT programme was 59g/cm² [95% confidence interval (CI) 37 to 82]; the between-group difference was 83g/cm² (95% CI 50 to 116; P<0.001). After 2 months, the between-group difference in the ICIQ-SF score was 3.3 points (P<0.001). The majority of participants reported improved body image and sense of well-being. CONCLUSIONS: A structured 2-month AHT programme for women showed short-term benefits in PFM tone and UI. In addition, study participants reported improved body image and sense of well-being, and programme satisfaction, as demonstrated by questionnaire at the end of the intervention period. Further research is needed to test the long-term effects and effectiveness of AHT compared with other PFM exercises. ClinicalTrials.gov Identifier NCT0221241.


Assuntos
Terapia por Exercício/métodos , Tono Muscular/fisiologia , Diafragma da Pelve/fisiopatologia , Incontinência Urinária/fisiopatologia , Incontinência Urinária/terapia , Adulto , Idoso , Estudos Cross-Over , Feminino , Humanos , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
15.
Med Sci Monit ; 26: e924811, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32719308

RESUMO

BACKGROUND Contracture is related to modulation of passive stiffness in muscle and tendon after spinal cord injury (SCI). Current clinical assessments of stiffness in muscles and tendons are subjective in patients with spinal cord injury. We proposed a quantitative method to evaluate stiffness of the gastrocnemius and Achilles tendon (AT) with a portable device, the MyotonPRO. The purpose of this study was to investigate the intraoperator and interoperator reliability of the MyotonPRO when used in patients after spinal cord injury. MATERIAL AND METHODS Fourteen patients with SCI participated in this study. Gastrocnemius stiffness and AT stiffness were measured with the MyotonPRO. RESULTS In participants with SCI, the intraclass correlation coefficient (ICC) values for intraoperator and interoperator reliability of stiffness measurements in the gastrocnemius and AT were excellent (all ICC >0.87), with relatively low values for standard error measurement (SEM) and minimal detectable change (MDC). CONCLUSIONS Our findings suggest that use of the MyotonPRO is feasible for evaluating stiffness of the gastrocnemius and AT in the lower limbs of patients with spinal cord injury.


Assuntos
Força Muscular/fisiologia , Tono Muscular/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Tendão do Calcâneo/fisiologia , Adolescente , Adulto , Idoso , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Amplitude de Movimento Articular/fisiologia , Reprodutibilidade dos Testes
16.
Nat Commun ; 11(1): 3661, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32694504

RESUMO

The relationship between orexin/hypocretin and rapid eye movement (REM) sleep remains elusive. Here, we find that a proportion of orexin neurons project to the sublaterodorsal tegmental nucleus (SLD) and exhibit REM sleep-related activation. In SLD, orexin directly excites orexin receptor-positive neurons (occupying ~3/4 of total-population) and increases gap junction conductance among neurons. Their interaction spreads the orexin-elicited partial-excitation to activate SLD network globally. Besides, the activated SLD network exhibits increased probability of synchronized firings. This synchronized excitation promotes the correspondence between SLD and its downstream target to enhance SLD output. Using optogenetics and fiber-photometry, we consequently find that orexin-enhanced SLD output prolongs REM sleep episodes through consolidating brain state activation/muscle tone inhibition. After chemogenetic silencing of SLD orexin signaling, a ~17% reduction of REM sleep amounts and disruptions of REM sleep muscle atonia are observed. These findings reveal a stabilization role of orexin in REM sleep.


Assuntos
Tronco Encefálico/fisiologia , Orexinas/metabolismo , Privação do Sono/fisiopatologia , Sono REM/fisiologia , Potenciais de Ação/fisiologia , Animais , Comportamento Animal , Tronco Encefálico/citologia , Modelos Animais de Doenças , Eletrodos Implantados , Eletroencefalografia , Eletromiografia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Tono Muscular/fisiologia , Neurônios/metabolismo , Optogenética , Receptores de Orexina/metabolismo , Orexinas/genética , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Vigília/fisiologia
17.
Biomed Mater Eng ; 31(3): 157-167, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32568168

RESUMO

BACKGROUND: Vascular smooth muscle cells (VSMCs) are one of the main components of arterial walls and actively remodel the arterial walls in which they reside through biomechanical signals applied to themselves. Contractile or differentiated VSMCs have been observed in normal blood vessels. In pathological vascular conditions, they become dedifferentiated from contractile to non-contractile or synthetic cells, and a similar change is observed when VSMCs are placed in culture conditions. The mechanisms regulating VSMC differentiation remain unclear at this stage. OBJECTIVE: In this paper we investigated the effects of substrate stiffness on the morphology, intercellular tension, and differentiation of VSMCs. METHODS: Rat VSMCs were cultured on polyacrylamide (PA) gels, with elastic moduli of 15 kPa, 40 kPa, and 85 kPa, and PDMS substrate with elastic modulus of 1 MPa, and their morphology, intercellular tension, and contractile differentiation were assessed. RESULTS: Using fluorescence microscope image-based analysis and nano-indentation imaging with atomic force microscopy, we found that cell spreading and stiffening were induced by substrate stiffening in VSMCs. Interestingly, VSMCs on PA gel substrates with medium stiffness (40 kPa) showed significant elongation and shape polarization, and their 𝛼-SMA with F-actin cytoskeleton expression ratio was significantly higher than those of cells on other substrates. CONCLUSION: The results indicate an existing optimal substrate stiffness for promoting VSMC differentiation, and also indicate that cell shape polarization might be a key factor for VSMC differentiation.


Assuntos
Elasticidade/fisiologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/fisiologia , Tecidos Suporte/química , Resinas Acrílicas/química , Resinas Acrílicas/farmacologia , Animais , Fenômenos Biomecânicos/fisiologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Forma Celular/efeitos dos fármacos , Forma Celular/fisiologia , Células Cultivadas , Dimetilpolisiloxanos/química , Dimetilpolisiloxanos/farmacologia , Módulo de Elasticidade/efeitos dos fármacos , Módulo de Elasticidade/fisiologia , Hidrogéis/química , Hidrogéis/farmacologia , Teste de Materiais , Tono Muscular/efeitos dos fármacos , Tono Muscular/fisiologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Miócitos de Músculo Liso/efeitos dos fármacos , Ratos , Propriedades de Superfície , Rigidez Vascular/efeitos dos fármacos
18.
J Drugs Dermatol ; 19(5): 556-558, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32484622

RESUMO

Arms and calves have long been a subject of interest in aesthetic medicine. Current surgical and non-invasive procedures focus on sagging skin and fat deposits without targeting the muscles. The aim of this study is to investigate the feasibility of high-intensity focused electromagnetic (HIFEM) technology for arm and calf toning through simultaneous fat reduction and muscle strengthening. In this case study, two subjects received four 20-minute HIFEM treatments of biceps, triceps, and calves, with the outcomes assessed by MRI. The analysis of MRI images showed an average increase in all three muscle groups, biceps muscle mass 17.1%, triceps muscle mass 10.2%, and gastrocnemius muscle mass increased by 14.6%. In addition, the arm fat thickness was decreased by 12.8% on average and the calf fat thickness decreased by 9.9%. The results suggest that HIFEM technology is a feasible modality for both arm and calf toning. However, it will be necessary to continue to validate this outcome in a larger sample size study. J Drugs Dermatol. 2020;19(5): doi:10.36849/JDD.2020.4546.


Assuntos
Técnicas Cosméticas , Terapia de Campo Magnético/métodos , Tono Muscular/fisiologia , Músculo Esquelético/fisiologia , Adulto , Braço , Feminino , Humanos , Perna (Membro) , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/diagnóstico por imagem , Resultado do Tratamento
19.
Br J Sports Med ; 54(18): 1081-1088, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32299793

RESUMO

OBJECTIVE: To systematically review risk factors for hamstring strain injury (HSI). DESIGN: Systematic review update. DATA SOURCES: Database searches: (1) inception to 2011 (original), and (2) 2011 to December 2018 (update). Citation tracking, manual reference and ahead of press searches. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies presenting prospective data evaluating factors associated with the risk of index and/or recurrent HSI. METHOD: Search result screening and risk of bias assessment. A best evidence synthesis for each factor and meta-analysis, where possible, to determine the association with risk of HSI. RESULTS: The 78 studies captured 8,319 total HSIs, including 967 recurrences, in 71,324 athletes. Older age (standardised mean difference=1.6, p=0.002), any history of HSI (risk ratio (RR)=2.7, p<0.001), a recent HSI (RR=4.8, p<0.001), previous anterior cruciate ligament (ACL) injury (RR=1.7, p=0.002) and previous calf strain injury (RR=1.5, p<0.001) were significant risk factors for HSI. From the best evidence synthesis, factors relating to sports performance and match play, running and hamstring strength were most consistently associated with HSI risk. The risk of recurrent HSI is best evaluated using clinical data and not the MRI characteristics of the index injury. SUMMARY/CONCLUSION: Older age and a history of HSI are the strongest risk factors for HSI. Future research may be directed towards exploring the interaction of risk factors and how these relationships fluctuate over time given the occurrence of index and recurrent HSI in sport is multifactorial.


Assuntos
Traumatismos em Atletas/epidemiologia , Músculos Isquiossurais/lesões , Entorses e Distensões/epidemiologia , Fatores Etários , Lesões do Ligamento Cruzado Anterior/epidemiologia , Traumatismos em Atletas/fisiopatologia , Eletromiografia , Humanos , Força Muscular/fisiologia , Tono Muscular/fisiologia , Músculo Esquelético/fisiologia , Fatores de Risco , Corrida/lesões , Entorses e Distensões/fisiopatologia
20.
Skeletal Radiol ; 49(8): 1231-1237, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32123955

RESUMO

OBJECTIVE: The purpose of this study was to characterize lower extremity passive muscle stiffness in a young, healthy, athletic population. It was hypothesized that males would exhibit greater stiffness than females and that hamstring stiffness would increase with increased passive hamstring stretch. METHODS: Male (n = 52, age 16.0 ± 1.3 years, height 180.3 ± 7.9 cm, weight 73.1 ± 11.8 kg) and female (n = 89, age 15.6 ± 1.3 years, height 169.7 ± 8.1 cm, weight 65.2 ± 13.2 kg) high school basketball athletes were recruited for this study. Shear wave elastography (SWE) was used to measure shear wave velocity (m/s) of the biceps femoris muscle at three leg positions (40%, 60%, and 80%) of the maximum passive 90-90 straight-leg raise position for each leg. Hamstring stiffness (kPa) was quantified from the SWE elastogram using custom processing software. RESULTS: Hamstring stiffness was significantly greater for males than females at every position on both the dominant and non-dominant limbs (p < 0.05). Hamstring stiffness was greater on the non-dominant limb than the dominant for females at the 40% position. Stiffness at 60% was greater than stiffness at 40% for males on both the dominant and non-dominant limbs. However, stiffness at 60% was greater than stiffness at 80% on the male non-dominant limb. Females demonstrated higher stiffness at 40% than both 60% and 80% for the dominant and non-dominant limbs. CONCLUSION: Healthy male basketball players had higher hamstring muscle stiffness than female players. Future studies may investigate what factors contribute to the large variability observed in muscle stiffness, resulting in mixed results on the effects of leg dominance and stretching positions.


Assuntos
Basquetebol/fisiologia , Técnicas de Imagem por Elasticidade , Músculos Isquiossurais/diagnóstico por imagem , Músculos Isquiossurais/fisiologia , Tono Muscular/fisiologia , Adolescente , Módulo de Elasticidade , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Fatores Sexuais
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