Esophageal tumors: The keys to diagnosis by pneumo-computed tomography.

OBJECTIVE: To review and describe the most characteristic radiological findings of the most frequent esophageal tumor lesions, with emphasis on the esophago-gastric distention technique pneumo-computed tomography performed in our institution. To know the main advantage of this distension technique. CONCLUSION: Malignant tumor lesions (predominantly squamous cell carcinoma in the mid esophagus and adenocarcinoma in the distal esophagus) present as asymmetric wall thickening, mucosal irregularity, or mass extending into adjacent organs with lymph node involvement. Benign tumors (mainly leiomyoma being the most frequent and others such as lipoma) present as endoluminal growth, with defined borders and homogeneous attenuation. Post-contrast enhancement is scarce or moderate. The technique of computed tomography pneumotomography technique achieves an additional distension of the esophageal lumen in all cases. It allows delimiting the superior and inferior borders of the lesions, helping the surgeon to define the therapeutic strategy.

Dissimilar expression of multidrug resistance mdr1 and bcrp by the replication of hepatitis C virus: role of the nonstructural 5A protein.

Multidrug resistance associated with the overexpression of ATP-dependent binding cassette (ABC) proteins is widely accepted as an important cause of treatment failure in patients with neoplastic or infectious diseases. Some of them play also a pivotal role in detoxification processes. Herein, we investigated the effect of hepatitis C virus (HCV) replication and nonstructural 5A (NS5A) protein on the expression and functional activity of two ABC transport proteins: MDR1 and BCRP. RT-quantitative real-time polymerase chain reaction (qPCR) was carried out for mdr1 and bcrp mRNAs in both Huh7 cells expressing NS5A and Huh7.5 cells containing either full-length- or subgenomic-HCV replicon systems. The functional activity of these pumps was studied by performing a dye efflux assay with DiOC2 and Rhodamine 123. A dose-dependent down-regulation of mdr1 expression was documented in Huh7 cells expressing the NS5A protein, as well as in both replicon systems. In contrast, a significant increase of bcrp expression in both systems was recorded, which were in full agreement with the dye efflux assay results. These results warrant further in vivo studies in HCV patients with cholestasis and/or patients that are refractive to the pharmacotherapy due to the activity of these pumps.

The expression levels of the translational factors eEF1A 1/2 correlate with cell growth but not apoptosis in hepatocellular carcinoma cell lines with different differentiation grade.

Despite the involvement of the elongation factors eEF1A (eEF1A1 and eEF1A2) in the development of different cancers no information is available on their possible contribution to the biology of hepatocellular carcinoma (HCC). We investigated the expression of both forms of eEF1A in HepG2 and JHH6 cell lines considered to be a good in vitro model of HCC at different stage of differentiation. Our data indicate that the mRNA amount of eEF1A1 is increased in both cell lines as compared to normal liver tissue, but eEF1A2 mRNA level is markedly increased only in JHH6. Moreover, the less differentiated cell line JHH6 displays higher EEF1A1 and EEF1A2 mRNAs levels and an higher nuclear-enriched/cytoplasm ratio of EEF1A protein compared to the better differentiated HepG2 cell line. Over-expression depends only partially on gene amplification. The more abundant mRNA levels and the higher nuclear-enriched/cytoplasm ratio of eEF1A in JHH6 neither correlate with apoptosis resistance nor with proliferation rate in sub-confluent cells. However, in confluent cells, a clear tendency to maintain JHH6 into the cell cycle was observed. In conclusion, we document the increased mRNA levels of EEF1A genes in HCC cell lines compared to normal liver. Additionally, we show the increased nuclear-enriched/cytoplasmic protein ratio of eEF1A and the marked raise of the expression of both eEF1A forms in JHH6 compared to HepG2, suggesting the possibility that eEF1A forms might become a relevant markers related to HCC tumor phenotype.

The use of carbon dioxide laser in pit and fissure caries prevention: clinical evaluation.

In this 4-year follow-up in vivo controlled study, 112 human permanent first molars from children between 6 and 11 years old were used to investigate the viability of the carbon dioxide (CO2) laser in promoting caries-free occlusal surfaces in permanent molars as an isolated form of treatment or associated with conventional fissure sealants. The findings suggest that occlusal caries prevention only by means of CO2 laser irradiation is not effective; that the utilization of photoactivated sealants, as well as its association with CO2 laser, applied over the occlusal fissures, are effective means of preventing occlusal caries, and that the application of CO2 laser over occlusal fissures prior to the application of a photoactivated fissure sealant improves the retention of the sealant.