Ana Luiza Peretti

Comparison of low level laser, ultrasonic therapy and association in joint pain in Wistar rats

INTRODUCTION Both therapeutic ultrasound as a low level laser therapy are used to control musculoskeletal pain, despite controversy about its effects, yet the literature is poor and also presents conflicting results on possible cumulative effects of techniques association. The aim was to compare the antinociceptive effects of low level laser therapy, therapeutic ultrasound and the association. METHODS 24 Wistar rats were divided into: GPL--induction of hyperesthesia in the right knee, and untreated; GUS--treated with therapeutic ultrasound (1 MHz, 0.4 W/cm2) GL--low intensity laser (830 nm, 8 J/cm2); GL+US--treated with both techniques. To produce the hyperesthesia 100 μl of 5% formalin solution were injected into the tibiofemoral joint space, which was assessed by von Frey filament digital before (EV1), 15 (EV2), 30 (EV3) and 60 (EV4) minutes after induction. RESULTS In comparison within groups, for the withdrawal threshold when the fi lament was applied to the knee, the back to baseline was observed only for GUS. Comparisons between groups were not different in EV3, and GL was higher than GPL. In EV4 the three groups effectively treated were higher than placebo. On withdrawal threshold on the plantar surface, GL showed return to baseline values already in EV3, and GUS and GL+US returned in EV4. Comparing the groups in EV3 there was a significantly lower threshold to compare GPL with GL and GUS (p <0.05), and there was only EV4 differences when comparing GPL with GUS. CONCLUSION Both modalities showed antinociceptive effects.

Nociceptive and Neuronal Evaluation of the Sciatic Nerve of Wistar Rats Subjected to Compression Injury and Treated with Resistive Exercise

Background. To investigate the climb stairs resistance exercise on nociception and axonal regeneration in the sciatic nerve of rats. Methods. 24 Wistar rats were divided: control group (CG—no injury), exercise group (EG—no injury with physical exercise), lesion group (LG—injury, but without exercise), and treated group (LEG—injury and physical exercise). LG and LEG were subjected to sciatic nerve compression with hemostat. From the 3rd day after injury began treatment with exercise, and after 22 days occurs the removal of a nerve fragment for morphological analysis. Results. Regarding allodynia, CG obtained values less than EG (p = 0.012) and larger than LG and LEG (p < 0.001). Histological results showed that CG and EG had normal appearance, as LG and LEG showed up with large amounts of inflammatory infiltration, degeneration and disruption of nerve fibers, and reduction of the myelin sheath; however LEG presented some regenerated fibers. From the morphometric data there were significant differences, for nerve fiber diameter, comparing CG with LG and LEG and comparing axon diameter and the thickness of the myelin of the CG to others. Conclusion. Climb stairs resistance exercise was not effective to speed up the regenerative process of axons.

Ação da vanilina ( Vanilla planifolia ) sobre a morfologia dos músculos tibial anterior e sóleo após lesão nervosa

RESUMO Objetivo Avaliar a acao da vanilina (Vanilla planifolia) sobre a morfologia dos musculos tibial anterior e soleo apos lesao nervosa periferica. Metodos Ratos Wistar foram divididos em quatro grupos, com sete animais cada, sendo Grupo Controle, Grupo Vanilina, Grupo Lesao e Grupo Lesao + Vanilina. Os animais dos Grupos Lesao e Grupo Lesao + Vanilina foram submetidos a lesao nervosa por meio da compressao do nervo isquiatico, e os Grupos Vanilina e Grupo Lesao + Vanilina foram tratados diariamente [...]ABSTRACT Objective To evaluate the action of vanillin (Vanilla planifolia) on the morphology of tibialis anterior and soleus muscles after peripheral nerve injury. Methods Wistar rats were divided into four groups, with seven animals each: Control Group, Vanillin Group, Injury Group, and Injury + Vanillin Group. The Injury Group and the Injury + Vanillin Group animals were submitted to nerve injury by compression of the sciatic nerve; the Vanillin Group and Injury + Vanillin Group, were treated daily with oral doses of vanillin (150mg/kg) from the 3rd to the 21st day after induction of nerve injury. At the end of the experiment, the tibialis anterior and soleus muscles were dissected and processed for light microscopy and submitted to morphological analysis. Results The nerve compression promoted morphological changes, typical of denervation, and the treatment with vanillin was responsible for different responses in the studied muscles. For the tibialis anterior, there was an increase in the number of satellite cells, central nuclei and fiber atrophy, as well as fascicular disorganization. In the soleus, only increased vascularization was observed, with no exacerbation of the morphological alterations in the fibers. Conclusion The treatment with vanillin promoted increase in intramuscular vascularization for the muscles studied, with pro-inflammatory potential for tibialis anterior, but not for soleus muscle.

Efeito do exercício resistido na redução do edema, nocicepção e regeneração nervosa em um modelo de compressão do nervo isquiático

Objetivos : Analisar os efeitos do exercicio fisico resistido de subida em escada, sobre o edema, nocicepcao e regeneracao nervosa de ratos Wistar , submetidos a compressao do nervo isquiatico. Metodos: Foram estudados 24 ratos Wistar , divididos igualmente entre quatro grupos: Grupo Controle, Grupo Exercicio, Grupo Lesao e Grupo Tratado – Lesao e Exercicio. O Grupo Lesao e o Grupo Tratado foram submetidos a compressao do nervo isquiatico com pinca hemostatica por 30 segundos. A partir do terceiro dia apos a lesao, iniciou-se o tratamento com exercicio resistido de subida em escada para o Grupo Exercicio e o Grupo Tratado. O tratamento consistiu em realizar duas series de 10 subidas na escada, com sobrecarga de 100 gramas e intervalo de um minuto entre uma serie e outra. O estudo foi conduzido por 22 dias e nesse tempo os animais foram avaliados quanto ao edema e a nocicepcao. No 22o dia de pos-operatorio, os animais foram anestesiados para retirada de um fragmento do nervo isquiatico para analise do numero de axonios e da densidade de fibras. Em seguida, ainda sob efeito da anestesia, os animais foram eutanasiados. Os nervos coletados seguiram protocolo de processamento histologico de rotina. As expressoes do Fator de Crescimento Neural e do Fator de Crescimento Derivado do Cerebro foram avaliadas por Western blotting . Resultados: Nao houve diferenca significativa entre os grupos no tamanho do edema. O Grupo Controle apresentou maior limiar nociceptivo comparado aos demais grupos. A analise morfometrica nao revelou diferenca significativa entre os grupos, quanto a quantidade de axonios e a densidade de fibras. A expressao do Fator de Crescimento Derivado do Cerebro foi maior no Grupo Lesao e no Grupo Tratado quando comparados ao Grupo Controle. Conclusoes : O exercicio fisico resistido de subida em escada, nos parâmetros propostos, nao foi eficaz para reduzir o edema, a nocicepcao ou aumentar o numero de axonios e a densidade de fibras nervosas apos lesao do nervo isquiatico.

Avaliação nociceptiva da associação entre exercício físico e fibrina rica em plaquetas em ratos Wistar submetidos ao modelo de compressão de nervo mediano

BACKGROUND AND OBJECTIVES: Platelet-rich fibrin is a new and promising technique to accelerate repair, with possible analgesic effects; however, there is still a gap with regard to peripheral nerve injury and the association with physical exercises. So, this study aimed at evaluating the effects of platelet-rich fibrin associated to physical exercises on nociception and edema in experimental median nerve compression model. METHODS: Thirty-six rats, all submitted to median nerve compression, were divided in six groups: G1: without additional manipulation; G2: compression and treated with platelet-rich fibrin; G3: compression and treated with free swimming; G4: compression and walking on a treadmill; G5: free swimming + platelet-rich fibrin; G6: walking on a treadmill + platelet-rich fibrin. Injury was induced by tying the median nerve with chrome plated catgut 4.0. Platelet-rich fibrin was obtained by centrifuging 1.5 mL of blood and positioning the fibrin clot directly on the compression region. Exercises were carried out during two weeks, between the 3rd and 14th postoperative days. Nociception and edema were evaluated, respectively, by flinch threshold and plethysmometer, in moments before injury and in the 3rd, 7th and 15th postoperative days. RESULTS: There have been no differences among groups, only among evaluations, showing increased nociception and edema, which has lasted or improved, respectively, over time. CONCLUSION: Platelet-rich fibrin alone or associated to physical exercises has not changed nociception and edema.BACKGROUND AND OBJECTIVES: Platelet-rich fibrin is a new and promising technique to accelerate repair, with possible analgesic effects; however, there is still a gap with regard to peripheral nerve injury and the association with physical exercises. So, this study aimed at evaluating the effects of platelet-rich fibrin associated to physical exercises on nociception and edema in experimental median nerve compression model. METHODS: Thirty-six rats, all submitted to median nerve compression, were divided in six groups: G1: without additional manipulation; G2: compression and treated with platelet-rich fibrin; G3: compression and treated with free swimming; G4: compression and walking on a treadmill; G5: free swimming + platelet-rich fibrin; G6: walking on a treadmill + platelet-rich fibrin. Injury was induced by tying the median nerve with chrome plated catgut 4.0. Platelet-rich fibrin was obtained by centrifuging 1.5 mL of blood and positioning the fibrin clot directly on the compression region. Exercises were carried out during two weeks, between the 3rd and 14th postoperative days. Nociception and edema were evaluated, respectively, by flinch threshold and plethysmometer, in moments before injury and in the 3rd, 7th and 15th postoperative days. RESULTS: There have been no differences among groups, only among evaluations, showing increased nociception and edema, which has lasted or improved, respectively, over time. CONCLUSION: Platelet-rich fibrin alone or associated to physical exercises has not changed nociception and edema.

Behavioral assessment of rats through the forced-swimming test

Objetivos: O exercicio fisico regular tem diversos efeitos beneficos, contudo, ha relatos de aumento na concentracao de corticosteroides endogenos, os quais podem inibir a neurogenese e piorar as funcoes cognitivas, sendo este um aspecto dubio do exercicio fisico. O objetivo deste estudo foi avaliar, por meio de testes comportamentais, o efeito do exercicio cronico por natacao forcada com e sem sobrecarga, sobre parâmetros de ansiedade em ratos Wistar. Metodos: Foram utilizados 24 ratos Wistar, separados em tres grupos: Grupo Controle – submetido apenas a avaliacoes e contato com a agua; Grupo Natacao – composto por animais submetidos a natacao com tempo progressivo; Grupo Natacao com Sobrecarga – composto por animais submetidos a natacao com sobrecarga de 10% do peso corporal. O exercicio ocorreu tres vezes por semana, no periodo vespertino, com aumento no tempo a cada duas semanas (20, 30 e 40 minutos), totalizando seis semanas. Foi realizado em um tanque de agua circular de 200 litros, com profundidade de 50 cm e temperatura da agua mantida entre 30 e 32o C. A ansiedade dos animais foi avaliada pelos testes Labirinto em Cruz Elevado e Campo Aberto. Resultados: Nao houve diferencas significativas em qualquer dos testes comportamentais, comparando os tres grupos. Conclusoes: Nao houve alteracao no padrao comportamental de ratos Wistar submetidos a diferentes protocolos de exercicio (natacao forcada com e sem sobrecarga) quando comparados ao grupo controle nao submetido a exercicios