Biomedical subjects

P Ragazzini

Publications and source records attributed to P Ragazzini.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Bone hemangioendothelioma: an immunohistochemical study related to histological malignancy and proliferative activity (NORs).

AIMS AND BACKGROUND: Forty-four bone hemangioendotheliomas (HEs) of different histological grades were studied to evaluate the expression and distribution of laminin, type IV collagen, cathepsin G and cathepsin D in cell differentiation and malignancy. RESULTS: In poorly-differentiated HEs the discontinuous distribution of laminin and type IV collagen around angioblastic cords, tubes and cavities revealed an irregular and disorganized basement membrane (BM) architecture corresponding to an increased cell proliferation and secretion of cathepsin D and cathepsin G by tumor cells. CONCLUSIONS: The mean nucleolar organizer region (NOR) area, as a measure of cell proliferation, was significantly higher in grade 4 malignancies than in lower grades, revealing novel prognostic parameters.

Adult↗

PubMedDate not supplied

Increased c-myc oncogene expression in Ewing's sarcoma: correlation with Ki67 proliferation index.

AIMS AND BACKGROUND: Ewing's sarcoma is a highly malignant musculoskeletal tumor composed of small round cells. Although important results have been achieved with surgery associated with chemotherapy, recurrent disease is still a major problem. In order to define new prognostic factors useful for therapeutic decision-making, we conducted a study on 38 Ewing's sarcoma samples in which c-myc oncogene expression and Ki67 proliferation index were correlated with clinical outcome. METHODS AND STUDY DESIGN: Nineteen patients developed metastases during follow-up and 10 of these patients died. C-myc and Ki67 protein expression was evaluated by immunohistochemistry performed on 5 microm formalin-fixed and paraffin-embedded sections, while the c-myc mRNA transcript was localized using in situ hybridization. RESULTS: A statistically positive correlation was found between c-myc protein and Ki67 (P = 0.001) and c-myc mRNA and Ki67 expression (P = 0.047). The 38 patients were divided into two groups using as the cutoff 50% of Ki67-positive cells. The disease-free survival and overall survival estimates were 68% and 90%, respectively, in the group of patients with a percentage of Ki67-positive cells <50%, and 25% and 50%, respectively, in the group with a percentage of Ki67-positive cells > or = 50%. The difference between the survival curves was statistically significant (P <0.05 and P <0.01). Furthermore, relapsed patients had a high and uniform expression of c-myc protein and mRNA compared to disease-free patients. CONCLUSION: These results suggest a possible role of the c-myc oncogene and Ki67 antigen in the malignant progression of Ewing's sarcoma.

Adolescent↗

PubMedDate not supplied

Additional methods of diagnosis in the histopathology of the musculoskeletal system.

In recent years because of their diagnostic importance techniques of immunohistochemistry have been increasingly employed; The use of specific cellular antibodies has allowed for the recognition of tumors of mesenchymal, epithelial, muscular, endothelial, and neuroendocrine origin, and, within these classes, for the revelation of different cellular populations. These techniques together with histochemical and ultramicroscopic studies help define not only the genesis but also the stage of differentiation and the cell function, which are important factors in the prognosis of tumors. These have proven to be particularly useful for the differential diagnosis of highly undifferentiated forms in which cellular morphology differs from that of the tissue of origin.

Bone Neoplasms↗