Biomedical subjects

Samuel Navarro

Publications and source records attributed to Samuel Navarro.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Study of proliferation and apoptosis in neuroblastoma. Their relation with other prognostic factors.

BACKGROUND: Our objective was to study the proliferation and apoptotic process in 111 cases of neuroblastoma (NB) and to seek their relationship with other prognostic factors and survival. METHODS: Immunohistochemistry following ABC peroxidase was carried out for PCNA, Ki-67, bcl-2, and p53 proteins. Apoptosis analysis was performed with in situ detection of chromosomal breakdown. Molecular detection of DNA ladders by electrophoresis and amplification of MYCN was studied with PCR and Southern blot. Statistical study was performed with Pearson chi(2) and Kruskal-Wallis tests and Cox regression. RESULTS: Our results indicate that proliferative factors PCNA and Ki-67 were correlated to each other as well as to advanced stage and MYCN amplification. Regarding apoptosis, we found expression of bcl-2 protein in cases of NB without differentiation and advanced stages. p53 protein showed an inverse relation with bcl-2 and cell death measured by assay protein. In situ determination of apoptosis was found mainly in differentiated and stage 4s cases. Multivariate analysis revealed protein as the most independent risk factor of our study. CONCLUSIONS: The study of cellular proliferation and apoptosis contributes with information of prognostic value that could be applied to the design of different protocols for treatment of neuroblastoma.

Apoptosis↗

PubMedDate not supplied

Prognostic significance of cell proliferation in human neuroblastoma: comparison with other prognostic factors.

Peripheral neuroblastic tumors (PNT), are heterogeneous neoplasms that include neuroblastoma (NB), ganglioneuroblastoma (GNB) and ganglioneuroma (GN) and present great biological heterogeneity. There are few reports analyzing PCNA and Ki-67 expression in PNT; however, controversy exists concerning the specificity of PCNA as a real proliferative marker. The objective of our study was to determine which of these cellular proliferation markers is more specific on cellular cycle and could contribute with more information on the cell cycle. We found that PCNA was expressed in NB unfavourable cases, with MYCN amplification and high mitosis-karyorrhexis-index (MKI). Whereas, Ki-67 showed statistical significance regarding cases unfavourable with intermediate and high MKI, aneuploid and stages 3 and 4. Survival showed that patients with tumor not expressing Ki-67 (MIB1) lived longer than those without PCNA (88.93 vs 74.05%). We conclude that Ki-67 expression permits reliable detection of the cellular proliferation neuroblastoma fraction and provides useful prognostic information when associated with other biological factors.

Aneuploidy↗

PubMedDate not supplied

Histological tumor grade correlates with HER2/c-erB-2 status in invasive breast cancer: a comparative analysis between immunohistochemical (CB11 clone and Herceptest), FISH and differential PCR procedures.

There is a growing clinical demand for analysis of the HER2/c-erbB-2 (HER2) status of breast cancer specimens because it provides valuable prognostic, predictive and therapeutic information. In this sense, a variety of methods is available for detection of HER2 status, although to date a reliable and sensitive test does not exist. In order to choose the most suitable procedure to assess HER2 status, we analyzed 102 invasive breast cancers for HER2 overexpression by means of immunohistochemistry (IHC), with the CB11 Mo-Ab and the Hercep Test kit, and for HER2 gene amplification by fluorescence in situ hyubridization (FISH) and differential PCR (dPCR). HER2 overexpression, determined by CB11 (group C) and HercepTest (2+ and 3+), was observed in 19 samples (18.6%) whereas genetic amplification was detected in 31 (30.4%) and 14 (13.7%) cases by FISH and dPCR, respectively. The majority of overexpressed/amplified specimens corresponded to high grade tumors. We found concordances of 78-80% and 93-95% between IHC vs FISH and IHC vs dPCR, respectively. Considering FISH procedure as a gold standard, we found a sensitivity and specificity of 48.4% and 94.3% for CB11 antibody, of 45.2% and 92.9% for HercepTest, and of 45.2% and for 100% for the dPCR. Thus, considering the sensitivity, specificity and the high grade of concordance between IHC and dPCR, we suggest the use of IHC for assessing HER2 status. However, due that sensitivity of IHC test is lower than FISH, we also suggest to carry out FISH on those cass in which IHC results are not definitive for its clinical evaluation.

Adenocarcinoma↗