NOVEL FAST ANALYTICAL METHODS FOR THE ANALYSIS OF FLUOXETINE IN PURE AND PHARMACEUTICAL DOSAGE FORM

Novel and accurate analytical methods were developed and validated for the characterization of Fluoxetine in its pure and pharmaceutical dosage form Prozac®. Fluoxetine was determined by IBA techniques (PIGE, PIXE and RBS). It has been also analyzed spectrophotometrically at 610 nm after oxidation with potassium permanganate in alkaline medium. In addition, Fluoxetine was kinetically determined using the initial rate method, the fixed absorbance method and the fixed time method. Moreover, a Gas chromatography - mass spectrometry technique is proposed for the investigation of Fluoxetine without a prederivatization phase. The spectrophotometric method was performed with a concentration array of 2-10 μg/mL at 610 nm and a regression coefficient (r) of 0.996. The fixed time method was the most suitable one to determine Fluoxetine with correlation coefficient value (r) of 0.9966. The Gas chromatography - mass spectrometry investigated the drug in a concentration range of 20-100 μg/mL and a regression coefficient (r) of 0.999. IBA analysis presented a precision of less than 3% and a very low limit of detection. Consequently, these proposed methods would be useful tools for determining Fluoxetine as all the assay results exposed satisfactory sensitivity, accuracy and reproducibilit

Oxidative Stress in Cancer

Contingent upon concentration, reactive oxygen species (ROS) influence cancer evolution in apparently contradictory ways, either initiating/stimulating tumorigenesis and supporting transformation/proliferation of cancer cells or causing cell death. To accommodate high ROS levels, tumor cells modify sulfur-based metabolism, NADPH generation, and the activity of antioxidant transcription factors. During initiation, genetic changes enable cell survival under high ROS levels by activating antioxidant transcription factors or increasing NADPH via the pentose phosphate pathway (PPP). During progression and metastasis, tumor cells adapt to oxidative stress by increasing NADPH in various ways, including activation of AMPK, the PPP, and reductive glutamine and folate metabolism

ICAR: endoscopic skull‐base surgery

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Poly-lactic acid nanoparticles (PLA-NP) promote physiological modifications in lung epithelial cells and are internalized by clathrin-coated pits and lipid rafts

BackgroundPoly-lactic acid nanoparticles (PLA-NP) are a type of polymeric NP, frequently used as nanomedicines, which have advantages over metallic NP such as the ability to maintain therapeutic drug levels for sustained periods of time. Despite PLA-NP being considered biocompatible, data concerning alterations in cellular physiology are scarce.MethodsWe conducted an extensive evaluation of PLA-NP biocompatibility in human lung epithelial A549 cells using high throughput screening and more complex methodologies. These included measurements of cytotoxicity, cell viability, immunomodulatory potential, and effects upon the cells’ proteome. We used non- and green-fluorescent PLA-NP with 63 and 66 nm diameters, respectively. Cells were exposed with concentrations of 2, 20, 100 and 200 µg/mL, for 24, 48 and 72 h, in most experiments. Moreover, possible endocytic mechanisms of internalization of PLA-NP were investigated, such as those involving caveolae, lipid rafts, macropinocytosis and clathrin-coated pits.ResultsCell viability and proliferation were not altered in response to PLA-NP. Multiplex analysis of secreted mediators revealed a low-level reduction of IL-12p70 and vascular epidermal growth factor (VEGF) in response to PLA-NP, while all other mediators assessed were unaffected. However, changes to the cells’ proteome were observed in response to PLA-NP, and, additionally, the cellular stress marker miR155 was found to reduce. In dual exposures of staurosporine (STS) with PLA-NP, PLA-NP enhanced susceptibility to STS-induced cell death. Finally, PLA-NP were rapidly internalized in association with clathrin-coated pits, and, to a lesser extent, with lipid rafts.ConclusionsThese data demonstrate that PLA-NP are internalized and, in general, tolerated by A549 cells, with no cytotoxicity and no secretion of pro-inflammatory mediators. However, PLA-NP exposure may induce modification of biological functions of A549 cells, which should be considered when designing drug delivery systems. Moreover, the pathways of PLA-NP internalization we detected could contribute to the improvement of selective uptake strategies

MUC1 Affects EGFR Trafficking and Signaling in Breast Cancer Cells

MUC1 is a large transmembrane glycoprotein that is overexpressed in about 90% of breast cancers. Importantly, MUC1 overexpression is not a mere consequence of breast tumorigenesis but can sufficiently induce breast cancer formation when overexpressed in the mammary gland. The oncogenic mechanism of MUC1 overexpression remains largely unknown. However, recent studies point towards an important role for MUC1 in signaling downstream of the epidermal growth factor receptor (EGFR), a member of the ErbB family of receptor tyrosine kinases, and a key mediator of tumorigenesis. Trafficking represents a critical aspect of MUC1 and EGFR biology, and both are endocytosed via a clathrin dependent pathway but follow different trafficking routes. While MUC1 is constitutively internalized and recycled back to the plasma membrane, EGFR is internalized in response to ligand binding and is ultimately trafficked to the lysosome to be degraded. EGFR degradation terminates its downstream signaling which when overactive can lead to cancer progression.In this work, we have demonstrated an important role for MUC1 in regulating EGFR trafficking. We showed that MUC1 expression can enhance the internalization of EGFR while inhibiting its ubiquitination. This results in a decrease in the degradation of the receptor and in an increased recycling in response to EGF. We then investigated the mechanism behind MUC1-dependent EGFR trafficking. We showed that, when MUC1 is present, EGFR colocalizes with MUC1 at the Rab11 and RME-1 positive perinuclear endocytic recycling compartment (ERC). Interestingly, MUC1 expression did not significantly alter the localization of EGFR at the Rab5-positive early endosome; However, MUC1 knockdown restored EGFR trafficking towards Rab7-positive late endosomes and away from the perinuclear ERC. These results describe a novel MUC1-dependent EGFR trafficking pathway in breast cancer cells. We investigated the effect of MUC1-dependent EGFR trafficking on EGFR signaling in cancer by analyzing tumor lysates from a Wnt-1 mouse model of breast cancer (MMTV-Wnt-1) crossed into a MUC1 overexpressing (MMFW) or a MUC1 null (WK) background. We observed an enhanced activation of ErbB1 and 2 but not ErbB3 in these tumors. This was accompanied by an increase in AKT but not MAPK pathway activation and in an increase in β-catenin and cyclinD1 expression. Taken together, our results identify MUC1 as a modulator of EGFR trafficking and describe a novel MUC1-dependent EGFR trafficking pathway. This altered EGFR trafficking results in enhanced EGFR activation and in the preferential activation of the PI3K/AKT pathway which could have significant implications for breast cancer biology and therapy

Critères d’évaluation tomodensitométriques et à l’échographie de contraste de la réponse tumorale aux traitements anti-angiogéniques des cancers du rein métastatiques

Our objective was to compare DCEUS at one month and the CT-scan at 2 months for the prediction of response in patients treated by tyrosine kinase inhibitors for metastatic renal cell carcinoma.We performed DCE-US in one target at baseline and D30. We selected patients with contrast-enhanced portal phase CT at baseline and after 2 months to calculate PFS. Response assessment using the Response Evaluation Criteria in Solid Tumors and Choi criteria was performed in targets including the DCE-US tumor. Results were correlated to the PFS. 81 patients were analyzed. All had DCEUS at baseline and one month. Thirty nine patients had CT-scan with contrast media injection for the Choi criteria analysis and were finally included. The median of follow-up was 18 months. The difference of PFS between the groups defined by this cut-point was 4 months (bad responders) and 14 months (good responders). Choi criteria has a great predictive value for PFS (p=0.0043). RECIST 1.1 cannot predict PFS in the early evaluation (p=0.1). The decrease of 90% of the AUC is not significant in our sub-group (p=0.14). Choi criteria has a great predictive value to early identify good responders. RECIST is not reliable. Results for DCE-US at one month are not significant probably due to a lack of statistical power.Notre objectif était de comparer l’échographie de contraste, les critères d’évaluation tomodensitométriques de la densité et de la taille dans l’appréciation précoce des patients atteints de cancer du rein métastatique, traités par inhibiteurs de la tyrosine-kinase. L’échographie de contraste était pratiquée avant traitement et à un mois. Nous avons sélectionné les patients ayant eu une tomodensitométrie avant traitement et à 2 mois pour calculer la survie sans progression. L’évaluation de la réponse au traitement a été réalisée à l’aide des critères RECIST 1.1 et ceux de Choi. Les résultats étaient rapportés à la survie sans progression (PFS). 81 patients ayant eu les deux échographies ont été inclus. 39 patients ayant eu les deux tomodensitométries au temps portal et de bonne qualité ont été analysés. La médiane de suivi était de 18 mois. Ceci permettait de séparer par la PFS les bons répondeurs (14 mois) des mauvais répondeurs (4 mois). Les critères de Choi ont permis de prédire la PFS de façon significative (p=0,0043), contrairement aux critères RECIST (p=0,1) et à l’aire sous la courbe mesurée en échographie de contraste (p=0,14). Ce dernier résultat est probablement du à un manque de puissance statistique compte tenu de l’effectif

The social context of tobacco products use among adolescents in Lebanon (MedSPAD-Lebanon)

AbstractBackgroundCurrent data from the Middle East suggest a rapid increase in the incidence of smoking water-pipes (narguileh in Lebanon) in parallel with cigarettes. The social context in which these two behaviors are initiated and associated has not been studied.MethodsData from a standardized questionnaire to measure the prevalence and practices related to cigarettes and narguileh consumption in a representative sample of 1097 children in grade 9 were extracted and analyzed for elements of the social context in which consumption occurs.Results and discussionAmong surveyed children (mean age 14.6), 3.9% were “frequent” cigarette smokers (more than nine times ever). Presence of parents and/or siblings who smoke is a key factor for initiation. Narguileh use is a social phenomenon, rarely smoked alone (<4%) with 19% of the surveyed children being “frequent” narguileh smokers (more than nine times ever). Almost half of these students (42%) have all their friends smoking narguileh.ConclusionsFurther analysis confirmed that narguileh use is now an accepted familial and social phenomenon, with restrictions apparently decreasing. These results necessitate drawing strategies to address this public health concern that is becoming more prevalent in Lebanon and elsewhere in the Middle East