Low-level laser (light) therapy (LLLT) on muscle tissue: performance, fatigue and repair benefited by the power of light

The use of low level laser (light) therapy (LLLT) has recently expanded to cover areas of medicine that were not previously thought of as the usual applications such as wound healing and inflammatory orthopedic conditions. One of these novel application areas is LLLT for muscle fatigue and muscle injury. Since it is becoming agreed that mitochondria are the principal photoacceptors present inside cells, and it is known that muscle cells are exceptionally rich in mitochondria, this suggests that LLLT should be highly beneficial in muscle injuries. The ability of LLLT to stimulate stem cells and progenitor cells means that muscle satellite cells may respond well to LLLT and help muscle repair. Furthermore the ability of LLLT to reduce inflammation and lessen oxidative stress is also beneficial in cases of muscle fatigue and injury. This review covers the literature relating to LLLT and muscles in both preclinical animal experiments and human clinical studies. Athletes, people with injured muscles, and patients with Duchenne muscular dystrophy may all benefit

Morphological Aspects And Cox-2 Expression After Exposure To 780-nm Laser Therapy In Injured Skeletal Muscle: An In Vivo Study.

The effectiveness of low-level laser therapy in muscle regeneration is still not well known. To investigate the effects of laser irradiation during muscle healing. For this purpose, 63 rats were distributed to 3 groups: non-irradiated control group (CG); group irradiated at 10 J/cm(2) (G10); and group irradiated at 50 J/cm(2) (G50). Each group was divided into 3 different subgroups (n=7), and on days 7, 14 and 21 post-injury the rats were sacrificed. Seven days post-surgery, the CG showed destroyed zones and extensive myofibrillar degeneration. For both treated groups, the necrosis area was smaller compared to the CG. On day 14 post-injury, treated groups demonstrated better tissue organization, with newly formed muscle fibers compared to the CG. On the 21(st) day, the irradiated groups showed similar patterns of tissue repair, with improved muscle structure at the site of the injury, resembling uninjured muscle tissue organization. Regarding collagen deposition, the G10 showed an increase in collagen synthesis. In the last period evaluated, both treated groups showed statistically higher values in comparison with the CG. Furthermore, laser irradiation at 10 J/cm(2) produced a down-regulation of cyclooxygenase 2 (Cox-2) immunoexpression on day 7 post-injury. Moreover, Cox-2 immunoexpression was decreased in both treated groups on day 14. Laser therapy at both fluencies stimulated muscle repair through the formation of new muscle fiber, increase in collagen synthesis, and down-regulation of Cox-2 expression.18395-40

Low intensity laser therapy accelerates muscle regeneration in aged rats

Background: Elderly people suffer from skeletal muscle disorders that undermine their daily activity and quality of life; some of these problems can be listed as but not limited to: sarcopenia, changes in central and peripheral nervous system, blood hypoperfusion, regenerative changes contributing to atrophy, and muscle weakness. Determination, proliferation and differentiation of satellite cells in the regenerative process are regulated by specific transcription factors, known as myogenic regulatory factors (MRFs). In the elderly, the activation of MRFs is inefficient which hampers the regenerative process. Recent studies found that low intensity laser therapy (LILT) has a stimulatory effect in the muscle regeneration process. However, the effects of this therapy when associated with aging are still unknown. Objective: This study aimed to evaluate the effects of LILT (λ=830 nm) on the tibialis anterior (TA) muscle of aged rats. Subjects and methods: The total of 56 male Wistar rats formed two population sets: old and young, with 28 animals in each set. Each of these sets were randomly divided into four groups of young rats (3 months of age) with n=7 per group and four groups of aged rats (10 months of age) with n=7 per group. These groups were submitted to cryoinjury + laser irradiation, cryoinjury only, laser irradiation only and the control group (no cryoinjury/no laser irradiation). The laser treatment was performed for 5 consecutive days. The first laser application was done 24 h after the injury (on day 2) and on the seventh day, the TA muscle was dissected and removed under anesthesia. After this the animals were euthanized. Histological analyses with toluidine blue as well as hematoxylin-eosin staining (for counting the blood capillaries) were performed for the lesion areas. In addition, MyoD and VEGF mRNA was assessed by quantitative polymerase chain reaction. Results: The results showed significant elevation (p<0.05) in MyoD and VEGF genes expression levels. Moreover, capillary blood count was more prominent in elderly rats in laser irradiated groups when compared to young animals. Conclusion: In conclusion, LILT increased the maturation of satellite cells into myoblasts and myotubes, enhancing the regenerative process of aged rats irradiated with laser.National Institutes of Health (U.S.) (grant RO1AI050875

Low-level laser therapy (LLLT) combined with swimming training improved the lipid profile in rats fed with high-fat diet

Obesity and associated dyslipidemia is the fastest growing health problem throughout the world. The combination of exercise and low-level laser therapy (LLLT) could be a new approach to the treatment of obesity and associated disease. In this work, the effects of LLLT associated with exercises on the lipid metabolism in regular and high-fat diet rats were verified. We used 64 rats divided in eight groups with eight rats each, designed: SC, sedentary chow diet; SCL, sedentary chow diet laser, TC, trained chow diet; TCL, trained chow diet laser; SH, sedentary high-fat diet; SHL, sedentary high-fat diet laser; TH, trained high-fat diet; and THL, trained high-fat diet laser. The exercise used was swimming during 8 weeks/90 min daily and LLLT (GA-Al-As, 830 nm) dose of 4.7 J/point and total energy 9.4 J per animal, applied to both gastrocnemius muscles after exercise. We analyzed biochemical parameters, percentage of fat, hepatic and muscular glycogen and relative mass of tissue, and weight percentage gain. The statistical test used was ANOVA, with post hoc Tukey–Kramer for multiple analysis between groups, and the significant level was p < 0.001, p < 0.01, and p < 0.05. LLLT decreased the total cholesterol (p < 0.05), triglycerides (p < 0.01), low-density lipoprotein cholesterol (p < 0.05), and relative mass of fat tissue (p < 0.05), suggesting increased metabolic activity and altered lipid pathways. The combination of exercise and LLLT increased the benefits of exercise alone. However, LLLT without exercise tended to increase body weight and fat content. LLLT may be a valuable addition to a regimen of diet and exercise for weight reduction and dyslipidemic control

A Força Aérea, Enquanto Agente de Protecção Civil, no Combate ao Terrorismo

Este estudo pretende determinar de que forma a Força Aérea Portuguesa (FAP), na sua condição de agente primário de proteção civil, poderá contribuir para a capacidade de resposta nacional perante ações terroristas com recurso a materiais nucleares, radiológicos, biológicos e químicos (NRBQ). Complementarmente será abordado o enquadramento doutrinário da defesa NRBQ (DNRBQ) na FAP e analisadas as suas capacidades reais de intervenção numa resposta a uma situação de terrorismo que envolva este tipo de produtos, relacionando-as com as competências dos outros agentes primários de proteção civil. Nesta perspetiva, aborda-se a estrutura de atuação implementada em alguns países europeus, que servirá como modelo de análise comparativa entre sistemas de resposta a incidentes desta natureza. Caracteriza-se o conceito de terrorismo associado a este tipo de dispositivos e as ações desenvolvidas por organizações internacionais, das quais Portugal é membro, objetivando a criação de mecanismos de resposta capazes de fazer face a este tipo de situações. Para procurar enquadrar a equipa que a FAP disponibiliza ao Estado-Maior General das Forças Armadas (EMGFA), apresenta-se a estrutura de DNRBQ e o modelo de organização da Equipa de Alerta NRBQ, entidade da FAP responsável pela atuação num cenário desta natureza, analisando o sistema nacional de proteção civil e traduzindo para a realidade nacional a capacidade de resposta que os agentes primários dispõem para atuarem em incidentes desta natureza. A forma como este objetivo é atingido é através da formulação de hipóteses que são sujeitas a validação, recorrendo a entrevistas, pesquisa bibliográfica e análise documental. Identifica-se a necessidade da criação de valências que cubram a DNRBQ, como garantia da segurança dos militares destacados em teatros de operações onde esta ameaça seja uma realidade, e adicionalmente a sua utilização pela Força Aérea, enquanto agente de proteção civil, no combate ao terrorismo. Identifica-se também a necessidade de reestruturar a diretiva que regula a DNRBQ, no sentido de a operacionalizar face à realidade da FAP e de traduzir a doutrina a ser adotada. Conclui-se que a DNRBQ deverá ser caracterizada por uma estrutura simples, centralizada num único local, que envolva as áreas operacional e de instrução, constituída por pequenas equipas especializadas que assegurem todas as componentes e, desta forma contribuam para a missão da FAP. No final deste estudo apresentam-se algumas recomendações que poderão contribuir para a reflexão sobre a utilidade das conclusões. Abstract: This study aims to determine how the Portuguese Air Force (PRTAF), in its capability as initial reaction element, may contribute to the national response capability in case of terrorist acts using chemical, biological, radiological and nuclear (CBRN) devices. In addition, the framework of the PRTAF guidelines for CBRN defence is evaluated and the actual response to terrorism acts involving such kind of materials is analyzed, linking them with the skills of the other elements. In this perspective, the response structure implemented in some European countries is discussed to serve as a model for a comparative analysis of the response systems to such incidents. The terrorism concept associated with such devices and the actions taken by the international organizations of which Portugal is a member are characterized aiming the creation of response mechanisms able to cope with such incidents. In order to frame the PRTAF CBRN Response Team available to the Armed Forces General Staff (EMGFA), the CBRN defence structure and the CBRN Response Team organization are presented. The national civil protection system is also considered and the first response capability to act in such incidents is also considered, bearing in mind the national reality. In this work, the hypotheses created were validated using interviews, literature research and document analysis. It is undeniable that there is a need for the CBRN defence capability in the PRTAF to ensure the safety of the troops which are deployed to areas of operations where this threat is a reality. In addition, this capability may be used to combat terrorism in the homeland. There is, also, a need to restructure the FAP CBRN defence directive in order to adjust it to nowadays situations and a need to translate the doctrine to be adopted. As a conclusion, the CBRN defence should be characterised by a simple structure, centralized in one place, involving operational and educational areas, consisting of small specialized teams that will ensure all components and thus contribute to the PRTAF’s main mission. At the end of the present study, there are some recommendations that may contribute to the debate on the usefulness of the findings

Treatment time of ultrasound therapy interferes with the organization of collagen fibers in rat tendons

BACKGROUND: The application time of therapeutic ultrasound is an infrequently studied dosimetric variable that affects tissue repair.OBJECTIVES: The aim of this study was to evaluate the effects of different treatment times of therapeutic ultrasound (US) on the organization of collagen fibers in the tendons of rats.METHOD: Forty Wistar rats were selected (300±45 g), and the rats were divided into five groups (n=8 for each group): Control, without tenotomy or any treatment; tenotomy group, with tenotomy and without treatment; US groups (US1, US2, and US3), subjected to tenotomy and treated with US for one, two, or three minutes per area of the transducer, respectively. The animals were sacrificed on the 12th post-operative day, and the tendons were surgically removed for analyses of the collagen fiber organization by means of birefringence analysis.RESULTS: The collagen fibers exhibited better aggregation and organization in the US3 group compared with the tenotomy group (p<0.05).CONCLUSIONS: The findings suggest that US applied for three minutes per treated area improves the organization of collagen fibers during rat tendon repair