Paper # 096

Versión en Español

Thymic microenvironmental changes in human congenital syphilis

Eliene C. Fonseca, Mônica P. Almeida, Évlin H. Maia, Dora M. F. Menezes and Wilson Savino*

[Title] [Introduction] [Results] [Discussion] [Pictures] [Bibliography]

MATERIALS & METHODS

Thymic tissue were obtained from necropsies of ten stillborn and four neonates dying from congenital syphilis, and two controls with normal thymuses, died due to prematurity and intrauterine anoxy.

HISTOLOGY: Thymus fragments were routinely processed, paraffin embedded and 4-5µm sections were stained with hematoxilin-eosin, Gomori's reticulin and Gomori's trichromic. Picrosyrius stain polarization method was used to differentiate type I collagen (very birrefringent, with thick yellow or red fibers in a dark background) from type III collagen -less refringent, thin greenish fibers (22).

IMMUNOFLUORESCENCE: antibodies specifically recognizing distinct extracellular matrix components were obtained from Pasteur Institute - Lyon, France. All were polyclonal immunosera anti types I, III and IV collagens. Fibronectin, laminin and all other antiserum did not exhibit any cross-reactivity with any other ECM molecule. The goat anti-rabbit Ig antibodies coupled to either fluorescein or rhodamine and fluorescein-labled anti-human IgG and IgM were purchased from Biosys (Coupiegne, France).

IMMUNOPEROXIDASE: Polyclonal antibody anti-human cytokeratin (wide spectrum) immunostained thymic epithelial cells (TEC) network. Goat anti-rabbit-biotinilated antibody and streptavidin-biotin-peroxidase complex were used to perform the immunoreaction (all reagents from Dako Corporation, Carpinteria, USA).

(-) negative

(±) trace of positivity

(+) weak positivity

(++) positive

(+++) strong positivity

• Title
• Introduction
• Results
• Pictures
• Discussion
• Bibliography