Tissue response evaluation of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant

PURPOSE:To evaluate the tissue response of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant.METHODS:A total of 20 male guinea pigs were divided into 2 groups. After paracentesis in both ears, a biodegradable polymer of poly lactic-co-glycolic acid was implanted in only one middle ear. Histological analysis using neutrophil exudate and vascular neoformation (acute inflammation) and fibroblast proliferation and mononuclear inflammatory cells (chronic inflammation) as parameters was performed after 10 and 30 days of survival (groups 1 and 2, respectively).RESULTS:Four ears in group 1 and 7 in group 2 had an increase of neutrophil exudate. Vascular neoformation occurred in ears with or without the implant, in both groups. Fibroblast proliferation and mononuclear inflammatory cells (lymphocytes and macrophages) increased in ears with implant in group 2.CONCLUSION:The tissue response by histological analysis of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant, showed no statistically significant difference between ears with or without the implant.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Department of OtorhinolaryngologyFederal University of Minas Gerais Faculty of PharmacyFederal University of Minas GeraisUSP Faculty of Medicine of Ribeirao PretoUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Department of Otorhinolaryngology and Head and Neck SurgeryFederal University of São PauloFederal University of São Paulo Medical SchoolUNIFESP, EPM, Department of OtorhinolaryngologyUNIFESP, EPM, Department of Otorhinolaryngology and Head and Neck SurgeryUNIFESP, Medical SchoolSciEL

Review of experimental models: sinusitis in rabbits

INTRODUCTION: In order to better understand the pathophysiology of rhinosinusitis, several attempts have been made to create the disease in an animal model. Among the studied rodents each has its advantages and disadvantages. Rabbits are considered more appropriate for studies that require surgical manipulation or invasive procedures. OBJECTIVES: To evaluate the most viable experimental model of rhinosinusitis in rabbits to be adopted in future studies. METHODS: An electronic search for studies with experimental models of rhinosinusitis in rabbits published in English and Portuguese between July of 1967 and January of 2013 was conducted in Medline, Pub Med, Cochrane, and CAPES databases, using the keywords "sinusitis", "rabbits", and "polyps". RESULTS: A total of 256 studies were retrieved, but in accordance with the inclusion and exclusion criteria, only ten studies were selected. Many different methods of response assessment were used in these studies. CONCLUSION: To date, there is no ideal experimental model for induction of acute or chronic rhinosinusitis in rabbits, but the rhinogenic model appears to be the most viable option for the continuity of studies of the disease

Avaliação da mucosa sinusal do coelho à presença de implante biodegradável Assessing the maxillary sinus mucosa of rabbits in the presence of biodegradable implants

Pensando em melhorar a qualidade de vida dos pacientes com doenças do humor vítreo, os oftalmologistas começaram a utilizar recentemente implantes biodegradáveis com corticoide. Estes mesmos implantes podem ser uma alternativa no tratamento da RSC e, para isso, realizamos um estudo experimental em seios maxilares de coelhos. OBJETIVO: Avaliar histologicamente a mucosa de seio maxilar de coelhos após a colocação de implante biodegradável de prednisolona. MÉTODO: Dezoito coelhos foram divididos aleatoriamente em dois grupos: Grupo 1: no seio maxilar esquerdo foi inserido um implante biodegradável com prednisolona; Grupo 2: No seio maxilar esquerdo foi inserido um implante biodegradável sem medicação. Os seios maxilares do lado direito serviram como controle. Após 7, 14 e 28 dias foram escolhidos aleatoriamente três coelhos de cada grupo e a resposta tecidual inflamatória foi avaliada. RESULTADOS: Foi encontrada diferença não significativa de inflamação na mucosa, quando comparamos o grupo de coelhos que receberam implantes com e sem medicação com o grupo controle; ou quando comparamos o grupo que recebeu implante com prednisolona com o grupo que recebeu implante sem medicação. CONCLUSÃO: Não foram observados sinais de toxicidade ou inflamação na mucosa do seio maxilar do coelho à presença do implante com ou sem prednisolona.<br>In an attempt to improve the quality of life of patients with vitreous humor disease, ophthalmologists began offering steroid-eluting biodegradable implants to their patients. These implants can be used as an alternative treatment for CRS and this is why this experimental study was carried out on rabbit maxillary sinuses. OBJECTIVE: This study aims to assess the histology of the mucosa of the maxillary sinuses of rabbits after the placement of a prednisolone-eluting biodegradable implant. METHOD: Eighteen rabbits were randomly divided into two groups: group 1 - subjects had drug-eluting implants placed on their left maxillary sinuses; group 2 - subjects had non-drug-eluting implants placed on their left maxillary sinuses. The right maxillary sinuses served as the controls. After seven, 14, and 28 days three rabbits in each group were randomly picked to have their tissue inflammatory response assessed. RESULTS: Levels of mucosal inflammation were not significantly different between the groups with and without drug-eluting implants and the control group, or when the groups with drug-eluting implants and non-drug-eluting implants were compared. CONCLUSION: Signs of toxicity or mucosal inflammation were not observed in the maxillary sinuses of rabbits given prednisolone-eluting implants or non-drug-eluting implants