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ABSTRACT Introduction: Tissue microarray (TMA) is considered an innovative method in several fields, with a great diversity of applications and advantages over traditional histomorphometric techniques. The most important advantage that TMA offers is the simultaneous evaluation of a large number of specimens from a limited source of material. However, TMA exhibits a high rate of non-viable samples in the final stages of the process, which compromise their use in analyzes that can not be repeated. Objective: Considering this disadvantage, the objective of this study was to optimize the methodology to maximize the viability of the samples, as well as to increase the efficiency of the technique. Material and methods: For this purpose, several variables involved in the construction of the recipient blocks, including paraffin composition, diameter, spacing distance, localization and type of the tissue samples in the block were tested in order to establish correlations between the quality of the values and the parameters studied. Results: The results showed that the blocks built with polymer-enriched paraffin, subjected to the fusion protocol at 37ºC, associated to a tempering, and constructed with one millimeter diameter samples and 1000 µm spacing between tissues, produced slides whith superior features. Conclusion: The data obtained from the physical and chemical adjustments of the TMA recipient blocks provided vital information that, when applied in TMA research projects, may reduce the losses associated with the method.
RESUMO Introdução: O microarranjo tecidual (MAT) é considerado um método inovador em vários campos, com uma vasta diversidade de aplicações e vantagens em relação às técnicas histomorfométricas clássicas. A vantagem mais importante que o MAT oferece é a avaliação simultânea de um grande número de espécimes de uma fonte limitada de material. Contudo, ele apresenta uma taxa elevada de amostras não viáveis nos estádios finais do processo, o que compromete sua utilização em análises que não podem ser repetidas. Objetivos: Considerando essa desvantagem, o objetivo deste estudo foi otimizar a metodologia para maximizar a viabilidade das amostras, bem como aumentar a eficiência da técnica. Material e métodos: Para tanto, foram testadas várias variáveis envolvidas na construção dos blocos receptores, como composição da parafina, diâmetro, distância de espaçamento, localização e tipo das amostras de tecido no bloco, a fim de estabelecer correlações entre a qualidade dos valores e os parâmetros estudados. Resultados: Os resultados mostraram que os blocos construídos com parafina enriquecida em polímero, submetidos ao protocolo de fusão a 37ºC, acoplados a ciclos de aquecimento e resfriamento e construídos com amostras de um milímetro de diâmetro e espaçamento entre os tecidos de 1000 µm, produziram lâminas com características superiores. Conclusão: Os dados obtidos dos ajustes físicos e químicos dos blocos de receptores de MAT forneceram informações vitais que, quando aplicadas em projetos de pesquisa de MAT, podem reduzir as perdas associadas ao método.
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Mucosite é uma inflamação da mucosa oral e/ou gastrintestinal ocasionada pelo tratamento antineoplásico caracterizada por eritema, úlceras dolorosas e formação de pseudomembrana. As condutas atuais para prevenção e tratamento são paliativas. A unha-de-gato (Uncaria tomentosa) é uma planta cujo extrato tem ação imunomoduladora, antiinflamatória, antioxidante, antiviral e antimutagênica. Este trabalho visou comparar clinicamente o efeito preventivo de três doses sistêmicas de UT nas mucosites bucais induzidas por 5-FU em hamsters Sírios dourados. Foram estudados 10 animais por grupo: GC (controle), G2 (2 mg de alcalóide/kg de animal), G5 (5mg/kg) e G10 (10 mg/kg), que foram sedados e receberam a solução de UT dos dias 1 ao 5 por gavagem. Para a indução da mucosite, nos dias 4 e 6 os animais foram anestesiados e receberam 5- FU via intraperitoneal nas doses de 100mg/kg e 60mg/ kg respectivamente e no dia 6 ranhura com fio ortodôntico em ambas mucosas. Nos dias 1, 8, 10, 12, 15 os animais foram pesados, anestesiados e tiveram suas mucosas evertidas para fotografia. Dois avaliadores calibrados, sem conhecimento dos grupos, avaliaram as fotografias e deram escores para as mucosites. Todos os animais apresentaram algum grau de mucosite, a perda de peso foi significativa no grupo G10 e nas condições deste estudo, a Uncaria tomentosa não preveniu ou tratou a mucosite.
Mucositis is an inflammation of oral and/or gastrointestinal mucosa caused by antineoplasic treatment, characterized by eritema, painful ulcers and pseudo membrane formation. There is no widely accepted protocol to prevent and/or to treat mucositis. Cat's claw (Uncaria Tomentosa - UT) is a plant with immunomoduladory, antinflammatory, antioxidant and antimutagenic properties. The objective of this study was to clinically compare the effects of three systemic doses of UT in Golden Sirius hamsters that had mucositis induced by 5-fluorouracil. The experimental groups were divided according to alkaloid dose present at the aqueous extracts of UT: GC (control group), G2 (2mg of alkaloid/kg of animal), G5 (5mg/kg) and G10 (10mg/kg), being ten animals per group, in a total of forty animals. To perform the experiment, the animals received UT extracts at days 1 to 5 through gavage, and to induce the mucositis, an intraperitoneal injection of 5-FU at days 4 and 6, besides, at day 6 a mechanical trauma with orthodontic wire on both mucosas was performed.At days 1, 8, 10, 12 and 15 the animals were weighted, anesthetized and their mucosas were everted to be photographed. Two calibrated observers, with no previous knowledge of the groups evaluated the images and scored the mucositis. All animals developed mucositis, the weight loss was significant in G10, and under the conditions of this study Uncaria tomentosa did not prevent neither treated mucositis.
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PURPOSE: We developed and characterized by histopathology and immunohistochemistry a syngeneic murine bladder tumor model derived from the MB49 tumor cell line. MATERIALS AND METHODS: Bladder tumor implantation was achieved by intravesical instillation of 5 x 10(5) MB49 tumor cells in C57BL/6 mice. A chemical lesion of the bladder was performed in order to promote intravesical tumor implantation. The bladder wall lesion was accomplished by transurethral instillation of silver nitrate (AgNO3). After 15 days, the animals were sacrificed, examined macroscopically for intravesical tumor and bladder weight. Histology and immunohistochemistry were performed using cytokeratin 7 (CK7), carcinoembrionic antigen (Dako-CEA), p53 and c-erbB2 oncoprotein (Her2/neu). RESULTS: Twenty-nine out of 30 animals (96.7 percent) developed intravesical tumors in a 15-day period. Macroscopically, the mean bladder weight was 0.196g (0.069-0.538g), 10 to 15 times the normal bladder weight. The immunohistochemical analysis showed significant membrane expression of CEA and CK7: a similar finding for human urothelial cancer. We also characterized absence of expression of p53 and anti-Her2/neu in the murine model. CONCLUSIONS: High tumor take rates were achieved by using the chemical induction of the bladder tumor. Although electric cauterization is widely described in the literature for syngeneic orthotopic animal models, the technique described in this study represents an alternative for intravesical bladder tumor implantation. Moreover, the histopathology and immunohistochemical analysis of the murine bladder tumor model derived from the MB49 cell line showed a resemblance to human infiltrating urothelial carcinoma, allowing clinical inference from experimental immunotherapy testing.