Relación entre las ciencias básicas y clínicas en la modulación central del dolor / Relationship between basic and clinical sciences in central pain modulation

Esta revisión busca proporcionar a los profesionales de la salud una mayor comprensión del dolor para su actividad clínica-asistencial. Basados en la hipóte-sis de neuroplasticidad presentada inicialmente por Ramón y Cajal y la teoría de la compuerta en la vía dolorosa presentada por Melzack y Wall, se ha ela-borado una revisión bibliográfica con el objetivo de abordar la modulación de la vía nociceptiva desde un punto de vista fisiopatológico. Asimismo, se presen-tan los principales resultados obtenidos durante los últimos años en nuestro laboratorio usando ratas Wistar hembras como modelo de dolor experimental. Finalmente, se describe un circuito original de modu-lación central a nivel del subnúcleo caudal del trigé-mino con una visión integral de los componentes del sistema nociceptivo orofacial, para ayudar al clínico a comprender situaciones de sensibilización central con perpetuación del dolor y cómo paulatinamente el sistema nervioso central pone en marcha un sistema de modulación para adaptarse y alcanzar un estado similar al basal (AU)

This review aims to provide health professionals with a better understanding of pain for their clinical-care activity. Based on the neuroplasticity hypothesis initially presented by Ramón and Cajal, and the gate theory in the pain pathway presented by Melzack and Wall, a literature review has been carried out with the aim of addressing the modulation of the nociceptive pathway from a pathophysiological point of view. The main results obtained in recent years in our laboratory using female Wistar rats as an experimental pain model are also presented. Finally, an original central modulation circuit at the level of the caudal trigeminal subnucleus is described with a comprehensive view of the components of the orofacial nociceptive system, to help the clinician to understand situations of central sensitization with perpetuation of pain and how the central nervous system gradually sets in motion a modulation system to adapt and reach a state similar to the basal one (AU)

Regiones del encéfalo vinculadas a la interpretación del dolor / Regions of the brain involved with the interpretation of the pain

Introducción: Entre el lugar del daño tisular y la percepción del dolor, ocurre una serie de eventos electroquímicos que se conocen como nocicepción y comprenden cuatro procesos neurofisiológicos conocidos como: transducción, transmisión, modulación y percepción. Objetivo: Aportar información actualizada sobre las regiones del encéfalo vinculadas a la interpretación del dolor. Material y Método: Se realizó una revisión bibliográfica, con vistas a esclarecer la interpretación de la señal nociceptiva. Se consultaron treinta y cinco artículos científicos, se determinó escoger un total de veintinueve por su relación directa con el propósito de la búsqueda, veintitrés de los cuales corresponden a los últimos 5 años publicados en revistas internacionales y nacionales. Desarrollo: Los axones nociceptivos se clasifican como A δ; y C, participan en la conducción de los potenciales de acción de la periferia al sistema nervioso central. La transmisión de la señal en forma de potenciales de acción se descodifica en áreas relacionadas con aspectos cognoscitivos, afectivo, emocional y conductual del dolor. Este disímil conjunto de estructuras se reconoce en la actualidad como matriz encefálica del dolor. Conclusiones: La matriz del dolor, corresponde a áreas encefálicas como las cortezas somestésicas SI y SII, implicadas en el aspecto discriminativo del dolor. La corteza cingulada anterior y la corteza insular están asociadas al componente afectivo emocional del dolor(AU)

Introduction: A series of electrochemical events called nociception occur between the tissue damage and the perception of pain. They include four neurophysiological processes known as: transduction, transmission, perception, and modulation. Objective: To provide up-to-date information about the regions of the brain involved with the interpretation of pain. Material and Method: A bibliographic review was carried out with the aim of clarifying the interpretation of the nociceptive signal. Thirty-five scientific articles were consulted, and a total of twenty-nine were chosen due to their direct relationship with the aim of the search, twenty-three of which correspond to the last five years of publication in national and international journals. Development: Nociceptive axons are classified as Aδ; and C, and participate in the conduction of action potential of the peripheral nervous system (PNS). The transmission of the signal in the form of action potential is decoded in areas related to cognoscitive, affective, and emotional aspects, and the behavioral area of pain. This dissimilar group of structures is recognized at present as the brain matrix of pain. Conclusions: The pain matrix corresponds to brain areas such as SI and SII somatosensory cortices, implied in the discriminative aspect of pain. Both the anterior cingulate cortex (ACC) and the anterior insular cortex (AIC) are associated with the emotional and affective component of pain(AU)

Jumping in aquatic environment after sciatic nerve compression: nociceptive evaluation and morphological characteristics of the soleus muscle of Wistar rats / Salto em meio aquático após compressão de nervo isquiático: avaliação nociceptiva e características morfológicas do músculo sóleo de ratos Wistar

ABSTRACT Objective To evaluate the effect of jumping in aquatic environment on nociception and in the soleus muscle of trained and not trained Wistar rats, in the treatment of compressive neuropathy of the sciatic nerve. Methods Twenty-five Wistar rats were distributed into five groups: Control, Lesion, Trained + Lesion, Lesion + Exercise, and Trained + Lesion + Exercise. The training was jumping exercise in water environment for 20 days prior to injury, and treatment after the injury. Nociception was evaluated in two occasions, before injury and seven after injury. On the last day of the experiment, the right soleus muscles were collected, processed and analyzed as to morphology and morphometry. Results In the assessment of nociception in the injury site, the Control Group had higher average than the rest, and the Lesion Group was larger than the Trained + Lesion and Lesion + Exercise Groups. The Control Group showed higher nociceptive threshold in paw, compared to the others. In the morphometric analysis, in relation to Control Group, all the injured groups showed decreased muscle fiber area, and in the Lesion Group was lower than in the Lesion + Exercise Group and Trained + Lesion Group. Considering the diameter of the muscle fiber, the Control Group had a higher average than the Trained + Lesion Group and the Trained + Lesion + Exercise Group; and the Lesion Group showed an average lower than the Trained + Lesion and Lesion + Exercise Groups. Conclusion Resistance exercise produced increased nociception. When performed prior or after nerve damage, it proved effective in avoiding hypotrophy. The combination of the two protocols led to decrease in diameter and area of the muscle fiber.

RESUMO Objetivo Avaliar os efeitos do salto em meio aquático, na nocicepção e no músculo sóleo, em ratos Wistar treinados e não treinados, no tratamento de neuropatia compressiva do nervo isquiático. Métodos Foram distribuídos em cinco grupos 25 ratos Wistar: Controle, Lesão, Treinado + Lesão, Lesão + Exercício e Treinado + Lesão + Exercício. O treino foi com exercício de salto em meio aquático durante 20 dias, prévio à lesão, e o tratamento ocorreu após a lesão. Foram realizadas avaliações da nocicepção, sendo uma pré-lesão e sete pós-lesão. No último dia de experimento, os músculos sóleos direitos foram coletados, processados e analisados por meio de morfologia e morfometria. Resultados Na avaliação da nocicepção no local da lesão, o Grupo Controle apresentou média maior que os demais, e o Grupo Lesão foi maior que os Grupos Treinado + Lesão e Lesão + Exercício. O Grupo Controle apresentou limiar nociceptivo na pata maior com relação aos demais. Nas análises morfométricas, em relação ao Grupo Controle, todos os grupos lesionados apresentaram diminuição da área da fibra muscular; o Grupo Lesão apresentou-se menor que os Grupos Treinado + Lesão e Lesão + Exercício. No diâmetro da fibra muscular, o Grupo Controle apresentou média maior que os Grupos Treinado + Lesão e Treinado + Lesão + Exercício, e o Grupo Lesão apresentou média menor que os Grupos Treinado + Lesão e Lesão + Exercício. Conclusão O exercício físico resistido produziu aumento da nocicepção. Quando realizado previamente ou após a lesão nervosa, mostrou-se eficaz em evitar a hipotrofia. A associação dos dois protocolos levou à diminuição do diâmetro e da área da fibra muscular.

Central release of nitric oxide mediates antinociception induced by aerobic exercise

Nitric oxide (NO) is a soluble gas that participates in important functions of the central nervous system, such as cognitive function, maintenance of synaptic plasticity for the control of sleep, appetite, body temperature, neurosecretion, and antinociception. Furthermore, during exercise large amounts of NO are released that contribute to maintaining body homeostasis. Besides NO production, physical exercise has been shown to induce antinociception. Thus, the present study aimed to investigate the central involvement of NO in exercise-induced antinociception. In both mechanical and thermal nociceptive tests, central [intrathecal (it) and intracerebroventricular (icv)] pretreatment with inhibitors of the NO/cGMP/KATP pathway (L-NOArg, ODQ, and glybenclamide) prevented the antinociceptive effect induced by aerobic exercise (AE). Furthermore, pretreatment (it, icv) with specific NO synthase inhibitors (L-NIO, aminoguanidine, and L-NPA) also prevented this effect. Supporting the hypothesis of the central involvement of NO in exercise-induced antinociception, nitrite levels in the cerebrospinal fluid increased immediately after AE. Therefore, the present study suggests that, during exercise, the NO released centrally induced antinociception.

Linhas de pesquisa em enfermagem: destaques filosóficos e epistemológicos / Research lines in nursing: phylosophical and epistemological highlights / Lineas de investigación en enfermería: destaques filosoficos y espistemologicos

RESUMONeste texto trata-se de explicar a investigação científica quanto às Linhas de Pesquisa e Prioridades de Enfermagem, com base na aplicação da teoria do conhecimento e como tangível à Subjetividade e à Objetividade no que concerne aos termos categoriais integrados na literatura como profissional, assistencial e organizacional.Objetivo:elucidar destaques filosóficos e epistemológicos mediante considerações significativas, essenciais, em favor da causalidade de questões no interesse da Enfermagem.Método:abordagem fundamentada nas proposições teóricas de Johannes Hessen, com referência a outros autores expertos no tema.Resultados:esclarecimento de aspectos substantivos e implicações adjetivas não só no interesse da investigação, ressaltando os significados essenciais do assunto, condizente com as elaborações de dissertações de mestrado e teses de doutorado de Enfermagem.Conclusão:trata-se de uma contribuição valiosa para esclarecer melhor detalhes da construção do conhecimento na temática e problemática do assunto posto em causa, as linhas de pesquisa em enfermagem.

ABSTRACTIn this paper scientific investigation is explained as related to the Nursing Research Lines and Priorities based on the theory of knowledge application and as tangible to Subjectivity and Objectivity on what relates to the integrated categorical terms in the literature as professional, caring and organizational.Objective:to elucidate philosophical and epistemological highlights in the face of meaningful, essential considerations, in favor of question causalities of interest to Nursing.Method:the reality approach is founded on the theoretical propositions of Johannes Hessen, with held attention to conceptions of other recognized authors.Results:one can state the exposition value to clarify substantive aspects and adjective implications, not only of interest to investigation, but just to pinpoint the essential meanings on the subject related to elaborated thesis and dissertations (Marters' and Doctoral).Conclusion:represents a valuable contribution to better clarify details on knowledge construction and on the subject theme under discussion.

RESUMENTratase de explicar la investigación científica cuanto a las Líneas de Investigación y Prioridades de Enfermería, en base de la aplicación de la teoría del conocimiento y como tangible a la Subjetividad y a la Objetividad en que concierne a los termos categorías integrados en la literatura como profesional, asistencial y organizacional.Objetivo:elucidar destaques filosóficos y epistemológicos mediante consideraciones en favor de la casualidad de cuestiones en el interés de la Enfermería.Método:es fundamentado en las proposiciones teóricas de Johannes Hessen y de otros autores consagrados.Resultados:clareamiento de aspectos sustantivo e implicaciones adjetivas no sólo el interés de la investigación, resaltando los significados esenciales del asunto coincidido con las elaboraciones de disertaciones y tesis (Maestría y Doctorado de Enfermería).Conclusión:texto representa una contribución valiosa para esclarecer mejor detalles de la construcción del conocimiento en la temática y problemática del asunto puesto en causa.

Effectiveness of hip muscle strengthening in patellofemoral pain syndrome patients: a systematic review

Introduction: Patellofemoral pain syndrome (PFPS) is characterized by anterior knee pain, which may limit the performance of functional activities. The influence of hip joint motion on the development of this syndrome has already been documented in the literature. In this regard, studies have investigated the effectiveness of hip muscle strengthening in patients with PFPS. Objectives: The aims of this systematic review were (1) to summarize the literature related to the effects of hip muscle strengthening on pain intensity, muscle strength, and function in individuals with PFPS and (2) to evaluate the methodological quality of the selected studies. Method: A search for randomized controlled clinical trials was conducted using the following databases: Google Scholar, MEDLINE, PEDro, LILACS, and SciELO. The selected studies had to distinguish the effects of hip muscle strengthening in a group of patients with PFPS, as compared to non-intervention or other kinds of intervention, and had to investigate the following outcomes: pain, muscle strength, and function. The methodological quality of the selected studies was analyzed by means of the PEDro scale. Results: Seven studies were selected. These studies demonstrated that hip muscle strengthening was effective in reducing pain. However, the studies disagreed regarding the treatments' ability to improve muscle strength. Improvement in functional capabilities after hip muscle strengthening was found in five studies. Conclusion: Hip muscle strengthening is effective in reducing the intensity of pain and improving functional capabilities in patients with PFPS, despite the lack of evidence for its ability to increase muscle strength. .

An interleukin-33/ST2 signaling deficiency reduces overt pain-like behaviors in mice

Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors.