Evaluación in vitro de las propiedades antivirales de extractos de Arachis hypogaea L. contra el virus del dengue serotipo 1

Dengue disease affects 50-100 million people every year worldwide. In Argentina, three serotypes circulate, with a major prevalence of DENV-1 (72%). Effective antiviral drugs are not currently available. Medicinal plants may contain bioactive principles capable of inhibiting the replication of the dengue virus, with Arachis hypogaea L. (peanut) standing out for its biological properties. The aim of the present work was to evaluate the antiviral activity of Tegument ethanolic extract (TEE) and Seed ethanolic extract (SEE) of peanuts against DENV-1 on Vero cells. TEE and SEE were obtained by simple alcoholic extraction. The 50% cytotoxic concentration (CC50) on Vero cells was determined by Neutral Red Uptake (NRU) and MTT assays at 7 days. Antiviral activity was then assessed throughout the replication cycle using the lysis plate reduction technique. Cell monolayers were infected with 50 PFU/well of DENV-1, and treated with TEE (30μg/mL) and SEE (300μg/mL) during adsorption and penetration and, in intracellular stages of replication, incubated 7 days at 37°C. Subsequently, the cells were fixed with formaldehyde solution (10%) and stained with violet crystal (1%). Lysis plates were counted and viral inhibition was determined. Antiviral action was then evaluated at different stages of the replication cycle using the same technique. Statistical analysis (t-test and ANOVA, p<0.05) was performed using Graph Pad Prism 6.0. The CC50 values were 169μg/mL and 65μg/mL for TEE and >1400μg/mL and 636μg/mL for SEE by NRU and MTT, respectively. The study of antiviral activity throughout the cycle of replication showed that TEE inhibited DENV-1 (92.5±0.9%) (p<0.001). The study of the target of action indicated that TEE acted in stages of viral adsorption and penetration (92.5±0.9%) but did not act in stages post-penetration (15.7±6.6%). Also, it exerted virucidal action (98±5.0.7%) and inhibited the virus (78±3.04%) in cellular pre-treatment (p<0.001). On the other hand, the SEE did not show inhibitory capacity against DENV-1 (23.1±2.9%). In conclusion, the data obtained demonstrates the potential application of tegument extract from peanut in the development of an antiviral phytotherapeutic against the dengue virus.La enfermedad del dengue afecta a 50-100 millones de personas cada año mundialmente. En Argentina, circulan tres serotipos, con presencia mayoritaria del DENV-1 (72%). No se dispone actualmente de medicamentos antivirales efectivos. Las plantas medicinales pueden contener principios bioactivos capaces de inhibir la replicación del virus del dengue, destacándose Arachis hypogaea L. (maní) por sus propiedades biológicas. El objetivo de este trabajo fue evaluar la actividad antiviral de los extractos etanólico de tegumento (EET) y semilla (EES) de maní frente a DENV-1 en células Vero. Los EET y EES se obtuvieron mediante extracción alcohólica simple. Se determinó la concentración citotóxica 50% (CC50) en células Vero, mediante captación de rojo neutro (RN) y reducción de MTT, a los 7 días. Luego, se evaluó la actividad antiviral durante todo el ciclo de replicación mediante la técnica de reducción de placas de lisis. Monocapas celulares fueron infectadas con 50 UFP/pocillo de DENV-1, y tratadas con EET (30μg/mL) y EES (300μg/mL) durante la adsorción y penetración y, en etapas intracelulares de replicación, se incubó 7 días a 37°C. Posteriormente, las células se fijaron con formaldehído (10%) y se tiñeron con cristal violeta (1%). Se contaron las placas de lisis y se determinó la inhibición viral. Luego, se evaluó la acción antiviral en diferentes etapas del ciclo de replicación empleando la misma técnica. Se realizó análisis estadístico (t-test y ANOVA, p<0,05) mediante Graph Pad Prism 6.0. Las CC50 fueron 169μg/mL y 65μg/mL  para EET y >1400μg/mL y 636μg/mL para EES por RN y MTT, respectivamente. El estudio de actividad antiviral en todo el ciclo mostró que EET inhibió en un 92,5±0,9% a DENV-1 (p<0,001). El estudio del blanco de acción indicó que EET actuó en etapas de Adsorción-Penetración viral (92,5±0,9%), sin acción en etapas posteriores a la penetración (15,7±6,6%). También, ejerció acción virucida (98,5±0,7%) e inhibió al virus un 78±3,04% en el pre-tratamiento celular (p<0,001). Por otra parte, el EES no mostró capacidad inhibitoria frente a DENV-1 (23,1±2,9%). En conclusión, los datos obtenidos demuestran la potencial aplicación del extracto de tegumento de maní en el desarrollo de un fitoterápico antiviral contra el virus del dengue.&nbsp

Neuro-radiosurgery treatments: MRI brain tumor seeded image segmentation based on a cellular automata model

Gross Tumor Volume (GTV) segmentation on medical images is an open issue in neuro-radiosurgery. Magnetic Resonance Imaging (MRI) is the most prominent modality in radiation therapy for soft-tissue anatomical districts. Gamma Knife stereotactic neuro-radiosurgery is a mini-invasive technique used to deal with inaccessible or insufficiently treated tumors. During the planning phase, the GTV is usually contoured by radiation oncologists using a manual segmentation procedure on MR images. This methodology is certainly time-consuming and operator-dependent. Delineation result repeatability, in terms of both intra- and inter-operator reliability, is only obtained by using computer-assisted approaches. In this paper a novel semi-automatic segmentation method, based on Cellular Automata, is proposed. The developed approach allows for the GTV segmentation and computes the lesion volume to be treated. The method was evaluated on 10 brain cancers, using both area-based and distance-based metrics

Evaluation of Platinum-based Therapy Response in Non-Small Cell Lung Cancer

Aim: To evaluate the clinical value of PET imaging for an early prediction of tumor response to platinum-based therapy in patients with non-small cell lung cancer (NSCLC). In order to avoid unnecessary toxicity of ineffective chemotherapy treatment, an early identification of NSCLC patients who benefit from this therapy is mandatory. Materials and methods: Seventeen patients are enrolled prospectively: 18F-FDG-PET examinations are carried out before treatment and after the first course. The lesions with the highest uptake in each patient are evaluated according to EORTC, PERCIST and RECIST classifications to discriminate between patients who respond (complete and partial response) from those who do not respond (stable and progressive disease) to treatment. Metabolic Tumor Volume (MTV) and Total Lesion Glycolysis (TLG) are also used to evaluate therapeutic response. MTV indicates the volume of metabolically active tumors; TLG is the product between SUV mean and MTV. In literature, there are no cut-off points for therapy evaluation based on TLG or MTV variations (Δ) in sequential scans. In order to estimate cut-off values for these parameters, receiver operating characteristic (ROC) curves are used. RECIST classification is used as the outcome for the ROC analysis. Kaplan-Meier test is used to calculate Overall Survival (OS) time. OS is compared between responders and non-responders using a log-rank test. The level of statistical significance is defined as a p-value (p) of less than 0.05. Results: The ROC analysis indicates a cut-off point of -36% for ΔTLG, and -8% for ΔMTV. The Kaplan-Meier analysis shows that RECIST, ∆TLG, and ∆MTV prove to be a significant prognostic factor for predicting OS. For RECIST responder patients median OS is 595 days whereas for non-responder patients median OS is 238 days. ΔTLG shows a median OS of 492 days for responders and 238 days for non-responders. ΔMTV shows a median of 423 days for responders versus 188 days for non-responders. Conversely, EORTC and PERCIST classifications are inadequate to discriminate between responder and non-responder patients (p>0.13). For this reason, we use ROC analysis to propose an alternative PERCIST threshold of 17% for an early therapy monitoring. Conclusion: PET examinations provide an early identification of patients who benefit from platinum-based treatment. Results confirm that TLG proves a strong early prognostic factor in patients with NSCLC and could play a significant role in the field of personalized medicine, avoiding the unnecessary administration of non-curative and toxic drugs to preserve the patient’s quality of life

Action of Aqueous Extracts of Phyllanthus niruri L. (Euphorbiaceae) leaves on Meristematic Root Cells of Allium cepa L.

This study aimed to evaluate the effects of aqueous extracts of dried Phyllanthus niruri L. (stonebreaker) leaves on Allium cepa L. root meristem cells at four concentrations, 0.02 (usual concentration), 0.04, 0.06 and 0.08mg/mL and exposure times of 24 and 48 hours. For each concentration we used a group of five onion bulbs that were first embedded in distilled water and then transferred to their respective concentrations. The radicles were collected and fixed in acetic acid (3:1) for 24 hours. The slides were prepared by the crushing technique and stained with 2% acetic orcein. Cells were analyzed throughout the cell cycle, totaling 5000 for each control and exposure time. The calculated mitotic indices were subjected to the Chi-squared statistical analysis (p<0.05). From the results obtained it was observed that all four concentrations tested had significant antiproliferative effect on the cell cycle of this test system. We also found the presence of cellular aberrations such as colchicined metaphases, anaphasic and telophasic bridges, and micronuclei in the two exposure times for all concentrations evaluated. Therefore, under the conditions studied the concentrations of aqueous extracts of leaves of P. niruri showed to be cytotoxic and genotoxic

The Apoptotic Effects of Toosendanin Are Partially Mediated by Activation of Deoxycytidine Kinase in HL-60 Cells

Triterpenoid toosendanin (TSN) exhibits potent cytotoxic activity through inducing apoptosis in a variety of cancer cell lines. However, the target and mechanism of the apoptotic effects by TSN remain unknown. In this study, we captured a specific binding protein of TSN in HL-60 cells by serial affinity chromatography and further identified it as deoxycytidine kinase (dCK). Combination of direct activation of dCK and inhibition of TSN-induced apoptosis by a dCK inhibitor confirmed that dCK is a target for TSN partially responsible for the apoptosis in HL-60 cells. Moreover, the activation of dCK by TSN was a result of conformational change, rather than auto-phosphorylation. Our results further imply that, in addition to the dATP increase by dCK activation in tumor cells, dCK may also involve in the apoptotic regulation

Psychology and the Aims of Normative Ethics

This chapter discusses the philosophical relevance of empirical research on moral cognition. It distinguishes three central aims of normative ethical theory: understanding the nature of moral agency, identifying morally right actions, and determining the justification of moral beliefs. For each of these aims, the chapter considers and rejects arguments against employing cognitive scientific research in normative inquiry. It concludes by suggesting that, whichever of the central aims one begins from, normative ethics is improved by engaging with the science of moral cognition