RESUMO
A wide interobserver variation is seen even among competent histopathologists in the routine diagnosis of cervical intraepithelial neoplasia (CIN). As a result, early detection of low-grade CIN (CIN 1) lesions, in particular, remains a major challenge both in routine diagnosis and in cervical screening. In this chapter, the salient diagnostic features of human papillomavirus infection and CIN lesions are demonstrated.
Assuntos
Papillomaviridae , Infecções por Papillomavirus/patologia , Displasia do Colo do Útero/patologia , Sequência de Bases , Colo do Útero/patologia , Colo do Útero/virologia , Primers do DNA , Feminino , Humanos , Invasividade Neoplásica , Papillomaviridae/classificação , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Displasia do Colo do Útero/virologiaRESUMO
Vasculogenesis and angiogenesis are regulated by the capacity of endothelial cells to adhere to each other and form new tubes. The presence and role of junctional adhesion molecules during physiological vasculogenesis is unknown. Using ultrastructural and immunocytochemical approaches, we compared the junctional phenotype of developing vessels of the first-trimester human placenta with vessels in the last trimester; the latter include newly formed terminal capillaries and the quiescent vascular bed. First-trimester placental vessels contained the adherens junctional molecules, vascular endothelial cadherin and alpha- and beta-catenin but lacked plakoglobin, the component of fully differentiated adherens junctions. Furthermore, these vessels did not contain the transmembrane tight junctional molecules occludin and claudin-1 and -2. This profile reflects the phenotype of terminal capillaries but differs from large vessels of the full-term placenta. Electron microscopic studies revealed that endothelial tight junctions are present in the first-trimester placenta. Thus, occludin and claudin-1 appear to play no part in the formation of endothelial tight junctions, but are a later requirement. In the early placenta, the predominant growth factor appears to be vascular endothelial growth factor (VEGF), whilst at term, angiopoietin-1 was present in large vessels, with intense angiopoietin-2 immunofluorescence (and VEGF) located in terminal villous capillaries. Thus, endothelial junctions in the human placenta possess two distinct molecular phenotypes, i.e. stable or dynamic, dependent on maturity and plasticity. These distinct phenotypes may be influenced by the angiopoietins/VEGF present in the placenta.
