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.

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.

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.

Abstract 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 β 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.

OBJETIVOS: verificar a eficácia da fita elástica de borracha no tratamento de grandes feridas de parede corpórea de coelhos por meio da tração de suas bordas. MÉTODOS: foram estudados 30 coelhos da raça Nova Zelândia, distribuídos em três grupos (n=10): Grupo 1. Cicatrização por segunda intenção. Grupo 2. Retirada e reposicionamento eutópico da pele como enxerto de pele total. Grupo 3. Aproximação das bordas da ferida com fita elástica de borracha. Em todos os animais, foi retirado segmento de pele e tecido subcutâneo até a fáscia musculoaponeurótica do dorso, de acordo com um molde de acrílico, com 12cm de comprimento por 8cm de largura. Todos os animais foram acompanhados durante 21 dias. RESULTADOS: dois animais dos grupos 1 e 2 apresentaram abscesso na ferida. No Grupo 2, houve perda parcial ou total do enxerto em 90% dos animais. O fechamento completo das feridas foi observado em quatro animais do Grupo 1, seis do Grupo 2 e oito do Grupo 3. Não houve diferença entre os valores de resistência cicatricial dos grupos 2 e 3, que foram maiores do que os do Grupo 1. As cicatrizes dos três grupos caracterizaram-se pela presença de tecido conjuntivo maduro entremeado por vasos sanguíneos e infiltrado inflamatório, predominantemente polimorfonuclear. CONCLUSÃO: a tração das bordas da ferida com fita elástica de borracha constitui método tão eficaz quanto o enxerto de pele para tratar grandes feridas de parede corpórea de coelhos.

OBJECTIVE: to verify the effectiveness of the rubber elastic band in the treatment of large wounds of the body wall of rabbits by means of traction of its edges. METHODS: we studied 30 New Zealand rabbits, divided into three groups (n=10): Group 1- healing by secondary intention; Group 2- removal and eutopic repositioning of skin as full thickness skin graft; Group 3- Approximation of wound edges with elastic rubber band. In all animals, we removed a segment of the back skin and subcutaneous tissue down to the fascia, in accordance with an acrylic mold of 8cm long by 12cm wide. All animals were observed for 21 days. RESULTS: two animals of groups 1 and 2 had wound abscess. In Group 2, there was partial or total graft loss in 90% of animals. The complete closure of the wounds was observed in four animals of Group 1, six of Group 2 and eight of Group 3. There was no difference between the scar resistance values of groups 2 and 3, which were higher than those in Group 1. The scars of the three groups were characterized by the presence of mature connective tissue mixed with blood vessels and inflammatory infiltration, predominantly polymorphonuclear. CONCLUSION: the tensile strength of the wound edges with rubber elastic band is as efficient as the skin graft to treat rabbits' large body wounds.