Biomedical subjects

S Staibano

Publications and source records attributed to S Staibano.

76 records · Page 5Linked to original sources

PubMedDate not supplied

Scatter factor receptor (c-Met) as possible prognostic factor in patients with oral squamous cell carcinoma.

This report was performed to study the biological role of c-Met in oral tumorigenesis by analyzing its expression in relation to clinicopathological features. Seventy-three cases of oral squamous cell carcinoma and 10 of normal mucosa were analysed for c-Met expression by immunohistochemistry. Normal oral squamous epithelium showed absent or low membranous positivity in the intermediate (malpighian-spinous) layer. Fifty-seven cases (78%) of carcinoma showed immunopositivity, with a prevalently membranous positivity and scattered areas also showing a cytoplasmic localization. Sixteen cases of carcinoma (22%) showed no positivity for c-Met. Among positive tumours, well-differentiated areas showed low or absent cytoplasmic positivity, while low-differentiated areas showed both membranous and cytoplasmic positivity. There was no statistically significant correlation between c-Met expression and sex, recurrence, staging or grading. The frequency of lymph node metastases was higher in c-Met-positive tumours (17/57, 29%) than in c-Met-negative ones (4/16, 25%). When analysed for prognostic significance, patients with negative/reduced c-Met expression had better survival rates than patients with high expression. The difference between survival rates was statistically significant (p<0.05). These data suggest that c-Met expression may be useful to identify cases of oral squamous cell carcinoma with a more aggressive and invasive phenotype.

Adult↗

PubMedDate not supplied

Tumor infiltrating lymphocytes in uveal melanoma: a link with clinical behavior?

Experimental and clinical evidence indicate that immunological mechanisms might be important in the clinical course of uveal malignant melanoma (UMM). We analyzed the amount and phenotype of tumor infiltrating lymphocytes (TIL) and the expression of the apoptosis-inducing molecule Fas and its ligand, FasL, on tumor cells and TIL in a selected series of UMM with the aim to establish if a correlation between their expression and the clinical behavior of UMM exists. TIL phenotype and Fas/FasL expression were evaluated by immunohistochemistry in 61 cases of formalin-fixed, paraffin-embedded UMM. Results were compared with the follow-up data of patients. Most of the UMM showed a prevalence of CD8+ CD3+ T lymphocytes, or CD4+ and CD8+ cells in equal amounts. UMM showed a variable expression of FasL, ranging from 0 to > 40% of neoplastic cells. Fas was always expressed in TIL, although with a variable extent. A subgroup of UMM showed in TIL a strongly reduced or even absent expression of TCR zeta-chain, involved in activation of T-lymphocytes. This subgroup was characterized by a worse outcome. We hypothesized that an impaired cytotoxic immune response due to the loss of the zeta-chain expression plays a primary role in the biological course of UMM. Our results indicate that the overcoming of the impairment of TCR function may represent a prerequisite for the development of new therapeutic strategies for managing UMM, suggesting that elimination of tumor cells may be possible by activation of cytotoxic cells present within ocular melanomas.

Adult↗

PubMedDate not supplied

Histiocytosis X of the thyroid gland.

Histiocytosis X rarely involves the thyroid gland and occurs as one of the unusual manifestations of systemic diseases. Diagnosis is based on the identification of the Langerhans' cells in an appropriate background. We report a case of histiocytosis X confined to the thyroid gland that represents the primary manifestation of the disease. A careful histological, immunohistochemical and ultrastructural study has been performed and problems of differential diagnosis are discussed.

Female↗

PubMedDate not supplied

[The distribution of intermediate filaments, histiocytic antigens and neural crest-related antigens in the adult dental pulp. An immunocytochemical approach].

MATERIALS AND METHODS: Ten human healthy teeth were extracted for orthodontic or surgical purposes and processed for histological and immunocytochemical examination with the streptavidin-biotin-peroxidase method. Highly purified antibodies were used to reveal the distribution of intermediate filaments (vimentin, desmin, alpha-smooth muscle actin), histiocytic antigens (alpha-1-antitrypsin, lysozyme), neural and neural-crest-associated antigens (neuron-specific enolase, chromogranin-A, S-100, synaptophysin, glial fibrillary acidic protein, neurofilaments) in the adult pulp tissue. RESULTS: Vimentin immunostaining was strongly positive in the network of pulpal fibroblasts. Desmin and alpha-smooth muscle actin were present only in the vessel walls. Staining for alpha-1-antitrypsin and lysozyme reveals a number of macrophage-like cells in the central portion of the pulp. Macrophages were the most dominating immunocompetent cells. Negative immunostaining for chromogranin-A demonstrated the absence of neuroendocrine antigens in the adult dental pulp. Immunostaining for neuron-specific enolase, S-100 protein, synaptophysin, glial fibrillary acidic protein and neurofilaments were positive, with different intensity, in nerve fibres, but no pulp cell was found to be immunoreactive. CONCLUSIONS: The conclusion is drawn that the lack of labelling of pulp cells by the neural associated antibodies could be due to differentiation processes during tissue development.

Adult↗