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Biomedical subjects

I Nenci

Publications and source records attributed to I Nenci.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Combined and sequential expression of p53, Rb, Ras and Bcl-2 in bronchial preneoplastic lesions.

AIMS AND BACKGROUND: Several simple molecular abnormalities have been detected in bronchial preneoplastic lesions, but the simultaneous presence of these alterations has been scarcely investigated. METHODS: We studied, by an immunohistochemical method, the expression of p53, Rb, Ras and Bcl-2 in 65 samples from surgical specimens and diagnostic biopsies selected for the presence of preneoplastic changes in the bronchial epithelium. To perform an analysis of the combined expression of all markers in the same areas, we accurately mapped every consecutive section on which immunohistochemical reactions were performed, subdividing each specimen into 25x microscopic fields, which allowed good topographical mapping. RESULTS: It was found that the frequency of p53-positive and Rb-negative microscopic fields was directly related to the morphological grading of lesions. On the other hand, Ras expression characterized high-grade lesions not showing squamous differentiation (non-squamous Cis). Regarding Bcl-2 expression, only slight differences in positivity distribution were found between the different lesions. More interesting was the parallel evaluation of all markers in the same areas: one of the main patterns, found to be correlated with the severity of histopathological features, was characterized by combined p53 hyperexpression/Rb hypoexpression; furthermore, when Ras and Bcl-2 hyperexpression were superimposed to the above pattern, the former mainly characterized non-squamous Cis, while the latter was present only in high-grade squamous lesions. However, the most frequently encountered pattern did not show any alteration of the studied markers, suggesting that other mechanisms could be involved in bronchial carcinogenesis. CONCLUSIONS: The detection of combined molecular abnormalities in bronchial preneoplasia could clarify the steps involved in lung carcinogenesis; furthermore, a simple and inexpensive method, such as immunohistochemistry, could be routinely applied also to cytologic specimens in order to detect those lesions, or patients, that are prone to progression towards lung cancer.

Biomarkers, Tumor↗
PubMedDate not supplied

Quality control for biomarker determination in oncology: the experience of the Italian Network for Quality Assessment of Tumor Biomarkers (INQAT).

Biomarker analysis and evaluation in oncology is the product of a number of processes (including managerial, technical and interpretation steps) which need to be monitored and controlled to prevent and correct errors and guarantee a satisfactory level of quality. Several biomarkers have recently moved to clinical validation studies and successively to clinical practice without any definition of standard procedures and/or quality control (QC) schemes necessary to guarantee the reproducibility of the laboratory information. In Italy several national scientific societies and single researchers have activated -- often on a pilot level -- specific external quality assessment protocols, thereby potentially jeopardizing the clinical reality even further. In view of the seriousness of the problem, in 1998 the Italian Ministry of Health sponsored a National Survey Project to coordinate and standardize the procedures and to develop QC programs for the analysis of cancer biomarkers of potential clinical relevance. Twelve QC programs focused on biomarkers and concerning morphological, immunohistochemical, biochemical, molecular, and immunoenzymatic assays were coordinated and implemented. Specifically, external QC programs for the analytical phase of immunohistochemical p53, Bcl-2, c-erb-2/neu/HER2, and microvessel density determination, of morphological evaluation of tumor differentiation grade, and of molecular p53 analysis were activated for the first time within the project. Several hundreds of Italian laboratories took part in these QC programs, the results of which are available on the web site of the Network (www.cqlaboncologico.it). Financial support from the Italian Government and the National Research Council (CNR) will guarantee the pursuit of activities that will be extended to new biomarkers, to preanalytical phases of the assays, and to revision of the criteria of clinical usefulness for evaluating the cost/benefit ratio.

Autoradiography↗
PubMedDate not supplied

Fine needle aspiration cytology of thyroid gland diseases.

From 1982 to 1987, 2,433 lesions of the thyroid gland in 1,796 patients were examined by fine needle aspiration (FNA). Cytopathology classified 66.91% of the aspirates as benign, 10.76% as thyroiditis, 4.89% as suspected (unspecified) neoplasia, 1.31% as positive for malignancy and 16.11% (392) as unsatisfactory. The histologic diagnoses in 257 cases were compared with cytologic diagnoses to determine the accuracy of FNA cytology of thyroid lesions, yielding a sensitivity of 71.43%, a specificity of 100% and an accuracy of 95.09%. This data strongly supports thyroid FNA as an important preoperative diagnostic tool. Follicular carcinomas were difficult to cytologically differentiate from nonmalignant follicular neoplasms, and papillary thyroid carcinomas less than 2 cm in diameter in elderly patients were frequently misdiagnosed or diagnosed only as "suspect lesion."

Adult↗
PubMedDate not supplied

Immunocytochemical detection of estrogen receptors by staining with monoclonal antibodies on cytologic specimens of human breast cancer.

A study was undertaken to test the possibility of determining the estrogen receptor (ER) content in human breast cancers by staining with commercial specific monoclonal antibodies (MAbs) on cytologic specimens (touch imprints and fine needle aspirates). The aspirates were suspended in a cell culture medium and cytocentrifuged onto slides to preserve their morphologic characteristics and to allow a proper immunocytochemical staining for ERs. MAb staining for ER was also performed on the respective surgical samples. The staining of cytologic samples for ER showed 100% specificity and 95% sensitivity in comparison to the staining of the histologic samples. Moreover, comparison of the percentage of stained cells in the cytologic specimens to the ER content in the respective surgical specimens, as assayed by the dextran-coated charcoal method, showed the MAb staining of cytologic samples to have 94% specificity and 100% sensitivity. These results support the reliability of MAb staining for ERs in cytologic samples and suggest that it could be the assay of choice in particular clinical settings in the evaluation of primary and recurrent breast cancers.

Antibodies, Monoclonal↗