Effect of platelet rich fibrin and beta tricalcium phosphate on bone healing. A histological study in pigs

To investigate the effect of platelet rich fibrin (PRF) and beta tricalcium phosphate (β-TCP), alone or in combination, on bone regeneration in pig tibial defects. METHODS: Four standardized defects were prepared in both tibias of three adult male pigs. The first defect was left unfilled as a control; the others were grafted with either PRF, β-TCP or PRF mixed with β-TCP. All animals were sacrificed on the 12th postoperative week and the tibial bones were removed, histologic sections were prepared and the experimental sites were examined microscopically and stereologically. RESULTS: Histologic and stereologic examination revealed more new bone formation in the defects filled with PRF mixed β-TCP than in the defects grafted with either β-TCP or PRF alone. CONCLUSION: The platelet rich fibrin and beta tricalcium phosphate combination effectively induces new bone formation.(AU)

Comparison of effects of unfractionated heparin and low molecular weight heparin on skin wound healing of rats / Comparação dos efeitos da heparina não fracionada e heparina de baixo peso molecular na cicatrização de feridas na pele de ratos

PURPOSE: To compare the effects of unfractionated heparin (UH) and a low molecular weight heparin (LMWH) on skin wound healing of rats. METHODS: Forty eight male Sprague-Dawley rats underwent 8mm full thickness dorsal skin wounds and were randomly assigned to three equal groups. In experimental group A, heparin sodium was injected at a concentration of 1000U/kg. In experimental group B, enoxaparin was injected at a concentration of 1mg/kg. Physiologic saline (0.5ml) was administered to the control group. Injections were made subcutaneously, once daily, for seven days. At 7th and 10th days tissue samples were taken from all rats. Histologic examination of these tissues was made under light microscope and scored. RESULTS: Histological examination showed a significant difference between the 7th and 10th day groups in wound healing. It was observed that wound healing of LMWH injected group is better. This difference is statistically significant at 10th day. CONCLUSIONS: Daily administration of single doses of unfractionated heparin and a low molecular weight heparin improves wound healing positively. Low molecular weight heparin induces wound healing more than unfractionated heparin.(AU)

OBJETIVO: Comparar os efeitos da heparina não fracionada (HNF) e da heparina de baixo peso molecular (HBPM) na cicatrização de feridas cutâneas de ratos. MÉTODOS: Quarenta e oito ratos machos Sprague-Dawley foram submetidos à ferida na pele dorsal com espessura total de 8mm e foram distribuídos aleatoriamente em três grupos iguais. No grupo experimental A, a heparina sódica foi injetada a uma concentração de 1000U/kg. No grupo experimental B, a enoxaparina foi injetada a uma concentração de 1mg/kg. Solução salina fisiológica (0,5ml) foi administrada para o grupo controle. As injeções foram feitas por via subcutânea, uma vez por dia, durante sete dias. Nos dias 7º e 10º amostras de tecido foram obtidas de todos os ratos. O exame histológico destes tecidos foi realizado em microscópio de luz. RESULTADOS: O exame histológico mostrou uma diferença significativa entre os grupos no 7º e 10º dias na cicatrização das feridas. Observou-se que a cicatrização de feridas do grupo com heparina de baixo peso molecular foi melhor. Esta diferença foi estatisticamente significante no 10º dia. CONCLUSÕES: A administração diária de doses únicas de heparina não fracionada e de heparina de baixo peso molecular melhora a cicatrização de feridas. A heparina de baixo peso molecular induz melhor a cicatrização de feridas do que a heparina não fracionada.(AU)