RESUMO
Pathogenicity of Treponema pallidum may depend upon the binding of Treponema pallidum to matrix proteins, especially to fibronectin. Infectious organism or cell to matrix interactions are mediated by a family of adhesion molecule receptors known as integrins. Once in the host, the pathogenic Treponema pallidumdum adheres to the vascular endothelium and readily penetrates surrounding tissues. Fibronectin plays an important role in the mediation of the attachment of Treponema pallidum to host cells, including endothelial cells. We found that the binding of Treponema pallidum to human dermal microvascular endothelial cells and to a glass surface coated with fibronectin is inhibited by the presence of arginine-glycine- aspartic acid (RGD), and analysis of the surface receptor revealed an antigenic similarity to an integrin molecule, namely alpha5. This ability to adhere to host endothelium and fibronectin is quite unique to T. pallidum among the treponemes, and may be a key pathogenic factor.
Assuntos
Humanos , Proteínas de Transporte/fisiologia , Membrana Celular/metabolismo , Células Cultivadas , Endotélio Vascular/citologia , Proteínas da Matriz Extracelular/metabolismo , Microcirculação , Pele/irrigação sanguínea , Treponema pallidum/fisiologiaRESUMO
A poroma is usually described as a benign neoplasm arising from ductal epithelium of eccrine gland. However, in recent years there have been several reports on poromas featuring with combined sebaceous, follicular, and ductal differentiation, and thus establishment of this separate disease entity, "apocrine poroma" may well be justified considering the common embryologic origin of folliculosebaceous-apocrine unit. In our case, the tumor presented as a dark red nodule on the pubic area, being revealed as poroid neoplasm with folliculosebaceous components embedded in the lobules. Immunohistochemically, poroid cells stained with lysozyme. Taking the immunohistochemical staining results as well as the histopathologic findings of folliculosebaceous differentiation into consideration, we have concluded that this tumor is a case of an "apocrine poroma".
Assuntos
Glândulas Écrinas , Epitélio , Muramidase , PoromaRESUMO
Syringomas are relatively common benign adnexal tumors that are usually located on the lower eyelids, although affecting other areas, including cheek, axillae, abdomen and vulva. Acral syringomas, located on distal extremities are vary rare and there is only one case reported in Korea. We report a case of a healthy 21-year-old woman with multiple, reddish brown syringomas located on both forearms and the dorsa of hands. The histologic findings were typical of syringomas.