Made available in DSpace on 2014-12-17T15:32:16Z (GMT). No. of bitstreams: 1 DeborahPPI.pdf: 1504501 bytes, checksum: a7d060d1016a25d3b60f572c27bd03bc (MD5) Previous issue date: 2008-10-14 / We investigated the immunohistochemistry expression of claudins -1 and -7 in ameloblastoma and in human dental germs on the pattern of distribution (focal, regional or diffuse), the cells that expressed (if central or peripheral) and the location of that expression in the cell components recital membrane, cytoplasm and nucleus. Among the 29 cases of ameloblastoma, 24 were type solid and 6 unicystic. In 7 mandibular specimens of human fetuses found dental germs from the stage of bud to the crown. We note that the pattern of expression in the dental germs was variable for claudinas studied according to the cell type and stage of differentiation and was invariate only in the cells of stellate reticulum. In epithelium internal of enamel organ, claudin-1 has been decreasing with the progression of differentiation as to claudina-7 that was found in the cells of the peripheral papilla. For ameloblastoma the expression was more significant than that observed in dental germs. Fisher s exact test no found association between the expression of claudinas cells in central and peripheral and the type of ameloblastoma (solid or unicystic). Thus, in general the claudin-1 was positive in the central cell of 93,1% of the cases and in peripheral cells of 51,7%. The claudin-7 was expressed in the cells of all cases central and peripheral cells from 89,7%. For both claudins the distribution was predominantly diffuse cells both in central and peripheral cells. Given our findings it is suggested that the expression of claudins may be indicative of the involvement of these molecules in morphogenetics events culminating with the dental development and that possibly influence the development of neoplastic ameloblastoma / Investigamos a express?o imuno-histoqu?mica das claudinas -1 e -7 em ameloblastomas e germes dentais humanos, avaliando o padr?o de distribui??o (focal, regional ou difuso), as c?lulas que as expressavam (central ou perif?rica) e a localiza??o dessa express?o nos constituintes celulares considerando membrana, citoplasma e n?cleo. Dentre os 29 casos de ameloblastomas, 23 eram do tipo s?lido e 6 unic?sticos. Nos 7 esp?cimes mandibulares de fetos humanos observamos germes dentais desde a fase de capuz at? a fase de coroa. Constatamos que o padr?o de express?o nos germes dentais foi vari?vel para as claudinas estudadas de acordo com o tipo celular e est?gio de diferencia??o assemelhando-se apenas nas c?lulas do ret?culo estrelado. No epit?lio interno a express?o da claudina-1 foi decrescente com a progress?o da diferencia??o enquanto para a claudina-7 foi verificada nas c?lulas perif?ricas da papila. Para os ameloblastomas, de forma geral, a express?o foi mais significativa do que aquela observada nos germes dentais. Foi aplicado o teste estat?stico de Fisher o qual n?o demonstrou associa??o entre a express?o das claudinas nas c?lulas centrais e perif?ricas e o tipo do ameloblastoma (s?lido ou unic?stico). De uma maneira geral, a claudina-1 foi positiva nas c?lulas centrais de 93,1% dos casos e nas c?lulas perif?ricas de 51,7%. A claudina-7 esteve expressa nas c?lulas centrais de todos os casos e nas c?lulas perif?ricas de 89,7%. Para ambas as claudinas a distribui??o foi predominantemente difusa tanto nas c?lulas centrais como nas c?lulas perif?ricas. Diante dos nossos achados sugere-se que a express?o das claudinas pode ser indicativa da participa??o destas mol?culas nos eventos morfogen?ticos que culminam com a forma??o dental e possivelmente influenciam o desenvolvimento neopl?sico dos ameloblastomas