Experimental model: historic and conceptual revision

Abstract

The qualification of the new knowledge is one of the oldest problems in experimental science. For this reason, one of Science' s priorities has been the search for experimental model, in order to produce knowledge in a more standardized way.The importance of inferring a knowledge generation' s model has derived from the need to exactly understand the mechanisms that generate these data. The greatest advantage of the experimental model is to allow understanding preditions and controling of the results and the method and, at same time, keep the bioethical principles concerning the " anima nobile" .To define " Experimental Model" has been controversial in the different areas. The difficulties in its definition comes from each area complexity and from the fact that a term demand other terms that are ambigous or used in a different sense.Individually, each definition is not sufficient to clearly describe its meaning. Thus, in general, one definition comprehend a little facet inside its own approach.Historically, the term " modulus" (from latin, derived from " modus" , little measure) is used since 23 B.C. throughout the eighteenth century. From the eleventh to fourteenth century, the used term was " standard" and " mould" ; from the fourteenth to sixteeth century, " measure" and from then on, " model" .From the seventh to nineteenth century, the model definition were mainly aimed at abstract models. For example, the philosopher Blaise Pascal, around 1650, described model as an act of spirit in which we can inspire ourselves (ouvrage d' esprit dont on peut s' inspirer). In the eighteenth century, the French encyclopedia, dated 1765 defines model as a generic sense, an original pattern, proposed to be copied or imitated by anyone. Horst Koller, in 1969, defined model as a simplified representation of reality derived only from abstraction and Brockhaus, in 1971, defined it, as a pattern, ideal, reproduction or graphic of things (enlarged, reduced or at natural size). At that time, model was a simplified representation of a part of reality, that could be material or idealistic, concrete or abstract and would describe a future or present state. 1The English language dictionaires describe model as a three dimensions representation in a reduced scale; a simplified description of a system; figure to be reproduced in any material; specific design or style of a structure or convenience; exemplary person, thing or ideal; example of person or thing to be copied or imitated; person to pose or be shown; its piece or copy.

Host responses induced by different animal models of periodontal disease: a literature review

“…7 The development of experimental models is important because they assist the understanding of the origin and development of human diseases. Thus, they must have an appropriate accuracy by means of prior evidence and by demonstration of the limitations on the reality that will be represented.…”

“…7 According to Genco et al, 10 finding an animal model of periodontal disease that reproduces all aspects of human disease is an impossible goal. They must necessarily allow for the evaluation of natural biological phenomena, whether induced or behavioral, that can be compared to the human phenomena in question.…”

“…Thus, they must have an appropriate accuracy by means of prior evidence and by demonstration of the limitations on the reality that will be represented. 7 The development of experimental models is important because they assist the understanding of the origin and development of human diseases. In medical science, they allow for a better understanding of physiology, the pathogenesis of diseases, the action of drugs, or the effects of surgical interventions.…”

“…They must necessarily allow for the evaluation of natural biological phenomena, whether induced or behavioral, that can be compared to the human phenomena in question. 7 According to Genco et al, 10 finding an animal model of periodontal disease that reproduces all aspects of human disease is an impossible goal. However, we can access models to study defined aspects of periodontal disease, such as etiology, the role of specific virulence factors, colonization mechanisms, the effect of cells and mediators on tissue responses, the role of other infections, and periodontal disease risk factors.…”

Experimental model of cutaneous radiation injury in rabbits

“…The rabbits, medium size animals, because of their immunological similarity to humans are the most frequently used for cutaneous tests such as the Draize test 4 . Their antibody development is considered resistant to radiation, differently than rats, mice and murines that aren't capable of presenting a similar immune response 5 .…”