Association of polypropylene scaffolds and mesenchymal stem cells for use in tissue engineering / Associação de arcabouço de polipropileno e células tronco mesenquimais para uso em engenharia de tecido

Tissue engineering replaces injured tissues by manipulating cells, making scaffolds, and using molecules that stimulate the tissue. Mesenchymal stem cells (MSCs) are good candidates for tissue engineering, as this is one of the cell types which are recruited to repair injured tissues. Scaffolds are structural devices that allow cell fixation and migration, with polypropylene meshes being an example. This study aims to evaluate the culture of adipose tissue-derived mesenchymal stem cells (ADSCs), isolated from C57Bl/6 GFP + mice, in two types of polypropylene meshes (macroporous and microporous) in conventional culture plates and plates coated with methacrylate, over a period of fifteen days. The objective was to obtain the best interaction protocol between the mesh and the cells. The choice of the best method was based on adherence, maintenance of adherence and viability during culture. The amount of ADSCs adhering was checked daily by counting in a Neubauer Chamber and by using a growth curve performed with the MTT assay. The ADSCs adhering to the meshes were visualized with DAPI, panotic, hematoxylin and eosin, immunohistochemistry (integrin), and immunofluorescence (actin). ADSCs adhere to all forms of culture and to the two types of polypropylene mesh. ADSCs adhered more to the microporous mesh, within the seven day period of culture and in the plates without methacrylate. Thus, polypropylene meshes offer a good scaffold for ADSCs to adhere to.

A engenharia de tecidos substitui tecidos danificados com a manipulação de células, confecção de arcabouços e a utilização de moléculas que estimulem o tecido. As células-tronco mesenquimais (MSCs) são boas candidatas para engenharia de tecido, pois são um dos tipos celulares recrutadas para a reparação de tecidos lesionados. O arcabouço deve ser um dispositivo estrutural que forneça uma estrutura para o crescimento e a diferenciação celular no sítio, sendo a tela de polipropileno um exemplo. O objetivo deste estudo foi avaliar o cultivo de células-tronco mesenquimais de tecido de adiposo (ADSCs), isoladas de camundongos C57Bl/6 GFP+, em dois tipos de telas de polipropileno (macroporosa e microporosa) em placas de cultura convencionais e revestidas com metacrilato, durante quinze dias, para obter o melhor protocolo de interação entre a tela e as células. A escolha do melhor método foi baseada na adesão, manutenção da adesão e viabilidade durante cultivo. A quantidade de ADSCs aderidas foi verificada diariamente em contagem em Câmara de Neubauer e através de uma curva de crescimento realizada através de ensaio de MTT. As ADSCs aderidas nas telas foram visualizadas com a marcação de DAPI, panótico, hematoxilina e eosina, imumo-histoquímica (integrina) e imunofluorescência (actina). Nas duas formas de cultivo e nos dois tipos de telas de polipropileno houve aderência das ADSCs. Houve maior aderência na tela microporosa, no período de sete dias de cultivo e em placas sem metacrilato. Conclui-se que a tela de polipropileno oferece um bom arcabouço para as ADSCs se aderirem.

Validation of a new technique to freezing and embedding tissue in Mohs surgery, using an animal model

ABSTRACT PURPOSE: To validate the innovative Dry Ice method, comparing it with two standard methods currently used for tissue processing in Mohs surgery, the Heat Sink method and the Miami Special. METHODS: Forty eight samples of pigs kin with the standard beveled Mohs technique were used, and randomly allocated into six groups. Each group was processed with one of the 3 methods and evaluated for: The freezing time, the depth required to cut into the block to obtain a complete section, and the quality of histological slides analyzed with a image software. The statistical analysis was performed with the software SAS(r) System. The inferential analysis was made by one-way ANOVA. RESULTS: The Miami Special showed a processing time significantly shorter than Dry Ice method and Heat Sink method. There was no significant difference in the depth required to cut into the blocks, and area of surgical margins visualized. CONCLUSION: The Dry Ice method was as efficient as the other two methods currently used in Mohs surgery, considering the individual advantages and disadvantages of each method.

Effect of histological processing and methacrylate sectioning on the area of gill tissue in teleost / Efeito do processamento histológico e seccionamento em metacrilato sobre a área de tecido branquial em teleósteo

Deformation of biological tissues may occur during histological processing and results in loss of accuracy when quantitative information about cells, tissues and organs is necessary. In this study, the gill tissue from armored catfish (Pterygoplichthys anisitsi) was quantified in each step of processing using the stereological principles. During processing for glycol methacrylate embedding, gill tissue from shrinks significantly but regains its original dimensions after sectioning.

Deformações nos tecidos podem ocorrer durante o processamento histológico e resultar em informações errôneas quando há necessidade de dados quantitativos sobre células, tecidos e órgãos. Neste estudo, o tecido branquial do cascudo (Pterygoplichthys anisitsi) foi quantificado em cada etapa do processamento utilizando os princípios de estereologia. O tecido branquial reduziu significativamente durante processamento histológico com metacrilato, mas retornou às suas dimensões iniciais depois de seccionadas, o que indica não ocorrer nenhuma perda na informação quantitativa do tecido.

Silicone gel implants for calf augmentation: 14 years experience / Implantes de silicone gel em panturrilhas: 14 anos de experiência

Based on experience of 131 operated patients submitted to calf augmentation, the authors describe the indications, surgical technique and complications of the method. The procedure is recommended to correct calf volume of congenital origin, neurological or traumatic sequela.

Morfologia do eptélio intestinal de ratos adultos utilizando-se como meio de inclusäo o paraplast e o glicometacrilato / Intestinal epithelium morphology of adults rats using as inclusion media paraplast and glycometacrylatel

Através da adequaçäo ao processamento histológico rotineiro buscamos aperfeiçoar a descriçäo morfológica por meio de melhor visualizaçäo das células presentes no epitélio intestinal. Para isso utilizamos segmentos iniciais e finais do intestino delgado de ratos adultos. As células absortivas, caliciformes, células de Paneth e células indiferenciadas apresentaram melhor nitidez na forma e na distribuiçäo dos elementos intracelulares graças às nuances de colorações distintas obtidos pela inclusäo do material em glicometacrilato e cortes de 2 g.m feitos com navalha de aço. As células enteroendócrinas, puderam ter seus grânulos evidenciados após inclusäo em paraplast, cortes de 4 g.m em navalha de aço, sendo corados pela prata amoniacal. A aplicaçäo destas técnicas, ao nosso ver, contribuem com melhorias do material didático para aulas práticas sobre o epitélio intestinal.

Matrices de inclusión para obtención de cortes de tejidos en vibrátomo en estudios citoquímicos / Embedding matrixes for obtaining vibratome tissue slices for cytochemistry studies

Para estudios citoquímicos en diferentes muestras de tejidos, de tamaño pequeños, se hace necesaria la utilización de una matriz inerte que genere soporte y estabilidad al tejido en el momento de obtener cortes de 50µm en vibrátomo. Por esta razón se ensayaron cinco matrices: agar granulado, agar purificado, agar-agar, agarosa y gelatina, a diferentes concentraciones. Tanto con el agar-agar como con la agarosa se obtuvieron los mejores resultados, puesto que estos ofrecen, mayor estabilidad al tejido, fluyen fácilmente al servirse y su textura es muy homogénea, requisitos necesarios para la obtención de cortes precisos, utilizables en citoquímica, inmunocitoquímica y trazados histoquímicos

Alterations of CDKN2 (MTS1/p16INK4A) gene in paraffin-embedded tumor tissues of human stomach, lung, cervix and liver cancers

The CDKN2 (MTS1/p16INK4A) gene, encoding cyclin dependent kinase inhibitor, was found to be homozygously deleted at a high frequency in cell lines from many different types of cancer and some primary cancers. To determine the frequency of CDKN2 mutations in most common human cancers in Korea, PCR and PCR-SSCP analyses for the exon 2 of CDKN2 were performed on each set of 20 formalin-fixed and paraffin-embedded tumor tissues of stomach adenocarcinomas, lung cancers, cervix cancers and hepatocellular carcinomas. No mutations in exon 2 of CDKN2 were found in 20 stomach adenocarcinomas. In contrast to rare mutations in stomach adenocarcinomas, a high frequency of CDKN2 mutations was identified in other 3 cancers, 11 of 20 (55%) lung cancers (7 of 10 NSCLCs and 4 of 10 SCLCs), 14 of 20 (70%) cervix cancers and 11 of 20 (55%) hepatocellular carcinomas. These results suggest that mutations of the CDKN2 gene might be an important genetic change in NSCLCs, cervix cancers and hepatocellular carcinomas.

Standardization of fixation, processing and staining methods for the central nervous system of vertebrates

This paper reports the standardization of methods used for processing and embedding various vertebrate brains of different size in paraffin. Other technical details developed for avoiding frequent difficulties arising during laboratory routine are also reported. Some modifications of the Nissl and Klüver-Barrera staining methods are proposed. These modifications include: 1) a Nissl stain solution with a rapid and efficient action with easier differentiation; 2) the use of a cheap microwave oven for the Klüver-Barrera stain. These procedures have the advantage of permitting Nissl and Klüver-Barrera staining of nervous tissue in about five and fifteen minutes respectively. The proposed procedures have been tested in brains obtained from fish, amphibians, reptiles and mammals of different body sizes. They are the result of our long experience in preparing slides for comparative studies. Serial sections of excellent quality were regularly obtained in all the specimens studied. These standardized methods, being simple and quick, are recommended for routine use in neurobiological laboratories.

Los cianoacrilatos en cirugía / Cyano-acrylates in surgery

Desde su introducción en la cirugía hace más de 35 años, los cianoacrilatos se han usado en diversos campos de las especialidades quirúrgicas. A pesar de sus múltiples ventajas sobre la sutura convencional, muchos cirujanos dejaron de usarlos por su gran histotoxicidad y las dificultades de su aplicación. En los últimos años, nuevamente se han comenzado a utilizar los olvidadod adhesivos con excelentes resultados. En esta revisión se comentan aspectos históricos, características físicas, químicas y biológicas de estos adhesivos; Métodos de síntesis, metabolismo, respuesta inmunitaria y carcinogénesis después de aplicarse en el organismo y usos actuales y potenciales de los cianoacrilatos en la cirugía