Objective: The knowledge about glycoproteome in skeletal muscle is limited and most of the information come from studies on aberrant glycosylation in inherited muscle diseases. This work describes the intracellular changes in sialylation of skeletal muscle fiber during the process of its transformation into a nurse cell after occupation by the nematode Trichinella spiralis. Results: The study was performed at defined time points post infection. Lectin histochemistry with TML, MAL and SNA detected increased production of sialylated glycoproteins within the affected fibers, and it was evaluated by acidic ninhydrin reaction in muscle homogenates. Increase of total sialyltransferase activity was estimated by measurement of incorporated CMP-N-[14 C]-acetylneuraminic acid, and immunohistochemistry showed higher expression of α-2,3-sialyltransferases II and IV within the affected fibers. SNA lectin affino-blots showed at least four protein bands with approximate molecular weight between 126 and 159 kDa, which were more reactive to SNA compared to their counterparts from the control samples. Conclusion: It is evident that skeletal muscle injury induced by Trichinella activates biosynthesis of glycoproteins bearing sialic acids, which are not present in the normal muscle fiber. However, the protein identity, function and the biological significance of these sialoglycoproteins remain to be elucidated. BG051PO001 Objective: Protozoal and helminthic infestations of the central nervous system (CNS) are rare and their incidence is less than 1 %. They are more common among children, the elderly and immunocompromised individuals and tend to follow a fatal course. Method: We report 2 cases of cerebral amebic abscess occurring in 2 immunocompetent men. Results: They were 2 men aged of 43 and 18 years old. Headache; altered mental status and fever were common presenting symptoms. In the 2 cases the diagnosis of cerebral abscess was suspected on cerebral CT scan. Histopathologic analysis revealed extensive areas of necrosis and hemorrhage with granulomatous lymphoplasmacytic inflammatory infiltrate. other conditions such as malignancy and tuberculosis. It occurs normally in the mouth and tonsils, however, it can sometimes occur in the chest, abdomen, pelvis or other areas of the body. Method: We describe a retrospective study about 56 cases of actinomycosis diagnosed over a 21-year-period (1990-2011) . Results: The 56 cases were divided in 20 cervicofacial actinomycosis, 18 genito-urinary tract actinomycosis, 8 cutaneous actinomycosis, 7 abdominal actinomycosis and 3 cases occur in central nervous system. All patients were symptomatic. The most frequent symptom consisted in fever. The diagnosis was based on histologic study in all cases. Tissue histologic studies show suppurative and granulomatous inflammatory changes, connective proliferation, in which bacteria form typical granular colonies composed of radiating gram positive filaments. Conclusion: Diagnosis of actinomycosis is usually made retrospectively by means of histologic examination of surgically obtained specimens, but rarely preoperatively. It is generally treated with long term antibiotics.