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1.
Rev Assoc Med Bras (1992) ; 65(9): 1174-1180, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618333

RESUMO

OBJECTIVE: The study aims to explore the relationship between preoperative anxiety and chronic postoperative pain. METHODS: A total of forty rats were divided into four groups, control, single-prolonged stress alone, Hysterectomy alone, and SPS+ Hysterectomy. The paw withdrawal mechanical thresholds (PWMT) were examined. qRT-PCR and western blotting assay were performed to detect the GFAP expression in astrocytes isolated from the anterior cingulate cortex (ACC) region. In addition, the long-term potentiation (LTP) in ACC was examined. RESULTS: Rats in the SPS group or the Hysterectomy alone group had no significant effect on chronic pain formation, but SPS can significantly induce chronic pain after surgery. Astrocytes were still active, and the LTP was significantly increased three days after modeling in the SPS+Hysterectomy group. CONCLUSIONS: anxiety can induce chronic pain by activating astrocytes in the ACC region.


Assuntos
Ansiedade/complicações , Astrócitos/metabolismo , Dor Crônica/etiologia , Dor Pós-Operatória/etiologia , Animais , Dor Crônica/psicologia , Modelos Animais de Doenças , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Giro do Cíngulo/metabolismo , Membro Posterior , Histerectomia , Potenciação de Longa Duração/fisiologia , Limiar da Dor/fisiologia , Dor Pós-Operatória/psicologia , Período Pré-Operatório , Distribuição Aleatória , Ratos Sprague-Dawley , Estresse Psicológico/etiologia , Fatores de Tempo
2.
Fisioterapia (Madr., Ed. impr.) ; 41(5): 299-302, sept.-oct. 2019. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-183939

RESUMO

Antecedentes y objetivo: La tenosinovitis estenosante (TE) es un trastorno inflamatorio que afecta a vainas y tendones flexores de los dedos. Los tratamientos no quirúrgicos presentan una efectividad limitada. Se ha evidenciado que las ondas de choque (OC) extracorpóreas reducen la presencia de fenómenos inflamatorios crónicos. Dado sus efectos, se postula como una alternativa al tratamiento de la TE. El objetivo de este trabajo es presentar el caso de una paciente con TE la cual fue tratada mediante OC. Descripción: Mujer de 77 años, jubilada, con diagnóstico de TE del tercer dedo de la mano derecha, presenta dolor palmar y chasquido asociado a bloqueo del dedo al realizar actividades que involucren flexoextensión. Se evaluó la intensidad del dolor, umbral de dolor a la presión, capacidad funcional, rango de movimiento, fuerza prensil y de pinza. Intervención: Se realizaron 6 sesiones de tratamiento con una frecuencia de una sesión/semana utilizando una programación de 2.000 pulsos, 6 Hz y 2,2 bar. No se realizó ningún otro tipo de intervención. Resultados: Se evidenció una reducción en la intensidad del dolor, aumento en el umbral del dolor a la presión, rango de movimiento, capacidad funcional, fuerza prensil y de pinza, así como cambios en el aspecto ecográfico de la polea y tendón afectados. Conclusión: La aplicación de OC presentó resultados positivos en el tratamiento de la paciente. En consecuencia, podría ser una opción para el manejo de sujetos con TE


Background and objective: Stenosing tenosynovitis (ST) is an inflammatory disorder that affects the sheaths and tendons of the flexor muscles of the fingers. Conservative treatments have limited effectiveness. It has been shown that extracorporeal shockwave therapy (ESWT) reduces the presence of chronic inflammatory phenomena. Given its effects, it is postulated as treatment alternative for stenosing tenosynovitis. The aim of this report is to present the case of a patient with ST which was treated with ESWT. Description: 77-year-old woman, retired, diagnosed with ST of the third right finger. The patient presented with palmar pain and clicking associated with finger lock when performing activities involving flexion-extension. Pain intensity, pressure pain threshold, functional capacity, range of motion, grip and pinch muscle strength were evaluated. Intervention: Six sessions of treatment were performed with a frequency of 1 session/week using a programming of 2000 pulses, 6 Hz and 2.2 bar. No other intervention was performed. Results: Reduction in the intensity of the pain, increase in pressure pain threshold, range of motion, functional capacity, grip and pinch force, as well as changes in the echographic appearance of the affected pulley and tendon were observed. Conclusion: Application of ESWT presented positive results in this patient. It could therefore be an option for the management of subjects with ST


Assuntos
Humanos , Feminino , Idoso , Ondas de Choque de Alta Energia/uso terapêutico , Tenossinovite/terapia , Limiar da Dor/fisiologia , Medição da Dor/métodos , Inquéritos e Questionários , Dinamômetro de Força Muscular
4.
Tohoku J Exp Med ; 248(3): 217-223, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31366820

RESUMO

Body composition (BC) is related to the pathogenesis of musculoskeletal disease, especially research focused on the role of fat and muscle mass. This study aimed to identify the associations between the pressure pain threshold (PPT) and pain-related factors including BC. A total of 64 healthy farmers (21 males and 43 females) were recruited, and baseline data were analyzed cross-sectionally. Demographic characteristics (sex, age, marital status, education duration, current status of smoking and alcohol drinking, height, body weight, and underlying diseases) and a psychologic characteristic (a Korean version of the Beck Depression Inventory [BDI]) were assessed. Additionally, body composition analysis using bioelectrical impedance analysis (BIA) was performed. PPT was measured by applying an increasing amount of blunt pressure using a 1 cm2 hard rubber end at the thenar region of the right hand with a constant increase in pressure of 50 kPa/s. The PPT was measured on a single day, and the average value was used for analysis. The male group (67.00 ± 9.12 years) was older than the female group (62.21 ± 6.77 years; p = 0.021). In the body composition analysis, only segmental water of the right arm was positively related to PPT (ß = 0.331, p = 0.030) in the multivariate linear regression analysis. In conclusion, hydration status was related to PPT with clinical implication that sufficient hydration could reduce the pain susceptibility. Thus, when assessing the painful condition, checking the hydration status could be helpful before the intensive treatment.


Assuntos
Água Corporal/metabolismo , Fazendeiros , Limiar da Dor/fisiologia , Pressão , Idoso , Composição Corporal , Índice de Massa Corporal , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade
5.
Cornea ; 38(10): 1291-1298, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31335538

RESUMO

PURPOSE: Women have a higher dry eye disease prevalence compared with men, although only relatively minor differences in the ocular surface have been observed. Interestingly, a sex difference in pain sensitivity is known, and recent research suggests that pain sensitivity is associated with dry eye symptoms. This study attempts to discern whether the association between pain sensitivity and dry eye symptoms varies between women and men. METHODS: In this prospective cross-sectional study, subjects were seen for one visit where they were asked to fill out a set of questionnaires consisting of the Pain Sensitivity Questionnaire, Ocular Surface Disease Index (OSDI), and other dry eye questionnaires. This was followed by an ocular surface assessment on both eyes. RESULTS: Two hundred eighty-seven subjects (194 women, 93 men) completed the study. Intersex differences in the ocular surface were noted. Even after accounting for these differences, an interaction effect between sex and Pain Sensitivity Questionnaire-minor score on dry eye symptoms was observed, with only women noting increased symptoms on the OSDI (P < 0.005) and other dry eye questionnaires (P values ranging from 0.01 to <0.005) with greater pain sensitivity. After controlling for other variables, women with the highest pain sensitivity had a 17-point higher OSDI score and greater symptoms, as reported by all the other dry questionnaires compared with their male counterparts. CONCLUSIONS: The role of pain sensitivity on dry eye symptoms appears to vary between women and men. This difference provides insight into why women have a significantly higher dry eye disease prevalence than men.


Assuntos
Síndromes do Olho Seco/diagnóstico , Dor Ocular/epidemiologia , Limiar da Dor/fisiologia , Qualidade de Vida , Adolescente , Adulto , Idoso , Estudos Transversais , Síndromes do Olho Seco/complicações , Síndromes do Olho Seco/epidemiologia , Dor Ocular/diagnóstico , Dor Ocular/etiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Prevalência , Estudos Prospectivos , Distribuição por Sexo , Fatores Sexuais , Inquéritos e Questionários , Estados Unidos/epidemiologia , Adulto Jovem
6.
J Physiol Sci ; 69(5): 769-777, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31267368

RESUMO

Operant methods that allow animals to avoid painful stimuli are interpreted to assess the aversive quality of pain; however, such measurements require investigator-initiated stimuli to animals. Here we developed a shuttle maze test to repeatedly assess activity associated nociception without forced stimulation. Rats ambulate back and forth between two treat feeders by taking either a short route with a prickly surfaced arch or a longer route with a smooth floor. L5-L6 spinal nerve ligation (SNL) reduced the preference for the short route with the arch, correlated with hypersensitivity in the hind paw. Oral gabapentin restored the short route preference and reduced hypersensitivity in SNL rats, and blockade of spinal α2-adrenoceptors reduced gabapentin's effects on hypersensitivity but not on preference index. These results suggest that SNL injury alters behavior in the shuttle maze test and that the shuttle maze test shows comparable results to reflexive hypersensitivity after SNL in magnitude and response to gabapentin.


Assuntos
Comportamento de Escolha/fisiologia , Traumatismos dos Nervos Periféricos/fisiopatologia , Animais , Modelos Animais de Doenças , Alimentos , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatologia , Ligadura/métodos , Masculino , Neuralgia/metabolismo , Neuralgia/fisiopatologia , Limiar da Dor/fisiologia , Ratos , Ratos Sprague-Dawley , Nervos Espinhais/metabolismo , Nervos Espinhais/fisiopatologia , Ácido gama-Aminobutírico/metabolismo
7.
J Sports Med Phys Fitness ; 59(10): 1635-1639, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31219256

RESUMO

BACKGROUND: The objective of the study is to determine whether higher pain thresholds are associated with better performance in long-distance runners. METHODS: Seventy participants, divided into groups of fast and non-fast runners according to peak results in a 10km run. Main Outcome Measures, Cold pressor test. RESULTS: Of the 70 participants, 28 were in the fastest group (less than 39 minutes in a 10km run) and 42 in the non-fast group. The faster group was characterized with older age (34.0±8.5 vs. 29.5±5.7, P=0.01), greater mean weekly running time (5.5 [0-17]) vs. 2 [0-10], P<0.001), and more years of running (10 [1.5-34.0] vs. 7 [0-20, P=0.05]). In a multivariable analysis longer cold pressor time was associated with faster 10Km run (OR 1.01, 95% CI 1.00-1.01). CONCLUSIONS: It seems that higher pain thresholds play an important role in the superior ability of long distance runners.


Assuntos
Limiar da Dor/fisiologia , Resistência Física/fisiologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Corrida/fisiologia
8.
J Clin Neurosci ; 65: 17-22, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31080004

RESUMO

Pain sensitivity is a recognized feature of fibromyalgia syndrome (FMS) but the contribution of spinal nociceptive circuitry to this phenomenon is unknown. Therefore, the objectives were to study the changes in spinal nociception i.e. nociceptive flexion reflex (NFR) in patients with FMS and to investigate correlation if any, between NFR threshold, pain duration and tender points in FMS. One hundred and three patients with FMS and 74 healthy volunteers participated in the study. To record NFR, sural nerve was stimulated in the retro malleolar region and the reflex response was recorded from the short head of biceps femoris muscle. NFR was elicited at significantly lower [21.0(18.0-25.0)V] thresholds in FMS group when compared to healthy subjects [30.0(24.75-35.0)V; p = 0.001] indicating hyperalgesic response to electrocutaneous stimulation in FMS patients. The latency and other parameters of NFR were comparable in both the groups. No significant correlation was found among NFR threshold and pain duration or tender points. On the basis of results of present study, it may be concluded that the functional deficit of the spinal nociceptive system can contribute to hyperalgesia in FMS. This is first study that correlates a marker of central hyper-excitability (NFR threshold) with clinical symptoms (pain duration and tender points) of FMS.


Assuntos
Fibromialgia/fisiopatologia , Hiperalgesia/fisiopatologia , Nociceptividade/fisiologia , Limiar da Dor/fisiologia , Adulto , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/fisiopatologia , Reflexo/fisiologia
9.
Complement Ther Med ; 44: 61-67, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31126577

RESUMO

OBJECTIVES: To determine the short-term effects of a modified Flexion-Distraction (FD) technique in comparison with a high-velocity low-back spinal manipulation (HVLA-SM) protocol on patients suffering from chronic low-back pain (CLBP). DESIGN AND METHODS: A randomized controlled trial. The sample was composed of 150 patients suffering from CLBP, who were randomly assigned to either a FD (n = 75) or a HVLA-SM (n = 75) group. The variables used to study pain were the scores of the Visual Analogue Scale (VAS) and the Pressure Pain Threshold (PPT) on trigger points (TrPs) of the quadratus lumborum. In addition, the Oswestry Disability Index (ODI) was used to measure disability, and Schober's test and the Finger Floor Distance test (FFDT) to measure changes in low-back spine motion. An Analysis of Covariance (ANCOVA) was used to measure group effect, and Number Needed to Treat (NNT) for effect size. RESULTS: Greater improvements occurred in the FD group, with a statistically significant group effect (p < 0.001) for all outcome variables. The ETA2 value was larger than 0.100 in the Schober's and FDD tests, larger than 0.200 in the case of ODI and PPT, and larger than 0.300 for VAS. OR = 0.07 [IC 95% = 0.03 to 0.18] and NNT = 2.08 [IC 95% = 1.64-2.84) yielded improved values for the FD group. CONCLUSION: For patients suffering from CLBP, greater improvements in pain and function were observed in the group receiving the modified FD treatment than in the HVLA-SM group.


Assuntos
Dor Lombar/terapia , Manipulação da Coluna/métodos , Medição da Dor/métodos , Adulto , Feminino , Humanos , Masculino , Limiar da Dor/fisiologia , Amplitude de Movimento Articular/fisiologia , Método Simples-Cego , Inquéritos e Questionários , Resultado do Tratamento
10.
Neuroscience ; 408: 259-271, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30999033

RESUMO

Human studies have repeatedly shown that conditioning pain modulation (CPM) exerts an overall descending inhibitory effect over spinal nociceptive activity. Previous studies have reported a reduction of the nociceptive withdrawal reflex (NWR) under CPM. Still, how descending control influences the muscle activation patterns involved in this protective behavior remains unknown. This study aimed to characterize the effects of CPM on the withdrawal pattern assessed by a muscle synergy analysis of several muscles involved in the lower limb NWR. To trigger descending inhibition, CPM paradigm was applied using the cold-pressor test (CPT) as conditioning stimulus. Sixteen healthy volunteers participated. The NWR was evoked by electrical stimulation on the arch of the foot before, during and after the CPT. Electromyographic (EMG) activity of two proximal (rectus femoris and biceps femoris) and two distal (tibialis anterior and soleus) muscles was recorded. A muscle synergy analysis was performed on the decomposition of the EMG signals, based on a non-negative matrix factorization algorithm. Results showed that two synergies (Module I and II) were sufficient to describe the NWR pattern. Under CPM, Module I activation amplitude was significantly reduced in a narrow time-window interval (118-156 ms) mainly affecting distal muscles, whereas Module II activation amplitude was significantly reduced in a wider time-window interval (150-250 ms), predominantly affecting proximal muscles. These findings suggest that proximal muscles are largely under supraspinal control. The descending inhibitory drive exerted onto the spinal cord may adjust the withdrawal pattern by differential recruitment of the muscles involved in the protective behavior.


Assuntos
Músculo Esquelético/fisiopatologia , Nociceptividade/fisiologia , Limiar da Dor/fisiologia , Dor/fisiopatologia , Reflexo/fisiologia , Adulto , Estimulação Elétrica , Eletromiografia , Feminino , Humanos , Masculino , Medição da Dor , Adulto Jovem
11.
Georgian Med News ; (287): 119-124, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30958302

RESUMO

The purpose of this study was to elucidate the relationship between thermal and mechanical sensation, as well as pain thresholds degrees and the dynamics of the TRPV1 level in almost healthy young males and females in the follicular and luteal phases of the OMC. We found gender differences for some pain sensation indices, taking into account OMC phases of females. Mechanical pain tolerance and heat pain thresholds were significantly higher in males compared with females in both phases of the OMC, also, mechanical pain, mechanical pressure, cold pain and heat sensation thresholds were insignificantly higher in males compared with females in follicular phase of the OMC and significantly higher - in luteal phase of the OMC. We haven't found any differences in cold sensation threshold between males and females in both phases of OMC. Moreover, we found significant gender and interphase differences in receptor protein TRPV1 level - the maximal level in females in luteal phase of the OMC, lower in males and minimal in females in follicular phase of the OMC.


Assuntos
Fase Folicular/fisiologia , Fase Luteal/fisiologia , Percepção da Dor/fisiologia , Limiar da Dor/fisiologia , Dor , Caracteres Sexuais , Canais de Cátion TRPV/metabolismo , Sensação Térmica/fisiologia , Adolescente , Adulto , Temperatura Baixa , Feminino , Temperatura Alta , Humanos , Masculino , Adulto Jovem
12.
Exp Brain Res ; 237(7): 1735-1744, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31030281

RESUMO

BACKGROUND AND OBJECTIVES: Pain is a complex experience involving both nociceptive and affective-cognitive mechanisms. The present study evaluated whether modulation of pain perception, employing a conditioned pain modulation (CPM) paradigm, is paralleled by changes in contact heat-evoked potentials (CHEPs), a brain response to nociceptive stimuli. METHODS: Participants were 25 healthy, pain-free, college students (12 males, 13 females, mean age 19.24 ± 0.97 years). Twenty computer-controlled heat stimuli were delivered to the non-dominant forearm and CHEPs were recorded at Cz using a 32-channel EEG system. After each stimulus, participants rated the intensity of the heat pain using the 0-100 numerical rating scale. The latency and amplitude of N2, P2 components as well as single-sweep spectral analysis of individual CHEPs were measured offline. For CPM, participants had to submerge their dominant foot into a neutral (32 °C) or noxious (0 °C) water bath. CHEPs and heat pain ratings were recorded in 3 different conditions: without CPM, after neutral CPM (32 °C) and after noxious CPM (0 °C). RESULTS: The noxious CPM induced a facilitatory pain response (p = 0.001) with an increase in heat pain following noxious CPM compared to neutral CPM (p = 0.001) and no CPM (p = 0.001). Changes in CHEPs did not differ between conditions when measured as N2-P2 peak-to-peak amplitude (p = 0.33) but the CPM significantly suppressed the CHEPs-related delta power (p = 0.03). Changes in heat pain in the noxious CPM were predicted by trait catastrophizing variables (p = 0.04). CONCLUSION: The current study revealed that pain facilitatory CPM is related to suppression of CHEPs delta power which could be related to dissociation between brain responses to noxious heat and pain perception.


Assuntos
Encéfalo/fisiopatologia , Catastrofização/fisiopatologia , Medição da Dor/métodos , Percepção da Dor/fisiologia , Dor/fisiopatologia , Catastrofização/diagnóstico , Catastrofização/psicologia , Eletroencefalografia/métodos , Feminino , Temperatura Alta/efeitos adversos , Humanos , Masculino , Fibras Nervosas Mielinizadas/fisiologia , Dor/diagnóstico , Dor/psicologia , Medição da Dor/psicologia , Limiar da Dor/fisiologia , Adulto Jovem
13.
Neurosci Lett ; 706: 18-23, 2019 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-31026533

RESUMO

We examined the effect of immobilization, low-intensity muscle contraction exercise, and transcutaneous electrical nerve stimulation (TENS) on tissue inflammation and acute pain following the onset of arthritis in a rat model. Sixty Wistar rats were divided into five groups: (1) Arthritis group, (2) arthritis and immobilization (Immobilization group), (3) arthritis and low intensity muscle contraction (Exercise group), (4) arthritis and TENS (TENS group), and (5) sham arthritis (Sham group). Arthritis was induced in the right knee joints by single injection of 3% kaolin and carrageenan. Immobilization of the right hindlimb was conducted by full extension of the right knee joints and full plantar flexion of the ankle joints using a plaster cast for 7 days after injection. The right quadriceps muscles were subjected to electrical stimulation (frequency: 50 Hz; intensity: 2-3 mA) for 20 min/day as contraction exercise for one week. TENS was delivered at 20 min/day for one week (frequency: 50 Hz; intensity: 1 mA). The pressure pain threshold (PPT) and paw withdrawal response (PWR) were evaluated at 1 and 7 days after injection. We also analyzed the number of CD68-positive cells in the synovium by immunohistochemistry and determined the expression level of calcitonin gene-related peptide (CGRP) in the spinal dorsal horn with immunofluorescence. Improvements of both PPT and PWR were observed in the Exercise group at 7 days after injection compared to those of the Arthritis and Immobilization groups, although only improvement of PPT was observed in the TENS group. The number of CD68-positive cells in the synovium and CGRP expression in the dorsal horn decreased only in the Exercise group. These results suggested that low-intensity muscle contraction exercise might be a better treatment for reduction of arthritis-induced inflammation and acute pain compared to immobilization and TENS.


Assuntos
Artrite Experimental/terapia , Sensibilização do Sistema Nervoso Central/fisiologia , Terapia por Exercício/métodos , Hiperalgesia/terapia , Inflamação/terapia , Contração Muscular/fisiologia , Medula Espinal/fisiopatologia , Animais , Artrite Experimental/fisiopatologia , Hiperalgesia/fisiopatologia , Inflamação/fisiopatologia , Músculo Esquelético/fisiopatologia , Medição da Dor , Limiar da Dor/fisiologia , Ratos , Ratos Wistar , Estimulação Elétrica Nervosa Transcutânea
14.
Rev Assoc Med Bras (1992) ; 65(3): 384-387, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30994837

RESUMO

Stretching exercises are widely used by the population before sporting activities. One of the most common technique is eccentric exercise. Here, we made a clinical examination of 98 subjects with equinus condition before activity and after 30 min of running (49 participants with previous eccentric exercise and 49 with no previously eccentric exercise). The clinical assessment of the Achilles tendon was based on the pressure pain threshold (PPT). We identified significant PPT changes between the previous eccentric stretching and the non-previous eccentric stretching group in the Achilles tendon evaluations. Based on our findings, we propose that subjects with equinus condition could use eccentric stretching in order to improve the Achilles tendon status.


Assuntos
Tendão do Calcâneo/fisiopatologia , Articulação do Tornozelo/fisiopatologia , Exercícios de Alongamento Muscular/métodos , Mialgia/prevenção & controle , Limiar da Dor/fisiologia , Corrida/fisiologia , Adulto , Tornozelo/fisiopatologia , Humanos , Masculino , Mialgia/fisiopatologia , Valores de Referência , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Resultado do Tratamento
15.
Phys Ther Sport ; 37: 150-156, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30978601

RESUMO

OBJECTIVES: To investigate the association of pain sensitivity and endogenous analgesia capacity, and training volume in a group of competitive swimmers. DESIGN: An observational multi-center study. SETTING: Multiple competitive swimming clubs. PARTICIPANTS: 102 healthy competitive swimmers. MAIN OUTCOME MEASURES: Training volume was estimated using self-reported information. Static and dynamic measures of pain were assessed using pressure pain thresholds (PPTs) and conditioned pain modulation (CPM), the latter as a measure of endogenous pain inhibition. Selected demographic and psychosocial measures were considered as possible confounding factors. RESULTS: Moderate positive correlations (0.38 < r < 0.44; p < 0.01) exist between self-reported training volume and PPTs at widespread body areas in competitive swimmers. These results were maintained during linear regression analysis while addressing possible confounding factors such as age and selected psychosocial factors. No associations were found between self-reported training volume and conditioned pain modulation (-0.08 < r < 0.06; p > 0.05). CONCLUSIONS: Self-reported swim training volume is associated with pain sensitivity in competitive swimmers. Swimmers who train more show higher pressure pain thresholds, indicating lower pain sensitivity. Swim training volume is not associated with endogenous nociceptive inhibitory capacity as determined using CPM.


Assuntos
Atletas , Limiar da Dor/fisiologia , Condicionamento Físico Humano/estatística & dados numéricos , Natação/fisiologia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Adulto Jovem
16.
J Neuroinflammation ; 16(1): 82, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975169

RESUMO

BACKGROUND: Neuropathic pain is caused by sensory nerve injury, but effective treatments are currently lacking. Microglia are activated in the spinal dorsal horn after sensory nerve injury and contribute to neuropathic pain. Accordingly, molecules expressed by these cells are considered potential targets for therapeutic strategies. Our previous gene screening study using a mouse model of motor nerve injury showed that the G-protein-coupled receptor 34 gene (GPR34) is induced by nerve injury. Because GPR34 is now considered a microglia-enriched gene, we explored the possibility that it might be involved in microglial activation in the dorsal horn in a mouse model of neuropathic pain. METHODS: mRNA expression of GPR34 and pro-inflammatory molecules was determined by quantitative real-time PCR in wild-type and GPR34-deficient mice with L4 spinal nerve injury. In situ hybridization was used to identify GPR34 expression in microglia, and immunohistochemistry with the microglial marker Iba1 was performed to examine microglial numbers and morphology. Mechanical sensitivity was evaluated by the von Frey hair test. Liquid chromatography-tandem mass spectrometry quantified expression of the ligand for GPR34, lysophosphatidylserine (LysoPS), in the dorsal horn, and a GPR34 antagonist was intrathecally administrated to examine the effect of inhibiting LysoPS-GPR34 signaling on mechanical sensitivity. RESULTS: GPR34 was predominantly expressed by microglia in the dorsal horn after L4 nerve injury. There were no histological differences in microglial numbers or morphology between WT and GPR34-deficient mice. However, nerve injury-induced pro-inflammatory cytokine expression levels in microglia and pain behaviors were significantly attenuated in GPR34-deficient mice. Furthermore, the intrathecal administration of the GPR34 antagonist reduced neuropathic pain. CONCLUSIONS: Inhibition of GPR34-mediated signal by GPR34 gene deletion reduced nerve injury-induced neuropathic pain by suppressing pro-inflammatory responses of microglia without affecting their morphology. Therefore, the suppression of GPR34 activity may have therapeutic potential for alleviating neuropathic pain.


Assuntos
Microglia/metabolismo , Neuralgia/metabolismo , Neuralgia/patologia , Receptores de Lisofosfolipídeos/metabolismo , Medula Espinal/patologia , Análise de Variância , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Fatores Reguladores de Interferon/metabolismo , Lisofosfolipídeos/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas dos Microfilamentos/metabolismo , Neuralgia/tratamento farmacológico , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Medição da Dor , Limiar da Dor/fisiologia , Proteína Quinase C/metabolismo , RNA Mensageiro/metabolismo , Receptores de Lisofosfolipídeos/antagonistas & inibidores , Receptores de Lisofosfolipídeos/genética , Fatores de Tempo
17.
Complement Ther Med ; 43: 312-318, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30935551

RESUMO

OBJECTIVES: This study aimed to compare the amount of deep tissue pressure and muscle relaxation between a soft inflatable rubber ball (SIRB) and a hard massage ball (HMB). DESIGN: Crossover experimental design study. INTERVENTIONS: Thirty participants with neck pain (age: 65.9 ± 3.4, Neck Disability Index score: 34.0% ± 15.2) pillowed a SIRB or an HMB beneath the suboccipital region in the supine position. For the baseline condition, participants pillowed a foam block without a ball. MAIN OUTCOME MEASURES: To quantify the amount of deep-tissue pressure by a ball, compressed soft tissue thickness was measured with lateral cervical radiographs. To assess muscle relaxation, the amount of muscle tension was determined using electromyography of the sternocleidomastoid and upper trapezius muscles. To monitor the cervical lordosis in each condition, the extension angles of the cervical vertebrae were quantified using the relative rotation angles. RESULTS: The compressed soft tissue thickness in the SIRB condition was significantly lower than that in the HMB condition. The normalised muscle activities exhibited that right sternocleidomastoid muscle activity in the HMB condition was significantly higher than that in the baseline and SIRB conditions. In the SIRB and HMB conditions, Numeric Rating Scale for pain was 0.2 ± 0.5 and 5.2 ± 1.4, respectively. CONCLUSIONS: Our findings demonstrate that a SIRB is more advantageous than an HMB for pressing the soft tissue deeply. This finding would be related to reduced muscle tension and discomfort in the SIRB condition when compared with the HMB condition.


Assuntos
Massagem/métodos , Síndromes da Dor Miofascial/terapia , Cervicalgia/terapia , Idoso , Vértebras Cervicais/fisiopatologia , Estudos Cross-Over , Feminino , Humanos , Masculino , Relaxamento Muscular/fisiologia , Tono Muscular/fisiologia , Músculos do Pescoço/fisiopatologia , Limiar da Dor/fisiologia , Pressão , Amplitude de Movimento Articular/fisiologia , Músculos Superficiais do Dorso/fisiopatologia , Pontos-Gatilho/fisiopatologia
18.
Neuroscience ; 409: 142-151, 2019 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-30940563

RESUMO

Stress is a non-specific, systemic, physiological response of the body to strong internal and external environmental stimuli. Accumulating evidence has suggested that stress, particularly chronic restraint stress (CRS), can reduce pain threshold and increase pain sensitivity. However, pathogenic and therapeutic mechanisms underlying CRS remain unclear. Here, we aimed to investigate roles of the brain-derived neurotrophic factor (BDNF)-mammalian target of rapamycin (mTOR) signaling pathway in CRS-induced abnormal pain sensitivity. CRS was successfully mimicked 7 days after model development, and paw withdrawal mechanical threshold (PWMT) and tail-flick latency (TFL) were evaluated. CRS significantly altered BDNF and mTOR phosphorylation in the anterior cingulate cortex and spinal cord but not in the hippocampus. On day 7, a single dose of 7,8-dihydroxyflavone, an activator of BDNF-tropomyosin receptor kinase B, was administered via intraperitoneal or intrathecal injection. Notably, only the intrathecal injection improved PWMT and TFL. Additionally, an intraperitoneal injection of rapamycin, an mTOR inhibitor, failed to induce any behavioral changes, whereas a single intrathecal injection of rapamycin improved abnormal CRS-induced PWMT and TFL. In conclusion, CRS can induce abnormal pain sensitivity, probably by altering the BDNF-mTOR signaling pathway in the spinal cord.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Hiperalgesia/metabolismo , Transdução de Sinais/fisiologia , Medula Espinal/metabolismo , Estresse Psicológico/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Masculino , Camundongos , Medição da Dor , Limiar da Dor/fisiologia , Fosforilação , Ratos , Ratos Sprague-Dawley , Restrição Física
19.
Neuroscience ; 406: 50-61, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30826522

RESUMO

Despite the high incidence of neuropathic pain, its mechanism remains unclear. Oxytocin (OXT) is an established endogenous polypeptide produced in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus. OXT, which is synthesized by OXT neurons in the SON and the magnocellular part of the PVN (mPVN), is delivered into the posterior pituitary (PP), then released into the systemic blood circulation. Meanwhile, OXT-containing neurosecretory cells in the parvocellular part of the PVN (pPVN) are directly projected to the spinal cord and are associated with sensory modulation. In this study, the OXT system in the hypothalamo-neurohypophysial and hypothalamo-spinal pathway was surveyed using a rat neuropathic pain model induced by partial sciatic nerve ligation (PSL). In the present study, we used transgenic rats expressing an OXT-monomeric red fluorescent protein 1 (mRFP1) fusion gene. In a neuropathic pain model, mechanical allodynia was observed, and glial cell activation was also confirmed via immunohistochemistry. In this neuropathic pain model, a significant increase in the OXT-mRFP1 expression was observed in the PP, the SON, mPVN, and pPVN. Furthermore, OXT-mRFP1 granules with positive fluorescent reaction were remarkably increased in laminae I and II of the ipsilateral dorsal horn. Although the plasma concentrations of OXT did not significantly change, a significant increase of the mRNA levels of OXT and mRFP1 in the SON, mPVN, and pPVN were observed. These results suggest that neuropathic pain induced by PSL upregulates hypothalamic OXT synthesis and transportation to the OXTergic axon terminals in the PP and spinal cord.


Assuntos
Proteínas Luminescentes/biossíntese , Neuralgia/metabolismo , Ocitocina/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Neuro-Hipófise/metabolismo , Medula Espinal/metabolismo , Animais , Proteínas Luminescentes/análise , Proteínas Luminescentes/genética , Masculino , Vias Neurais/química , Vias Neurais/metabolismo , Ocitocina/análise , Limiar da Dor/fisiologia , Núcleo Hipotalâmico Paraventricular/química , Neuro-Hipófise/química , Ratos , Ratos Transgênicos , Ratos Wistar , Medula Espinal/química , Núcleo Supraóptico/química , Núcleo Supraóptico/metabolismo , Regulação para Cima/fisiologia
20.
Pain ; 160(5): 1070-1081, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30855519

RESUMO

Rare pain-insensitive individuals offer unique insights into how pain circuits function and have led to the development of new strategies for pain control. We investigated pain sensitivity in humans with WAGR (Wilms tumor, aniridia, genitourinary anomaly, and range of intellectual disabilities) syndrome, who have variably sized heterozygous deletion of the 11p13 region. The deletion region can be inclusive or exclusive of the brain-derived neurotrophic factor (BDNF) gene, a crucial trophic factor for nociceptive afferents. Nociceptive responses assessed by quantitative sensory testing demonstrated reduced pain sensitivity only in the WAGR subjects whose deletion boundaries included the BDNF gene. Corresponding behavioral assessments were made in heterozygous Bdnf knockout rats to examine the specific role of Bdnf. These analogous experiments revealed impairment of Aδ- and C-fiber-mediated heat nociception, determined by acute nociceptive thermal stimuli, and in aversive behaviors evoked when the rats were placed on a hot plate. Similar results were obtained for C-fiber-mediated cold responses and cold avoidance on a cold-plate device. Together, these results suggested a blunted responsiveness to aversive stimuli. Our parallel observations in humans and rats show that hemizygous deletion of the BDNF gene reduces pain sensitivity and establishes BDNF as a determinant of nociceptive sensitivity.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Limiar da Dor/fisiologia , Dor/etiologia , Síndrome WAGR/complicações , Síndrome WAGR/genética , Adolescente , Adulto , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Criança , Feminino , Gânglios Espinais/metabolismo , Gânglios Espinais/patologia , Perfilação da Expressão Gênica , Humanos , Hiperalgesia/genética , Hiperalgesia/fisiopatologia , Lasers/efeitos adversos , Masculino , Mutação/genética , Dor/genética , Medição da Dor , Estimulação Física/efeitos adversos , Ratos , Ratos Transgênicos , Medula Espinal/metabolismo , Medula Espinal/patologia , Adulto Jovem
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