The use of planarians as in vivo animal model to study laser biomodulation effects

A variety of effects is attributed to the photo stimulation of tissues, such as improved healing of ulcers, analgesic and anti-inflammatory effects, stimulation of the proliferation of cells of different origins and stimulation of bone repair. Some investigations that make qualitative evaluations, like wound healing and evaluation of pain and edema, can be conducted in human subjects. However, deeper investigations on the mechanisms of action of the light stimulus and other quantitative works that requires biopsies or destructive analysis has to be carried out in animal models or in cell cultures. In this work, we propose the use of planarians as a model to study laser-tissue interaction. Contrasting with cell cultures and unicellular organisms, planarians are among the simplest organism having tissue layers, central nerve system, digestive and excretory system that might have been platforms for the evolution of the complex and highly organized tissues and organs found in higher organisms. For the present study, 685 nm laser radiation was employed. Planarians were cut transversally, in a plane posterior to the auricles. The body fragments were left to regenerate and the proliferation dynamics of stem cells was studied by using histological analysis. Maximum cell count was obtained for the laser treated group at the 4th experimental day. At that experimental time, we also had the largest difference between the irradiated and the non-irradiated control group. We concluded that the studied flatworm could be an interesting animal model for in vivo studies of laser-tissue interactions.

O bem-estar animal: como avaliá-lo e promovê-lo

The traffic of wild animals can be identified as the main cause of finding captive animals in zoos and sorting centers in Brazil. The maintenance of these animals in captivity is usually justified by the prevention of total loss of individuals of that specie, if it becomes extinct in the wild, and also, the importance of these subjects in studies of basic biology of the species. Keeping animals in captivity environment brings the need to ensure the welfare of them. The high population density and limited space are some of the possible stressors that these individuals face in capivity. Even the low pressure feeding and food easily available could be stressors, since they change the budget activities typical of the specie, causing sedentary behavior and sometimes depression. The captive environment and activities related to it (handling, transport, social change and social isolation) could compromise the animal welfare. Reduction in life expectancy, impaired growth and reproduction, personal injury, illness, immunosuppression, exacerbated adrenal activity and abnormal behavior, are events often lonked to compromised welfare. Hence, assessment and promoter methods are used to provide the welfare to captive animals. The assessment can be made by hormonal and/or behavioral measures. Both are extremely important, and usually are used in combination, to provide more tangible results about the condition of the animal. The promotion of animal welfare can be accomplished through environmental enrichment, a technique which aims to provide a more complex and diverse environment, increasing the possibility of the animal express more natural behavior, or characteristic of the species. Thus, the objective of this dissertation is discuss the importance of animal welfare and the ways this can be evaluated and promoted... (Complete abstract click electronic access below)

Os segredos que a natureza encerra: uso de conceitos e modelos da física para investigar questões do mundo animal

Physics governs all working patterns of the universe and could not be otherwise in a biological environment. Living things depend directly on laws and physical models to compose their body structure, allow its survival in certain environments, communication between individuals and groups and also to establish a complex sensorial system that allows interaction with the environment that surrounds them. With the advancement of science and technology, new ideas are required, and thus, many researchers began to turn their attention to those systems found in nature, as these systems often present practical solutions and with maximum efficiency. This imitation of biological systems, applied in creating innovative technological resources, is called Biomimetics. To study the biological systems based on physical concepts is essential the creation of models. These allow the distinction of the effects of the issue really essential and may be ignored side effects that do not have an effective participation in the phenomenon being analyzed. In this Work Completion of course will be studied the phenomenon of countercurrent heat exchangers, present in various situations of nature, focusing on their participation in the legs of birds, also the balance of certain birds that are supported on one leg and possible inspiration of these phenomena in the fields of engineering. Also included are videos that allow better understanding of the studied subjects