Comparison among bone marrow mesenchymal stem and mononuclear cells to promote functional recovery after spinal cord injury in rabbits

Abstract Purpose: To investigate the efficacy of allogeneic mesenchymal stem-cells and autologous mononuclear cells to promote sensorimotor recovery and tissue rescue. Methods: Female rabbits were submitted to the epidural balloon inflation method and the intravenous cells administrations were made after 8 hours or seven days after injury induction. Sensorimotor evaluation of the hindlimbs was performed, and the euthanasia was made thirty days after the treatment. Spinal cords were stained with hematoxylin and eosin. Results: Both therapies given 8 hours after the injury promoted the sensorimotor recovery after a week. Only the group treated after a week with mononuclear cells showed no significant recovery at post-injury day 14. In the days 21 and 28, all treatments promoted significant recovery. Histopathological analysis showed no difference among the experimental groups. Our results showed that both bone marrow-derived cell types promoted significant sensorimotor recovery after injury, and the treatment made at least a week after injury is efficient. Conclusion: The possibilities of therapy with bone marrow-derived cells are large, increasing the therapeutic arsenal for the treatment of spinal cord injury.

Effects of propofol in lipid-based emulsion and in microemulsion on the incidence of endothelial lesion in rabbits

PURPOSE: To compare the incidence of endothelial injury after single-dose or continuous propofol infusion in conventional lipid-based emulsion (LE) versus microemulsion (ME). METHODS: Forty-two rabbits (2.5-4.5 Kg) were randomly allocated into seven groups of six animals each: SHAM- surgical treatment alone; Bolus Control Group - 3 mL-intravenous (IV) bolus of saline; Continuous Infusion Control Group - 3 mL- IV bolus of saline followed by a continuous infusion of 0.2 ml/kg/min for 60 min; Bolus LE Propofol Group - IV bolus of LE propofol (3 mg/kg); Bolus ME Propofol Group - IV ME propofol bolus (3 mg/kg); Continuous LE Propofol Group - IV LE propofol bolus (3 mg/kg) followed by a continuous infusion of 0.2 ml/kg/min for 60 min; Continuous ME Propofol Group - IV ME propofol bolus (3 mg/kg) followed by a continuous infusion of 0.2 ml/kg/min for 60 min. RESULTS: There were no statistically significant differences between the studied groups in blood pressure, in central venous pressure and in the biochemical profile. No significant differences were found in inflammatory mediators and in tissue analysis between the two emulsions. CONCLUSION: Microemulsion and lipid-based emulsion propofol had similar inflammatory, biochemical and microscopy profiles. Thus, microemulsion propofol can be used as an alternative to lipid-based emulsion propofol.

Galea and periosteum flap filled with bone fragments in rabbits

PURPOSE: To study the bone viability of a vascularized galea and periosteum flap filled with bone fragments, as a substitute of the bone graft in facial reconstructive surgery. METHODS: Forty rabbits were studied, and divided in two groups. One had a simple galea and periosteum flap done and the other had the same flap done and filled with bone fragments of the calvaria. The bone formation was evaluated by radiographies, macroscopic and microscopic analysis. RESULTS: The bone neoformation in both groups with differences in bone morphology and structure especially at histological analysis. CONCLUSION: This study demonstrated osseous formation in both groups of galea and periosteum flaps, with and without bone fragments.

Evaluation of the abdominal wall cicatrization of rabbits exposed to nicotine and undergone abdominoplasty using nylon thread or cyanoacrylate / Avaliação da cicatrização da parede abdominal de coelhos expostos à nicotina e submetidos à abdominoplastia, utilizando-se nylon ou cianocrilato

PURPOSE: To compare the wound healing of the abdominal wall of rabbits exposed to nicotine and submitted to abdominoplasty using 2-octyl cyanoacrylate or nylon thread for the surgery suture. METHODS: Thirty two rabbits were used. They were divided in subgroups: A1, A2, B1 e B2. Group A received saline 0.9%; group B received nicotine, both groups for 14 days before surgery. We performed an abdominoplasty with a nylon suture into the A1 and B1 subgroups; as for A2 and B2 groups the suture was performed with cyanoacrylate. The euthanasia happened in the 14th post-operative day. After, we evaluated: swollen process, fibroblast proliferation, collagen, neovascularization, and macroscope and microscope epithelization of the scars. RESULTS: We observed the presence of eosinophils in all scars exposed to the cyanoacrylate, and a significant increase of neovascularization in the subgroup B2 comparing to the A2 one (p=0.037). The other variables haven't showed any statistical difference. CONCLUSIONS: Nicotine hasn't influenced the swollen process, the fibroblast proliferation, the presence of collagen, neither the epithelialization. The neovascularization showed cicatricial immaturity when comparing group A2 to group B2. The eosinophils in the scars repaired with glue showed that the substance has acted as an allergen.

OBJETIVO: Comparar a cicatrização da parede abdominal de coelhos expostos à nicotina e submetidos à abdominoplastia utilizando 2-octil cianoacrilato ou nylon na síntese cirúrgica. MÉTODOS: Utilizou-se 32 coelhos. Estes foram distribuídos em subgrupos: A1, A2, B1 e B2. O grupo A recebeu solução de NaCl 0,9%; o B recebeu nicotina, ambos durante 14 dias do pré-operatório. Nos subgrupos A1 e B1 foi realizada abdominoplastia e sutura com "nylon"; enquanto A2 e B2 a síntese ocorreu com cianoacrilato. A eutanásia ocorreu no 14º dia do pós-operatório. Na pesquisa avaliou-se: processo inflamatório, proliferação fibroblástica, colágeno, neovascularização, epitelização macro e microscópica das cicatrizes. RESULTADOS: Observou-se presença de eosinofilia em todas as cicatrizes expostas ao cianoacrilato, e aumento significativo da neovascularização no subgrupo B2 em comparação com o A2 (p=0,037). Demais variáveis não apresentaram diferença estatística. CONCLUSÕES: A nicotina não influenciou o processo inflamatório, a proliferação fibroblástica, a presença de colágeno e a epitelização. A neovascularização indicou imaturidade cicatricial na comparação dos grupos A2 e B2. A eosinofilia nas cicatrizes reparadas com cola indica que a substância atuou como alergeno.

L-arginine in the ischemic phase protects against liver ischemia-reperfusion injury / A L-arginina durante a fase isquêmica protege o fígado das lesões de isquemia e reperfusão

PURPOSE: To investigate the effects of intravenous L-arginine (LG) infusion on liver morphology, function and proinflammatory response of cytokines during the early phase of ischemia-reperfusion injury (IRI). METHODS: Thirty rabbits were subjected to 60 minutes of hepatic ischemia and 120 minutes of reperfusion. An intravenous injection of saline or L-arginine was administered five minutes before the ischemia and five minutes before initiating the reperfusion and at the 55th and 115th minutes after the ischemia. Samples were collected for histological analysis of the liver and measurements of the serum AST, ALT and LDH and the cytokines IL-6 and TNF-alpha. RESULTS: It was observed a significant reduction of sinusoidal congestion, cytoplasmic vacuolization, infiltration of polymorphonuclear leukocyte, nuclear pyknosis, necrosis and steatosis in liver tissue, as well as AST, ALT and LDH after injection of LG in the ischemia (p <0.001). Lower levels of IL-6 and TNF-alpha were associated with LG infusion during ischemia. Higher levels these proteins were observed in animals receiving LG during reperfusion. CONCLUSION: L-arginine protects the liver against ischemia/reperfusion injury, mainly when is administered during the ischemic phase.

OBJETIVO: Investigar os efeitos da infusão endovenosa da L-arginina (LG) na morfologia, função e resposta de citocinas pró-inflamatórias do fígado durante a fase precoce da lesão de isquemia e reperfusão (IRI). MÉTODOS: Trinta coelhos foram submetidos a 60 minutos de isquemia hepática e 120 minutos de reperfusão. Foi administrada injecção intravenosa de solução salina ou L-arginina aos cinco minutos antes de iniciar a isquemia e cinco minutos antes de iniciar a reperfusão e aos 55 e 115 minutos após o início da isquemia. Realizou-se análise histológica do fígado e dosagens séricas de AST, ALT, LDH, citocinas IL-6 e TNF-alfa. RESULTADOS: Ocorreu redução significante da congestão sinusoidal, vacuolização citoplasmática, infiltração de leucócitos polimorfonucleares, picnose nuclear, necrose e esteatose no tecido hepático, assim como nos níveis de AST, ALT e LDH após a injeção da LG na isquemia (p<0,001). Níveis mais baixos de IL-6 e TNF-alfa foram associados com a infusão LG durante a isquemia. Níveis mais elevados dessas proteínas foram observados nos animais que receberam LG durante a reperfusão. CONCLUSÃO: A L-arginina protegeu o fígado contra a lesão de isquemia e reperfusão principalmente quando administrada durante a fase de isquemia.

Evaluation of healing prosthetic materials polyester mesh resorbable film and collagen elastin matrix /polypropylene used in rabbits abdominal wall defects / Avaliação da cicatrização da tela de poliéster com lâmina absorvível e a tela de colágeno-elastina/polipropileno utilizadas no reparo de lesões da parede abdominal de coelhos

PURPOSE: To compare polyester with absorbable layer prosthesis with collagen-elastin/polypropylene prosthesis in the repair of abdominal wall defects. METHODS: The 16 studied rabbits were divided in groups A and B (euthanized on the 30th and 60th days, after the implant of the mesh). The animals underwent laparotomy and received a 2cm wall "defect" on each side of the Alba linea. The repair was made with the suture of a polyester mesh with absorbable film on the left side of the Alba Linea and with collagen-elastin/polypropylene mesh on the right side. Adherences were classified according to Nair Score and microscopic evaluation observing types I and III collagen formation and other immunohistochemical analyses. RESULTS: There were no significant differences in adhesion formation. The collagen type I showed higher deposition in polyester with absorbable layer. In group B, the difference between the meshes was significant, with higher collagen III deposition in polyester with absorbable layer (60º P.O.). About the metalloproteinases, the presence of MMP -1 and MMP-8 were about the same; the expression of MMP-13 increased near to the 60th day. CONCLUSIONS: There is no significant difference between the two meshes in adhesion formation and immunohystochemical evaluation. The polyester mesh resorbable film presented a higher deposition of collagen.

OBJETIVO: Comparar a tela poliéster com lâmina absorvível e a confeccionada pela aposição da tela de colágeno-elastina/polipropileno no reparo de lesões da parede abdominal. MÉTODOS: Foram avaliados 16 coelhos, divididos aleatoriamente em dois grupos e submetidos a eutanásia no 30º e no 60º dia P.O. Os animais foram submetidos à laparotomia e confecção de dois defeitos triangulares de 2 cm, de espessura total, na parede abdominal ventral. A correção foi realizada através de fixação, na metade esquerda da linha alba, da tela de poliéster com lâmina absorvível e na direita, tela composta por colágeno-elastina/polipropileno. As aderências foram classificadas conforme o escore de Nair e a avaliação microscópica incluiu avaliação do colágeno (tipos I e III) e imunoistoquímica. RESULTADOS: Não houve diferença quanto à formação de aderências. O colágeno tipo I apresentou maior concentração com a tela Poliéster com lâmina absorvível. No grupo B foi encontrada diferença significativa entre as telas, com aumento do colágeno tipo III com a tela Poliéster com lâmina absorvível (60º P.O.). A avaliação das metaloproteinases MMP-1 e MMP-8 não apresentaram diferença significativa; a MMP-13 apresentou aumento significativo na imunoexpressão no 60º P.O. CONCLUSÕES: Não há diferença significativa entre as telas quanto às aderências e avaliação imunoistoquímica. A tela de poliéster com lâmina absorvível apresenta maior formação de colágeno.

Effects of acetylsalicylic acid and acetic acid solutions on VX2 liver carcinoma in rabbits: in vivo analysis / Efeitos das soluções de aspirina e de ácido acético em fígado de coelhos portadores de tumor hepático VX2. Análise in vivo

PURPOSE: To analyze, in vitro, the effects of acetylsalicylic acid (aspirin) and acetic acid solutions on VX2 carcinoma cells in the liver of rabbits with VX2 hepatic tumors; to determine the histolytic and anatomopathological characteristics of the solutions; and to evaluate the eventual biochemical and hepatic changes. METHODS: A total of 48 rabbits were evaluated. The animals were randomized into two groups, protocol 3 (study group) and protocol 4 (controls), and each group was then subdivided into 3 subgroups. Four days after implantation of the tumor in the liver, median laparotomy was performed with a 0.4-ml injection of a solution of either aspirin (5.0 percent), acetic acid (5.0 percent) or saline. The animals were sacrificed after 24 hours (protocol 3) or after 11 days (protocol 4). Body weight, clinical evolution and biochemical levels, as well as the abdominal and thoracic cavities, were evaluated, and liver microscopy was performed. RESULTS: No changes in clinical evolution, body weight or biochemical levels were reported. However, an increase in alkaline phosphatase was observed in protocol 4 (controls). The tumor was eliminated in both protocols. CONCLUSION: Acetylsalicylic acid and acetic acid solutions cause the destruction of experimental hepatic tumors.

OBJETIVO: Analisar os efeitos das soluções de aspirina e de ácido acético, in vivo, em fígado de coelhos portadores de tumor hepático VX2, verificando o efeito histolítico e anatomo-patológico das soluções e eventuais alterações bioquímicas hepáticas. MÉTODOS: Utilizou-se 48 coelhos, divididos em 2 protocolos experimentais(3 e 4), subdivididos em 3 grupos cada. Após 4 dias da implantação do tumor no fígado, procedeu-se a laparotomia mediana, com injeção de 0,4 ml da solução de aspirina (5,0 por cento), de ácido acético (5,0 por cento) e solução salina; o sacrifício ocorreu apos 24 horas (protocolo 3) e 11 dias (protocolo 4); avaliou-se o peso, evolução clinica, dosagens bioquímicas, cavidade abdominal e torácica e microscopia do fígado. RESULTADOS: Não foram observadas alterações na evolução clinica, peso e nas dosagens bioquímicas, apenas elevação da fosfatase alcalina no grupo controle do protocolo 4. Observamos desaparecimento do tumor em ambos os protocolos. CONCLUSÃO: As soluções de ácido acético e ácido acetilsalicílico acarretam destruição do tumor hepático experimental.