Ética e bem-estar em animais de laboratório / Ethics and welfare in laboratory animals

A utilização de animais de laboratório nos trabalhos experimentais de pesquisa científica tem sido de fundamental importância. Diversas espécies de animais são estudadas e utilizadas na experimentação, porém o camundongo é o animal mais usado nesses procedimentos, destacando-se como um modelo experimental de grande importância para a ciência. A cobaia é conhecida, por muitos, como símbolo representativo dos animais de laboratório, atualmente, as cobaias são muito utilizadas em experimentações ligadas à nutrição, farmacologia, imunologia, alergia, radiologia etc. Coelho é um modelo animal que destaca indubitável importância para o cresci-mento científico e tecnológico da sociedade no âmbito laboratorial. Um dos animais normalmente utilizados em laboratório é o hamster (Mesocricetus auratus) e isso se deve a seus atributos biológicos. A variedade doméstica de Rattus norvegicustem sido empregada para fins experimentais em virtude da facilidade de manejo, prolificidade, alojamento.

The use of laboratory animals in experimental scientific research has been of fundamental importance. Several species of animals are studied and used in the experimentation, but the mouse is the animal most used in these procedures, standing out as an experimental model of great importance for science. The guinea pig is known by many as a representative symbol of laboratory animals. Currently, guinea pigs are widely used in experiments linked to nutrition, pharmacology, immunology, allergy, radiology, etc. Rabbit is an animal model that highlights undoubted importance for the scientific and technological growth of society in the laboratory. One of the animals normally used in the laboratory is the hamster (Mesocricetus auratus) and this is due to its biological attributes. The domestic variety of Rattus norvegicus has been used for experimental purposes due to the ease of handling, prolificacy, lodging.

Ética e bem-estar em animais de laboratório / Ethics and welfare in laboratory animals

A utilização de animais de laboratório nos trabalhos experimentais de pesquisa científica tem sido de fundamental importância. Diversas espécies de animais são estudadas e utilizadas na experimentação, porém o camundongo é o animal mais usado nesses procedimentos, destacando-se como um modelo experimental de grande importância para a ciência. A cobaia é conhecida, por muitos, como símbolo representativo dos animais de laboratório, atualmente, as cobaias são muito utilizadas em experimentações ligadas à nutrição, farmacologia, imunologia, alergia, radiologia etc. Coelho é um modelo animal que destaca indubitável importância para o cresci-mento científico e tecnológico da sociedade no âmbito laboratorial. Um dos animais normalmente utilizados em laboratório é o hamster (Mesocricetus auratus) e isso se deve a seus atributos biológicos. A variedade doméstica de Rattus norvegicustem sido empregada para fins experimentais em virtude da facilidade de manejo, prolificidade, alojamento.(AU)

The use of laboratory animals in experimental scientific research has been of fundamental importance. Several species of animals are studied and used in the experimentation, but the mouse is the animal most used in these procedures, standing out as an experimental model of great importance for science. The guinea pig is known by many as a representative symbol of laboratory animals. Currently, guinea pigs are widely used in experiments linked to nutrition, pharmacology, immunology, allergy, radiology, etc. Rabbit is an animal model that highlights undoubted importance for the scientific and technological growth of society in the laboratory. One of the animals normally used in the laboratory is the hamster (Mesocricetus auratus) and this is due to its biological attributes. The domestic variety of Rattus norvegicus has been used for experimental purposes due to the ease of handling, prolificacy, lodging.(AU)

Stereological and morphometric study of type 3 collagen formation in the cutaneous wounds of diabetic mice treated with mesenchymal stem cells

Introduction: Wound healing is a progressive, essential and complex physiological process that occurs as a restorative response after a tissue injury. It involves three phases: inflammation, proliferation and maturation. Exogenous, endogenous and pathological factors may interfere in the cicatricial process in humans and animals by altering the balance between the synthesis, degradation and remodelling of collagen and elastic fibres. Diabetes mellitus is a progressive metabolic disease that alters elastogenesis and collagenesis and induces delays in the healing process. Scientific evidence suggests that mesenchymal stem cells modulate the cicatricial response. Thus the objective of this work was to perform stereological and morphometric analysis to determine the formation of dermal fibres in cutaneous fragments of a murine model of diabetes mellitus.Materials, Methods & Results: Histological sections were obtained from the cutaneous wounds of diabetic mice. The cutaneous wounds were previously treated with autogenous mesenchymal stem cells, physiological solution or polyurethane membrane. The histological sections were subsequently processed and stained for type 1 and 3 collagen fibres and elastic fibres using Picrosirius Red and Weigert staining, respectively. Histological sections stained with Picrosirius Red presented three types of birefringence under polarised light microscopy that corresponded to red colours for type 1 collagen and green and yellow colours for type 3 collagen. Weigert staining presented three colours for histological structures under white light microscopy that corresponded to black colours for elastic fibres, variations in colour from pink to purple for other structures and dermal attachments. The elastic fibres, represented by a black colour, presented in a heterogeneous form and were either identified as thin, punctiform or rectangular fibres or as elastic agglomerates.[....]

Stereological and morphometric study of type 3 collagen formation in the cutaneous wounds of diabetic mice treated with mesenchymal stem cells

Introduction: Wound healing is a progressive, essential and complex physiological process that occurs as a restorative response after a tissue injury. It involves three phases: inflammation, proliferation and maturation. Exogenous, endogenous and pathological factors may interfere in the cicatricial process in humans and animals by altering the balance between the synthesis, degradation and remodelling of collagen and elastic fibres. Diabetes mellitus is a progressive metabolic disease that alters elastogenesis and collagenesis and induces delays in the healing process. Scientific evidence suggests that mesenchymal stem cells modulate the cicatricial response. Thus the objective of this work was to perform stereological and morphometric analysis to determine the formation of dermal fibres in cutaneous fragments of a murine model of diabetes mellitus.Materials, Methods & Results: Histological sections were obtained from the cutaneous wounds of diabetic mice. The cutaneous wounds were previously treated with autogenous mesenchymal stem cells, physiological solution or polyurethane membrane. The histological sections were subsequently processed and stained for type 1 and 3 collagen fibres and elastic fibres using Picrosirius Red and Weigert staining, respectively. Histological sections stained with Picrosirius Red presented three types of birefringence under polarised light microscopy that corresponded to red colours for type 1 collagen and green and yellow colours for type 3 collagen. Weigert staining presented three colours for histological structures under white light microscopy that corresponded to black colours for elastic fibres, variations in colour from pink to purple for other structures and dermal attachments. The elastic fibres, represented by a black colour, presented in a heterogeneous form and were either identified as thin, punctiform or rectangular fibres or as elastic agglomerates.[....](AU)

Xenogeneic mesenchymal stem cells in the formation of hyaline cartilage in osteochondral goat failure

Background: Osteochondral knee failures are among the most common causes of disability among the elderly human population and animal athletes. The xenogeneic transplantation of mesenchymal stem cells is a questionable therapeutic alternative that, despite the low expression of Major Histocompatibility Complex type II by these cells, still has relevant uncertainties about the safety and clinical efficacy. The main objective of the present study was to investigate whether the xenogeneic transplantation of mesenchymal stem cells induces hyaline cartilage formation, without histopathological evidence of rejection, in osteochondral failures of goats.Materials, Methods & Results: Five female goats were used, submitted to three surgical osteocondral failures in the right knee, treated with xenogenic mesenchymal stem cells of dental pulp, xenogenic platelet-rich plasma and hemostatic sponge of hydrolyzed collagen, respectively. The lesions were evaluated after 60 days of treatment, aiming to identify the presence of hyaline cartilage or fibrocartilage and the subchondral bone pattern (regenerated or disorganized). Transplantation of xenogenic mesenchymal stem cells induced predominant formation of hyaline cartilage (P 0.05). Macroscopically, the lesions of the stem cell treated group showed formation of firm repair tissue, opaque staining, integrated with adjacent cartilage and with the failure filling almost completely. The groups treated with PRP and hemostatic sponge of hydrolyzed collagen presented, on average, partial filling of the lesion, with irregular shape and darkened coloration.[...]

Xenogeneic mesenchymal stem cells in the formation of hyaline cartilage in osteochondral goat failure

Background: Osteochondral knee failures are among the most common causes of disability among the elderly human population and animal athletes. The xenogeneic transplantation of mesenchymal stem cells is a questionable therapeutic alternative that, despite the low expression of Major Histocompatibility Complex type II by these cells, still has relevant uncertainties about the safety and clinical efficacy. The main objective of the present study was to investigate whether the xenogeneic transplantation of mesenchymal stem cells induces hyaline cartilage formation, without histopathological evidence of rejection, in osteochondral failures of goats.Materials, Methods & Results: Five female goats were used, submitted to three surgical osteocondral failures in the right knee, treated with xenogenic mesenchymal stem cells of dental pulp, xenogenic platelet-rich plasma and hemostatic sponge of hydrolyzed collagen, respectively. The lesions were evaluated after 60 days of treatment, aiming to identify the presence of hyaline cartilage or fibrocartilage and the subchondral bone pattern (regenerated or disorganized). Transplantation of xenogenic mesenchymal stem cells induced predominant formation of hyaline cartilage (P < 0.05), with no histopathological evidence of inflammation when compared to the other treatments. Therapies with xenogeneic platelet-rich plasma and hemostatic sponge of hydrolyzed collagen induced greater formation of fibrocartilaginous cartilage, with no significant difference between them (P > 0.05). Macroscopically, the lesions of the stem cell treated group showed formation of firm repair tissue, opaque staining, integrated with adjacent cartilage and with the failure filling almost completely. The groups treated with PRP and hemostatic sponge of hydrolyzed collagen presented, on average, partial filling of the lesion, with irregular shape and darkened coloration.[...](AU)