Effects of cyclosporin, nifedipine and phenytoin on gingival myofibroblast transdifferentiation in monkeys

Abstract Objective: Myofibroblasts have been associated with the development of several pathologic fibrotic conditions. This longitudinal study aims to assess the proliferative and antiapoptotic effects of cyclosporin, nifedipine and phenytoin on gingival connective tissue cells of nonhuman primate, as well as to analyze a possible role of myofibroblasts in gingival overgrowth. Materials and Methods: Gingival samples from the right superior canine area were obtained from 12 male monkeys ( Sapajus spp ) to comprise the control group. After one week, the animals were randomly assigned to three groups, which received daily oral doses of cyclosporin, nifedipine or phenytoin for 120 days. Gingival samples were collected from the left superior canine area of two animals of each group at 52 and 120 days. Histological sections were stained with hematoxylin and eosin, and immunoreacted against α-SMA, Ki- 67 and bcl-2. Results: α-SMA immunoreaction was negative in the control and experimental groups. Similarly, no difference between groups concerning immunostaining against Ki-67 and bcl-2 was observed in connective tissue cells. Conclusion: Based on this methodology, it may be concluded that gingival overgrowths induced by cyclosporin, nifedipine and phenytoin are not associated with neither myofibroblast transdifferentiation, proliferation nor apoptosis of gingival connective cells in monkeys.

Granuloma periférico de células gigantes: histopatologia e imunohistoquímica anti-PCNA e anti-a-actina de músculo liso: análise quantitativa / Peripheral giant cell granuloa: histopatology and anti-PCNA immunohistochemistry and anti-a-actine of smooth muscle: quantitative analysis

O granuloma periférico de células gigantes (GPCG) é uma lesão reacional freqüentemente encontrada no periodonto. O objetivo do presente estudo foi avaliar estas lesões, através da histopatologia, estudo das fibras colágenas e elásticas, imunohistoquímica anti-a-actina de músculo liso para avaliação dos vasos e a atividade proliferativa através da imunohistoquímica anti-PCNA. Foram selecionadas 26 lesões de GPCG incluídas em blocos de parafina. Não houve diferenças estatisticamente significantes entre indivíduos de diferentes sexos, idades e achados histopatológicos com relação a fibras colágenas, fibras elásticas e células gigantes. A densidade de volume (Vv) dos vasos foi estatisticamente significante maior em indivíduos com mais de 18 anos quando comparados com menores de 18 anos. As células gigantes foram PCNA negativas e o Vv de PCNA também não mostrou diferenças estatisticamente significantes entre indivíduos de diferentes sexos, idades e achados histopatológicos. O volume ocupado por vasos, fibras colágenas e elásticas e células gigantes nas lesões de GPCG representou cerca de 25% do volume total. Os resultados deste estudo reforçam o comportamento reacional das lesões de GPCG.

Expressäo imuno-histoquímica da vimentina e do HHF-35 em fibroma de células gigantes, hiperplasia fibrosa e fibroma da mucosa oral / Immunohistochemical exppression of vimentin and HHF-35 in giant cell fibroma, fibrous hyperplasia and fibroma of the oral mucosa

O fibroma de células gigantes, a hiperplasia fibrosa e o fibroma constituem algumas das mais freqüentes lesöes fibrosas orais, compartilhando características clínicas e histopatológicas. Este estudo teve o objetivo de investigar a imunorreatividade das células gigantes estreladas mono, bi ou multinucleadas, características do fibroma de células gigantes e, ocasionalmente presentes na hiperplasia fibrosa e no fibroma, a anticorpos anti-vimentina e anti-actina de músculo (HHF-35), visando detectar características fenotípicas destas células. Os resultados demonstraram que na maioria dos casos houve imunorreatividade para a vimentina, sugerindo um fenótipo fibroblástico para estas células

Actin versus vimentin in myoepithelial cells of salivary gland tumors: a comparative study / Actina versus vimentina em células mioepiteliais de tumores de glândulas salivares: estudo comparativo

Vimentin versus actin expression was immunohistochemically studied in myoepithelial cells of 24 salivary gland tumors in which the participation of myoepithelial cells as a tumoral component has been postulated: two basal adenomas, seven pleomorphic adenomas, two myoepithelial, seven adenoid cystic carcinomas (two tubular, four cribriform, one solid), six polimorphous low-grade adenocarcinomas. Immunostaining was carried out in formalin-fixed tissue serial sections (3 µm) by the avidin-biotin method, using the antibody vimentin (Dako Corp., Carpenteria, Calif.) and the antibody HHF35 anti-muscle actin (Enzo Biochemical, N.Y.). Our results have confirmed positive staining for vimentin in all salivary tumors studied, although in some tumors it was only in focal areas. The staining for the HHF35 antibody to muscle actin was only consistently found in the adenoid cystic carcinomas of the tubular and cribriform patterns. This study suggests that actin is at least somewhat replace by vimentin in neoplastic tumoral cells. Therefore vimentin can be used to define the participation and distribution of myoepithelial cells in these tumors