Low intensity laser (830 nm) functional to recover of the sciatic nerve in rats

OBJETIVO: Avaliar o efeito do laser de baixa intensidade na melhora funcional da marcha de ratos após esmagamento do nervo ciático. MÉTODOS: Foram utilizados 18 ratos divididos alea-to-riamente em dois grupos: controle (sham) e irradiado com densidade de energia de 40J/cm², em 21 dias consecutivos, utilizando o laser 830nm (AsGaAl). Os animais foram submetidos ao esmagamento do nervo ciático direito com o dispositivo portátil de peso morto e avaliados pelo "Índice Funcional do Ciático" (IFC). As pegadas foram coletadas no pré-operatório, 7º, 14º e 21º dias pós-operatório. RESULTADOS: Os resultados do IFC foram significantes quando comparados os grupos no 7º e 14º dia pós-operatório (p<0,05). No 21º dia pós-operatório não houve diferença entre os grupos. Na avaliação intra-grupos houve diferença entre todas as semanas avaliadas (p<0,01). Os animais irradiados apresentaram melhora no padrão da marcha, demonstrada pelos valores do IFC nos períodos iniciais, mas ao final das 3 semanas, houve uma recuperação similar. CONCLUSÃO: A laserterapia de baixa intensidade mostrou ser eficaz no estímulo da aceleração da regeneração nervosa do ciático de ratos após esmagamento.OBJECTIVE: This study aimed to evaluate the effect of low-intensity laser on functional improvement of the walking of rats after sciatic nerve axonotmesis. METHODS: We used 18 rats divided randomly in two groups: control (Sham) and irradiated with an energy density of 40J/cm² for 21 consecutive days, using 830nm laser (AsGaAl). The animals were subjected to right sciatic nerve crushing by a portable device and assessed by the "Sciatic Functional Index" (SFI) at an acrylic platform through video recorded by a digital camera. The footprints were collected preoperatively, and on the 7th, 14th and 21st postoperative days. RESULTS: The results of the SFI were significant when comparing the groups on the 7th and 14th postoperative day (p<0.05). On the 21st postoperative day there was no difference between groups. There were intra-group differences detected in each evaluated week (p<0.01). The irradiated animals showed improvement in motion pattern, shown by the SFI values in the initial periods, but after 3 weeks, there was a similar recovery. CONCLUSION: The low-intensity laser has shown to be effective in accelerating regeneration of the sciatic nerve of rats after crushing.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Electromyography in muscle activation lumbar region in a comparison between manual therapy and photobiomodulation associated with kinesiotherapy in individuals with low back pain

Introduction: About 10 million people have low back pain (LBP) disability in Brazil, and several therapies are used to treat this condition, such as kinesiotherapy, manual therapy (MT) and photobiomodulation-PBM. Although studies have investigated the use of these methods in LBP, research seeking to evaluate the efficacy of the association between techniques is still needed. Objective: To evaluate the activation of the muscles lumbar region with the influence of PBM and MT associated with kinesiotherapy in the treatment of LBP. Methods: Twenty individuals with chronic LBP were randomly divided into two groups. The first group (MT) received vertebral mobilization associated with a kinesiotherapy exercise program, while the second group (830nm-PBM) received PBM associated with the exercise program, twice a week for 8 weeks. It was performed an evaluation of pain perceived by the visual analogic scale (VAS), lumbar disability by the Oswestry questionnaire, muscle strength by strain gauge and activation through surface electromyography, before and after the treatment protocol. EMG data analysis was performed by MatLab® software. The ANOVA two-way test was used (degree of significance p≤0.05), and the effects size by Hedge test. Results: Considering pain, the two groups presented a significant result (p<0.05). In muscle activation only the multifidus obtained different during side bridge (p<0.05) when compared intragroups. But none of the variables were different when evaluating intergroups. Conclusion: Both MT and PBM associated with kinesiotherapy for 8 weeks are effective in reducing pain, improving motor control and stability of the lumbar spine in patients with chronic LBP

Ascorbic acid iontophoresis for chondral gain in rats with arthritis

OBJECTIVES: To examine the cellularity and thickness of the articular cartilage of the femur in rats with arthritis after treatment with iontophoresis. METHODS: To evaluate these objectives, a histological analysis was performed on hematoxylin and eosin, where cellularity and cartilage thickness were observed and evaluated qualitatively and quantitatively by manual counting by 700.09µm² area. RESULTS: The group treated with IAA had normal cellularity (40.1 cells/μm2) and maintenance of non-calcified cartilage (75.5μm), suggesting normal thickness. The non-treated group C+, on the other hand, had a lower mean number of chondrocytes (13.0μm2) (P <0.05) and, when the cartilage thickness was compared, it showed higher average thickness of calcified cartilage (104.8 mm) and lower mean of non-calcified cartilage (53.3μm) CONCLUSION: The use of iontophoresis with L-ascorbic acid by continuous electric current contributed to a quantitative gain of chondrocytes and improved the thickness distribution of calcified and non-calcified cartilage. Level of Evidence III, Case Control Study.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Low-Level Laser Therapy on the Viability of Skin Flap in Rats Subjected to Deleterious Effect of Nicotine

Objective: The purpose of this study was to evaluate the effect of 830-nm laser in blocking the action of nicotine on the viability of skin flap. Background data: The authors have analyzed the deleterious effect of cigarette smoke or nicotine on the skin flap alone with evidence of increased skin necrosis in the flap. Materials and methods: Twenty-four Wistar-albino rats were divided into three groups of eight animals each: Group 1 (control), subjected to a surgical technique to obtain a flap for cranial base, laser irradiation simulation, and a subcutaneous injection of saline; Group 2, similar to Group 1, with subcutaneous injection of nicotine (2mg/kg/day) for a period of 1 week before and 1 week after surgery; and Group 3, similar to Group 2, with skin flaps subjected to a lambda 830-nm laser irradiation. The laser parameters used were: power 30 mW, beam area 0.07cm(2), irradiance 429 mW/cm(2), irradiation time 84 sec, total energy 2.52J, and energy density 36J/cm(2). The laser was used immediately after surgery and for 4 consecutive days, in one point at 2.5 cm of the flap cranial base. The areas of necrosis were examined by two macroscopic analyses: paper template and Mini-Mop (R). The pervious blood vessels were also counted. Results: The results were statistically analyzed by ANOVA and post-test contrast orthogonal method (multiple comparisons), showing that the laser decreased the area of necrosis in flaps subjected to nicotine, and consequently, increased the number of blood vessels (p < 0.05). Conclusions: The laser proved to be an effective way to decrease the area of necrosis in rats subjected to nicotine, making them similar to the control group

Viabilidade do retalho cutâneo randômico dorsal em camundongos submetidos à fotobiomodulação e ultrassom terapêutico

Introdução: O retalho cutâneo é uma técnica cirúrgica amplamente empregada na prática clínica e comumente apresenta complicações pós-operatórias, portanto, elucidar intervenções que auxiliem na conservação do tecido são fundamentais. A fotobiomodulação (PBM) e o ultrassom terapêutico (UST) são alternativas não invasivas que auxiliam no reparo tecidual, contudo, ainda não há consenso sobre os parâmetros a serem utilizados. Objetivo: Descrever a efetividade dos diferentes parâmetros da PBM e do UST na viabilidade do retalho cutâneo randômico dorsal em camundongos. Métodos: Utilizou-se 55 camundongos Swiss, distribuídos em onze grupos. Os animais foram submetidos à técnica cirúrgica com a revascularização da área limitada através de uma barreira plástica (poliéster/polietileno) da mesma dimensão do retalho. Aplicou-se a PBM ou UST durante cinco dias consecutivos. O registro fotográfico e termográfico foi realizado com as câmeras Cyber-Shot DSC-P72 e FlirC2, sendo posteriormente analisados nos softwares ImageJ® e FLIR Tools, respectivamente. Na análise estatística, os dados foram submetidos ao software GraphPad Prism® 8.0 e ao teste Shapiro-Wilk para a análise da normalidade. Realizou-se a análise de variância (ANOVA TWO-WAY) e pós-teste de Tukey, com nível de significância de 5%. Resultados: Os grupos-5 (PBM 830nm; 10J/cm²) e 6 (UST 3MHz; 0,4W/cm²) apresentaram as maiores porcentagens de tecido viável no terceiro e quinto dia do experimento, sendo estatisticamente significativas quando comparados aos outros grupos. A temperatura reduziu significativamente no grupo-1 quando comparado aos demais no pós-operatório. Conclusão: O UST contínuo à 3MHz e PBM 830nm, foram mais eficazes em melhorar a viabilidade do retalho cutâneo randômico dorsal em camundongos