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BACKGROUND: The treatment of 3rd degree burns represents a major medical challenge. Pinus vegetable cellulose is a biomaterial with characteristic similar to bacterial cellulose. AIM: To evaluate the safety of cellulose membrane (Pinus sp) in the treatment of 3rd burns in rats and to compare its effectiveness with the bacterial membrane already on the market. METHOD: Thirty-three Wistar rats were beaten with a 3rd degree burn on back skin by applying water at 98º C for 30 s. Then, they were divided into three groups (n=11): group 1 - simple dressing with gauze; group 2 - dressing with bacterial cellulose membrane; and group 3 - dressing with vegetable cellulose membrane. The animals were maintained for 15 days to check the general clinical status, macroscopic aspect, contraction of the wounds and microscopic analysis for the degree of healing and collagenization. RESULTS: They were clinically well during the experiment. During the removal of the dressing, there was bleeding in the wound of the control group, unlike the groups treated with cellulose membranes, which protected the bed from injury. The macroscopic evaluation showed a greater contraction of the wounds treated with the membranes in relation to the control. A microscopic analysis revealed that most of the wounds were in advanced healing degree with predominance of mature collagen in all groups. CONCLUSION: Pinus sp cellulose membrane showed efficacy similar to that of the bacterial membrane in the treatment of 3rd degree burns.

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ABSTRACT Background: The treatment of 3rd degree burns represents a major medical challenge. Pinus vegetable cellulose is a biomaterial with characteristic similar to bacterial cellulose. Aim: To evaluate the safety of cellulose membrane (Pinus sp) in the treatment of 3rd burns in rats and to compare its effectiveness with the bacterial membrane already on the market. Method: Thirty-three Wistar rats were beaten with a 3rd degree burn on back skin by applying water at 98º C for 30 s. Then, they were divided into three groups (n=11): group 1 - simple dressing with gauze; group 2 - dressing with bacterial cellulose membrane; and group 3 - dressing with vegetable cellulose membrane. The animals were maintained for 15 days to check the general clinical status, macroscopic aspect, contraction of the wounds and microscopic analysis for the degree of healing and collagenization. Results: They were clinically well during the experiment. During the removal of the dressing, there was bleeding in the wound of the control group, unlike the groups treated with cellulose membranes, which protected the bed from injury. The macroscopic evaluation showed a greater contraction of the wounds treated with the membranes in relation to the control. A microscopic analysis revealed that most of the wounds were in advanced healing degree with predominance of mature collagen in all groups. Conclusion: Pinus sp cellulose membrane showed efficacy similar to that of the bacterial membrane in the treatment of 3rd degree burns.

RESUMO Racional: O tratamento das queimaduras de 3˚ grau representa grande desafio na área médica. A celulose vegetal de pinus é biomaterial com características semelhantes às da celulose bacteriana. Objetivo: Avaliar a segurança da membrana de celulose vegetal (Pinus sp) no tratamento de queimaduras de terceiro grau em ratos e comparar sua eficácia com a da membrana bacteriana já comercializada. Método: Trinta e três ratos Wistar foram submetidos à queimadura de 3º grau na pele do dorso mediante aplicação de água a 98º C durante 30 s. Em seguida, foram distribuídos em três grupos (n=11): grupo 1 - curativo simples com gaze; grupo 2 - curativo com membrana de celulose bacteriana; e grupo 3 - curativo com membrana de celulose vegetal . Os animais foram avaliados durante 15 dias para verificar o estado clínico geral, aspecto macroscópico, contração das feridas e análise microscópica pelo grau de cicatrização e colagenizacao. Resultados: Permaneceram clinicamente bem durante o experimento. Durante a retirada do curativo houve sangramento na ferida do grupo controle, diferentemente dos grupos tratados com as membranas de celulose, que protegeram o leito da lesão. A análise microscópica mostrou que a maioria das feridas apresentava-se em grau avançado de cicatrização, com predomínio de colágeno maduro em todos os grupos. Houve maior contração das feridas tratadas com as membranas em relação ao grupo controle. Conclus ão: A membrana de celulose de Pinus sp apresentou eficácia semelhante à da membrana bacteriana no tratamento de queimaduras de 3˚ grau.

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BACKGROUND: Crusts in 7th follow-up day: G1 yes; G2 no; G3 no (left to right). Bespite all the advances in medicine and the wide variety of dressings available, the treatment of burn wounds still represents an important medical challenge. The pinus cellulose membrane dressing is a biomaterial with characteristics similar to those of bacterial cellulose, but with lower cost. AIM: To evaluate the efficacy of pinus nanocellulose membrane on healing of deep second degree burns in rats and compare with Membracel®. METHOD: Thirty male Wistar rats were submitted to deep second degree burn in dorse, with boiling water at 97o C for 20 s, generating a 314 mm² area wound. The animals were distributed in three dressing groups (n=10): group 1 - simple gauze; group 2 - bacterial cellulose membrane (Membracel®); and group 3 - pinus cellulose membrane. They were evaluated for 20 days to verify clinical condition, macro and microscopic appearance and wound contraction. RESULTS: All of them remained clinically well with no differences in weight. Crusts were observed in group 1, and none in groups 2 and 3. Regarding to scar contraction, groups 2 and 3 were similar, better than group 1. Microscopic analysis showed predominance of advanced healing degree in groups 1 and 3, and initial in group 2. Mature collagen was predominant in all groups. CONCLUSION: The pinus nanocellulose membrane is effective in the treatment of experimental second degree burn in rats and its effectiveness is similar to that of the bacterial nanocellular membrane.

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ABSTRACT Background: Despite all the advances in medicine and the wide variety of dressings available, the treatment of burn wounds still represents an important medical challenge. The pinus cellulose membrane dressing is a biomaterial with characteristics similar to those of bacterial cellulose, but with lower cost. Aim: To evaluate the efficacy of pinus nanocellulose membrane on healing of deep second degree burns in rats and compare with Membracel®. Method: Thirty male Wistar rats were submitted to deep second degree burn in dorse, with boiling water at 97o C for 20 s, generating a 314 mm² area wound. The animals were distributed in three dressing groups (n=10): group 1 - simple gauze; group 2 - bacterial cellulose membrane (Membracel®); and group 3 - pinus cellulose membrane. They were evaluated for 20 days to verify clinical condition, macro and microscopic appearance and wound contraction. Results: All of them remained clinically well with no differences in weight. Crusts were observed in group 1, and none in groups 2 and 3. Regarding to scar contraction, groups 2 and 3 were similar, better than group 1. Microscopic analysis showed predominance of advanced healing degree in groups 1 and 3, and initial in group 2. Mature collagen was predominant in all groups. Conclusion: The pinus nanocellulose membrane is effective in the treatment of experimental second degree burn in rats and its effectiveness is similar to that of the bacterial nanocellular membrane.

RESUMO Racional: Apesar de todos os avanços da medicina e da grande variedade de curativos disponíveis, o tratamento das queimaduras ainda representa importante desafio médico. O curativo de membrana de celulose de pinus é biomaterial com características semelhantes à de celulose bacteriana, mas de menor custo. Objetivo: Avaliar a eficácia da membrana de nanocelulose de pinus na cicatrização de queimaduras profundas de segundo grau em ratos e comparar com a Membracel®. Método: Trinta ratos Wistar machos foram submetidos à queimadura profunda de segundo grau em dorso, com água fervente a 97o C por 20 s, gerando lesão de 314 mm². Os animais foram distribuídos em três grupos de curativos (n = 10): grupo 1 - gaze simples; grupo 2 - membrana de celulose bacteriana (Membracel®); e grupo 3 - membrana de celulose de pinus. Eles foram avaliados por 20 dias para verificar o quadro clínico, aspecto macro e microscópico e a contração da ferida. Resultados: Todos permaneceram clinicamente bem, sem diferenças de peso. Crostas foram observadas no grupo 1 e nenhuma nos grupos 2 e 3. Em relação à contração da cicatriz, os grupos 2 e 3 foram semelhantes, melhores que o grupo 1. A análise microscópica mostrou predomínio de grau de cicatrização avançado nos grupos 1 e 3, e inicial no grupo 2. O colágeno maduro foi predominante em todos os grupos. Conclusão: A membrana de nanocelulose de pinus é eficaz no tratamento de queimaduras experimentais de segundo grau em ratos e sua eficácia é semelhante à da membrana nanocelular bacteriana.

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OBJECTIVE: This study aimed to evaluate the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the experimental model of Achilles tendon injury. METHODS: Twelve white male adults New Zealand rabbits were divided into two groups, a group with resection of the central portion of the Achilles tendon (n = 8) and a control group (n = 4). Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed 4 weeks after the surgical procedure, followed by histological analysis of the tendons. RESULTS: The main finding of this study was the difference (p < 0.001) in peak contrast enhancement on DCE-MRI, which demonstrated that the operated group had greater contrast uptake. The operated tendons showed histological disruption of their architecture, and cluttered appearance of tendinous fibers, with vascular and fibroblast proliferations. CONCLUSION: DCE-MRI is a technique with a potential to demonstrate changes in the vascularity pattern of the Achilles tendon before and after operation. DCE-MRI has a potential to be used in studies of tendinosis diagnosis and surgical follow-up. Level of evidence II, Experimental Study .

OBJETIVOS: Avaliar a captação do gadolínio (Gd) à ressonância magnética (DCRM) em modelo experimental de lesão do tendão de Aquiles. MÉTODOS: Foram utilizados 12 coelhos machos, adultos e brancos da raça Nova Zelândia, distribuídos em dois grupos: operados (n = 8), com ressecção da porção central do tendão de Aquiles; e o grupo controle (n=4). Após quatro semanas, realizou-se ressonância magnética com técnica de avaliação dinâmica do meio de contraste, seguido de analise histológica dos tendões. RESULTADOS: Houve diferença (p <0,001) do pico máximo de realce de contraste, na DCRM dinâmica do tendão de Aquiles entre os grupos operado e controle, sendo evidenciada maior captação de contraste no grupo operado. À histologia, os tendões operados apresentaram desorganização de sua arquitetura, fibras tendíneas de aspecto desordenado, com neoformação vascular e proliferação de fibroblastos. CONCLUSÃO: A DCRM apresentou potencial de demonstrar alterações do padrão de vascularização do tendão de Aquiles no pré e pós-operatório. A DCRM apresenta potencial para ser usada em estudos para controle de tratamento e diagnóstico da tendinose. Nível de evidência II, Estudo Experimental .

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ABSTRACT Objective: This study aimed to evaluate the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the experimental model of Achilles tendon injury. Methods: Twelve white male adults New Zealand rabbits were divided into two groups, a group with resection of the central portion of the Achilles tendon (n = 8) and a control group (n = 4). Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed 4 weeks after the surgical procedure, followed by histological analysis of the tendons. Results: The main finding of this study was the difference (p < 0.001) in peak contrast enhancement on DCE-MRI, which demonstrated that the operated group had greater contrast uptake. The operated tendons showed histological disruption of their architecture, and cluttered appearance of tendinous fibers, with vascular and fibroblast proliferations. Conclusion: DCE-MRI is a technique with a potential to demonstrate changes in the vascularity pattern of the Achilles tendon before and after operation. DCE-MRI has a potential to be used in studies of tendinosis diagnosis and surgical follow-up. Level of evidence II, Experimental Study.

RESUMO Objetivos: Avaliar a captação do gadolínio (Gd) à ressonância magnética (DCRM) em modelo experimental de lesão do tendão de Aquiles. Métodos: Foram utilizados 12 coelhos machos, adultos e brancos da raça Nova Zelândia, distribuídos em dois grupos: operados (n = 8), com ressecção da porção central do tendão de Aquiles; e o grupo controle (n=4). Após quatro semanas, realizou-se ressonância magnética com técnica de avaliação dinâmica do meio de contraste, seguido de analise histológica dos tendões. Resultados: Houve diferença (p <0,001) do pico máximo de realce de contraste, na DCRM dinâmica do tendão de Aquiles entre os grupos operado e controle, sendo evidenciada maior captação de contraste no grupo operado. À histologia, os tendões operados apresentaram desorganização de sua arquitetura, fibras tendíneas de aspecto desordenado, com neoformação vascular e proliferação de fibroblastos. Conclusão: A DCRM apresentou potencial de demonstrar alterações do padrão de vascularização do tendão de Aquiles no pré e pós-operatório. A DCRM apresenta potencial para ser usada em estudos para controle de tratamento e diagnóstico da tendinose. Nível de evidência II, Estudo Experimental.

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PURPOSE: To evaluate the hepatic changes associated with gastric ischemia. METHODS: Thirty male rabbits were studied, distributed in 3 groups (n=10). Group 1: ligature and section of the gastric vasculature and removal of the liver after three hours; Group 2: ligature and section of the gastric vasculature and removal of the liver after 6 hours; Group 3: ligature and section of the gastric vasculature and removal of the liver after 12 hours. Blood samples were collected immediately before surgery and after the determined time of ischemia in each group to evaluate the hepatic function. After the death of the rabbits, the liver was removed for macro and microscopic study. RESULTS: An increase in aminotransferases and bilirubin occurred in groups 2 and 3. Total protein and albumin diminished in all of the animals. All of the rabbits from groups 2 and 3 presented hepatocellular necrosis. CONCLUSION: The devascularization of the stomach for a period of above three hours is associated with hepatic morphological and functional disorders.

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Abstract Purpose: To evaluate the hepatic changes associated with gastric ischemia. Methods: Thirty male rabbits were studied, distributed in 3 groups (n=10). Group 1: ligature and section of the gastric vasculature and removal of the liver after three hours; Group 2: ligature and section of the gastric vasculature and removal of the liver after 6 hours; Group 3: ligature and section of the gastric vasculature and removal of the liver after 12 hours. Blood samples were collected immediately before surgery and after the determined time of ischemia in each group to evaluate the hepatic function. After the death of the rabbits, the liver was removed for macro and microscopic study. Results: An increase in aminotransferases and bilirubin occurred in groups 2 and 3. Total protein and albumin diminished in all of the animals. All of the rabbits from groups 2 and 3 presented hepatocellular necrosis. Conclusion: The devascularization of the stomach for a period of above three hours is associated with hepatic morphological and functional disorders.

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Purpose:To evaluate the hepatic changes associated with gastric ischemia.Methods:Thirty male rabbits were studied, distributed in 3 groups (n=10). Group 1: ligature and section of the gastric vasculature and removal of the liver after three hours; Group 2: ligature and section of the gastric vasculature and removal of the liver after 6 hours; Group 3: ligature and section of the gastric vasculature and removal of the liver after 12 hours. Blood samples were collected immediately before surgery and after the determined time of ischemia in each group to evaluate the hepatic function. After the death of the rabbits, the liver was removed for macro and microscopic study.Results:An increase in aminotransferases and bilirubin occurred in groups 2 and 3. Total protein and albumin diminished in all of the animals. All of the rabbits from groups 2 and 3 presented hepatocellular necrosis.Conclusion:The devascularization of the stomach for a period of above three hours is associated with hepatic morphological and functional disorders.(AU)

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PURPOSE: To compare wound healing performed with cold blade (CSB) and ultrasonic harmonic scalpel (UHS) in the abdominal aponeurosis of rats. METHODS: Eighty Wistar rats divided into two groups and underwent midline incision in the linea alba with cold blade and harmonic ultrasonic scalpel. Analysis were performed in subgroups of 10 animals after 3, 7, 14 and 21 days. Macroscopically was observed the presence of hematoma, infection, wound dehiscence, fistula and adherences. Microscopically were used collagen and immunohistochemical staining methods. RESULTS: Macroscopic, complications showed no statistical difference. Immunohistochemical analysis for MMP-9 was more intense in UHS group (p<0.05). TGF ß presented its lower expression in UHS group at 14 and 21 days, with no statistical difference at 3 and 7 days (p<0.05). α-AML expression appeared higher in UHS group after 14 days and remained similar in others (p<0.05). Collagen deposition had no change in type I, and increased in type III in UHS; at 7th day the deposition was higher in CSB group; at 14th was similar in both groups (p<0.001). CONCLUSION: UHS compared to the CSB has higher lesion area at the time of the incision; as well as it led to the delay of regeneration and scar maturation process.

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