Histological evaluation of capsules formed by texturized silicone implants with and without polyester mesh coverage (Parietex®). A study on female rats.

PURPOSE: To evaluate capsules formed by microtextured silicone implants with and without Parietex® mesh coverage histologically. METHODS: Sixty Wistar rats were divided in two groups (meshed and unmeshed). Each group was, then, divided into two subgroups for evaluation at 30 and 90 days. Capsules were analyzed based on hematoxylin and eosin (HE) and picrosirius staining. RESULTS: The number of fibroblasts, neutrophils and macrophages was similar among all subgroups. There was a higher lymphocyte reaction in the 30-day meshed group (p = 0.003). Giant cell reaction, granulation tissue and neoangiogenesis were similar among the subgroups. Synovial metaplasia was milder at 90-day in the unmeshed (p = 0.002) and meshed group (p < 0.001). Capsular thickness was significantly greater in the meshed samples (30-day p < 0.001 and 90-day p < 0.001). There was a similar amount of collagen types I and III in both groups. CONCLUSIONS: The mesh-covered implants produced capsules similar to the microtextured ones when analyzing inflammatory variables. Synovial metaplasia was milder at 90 than at 30 days, and the capsular thickness was significantly greater in the meshed group. A similar amount of collagen types I and III was observed. Due to these characteristics, the mesh coverage did not seem to significantly affect the local inflammatory activity.

Histological evaluation of capsules formed by silicon implants coated with polyurethane foam and with a textured surface in rats.

PURPOSE:: To assess the capsules formed by silicone implants coated with polyurethane foam and with a textured surface. METHODS:: Sixty-four Wistar albinus rats were divided into two groups of 32 each using polyurethane foam and textured surface. The capsules around the implants were analyzed for 30, 50, 70 and 90 days. Were analyzed the following parameters: foreign body reaction, granulation tissue, presence of myofibroblasts, neoangiogenesis, presence of synovial metaplasia, capsular thickness, total area and collagen percentage of type I and III, in capsules formed around silicone implants in both groups. RESULTS:: The foreign body reaction was only present in the four polyurethane subgroups. The formation of granulation tissue and the presence of myofibroblasts were higher in the four polyurethane subgroups. Regarding to neoangiogenesis and synovial metaplasia, there was no statistical difference between the groups. Polyurethane group presented (all subgroups) a greater capsule thickness, a smaller total area and collagen percentage of type I and a higher percentage area of type III, with statistical difference. CONCLUSION:: The use of polyurethane-coated implants should be stimulated by the long-term results in a more stable capsule and a lower incidence of capsular contracture, despite developing a more intense and delayed inflammatory reaction in relation to implants with textured surface.

Histological evaluation of capsules formed by texturized silicone implants with and without polyester mesh coverage (Parietex®). A study on female rats

ABSTRACT Purpose To evaluate capsules formed by microtextured silicone implants with and without Parietex® mesh coverage histologically. Methods Sixty Wistar rats were divided in two groups (meshed and unmeshed). Each group was, then, divided into two subgroups for evaluation at 30 and 90 days. Capsules were analyzed based on hematoxylin and eosin (HE) and picrosirius staining. Results The number of fibroblasts, neutrophils and macrophages was similar among all subgroups. There was a higher lymphocyte reaction in the 30-day meshed group (p = 0.003). Giant cell reaction, granulation tissue and neoangiogenesis were similar among the subgroups. Synovial metaplasia was milder at 90-day in the unmeshed (p = 0.002) and meshed group (p < 0.001). Capsular thickness was significantly greater in the meshed samples (30-day p < 0.001 and 90-day p < 0.001). There was a similar amount of collagen types I and III in both groups. Conclusions The mesh-covered implants produced capsules similar to the microtextured ones when analyzing inflammatory variables. Synovial metaplasia was milder at 90 than at 30 days, and the capsular thickness was significantly greater in the meshed group. A similar amount of collagen types I and III was observed. Due to these characteristics, the mesh coverage did not seem to significantly affect the local inflammatory activity.

[Collagen synthesis after the implantation of polypropylene nets in the abdominal wall of young and old rats]. / Síntese de colágeno após a implantação de telas de polipropileno em parede abdominal de ratos jovens e velhos.

PURPOSE: Some investigators have stated that collagen synthesis is slower in elderly individuals, others have reported a reduction of collagen I and III synthesis, and still others have reported normal synthesis. The objective of the present study was to determine the collagen deposition occurring through the pores of a propylene net implanted in the abdominal wall of young adult rats compared to old rats. METHODS: Ten male rats aged 100 to 120 days and 10 rats aged 850 to 900 days were used. Under inhalatory anesthesia, a median incision was made in the ventral abdominal wall and a 4 cm2 gap was formed. The muscle-aponeurosis plane was removed and the peritoneal plane was maintained. The gap was corrected with a polypropylene mesh fixed with separate 5.0 polypropylene sutures and the skin margins were joined. The animals were sacrificed 30 days later and the ventral abdominal wall with the prosthesis was removed. The flap with the graft was divided into 2 parts, one for the traction assay and the other for histopathological study. The sections obtained were stained with hematoxylin-eosin and Sirius-red and examined under a polarized light microscope using the Image Plus software. RESULTS: The traction assay did not demonstrate a significant difference in resistance between groups. An acute-chronic inflammatory reaction with large quantities of giant foreign body cells was present at similar intensity in both groups, the same being observed for total collagen concentration (p=0.1440) and type I collagen concentration (p=0.3981). In contrast, type III collagen concentration was higher in the sections from old animals (p=0.0364). CONCLUSIONS: These results permit us to conclude that aging does not impair the resistance gain or collagen deposition, although a delayed tissue maturation occurs.

Histological evaluation of capsules formed by silicon implants coated with polyurethane foam and with a textured surface in rats

ABSTRACT PURPOSE: To assess the capsules formed by silicone implants coated with polyurethane foam and with a textured surface. METHODS: Sixty-four Wistar albinus rats were divided into two groups of 32 each using polyurethane foam and textured surface. The capsules around the implants were analyzed for 30, 50, 70 and 90 days. Were analyzed the following parameters: foreign body reaction, granulation tissue, presence of myofibroblasts, neoangiogenesis, presence of synovial metaplasia, capsular thickness, total area and collagen percentage of type I and III, in capsules formed around silicone implants in both groups. RESULTS: The foreign body reaction was only present in the four polyurethane subgroups. The formation of granulation tissue and the presence of myofibroblasts were higher in the four polyurethane subgroups. Regarding to neoangiogenesis and synovial metaplasia, there was no statistical difference between the groups. Polyurethane group presented (all subgroups) a greater capsule thickness, a smaller total area and collagen percentage of type I and a higher percentage area of type III, with statistical difference. CONCLUSION: The use of polyurethane-coated implants should be stimulated by the long-term results in a more stable capsule and a lower incidence of capsular contracture, despite developing a more intense and delayed inflammatory reaction in relation to implants with textured surface.

Diminuição da expressão imuno-histoquímica de moléculasde adesão em carcinomas escamosos de mucosa oral / Reduction of immunohistochemical expression of adhesion molecules in squamous carcinoma of oral mucosa

Objetivos: Comparar a expressão imuno-histoquímica da E-caderina e da Beta-catenina de lesões escamosaspré-neoplásicas e neoplásicas de mucosa oral de amostras emblocadas em parafina. Materiais e métodos:Foram selecionadas 15 amostras de mucosa oral de pacientes apresentando hiperplasia com ou sem displasialeve (grupo 1); 5 amostras apresentando displasia moderada, acentuada ou carcinoma in situ (grupo 2); e12 amostras apresentando carcinoma de células escamosas invasor (grupo 3). Essas amostras foram submetidasà técnica de imuno-histoquímica com anticorpos primários monoclonais anti-E-caderina e anti-Betacatenina.A leitura em microscopia óptica compreendeu a expressão tecidual desses marcadores no epitélioescamoso das amostras de mucosa oral – lesadas ou não. A expressão imuno-histoquímica dessas moléculasde adesão foi classificada, segundo a sua intensidade de marcação tecidual, em negativa, positiva fraca epositiva forte. Resultados: A expressão de E-caderina foi forte em 93,3% dos casos do grupo 1 (hiperplasia/displasia leve), e 100% dos casos demonstraram forte expressão para a Beta-catenina nesse mesmo grupo. Contudo, no grupo 3 (carcinoma de célula escamosa), somente 42% dos casos foram fortemente positivospara E-caderina e 25% deles para Beta-catenina. Conclusões: A E-caderina e a Beta-catenina diminuíram asua expressão segundo a progressão tumoral do carcinoma de mucosa oral, reforçando um dos mecanismosrelacionados com a sua carcinogênese.

Objectives: To compare the immunohistochemical expression of E-cadherin and Beta-catenin in squamous pre-malignant and malignant lesions of formalin fixed paraffin embedded buccal mucosa samples. Materials e methods: Selected 15 samples of buccal mucosa of patients with hyperplasia with or without mild dysplasia (group 1), 5 samples showing moderate dysplasia, severe or carcinoma in situ (group 2) and 12 samples presenting invasive squamous cell carcinoma (group 3). These samples were subjected to immunohistochemistry with anti-E-cadherin and anti-Beta-catenin monoclonal antibodies. The expression of these markers in tissue samples injured or not were analyzed in accordance of positivity that was observed in epithelium stratum. The immunohistochemical expression of these adhesion molecules was classified according to their intensity in negative, weak positive and strong positive. Results: The expression of E-cadherin was strong at 93.3% of patients in group 1, and 100% of the cases showed strong expression of Beta-catenin in the same group. However, in group 3, only 42% of cases were strongly positive for E-cadherin and 25% of them to Beta-catenin. Conclusions: The E-cadherin and Beta-catenin decreased their expression according to tumor progression, from hiperplasia/mild dysplasia lesion to buccal invasive carcinoma and this fact may be related of the carcinogenesis mechanisms.

Utilização de brocas trefina para a confecção de tissue microarray / Use of trephine drills for the production of tissue microarray

Objetivos: Descrever e validar uma técnica alternativa econômica e eficiente para a confecção de amostras teciduais com arranjo matricial (tissue microarrays, TMA). Materiais e métodos: Utilizou-se um motor, um micromotor, um contra-ângulo redutor 16:1 e brocas trefina de aço inoxidável para osso. Análise histomorfométrica do volume das células acinares de glândulas parótidas foi realizada. Para testar marcadores imunoistoquímicos para células mioepiteliais, acinares e ductais das parótidas foram utilizados calponina e PCNA. Resultados: Na análise macroscópica e microscópica das lâminas, não foi encontrada perda total do tissue e nem mesmo deslocamento (parcial e/ou total) deste, sendo as perdas teciduais observadas apenas parciais. Das 90 lâminas analisadas, 59 (65%) obtiveram de 50% a 100% do tissue com ausência de artefato, deslocamento ou perda de tecido. Conclusão: O equipamento proposto pelos autores para a confecção deamostras teciduais com arranjo matricial representa uma alternativa econômica e eficiente.

Objectives: To describe and validate an inexpensive and efficient alternative for the production of tissue microarrays (TMA). Materials and methods: An electric-motor, a hand-piece, a reducing contra-angle hand-piece 16:1 and trephine stainless steel drills for bones were used in this study. A histomorphometric assessment of the volume of the acinar cells of parotid glands was performed. Calponin and PCNA were used to test the immunohistochemical markers for myoepithelial, acinar and ductal cells of parotid glands. Results: During the macroscopic and microscopic analysis, total loss of sections was not observed in any slide as well as artifactual ungluing (total and/or partial) of the sections. The loss of sections was partial. Fifty nine (65%) out of 90 slides showed 50%-100% of the tissue without technical artifact, artifactual ungluing or loss of the section. Conclusion: The equipment proposed by the authors for the production of arrays represents an inexpensive and efficient alternative.

Síntese de colágeno após a implantacão de telas de polipropileno em parede abdominal de ratos jovens e velhos / Collagen synthesis after the implantation of polypropylene nets in the abdominal wall of young and old rats

OBJETIVO: Alguns autores afirmam que a síntese do colágeno em indivíduos idosos é mais lenta, outros que há diminuicão da síntese de colágeno I e III e outros que é normal. O objetivo deste estudo foi reconhecer a deposicão de colágeno através dos poros de tela de polipropileno, implantada em parede abdominal de ratos adultos jovens e comparar à de ratos velhos. MÉTODOS: Utilizaram-se 10 ratos machos com idade entre 100 e 120 dias e 10 ratos com idade entre 850 e 900 dias. Sob anestesia inalatória fez-se uma incisão mediana na parede abdominal ventral e produziu-se uma falha com 4 cmy, retirando-se o plano músculo-aponevrótico, mantendo-se o plano peritoneal. Corrigiu-se a falha com malha de polipropileno fixada com pontos separados de fio 5.0, também de polipropileno e fez-se a síntese da pele. Após 30 dias fez-se a eutanásia e retirou-se a parede abdominal ventral com a prótese. Dividiu-se o retalho com o enxerto em 2 partes, uma ensaio de tracão e a outra para estudo histopatológico. Coraram-se os cortes obtidos pela hematoxilina e eosina e Sirius-red. Estes foram examinados em microscópio de luz polarizada através do programa Image Plus. RESULTADOS: O ensaio de tracão não demonstrou diferenca significante de resistência entre os dois grupos. Reacão inflamatória agudo-crônica, com grande quantidade de células gigantes de corpo estranho, esteve presente nos dois grupos com intensidade semelhante, o mesmo acontecendo com a concentracão total de colágeno (p=0,1440) e de colágeno tipo I (p=0,3981). Já a concentracão de colágeno tipo III era maior nos cortes dos animais velhos (p=0,0364). CONCLUSAO: Estes resultados permitem concluir que o envelhecimento não prejudica o ganho de resistência e a deposicão de colágeno, porém existe atraso da maturacão tecidual.

Estudo comparativo da biocompatibilidade da submucosa intestinal porcina e pericárdio bovino usados como enxertos na veia cava de cães / Comparative study of the biocompatibility of the porcine intestinal submucosa and bovine pericardium used as grafts in the inferior cava vein of dogs

OBJETIVO: Comparar a biocompatibilidade entre submucosa de intestino delgado (SID) porcino e o pericárdio bovino como enxerto no reparo de lesões criadas na veia cava inferior de cães. MÉTODOS: Dezesseis cães foram submetidos a laparotomia. Após a abertura da cavidade abdominal a veia cava foi identificada e em seguida procedeu-se com a retirada de um segmento elíptico de 1,5X3cm de sua parede anterior. Em 8 animais o defeito foi reparado com SID porcino (grupo A) e nos 8 animais restantes o defeito foi reparado com pericárdio bovino (grupo B).No 30º dia de P.O. realizou-se uma ultra-sonografia e a eutanásia foi realizada no 40ºdia de pós-operatório. RESULTADOS: Observou-se estenose da veia cava em 1 cão do grupo do grupo A e em 2 animais do grupo B além de trombose em 1 cão desse mesmo grupo. A análise microscópica revelou um processo inflamatório crônico moderado em ambos os grupos. A endotelizacão do enxerto, regeneracão de fibras musculares lisas e depósito de colágeno também foi similar nos 2 grupos estudados. CONCLUSAO: A SID provou ser um excelente substrato para a regeneracão vascular quando implantado em veia cava superior, contudo os resultados encontrados não diferem daqueles observados com o uso de pericárdio bovino.