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1.
Molecules ; 26(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34443434

RESUMO

The aerial part of Biebersteinia heterostemon Maxim. (Geraniaceae Biebersteiniaceae) known as ming jian na bao in Chinese, has been traditionally used in Tibetan folk medicine for treatment of diabetes and hypertension. The aim of the present study was to evaluate the effects of galegine obtained from an ethanol extract of the entire Biebersteinia heterostemon plant on the rat's cardiovascular system in order to characterize its contributions as an antihypertensive agent. The antihypertensive effect of galegine was investigated in pentobarbital-anesthetized hypertensive rats at three dose levels based on the LD50 of galegine. Meanwhile a positive control group received dimaprit with the same procedure. Dimaprit infusion induced a significant hypotension which declined by an average margin of 20%. Simultaneously, single administration of galegine at the doses of 2.5, 5, and 10 mg/kg by intraperitoneal injection induced an immediate and dose-dependent decrease in mean arterial blood pressure (MABP) by an average margin of 40% with a rapid increase in heart rate (HR). We demonstrated that galegine is effective in reducing blood pressure in anesthetized hypertensive rats with rapid onset and a dose-related duration of the effects. The results indicate that galegine was the bioactive compound which can be used as a pharmacophore to design new hypertensive agents.


Assuntos
Anti-Hipertensivos/farmacologia , Guanidinas/farmacologia , Magnoliopsida/química , Animais , Anti-Hipertensivos/química , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Dimaprit/farmacologia , Feminino , Guanidinas/química , Guanidinas/uso terapêutico , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Masculino , Camundongos , Ratos Sprague-Dawley
2.
J Physiol ; 599(1): 289-305, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33067807

RESUMO

KEY POINTS: Cortical activity underlying movement-evoked pain is not well understood, despite being a key symptom of chronic musculoskeletal pain. We combined high-density electroencephalography with a full-body reaching protocol in a virtual reality environment to assess cortical activity during movement-evoked pain in chronic low back pain. Movement-evoked pain in individuals with chronic low back pain was associated with longer reaction times, delayed peak velocity and greater movement variability. Movement-evoked pain was associated with attenuated disinhibition in prefrontal motor areas, as evidenced by an attenuated reduction in beta power in the premotor cortex and supplementary motor area. ABSTRACT: Although experimental pain alters neural activity in the cortex, evidence of changes in neural activity in individuals with chronic low back pain (cLBP) remains scarce and results are inconsistent. One of the challenges in studying cLBP is that the clinical pain fluctuates over time and often changes during movement. The goal of the present study was to address this challenge by recording high-density electroencephalography (HD-EEG) data during a full-body reaching task to understand neural activity during movement-evoked pain. HD-EEG data were analysed using independent component analyses, source localization and measure projection analyses to compare neural oscillations between individuals with cLBP who experienced movement-evoked pain and pain-free controls. We report two novel findings. First, movement-evoked pain in individuals with cLBP was associated with longer reaction times, delayed peak velocity and greater movement variability. Second, movement-evoked pain was associated with an attenuated reduction in beta power in the premotor cortex and supplementary motor area. Our observations move the field forward by revealing attenuated disinhibition in prefrontal motor areas during movement-evoked pain in cLBP.


Assuntos
Dor Lombar , Córtex Motor , Eletroencefalografia , Humanos , Movimento , Percepção da Dor
3.
IEEE Trans Neural Syst Rehabil Eng ; 28(12): 3074-3082, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33232238

RESUMO

Virtual reality (VR) can be used to create environments that are not possible in the real-world. Producing movements in VR holds enormous promise for rehabilitation and offers a platform from which to understand the neural control of movement. However, no study has examined the impact of a 3D fully immersive head-mounted display (HMD) VR system on the integrity of neural data. We assessed the quality of 64-channel EEG data with and without HMD VR during rest and during a full-body reaching task. We compared resting EEG while subjects completed three conditions: No HMD (EEG-only), HMD powered off (VR-off), and HMD powered on (VR-on). Within the same session, EEG were collected while subjects completed full-body reaching movements in two conditions (EEG-only, VR-on). During rest, no significant differences in data quality and power spectrum were observed between EEG-only, VR-off, and VR-on conditions. During reaching movements, the proportion of components attributed to the brain was greater in the EEG-only condition compared to the VR-on condition. Despite this difference, neural oscillations in source space were not significantly different between conditions, with both conditions associated with decreases in alpha and beta power in sensorimotor cortex during movements. Our findings demonstrate that the integrity of EEG data can be maintained while individuals execute full-body reaching movements within an immersive 3D VR environment. Clinical impact: Integrating VR and EEG is a viable approach to understanding the cortical processes of movement. Simultaneously recording movement and brain activity in combination with VR provides the foundation for neurobiologically informed rehabilitation therapies.


Assuntos
Realidade Virtual , Eletroencefalografia , Humanos , Movimento , Modalidades de Fisioterapia , Interface Usuário-Computador
4.
Cereb Cortex Commun ; 1(1): tgaa048, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32984818

RESUMO

Dystonia involves sustained or repetitive muscle contractions, affects different skeletal muscles, and may be associated with tremor. Few studies have investigated if cortical pathophysiology is impaired even when dystonic muscles are not directly engaged and during the presence of dystonic tremor (DT). Here, we recorded high-density electroencephalography and time-locked behavioral data in 2 cohorts of patients and controls during the performance of head movements, upper limb movements, and grip force. Patients with cervical dystonia had reduced movement-related desynchronization in the alpha and beta bands in the bilateral sensorimotor cortex during head turning movements, produced by dystonic muscles. Reduced desynchronization in the upper beta band in the ipsilateral motor and bilateral sensorimotor cortex was found during upper limb planar movements, produced by non-dystonic muscles. In a precision grip task, patients with DT had reduced movement-related desynchronization in the alpha and beta bands in the bilateral sensorimotor cortex. We observed a general pattern of abnormal sensorimotor cortical desynchronization that was present across the head and upper limb motor tasks, in patients with and without DT when compared with controls. Our findings suggest that abnormal cortical desynchronization is a general feature of dystonia that should be a target of pharmacological and other therapeutic interventions.

5.
Brain Res ; 1748: 147085, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32898506

RESUMO

Motor- and pain-related processes separately induce a reduction in alpha and beta power. When movement and pain occur simultaneously but are independent of each other, the effects on alpha and beta power are additive. It is not clear whether this additive effect is evident during motor-evoked pain in individuals with chronic pain. We combined highdensity electroencephalography (EEG) with a paradigm in which motor-evoked pain was induced during a jaw force task. Participants with chronic jaw pain and pain-free controls produced jaw force at 2% and 15% of their maximum voluntary contraction. The chronic jaw pain group showed exacerbated motor-evoked pain as force amplitude increased and showed increased motor variability and motor error irrespective of force amplitude. The chronic jaw pain group had an attenuated decrease in power in alpha and lower-beta frequencies in the occipital cortex during the anticipation and experience of motor-evoked pain. Rather than being additive, motor-evoked pain attenuated the modulation of alpha and beta power, and this was most evident in occipital cortex. Our findings provide the first evidence of changes in neural oscillations in the cortex during motor-evoked jaw pain.

6.
Neuroimage Clin ; 24: 101964, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31412309

RESUMO

Pain perception is associated with priming of the motor system and the orienting of attention in healthy adults. These processes correspond with decreases in alpha and beta power in the sensorimotor and parietal cortices. The goal of the present study was to determine whether these findings extend to individuals with chronic pain. Individuals with chronic jaw pain and pain-free controls anticipated and experienced a low pain or a moderate pain-eliciting heat stimulus. Although stimuli were calibrated for each subject, stimulus temperature was not different between groups. High-density EEG data were collected during the anticipation and heat stimulation periods and were analyzed using independent component analyses, EEG source localization, and measure projection analyses. Direct directed transfer function was also estimated to identify frequency specific effective connectivity between regions. Between group differences were most evident during the heat stimulation period. We report three novel findings. First, the chronic jaw pain group had a relative increase in alpha and beta power and a relative decrease in theta and gamma power in sensorimotor cortex. Second, the chronic jaw pain group had a relative increase in power in the alpha and beta bands in parietal cortex. Third, the chronic jaw pain group had less connectivity strength in the beta and gamma bands between sensorimotor cortex and parietal cortex. Our findings show that the effect of chronic pain attenuates rather than magnifies neural responses to heat stimuli. We interpret these findings in the context of system-level changes in intrinsic sensorimotor and attentional circuits in chronic pain.


Assuntos
Dor Crônica/fisiopatologia , Lobo Parietal/fisiopatologia , Córtex Sensório-Motor/fisiopatologia , Transtornos da Articulação Temporomandibular/fisiopatologia , Adulto , Eletroencefalografia , Feminino , Humanos , Arcada Osseodentária , Masculino , Percepção da Dor/fisiologia
7.
Pain ; 159(12): 2547-2564, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30439720

RESUMO

Changes in brain function in chronic pain have been studied using paradigms that deliver acute pain-eliciting stimuli or assess the brain at rest. Although motor disability accompanies many chronic pain conditions, few studies have directly assessed brain activity during motor function in individuals with chronic pain. Using chronic jaw pain as a model, we assessed brain activity during a precisely controlled grip force task and during a precisely controlled pain-eliciting stimulus on the forearm. We used multivariate analyses to identify regions across the brain whose activity together best separated the groups. We report 2 novel findings. First, although the parameters of grip force production were similar between the groups, the functional activity in regions including the prefrontal cortex, insula, and thalamus best separated the groups. Second, although stimulus intensity and pain perception were similar between the groups, functional activity in brain regions including the dorsal lateral prefrontal cortex, rostral ventral premotor cortex, and inferior parietal lobule best separated the groups. Our observations suggest that chronic jaw pain is associated with changes in how the brain processes motor and pain-related information even when the effector producing the force or experiencing the pain-eliciting stimulus is distant from the jaw. We also demonstrate that motor tasks and multivariate analyses offer alternative approaches for studying brain function in chronic jaw pain.


Assuntos
Encéfalo/diagnóstico por imagem , Dor Crônica/diagnóstico por imagem , Dor Crônica/patologia , Dor Crônica/fisiopatologia , Arcada Osseodentária/patologia , Atividade Motora/fisiologia , Adolescente , Adulto , Idoso , Mapeamento Encefálico , Feminino , Antebraço/inervação , Humanos , Processamento de Imagem Assistida por Computador , Modelos Lineares , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Oxigênio/sangue , Estimulação Física/efeitos adversos , Inquéritos e Questionários , Escala Visual Analógica , Adulto Jovem
9.
J Pain ; 19(6): 636-648, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29477760

RESUMO

Musculoskeletal pain changes how people move. Although experimental pain is associated with increases in the variability of motor output, it is not clear whether motor-evoked pain in clinical conditions is also associated with increases in variability. In the current study, we measured jaw force production during a visually guided force paradigm in which individuals with chronic jaw pain and control subjects produced force at 2% of their maximum voluntary contraction (low target force level) and at 15% of their maximum voluntary contraction (high target force level). State measures of pain were collected before and after each trial. Trait measures of pain intensity and pain interference, self-report measures of jaw function, and measures of depression, anxiety, and fatigue were also collected. We showed that the chronic jaw pain group exhibited greater force variability compared with controls irrespective of the force level, whereas the accuracy of force production did not differ between groups. Furthermore, predictors of force variability shifted from trait measures of pain intensity and pain interference at the low force level to state measures of pain intensity at the high force level. Our observations show that motor-evoked jaw pain is associated with increases in force variability that are predicted by a combination of trait measures and state measures of pain intensity and pain interference. PERSPECTIVE: Chronic jaw pain is characterized by increases in variability during force production, which can be predicted by pain intensity and pain interference. This report could help clinicians better understand the long-term consequences of chronic jaw pain on the motor system.


Assuntos
Força de Mordida , Dor Crônica/fisiopatologia , Arcada Osseodentária/fisiopatologia , Dor Musculoesquelética/fisiopatologia , Transtornos da Articulação Temporomandibular/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Movimento/fisiologia , Contração Muscular/fisiologia
10.
Clin Rehabil ; 31(2): 225-233, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26893457

RESUMO

OBJECTIVES: To investigate the treatment effects of bilateral robotic priming combined with the task-oriented approach on motor impairment, disability, daily function, and quality of life in patients with subacute stroke. DESIGN: A randomized controlled trial. SETTING: Occupational therapy clinics in medical centers. SUBJECTS: Thirty-one subacute stroke patients were recruited. INTERVENTIONS: Participants were randomly assigned to receive bilateral priming combined with the task-oriented approach (i.e., primed group) or to the task-oriented approach alone (i.e., unprimed group) for 90 minutes/day, 5 days/week for 4 weeks. The primed group began with the bilateral priming technique by using a bimanual robot-aided device. MAIN MEASURES: Motor impairments were assessed by the Fugal-Meyer Assessment, grip strength, and the Box and Block Test. Disability and daily function were measured by the modified Rankin Scale, the Functional Independence Measure, and actigraphy. Quality of life was examined by the Stroke Impact Scale. RESULTS: The primed and unprimed groups improved significantly on most outcomes over time. The primed group demonstrated significantly better improvement on the Stroke Impact Scale strength subscale ( p = 0.012) and a trend for greater improvement on the modified Rankin Scale ( p = 0.065) than the unprimed group. CONCLUSION: Bilateral priming combined with the task-oriented approach elicited more improvements in self-reported strength and disability degrees than the task-oriented approach by itself. Further large-scale research with at least 31 participants in each intervention group is suggested to confirm the study findings.


Assuntos
Avaliação da Deficiência , Terapia por Exercício/métodos , Terapia Ocupacional/instrumentação , Reabilitação do Acidente Vascular Cerebral/métodos , Atividades Cotidianas , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Ocupacional/métodos , Projetos Piloto , Prognóstico , Recuperação de Função Fisiológica/fisiologia , Valores de Referência , Robótica , Estatísticas não Paramétricas , Acidente Vascular Cerebral/fisiopatologia , Análise e Desempenho de Tarefas , Resultado do Tratamento , Extremidade Superior/fisiopatologia
11.
J Neurophysiol ; 117(2): 786-795, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-27903639

RESUMO

The translation of brief, millisecond-long pain-eliciting stimuli to the subjective perception of pain is associated with changes in theta, alpha, beta, and gamma oscillations over sensorimotor cortex. However, when a pain-eliciting stimulus continues for minutes, regions beyond the sensorimotor cortex, such as the prefrontal cortex, are also engaged. Abnormalities in prefrontal cortex have been associated with chronic pain states, but conventional, millisecond-long EEG paradigms do not engage prefrontal regions. In the current study, we collected high-density EEG data during an experimental paradigm in which subjects experienced a 4-s, low- or high-intensity pain-eliciting stimulus. EEG data were analyzed using independent component analyses, EEG source localization analyses, and measure projection analyses. We report three novel findings. First, an increase in pain perception was associated with an increase in gamma and theta power in a cortical region that included medial prefrontal cortex. Second, a decrease in lower beta power was associated with an increase in pain perception in a cortical region that included the contralateral sensorimotor cortex. Third, we used machine learning for automated classification of EEG data into low- and high-pain classes. Theta and gamma power in the medial prefrontal region and lower beta power in the contralateral sensorimotor region served as features for classification. We found a leave-one-out cross-validation accuracy of 89.58%. The development of biological markers for pain states continues to gain traction in the literature, and our findings provide new information that advances this body of work.NEW & NOTEWORTHY The development of a biological marker for pain continues to gain traction in literature. Our findings show that high- and low-pain perception in human subjects can be classified with 89% accuracy using high-density EEG data from prefrontal cortex and contralateral sensorimotor cortex. Our approach represents a novel neurophysiological paradigm that advances the literature on biological markers for pain.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Processamento Eletrônico de Dados , Percepção da Dor/fisiologia , Dor/fisiopatologia , Adolescente , Eletroencefalografia , Feminino , Humanos , Masculino , Estimulação Física/efeitos adversos , Escalas de Graduação Psiquiátrica , Temperatura , Escala Visual Analógica , Adulto Jovem
12.
Zhongguo Zhong Yao Za Zhi ; 39(7): 1179-84, 2014 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-25011250

RESUMO

A robust, direct, rapid and non-destructive X-ray diffraction crystallography method for detecting the Tibetan medicine Zuotai is presented. Powder samples of Zuotai, cinnabar and calomel were unambiguously characterized using powder X-ray diffractometry (PXRD) by comparing a practical identification of metacinnabar in the analyzed material, which confirmed the present of metacinnabar in Zuotai. At the same time, 11 strong lines in the fingerprint of Zuotai were selected to indicate the effective constituents of Zuotai, which were listed in the form of d-( I/I0 )%: metacinnabar 3.356 4/100, 2.061 4/55.0, 2.911 8/35.0, 1.760 1/37.0, 1.339 5/12.0, 1.304 5/10.0, 1.192 0/10.0, 1.683 4/7.0, 1.458 0/5.6. sulfur 3.824 4/100, 3.197 5/40.2, 3.442 2/38.1, 3.095 6/19.7, 5.690 9/16.8, 2.851 0/16.3, 2.414 4/11.3. The results showed that mercury chemical state is metacinnabar with sulfur in Tibetan medicine Zuotai. This method should be supplemented to quality control of rare traditonal Chinese medicine.


Assuntos
Medicamentos de Ervas Chinesas/química , Medicina Tradicional Tibetana , Tibet , Difração de Raios X
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