1,721,073 research outputs found
Multivariate analysis of prognostic factors in T3 N0 laryngeal carcinoma treated with total laryngectomy
No full textOBJECTIVE: The aim of our study was to clarify the real importance of 16 possible prognostic factors analyzed retrospectively for the disease-free interval and survival of a total of 327 patients with T3 N0 M0 laryngeal carcinoma treated with total laryngectomy. METHODS: The role of each possible prognostic factor and their joint effect was explored by Cox proportional hazard survival analysis. RESULTS and CONCLUSIONS: In a Cox univariate analysis for the whole group, tumor site, pattern of growth, tumor size, histologic grading, lymph node status, and the occurrence of postoperative complications were predictive of the risk of tumor recurrence. In univariate analysis, all these factors except for pattern of tumor growth, neck treatment and postoperative complications maintained their prognostic value when analyzed as predictors of survival; however, the loco-regional control of disease was the most significant one. In a Cox multivariate analysis tumor size, histologic grading and postoperative complications had a significant impact on disease-free survival, whereas only histologic grading and loco-regional failure apeared to be prognostic with a significant decrease in overall survival. Copyright © 2003 by the American Academy of Otolaryngology-Head and Neck Surgery Foundation, Inc
Correlation between nitric oxide synthase and cyclooxygenase-2 pathways in head and neck squamous cell carcinoma
No full textWe investigated the interactions between inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) pathways in head and neck squamous cell carcinomas (HNSCCs) and in two carcinoma cell lines. HNSCCs showed an up-regulation of both pathways which were strongly correlated with each other (p=0.02) and with tumor vascularization (p=0.0001 and p=0.008, respectively). In carcinoma cells, Escherichia coli lipopolysaccharide (LPS) and EGF treatment up-regulated both pathways. NOS inhibitor N(G)-monomethyl-L-arginine methyl ester (L-NAME) inhibited this up-regulation. LPS or EGF induced iNOS expression that was not altered by NOS or COX-2 inhibitors. Conversely, LPS or EGF promoted COX-2 expression that was decreased by L-NAME. The NO donor S-nitroso-acetyl-penicillamine (SNAP) up-regulated COX-2 pathway and this effect was reduced by the guanylate cyclase inhibitor methylene blue. Thus, in squamous carcinoma cells, NO increases the activity of COX-2 pathway and this effect is probably mediated by endocellular cGMP level, with potential implications on tumor growth, angiogenesis, and therapy
Cumulative prognostic value of p53 mutations and bcl-2 protein expression in head-and-neck cancer treated by radiotherapy
No full textWe investigated the prognostic significance of p53-gene mutation (exon 5-9) and bcl-2-protein expression in primary squamous-cell carcinoma of the head and neck (HNSCC) treated by curative radiotherapy (RT). Primary squamous-cell carcinomas for analysis were obtained from 85 consecutive head- and-neck-cancer patients, with complete follow-up data. We detected bcl-2 protein in 24% (20/85) of HNSCC studied; 38 (45%) of the 85 tumours had cells bearing p53 mutations. A strong association was observed between tobacco exposure and bcl-2-protein expression (p = 0.003), an association also evident in those patients who had a p53-mutated carcinoma (p = 0.049). Moreover, we found that most of the bcl-2-positive cancers (70%) were also mutated in the p53 gene (p = 0.010). In univariate and in multivariate analyses, the simultaneous detection of bcl-2 expression and a p53-gene mutation in a tumour biopsy specimen was associated with greater risk of locoregional failure (p = 0.002 and 0.001 respectively) and worse survival (p = 0.045 and 0.033) within 5 years in HNSCC patients treated by RT. The present study shows a cumulative prognostic value of simultaneous detection of bcl-2 over-expression and p53-gene aberration in some primary HNSCC treated with conventional RT, and provides further evidence for cross-talk between p53 and bcl-2, suggesting that these genes are important determinants of radiation-induced apoptosis, thereby modulating resistance to RT
Cyclooxygenase-2 Pathway Correlates with VEGF Expression in Head and Neck Cancer. Implications for Tumor Angiogenesis and Metastasis
No full textAbstractWe evaluated the role of COX-2 pathway in 35 head and neck cancers (HNCs) by analyzing COX-2 expression and prostaglandin E2 (PGE2) production in relation to tumor angiogenesis and lymph node metastasis. COX-2 activity was also correlated to vascular endothelial growth factor (VEGF) mRNA and protein expression. COX-2 mRNA and protein expression was higher in tumor samples than in normal mucosa. PGE2 levels were higher in the tumor front zone in comparison with tumor core and normal mucosa (P<0001). Specimens from patients with lymph node metastasis exhibited higher COX-2 protein expression (P=.0074), PGEZ levels (P=.0011) and microvessel density (P<.0001) than specimens from patients without metastasis. A significant correlation between COX-2 and tumor vascularization (rs=0.450, P=.007) as well as between COX-2 and microvessel density with VEGF expression in tumor tissues was found (rs=0.450, P=.007; rs=0.620, P=.0001, respectively). The induction of COX-2 mRNA and PGE2 synthesis by EGF and Escherichia coli lipopolysaccharide (LPS) in A-431 and SCC-9 cell lines, resulted in an increase in VEGF mRNA and protein production. Indomethacin and celecoxib reversed the EGF- and LPS-dependent COX-2, VEGF, and PGE2 increases. This study suggests a central role of COX-2 pathway in HNC angiogenesis by modulating VEGF production and indicates that COX-2 inhibitors may be useful in HNC treatment
Comparison of the usefulness of Doppler-derived deceleration time versus plasma brain natriuretic peptide to predict left ventricular remodeling after mechanical revascularization in patient with ST-elevationacute myocardial infarction and left ventricular systolic dysfunction.
No full textMinimally invasive versus traditional chest surgical approach in patients with reduced renal function.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
É NECESSARIO MIGLIORARE LA QUALITÀ ESPOSITIVA DEGLI ARTICOLI SCIENTIFICI. LA STIMA DELL'ACCURATEZZA DEGLI STUDI DIAGNOSTICI È CONDIZIONATA DALLA CHIARA DESCRIZIONE DELLA LORO STRUTTURA
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